aboutsummaryrefslogblamecommitdiffstats
path: root/lib/kernel/src/inet_config.erl
blob: 1ddbdcec25d5fc298ce84e76f7e2104a4f5c3743 (plain) (tree)
1
2
3
4
5
6
7
8
9
10
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
                   
  
                                                        
  



                                                                      
  


                                                                         
  







                                                 
                                                                           

















                                                         





                                                                          
                       



























































                                                                                   





                                                     
                                                   

                                                           


                                                  

                                                          









































































                                                                           

































































































































































































































































































































































































                                                                                          
%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1997-2011. 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(inet_config).

-include("inet_config.hrl").
-include("inet.hrl").

-import(lists, [foreach/2, member/2, reverse/1]).

%% Avoid warning for local function error/2 clashing with autoimported BIF.
-compile({no_auto_import,[error/2]}).
-export([init/0]).

-export([do_load_resolv/2]).

%%
%% Must be called after inet_db:start
%%
%% Order in which to load inet_db data:
%% 1. Hostname  (possibly derive domain and search)
%% 2. OS default  /etc/resolv.conf,  Windows registry etc
%%    a) Hosts database
%%    b) Resolver options 
%% 3. Config (kernel app)
%% 4. Root   (otp root)
%% 5. Home   (user inetrc)
%%
%%
-spec init() -> 'ok'.
init() ->
    set_hostname(),

    %% Note: In shortnames (or non-distributed) mode we don't need to know
    %% our own domain name. In longnames mode we do and we can't rely on 
    %% the user to provide it (by means of inetrc), so we need to look 
    %% for it ourselves.

    OsType = os:type(),
    do_load_resolv(OsType, erl_dist_mode()),

    case OsType of
	{unix,Type} ->
	    if Type =:= linux ->
		    %% It may be the case that the domain name was not set
		    %% because the hostname was short. But NOW we can look it
		    %% up and get the long name and the domain name from it.
		    
		    %% FIXME: The second call to set_hostname will insert
		    %% a duplicate entry in the search list.
		    
		    case inet_db:res_option(domain) of
			"" ->
			    case inet:gethostbyname(inet_db:gethostname()) of
				{ok,#hostent{h_name = []}} ->
				    ok;
				{ok,#hostent{h_name = HostName}} ->
				    set_hostname({ok,HostName});
				_ ->
				    ok
			    end;
			_ ->
			    ok
		    end;
	       true -> ok
	    end,    
	    add_dns_lookup(inet_db:res_option(lookup));
	_ ->
	    ok
    end,

    %% Read inetrc file, if it exists.
    {RcFile,CfgFiles,CfgList} = read_rc(),

    %% Possibly read config files or system registry
    lists:foreach(fun({file,hosts,File}) ->
			  load_hosts(File, unix);
		     ({file,Func,File}) ->
			  load_resolv(File, Func);
		     ({registry,win32}) ->
			  case OsType of
			      {win32,WinType} ->
				  win32_load_from_registry(WinType);
			      _ ->
				  error("can not read win32 system registry~n", [])
			  end
		  end, CfgFiles),

    %% Add inetrc config entries
    case inet_db:add_rc_list(CfgList) of
	ok -> ok;
	_  -> error("syntax error in ~s~n", [RcFile])
    end,

    %% Set up a resolver configuration file for inet_res,
    %% unless that already has been done
    case OsType of
	{unix,_} ->
	    %% The Etc variable enables us to run tests with other 
	    %% configuration files than the normal ones 
	    Etc =
		case os:getenv("ERL_INET_ETC_DIR") of
		    false ->
			?DEFAULT_ETC;
		    _EtcDir ->
			_EtcDir
		end,
	    case inet_db:res_option(resolv_conf) of
		undefined ->
		    inet_db:res_option(
		      resolv_conf_name,
		      filename:join(Etc, ?DEFAULT_RESOLV));
		_ -> ok
	    end,
	    case inet_db:res_option(hosts_file) of
		undefined ->
		    inet_db:res_option(
		      hosts_file_name,
		      filename:join(Etc, ?DEFAULT_HOSTS));
		_ -> ok
	    end;
	_ -> ok
    end.



