aboutsummaryrefslogblamecommitdiffstats
path: root/lib/snmp/src/agent/snmpa_agent.erl
blob: 95199065b34c7a19b1804a6f2c51da56ea2d3317 (plain) (tree)
1
2
3
4
5
6
7
8
9
10
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
4153
4154
4155
4156
4157
4158
4159
4160
4161
4162
4163
4164
4165
4166
4167
4168
4169
4170
4171
4172
4173
4174
4175
4176
4177
4178
4179
4180
4181
4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
4197
4198
4199
4200
4201
4202
4203
4204
4205
4206
4207
4208
4209
4210
4211
4212
4213
4214
4215
4216
4217
4218
4219
4220
4221
4222
4223
4224
4225
4226
4227
4228
4229
4230
4231
4232
4233
4234
4235
4236
4237
4238
4239
4240
4241
4242
4243
4244
4245
4246
4247
4248
4249
4250
4251
4252
4253
4254
4255
4256
4257
4258
4259
4260
4261
4262

                   


                                                        




                                                                      
  



                                                                         
  















                                                                         
                                   
















                                                       
                                  









                                                                 
                               




                                                             



                                                                 














                                                














                                                                      


























                                                                        





                                                       








                                                                    































                                                                     

                                   












































































































                                                                        



                                                  














                                                                 






















                                                              



































                                                                

                                        

















                                                           

                                            




























































                                                                         

                                                       



























































































































                                                                              








                                                    







                                                                  




















                                                                               





















































































                                                                                            
 















































































                                                                            

                                                            











                                                                             



























                                                                          
                                                                 
                                                                 








                                                 

                                                                
                                               






                                                                 
                                                                       
                                                                  












































































































                                                                         
 


                                                                        
















                                                                        
                                                                  
                                                                   








                                                       























                                                                          
                        

                                                                       






































                                                                                                           
                                                         







































                                                                             
                                                                


































































































































































































                                                                               

                                                             

                                                      
                                                                    


                              
                                                                       























































                                                                               

                                                                    



























                                                                         


































                                                         


          



































                                                           




                               




                                                              
























                                                                   

                                  

                                             
                                









                                    

                                                       
 

                                  
 




                                                 















































































































                                                                             


                                                                   
                 
                                                                       

                                                   

                                                               

                                              

                                                           
 

                                                          
                                                              
                                                   
                         

                                                                      








                                                              













































                                                                             

                                                           

                                                           

                                      





                                                                      

                                      


                                                                        


                                                      

                                                                        























                                                                   

                                                         
                                                         
                                                                    


                                                                    

                                                     

                                                     

                                                                                


                                         

                                                       

                                                       
                                                                     

                                                                

                                                     

                                                     

                                                                                





                                                                        
                    
                                                             



                                                                              


                                                              
                                                                    
 
                                                                  







                                                                  

                                                                        












                                                                        

                                                          

                            
 
                                                             
                                                        


                                         


                                                      























































                                                                              

                                                                       
                                            





                                                                          















                                                                         

                                                               



































                                                                             

                                                                  















                                                         

                                                                         





                                                                    

                                                                        

        


                                                                        


                                                                          
                                    




                                                                  
                                                                        




                                                               

                                                                          



                                                                     


                                                                       















































































































































































































































































































































                                                                                  

                                                                         





                                                
                                                    

                                                                       
                                               



















                                                                                
                                               



                                                      
                                                       















                                                                         





                                                   
                                              

                                                                               







                                                                           
                                              























































                                                                      

                                                                         























































































































































































































































































































































































































































































                                                                               






                                                                              

                                   

                                                        
                         

                                                                 
 
                    

                                     




                                                              
                             
                                                                   




                                           
                                                         



                                                                             
                                                                              
 


                                                                                    


                                                 

                                                     
                                                            
                                   

                                                       

                                                                            
                                       





                                                              

                                                                           





                                                                  

                                                 



                                                             
                                                                               
                                              



                                                                       

                                                               
                                                                
                                         


                                                              

                                                                       
                                                               

                                                  
                                                                






                                                                         
                                                                




                                                                      

                                                                        








                                                              
                                                        







                                                                     

                                                                        







                                                    
                                                                







                                                       
                                                                




                                                                         

                                                                        











                                                                                

                                                                        



                                                                               

                                                                        














                                                                       
                                                        





                                                     

                                                                          









                                                                           

                                                                               


                                                                       

                                                                           











                                                               
                                                              



                                                                    



                                            









                                                                  
 





















































































































































































































































                                                                               





                                                                   
                                                                    

                                                                                
                                       



                                     


                                                                                
                                                                 
                                

                                                    

                                                     
                                               








                                                                               
                                                      


                                                                             

                                                                               







                                                                        



                                                                             







                                                           
 
















































                                                                       
                                                                           
                             



                                                                              







                                        







                                                                    


                                   
                                                                          



                                            
                                                         




                                                                     

                                                              










                                                                  



                                                 
                                    


                                                      
                                                    
                                       

                                                           
                                                             


                                                                               
                                                            


                                                              


                                                                  









                                                              
                                         
                                      
                                                              











































































































































                                                                                

                                                                               







































































































































































































































































































































































































































































































                                                                                        


                                           




































                                                                        
%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1996-2010. All Rights Reserved.
%%
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
%% compliance with the License. You should have received a copy of the
%% Erlang Public License along with this software. If not, it can be
%% retrieved online at http://www.erlang.org/.
%%
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
%% the License for the specific language governing rights and limitations
%% under the License.
%%
%% %CopyrightEnd%
%%
-module(snmpa_agent).

-include_lib("kernel/include/file.hrl").
-include("snmpa_internal.hrl").
-include("snmp_types.hrl").
-include("snmp_debug.hrl").
-include("snmp_verbosity.hrl").
-include("SNMP-FRAMEWORK-MIB.hrl").

%% External exports
-export([start_link/4, start_link/5, stop/1]).
-export([subagent_set/2, 
	 load_mibs/2, unload_mibs/2, which_mibs/1, whereis_mib/2, info/1,
	 register_subagent/3, unregister_subagent/2,
	 send_trap/6, send_trap/7, 
         register_notification_filter/5,
         unregister_notification_filter/2,
         which_notification_filter/1,
 	 get_net_if/1]).
-export([
	 discovery/6, 
	 is_originating_discovery_enabled/0,
	 is_terminating_discovery_enabled/0,
	 terminating_discovery_stage2/0,
	 terminating_trigger_username/0
	]).
-export([verbosity/2, dump_mibs/1, dump_mibs/2]).
-export([validate_err/3, make_value_a_correct_value/3, 
	 do_get/3, do_get/4, 
	 get/2, get/3, get_next/2, get_next/3]).
-export([mib_of/1, mib_of/2, me_of/1, me_of/2,
	 invalidate_mibs_cache/1,
	 which_mibs_cache_size/1, 
	 enable_mibs_cache/1, disable_mibs_cache/1,
	 gc_mibs_cache/1, gc_mibs_cache/2, gc_mibs_cache/3,
	 enable_mibs_cache_autogc/1, disable_mibs_cache_autogc/1,
	 update_mibs_cache_age/2, 
	 update_mibs_cache_gclimit/2]).
-export([get_agent_mib_storage/0, db/1, 
	 backup/2]).
-export([get_log_type/1,      set_log_type/2]).
-export([get_request_limit/1, set_request_limit/2]).
-export([invalidate_ca_cache/0]).
-export([increment_counter/3]).
-export([restart_worker/1, restart_set_worker/1]).

%% Internal exports
-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
	 terminate/2, code_change/3, tr_var/2, tr_varbind/1,
	 handle_pdu/8, worker/2, worker_loop/1, do_send_trap/7]).
%% <BACKWARD-COMPAT>
-export([handle_pdu/7]).
%% </BACKWARD-COMPAT>

-ifndef(default_verbosity).
-define(default_verbosity,silence).
-endif.

-define(empty_pdu_size, 21).

-ifdef(snmp_extended_verbosity).
-define(vt(F,A), ?vtrace(F, A)).
-else.
-define(vt(_F, _A), ok).
-endif.

-define(DISCO_TERMINATING_TRIGGER_USERNAME, "").

-ifdef(snmp_debug).
-define(GS_START_LINK3(Prio, Parent, Ref, Opts),
        gen_server:start_link(?MODULE, [Prio, Parent, Ref, Opts],
                              [{debug,[trace]}])).
-define(GS_START_LINK4(Prio, Name, Parent, Ref, Opts),
        gen_server:start_link({local, Name}, ?MODULE, 
			      [Prio, Parent, Ref, Opts],
                              [{debug,[trace]}])).
-else.
-define(GS_START_LINK3(Prio, Parent, Ref, Opts),
        gen_server:start_link(?MODULE, [Prio, Parent, Ref, Opts],[])).
-define(GS_START_LINK4(Prio, Name, Parent, Ref, Opts),
        gen_server:start_link({local, Name}, ?MODULE, 
			      [Prio, Parent, Ref, Opts],[])).
-endif.

%% Increment this whenever a change is made to the worker interface 
-define(WORKER_INTERFACE_VERSION, 1).

%% -- Utility macros for creating worker commands --
-define(mk_pdu_wreq(Vsn, Pdu, PduMS, ACMData, Address, GbMaxVBs, Extra),
	#wrequest{cmd  = handle_pdu, 
		  info = [{vsn,        Vsn}, 
			  {pdu,        Pdu}, 
			  {pdu_ms,     PduMS}, 
			  {acm_data,   ACMData}, 
			  {addr,       Address}, 
			  {gb_max_vbs, GbMaxVBs}, 
			  {extra,      Extra}]}.
-define(mk_send_trap_wreq(TrapRec, NotifyName, ContextName, 
			  Recv, Vbs, LocalEngineID),
	#wrequest{cmd  = handle_pdu, 
		  info = [{trap_rec,        TrapRec}, 
			  {notify_name,     NotifyName}, 
			  {context_name,    ContextName}, 
			  {receiver,        Recv}, 
			  {varbinds,        Vbs}, 
			  {local_engine_id, LocalEngineID}]}.
-define(mk_terminate_wreq(), #wrequest{cmd = terminate, info = []}).
-define(mk_verbosity_wreq(V), #wrequest{cmd  = verbosity, 
					info = [{verbosity, V}]}).


-record(notification_filter, {id, mod, data}).
-record(disco, 
	{from, rec, sender, target, engine_id, 
	 sec_level, ctx, ivbs, stage, handler, extra}).

%% This record is used when sending requests to the worker processes
-record(wrequest, 
	{
	  version = ?WORKER_INTERFACE_VERSION, 
	  cmd, 
	  info
	 }
       ).


%%-----------------------------------------------------------------
%% The agent is multi-threaded, i.e. each request is handled
%% by a separate process.  However, in the normal case, there
%% is just one request handled at the time.  In order to improve
%% performance, there is always two worker processes alive.  They are
%% created at initialization time.  There is always one worker
%% dedicated to SET-handling.  When a get*-request is received,
%% it is sent to the worker, and the worker is marked as busy.
%% If a request is received when the worker is busy, a new temporary
%% worker is spawned.
%% Code change
%% ===========
%% Note that the worker(s) execute the same module as the master
%% agent. For code change we have two options - ignore the workers,
%% or send them a code change message.
%%-----------------------------------------------------------------
-record(state, {type, 
		parent, 
		worker, 
		worker_state = ready,
		set_worker, 
		multi_threaded, 
		ref, 
		vsns,
		nfilters = [],
		note_store,
		mib_server,   %% Currently unused
		net_if,       %% Currently unused
		net_if_mod,   
		backup,
		disco,
		mibs_cache_request,
		gb_max_vbs}).


%%%-----------------------------------------------------------------
%%% This module implements the agent machinery; both for the master
%%% agent and the subagents.
%%%-----------------------------------------------------------------
%%% Table of contents
%%% =================
%%% 1. Interface
%%% 2. Main loop
%%% 3. GET REQUEST
%%% 4. GET-NEXT REQUEST
%%% 5. GET-BULK REQUEST
%%% 6. SET REQUEST
%%% 7. Misc functions
%%%-----------------------------------------------------------------

%%-----------------------------------------------------------------
%% Parent is a Pid (of master_agent) or none
%% Options is a list of Option, where Option is
%%   {mibs, Mibs}
%%   {net_if, NetIfModule}
%%   {priority, Prio}
%%   {verbosity, Verbosity}
%%   {multi_threaded, Bool} true means that SETs are serialized,
%%      while GETs are concurrent, even with a SET.
%%   {set_mechanism, SetModule}           % undocumented feature
%%
%% The following options are now removed - they are not needed
%% anymore when VACM is standard for authentication, and works
%% with all versions, and trap sending is standardized too.
%%   {authentication_service, AuthModule} % undocumented feature
%%   {trap_mechanism, TrapModule}         % undocumented feature
%% Note: authentication_service is reintroduced for AXD301 (OTP-3324).
%%-----------------------------------------------------------------
start_link(Prio, Parent, Ref, Options) ->
    ?d("start_link -> entry with"
	"~n   Prio:    ~p"
	"~n   Parent:  ~p"
	"~n   Ref:     ~p"
	"~n   Options: ~p", [Prio, Parent, Ref, Options]),
    %% gen_server:start_link(?MODULE, [Prio, Parent, Ref, Options], []).
    ?GS_START_LINK3(Prio, Parent, Ref, Options).

start_link(Prio, Name, Parent, Ref, Options) ->
    ?d("start_link -> entry with"
	"~n   Prio:    ~p"
	"~n   Name:    ~p"
	"~n   Parent:  ~p"
	"~n   Ref:     ~p"
	"~n   Options: ~p", [Prio, Name, Parent, Ref, Options]),
%     gen_server:start_link({local, Name}, ?MODULE, 
% 			  [Prio, Parent, Ref, Options], []).
    ?GS_START_LINK4(Prio, Name, Parent, Ref, Options).

stop(Agent) -> call(Agent, stop).

restart_worker(Agent) ->
    call(Agent, restart_worker).

restart_set_worker(Agent) ->
    call(Agent, restart_set_worker).

get_log_type(Agent) ->
    call(Agent, get_log_type).

set_log_type(Agent, NewType) ->
    call(Agent, {set_log_type, NewType}).

get_request_limit(Agent) ->
    call(Agent, get_request_limit).

set_request_limit(Agent, NewLimit) ->
    call(Agent, {set_request_limit, NewLimit}).

mib_of(Oid) when is_list(Oid) ->
    mib_of(snmp_master_agent, Oid).

mib_of(Agent, Oid) when is_list(Oid) ->
    call(Agent, {mib_of, Oid}).

me_of(Oid) when is_list(Oid) ->
    me_of(snmp_master_agent, Oid).

me_of(Agent, Oid) when is_list(Oid) ->
    call(Agent, {me_of, Oid}).


invalidate_mibs_cache(Agent) ->
    call(Agent, {mibs_cache_request, invalidate_cache}).


gc_mibs_cache(Agent) ->
    call(Agent, {mibs_cache_request, gc_cache}).

gc_mibs_cache(Agent, Age) ->
    call(Agent, {mibs_cache_request, {gc_cache, Age}}).

gc_mibs_cache(Agent, Age, GcLimit) ->
    call(Agent, {mibs_cache_request, {gc_cache, Age, GcLimit}}).


enable_mibs_cache(Agent) ->
    call(Agent, {mibs_cache_request, enable_cache}).

disable_mibs_cache(Agent) ->
    call(Agent, {mibs_cache_request, disable_cache}).


which_mibs_cache_size(Agent) ->
    call(Agent, {mibs_cache_request, cache_size}).


enable_mibs_cache_autogc(Agent) ->
    call(Agent, {mibs_cache_request, enable_autogc}).

disable_mibs_cache_autogc(Agent) ->
    call(Agent, {mibs_cache_request, disable_autogc}).


update_mibs_cache_gclimit(Agent, GcLimit) ->
    call(Agent, {mibs_cache_request, {update_gclimit, GcLimit}}).


update_mibs_cache_age(Agent, Age) ->
    call(Agent, {mibs_cache_request, {update_age, Age}}).


increment_counter(Counter, Initial, Max) ->
    %% This is to make sure no one else increments our counter
    Key = {Counter, self()}, 

    %% Counter data
    Position  = 2, 
    Increment = 1, 
    Threshold = Max,
    SetValue  = Initial, 
    UpdateOp  = {Position, Increment, Threshold, SetValue},
    
    %% And now for the actual increment
    Tab = snmp_agent_table, 
    case (catch ets:update_counter(Tab, Key, UpdateOp)) of
	{'EXIT', {badarg, _}} ->
	    %% Oups, first time
	    ets:insert(Tab, {Key, Initial}),
	    Initial;
	Next when is_integer(Next) ->
	    Next
    end.


init([Prio, Parent, Ref, Options]) ->
    ?d("init -> entry with"
	"~n   Prio:    ~p"
	"~n   Parent:  ~p"
	"~n   Ref:     ~p"
	"~n   Options: ~p", [Prio, Parent, Ref, Options]),
    case (catch do_init(Prio, Parent, Ref, Options)) of
	{ok, State} ->
	    ?vdebug("started",[]),
	    {ok, State};
	{error, Reason} ->
	    config_err("failed starting agent: ~n~p", [Reason]),
	    {stop, Reason}
    end.

do_init(Prio, Parent, Ref, Options) ->
    process_flag(priority, Prio),
    put(sname,short_name(Parent)),
    put(verbosity,get_verbosity(Options)),
    ?vlog("starting with: "
	  "~n   Prio:    ~p"
	  "~n   Parent:  ~p"
	  "~n   Ref:     ~p"
	  "~n   Options: ~p",[Prio, Parent, Ref, Options]),

    Mibs       = get_mibs(Options),
    SetModule  = get_set_mechanism(Options),
    put(set_module, SetModule),

    %% OTP-3324. For AXD301.
    AuthModule = get_authentication_service(Options),
    put(auth_module, AuthModule),

    MultiT  = get_multi_threaded(Options),
    Vsns    = get_versions(Options),

    GbMaxVbs = get_gb_max_vbs(Options), 

    NS = start_note_store(Prio, Ref, Options),
    {Type, NetIfPid, NetIfMod} = 
	start_net_if(Parent, Prio, Ref, Vsns, NS, Options),

    MibPid = start_mib_server(Prio, Ref, Mibs, Options),
    
    put(net_if, NetIfPid),
    put(mibserver, MibPid),
    process_flag(trap_exit, true),
    {Worker, SetWorker} = workers_start(MultiT),
    {ok, #state{type           = Type, 
		parent         = Parent, 
		worker         = Worker,
		set_worker     = SetWorker,
		multi_threaded = MultiT, 
		ref            = Ref,
		vsns           = Vsns,
		note_store     = NS,
		net_if_mod     = NetIfMod,
		gb_max_vbs     = GbMaxVbs}}.


start_note_store(Prio, Ref, Options) ->
    ?vdebug("start_note_store -> with Prio: ~p", [Prio]),
    NsOpts = get_note_store_opt(Options),

    ?vtrace("start_note_store -> NsOpts: ~p", [NsOpts]),

    case (catch snmpa_misc_sup:start_note_store(Prio, Ref, NsOpts)) of
	{ok, Pid} ->
	    ?vdebug("start_note_store -> Pid: ~p", [Pid]),
	    Pid;
	{error, Reason} -> 
	    ?vinfo("error starting note store: ~n~p",[Reason]),
	    throw({error, {note_store_error, Reason}});
	{'EXIT', Reason} ->
	    ?vinfo("exit starting note store: ~n~p",[Reason]),
	    throw({error, {note_store_exit, Reason}});
	Error ->
	    ?vinfo("failed starting note store: ~n~p",[Error]),
	    throw({error, {note_store_failed, Error}})
    end.
    

start_net_if(none, Prio, Ref, Vsns, NoteStore, Options) ->
    ?vdebug("start_net_if(none) -> with Prio: ~p", [Prio]),
    NetIfOpts = get_net_if_opt(Options),
    Verbosity = get_net_if_verbosity(NetIfOpts),
    Mod       = get_net_if_module(NetIfOpts),
    NiOptions = get_net_if_options(NetIfOpts),
    NiOpts    = [{versions,  Vsns}, 
		 {verbosity, Verbosity} | NiOptions],
    
    ?vtrace("start_net_if -> "
	    "~n   Mod:    ~p"
	    "~n   NiOpts: ~p",[Mod, NiOpts]),

    case (catch snmpa_misc_sup:start_net_if(Prio, NoteStore, Ref, self(),
					    Mod, NiOpts)) of
	{ok, Pid} -> 
	    ?vdebug("start_net_if -> Pid: ~p", [Pid]),
	    {master_agent, Pid, Mod};
	{error, Reason} -> 
	    ?vinfo("error starting net if: ~n~p",[Reason]),
	    throw({error, {net_if_error, Reason}});
	{'EXIT', Reason} ->
	    ?vinfo("exit starting net if: ~n~p",[Reason]),
	    throw({error, {net_if_exit, Reason}});
	Error ->
	    ?vinfo("failed starting net if: ~n~p",[Error]),
	    throw({error, {net_if_failed, Error}})
    end;
start_net_if(Parent, _Prio, _Ref, _Vsns, _NoteStore, _Options) 
  when is_pid(Parent) ->
    ?vdebug("start_net_if(~p) -> subagent => ignore", [Parent]),
    {subagent, undefined, undefined}.
    
    
start_mib_server(Prio, Ref, Mibs, Options) ->
    ?vdebug("start_mib_server -> with Prio: ~p", [Prio]),
    MibStorage = get_mib_storage(Options),
    MibsOpts   = [{mib_storage, MibStorage} | 
		  get_option(mib_server, Options, [])],

    ?vtrace("start_mib_server -> "
	    "~n   Mibs:     ~p"
	    "~n   MibsOpts: ~p", [Mibs, MibsOpts]),

    case (catch snmpa_misc_sup:start_mib_server(Prio, Ref, Mibs, MibsOpts)) of
	{ok, Pid} ->
	    ?vdebug("start_mib_server -> Pid: ~p", [Pid]),
	    Pid;
	{error, Reason} -> 
	    ?vinfo("error starting mib server: ~n~p",[Reason]),
	    throw({error, {mib_server_error, Reason}});
	{'EXIT', Reason} ->
	    ?vinfo("exit starting mib server: ~n~p",[Reason]),
	    throw({error, {mib_server_exit, Reason}});
	Error ->
	    ?vinfo("failed starting mib server: ~n~p",[Error]),
	    throw({error, {mib_server_failed, Error}})
    end.


%%-----------------------------------------------------------------
%% Purpose: We must calculate the length of an empty Pdu.  This
%%          length is used to calculate the max pdu size allowed
%%          for each get-bulk-request. This size is 
%%          dependent on the varbinds. It is calculated
%%          as EmptySize + 8.  8 comes from the fact that the
%%          maximum pdu size needs 31 bits which needs 5 * 7 bits to be
%%          expressed. One 7bit octet is already present in the
%%          empty pdu, leaving 4 more 7bit octets. The length is
%%          repeated twice, once for the varbinds, and once for the
%%          entire pdu; 2 * 4 = 8.
%% Actually, this function is not used, we use a constant instead.
%%-----------------------------------------------------------------
%% Ret: 21
%% empty_pdu() ->
%%     Pdu = #pdu{type         = 'get-response', 
%%                request_id   = 1,
%% 	          error_status = noError, 
%%                error_index  = 0, 
%%                varbinds     = []},
%%     length(snmp_pdus:enc_pdu(Pdu)) + 8.


