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
31 #include "netif/ppp/ppp_opts.h"
32 #if PPP_SUPPORT && defined(HAVE_MULTILINK) /* don't build if not configured for use in lwipopts.h */
33
34 /* Multilink support
35 *
36 * Multilink uses Samba TDB (Trivial Database Library), which
37 * we cannot port, because it needs a filesystem.
38 *
39 * We have to choose between doing a memory-shared TDB-clone,
40 * or dropping multilink support at all.
41 */
42
43 #include <string.h>
44 #include <ctype.h>
45 #include <stdlib.h>
46 #include <netdb.h>
47 #include <errno.h>
48 #include <signal.h>
49 #include <netinet/in.h>
50 #include <unistd.h>
51
52 #include "netif/ppp/ppp_impl.h"
53
54 #include "netif/ppp/fsm.h"
55 #include "netif/ppp/lcp.h"
56 #include "netif/ppp/tdb.h"
57
58 bool endpoint_specified; /* user gave explicit endpoint discriminator */
59 char *bundle_id; /* identifier for our bundle */
60 char *blinks_id; /* key for the list of links */
61 bool doing_multilink; /* multilink was enabled and agreed to */
62 bool multilink_master; /* we own the multilink bundle */
63
64 extern TDB_CONTEXT *pppdb;
65 extern char db_key[];
66
67 static void make_bundle_links (int append);
68 static void remove_bundle_link (void);
69 static void iterate_bundle_links (void (*func) (char *));
70
71 static int get_default_epdisc (struct epdisc *);
72 static int parse_num (char *str, const char *key, int *valp);
73 static int owns_unit (TDB_DATA pid, int unit);
74
75 #define set_ip_epdisc(ep, addr) do { \
76 ep->length = 4; \
77 ep->value[0] = addr >> 24; \
78 ep->value[1] = addr >> 16; \
79 ep->value[2] = addr >> 8; \
80 ep->value[3] = addr; \
81 } while (0)
82
83 #define LOCAL_IP_ADDR(addr) \
84 (((addr) & 0xff000000) == 0x0a000000 /* 10.x.x.x */ \
85 || ((addr) & 0xfff00000) == 0xac100000 /* 172.16.x.x */ \
86 || ((addr) & 0xffff0000) == 0xc0a80000) /* 192.168.x.x */
87
88 #define process_exists(n) (kill((n), 0) == 0 || errno != ESRCH)
89
90 void
mp_check_options()91 mp_check_options()
92 {
93 lcp_options *wo = &lcp_wantoptions[0];
94 lcp_options *ao = &lcp_allowoptions[0];
95
96 doing_multilink = 0;
97 if (!multilink)
98 return;
99 /* if we're doing multilink, we have to negotiate MRRU */
100 if (!wo->neg_mrru) {
101 /* mrru not specified, default to mru */
102 wo->mrru = wo->mru;
103 wo->neg_mrru = 1;
104 }
105 ao->mrru = ao->mru;
106 ao->neg_mrru = 1;
107
108 if (!wo->neg_endpoint && !noendpoint) {
109 /* get a default endpoint value */
110 wo->neg_endpoint = get_default_epdisc(&wo->endpoint);
111 }
112 }
113
114 /*
115 * Make a new bundle or join us to an existing bundle
116 * if we are doing multilink.
