aboutsummaryrefslogblamecommitdiffstats
path: root/lib/snmp/src/agent/snmpa_mib_data_tttn.erl
blob: 9b4493a03f241e977de4bd1b71796b308cd80cc5 (plain) (tree)
1
2
3
4
5
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277


                   
                                                        
   










                                                                           


                 
 
                             
 
 
                                                                    


                                         








                                                                

                                                                   


                                                               
    
                                                                    
 

                                             
 
                              
                                                 
 






                                                        













                                                                    

                  






















                                                                    

                        




                                                
                  











                                    
                        
                   
                         





















                                                                          
                                                                           






                                                                         
              

                                                                   

                                                            



                                                          

                                                                           
                                      








                                                                          
                                           








                                                                            
                                           








                                                                  
                                               
           
                                                        

                            
                                     



                         
                                          
                                     
                       

                               







                                                                        
                                                    










                                                                        

                               


                                        
                                           
                                                 
                                             




















                                                                               


                                                                      


                                                                         






                                                         

                                    
                                           
                                           







                                                               
                                            





                                                                      

                              

                                                            





                              


                                                             

                






                                                               

                                         























































































                                                                          

                               


                                        
                                                                        
                                                            

                                                      


                                                                    

                                


                           
                                      


        






                                     








                                                             
                                                              







                                                                        

                                                   







                                                                        

                                                          










                                                                        

                                                               

                                        

                          











                                                                             
                                                     








                                                                   
                                       






                                                                        






                                                 
                                        



                                                             



                                                                              

                                                             





                                                                         



                                  
                  



                                                               










                                                                        
 

                                

                                      
                                            
                                             
                                             
                                              
                                                                     
       
 

                                


                                        



                                                                            
                                                     
                                                         
                                                      


                                                                        
                          
                                                                 

                                   


        






                                            











































































































                                                                            
                                              
                                
                             























                                                                           
                                              
                                           
                             


                                         
                                                               









                                                                     
                                              
                                
                             
















































































                                                                         

                                                      






































































                                                                            

                                                            














                                                                            
 






























                                                                              

                                                      











                                                                            

                                                            


























































































































































































































































































































                                                                                
 


                                                                            
 






                                                                          
 








                                                                         

                                   

                                                                  
                                         
 
                          
       
                                                 
                                                                  
                                              

                                                             
                                    

                                                        
                                         




                                                                        
                                                                         




                                                                               
                       




















                                                                       









                                                          
       


                               




                                                                        
                                                 



                                                      
                                  













                                                                  
                                  
                                                                  
                                  




                                                                        

                                                   
































                                                                             



                                         

          



                                         

          
 
%%
%% %CopyrightBegin%
%% 
%% Copyright Ericsson AB 1996-2016. All Rights Reserved.
%% 
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
%% You may obtain a copy of the License at
%%
%%     http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%% 
%% %CopyrightEnd%
%%

-module(snmpa_mib_data_tttn).


%%%-----------------------------------------------------------------
%%% 
%%%            TTTN - TupleTreeTupleNodes
%%% 
%%% This module implements the MIB (internal) data structures.
%%% The TTTN MIB Data structure consists of three items: 
%%% 
%%%      1) A mib-storage (as specified when new is called) for 
%%%         the data associated with each variable, table, 
%%%         table-entry and table-column in the MIB. 
%%%      2) A tree contains information of the Oids in the MIB. 
%%%      3) A list of registered subagents. 
%%% 
%%% The subagent information is consequently duplicated. It resides
%%% both in the tree and in the list.
%%%
%%% When a mib is loaded, the tree is built from the plain list
%%% in the binary file.
%%% 
%%%-----------------------------------------------------------------

-include_lib("snmp/include/snmp_types.hrl").
-include_lib("snmp/src/misc/snmp_debug.hrl").

-define(VMODULE,"MDATA_TTTN").
-include_lib("snmp/src/misc/snmp_verbosity.hrl").

-behaviour(snmpa_mib_data).

-define(MIB_DATA, snmpa_mib_data).
-define(MIB_NODE, snmpa_mib_node).
-define(MIB_TREE, snmpa_mib_tree).
-define(DUMMY_TREE_GENERATION, 1).
-define(DEFAULT_TREE, {tree,{undefined_node},internal}).


%%%-----------------------------------------------------------------
%%% Table of contents
%%% =================
%%% 1. Interface
%%% 2. Implementation of tree access
%%% 3. Tree building functions
%%% 4. Tree merging
%%% 5. Tree deletion routines
%%% 6. Functions for subagent handling
%%% 7. Misc functions
%%%-----------------------------------------------------------------

-record(mib_data, 
	{
	  %% Mib storage module
	  module :: snmpa:mib_storage_module(),  

	  %% A database of loaded mibs
	  %% #mib_info{}
	  mib_db,  

	  %% A database with information about each node in the tree
	  %% #node_info{}
	  node_db, 

	  %% A database containing _one_ record with the tree
	  %% without the subagent(s). 
	  %% (the reason for this is part to get replication 
	  %% and part out of convenience)
	  %% #tree{}
	  tree_db, 

	  %% The root node (same as the tree part of the tree_db 
	  %% but with the subagents added). 
	  tree, 
	  
	  %% A list of {SAPid, Oid}
	  subagents = []
	 }).

-record(mib_info,  {name, symbolic, file_name}).
-record(node_info, {oid, mib_name, me}).


%% (behaviour) API
-export([new/1, 
	 close/1, 
	 sync/1, 
	 load_mib/4, 
	 unload_mib/4, 
	 lookup/2, 
	 next/3, 
	 register_subagent/3, 
	 unregister_subagent/2, 
	 dump/2, 
	 which_mib/2, which_mibs/1, 
	 whereis_mib/2, 
	 info/1, info/2,
	 backup/2, 
	 code_change/4]).


%%-----------------------------------------------------------------
%% A tree is represented as a N-tuple, where each element is a
%% node. A node is:
%% 1) {tree, Tree, Info} where Info can be {table, Id}, {table_entry, Id}
%%                                        or perhaps 'internal'
%% 2) undefined_node  (memory optimization (instead of {node, undefined}))
%% 3) {node, Info} where Info can be {subagent, Pid}, {variable, Id}, 
%%                                   {table_column, Id}
%% Id is {MibName, MibEntry}
%% The over all root is represented as {tree, Tree, internal}.
%%
%% tree() = {tree, nodes(), tree_info()}
%% nodes() = {tree() | node() | undefined_node, ...}
%% node() = {node, node_info()}
%% tree_info() = {table, Id} | {table_entry, Id} | internal
%% node_info() = {subagent, Pid} | {variable, Id} | {table_colum, Id}
%%-----------------------------------------------------------------

%% This record is what is stored in the database. The 'tree' part
%% is described above...
-record(tree, {generation = ?DUMMY_TREE_GENERATION, root = ?DEFAULT_TREE}).