%%%--------------------------------------------------
%%% 1. Interface
%%%--------------------------------------------------
%% Called by administrator (not subagent; deadlock could occur)
register_subagent(Agent, SubTreeOid, SubagentPid) ->
    call(Agent, {register_subagent, SubTreeOid, SubagentPid}).

%% Called by administrator (not subagent; deadlock could occur)
unregister_subagent(Agent, SubagentOidOrPid) ->
    call(Agent, {unregister_subagent, SubagentOidOrPid}).


%%-----------------------------------------------------------------
%% These subagent_ functions either return a value, or exits
%% with {nodedown, Node} | Reason.
%%-----------------------------------------------------------------
subagent_get(SubAgent, Varbinds, IsNotification) ->
    PduData = get_pdu_data(),
    call(SubAgent, {subagent_get, Varbinds, PduData, IsNotification}).

subagent_get_next(SubAgent, MibView, Varbinds) ->
    PduData = get_pdu_data(),
    call(SubAgent, {subagent_get_next, MibView, Varbinds, PduData}).

subagent_set(SubAgent, Arguments) ->
    PduData = get_pdu_data(),
    call(SubAgent, {subagent_set, Arguments, PduData}).


%% Called by administrator (not agent; deadlock would occur)
load_mibs(Agent, Mibs) ->
    call(Agent, {load_mibs, Mibs}).

%% Called by administrator (not agent; deadlock would occur)
unload_mibs(Agent, Mibs) ->
    call(Agent, {unload_mibs, Mibs}).

which_mibs(Agent) ->
    call(Agent, which_mibs).

whereis_mib(Agent, Mib) ->
    call(Agent, {whereis_mib, Mib}).

info(Agent) ->
    call(Agent, info).


get_net_if(Agent) ->
    call(Agent, get_net_if).


register_notification_filter(Agent, Id, Mod, Args, Where) 
  when (Where =:= first) orelse (Where =:= last) ->
    case (catch verify_notification_filter_behaviour(Mod)) of
	ok ->
	    call(Agent, {register_notification_filter, Id, Mod, Args, Where});
	Error ->
	    Error
    end;
register_notification_filter(Agent, Id, Mod, Args, {Loc, _Id} = Where) 
  when (Loc =:= insert_before) orelse (Loc =:= insert_after) ->
    case (catch verify_notification_filter_behaviour(Mod)) of
	ok ->
	    call(Agent, {register_notification_filter, Id, Mod, Args, Where});
	 Error ->
	    Error
    end.

verify_notification_filter_behaviour(Mod) ->
    snmp_misc:verify_behaviour(snmpa_notification_filter, Mod).

unregister_notification_filter(Agent, Id) ->
    call(Agent, {unregister_notification_filter, Id}).

which_notification_filter(Agent) ->
    call(Agent, which_notification_filter).


send_trap(Agent, Trap, NotifyName, CtxName, Recv, Varbinds) ->
    ?d("send_trap -> entry with"
       "~n   self():        ~p"
       "~n   Agent:         ~p [~p]"
       "~n   Trap:          ~p"
       "~n   NotifyName:    ~p"
       "~n   CtxName:       ~p"
       "~n   Recv:          ~p"
       "~n   Varbinds:      ~p", 
       [self(), Agent, wis(Agent), 
	Trap, NotifyName, CtxName, Recv, Varbinds]),
    Msg = {send_trap, Trap, NotifyName, CtxName, Recv, Varbinds}, 
    case (wis(Agent) =:= self()) of
	false ->
	    call(Agent, Msg);
	true ->
	    Agent ! Msg
    end.

send_trap(Agent, Trap, NotifyName, CtxName, Recv, Varbinds, LocalEngineID) ->
    ?d("send_trap -> entry with"
       "~n   self():        ~p"
       "~n   Agent:         ~p [~p]"
       "~n   Trap:          ~p"
       "~n   NotifyName:    ~p"
       "~n   CtxName:       ~p"
       "~n   Recv:          ~p"
       "~n   Varbinds:      ~p" 
       "~n   LocalEngineID: ~p", 
       [self(), Agent, wis(Agent), 
	Trap, NotifyName, CtxName, Recv, Varbinds, LocalEngineID]),
    Msg = 
	{send_trap, Trap, NotifyName, CtxName, Recv, Varbinds, LocalEngineID}, 
    case (wis(Agent) =:= self()) of
	false ->
	    call(Agent, Msg);
	true ->
	    Agent ! Msg
    end.


%% -- Discovery functions --

disco_opts() ->
    case ets:lookup(snmp_agent_table, discovery) of
	[] -> 
	    [];
	[{discovery, DiscoOptions}] ->
	    DiscoOptions
    end.
    
originating_disco_opts() ->
    DiscoOpts = disco_opts(),
    case lists:keysearch(originating, 1, DiscoOpts) of
	{value, {originating, OrigDisco}} ->
	    OrigDisco;
	_ ->
	    []
    end.
	
is_originating_discovery_enabled() ->
    OrigDisco = originating_disco_opts(), 
    case lists:keysearch(enable, 1, OrigDisco) of
	{value, {enable, false}} ->
	    false;
	_ ->
	    true
    end.
    
terminating_disco_opts() ->
    DiscoOpts = disco_opts(),
    case lists:keysearch(terminating, 1, DiscoOpts) of
	{value, {terminating, TermDisco}} ->
	    TermDisco;
	_ ->
	    []
    end.
	
is_terminating_discovery_enabled() ->
    TermDisco = terminating_disco_opts(),
    case lists:keysearch(enable, 1, TermDisco) of
	{value, {enable, false}} ->
	    false;
	_ ->
	    true
    end.
    
terminating_discovery_stage2() ->
    Default   = discovery, 
    TermDisco = terminating_disco_opts(),
    case lists:keysearch(stage2, 1, TermDisco) of
	{value, {stage2, Stage2}} when ((Stage2 =:= discovery) orelse (Stage2 =:= plain)) ->
	    Stage2;
	_ ->
	    Default 
    end.

terminating_trigger_username() ->
    Default   = ?DISCO_TERMINATING_TRIGGER_USERNAME,
    TermDisco = terminating_disco_opts(),
    case lists:keysearch(trigger_username, 1, TermDisco) of
	{value, {trigger_username, Trigger}} when is_list(Trigger) ->
	    Trigger;
	_ ->
	    Default
    end.

    
discovery(TargetName, Notification, ContextName, Varbinds, 
	  DiscoHandler, ExtraInfo) ->
    case is_originating_discovery_enabled() of
	true ->
	    Agent = snmp_master_agent, 
	    call(Agent, 
		 {discovery, 
		  TargetName, Notification, ContextName, Varbinds, 
		  DiscoHandler, ExtraInfo});
	false ->
	    {error, not_enabled}
    end.

wis(Pid) when is_pid(Pid) ->
    Pid;
wis(Atom) when is_atom(Atom) ->
    whereis(Atom).


forward_trap(Agent, TrapRecord, NotifyName, CtxName, Recv, Varbinds) ->
    Agent ! {forward_trap, TrapRecord, NotifyName, CtxName, Recv, Varbinds}.


%%-----------------------------------------------------------------
%% Args: Vars = [Oid]
%% Returns: [Value]
%% Called from a program to get variables.  Don't call this from
%% an instrumentation function; deadlock can occur!
%%-----------------------------------------------------------------
get(Agent, Vars) -> 
    call(Agent, {get, Vars, ""}).

get(Agent, Vars, Context) -> 
    call(Agent, {get, Vars, Context}).

get_next(Agent, Vars) -> 
    call(Agent, {get_next, Vars, ""}).

get_next(Agent, Vars, Context) -> 
    call(Agent, {get_next, Vars, Context}).


%%-----------------------------------------------------------------

backup(Agent, BackupDir) when is_list(BackupDir) ->
    call(Agent, {backup, BackupDir}).


%%-----------------------------------------------------------------
%% Runtime debug support.
%%-----------------------------------------------------------------
dump_mibs(Agent) -> 
    call(Agent, dump_mibs).
dump_mibs(Agent, File) when is_list(File) -> 
    call(Agent, {dump_mibs, File}).


%%-----------------------------------------------------------------
%% Runtime debug (verbosity) support.
%%-----------------------------------------------------------------
verbosity(net_if,Verbosity) -> 
    cast(snmp_master_agent,{net_if_verbosity,Verbosity});
verbosity(mib_server,Verbosity) -> 
    cast(snmp_master_agent,{mib_server_verbosity,Verbosity});
verbosity(note_store,Verbosity) -> 
    cast(snmp_master_agent,{note_store_verbosity,Verbosity});
verbosity(sub_agents,Verbosity) -> 
    cast(snmp_master_agent,{sub_agents_verbosity,Verbosity});
verbosity(master_agent,Verbosity) -> 
    cast(snmp_master_agent,{verbosity,Verbosity});
verbosity(Agent,{sub_agents,Verbosity}) -> 
    cast(Agent,{sub_agents_verbosity,Verbosity});
verbosity(Agent,Verbosity) -> 
    cast(Agent,{verbosity,Verbosity}).


%%%--------------------------------------------------

get_agent_mib_storage() ->
    ets:lookup_element(snmp_agent_table, agent_mib_storage, 2).

db(Tab) ->
    {Tab, get_agent_mib_storage()}.


%%%--------------------------------------------------
%%% 2. Main loop
%%%--------------------------------------------------
%% gen_server:reply(From, Reply)
handle_info({discovery_response, Response}, S) ->
    ?vdebug("handle_info(discovery_response) -> entry with"
	    "~n   Response: ~p", [Response]),    
    NewS = handle_discovery_response(S, Response),
    {noreply, NewS};
    
handle_info({snmp_pdu, Vsn, Pdu, PduMS, ACMData, Address, Extra}, S) ->
    ?vdebug("handle_info(snmp_pdu) -> entry with"
	    "~n   Vsn:     ~p"
	    "~n   Pdu:     ~p"
	    "~n   Address: ~p"
	    "~n   Extra:   ~p", [Vsn, Pdu, Address, Extra]),
    
    NewS = handle_snmp_pdu(is_valid_pdu_type(Pdu#pdu.type),
			   Vsn, Pdu, PduMS, ACMData, Address, Extra, S),

    {noreply, NewS};

handle_info(worker_available, S) ->
    ?vdebug("worker available",[]),
    {noreply, S#state{worker_state = ready}};

handle_info({send_trap, Trap, NotifyName, ContextName, Recv, Varbinds}, S) ->
    ?vlog("[handle_info] send trap request:"
	  "~n   Trap:          ~p"
	  "~n   NotifyName:    ~p"
	  "~n   ContextName:   ~p"
	  "~n   Recv:          ~p" 
	  "~n   Varbinds:      ~p", 
	  [Trap, NotifyName, ContextName, Recv, Varbinds]),
    LocalEngineID = ?DEFAULT_LOCAL_ENGINE_ID, 
    case catch handle_send_trap(S, Trap, NotifyName, ContextName,
				Recv, Varbinds, LocalEngineID) of
	{ok, NewS} ->
	    {noreply, NewS};
	{'EXIT', R} ->
	    ?vinfo("Trap not sent:~n   ~p", [R]),
	    {noreply, S};
	_ ->
	    {noreply, S}
    end;

handle_info({send_trap, Trap, NotifyName, ContextName, Recv, Varbinds, 
	     LocalEngineID}, S) ->
    ?vlog("[handle_info] send trap request:"
	  "~n   Trap:          ~p"
	  "~n   NotifyName:    ~p"
	  "~n   ContextName:   ~p"
	  "~n   Recv:          ~p" 
	  "~n   Varbinds:      ~p" 
	  "~n   LocalEngineID: ~p", 
	  [Trap, NotifyName, ContextName, Recv, Varbinds, LocalEngineID]),
    case catch handle_send_trap(S, Trap, NotifyName, ContextName,
				Recv, Varbinds, LocalEngineID) of
	{ok, NewS} ->
	    {noreply, NewS};
	{'EXIT', R} ->
	    ?vinfo("Trap not sent:~n   ~p", [R]),
	    {noreply, S};
	_ ->
	    {noreply, S}
    end;

handle_info({forward_trap, TrapRecord, NotifyName, ContextName, 
	     Recv, Varbinds}, S) ->
    ?vlog("[handle_info] forward trap request:"
	  "~n   TrapRecord:    ~p"
	  "~n   NotifyName:    ~p"
	  "~n   ContextName:   ~p"
	  "~n   Recv:          ~p"
	  "~n   Varbinds:      ~p", 
	  [TrapRecord, NotifyName, ContextName, Recv, Varbinds]),
    LocalEngineID = ?DEFAULT_LOCAL_ENGINE_ID, 
    case (catch maybe_send_trap(S, TrapRecord, NotifyName, ContextName,
				Recv, Varbinds, LocalEngineID)) of
	{ok, NewS} ->
	    {noreply, NewS};
	{'EXIT', R} ->
	    ?vinfo("Trap not sent:~n   ~p", [R]),
	    {noreply, S};
	_ ->
	    {noreply, S}
    end;

handle_info({backup_done, Reply}, #state{backup = {_, From}} = S) ->
    ?vlog("[handle_info] backup done:"
	  "~n   Reply: ~p", [Reply]),
    gen_server:reply(From, Reply),
    {noreply, S#state{backup = undefined}};


handle_info(invalidate_ca_cache, S) ->
    invalidate_ca_cache(),
    {noreply, S};


%%-----------------------------------------------------------------
%% If a process crashes, we first check to see if it was the mib,
%% net-if or note-store.
%% Otherwise, we check to see if it was a subagent. In this case
%% we unregister the sa, and unlink us from the sa.
%%-----------------------------------------------------------------
handle_info({'EXIT', Pid, Reason}, #state{note_store = Pid} = S) ->
    ?vlog("note store (~p) exited for reason ~n~p", [Pid, Reason]),
    error_msg("note-store exited: ~n~p", [Reason]),
    {stop, {note_store_exit, Reason}, S#state{note_store = undefined}};
handle_info({'EXIT', Pid, Reason}, #state{worker = Pid} = S) ->
    ?vlog("worker (~p) exited -> create new ~n   ~p", [Pid, Reason]),
    NewWorker = worker_start(), 
    {noreply, S#state{worker = NewWorker}};
handle_info({'EXIT', Pid, Reason}, #state{set_worker = Pid} = S) ->
    ?vlog("set-worker (~p) exited -> create new ~n   ~p", [Pid,Reason]),
    NewWorker = set_worker_start(), 
    {noreply, S#state{set_worker = NewWorker}};
handle_info({'EXIT', Pid, Reason}, #state{parent = Pid} = S) ->
    ?vlog("parent (~p) exited for reason ~n~p", [Pid,Reason]),
    {stop, {parent_died, Reason}, S};
handle_info({'EXIT', Pid, Reason}, #state{backup = {Pid, From}} = S) ->
    ?vlog("backup server (~p) exited for reason ~n~p", [Pid, Reason]),
    case Reason of
	normal ->
	    {noreply, S};
	_ ->
	    gen_server:reply(From, {error, Reason}),
	    {noreply, S#state{backup = undefined}}
    end;
handle_info({'EXIT', Pid, Reason}, S) ->
    ?vlog("~p exited for reason ~p", [Pid, Reason]),
    Mib   = get(mibserver),
    NetIf = get(net_if),
    case Pid of
	Mib ->
	    error_msg("mib-server exited: ~n~p", [Reason]),
	    {stop, {mib_server_exit, Reason}, S};
	NetIf ->
	    error_msg("net-if exited: ~n~p", [Reason]),
	    {stop, {net_if_exit, Reason}, S};
	_ ->
	    %% Could be a sub-agent
	    SAs = snmpa_mib:info(Mib, subagents),
	    case lists:keysearch(Pid, 1, SAs) of
		{value, _} ->
		    ?vlog("subagent exit", []),
		    snmpa_mib:unregister_subagent(Mib, Pid),
		    unlink(Pid);
		_ -> 
		    %% Otherwise it was probably a worker thread - ignore
		    ok
	    end,
	    {noreply, S}
    end;
handle_info({'DOWN', Ref, process, Pid, {mibs_cache_reply, Reply}}, 
	    #state{mibs_cache_request = {Pid, Ref, From}} = S) ->
    ?vlog("reply from the mibs cache request handler (~p): ~n~p", 
	  [Pid, Reply]),
    gen_server:reply(From, Reply),
    {noreply, S#state{mibs_cache_request = undefined}};

handle_info(Info, S) ->
    warning_msg("received unexpected info: ~n~p", [Info]),
    {noreply, S}.

handle_call(restart_worker, _From, #state{worker = Pid} = S) ->
    if 
	is_pid(Pid) ->
	    ?vlog("[handle_call] restart worker ~p", [Pid]),
	    exit(Pid, kill);
	true ->
	    ?vlog("[handle_call] not multi-threaded => "
		  "ignoring restart request", []),
	    ok
    end,
    {reply, ok, S};
handle_call(restart_set_worker, _From, #state{set_worker = Pid} = S) ->
    if
	is_pid(Pid) ->
	    ?vlog("[handle_call] restart set worker: ~p", [Pid]),
	    exit(Pid, kill);
	true ->
	    ?vlog("[handle_call] not multi-threaded => "
		  "ignoring restart request", []),
	    ok
    end,
    {reply, ok, S};

handle_call({send_trap, Trap, NotifyName, ContextName, Recv, Varbinds}, 
	    _From, S) ->
    ?vlog("[handle_call] send trap request:"
	  "~n   Trap:          ~p"
	  "~n   NotifyName:    ~p"
	  "~n   ContextName:   ~p"
	  "~n   Recv:          ~p" 
	  "~n   Varbinds:      ~p", 
	  [Trap, NotifyName, ContextName, Recv, Varbinds]),
    LocalEngineID = 
	case S#state.type of
	    master_agent ->
		?DEFAULT_LOCAL_ENGINE_ID;
	    _ -> 
		%% subagent - 
		%% we don't need this, eventually the trap sent request 
		%% will reach the master-agent and then it will look up 
		%% the proper engine id.
		ignore
	end,
    case (catch handle_send_trap(S, Trap, NotifyName, ContextName,
				 Recv, Varbinds, LocalEngineID)) of
	{ok, NewS} ->
	    {reply, ok, NewS};
	{'EXIT', Reason} ->
	    ?vinfo("Trap not sent:~n   ~p", [Reason]),
	    {reply, {error, {send_failed, Reason}}, S};
	_ ->
	    ?vinfo("Trap not sent", []),
	    {reply, {error, send_failed}, S}
    end;

handle_call({send_trap, Trap, NotifyName, 
	     ContextName, Recv, Varbinds, LocalEngineID}, 
	    _From, S) ->
    ?vlog("[handle_call] send trap request:"
	  "~n   Trap:          ~p"
	  "~n   NotifyName:    ~p"
	  "~n   ContextName:   ~p"
	  "~n   Recv:          ~p" 
	  "~n   Varbinds:      ~p" 
	  "~n   LocalEngineID: ~p", 
	  [Trap, NotifyName, ContextName, Recv, Varbinds, LocalEngineID]),
    case (catch handle_send_trap(S, Trap, NotifyName, ContextName,
				 Recv, Varbinds, LocalEngineID)) of
	{ok, NewS} ->
	    {reply, ok, NewS};
	{'EXIT', Reason} ->
	    ?vinfo("Trap not sent:~n   ~p", [Reason]),
	    {reply, {error, {send_failed, Reason}}, S};
	_ ->
	    ?vinfo("Trap not sent", []),
	    {reply, {error, send_failed}, S}
    end;

handle_call({discovery, 
	     TargetName, Notification, ContextName, Vbs, DiscoHandler, 
	     ExtraInfo}, 
	    From, 
	    #state{disco = undefined} = S) ->
    ?vlog("[handle_call] initiate discovery process:"
	  "~n   TargetName:   ~p"
	  "~n   Notification: ~p"
	  "~n   ContextName:  ~p"
	  "~n   Vbs:          ~p"
	  "~n   DiscoHandler: ~p"
	  "~n   ExtraInfo:    ~p", 
	  [TargetName, Notification, ContextName, Vbs, 
	   DiscoHandler, ExtraInfo]),
    case handle_discovery(S, From, TargetName, 
			  Notification, ContextName, Vbs, DiscoHandler, 
			  ExtraInfo) of
	{ok, NewS} ->
	    ?vtrace("[handle_call] first stage of discovery process initiated",
		    []),
	    {noreply, NewS};
	{error, _} = Error ->
	    {reply, Error, S}
    end;
handle_call({discovery, _TargetName, _Notification, _ContextName, _Vbs, _DiscoHandler, _ExtraInfo}, _From, 
	    #state{disco = DiscoData} = S) ->
    Reply = {error, {discovery_in_progress, DiscoData}}, 
    {reply, Reply, S};
handle_call({subagent_get, Varbinds, PduData, IsNotification}, _From, S) ->
    ?vlog("[handle_call] subagent get:"
	  "~n   Varbinds: ~p"
	  "~n   PduData:  ~p", 
	  [Varbinds,PduData]),
    put_pdu_data(PduData),
    {reply, do_get(Varbinds, IsNotification), S};
handle_call({subagent_get_next, MibView, Varbinds, PduData}, _From, S) ->
    ?vlog("[handle_call] subagent get-next:"
	  "~n   MibView:  ~p"
	  "~n   Varbinds: ~p"
	  "~n   PduData:  ~p", 
	  [MibView,Varbinds,PduData]),
    put_pdu_data(PduData),
    {reply, do_get_next(MibView, Varbinds, infinity), S};
handle_call({subagent_set, Arguments, PduData}, _From, S) ->
    ?vlog("[handle_call] subagent set:"
	  "~n   Arguments: ~p"
	  "~n   PduData:   ~p", 
	  [Arguments,PduData]),
    put_pdu_data(PduData),
    {reply, do_subagent_set(Arguments), S};

handle_call({get, Vars, Context}, _From, S) ->
    ?vlog("[handle_call] get:"
	  "~n   Vars:    ~p"
	  "~n   Context: ~p", [Vars, Context]),
    put_pdu_data({undefined, undefined, undefined, undefined, Context}),
    case catch mapfoldl({?MODULE, tr_var}, [], 1, Vars) of
	{error, Reason} -> {reply, {error, Reason}, S};
	{_, Varbinds} ->
	    ?vdebug("Varbinds: ~p",[Varbinds]),
	    Reply =
		case do_get(Varbinds, false) of
		    {noError, 0, NewVarbinds} ->
			Vbs = lists:keysort(#varbind.org_index, NewVarbinds),
			[Value || #varbind{value = Value} <- Vbs];
		    {ErrorStatus, ErrIndex, _} ->
			N = lists:nth(ErrIndex, Vars),
			{error, {ErrorStatus, N}}
		end,
	    {reply, Reply, S}
    end;

