ViewVC Help
View File | Revision Log | Show Annotations | View Changeset | Root Listing
root/svn/ircd-hybrid/trunk/src/s_auth.c
Revision: 2181
Committed: Tue Jun 4 11:03:41 2013 UTC (12 years, 2 months ago) by michael
Content type: text/x-csrc
File size: 15207 byte(s)
Log Message:
- Fixed debug assertion being triggered on ident lookup
  as reported by Stuart Walsh

File Contents

# Content
1 /*
2 * ircd-hybrid: an advanced Internet Relay Chat Daemon(ircd).
3 * s_auth.c: Functions for querying a users ident.
4 *
5 * Copyright (C) 2002 by the past and present ircd coders, and others.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
20 * USA
21 *
22 * $Id$
23 */
24
25 /*
26 * Changes:
27 * July 6, 1999 - Rewrote most of the code here. When a client connects
28 * to the server and passes initial socket validation checks, it
29 * is owned by this module (auth) which returns it to the rest of the
30 * server when dns and auth queries are finished. Until the client is
31 * released, the server does not know it exists and does not process
32 * any messages from it.
33 * --Bleep Thomas Helvey <tomh@inxpress.net>
34 */
35
36 #include "stdinc.h"
37 #include "list.h"
38 #include "ircd_defs.h"
39 #include "fdlist.h"
40 #include "s_auth.h"
41 #include "conf.h"
42 #include "client.h"
43 #include "event.h"
44 #include "hook.h"
45 #include "irc_string.h"
46 #include "ircd.h"
47 #include "packet.h"
48 #include "irc_res.h"
49 #include "s_bsd.h"
50 #include "log.h"
51 #include "send.h"
52 #include "mempool.h"
53
54
55 static const char *HeaderMessages[] = {
56 ":%s NOTICE AUTH :*** Looking up your hostname...",
57 ":%s NOTICE AUTH :*** Found your hostname",
58 ":%s NOTICE AUTH :*** Couldn't look up your hostname",
59 ":%s NOTICE AUTH :*** Checking Ident",
60 ":%s NOTICE AUTH :*** Got Ident response",
61 ":%s NOTICE AUTH :*** No Ident response",
62 ":%s NOTICE AUTH :*** Your forward and reverse DNS do not match, ignoring hostname.",
63 ":%s NOTICE AUTH :*** Your hostname is too long, ignoring hostname"
64 };
65
66 enum {
67 REPORT_DO_DNS,
68 REPORT_FIN_DNS,
69 REPORT_FAIL_DNS,
70 REPORT_DO_ID,
71 REPORT_FIN_ID,
72 REPORT_FAIL_ID,
73 REPORT_IP_MISMATCH,
74 REPORT_HOST_TOOLONG
75 };
76
77 #define sendheader(c, i) sendto_one((c), HeaderMessages[(i)], me.name)
78
79 static dlink_list auth_doing_list = { NULL, NULL, 0 };
80
81 static EVH timeout_auth_queries_event;
82
83 static PF read_auth_reply;
84 static CNCB auth_connect_callback;
85
86 /* auth_init
87 *
88 * Initialise the auth code
89 */
90 void
91 auth_init(void)
92 {
93 eventAddIsh("timeout_auth_queries_event", timeout_auth_queries_event, NULL, 1);
94 }
95
96 /*
97 * make_auth_request - allocate a new auth request
98 */
99 static struct AuthRequest *
100 make_auth_request(struct Client *client)
101 {
102 struct AuthRequest *request = &client->localClient->auth;
103
104 memset(request, 0, sizeof(*request));
105
106 request->client = client;
107 request->timeout = CurrentTime + CONNECTTIMEOUT;
108
109 return request;
110 }
111
112 /*
113 * release_auth_client - release auth client from auth system
114 * this adds the client into the local client lists so it can be read by
115 * the main io processing loop
116 */
117 void
118 release_auth_client(struct AuthRequest *auth)
119 {
120 struct Client *client = auth->client;
121
122 if (IsDoingAuth(auth) || IsDNSPending(auth))
123 return;
124
125 if (dlinkFind(&auth_doing_list, auth))
126 dlinkDelete(&auth->node, &auth_doing_list);
127
128 /*
129 * When a client has auth'ed, we want to start reading what it sends
130 * us. This is what read_packet() does.
