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Date:: Thu Dec 26 17:04:54 2002 UTC
Message:: - replaced a lot of strcpy() calls with strlcpy() which is more secure.
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  1 46ec0f24 2002-05-27 alex /*
  2 46ec0f24 2002-05-27 alex  * ngIRCd -- The Next Generation IRC Daemon
  3 46ec0f24 2002-05-27 alex  * Copyright (c)2001,2002 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 695631b2 2002-12-26 alex static char UNUSED id[] = "$Id: resolve.c,v 1.5 2002/12/26 17:04:54 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 46ec0f24 2002-05-27 alex #include "conn.h"
 31 46ec0f24 2002-05-27 alex #include "defines.h"
 32 46ec0f24 2002-05-27 alex #include "log.h"
 33 46ec0f24 2002-05-27 alex 
 34 46ec0f24 2002-05-27 alex #include "exp.h"
 35 46ec0f24 2002-05-27 alex #include "resolve.h"
 36 46ec0f24 2002-05-27 alex 
 37 46ec0f24 2002-05-27 alex 
 38 46ec0f24 2002-05-27 alex LOCAL VOID Do_ResolveAddr PARAMS(( struct sockaddr_in *Addr, INT w_fd ));
 39 46ec0f24 2002-05-27 alex LOCAL VOID Do_ResolveName PARAMS(( CHAR *Host, INT w_fd ));
 40 46ec0f24 2002-05-27 alex 
 41 46ec0f24 2002-05-27 alex #ifdef h_errno
 42 f7327524 2002-05-30 alex LOCAL CHAR *Get_Error PARAMS(( INT H_Error ));
 43 46ec0f24 2002-05-27 alex #endif
 44 46ec0f24 2002-05-27 alex 
 45 46ec0f24 2002-05-27 alex 
 46 46ec0f24 2002-05-27 alex GLOBAL VOID
 47 46ec0f24 2002-05-27 alex Resolve_Init( VOID )
 48 46ec0f24 2002-05-27 alex {
 49 46ec0f24 2002-05-27 alex 	/* Modul initialisieren */
 50 46ec0f24 2002-05-27 alex 
 51 46ec0f24 2002-05-27 alex 	FD_ZERO( &Resolver_FDs );
 52 46ec0f24 2002-05-27 alex } /* Resolve_Init */
 53 46ec0f24 2002-05-27 alex 
 54 46ec0f24 2002-05-27 alex 
 55 46ec0f24 2002-05-27 alex GLOBAL RES_STAT *
 56 46ec0f24 2002-05-27 alex Resolve_Addr( struct sockaddr_in *Addr )
 57 46ec0f24 2002-05-27 alex {
 58 46ec0f24 2002-05-27 alex 	/* IP (asyncron!) aufloesen. Bei Fehler, z.B. wenn der
 59 46ec0f24 2002-05-27 alex 	 * Child-Prozess nicht erzeugt werden kann, wird NULL geliefert.