handle_call({get_next, Vars, Context}, _From, S) ->
    ?vlog("[handle_call] get_next:"
          "~n   Vars:    ~p"
          "~n   Context: ~p",[Vars, Context]),
    put_pdu_data({undefined, undefined, undefined, undefined, Context}),
    case catch mapfoldl({?MODULE, tr_var}, [], 1, Vars) of
        {error, Reason} -> {reply, {error, Reason}, S};
        {_, Varbinds} ->
            ?vdebug("Varbinds: ~p",[Varbinds]),
            MibView = snmpa_acm:get_root_mib_view(),
            Reply =
                case do_get_next(MibView, Varbinds, infinity) of
                    {noError, 0, NewVarbinds} ->
                        Vbs = lists:keysort(#varbind.org_index, NewVarbinds),
			[{Oid,Val} || #varbind{oid = Oid, value = Val} <- Vbs];
                    {ErrorStatus, ErrIndex, _} ->
                        N = lists:nth(ErrIndex, Vars),
                        {error, {ErrorStatus, N}}
                end,
            {reply, Reply, S}
    end;

handle_call({do_get, MibView, UnsortedVarbinds, IsNotification, PduData}, 
	    _From, S) ->
    ?vlog("[handle_call] do_get:"
	  "~n   MibView:          ~p"
	  "~n   UnsortedVarbinds: ~p"
	  "~n   IsNotification:   ~p" 
	  "~n   PduData:          ~p", 
	  [MibView, UnsortedVarbinds, IsNotification, PduData]),
    put_pdu_data(PduData),
    Reply = do_get(MibView, UnsortedVarbinds, IsNotification),
    {reply, Reply, S};

handle_call({register_subagent, SubTreeOid, SubagentPid}, _From, S) ->
    Reply = 
	case snmpa_mib:register_subagent(get(mibserver),
					SubTreeOid, SubagentPid) of
	    ok -> link(SubagentPid), ok;
	    Error -> Error
	end,
    {reply, Reply, S};

handle_call({unregister_subagent, SubagentPid}, _From, S) 
  when is_pid(SubagentPid) ->
    ?vlog("[handle_call] unregister subagent ~p", [SubagentPid]),
    Reply = snmpa_mib:unregister_subagent(get(mibserver), SubagentPid),
    unlink(SubagentPid),
    {reply, Reply, S};

handle_call({unregister_subagent, SubTreeOid}, _From, S) ->
    ?vlog("[handle_call] unregister subagent ~p", [SubTreeOid]),
    Reply = 
	case snmpa_mib:unregister_subagent(get(mibserver), SubTreeOid) of
	    {ok, DeletedSubagentPid} ->
		SAs = snmpa_mib:info(get(mibserver), subagents),
		case lists:keysearch(DeletedSubagentPid, 1, SAs) of
		    {value, _} -> ok;
		    _ -> unlink(DeletedSubagentPid)
		end,
		ok;
	    Error ->
		Error
	end,
    {reply, Reply, S};

handle_call({load_mibs, Mibs}, _From, S) ->
    ?vlog("load mibs ~p", [Mibs]),
    {reply, snmpa_mib:load_mibs(get(mibserver), Mibs), S};

handle_call({unload_mibs, Mibs}, _From, S) ->
    ?vlog("unload mibs ~p", [Mibs]),
    {reply, snmpa_mib:unload_mibs(get(mibserver), Mibs), S};

handle_call(which_mibs, _From, S) ->
    ?vlog("which mibs", []),
    {reply, snmpa_mib:which_mibs(get(mibserver)), S};

handle_call({whereis_mib, Mib}, _From, S) ->
    ?vlog("whereis mib ~p", [Mib]),
    {reply, snmpa_mib:whereis_mib(get(mibserver), Mib), S};

handle_call({mibs_cache_request, MibsCacheReq}, From, S) ->
    ?vlog("mibs_cache_request: ~p", [MibsCacheReq]),
    {MibsCacheWorker, Ref} = 
	handle_mibs_cache_request(get(mibserver), MibsCacheReq),
    NewS = S#state{mibs_cache_request = {MibsCacheWorker, Ref, From}},
    {noreply, NewS};

handle_call(info, _From, S) ->
    ?vlog("info", []),
    Vsns  = S#state.vsns,
    Stats = get_stats_counters(), 
    AI    = agent_info(S),
    NI    = net_if_info(S),
    NS    = note_store_info(S),
    SS    = symbolic_store_info(),
    LD    = local_db_info(),
    MS    = mib_server_info(), 
    Info  = [{vsns,           Vsns}, 
	     {stats_counters, Stats},
	     {agent,          AI}, 
	     {net_if,         NI}, 
	     {note_store,     NS},
	     {symbolic_store, SS},
	     {local_db,       LD},
	     {mib_server,     MS}], 
    {reply, Info, S};

handle_call(get_net_if, _From, S) ->
    {reply, get(net_if), S};

handle_call({backup, BackupDir}, From, S) ->
    ?vlog("backup: ~p", [BackupDir]),
    Pid = self(),
    V   = get(verbosity),
    MS  = get(mibserver),
    BackupServer = 
	erlang:spawn_link(
	  fun() ->
		  put(sname, abs),
		  put(verbosity, V),
		  Dir   = filename:join([BackupDir]),
		  Reply = handle_backup(Dir, MS),
		  Pid ! {backup_done, Reply},
		  unlink(Pid)
	  end),
    ?vtrace("backup server: ~p", [BackupServer]),
    {noreply, S#state{backup = {BackupServer, From}}};
    
handle_call(dump_mibs, _From, S) ->
    Reply = snmpa_mib:dump(get(mibserver)),
    {reply, Reply, S};
    
handle_call({dump_mibs,File}, _From, S) ->
    Reply = snmpa_mib:dump(get(mibserver),File),
    {reply, Reply, S};
    
handle_call({register_notification_filter, Id, Mod, Data, Where}, _From, 
	    #state{nfilters = NFs} = S) ->
    ?vlog("register_notification_filter -> "
	  "~n   Id:    ~p"
	  "~n   Mod:   ~p"
	  "~n   Where: ~p", [Id, Mod, Where]),
    case lists:keymember(Id, 2, NFs) of
	true ->
	    {reply, {error, {already_registered, Id}}, S};
	false ->
	    NF = #notification_filter{id = Id, mod = Mod, data = Data},
	    {Reply, NewNFs} = add_notification_filter(Where, NF, NFs),
	    {reply, Reply, S#state{nfilters = NewNFs}}
    end;

handle_call({unregister_notification_filter, Id}, _From, 
	    #state{nfilters = NFs} = S) ->
    ?vlog("unregister_notification_filter -> "
	  "~n   Id: ~p", [Id]),
    case lists:keydelete(Id, 2, NFs) of
	NFs ->
	    {reply, {error, {not_found, Id}}, S};
	NFs2 ->
	    {reply, ok, S#state{nfilters = NFs2}}
    end;

handle_call(which_notification_filter, _From, 
	    #state{nfilters = NFs} = S) ->
    ?vlog("which_notification_filter", []),
    {reply, [Id || #notification_filter{id = Id} <- NFs], S};

handle_call({mib_of, Oid}, _From, S) ->
    Reply = handle_mib_of(get(mibserver), Oid),
    {reply, Reply, S};

handle_call({me_of, Oid}, _From, S) ->
    Reply = handle_me_of(get(mibserver), Oid),
    {reply, Reply, S};

handle_call(get_log_type, _From, S) ->
    ?vlog("get_log_type", []),
    Reply = handle_get_log_type(S), 
    {reply, Reply, S};
    
handle_call({set_log_type, NewType}, _From, S) ->
    ?vlog("set_log_type -> "
	  "~n   NewType: ~p", [NewType]),
    Reply = handle_set_log_type(S, NewType), 
    {reply, Reply, S};
    
handle_call(get_request_limit, _From, S) ->
    ?vlog("get_request_limit", []),
    Reply = handle_get_request_limit(S), 
    {reply, Reply, S};
    
handle_call({set_request_limit, NewLimit}, _From, S) ->
    ?vlog("set_request_limit -> "
	  "~n   NewLimit: ~p", [NewLimit]),
    Reply = handle_set_request_limit(S, NewLimit), 
    {reply, Reply, S};
    
handle_call(stop, _From, S) ->
    {stop, normal, ok, S};

handle_call(Req, _From, S) ->
    warning_msg("received unknown request: ~n~p", [Req]),
    Reply = {error, {unknown, Req}}, 
    {reply, Reply, S}.
    
handle_cast({verbosity, Verbosity}, S) ->
    ?vlog("verbosity: ~p -> ~p",[get(verbosity), Verbosity]),
    put(verbosity,snmp_verbosity:validate(Verbosity)),
    case S#state.worker of
	Pid when is_pid(Pid) -> Pid ! ?mk_verbosity_wreq(Verbosity);
	_ -> ok
    end,
    case S#state.set_worker of
	Pid2 when is_pid(Pid2) -> Pid2 ! ?mk_verbosity_wreq(Verbosity);
	_ -> ok
    end,
    {noreply, S};
    
handle_cast({sub_agents_verbosity,Verbosity}, S) ->
    ?vlog("sub_agents verbosity: ~p",[Verbosity]),
    subagents_verbosity(Verbosity),
    {noreply, S};
    
%% This should only happen if we are a master_agent
handle_cast({net_if_verbosity, Verbosity}, S) ->
    net_if_verbosity(get(net_if), Verbosity),
    {noreply, S};
    
handle_cast({mib_server_verbosity, Verbosity}, S) ->
    mib_server_verbosity(get(mibserver),Verbosity),
    {noreply, S};
    
handle_cast({note_store_verbosity, Verbosity}, #state{note_store = Pid} = S) ->
    note_store_verbosity(Pid,Verbosity),
    {noreply, S};
    
handle_cast(Msg, S) ->
    warning_msg("received unknown message: ~n~p", [Msg]),
    {noreply, S}.

    
terminate(shutdown, #state{worker     = Worker,
			   set_worker = SetWorker,
			   backup     = Backup, 
			   ref = Ref}) ->
    %% Ordered shutdown - stop misc-workers, net_if, mib-server and note-store.
    backup_server_stop(Backup), 
    worker_stop(Worker, 100),
    worker_stop(SetWorker, 100),
    snmpa_misc_sup:stop_net_if(Ref), 
    snmpa_misc_sup:stop_mib_server(Ref);
terminate(_Reason, _S) ->
    %% We crashed!  We will reuse net_if and mib if we get restarted.
    ok.


handle_mibs_cache_request(MibServer, Req) ->
    {MibsCacheWorker, MibsCacheRef} = 
	spawn_monitor(
	  fun() -> 
		  Reply = 
		      case Req of
			  invalidate_cache ->
			      snmpa_mib:invalidate_cache(MibServer);
			  gc_cache ->
			      snmpa_mib:gc_cache(MibServer);
			  {gc_cache, Age} ->
			      snmpa_mib:gc_cache(MibServer, Age);
			  {gc_cache, Age, GcLimit} ->
			      snmpa_mib:gc_cache(MibServer, Age, GcLimit);
			  cache_size ->
			      snmpa_mib:which_cache_size(MibServer);
			  enable_cache ->
			      snmpa_mib:enable_cache(MibServer);
			  disable_cache ->
			      snmpa_mib:disable_cache(MibServer);
			  enable_autogc ->
			      snmpa_mib:enable_cache_autogc(MibServer);
			  disable_autogc ->
			      snmpa_mib:disable_cache_autogc(MibServer);
			  {update_gclimit, GcLimit} ->
			      snmpa_mib:update_cache_gclimit(MibServer, 
							      GcLimit);
			  {update_age, Age} ->
			      snmpa_mib:update_cache_age(MibServer, Age);
			  _ ->
			      {error, {unknown_mibs_cache_request, Req}}
		      end,
		  exit({mibs_cache_reply, Reply})
	  end),
    {MibsCacheWorker, MibsCacheRef}.

		        
%%-----------------------------------------------------------------
%% Code replacement
%% 
%%-----------------------------------------------------------------

%% Downgrade
%%
code_change({down, _Vsn}, S1, downgrade_to_pre_4_17_3) ->
    #state{type               = Type, 
	   parent             = Parent, 
	   worker             = Worker, 
	   worker_state       = WorkerState,
	   set_worker         = SetWorker, 
	   multi_threaded     = MT, 
	   ref                = Ref, 
	   vsns               = Vsns,
	   nfilters           = NF,
	   note_store         = NoteStore,
	   mib_server         = MS, 
	   net_if             = NetIf, 
	   net_if_mod         = NetIfMod, 
	   backup             = Backup,
	   disco              = Disco,
	   mibs_cache_request = MCR} = S1, 
    S2 = {state, 
	  type               = Type, 
	  parent             = Parent, 
	  worker             = Worker, 
	  worker_state       = WorkerState,
	  set_worker         = SetWorker, 
	  multi_threaded     = MT, 
	  ref                = Ref, 
	  vsns               = Vsns,
	  nfilters           = NF,
	  note_store         = NoteStore,
	  mib_server         = MS, 
	  net_if             = NetIf, 
	  net_if_mod         = NetIfMod, 
	  backup             = Backup,
	  disco              = Disco,
	  mibs_cache_request = MCR}, 
    {ok, S2};

%% Upgrade
%%
code_change(_Vsn, S1, upgrade_from_pre_4_17_3) ->
    {state, 
     type               = Type, 
     parent             = Parent, 
     worker             = Worker, 
     worker_state       = WorkerState,
     set_worker         = SetWorker, 
     multi_threaded     = MT, 
     ref                = Ref, 
     vsns               = Vsns,
     nfilters           = NF,
     note_store         = NoteStore,
     mib_server         = MS, 
     net_if             = NetIf, 
     net_if_mod         = NetIfMod, 
     backup             = Backup,
     disco              = Disco,
     mibs_cache_request = MCR} = S1,
    S2 = #state{type               = Type, 
		parent             = Parent, 
		worker             = Worker, 
		worker_state       = WorkerState,
		set_worker         = SetWorker, 
		multi_threaded     = MT, 
		ref                = Ref, 
		vsns               = Vsns,
		nfilters           = NF,
		note_store         = NoteStore,
		mib_server         = MS, 
		net_if             = NetIf, 
		net_if_mod         = NetIfMod, 
		backup             = Backup,
		disco              = Disco,
		mibs_cache_request = MCR,
		gb_max_vbs         = ?DEFAULT_GB_MAX_VBS}, 
    {ok, S2};

code_change(_Vsn, S, _Extra) ->
    {ok, S}.


%% workers_restart(#state{worker = W, set_worker = SW} = S) ->
%%     Worker    = worker_restart(W),
%%     SetWorker = set_worker_restart(SW),
%%     S#state{worker     = Worker, 
%% 	    set_worker = SetWorker}.


%%-----------------------------------------------------------------

backup_server_stop({Pid, _}) when is_pid(Pid) ->
    exit(Pid, kill);
backup_server_stop(_) ->
    ok.


workers_start(true) ->
    ?vdebug("start worker and set-worker",[]),
    {worker_start(), set_worker_start()};
workers_start(_) ->
    {undefined, undefined}.

worker_start() ->
    worker_start(get()).

set_worker_start() ->
    worker_start([{master, self()} | get()]).

worker_start(Dict) ->
    proc_lib:spawn_link(?MODULE, worker, [self(), Dict]).

%% worker_stop(Pid) ->
%%     worker_stop(Pid, infinity).

worker_stop(Pid, Timeout) when is_pid(Pid) ->
    Pid ! ?mk_terminate_wreq(), 
    receive 
	{'EXIT', Pid, normal} ->
	    ok
    after Timeout ->
	    (catch exit(Pid, kill)),
	    ok
    end;
worker_stop(_, _) ->
    ok.

%% set_worker_restart(Pid) ->
%%     worker_restart(Pid, [{master, self()} | get()]).

%% worker_restart(Pid) ->
%%     worker_restart(Pid, get()).

%% worker_restart(Pid, Dict) when is_pid(Pid) -> 
%%     worker_stop(Pid),
%%     worker_start(Dict);
%% worker_restart(Any, _Dict) ->
%%     Any.


%%-----------------------------------------------------------------

handle_backup(BackupDir, MibServer) ->
    ?vlog("handle_backup -> entry with"
	  "~n   BackupDir: ~p", [BackupDir]),
    case ets:lookup(snmp_agent_table, db_dir) of
	[{db_dir, BackupDir}] ->
	    ?vinfo("handle_backup -> backup dir and db dir the same", []),
	    {error, db_dir};
	_ ->
	    case file:read_file_info(BackupDir) of
		{ok, #file_info{type = directory}} ->
		    ?vdebug("handle_backup -> backup dir ok", []),

		    VacmRes = (catch snmpa_vacm:backup(BackupDir)),
		    ?vtrace("handle_backup -> "
			    "~n   VacmRes: ~p", [VacmRes]),

		    LdbRes  = (catch snmpa_local_db:backup(BackupDir)),
		    ?vtrace("handle_backup -> "
			    "~n   LdbRes: ~p", [LdbRes]),

		    MsRes   = (catch snmpa_mib:backup(MibServer, BackupDir)),
		    ?vtrace("handle_backup -> "
			    "~n   MsRes: ~p", [MsRes]),

		    SsRes   = (catch snmpa_symbolic_store:backup(BackupDir)),
		    ?vtrace("handle_backup -> "
			    "~n   SsRes: ~p", [SsRes]),
		    handle_backup_res([{vacm,           VacmRes}, 
				       {local_db,       LdbRes},
				       {mib_server,     MsRes},
				       {symbolic_store, SsRes}]);
		{ok, _} ->
		    ?vinfo("handle_backup -> backup dir not a dir", []),
		    {error, not_a_directory};
		Error ->
		    ?vinfo("handle_backup -> Error: ~p", [Error]),
		    Error
	    end
    end.


handle_backup_res(Results) ->
    handle_backup_res(Results, []).

handle_backup_res([], []) ->
    ok;
handle_backup_res([], Acc) ->
    {error, lists:reverse(Acc)};
handle_backup_res([{_, ok}|Results], Acc) ->
    handle_backup_res(Results, Acc);
handle_backup_res([{Who, {error, Reason}}|Results], Acc) ->
    handle_backup_res(Results, [{Who, Reason}|Acc]);
handle_backup_res([{Who, Crap}|Results], Acc) ->
    handle_backup_res(Results, [{Who, Crap}|Acc]).


%%-----------------------------------------------------------------
%% We must cheat to get the community string out of the ACM data,
%% because we (for some reason) support the function
%% snmpa:current_community().
%%-----------------------------------------------------------------
cheat({community, _SecModel, Community, _IpUdp}, Address, ContextName) ->
    {Community, Address, ContextName};
cheat(_, Address, ContextName) ->
    {"", Address, ContextName}.


%% This function will either be in the context of the:
%% 1) master-agent
%% 2) set-worker
%% 3) user code 
%%    ( calling e.g. snmp_community_mib:snmpCommunityTable(set, ...) )
invalidate_ca_cache() ->
    case get(master) of
        undefined -> % 1 or 3
            case get(auth_module) of
		undefined -> % 3
		    %% Ouch, we are not running in the context of the 
		    %% master agent either. Check if we are on the 
		    %% master-agent node. If so, sent it there,
		    case whereis(snmp_master_agent) of
			MasterAgent when is_pid(MasterAgent) ->
			    case node(MasterAgent) =:= node() of
				true ->
				    %% Ok, we are on the node running the
				    %% master_agent process, so sent it there
				    MasterAgent ! invalidate_ca_cache;
				false ->
				    %% This is running on a sub-agent node, 
				    %% so sent skip it
				    ok
			    end;
			_ -> % Not on this node 
			    ok
		    end;
		AuthMod -> % 1
		    AuthMod:invalidate_ca_cache()
	    end;
        Pid -> % 2
            Pid ! invalidate_ca_cache
    end.


%%-----------------------------------------------------------------
%% Threads and workers
%% 
%%-----------------------------------------------------------------

%% This functions spawns a temporary worker process, 
%% that evaluates one request and then silently exits. 
spawn_thread(Vsn, Pdu, PduMS, ACMData, Address, GbMaxVBs, Extra) ->
    Dict = get(),
    Args = [Vsn, Pdu, PduMS, ACMData, Address, GbMaxVBs, Extra, Dict], 
    proc_lib:spawn_link(?MODULE, handle_pdu, Args).

spawn_trap_thread(TrapRec, NotifyName, ContextName, Recv, Vbs, 
		  LocalEngineID) ->
    Dict = get(),
    proc_lib:spawn_link(?MODULE, do_send_trap,
			[TrapRec, NotifyName, ContextName, 
			 Recv, Vbs, LocalEngineID, Dict]).

do_send_trap(TrapRec, NotifyName, ContextName, Recv, Vbs, 
	     LocalEngineID, Dict) ->
    lists:foreach(fun({Key, Val}) -> put(Key, Val) end, Dict),
    put(sname, trap_sender_short_name(get(sname))),
    ?vlog("starting",[]),
    snmpa_trap:send_trap(TrapRec, NotifyName, ContextName, Recv, Vbs, 
			 LocalEngineID, get(net_if)).

worker(Master, Dict) ->
    lists:foreach(fun({Key, Val}) -> put(Key, Val) end, Dict),
    put(sname, worker_short_name(get(sname))),
    ?vlog("starting",[]),
    worker_loop(Master).

worker_loop(Master) ->
    receive
	#wrequest{cmd  = handle_pdu, 
		  info = Info} ->
	    ?vtrace("worker_loop -> received handle_pdu request", []),
	    Vsn      = proplists:get_value(vsn,        Info),
	    Pdu      = proplists:get_value(pdu,        Info),
	    PduMS    = proplists:get_value(pdu_ms,     Info),
	    ACMData  = proplists:get_value(acm_data,   Info),
	    Address  = proplists:get_value(addr,       Info),
	    GbMaxVBs = proplists:get_value(gb_max_vbs, Info),
	    Extra    = proplists:get_value(extra,      Info),
	    handle_pdu2(Vsn, Pdu, PduMS, ACMData, Address, GbMaxVBs, Extra), 
	    ok;


	#wrequest{cmd  = send_trap, 
		  info = Info} ->
	    ?vtrace("worker_loop -> send trap", []),
	    TrapRec       = proplists:get_value(trap_rec,        Info),
	    NotifyName    = proplists:get_value(notify_name,     Info),
	    ContextName   = proplists:get_value(context_name,    Info),
	    Recv          = proplists:get_value(receiver,        Info),
	    Vbs           = proplists:get_value(vbs,             Info),
	    LocalEngineID = proplists:get_value(local_engine_id, Info),
	    snmpa_trap:send_trap(TrapRec, NotifyName, 
				 ContextName, Recv, Vbs, LocalEngineID, 
				 get(net_if)),
	    ok;


	#wrequest{cmd  = verbosity, 
		  info = Info} ->
	    Verbosity = proplists:get_value(verbosity, Info),
	    put(verbosity, snmp_verbosity:validate(Verbosity)),
	    ok;


	#wrequest{cmd  = terminate} ->
	    exit(normal);


	%% *************************************************************
	%% 
	%%         Kept for backward compatibillity reasons
	%% 
	%% *************************************************************

	{Vsn, Pdu, PduMS, ACMData, Address, Extra} ->
	    ?vtrace("worker_loop -> received request", []),
	    handle_pdu2(Vsn, Pdu, PduMS, ACMData, Address, 
			?DEFAULT_GB_MAX_VBS, Extra),
	    Master ! worker_available;

	%% We don't trap exits!
	{TrapRec, NotifyName, ContextName, Recv, Vbs} -> 
	    ?vtrace("worker_loop -> send trap:"
		    "~n   ~p", [TrapRec]),
	    snmpa_trap:send_trap(TrapRec, NotifyName, 
				 ContextName, Recv, Vbs, get(net_if)),
	    Master ! worker_available;

	%% We don't trap exits!
	{send_trap, 
	 TrapRec, NotifyName, ContextName, Recv, Vbs, LocalEngineID} -> 
	    ?vtrace("worker_loop -> send trap:"
		    "~n   ~p", [TrapRec]),
	    snmpa_trap:send_trap(TrapRec, NotifyName, 
				 ContextName, Recv, Vbs, LocalEngineID, 
				 get(net_if)),
	    Master ! worker_available;

	{verbosity, Verbosity} ->
	    put(verbosity,snmp_verbosity:validate(Verbosity));

	terminate ->
	    exit(normal);

	_X ->
	    %% ignore
	    ok

    after 30000 ->
	    %% This is to assure that the worker process leaves a
	    %% possibly old version of this module.
	    ok
    end,
    ?MODULE:worker_loop(Master).


