2 * ngIRCd -- The Next Generation IRC Daemon
3 * Copyright (c)2001-2014 Alexander Barton (alex@barton.de) and Contributors.
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.
12 #define RESOLVER_TIMEOUT (Conf_PongTimeout*3)/4
18 * Asynchronous resolver
27 #include <sys/types.h>
28 #include <sys/socket.h>
29 #include <netinet/in.h>
41 #include "ng_ipaddr.h"
45 static void Do_ResolveAddr PARAMS(( const ng_ipaddr_t *Addr, int Sock, int w_fd ));
46 static void Do_ResolveName PARAMS(( const char *Host, int w_fd ));
49 extern bool Conf_ConnectIPv4;
50 extern bool Conf_ConnectIPv6;
55 * Resolve IP (asynchronous!).
58 Resolve_Addr(PROC_STAT * s, const ng_ipaddr_t *Addr, int identsock,
59 void (*cbfunc) (int, short))
66 pid = Proc_Fork(s, pipefd, cbfunc, RESOLVER_TIMEOUT);
68 LogDebug("Resolver for %s created (PID %d).", ng_ipaddr_tostr(Addr), pid);
70 } else if( pid == 0 ) {
72 Log_Init_Subprocess("Resolver");
73 Conn_CloseAllSockets(identsock);
74 Do_ResolveAddr(Addr, identsock, pipefd[1]);
75 Log_Exit_Subprocess("Resolver");
83 * Resolve hostname (asynchronous!).
86 Resolve_Name( PROC_STAT *s, const char *Host, void (*cbfunc)(int, short))
93 pid = Proc_Fork(s, pipefd, cbfunc, RESOLVER_TIMEOUT);
96 Log( LOG_DEBUG, "Resolver for \"%s\" created (PID %d).", Host, pid );
98 } else if( pid == 0 ) {
100 Log_Init_Subprocess("Resolver");
101 Conn_CloseAllSockets(NONE);
102 Do_ResolveName(Host, pipefd[1]);
103 Log_Exit_Subprocess("Resolver");
109 #if !defined(HAVE_WORKING_GETADDRINFO) || !defined(HAVE_GETNAMEINFO)
112 Get_Error( int H_Error )
114 /* Get error message for H_Error */
117 return "host not found";
119 return "name valid but no IP address defined";
121 return "name server error";
123 return "name server temporary not available";
125 return "unknown error";
131 /* Do "IDENT" (aka "AUTH") lookup and append result to resolved_addr array */
133 Do_IdentQuery(int identsock, array *resolved_addr)
141 Log_Subprocess(LOG_DEBUG, "Doing IDENT lookup on socket %d ...",
143 res = ident_id( identsock, 10 );
144 Log_Subprocess(LOG_DEBUG, "Ok, IDENT lookup on socket %d done: \"%s\"",
145 identsock, res ? res : "(NULL)");
146 if (!res) /* no result */
148 if (!array_cats(resolved_addr, res))
149 Log_Subprocess(LOG_WARNING,
150 "Resolver: Cannot copy IDENT result: %s!",
156 (void) resolved_addr;
162 * perform reverse DNS lookup and put result string into resbuf.
163 * If no hostname could be obtained, this function stores the string representation of
164 * the IP address in resbuf and returns false.
