1 /************************************************************************
2 * IRC - Internet Relay Chat, src/s_auth.c
3 * Copyright (C) 1992 Darren Reed
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 1, or (at your option)
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 * July 6, 1999 - Rewrote most of the code here. When a client connects
21 * to the server and passes initial socket validation checks, it
22 * is owned by this module (auth) which returns it to the rest of the
23 * server when dns and auth queries are finished. Until the client is
24 * released, the server does not know it exists and does not process
25 * any messages from it.
26 * --Bleep Thomas Helvey <tomh@inxpress.net>
29 * @brief Implementation of DNS and ident lookups.
38 #include "ircd_alloc.h"
39 #include "ircd_chattr.h"
40 #include "ircd_events.h"
41 #include "ircd_features.h"
43 #include "ircd_osdep.h"
44 #include "ircd_snprintf.h"
45 #include "ircd_string.h"
48 #include "querycmds.h"
55 #include "sys.h" /* TRUE bleah */
57 #include <netdb.h> /* struct hostent */
63 /* #include <assert.h> -- Now using assert in ircd_log.h */
64 #include <sys/socket.h>
65 #include <sys/ioctl.h>
67 /** Array of message text (with length) pairs for AUTH status
68 * messages. Indexed using #ReportType. */
72 } HeaderMessages [] = {
73 #define MSG(STR) { STR, sizeof(STR) - 1 }
74 MSG("NOTICE AUTH :*** Looking up your hostname\r\n"),
75 MSG("NOTICE AUTH :*** Found your hostname\r\n"),
76 MSG("NOTICE AUTH :*** Found your hostname, cached\r\n"),
77 MSG("NOTICE AUTH :*** Couldn't look up your hostname\r\n"),
78 MSG("NOTICE AUTH :*** Checking Ident\r\n"),
79 MSG("NOTICE AUTH :*** Got ident response\r\n"),
80 MSG("NOTICE AUTH :*** No ident response\r\n"),
81 MSG("NOTICE AUTH :*** Your forward and reverse DNS do not match, "
82 "ignoring hostname.\r\n"),
83 MSG("NOTICE AUTH :*** Invalid hostname\r\n")
87 /** Enum used to index messages in the HeaderMessages[] array. */
100 /** Sends response \a r (from #ReportType) to client \a c. */
101 #define sendheader(c, r) \
102 send(cli_fd(c), HeaderMessages[(r)].message, HeaderMessages[(r)].length, 0)
104 static void release_auth_client(struct Client* client);
105 void free_auth_request(struct AuthRequest* auth);
107 /** Verify that a hostname is valid, i.e., only contains characters
108 * valid for a hostname and that a hostname is not too long.
109 * @param host Hostname to check.
110 * @param maxlen Maximum length of hostname, not including NUL terminator.
111 * @return Non-zero if the hostname is valid.
114 auth_verify_hostname(const char *host, int maxlen)
118 /* Walk through the host name */
119 for (i = 0; host[i]; i++)
120 /* If it's not a hostname character or if it's too long, return false */
121 if (!IsHostChar(host[i]) || i >= maxlen)
124 return 1; /* it's a valid hostname */
127 /** Timeout a given auth request.
128 * @param ev A timer event whose associated data is the expired struct
131 static void auth_timeout_callback(struct Event* ev)
133 struct AuthRequest* auth;
135 assert(0 != ev_timer(ev));
136 assert(0 != t_data(ev_timer(ev)));
138 auth = (struct AuthRequest*) t_data(ev_timer(ev));
140 if (ev_type(ev) == ET_DESTROY) { /* being destroyed */
141 auth->flags &= ~AM_TIMEOUT;
143 if (!(auth->flags & AM_FREE_MASK)) {
144 Debug((DEBUG_LIST, "Freeing auth from timeout callback; %p [%p]", auth,
146 MyFree(auth); /* done with it, finally */
149 assert(ev_type(ev) == ET_EXPIRE);
151 destroy_auth_request(auth, 1);
155 /** Handle socket I/O activity.
156 * @param ev A socket event whos associated data is the active struct
159 static void auth_sock_callback(struct Event* ev)
161 struct AuthRequest* auth;
163 assert(0 != ev_socket(ev));
164 assert(0 != s_data(ev_socket(ev)));
166 auth = (struct AuthRequest*) s_data(ev_socket(ev));
168 switch (ev_type(ev)) {
169 case ET_DESTROY: /* being destroyed */
170 auth->flags &= ~AM_SOCKET;
172 if (!(auth->flags & AM_FREE_MASK)) {
173 Debug((DEBUG_LIST, "Freeing auth from sock callback; %p [%p]", auth,
175 MyFree(auth); /* done with it finally */
179 case ET_CONNECT: /* socket connection completed */
180 Debug((DEBUG_LIST, "Connection completed for auth %p [%p]; sending query",
181 auth, ev_socket(ev)));
182 socket_state(&auth->socket, SS_CONNECTED);
183 send_auth_query(auth);
186 case ET_READ: /* socket is readable */
187 case ET_EOF: /* end of file on socket */
188 case ET_ERROR: /* error on socket */
189 Debug((DEBUG_LIST, "Auth socket %p [%p] readable", auth, ev_socket(ev)));
190 read_auth_reply(auth);
194 assert(0 && "Unrecognized event in auth_socket_callback().");
199 /** Stop an auth request completely.
