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1 | /* | |
2 | * ircd-ratbox: A slightly useful ircd. | |
3 | * s_auth.c: Functions for querying a users ident. | |
4 | * | |
5 | * Copyright (C) 1990 Jarkko Oikarinen and University of Oulu, Co Center | |
6 | * Copyright (C) 1996-2002 Hybrid Development Team | |
7 | * Copyright (C) 2002-2005 ircd-ratbox development team | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License as published by | |
11 | * the Free Software Foundation; either version 2 of the License, or | |
12 | * (at your option) any later version. | |
13 | * | |
14 | * This program is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | * GNU General Public License for more details. | |
18 | * | |
19 | * You should have received a copy of the GNU General Public License | |
20 | * along with this program; if not, write to the Free Software | |
21 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 | |
22 | * USA | |
23 | * | |
24 | */ | |
25 | ||
26 | /* | |
27 | * Changes: | |
28 | * July 6, 1999 - Rewrote most of the code here. When a client connects | |
29 | * to the server and passes initial socket validation checks, it | |
30 | * is owned by this module (auth) which returns it to the rest of the | |
31 | * server when dns and auth queries are finished. Until the client is | |
32 | * released, the server does not know it exists and does not process | |
33 | * any messages from it. | |
34 | * --Bleep Thomas Helvey <tomh@inxpress.net> | |
35 | */ | |
36 | #include "stdinc.h" | |
37 | #include "defaults.h" | |
38 | #include "s_auth.h" | |
39 | #include "s_conf.h" | |
40 | #include "client.h" | |
41 | #include "match.h" | |
42 | #include "ircd.h" | |
43 | #include "numeric.h" | |
44 | #include "packet.h" | |
45 | #include "dns.h" | |
46 | #include "logger.h" | |
47 | #include "s_stats.h" | |
48 | #include "send.h" | |
49 | #include "hook.h" | |
50 | #include "blacklist.h" | |
51 | #include "s_assert.h" | |
52 | ||
53 | struct AuthRequest | |
54 | { | |
55 | rb_dlink_node node; | |
56 | struct Client *client; /* pointer to client struct for request */ | |
57 | uint16_t dns_id; /* DNS Query */ | |
58 | unsigned int flags; /* current state of request */ | |
59 | rb_fde_t *F; /* file descriptor for auth queries */ | |
60 | time_t timeout; /* time when query expires */ | |
61 | uint16_t lport; | |
62 | uint16_t rport; | |
63 | }; | |
64 | ||
65 | /* | |
66 | * flag values for AuthRequest | |
67 | * NAMESPACE: AM_xxx - Authentication Module | |
68 | */ | |
69 | #define AM_AUTH_CONNECTING (1 << 0) | |
70 | #define AM_AUTH_PENDING (1 << 1) | |
71 | #define AM_DNS_PENDING (1 << 2) | |
72 | ||
73 | #define SetDNSPending(x) ((x)->flags |= AM_DNS_PENDING) | |
74 | #define ClearDNSPending(x) ((x)->flags &= ~AM_DNS_PENDING) | |
75 | #define IsDNSPending(x) ((x)->flags & AM_DNS_PENDING) | |
76 | ||
77 | #define SetAuthConnect(x) ((x)->flags |= AM_AUTH_CONNECTING) | |
78 | #define ClearAuthConnect(x) ((x)->flags &= ~AM_AUTH_CONNECTING) | |
79 | #define IsAuthConnect(x) ((x)->flags & AM_AUTH_CONNECTING) | |
80 | ||
81 | #define SetAuthPending(x) ((x)->flags |= AM_AUTH_PENDING) | |
82 | #define ClearAuthPending(x) ((x)->flags &= AM_AUTH_PENDING) | |
83 | #define IsAuthPending(x) ((x)->flags & AM_AUTH_PENDING) | |
84 | ||