%%-----------------------------------------------------------------
%%-----------------------------------------------------------------

handle_snmp_pdu(true, Vsn, Pdu, PduMS, ACMData, Address, Extra, 
		#state{multi_threaded = false, 
		       gb_max_vbs     = GbMaxVBs} = S) ->
    ?vtrace("handle_snmp_pdu -> single-thread agent",[]),
    handle_pdu2(Vsn, Pdu, PduMS, ACMData, Address, GbMaxVBs, Extra),
    S;
handle_snmp_pdu(true, Vsn, #pdu{type = 'set-request'} = Pdu, PduMS, 
		ACMData, Address, Extra, 
		#state{set_worker = Worker, 
		       gb_max_vbs = GbMaxVBs} = S) ->
    ?vtrace("handle_snmp_pdu -> multi-thread agent: "
	    "send set-request to main worker",[]),
    WRequest = ?mk_pdu_wreq(Vsn, Pdu, PduMS, ACMData, Address, GbMaxVBs, Extra),
    Worker ! WRequest, 
    S#state{worker_state = busy};
handle_snmp_pdu(true, Vsn, Pdu, PduMS, 
		ACMData, Address, Extra, 
		#state{worker_state = busy, 
		       gb_max_vbs   = GbMaxVBs} = S) ->
    ?vtrace("handle_snmp_pdu -> multi-thread agent: "
	    "main worker busy - create new worker",[]),
    spawn_thread(Vsn, Pdu, PduMS, ACMData, Address, GbMaxVBs, Extra),
    S;
handle_snmp_pdu(true, Vsn, Pdu, PduMS, ACMData, Address, Extra, 
		#state{worker     = Worker, 
		       gb_max_vbs = GbMaxVBs} = S) ->
    ?vtrace("handle_snmp_pdu -> multi-thread agent: "
	    "send to main worker",[]),
    WRequest = ?mk_pdu_wreq(Vsn, Pdu, PduMS, ACMData, Address, GbMaxVBs, Extra),
    Worker ! WRequest, 
    S#state{worker_state = busy};
handle_snmp_pdu(_, _Vsn, _Pdu, _PduMS, _ACMData, _Address, _Extra, S) ->
    S.


%% Called via the spawn_thread function
%% <BACKWARD-COMPAT>
handle_pdu(Vsn, Pdu, PduMS, ACMData, Address, Extra, Dict) ->
    handle_pdu(Vsn, Pdu, PduMS, ACMData, Address, ?DEFAULT_GB_MAX_VBS, Extra, 
	       Dict).
%% </BACKWARD-COMPAT>
handle_pdu(Vsn, Pdu, PduMS, ACMData, Address, GbMaxVBs, Extra, Dict) ->
    lists:foreach(fun({Key, Val}) -> put(Key, Val) end, Dict),
    put(sname, pdu_handler_short_name(get(sname))),
    ?vlog("new worker starting",[]),
    handle_pdu2(Vsn, Pdu, PduMS, ACMData, Address, GbMaxVBs, Extra).

handle_pdu2(Vsn, Pdu, PduMS, ACMData, Address, GbMaxVBs, Extra) ->
    %% OTP-3324
    AuthMod = get(auth_module),
    case AuthMod:init_check_access(Pdu, ACMData) of
	{ok, MibView, ContextName} ->
	    ?vlog("handle_pdu -> ok:"
		  "~n   MibView:     ~p"
		  "~n   ContextName: ~p", [MibView, ContextName]),
	    AgentData = cheat(ACMData, Address, ContextName),
	    do_handle_pdu(MibView, Vsn, Pdu, PduMS, ACMData, AgentData, 
			  GbMaxVBs, Extra);
	{error, Reason} ->
	    ?vlog("handle_pdu -> error:"
		  "~n   Reason: ~p", [Reason]),
	    handle_acm_error(Vsn, Reason, Pdu, ACMData, Address, Extra);
	{discarded, Variable, Reason} ->
	    ?vlog("handle_pdu -> discarded:"
		  "~n   Variable: ~p"
		  "~n   Reason:   ~p", [Variable, Reason]),
	    get(net_if) ! {discarded_pdu, Vsn, Pdu#pdu.request_id,
			   ACMData, Variable, Extra}
    end.

do_handle_pdu(MibView, Vsn, Pdu, PduMS, 
	      ACMData, {Community, Address, ContextName}, 
	      GbMaxVBs, Extra) ->
    
    put(net_if_data, Extra),

    RePdu = process_msg(MibView, Vsn, Pdu, PduMS, Community, 
			Address, ContextName, GbMaxVBs),

    ?vtrace("do_handle_pdu -> processed:"
	    "~n   RePdu: ~p", [RePdu]),
    NetIf = get(net_if), 
    NetIf ! {snmp_response, Vsn, RePdu, 
	     RePdu#pdu.type, ACMData, Address, Extra}.


handle_acm_error(Vsn, Reason, Pdu, ACMData, Address, Extra) ->
    #pdu{type = Type, request_id = ReqId, varbinds = Vbs} = Pdu,
    RawErrStatus = snmpa_acm:error2status(Reason),
    case is_valid_pdu_type(Type) of
	true ->
	    %% RawErrStatus can be authorizationError or genErr.  If it is
	    %% authorizationError, we'll have to do different things, 
	    %% depending on which SNMP version is used.
	    %% v1 - noSuchName error
	    %% v2 - GET: all variables 'noSuchObject'
	    %%      NEXT/BULK: all variables 'endOfMibView'
	    %%      SET: noAccess error
	    %% v3 - authorizationError error
	    %%
	    %% NOTE: this procedure is not yet defined in the coex document!
	    ?vdebug("~n   Raw error status: ~w",[RawErrStatus]),
	    Idx = case Vbs of
		      [] -> 0;
		      _ -> 1
		  end,
	    RePdu =
		if
		    Vsn =:= 'version-1' ->
			ErrStatus = v2err_to_v1err(RawErrStatus),
			make_response_pdu(ReqId, ErrStatus, Idx, Vbs, Vbs);
		    Vsn =:= 'version-3' ->
			make_response_pdu(ReqId, RawErrStatus, Idx, Vbs, Vbs);
		    Type =:= 'get-request' ->  % this is v2
			ReVbs = lists:map(
				  fun(Vb) -> 
					  Vb#varbind{value=noSuchObject} 
				  end,
				  Vbs),
			make_response_pdu(ReqId, noError, 0, Vbs, ReVbs);
		    Type =:= 'set-request' ->
			make_response_pdu(ReqId, noAccess, Idx, Vbs, Vbs);
		    true -> % next or bulk
			ReVbs = lists:map(
				  fun(Vb) -> 
					  Vb#varbind{value=endOfMibView} 
				  end,
				  Vbs),
			make_response_pdu(ReqId, noError, 0, Vbs, ReVbs)
		end,
	    get(net_if) ! {snmp_response, Vsn, RePdu, 
			   'get-response', ACMData, Address, Extra};
	false ->
	    ?vdebug("~n   Raw error status: ~w"
		    "~n   invalid pdu type: ~w", 
		    [RawErrStatus,Type]),
	    ok
    end.


handle_send_trap(S, TrapName, NotifyName, ContextName, Recv, Varbinds, 
		 LocalEngineID) ->
    ?vtrace("handle_send_trap -> entry with"
	"~n   S#state.type:  ~p"
	"~n   TrapName:      ~p"
	"~n   NotifyName:    ~p"
	"~n   ContextName:   ~p"
	"~n   LocalEngineID: ~p", 
	[S#state.type, TrapName, NotifyName, ContextName, LocalEngineID]),
    case snmpa_trap:construct_trap(TrapName, Varbinds) of
	{ok, TrapRecord, VarList} ->
	    ?vtrace("handle_send_trap -> construction complete: "
		    "~n   TrapRecord: ~p"
		    "~n   VarList: ~p",
		    [TrapRecord, VarList]),
	    case S#state.type of
		subagent ->
		    ?vtrace("handle_send_trap -> [sub] forward trap",[]),
		    maybe_forward_trap(S, TrapRecord, NotifyName,
				       ContextName, Recv, VarList),
		    {ok, S};
		master_agent ->
		    ?vtrace("handle_send_trap -> "
			    "[master] handle send trap",[]),
		    maybe_send_trap(S, TrapRecord, NotifyName,
				    ContextName, Recv, VarList,
				    LocalEngineID)
	    end;
	error ->
	    error
    end.
				

maybe_forward_trap(#state{parent = Parent, nfilters = NFs} = S,
		   TrapRec, NotifyName, ContextName, Recv, V) ->
    ?vtrace("maybe_forward_trap -> entry with"
	    "~n   NFs: ~p", [NFs]),
    case filter_notification(NFs, [], TrapRec) of
	{dont_send, [], Id} ->
	    ?vdebug("trap not forwarded [filter ~p]", [Id]),
	    {ok, S};
	
	{dont_send, Removed, Id} ->
	    ?vdebug("trap not forwarded [filter ~p]", [Id]),
	    NFs2 = del_notification_filter(Removed, NFs),
	    {ok, S#state{nfilters = NFs2}};
	
	{send, [], TrapRec2} ->
	    ?vtrace("maybe_forward_trap -> forward trap:"
		    "~n   ~p", [TrapRec2]),
	    forward_trap(Parent, TrapRec2, NotifyName, ContextName, Recv, V),
	    {ok, S};
	
	{send, Removed, TrapRec2} ->
	    ?vtrace("maybe_forward_trap -> forward trap:"
		    "~n   ~p", [TrapRec2]),
	    forward_trap(Parent, TrapRec2, NotifyName, ContextName, Recv, V),
	    NFs2 = del_notification_filter(Removed, NFs),
	    {ok, S#state{nfilters = NFs2}}
    end.


maybe_send_trap(#state{nfilters = NFs} = S, 
		TrapRec, NotifyName, ContextName, Recv, Varbinds, 
		LocalEngineID) ->
    ?vtrace("maybe_send_trap -> entry with"
	    "~n   NFs: ~p", [NFs]),
    case filter_notification(NFs, [], TrapRec) of
	{dont_send, [], Id} ->
	    ?vdebug("trap not sent [filter ~p]",[Id]),
	    {ok, S};
	
	{dont_send, Removed, Id} ->
	    ?vdebug("trap not sent [filter ~p]",[Id]),
	    NFs2 = del_notification_filter(Removed, NFs),
	    {ok, S#state{nfilters = NFs2}};
	
	{send, [], TrapRec2} ->
	    ?vtrace("maybe_send_trap -> send trap:"
		    "~n   ~p", [TrapRec2]),
	    do_handle_send_trap(S, TrapRec2, 
				NotifyName, ContextName, Recv, Varbinds, 
				LocalEngineID);
	
	{send, Removed, TrapRec2} ->
	    ?vtrace("maybe_send_trap -> send trap:"
		    "~n   ~p", [TrapRec2]),
	    NFs2 = del_notification_filter(Removed, NFs),
	    do_handle_send_trap(S#state{nfilters = NFs2}, TrapRec2, 
				NotifyName, ContextName, Recv, Varbinds,
				LocalEngineID)
    end.
   
do_handle_send_trap(S, TrapRec, NotifyName, ContextName, Recv, Varbinds,
		   LocalEngineID) ->
    Vbs = snmpa_trap:try_initialise_vars(get(mibserver), Varbinds),
    case S#state.type of
	subagent ->
	    forward_trap(S#state.parent, TrapRec, NotifyName, ContextName,
			 Recv, Vbs),
	    {ok, S};
	master_agent when S#state.multi_threaded =:= false ->
	    ?vtrace("do_handle_send_trap -> send trap:"
		    "~n   ~p", [TrapRec]),
	    snmpa_trap:send_trap(TrapRec, NotifyName, ContextName,
				 Recv, Vbs, LocalEngineID, get(net_if)),
	    {ok, S};
	master_agent when S#state.worker_state =:= busy ->
	    %% Main worker busy => create new worker
	    ?vtrace("do_handle_send_trap -> main worker busy: "
		    "spawn a trap sender", []),
	    spawn_trap_thread(TrapRec, NotifyName, ContextName, Recv, Vbs,
			      LocalEngineID),
	    {ok, S};
	master_agent ->
	    %% Send to main worker
	    ?vtrace("do_handle_send_trap -> send to main worker",[]),
	    S#state.worker ! ?mk_send_trap_wreq(TrapRec, NotifyName, 
						ContextName, Recv, Vbs,
						LocalEngineID),
	    {ok, S#state{worker_state = busy}}
    end.
    

filter_notification([], RemoveNFs, Notif) ->
    ?vtrace("filter_notification -> done when"
	    "~n   RemoveNFs: ~p"
	    "~n   Notif:     ~p", [RemoveNFs, Notif]),
    {send, RemoveNFs, Notif};
filter_notification([NF|NFs], RemoveNFs, Notif0) ->
    ?vtrace("filter_notification -> entry with"
	    "~n   NF:        ~p"
	    "~n   RemoveNFs: ~p"
	    "~n   Notif0:    ~p", [NF, RemoveNFs, Notif0]),
    case do_filter_notification(NF, Notif0) of
	{dont_send, Id} ->
	    {dont_send, RemoveNFs, Id};
	{send, Notif} ->
	    filter_notification(NFs, RemoveNFs, Notif);
	{error, Id} ->
	    filter_notification(NFs, [Id|RemoveNFs], Notif0)
    end.

do_filter_notification(#notification_filter{id = Id, mod = Mod, data = Data}, 
		       Notif) ->
    case (catch Mod:handle_notification(Notif, Data)) of
	dont_send ->
	    {dont_send, Id};
	send ->
	    {send, Notif};
	{send, NewNotif} ->
	    {send, NewNotif};
	Else ->
	    user_err("notification filter ~p removed: ~n~p", [Id, Else]),
	    {error, Id}
    end.


add_notification_filter(first, NewNF, NFs) ->
    {ok, [NewNF | NFs]};
add_notification_filter(last, NewNF, NFs) ->
    {ok, lists:append(NFs, [NewNF])};
add_notification_filter(Where, NewNF, NFs) ->
    case add_nf(Where, NewNF, NFs, []) of
	{ok, NFs2} ->
	    {ok, NFs2};
	Error ->
	    {Error, NFs}
    end.

add_nf({_Loc, Id}, _NewNF, [], _Acc) ->
    {error, {not_found, Id}};
add_nf({insert_before, Id}, NewNF, [NF|NFs], Acc) 
  when Id =:= NF#notification_filter.id ->
    {ok, lists:reverse(Acc) ++ [NewNF,NF|NFs]};
add_nf({insert_after, Id}, NewNF, [NF|NFs], Acc) 
  when Id =:= NF#notification_filter.id ->
    {ok, lists:reverse(Acc) ++ [NF,NewNF|NFs]};
add_nf(Where, NewNF, [NF|NFs], Acc) ->
    add_nf(Where, NewNF, NFs, [NF|Acc]).
    

del_notification_filter(IDs, NFs) ->
    Fun = fun(Id, NFilters) -> lists:keydelete(Id, 2, NFilters) end,
    lists:foldl(Fun, NFs, IDs).


handle_discovery(#state{type = master_agent} = S, From, 
		 TargetName, Notification, ContextName, Varbinds, 
		 DiscoHandler, ExtraInfo) ->
    ?vtrace("handle_discovery -> entry with"
	    "~n   TargetName:   ~p" 
	    "~n   Notification: ~p" 
	    "~n   ContextName:  ~p" 
	    "~n   Varbinds:     ~p", 
	    [TargetName, Notification, ContextName, Varbinds]),
    case snmpa_trap:construct_trap(Notification, Varbinds) of
	{ok, Record, InitVars} ->
	    ?vtrace("handle_discovery -> trap construction complete: "
		    "~n   Record:   ~p"
		    "~n   InitVars: ~p", [Record, InitVars]),
	    send_discovery(S, From, TargetName, 
			   Record, ContextName, InitVars, 
			   DiscoHandler, ExtraInfo);
	error ->
	    {error, failed_constructing_notification}
    end;
handle_discovery(_S, _From, 
		 _TargetName, _Notification, _ContextName, _Varbinds, 
		 _DiscoHandler, _ExtraInfo) ->
    {error, only_master_discovery}.
				
%% We ignore if the master agent is multi-threaded or not.
%% 
send_discovery(S, From, 
	       TargetName, Record, ContextName, InitVars, 
	       DiscoHandler, ExtraInfo) ->
    case snmpa_trap:send_discovery(TargetName, Record, ContextName,
				   InitVars, get(net_if)) of
	{ok, Sender, SecLevel} ->
	    Disco = #disco{from      = From, 
			   rec       = Record,
			   sender    = Sender, 
			   target    = TargetName, 
			   sec_level = SecLevel,
			   ctx       = ContextName,
			   ivbs      = InitVars, 
			   stage     = 1,
			   handler   = DiscoHandler,
			   extra     = ExtraInfo}, 
	    {ok, S#state{disco = Disco}};
	Error ->
	    ?vlog("send_discovery -> failed sending discovery: "
		    "~n   Error: ~p", [Error]),
	    Error
    end.


handle_discovery_response(#state{disco = #disco{from = From}} = S, 
			  {error, _} = Error) ->
    ?vlog("handle_discovery_response -> entry with"
	  "~n   From:  ~p"
	  "~n   Error: ~p", [From, Error]),
    gen_server:reply(From, Error),
    S#state{disco = undefined};

handle_discovery_response(#state{disco = #disco{target = TargetName, 
						stage  = 1,
						extra  = ExtraInfo} = Disco} = S, 
			  {ok, _Pdu, ManagerEngineId}) 
  when is_record(Disco, disco) ->
    ?vlog("handle_discovery_response(1) -> entry with"
	  "~n   TargetName:      ~p"
	  "~n   ManagerEngineId: ~p", [TargetName, ManagerEngineId]),
    %% This is end of stage 1.
    %% So, first we need to update the database with the EngineId of the 
    %% manager and then deside if we should continue with stage 2. E.g.
    %% establish authenticated communication. 
    case snmp_target_mib:set_target_engine_id(TargetName, ManagerEngineId) of
	true when Disco#disco.sec_level =:= ?'SnmpSecurityLevel_noAuthNoPriv' ->
	    %% Ok, we are done
	    From    = Disco#disco.from,
	    Handler = Disco#disco.handler, 
	    Reply   = 
		case handle_discovery_stage1_finish(Handler, 
						    TargetName, 
						    ManagerEngineId, 
						    ExtraInfo) of
		    {ok, _} ->
			{ok, ManagerEngineId};
		    Error ->
			Error
		end,
	    gen_server:reply(From, Reply),
	    S#state{disco = undefined};

	true when Disco#disco.sec_level =/= ?'SnmpSecurityLevel_noAuthNoPriv' ->
	    %% Ok, time for stage 2
	    %% Send the same inform again, 
	    %% this time we have the proper EngineId

	    From    = Disco#disco.from,
	    Handler = Disco#disco.handler, 

	    case handle_discovery_stage1_finish(Handler, 
						TargetName, 
						ManagerEngineId, 
						ExtraInfo) of
		{ok, NewExtraInfo} ->
		    ?vdebug("handle_discovery_response(1) -> "
			    "we are done with stage 1 - "
			    "continue with stage 2", []),
		    #disco{rec  = Record,
			   ctx  = ContextName,
			   ivbs = InitVars} = Disco, 
		    case snmpa_trap:send_discovery(TargetName, Record, 
						   ContextName,
						   InitVars, get(net_if)) of
			{ok, Sender, _SecLevel} ->
			    ?vdebug("handle_discovery_response(1) -> "
				    "stage 2 trap sent", []),
			    Disco2 = Disco#disco{sender    = Sender, 
						 engine_id = ManagerEngineId, 
						 stage     = 2,
						 extra     = NewExtraInfo}, 
			    S#state{disco = Disco2};
			Error ->
			    ?vlog("handle_discovery_response(1) -> "
				  "failed sending stage 2 trap: "
				  "~n   ~p", [Error]),
			    error_msg("failed sending second "
				      "discovery message: "
				      "~n   ~p", [Error]),
			    Reply = {error, {second_send_failed, Error}}, 
			    gen_server:reply(From, Reply),
			    S#state{disco = undefined}
		    end;
		{error, Reason} = Error ->
		    ?vlog("handle_discovery_response(1) -> "
			  "stage 1 finish failed: "
			  "~n   ~p", [Reason]),
		    gen_server:reply(From, Error),
		    S#state{disco = undefined}
	    end;
	false ->
	    ?vinfo("handle_discovery_response(1) -> "
		   "failed setting doscovered engine-id - "
		   "inform the user", []),
	    From   = Disco#disco.from,
	    Reason = {failed_setting_engine_id, TargetName, ManagerEngineId},
	    gen_server:reply(From, {error, Reason}),
	    S#state{disco = undefined}

    end;

handle_discovery_response(#state{disco = #disco{from = From, 
						engine_id = EngineID, 
						stage = 2}} = S, 
			  {ok, _Pdu}) ->
    ?vlog("handle_discovery_response(2) -> entry with"
	  "~n   From: ~p", [From]),
    gen_server:reply(From, {ok, EngineID}),
    S#state{disco = undefined};

handle_discovery_response(#state{disco = #disco{from = From}} = S, Crap) ->
    Reason = {invalid_response, Crap}, 
    gen_server:reply(From, {error, Reason}),
    S#state{disco = undefined};

handle_discovery_response(S, Crap) ->
    warning_msg("Received unexpected discovery response: ~p", [Crap]),
    S.

