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);
97 Log( LOG_DEBUG, "Resolver for \"%s\" created (PID %d).", Host, pid );
100 } else if( pid == 0 ) {
102 Log_Init_Subprocess("Resolver");
103 Conn_CloseAllSockets(NONE);
104 Do_ResolveName(Host, pipefd[1]);
105 Log_Exit_Subprocess("Resolver");
111 #if !defined(HAVE_WORKING_GETADDRINFO) || !defined(HAVE_GETNAMEINFO)
114 Get_Error( int H_Error )
116 /* Get error message for H_Error */
119 return "host not found";
121 return "name valid but no IP address defined";
123 return "name server error";
125 return "name server temporary not available";
127 return "unknown error";
133 /* Do "IDENT" (aka "AUTH") lookup and append result to resolved_addr array */
135 Do_IdentQuery(int identsock, array *resolved_addr)
144 Log_Subprocess(LOG_DEBUG, "Doing IDENT lookup on socket %d ...",
147 res = ident_id( identsock, 10 );
149 Log_Subprocess(LOG_DEBUG, "Ok, IDENT lookup on socket %d done: \"%s\"",
150 identsock, res ? res : "(NULL)");
152 if (!res) /* no result */
154 if (!array_cats(resolved_addr, res))
155 Log_Subprocess(LOG_WARNING,
156 "Resolver: Cannot copy IDENT result: %s!",
162 (void) resolved_addr;
168 * perform reverse DNS lookup and put result string into resbuf.
169 * If no hostname could be obtained, this function stores the string representation of
170 * the IP address in resbuf and returns false.
171 * @param IpAddr ip address to resolve
172 * @param resbuf result buffer to store DNS name/string representation of ip address
173 * @param reslen size of result buffer (must be >= NGT_INET_ADDRSTRLEN)
174 * @return true if reverse lookup successful, false otherwise
177 ReverseLookup(const ng_ipaddr_t *IpAddr, char *resbuf, size_t reslen)
179 char tmp_ip_str[NG_INET_ADDRSTRLEN];
181 #ifdef HAVE_GETNAMEINFO
182 static const char funcname[]="getnameinfo";
187 res = getnameinfo((struct sockaddr *) IpAddr, ng_ipaddr_salen(IpAddr),
188 resbuf, (socklen_t)reslen, NULL, 0, NI_NAMEREQD);
192 if (res == EAI_SYSTEM)
193 errmsg = strerror(errno);
195 errmsg = gai_strerror(res);
197 const struct sockaddr_in *Addr = (const struct sockaddr_in *) IpAddr;
199 static const char funcname[]="gethostbyaddr";
201 h = gethostbyaddr((char *)&Addr->sin_addr, sizeof(Addr->sin_addr), AF_INET);
203 if (strlcpy(resbuf, h->h_name, reslen) < reslen)
205 errmsg = "hostname too long";
208 errmsg = Get_Error(h_errno);
210 errmsg = "unknown error";
211 # endif /* h_errno */
213 #endif /* HAVE_GETNAMEINFO */
216 assert(reslen >= NG_INET_ADDRSTRLEN);
217 ng_ipaddr_tostr_r(IpAddr, tmp_ip_str);
219 Log_Subprocess(LOG_WARNING, "Can't resolve address \"%s\": %s [%s].",
220 tmp_ip_str, errmsg, funcname);
221 strlcpy(resbuf, tmp_ip_str, reslen);
227 * perform DNS lookup of given host name and fill IpAddr with a list of
228 * ip addresses associated with that name.
229 * ip addresses found are stored in the "array *IpAddr" argument (type ng_ipaddr_t)
230 * @param hostname The domain name to look up.