%%%======================================================================
%%% 1. Interface
%%%======================================================================

%%-----------------------------------------------------------------
%% Func: new/1
%% Returns: A representation of mib data.
%%-----------------------------------------------------------------

%% Where -> A list of nodes where the tables will be created
new(MibStorage) ->
    Mod  = snmp_misc:get_option(module,  MibStorage), 
    Opts = snmp_misc:get_option(options, MibStorage, []), 

    %% First we must check if there is already something to read
    %% If a database already exists, then the tree structure has to be read
    ?vdebug("open (mib) database",[]),
    MibDb = 
	case Mod:open(?MIB_DATA, mib_info, record_info(fields, mib_info), 
		      set, Opts) of
	    {ok, T1} ->
		T1;
	    {error, Reason1} ->
		throw({error, {open, mib_data, Reason1}})
	end,

    ?vdebug("open (mib) node database",[]),
    NodeDb = 
	case Mod:open(?MIB_NODE, node_info, record_info(fields, node_info), 
		      set, Opts) of
	    {ok, T2} ->
		T2;
	    {error, Reason2} ->
		throw({error, {open, mib_node, Reason2}})
	end,

    ?vdebug("open (mib) tree database",[]),
    TreeDb = 
	case Mod:open(?MIB_TREE, tree, record_info(fields, tree), 
		      set, Opts) of
	    {ok, T3} ->
		T3;
	    {error, Reason3} ->
		throw({error, {open, mib_tree, Reason3}})
	end,

    ?vdebug("write the default (mib) tree",[]),
    Tree = 
	case Mod:read(TreeDb, ?DUMMY_TREE_GENERATION) of
	    false ->
		T = #tree{},
		Mod:write(TreeDb, T),
		T;
	    {value, T} ->
		T
	end,
    ?vdebug("install (existing) mibs",[]),
    install_mibs(Mod, MibDb, NodeDb),
    ?vdebug("done",[]),
    #mib_data{module  = Mod, 
	      mib_db  = MibDb, 
	      node_db = NodeDb,
	      tree_db = TreeDb, 
	      tree    = Tree}.


%%----------------------------------------------------------------------
%% Returns: new mib data | {error, Reason}
%%----------------------------------------------------------------------
load_mib(MibData, FileName, MeOverride, TeOverride) 
  when is_record(MibData,mib_data) andalso is_list(FileName) -> 
    ?vlog("load mib file: ~p",[FileName]),
    ActualFileName = filename:rootname(FileName, ".bin") ++ ".bin",
    MibName = list_to_atom(filename:basename(FileName, ".bin")),
    (catch do_load_mib(MibData, ActualFileName, MibName, 
                       MeOverride, TeOverride)).

do_load_mib(MibData, ActualFileName, MibName, MeOverride, TeOverride) ->
    ?vtrace("do_load_mib -> entry with"
        "~n  ActualFileName: ~s"
        "~n  MibName:        ~p",[ActualFileName, MibName]),
    #mib_data{module  = Mod, 
	      mib_db  = MibDb, 
	      node_db = NodeDb, 
	      %% tree_db = TreeDb,
	      tree    = Tree} = MibData,
    verify_not_loaded(Mod, MibDb, MibName),
    ?vtrace("do_load_mib -> already loaded mibs:"
	    "~n   ~p", [loaded(Mod, MibDb)]),
    Mib = do_read_mib(ActualFileName),
    ?vtrace("do_load_mib -> read mib ~s",[Mib#mib.name]),
    NonInternalMes = 
        lists:filter(fun(ME) -> maybe_drop_me(ME) end, Mib#mib.mes),
    OldRoot = Tree#tree.root,
    T = build_tree(NonInternalMes, MibName),
    ?d("load_mib -> "
	"~n   OldRoot: ~p"
	"~n   T:       ~p", [OldRoot, T]),
    case (catch merge_nodes(T, OldRoot)) of
	{error_merge_nodes, Node1, Node2} ->
	    ?vlog("error merging nodes:"
		"~n~p~nand~n~p", [Node1,Node2]),
	    {error, oid_conflict};
	NewRoot when is_tuple(NewRoot) andalso (element(1,NewRoot) =:= tree) ->
 	    ?d("load_mib -> "
 		"~n   NewRoot: ~p", [NewRoot]),
	    Symbolic = not lists:member(no_symbolic_info, Mib#mib.misc),
	    case (catch check_notif_and_mes(TeOverride, MeOverride, Symbolic, 
					    Mib#mib.traps, NonInternalMes)) of
		true ->
		    install_mes(Mod, NodeDb, MibName, NonInternalMes),
		    install_mib(Mod, 
				MibDb, Symbolic, Mib, 
				MibName, ActualFileName, NonInternalMes),
		    ?vtrace("installed mib ~s", [Mib#mib.name]),
		    Tree2 = Tree#tree{root = NewRoot},
		    {ok, MibData#mib_data{tree = Tree2}};
		Else -> 
		    Else
	    end
    end.


verify_not_loaded(Mod, Tab, Name) ->
    case Mod:read(Tab, Name) of
        {value, #mib_info{name = Name}} -> 
            throw({error, already_loaded});
        false ->
            ok
    end.

do_read_mib(ActualFileName) ->
    case snmp_misc:read_mib(ActualFileName) of
        {error, Reason} -> 
            ?vlog("Failed reading mib file ~p with reason: ~p",
		  [ActualFileName, Reason]),
            throw({error, Reason});
        {ok, Mib} ->
            Mib
    end.

%% The Tree DB is handled in a special way since it can be very large.
sync(#mib_data{module  = Mod, 
	       mib_db  = M, 
	       node_db = N, 
	       tree_db = T, tree = Tree, subagents = []}) ->
    Mod:sync(M),
    Mod:sync(N),
    Mod:write(T, Tree),
    Mod:sync(T);
sync(#mib_data{module  = Mod, 
	       mib_db  = M, 
	       node_db = N, 
	       tree_db = T, tree = Tree, subagents = SAs}) ->

    Mod:sync(M),
    Mod:sync(N),

    %% Ouch. Since the subagent info is dynamic we do not 
    %% want to store the tree containing subagent info. So, we 
    %% have to create a tmp tree without those and store it.

    case delete_subagents(Tree, SAs) of
	{ok, TreeWithoutSAs} ->
	    Mod:write(T, TreeWithoutSAs),
	    Mod:sync(T);
	Error ->
	    Error
    end.

delete_subagents(Tree, []) ->
    {ok, Tree};
delete_subagents(Tree0, [{_, Oid}|SAs]) ->
    case (catch delete_subagent(Tree0, Oid)) of
	{tree, _Tree, _Info} = Tree1 ->
	    delete_subagents(Tree1, SAs);
	_Error ->
	    {error, {'invalid oid', Oid}} 
    end.

%%----------------------------------------------------------------------
%% (OTP-3601)
%%----------------------------------------------------------------------
check_notif_and_mes(TeOverride,MeOverride,Symbolic,Traps,MEs) ->
    ?vtrace("check notifications and mib entries",[]),
    check_notifications(TeOverride,Symbolic,Traps),
    check_mes(MeOverride,MEs).

check_notifications(true, _Symbolic, _Traps) ->
    ?vtrace("trapentry override = true => skip check",[]),
    true;
check_notifications(_, Symbolic, Traps) -> 
    check_notifications(Symbolic, Traps).

check_notifications(true, Traps) ->
    check_notifications(Traps);
check_notifications(_, _) -> true.

check_notifications([]) -> true;
check_notifications([#trap{trapname = Key} = Trap | Traps]) ->
    ?vtrace("check notification [trap] with Key: ~p",[Key]),
    case snmpa_symbolic_store:get_notification(Key) of
	{value, Trap} -> check_notifications(Traps);
	{value,    _} -> throw({error, {'trap already defined', Key}});
	undefined     -> check_notifications(Traps)
    end;
check_notifications([#notification{trapname = Key} = Notif | Traps]) ->
    ?vtrace("check notification [notification] with Key: ~p",[Key]),
    case snmpa_symbolic_store:get_notification(Key) of
	{value, Notif} -> 
	    check_notifications(Traps);
	{value,     _} -> 
	    throw({error, {'notification already defined', Key}});
	undefined      -> 
	    check_notifications(Traps)
    end;
check_notifications([Crap | Traps]) ->
    ?vlog("skipped check of: ~n~p",[Crap]),
    check_notifications(Traps).

check_mes(true,_) ->
    ?vtrace("mibentry override = true => skip check",[]),
    true; 
check_mes(_,MEs) ->
    check_mes(MEs).

check_mes([]) -> true;
check_mes([#me{aliasname = Name, oid = Oid1} | MEs]) ->
    ?vtrace("check mib entries with aliasname: ~p",[Name]),
    case snmpa_symbolic_store:aliasname_to_oid(Name) of
	{value, Oid1} -> 
	    check_mes(MEs);
	{value, Oid2} -> 
	    ?vinfo("~n   expecting '~p'~n   but found '~p'",[Oid1, Oid2]),
	    throw({error, {'mibentry already defined', Name}});
	false -> 
	    check_mes(MEs)
    end;
check_mes([Crap | MEs]) ->
    ?vlog("skipped check of: ~n~p",[Crap]),
    check_mes(MEs).
    