handle_discovery_stage1_finish(Handler, TargetName, ManagerEngineID, 
			       ExtraInfo) ->
    case (catch Handler:stage1_finish(TargetName, ManagerEngineID, 
				      ExtraInfo)) of
	ignore ->
	    ?vtrace("handle_discovery_stage1_finish -> "
		    "we are done - [ignore] inform the user", []),
	    {ok, ExtraInfo};

	{ok, UsmEntry} when is_tuple(UsmEntry) ->
	    ?vtrace("handle_discovery_stage1_finish -> "
		    "received usm entry - attempt to add it", []),
	    case add_usm_users([UsmEntry]) of
		ok ->
		    {ok,  ExtraInfo};
		Error ->
		    Error
	    end;

	{ok, UsmEntry, NewExtraInfo} when is_tuple(UsmEntry) ->
	    ?vtrace("handle_discovery_stage1_finish -> "
		    "received usm entry - attempt to add it", []),
	    case add_usm_users([UsmEntry]) of
		ok ->
		    {ok, NewExtraInfo};
		Error ->
		    Error
	    end;

	{ok, UsmEntries} when is_list(UsmEntries) ->
	    ?vtrace("handle_discovery_stage1_finish -> "
		    "received usm entries - attempt to add them", []),
	    case add_usm_users(UsmEntries) of
		ok ->
		    {ok, ExtraInfo};
		Error ->
		    Error
	    end;

	{ok, UsmEntries, NewExtraInfo} when is_list(UsmEntries) ->
	    ?vtrace("handle_discovery_stage1_finish -> "
		    "received usm entries - attempt to add them", []),
	    case add_usm_users(UsmEntries) of
		ok ->
		    {ok, NewExtraInfo};
		Error ->
		    Error
	    end;

	{'EXIT', Reason} ->
	    ?vlog("handle_discovery_stage1_finish -> stage 1 function exited: "
		  "~n   ~p", [Reason]),
	    {error, {finish_exit, Reason, ManagerEngineID}};

	{error, Reason} ->
	    ?vlog("handle_discovery_stage1_finish -> stage 1 function error: "
		  "~n   ~p", [Reason]),
	    {error, {finish_error, Reason, ManagerEngineID}};

	Unknown ->
	    ?vlog("handle_discovery_stage1_finish -> stage 1 function unknown: "
		  "~n   ~p", [Unknown]),
	    {error, {finish_failed, Unknown, ManagerEngineID}}
    end.

add_usm_users([]) ->
    ok;
add_usm_users([UsmEntry|UsmEntries]) when is_tuple(UsmEntry) ->
    ?vtrace("add_usm_users -> attempt to add entry (~w)", 
	    [element(1, UsmEntry)]),
    case snmp_user_based_sm_mib:add_user(UsmEntry) of
	{ok, _} ->
	    add_usm_users(UsmEntries);
	{error, Reason} ->
	    ?vlog("add_usm_users -> failed adding usm entry: "
		  "~n   ~p", [Reason]),
	    {error, {failed_adding_entry, Reason, UsmEntry}}
    end.

    
handle_me_of(MibServer, Oid) ->
    case snmpa_mib:lookup(MibServer, Oid) of
	{variable, ME} ->
	    {ok, ME};
	{table_column, ME, _TableEntryOid} ->
	    {ok, ME};
	{subagent, SubAgentPid, _SANextOid} ->
	    {error, {subagent, SubAgentPid}};
	{false, Reason} ->
	    {error, Reason};
	Else ->
	    {error, Else}
    end.

   
handle_mib_of(MibServer, Oid) ->
    snmpa_mib:which_mib(MibServer, Oid).


%%-----------------------------------------------------------------
%% Func: process_msg/7
%% Returns: RePdu
%%-----------------------------------------------------------------
process_msg(MibView, Vsn, Pdu, PduMS, Community, {Ip, Udp}, ContextName, 
	    GbMaxVBs) ->
    #pdu{request_id = ReqId} = Pdu,
    put(snmp_address, {tuple_to_list(Ip), Udp}),
    put(snmp_request_id, ReqId),
    put(snmp_community, Community),
    put(snmp_context, ContextName),
    ?vtrace("process ~p",[Pdu#pdu.type]),
    process_pdu(Pdu, PduMS, Vsn, MibView, GbMaxVBs).

process_pdu(#pdu{type='get-request', request_id = ReqId, varbinds=Vbs},
	    _PduMS, Vsn, MibView, _GbMaxVBs) ->
    ?vtrace("get ~p",[ReqId]),
    Res = get_err(do_get(MibView, Vbs, false)),
    ?vtrace("get result: "
	    "~n   ~p",[Res]),
    {ErrStatus, ErrIndex, ResVarbinds} =
	if
	    Vsn =:= 'version-1' -> validate_get_v1(Res);
	    true -> Res
	end,
    ?vtrace("get final result: "
	    "~n   Error status: ~p"
	    "~n   Error index:  ~p"
	    "~n   Varbinds:     ~p",
	    [ErrStatus,ErrIndex,ResVarbinds]),
    ResponseVarbinds = lists:keysort(#varbind.org_index, ResVarbinds),
    ?vtrace("response varbinds: "
	    "~n   ~p",[ResponseVarbinds]),
    make_response_pdu(ReqId, ErrStatus, ErrIndex, Vbs, ResponseVarbinds);

process_pdu(#pdu{type = 'get-next-request', request_id = ReqId, varbinds = Vbs},
	    _PduMS, Vsn, MibView, _GbMaxVBs) ->
    ?vtrace("process get-next-request -> entry with"
	    "~n   ReqId:   ~p"
	    "~n   Vbs:     ~p"
	    "~n   MibView: ~p",[ReqId, Vbs, MibView]),
    Res = get_err(do_get_next(MibView, Vbs, infinity)),
    ?vtrace("get-next result: "
	    "~n   ~p",[Res]),
    {ErrStatus, ErrIndex, ResVarbinds} = 
	if
	    Vsn =:= 'version-1' -> validate_next_v1(Res, MibView);
	    true -> Res
	end,
    ?vtrace("get-next final result -> validation result:"
	    "~n   Error status: ~p"
	    "~n   Error index:  ~p"
	    "~n   Varbinds:     ~p",[ErrStatus,ErrIndex,ResVarbinds]),
    ResponseVarbinds = lists:keysort(#varbind.org_index, ResVarbinds),
    ?vtrace("get-next final result -> response varbinds: "
	    "~n   ~p",[ResponseVarbinds]),
    make_response_pdu(ReqId, ErrStatus, ErrIndex, Vbs, ResponseVarbinds);

process_pdu(#pdu{type         = 'get-bulk-request',
		 request_id   = ReqId,
		 varbinds     = Vbs,
		 error_status = NonRepeaters, 
		 error_index  = MaxRepetitions},
	    PduMS, _Vsn, MibView, GbMaxVBs) ->
    {ErrStatus, ErrIndex, ResponseVarbinds} = 
	get_err(do_get_bulk(MibView, NonRepeaters, MaxRepetitions, PduMS, Vbs, 
			    GbMaxVBs)),
    ?vtrace("get-bulk final result: "
	    "~n   Error status:     ~p"
	    "~n   Error index:      ~p"
	    "~n   Respons varbinds: ~p",
	    [ErrStatus,ErrIndex,ResponseVarbinds]),
    make_response_pdu(ReqId, ErrStatus, ErrIndex, Vbs, ResponseVarbinds);

process_pdu(#pdu{type = 'set-request', request_id = ReqId, varbinds = Vbs},
	    _PduMS, Vsn, MibView, _GbMaxVbs)->
    Res = do_set(MibView, Vbs),
    ?vtrace("set result: "
	    "~n   ~p",[Res]),
    {ErrStatus, ErrIndex} =
	if 
	    Vsn =:= 'version-1' -> validate_err(v2_to_v1, Res);
	    true -> Res
	end,
    ?vtrace("set final result: "
	    "~n   Error status: ~p"
	    "~n   Error index:  ~p",[ErrStatus,ErrIndex]),
    make_response_pdu(ReqId, ErrStatus, ErrIndex, Vbs, Vbs).

%%-----------------------------------------------------------------
%% Transform a value == noSuchInstance | noSuchObject or a 
%% Counter64 type to a noSuchName error for the whole pdu.
%% Args: {Error, Index, Vbs}
%% Returns: {NewError, NewIndex, NewVbs}
%%-----------------------------------------------------------------
validate_get_v1({noError, _, ResponseVarbinds}) ->
    case validate_get_v1_2(ResponseVarbinds) of
	true -> {noError, 0, ResponseVarbinds};
	{Error, Index} -> {Error, Index, []} % dummy vbs
    end;
validate_get_v1({ErrStatus, ErrIndex, ResponseVarbinds}) ->
    {v2err_to_v1err(ErrStatus), ErrIndex, ResponseVarbinds}.

validate_get_v1_2([Vb | Vbs]) 
  when ((Vb#varbind.value =/= noSuchInstance) andalso 
	(Vb#varbind.value =/= noSuchObject) andalso 
	(Vb#varbind.variabletype =/= 'Counter64')) ->
    validate_get_v1_2(Vbs);
validate_get_v1_2([Vb | _Vbs]) ->
    {noSuchName, Vb#varbind.org_index};
validate_get_v1_2([]) ->
    true.

%%-----------------------------------------------------------------
%% Transform a value == endOfMibView to a noSuchName for the
%% whole pdu, and do another get-next for any Counter64 value.
%% Args: {Error, Index, Vbs}
%% Returns: {NewError, NewIndex, NewVbs}
%%-----------------------------------------------------------------
validate_next_v1({noError, _, ResponseVarbinds}, MibView) ->
    case validate_next_v1_2(ResponseVarbinds, MibView, []) of
	{true, NVbs} -> {noError, 0, NVbs};
	{Error, Index} -> {Error, Index, []} % dummy vbs
    end;
validate_next_v1({ErrStatus, ErrIndex, ResponseVarbinds}, _MibView) ->
    {v2err_to_v1err(ErrStatus), ErrIndex, ResponseVarbinds}.

validate_next_v1_2([Vb | _Vbs], _MibView, _Res)
  when Vb#varbind.value =:= endOfMibView ->
    {noSuchName, Vb#varbind.org_index};
validate_next_v1_2([Vb | Vbs], MibView, Res)
  when Vb#varbind.variabletype =:= 'Counter64' ->
    case validate_next_v1(
	   do_get_next(MibView, [mk_next_oid(Vb)], infinity), MibView) of
	{noError, 0, [NVb]} ->
	    validate_next_v1_2(Vbs, MibView, [NVb | Res]);
	{Error, Index, _OrgVb} ->
	    {Error, Index}
    end;
validate_next_v1_2([Vb | Vbs], MibView, Res) ->
    validate_next_v1_2(Vbs, MibView, [Vb | Res]);
validate_next_v1_2([], _MibView, Res) ->
    {true, Res}.

%%-----------------------------------------------------------------
%% Optimization. When we get to a Counter64 object that is a table
%% column, we'll try to find the next instance. This will be the
%% next row in the table, which is a Counter64 value as well. This
%% means that we will loop through the entire table, until we find
%% a column that isn't a Counter64 column. We can optimze this by
%% adding 1 to the column-no in the oid of this instance.
%% If the table is implemented by a subagent this does not help,
%% we'll call that subagent many times. But it shouldn't be any
%% problems.
%%-----------------------------------------------------------------
mk_next_oid(Vb) ->
    case snmpa_mib:lookup(get(mibserver), Oid = Vb#varbind.oid) of
	{table_column, _MibEntry, TableEntryOid} ->
	    [Col | _] = Oid -- TableEntryOid,
	    Vb#varbind{oid = TableEntryOid ++ [Col+1]};
	_ ->
	    Vb
    end.

%%%-----------------------------------------------------------------
%%% 3. GET REQUEST
%%% --------------
%%%   According to RFC1157, section 4.1.2 and RFC1905, section 4.2.1.
%%%   In rfc1157:4.1.2 it isn't specified if noSuchName should be
%%%   returned even if some other varbind generates a genErr.
%%%   In rfc1905:4.2.1 this is not a problem since exceptions are
%%%   used, and thus a genErr will be returned anyway.
%%%-----------------------------------------------------------------

%%-----------------------------------------------------------------
%% Func: do_get/3
%% Purpose: do_get handles "getRequests".
%% Pre: incoming varbinds have type == 'NULL', value == unSpecified
%% Returns: {noError, 0, ListOfNewVarbinds} |
%%          {ErrorStatus, ErrorIndex, []}
%%-----------------------------------------------------------------

%% If this function is called from a worker-process, we *may* 
%% need to tunnel into the master-agent and let it do the 
%% work

do_get(MibView, UnsortedVarbinds, IsNotification) ->
    do_get(MibView, UnsortedVarbinds, IsNotification, false).

do_get(MibView, UnsortedVarbinds, IsNotification, ForceMaster) ->
    ?vtrace("do_get -> entry with"
	    "~n   MibView:          ~p"
	    "~n   UnsortedVarbinds: ~p"
	    "~n   IsNotification:   ~p", 
	    [MibView, UnsortedVarbinds, IsNotification]),
    case (whereis(snmp_master_agent) =:= self()) of
	false when (ForceMaster =:= true) ->
	    %% I am a lowly worker process, handoff to the master agent
	    PduData = get_pdu_data(), 
	    call(snmp_master_agent, 
		 {do_get, MibView, UnsortedVarbinds, IsNotification, PduData});

	_ ->
	    %% This is me, the master, so go ahead
	    {OutSideView, InSideView} = 
		split_vbs_view(UnsortedVarbinds, MibView),
	    {Error, Index, NewVbs} = 
		do_get(InSideView, IsNotification),
	    {Error, Index, NewVbs ++ OutSideView}

    end.


split_vbs_view(Vbs, MibView) ->
    ?vtrace("split the varbinds view", []),
    split_vbs_view(Vbs, MibView, [], []).

split_vbs_view([Vb | Vbs], MibView, Out, In) ->
    case snmpa_acm:validate_mib_view(Vb#varbind.oid, MibView) of
	true -> split_vbs_view(Vbs, MibView, Out, [Vb | In]);
	false -> split_vbs_view(Vbs, MibView,
				[Vb#varbind{value = noSuchObject} | Out], In)
    end;
split_vbs_view([], _MibView, Out, In) ->
    {Out, In}.
	    
do_get(UnsortedVarbinds, IsNotification) ->
    {MyVarbinds, SubagentVarbinds} = sort_varbindlist(UnsortedVarbinds),
    case do_get_local(MyVarbinds, [], IsNotification) of
	{noError, 0, NewMyVarbinds} ->
	    case do_get_subagents(SubagentVarbinds, IsNotification) of
		{noError, 0, NewSubagentVarbinds} ->
		    {noError, 0, NewMyVarbinds ++ NewSubagentVarbinds};
		{ErrorStatus, ErrorIndex, _} ->
		    {ErrorStatus, ErrorIndex, []}
	    end;
	{ErrorStatus, ErrorIndex, _} -> 
	    {ErrorStatus, ErrorIndex, []}
    end.

%%-----------------------------------------------------------------
%% Func: do_get_local/3
%% Purpose: Loop the variablebindings list. We know that each varbind
%%          in that list belongs to us.
%% Returns: {noError, 0, ListOfNewVarbinds} |
%%          {ErrorStatus, ErrorIndex, []}
%%-----------------------------------------------------------------
do_get_local([Vb | Vbs], Res, IsNotification) ->
    case try_get(Vb, IsNotification) of
	NewVb when is_record(NewVb, varbind) ->
	    do_get_local(Vbs, [NewVb | Res], IsNotification);
	ListOfNewVb when is_list(ListOfNewVb) ->
	    do_get_local(Vbs, lists:append(ListOfNewVb, Res), IsNotification);
	{error, Error, OrgIndex} ->
	    {Error, OrgIndex, []}
    end;
do_get_local([], Res, _IsNotification) -> 
    {noError, 0, Res}.

%%-----------------------------------------------------------------
%% Func: do_get_subagents/2
%% Purpose: Loop the list of varbinds for different subagents.
%%          For each of them, call sub_agent_get to retreive
%%          the values for them.
%% Returns: {noError, 0, ListOfNewVarbinds} |
%%          {ErrorStatus, ErrorIndex, []}
%%-----------------------------------------------------------------
do_get_subagents(SubagentVarbinds, IsNotification) ->
    do_get_subagents(SubagentVarbinds, [], IsNotification).
do_get_subagents([{SubAgentPid, SAVbs} | Tail], Res, IsNotification) ->
    {_SAOids, Vbs} = sa_split(SAVbs),
    case catch subagent_get(SubAgentPid, Vbs, IsNotification) of
	{noError, 0, NewVbs} ->
	    do_get_subagents(Tail, lists:append(NewVbs, Res), IsNotification);
	{ErrorStatus, ErrorIndex, _} ->
	    {ErrorStatus, ErrorIndex, []};
	{'EXIT', Reason} ->
	    user_err("Lost contact with subagent (get) ~w. Using genErr", 
		     [Reason]),
	    {genErr, 0, []} 
    end;
do_get_subagents([], Res, _IsNotification) ->
    {noError, 0, Res}.


%%-----------------------------------------------------------------
%% Func: try_get/2
%% Returns: {error, ErrorStatus, OrgIndex} |
%%          #varbind |
%%          List of #varbind
%%-----------------------------------------------------------------
try_get(IVb, IsNotification) when is_record(IVb, ivarbind) ->
    ?vtrace("try_get(ivarbind) -> entry with"
	    "~n   IVb: ~p", [IVb]),
    get_var_value_from_ivb(IVb, IsNotification);
try_get({TableOid, TableVbs}, IsNotification) ->
    ?vtrace("try_get(table) -> entry with"
	    "~n   TableOid: ~p"
	    "~n   TableVbs: ~p", [TableOid, TableVbs]),
    [#ivarbind{mibentry = MibEntry}|_] = TableVbs,
    {NoAccessVbs, AccessVbs} =
	check_all_table_vbs(TableVbs, IsNotification, [], []),
    case get_tab_value_from_mib(MibEntry, TableOid, AccessVbs) of
	{error, ErrorStatus, OrgIndex} ->
	    {error, ErrorStatus, OrgIndex};
	NVbs ->
	    NVbs ++ NoAccessVbs
    end.

%%-----------------------------------------------------------------
%% Make sure all requested columns are accessible.
%%-----------------------------------------------------------------
check_all_table_vbs([IVb| IVbs], IsNotification, NoA, A) ->
    #ivarbind{mibentry = Me, varbind = Vb} = IVb,
    case Me#me.access of
	'not-accessible' -> 
	    NNoA = [Vb#varbind{value = noSuchInstance} | NoA],
	    check_all_table_vbs(IVbs, IsNotification, NNoA, A);
	'accessible-for-notify' when IsNotification =:= false -> 
	    NNoA = [Vb#varbind{value = noSuchInstance} | NoA],
	    check_all_table_vbs(IVbs, IsNotification, NNoA, A);
	'write-only' -> 
	    NNoA = [Vb#varbind{value = noSuchInstance} | NoA],
	    check_all_table_vbs(IVbs, IsNotification, NNoA, A);
	_ ->
	    check_all_table_vbs(IVbs, IsNotification, NoA, [IVb | A])
    end;
check_all_table_vbs([], _IsNotification, NoA, A) -> {NoA, A}.

%%-----------------------------------------------------------------
%% Returns: {error, ErrorStatus, OrgIndex} |
%%          #varbind
%%-----------------------------------------------------------------
get_var_value_from_ivb(IVb, IsNotification)
  when IVb#ivarbind.status =:= noError ->
    ?vtrace("get_var_value_from_ivb(noError) -> entry", []),
    #ivarbind{mibentry = Me, varbind = Vb} = IVb,
    #varbind{org_index = OrgIndex, oid = Oid} = Vb,
    case Me#me.access of
	'not-accessible' -> 
	    Vb#varbind{value = noSuchInstance};
	'accessible-for-notify' when IsNotification =:= false -> 
	    Vb#varbind{value = noSuchInstance};
	'write-only' -> 
	    Vb#varbind{value = noSuchInstance};
	_ -> 
	    case get_var_value_from_mib(Me, Oid) of
		{value, Type, Value} ->
		    Vb#varbind{variabletype = Type, value = Value};
		{error, ErrorStatus} ->
		    {error, ErrorStatus, OrgIndex}
	    end
    end;
get_var_value_from_ivb(#ivarbind{status = Status, varbind = Vb}, _) ->
    ?vtrace("get_var_value_from_ivb(~p) -> entry", [Status]),
    Vb#varbind{value = Status}.

%%-----------------------------------------------------------------
%% Func: get_var_value_from_mib/1
%% Purpose: 
%% Returns: {error, ErrorStatus} |
%%          {value, Type, Value}
%%-----------------------------------------------------------------
%% Pre: Oid is a correct instance Oid (lookup checked that).
%% Returns: A correct return value (see make_value_a_correct_value)
get_var_value_from_mib(#me{entrytype = variable,
			   asn1_type = ASN1Type,
			   mfa       = {Mod, Func, Args}},
		       _Oid) ->
    ?vtrace("get_var_value_from_mib(variable) -> entry when"
	    "~n   Mod:  ~p"
	    "~n   Func: ~p"
	    "~n   Args: ~p", [Mod, Func, Args]),
    Result = (catch dbg_apply(Mod, Func, [get | Args])),
    % mib shall return {value, <a-nice-value-within-range>} |
    % {noValue, noSuchName} (v1) | 
    % {noValue, noSuchObject | noSuchInstance} (v2, v1)
    % everything else (including 'genErr') will generate 'genErr'.
    make_value_a_correct_value(Result, ASN1Type, {Mod, Func, Args});

get_var_value_from_mib(#me{entrytype = table_column,
			   oid       = MeOid,
			   asn1_type = ASN1Type,
			   mfa       = {Mod, Func, Args}},
		       Oid) ->
    ?vtrace("get_var_value_from_mib(table_column) -> entry when"
	    "~n   MeOid: ~p"
	    "~n   Mod:   ~p"
	    "~n   Func:  ~p"
	    "~n   Args:  ~p"
	    "~n   Oid:   ~p", [MeOid, Mod, Func, Args, Oid]),
    Col = lists:last(MeOid),
    Indexes = snmp_misc:diff(Oid, MeOid),
    [Result] = (catch dbg_apply(Mod, Func, [get, Indexes, [Col] | Args])),
    make_value_a_correct_value(Result, ASN1Type, 
			       {Mod, Func, Args, Indexes, Col}).


