1 /* $OpenBSD: pf_osfp.c,v 1.48 2024/04/13 23:44:11 jsg Exp $ */ 2 3 /* 4 * Copyright (c) 2003 Mike Frantzen <frantzen@w4g.org> 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 * 18 */ 19 20 #include <sys/param.h> 21 #include <sys/socket.h> 22 #ifdef _KERNEL 23 #include <sys/systm.h> 24 #include <sys/pool.h> 25 #endif /* _KERNEL */ 26 #include <sys/queue.h> 27 #include <sys/mbuf.h> 28 #include <sys/syslog.h> 29 30 #include <net/if.h> 31 32 #include <netinet/in.h> 33 #include <netinet/ip.h> 34 #include <netinet/ip_icmp.h> 35 #include <netinet/tcp.h> 36 #include <netinet/udp.h> 37 38 #ifdef INET6 39 #include <netinet/ip6.h> 40 #include <netinet/icmp6.h> 41 #endif /* INET6 */ 42 43 #include <net/pfvar.h> 44 #include <net/pfvar_priv.h> 45 46 #ifdef _KERNEL 47 typedef struct pool pool_t; 48 49 #else /* !_KERNEL */ 50 /* Userland equivalents so we can lend code to tcpdump et al. */ 51 52 #include <arpa/inet.h> 53 #include <errno.h> 54 #include <stdio.h> 55 #include <stdlib.h> 56 #include <string.h> 57 #include <netdb.h> 58 #define pool_t int 59 #define pool_get(pool, flags) malloc(*(pool)) 60 #define pool_put(pool, item) free(item) 61 #define pool_init(pool, size, a, ao, f, m, p) (*(pool)) = (size) 62 63 #define PF_LOCK() 64 #define PF_UNLOCK() 65 #define PF_ASSERT_LOCKED() 66 67 #ifdef PFDEBUG 68 #include <sys/stdarg.h> /* for DPFPRINTF() */ 69 #endif /* PFDEBUG */ 70 71 #endif /* _KERNEL */ 72 73 /* 74 * Protection/ownership: 75 * I immutable after pf_osfp_initialize() 76 * p pf_lock 77 */ 78 79 SLIST_HEAD(pf_osfp_list, pf_os_fingerprint) pf_osfp_list = 80 SLIST_HEAD_INITIALIZER(pf_osfp_list); /* [p] */ 81 pool_t pf_osfp_entry_pl; /* [I] */ 82 pool_t pf_osfp_pl; /* [I] */ 83 84 struct pf_os_fingerprint *pf_osfp_find(struct pf_os_fingerprint *, 85 u_int8_t); 86 struct pf_os_fingerprint *pf_osfp_find_exact(struct pf_os_fingerprint *); 87 void pf_osfp_insert(struct pf_os_fingerprint *); 88 89 90 #ifdef _KERNEL 91 /* 92 * Passively fingerprint the OS of the host (IPv4 TCP SYN packets only) 93 * Returns the list of possible OSes. 94 */ 95 struct pf_osfp_enlist * 96 pf_osfp_fingerprint(struct pf_pdesc *pd) 97 { 98 struct tcphdr *th = &pd->hdr.tcp; 99 struct ip *ip = NULL; 100 struct ip6_hdr *ip6 = NULL; 101 char hdr[60]; 102 103 if (pd->proto != IPPROTO_TCP) 104 return (NULL); 105 106 switch (pd->af) { 107 case AF_INET: 108 ip = mtod(pd->m, struct ip *); 109 break; 110 case AF_INET6: 111 ip6 = mtod(pd->m, struct ip6_hdr *); 112 break; 113 } 114 if (!pf_pull_hdr(pd->m, pd->off, hdr, th->th_off << 2, NULL, pd->af)) 115 return (NULL); 116 117 return (pf_osfp_fingerprint_hdr(ip, ip6, (struct tcphdr *)hdr)); 118 } 119 #endif /* _KERNEL */ 120 121 struct pf_osfp_enlist * 122 pf_osfp_fingerprint_hdr(const struct ip *ip, const struct ip6_hdr *ip6, 123 const struct tcphdr *tcp) 124 { 125 struct pf_os_fingerprint fp, *fpresult; 126 int cnt, optlen = 0; 127 const u_int8_t *optp; 128 #ifdef _KERNEL 129 char srcname[128]; 130 #else /* !