85 | #define ClearAuth(x) ((x)->flags &= ~(AM_AUTH_PENDING | AM_AUTH_CONNECTING)) | |
86 | #define IsDoingAuth(x) ((x)->flags & (AM_AUTH_PENDING | AM_AUTH_CONNECTING)) | |
87 | ||
88 | /* | |
89 | * a bit different approach | |
90 | * this replaces the original sendheader macros | |
91 | */ | |
92 | ||
93 | static const char *HeaderMessages[] = | |
94 | { | |
95 | ":*** Looking up your hostname...", | |
96 | ":*** Found your hostname", | |
97 | ":*** Couldn't look up your hostname", | |
98 | ":*** Checking Ident", | |
99 | ":*** Got Ident response", | |
100 | ":*** No Ident response", | |
101 | ":*** Your hostname is too long, ignoring hostname", | |
102 | ":*** Your forward and reverse DNS do not match, ignoring hostname", | |
103 | ":*** Cannot verify hostname validity, ignoring hostname", | |
104 | }; | |
105 | ||
106 | typedef enum | |
107 | { | |
108 | REPORT_DO_DNS, | |
109 | REPORT_FIN_DNS, | |
110 | REPORT_FAIL_DNS, | |
111 | REPORT_DO_ID, | |
112 | REPORT_FIN_ID, | |
113 | REPORT_FAIL_ID, | |
114 | REPORT_HOST_TOOLONG, | |
115 | REPORT_HOST_MISMATCH, | |
116 | REPORT_HOST_UNKNOWN | |
117 | } | |
118 | ReportType; | |
119 | ||
120 | #define sendheader(c, r) sendto_one_notice(c, "%s", HeaderMessages[(r)]) | |
121 | ||
122 | static rb_dlink_list auth_poll_list; | |
123 | static rb_bh *auth_heap; | |
124 | static EVH timeout_auth_queries_event; | |
125 | ||
126 | static PF read_auth_reply; | |
127 | static CNCB auth_connect_callback; | |
128 | ||
129 | /* | |
130 | * init_auth() | |
131 | * | |
132 | * Initialise the auth code | |
133 | */ | |
134 | void | |
135 | init_auth(void) | |
136 | { | |
137 | /* This hook takes a struct Client for its argument */ | |
138 | memset(&auth_poll_list, 0, sizeof(auth_poll_list)); | |
139 | rb_event_addish("timeout_auth_queries_event", timeout_auth_queries_event, NULL, 1); | |
140 | auth_heap = rb_bh_create(sizeof(struct AuthRequest), LCLIENT_HEAP_SIZE, "auth_heap"); | |
141 | } | |
142 | ||
143 | /* | |
144 | * make_auth_request - allocate a new auth request | |
145 | */ | |
146 | static struct AuthRequest * | |
147 | make_auth_request(struct Client *client) | |
148 | { | |
149 | struct AuthRequest *request = rb_bh_alloc(auth_heap); | |
150 | client->localClient->auth_request = request; | |
151 | request->F = NULL; | |
152 | request->client = client; | |
153 | request->timeout = rb_current_time() + ConfigFileEntry.connect_timeout; | |
154 | return request; | |
155 | } | |
156 | ||
157 | /* | |
158 | * free_auth_request - cleanup auth request allocations | |
159 | */ | |
160 | static void | |
161 | free_auth_request(struct AuthRequest *request) | |
162 | { | |
163 | rb_bh_free(auth_heap, request); | |
164 | } | |
165 | ||
166 | /* | |
167 | * release_auth_client - release auth client from auth system | |
168 | * this adds the client into the local client lists so it can be read by | |
169 | * the main io processing loop | |
170 | */ | |
171 | static void | |
172 | release_auth_client(struct AuthRequest *auth) | |
173 | { | |
174 | struct Client *client = auth->client; | |
175 | ||
176 | if(IsDNSPending(auth) || IsDoingAuth(auth)) | |
177 | return; | |
178 | ||
179 | client->localClient->auth_request = NULL; | |
180 | rb_dlinkDelete(&auth->node, &auth_poll_list); | |
181 | free_auth_request(auth); | |
182 | ||
183 | /* | |
