1 46ec0f24 2002-05-27 alex /*
  2 46ec0f24 2002-05-27 alex  * ngIRCd -- The Next Generation IRC Daemon
  3 b79b315d 2003-12-27 alex  * Copyright (c)2001-2003 by Alexander Barton (alex@barton.de)
  4 46ec0f24 2002-05-27 alex  *
  5 490f28ff 2002-12-12 alex  * This program is free software; you can redistribute it and/or modify
  6 490f28ff 2002-12-12 alex  * it under the terms of the GNU General Public License as published by
  7 490f28ff 2002-12-12 alex  * the Free Software Foundation; either version 2 of the License, or
  8 490f28ff 2002-12-12 alex  * (at your option) any later version.
  9 490f28ff 2002-12-12 alex  * Please read the file COPYING, README and AUTHORS for more information.
 10 46ec0f24 2002-05-27 alex  *
 11 490f28ff 2002-12-12 alex  * Asynchronous resolver
 12 46ec0f24 2002-05-27 alex  */
 13 46ec0f24 2002-05-27 alex 
 14 46ec0f24 2002-05-27 alex 
 15 46ec0f24 2002-05-27 alex #include "portab.h"
 16 46ec0f24 2002-05-27 alex 
 17 3012c232 2004-05-11 alex static char UNUSED id[] = "$Id: resolve.c,v 1.9 2004/05/11 00:01:11 alex Exp $";
 18 490f28ff 2002-12-12 alex 
 19 46ec0f24 2002-05-27 alex #include "imp.h"
 20 46ec0f24 2002-05-27 alex #include <assert.h>
 21 46ec0f24 2002-05-27 alex #include <errno.h>
 22 46ec0f24 2002-05-27 alex #include <stdlib.h>
 23 46ec0f24 2002-05-27 alex #include <string.h>
 24 46ec0f24 2002-05-27 alex #include <unistd.h>
 25 46ec0f24 2002-05-27 alex #include <sys/socket.h>
 26 46ec0f24 2002-05-27 alex #include <netinet/in.h>
 27 46ec0f24 2002-05-27 alex #include <arpa/inet.h>
 28 46ec0f24 2002-05-27 alex #include <netdb.h>
 29 46ec0f24 2002-05-27 alex 
 30 b79b315d 2003-12-27 alex #ifdef IDENTAUTH
 31 b79b315d 2003-12-27 alex #ifdef HAVE_IDENT_H
 32 b79b315d 2003-12-27 alex #include <ident.h>
 33 b79b315d 2003-12-27 alex #endif
 34 b79b315d 2003-12-27 alex #endif
 35 b79b315d 2003-12-27 alex 
 36 46ec0f24 2002-05-27 alex #include "conn.h"
 37 46ec0f24 2002-05-27 alex #include "defines.h"
 38 46ec0f24 2002-05-27 alex #include "log.h"
 39 46ec0f24 2002-05-27 alex 
 40 46ec0f24 2002-05-27 alex #include "exp.h"
 41 46ec0f24 2002-05-27 alex #include "resolve.h"
 42 46ec0f24 2002-05-27 alex 
 43 46ec0f24 2002-05-27 alex 
 44 b79b315d 2003-12-27 alex #ifdef IDENTAUTH
 45 b79b315d 2003-12-27 alex LOCAL VOID Do_ResolveAddr PARAMS(( struct sockaddr_in *Addr, INT Sock, INT w_fd ));
 46 b79b315d 2003-12-27 alex #else
 47 46ec0f24 2002-05-27 alex LOCAL VOID Do_ResolveAddr PARAMS(( struct sockaddr_in *Addr, INT w_fd ));
 48 b79b315d 2003-12-27 alex #endif
 49 b79b315d 2003-12-27 alex 
 50 46ec0f24 2002-05-27 alex LOCAL VOID Do_ResolveName PARAMS(( CHAR *Host, INT w_fd ));
 51 46ec0f24 2002-05-27 alex 
 52 46ec0f24 2002-05-27 alex #ifdef h_errno
