1 /*
2 * multilink.c - support routines for multilink.
3 *
4 * Copyright (c) 2000-2002 Paul Mackerras. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 *
13 * 2. The name(s) of the authors of this software must not be used to
14 * endorse or promote products derived from this software without
15 * prior written permission.
16 *
17 * 3. Redistributions of any form whatsoever must retain the following
18 * acknowledgment:
19 * "This product includes software developed by Paul Mackerras
20 * <paulus@samba.org>".
21 *
22 * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
23 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
24 * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
25 * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
26 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
27 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
28 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
29 */
30 #include <string.h>
31 #include <ctype.h>
32 #include <stdlib.h>
33 #include <netdb.h>
34 #include <errno.h>
35 #include <signal.h>
36 #include <netinet/in.h>
37 #include <unistd.h>
38
39 #include "pppd.h"
40 #include "fsm.h"
41 #include "lcp.h"
42 #include "tdb.h"
43
44 bool endpoint_specified; /* user gave explicit endpoint discriminator */
45 char *bundle_id; /* identifier for our bundle */
46 char *blinks_id; /* key for the list of links */
47 bool doing_multilink; /* multilink was enabled and agreed to */
48 bool multilink_master; /* we own the multilink bundle */
49
50 extern TDB_CONTEXT *pppdb;
51 extern char db_key[];
52
53 static void make_bundle_links __P((int append));
54 static void remove_bundle_link __P((void));
55 static void iterate_bundle_links __P((void (*func) __P((char *))));
56
57 static int get_default_epdisc __P((struct epdisc *));
58 static int parse_num __P((char *str, const char *key, int *valp));
59 static int owns_unit __P((TDB_DATA pid, int unit));
60
61 #define set_ip_epdisc(ep, addr) do { \
62 ep->length = 4; \
63 ep->value[0] = addr >> 24; \
64 ep->value[1] = addr >> 16; \
65 ep->value[2] = addr >> 8; \
66 ep->value[3] = addr; \
67 } while (0)
68
69 #define LOCAL_IP_ADDR(addr) \
70 (((addr) & 0xff000000) == 0x0a000000 /* 10.x.x.x */ \
71 || ((addr) & 0xfff00000) == 0xac100000 /* 172.16.x.x */ \
72 || ((addr) & 0xffff0000) == 0xc0a80000) /* 192.168.x.x */
73
74 #define process_exists(n) (kill((n), 0) == 0 || errno != ESRCH)
75
76 void
mp_check_options()77 mp_check_options()
78 {
79 lcp_options *wo = &lcp_wantoptions[0];
80 lcp_options *ao = &lcp_allowoptions[0];
81
82 doing_multilink = 0;
83 if (!multilink)
84 return;
85 /* if we're doing multilink, we have to negotiate MRRU */
86 if (!wo->neg_mrru) {
87 /* mrru not specified, default to mru */
88 wo->mrru = wo->mru;
89 wo->neg_mrru = 1;
90 }
91 ao->mrru = ao->mru;
92 ao->neg_mrru = 1;
93
94 if (!wo->neg_endpoint && !noendpoint) {
95 /* get a default endpoint value */
96 wo->neg_endpoint = get_default_epdisc(&wo->endpoint);
97 }
98 }
99
100 /*
101 * Make a new bundle or join us to an existing bundle
102 * if we are doing multilink.