184 | * When a client has auth'ed, we want to start reading what it sends | |
185 | * us. This is what read_packet() does. | |
186 | * -- adrian | |
187 | */ | |
188 | rb_dlinkAddTail(client, &client->node, &global_client_list); | |
189 | read_packet(client->localClient->F, client); | |
190 | } | |
191 | ||
192 | /* | |
193 | * auth_dns_callback - called when resolver query finishes | |
194 | * if the query resulted in a successful search, hp will contain | |
195 | * a non-null pointer, otherwise hp will be null. | |
196 | * set the client on it's way to a connection completion, regardless | |
197 | * of success of failure | |
198 | */ | |
199 | static void | |
200 | auth_dns_callback(const char *result, int status, int aftype, void *vptr) | |
201 | { | |
202 | struct AuthRequest *auth = (struct AuthRequest *) vptr; | |
203 | ClearDNSPending(auth); | |
204 | ||
205 | /* XXX: this shouldn't happen, but it does. -nenolod */ | |
206 | if(auth->client->localClient == NULL) | |
207 | { | |
208 | sendto_realops_snomask(SNO_GENERAL, L_ALL, | |
209 | "auth_dns_callback(): auth->client->localClient (%s) is NULL", get_client_name(auth->client, HIDE_IP)); | |
210 | ||
211 | rb_dlinkDelete(&auth->node, &auth_poll_list); | |
212 | free_auth_request(auth); | |
213 | ||
214 | /* and they will silently drop through and all will hopefully be ok... -nenolod */ | |
215 | return; | |
216 | } | |
217 | ||
218 | if(result != NULL && status) | |
219 | { | |
220 | int good = 1; | |
221 | ||
222 | if(good && strlen(result) <= HOSTLEN) | |
223 | { | |
224 | rb_strlcpy(auth->client->host, result, sizeof(auth->client->host)); | |
225 | sendheader(auth->client, REPORT_FIN_DNS); | |
226 | } | |
227 | else if (strlen(result) > HOSTLEN) | |
228 | sendheader(auth->client, REPORT_HOST_TOOLONG); | |
229 | } | |
230 | else | |
231 | sendheader(auth->client, REPORT_FAIL_DNS); | |
232 | ||
233 | release_auth_client(auth); | |
234 | } | |
235 | ||
236 | /* | |
237 | * authsenderr - handle auth send errors | |
238 | */ | |
239 | static void | |
240 | auth_error(struct AuthRequest *auth) | |
241 | { | |
242 | ++ServerStats.is_abad; | |
243 | ||
244 | rb_close(auth->F); | |
245 | auth->F = NULL; | |
246 | ||
247 | ClearAuth(auth); | |
248 | sendheader(auth->client, REPORT_FAIL_ID); | |
249 | ||
250 | release_auth_client(auth); | |
251 | } | |
252 | ||
253 | /* | |
254 | * start_auth_query - Flag the client to show that an attempt to | |
255 | * contact the ident server on | |
256 | * the client's host. The connect and subsequently the socket are all put | |
257 | * into 'non-blocking' mode. Should the connect or any later phase of the | |
258 | * identifing process fail, it is aborted and the user is given a username | |
259 | * of "unknown". | |
260 | */ | |
261 | static int | |
262 | start_auth_query(struct AuthRequest *auth) | |
263 | { | |
264 | struct rb_sockaddr_storage localaddr, destaddr; | |
265 | rb_fde_t *F; | |
266 | int family; | |
267 | ||
268 | if(IsAnyDead(auth->client)) | |
269 | return 0; | |
270 | ||
271 | family = GET_SS_FAMILY(&auth->client->localClient->ip); | |
272 | if((F = rb_socket(family, SOCK_STREAM, 0, "ident")) == NULL) | |
273 | { | |
274 | ilog_error("creating auth stream socket"); | |
275 | ++ServerStats.is_abad; | |
276 | return 0; | |
277 | } | |