 53 f7327524 2002-05-30 alex LOCAL CHAR *Get_Error PARAMS(( INT H_Error ));
 54 46ec0f24 2002-05-27 alex #endif
 55 46ec0f24 2002-05-27 alex 
 56 46ec0f24 2002-05-27 alex 
 57 46ec0f24 2002-05-27 alex GLOBAL VOID
 58 46ec0f24 2002-05-27 alex Resolve_Init( VOID )
 59 46ec0f24 2002-05-27 alex {
 60 b79b315d 2003-12-27 alex 	/* Initialize module */
 61 46ec0f24 2002-05-27 alex 
 62 46ec0f24 2002-05-27 alex 	FD_ZERO( &Resolver_FDs );
 63 46ec0f24 2002-05-27 alex } /* Resolve_Init */
 64 46ec0f24 2002-05-27 alex 
 65 46ec0f24 2002-05-27 alex 
 66 b79b315d 2003-12-27 alex #ifdef IDENTAUTH
 67 46ec0f24 2002-05-27 alex GLOBAL RES_STAT *
 68 b79b315d 2003-12-27 alex Resolve_Addr( struct sockaddr_in *Addr, int Sock )
 69 b79b315d 2003-12-27 alex #else
 70 b79b315d 2003-12-27 alex GLOBAL RES_STAT *
 71 46ec0f24 2002-05-27 alex Resolve_Addr( struct sockaddr_in *Addr )
 72 b79b315d 2003-12-27 alex #endif
 73 46ec0f24 2002-05-27 alex {
 74 b79b315d 2003-12-27 alex 	/* Resolve IP (asynchronous!). On errors, e.g. if the child process
 75 b79b315d 2003-12-27 alex 	 * can't be forked, this functions returns NULL. */
 76 46ec0f24 2002-05-27 alex 
 77 46ec0f24 2002-05-27 alex 	RES_STAT *s;
 78 46ec0f24 2002-05-27 alex 	INT pid;
 79 46ec0f24 2002-05-27 alex 
 80 b79b315d 2003-12-27 alex 	/* Allocate memory */
 81 cb76d96e 2004-03-11 alex 	s = (RES_STAT *)malloc( sizeof( RES_STAT ));
 82 46ec0f24 2002-05-27 alex 	if( ! s )
 83 46ec0f24 2002-05-27 alex 	{
 84 63c36773 2002-06-09 alex 		Log( LOG_EMERG, "Resolver: Can't allocate memory! [Resolve_Addr]" );
 85 46ec0f24 2002-05-27 alex 		return NULL;
 86 46ec0f24 2002-05-27 alex 	}
 87 46ec0f24 2002-05-27 alex 
 88 b79b315d 2003-12-27 alex 	/* Initialize pipe for result */
 89 46ec0f24 2002-05-27 alex 	if( pipe( s->pipe ) != 0 )
 90 46ec0f24 2002-05-27 alex 	{
 91 46ec0f24 2002-05-27 alex 		free( s );
 92 46ec0f24 2002-05-27 alex 		Log( LOG_ALERT, "Resolver: Can't create output pipe: %s!", strerror( errno ));
 93 46ec0f24 2002-05-27 alex 		return NULL;
 94 46ec0f24 2002-05-27 alex 	}
 95 46ec0f24 2002-05-27 alex 
 96 b79b315d 2003-12-27 alex 	/* For sub-process */
 97 46ec0f24 2002-05-27 alex 	pid = fork( );
 98 46ec0f24 2002-05-27 alex 	if( pid > 0 )
 99 46ec0f24 2002-05-27 alex 	{
100 b79b315d 2003-12-27 alex 		/* Main process */
101 46ec0f24 2002-05-27 alex 		Log( LOG_DEBUG, "Resolver for %s created (PID %d).", inet_ntoa( Addr->sin_addr ), pid );
102 46ec0f24 2002-05-27 alex 		FD_SET( s->pipe[0], &Resolver_FDs );
103 46ec0f24 2002-05-27 alex 		if( s->pipe[0] > Conn_MaxFD ) Conn_MaxFD = s->pipe[0];
104 46ec0f24 2002-05-27 alex 		s->pid = pid;
105 3012c232 2004-05-11 alex 		s->stage = 0;
106 3012c232 2004-05-11 alex 		s->bufpos = 0;
107 46ec0f24 2002-05-27 alex 		return s;