103 */
104 int
mp_join_bundle()105 mp_join_bundle()
106 {
107 lcp_options *go = &lcp_gotoptions[0];
108 lcp_options *ho = &lcp_hisoptions[0];
109 lcp_options *ao = &lcp_allowoptions[0];
110 int unit, pppd_pid;
111 int l, mtu;
112 char *p;
113 TDB_DATA key, pid, rec;
114
115 if (doing_multilink) {
116 /* have previously joined a bundle */
117 if (!go->neg_mrru || !ho->neg_mrru) {
118 notice("oops, didn't get multilink on renegotiation");
119 lcp_close(0, "multilink required");
120 return 0;
121 }
122 /* XXX should check the peer_authname and ho->endpoint
123 are the same as previously */
124 return 0;
125 }
126
127 if (!go->neg_mrru || !ho->neg_mrru) {
128 /* not doing multilink */
129 if (go->neg_mrru)
130 notice("oops, multilink negotiated only for receive");
131 mtu = ho->neg_mru? ho->mru: PPP_MRU;
132 if (mtu > ao->mru)
133 mtu = ao->mru;
134 if (demand) {
135 /* already have a bundle */
136 cfg_bundle(0, 0, 0, 0);
137 netif_set_mtu(0, mtu);
138 return 0;
139 }
140 make_new_bundle(0, 0, 0, 0);
141 set_ifunit(1);
142 netif_set_mtu(0, mtu);
143 return 0;
144 }
145
146 doing_multilink = 1;
147
148 /*
149 * Find the appropriate bundle or join a new one.
150 * First we make up a name for the bundle.
151 * The length estimate is worst-case assuming every
152 * character has to be quoted.
153 */
154 l = 4 * strlen(peer_authname) + 10;
155 if (ho->neg_endpoint)
156 l += 3 * ho->endpoint.length + 8;
157 if (bundle_name)
158 l += 3 * strlen(bundle_name) + 2;
159 bundle_id = malloc(l);
160 if (bundle_id == 0)
161 novm("bundle identifier");
162
163 p = bundle_id;
164 p += slprintf(p, l-1, "BUNDLE=\"%q\"", peer_authname);
165 if (ho->neg_endpoint || bundle_name)
166 *p++ = '/';
167 if (ho->neg_endpoint)
168 p += slprintf(p, bundle_id+l-p, "%s",
169 epdisc_to_str(&ho->endpoint));
170 if (bundle_name)
171 p += slprintf(p, bundle_id+l-p, "/%v", bundle_name);
172
173 /* Make the key for the list of links belonging to the bundle */
174 l = p - bundle_id;
175 blinks_id = malloc(l + 7);
176 if (blinks_id == NULL)
177 novm("bundle links key");
178 slprintf(blinks_id, l + 7, "BUNDLE_LINKS=%s", bundle_id + 7);
179
180 /*
181 * For demand mode, we only need to configure the bundle
182 * and attach the link.
183 */
184 mtu = MIN(ho->mrru, ao->mru);
185 if (demand) {
186 cfg_bundle(go->mrru, ho->mrru, go->neg_ssnhf, ho->neg_ssnhf);
187 netif_set_mtu(0, mtu);
188 script_setenv("BUNDLE", bundle_id + 7, 1);
189 return 0;
190 }
191
192 /*
193 * Check if the bundle ID is already in the database.
