2 * ngIRCd -- The Next Generation IRC Daemon
3 * Copyright (c)2001-2003 by Alexander Barton (alex@barton.de)
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 * Please read the file COPYING, README and AUTHORS for more information.
11 * Asynchronous resolver
17 static char UNUSED id[] = "$Id: resolve.c,v 1.20 2005/09/11 11:42:48 fw Exp $";
25 #include <sys/socket.h>
26 #include <netinet/in.h>
27 #include <arpa/inet.h>
46 static void Do_ResolveAddr PARAMS(( struct sockaddr_in *Addr, int Sock, int w_fd ));
48 static void Do_ResolveAddr PARAMS(( struct sockaddr_in *Addr, int w_fd ));
51 static void Do_ResolveName PARAMS(( char *Host, int w_fd ));
54 static char *Get_Error PARAMS(( int H_Error ));
57 static RES_STAT *New_Res_Stat PARAMS(( void ));
61 cb_resolver(int fd, short unused) {
62 (void) unused; /* shut up compiler warning */
63 Read_Resolver_Result(fd);
69 Resolve_Addr( struct sockaddr_in *Addr, int Sock )
72 Resolve_Addr( struct sockaddr_in *Addr )
75 /* Resolve IP (asynchronous!). On errors, e.g. if the child process
76 * can't be forked, this functions returns NULL. */
82 if( ! s ) return NULL;
89 Log( LOG_DEBUG, "Resolver for %s created (PID %d).", inet_ntoa( Addr->sin_addr ), pid );
90 if (!io_setnonblock( s->pipe[0] )) {
91 Log( LOG_DEBUG, "Could not set Non-Blocking mode for pipefd %d", s->pipe[0] );
94 if (!io_event_create( s->pipe[0], IO_WANTREAD, cb_resolver )) {
95 Log( LOG_DEBUG, "Could not add pipefd %dto event watchlist: %s",
96 s->pipe[0], strerror(errno) );
101 } else if( pid == 0 ) {
104 Log_Init_Resolver( );
106 Do_ResolveAddr( Addr, Sock, s->pipe[1] );
108 Do_ResolveAddr( Addr, s->pipe[1] );
110 Log_Exit_Resolver( );
114 Log( LOG_CRIT, "Resolver: Can't fork: %s!", strerror( errno ));
125 Resolve_Name( char *Host )
127 /* Resolve hostname (asynchronous!). On errors, e.g. if the child
128 * process can't be forked, this functions returns NULL. */
134 if( ! s ) return NULL;
136 /* Fork sub-process */
141 Log( LOG_DEBUG, "Resolver for \"%s\" created (PID %d).", Host, pid );
142 if (!io_setnonblock( s->pipe[0] )) {
143 Log( LOG_DEBUG, "Could not set Non-Blocking mode for pipefd %d", s->pipe[0] );
146 if (!io_event_create( s->pipe[0], IO_WANTREAD, cb_resolver )) {
147 Log( LOG_DEBUG, "Could not add pipefd %dto event watchlist: %s",
148 s->pipe[0], strerror(errno) );
153 } else if( pid == 0 ) {
156 Log_Init_Resolver( );
157 Do_ResolveName( Host, s->pipe[1] );
158 Log_Exit_Resolver( );
162 Log( LOG_CRIT, "Resolver: Can't fork: %s!", strerror( errno ));
174 Do_ResolveAddr( struct sockaddr_in *Addr, int Sock, int w_fd )
177 Do_ResolveAddr( struct sockaddr_in *Addr, int w_fd )
180 /* Resolver sub-process: resolve IP address and write result into
183 char hostname[HOST_LEN];
184 char ipstr[HOST_LEN];
187 struct in_addr *addr;
194 array_init(&resolved_addr);
196 /* Resolve IP address */
198 Log_Resolver( LOG_DEBUG, "Now resolving %s ...", inet_ntoa( Addr->sin_addr ));
200 h = gethostbyaddr( (char *)&Addr->sin_addr, sizeof( Addr->sin_addr ), AF_INET );
203 Log_Resolver( LOG_WARNING, "Can't resolve address \"%s\": %s!", inet_ntoa( Addr->sin_addr ), Get_Error( h_errno ));
205 Log_Resolver( LOG_WARNING, "Can't resolve address \"%s\"!", inet_ntoa( Addr->sin_addr ));
207 strlcpy( hostname, inet_ntoa( Addr->sin_addr ), sizeof( hostname ));