 60 46ec0f24 2002-05-27 alex 	 * Der Host kann dann nicht aufgeloest werden. */
 61 46ec0f24 2002-05-27 alex 
 62 46ec0f24 2002-05-27 alex 	RES_STAT *s;
 63 46ec0f24 2002-05-27 alex 	INT pid;
 64 46ec0f24 2002-05-27 alex 
 65 46ec0f24 2002-05-27 alex 	/* Speicher anfordern */
 66 46ec0f24 2002-05-27 alex 	s = malloc( sizeof( RES_STAT ));
 67 46ec0f24 2002-05-27 alex 	if( ! s )
 68 46ec0f24 2002-05-27 alex 	{
 69 63c36773 2002-06-09 alex 		Log( LOG_EMERG, "Resolver: Can't allocate memory! [Resolve_Addr]" );
 70 46ec0f24 2002-05-27 alex 		return NULL;
 71 46ec0f24 2002-05-27 alex 	}
 72 46ec0f24 2002-05-27 alex 
 73 46ec0f24 2002-05-27 alex 	/* Pipe fuer Antwort initialisieren */
 74 46ec0f24 2002-05-27 alex 	if( pipe( s->pipe ) != 0 )
 75 46ec0f24 2002-05-27 alex 	{
 76 46ec0f24 2002-05-27 alex 		free( s );
 77 46ec0f24 2002-05-27 alex 		Log( LOG_ALERT, "Resolver: Can't create output pipe: %s!", strerror( errno ));
 78 46ec0f24 2002-05-27 alex 		return NULL;
 79 46ec0f24 2002-05-27 alex 	}
 80 46ec0f24 2002-05-27 alex 
 81 46ec0f24 2002-05-27 alex 	/* Sub-Prozess erzeugen */
 82 46ec0f24 2002-05-27 alex 	pid = fork( );
 83 46ec0f24 2002-05-27 alex 	if( pid > 0 )
 84 46ec0f24 2002-05-27 alex 	{
 85 46ec0f24 2002-05-27 alex 		/* Haupt-Prozess */
 86 46ec0f24 2002-05-27 alex 		Log( LOG_DEBUG, "Resolver for %s created (PID %d).", inet_ntoa( Addr->sin_addr ), pid );
 87 46ec0f24 2002-05-27 alex 		FD_SET( s->pipe[0], &Resolver_FDs );
 88 46ec0f24 2002-05-27 alex 		if( s->pipe[0] > Conn_MaxFD ) Conn_MaxFD = s->pipe[0];
 89 46ec0f24 2002-05-27 alex 		s->pid = pid;
 90 46ec0f24 2002-05-27 alex 		return s;
 91 46ec0f24 2002-05-27 alex 	}
 92 46ec0f24 2002-05-27 alex 	else if( pid == 0 )
 93 46ec0f24 2002-05-27 alex 	{
 94 46ec0f24 2002-05-27 alex 		/* Sub-Prozess */
 95 46ec0f24 2002-05-27 alex 		Log_Init_Resolver( );
 96 46ec0f24 2002-05-27 alex 		Do_ResolveAddr( Addr, s->pipe[1] );
 97 46ec0f24 2002-05-27 alex 		Log_Exit_Resolver( );
 98 46ec0f24 2002-05-27 alex 		exit( 0 );
 99 46ec0f24 2002-05-27 alex 	}
100 46ec0f24 2002-05-27 alex 	else
101 46ec0f24 2002-05-27 alex 	{
102 46ec0f24 2002-05-27 alex 		/* Fehler */
103 46ec0f24 2002-05-27 alex 		free( s );
104 46ec0f24 2002-05-27 alex 		Log( LOG_CRIT, "Resolver: Can't fork: %s!", strerror( errno ));
105 46ec0f24 2002-05-27 alex 		return NULL;
106 46ec0f24 2002-05-27 alex 	}
107 46ec0f24 2002-05-27 alex } /* Resolve_Addr */
108 46ec0f24 2002-05-27 alex 
109 46ec0f24 2002-05-27 alex 
110 46ec0f24 2002-05-27 alex GLOBAL RES_STAT *
111 46ec0f24 2002-05-27 alex Resolve_Name( CHAR *Host )
112 46ec0f24 2002-05-27 alex {
113 46ec0f24 2002-05-27 alex 	/* Hostnamen (asyncron!) aufloesen. Bei Fehler, z.B. wenn der
114 46ec0f24 2002-05-27 alex 	 * Child-Prozess nicht erzeugt werden kann, wird NULL geliefert.