194 */
195 unit = -1;
196 lock_db();
197 key.dptr = bundle_id;
198 key.dsize = p - bundle_id;
199 pid = tdb_fetch(pppdb, key);
200 if (pid.dptr != NULL) {
201 /* bundle ID exists, see if the pppd record exists */
202 rec = tdb_fetch(pppdb, pid);
203 if (rec.dptr != NULL && rec.dsize > 0) {
204 /* make sure the string is null-terminated */
205 rec.dptr[rec.dsize-1] = 0;
206 /* parse the interface number */
207 parse_num(rec.dptr, "IFNAME=ppp", &unit);
208 /* check the pid value */
209 if (!parse_num(rec.dptr, "PPPD_PID=", &pppd_pid)
210 || !process_exists(pppd_pid)
211 || !owns_unit(pid, unit))
212 unit = -1;
213 free(rec.dptr);
214 }
215 free(pid.dptr);
216 }
217
218 if (unit >= 0) {
219 /* attach to existing unit */
220 if (bundle_attach(unit)) {
221 set_ifunit(0);
222 script_setenv("BUNDLE", bundle_id + 7, 0);
223 make_bundle_links(1);
224 unlock_db();
225 info("Link attached to %s", ifname);
226 return 1;
227 }
228 /* attach failed because bundle doesn't exist */
229 }
230
231 /* we have to make a new bundle */
232 make_new_bundle(go->mrru, ho->mrru, go->neg_ssnhf, ho->neg_ssnhf);
233 set_ifunit(1);
234 netif_set_mtu(0, mtu);
235 script_setenv("BUNDLE", bundle_id + 7, 1);
236 make_bundle_links(0);
237 unlock_db();
238 info("New bundle %s created", ifname);
239 multilink_master = 1;
240 return 0;
241 }
242
mp_exit_bundle()243 void mp_exit_bundle()
244 {
245 lock_db();
246 remove_bundle_link();
247 unlock_db();
248 }
249
sendhup(char * str)250 static void sendhup(char *str)
251 {
252 int pid;
253
254 if (parse_num(str, "PPPD_PID=", &pid) && pid != getpid()) {
255 if (debug)
256 dbglog("sending SIGHUP to process %d", pid);
257 kill(pid, SIGHUP);
258 }
259 }
260
mp_bundle_terminated()261 void mp_bundle_terminated()
262 {
263 TDB_DATA key;
264
265 bundle_terminating = 1;
266 upper_layers_down(0);
267 notice("Connection terminated.");
268 print_link_stats();
269 if (!demand) {
270 remove_pidfiles();
271 script_unsetenv("IFNAME");
272 }
273
274 lock_db();
275 destroy_bundle();
276 iterate_bundle_links(sendhup);
277 key.dptr = blinks_id;
278 key.dsize = strlen(blinks_id);
279 tdb_delete(pppdb, key);
280 unlock_db();
281
282 new_phase(PHASE_DEAD);
283 }
284
make_bundle_links(int append)285 static void make_bundle_links(int append)
286 {
287 TDB_DATA key, rec;
288 char *p;
289 char entry[32];
290 int l;
291
292 key.dptr = blinks_id;
293 key.dsize = strlen(blinks_id);
294 slprintf(entry, sizeof(entry), "%s;", db_key);
295 p = entry;
296 if (append) {
297 rec = tdb_fetch(pppdb, key);
298 if (rec.dptr != NULL && rec.dsize > 0) {
299 rec.dptr[rec.dsize-1] = 0;
300 if (strstr(rec.dptr, db_key) != NULL) {
301 /* already in there? strange */
302 warn("link entry already exists in tdb");
303 return;
304 }
305 l = rec.dsize + strlen(entry);
306 p = malloc(l);
307 if (p == NULL)
308 novm("bundle link list");
309 slprintf(p, l, "%s%s", rec.dptr, entry);
310 } else {
311 warn("bundle link list not found");
312 }
313 if (rec.dptr != NULL)
314 free(rec.dptr);
315 }
316 rec.dptr = p;
317 rec.dsize = strlen(p) + 1;
318 if (tdb_store(pppdb, key, rec, TDB_REPLACE))
319 error("couldn't %s bundle link list",
320 append? "update": "create");
321 if (p != entry)
322 free(p);
323 }
324
