pppd/multilink.c

   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
  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
 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
 243 void mp_exit_bundle()
 244 {
 245         lock_db();
 246         remove_bundle_link();
 247         unlock_db();
 248 }
 249
 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
 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         doing_multilink = 0;
 285         multilink_master = 0;
 286 }
 287
 288 static void make_bundle_links(int append)
 289 {
 290         TDB_DATA key, rec;
 291         char *p;
 292         char entry[32];
 293         int l;
 294
 295         key.dptr = blinks_id;
 296         key.dsize = strlen(blinks_id);
 297         slprintf(entry, sizeof(entry), "%s;", db_key);
 298         p = entry;
 299         if (append) {
 300                 rec = tdb_fetch(pppdb, key);
 301                 if (rec.dptr != NULL && rec.dsize > 0) {
 302                         rec.dptr[rec.dsize-1] = 0;
 303                         if (strstr(rec.dptr, db_key) != NULL) {
 304                                 /* already in there? strange */
 305                                 warn("link entry already exists in tdb");
 306                                 return;
 307                         }
 308                         l = rec.dsize + strlen(entry);
 309                         p = malloc(l);
 310                         if (p == NULL)
 311                                 novm("bundle link list");
 312                         slprintf(p, l, "%s%s", rec.dptr, entry);
 313                 } else {
 314                         warn("bundle link list not found");
 315                 }
 316                 if (rec.dptr != NULL)
 317                         free(rec.dptr);
 318         }
 319         rec.dptr = p;
 320         rec.dsize = strlen(p) + 1;
 321         if (tdb_store(pppdb, key, rec, TDB_REPLACE))
 322                 error("couldn't %s bundle link list",
 323                       append? "update": "create");
 324         if (p != entry)
 325                 free(p);
 326 }
 327
 328 static void remove_bundle_link()
 329 {
 330         TDB_DATA key, rec;
 331         char entry[32];
 332         char *p, *q;
 333         int l;
 334
 335         key.dptr = blinks_id;
 336         key.dsize = strlen(blinks_id);
 337         slprintf(entry, sizeof(entry), "%s;", db_key);
 338
 339         rec = tdb_fetch(pppdb, key);
 340         if (rec.dptr == NULL || rec.dsize <= 0) {
 341                 if (rec.dptr != NULL)
 342                         free(rec.dptr);
 343                 return;
 344         }
 345         rec.dptr[rec.dsize-1] = 0;
 346         p = strstr(rec.dptr, entry);
 347         if (p != NULL) {
 348                 q = p + strlen(entry);
 349                 l = strlen(q) + 1;
 350                 memmove(p, q, l);
 351                 rec.dsize = p - rec.dptr + l;
 352                 if (tdb_store(pppdb, key, rec, TDB_REPLACE))
 353                         error("couldn't update bundle link list (removal)");
 354         }
 355         free(rec.dptr);
 356 }
 357
 358 static void iterate_bundle_links(void (*func)(char *))
 359 {
 360         TDB_DATA key, rec, pp;
 361         char *p, *q;
 362
 363         key.dptr = blinks_id;
 364         key.dsize = strlen(blinks_id);
 365         rec = tdb_fetch(pppdb, key);
 366         if (rec.dptr == NULL || rec.dsize <= 0) {
 367                 error("bundle link list not found (iterating list)");
 368                 if (rec.dptr != NULL)
 369                         free(rec.dptr);
 370                 return;
 371         }
 372         p = rec.dptr;
 373         p[rec.dsize-1] = 0;
 374         while ((q = strchr(p, ';')) != NULL) {
 375                 *q = 0;
 376                 key.dptr = p;
 377                 key.dsize = q - p;
 378                 pp = tdb_fetch(pppdb, key);
 379                 if (pp.dptr != NULL && pp.dsize > 0) {
 380                         pp.dptr[pp.dsize-1] = 0;
 381                         func(pp.dptr);
 382                 }
 383                 if (pp.dptr != NULL)
 384                         free(pp.dptr);
 385                 p = q + 1;
 386         }
 387         free(rec.dptr);
 388 }
 389
 390 static int
 391 parse_num(str, key, valp)
 392      char *str;
 393      const char *key;
 394      int *valp;
 395 {
 396         char *p, *endp;
 397         int i;
 398
 399         p = strstr(str, key);
 400         if (p != 0) {
 401                 p += strlen(key);
 402                 i = strtol(p, &endp, 10);
 403                 if (endp != p && (*endp == 0 || *endp == ';')) {
 404                         *valp = i;
 405                         return 1;
 406                 }
 407         }
 408         return 0;
 409 }
 410
 411 /*
 412  * Check whether the pppd identified by `key' still owns ppp unit `unit'.