%% For table operations we need to pass RestOid down to the table-function.
%% Its up to the table-function to check for noSuchInstance (ex: a 
%% non-existing row).
%% Returns: {error, ErrorStatus, OrgIndex} |
%%          {value, Type, Value}
get_tab_value_from_mib(#me{mfa = {Mod, Func, Args}}, TableOid, TableVbs) ->
    ?vtrace("get_tab_value_from_mib -> entry when"
	    "~n   Mod:  ~p"
	    "~n   Func: ~p"
	    "~n   Args: ~p", [Mod, Func, Args]),
    TableOpsWithShortOids = deletePrefixes(TableOid, TableVbs),
    SortedVBsRows = snmpa_svbl:sort_varbinds_rows(TableOpsWithShortOids), 
    case get_value_all_rows(SortedVBsRows, Mod, Func, Args, []) of
	{Error, Index} ->
	    #ivarbind{varbind = Vb} = lists:nth(Index, TableVbs),
	    {error, Error, Vb#varbind.org_index};
	ListOfValues -> 
	    merge_varbinds_and_value(TableVbs, ListOfValues)
    end.

%%-----------------------------------------------------------------
%% Values is a scrambled list of {CorrectValue, Index}, where Index
%% is index into the #ivarbind list. So for each Value, we must
%% find the corresponding #ivarbind, and merge them into a new
%% #varbind.
%% The Values list comes from validate_tab_res.
%%-----------------------------------------------------------------
merge_varbinds_and_value(IVbs, [{{value, Type, Value}, Index} | Values]) ->
    #ivarbind{varbind = Vb} = lists:nth(Index, IVbs),
    [Vb#varbind{variabletype = Type, value = Value} |
     merge_varbinds_and_value(IVbs, Values)];
merge_varbinds_and_value(_, []) -> [].
    
get_value_all_rows([{[], OrgCols} | Rows], Mod, Func, Args, Res) ->
    ?vtrace("get_value_all_rows -> entry when"
	    "~n   OrgCols: ~p", [OrgCols]),
    Cols   = [{{value, noValue, noSuchInstance}, Index} || 
		 {_Col, _ASN1Type, Index} <- OrgCols], 
    NewRes = lists:append(Cols, Res),
    get_value_all_rows(Rows, Mod, Func, Args, NewRes);
get_value_all_rows([{RowIndex, OrgCols} | Rows], Mod, Func, Args, Res) ->
    ?vtrace("get_value_all_rows -> entry when"
	    "~n   RowIndex: ~p"
	    "~n   OrgCols:  ~p", [RowIndex, OrgCols]),
    {DOrgCols, Dup} = remove_duplicates(OrgCols),
    Cols   = delete_index(DOrgCols),
    Result = (catch dbg_apply(Mod, Func, [get, RowIndex, Cols | Args])),
    case validate_tab_res(Result, DOrgCols, {Mod, Func, Args}) of
	Values when is_list(Values) ->
	    NVals  = restore_duplicates(Dup, Values),
	    NewRes = lists:append(NVals, Res),
	    get_value_all_rows(Rows, Mod, Func, Args, NewRes);
	{error, ErrorStatus, Index} ->
	    validate_err(row_set, {ErrorStatus, Index}, {Mod, Func, Args})
    end;
get_value_all_rows([], _Mod, _Func, _Args, Res) -> 
    ?vtrace("get_value_all_rows -> entry when done"
	    "~n   Res: ~p", [Res]),
    Res.

%%-----------------------------------------------------------------
%% Returns: list of {ShortOid, ASN1TYpe}
%%-----------------------------------------------------------------
deletePrefixes(Prefix, [#ivarbind{varbind = Varbind, mibentry = ME} | Vbs]) ->
    #varbind{oid = Oid} = Varbind,
    [{snmp_misc:diff(Oid, Prefix), ME#me.asn1_type} |
     deletePrefixes(Prefix, Vbs)];
deletePrefixes(_Prefix, []) -> [].

%%-----------------------------------------------------------------
%% Args: {RowIndex, list of {ShortOid, ASN1Type}}
%% Returns: list of Col
%%-----------------------------------------------------------------
delete_index([{Col, _Val, _OrgIndex} | T]) ->
    [Col | delete_index(T)];
delete_index([]) -> [].

%%-----------------------------------------------------------------
%% This function is called before 'get' on a table, and removes
%% any duplicate columns.  It returns {Cols, DupInfo}.  The Cols
%% are the unique columns.  The instrumentation function is
%% called to get the values.  These values, together with the
%% DupInfo, is later passed to restore_duplicates, which uses
%% the retrieved values to reconstruct the original column list,
%% but with the retrieved value for each column.
%%-----------------------------------------------------------------
remove_duplicates(Cols) ->
    remove_duplicates(Cols, [], []).


remove_duplicates([{Col, V1, OrgIdx1}, {Col, V2, OrgIdx2} | T], NCols, Dup) ->
    remove_duplicates([{Col, V1, OrgIdx1} | T], NCols, 
		      [{Col, V2, OrgIdx2} | Dup]);
remove_duplicates([Col | T], NCols, Dup) ->
    remove_duplicates(T, [Col | NCols], Dup);
remove_duplicates([], NCols, Dup) ->
    {lists:reverse(NCols), lists:reverse(Dup)}.

restore_duplicates([], Cols) ->
    [{Val, OrgIndex} || {_Col, Val, OrgIndex} <- Cols];
restore_duplicates([{Col, _Val2, OrgIndex2} | Dup],
		   [{Col, NVal, OrgIndex1} | Cols]) ->
    [{NVal, OrgIndex2} |
     restore_duplicates(Dup, [{Col, NVal, OrgIndex1} | Cols])];
restore_duplicates(Dup, [{_Col, Val, OrgIndex} | T]) ->
    [{Val, OrgIndex} | restore_duplicates(Dup, T)].

%% Maps the column number to Index.
% col_to_index(0, _) -> 0;
% col_to_index(Col, [{Col, _, Index}|_]) ->
%     Index;
% col_to_index(Col, [_|Cols]) ->
%     col_to_index(Col, Cols).

%%-----------------------------------------------------------------
%% Three cases:
%%   1) All values ok
%%   2) table_func returned {Error, ...}
%%   3) Some value in Values list is erroneous.
%% Args: Value is a list of values from table_func(get..)
%%       OrgCols is a list with {Col, ASN1Type, OrgIndex} 
%%         each element in Values and OrgCols correspond to each
%%         other.
%%-----------------------------------------------------------------
validate_tab_res(Values, OrgCols, Mfa) when is_list(Values) ->
    {_Col, _ASN1Type, OneIdx} = hd(OrgCols),
    validate_tab_res(Values, OrgCols, Mfa, [], OneIdx);
validate_tab_res({noValue, Error}, OrgCols, Mfa) ->
    Values = lists:duplicate(length(OrgCols), {noValue, Error}),
    validate_tab_res(Values, OrgCols, Mfa);
validate_tab_res({genErr, Col}, OrgCols, Mfa) ->
    case lists:keysearch(Col, 1, OrgCols) of
	{value, {_Col, _ASN1Type, Index}} ->
	    {error, genErr, Index};
	_ ->
	    user_err("Invalid column in {genErr, ~w} from ~w (get)",
		     [Col, Mfa]),
	    [{_Col, _ASN1Type, Index} | _] = OrgCols,
	    {error, genErr, Index}
    end;
validate_tab_res(genErr, [{_Col, __ASN1Type, Index} | _OrgCols], _Mfa) ->
    {error, genErr, Index};
validate_tab_res(Error, [{_Col, _ASN1Type, Index} | _OrgCols], Mfa) ->
    user_err("Invalid return value ~w from ~w (get)",[Error, Mfa]),
    {error, genErr, Index}.

validate_tab_res([Value | Values], 
		 [{Col, ASN1Type, Index} | OrgCols],
		 Mfa, Res, I) ->
    %% This one makes it possible to return a list of genErr, which
    %% is not allowed according to the manual.  But that's ok, as
    %% everything else will generate a genErr! (the only problem is
    %% that it won't generate a user_error).
    case make_value_a_correct_value(Value, ASN1Type, Mfa) of
	{error, ErrorStatus} ->
	    {error, ErrorStatus, Index};
	CorrectValue ->
	    NewRes = [{Col, CorrectValue, Index} | Res],
	    validate_tab_res(Values, OrgCols, Mfa, NewRes, I)
    end;
validate_tab_res([], [], _Mfa, Res, _I) -> 
    lists:reverse(Res);
validate_tab_res([], [{_Col, _ASN1Type, Index}|_], Mfa, _Res, _I) ->
    user_err("Too few values returned from ~w (get)", [Mfa]),
    {error, genErr, Index};
validate_tab_res(_TooMany, [], Mfa, _Res, I) ->
    user_err("Too many values returned from ~w (get)", [Mfa]),
    {error, genErr, I}.


%%%-----------------------------------------------------------------
%%% 4. GET-NEXT REQUEST
%%% --------------
%%%   According to RFC1157, section 4.1.3 and RFC1905, section 4.2.2.
%%%-----------------------------------------------------------------
%%-----------------------------------------------------------------
%% Func: do_get_next/2
%% Purpose: do_get_next handles "getNextRequests".
%% Note: Even if it is SNMPv1, a varbind's value can be
%%       endOfMibView. This is converted to noSuchName in process_pdu.
%% Returns: {noError, 0, ListOfNewVarbinds} |
%%          {ErrorStatus, ErrorIndex, []}
%% Note2: ListOfNewVarbinds is not sorted in any order!!!
%% Alg: First, the variables are sorted in OID order.
%%
%%      Second, next in the MIB is performed for each OID, and
%%      the result is collected as: if next oid is a variable,
%%      perform a get to retrieve its value; if next oid is in a
%%      table, save this value and continue until we get an oid
%%      outside this table. Then perform get_next on the table,
%%      and continue with all endOfTables and the oid outside the
%%      table; if next oid is an subagent, save this value and
%%      continue as in the table case.
%%
%%      Third, each response is checked for endOfMibView, or (for
%%      subagents) that the Oid returned has the correct prefix.
%%      (This is necessary since an SA can be registered under many
%%      separated subtrees, and if the last variable in the first
%%      subtree is requested in a next, the SA will return the first
%%      variable in the second subtree. This might be working, since
%%      there may be a variable in between these subtrees.) For each
%%      of these, a new get-next is performed, one at a time.
%%      This alg. might be optimised in several ways. The most 
%%      striking one is that the same SA might be called several
%%      times, when one time should be enough. But it isn't clear
%%      that this really matters, since many nexts across the same
%%      subagent must be considered to be very rare.
%%-----------------------------------------------------------------

%% It may be a bit agressive to check this already, 
%% but since it is a security measure, it makes sense.
do_get_next(_MibView, UnsortedVarbinds, GbMaxVBs) 
  when (is_integer(GbMaxVBs) andalso (length(UnsortedVarbinds) > GbMaxVBs)) ->
    {tooBig, 0, []}; % What is the correct index in this case?
do_get_next(MibView, UnsortedVBs, GbMaxVBs) ->
    ?vt("do_get_next -> entry when"
 	"~n   MibView:          ~p"
 	"~n   UnsortedVBs: ~p", [MibView, UnsortedVBs]),
    SortedVBs = oid_sort_vbs(UnsortedVBs),
    ?vt("do_get_next -> "
 	"~n   SortedVBs: ~p", [SortedVBs]),
    next_loop_varbinds([], SortedVBs, MibView, [], [], GbMaxVBs).

oid_sort_vbs(Vbs) ->
    lists:keysort(#varbind.oid, Vbs).

next_loop_varbinds(_, Vbs, _MibView, Res, _LAVb, GbMaxVBs) 
  when (is_integer(GbMaxVBs) andalso 
	((length(Vbs) + length(Res)) > GbMaxVBs)) ->
    {tooBig, 0, []}; % What is the correct index in this case?

%% LAVb is Last Accessible Vb
next_loop_varbinds([], [Vb | Vbs], MibView, Res, LAVb, GbMaxVBs) ->
    ?vt("next_loop_varbinds -> entry when"
 	"~n   Vb:      ~p"
 	"~n   MibView: ~p", [Vb, MibView]),
    case varbind_next(Vb, MibView) of
	endOfMibView ->
	    ?vt("next_loop_varbind -> endOfMibView", []),
	    RVb = if LAVb =:= [] -> Vb;
		     true -> LAVb
		  end,
	    NewVb = RVb#varbind{variabletype = 'NULL', value = endOfMibView},
	    next_loop_varbinds([], Vbs, MibView, [NewVb | Res], [], GbMaxVBs);

	{variable, ME, VarOid} when ((ME#me.access =/= 'not-accessible') andalso 
				     (ME#me.access =/= 'write-only') andalso 
				     (ME#me.access =/= 'accessible-for-notify')) -> 
	    ?vt("next_loop_varbind -> variable: "
		"~n   ME:     ~p"
		"~n   VarOid: ~p", [ME, VarOid]),
	    case try_get_instance(Vb, ME) of
		{value, noValue, _NoSuchSomething} ->
		    ?vt("next_loop_varbind -> noValue", []),
		    %% Try next one
		    NewVb = Vb#varbind{oid   = VarOid, 
				       value = 'NULL'},
		    next_loop_varbinds([], [NewVb | Vbs], MibView, Res, [], 
				       GbMaxVBs);
		{value, Type, Value} ->
		    ?vt("next_loop_varbind -> value"
			"~n   Type:  ~p"
			"~n   Value: ~p", [Type, Value]),
		    NewVb = Vb#varbind{oid          = VarOid, 
				       variabletype = Type,
				       value        = Value},
		    next_loop_varbinds([], Vbs, MibView, [NewVb | Res], [],
				       GbMaxVBs);
		{error, ErrorStatus} ->
		    ?vdebug("next loop varbinds:"
			    "~n   ErrorStatus: ~p",[ErrorStatus]),
		    {ErrorStatus, Vb#varbind.org_index, []}
	    end;
	{variable, _ME, VarOid} -> 
	    ?vt("next_loop_varbind -> variable: "
		"~n   VarOid: ~p", [VarOid]),
	    RVb = if LAVb =:= [] -> Vb;
		     true -> LAVb
		  end,
	    NewVb = Vb#varbind{oid = VarOid, value = 'NULL'},
	    next_loop_varbinds([], [NewVb | Vbs], MibView, Res, RVb, GbMaxVBs);
	{table, TableOid, TableRestOid, ME} ->
	    ?vt("next_loop_varbind -> table: "
		"~n   TableOid:     ~p"
		"~n   TableRestOid: ~p"
		"~n   ME:           ~p", [TableOid, TableRestOid, ME]),
	    next_loop_varbinds({table, TableOid, ME,
				[{tab_oid(TableRestOid), Vb}]},
			       Vbs, MibView, Res, [], GbMaxVBs);
	{subagent, SubAgentPid, SAOid} ->
	    ?vt("next_loop_varbind -> subagent: "
		"~n   SubAgentPid: ~p"
		"~n   SAOid:       ~p", [SubAgentPid, SAOid]),
	    NewVb = Vb#varbind{variabletype = 'NULL', value = 'NULL'},
	    next_loop_varbinds({subagent, SubAgentPid, SAOid, [NewVb]},
			       Vbs, MibView, Res, [], GbMaxVBs)
    end;
next_loop_varbinds({table, TableOid, ME, TabOids},
		   [Vb | Vbs], MibView, Res, _LAVb, GbMaxVBs) ->
    ?vt("next_loop_varbinds(table) -> entry with"
 	"~n   TableOid: ~p"
 	"~n   Vb:       ~p", [TableOid, Vb]),
    case varbind_next(Vb, MibView) of
	{table, TableOid, TableRestOid, _ME} ->
	    next_loop_varbinds({table, TableOid, ME,
				[{tab_oid(TableRestOid), Vb} | TabOids]},
			       Vbs, MibView, Res, [], GbMaxVBs);
	_ ->
	    case get_next_table(ME, TableOid, TabOids, MibView) of
		{ok, TabRes, TabEndOfTabVbs} ->
		    NewVbs = lists:append(TabEndOfTabVbs, [Vb | Vbs]),
		    NewRes = lists:append(TabRes, Res),
		    next_loop_varbinds([], NewVbs, MibView, NewRes, [], 
				       GbMaxVBs);
		{ErrorStatus, OrgIndex} ->
		    ?vdebug("next loop varbinds: next varbind"
			    "~n   ErrorStatus: ~p"
			    "~n   OrgIndex:    ~p",
			    [ErrorStatus,OrgIndex]),
		    {ErrorStatus, OrgIndex, []}
	    end
    end;
next_loop_varbinds({table, TableOid, ME, TabOids},
		   [], MibView, Res, _LAVb, GbMaxVBs) ->
    ?vt("next_loop_varbinds(table) -> entry with"
	"~n   TableOid: ~p", [TableOid]),
    case get_next_table(ME, TableOid, TabOids, MibView) of
	{ok, TabRes, TabEndOfTabVbs} ->
 	    ?vt("next_loop_varbinds(table) -> get_next_table result:"
		"~n   TabRes:         ~p"
		"~n   TabEndOfTabVbs: ~p", [TabRes, TabEndOfTabVbs]),
	    NewRes = lists:append(TabRes, Res),
	    next_loop_varbinds([], TabEndOfTabVbs, MibView, NewRes, [], 
			       GbMaxVBs);
	{ErrorStatus, OrgIndex} ->
	    ?vdebug("next loop varbinds: next table"
		    "~n   ErrorStatus: ~p"
		    "~n   OrgIndex:    ~p",
		    [ErrorStatus,OrgIndex]),
	    {ErrorStatus, OrgIndex, []}
    end;
next_loop_varbinds({subagent, SAPid, SAOid, SAVbs},
		   [Vb | Vbs], MibView, Res, _LAVb, GbMaxVBs) ->
    ?vt("next_loop_varbinds(subagent) -> entry with"
	"~n   SAPid: ~p"
	"~n   SAOid: ~p"
 	"~n   Vb:    ~p", [SAPid, SAOid, Vb]),
    case varbind_next(Vb, MibView) of
	{subagent, _SubAgentPid, SAOid} ->
	    next_loop_varbinds({subagent, SAPid, SAOid,
				[Vb | SAVbs]},
			       Vbs, MibView, Res, [], GbMaxVBs);
	_ ->
	    case get_next_sa(SAPid, SAOid, SAVbs, MibView) of
		{ok, SARes, SAEndOfMibViewVbs} ->
		    NewVbs = lists:append(SAEndOfMibViewVbs, [Vb | Vbs]),
		    NewRes = lists:append(SARes, Res),
		    next_loop_varbinds([], NewVbs, MibView, NewRes, [], 
				       GbMaxVBs);
		{noSuchName, OrgIndex} ->
		    %% v1 reply, treat this Vb as endOfMibView, and try again
		    %% for the others.
		    case lists:keysearch(OrgIndex, #varbind.org_index, SAVbs) of
			{value, EVb} ->
			    NextOid = next_oid(SAOid),
			    EndOfVb = 
				EVb#varbind{oid = NextOid,
					    value = {endOfMibView, NextOid}},
			    case lists:delete(EVb, SAVbs) of
				[] ->
				    next_loop_varbinds([], [EndOfVb, Vb | Vbs],
						       MibView, Res, [],
						       GbMaxVBs);
				TryAgainVbs ->
				    next_loop_varbinds({subagent, SAPid, SAOid,
							TryAgainVbs},
						       [EndOfVb, Vb | Vbs],
						       MibView, Res, [],
						       GbMaxVBs)
			    end;
			false ->
			    %% bad index from subagent
			    {genErr, (hd(SAVbs))#varbind.org_index, []}
		    end;
		{ErrorStatus, OrgIndex} ->
 		    ?vdebug("next loop varbinds: next subagent"
 			    "~n   Vb:          ~p"
 			    "~n   ErrorStatus: ~p"
 			    "~n   OrgIndex:    ~p",
 			    [Vb,ErrorStatus,OrgIndex]),
		    {ErrorStatus, OrgIndex, []}
	    end
    end;
next_loop_varbinds({subagent, SAPid, SAOid, SAVbs},
		   [], MibView, Res, _LAVb, GbMaxVBs) ->
     ?vt("next_loop_varbinds(subagent) -> entry with"
	 "~n   SAPid: ~p"
	 "~n   SAOid: ~p", [SAPid, SAOid]),
    case get_next_sa(SAPid, SAOid, SAVbs, MibView) of
	{ok, SARes, SAEndOfMibViewVbs} ->
	    NewRes = lists:append(SARes, Res),
	    next_loop_varbinds([], SAEndOfMibViewVbs, MibView, NewRes, [],
			       GbMaxVBs);
	{noSuchName, OrgIndex} ->
	    %% v1 reply, treat this Vb as endOfMibView, and try again for
	    %% the others.
	    case lists:keysearch(OrgIndex, #varbind.org_index, SAVbs) of
		{value, EVb} ->
		    NextOid = next_oid(SAOid),
		    EndOfVb = EVb#varbind{oid = NextOid,
					  value = {endOfMibView, NextOid}},
		    case lists:delete(EVb, SAVbs) of
			[] ->
			    next_loop_varbinds([], [EndOfVb], MibView, Res, [],
					       GbMaxVBs);
			TryAgainVbs ->
			    next_loop_varbinds({subagent, SAPid, SAOid,
						TryAgainVbs},
					       [EndOfVb], MibView, Res, [],
					       GbMaxVBs)
		    end;
		false ->
		    %% bad index from subagent
		    {genErr, (hd(SAVbs))#varbind.org_index, []}
	    end;
	{ErrorStatus, OrgIndex} ->
 	    ?vdebug("next loop varbinds: next subagent"
 		    "~n   ErrorStatus: ~p"
 		    "~n   OrgIndex:    ~p",
 		    [ErrorStatus,OrgIndex]),
 	    {ErrorStatus, OrgIndex, []}
    end;
next_loop_varbinds([], [], _MibView, Res, _LAVb, _GbMaxVBs) ->
    ?vt("next_loop_varbinds -> entry when done", []),
    {noError, 0, Res}.

try_get_instance(_Vb, #me{mfa = {M, F, A}, asn1_type = ASN1Type}) ->
    ?vtrace("try_get_instance -> entry with"
	    "~n   M: ~p"
	    "~n   F: ~p"
	    "~n   A: ~p", [M,F,A]),
    Result = (catch dbg_apply(M, F, [get | A])),
    % mib shall return {value, <a-nice-value-within-range>} |
    % {noValue, noSuchName} (v1) | 
    % {noValue, noSuchObject | noSuchInstance} (v2, v1)
    % everything else (including 'genErr') will generate 'genErr'.
    make_value_a_correct_value(Result, ASN1Type, {M, F, A}).

tab_oid([]) -> [0];
tab_oid(X) -> X.