remove_bundle_link()325 static void remove_bundle_link()
326 {
327 TDB_DATA key, rec;
328 char entry[32];
329 char *p, *q;
330 int l;
331
332 key.dptr = blinks_id;
333 key.dsize = strlen(blinks_id);
334 slprintf(entry, sizeof(entry), "%s;", db_key);
335
336 rec = tdb_fetch(pppdb, key);
337 if (rec.dptr == NULL || rec.dsize <= 0) {
338 if (rec.dptr != NULL)
339 free(rec.dptr);
340 return;
341 }
342 rec.dptr[rec.dsize-1] = 0;
343 p = strstr(rec.dptr, entry);
344 if (p != NULL) {
345 q = p + strlen(entry);
346 l = strlen(q) + 1;
347 memmove(p, q, l);
348 rec.dsize = p - rec.dptr + l;
349 if (tdb_store(pppdb, key, rec, TDB_REPLACE))
350 error("couldn't update bundle link list (removal)");
351 }
352 free(rec.dptr);
353 }
354
iterate_bundle_links(void (* func)(char *))355 static void iterate_bundle_links(void (*func)(char *))
356 {
357 TDB_DATA key, rec, pp;
358 char *p, *q;
359
360 key.dptr = blinks_id;
361 key.dsize = strlen(blinks_id);
362 rec = tdb_fetch(pppdb, key);
363 if (rec.dptr == NULL || rec.dsize <= 0) {
364 error("bundle link list not found (iterating list)");
365 if (rec.dptr != NULL)
366 free(rec.dptr);
367 return;
368 }
369 p = rec.dptr;
370 p[rec.dsize-1] = 0;
371 while ((q = strchr(p, ';')) != NULL) {
372 *q = 0;
373 key.dptr = p;
374 key.dsize = q - p;
375 pp = tdb_fetch(pppdb, key);
376 if (pp.dptr != NULL && pp.dsize > 0) {
377 pp.dptr[pp.dsize-1] = 0;
378 func(pp.dptr);
379 }
380 if (pp.dptr != NULL)
381 free(pp.dptr);
382 p = q + 1;
383 }
384 free(rec.dptr);
385 }
386
387 static int
parse_num(str,key,valp)388 parse_num(str, key, valp)
389 char *str;
390 const char *key;
391 int *valp;
392 {
393 char *p, *endp;
394 int i;
395
396 p = strstr(str, key);
397 if (p != 0) {
398 p += strlen(key);
399 i = strtol(p, &endp, 10);
400 if (endp != p && (*endp == 0 || *endp == ';')) {
401 *valp = i;
402 return 1;
403 }
404 }
405 return 0;
406 }
407
408 /*
409 * Check whether the pppd identified by `key' still owns ppp unit `unit'.
410 */
411 static int
owns_unit(key,unit)412 owns_unit(key, unit)
413 TDB_DATA key;
414 int unit;
415 {
416 char ifkey[32];
417 TDB_DATA kd, vd;
418 int ret = 0;
419
420 slprintf(ifkey, sizeof(ifkey), "IFNAME=ppp%d", unit);
421 kd.dptr = ifkey;
422 kd.dsize = strlen(ifkey);
423 vd = tdb_fetch(pppdb, kd);
424 if (vd.dptr != NULL) {
425 ret = vd.dsize == key.dsize
426 && memcmp(vd.dptr, key.dptr, vd.dsize) == 0;
427 free(vd.dptr);
428 }
429 return ret;
430 }
431
432 static int
get_default_epdisc(ep)433 get_default_epdisc(ep)
434 struct epdisc *ep;
435 {
436 char *p;
437 struct hostent *hp;
438 u_int32_t addr;
439
440 /* First try for an ethernet MAC address */
441 p = get_first_ethernet();
442 if (p != 0 && get_if_hwaddr(ep->value, p) >= 0) {
443 ep->class = EPD_MAC;
444 ep->length = 6;
445 return 1;
446 }
447
448 /* see if our hostname corresponds to a reasonable IP address */
449 hp = gethostbyname(hostname);
450 if (hp != NULL) {
451 addr = *(u_int32_t *)hp->h_addr;
452 if (!bad_ip_adrs(addr)) {
453 addr = ntohl(addr);
454 if (!LOCAL_IP_ADDR(addr)) {
455 ep->class = EPD_IP;
456 set_ip_epdisc(ep, addr);
457 return 1;
458 }
459 }
460 }
461
462 return 0;
463 }
464
465 /*
466 * epdisc_to_str - make a printable string from an endpoint discriminator.