115 46ec0f24 2002-05-27 alex 	 * Der Host kann dann nicht aufgeloest werden. */
116 46ec0f24 2002-05-27 alex 
117 46ec0f24 2002-05-27 alex 	RES_STAT *s;
118 46ec0f24 2002-05-27 alex 	INT pid;
119 46ec0f24 2002-05-27 alex 
120 46ec0f24 2002-05-27 alex 	/* Speicher anfordern */
121 46ec0f24 2002-05-27 alex 	s = malloc( sizeof( RES_STAT ));
122 46ec0f24 2002-05-27 alex 	if( ! s )
123 46ec0f24 2002-05-27 alex 	{
124 63c36773 2002-06-09 alex 		Log( LOG_EMERG, "Resolver: Can't allocate memory! [Resolve_Name]" );
125 46ec0f24 2002-05-27 alex 		return NULL;
126 46ec0f24 2002-05-27 alex 	}
127 46ec0f24 2002-05-27 alex 
128 46ec0f24 2002-05-27 alex 	/* Pipe fuer Antwort initialisieren */
129 46ec0f24 2002-05-27 alex 	if( pipe( s->pipe ) != 0 )
130 46ec0f24 2002-05-27 alex 	{
131 46ec0f24 2002-05-27 alex 		free( s );
132 46ec0f24 2002-05-27 alex 		Log( LOG_ALERT, "Resolver: Can't create output pipe: %s!", strerror( errno ));
133 46ec0f24 2002-05-27 alex 		return NULL;
134 46ec0f24 2002-05-27 alex 	}
135 46ec0f24 2002-05-27 alex 
136 46ec0f24 2002-05-27 alex 	/* Sub-Prozess erzeugen */
137 46ec0f24 2002-05-27 alex 	pid = fork( );
138 46ec0f24 2002-05-27 alex 	if( pid > 0 )
139 46ec0f24 2002-05-27 alex 	{
140 46ec0f24 2002-05-27 alex 		/* Haupt-Prozess */
141 46ec0f24 2002-05-27 alex 		Log( LOG_DEBUG, "Resolver for \"%s\" created (PID %d).", Host, pid );
142 46ec0f24 2002-05-27 alex 		FD_SET( s->pipe[0], &Resolver_FDs );
143 46ec0f24 2002-05-27 alex 		if( s->pipe[0] > Conn_MaxFD ) Conn_MaxFD = s->pipe[0];
144 46ec0f24 2002-05-27 alex 		s->pid = pid;
145 46ec0f24 2002-05-27 alex 		return s;
146 46ec0f24 2002-05-27 alex 	}
147 46ec0f24 2002-05-27 alex 	else if( pid == 0 )
148 46ec0f24 2002-05-27 alex 	{
149 46ec0f24 2002-05-27 alex 		/* Sub-Prozess */
150 46ec0f24 2002-05-27 alex 		Log_Init_Resolver( );
151 46ec0f24 2002-05-27 alex 		Do_ResolveName( Host, s->pipe[1] );
152 46ec0f24 2002-05-27 alex 		Log_Exit_Resolver( );
153 46ec0f24 2002-05-27 alex 		exit( 0 );
154 46ec0f24 2002-05-27 alex 	}
155 46ec0f24 2002-05-27 alex 	else
156 46ec0f24 2002-05-27 alex 	{
157 46ec0f24 2002-05-27 alex 		/* Fehler */
158 46ec0f24 2002-05-27 alex 		free( s );
159 46ec0f24 2002-05-27 alex 		Log( LOG_CRIT, "Resolver: Can't fork: %s!", strerror( errno ));
160 46ec0f24 2002-05-27 alex 		return NULL;
161 46ec0f24 2002-05-27 alex 	}
162 46ec0f24 2002-05-27 alex } /* Resolve_Name */
163 46ec0f24 2002-05-27 alex 
164 46ec0f24 2002-05-27 alex 
165 46ec0f24 2002-05-27 alex LOCAL VOID
166 46ec0f24 2002-05-27 alex Do_ResolveAddr( struct sockaddr_in *Addr, INT w_fd )
167 46ec0f24 2002-05-27 alex {