117 */
118 int
mp_join_bundle()119 mp_join_bundle()
120 {
121 lcp_options *go = &lcp_gotoptions[0];
122 lcp_options *ho = &lcp_hisoptions[0];
123 lcp_options *ao = &lcp_allowoptions[0];
124 int unit, pppd_pid;
125 int l, mtu;
126 char *p;
127 TDB_DATA key, pid, rec;
128
129 if (doing_multilink) {
130 /* have previously joined a bundle */
131 if (!go->neg_mrru || !ho->neg_mrru) {
132 notice("oops, didn't get multilink on renegotiation");
133 lcp_close(pcb, "multilink required");
134 return 0;
135 }
136 /* XXX should check the peer_authname and ho->endpoint
137 are the same as previously */
138 return 0;
139 }
140
141 if (!go->neg_mrru || !ho->neg_mrru) {
142 /* not doing multilink */
143 if (go->neg_mrru)
144 notice("oops, multilink negotiated only for receive");
145 mtu = ho->neg_mru? ho->mru: PPP_MRU;
146 if (mtu > ao->mru)
147 mtu = ao->mru;
148 if (demand) {
149 /* already have a bundle */
150 cfg_bundle(0, 0, 0, 0);
151 netif_set_mtu(pcb, mtu);
152 return 0;
153 }
154 make_new_bundle(0, 0, 0, 0);
155 set_ifunit(1);
156 netif_set_mtu(pcb, mtu);
157 return 0;
158 }
159
160 doing_multilink = 1;
161
162 /*
163 * Find the appropriate bundle or join a new one.
164 * First we make up a name for the bundle.
165 * The length estimate is worst-case assuming every
166 * character has to be quoted.
167 */
168 l = 4 * strlen(peer_authname) + 10;
169 if (ho->neg_endpoint)
170 l += 3 * ho->endpoint.length + 8;
171 if (bundle_name)
172 l += 3 * strlen(bundle_name) + 2;
173 bundle_id = malloc(l);
174 if (bundle_id == 0)
175 novm("bundle identifier");
176
177 p = bundle_id;
178 p += slprintf(p, l-1, "BUNDLE=\"%q\"", peer_authname);
179 if (ho->neg_endpoint || bundle_name)
180 *p++ = '/';
181 if (ho->neg_endpoint)
182 p += slprintf(p, bundle_id+l-p, "%s",
183 epdisc_to_str(&ho->endpoint));
184 if (bundle_name)
185 p += slprintf(p, bundle_id+l-p, "/%v", bundle_name);
186
187 /* Make the key for the list of links belonging to the bundle */
188 l = p - bundle_id;
189 blinks_id = malloc(l + 7);
190 if (blinks_id == NULL)
191 novm("bundle links key");
192 slprintf(blinks_id, l + 7, "BUNDLE_LINKS=%s", bundle_id + 7);
193
194 /*
195 * For demand mode, we only need to configure the bundle
196 * and attach the link.
197 */
198 mtu = LWIP_MIN(ho->mrru, ao->mru);
199 if (demand) {
200 cfg_bundle(go->mrru, ho->mrru, go->neg_ssnhf, ho->neg_ssnhf);
201 netif_set_mtu(pcb, mtu);
202 script_setenv("BUNDLE", bundle_id + 7, 1);
203 return 0;
204 }
205
206 /*
207 * Check if the bundle ID is already in the database.
208 */
209 unit = -1;
210 lock_db();
211 key.dptr = bundle_id;
212 key.dsize = p - bundle_id;
213 pid = tdb_fetch(pppdb, key);
214 if (pid.dptr != NULL) {
215 /* bundle ID exists, see if the pppd record exists */
216 rec = tdb_fetch(pppdb, pid);
217 if (rec.dptr != NULL && rec.dsize > 0) {
218 /* make sure the string is null-terminated */
219 rec.dptr[rec.dsize-1] = 0;
220 /* parse the interface number */
221 parse_num(rec.dptr, "IFNAME=ppp", &unit);
222 /* check the pid value */