165 * @param IpAddr ip address to resolve
166 * @param resbuf result buffer to store DNS name/string representation of ip address
167 * @param reslen size of result buffer (must be >= NGT_INET_ADDRSTRLEN)
168 * @return true if reverse lookup successful, false otherwise
171 ReverseLookup(const ng_ipaddr_t *IpAddr, char *resbuf, size_t reslen)
173 char tmp_ip_str[NG_INET_ADDRSTRLEN];
175 #ifdef HAVE_GETNAMEINFO
176 static const char funcname[]="getnameinfo";
181 res = getnameinfo((struct sockaddr *) IpAddr, ng_ipaddr_salen(IpAddr),
182 resbuf, (socklen_t)reslen, NULL, 0, NI_NAMEREQD);
186 if (res == EAI_SYSTEM)
187 errmsg = strerror(errno);
189 errmsg = gai_strerror(res);
191 const struct sockaddr_in *Addr = (const struct sockaddr_in *) IpAddr;
193 static const char funcname[]="gethostbyaddr";
195 h = gethostbyaddr((char *)&Addr->sin_addr, sizeof(Addr->sin_addr), AF_INET);
197 if (strlcpy(resbuf, h->h_name, reslen) < reslen)
199 errmsg = "hostname too long";
202 errmsg = Get_Error(h_errno);
204 errmsg = "unknown error";
205 # endif /* h_errno */
207 #endif /* HAVE_GETNAMEINFO */
210 assert(reslen >= NG_INET_ADDRSTRLEN);
211 ng_ipaddr_tostr_r(IpAddr, tmp_ip_str);
213 Log_Subprocess(LOG_WARNING, "Can't resolve address \"%s\": %s [%s].",
214 tmp_ip_str, errmsg, funcname);
215 strlcpy(resbuf, tmp_ip_str, reslen);
221 * perform DNS lookup of given host name and fill IpAddr with a list of
222 * ip addresses associated with that name.
223 * ip addresses found are stored in the "array *IpAddr" argument (type ng_ipaddr_t)
224 * @param hostname The domain name to look up.
225 * @param IpAddr pointer to empty and initialized array to store results
226 * @return true if lookup successful, false if domain name not found
229 #ifdef HAVE_WORKING_GETADDRINFO
230 ForwardLookup(const char *hostname, array *IpAddr, int af)
232 ForwardLookup(const char *hostname, array *IpAddr, UNUSED int af)
237 #ifdef HAVE_WORKING_GETADDRINFO
239 struct addrinfo *a, *ai_results;
240 static struct addrinfo hints;
242 hints.ai_socktype = SOCK_STREAM;
243 hints.ai_protocol = IPPROTO_TCP;
244 hints.ai_family = af;
246 memset(&addr, 0, sizeof(addr));
248 res = getaddrinfo(hostname, NULL, &hints, &ai_results);
252 Log_Subprocess(LOG_WARNING, "Can't resolve \"%s\": %s", hostname, strerror(errno));
255 Log_Subprocess(LOG_WARNING, "Can't resolve \"%s\": %s", hostname, gai_strerror(res));
259 for (a = ai_results; a != NULL; a = a->ai_next) {
260 assert((size_t)a->ai_addrlen <= sizeof(addr));
262 if ((size_t)a->ai_addrlen > sizeof(addr))
265 memcpy(&addr, a->ai_addr, a->ai_addrlen);
267 if (!array_catb(IpAddr, (char *)&addr, sizeof(addr)))
271 freeaddrinfo(ai_results);
274 struct hostent *h = gethostbyname(hostname);
278 Log_Subprocess(LOG_WARNING, "Can't resolve \"%s\": %s",
279 hostname, Get_Error(h_errno));
281 Log_Subprocess(LOG_WARNING, "Can't resolve \"%s\"", hostname);
285 memset(&addr, 0, sizeof(addr));
287 addr.sin4.sin_family = AF_INET;
288 memcpy(&addr.sin4.sin_addr, h->h_addr, sizeof(struct in_addr));
290 return array_copyb(IpAddr, (char *)&addr, sizeof(addr));