131 * -- adrian
132 */
133 client->localClient->allow_read = MAX_FLOOD;
134 comm_setflush(&client->localClient->fd, 1000, flood_recalc, client);
135
136 dlinkAdd(client, &client->node, &global_client_list);
137
138 client->localClient->since = CurrentTime;
139 client->localClient->lasttime = CurrentTime;
140 client->localClient->firsttime = CurrentTime;
141 client->flags |= FLAGS_FINISHED_AUTH;
142
143 read_packet(&client->localClient->fd, client);
144 }
145
146 /*
147 * auth_dns_callback - called when resolver query finishes
148 * if the query resulted in a successful search, name will contain
149 * a non-NULL pointer, otherwise name will be NULL.
150 * set the client on it's way to a connection completion, regardless
151 * of success of failure
152 */
153 static void
154 auth_dns_callback(void *vptr, const struct irc_ssaddr *addr, const char *name)
155 {
156 struct AuthRequest *auth = vptr;
157
158 ClearDNSPending(auth);
159
160 if (name != NULL)
161 {
162 const struct sockaddr_in *v4, *v4dns;
163 #ifdef IPV6
164 const struct sockaddr_in6 *v6, *v6dns;
165 #endif
166 int good = 1;
167
168 #ifdef IPV6
169 if (auth->client->localClient->ip.ss.ss_family == AF_INET6)
170 {
171 v6 = (const struct sockaddr_in6 *)&auth->client->localClient->ip;
172 v6dns = (const struct sockaddr_in6 *)addr;
173 if (memcmp(&v6->sin6_addr, &v6dns->sin6_addr, sizeof(struct in6_addr)) != 0)
174 {
175 sendheader(auth->client, REPORT_IP_MISMATCH);
176 good = 0;
177 }
178 }
179 else
180 #endif
181 {
182 v4 = (const struct sockaddr_in *)&auth->client->localClient->ip;
183 v4dns = (const struct sockaddr_in *)addr;
184 if(v4->sin_addr.s_addr != v4dns->sin_addr.s_addr)
185 {
186 sendheader(auth->client, REPORT_IP_MISMATCH);
187 good = 0;
188 }
189 }
190 if (good && strlen(name) <= HOSTLEN)
191 {
192 strlcpy(auth->client->host, name,
193 sizeof(auth->client->host));
194 sendheader(auth->client, REPORT_FIN_DNS);
195 }
196 else if (strlen(name) > HOSTLEN)
197 sendheader(auth->client, REPORT_HOST_TOOLONG);
198 }
199 else
200 sendheader(auth->client, REPORT_FAIL_DNS);
201
202 release_auth_client(auth);
203 }
204
205 /*
206 * authsenderr - handle auth send errors
207 */
208 static void
209 auth_error(struct AuthRequest *auth)
210 {
211 ++ServerStats.is_abad;
212
213 fd_close(&auth->fd);
214
215 ClearAuth(auth);
216
217 sendheader(auth->client, REPORT_FAIL_ID);
218
219 release_auth_client(auth);
220 }
221
222 /*
223 * start_auth_query - Flag the client to show that an attempt to
224 * contact the ident server on
225 * the client's host. The connect and subsequently the socket are all put
226 * into 'non-blocking' mode. Should the connect or any later phase of the
227 * identifing process fail, it is aborted and the user is given a username
228 * of "unknown".