200 * @param auth The struct AuthRequest to cancel.
201 * @param send_reports If non-zero, report the failure to the user and
204 void destroy_auth_request(struct AuthRequest* auth, int send_reports)
206 if (IsDoingAuth(auth)) {
210 socket_del(&auth->socket);
213 if (send_reports && IsUserPort(auth->client))
214 sendheader(auth->client, REPORT_FAIL_ID);
217 if (IsDNSPending(auth)) {
218 delete_resolver_queries(auth);
219 if (send_reports && IsUserPort(auth->client))
220 sendheader(auth->client, REPORT_FAIL_DNS);
224 log_write(LS_RESOLVER, L_INFO, 0, "DNS/AUTH timeout %s",
225 get_client_name(auth->client, HIDE_IP));
226 release_auth_client(auth->client);
229 free_auth_request(auth);
232 /** Allocate a new auth request.
233 * @param client The client being looked up.
234 * @return The newly allocated auth request.
236 static struct AuthRequest* make_auth_request(struct Client* client)
238 struct AuthRequest* auth =
239 (struct AuthRequest*) MyMalloc(sizeof(struct AuthRequest));
241 memset(auth, 0, sizeof(struct AuthRequest));
242 auth->flags = AM_TIMEOUT;
244 auth->client = client;
245 cli_auth(client) = auth;
246 timer_add(timer_init(&auth->timeout), auth_timeout_callback, (void*) auth,
247 TT_RELATIVE, feature_int(FEAT_AUTH_TIMEOUT));
251 /** Clean up auth request allocations (event loop objects, etc).
252 * @param auth The request to clean up.
254 void free_auth_request(struct AuthRequest* auth)
258 Debug((DEBUG_LIST, "Deleting auth socket for %p", auth->client));
259 socket_del(&auth->socket);
261 Debug((DEBUG_LIST, "Deleting auth timeout timer for %p", auth->client));
262 timer_del(&auth->timeout);
265 /** Release auth client from auth system. This adds the client into
266 * the local client lists so it can be read by the main io processing
268 * @param client The client to release.
270 static void release_auth_client(struct Client* client)
273 cli_auth(client) = 0;
274 cli_lasttime(client) = cli_since(client) = CurrentTime;
275 if (cli_fd(client) > HighestFd)
276 HighestFd = cli_fd(client);
277 LocalClientArray[cli_fd(client)] = client;
279 add_client_to_list(client);
280 socket_events(&(cli_socket(client)), SOCK_ACTION_SET | SOCK_EVENT_READABLE);
281 Debug((DEBUG_INFO, "Auth: release_auth_client %s@%s[%s]",
282 cli_username(client), cli_sockhost(client), cli_sock_ip(client)));
285 /** Terminate a client's connection due to auth failure.
286 * @param auth The client to terminate.
288 static void auth_kill_client(struct AuthRequest* auth)
292 if (IsDNSPending(auth))
293 delete_resolver_queries(auth);
294 IPcheck_disconnect(auth->client);
295 Count_unknowndisconnects(UserStats);
296 cli_auth(auth->client) = 0;
297 free_client(auth->client);
298 free_auth_request(auth);
301 /** Handle a complete DNS lookup. Send the client on it's way to a
302 * connection completion, regardless of success or failure -- unless
303 * there was a mismatch and KILL_IPMISMATCH is set.
304 * @param vptr The pending struct AuthRequest.
305 * @param hp Pointer to the DNS reply (or NULL, if lookup failed).
307 static void auth_dns_callback(void* vptr, const struct irc_in_addr *addr, const char *h_name)
309 struct AuthRequest* auth = (struct AuthRequest*) vptr;
312 * need to do this here so auth_kill_client doesn't
313 * try have the resolver delete the query it's about
314 * to delete anyways. --Bleep
316 ClearDNSPending(auth);
320 * Verify that the host to ip mapping is correct both ways and that
321 * the ip#(s) for the socket is listed for the host.
