1/* $NetBSD: multilink.c,v 1.5 2021/01/09 16:39:28 christos Exp $ */ 2 3/* 4 * multilink.c - support routines for multilink. 5 * 6 * Copyright (c) 2000-2002 Paul Mackerras. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 15 * 2. The name(s) of the authors of this software must not be used to 16 * endorse or promote products derived from this software without 17 * prior written permission. 18 * 19 * 3. Redistributions of any form whatsoever must retain the following 20 * acknowledgment: 21 * "This product includes software developed by Paul Mackerras 22 * <paulus@samba.org>". 23 * 24 * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO 25 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 26 * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY 27 * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 28 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN 29 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING 30 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 31 */ 32 33#include <sys/cdefs.h> 34__RCSID("$NetBSD: multilink.c,v 1.5 2021/01/09 16:39:28 christos Exp $"); 35 36#include <string.h> 37#include <ctype.h> 38#include <stdlib.h> 39#include <netdb.h> 40#include <errno.h> 41#include <signal.h> 42#include <netinet/in.h> 43#include <unistd.h> 44 45#include "pppd.h" 46#include "fsm.h" 47#include "lcp.h" 48#include "tdb.h" 49 50bool endpoint_specified; /* user gave explicit endpoint discriminator */ 51char *bundle_id; /* identifier for our bundle */ 52char *blinks_id; /* key for the list of links */ 53bool doing_multilink; /* multilink was enabled and agreed to */ 54bool multilink_master; /* we own the multilink bundle */ 55 56extern TDB_CONTEXT *pppdb; 57extern char db_key[]; 58 59static void make_bundle_links(int append); 60static void remove_bundle_link(void); 61static void iterate_bundle_links(void (*func)(char *)); 62 63static int get_default_epdisc(struct epdisc *); 64static int parse_num(char *str, const char *key, int *valp); 65static int owns_unit(TDB_DATA pid, int unit); 66 67#define set_ip_epdisc(ep, addr) do { \ 68 ep->length = 4; \ 69 ep->value[0] = addr >> 24; \ 70 ep->value[1] = addr >> 16; \ 71 ep->value[2] = addr >> 8; \ 72 ep->value[3] = addr; \ 73} while (0) 74 75#define LOCAL_IP_ADDR(addr) \ 76 (((addr) & 0xff000000) == 0x0a000000 /* 10.x.x.x */ \ 77 || ((addr) & 0xfff00000) == 0xac100000 /* 172.16.x.x */ \ 78 || ((addr) & 0xffff0000) == 0xc0a80000) /* 192.168.x.x */ 79 80#define process_exists(n) (kill((n), 0) == 0 || errno != ESRCH) 81 82void 83mp_check_options(void) 84{ 85 lcp_options *wo = &lcp_wantoptions[0]; 86 lcp_options *ao = &lcp_allowoptions[0]; 87 88 doing_multilink = 0; 89 if (!multilink) 90 return; 91 /* if we're doing multilink, we have to negotiate MRRU */ 92 if (!wo->neg_mrru) { 93 /* mrru not specified, default to mru */ 94 wo->mrru = wo->mru; 95 wo->neg_mrru = 1; 96 } 97 ao->mrru = ao->mru; 98 ao->neg_mrru = 1; 99 100 if (!wo->neg_endpoint && !noendpoint) { 101 /* get a default endpoint value */ 102 wo->neg_endpoint = get_default_epdisc(&wo->endpoint); 103 } 104} 105 106/* 107 * Make a new bundle or join us to an existing bundle 108 * if we are doing multilink. 