229 */
230 static int
231 start_auth_query(struct AuthRequest *auth)
232 {
233 struct irc_ssaddr localaddr;
234 socklen_t locallen = sizeof(struct irc_ssaddr);
235 #ifdef IPV6
236 struct sockaddr_in6 *v6;
237 #else
238 struct sockaddr_in *v4;
239 #endif
240
241 /* open a socket of the same type as the client socket */
242 if (comm_open(&auth->fd, auth->client->localClient->ip.ss.ss_family,
243 SOCK_STREAM, 0, "ident") == -1)
244 {
245 report_error(L_ALL, "creating auth stream socket %s:%s",
246 get_client_name(auth->client, SHOW_IP), errno);
247 ilog(LOG_TYPE_IRCD, "Unable to create auth socket for %s",
248 get_client_name(auth->client, SHOW_IP));
249 ++ServerStats.is_abad;
250 return 0;
251 }
252
253 sendheader(auth->client, REPORT_DO_ID);
254
255 /*
256 * get the local address of the client and bind to that to
257 * make the auth request. This used to be done only for
258 * ifdef VIRTUAL_HOST, but needs to be done for all clients
259 * since the ident request must originate from that same address--
260 * and machines with multiple IP addresses are common now
261 */
262 memset(&localaddr, 0, locallen);
263 getsockname(auth->client->localClient->fd.fd, (struct sockaddr*)&localaddr,
264 &locallen);
265
266 #ifdef IPV6
267 remove_ipv6_mapping(&localaddr);
268 v6 = (struct sockaddr_in6 *)&localaddr;
269 v6->sin6_port = htons(0);
270 #else
271 localaddr.ss_len = locallen;
272 v4 = (struct sockaddr_in *)&localaddr;
273 v4->sin_port = htons(0);
274 #endif
275 localaddr.ss_port = htons(0);
276
277 comm_connect_tcp(&auth->fd, auth->client->sockhost, 113,
278 (struct sockaddr *)&localaddr, localaddr.ss_len, auth_connect_callback,
279 auth, auth->client->localClient->ip.ss.ss_family,
280 GlobalSetOptions.ident_timeout);
281 return 1; /* We suceed here for now */
282 }
283
284 /*
285 * GetValidIdent - parse ident query reply from identd server
286 *
287 * Inputs - pointer to ident buf
288 * Output - NULL if no valid ident found, otherwise pointer to name
289 * Side effects -
290 */
291 /*
292 * A few questions have been asked about this mess, obviously
293 * it should have been commented better the first time.
294 * The original idea was to remove all references to libc from ircd-hybrid.
295 * Instead of having to write a replacement for sscanf(), I did a
296 * rather gruseome parser here so we could remove this function call.
297 * Note, that I had also removed a few floating point printfs as well (though
298 * now we are still stuck with a few...)
299 * Remember, we have a replacement ircd sprintf, we have bleeps fputs lib
300 * it would have been nice to remove some unneeded code.