168 46ec0f24 2002-05-27 alex 	/* Resolver Sub-Prozess: IP aufloesen und Ergebnis in Pipe schreiben. */
169 46ec0f24 2002-05-27 alex 
170 46ec0f24 2002-05-27 alex 	CHAR hostname[HOST_LEN];
171 46ec0f24 2002-05-27 alex 	struct hostent *h;
172 46ec0f24 2002-05-27 alex 
173 46ec0f24 2002-05-27 alex 	Log_Resolver( LOG_DEBUG, "Now resolving %s ...", inet_ntoa( Addr->sin_addr ));
174 46ec0f24 2002-05-27 alex 
175 46ec0f24 2002-05-27 alex 	/* Namen aufloesen */
176 46ec0f24 2002-05-27 alex 	h = gethostbyaddr( (CHAR *)&Addr->sin_addr, sizeof( Addr->sin_addr ), AF_INET );
177 695631b2 2002-12-26 alex 	if( h ) strlcpy( hostname, h->h_name, sizeof( hostname ));
178 46ec0f24 2002-05-27 alex 	else
179 46ec0f24 2002-05-27 alex 	{
180 46ec0f24 2002-05-27 alex #ifdef h_errno
181 46ec0f24 2002-05-27 alex 		Log_Resolver( LOG_WARNING, "Can't resolve address \"%s\": %s!", inet_ntoa( Addr->sin_addr ), Get_Error( h_errno ));
182 46ec0f24 2002-05-27 alex #else
183 46ec0f24 2002-05-27 alex 		Log_Resolver( LOG_WARNING, "Can't resolve address \"%s\"!", inet_ntoa( Addr->sin_addr ));
184 46ec0f24 2002-05-27 alex #endif	
185 695631b2 2002-12-26 alex 		strlcpy( hostname, inet_ntoa( Addr->sin_addr ), sizeof( hostname ));
186 46ec0f24 2002-05-27 alex 	}
187 46ec0f24 2002-05-27 alex 
188 46ec0f24 2002-05-27 alex 	/* Antwort an Parent schreiben */
189 46ec0f24 2002-05-27 alex 	if( write( w_fd, hostname, strlen( hostname ) + 1 ) != ( strlen( hostname ) + 1 ))
190 46ec0f24 2002-05-27 alex 	{
191 46ec0f24 2002-05-27 alex 		Log_Resolver( LOG_CRIT, "Resolver: Can't write to parent: %s!", strerror( errno ));
192 46ec0f24 2002-05-27 alex 		close( w_fd );
193 46ec0f24 2002-05-27 alex 		return;
194 46ec0f24 2002-05-27 alex 	}
195 46ec0f24 2002-05-27 alex 
196 46ec0f24 2002-05-27 alex 	Log_Resolver( LOG_DEBUG, "Ok, translated %s to \"%s\".", inet_ntoa( Addr->sin_addr ), hostname );
197 46ec0f24 2002-05-27 alex } /* Do_ResolveAddr */
198 46ec0f24 2002-05-27 alex 
199 46ec0f24 2002-05-27 alex 
200 46ec0f24 2002-05-27 alex LOCAL VOID
201 46ec0f24 2002-05-27 alex Do_ResolveName( CHAR *Host, INT w_fd )
202 46ec0f24 2002-05-27 alex {
203 46ec0f24 2002-05-27 alex 	/* Resolver Sub-Prozess: Name aufloesen und Ergebnis in Pipe schreiben. */
204 46ec0f24 2002-05-27 alex 
205 46ec0f24 2002-05-27 alex 	CHAR ip[16];
206 46ec0f24 2002-05-27 alex 	struct hostent *h;
207 46ec0f24 2002-05-27 alex 	struct in_addr *addr;
208 46ec0f24 2002-05-27 alex 
209 46ec0f24 2002-05-27 alex 	Log_Resolver( LOG_DEBUG, "Now resolving \"%s\" ...", Host );
210 46ec0f24 2002-05-27 alex 
211 46ec0f24 2002-05-27 alex 	/* Namen aufloesen */
212 46ec0f24 2002-05-27 alex 	h = gethostbyname( Host );