%%----------------------------------------------------------------------
%% Returns: new mib data | {error, Reason}
%%----------------------------------------------------------------------
unload_mib(MibData, FileName, _, _) when is_list(FileName) -> 
    MibName = list_to_atom(filename:basename(FileName, ".bin")),
    (catch do_unload_mib(MibData, MibName)).

do_unload_mib(MibData, MibName) ->
    ?vtrace("do_unload_mib -> entry with"
	"~n   MibName: ~p", [MibName]),
    #mib_data{module  = Mod, 
	      mib_db  = MibDb, 
	      node_db = NodeDb, 
	      %% tree_db = TreeDb, 
	      tree    = Tree} = MibData,
    #mib_info{symbolic = Symbolic} = verify_loaded(Mod, MibDb, MibName),
    NewRoot = delete_mib_from_tree(MibName, Tree#tree.root),
    MEs = uninstall_mes(Mod, NodeDb, MibName),
    uninstall_mib(Mod, MibDb, Symbolic, MibName, MEs),
    NewMibData = MibData#mib_data{tree = Tree#tree{root = NewRoot}},
    {ok, NewMibData}.

verify_loaded(Mod, Tab, Name) ->
    case Mod:read(Tab, Name) of
        {value, MibInfo} ->
            MibInfo;
        false ->
            throw({error, not_loaded})
    end.
    
    
close(#mib_data{module  = Mod, 
		mib_db  = MibDb, 
		node_db = NodeDb, 
		tree_db = TreeDb}) ->
    Mod:close(MibDb),
    Mod:close(NodeDb),
    Mod:close(TreeDb),
    ok.

register_subagent(#mib_data{tree = T} = MibData, Oid, Pid) ->
    case insert_subagent(Oid, T#tree.root) of
	{error, Reason} -> 
	    {error, Reason};
	NewRootTree ->
	    SAs = [{Pid, Oid} | MibData#mib_data.subagents],
	    T2 = T#tree{root = NewRootTree},
	    {ok, MibData#mib_data{tree = T2, subagents = SAs}}
    end.


%%----------------------------------------------------------------------
%% Purpose: Get a list of all loaded mibs
%% Returns: [{Name, File}]
%%----------------------------------------------------------------------

which_mibs(#mib_data{module = Mod, mib_db = Db}) ->
    Mibs = Mod:tab2list(Db),
    [{Name, File} || #mib_info{name = Name, file_name = File} <- Mibs].


%%----------------------------------------------------------------------
%% Purpose: Get a list of all loaded mibs
%% Returns: [{Name, File}]
%%----------------------------------------------------------------------

whereis_mib(#mib_data{module = Mod, mib_db = Db}, Name) ->
    case Mod:read(Db, Name) of
        {value, #mib_info{file_name = File}} ->
	    {ok, File};
	false ->
	    {error, not_found}
    end.


%%----------------------------------------------------------------------
%% Purpose: Deletes SA with Pid from all subtrees it handles.
%% Returns: NewMibData.
%%----------------------------------------------------------------------
unregister_subagent(#mib_data{subagents = SAs} = MibData, Pid) 
  when is_pid(Pid) ->
    SAs = MibData#mib_data.subagents,
    case lists:keysearch(Pid, 1, SAs) of
	false -> 
	    {ok, MibData};
	{value, {Pid, Oid}} ->
	    % we should never get an error since Oid is found in MibData.
	    {ok, NewMibData, _DeletedSA} = unregister_subagent(MibData, Oid),
	    % continue if the same Pid handles other mib subtrees.
	    unregister_subagent(NewMibData, Pid)
    end;

%%----------------------------------------------------------------------
%% Purpose: Deletes one unique subagent. 
%% Returns: {error, Reason} | {ok, NewMibData, DeletedSubagentPid}
%%----------------------------------------------------------------------
unregister_subagent(#mib_data{tree = T} = MibData, Oid) when is_list(Oid) ->
    case (catch delete_subagent(T#tree.root, Oid)) of
	{tree, Tree, Info} ->
	    OldSAs = MibData#mib_data.subagents,
	    {value, {Pid, _Oid}} = lists:keysearch(Oid, 2, OldSAs),
	    SAs = lists:keydelete(Oid, 2, OldSAs),
	    T2 = T#tree{root = {tree, Tree, Info}},
	    {ok, 
	     MibData#mib_data{tree = T2, subagents = SAs},
	     Pid};
	_ ->
	    {error, {invalid_oid, Oid}}
    end.

%%----------------------------------------------------------------------
%% Purpose: To inpect memory usage, loaded mibs, registered subagents
%%----------------------------------------------------------------------
info(MibData) ->
    ?vtrace("retrieve info",[]),
    #mib_data{module    = Mod, 
	      mib_db    = MibDb, 
	      node_db   = NodeDb, 
	      tree_db   = TreeDb, 
	      tree      = Tree, 
	      subagents = SAs} = MibData,
    LoadedMibs = old_format(Mod:tab2list(MibDb)),
    TreeSize = snmp_misc:mem_size(Tree),
    {memory, ProcSize} = erlang:process_info(self(), memory),
    MibDbSize  = Mod:info(MibDb,  memory),
    NodeDbSize = Mod:info(NodeDb, memory),
    TreeDbSize = Mod:info(TreeDb, memory),
    [{loaded_mibs, LoadedMibs}, {subagents, SAs}, {tree_size_bytes, TreeSize},
     {process_memory, ProcSize}, 
     {db_memory, [{mib,MibDbSize},{node,NodeDbSize},{tree,TreeDbSize}]}].

info(#mib_data{module = Mod, mib_db = MibDb}, loaded_mibs) ->
    Mibs = Mod:tab2list(MibDb),
    [filename:rootname(FN, ".bin") || #mib_info{file_name = FN} <- Mibs];
info(#mib_data{tree = Tree}, tree_size_bytes) ->
    snmp_misc:mem_size(Tree);
info(_, process_memory) ->
    {memory, ProcSize} = erlang:process_info(self(),memory),
    ProcSize;
info(#mib_data{module  = Mod, 
	       mib_db  = MibDb, 
	       node_db = NodeDb, 
	       tree_db = TreeDb}, 
     db_memory) ->
    MibDbSize  = Mod:info(MibDb,  memory),
    NodeDbSize = Mod:info(NodeDb, memory),
    TreeDbSize = Mod:info(TreeDb, memory),
    [{mib, MibDbSize}, {node, NodeDbSize}, {tree, TreeDbSize}];
info(#mib_data{subagents = SAs}, subagents) ->
    SAs.

old_format(LoadedMibs) ->
    ?vtrace("convert mib info to old format",[]),
    [{N,S,F} || #mib_info{name=N,symbolic=S,file_name=F} <- LoadedMibs].