291 #endif /* HAVE_GETADDRINFO */
296 Addr_in_list(const array *resolved_addr, const ng_ipaddr_t *Addr)
298 char tmp_ip_str[NG_INET_ADDRSTRLEN];
299 const ng_ipaddr_t *tmpAddrs = array_start(resolved_addr);
300 size_t len = array_length(resolved_addr, sizeof(*tmpAddrs));
306 if (ng_ipaddr_ipequal(Addr, tmpAddrs))
311 /* failed; print list of addresses */
312 ng_ipaddr_tostr_r(Addr, tmp_ip_str);
313 len = array_length(resolved_addr, sizeof(*tmpAddrs));
314 tmpAddrs = array_start(resolved_addr);
317 Log_Subprocess(LOG_WARNING, "Address mismatch: %s != %s",
318 tmp_ip_str, ng_ipaddr_tostr(tmpAddrs));
328 Log_Forgery_NoIP(const char *ip, const char *host)
330 Log_Subprocess(LOG_WARNING,
331 "Possible forgery: %s resolved to \"%s\", which has no IP address!",
336 Log_Forgery_WrongIP(const char *ip, const char *host)
338 Log_Subprocess(LOG_WARNING,
339 "Possible forgery: %s resolved to \"%s\", which points to a different address!",
345 ArrayWrite(int fd, const array *a)
347 size_t len = array_bytes(a);
348 const char *data = array_start(a);
352 if( (size_t)write(fd, data, len) != len )
353 Log_Subprocess( LOG_CRIT, "Resolver: Can't write to parent: %s!",
359 Do_ResolveAddr(const ng_ipaddr_t *Addr, int identsock, int w_fd)
361 /* Resolver sub-process: resolve IP address and write result into
363 char hostname[CLIENT_HOST_LEN];
364 char tmp_ip_str[NG_INET_ADDRSTRLEN];
368 array_init(&resolved_addr);
369 ng_ipaddr_tostr_r(Addr, tmp_ip_str);
370 Log_Subprocess(LOG_DEBUG, "Now resolving %s ...", tmp_ip_str);
371 if (!ReverseLookup(Addr, hostname, sizeof(hostname)))
374 if (ForwardLookup(hostname, &resolved_addr, ng_ipaddr_af(Addr))) {
375 if (!Addr_in_list(&resolved_addr, Addr)) {
376 Log_Forgery_WrongIP(tmp_ip_str, hostname);
377 strlcpy(hostname, tmp_ip_str, sizeof(hostname));
380 Log_Forgery_NoIP(tmp_ip_str, hostname);
381 strlcpy(hostname, tmp_ip_str, sizeof(hostname));
383 Log_Subprocess(LOG_DEBUG, "Ok, translated %s to \"%s\".", tmp_ip_str, hostname);
385 len = strlen(hostname);
386 hostname[len] = '\n';
387 if (!array_copyb(&resolved_addr, hostname, ++len)) {
388 Log_Subprocess(LOG_CRIT,
389 "Resolver: Can't copy resolved name: %s!",
391 array_free(&resolved_addr);
395 Do_IdentQuery(identsock, &resolved_addr);
397 ArrayWrite(w_fd, &resolved_addr);
399 array_free(&resolved_addr);
400 } /* Do_ResolveAddr */
404 Do_ResolveName( const char *Host, int w_fd )
406 /* Resolver sub-process: resolve name and write result into pipe
412 Log_Subprocess(LOG_DEBUG, "Now resolving \"%s\" ...", Host);
414 array_init(&IpAddrs);
418 assert(Conf_ConnectIPv6 || Conf_ConnectIPv4);
420 if (!Conf_ConnectIPv6)
422 if (!Conf_ConnectIPv4)
427 if (!ForwardLookup(Host, &IpAddrs, af)) {
431 len = array_length(&IpAddrs, sizeof(*addr));
433 addr = array_start(&IpAddrs);
435 for (; len > 0; --len,addr++) {
436 Log_Subprocess(LOG_DEBUG, "translated \"%s\" to %s.",
437 Host, ng_ipaddr_tostr(addr));
439 /* Write result into pipe to parent */
440 ArrayWrite(w_fd, &IpAddrs);
442 array_free(&IpAddrs);
443 } /* Do_ResolveName */