%%-----------------------------------------------------------------
%% Perform a next, using the varbinds Oid if value is simple
%% value. If value is {endOf<something>, NextOid}, use NextOid.
%% This case happens when a table has returned endOfTable, or
%% a subagent has returned endOfMibView.
%%-----------------------------------------------------------------
varbind_next(#varbind{value = Value, oid = Oid}, MibView) ->
    ?vt("varbind_next -> entry with"
 	"~n   Value:   ~p"
 	"~n   Oid:     ~p"
 	"~n   MibView: ~p", [Value, Oid, MibView]),
    case Value of
	{endOfTable, NextOid} ->
	    snmpa_mib:next(get(mibserver), NextOid, MibView);
	{endOfMibView, NextOid} ->
	    snmpa_mib:next(get(mibserver), NextOid, MibView);
	_ ->
	    snmpa_mib:next(get(mibserver), Oid, MibView)
    end.

get_next_table(#me{mfa = {M, F, A}}, TableOid, TableOids, MibView) ->
    % We know that all TableOids have at least a column number as oid
    ?vt("get_next_table -> entry with"
	"~n   M:         ~p"
	"~n   F:         ~p"
	"~n   A:         ~p"
	"~n   TableOid:  ~p"
	"~n   TableOids: ~p"
	"~n   MibView:   ~p", [M, F, A, TableOid, TableOids, MibView]),
    Sorted = snmpa_svbl:sort_varbinds_rows(TableOids),
    case get_next_values_all_rows(Sorted, M,F,A, [], TableOid) of
	NewVbs when is_list(NewVbs) ->
 	    ?vt("get_next_table -> "
		"~n   NewVbs: ~p", [NewVbs]),
	    % We must now check each Vb for endOfTable and that it is
	    % in the MibView. If not, it becomes a endOfTable. We 
	    % collect all of these together.
	    transform_tab_next_result(NewVbs, {[], []}, MibView);
	{ErrorStatus, OrgIndex} ->
	    {ErrorStatus, OrgIndex}
    end.

get_next_values_all_rows([Row | Rows], M, F, A, Res, TabOid) ->
    {RowIndex, TableOids} = Row,
    Cols = delete_index(TableOids),
    ?vt("get_next_values_all_rows -> "
	"~n   Cols: ~p", [Cols]),
    Result = (catch dbg_apply(M, F, [get_next, RowIndex, Cols | A])),
    ?vt("get_next_values_all_rows -> "
 	"~n   Result: ~p", [Result]),
    case validate_tab_next_res(Result, TableOids, {M, F, A}, TabOid) of
	Values when is_list(Values) -> 
 	    ?vt("get_next_values_all_rows -> "
 		"~n   Values: ~p", [Values]),
	    NewRes = lists:append(Values, Res),
	    get_next_values_all_rows(Rows, M, F, A, NewRes, TabOid);
	{ErrorStatus, OrgIndex} ->
	    {ErrorStatus, OrgIndex}
    end;
get_next_values_all_rows([], _M, _F, _A, Res, _TabOid) ->
    Res.

transform_tab_next_result([Vb | Vbs], {Res, EndOfs}, MibView) ->
    case Vb#varbind.value of
	{endOfTable, _} ->
%% 	    ?vtrace("transform_tab_next_result -> endOfTable: "
%% 		"split varbinds",[]),
%% 	    R = split_varbinds(Vbs, Res, [Vb | EndOfs]),
%% 	    ?vtrace("transform_tab_next_result -> "
%% 		"~n   R: ~p", [R]),
%% 	    R;
	    split_varbinds(Vbs, Res, [Vb | EndOfs]);
	_ ->
	    case snmpa_acm:validate_mib_view(Vb#varbind.oid, MibView) of
		true ->
		    transform_tab_next_result(Vbs, {[Vb|Res], EndOfs},MibView);
		_ ->
		    Oid = Vb#varbind.oid,
		    NewEndOf = Vb#varbind{value = {endOfTable, Oid}},
		    transform_tab_next_result(Vbs, {Res, [NewEndOf | EndOfs]},
					      MibView)
	    end
    end;
transform_tab_next_result([], {Res, EndOfs}, _MibView) ->
    ?vt("transform_tab_next_result -> entry with: "
 	"~n   Res:    ~p"
 	"~n   EndIfs: ~p",[Res, EndOfs]),
    {ok, Res, EndOfs}.

%%-----------------------------------------------------------------
%% Three cases:
%%   1) All values ok
%%   2) table_func returned {Error, ...}
%%   3) Some value in Values list is erroneous.
%% Args: Value is a list of values from table_func(get_next, ...)
%%       TableOids is a list of {TabRestOid, OrgVb} 
%%         each element in Values and TableOids correspond to each
%%         other.
%% Returns: List of NewVarbinds |
%%          {ErrorStatus, OrgIndex}
%%          (In the NewVarbinds list, the value may be endOfTable)
%%-----------------------------------------------------------------
validate_tab_next_res(Values, TableOids, Mfa, TabOid) ->
     ?vt("validate_tab_next_res -> entry with: "
	 "~n   Values:     ~p"
	 "~n   TableOids:  ~p"
	 "~n   Mfa:        ~p"
	 "~n   TabOid:     ~p", [Values, TableOids, Mfa, TabOid]),
    {_Col, _ASN1Type, OneIdx} = hd(TableOids),
    validate_tab_next_res(Values, TableOids, Mfa, [], TabOid,
			  next_oid(TabOid), OneIdx).
validate_tab_next_res([{NextOid, Value} | Values],
		      [{_ColNo, OrgVb, _Index} | TableOids],
		      Mfa, Res, TabOid, TabNextOid, I) ->
    ?vt("validate_tab_next_res -> entry with: "
 	"~n   NextOid:    ~p"
 	"~n   Value:      ~p"
 	"~n   Values:     ~p"
 	"~n   TableOids:  ~p"
 	"~n   Mfa:        ~p"
 	"~n   TabOid:     ~p", 
 	[NextOid, Value, Values, TableOids, Mfa, TabOid]),
    #varbind{org_index = OrgIndex} = OrgVb,
    ?vt("validate_tab_next_res -> OrgIndex: ~p", [OrgIndex]),
    NextCompleteOid = lists:append(TabOid, NextOid),
    case snmpa_mib:lookup(get(mibserver), NextCompleteOid) of
	{table_column, #me{asn1_type = ASN1Type}, _TableEntryOid} ->
  	    ?vt("validate_tab_next_res -> ASN1Type: ~p", [ASN1Type]),
	    case make_value_a_correct_value({value, Value}, ASN1Type, Mfa) of
		{error, ErrorStatus} ->
 		    ?vt("validate_tab_next_res -> "
 			"~n   ErrorStatus: ~p", [ErrorStatus]),
		    {ErrorStatus, OrgIndex};
		{value, Type, NValue} ->
 		    ?vt("validate_tab_next_res -> "
     			"~n   Type:   ~p"
			"~n   NValue: ~p", [Type, NValue]),
		    NewVb = OrgVb#varbind{oid = NextCompleteOid,
					  variabletype = Type, value = NValue},
		    validate_tab_next_res(Values, TableOids, Mfa,
					  [NewVb | Res], TabOid, TabNextOid, I)
	    end;
	Error ->
	    user_err("Invalid oid ~w from ~w (get_next). Using genErr => ~p",
		     [NextOid, Mfa, Error]),
	    {genErr, OrgIndex}
    end;
validate_tab_next_res([endOfTable | Values],
		      [{_ColNo, OrgVb, _Index} | TableOids],
		      Mfa, Res, TabOid, TabNextOid, I) ->
     ?vt("validate_tab_next_res(endOfTable) -> entry with: "
	 "~n   Values:     ~p"
	 "~n   OrgVb:      ~p"
	 "~n   TableOids:  ~p"
	 "~n   Mfa:        ~p"
	 "~n   Res:        ~p"
	 "~n   TabOid:     ~p"
	 "~n   TabNextOid: ~p"
	 "~n   I:          ~p",
	 [Values, OrgVb, TableOids, Mfa, Res, TabOid, TabNextOid, I]),
    NewVb = OrgVb#varbind{value = {endOfTable, TabNextOid}},
    validate_tab_next_res(Values, TableOids, Mfa, [NewVb | Res],
			  TabOid, TabNextOid, I);
validate_tab_next_res([], [], _Mfa, Res, _TabOid, _TabNextOid, _I) ->
    Res;
validate_tab_next_res([], [{_Col, _OrgVb, Index}|_], Mfa, _Res, _, _, _I) ->
    user_err("Too few values returned from ~w (get_next)", [Mfa]),
    {genErr, Index};
validate_tab_next_res({genErr, ColNumber}, OrgCols,
		      Mfa, _Res, _TabOid, _TabNextOid, _I) ->
    OrgIndex = snmpa_svbl:col_to_orgindex(ColNumber, OrgCols),
    validate_err(table_next, {genErr, OrgIndex}, Mfa);
validate_tab_next_res({error, Reason}, [{_ColNo, OrgVb, _Index} | _TableOids],
		      Mfa, _Res, _TabOid, _TabNextOid, _I) ->
    #varbind{org_index = OrgIndex} = OrgVb,
    user_err("Erroneous return value ~w from ~w (get_next)",
	     [Reason, Mfa]),
    {genErr, OrgIndex};
validate_tab_next_res(Error, [{_ColNo, OrgVb, _Index} | _TableOids],
		      Mfa, _Res, _TabOid, _TabNextOid, _I) ->
    #varbind{org_index = OrgIndex} = OrgVb,
    user_err("Invalid return value ~w from ~w (get_next)",
	     [Error, Mfa]),
    {genErr, OrgIndex};
validate_tab_next_res(TooMany, [], Mfa, _Res, _, _, I) ->
    user_err("Too many values ~w returned from ~w (get_next)",
	     [TooMany, Mfa]),
    {genErr, I}.

%%-----------------------------------------------------------------
%% Func: get_next_sa/4
%% Purpose: Loop the list of varbinds for the subagent.
%%          Call subagent_get_next to retreive
%%          the next varbinds.
%% Returns: {ok, ListOfNewVbs, ListOfEndOfMibViewsVbs} |
%%          {ErrorStatus, ErrorIndex}
%%-----------------------------------------------------------------
get_next_sa(SAPid, SAOid, SAVbs, MibView) ->
    case catch subagent_get_next(SAPid, MibView, SAVbs) of
	{noError, 0, NewVbs} ->
	    NewerVbs = transform_sa_next_result(NewVbs,SAOid,next_oid(SAOid)),
	    split_varbinds(NewerVbs, [], []);
	{ErrorStatus, ErrorIndex, _} ->
	    {ErrorStatus, ErrorIndex};
	{'EXIT', Reason} ->
	    user_err("Lost contact with subagent (next) ~w. Using genErr",
		     [Reason]),
	    {genErr, 0}
    end.

%%-----------------------------------------------------------------
%% Check for wrong prefix returned or endOfMibView, and convert
%% into {endOfMibView, SANextOid}.
%%-----------------------------------------------------------------
transform_sa_next_result([Vb | Vbs], SAOid, SANextOid)
  when Vb#varbind.value =:= endOfMibView ->
    [Vb#varbind{value = {endOfMibView, SANextOid}} |
     transform_sa_next_result(Vbs, SAOid, SANextOid)];
transform_sa_next_result([Vb | Vbs], SAOid, SANextOid) ->
    case lists:prefix(SAOid, Vb#varbind.oid) of
	true ->
	    [Vb | transform_sa_next_result(Vbs, SAOid, SANextOid)];
	_ ->
	    [Vb#varbind{oid = SANextOid, value = {endOfMibView, SANextOid}} |
	     transform_sa_next_result(Vbs, SAOid, SANextOid)]
    end;
transform_sa_next_result([], _SAOid, _SANextOid) ->
    [].

split_varbinds([Vb | Vbs], Res, EndOfs) ->
    case Vb#varbind.value of
	{endOfMibView, _} -> split_varbinds(Vbs, Res, [Vb | EndOfs]);
	{endOfTable, _} -> split_varbinds(Vbs, Res, [Vb | EndOfs]);
	_ -> split_varbinds(Vbs, [Vb | Res], EndOfs)
    end;
split_varbinds([], Res, EndOfs) -> {ok, Res, EndOfs}.

next_oid(Oid) ->
    case lists:reverse(Oid) of
	[H | T] -> lists:reverse([H+1 | T]);
	[] -> []
    end.


%%%-----------------------------------------------------------------
%%% 5. GET-BULK REQUEST
%%% 
%%% In order to prevent excesses in reply sizes there are two 
%%% preventive methods in place. One is to check that the encode
%%% size does not exceed Max PDU size (this is mentioned in the
%%% standard). The other is a simple VBs limit. That is, the 
%%% resulting response cannot contain more then this number of VBs.
%%%-----------------------------------------------------------------

do_get_bulk(MibView, NonRepeaters, MaxRepetitions, PduMS, Varbinds, GbMaxVBs) ->
    ?vtrace("do_get_bulk -> entry with"
	    "~n   MibView:        ~p"
	    "~n   NonRepeaters:   ~p"
	    "~n   MaxRepetitions: ~p"
	    "~n   PduMS:          ~p"
	    "~n   Varbinds:       ~p"
	    "~n   GbMaxVBs:       ~p",
	    [MibView, NonRepeaters, MaxRepetitions, PduMS, Varbinds, GbMaxVBs]),
    {NonRepVbs, RestVbs} = split_vbs(NonRepeaters, Varbinds, []),
    ?vt("do_get_bulk -> split: "
	"~n   NonRepVbs: ~p"
	"~n   RestVbs:   ~p", [NonRepVbs, RestVbs]),
    case do_get_next(MibView, NonRepVbs, GbMaxVBs) of
	{noError, 0, UResNonRepVbs} ->
	    ?vt("do_get_bulk -> next noError: "
		"~n   UResNonRepVbs: ~p", [UResNonRepVbs]),
	    ResNonRepVbs = lists:keysort(#varbind.org_index, UResNonRepVbs),
	    %% Decode the first varbinds, produce a reversed list of
	    %% listOfBytes.
	    case (catch enc_vbs(PduMS - ?empty_pdu_size, ResNonRepVbs)) of
 		{error, Idx, Reason} ->
		    user_err("failed encoding varbind ~w:~n~p", [Idx, Reason]),
                    {genErr, Idx, []};
                {SizeLeft, Res} when is_integer(SizeLeft) and is_list(Res) ->
 		    ?vtrace("do_get_bulk -> encoded: "
			    "~n   SizeLeft: ~p"
			    "~n   Res:      ~w", [SizeLeft, Res]),
		    case (catch do_get_rep(SizeLeft, MibView, MaxRepetitions,
					   RestVbs, Res, 
					   length(UResNonRepVbs), GbMaxVBs)) of
			{error, Idx, Reason} ->
			    user_err("failed encoding varbind ~w:~n~p", 
				     [Idx, Reason]),
			    {genErr, Idx, []};
			Res when is_list(Res) ->
			    ?vtrace("do get bulk -> Res: "
				    "~n   ~w", [Res]),
			    {noError, 0, conv_res(Res)};
			{noError, 0, Data} = OK ->
			    ?vtrace("do get bulk -> OK: "
				    "~n   length(Data): ~w", [length(Data)]),
			    OK;
			Else ->
			    ?vtrace("do get bulk -> Else: "
				    "~n   ~w", [Else]),
			    Else
		    end;
		Res when is_list(Res) ->
		    {noError, 0, conv_res(Res)}
	    end;

	{ErrorStatus, Index, _} ->
	    ?vdebug("do get bulk: "
		    "~n   ErrorStatus: ~p"
		    "~n   Index:       ~p",[ErrorStatus, Index]),
	    {ErrorStatus, Index, []}
    end.

% sz(L) when list(L) -> length(L);
% sz(B) when binary(B) -> size(B);
% sz(_) -> unknown.

split_vbs(N, Varbinds, Res) when N =< 0 -> {Res, Varbinds};
split_vbs(N, [H | T], Res) -> split_vbs(N-1, T, [H | Res]);
split_vbs(_N, [], Res) -> {Res, []}.
     
enc_vbs(SizeLeft, Vbs) ->
    ?vt("enc_vbs -> entry with"
	"~n   SizeLeft: ~w", [SizeLeft]),
    Fun = fun(Vb, {Sz, Res}) when Sz > 0 ->
		  ?vt("enc_vbs -> (fun) entry with"
		      "~n   Vb:  ~p"
		      "~n   Sz:  ~p"
		      "~n   Res: ~w", [Vb, Sz, Res]),
		  case (catch snmp_pdus:enc_varbind(Vb)) of
		      {'EXIT', Reason} ->
			  ?vtrace("enc_vbs -> encode failed: "
				  "~n   Reason: ~p", [Reason]),
			  throw({error, Vb#varbind.org_index, Reason});
		      X ->
			  ?vt("enc_vbs -> X: ~w", [X]),
			  Lx = length(X),
			  ?vt("enc_vbs -> Lx: ~w", [Lx]),
			  if
			      Lx < Sz ->
				  {Sz - length(X), [X | Res]};
			      true ->
				  throw(Res)
			  end
		  end;
	     (_Vb, {_Sz, [_H | T]}) ->
		  ?vt("enc_vbs -> (fun) entry with"
		      "~n   T: ~p", [T]),
		  throw(T);
	     (_Vb, {_Sz, []}) ->
		  ?vt("enc_vbs -> (fun) entry", []),
		  throw([])
	  end,
    lists:foldl(Fun, {SizeLeft, []}, Vbs).

do_get_rep(Sz, MibView, MaxRepetitions, Varbinds, Res, GbNumVBs, GbMaxVBs) 
  when MaxRepetitions >= 0 ->
    do_get_rep(Sz, MibView, 0, MaxRepetitions, Varbinds, Res, 
	       GbNumVBs, GbMaxVBs);
do_get_rep(Sz, MibView, _MaxRepetitions, Varbinds, Res, GbNumVBs, GbMaxVBs) ->
    do_get_rep(Sz, MibView, 0, 0, Varbinds, Res, GbNumVBs, GbMaxVBs).

conv_res(ResVarbinds) ->
    conv_res(ResVarbinds, []).
conv_res([VbListOfBytes | T], Bytes) ->
    conv_res(T, VbListOfBytes ++ Bytes);
conv_res([], Bytes) ->
    Bytes.

%% The only only other value, then a positive integer, is infinity.
do_get_rep(_Sz, _MibView, Count, Max, _, _Res, GbNumVBs, GbMaxVBs) 
  when (is_integer(GbMaxVBs) andalso (GbNumVBs > GbMaxVBs)) ->
    ?vinfo("Max Get-BULK VBs limit (~w) exceeded (~w) when:"
	   "~n   Count: ~p"
	   "~n   Max:   ~p", [GbMaxVBs, GbNumVBs, Count, Max]),
    {tooBig, 0, []};
do_get_rep(_Sz, _MibView, Max, Max, _, Res, _GbNumVBs, _GbMaxVBs) ->
    ?vt("do_get_rep -> done when: "
	"~n   Res: ~p", [Res]),
    {noError, 0, conv_res(Res)};
do_get_rep(Sz, MibView, Count, Max, Varbinds, Res, GbNumVBs, GbMaxVBs) -> 
    ?vt("do_get_rep -> entry when: "
	"~n   Sz:    ~p"
	"~n   Count: ~p"
	"~n   Res:   ~w", [Sz, Count, Res]),
    case try_get_bulk(Sz, MibView, Varbinds, GbMaxVBs) of
	{noError, NextVarbinds, SizeLeft, Res2} -> 
	    ?vt("do_get_rep -> noError: "
		"~n   SizeLeft: ~p"
		"~n   Res2:     ~p", [SizeLeft, Res2]),
	    do_get_rep(SizeLeft, MibView, Count+1, Max, NextVarbinds,
		       Res2 ++ Res, 
		       GbNumVBs + length(Varbinds), GbMaxVBs);
	{endOfMibView, _NextVarbinds, _SizeLeft, Res2} -> 
	    ?vt("do_get_rep -> endOfMibView: "
		"~n   Res2: ~p", [Res2]),
	    {noError, 0, conv_res(Res2 ++ Res)};
	{ErrorStatus, Index} ->
	    ?vtrace("do_get_rep -> done when error: "
		    "~n   ErrorStatus: ~p"
		    "~n   Index:       ~p", [ErrorStatus, Index]),
	    {ErrorStatus, Index, []}
    end.

org_index_sort_vbs(Vbs) ->
    lists:keysort(#varbind.org_index, Vbs).

try_get_bulk(Sz, MibView, Varbinds, GbMaxVBs) -> 
    ?vt("try_get_bulk -> entry with"
	"~n   Sz:       ~w"
	"~n   MibView:  ~w"
	"~n   Varbinds: ~w", [Sz, MibView, Varbinds]),
    case do_get_next(MibView, Varbinds, GbMaxVBs) of
	{noError, 0, UNextVarbinds} -> 
	    ?vt("try_get_bulk -> noError: "
		"~n   UNextVarbinds: ~p", [UNextVarbinds]),
	    NextVarbinds = org_index_sort_vbs(UNextVarbinds),
	    case (catch enc_vbs(Sz, NextVarbinds)) of
		{error, Idx, Reason} ->
		    user_err("failed encoding varbind ~w:~n~p", [Idx, Reason]),
		    ?vtrace("try_get_bulk -> encode error: "
			    "~n   Idx:    ~p"
			    "~n   Reason: ~p", [Idx, Reason]),
		    {genErr, Idx};
		{SizeLeft, Res} when is_integer(SizeLeft) andalso 
				     is_list(Res) ->
		    ?vt("try get bulk -> encode ok: "
			"~n   SizeLeft: ~w"
			"~n   Res:      ~w", [SizeLeft, Res]),
		    {check_end_of_mibview(NextVarbinds),
		     NextVarbinds, SizeLeft, Res};
		Res when is_list(Res) ->
		    ?vt("try get bulk -> Res: "
			"~n   ~w", [Res]),
		    {endOfMibView, [], 0, Res}
	    end;
	{ErrorStatus, Index, _} ->
	    ?vt("try_get_bulk -> error: "
		"~n   ErrorStatus: ~p"
		"~n   Index:       ~p", [ErrorStatus, Index]),
	    {ErrorStatus, Index}
    end.

%% If all variables in this pass are endOfMibView,
%% there is no reason to continue.
check_end_of_mibview([#varbind{value = endOfMibView} | T]) ->
    check_end_of_mibview(T);
check_end_of_mibview([]) -> endOfMibView;
check_end_of_mibview(_) -> noError.


%%%--------------------------------------------------
%%% 6. SET REQUEST
%%%--------------------------------------------------
%% return:  {ErrStatus, ErrIndex}
%% where ErrIndex is an index in Varbinds list (not org_index (user-functions
%% doesn't see org_index)).
do_set(MibView, UnsortedVarbinds) ->
    SetModule = get(set_module),
    ?vtrace("set module: ~p",[SetModule]),
    apply(SetModule, do_set, [MibView, UnsortedVarbinds]).

do_subagent_set(Arguments) ->
    SetModule = get(set_module),
    apply(SetModule, do_subagent_set, [Arguments]).

%%%-----------------------------------------------------------------
%%% 7. Misc functions
%%%-----------------------------------------------------------------
sort_varbindlist(Varbinds) ->
    snmpa_svbl:sort_varbindlist(get(mibserver), Varbinds).

sa_split(SubagentVarbinds) ->
    snmpa_svbl:sa_split(SubagentVarbinds).

make_response_pdu(ReqId, ErrStatus, ErrIndex, OrgVarbinds, _ResponseVarbinds)
  when ErrIndex =/= 0 ->
    #pdu{type = 'get-response', request_id = ReqId, error_status = ErrStatus,
	 error_index = ErrIndex, varbinds = OrgVarbinds};
make_response_pdu(ReqId, ErrStatus, ErrIndex, _OrgVarbinds, ResponseVarbinds) ->
    #pdu{type = 'get-response', request_id = ReqId, error_status = ErrStatus,
	 error_index = ErrIndex, varbinds = ResponseVarbinds}.

