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root/svn/ircd-hybrid/branches/8.2.x/src/auth.c
Revision: 4866
Committed: Fri Nov 7 20:04:13 2014 UTC (9 years, 5 months ago) by michael
Content type: text/x-csrc
File size: 13884 byte(s)
Log Message:
- auth.c:start_auth_query(): removed archaic comment

File Contents

# Content
1 /*
2 * ircd-hybrid: an advanced, lightweight Internet Relay Chat Daemon (ircd)
3 *
4 * Copyright (c) 1997-2014 ircd-hybrid development team
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
19 * USA
20 */
21
22 /*! \file auth.c
23 * \brief Functions for querying a users ident.
24 * \version $Id$
25 */
26
27 /*
28 * Changes:
29 * July 6, 1999 - Rewrote most of the code here. When a client connects
30 * to the server and passes initial socket validation checks, it
31 * is owned by this module (auth) which returns it to the rest of the
32 * server when dns and auth queries are finished. Until the client is
33 * released, the server does not know it exists and does not process
34 * any messages from it.
35 * --Bleep Thomas Helvey <tomh@inxpress.net>
36 */
37
38 #include "stdinc.h"
39 #include "list.h"
40 #include "ircd_defs.h"
41 #include "fdlist.h"
42 #include "auth.h"
43 #include "conf.h"
44 #include "client.h"
45 #include "event.h"
46 #include "irc_string.h"
47 #include "ircd.h"
48 #include "packet.h"
49 #include "res.h"
50 #include "s_bsd.h"
51 #include "log.h"
52 #include "send.h"
53 #include "mempool.h"
54
55
56 static const char *const HeaderMessages[] =
57 {
58 ":*** Looking up your hostname",
59 ":*** Found your hostname",
60 ":*** Couldn't look up your hostname",
61 ":*** Checking Ident",
62 ":*** Got Ident response",
63 ":*** No Ident response",
64 ":*** Your forward and reverse DNS do not match, ignoring hostname",
65 ":*** Your hostname is too long, ignoring hostname"
66 };
67
68 enum
69 {
70 REPORT_DO_DNS,
71 REPORT_FIN_DNS,
72 REPORT_FAIL_DNS,
73 REPORT_DO_ID,
74 REPORT_FIN_ID,
75 REPORT_FAIL_ID,
76 REPORT_IP_MISMATCH,
77 REPORT_HOST_TOOLONG
78 };
79
80 #define sendheader(c, i) sendto_one_notice((c), &me, HeaderMessages[(i)])
81
82 static dlink_list auth_pending_list;
83 static void read_auth_reply(fde_t *, void *);
84 static void auth_connect_callback(fde_t *, int, void *);
85
86
87 /*
88 * make_auth_request - allocate a new auth request
89 */
90 static struct AuthRequest *
91 make_auth_request(struct Client *client)
92 {
93 struct AuthRequest *const request = &client->connection->auth;
94
95 memset(request, 0, sizeof(*request));
96
97 request->client = client;
98 request->timeout = CurrentTime + CONNECTTIMEOUT;
99
100 return request;
101 }
102
103 /*
104 * release_auth_client - release auth client from auth system
105 * this adds the client into the local client lists so it can be read by
106 * the main io processing loop
107 */
108 void
109 release_auth_client(struct AuthRequest *auth)
110 {
111 struct Client *const client = auth->client;
112
113 if (IsDoingAuth(auth) || IsDNSPending(auth))
114 return;
115
116 if (IsInAuth(auth))
117 {
118 dlinkDelete(&auth->node, &auth_pending_list);
119 ClearInAuth(auth);
120 }
121
122 /*
123 * When a client has auth'ed, we want to start reading what it sends
124 * us. This is what read_packet() does.
125 * -- adrian
126 */
127 client->connection->allow_read = MAX_FLOOD;
128 comm_setflush(&client->connection->fd, 1000, flood_recalc, client);
129
130 client->connection->since = CurrentTime;
131 client->connection->lasttime = CurrentTime;
132 client->connection->firsttime = CurrentTime;
133 client->flags |= FLAGS_FINISHED_AUTH;
134
135 read_packet(&client->connection->fd, client);
136 }
137
138 /*
139 * auth_dns_callback - called when resolver query finishes
140 * if the query resulted in a successful search, name will contain
141 * a non-NULL pointer, otherwise name will be NULL.