109 */ 110int 111mp_join_bundle(void) 112{ 113 lcp_options *go = &lcp_gotoptions[0]; 114 lcp_options *ho = &lcp_hisoptions[0]; 115 lcp_options *ao = &lcp_allowoptions[0]; 116 int unit, pppd_pid; 117 int l, mtu; 118 char *p; 119 TDB_DATA key, pid, rec; 120 121 if (doing_multilink) { 122 /* have previously joined a bundle */ 123 if (!go->neg_mrru || !ho->neg_mrru) { 124 notice("oops, didn't get multilink on renegotiation"); 125 lcp_close(0, "multilink required"); 126 return 0; 127 } 128 /* XXX should check the peer_authname and ho->endpoint 129 are the same as previously */ 130 return 0; 131 } 132 133 if (!go->neg_mrru || !ho->neg_mrru) { 134 /* not doing multilink */ 135 if (go->neg_mrru) 136 notice("oops, multilink negotiated only for receive"); 137 mtu = ho->neg_mru? ho->mru: PPP_MRU; 138 if (mtu > ao->mru) 139 mtu = ao->mru; 140 if (demand) { 141 /* already have a bundle */ 142 cfg_bundle(0, 0, 0, 0); 143 netif_set_mtu(0, mtu); 144 return 0; 145 } 146 make_new_bundle(0, 0, 0, 0); 147 set_ifunit(1); 148 netif_set_mtu(0, mtu); 149 return 0; 150 } 151 152 doing_multilink = 1; 153 154 /* 155 * Find the appropriate bundle or join a new one. 156 * First we make up a name for the bundle. 157 * The length estimate is worst-case assuming every 158 * character has to be quoted. 159 */ 160 l = 4 * strlen(peer_authname) + 10; 161 if (ho->neg_endpoint) 162 l += 3 * ho->endpoint.length + 8; 163 if (bundle_name) 164 l += 3 * strlen(bundle_name) + 2; 165 bundle_id = malloc(l); 166 if (bundle_id == 0) 167 novm("bundle identifier"); 168 169 p = bundle_id; 170 p += slprintf(p, l-1, "BUNDLE=\"%q\"", peer_authname); 171 if (ho->neg_endpoint || bundle_name) 172 *p++ = '/'; 173 if (ho->neg_endpoint) 174 p += slprintf(p, bundle_id+l-p, "%s", 175 epdisc_to_str(&ho->endpoint)); 176 if (bundle_name) 177 p += slprintf(p, bundle_id+l-p, "/%v", bundle_name); 178 179 /* Make the key for the list of links belonging to the bundle */ 180 l = p - bundle_id; 181 blinks_id = malloc(l + 7); 182 if (blinks_id == NULL) 183 novm("bundle links key"); 184 slprintf(blinks_id, l + 7, "BUNDLE_LINKS=%s", bundle_id + 7); 185 186 /* 187 * For demand mode, we only need to configure the bundle 188 * and attach the link. 189 */ 190 mtu = MIN(ho->mrru, ao->mru); 191 if (demand) { 192 cfg_bundle(go->mrru, ho->mrru, go->neg_ssnhf, ho->neg_ssnhf); 193 netif_set_mtu(0, mtu); 194 script_setenv("BUNDLE", bundle_id + 7, 1); 195 return 0; 196 } 197 198 /* 199 * Check if the bundle ID is already in the database. 200 */ 201 unit = -1; 202 lock_db(); 203 key.dptr = bundle_id; 204 key.dsize = p - bundle_id; 205 pid = tdb_fetch(pppdb, key); 206 if (pid.dptr != NULL) { 207 /* bundle ID exists, see if the pppd record exists */ 208 rec = tdb_fetch(pppdb, pid); 209 if (rec.dptr != NULL && rec.dsize > 0) { 210 /* make sure the string is null-terminated */ 211 rec.dptr[rec.dsize-1] = 0; 212 /* parse the interface number */ 213 parse_num(rec.dptr, "UNIT=", &unit); 214 /* check the pid value */ 215 if (!parse_num(rec.dptr, "PPPD_PID=", &pppd_pid) 216 || !process_exists(pppd_pid) 217 || !owns_unit(pid, unit)) 218 unit = -1; 219 free(rec.dptr); 220 } 221 free(pid.dptr); 222 } 223 224 if (unit >= 0) { 225 /* attach to existing unit */ 226 if (bundle_attach(unit)) { 227 set_ifunit(0); 228 script_setenv("BUNDLE", bundle_id + 7, 0); 229 make_bundle_links(1); 230 unlock_db(); 231 info("Link attached to %s", ifname); 232 return 1; 233 } 234 /* attach failed because bundle doesn't exist */ 235 } 236 237 /* we have to make a new bundle */ 238 make_new_bundle(go->mrru, ho->mrru, go->neg_ssnhf, ho->neg_ssnhf); 