erl_dist_mode() ->
    case init:get_argument(sname) of
	{ok,[[_SName]]} -> shortnames;
	_ ->
	    case init:get_argument(name) of
		{ok,[[_Name]]} -> longnames;
		_ -> nonames
	    end
    end.

do_load_resolv({unix,Type}, longnames) ->
    %% The Etc variable enables us to run tests with other 
    %% configuration files than the normal ones 
    Etc = case os:getenv("ERL_INET_ETC_DIR") of
	      false -> ?DEFAULT_ETC;
	      _EtcDir -> 
		  _EtcDir				 
	  end,
    load_resolv(filename:join(Etc, ?DEFAULT_RESOLV), resolv),
    case Type of
	freebsd ->	    %% we may have to check version (2.2.2)
	    load_resolv(filename:join(Etc,"host.conf"), host_conf_freebsd);
	'bsd/os' ->
	    load_resolv(filename:join(Etc,"irs.conf"), host_conf_bsdos);
	sunos ->
	    case os:version() of
		{Major,_,_} when Major >= 5 ->
		    load_resolv(filename:join(Etc,"nsswitch.conf"), 
				nsswitch_conf);
		_ -> 
		    ok
	    end;
	netbsd ->
	    case os:version() of
		{Major,Minor,_} when Major >= 1, Minor >= 4 ->
		    load_resolv(filename:join(Etc,"nsswitch.conf"), 
				nsswitch_conf);
		_ ->
		    ok
	    end;		
	linux ->
	    case load_resolv(filename:join(Etc,"host.conf"),
			     host_conf_linux) of
		ok ->
		    ok;
		_ ->
		    load_resolv(filename:join(Etc,"nsswitch.conf"), 
				nsswitch_conf)
	    end;
	_ ->
	    ok
    end,
    inet_db:set_lookup([native]);

do_load_resolv({win32,Type}, longnames) ->	
    win32_load_from_registry(Type),
    inet_db:set_lookup([native]);

do_load_resolv(vxworks, _) ->	
    vxworks_load_hosts(),
    inet_db:set_lookup([file, dns]),
    case os:getenv("ERLRESCONF") of
	false ->
	    no_ERLRESCONF;
	Resolv ->
	    load_resolv(Resolv, resolv)
    end;

do_load_resolv(_, _) ->
    inet_db:set_lookup([native]).

add_dns_lookup(L) ->
    case lists:member(dns,L) of
	true -> ok;
	_ ->
	    case application:get_env(kernel,inet_dns_when_nis) of
		{ok,true} -> 
		    add_dns_lookup(L,[]);
		_ ->
		    ok
	    end
    end.

add_dns_lookup([yp|T],Acc) ->
    add_dns_lookup(T,[yp,dns|Acc]);
add_dns_lookup([H|T],Acc) ->
    add_dns_lookup(T,[H|Acc]);
add_dns_lookup([],Acc) ->
    inet_db:set_lookup(reverse(Acc)).

%%
%% Set the hostname (SHORT)
%% If hostname is long use the suffix as default domain
%% and initalize the search option with the parts of domain
%%
set_hostname() ->
    case inet_udp:open(0,[]) of
	{ok,U} ->
	    Res = inet:gethostname(U),
	    inet_udp:close(U),
	    set_hostname(Res);
	_ ->
	    set_hostname({ok, []})
    end.

set_hostname({ok,Name}) when length(Name) > 0 ->
    {Host, Domain} = lists:splitwith(fun($.) -> false;
					(_)  -> true
				     end, Name),
    inet_db:set_hostname(Host),
    set_search_dom(Domain);
set_hostname({ok,[]}) ->
    inet_db:set_hostname("nohost"),
    set_search_dom("nodomain").

set_search_dom([$.|Domain]) ->
    %% leading . not removed by dropwhile above.
    inet_db:set_domain(Domain),
    inet_db:ins_search(Domain),
    ok;
set_search_dom([]) ->
    ok;
set_search_dom(Domain) ->
    inet_db:set_domain(Domain),
    inet_db:ins_search(Domain),
    ok.