223 if (!parse_num(rec.dptr, "PPPD_PID=", &pppd_pid)
224 || !process_exists(pppd_pid)
225 || !owns_unit(pid, unit))
226 unit = -1;
227 free(rec.dptr);
228 }
229 free(pid.dptr);
230 }
231
232 if (unit >= 0) {
233 /* attach to existing unit */
234 if (bundle_attach(unit)) {
235 set_ifunit(0);
236 script_setenv("BUNDLE", bundle_id + 7, 0);
237 make_bundle_links(1);
238 unlock_db();
239 info("Link attached to %s", ifname);
240 return 1;
241 }
242 /* attach failed because bundle doesn't exist */
243 }
244
245 /* we have to make a new bundle */
246 make_new_bundle(go->mrru, ho->mrru, go->neg_ssnhf, ho->neg_ssnhf);
247 set_ifunit(1);
248 netif_set_mtu(pcb, mtu);
249 script_setenv("BUNDLE", bundle_id + 7, 1);
250 make_bundle_links(pcb);
251 unlock_db();
252 info("New bundle %s created", ifname);
253 multilink_master = 1;
254 return 0;
255 }
256
mp_exit_bundle()257 void mp_exit_bundle()
258 {
259 lock_db();
260 remove_bundle_link();
261 unlock_db();
262 }
263
sendhup(char * str)264 static void sendhup(char *str)
265 {
266 int pid;
267
268 if (parse_num(str, "PPPD_PID=", &pid) && pid != getpid()) {
269 if (debug)
270 dbglog("sending SIGHUP to process %d", pid);
271 kill(pid, SIGHUP);
272 }
273 }
274
mp_bundle_terminated()275 void mp_bundle_terminated()
276 {
277 TDB_DATA key;
278
279 bundle_terminating = 1;
280 upper_layers_down(pcb);
281 notice("Connection terminated.");
282 #if PPP_STATS_SUPPORT
283 print_link_stats();
284 #endif /* PPP_STATS_SUPPORT */
285 if (!demand) {
286 remove_pidfiles();
287 script_unsetenv("IFNAME");
288 }
289
290 lock_db();
291 destroy_bundle();
292 iterate_bundle_links(sendhup);
293 key.dptr = blinks_id;
294 key.dsize = strlen(blinks_id);
295 tdb_delete(pppdb, key);
296 unlock_db();
297
298 new_phase(PPP_PHASE_DEAD);
299
300 doing_multilink = 0;
301 multilink_master = 0;
302 }
303
make_bundle_links(int append)304 static void make_bundle_links(int append)
305 {
306 TDB_DATA key, rec;
307 char *p;
308 char entry[32];
309 int l;
310
311 key.dptr = blinks_id;
312 key.dsize = strlen(blinks_id);
313 slprintf(entry, sizeof(entry), "%s;", db_key);
314 p = entry;
315 if (append) {
316 rec = tdb_fetch(pppdb, key);
317 if (rec.dptr != NULL && rec.dsize > 0) {
318 rec.dptr[rec.dsize-1] = 0;
319 if (strstr(rec.dptr, db_key) != NULL) {
320 /* already in there? strange */
321 warn("link entry already exists in tdb");
322 return;
323 }
324 l = rec.dsize + strlen(entry);
325 p = malloc(l);
326 if (p == NULL)
327 novm("bundle link list");
328 slprintf(p, l, "%s%s", rec.dptr, entry);
329 } else {
330 warn("bundle link list not found");
331 }
332 if (rec.dptr != NULL)
333 free(rec.dptr);
334 }
335 rec.dptr = p;
336 rec.dsize = strlen(p) + 1;
337 if (tdb_store(pppdb, key, rec, TDB_REPLACE))
338 error("couldn't %s bundle link list",
339 append? "update": "create");
340 if (p != entry)
341 free(p);
342 }
343
remove_bundle_link()344 static void remove_bundle_link()
345 {
346 TDB_DATA key, rec;
347 char entry[32];
348 char *p, *q;
349 int l;
350
351 key.dptr = blinks_id;
352 key.dsize = strlen(blinks_id);