213 46ec0f24 2002-05-27 alex 	if( h )
214 46ec0f24 2002-05-27 alex 	{
215 46ec0f24 2002-05-27 alex 		addr = (struct in_addr *)h->h_addr;
216 695631b2 2002-12-26 alex 		strlcpy( ip, inet_ntoa( *addr ), sizeof( ip ));
217 46ec0f24 2002-05-27 alex 	}
218 46ec0f24 2002-05-27 alex 	else
219 46ec0f24 2002-05-27 alex 	{
220 46ec0f24 2002-05-27 alex #ifdef h_errno
221 46ec0f24 2002-05-27 alex 		Log_Resolver( LOG_WARNING, "Can't resolve \"%s\": %s!", Host, Get_Error( h_errno ));
222 46ec0f24 2002-05-27 alex #else
223 46ec0f24 2002-05-27 alex 		Log_Resolver( LOG_WARNING, "Can't resolve \"%s\"!", Host );
224 46ec0f24 2002-05-27 alex #endif
225 46ec0f24 2002-05-27 alex 		strcpy( ip, "" );
226 46ec0f24 2002-05-27 alex 	}
227 46ec0f24 2002-05-27 alex 
228 46ec0f24 2002-05-27 alex 	/* Antwort an Parent schreiben */
229 46ec0f24 2002-05-27 alex 	if( write( w_fd, ip, strlen( ip ) + 1 ) != ( strlen( ip ) + 1 ))
230 46ec0f24 2002-05-27 alex 	{
231 46ec0f24 2002-05-27 alex 		Log_Resolver( LOG_CRIT, "Resolver: Can't write to parent: %s!", strerror( errno ));
232 46ec0f24 2002-05-27 alex 		close( w_fd );
233 46ec0f24 2002-05-27 alex 		return;
234 46ec0f24 2002-05-27 alex 	}
235 46ec0f24 2002-05-27 alex 
236 46ec0f24 2002-05-27 alex 	if( ip[0] ) Log_Resolver( LOG_DEBUG, "Ok, translated \"%s\" to %s.", Host, ip );
237 46ec0f24 2002-05-27 alex } /* Do_ResolveName */
238 46ec0f24 2002-05-27 alex 
239 46ec0f24 2002-05-27 alex 
240 46ec0f24 2002-05-27 alex #ifdef h_errno
241 46ec0f24 2002-05-27 alex 
242 46ec0f24 2002-05-27 alex LOCAL CHAR *
243 46ec0f24 2002-05-27 alex Get_Error( INT H_Error )
244 46ec0f24 2002-05-27 alex {
245 46ec0f24 2002-05-27 alex 	/* Fehlerbeschreibung fuer H_Error liefern */
246 46ec0f24 2002-05-27 alex 
247 46ec0f24 2002-05-27 alex 	switch( H_Error )
248 46ec0f24 2002-05-27 alex 	{
249 46ec0f24 2002-05-27 alex 		case HOST_NOT_FOUND:
250 46ec0f24 2002-05-27 alex 			return "host not found";
251 46ec0f24 2002-05-27 alex 		case NO_DATA:
252 46ec0f24 2002-05-27 alex 			return "name valid but no IP address defined";
253 46ec0f24 2002-05-27 alex 		case NO_RECOVERY:
254 46ec0f24 2002-05-27 alex 			return "name server error";
255 46ec0f24 2002-05-27 alex 		case TRY_AGAIN:
256 46ec0f24 2002-05-27 alex 			return "name server temporary not available";
257 46ec0f24 2002-05-27 alex 		default:
258 46ec0f24 2002-05-27 alex 			return "unknown error";
259 46ec0f24 2002-05-27 alex 	}
260 46ec0f24 2002-05-27 alex } /* Get_Error */
261 46ec0f24 2002-05-27 alex 
262 46ec0f24 2002-05-27 alex #endif
263 46ec0f24 2002-05-27 alex 
264 46ec0f24 2002-05-27 alex 
265 46ec0f24 2002-05-27 alex /* -eof- */