%%
%% Load resolver data
%%
load_resolv(File, Func) ->
    case get_file(File) of
	{ok,Bin} ->
            case inet_parse:Func(File, {chars, Bin}) of
		{ok, Ls} ->
		    inet_db:add_rc_list(Ls);
		{error, Reason} ->
		    error("parse error in file ~s: ~p", [File, Reason])
	    end;
	Error ->
	    warning("file not found ~s: ~p~n", [File, Error])
    end.

%%
%% Load a UNIX hosts file
%%
load_hosts(File,Os) ->
    case get_file(File) of
	{ok,Bin} ->
	    case inet_parse:hosts(File,{chars,Bin}) of
		{ok, Ls} ->
		    foreach(
		      fun({IP, Name, Aliases}) -> 
			      inet_db:add_host(IP, [Name|Aliases]) end,
		      Ls);
		{error, Reason} ->
		    error("parse error in file ~s: ~p", [File, Reason])
	    end;
	Error ->
	    case Os of
		unix ->
		    error("file not found ~s: ~p~n", [File, Error]);
		_ -> 
		    %% for windows or nt the hosts file is not always there
		    %% and we don't require it
		    ok
	    end
    end.

%%
%% Load resolver data from Windows registry
%%
win32_load_from_registry(Type) ->
    %% The TcpReg variable enables us to run tests with other registry configurations than
    %% the normal ones 
    TcpReg = case os:getenv("ERL_INET_ETC_DIR") of
		 false -> [];
		 _TReg -> _TReg
	     end,
    {ok, Reg} = win32reg:open([read]),
    {TcpIp,HFileKey} =
    case Type of
	nt ->
	    case TcpReg of
		[] -> 
		    {"\\hklm\\system\\CurrentControlSet\\Services\\TcpIp\\Parameters",
		     "DataBasePath" };
		Other ->
		    {Other,"DataBasePath"}
	    end;
	windows ->
	    case TcpReg of 
		[] ->
		    {"\\hklm\\system\\CurrentControlSet\\Services\\VxD\\MSTCP",
		     "LMHostFile" };
		Other ->
		    {Other,"LMHostFile"}
	    end
    end,
    Result = 
	case win32reg:change_key(Reg,TcpIp) of
	    ok ->
		win32_load1(Reg,Type,HFileKey);
	    {error, _Reason} ->
		error("Failed to locate TCP/IP parameters (is TCP/IP installed)?",
		      [])
	end,
    win32reg:close(Reg),
    Result.

win32_load1(Reg,Type,HFileKey) ->
    Names = [HFileKey, "Domain", "DhcpDomain", 
	     "EnableDNS", "NameServer", "SearchList"],
    case win32_get_strings(Reg, Names) of
	[DBPath0, Domain, DhcpDomain, 
	 _EnableDNS, NameServers0, Search] ->
	    inet_db:set_domain(
	      case Domain of "" -> DhcpDomain; _ -> Domain end),
	    NameServers = win32_split_line(NameServers0,Type),
	    AddNs = fun(Addr) ->
			    case inet_parse:address(Addr) of
				{ok, Address} ->
				    inet_db:add_ns(Address);
				{error, _} ->
				    error("Bad TCP/IP address in registry", [])
			    end
		    end,
	    foreach(AddNs, NameServers),
	    Searches0 = win32_split_line(Search,Type),
	    Searches = case member(Domain, Searches0) of
			   true  -> Searches0;
			   false -> [Domain|Searches0]
		       end,
	    foreach(fun(D) -> inet_db:add_search(D) end, Searches),
	    if Type =:= nt ->
		    DBPath = win32reg:expand(DBPath0),
		    load_hosts(filename:join(DBPath, "hosts"),nt);
		Type =:= windows ->
		    load_hosts(filename:join(DBPath0,""),windows)
	    end,
%% Maybe activate this later as an optimization
%% For now we use native always as the SAFE way
%%	    case NameServers of
%%		[] -> inet_db:set_lookup([native, file]);
%%		_  -> inet_db:set_lookup([dns, file, native])
%%	    end;
	    true;
	{error, _Reason} ->
	    error("Failed to read TCP/IP parameters from registry", [])
    end.