278 | ||
279 | /* | |
280 | * TBD: this is a pointless arbitrary limit .. we either have a socket or not. -nenolod | |
281 | */ | |
282 | if((maxconnections - 10) < rb_get_fd(F)) | |
283 | { | |
284 | sendto_realops_snomask(SNO_GENERAL, L_ALL, | |
285 | "Can't allocate fd for auth on %s", | |
286 | get_client_name(auth->client, SHOW_IP)); | |
287 | rb_close(F); | |
288 | return 0; | |
289 | } | |
290 | ||
291 | sendheader(auth->client, REPORT_DO_ID); | |
292 | ||
293 | /* | |
294 | * get the local address of the client and bind to that to | |
295 | * make the auth request. This used to be done only for | |
296 | * ifdef VIRTUAL_HOST, but needs to be done for all clients | |
297 | * since the ident request must originate from that same address-- | |
298 | * and machines with multiple IP addresses are common now | |
299 | */ | |
300 | localaddr = auth->client->preClient->lip; | |
301 | ||
302 | /* XXX mangle_mapped_sockaddr((struct sockaddr *)&localaddr); */ | |
303 | #ifdef RB_IPV6 | |
304 | if(GET_SS_FAMILY(&localaddr) == AF_INET6) | |
305 | { | |
306 | auth->lport = ntohs(((struct sockaddr_in6 *)&localaddr)->sin6_port); | |
307 | ((struct sockaddr_in6 *)&localaddr)->sin6_port = 0; | |
308 | } | |
309 | else | |
310 | #endif | |
311 | { | |
312 | auth->lport = ntohs(((struct sockaddr_in *)&localaddr)->sin_port); | |
313 | ((struct sockaddr_in *)&localaddr)->sin_port = 0; | |
314 | } | |
315 | ||
316 | destaddr = auth->client->localClient->ip; | |
317 | #ifdef RB_IPV6 | |
318 | if(GET_SS_FAMILY(&localaddr) == AF_INET6) | |
319 | { | |
320 | auth->rport = ntohs(((struct sockaddr_in6 *)&destaddr)->sin6_port); | |
321 | ((struct sockaddr_in6 *)&destaddr)->sin6_port = htons(113); | |
322 | } | |
323 | else | |
324 | #endif | |
325 | { | |
326 | auth->rport = ntohs(((struct sockaddr_in *)&destaddr)->sin_port); | |
327 | ((struct sockaddr_in *)&destaddr)->sin_port = htons(113); | |
328 | } | |
329 | ||
330 | auth->F = F; | |
331 | SetAuthConnect(auth); | |
332 | ||
333 | rb_connect_tcp(F, (struct sockaddr *)&destaddr, | |
334 | (struct sockaddr *) &localaddr, GET_SS_LEN(&localaddr), | |
335 | auth_connect_callback, auth, | |
336 | GlobalSetOptions.ident_timeout); | |
337 | return 1; /* We suceed here for now */ | |
338 | } | |
339 | ||
340 | /* | |
341 | * GetValidIdent - parse ident query reply from identd server | |
342 | * | |
343 | * Inputs - pointer to ident buf | |
344 | * Output - NULL if no valid ident found, otherwise pointer to name | |
345 | * Side effects - | |
346 | */ | |
347 | static char * | |
348 | GetValidIdent(char *buf) | |
349 | { | |
350 | int remp = 0; | |
351 | int locp = 0; | |
352 | char *colon1Ptr; | |
353 | char *colon2Ptr; | |
354 | char *colon3Ptr; | |
355 | char *commaPtr; | |
356 | char *remotePortString; | |
357 | ||
358 | /* All this to get rid of a sscanf() fun. */ | |
359 | remotePortString = buf; | |
360 | ||
361 | colon1Ptr = strchr(remotePortString, ':'); | |
362 | if(!colon1Ptr) | |
363 | return 0; | |
364 | ||
365 | *colon1Ptr = '\0'; | |
366 | colon1Ptr++; | |
367 | colon2Ptr = strchr(colon1Ptr, ':'); | |
368 | if(!colon2Ptr) | |
369 | return 0; | |
370 | ||
371 | *colon2Ptr = '\0'; | |
372 | colon2Ptr++; | |
373 | commaPtr = strchr(remotePortString, ','); | |
374 | ||
375 | if(!commaPtr) | |
376 | return 0; | |