    
%%----------------------------------------------------------------------
%% A total dump for debugging.
%%----------------------------------------------------------------------

dump(#mib_data{module  = Mod, 
	       mib_db  = MibDb, 
	       node_db = NodeDb, 
	       tree    = Tree}, io) ->
    (catch io:format("MIB-tables:~n~p~n~n", 
		     [Mod:tab2list(MibDb)])),
    (catch io:format("MIB-entries:~n~p~n~n", 
		     [Mod:tab2list(NodeDb)])),
    (catch io:format("Tree:~n~p~n", [Tree])), % good luck reading it!
    ok;

dump(#mib_data{module  = Mod, 
	       mib_db  = MibDb, 
	       node_db = NodeDb, 
	       tree    = Tree}, File) ->
    case file:open(File, [write]) of
	{ok, Fd} ->
	    io:format(Fd,"~s~n", 
		      [snmp:date_and_time_to_string(snmp:date_and_time())]),
	    (catch io:format(Fd,"MIB-tables:~n~p~n~n",
			     [Mod:tab2list(MibDb)])),
	    (catch io:format(Fd, "MIB-entries:~n~p~n~n", 
			     [Mod:tab2list(NodeDb)])),
	    io:format(Fd,"Tree:~n~p~n", [Tree]), % good luck reading it!
	    file:close(Fd),
	    ok;
	{error, Reason} ->
	    ?vinfo("~n   Failed opening file '~s' for reason ~p",
		   [File, Reason]),
	    {error, Reason}
    end.


backup(#mib_data{module  = Mod, 
		 mib_db  = M, 
		 node_db = N, 
		 tree_db = T}, BackupDir) ->
    MRes = Mod:backup(M, BackupDir),
    NRes = Mod:backup(N, BackupDir),
    TRes = Mod:backup(T, BackupDir),
    handle_backup_res([{mib_db, MRes}, {node_db, NRes}, {tree_db, TRes}]).

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

handle_backup_res([], []) ->
    ok;
handle_backup_res([], Err) ->
    {error, lists:reverse(Err)};
handle_backup_res([{_, ok}|Res], Err) ->
    handle_backup_res(Res, Err);
handle_backup_res([{Tag, {error, Reason}}|Res], Err) ->
    handle_backup_res(Res, [{Tag, Reason}|Err]);
handle_backup_res([{Tag, Error}|Res], Err) ->
    handle_backup_res(Res, [{Tag, Error}|Err]).


%%%======================================================================
%%% 2. Implementation of tree access
%%%    lookup and next.
%%%======================================================================


which_mib(#mib_data{tree = T} = D, Oid) ->
    ?vtrace("which_mib -> entry with"
	    "~n   Oid: ~p",[Oid]),	    
    case (catch find_node(D, T#tree.root, Oid, [])) of
	{variable, _ME, Mib} ->
	    ?vtrace("which_mib -> variable:"
		"~n   Mib: ~p", [Mib]),	    
	    {ok, Mib};
	{table, _EntryME, _, Mib} ->
	    ?vtrace("which_mib -> table:"
		"~n   Mib: ~p", [Mib]),	    
	    {ok, Mib};
	{subagent, SubAgentPid, _SANextOid} ->
	    ?vtrace("which_mib -> subagent:"
		"~n   SubAgentPid: ~p", [SubAgentPid]),	    
	    {error, {subagent, SubAgentPid}};
	{false, ErrorCode} -> 
	    ?vtrace("which_mib -> false:"
		"~n   ErrorCode: ~p",[ErrorCode]),	    
	    {error, ErrorCode};
	false -> 
	    ?vtrace("which_mib -> false",[]),	    
	    {error, noSuchObject};
	{'EXIT', R} -> 
	    ?vtrace("which_mib -> exit:"
		"~n   R:  ~p",[R]),	    
	    {error, noSuchObject}
    end.


%%-----------------------------------------------------------------
%% Func: lookup/2
%% Purpose: Finds the mib entry corresponding to the Oid. If it is a
%%          variable, the Oid must be <Oid for var>.0 and if it is
%%          a table, Oid must be <table>.<entry>.<col>.<any>
%% Returns: {variable, MibEntry} |
%%          {table_column, MibEntry, TableEntryOid} |
%%          {subagent, SubAgentPid, SAOid} |
%%          {false, Reason}
%%-----------------------------------------------------------------
lookup(#mib_data{tree = T} = D, Oid) ->
     ?vtrace("lookup -> entry with"
 	"~n   Oid: ~p",[Oid]),	    
    case (catch find_node(D, T#tree.root, Oid, [])) of
	{variable, ME, _Mib} when is_record(ME, me) -> 
	    ?vtrace("lookup -> variable:"
		"~n   ME: ~p",[ME]),	    
	    {variable, ME};
	{table, EntryME, {ColME, TableEntryOid}, _Mib} ->
	    ?vtrace("lookup -> table:"
		"~n   EntryME:          ~p"
		"~n   ColME:            ~p"
		"~n   RevTableEntryOid: ~p",
		[EntryME, ColME, TableEntryOid]),	    
	    MFA = EntryME#me.mfa,
	    RetME = ColME#me{mfa = MFA},
	    {table_column, RetME, TableEntryOid};
	{subagent, SubAgentPid, SANextOid} ->
	    ?vtrace("lookup -> subagent:"
		"~n   SubAgentPid: ~p"
		"~n   SANextOid:   ~p", [SubAgentPid, SANextOid]),	    
	    {subagent, SubAgentPid, SANextOid};
	{false, ErrorCode} -> 
	    ?vtrace("lookup -> false:"
		"~n   ErrorCode: ~p",[ErrorCode]),	    
	    {false, ErrorCode};
	false -> 
	    ?vtrace("lookup -> false",[]),	    
	    {false, noSuchObject};
	{'EXIT', R} -> 
	    ?vtrace("lookup -> exit:"
		"~n   R:  ~p",[R]),	    
	    {false, noSuchObject}
    end.


find_node(D, {tree, Tree, {table, _}}, RestOfOid, RevOid) ->
     ?vtrace("find_node(tree,table) -> entry with"
 	"~n   RestOfOid: ~p"
 	"~n   RevOid:    ~p",[RestOfOid, RevOid]),
    find_node(D, {tree, Tree, internal}, RestOfOid, RevOid);
find_node(D, {tree, Tree, {table_entry, _}}, RestOfOid, RevOid) ->
     ?vtrace("find_node(tree,table_entry) -> entry with"
 	"~n   RestOfOid: ~p"
 	"~n   RevOid:    ~p",[RestOfOid, RevOid]),
    #mib_data{module = Mod, node_db = Db} = D,
    Oid = lists:reverse(RevOid),
    case Mod:read(Db, Oid) of
	{value, #node_info{me = ME, mib_name = Mib}} ->
	    case find_node(D, {tree, Tree, internal}, RestOfOid, RevOid) of
		{false, ErrorCode} -> {false, ErrorCode};
		Val -> {table, ME, Val, Mib}
	    end;
	false ->
	    ?vinfo("find_node -> could not find table_entry ME with"
		"~n   RevOid:    ~p"
		"~n   when"
		"~n   RestOfOid: ~p", 
		[RevOid, RestOfOid]),
	    false
    end;
find_node(D, {tree, Tree, _Internal}, [Int | RestOfOid], RevOid) ->
    ?vtrace("find_node(tree) -> entry with"
	"~n   Int:       ~p"
	"~n   RestOfOid: ~p"
	"~n   RevOid:    ~p",[Int, RestOfOid, RevOid]),
    find_node(D, element(Int+1, Tree), RestOfOid, [Int | RevOid]);
find_node(D, {node, {table_column, _}}, RestOfOid, [ColInt | RevOid]) ->
     ?vtrace("find_node(tree,table_column) -> entry with"
 	"~n   RestOfOid: ~p"
 	"~n   ColInt:    ~p"
 	"~n   RevOid:    ~p",[RestOfOid, ColInt, RevOid]),
    #mib_data{module = Mod, node_db = Db} = D,
    Oid = lists:reverse([ColInt | RevOid]),
    case Mod:read(Db, Oid) of
	{value, #node_info{me = ME}} ->
	    {ME, lists:reverse(RevOid)}; 
	false ->
	    X = Mod:read(Db, lists:reverse([ColInt | RevOid])),
	    ?vinfo("find_node -> could not find table_column ME with"
		"~n   RevOid: ~p"
		"~n   trying  [~p|~p]"
		"~n   X:      ~p", 
		[RevOid, [ColInt | RevOid], X]),
	    false
    end;
find_node(D, {node, {variable, _MibName}}, [0], RevOid) ->
     ?vtrace("find_node(tree,variable,[0]) -> entry with"
 	"~n   RevOid:    ~p",[RevOid]),
    #mib_data{module = Mod, node_db = Db} = D,
    Oid = lists:reverse(RevOid),
    case Mod:read(Db, Oid) of
	{value, #node_info{me = ME, mib_name = Mib}} ->
	    {variable, ME, Mib};
	false ->
	    ?vinfo("find_node -> could not find variable ME with"
		"~n   RevOid: ~p", [RevOid]),
	    false
    end;
find_node(_D, {node, {variable, _MibName}}, [], _RevOid) ->
    ?vtrace("find_node(tree,variable,[]) -> entry",[]),
    {false, noSuchObject};
find_node(_D, {node, {variable, _MibName}}, _, _RevOid) ->
    ?vtrace("find_node(tree,variable) -> entry",[]),
    {false, noSuchInstance};
find_node(D, {node, subagent}, _RestOfOid, SARevOid) ->
    ?vtrace("find_node(tree,subagent) -> entry with"
 	"~n   SARevOid:    ~p",[SARevOid]),
    #mib_data{subagents = SAs} = D,
    SAOid = lists:reverse(SARevOid),
    case lists:keysearch(SAOid, 2, SAs) of
	{value, {SubAgentPid, SAOid}} ->
	    {subagent, SubAgentPid, SAOid};
	false ->
	    ?vinfo("find_node -> could not find subagent with"
		"~n   SAOid: ~p"
		"~n   SAs:   ~p", [SAOid, SAs]),
	    false
    end;    
find_node(_D, Node, _RestOfOid, _RevOid) ->
    ?vtrace("find_node -> failed:~n~p",[Node]),
    {false, noSuchObject}.


