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 1.18 2005/09/02 21:47:30 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;
90 Log( LOG_DEBUG, "Resolver for %s created (PID %d).", inet_ntoa( Addr->sin_addr ), pid );
91 if (!io_setnonblock( s->pipe[0] )) {
92 Log( LOG_DEBUG, "Could not set Non-Blocking mode for pipefd %d", s->pipe[0] );
95 if (!io_event_create( s->pipe[0], IO_WANTREAD, cb_resolver )) {
96 Log( LOG_DEBUG, "Could not add pipefd %dto event watchlist: %s",
97 s->pipe[0], strerror(errno) );
107 Log_Init_Resolver( );
109 Do_ResolveAddr( Addr, Sock, s->pipe[1] );
111 Do_ResolveAddr( Addr, s->pipe[1] );
113 Log_Exit_Resolver( );
117 Log( LOG_CRIT, "Resolver: Can't fork: %s!", strerror( errno ));
128 Resolve_Name( char *Host )
130 /* Resolve hostname (asynchronous!). On errors, e.g. if the child
131 * process can't be forked, this functions returns NULL. */
137 if( ! s ) return NULL;
139 /* Fork sub-process */
145 Log( LOG_DEBUG, "Resolver for \"%s\" created (PID %d).", Host, pid );
146 if (!io_setnonblock( s->pipe[0] )) {
147 Log( LOG_DEBUG, "Could not set Non-Blocking mode for pipefd %d", s->pipe[0] );
150 if (!io_event_create( s->pipe[0], IO_WANTREAD, cb_resolver )) {
151 Log( LOG_DEBUG, "Could not add pipefd %dto event watchlist: %s",
152 s->pipe[0], strerror(errno) );
162 Log_Init_Resolver( );
163 Do_ResolveName( Host, s->pipe[1] );
164 Log_Exit_Resolver( );
168 Log( LOG_CRIT, "Resolver: Can't fork: %s!", strerror( errno ));
180 Do_ResolveAddr( struct sockaddr_in *Addr, int Sock, int w_fd )
183 Do_ResolveAddr( struct sockaddr_in *Addr, int w_fd )
186 /* Resolver sub-process: resolve IP address and write result into
189 char hostname[HOST_LEN];
190 char ipstr[HOST_LEN];
193 struct in_addr *addr;
199 /* Resolve IP address */
201 Log_Resolver( LOG_DEBUG, "Now resolving %s ...", inet_ntoa( Addr->sin_addr ));
203 h = gethostbyaddr( (char *)&Addr->sin_addr, sizeof( Addr->sin_addr ), AF_INET );
206 Log_Resolver( LOG_WARNING, "Can't resolve address \"%s\": %s!", inet_ntoa( Addr->sin_addr ), Get_Error( h_errno ));
208 Log_Resolver( LOG_WARNING, "Can't resolve address \"%s\"!", inet_ntoa( Addr->sin_addr ));
210 strlcpy( hostname, inet_ntoa( Addr->sin_addr ), sizeof( hostname ));
212 strlcpy( hostname, h->h_name, sizeof( hostname ));
214 h = gethostbyname( hostname );
216 if (memcmp(h->h_addr, &Addr->sin_addr, sizeof (struct in_addr))) {
217 addr = (struct in_addr*) h->h_addr;
218 strlcpy(ipstr, inet_ntoa(*addr), sizeof ipstr);
219 ntoaptr = inet_ntoa( Addr->sin_addr );
220 Log(LOG_WARNING,"Possible forgery: %s resolved to %s (which is at ip %s!)",
221 ntoaptr, hostname, ipstr);
222 strlcpy( hostname, ntoaptr, sizeof hostname);
225 ntoaptr = inet_ntoa( Addr->sin_addr );
226 Log(LOG_WARNING, "Possible forgery: %s resolved to %s (which has no ip address)",
228 strlcpy( hostname, ntoaptr, sizeof hostname);
231 Log_Resolver( LOG_DEBUG, "Ok, translated %s to \"%s\".", inet_ntoa( Addr->sin_addr ), hostname );
233 /* Write resolver result into pipe to parent */
234 len = strlen( hostname );
235 hostname[len] = '\n'; len++;
236 if( (size_t)write( w_fd, hostname, len ) != (size_t)len )
238 Log_Resolver( LOG_CRIT, "Resolver: Can't write to parent: %s!", strerror( errno ));
244 /* Do "IDENT" (aka "AUTH") lookup and write result to parent */
245 Log_Resolver( LOG_DEBUG, "Doing IDENT lookup on socket %d ...", Sock );
246 res = ident_id( Sock, 10 );
247 Log_Resolver( LOG_DEBUG, "Ok, IDENT lookup on socket %d done: \"%s\"", Sock, res ? res : "" );
249 /* Write IDENT result into pipe to parent */
256 if( (size_t)write( w_fd, res ? res : "\n", len ) != (size_t)len )
258 Log_Resolver( LOG_CRIT, "Resolver: Can't write to parent (IDENT): %s!", strerror( errno ));
263 } /* Do_ResolveAddr */
267 Do_ResolveName( char *Host, int w_fd )
269 /* Resolver sub-process: resolve name and write result into pipe
274 struct in_addr *addr;
277 Log_Resolver( LOG_DEBUG, "Now resolving \"%s\" ...", Host );
279 /* Resolve hostname */
280 h = gethostbyname( Host );
283 addr = (struct in_addr *)h->h_addr;
284 strlcpy( ip, inet_ntoa( *addr ), sizeof( ip ));
289 Log_Resolver( LOG_WARNING, "Can't resolve \"%s\": %s!", Host, Get_Error( h_errno ));
291 Log_Resolver( LOG_WARNING, "Can't resolve \"%s\"!", Host );
295 if( ip[0] ) Log_Resolver( LOG_DEBUG, "Ok, translated \"%s\" to %s.", Host, ip );
297 /* Write result into pipe to parent */
299 ip[len] = '\n'; len++;
300 if( (size_t)write( w_fd, ip, len ) != (size_t)len )
302 Log_Resolver( LOG_CRIT, "Resolver: Can't write to parent: %s!", strerror( errno ));
305 } /* Do_ResolveName */
311 Get_Error( int H_Error )
313 /* Get error message for H_Error */
318 return "host not found";
320 return "name valid but no IP address defined";
322 return "name server error";
324 return "name server temporary not available";
326 return "unknown error";
338 /* Allocate memory */
339 s = (RES_STAT *)malloc( sizeof( RES_STAT ));
342 Log( LOG_EMERG, "Resolver: Can't allocate memory! [Resolve_Addr]" );
346 /* Initialize pipe for result */
347 if( pipe( s->pipe ) != 0 )
350 Log( LOG_ALERT, "Resolver: Can't create output pipe: %s!", strerror( errno ));
355 array_init(&s->buffer);