108 46ec0f24 2002-05-27 alex 	}
109 46ec0f24 2002-05-27 alex 	else if( pid == 0 )
110 46ec0f24 2002-05-27 alex 	{
111 b79b315d 2003-12-27 alex 		/* Sub process */
112 46ec0f24 2002-05-27 alex 		Log_Init_Resolver( );
113 b79b315d 2003-12-27 alex #ifdef IDENTAUTH
114 b79b315d 2003-12-27 alex 		Do_ResolveAddr( Addr, Sock, s->pipe[1] );
115 b79b315d 2003-12-27 alex #else
116 46ec0f24 2002-05-27 alex 		Do_ResolveAddr( Addr, s->pipe[1] );
117 b79b315d 2003-12-27 alex #endif
118 46ec0f24 2002-05-27 alex 		Log_Exit_Resolver( );
119 46ec0f24 2002-05-27 alex 		exit( 0 );
120 46ec0f24 2002-05-27 alex 	}
121 46ec0f24 2002-05-27 alex 	else
122 46ec0f24 2002-05-27 alex 	{
123 b79b315d 2003-12-27 alex 		/* Error! */
124 46ec0f24 2002-05-27 alex 		free( s );
125 46ec0f24 2002-05-27 alex 		Log( LOG_CRIT, "Resolver: Can't fork: %s!", strerror( errno ));
126 46ec0f24 2002-05-27 alex 		return NULL;
127 46ec0f24 2002-05-27 alex 	}
128 46ec0f24 2002-05-27 alex } /* Resolve_Addr */
129 46ec0f24 2002-05-27 alex 
130 46ec0f24 2002-05-27 alex 
131 46ec0f24 2002-05-27 alex GLOBAL RES_STAT *
132 46ec0f24 2002-05-27 alex Resolve_Name( CHAR *Host )
133 46ec0f24 2002-05-27 alex {
134 b79b315d 2003-12-27 alex 	/* Resolve hostname (asynchronous!). On errors, e.g. if the child
135 b79b315d 2003-12-27 alex 	 * process can't be forked, this functions returns NULL. */
136 46ec0f24 2002-05-27 alex 
137 46ec0f24 2002-05-27 alex 	RES_STAT *s;
138 46ec0f24 2002-05-27 alex 	INT pid;
139 46ec0f24 2002-05-27 alex 
140 b79b315d 2003-12-27 alex 	/* Allocate memory */
141 cb76d96e 2004-03-11 alex 	s = (RES_STAT *)malloc( sizeof( RES_STAT ));
142 46ec0f24 2002-05-27 alex 	if( ! s )
143 46ec0f24 2002-05-27 alex 	{
144 63c36773 2002-06-09 alex 		Log( LOG_EMERG, "Resolver: Can't allocate memory! [Resolve_Name]" );
145 46ec0f24 2002-05-27 alex 		return NULL;
146 46ec0f24 2002-05-27 alex 	}
147 46ec0f24 2002-05-27 alex 
148 b79b315d 2003-12-27 alex 	/* Initialize the pipe for the result */
149 46ec0f24 2002-05-27 alex 	if( pipe( s->pipe ) != 0 )
150 46ec0f24 2002-05-27 alex 	{
151 46ec0f24 2002-05-27 alex 		free( s );
152 46ec0f24 2002-05-27 alex 		Log( LOG_ALERT, "Resolver: Can't create output pipe: %s!", strerror( errno ));
153 46ec0f24 2002-05-27 alex 		return NULL;
154 46ec0f24 2002-05-27 alex 	}
155 46ec0f24 2002-05-27 alex 
156 b79b315d 2003-12-27 alex 	/* Fork sub-process */
157 46ec0f24 2002-05-27 alex 	pid = fork( );
158 46ec0f24 2002-05-27 alex 	if( pid > 0 )
159 46ec0f24 2002-05-27 alex 	{
160 b79b315d 2003-12-27 alex 		/* Main process */
161 46ec0f24 2002-05-27 alex 		Log( LOG_DEBUG, "Resolver for \"%s\" created (PID %d).", Host, pid );
162 46ec0f24 2002-05-27 alex 		FD_SET( s->pipe[0], &Resolver_FDs );
163 46ec0f24 2002-05-27 alex 		if( s->pipe[0] > Conn_MaxFD ) Conn_MaxFD = s->pipe[0];