%%-----------------------------------------------------------------
%% Func: next/3
%% Purpose: Finds the lexicographically next oid.
%% Returns: endOfMibView |
%%          {subagent, SubAgentPid, SAOid} |
%%          {variable, MibEntry, VarOid} |
%%          {table, TableOid, TableRestOid, MibEntry}
%% If a variable is returnes, it is in the MibView.
%% If a table or subagent is returned, it *may* be in the MibView.
%%-----------------------------------------------------------------
next(#mib_data{tree = T} = D, Oid, MibView) ->
    case catch next_node(D, T#tree.root, Oid, [], MibView) of
	false -> endOfMibView;
	Else -> Else
    end.

%%-----------------------------------------------------------------
%% This function is used as long as we have any Oid left. Take
%% one integer at a time from the Oid, and traverse the tree
%% accordingly. When the Oid is empty, call find_next.
%% Returns: {subagent, SubAgentPid, SAOid} |
%%          false |
%%          {variable, MibEntry, VarOid} |
%%          {table, TableOid, TableRestOid, MibEntry}
%%-----------------------------------------------------------------
next_node(_D, undefined_node, _Oid, _RevOidSoFar, _MibView) ->
    ?vtrace("next_node(undefined_node) -> entry", []),
    false;

next_node(_D, {tree, Tree, {table_entry, _Id}}, [Int | _Oid], 
	  _RevOidSoFar, _MibView)
  when Int+1 > size(Tree) ->
    ?vtrace("next_node(tree,table_entry) -> entry when not found whith"
	"~n   Int:        ~p"
	"~n   size(Tree): ~p", [Int, size(Tree)]),
    false;
next_node(D, {tree, Tree, {table_entry, _MibName}},
	  Oid, RevOidSoFar, MibView) ->
    ?vtrace("next_node(tree,table_entry) -> entry when"
	"~n   size(Tree):  ~p"
	"~n   Oid:         ~p"
	"~n   RevOidSoFar: ~p"
	"~n   MibView:     ~p", [size(Tree), Oid, RevOidSoFar, MibView]),
    OidSoFar = lists:reverse(RevOidSoFar),
    case snmpa_acm:is_definitely_not_in_mib_view(OidSoFar, MibView) of
	true -> 
	    ?vdebug("next_node(tree,table_entry) -> not in mib view",[]),
	    false;
	_ -> 
	    #mib_data{module = Mod, node_db = Db} = D,
	    case Mod:read(Db, OidSoFar) of
		false ->
		    ?vinfo("next_node -> could not find table_entry with"
			"~n   OidSoFar: ~p", [OidSoFar]),
		    false;
		{value, #node_info{me = ME}} ->
		    ?vtrace("next_node(tree,table_entry) -> found: ~n   ~p",
			[ME]),
		    {table, OidSoFar, Oid, ME}
	    end
    end;

next_node(D, {tree, Tree, _Info}, [Int | RestOfOid], RevOidSoFar, MibView) 
  when (Int < size(Tree)) andalso (Int >= 0) ->
    ?vtrace("next_node(tree) -> entry when"
	"~n   size(Tree):  ~p"
	"~n   Int:         ~p"
	"~n   RestOfOid:   ~p"
	"~n   RevOidSoFar: ~p"
	"~n   MibView:     ~p", 
	[size(Tree), Int, RestOfOid, RevOidSoFar, MibView]),
    case next_node(D, element(Int+1,Tree), 
		   RestOfOid, [Int|RevOidSoFar], MibView) of
	false -> 
	    find_next(D, {tree, Tree, _Info}, Int+1, RevOidSoFar, MibView);
	Else -> 
	    Else
    end;
%% no solution
next_node(D, {tree, Tree, _Info}, [], RevOidSoFar, MibView) ->
    ?vtrace("next_node(tree,[]) -> entry when"
	"~n   size(Tree):  ~p"
	"~n   RevOidSoFar: ~p"
	"~n   MibView:     ~p", 
	[size(Tree), RevOidSoFar, MibView]),
    find_next(D, {tree, Tree, _Info}, 0, RevOidSoFar, MibView);
next_node(_D, {tree, Tree, _Info}, _RestOfOid, _RevOidSoFar, _MibView) ->
    ?vtrace("next_node(tree) -> entry when"
	"~n   size(Tree):  ~p", [size(Tree)]),
    false;

next_node(D, {node, subagent}, Oid, RevOidSoFar, MibView) ->
    ?vtrace("next_node(node,subagent) -> entry when"
	"~n   Oid:         ~p"
	"~n   RevOidSoFar: ~p"
	"~n   MibView:     ~p", 
	[Oid, RevOidSoFar, MibView]),
    OidSoFar = lists:reverse(RevOidSoFar),
    case snmpa_acm:is_definitely_not_in_mib_view(OidSoFar, MibView) of
	true -> 
	    false;
	_ -> 
	    #mib_data{subagents = SAs} = D,
	    case lists:keysearch(OidSoFar, 2, SAs) of
		{value, {SubAgentPid, OidSoFar}} ->
		    {subagent, SubAgentPid, OidSoFar};
		_ ->
		    ?vinfo("next_node -> could not find subagent with"
			"~n   OidSoFar: ~p"
			"~n   SAs:      ~p", [OidSoFar, SAs]),
		    false
	    end
    end;
    
next_node(D, {node, {variable, _MibName}}, [], RevOidSoFar, MibView) ->
    ?vtrace("next_node(node,variable,[]) -> entry when"
	"~n   RevOidSoFar: ~p"
	"~n   MibView:     ~p", 
	[RevOidSoFar, MibView]),
    OidSoFar = lists:reverse([0 | RevOidSoFar]),
    case snmpa_acm:validate_mib_view(OidSoFar, MibView) of
	true ->
	    #mib_data{module = Mod, node_db = Db} = D,
	    case Mod:read(Db, lists:reverse(RevOidSoFar)) of
		false ->
		    ?vinfo("next_node -> could not find variable with"
			"~n   RevOidSoFar: ~p", [RevOidSoFar]),
		    false;
		{value, #node_info{me = ME}} ->
		    {variable, ME, OidSoFar}
	    end;
	_ -> 
	    false
    end;

next_node(_D, {node, {variable, _MibName}}, _Oid, _RevOidSoFar, _MibView) ->
    ?vtrace("next_node(node,variable) -> entry", []),
    false.