353 slprintf(entry, sizeof(entry), "%s;", db_key);
354
355 rec = tdb_fetch(pppdb, key);
356 if (rec.dptr == NULL || rec.dsize <= 0) {
357 if (rec.dptr != NULL)
358 free(rec.dptr);
359 return;
360 }
361 rec.dptr[rec.dsize-1] = 0;
362 p = strstr(rec.dptr, entry);
363 if (p != NULL) {
364 q = p + strlen(entry);
365 l = strlen(q) + 1;
366 memmove(p, q, l);
367 rec.dsize = p - rec.dptr + l;
368 if (tdb_store(pppdb, key, rec, TDB_REPLACE))
369 error("couldn't update bundle link list (removal)");
370 }
371 free(rec.dptr);
372 }
373
iterate_bundle_links(void (* func)(char *))374 static void iterate_bundle_links(void (*func)(char *))
375 {
376 TDB_DATA key, rec, pp;
377 char *p, *q;
378
379 key.dptr = blinks_id;
380 key.dsize = strlen(blinks_id);
381 rec = tdb_fetch(pppdb, key);
382 if (rec.dptr == NULL || rec.dsize <= 0) {
383 error("bundle link list not found (iterating list)");
384 if (rec.dptr != NULL)
385 free(rec.dptr);
386 return;
387 }
388 p = rec.dptr;
389 p[rec.dsize-1] = 0;
390 while ((q = strchr(p, ';')) != NULL) {
391 *q = 0;
392 key.dptr = p;
393 key.dsize = q - p;
394 pp = tdb_fetch(pppdb, key);
395 if (pp.dptr != NULL && pp.dsize > 0) {
396 pp.dptr[pp.dsize-1] = 0;
397 func(pp.dptr);
398 }
399 if (pp.dptr != NULL)
400 free(pp.dptr);
401 p = q + 1;
402 }
403 free(rec.dptr);
404 }
405
406 static int
parse_num(str,key,valp)407 parse_num(str, key, valp)
408 char *str;
409 const char *key;
410 int *valp;
411 {
412 char *p, *endp;
413 int i;
414
415 p = strstr(str, key);
416 if (p != 0) {
417 p += strlen(key);
418 i = strtol(p, &endp, 10);
419 if (endp != p && (*endp == 0 || *endp == ';')) {
420 *valp = i;
421 return 1;
422 }
423 }
424 return 0;
425 }
426
427 /*
428 * Check whether the pppd identified by `key' still owns ppp unit `unit'.
429 */
430 static int
owns_unit(key,unit)431 owns_unit(key, unit)
432 TDB_DATA key;
433 int unit;
434 {
435 char ifkey[32];
436 TDB_DATA kd, vd;
437 int ret = 0;
438
439 slprintf(ifkey, sizeof(ifkey), "IFNAME=ppp%d", unit);
440 kd.dptr = ifkey;
441 kd.dsize = strlen(ifkey);
442 vd = tdb_fetch(pppdb, kd);
443 if (vd.dptr != NULL) {
444 ret = vd.dsize == key.dsize
445 && memcmp(vd.dptr, key.dptr, vd.dsize) == 0;
446 free(vd.dptr);
447 }
448 return ret;
449 }
450
451 static int
get_default_epdisc(ep)452 get_default_epdisc(ep)
453 struct epdisc *ep;
454 {
455 char *p;
456 struct hostent *hp;
457 u32_t addr;
458
459 /* First try for an ethernet MAC address */
460 p = get_first_ethernet();
461 if (p != 0 && get_if_hwaddr(ep->value, p) >= 0) {
462 ep->class = EPD_MAC;
463 ep->length = 6;
464 return 1;
465 }
466
467 /* see if our hostname corresponds to a reasonable IP address */
468 hp = gethostbyname(hostname);
469 if (hp != NULL) {
470 addr = *(u32_t *)hp->h_addr;
471 if (!bad_ip_adrs(addr)) {
472 addr = lwip_ntohl(addr);
473 if (!LOCAL_IP_ADDR(addr)) {
474 ep->class = EPD_IP;
475 set_ip_epdisc(ep, addr);
476 return 1;
477 }
478 }
479 }
480
481 return 0;
482 }
483
484 /*
485 * epdisc_to_str - make a printable string from an endpoint discriminator.