164 46ec0f24 2002-05-27 alex 		s->pid = pid;
165 3012c232 2004-05-11 alex 		s->stage = 0;
166 3012c232 2004-05-11 alex 		s->bufpos = 0;
167 46ec0f24 2002-05-27 alex 		return s;
168 46ec0f24 2002-05-27 alex 	}
169 46ec0f24 2002-05-27 alex 	else if( pid == 0 )
170 46ec0f24 2002-05-27 alex 	{
171 b79b315d 2003-12-27 alex 		/* Sub process */
172 46ec0f24 2002-05-27 alex 		Log_Init_Resolver( );
173 46ec0f24 2002-05-27 alex 		Do_ResolveName( Host, s->pipe[1] );
174 46ec0f24 2002-05-27 alex 		Log_Exit_Resolver( );
175 46ec0f24 2002-05-27 alex 		exit( 0 );
176 46ec0f24 2002-05-27 alex 	}
177 46ec0f24 2002-05-27 alex 	else
178 46ec0f24 2002-05-27 alex 	{
179 b79b315d 2003-12-27 alex 		/* Error! */
180 46ec0f24 2002-05-27 alex 		free( s );
181 46ec0f24 2002-05-27 alex 		Log( LOG_CRIT, "Resolver: Can't fork: %s!", strerror( errno ));
182 46ec0f24 2002-05-27 alex 		return NULL;
183 46ec0f24 2002-05-27 alex 	}
184 46ec0f24 2002-05-27 alex } /* Resolve_Name */
185 46ec0f24 2002-05-27 alex 
186 46ec0f24 2002-05-27 alex 
187 b79b315d 2003-12-27 alex #ifdef IDENTAUTH
188 46ec0f24 2002-05-27 alex LOCAL VOID
189 b79b315d 2003-12-27 alex Do_ResolveAddr( struct sockaddr_in *Addr, int Sock, INT w_fd )
190 b79b315d 2003-12-27 alex #else
191 b79b315d 2003-12-27 alex LOCAL VOID
192 46ec0f24 2002-05-27 alex Do_ResolveAddr( struct sockaddr_in *Addr, INT w_fd )
193 b79b315d 2003-12-27 alex #endif
194 46ec0f24 2002-05-27 alex {
195 b79b315d 2003-12-27 alex 	/* Resolver sub-process: resolve IP address and write result into
196 b79b315d 2003-12-27 alex 	 * pipe to parent. */
197 46ec0f24 2002-05-27 alex 
198 46ec0f24 2002-05-27 alex 	CHAR hostname[HOST_LEN];
199 46ec0f24 2002-05-27 alex 	struct hostent *h;
200 3012c232 2004-05-11 alex 	INT len;
201 b79b315d 2003-12-27 alex #ifdef IDENTAUTH
202 b79b315d 2003-12-27 alex 	CHAR *res;
203 b79b315d 2003-12-27 alex #endif
204 46ec0f24 2002-05-27 alex 
205 b79b315d 2003-12-27 alex 	/* Resolve IP address */
206 3012c232 2004-05-11 alex 	Log_Resolver( LOG_DEBUG, "Now resolving %s ...", inet_ntoa( Addr->sin_addr ));
207 46ec0f24 2002-05-27 alex 	h = gethostbyaddr( (CHAR *)&Addr->sin_addr, sizeof( Addr->sin_addr ), AF_INET );
208 695631b2 2002-12-26 alex 	if( h ) strlcpy( hostname, h->h_name, sizeof( hostname ));
209 46ec0f24 2002-05-27 alex 	else
210 46ec0f24 2002-05-27 alex 	{
211 46ec0f24 2002-05-27 alex #ifdef h_errno
212 46ec0f24 2002-05-27 alex 		Log_Resolver( LOG_WARNING, "Can't resolve address \"%s\": %s!", inet_ntoa( Addr->sin_addr ), Get_Error( h_errno ));
213 46ec0f24 2002-05-27 alex #else
214 46ec0f24 2002-05-27 alex 		Log_Resolver( LOG_WARNING, "Can't resolve address \"%s\"!", inet_ntoa( Addr->sin_addr ));
215 46ec0f24 2002-05-27 alex #endif	