377 | ||
378 | *commaPtr = '\0'; | |
379 | commaPtr++; | |
380 | ||
381 | remp = atoi(remotePortString); | |
382 | if(!remp) | |
383 | return 0; | |
384 | ||
385 | locp = atoi(commaPtr); | |
386 | if(!locp) | |
387 | return 0; | |
388 | ||
389 | /* look for USERID bordered by first pair of colons */ | |
390 | if(!strstr(colon1Ptr, "USERID")) | |
391 | return 0; | |
392 | ||
393 | colon3Ptr = strchr(colon2Ptr, ':'); | |
394 | if(!colon3Ptr) | |
395 | return 0; | |
396 | ||
397 | *colon3Ptr = '\0'; | |
398 | colon3Ptr++; | |
399 | return (colon3Ptr); | |
400 | } | |
401 | ||
402 | /* | |
403 | * start_auth - starts auth (identd) and dns queries for a client | |
404 | */ | |
405 | void | |
406 | start_auth(struct Client *client) | |
407 | { | |
408 | struct AuthRequest *auth = 0; | |
409 | s_assert(0 != client); | |
410 | if(client == NULL) | |
411 | return; | |
412 | ||
413 | auth = make_auth_request(client); | |
414 | ||
415 | sendheader(client, REPORT_DO_DNS); | |
416 | ||
417 | /* No DNS cache now, remember? -- adrian */ | |
418 | auth->dns_id = lookup_ip(client->sockhost, GET_SS_FAMILY(&client->localClient->ip), auth_dns_callback, auth); | |
419 | ||
420 | SetDNSPending(auth); | |
421 | ||
422 | if(ConfigFileEntry.disable_auth == 0) | |
423 | start_auth_query(auth); | |
424 | ||
425 | rb_dlinkAdd(auth, &auth->node, &auth_poll_list); | |
426 | } | |
427 | ||
428 | /* | |
429 | * timeout_auth_queries - timeout resolver and identd requests | |
430 | * allow clients through if requests failed | |
431 | */ | |
432 | static void | |
433 | timeout_auth_queries_event(void *notused) | |
434 | { | |
435 | rb_dlink_node *ptr; | |
436 | rb_dlink_node *next_ptr; | |
437 | struct AuthRequest *auth; | |
438 | ||
439 | RB_DLINK_FOREACH_SAFE(ptr, next_ptr, auth_poll_list.head) | |
440 | { | |
441 | auth = ptr->data; | |
442 | ||
443 | if(auth->timeout < rb_current_time()) | |
444 | { | |
445 | if(auth->F != NULL) | |
446 | rb_close(auth->F); | |
447 | ||
448 | if(IsDoingAuth(auth)) | |
449 | { | |
450 | ClearAuth(auth); | |
451 | ++ServerStats.is_abad; | |
452 | sendheader(auth->client, REPORT_FAIL_ID); | |
453 | auth->client->localClient->auth_request = NULL; | |
454 | } | |
455 | if(IsDNSPending(auth)) | |
456 | { | |
457 | ClearDNSPending(auth); | |
458 | cancel_lookup(auth->dns_id); | |
459 | sendheader(auth->client, REPORT_FAIL_DNS); | |
460 | } | |
461 | ||
462 | auth->client->localClient->lasttime = rb_current_time(); | |
463 | release_auth_client(auth); | |
464 | } | |
465 | } | |
466 | } | |
467 | ||
468 | /* | |
469 | * auth_connect_callback() - deal with the result of rb_connect_tcp() | |
470 | * | |
471 | * If the connection failed, we simply close the auth fd and report | |
472 | * a failure. If the connection suceeded send the ident server a query | |
473 | * giving "theirport , ourport". The write is only attempted *once* so | |
474 | * it is deemed to be a fail if the entire write doesn't write all the | |
475 | * data given. This shouldnt be a problem since the socket should have | |
476 | * a write buffer far greater than this message to store it in should | |
477 | * problems arise. -avalon | |
478 | */ | |
479 | static void | |
480 | auth_connect_callback(rb_fde_t *F, int error, void *data) | |
481 | { | |
482 | struct AuthRequest *auth = data; | |