%%-----------------------------------------------------------------
%% This function is used to find the first leaf from where we
%% are.
%% Returns: {subagent, SubAgentPid, SAOid} |
%%          false |
%%          {variable, MibEntry, VarOid} |
%%          {table, TableOid, TableRestOid, MibEntry}
%% PRE: This function must always be called with a {internal, Tree}
%%      node.
%%-----------------------------------------------------------------
find_next(D, {tree, Tree, internal}, Idx, RevOidSoFar, MibView) 
  when Idx < size(Tree) ->
    case find_next(D, element(Idx+1, Tree), 0, [Idx| RevOidSoFar], MibView) of
	false -> 
	    find_next(D, {tree, Tree, internal}, Idx+1, RevOidSoFar, MibView);
	Other -> 
	    Other
    end;
find_next(_D, {tree, _Tree, internal}, _Idx, _RevOidSoFar, _MibView) ->
    false;
find_next(_D, undefined_node, _Idx, _RevOidSoFar, _MibView) ->
    false;
find_next(D, {tree, Tree, {table, _MibName}}, Idx, RevOidSoFar, MibView) ->
    find_next(D, {tree, Tree, internal}, Idx, RevOidSoFar, MibView);
find_next(D, {tree, _Tree, {table_entry, _MibName}}, _Index,
	  RevOidSoFar, MibView) ->
    OidSoFar = lists:reverse(RevOidSoFar),
    case snmpa_acm:is_definitely_not_in_mib_view(OidSoFar, MibView) of
	true -> 
	    false;
	_ -> 
	    #mib_data{module = Mod, node_db = Db} = D,
	    case Mod:read(Db, OidSoFar) of
		false ->
		    ?vinfo("find_next -> could not find table_entry ME with"
			"~n   OidSoFar: ~p", [OidSoFar]),
		    false;
		{value, #node_info{me = ME}} ->
		    {table, OidSoFar, [], ME}
	    end
    end;
find_next(D, {node, {variable, _MibName}}, _Idx, RevOidSoFar, MibView) ->
    OidSoFar = lists:reverse([0 | RevOidSoFar]),
    case snmpa_acm:validate_mib_view(OidSoFar, MibView) of
	true -> 
	    #mib_data{module = Mod, node_db = Db} = D,
	    case Mod:read(Db, lists:reverse(RevOidSoFar)) of
		false ->
		    ?vinfo("find_next -> could not find variable with"
			"~n   RevOidSoFar: ~p", [RevOidSoFar]),
		    false;
		{value, #node_info{me = ME}} ->
		    {variable, ME, OidSoFar}
	    end;
	_ -> 
	    false
    end;
find_next(D, {node, subagent}, _Idx, RevOidSoFar, MibView) ->
    OidSoFar = lists:reverse(RevOidSoFar),
    case snmpa_acm:is_definitely_not_in_mib_view(OidSoFar, MibView) of
	true -> 
	    false;
	_ -> 
	    #mib_data{subagents = SAs} = D,
	    case lists:keysearch(OidSoFar, 2, SAs) of
		{value, {SubAgentPid, OidSoFar}} ->
		    {subagent, SubAgentPid, OidSoFar};
		false ->
		    ?vinfo("find_node -> could not find subagent with"
			"~n   OidSoFar: ~p"
			"~n   SAs:      ~p", [OidSoFar, SAs]),
		    false
	    end
    end.

%%%======================================================================
%%% 3. Tree building functions
%%%    Used when loading mibs.
%%%======================================================================

build_tree(Mes, MibName) ->
    ?d("build_tree -> "
	"~n   Mes: ~p", [Mes]),
    {ListTree, []}  = build_subtree([], Mes, MibName),
    {tree, convert_tree(ListTree), internal}.

%%----------------------------------------------------------------------
%% Purpose: Builds the tree where all oids have prefix equal to LevelPrefix.
%% Returns: {Tree, RestMes}
%% RestMes are Mes that should not be in this subtree.
%% The Tree is a temporary and simplified data structure that is easy to
%% convert to the final tuple tree used by the MIB process.
%% A Node is represented as in the final tree.
%% The tree is not represented as a N-tuple, but as an Index-list.
%% Example: Temporary: [{1, Node1}, {3, Node3}]
%%          Final:     {Node1, undefined_node, Node3}
%% Pre: Mes are sorted on oid.
%%----------------------------------------------------------------------
build_subtree(LevelPrefix, [Me | Mes], MibName) ->
    ?vtrace("build subtree -> ~n"
	   "   oid:         ~p~n"
	   "   LevelPrefix: ~p~n"
	   "   MibName:     ~p", [Me#me.oid, LevelPrefix, MibName]),
    EType = Me#me.entrytype,
    ?vtrace("build subtree -> EType = ~p",[EType]),
    case in_subtree(LevelPrefix, Me) of
	above ->
	    ?vtrace("build subtree -> above",[]),
	    {[], [Me|Mes]};
	{node, Index} ->
	    ?vtrace("build subtree -> node at ~p",[Index]),
	    {Tree, RestMes} = build_subtree(LevelPrefix, Mes, MibName),
	    {[{Index, {node, {EType, MibName}}} | Tree], RestMes};
	{subtree, Index, NewLevelPrefix} ->
	    ?vtrace("build subtree -> subtree at"
		    "~n   ~w with ~w",
		   [Index, NewLevelPrefix]),
	    {BelowTree, RestMes} = 
		build_subtree(NewLevelPrefix, Mes, MibName),
	    {CurTree, RestMes2} = 
		build_subtree(LevelPrefix, RestMes, MibName),
	    {[{Index, {tree, BelowTree, {EType,MibName}}}| CurTree], RestMes2};
	{internal_subtree, Index, NewLevelPrefix} ->
	    ?vtrace("build subtree -> internal_subtree at"
		    "~n   ~w with ~w",
		   [Index,NewLevelPrefix]),
	    {BelowTree, RestMes} =
		build_subtree(NewLevelPrefix, [Me | Mes], MibName),
	    {CurTree, RestMes2} =
		build_subtree(LevelPrefix, RestMes, MibName),
	    {[{Index, {tree, BelowTree, internal}} | CurTree], RestMes2}
    end;

build_subtree(_LevelPrefix, [], _MibName) -> 
    ?vtrace("build subtree -> done", []),
    {[], []}.

%%--------------------------------------------------
%% Purpose: Determine how/if/where Me should be inserted in subtree
%%          with LevelPrefix. This function does not build any tree, only 
%%          determinses what should be done (by build subtree).
%% Returns:
%% above - Indicating that this ME should _not_ be in this subtree.
%% {node, Index} - yes, construct a node with index Index on this level
%% {internal_subtree, Index, NewLevelPrefix} - yes, there should be an
%%   internal subtree at this index.
%% {subtree, Index, NewLevelPrefix} - yes, construct a subtree with 
%%   NewLevelPrefix and insert this on current level in position Index.
%%--------------------------------------------------
in_subtree(LevelPrefix, Me) ->
    case lists:prefix(LevelPrefix, Me#me.oid) of
	true when length(Me#me.oid) > length(LevelPrefix) ->
	    classify_how_in_subtree(LevelPrefix, Me);
	_ ->
	    above
    end.