216 695631b2 2002-12-26 alex 		strlcpy( hostname, inet_ntoa( Addr->sin_addr ), sizeof( hostname ));
217 46ec0f24 2002-05-27 alex 	}
218 3012c232 2004-05-11 alex 	Log_Resolver( LOG_DEBUG, "Ok, translated %s to \"%s\".", inet_ntoa( Addr->sin_addr ), hostname );
219 46ec0f24 2002-05-27 alex 
220 3012c232 2004-05-11 alex 	/* Write resolver result into pipe to parent */
221 3012c232 2004-05-11 alex 	len = strlen( hostname ); 
222 3012c232 2004-05-11 alex 	hostname[len] = '\n'; len++;
223 3012c232 2004-05-11 alex 	if( (size_t)write( w_fd, hostname, len ) != (size_t)len )
224 46ec0f24 2002-05-27 alex 	{
225 46ec0f24 2002-05-27 alex 		Log_Resolver( LOG_CRIT, "Resolver: Can't write to parent: %s!", strerror( errno ));
226 46ec0f24 2002-05-27 alex 		close( w_fd );
227 46ec0f24 2002-05-27 alex 		return;
228 46ec0f24 2002-05-27 alex 	}
229 3012c232 2004-05-11 alex 
230 b79b315d 2003-12-27 alex #ifdef IDENTAUTH
231 3012c232 2004-05-11 alex 	/* Do "IDENT" (aka "AUTH") lookup and write result to parent */
232 3012c232 2004-05-11 alex 	Log_Resolver( LOG_DEBUG, "Doing IDENT lookup on socket %d ...", Sock );
233 3012c232 2004-05-11 alex 	res = ident_id( Sock, 10 );
234 3012c232 2004-05-11 alex 	Log_Resolver( LOG_DEBUG, "Ok, IDENT lookup on socket %d done: \"%s\"", Sock, res ? res : "" );
235 3012c232 2004-05-11 alex 
236 3012c232 2004-05-11 alex 	/* Write IDENT result into pipe to parent */
237 3012c232 2004-05-11 alex 	len = strlen( res ? res : "" );
238 3012c232 2004-05-11 alex 	if( res != NULL ) res[len] = '\n';
239 3012c232 2004-05-11 alex 	len++;
240 3012c232 2004-05-11 alex 	if( (size_t)write( w_fd, res ? res : "\n", len ) != (size_t)len )
241 b79b315d 2003-12-27 alex 	{
242 b79b315d 2003-12-27 alex 		Log_Resolver( LOG_CRIT, "Resolver: Can't write to parent (IDENT): %s!", strerror( errno ));
243 b79b315d 2003-12-27 alex 		close( w_fd );
244 b79b315d 2003-12-27 alex 	}
245 b79b315d 2003-12-27 alex 	free( res );
246 b79b315d 2003-12-27 alex #endif
247 46ec0f24 2002-05-27 alex } /* Do_ResolveAddr */
248 46ec0f24 2002-05-27 alex 
249 46ec0f24 2002-05-27 alex 
250 46ec0f24 2002-05-27 alex LOCAL VOID
251 46ec0f24 2002-05-27 alex Do_ResolveName( CHAR *Host, INT w_fd )
252 46ec0f24 2002-05-27 alex {
253 b79b315d 2003-12-27 alex 	/* Resolver sub-process: resolve name and write result into pipe
254 b79b315d 2003-12-27 alex 	 * to parent. */
255 46ec0f24 2002-05-27 alex 
256 46ec0f24 2002-05-27 alex 	CHAR ip[16];
257 46ec0f24 2002-05-27 alex 	struct hostent *h;
258 46ec0f24 2002-05-27 alex 	struct in_addr *addr;
259 3012c232 2004-05-11 alex 	INT len;
260 46ec0f24 2002-05-27 alex 
261 46ec0f24 2002-05-27 alex 	Log_Resolver( LOG_DEBUG, "Now resolving \"%s\" ...", Host );
262 46ec0f24 2002-05-27 alex 