467 */
468
469 static char *endp_class_names[] = {
470 "null", "local", "IP", "MAC", "magic", "phone"
471 };
472
473 char *
epdisc_to_str(ep)474 epdisc_to_str(ep)
475 struct epdisc *ep;
476 {
477 static char str[MAX_ENDP_LEN*3+8];
478 u_char *p = ep->value;
479 int i, mask = 0;
480 char *q, c, c2;
481
482 if (ep->class == EPD_NULL && ep->length == 0)
483 return "null";
484 if (ep->class == EPD_IP && ep->length == 4) {
485 u_int32_t addr;
486
487 GETLONG(addr, p);
488 slprintf(str, sizeof(str), "IP:%I", htonl(addr));
489 return str;
490 }
491
492 c = ':';
493 c2 = '.';
494 if (ep->class == EPD_MAC && ep->length == 6)
495 c2 = ':';
496 else if (ep->class == EPD_MAGIC && (ep->length % 4) == 0)
497 mask = 3;
498 q = str;
499 if (ep->class <= EPD_PHONENUM)
500 q += slprintf(q, sizeof(str)-1, "%s",
501 endp_class_names[ep->class]);
502 else
503 q += slprintf(q, sizeof(str)-1, "%d", ep->class);
504 c = ':';
505 for (i = 0; i < ep->length && i < MAX_ENDP_LEN; ++i) {
506 if ((i & mask) == 0) {
507 *q++ = c;
508 c = c2;
509 }
510 q += slprintf(q, str + sizeof(str) - q, "%.2x", ep->value[i]);
511 }
512 return str;
513 }
514
hexc_val(int c)515 static int hexc_val(int c)
516 {
517 if (c >= 'a')
518 return c - 'a' + 10;
519 if (c >= 'A')
520 return c - 'A' + 10;
521 return c - '0';
522 }
523
524 int
str_to_epdisc(ep,str)525 str_to_epdisc(ep, str)
526 struct epdisc *ep;
527 char *str;
528 {
529 int i, l;
530 char *p, *endp;
531
532 for (i = EPD_NULL; i <= EPD_PHONENUM; ++i) {
533 int sl = strlen(endp_class_names[i]);
534 if (strncasecmp(str, endp_class_names[i], sl) == 0) {
535 str += sl;
536 break;
537 }
538 }
539 if (i > EPD_PHONENUM) {
540 /* not a class name, try a decimal class number */
541 i = strtol(str, &endp, 10);
542 if (endp == str)
543 return 0; /* can't parse class number */
544 str = endp;
545 }
546 ep->class = i;
547 if (*str == 0) {
548 ep->length = 0;
549 return 1;
550 }
551 if (*str != ':' && *str != '.')
552 return 0;
553 ++str;
554
555 if (i == EPD_IP) {
556 u_int32_t addr;
557 i = parse_dotted_ip(str, &addr);
558 if (i == 0 || str[i] != 0)
559 return 0;
560 set_ip_epdisc(ep, addr);
561 return 1;
562 }
563 if (i == EPD_MAC && get_if_hwaddr(ep->value, str) >= 0) {
564 ep->length = 6;
565 return 1;
566 }
567
568 p = str;
569 for (l = 0; l < MAX_ENDP_LEN; ++l) {
570 if (*str == 0)
571 break;
572 if (p <= str)
573 for (p = str; isxdigit(*p); ++p)
574 ;
575 i = p - str;
576 if (i == 0)
577 return 0;
578 ep->value[l] = hexc_val(*str++);
579 if ((i & 1) == 0)
580 ep->value[l] = (ep->value[l] << 4) + hexc_val(*str++);
581 if (*str == ':' || *str == '.')
582 ++str;
583 }
584 if (*str != 0 || (ep->class == EPD_MAC && l != 6))
585 return 0;
586 ep->length = l;
587 return 1;
588 }
589
590