209 strlcpy( hostname, h->h_name, sizeof( hostname ));
211 h = gethostbyname( hostname );
213 if (memcmp(h->h_addr, &Addr->sin_addr, sizeof (struct in_addr))) {
214 addr = (struct in_addr*) h->h_addr;
215 strlcpy(ipstr, inet_ntoa(*addr), sizeof ipstr);
216 ntoaptr = inet_ntoa( Addr->sin_addr );
217 Log(LOG_WARNING,"Possible forgery: %s resolved to %s (which is at ip %s!)",
218 ntoaptr, hostname, ipstr);
219 strlcpy( hostname, ntoaptr, sizeof hostname);
222 ntoaptr = inet_ntoa( Addr->sin_addr );
223 Log(LOG_WARNING, "Possible forgery: %s resolved to %s (which has no ip address)",
225 strlcpy( hostname, ntoaptr, sizeof hostname);
228 Log_Resolver( LOG_DEBUG, "Ok, translated %s to \"%s\".", inet_ntoa( Addr->sin_addr ), hostname );
230 len = strlen( hostname );
231 hostname[len] = '\n'; len++;
232 if (!array_copyb(&resolved_addr, hostname, len )) {
233 Log_Resolver( LOG_CRIT, "Resolver: Can't copy resolved name: %s!", strerror( errno ));
239 /* Do "IDENT" (aka "AUTH") lookup and append result to resolved_addr array */
240 Log_Resolver( LOG_DEBUG, "Doing IDENT lookup on socket %d ...", Sock );
241 res = ident_id( Sock, 10 );
242 Log_Resolver( LOG_DEBUG, "Ok, IDENT lookup on socket %d done: \"%s\"", Sock, res ? res : "" );
245 if (!array_cats(&resolved_addr, res))
246 Log_Resolver(LOG_WARNING, "Resolver: Cannot copy IDENT result: %s!", strerror(errno));
247 /* try to omit ident and return hostname only */
250 if (!array_catb(&resolved_addr, "\n", 1)) {
252 Log_Resolver(LOG_CRIT, "Resolver: Cannot copy result: %s!", strerror(errno));
253 array_free(&resolved_addr);
259 len = array_bytes(&resolved_addr);
260 if( (size_t)write( w_fd, array_start(&resolved_addr), len) != len )
261 Log_Resolver( LOG_CRIT, "Resolver: Can't write result to parent: %s!", strerror( errno ));
264 array_free(&resolved_addr);
265 } /* Do_ResolveAddr */
269 Do_ResolveName( char *Host, int w_fd )
271 /* Resolver sub-process: resolve name and write result into pipe
276 struct in_addr *addr;
279 Log_Resolver( LOG_DEBUG, "Now resolving \"%s\" ...", Host );
281 /* Resolve hostname */
282 h = gethostbyname( Host );
284 addr = (struct in_addr *)h->h_addr;
285 strlcpy( ip, inet_ntoa( *addr ), sizeof( ip ));
288 Log_Resolver( LOG_WARNING, "Can't resolve \"%s\": %s!", Host, Get_Error( h_errno ));
290 Log_Resolver( LOG_WARNING, "Can't resolve \"%s\"!", Host );
294 if( ip[0] ) Log_Resolver( LOG_DEBUG, "Ok, translated \"%s\" to %s.", Host, ip );
296 /* Write result into pipe to parent */
298 ip[len] = '\n'; len++;
299 if( (size_t)write( w_fd, ip, len ) != (size_t)len ) {
300 Log_Resolver( LOG_CRIT, "Resolver: Can't write to parent: %s!", strerror( errno ));
303 } /* Do_ResolveName */
309 Get_Error( int H_Error )
311 /* Get error message for H_Error */
316 return "host not found";
318 return "name valid but no IP address defined";
320 return "name server error";
322 return "name server temporary not available";
324 return "unknown error";
336 /* Allocate memory */
337 s = (RES_STAT *)malloc( sizeof( RES_STAT ));
340 Log( LOG_EMERG, "Resolver: Can't allocate memory! [Resolve_Addr]" );
344 /* Initialize pipe for result */
345 if( pipe( s->pipe ) != 0 )
348 Log( LOG_ALERT, "Resolver: Can't create output pipe: %s!", strerror( errno ));
353 array_init(&s->buffer);