%%--------------------------------------------------
%% See comment about in_subtree/2.  This function takes care of all cases
%% where the ME really should be in _this_ subtree (not above).
%%--------------------------------------------------
classify_how_in_subtree(LevelPrefix, Me) 
  when (length(Me#me.oid) =:= (length(LevelPrefix) + 1)) ->
    Oid = Me#me.oid,
    case node_or_subtree(Me#me.entrytype) of
	subtree ->
	    {subtree, lists:last(Oid), Oid};
	node ->
	    {node, lists:last(Oid)}
    end;

classify_how_in_subtree(LevelPrefix, Me) 
  when (length(Me#me.oid) > (length(LevelPrefix) + 1)) ->
    L1 = length(LevelPrefix) + 1,
    Oid = Me#me.oid,
    {internal_subtree, lists:nth(L1, Oid), lists:sublist(Oid, 1, L1)}.

%%--------------------------------------------------
%% Determines how to treat different kinds om MEs in the tree building process.
%% Pre: all internal nodes have been removed.
%%--------------------------------------------------
node_or_subtree(table) -> subtree;
node_or_subtree(table_entry) -> subtree;
node_or_subtree(variable) -> node;
node_or_subtree(table_column) -> node.

%%--------------------------------------------------
%% Purpose: (Recursively) Converts a temporary tree (see above) to a final tree.
%% If input is a ListTree, output is a TupleTree.
%% If input is a Node, output is the same Node.
%% Pre: All Indexes are >= 0.
%%--------------------------------------------------
convert_tree({Index, {tree, Tree, Info}}) when Index >= 0 ->
    L = lists:map(fun convert_tree/1, Tree),
    {Index, {tree, dict_list_to_tuple(L), Info}};
convert_tree({Index, {node, Info}}) when Index >= 0 ->
    {Index, {node, Info}};
convert_tree(Tree) when is_list(Tree) ->
    L = lists:map(fun convert_tree/1, Tree),
    dict_list_to_tuple(L).

%%----------------------------------------------------------------------
%% Purpose: Converts a single level (that is non-recursively) from
%%          the temporary indexlist to the N-tuple.
%% Input: A list of {Index, Data}.
%% Output: A tuple where element Index is Data.
%%----------------------------------------------------------------------
dict_list_to_tuple(L) ->
    L2 = lists:keysort(1, L),
    list_to_tuple(integrate_indexes(0, L2)).

%%----------------------------------------------------------------------
%% Purpose: Helper function for dict_list_to_tuple/1.
%%          Converts an indexlist to a N-list.
%% Input: A list of {Index, Data}.
%% Output: A (usually longer, never shorter) list where element Index is Data.
%% Example: [{1,hej}, {3, sven}] will give output 
%% [undefined_node, hej, undefined_node, sven].
%% Initially CurIndex should be 0.
%%----------------------------------------------------------------------
integrate_indexes(CurIndex, [{CurIndex, Data} | T]) ->
    [Data | integrate_indexes(CurIndex + 1, T)];
integrate_indexes(_Index, []) ->
    [];
integrate_indexes(CurIndex, L) ->
    [undefined_node | integrate_indexes(CurIndex + 1, L)].

%%%======================================================================
%%% 4. Tree merging
%%%    Used by: load mib, insert subagent.
%%%======================================================================

%%----------------------------------------------------------------------
%% Arg: Two root nodes (that is to be merged).
%% Returns: A new root node where the nodes have been merger to one.
%%----------------------------------------------------------------------
merge_nodes(Same, Same) -> 
    Same;
merge_nodes(Node, undefined_node) -> 
    Node;
merge_nodes(undefined_node, Node) -> 
    Node;
merge_nodes({tree, Tree1, internal}, {tree, Tree2, internal}) ->
    {tree, merge_levels(tuple_to_list(Tree1),tuple_to_list(Tree2)), internal};
merge_nodes(Node1, Node2) ->
    throw({error_merge_nodes, Node1, Node2}).

%%----------------------------------------------------------------------
%% Arg: Two levels to be merged.
%%      Here, a level is represented as a list of nodes. A list is easier
%%      to extend than a tuple.
%% Returns: The resulting, merged level tuple.
%%----------------------------------------------------------------------
merge_levels(Level1, Level2) when length(Level1) =:= length(Level2) ->
    MergeNodes = fun(N1, N2) -> merge_nodes(N1, N2) end,
    list_to_tuple(snmp_misc:multi_map(MergeNodes, [Level1, Level2]));
merge_levels(Level1, Level2) when length(Level1) > length(Level2) ->
    merge_levels(Level1, Level2 ++ 
		 undefined_nodes_list(length(Level1) - length(Level2)));
merge_levels(Level1, Level2) when length(Level1) < length(Level2) ->
    merge_levels(Level2, Level1).

undefined_nodes_list(N) -> lists:duplicate(N, undefined_node).


%%%======================================================================
%%% 5. Tree deletion routines
%%%    (for unload mib)
%%%======================================================================

%%----------------------------------------------------------------------
%% Purpose:  Actually kicks of the tree reconstruction.
%% Returns: {list of removed MEs, NewTree}
%%----------------------------------------------------------------------
delete_mib_from_tree(MibName, {tree, Tree, internal}) ->
    case delete_tree(Tree, MibName) of
	[] -> 
	    {tree, {undefined_node}, internal}; % reduce
	LevelList -> 
	    {tree, list_to_tuple(LevelList), internal}
    end.

%%----------------------------------------------------------------------
%% Purpose: Deletes all nodes associated to MibName from this level and
%%          all levels below.
%%          If the new level does not contain information (that is, no 
%%          other mibs use it) anymore the empty list is returned.
%% Returns: {MEs, The new level represented as a list}
%%----------------------------------------------------------------------
delete_tree(Tree, MibName) when is_tuple(Tree) ->
    NewLevel = delete_nodes(tuple_to_list(Tree), MibName, []),
    case lists:filter(fun drop_undefined_nodes/1,NewLevel) of
	[] -> [];
	_A_perhaps_shorted_list ->
	    NewLevel  % some other mib needs this level
    end.
    
%%----------------------------------------------------------------------
%% Purpose: Nodes belonging to MibName are removed from the tree.
%%          Recursively deletes sub trees to this node.
%% Returns: {MEs, NewNodesList}
%%----------------------------------------------------------------------
delete_nodes([], _MibName, AccNodes) ->
    lists:reverse(AccNodes);

delete_nodes([{node, {variable, MibName}}|T], MibName, AccNodes) ->
    delete_nodes(T, MibName, [undefined_node | AccNodes]);

delete_nodes([{node, {table_column, MibName}}|T], MibName, AccNodes) ->
    delete_nodes(T, MibName, [undefined_node | AccNodes]);

delete_nodes([{tree, _Tree, {table, MibName}}|T], MibName, AccNodes) ->
    delete_nodes(T, MibName, [undefined_node | AccNodes]);

delete_nodes([{tree, _Tree, {table_entry, MibName}}|T], MibName, AccNodes) ->
    delete_nodes(T, MibName, [undefined_node | AccNodes]);

delete_nodes([{tree, Tree, Info}|T], MibName, AccNodes) ->
    case delete_tree(Tree, MibName) of
	[] -> % tree completely deleted
	    delete_nodes(T, MibName, [undefined_node | AccNodes]);
	LevelList ->
	    delete_nodes(T, MibName, 
			 [{tree, list_to_tuple(LevelList), Info} | AccNodes])
    end;

delete_nodes([NodeToKeep|T], MibName, AccNodes) ->
    delete_nodes(T, MibName, [NodeToKeep | AccNodes]).

drop_undefined_nodes(undefined_node) -> false;
drop_undefined_nodes(_) -> true.