231 * @param IpAddr pointer to empty and initialized array to store results
232 * @return true if lookup successful, false if domain name not found
235 #ifdef HAVE_WORKING_GETADDRINFO
236 ForwardLookup(const char *hostname, array *IpAddr, int af)
238 ForwardLookup(const char *hostname, array *IpAddr, UNUSED int af)
243 #ifdef HAVE_WORKING_GETADDRINFO
245 struct addrinfo *a, *ai_results;
246 static struct addrinfo hints;
248 hints.ai_socktype = SOCK_STREAM;
249 hints.ai_protocol = IPPROTO_TCP;
250 hints.ai_family = af;
252 memset(&addr, 0, sizeof(addr));
254 res = getaddrinfo(hostname, NULL, &hints, &ai_results);
258 Log_Subprocess(LOG_WARNING, "Can't resolve \"%s\": %s", hostname, strerror(errno));
261 Log_Subprocess(LOG_WARNING, "Can't resolve \"%s\": %s", hostname, gai_strerror(res));
265 for (a = ai_results; a != NULL; a = a->ai_next) {
266 assert((size_t)a->ai_addrlen <= sizeof(addr));
268 if ((size_t)a->ai_addrlen > sizeof(addr))
271 memcpy(&addr, a->ai_addr, a->ai_addrlen);
273 if (!array_catb(IpAddr, (char *)&addr, sizeof(addr)))
277 freeaddrinfo(ai_results);
280 struct hostent *h = gethostbyname(hostname);
284 Log_Subprocess(LOG_WARNING, "Can't resolve \"%s\": %s",
285 hostname, Get_Error(h_errno));
287 Log_Subprocess(LOG_WARNING, "Can't resolve \"%s\"", hostname);
291 memset(&addr, 0, sizeof(addr));
293 addr.sin4.sin_family = AF_INET;
294 memcpy(&addr.sin4.sin_addr, h->h_addr, sizeof(struct in_addr));
296 return array_copyb(IpAddr, (char *)&addr, sizeof(addr));
297 #endif /* HAVE_GETADDRINFO */
302 Addr_in_list(const array *resolved_addr, const ng_ipaddr_t *Addr)
304 char tmp_ip_str[NG_INET_ADDRSTRLEN];
305 const ng_ipaddr_t *tmpAddrs = array_start(resolved_addr);
306 size_t len = array_length(resolved_addr, sizeof(*tmpAddrs));
312 if (ng_ipaddr_ipequal(Addr, tmpAddrs))
317 /* failed; print list of addresses */
318 ng_ipaddr_tostr_r(Addr, tmp_ip_str);
319 len = array_length(resolved_addr, sizeof(*tmpAddrs));
320 tmpAddrs = array_start(resolved_addr);
323 Log_Subprocess(LOG_WARNING, "Address mismatch: %s != %s",
324 tmp_ip_str, ng_ipaddr_tostr(tmpAddrs));
334 Log_Forgery_NoIP(const char *ip, const char *host)
336 Log_Subprocess(LOG_WARNING,
337 "Possible forgery: %s resolved to \"%s\", which has no IP address!",
342 Log_Forgery_WrongIP(const char *ip, const char *host)
344 Log_Subprocess(LOG_WARNING,
345 "Possible forgery: %s resolved to \"%s\", which points to a different address!",
351 ArrayWrite(int fd, const array *a)
353 size_t len = array_bytes(a);
354 const char *data = array_start(a);
358 if( (size_t)write(fd, data, len) != len )
359 Log_Subprocess( LOG_CRIT, "Resolver: Can't write to parent: %s!",
365 Do_ResolveAddr(const ng_ipaddr_t *Addr, int identsock, int w_fd)
367 /* Resolver sub-process: resolve IP address and write result into
369 char hostname[CLIENT_HOST_LEN];
370 char tmp_ip_str[NG_INET_ADDRSTRLEN];
374 array_init(&resolved_addr);
375 ng_ipaddr_tostr_r(Addr, tmp_ip_str);
377 Log_Subprocess(LOG_DEBUG, "Now resolving %s ...", tmp_ip_str);
379 if (!ReverseLookup(Addr, hostname, sizeof(hostname)))
382 if (ForwardLookup(hostname, &resolved_addr, ng_ipaddr_af(Addr))) {
383 if (!Addr_in_list(&resolved_addr, Addr)) {
384 Log_Forgery_WrongIP(tmp_ip_str, hostname);
385 strlcpy(hostname, tmp_ip_str, sizeof(hostname));
388 Log_Forgery_NoIP(tmp_ip_str, hostname);
389 strlcpy(hostname, tmp_ip_str, sizeof(hostname));
392 Log_Subprocess(LOG_DEBUG, "Ok, translated %s to \"%s\".", tmp_ip_str, hostname);
395 len = strlen(hostname);
396 hostname[len] = '\n';
397 if (!array_copyb(&resolved_addr, hostname, ++len)) {
398 Log_Subprocess(LOG_CRIT,
399 "Resolver: Can't copy resolved name: %s!",
401 array_free(&resolved_addr);
405 Do_IdentQuery(identsock, &resolved_addr);
407 ArrayWrite(w_fd, &resolved_addr);
409 array_free(&resolved_addr);
410 } /* Do_ResolveAddr */
414 Do_ResolveName( const char *Host, int w_fd )
416 /* Resolver sub-process: resolve name and write result into pipe
424 Log_Subprocess(LOG_DEBUG, "Now resolving \"%s\" ...", Host);
426 array_init(&IpAddrs);
430 assert(Conf_ConnectIPv6 || Conf_ConnectIPv4);
432 if (!Conf_ConnectIPv6)
434 if (!Conf_ConnectIPv4)
439 if (!ForwardLookup(Host, &IpAddrs, af)) {
444 len = array_length(&IpAddrs, sizeof(*addr));
446 addr = array_start(&IpAddrs);
448 for (; len > 0; --len,addr++) {
449 Log_Subprocess(LOG_DEBUG, "translated \"%s\" to %s.",
450 Host, ng_ipaddr_tostr(addr));
453 /* Write result into pipe to parent */
454 ArrayWrite(w_fd, &IpAddrs);
456 array_free(&IpAddrs);
457 } /* Do_ResolveName */