483 | char authbuf[32]; | |
484 | int authlen; | |
485 | ||
486 | /* Check the error */ | |
487 | if(error != RB_OK) | |
488 | { | |
489 | /* We had an error during connection :( */ | |
490 | auth_error(auth); | |
491 | return; | |
492 | } | |
493 | ||
494 | snprintf(authbuf, sizeof(authbuf), "%u , %u\r\n", | |
495 | auth->rport, auth->lport); | |
496 | authlen = strlen(authbuf); | |
497 | ||
498 | if(rb_write(auth->F, authbuf, authlen) != authlen) | |
499 | { | |
500 | auth_error(auth); | |
501 | return; | |
502 | } | |
503 | ClearAuthConnect(auth); | |
504 | SetAuthPending(auth); | |
505 | read_auth_reply(auth->F, auth); | |
506 | } | |
507 | ||
508 | ||
509 | /* | |
510 | * read_auth_reply - read the reply (if any) from the ident server | |
511 | * we connected to. | |
512 | * We only give it one shot, if the reply isn't good the first time | |
513 | * fail the authentication entirely. --Bleep | |
514 | */ | |
515 | #define AUTH_BUFSIZ 128 | |
516 | ||
517 | static void | |
518 | read_auth_reply(rb_fde_t *F, void *data) | |
519 | { | |
520 | struct AuthRequest *auth = data; | |
521 | char *s = NULL; | |
522 | char *t = NULL; | |
523 | int len; | |
524 | int count; | |
525 | char buf[AUTH_BUFSIZ + 1]; /* buffer to read auth reply into */ | |
526 | ||
527 | len = rb_read(F, buf, AUTH_BUFSIZ); | |
528 | ||
529 | if(len < 0 && rb_ignore_errno(errno)) | |
530 | { | |
531 | rb_setselect(F, RB_SELECT_READ, read_auth_reply, auth); | |
532 | return; | |
533 | } | |
534 | ||
535 | if(len > 0) | |
536 | { | |
537 | buf[len] = '\0'; | |
538 | ||
539 | if((s = GetValidIdent(buf))) | |
540 | { | |
541 | t = auth->client->username; | |
542 | ||
543 | while (*s == '~' || *s == '^') | |
544 | s++; | |
545 | ||
546 | for (count = USERLEN; *s && count; s++) | |
547 | { | |
548 | if(*s == '@' || *s == '\r' || *s == '\n') | |
549 | { | |
550 | break; | |
551 | } | |
552 | if(!IsSpace(*s) && *s != ':' && *s != '[') | |
553 | { | |
554 | *t++ = *s; | |
555 | count--; | |
556 | } | |
557 | } | |
558 | *t = '\0'; | |
559 | } | |
560 | } | |
561 | ||
562 | rb_close(auth->F); | |
563 | auth->F = NULL; | |
564 | ClearAuth(auth); | |
565 | ||
566 | if(s == NULL) | |
567 | { | |
568 | ++ServerStats.is_abad; | |
569 | strcpy(auth->client->username, "unknown"); | |
570 | sendheader(auth->client, REPORT_FAIL_ID); | |
571 | } | |
572 | else | |
573 | { | |
574 | sendheader(auth->client, REPORT_FIN_ID); | |
575 | ++ServerStats.is_asuc; | |
576 | SetGotId(auth->client); | |
577 | } | |
578 | ||
579 | release_auth_client(auth); | |
580 | } | |
581 | ||
582 | ||
583 | ||
584 | /* | |
585 | * delete_auth_queries() | |
586 | */ | |
587 | void | |
588 | delete_auth_queries(struct Client *target_p) | |
589 | { | |
590 | struct AuthRequest *auth; | |
591 | ||
592 | if(target_p == NULL || target_p->localClient == NULL || | |
593 | target_p->localClient->auth_request == NULL) | |
594 | return; | |
595 | ||
596 | auth = target_p->localClient->auth_request; | |
597 | target_p->localClient->auth_request = NULL; | |
598 | ||
599 | if(IsDNSPending(auth)) | |
600 | cancel_lookup(auth->dns_id); | |
601 | ||
602 | if(auth->F != NULL) | |
603 | rb_close(auth->F); | |
604 | ||
605 | rb_dlinkDelete(&auth->node, &auth_poll_list); | |
606 | free_auth_request(auth); | |
607 | } |