142 * set the client on it's way to a connection completion, regardless
143 * of success of failure
144 */
145 static void
146 auth_dns_callback(void *vptr, const struct irc_ssaddr *addr, const char *name, size_t namelength)
147 {
148 struct AuthRequest *const auth = vptr;
149
150 ClearDNSPending(auth);
151
152 if (!EmptyString(name))
153 {
154 if (auth->client->connection->ip.ss.ss_family == AF_INET6)
155 {
156 const struct sockaddr_in6 *const v6 = (const struct sockaddr_in6 *)&auth->client->connection->ip;
157 const struct sockaddr_in6 *const v6dns = (const struct sockaddr_in6 *)addr;
158
159 if (memcmp(&v6->sin6_addr, &v6dns->sin6_addr, sizeof(struct in6_addr)) != 0)
160 {
161 sendheader(auth->client, REPORT_IP_MISMATCH);
162 release_auth_client(auth);
163 return;
164 }
165 }
166 else
167 {
168 const struct sockaddr_in *const v4 = (const struct sockaddr_in *)&auth->client->connection->ip;
169 const struct sockaddr_in *const v4dns = (const struct sockaddr_in *)addr;
170
171 if (v4->sin_addr.s_addr != v4dns->sin_addr.s_addr)
172 {
173 sendheader(auth->client, REPORT_IP_MISMATCH);
174 release_auth_client(auth);
175 return;
176 }
177 }
178
179 if (namelength > HOSTLEN)
180 sendheader(auth->client, REPORT_HOST_TOOLONG);
181 else
182 {
183 strlcpy(auth->client->host, name, sizeof(auth->client->host));
184 sendheader(auth->client, REPORT_FIN_DNS);
185 }
186 }
187 else
188 sendheader(auth->client, REPORT_FAIL_DNS);
189
190 release_auth_client(auth);
191 }
192
193 /*
194 * authsenderr - handle auth send errors
195 */
196 static void
197 auth_error(struct AuthRequest *auth)
198 {
199 ++ServerStats.is_abad;
200
201 fd_close(&auth->fd);
202
203 ClearAuth(auth);
204
205 sendheader(auth->client, REPORT_FAIL_ID);
206
207 release_auth_client(auth);
208 }
209
210 /*
211 * start_auth_query - Flag the client to show that an attempt to
212 * contact the ident server on
213 * the client's host. The connect and subsequently the socket are all put
214 * into 'non-blocking' mode. Should the connect or any later phase of the
215 * identifing process fail, it is aborted and the user is given a username
216 * of "unknown".
217 */
218 static int
219 start_auth_query(struct AuthRequest *auth)
220 {
221 struct irc_ssaddr localaddr;
222 socklen_t locallen = sizeof(struct irc_ssaddr);
223 struct sockaddr_in6 *v6;
224
225 /* open a socket of the same type as the client socket */
226 if (comm_open(&auth->fd, auth->client->connection->ip.ss.ss_family,
227 SOCK_STREAM, 0, "ident") == -1)
228 {
229 report_error(L_ALL, "creating auth stream socket %s:%s",
230 get_client_name(auth->client, SHOW_IP), errno);
231 ++ServerStats.is_abad;
232 return 0;
233 }
234
235 sendheader(auth->client, REPORT_DO_ID);
236
237 /*
238 * Get the local address of the client and bind to that to
239 * make the auth request.