239 set_ifunit(1); 240 netif_set_mtu(0, mtu); 241 script_setenv("BUNDLE", bundle_id + 7, 1); 242 make_bundle_links(0); 243 unlock_db(); 244 info("New bundle %s created", ifname); 245 multilink_master = 1; 246 return 0; 247} 248 249void mp_exit_bundle(void) 250{ 251 lock_db(); 252 remove_bundle_link(); 253 unlock_db(); 254} 255 256static void sendhup(char *str) 257{ 258 int pid; 259 260 if (parse_num(str, "PPPD_PID=", &pid) && pid != getpid()) { 261 if (debug) 262 dbglog("sending SIGHUP to process %d", pid); 263 kill(pid, SIGHUP); 264 } 265} 266 267void mp_bundle_terminated(void) 268{ 269 TDB_DATA key; 270 271 bundle_terminating = 1; 272 upper_layers_down(0); 273 notice("Connection terminated."); 274 print_link_stats(); 275 if (!demand) { 276 remove_pidfiles(); 277 script_unsetenv("IFNAME"); 278 } 279 280 lock_db(); 281 destroy_bundle(); 282 iterate_bundle_links(sendhup); 283 key.dptr = blinks_id; 284 key.dsize = strlen(blinks_id); 285 tdb_delete(pppdb, key); 286 unlock_db(); 287 288 new_phase(PHASE_DEAD); 289 290 doing_multilink = 0; 291 multilink_master = 0; 292} 293 294static void make_bundle_links(int append) 295{ 296 TDB_DATA key, rec; 297 char *p; 298 char entry[32]; 299 int l; 300 301 key.dptr = blinks_id; 302 key.dsize = strlen(blinks_id); 303 slprintf(entry, sizeof(entry), "%s;", db_key); 304 p = entry; 305 if (append) { 306 rec = tdb_fetch(pppdb, key); 307 if (rec.dptr != NULL && rec.dsize > 0) { 308 rec.dptr[rec.dsize-1] = 0; 309 if (strstr(rec.dptr, db_key) != NULL) { 310 /* already in there? strange */ 311 warn("link entry already exists in tdb"); 312 return; 313 } 314 l = rec.dsize + strlen(entry); 315 p = malloc(l); 316 if (p == NULL) 317 novm("bundle link list"); 318 slprintf(p, l, "%s%s", rec.dptr, entry); 319 } else { 320 warn("bundle link list not found"); 321 } 322 if (rec.dptr != NULL) 323 free(rec.dptr); 324 } 325 rec.dptr = p; 326 rec.dsize = strlen(p) + 1; 327 if (tdb_store(pppdb, key, rec, TDB_REPLACE)) 328 error("couldn't %s bundle link list", 329 append? "update": "create"); 330 if (p != entry) 331 free(p); 332} 333 334static void remove_bundle_link(void) 335{ 336 TDB_DATA key, rec; 337 char entry[32]; 338 char *p, *q; 339 int l; 340 341 key.dptr = blinks_id; 342 key.dsize = strlen(blinks_id); 343 slprintf(entry, sizeof(entry), "%s;", db_key); 344 345 rec = tdb_fetch(pppdb, key); 346 if (rec.dptr == NULL || rec.dsize <= 0) { 347 if (rec.dptr != NULL) 348 free(rec.dptr); 349 return; 350 } 351 rec.dptr[rec.dsize-1] = 0; 352 p = strstr(rec.dptr, entry); 353 if (p != NULL) { 354 q = p + strlen(entry); 355 l = strlen(q) + 1; 356 memmove(p, q, l); 357 rec.dsize = p - rec.dptr + l; 358 if (tdb_store(pppdb, key, rec, TDB_REPLACE)) 359 error("couldn't update bundle link list (removal)"); 360 } 361 free(rec.dptr); 362} 363 364static void iterate_bundle_links(void (*func)(char *)) 365{ 366 TDB_DATA key, rec, pp; 367 char *p, *q; 368 369 key.dptr = blinks_id; 370 key.dsize = strlen(blinks_id); 371 rec = tdb_fetch(pppdb, key); 372 if (rec.dptr == NULL || rec.dsize <= 0) { 373 error("bundle link list not found (iterating list)"); 374 if (rec.dptr != NULL) 375 free(rec.dptr); 376 return; 377 } 378 p = rec.dptr; 379 p[rec.dsize-1] = 0; 380 while ((q = strchr(p, ';')) != NULL) { 381 *q = 0; 382 key.dptr = p; 383 key.dsize = q - p; 384 pp = tdb_fetch(pppdb, key); 385 if (pp.dptr != NULL && pp.dsize > 0) { 386 pp.dptr[pp.dsize-1] = 0; 387 func(pp.dptr); 388 } 389 if (pp.dptr != NULL) 390 free(pp.dptr); 391 p = q + 1; 392 } 393 free(rec.dptr); 394} 395 396static int 397parse_num(char *str, const char *key, int *valp) 398{ 399 char *p, *endp; 400 int i; 401 402 p = strstr(str, key); 403 if (p != 0) { 404 p += strlen(key); 405 i = strtol(p, &endp, 10); 406 if (endp != p && (*endp == 0 || *endp == ';')) { 407 *valp = i; 408 return 1; 409 } 410 } 411 return 0; 412} 413 414/* 415 * Check whether the pppd identified by `key' still owns ppp unit `unit'. 416 */ 417static int 418owns_unit(TDB_DATA key, int unit) 419{ 420 char ifkey[32]; 421 TDB_DATA kd, vd; 422 int ret = 0; 423 424 slprintf(ifkey, sizeof(ifkey), "UNIT=%d", unit); 425 kd.dptr = ifkey; 426 kd.dsize = strlen(ifkey); 427 vd = tdb_fetch(pppdb, kd); 428 if (vd.dptr != NULL) { 429 ret = vd.dsize == key.dsize 430 && memcmp(vd.dptr, key.dptr, vd.dsize) == 0; 431 free(vd.dptr); 432 } 433 return ret; 434} 435 436static int 437get_default_epdisc(struct epdisc *ep) 438{ 439 struct hostent *hp; 440 u_int32_t addr; 441 442 /* First try for an ethernet MAC address */ 443 if (get_first_ether_hwaddr(ep->value) >= 0) { 444 ep->class = EPD_MAC; 445 ep->length = 6; 446 return 1; 447 } 448 449 /* see if our hostname corresponds to a reasonable IP address */ 450 hp = gethostbyname(hostname); 451 if (hp != NULL) { 452 addr = *(u_int32_t *)hp->h_addr; 453 if (!bad_ip_adrs(addr)) { 454 addr = ntohl(addr); 455 if (!LOCAL_IP_ADDR(addr)) { 456 ep->class = EPD_IP; 457 set_ip_epdisc(ep, addr); 458 return 1; 459 } 460 } 461 } 462 463 return 0; 464} 465 466/* 467 * epdisc_to_str - make a printable string from an endpoint discriminator. 468 */ 469 470static char *endp_class_names[] = { 471 "null", "local", "IP", "MAC", "magic", "phone" 472}; 473 474char * 475epdisc_to_str(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 515static 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 524int 525str_to_epdisc(struct epdisc *ep, char *str) 526{ 527 int i, l; 528 char *p, *endp; 529 530 for (i = EPD_NULL; i <= EPD_PHONENUM; ++i) { 531 int sl = strlen(endp_class_names[i]); 532 if (strncasecmp(str, endp_class_names[i], sl) == 0) { 533 str += sl; 534 break; 535 } 536 } 537 if (i > EPD_PHONENUM) { 538 /* not a class name, try a decimal class number */ 539 i = strtol(str, &endp, 10); 540 if (endp == str) 541 return 0; /* can't parse class number */ 542 str = endp; 543 } 544 ep->class = i; 545 if (*str == 0) { 546 ep->length = 0; 547 return 1; 548 } 549 if (*str != ':' && *str != '.') 550 return 0; 551 ++str; 552 553 if (i == EPD_IP) { 554 u_int32_t addr; 555 i = parse_dotted_ip(str, &addr); 556 if (i == 0 || str[i] != 0) 557 return 0; 558 set_ip_epdisc(ep, addr); 559 return 1; 560 } 561 if (i == EPD_MAC && get_if_hwaddr(ep->value, str) >= 0) { 562 ep->length = 6; 563 return 1; 564 } 565 566 p = str; 567 for (l = 0; l < MAX_ENDP_LEN; ++l) { 568 if (*str == 0) 569 break; 570 if (p <= str) 571 for (p = str; isxdigit((unsigned char)*p); ++p) 572 ; 573 i = p - str; 574 if (i == 0) 575 return 0; 576 ep->value[l] = hexc_val(*str++); 577 if ((i & 1) == 0) 578 ep->value[l] = (ep->value[l] << 4) + hexc_val(*str++); 579 if (*str == ':' || *str == '.') 580 ++str; 581 } 582 if (*str != 0 || (ep->class == EPD_MAC && l != 6)) 583 return 0; 584 ep->length = l; 585 return 1; 586} 587