 413  */
 414 static int
 415 owns_unit(key, unit)
 416      TDB_DATA key;
 417      int unit;
 418 {
 419         char ifkey[32];
 420         TDB_DATA kd, vd;
 421         int ret = 0;
 422
 423         slprintf(ifkey, sizeof(ifkey), "IFNAME=ppp%d", unit);
 424         kd.dptr = ifkey;
 425         kd.dsize = strlen(ifkey);
 426         vd = tdb_fetch(pppdb, kd);
 427         if (vd.dptr != NULL) {
 428                 ret = vd.dsize == key.dsize
 429                         && memcmp(vd.dptr, key.dptr, vd.dsize) == 0;
 430                 free(vd.dptr);
 431         }
 432         return ret;
 433 }
 434
 435 static int
 436 get_default_epdisc(ep)
 437      struct epdisc *ep;
 438 {
 439         char *p;
 440         struct hostent *hp;
 441         u_int32_t addr;
 442
 443         /* First try for an ethernet MAC address */
 444         p = get_first_ethernet();
 445         if (p != 0 && get_if_hwaddr(ep->value, p) >= 0) {
 446                 ep->class = EPD_MAC;
 447                 ep->length = 6;
 448                 return 1;
 449         }
 450
 451         /* see if our hostname corresponds to a reasonable IP address */
 452         hp = gethostbyname(hostname);
 453         if (hp != NULL) {
 454                 addr = *(u_int32_t *)hp->h_addr;
 455                 if (!bad_ip_adrs(addr)) {
 456                         addr = ntohl(addr);
 457                         if (!LOCAL_IP_ADDR(addr)) {
 458                                 ep->class = EPD_IP;
 459                                 set_ip_epdisc(ep, addr);
 460                                 return 1;
 461                         }
 462                 }
 463         }
 464
 465         return 0;
 466 }
 467
 468 /*
 469  * epdisc_to_str - make a printable string from an endpoint discriminator.
 470  */
 471
 472 static char *endp_class_names[] = {
 473     "null", "local", "IP", "MAC", "magic", "phone"
 474 };
 475
 476 char *
 477 epdisc_to_str(ep)
 478      struct epdisc *ep;
 479 {
 480         static char str[MAX_ENDP_LEN*3+8];
 481         u_char *p = ep->value;
 482         int i, mask = 0;
 483         char *q, c, c2;
 484
 485         if (ep->class == EPD_NULL && ep->length == 0)
 486                 return "null";
 487         if (ep->class == EPD_IP && ep->length == 4) {
 488                 u_int32_t addr;
 489
 490                 GETLONG(addr, p);
 491                 slprintf(str, sizeof(str), "IP:%I", htonl(addr));
 492                 return str;
 493         }
 494
 495         c = ':';
 496         c2 = '.';
 497         if (ep->class == EPD_MAC && ep->length == 6)
 498                 c2 = ':';
 499         else if (ep->class == EPD_MAGIC && (ep->length % 4) == 0)
 500                 mask = 3;
 501         q = str;
 502         if (ep->class <= EPD_PHONENUM)
 503                 q += slprintf(q, sizeof(str)-1, "%s",
 504                               endp_class_names[ep->class]);
 505         else
 506                 q += slprintf(q, sizeof(str)-1, "%d", ep->class);
 507         c = ':';
 508         for (i = 0; i < ep->length && i < MAX_ENDP_LEN; ++i) {
 509                 if ((i & mask) == 0) {
 510                         *q++ = c;
 511                         c = c2;
 512                 }
 513                 q += slprintf(q, str + sizeof(str) - q, "%.2x", ep->value[i]);
 514         }
 515         return str;
 516 }
 517
 518 static int hexc_val(int c)
 519 {
 520         if (c >= 'a')
 521                 return c - 'a' + 10;
 522         if (c >= 'A')
 523                 return c - 'A' + 10;
 524         return c - '0';
 525 }
 526
 527 int
 528 str_to_epdisc(ep, str)
 529      struct epdisc *ep;
 530      char *str;
 531 {
 532         int i, l;
 533         char *p, *endp;
 534
 535         for (i = EPD_NULL; i <= EPD_PHONENUM; ++i) {
 536                 int sl = strlen(endp_class_names[i]);
 537                 if (strncasecmp(str, endp_class_names[i], sl) == 0) {
 538                         str += sl;
 539                         break;
 540                 }
 541         }
 542         if (i > EPD_PHONENUM) {
 543                 /* not a class name, try a decimal class number */
 544                 i = strtol(str, &endp, 10);
 545                 if (endp == str)
 546                         return 0;       /* can't parse class number */
 547                 str = endp;
 548         }
 549         ep->class = i;
 550         if (*str == 0) {
 551                 ep->length = 0;
 552                 return 1;
 553         }
 554         if (*str != ':' && *str != '.')
 555                 return 0;
 556         ++str;
 557
 558         if (i == EPD_IP) {
 559                 u_int32_t addr;
 560                 i = parse_dotted_ip(str, &addr);
 561                 if (i == 0 || str[i] != 0)
 562                         return 0;
 563                 set_ip_epdisc(ep, addr);
 564                 return 1;
 565         }
 566         if (i == EPD_MAC && get_if_hwaddr(ep->value, str) >= 0) {
 567                 ep->length = 6;
 568                 return 1;
 569         }
 570
 571         p = str;
 572         for (l = 0; l < MAX_ENDP_LEN; ++l) {
 573                 if (*str == 0)
 574                         break;
 575                 if (p <= str)
 576                         for (p = str; isxdigit(*p); ++p)
 577                                 ;
 578                 i = p - str;
 579                 if (i == 0)
 580                         return 0;
 581                 ep->value[l] = hexc_val(*str++);
 582                 if ((i & 1) == 0)
 583                         ep->value[l] = (ep->value[l] << 4) + hexc_val(*str++);
 584                 if (*str == ':' || *str == '.')
 585                         ++str;
 586         }
 587         if (*str != 0 || (ep->class == EPD_MAC && l != 6))
 588                 return 0;
 589         ep->length = l;
 590         return 1;
 591 }
 592