240 */
241 memset(&localaddr, 0, locallen);
242 getsockname(auth->client->connection->fd.fd, (struct sockaddr*)&localaddr,
243 &locallen);
244
245 remove_ipv6_mapping(&localaddr);
246 v6 = (struct sockaddr_in6 *)&localaddr;
247 v6->sin6_port = htons(0);
248 localaddr.ss_port = htons(0);
249
250 comm_connect_tcp(&auth->fd, auth->client->sockhost, RFC1413_PORT,
251 (struct sockaddr *)&localaddr, localaddr.ss_len, auth_connect_callback,
252 auth, auth->client->connection->ip.ss.ss_family,
253 GlobalSetOptions.ident_timeout);
254 return 1; /* We suceed here for now */
255 }
256
257 /*
258 * start_auth
259 *
260 * inputs - pointer to client to auth
261 * output - NONE
262 * side effects - starts auth (identd) and dns queries for a client
263 */
264 void
265 start_auth(struct Client *client_p)
266 {
267 struct AuthRequest *const auth = make_auth_request(client_p);
268
269 SetInAuth(auth);
270 dlinkAddTail(auth, &auth->node, &auth_pending_list);
271
272 sendheader(client_p, REPORT_DO_DNS);
273
274 SetDNSPending(auth);
275
276 if (ConfigGeneral.disable_auth == 0)
277 {
278 SetDoingAuth(auth);
279 start_auth_query(auth);
280 }
281
282 gethost_byaddr(auth_dns_callback, auth, &client_p->connection->ip);
283 }
284
285 /*
286 * timeout_auth_queries - timeout resolver and identd requests
287 * allow clients through if requests failed
288 */
289 static void
290 timeout_auth_queries_event(void *notused)
291 {
292 dlink_node *node = NULL, *node_next = NULL;
293
294 DLINK_FOREACH_SAFE(node, node_next, auth_pending_list.head)
295 {
296 struct AuthRequest *auth = node->data;
297
298 if (auth->timeout > CurrentTime)
299 break;
300
301 if (IsDoingAuth(auth))
302 {
303 ++ServerStats.is_abad;
304 fd_close(&auth->fd);
305 ClearAuth(auth);
306 sendheader(auth->client, REPORT_FAIL_ID);
307 }
308
309 if (IsDNSPending(auth))
310 {
311 delete_resolver_queries(auth);
312 ClearDNSPending(auth);
313 sendheader(auth->client, REPORT_FAIL_DNS);
314 }
315
316 release_auth_client(auth);
317 }
318 }
319
320 /*
321 * auth_connect_callback() - deal with the result of comm_connect_tcp()
322 *
323 * If the connection failed, we simply close the auth fd and report
324 * a failure. If the connection suceeded send the ident server a query
325 * giving "theirport , ourport". The write is only attempted *once* so
326 * it is deemed to be a fail if the entire write doesn't write all the
327 * data given. This shouldnt be a problem since the socket should have
328 * a write buffer far greater than this message to store it in should
329 * problems arise. -avalon
330 */
331 static void
332 auth_connect_callback(fde_t *fd, int error, void *data)
333 {
334 struct AuthRequest *const auth = data;
335 struct irc_ssaddr us;
336 struct irc_ssaddr them;
337 char authbuf[16];
338 socklen_t ulen = sizeof(struct irc_ssaddr);
339 socklen_t tlen = sizeof(struct irc_ssaddr);
340 uint16_t uport, tport;
341 struct sockaddr_in6 *v6;
342
343 if (error != COMM_OK)
344 {
345 auth_error(auth);
346 return;
347 }
348
349 if (getsockname(auth->client->connection->fd.fd, (struct sockaddr *)&us, &ulen) ||
350 getpeername(auth->client->connection->fd.fd, (struct sockaddr *)&them, &tlen))
351 {
352 report_error(L_ALL, "auth get{sock,peer}name error %s:%s",
353 get_client_name(auth->client, SHOW_IP), errno);
354 auth_error(auth);
355 return;
356 }
357
358 v6 = (struct sockaddr_in6 *)&us;
359 uport = ntohs(v6->sin6_port);
360 v6 = (struct sockaddr_in6 *)&them;
361 tport = ntohs(v6->sin6_port);
362 remove_ipv6_mapping(&us);
363 remove_ipv6_mapping(&them);
364
365 snprintf(authbuf, sizeof(authbuf), "%u, %u\r\n", tport, uport);
366
367 if (send(fd->fd, authbuf, strlen(authbuf), 0) == -1)
368 {
369 auth_error(auth);
370 return;
371 }
372
373 comm_setselect(fd, COMM_SELECT_READ, read_auth_reply, auth, 0);
374 }
375
376 /** Enum used to index ident reply fields in a human-readable way. */
377 enum IdentReplyFields
378 {
379 IDENT_PORT_NUMBERS,
380 IDENT_REPLY_TYPE,
381 IDENT_OS_TYPE,
382 IDENT_INFO,
383 USERID_TOKEN_COUNT
384 };
385
386 /** Parse an ident reply line and extract the userid from it.
387 * \param reply The ident reply line.