win32_split_line(Line,nt) -> inet_parse:split_line(Line);
win32_split_line(Line,windows) -> string:tokens(Line, ",").

win32_get_strings(Reg, Names) ->
    win32_get_strings(Reg, Names, []).

win32_get_strings(Reg, [Name|Rest], Result) ->
    case win32reg:value(Reg, Name) of
	{ok, Value} when is_list(Value) ->
	    win32_get_strings(Reg, Rest, [Value|Result]);
	{ok, _NotString} ->
	    {error, not_string};
	{error, _Reason} ->
	    win32_get_strings(Reg, Rest, [""|Result])
    end;
win32_get_strings(_, [], Result) ->
    lists:reverse(Result).

%%
%% Load host data from VxWorks hostShow command
%%

vxworks_load_hosts() ->
    HostShow = os:cmd("hostShow"),
    case check_hostShow(HostShow) of
	Hosts when is_list(Hosts) ->
	    case inet_parse:hosts_vxworks({chars, Hosts}) of
		{ok, Ls} ->
		    foreach(
		      fun({IP, Name, Aliases}) -> 
			      inet_db:add_host(IP, [Name|Aliases])
		      end,
		      Ls);
		{error,Reason} ->
		    error("parser error VxWorks hostShow ~s", [Reason])
	    end;
	_Error ->
	    error("error in VxWorks hostShow~s~n", [HostShow])
    end.

%%
%% Check if hostShow yields at least two line; the first one
%% starting with "hostname", the second one starting with
%% "--------".
%% Returns: list of hosts in VxWorks notation
%% rows of 'Name          IP                [Aliases]  \n'
%% if hostShow yielded these two lines, false otherwise.
check_hostShow(HostShow) ->
    check_hostShow(["hostname", "--------"], HostShow).

check_hostShow([], HostShow) ->
    HostShow;
check_hostShow([String_match|Rest], HostShow) ->
    case lists:prefix(String_match, HostShow) of
	true ->
	    check_hostShow(Rest, next_line(HostShow));
	false ->
	    false
    end.

next_line([]) ->
    [];
next_line([$\n|Rest]) ->
    Rest;
next_line([_First|Rest]) ->
    next_line(Rest).

read_rc() ->
    {RcFile,CfgList} = read_inetrc(),
    case extract_cfg_files(CfgList, [], []) of
	{CfgFiles,CfgList1} ->
	    {RcFile,CfgFiles,CfgList1};
	error ->
	    {error,[],[]}
    end.



extract_cfg_files([E = {file,Type,_File} | Es], CfgFiles, CfgList) ->
    extract_cfg_files1(Type, E, Es, CfgFiles, CfgList);
extract_cfg_files([E = {registry,Type} | Es], CfgFiles, CfgList) ->
    extract_cfg_files1(Type, E, Es, CfgFiles, CfgList);
extract_cfg_files([E | Es], CfgFiles, CfgList) ->
    extract_cfg_files(Es, CfgFiles, [E | CfgList]);
extract_cfg_files([], CfgFiles, CfgList) ->
    {reverse(CfgFiles),reverse(CfgList)}.