263 b79b315d 2003-12-27 alex 	/* Resolve hostname */
264 46ec0f24 2002-05-27 alex 	h = gethostbyname( Host );
265 46ec0f24 2002-05-27 alex 	if( h )
266 46ec0f24 2002-05-27 alex 	{
267 46ec0f24 2002-05-27 alex 		addr = (struct in_addr *)h->h_addr;
268 695631b2 2002-12-26 alex 		strlcpy( ip, inet_ntoa( *addr ), sizeof( ip ));
269 46ec0f24 2002-05-27 alex 	}
270 46ec0f24 2002-05-27 alex 	else
271 46ec0f24 2002-05-27 alex 	{
272 46ec0f24 2002-05-27 alex #ifdef h_errno
273 46ec0f24 2002-05-27 alex 		Log_Resolver( LOG_WARNING, "Can't resolve \"%s\": %s!", Host, Get_Error( h_errno ));
274 46ec0f24 2002-05-27 alex #else
275 46ec0f24 2002-05-27 alex 		Log_Resolver( LOG_WARNING, "Can't resolve \"%s\"!", Host );
276 46ec0f24 2002-05-27 alex #endif
277 46ec0f24 2002-05-27 alex 		strcpy( ip, "" );
278 46ec0f24 2002-05-27 alex 	}
279 3012c232 2004-05-11 alex 	if( ip[0] ) Log_Resolver( LOG_DEBUG, "Ok, translated \"%s\" to %s.", Host, ip );
280 46ec0f24 2002-05-27 alex 
281 b79b315d 2003-12-27 alex 	/* Write result into pipe to parent */
282 3012c232 2004-05-11 alex 	len = strlen( ip );
283 3012c232 2004-05-11 alex 	ip[len] = '\n'; len++;
284 3012c232 2004-05-11 alex 	if( (size_t)write( w_fd, ip, len ) != (size_t)len )
285 46ec0f24 2002-05-27 alex 	{
286 46ec0f24 2002-05-27 alex 		Log_Resolver( LOG_CRIT, "Resolver: Can't write to parent: %s!", strerror( errno ));
287 46ec0f24 2002-05-27 alex 		close( w_fd );
288 46ec0f24 2002-05-27 alex 	}
289 46ec0f24 2002-05-27 alex } /* Do_ResolveName */
290 46ec0f24 2002-05-27 alex 
291 46ec0f24 2002-05-27 alex 
292 46ec0f24 2002-05-27 alex #ifdef h_errno
293 46ec0f24 2002-05-27 alex 
294 46ec0f24 2002-05-27 alex LOCAL CHAR *
295 46ec0f24 2002-05-27 alex Get_Error( INT H_Error )
296 46ec0f24 2002-05-27 alex {
297 b79b315d 2003-12-27 alex 	/* Get error message for H_Error */
298 46ec0f24 2002-05-27 alex 
299 46ec0f24 2002-05-27 alex 	switch( H_Error )
300 46ec0f24 2002-05-27 alex 	{
301 46ec0f24 2002-05-27 alex 		case HOST_NOT_FOUND:
302 46ec0f24 2002-05-27 alex 			return "host not found";
303 46ec0f24 2002-05-27 alex 		case NO_DATA:
304 46ec0f24 2002-05-27 alex 			return "name valid but no IP address defined";
305 46ec0f24 2002-05-27 alex 		case NO_RECOVERY:
306 46ec0f24 2002-05-27 alex 			return "name server error";
307 46ec0f24 2002-05-27 alex 		case TRY_AGAIN:
308 46ec0f24 2002-05-27 alex 			return "name server temporary not available";
309 46ec0f24 2002-05-27 alex 		default:
310 46ec0f24 2002-05-27 alex 			return "unknown error";
311 46ec0f24 2002-05-27 alex 	}
312 46ec0f24 2002-05-27 alex } /* Get_Error */
313 46ec0f24 2002-05-27 alex 
314 46ec0f24 2002-05-27 alex #endif
315 46ec0f24 2002-05-27 alex 
316 46ec0f24 2002-05-27 alex 
317 46ec0f24 2002-05-27 alex /* -eof- */