388 * \return The userid, or NULL on parse failure.
389 */
390 static const char *
391 check_ident_reply(char *const reply)
392 {
393 char *token = NULL, *end = NULL;
394 char *vector[USERID_TOKEN_COUNT];
395 const int count = token_vector(reply, ':', vector, USERID_TOKEN_COUNT);
396
397 if (USERID_TOKEN_COUNT != count)
398 return NULL;
399
400 /*
401 * Second token is the reply type
402 */
403 token = vector[IDENT_REPLY_TYPE];
404
405 if (EmptyString(token))
406 return NULL;
407
408 while (IsSpace(*token))
409 ++token;
410
411 if (strncmp(token, "USERID", 6))
412 return NULL;
413
414 /*
415 * Third token is the os type
416 */
417 token = vector[IDENT_OS_TYPE];
418
419 if (EmptyString(token))
420 return NULL;
421
422 while (IsSpace(*token))
423 ++token;
424
425 /*
426 * Unless "OTHER" is specified as the operating system type, the server
427 * is expected to return the "normal" user identification of the owner
428 * of this connection. "Normal" in this context may be taken to mean a
429 * string of characters which uniquely identifies the connection owner
430 * such as a user identifier assigned by the system administrator and
431 * used by such user as a mail identifier, or as the "user" part of a
432 * user/password pair used to gain access to system resources. When an
433 * operating system is specified (e.g., anything but "OTHER"), the user
434 * identifier is expected to be in a more or less immediately useful
435 * form - e.g., something that could be used as an argument to "finger"
436 * or as a mail address.
437 */
438 if (!strncmp(token, "OTHER", 5))
439 return NULL;
440
441 /*
442 * Fourth token is the username
443 */
444 token = vector[IDENT_INFO];
445
446 if (EmptyString(token))
447 return NULL;
448
449 while (IsSpace(*token))
450 ++token;
451
452 while (*token == '~' || *token == '^')
453 ++token;
454
455 /*
456 * Look for the end of the username, terminators are '\0, @, <SPACE>, :'
457 */
458 for (end = token; *end; ++end)
459 if (IsSpace(*end) || '@' == *end || ':' == *end)
460 break;
461 *end = '\0';
462
463 return token;
464 }
465
466 /*
467 * read_auth_reply - read the reply (if any) from the ident server
468 * we connected to.
469 * We only give it one shot, if the reply isn't good the first time
470 * fail the authentication entirely. --Bleep
471 */
472 static void
473 read_auth_reply(fde_t *fd, void *data)
474 {
475 struct AuthRequest *const auth = data;
476 const char *username = NULL;
477 ssize_t len = 0;
478 char buf[RFC1413_BUFSIZ + 1];
479
480 if ((len = recv(fd->fd, buf, RFC1413_BUFSIZ, 0)) > 0)
481 {
482 buf[len] = '\0';
483 username = check_ident_reply(buf);
484 }
485
486 fd_close(fd);
487
488 ClearAuth(auth);
489
490 if (EmptyString(username))
491 {
492 sendheader(auth->client, REPORT_FAIL_ID);
493 ++ServerStats.is_abad;
494 }
495 else
496 {
497 strlcpy(auth->client->username, username, sizeof(auth->client->username));
498 sendheader(auth->client, REPORT_FIN_ID);
499 ++ServerStats.is_asuc;
500 SetGotId(auth->client);
501 }
502
503 release_auth_client(auth);
504 }
505
506 /*
507 * delete_auth()
508 */
509 void
510 delete_auth(struct AuthRequest *auth)
511 {
512 if (IsDNSPending(auth))
513 delete_resolver_queries(auth);
514
515 if (IsDoingAuth(auth))
516 fd_close(&auth->fd);
517
518 if (IsInAuth(auth))
519 {
520 dlinkDelete(&auth->node, &auth_pending_list);
521 ClearInAuth(auth);
522 }
523 }
524
525 /* auth_init
526 *
527 * Initialise the auth code
528 */
529 void
530 auth_init(void)
531 {
532 static struct event timeout_auth_queries =
533 {
534 .name = "timeout_auth_queries_event",
535 .handler = timeout_auth_queries_event,
536 .when = 1
537 };
538
539 event_add(&timeout_auth_queries, NULL);
540 }

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