323 if (irc_in_addr_cmp(addr, &cli_ip(auth->client))) {
324 if (IsUserPort(auth->client))
325 sendheader(auth->client, REPORT_IP_MISMATCH);
326 sendto_opmask_butone(0, SNO_IPMISMATCH, "IP# Mismatch: %s != %s[%s]",
327 cli_sock_ip(auth->client), h_name,
329 if (feature_bool(FEAT_KILL_IPMISMATCH)) {
330 auth_kill_client(auth);
334 else if (!auth_verify_hostname(h_name, HOSTLEN))
336 if (IsUserPort(auth->client))
337 sendheader(auth->client, REPORT_INVAL_DNS);
341 ircd_strncpy(cli_sockhost(auth->client), h_name, HOSTLEN);
342 if (IsUserPort(auth->client))
343 sendheader(auth->client, REPORT_FIN_DNS);
348 * this should have already been done by s_bsd.c in add_connection
350 * strcpy(auth->client->sockhost, auth->client->sock_ip);
352 if (IsUserPort(auth->client))
353 sendheader(auth->client, REPORT_FAIL_DNS);
355 if (!IsDoingAuth(auth)) {
356 release_auth_client(auth->client);
357 free_auth_request(auth);
361 /** Handle auth send errors.
362 * @param auth The request that saw the failure.
363 * @param kill If non-zero, a critical error; close the client's connection.
365 static void auth_error(struct AuthRequest* auth, int kill)
367 ++ServerStats->is_abad;
372 socket_del(&auth->socket);
374 if (IsUserPort(auth->client))
375 sendheader(auth->client, REPORT_FAIL_ID);
379 * we can't read the client info from the client socket,
380 * close the client connection and free the client
381 * Need to do this before we ClearAuth(auth) so we know
382 * which list to remove the query from. --Bleep
384 auth_kill_client(auth);
390 if (!IsDNSPending(auth)) {
391 release_auth_client(auth->client);
392 free_auth_request(auth);
396 /** Flag the client to show an attempt to contact the ident server on
397 * the client's host. Should the connect or any later phase of the
398 * identifying process fail, it is aborted and the user is given a
399 * username of "unknown".
400 * @param auth The request for which to start the ident lookup.
401 * @return Non-zero on success; zero if unable to start the lookup.
403 static int start_auth_query(struct AuthRequest* auth)
405 struct irc_sockaddr remote_addr;
406 struct irc_sockaddr local_addr;
411 assert(0 != auth->client);
414 * get the local address of the client and bind to that to
415 * make the auth request. This used to be done only for
416 * ifdef VIRTUAL_HOST, but needs to be done for all clients
417 * since the ident request must originate from that same address--
418 * and machines with multiple IP addresses are common now
420 memset(&local_addr, 0, sizeof(local_addr));
421 os_get_sockname(cli_fd(auth->client), &local_addr);
423 fd = os_socket(&local_addr, SOCK_STREAM, "auth query");
425 ++ServerStats->is_abad;
428 if (IsUserPort(auth->client))
429 sendheader(auth->client, REPORT_DO_ID);
430 memcpy(&remote_addr.addr, &cli_ip(auth->client), sizeof(remote_addr.addr));
431 remote_addr.port = 113;
433 if ((result = os_connect_nonb(fd, &remote_addr)) == IO_FAILURE ||
434 !socket_add(&auth->socket, auth_sock_callback, (void*) auth,
435 result == IO_SUCCESS ? SS_CONNECTED : SS_CONNECTING,
436 SOCK_EVENT_READABLE, fd)) {
437 ServerStats->is_abad++;
439 * No error report from this...
442 if (IsUserPort(auth->client))
443 sendheader(auth->client, REPORT_FAIL_ID);
447 auth->flags |= AM_SOCKET;
450 SetAuthConnect(auth);
451 if (result == IO_SUCCESS)
452 send_auth_query(auth); /* this does a SetAuthPending(auth) for us */
457 /** Enum used to index ident reply fields in a human-readable way. */
458 enum IdentReplyFields {
466 /** Parse an ident reply line and extract the userid from it.
467 * @param reply The ident reply line.
468 * @return The userid, or NULL on parse failure.
470 static char* check_ident_reply(char* reply)
474 char* vector[USERID_TOKEN_COUNT];
475 int count = token_vector(reply, ':', vector, USERID_TOKEN_COUNT);
477 if (USERID_TOKEN_COUNT != count)
480 * second token is the reply type
482 token = vector[IDENT_REPLY_TYPE];
483 if (EmptyString(token))
486 while (IsSpace(*token))
489 if (0 != strncmp(token, "USERID", 6))
493 * third token is the os type
495 token = vector[IDENT_OS_TYPE];
496 if (EmptyString(token))
498 while (IsSpace(*token))
502 * Unless "OTHER" is specified as the operating system
503 * type, the server is expected to return the "normal"
504 * user identification of the owner of this connection.