extract_cfg_files1(Type, E, Es, CfgFiles, CfgList) ->
    case valid_type(Type) of
	true ->
	    extract_cfg_files(Es, [E | CfgFiles], CfgList);
	false ->
	    error("invalid config value ~w in inetrc~n", [Type]),
	    error
    end.

valid_type(resolv) ->            true;
valid_type(host_conf_freebsd) -> true;
valid_type(host_conf_bsdos) ->   true;
valid_type(host_conf_linux) ->   true;
valid_type(nsswitch_conf) ->     true;
valid_type(hosts) ->             true;
valid_type(win32) ->             true;
valid_type(_) ->                 false.

read_inetrc() ->
   case application:get_env(inetrc) of
       {ok,File} ->
	   try_get_rc(File);
       _ ->
	   case os:getenv("ERL_INETRC") of
	       false ->
		   {nofile,[]};
	       File ->
		   try_get_rc(File)
	   end
   end.

try_get_rc(File) ->
    case get_rc(File) of
	error -> {nofile,[]};
	Ls ->    {File,Ls}
    end.    

get_rc(File) ->
    case get_file(File) of
	{ok,Bin} ->
	    case parse_inetrc(Bin) of
		{ok,Ls} -> 
		    Ls;
		_Error -> 
		    error("parse error in ~s~n", [File]),
		    error
	    end;
	_Error -> 
	    error("file ~s not found~n", [File]),
	    error
    end.

%% XXX Check if we really need to prim load the stuff
get_file(File) ->
    case erl_prim_loader:get_file(File) of
	{ok,Bin,_} -> {ok,Bin};
	Error -> Error
    end.

error(Fmt, Args) ->
    error_logger:error_msg("inet_config: " ++ Fmt, Args).

warning(Fmt, Args) ->
    case application:get_env(kernel,inet_warnings) of
	%{ok,silent} -> ok;
	{ok,on} -> 
	    error_logger:info_msg("inet_config:" ++ Fmt, Args);
	_ ->
	    ok
    end.

%% 
%% Parse inetrc, i.e. make a binary of a term list.
%% The extra newline is to let the user ignore the whitespace !!!
%% Ignore leading whitespace before a token (due to bug in erl_scan) !
%% 
parse_inetrc(Bin) ->
    Str = binary_to_list(Bin) ++ "\n", 
    parse_inetrc(Str, 1, []).

parse_inetrc_skip_line([], _Line, Ack) ->
    {ok, reverse(Ack)};
parse_inetrc_skip_line([$\n|Str], Line, Ack) ->
    parse_inetrc(Str, Line+1, Ack);
parse_inetrc_skip_line([_|Str], Line, Ack) ->
    parse_inetrc_skip_line(Str, Line, Ack).

parse_inetrc([$%|Str], Line, Ack) ->
    parse_inetrc_skip_line(Str, Line, Ack);
parse_inetrc([$\s|Str], Line, Ack) ->
    parse_inetrc(Str, Line, Ack);
parse_inetrc([$\n |Str], Line, Ack) ->
    parse_inetrc(Str, Line+1, Ack);
parse_inetrc([$\t|Str], Line, Ack) ->
    parse_inetrc(Str, Line, Ack);
parse_inetrc([], _, Ack) ->
    {ok, reverse(Ack)};


%% The clauses above are here due to a bug in erl_scan (OTP-1449).

parse_inetrc(Str, Line, Ack) ->
    case erl_scan:tokens([], Str, Line) of
	{done, {ok, Tokens, EndLine}, MoreChars} ->
	    case erl_parse:parse_term(Tokens) of
		{ok, Term} ->
		    parse_inetrc(MoreChars, EndLine, [Term|Ack]);
		Error ->
		    {error, {'parse_inetrc', Error}}
	    end;
	{done, {eof, _}, _} ->
	    {ok, reverse(Ack)};
	{done, Error, _} ->
	    {error, {'scan_inetrc', Error}};
	{more, _} -> %% Bug in erl_scan !!
	    {error, {'scan_inetrc', {eof, Line}}}
    end.