301 * Oh well. If we don't remove libc stuff totally, then it would be
302 * far cleaner to use sscanf()
303 *
304 * - Dianora
305 */
306 static char *
307 GetValidIdent(char *buf)
308 {
309 int remp = 0;
310 int locp = 0;
311 char* colon1Ptr;
312 char* colon2Ptr;
313 char* colon3Ptr;
314 char* commaPtr;
315 char* remotePortString;
316
317 /* All this to get rid of a sscanf() fun. */
318 remotePortString = buf;
319
320 if ((colon1Ptr = strchr(remotePortString,':')) == NULL)
321 return 0;
322 *colon1Ptr = '\0';
323 colon1Ptr++;
324
325 if ((colon2Ptr = strchr(colon1Ptr,':')) == NULL)
326 return 0;
327 *colon2Ptr = '\0';
328 colon2Ptr++;
329
330 if ((commaPtr = strchr(remotePortString, ',')) == NULL)
331 return 0;
332 *commaPtr = '\0';
333 commaPtr++;
334
335 if ((remp = atoi(remotePortString)) == 0)
336 return 0;
337
338 if ((locp = atoi(commaPtr)) == 0)
339 return 0;
340
341 /* look for USERID bordered by first pair of colons */
342 if (strstr(colon1Ptr, "USERID") == NULL)
343 return 0;
344
345 if ((colon3Ptr = strchr(colon2Ptr,':')) == NULL)
346 return 0;
347 *colon3Ptr = '\0';
348 colon3Ptr++;
349 return (colon3Ptr);
350 }
351
352 /*
353 * start_auth
354 *
355 * inputs - pointer to client to auth
356 * output - NONE
357 * side effects - starts auth (identd) and dns queries for a client
358 */
359 void
360 start_auth(struct Client *client)
361 {
362 struct AuthRequest *auth = NULL;
363
364 assert(client != NULL);
365
366 auth = make_auth_request(client);
367 dlinkAdd(auth, &auth->node, &auth_doing_list);
368
369 sendheader(client, REPORT_DO_DNS);
370
371 SetDNSPending(auth);
372
373 if (ConfigFileEntry.disable_auth == 0)
374 {
375 SetDoingAuth(auth);
376 start_auth_query(auth);
377 }
378
379 gethost_byaddr(auth_dns_callback, auth, &client->localClient->ip);
380 }
381
382 /*
383 * timeout_auth_queries - timeout resolver and identd requests
384 * allow clients through if requests failed
385 */
386 static void
387 timeout_auth_queries_event(void *notused)
388 {
389 dlink_node *ptr = NULL, *next_ptr = NULL;
390
391 DLINK_FOREACH_SAFE(ptr, next_ptr, auth_doing_list.head)
392 {
393 struct AuthRequest *auth = ptr->data;
394
395 if (auth->timeout > CurrentTime)
396 continue;
397
398 if (IsDoingAuth(auth))
399 {
400 ++ServerStats.is_abad;
401 fd_close(&auth->fd);
402 ClearAuth(auth);
403 sendheader(auth->client, REPORT_FAIL_ID);
404 }
405
406 if (IsDNSPending(auth))
407 {
408 delete_resolver_queries(auth);
409 ClearDNSPending(auth);
410 sendheader(auth->client, REPORT_FAIL_DNS);
411 }
412
413 ilog(LOG_TYPE_IRCD, "DNS/AUTH timeout %s",
414 get_client_name(auth->client, SHOW_IP));
415 release_auth_client(auth);
416 }
417 }
418
419 /*
420 * auth_connect_callback() - deal with the result of comm_connect_tcp()
421 *
422 * If the connection failed, we simply close the auth fd and report
423 * a failure. If the connection suceeded send the ident server a query
424 * giving "theirport , ourport". The write is only attempted *once* so
425 * it is deemed to be a fail if the entire write doesn't write all the
426 * data given. This shouldnt be a problem since the socket should have
427 * a write buffer far greater than this message to store it in should
428 * problems arise. -avalon
429 */
430 static void
431 auth_connect_callback(fde_t *fd, int error, void *data)
432 {
433 struct AuthRequest *auth = data;
434 struct irc_ssaddr us;
435 struct irc_ssaddr them;
436 char authbuf[32];
437 socklen_t ulen = sizeof(struct irc_ssaddr);