505 * "Normal" in this context may be taken to mean a string
506 * of characters which uniquely identifies the connection
507 * owner such as a user identifier assigned by the system
508 * administrator and used by such user as a mail
509 * identifier, or as the "user" part of a user/password
510 * pair used to gain access to system resources. When an
511 * operating system is specified (e.g., anything but
512 * "OTHER"), the user identifier is expected to be in a
513 * more or less immediately useful form - e.g., something
514 * that could be used as an argument to "finger" or as a
517 if (0 == strncmp(token, "OTHER", 5))
520 * fourth token is the username
522 token = vector[IDENT_INFO];
523 if (EmptyString(token))
525 while (IsSpace(*token))
528 * look for the end of the username, terminators are '\0, @, <SPACE>, :'
530 for (end = token; *end; ++end) {
531 if (IsSpace(*end) || '@' == *end || ':' == *end)
538 /** Starts auth (identd) and dns queries for a client.
539 * @param client The client for which to start queries.
541 void start_auth(struct Client* client)
543 struct AuthRequest* auth = 0;
547 auth = make_auth_request(client);
550 Debug((DEBUG_INFO, "Beginning auth request on client %p", client));
552 if (!feature_bool(FEAT_NODNS)) {
553 if (irc_in_addr_is_loopback(&cli_ip(client)))
554 strcpy(cli_sockhost(client), cli_name(&me));
556 if (IsUserPort(auth->client))
557 sendheader(client, REPORT_DO_DNS);
558 gethost_byaddr(&cli_ip(client), auth_dns_callback, auth);
563 if (start_auth_query(auth)) {
564 Debug((DEBUG_LIST, "identd query for %p initiated successfully",
566 } else if (IsDNSPending(auth)) {
567 Debug((DEBUG_LIST, "identd query for %p not initiated successfully; "
568 "waiting on DNS", auth->client));
570 Debug((DEBUG_LIST, "identd query for %p not initiated successfully; "
571 "no DNS pending; releasing immediately", auth->client));
572 free_auth_request(auth);
573 release_auth_client(client);
577 /** Send the ident server a query giving "theirport , ourport". The
578 * write is only attempted *once* so it is deemed to be a fail if the
579 * entire write doesn't write all the data given. This shouldn't be a
580 * problem since the socket should have a write buffer far greater
581 * than this message to store it in should problems arise. -avalon
582 * @param auth The request to send.
584 void send_auth_query(struct AuthRequest* auth)
586 struct irc_sockaddr us;
587 struct irc_sockaddr them;
592 assert(0 != auth->client);
594 if (!os_get_sockname(cli_fd(auth->client), &us) ||
595 !os_get_peername(cli_fd(auth->client), &them)) {
599 ircd_snprintf(0, authbuf, sizeof(authbuf), "%u , %u\r\n",
600 (unsigned int) them.port,
601 (unsigned int) us.port);
603 if (IO_SUCCESS == os_send_nonb(auth->fd, authbuf, strlen(authbuf), &count)) {
604 ClearAuthConnect(auth);
605 SetAuthPending(auth);
612 /** Read the reply (if any) from the ident server we connected to. We
613 * only give it one shot, if the reply isn't good the first time fail
614 * the authentication entirely. --Bleep
615 * @param auth The request to read.
617 void read_auth_reply(struct AuthRequest* auth)
622 * rfc1453 sez we MUST accept 512 bytes
624 char buf[BUFSIZE + 1];
627 assert(0 != auth->client);
628 assert(auth == cli_auth(auth->client));
630 if (IO_SUCCESS == os_recv_nonb(auth->fd, buf, BUFSIZE, &len)) {
632 Debug((DEBUG_LIST, "Auth %p [%p] reply: %s", auth, &auth->socket, buf));
633 username = check_ident_reply(buf);
634 Debug((DEBUG_LIST, "Username: %s", username));
639 Debug((DEBUG_LIST, "Deleting auth [%p] socket %p", auth, &auth->socket));
640 socket_del(&auth->socket);
643 if (!EmptyString(username)) {
644 ircd_strncpy(cli_username(auth->client), username, USERLEN);
646 * Not needed, struct is zeroed by memset
647 * auth->client->username[USERLEN] = '\0';
649 SetGotId(auth->client);
650 ++ServerStats->is_asuc;
651 if (IsUserPort(auth->client))
652 sendheader(auth->client, REPORT_FIN_ID);
655 ++ServerStats->is_abad;
658 if (!IsDNSPending(auth)) {
659 release_auth_client(auth->client);
660 free_auth_request(auth);