486 */
487
488 static char *endp_class_names[] = {
489 "null", "local", "IP", "MAC", "magic", "phone"
490 };
491
492 char *
epdisc_to_str(ep)493 epdisc_to_str(ep)
494 struct epdisc *ep;
495 {
496 static char str[MAX_ENDP_LEN*3+8];
497 u_char *p = ep->value;
498 int i, mask = 0;
499 char *q, c, c2;
500
501 if (ep->class == EPD_NULL && ep->length == 0)
502 return "null";
503 if (ep->class == EPD_IP && ep->length == 4) {
504 u32_t addr;
505
506 GETLONG(addr, p);
507 slprintf(str, sizeof(str), "IP:%I", lwip_htonl(addr));
508 return str;
509 }
510
511 c = ':';
512 c2 = '.';
513 if (ep->class == EPD_MAC && ep->length == 6)
514 c2 = ':';
515 else if (ep->class == EPD_MAGIC && (ep->length % 4) == 0)
516 mask = 3;
517 q = str;
518 if (ep->class <= EPD_PHONENUM)
519 q += slprintf(q, sizeof(str)-1, "%s",
520 endp_class_names[ep->class]);
521 else
522 q += slprintf(q, sizeof(str)-1, "%d", ep->class);
523 c = ':';
524 for (i = 0; i < ep->length && i < MAX_ENDP_LEN; ++i) {
525 if ((i & mask) == 0) {
526 *q++ = c;
527 c = c2;
528 }
529 q += slprintf(q, str + sizeof(str) - q, "%.2x", ep->value[i]);
530 }
531 return str;
532 }
533
hexc_val(int c)534 static int hexc_val(int c)
535 {
536 if (c >= 'a')
537 return c - 'a' + 10;
538 if (c >= 'A')
539 return c - 'A' + 10;
540 return c - '0';
541 }
542
543 int
str_to_epdisc(ep,str)544 str_to_epdisc(ep, str)
545 struct epdisc *ep;
546 char *str;
547 {
548 int i, l;
549 char *p, *endp;
550
551 for (i = EPD_NULL; i <= EPD_PHONENUM; ++i) {
552 int sl = strlen(endp_class_names[i]);
553 if (strncasecmp(str, endp_class_names[i], sl) == 0) {
554 str += sl;
555 break;
556 }
557 }
558 if (i > EPD_PHONENUM) {
559 /* not a class name, try a decimal class number */
560 i = strtol(str, &endp, 10);
561 if (endp == str)
562 return 0; /* can't parse class number */
563 str = endp;
564 }
565 ep->class = i;
566 if (*str == 0) {
567 ep->length = 0;
568 return 1;
569 }
570 if (*str != ':' && *str != '.')
571 return 0;
572 ++str;
573
574 if (i == EPD_IP) {
575 u32_t addr;
576 i = parse_dotted_ip(str, &addr);
577 if (i == 0 || str[i] != 0)
578 return 0;
579 set_ip_epdisc(ep, addr);
580 return 1;
581 }
582 if (i == EPD_MAC && get_if_hwaddr(ep->value, str) >= 0) {
583 ep->length = 6;
584 return 1;
585 }
586
587 p = str;
588 for (l = 0; l < MAX_ENDP_LEN; ++l) {
589 if (*str == 0)
590 break;
591 if (p <= str)
592 for (p = str; isxdigit(*p); ++p)
593 ;
594 i = p - str;
595 if (i == 0)
596 return 0;
597 ep->value[l] = hexc_val(*str++);
598 if ((i & 1) == 0)
599 ep->value[l] = (ep->value[l] << 4) + hexc_val(*str++);
600 if (*str == ':' || *str == '.')
601 ++str;
602 }
603 if (*str != 0 || (ep->class == EPD_MAC && l != 6))
604 return 0;
605 ep->length = l;
606 return 1;
607 }
608
609 #endif /* PPP_SUPPORT && HAVE_MULTILINK */
610