438 socklen_t tlen = sizeof(struct irc_ssaddr);
439 uint16_t uport, tport;
440 #ifdef IPV6
441 struct sockaddr_in6 *v6;
442 #else
443 struct sockaddr_in *v4;
444 #endif
445
446 if (error != COMM_OK)
447 {
448 auth_error(auth);
449 return;
450 }
451
452 if (getsockname(auth->client->localClient->fd.fd, (struct sockaddr *)&us,
453 &ulen) ||
454 getpeername(auth->client->localClient->fd.fd, (struct sockaddr *)&them,
455 &tlen))
456 {
457 ilog(LOG_TYPE_IRCD, "auth get{sock,peer}name error for %s",
458 get_client_name(auth->client, SHOW_IP));
459 auth_error(auth);
460 return;
461 }
462
463 #ifdef IPV6
464 v6 = (struct sockaddr_in6 *)&us;
465 uport = ntohs(v6->sin6_port);
466 v6 = (struct sockaddr_in6 *)&them;
467 tport = ntohs(v6->sin6_port);
468 remove_ipv6_mapping(&us);
469 remove_ipv6_mapping(&them);
470 #else
471 v4 = (struct sockaddr_in *)&us;
472 uport = ntohs(v4->sin_port);
473 v4 = (struct sockaddr_in *)&them;
474 tport = ntohs(v4->sin_port);
475 us.ss_len = ulen;
476 them.ss_len = tlen;
477 #endif
478
479 snprintf(authbuf, sizeof(authbuf), "%u , %u\r\n", tport, uport);
480
481 if (send(fd->fd, authbuf, strlen(authbuf), 0) == -1)
482 {
483 auth_error(auth);
484 return;
485 }
486
487 read_auth_reply(&auth->fd, auth);
488 }
489
490 /*
491 * read_auth_reply - read the reply (if any) from the ident server
492 * we connected to.
493 * We only give it one shot, if the reply isn't good the first time
494 * fail the authentication entirely. --Bleep
495 */
496 #define AUTH_BUFSIZ 128
497
498 static void
499 read_auth_reply(fde_t *fd, void *data)
500 {
501 struct AuthRequest *auth = data;
502 char *s = NULL;
503 char *t = NULL;
504 int len;
505 int count;
506 char buf[AUTH_BUFSIZ + 1]; /* buffer to read auth reply into */
507
508 /* Why?
509 * Well, recv() on many POSIX systems is a per-packet operation,
510 * and we do not necessarily want this, because on lowspec machines,
511 * the ident response may come back fragmented, thus resulting in an
512 * invalid ident response, even if the ident response was really OK.
513 *
514 * So PLEASE do not change this code to recv without being aware of the
515 * consequences.
516 *
517 * --nenolod
518 */
519 len = read(fd->fd, buf, AUTH_BUFSIZ);
520
521 if (len < 0)
522 {
523 if (ignoreErrno(errno))
524 comm_setselect(fd, COMM_SELECT_READ, read_auth_reply, auth, 0);
525 else
526 auth_error(auth);
527 return;
528 }
529
530 if (len > 0)
531 {
532 buf[len] = '\0';
533
534 if ((s = GetValidIdent(buf)))
535 {
536 t = auth->client->username;
537
538 while (*s == '~' || *s == '^')
539 s++;
540
541 for (count = USERLEN; *s && count; s++)
542 {
543 if (*s == '@')
544 break;
545 if (!IsSpace(*s) && *s != ':' && *s != '[')
546 {
547 *t++ = *s;
548 count--;
549 }
550 }
551
552 *t = '\0';
553 }
554 }
555
556 fd_close(fd);
557
558 ClearAuth(auth);
559
560 if (s == NULL)
561 {
562 sendheader(auth->client, REPORT_FAIL_ID);
563 ++ServerStats.is_abad;
564 }
565 else
566 {
567 sendheader(auth->client, REPORT_FIN_ID);
568 ++ServerStats.is_asuc;
569 SetGotId(auth->client);
570 }
571
572 release_auth_client(auth);
573 }
574
575 /*
576 * delete_auth()
577 */
578 void
579 delete_auth(struct AuthRequest *auth)
580 {
581 if (IsDNSPending(auth))
582 delete_resolver_queries(auth);
583
584 if (IsDoingAuth(auth))
585 fd_close(&auth->fd);
586
587 if (dlinkFind(&auth_doing_list, auth))
588 dlinkDelete(&auth->node, &auth_doing_list);
589 }

Properties

Name Value
svn:eol-style native
svn:keywords Id Revision