%%%======================================================================
%%% 6. Functions for subagent handling
%%%======================================================================

%%----------------------------------------------------------------------
%% Returns: A new Root|{error, reason}
%%----------------------------------------------------------------------
insert_subagent(Oid, OldRoot) ->
    ListTree = build_tree_for_subagent(Oid),
    case catch convert_tree(ListTree) of
	{'EXIT', _Reason} ->
	    {error, 'cannot construct tree from oid'};
	Level when is_tuple(Level) ->
	    T = {tree, Level, internal},
	    case catch merge_nodes(T, OldRoot) of
		{error_merge_nodes, _Node1, _Node2} ->
		    {error, oid_conflict};
		NewRoot when is_tuple(NewRoot) andalso 
			     (element(1, NewRoot) =:= tree) ->
		    NewRoot
	    end
    end.

build_tree_for_subagent([Index]) ->
    [{Index, {node, subagent}}];

build_tree_for_subagent([Index | T]) ->
    [{Index, {tree, build_tree_for_subagent(T), internal}}].


%%----------------------------------------------------------------------
%% Returns: A new tree where the subagent at Oid (2nd arg) has been deleted.
%%----------------------------------------------------------------------

delete_subagent({tree, Tree, Info}, [Index]) ->
    {node, subagent} = element(Index+1, Tree),
    {tree, setelement(Index+1, Tree, undefined_node), Info};
delete_subagent({tree, Tree, Info}, [Index | TI]) ->
    {tree, setelement(Index+1, Tree,
		      delete_subagent(element(Index+1, Tree), TI)), Info}.


%%%======================================================================
%%% 7. Misc functions
%%%======================================================================

%%----------------------------------------------------------------------
%% Installs the mibs found in the database when starting the agent.
%% Basically calls the instrumentation functions for all non-internal
%% mib-entries
%%----------------------------------------------------------------------
install_mibs(Mod, MibDb, NodeDb) ->
    MibNames = loaded(Mod, MibDb),
    ?vtrace("install_mibs -> found following mibs in database: ~n"
	"~p", [MibNames]),
    install_mibs2(Mod, NodeDb, MibNames).

install_mibs2(_, _, []) ->
    ok;
install_mibs2(Mod, NodeDb, [MibName|MibNames]) ->
    Pattern = #node_info{oid = '_', mib_name = MibName, me = '_'},
    Nodes = Mod:match_object(NodeDb, Pattern),
    MEs = [ME || #node_info{me = ME} <- Nodes],
    ?vtrace("install_mibs2 -> installing ~p MEs for mib ~p", 
	    [length(MEs), MibName]),
    NewF = fun(ME) -> call_instrumentation(ME, new) end,
    lists:foreach(NewF, MEs),
    install_mibs2(Mod, NodeDb, MibNames).
    
    
%%----------------------------------------------------------------------
%% Does all side effect stuff during load_mib.
%%----------------------------------------------------------------------
install_mib(Mod, Db, Symbolic, Mib, MibName, FileName, NonInternalMes) ->
    ?vdebug("install_mib -> entry with"
	    "~n   Symbolic: ~p"
	    "~n   MibName:  ~p"
	    "~n   FileName: ~p", [Symbolic, MibName, FileName]),
    Rec = #mib_info{name = MibName, symbolic = Symbolic, file_name = FileName},
    Mod:write(Db, Rec),
    install_mib2(Symbolic, MibName, Mib),
    NewF = fun(ME) -> call_instrumentation(ME, new) end,
    lists:foreach(NewF, NonInternalMes).

install_mib2(true, MibName, Mib) ->
    #mib{table_infos    = TabInfos,
	 variable_infos = VarInfos,
	 mes            = MEs,
	 asn1_types     = ASN1Types,
	 traps          = Traps} = Mib,
    snmpa_symbolic_store:add_table_infos(MibName, TabInfos),
    snmpa_symbolic_store:add_variable_infos(MibName, VarInfos),
    snmpa_symbolic_store:add_aliasnames(MibName, MEs),
    snmpa_symbolic_store:add_types(MibName, ASN1Types),
    SetF = fun(Trap) -> 
		   snmpa_symbolic_store:set_notification(Trap, MibName)
	   end,
    lists:foreach(SetF, Traps);
install_mib2(_, _, _) ->
    ok.

install_mes(Mod, Db, MibName, MEs) ->
    Write = fun(#me{oid = Oid} = ME) ->
		    Node = #node_info{oid      = Oid, 
				      mib_name = MibName, 
				      me       = ME},
		    Mod:write(Db, Node)
	    end,
    install_mes(Write, MEs).

install_mes(_Write, []) ->
    ok;
install_mes(Write, [ME|MEs]) ->
    Write(ME),
    install_mes(Write, MEs).


%%----------------------------------------------------------------------
%% Does all side effect stuff during unload_mib.
%%----------------------------------------------------------------------
uninstall_mib(Mod, Db, Symbolic, MibName, MEs) ->
    ?vtrace("uninstall_mib -> entry with"
	"~n   Db:       ~p"
	"~n   Symbolic: ~p"
	"~n   MibName:  ~p", [Db, Symbolic, MibName]),
    Res = Mod:delete(Db, MibName),
    ?vtrace("uninstall_mib -> (mib) db delete result: ~p", [Res]),
    uninstall_mib2(Symbolic, MibName),
    DelF = fun(ME) -> call_instrumentation(ME, delete) end,
    lists:foreach(DelF, MEs).

uninstall_mib2(true, MibName) ->
    snmpa_symbolic_store:delete_table_infos(MibName),
    snmpa_symbolic_store:delete_variable_infos(MibName),
    snmpa_symbolic_store:delete_aliasnames(MibName),
    snmpa_symbolic_store:delete_types(MibName),
    snmpa_symbolic_store:delete_notifications(MibName);
uninstall_mib2(_, _) ->
    ok.

uninstall_mes(Mod, Db, MibName) ->
    Pattern = #node_info{oid = '_', mib_name = MibName, me = '_'},
    Mod:match_delete(Db, Pattern).


%%----------------------------------------------------------------------
%% Create a list of the names of all the loaded mibs
%%----------------------------------------------------------------------
loaded(Mod, Db) ->
    [N || #mib_info{name = N} <- Mod:tab2list(Db)].
    

%%----------------------------------------------------------------------
%% Calls MFA-instrumentation with 'new' or 'delete' operation.
%%----------------------------------------------------------------------
call_instrumentation(#me{entrytype = variable, mfa={M,F,A}}, Operation) ->
    ?vtrace("call instrumentation with"
	    "~n   entrytype: variable"
	    "~n   MFA:       {~p,~p,~p}"
	    "~n   Operation: ~p",
	    [M,F,A,Operation]),
    catch apply(M, F, [Operation | A]);
call_instrumentation(#me{entrytype = table_entry, mfa={M,F,A}}, Operation) ->
    ?vtrace("call instrumentation with"
	    "~n   entrytype: table_entry"
	    "~n   MFA:       {~p,~p,~p}"
	    "~n   Operation: ~p",
	    [M,F,A,Operation]),
    catch apply(M, F, [Operation | A]);
call_instrumentation(_ShitME, _Operation) ->
    done.


maybe_drop_me(#me{entrytype = internal}) -> false;
maybe_drop_me(#me{entrytype = group}) -> false;
maybe_drop_me(#me{imported = true}) -> false;
maybe_drop_me(_) -> true.


%%----------------------------------------------------------------------
%% Code change functions
%%----------------------------------------------------------------------

code_change(down, _Vsn, _Extra, State) ->
    ?d("code_change(down) -> entry when"
       "~n   Vsn:   ~p"
       "~n   Extra: ~p", [_Vsn, _Extra]),
    State;

code_change(up, _Vsn, _Extra, State) ->
    ?d("code_change(up) -> entry when"
       "~n   Vsn:   ~p"
       "~n   Extra: ~p", [_Vsn, _Extra]),
    State.