%% Valid errormsgs for different operations.
validate_err(consistency_check, {'EXIT', _Reason}, _) ->
    {genErr, 0};
validate_err(consistency_check, X, _) ->
    X;

validate_err(is_set_ok, noError, _) -> noError;
validate_err(is_set_ok, noCreation, _) -> noCreation;
validate_err(is_set_ok, inconsistentValue, _) -> inconsistentValue;
validate_err(is_set_ok, resourceUnavailable, _) -> resourceUnavailable;
validate_err(is_set_ok, inconsistentName, _) -> inconsistentName;
validate_err(is_set_ok, badValue, _) -> badValue;
validate_err(is_set_ok, wrongValue, _) -> wrongValue;
validate_err(is_set_ok, noSuchName, _) -> noSuchName;
validate_err(is_set_ok, noAccess, _) -> noAccess;
validate_err(is_set_ok, notWritable, _) -> notWritable;
validate_err(is_set_ok, genErr, _) -> genErr;
validate_err(is_set_ok, X, Mfa) -> 
    user_err("~w with is_set_ok, returned: ~w. Using genErr.",
	     [Mfa, X]),
    genErr;

validate_err(set, commitFailed, _) -> commitFailed;
validate_err(set, undoFailed, _) -> undoFailed;
validate_err(set, noError, _) -> noError;
validate_err(set, genErr, _) -> genErr;
validate_err(set, X, Mfa) -> 
    user_err("~w with set, returned: ~w. Using genErr.",
	     [Mfa, X]),
    genErr;

validate_err(undo, undoFailed, _) -> undoFailed;
validate_err(undo, noError, _) -> noError;
validate_err(undo, genErr, _) -> genErr;
validate_err(undo, X, Mfa) -> 
    user_err("~w with undo, returned: ~w. Using genErr.",
	     [Mfa, X]),
    genErr;

validate_err(table_is_set_ok, {Err, Idx}, Mfa) when is_integer(Idx) ->
    {validate_err(is_set_ok, Err, Mfa), Idx};
validate_err(table_is_set_ok, X, Mfa) ->
    user_err("~w with is_set_ok (table), returned: ~w. Using genErr.",
	     [Mfa, X]),
    {genErr, 0};

validate_err(row_is_set_ok, {Err, Idx}, _) when is_integer(Idx) ->
    {Err, Idx};
validate_err(row_is_set_ok, {_Err, {false, BadCol}}, Mfa) ->
    user_err("~w with is_set_ok (table), returned bad column: "
	     "~w. Using genErr.", [Mfa, BadCol]),
    {genErr, 0};

validate_err(table_undo, {Err, Idx}, Mfa) when is_integer(Idx) ->
    {validate_err(undo, Err, Mfa), Idx};
validate_err(table_undo, X, Mfa) ->
    user_err("~w with undo (table), returned: ~w. Using genErr.",
	     [Mfa, X]),
    {genErr, 0};

validate_err(row_undo, {Err, Idx}, _) when is_integer(Idx) ->
    {Err, Idx};
validate_err(row_undo, {_Err, {false, BadCol}}, Mfa) ->
    user_err("~w with undo (table), returned bad column: "
	     "~w. Using genErr.", [Mfa, BadCol]),
    {genErr, 0};

validate_err(table_set, {Err, Idx}, Mfa) when is_integer(Idx) ->
    {validate_err(set, Err, Mfa), Idx};
validate_err(table_set, X, Mfa) ->
    user_err("~w with set (table), returned: ~w. Using genErr.",
	     [Mfa, X]),
    {genErr, 0};

validate_err(row_set, {Err, Idx}, _) when is_integer(Idx) ->
    {Err, Idx};
validate_err(row_set, {_Err, {false, BadCol}}, Mfa) ->
    user_err("~w with set (table), returned bad column: "
	     "~w. Using genErr.", [Mfa, BadCol]),
    {genErr, 0};

validate_err(table_next, {Err, Idx}, _Mfa) when is_integer(Idx) ->
    {Err, Idx};
validate_err(table_next, {_Err, {false, BadCol}}, Mfa) ->
    user_err("~w with get_next, returned bad column: "
	     "~w. Using genErr.", [Mfa, BadCol]),
    {genErr, 0}.

validate_err(v2_to_v1, {V2Err, Index}) ->
    {v2err_to_v1err(V2Err), Index};
validate_err(v2_to_v1, _) ->
    {genErr, 0}.

get_err({ErrC, ErrI, Vbs}) ->
    {get_err_i(ErrC), ErrI, Vbs}.

get_err_i(noError) -> noError;
get_err_i(tooBig) -> tooBig;    % OTP-9700 
get_err_i(ES) -> ?vtrace("convert ErrorStatus '~p' to 'genErr'", [ES]), genErr.

v2err_to_v1err(noError) ->            noError;
v2err_to_v1err(noAccess) ->           noSuchName;
v2err_to_v1err(noCreation) ->         noSuchName;
v2err_to_v1err(notWritable) ->        noSuchName;
v2err_to_v1err(wrongLength) ->        badValue;
v2err_to_v1err(wrongEncoding) ->      badValue;
v2err_to_v1err(wrongType) ->          badValue;
v2err_to_v1err(wrongValue) ->         badValue;
v2err_to_v1err(inconsistentValue) ->  badValue;
v2err_to_v1err(inconsistentName) ->   noSuchName;
v2err_to_v1err(noSuchName) ->         noSuchName;
v2err_to_v1err(badValue) ->           badValue;
v2err_to_v1err(authorizationError) -> noSuchName;
%% genErr | resourceUnavailable | undoFailed | commitFailed -> genErr
v2err_to_v1err(_Error) ->             genErr.

%%-----------------------------------------------------------------
%% transforms a (hopefully correct) return value ((perhaps) from a 
%% mib-function) to a typed and guaranteed correct return value.
%% An incorrect return value is transformed to {error, genErr}.
%% A correct return value is on the form: 
%% {error, <error-msg>} | {value, <variable-type>, <value>}
%%-----------------------------------------------------------------
make_value_a_correct_value({value, Val}, Asn1, Mfa)
  when Asn1#asn1_type.bertype =:= 'INTEGER' ->
    check_integer(Val, Asn1, Mfa);

make_value_a_correct_value({value, Val}, Asn1, Mfa)
  when Asn1#asn1_type.bertype =:= 'Counter32' ->
    check_integer(Val, Asn1, Mfa);

make_value_a_correct_value({value, Val}, Asn1, Mfa)
  when Asn1#asn1_type.bertype =:= 'Unsigned32' ->
    check_integer(Val, Asn1, Mfa);

make_value_a_correct_value({value, Val}, Asn1, Mfa)
  when Asn1#asn1_type.bertype =:= 'TimeTicks' ->
    check_integer(Val, Asn1, Mfa);

make_value_a_correct_value({value, Val}, Asn1, Mfa)
  when Asn1#asn1_type.bertype =:= 'Counter64' ->
    check_integer(Val, Asn1, Mfa);

make_value_a_correct_value({value, Val}, Asn1, Mfa)
  when (Asn1#asn1_type.bertype =:= 'BITS') andalso is_list(Val) ->
    {value,Kibbles} = snmp_misc:assq(kibbles,Asn1#asn1_type.assocList),
    case snmp_misc:bits_to_int(Val,Kibbles) of
	error ->
	    wrongValue(Val, Mfa);
	Int ->
	    make_value_a_correct_value({value,Int},Asn1,Mfa)
    end;

make_value_a_correct_value({value, Val}, Asn1, Mfa)
  when (Asn1#asn1_type.bertype =:= 'BITS') andalso is_integer(Val) ->
    {value,Kibbles} = snmp_misc:assq(kibbles,Asn1#asn1_type.assocList),
    {_Kibble,BitNo} = lists:last(Kibbles),
    case (1 bsl (BitNo+1)) of
	X when Val < X ->
	    {value,'BITS',Val};
	_Big ->
	    wrongValue(Val, Mfa)
    end;

make_value_a_correct_value({value, String},
			   #asn1_type{bertype = 'OCTET STRING',
				      hi = Hi, lo = Lo}, Mfa) ->
    check_octet_string(String, Hi, Lo, Mfa, 'OCTET STRING');

make_value_a_correct_value({value, String},
			   #asn1_type{bertype = 'IpAddress',
				      hi = Hi, lo = Lo}, Mfa) ->
    check_octet_string(String, Hi, Lo, Mfa, 'IpAddress');

make_value_a_correct_value({value, Oid},
			   #asn1_type{bertype = 'OBJECT IDENTIFIER'},
			   _Mfa) ->
    case snmp_misc:is_oid(Oid) of
	true  -> {value, 'OBJECT IDENTIFIER', Oid};
	_Else -> {error, wrongType}
    end;

make_value_a_correct_value({value, Val}, Asn1, _Mfa)
  when Asn1#asn1_type.bertype =:= 'Opaque' ->
    if is_list(Val) -> {value, 'Opaque', Val};
       true -> {error, wrongType}
    end;

make_value_a_correct_value({noValue, noSuchObject}, _ASN1Type, _Mfa) ->
    {value, noValue, noSuchObject};
make_value_a_correct_value({noValue, noSuchInstance}, _ASN1Type, _Mfa) ->
    {value, noValue, noSuchInstance};
make_value_a_correct_value({noValue, noSuchName}, _ASN1Type, _Mfa) ->
    %% Transform this into a v2 value.  It is converted to noSuchName
    %% later if it was v1.  If it was v2, we use noSuchInstance.
    {value, noValue, noSuchInstance};
%% For backwards compatibility only - we really shouldn't allow this;
%% it makes no sense to return unSpecified for a variable! But we did
%% allow it previously. -- We transform unSpecified to noSuchInstance
%% (OTP-3303).
make_value_a_correct_value({noValue, unSpecified}, _ASN1Type, _Mfa) ->
    {value, noValue, noSuchInstance};
make_value_a_correct_value(genErr, _ASN1Type, _MFA) ->
    {error, genErr};

make_value_a_correct_value(_WrongVal, _ASN1Type, undef) ->
    {error, genErr};

make_value_a_correct_value(WrongVal, ASN1Type, Mfa) ->
    user_err("Got ~w from ~w. (~w) Using genErr",
	     [WrongVal, Mfa, ASN1Type]),
    {error, genErr}.

check_integer(Val, Asn1, Mfa) ->
    case Asn1#asn1_type.assocList of
	undefined -> check_size(Val, Asn1, Mfa);
	Alist ->
	    case snmp_misc:assq(enums, Alist) of
		{value, Enums} -> check_enums(Val, Asn1, Enums, Mfa);
		false -> check_size(Val, Asn1, Mfa)
	    end
    end.

check_octet_string(String, Hi, Lo, Mfa, Type) ->
    Len = (catch length(String)), % it might not be a list
    case snmp_misc:is_string(String) of
	true when Lo =:= undefined -> {value, Type, String};
	true when Len =< Hi, Len >= Lo ->
	    {value, Type, String};
	true ->
	    wrongLength(String, Mfa);
	_Else ->
	    wrongType(String, Mfa)
    end.

check_size(Val, #asn1_type{lo = Lo, hi = Hi, bertype = Type}, Mfa) 
  when is_integer(Val) ->
    ?vtrace("check size of integer: "
	    "~n   Value:       ~p"
	    "~n   Upper limit: ~p"
	    "~n   Lower limit: ~p"
	    "~n   BER-type:    ~p",
	    [Val,Hi,Lo,Type]),
    if
	(Lo =:= undefined) andalso (Hi =:= undefined) -> {value, Type, Val};
	(Lo =:= undefined) andalso is_integer(Hi) andalso (Val =< Hi) ->
	    {value, Type, Val};
	is_integer(Lo) andalso (Val >= Lo) andalso (Hi =:= undefined) ->
	    {value, Type, Val};
	is_integer(Lo) andalso is_integer(Hi) andalso (Val >= Lo) andalso (Val =< Hi) ->
	    {value, Type, Val};
	true ->
	    wrongValue(Val, Mfa)
    end;
check_size(Val, _, Mfa) ->
    wrongType(Val, Mfa).

check_enums(Val, Asn1, Enums, Mfa) ->
    Association = 
	if
	    is_integer(Val) -> lists:keysearch(Val, 2, Enums);
	    is_atom(Val)    -> lists:keysearch(Val, 1, Enums);
	    true            -> {error, wrongType}
    end,
    case Association of
	{value, {_AliasIntName, Val2}} -> 
	    {value, Asn1#asn1_type.bertype, Val2};
	false ->
	    wrongValue(Val, Mfa);
	{error, wrongType} ->
	    wrongType(Val, Mfa)
    end.

wrongLength(Val, Mfa) ->
    report_err(Val, Mfa, wrongLength).

wrongValue(Val, Mfa) ->
    report_err(Val, Mfa, wrongValue).

wrongType(Val, Mfa) ->
    report_err(Val, Mfa, wrongType).

report_err(_Val, undef, Err) ->
    {error, Err};
report_err(Val, Mfa, Err) ->
    user_err("Got ~p from ~w. Using ~w", [Val, Mfa, Err]),
    {error, Err}.

is_valid_pdu_type('get-request')      -> true;
is_valid_pdu_type('get-next-request') -> true;
is_valid_pdu_type('get-bulk-request') -> true;
is_valid_pdu_type('set-request')      -> true;
is_valid_pdu_type(_)                  -> false.

get_pdu_data() ->
    {get(net_if_data), 
     get(snmp_request_id),
     get(snmp_address), 
     get(snmp_community), 
     get(snmp_context)}.

put_pdu_data({Extra, ReqId, Address, Community, ContextName}) -> 
    {put(net_if_data, Extra),
     put(snmp_address, Address),
     put(snmp_request_id, ReqId),
     put(snmp_community, Community),
     put(snmp_context, ContextName)}.

tr_var(Oid, Idx) ->
    case snmp_misc:is_oid(Oid) of
	true ->
	    {#varbind{oid = Oid, value = unSpecified, org_index = Idx},
	     Idx+1};
	false -> throw({error, {bad_oid, Oid}})
    end.

tr_varbind(#varbind{value = Value}) -> Value.

mapfoldl(F, Eas, Accu0, [Hd|Tail]) ->
    {R,Accu1} = apply(F, [Hd,Accu0|Eas]),
    {Accu2,Rs} = mapfoldl(F, Eas, Accu1, Tail),
    {Accu2,[R|Rs]};
mapfoldl(_F, _Eas, Accu, []) -> {Accu,[]}.

%%-----------------------------------------------------------------
%% Runtime debugging of the agent.
%%-----------------------------------------------------------------

dbg_apply(M,F,A) ->
    case get(verbosity) of
	silence -> 
	    apply(M,F,A);
	_ ->
	    ?vlog("~n   apply: ~w,~w,~p~n", [M,F,A]),
	    Res = (catch apply(M,F,A)),
	    case Res of
		{'EXIT', Reason} ->
		    ?vinfo("Call to: "
			   "~n   Module:   ~p"
			   "~n   Function: ~p"
			   "~n   Args:     ~p"
			   "~n"
			   "~nresulted in an exit"
			   "~n"
			   "~n   ~p", [M, F, A, Reason]);
		_ ->
		    ?vlog("~n   returned: ~p", [Res])
	    end,
	    Res
    end.


short_name(none) -> ma;
short_name(_Pid) -> sa.

worker_short_name(ma) -> maw;
worker_short_name(_)  -> saw.

trap_sender_short_name(ma) -> mats;
trap_sender_short_name(_)  -> sats.

pdu_handler_short_name(ma) -> maph;
pdu_handler_short_name(_)  -> saph.


mib_server_verbosity(Pid,Verbosity) when is_pid(Pid) ->
    snmpa_mib:verbosity(Pid,Verbosity);
mib_server_verbosity(_Pid,_Verbosity) ->
    ok.

note_store_verbosity(Pid,Verbosity) when is_pid(Pid) ->
    snmp_note_store:verbosity(Pid,Verbosity);
note_store_verbosity(_Pid,_Verbosity) ->
    ok.

subagents_verbosity(V) ->
    subagents_verbosity(catch snmpa_mib:info(get(mibserver),subagents),V).

subagents_verbosity([],_V) ->
    ok;
subagents_verbosity([{Pid,_Oid}|T],V) ->
    catch verbosity(Pid,V),             %% On the agent
    catch verbosity(Pid,{subagents,V}), %% and it's subagents
    subagents_verbosity(T,V);
subagents_verbosity(_,_V) ->
    ok.


%% ---------------------------------------------------------------------

handle_get_log_type(#state{net_if_mod = Mod}) 
  when Mod =/= undefined ->
    case (catch Mod:get_log_type(get(net_if))) of
	{'EXIT', _} ->
            {error, not_supported};
        Else ->
            Else
    end;
handle_get_log_type(_) ->
    {error, not_supported}.

handle_set_log_type(#state{net_if_mod = Mod}, NewType) 
  when Mod =/= undefined ->
    case (catch Mod:set_log_type(get(net_if), NewType)) of
	{'EXIT', _} ->
            {error, not_supported};
        Else ->
            Else
    end;
handle_set_log_type(_, _) ->
    {error, not_supported}.


handle_get_request_limit(#state{net_if_mod = Mod}) 
  when Mod =/= undefined ->
    case (catch Mod:get_request_limit(get(net_if))) of
	{'EXIT', _} ->
            {error, not_supported};
        Else ->
            Else
    end;
handle_get_request_limit(_) ->
    {error, not_supported}.

handle_set_request_limit(#state{net_if_mod = Mod}, NewLimit) 
  when Mod =/= undefined ->
    case (catch Mod:set_request_limit(get(net_if), NewLimit)) of
	{'EXIT', _} ->
            {error, not_supported};
        Else ->
            Else
    end;
handle_set_request_limit(_, _) ->
    {error, not_supported}.


agent_info(#state{worker = W, set_worker = SW}) ->	 
    case (catch get_agent_info(W, SW)) of
	Info when is_list(Info) ->
	    Info;
	E ->
	    [{error, E}]
    end.

get_agent_info(W, SW) ->
    MASz   = proc_mem(self()),
    WSz    = proc_mem(W),
    SWSz   = proc_mem(SW),
    ATSz   = tab_mem(snmp_agent_table),
    CCSz   = tab_mem(snmp_community_cache),
    VacmSz = tab_mem(snmpa_vacm),
    [{process_memory, [{master_agent, MASz}, 
		       {worker,       WSz}, 
		       {set_worker,   SWSz}]}, 
     {db_memory, [{agent,           ATSz}, 
		  {community_cache, CCSz}, 
		  {vacm,            VacmSz}]}].

proc_mem(P) when is_pid(P) ->
    case (catch erlang:process_info(P, memory)) of
	{memory, Sz} when is_integer(Sz) ->
	    Sz;
	_ ->
	    undefined
    end;
proc_mem(_) ->
    undefined.

tab_mem(T) ->
    case (catch ets:info(T, memory)) of
	Sz when is_integer(Sz) ->
	    Sz;
	_ ->
	    undefined
    end.

net_if_info(#state{net_if_mod = Mod}) when Mod =/= undefined ->
    case (catch Mod:info(get(net_if))) of
	Info when is_list(Info) ->
	    Info;
	E ->
	    [{error, E}]
    end;
net_if_info(_) ->
    %% This could be a result of a code upgrade
    %% Make best effert
    [{process_memory, proc_mem(get(net_if))}].

note_store_info(#state{note_store = NS}) ->
    case (catch snmp_note_store:info(NS)) of
	Info when is_list(Info) ->
	    Info;
	E ->
	    [{error, E}]
    end.

symbolic_store_info() ->
    case (catch snmpa_symbolic_store:info()) of
	Info when is_list(Info) ->
	    Info;
	E ->
	    [{error, E}]
    end.

local_db_info() ->
    case (catch snmpa_local_db:info()) of
	Info when is_list(Info) ->
	    Info;
	E ->
	    [{error, E}]
    end.

mib_server_info() ->
    case (catch snmpa_mib:info(get(mibserver))) of
	Info when is_list(Info) ->
	    Info;
	E ->
	    [{error, E}]
    end.
	
get_stats_counters() ->
    Counters = snmpa_mpd:counters(),
    get_stats_counters(Counters, []).

get_stats_counters([], Acc) ->
    lists:reverse(Acc);
get_stats_counters([Counter|Counters], Acc) ->
    case ets:lookup(snmp_agent_table, Counter) of
	[CounterVal] ->
	    get_stats_counters(Counters, [CounterVal|Acc]);
	_ ->
	    get_stats_counters(Counters, Acc)
    end.


%% ---------------------------------------------------------------------

%% info_msg(F, A) ->
%%     ?snmpa_info(F, A).

warning_msg(F, A) ->
    ?snmpa_warning(F, A).

error_msg(F, A) ->
    ?snmpa_error(F, A).

%% --- 

config_err(F, A) ->
    snmpa_error:config_err(F, A).

user_err(F, A) ->
    snmpa_error:user_err(F, A).


%% ---------------------------------------------------------------------

call(Server, Req) ->
    gen_server:call(Server, Req, infinity).

cast(Server, Msg) ->
    gen_server:cast(Server, Msg).


%% ---------------------------------------------------------------------

get_verbosity(Opts) ->
    get_option(verbosity, Opts, ?default_verbosity).

get_mibs(Opts) ->
    get_option(mibs, Opts, []).

get_mib_storage(Opts) ->
    get_option(mib_storage, Opts, ets).

get_set_mechanism(Opts) ->
    get_option(set_mechanism, Opts, snmpa_set).

get_authentication_service(Opts) ->
    get_option(authentication_service, Opts, snmpa_acm).

get_multi_threaded(Opts) ->
    get_option(multi_threaded, Opts, false).

get_versions(Opts) ->
    get_option(versions, Opts, [v1,v2,v3]).

get_gb_max_vbs(Opts) ->
    get_option(gb_max_vbs, Opts, infinity).

get_note_store_opt(Opts) ->
    get_option(note_store, Opts, []).

get_net_if_opt(Opts) ->
    get_option(net_if, Opts, []).

get_net_if_verbosity(Opts) ->
    get_option(verbosity, Opts, silence).

get_net_if_module(Opts) ->
    get_option(module, Opts, snmpa_net_if).

get_net_if_options(Opts) ->
    get_option(options, Opts, []).


net_if_verbosity(Pid,Verbosity) when is_pid(Pid) ->
    Pid ! {verbosity,Verbosity};
net_if_verbosity(_Pid,_Verbosity) ->
    ok.


get_option(Key, Opts, Default) ->
    snmp_misc:get_option(Key, Opts, Default).


%% ---------------------------------------------------------------------


%% i(F) ->
%%     i(F, []).

%% i(F, A) ->
%%     io:format("~p: " ++ F ++ "~n", [?MODULE|A]).