_KERNEL */ 131 char srcname[NI_MAXHOST]; 132 #endif /* _KERNEL */ 133 134 if ((tcp->th_flags & (TH_SYN|TH_ACK)) != TH_SYN) 135 return (NULL); 136 if (ip) { 137 if ((ip->ip_off & htons(IP_OFFMASK)) != 0) 138 return (NULL); 139 } 140 141 memset(&fp, 0, sizeof(fp)); 142 143 if (ip) { 144 #ifndef _KERNEL 145 struct sockaddr_in sin; 146 #endif /* _KERNEL */ 147 148 fp.fp_psize = ntohs(ip->ip_len); 149 fp.fp_ttl = ip->ip_ttl; 150 if (ip->ip_off & htons(IP_DF)) 151 fp.fp_flags |= PF_OSFP_DF; 152 #ifdef _KERNEL 153 inet_ntop(AF_INET, &ip->ip_src, srcname, sizeof(srcname)); 154 #else /* !_KERNEL */ 155 memset(&sin, 0, sizeof(sin)); 156 sin.sin_family = AF_INET; 157 sin.sin_len = sizeof(struct sockaddr_in); 158 sin.sin_addr = ip->ip_src; 159 (void)getnameinfo((struct sockaddr *)&sin, 160 sizeof(struct sockaddr_in), srcname, sizeof(srcname), 161 NULL, 0, NI_NUMERICHOST); 162 #endif /* _KERNEL */ 163 } 164 #ifdef INET6 165 else if (ip6) { 166 #ifndef _KERNEL 167 struct sockaddr_in6 sin6; 168 #endif /* !_KERNEL */ 169 170 /* jumbo payload? */ 171 fp.fp_psize = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen); 172 fp.fp_ttl = ip6->ip6_hlim; 173 fp.fp_flags |= PF_OSFP_DF; 174 fp.fp_flags |= PF_OSFP_INET6; 175 #ifdef _KERNEL 176 inet_ntop(AF_INET6, &ip6->ip6_src, srcname, sizeof(srcname)); 177 #else /* !_KERNEL */ 178 memset(&sin6, 0, sizeof(sin6)); 179 sin6.sin6_family = AF_INET6; 180 sin6.sin6_len = sizeof(struct sockaddr_in6); 181 sin6.sin6_addr = ip6->ip6_src; 182 (void)getnameinfo((struct sockaddr *)&sin6, 183 sizeof(struct sockaddr_in6), srcname, sizeof(srcname), 184 NULL, 0, NI_NUMERICHOST); 185 #endif /* !_KERNEL */ 186 } 187 #endif /* INET6 */ 188 else 189 return (NULL); 190 fp.fp_wsize = ntohs(tcp->th_win); 191 192 193 cnt = (tcp->th_off << 2) - sizeof(*tcp); 194 optp = (const u_int8_t *)((const char *)tcp + sizeof(*tcp)); 195 for (; cnt > 0; cnt -= optlen, optp += optlen) { 196 if (*optp == TCPOPT_EOL) 197 break; 198 199 fp.fp_optcnt++; 200 if (*optp == TCPOPT_NOP) { 201 fp.fp_tcpopts = (fp.fp_tcpopts << PF_OSFP_TCPOPT_BITS) | 202 PF_OSFP_TCPOPT_NOP; 203 optlen = 1; 204 } else { 205 if (cnt < 2) 206 return (NULL); 207 optlen = optp[1]; 208 if (optlen > cnt || optlen < 2) 209 return (NULL); 210 switch (*optp) { 211 case TCPOPT_MAXSEG: 212 if (optlen >= TCPOLEN_MAXSEG) 213 memcpy(&fp.fp_mss, &optp[2], 214 sizeof(fp.fp_mss)); 215 fp.fp_tcpopts = (fp.fp_tcpopts << 216 PF_OSFP_TCPOPT_BITS) | PF_OSFP_TCPOPT_MSS; 217 fp.fp_mss = ntohs(fp.fp_mss); 218 break; 219 case TCPOPT_WINDOW: 220 if (optlen >= TCPOLEN_WINDOW) 221 memcpy(&fp.fp_wscale, &optp[2], 222 sizeof(fp.fp_wscale)); 223 fp.fp_tcpopts = (fp.fp_tcpopts << 224 PF_OSFP_TCPOPT_BITS) | 225 PF_OSFP_TCPOPT_WSCALE; 226 break; 227 case TCPOPT_SACK_PERMITTED: 228 fp.fp_tcpopts = (fp.fp_tcpopts << 229 PF_OSFP_TCPOPT_BITS) | PF_OSFP_TCPOPT_SACK; 230 break; 231 case TCPOPT_TIMESTAMP: 232 if (optlen >= TCPOLEN_TIMESTAMP) { 233 u_int32_t ts; 234 memcpy(&ts, &optp[2], sizeof(ts)); 235 if (ts == 0) 236 fp.fp_flags |= PF_OSFP_TS0; 237 238 } 239 fp.fp_tcpopts = (fp.fp_tcpopts << 240 PF_OSFP_TCPOPT_BITS) | PF_OSFP_TCPOPT_TS; 241 break; 242 default: 243 return (NULL); 244 } 245 } 246 optlen = MAX(optlen, 1); /* paranoia */ 247 } 248 249 DPFPRINTF(LOG_INFO, 250 "fingerprinted %s:%d %d:%d:%d:%d:%llx (%d) " 251 "(TS=%s,M=%s%d,W=%s%d)", 252 srcname, ntohs(tcp->th_sport), 253 fp.fp_wsize, fp.fp_ttl, (fp.fp_flags & PF_OSFP_DF) != 0, 254 fp.fp_psize, (long long int)fp.fp_tcpopts, fp.fp_optcnt, 255 (fp.fp_flags & PF_OSFP_TS0) ? "0" : "", 256 (fp.fp_flags & PF_OSFP_MSS_MOD) ? "%" : 257 (fp.fp_flags & PF_OSFP_MSS_DC) ? "*" : "", 258 fp.fp_mss, 259 (fp.fp_flags & PF_OSFP_WSCALE_MOD) ? "%" : 260 (fp.fp_flags & PF_OSFP_WSCALE_DC) ? "*" : "", 261 fp.fp_wscale); 262 263 if ((fpresult = pf_osfp_find(&fp, PF_OSFP_MAXTTL_OFFSET))) 264 return (&fpresult->fp_oses); 265 return (NULL); 266 } 267 268 /* Match a fingerprint ID against a list of OSes */ 269 int 270 pf_osfp_match(struct pf_osfp_enlist *list, pf_osfp_t os) 271 { 272 struct pf_osfp_entry *entry; 273 int os_class, os_version, os_subtype; 274 int en_class, en_version, en_subtype; 275 276 if (os == PF_OSFP_ANY) 277 return (1); 278 if (list == NULL) { 279 DPFPRINTF(LOG_INFO, "osfp no match against %x", os); 280 return (os == PF_OSFP_UNKNOWN); 281 } 282 PF_OSFP_UNPACK(os, os_class, os_version, os_subtype); 283 SLIST_FOREACH(entry, list, fp_entry) { 284 PF_OSFP_UNPACK(entry->fp_os, en_class, en_version, en_subtype); 285 if ((os_class == PF_OSFP_ANY || en_class == os_class) && 286 (os_version == PF_OSFP_ANY || en_version == os_version) && 287 (os_subtype == PF_OSFP_ANY || en_subtype == os_subtype)) { 288 DPFPRINTF(LOG_INFO, 289 "osfp matched %s %s %s %x==%x", 290 entry->fp_class_nm, entry->fp_version_nm, 291 entry->fp_subtype_nm, os, entry->fp_os); 292 return (1); 293 } 294 } 295 DPFPRINTF(LOG_INFO, "fingerprint 0x%x didn't match", os); 296 return (0); 297 } 298 299 /* Initialize the OS fingerprint system */ 300 void 301 pf_osfp_initialize(void) 302 { 303 pool_init(&pf_osfp_entry_pl, sizeof(struct pf_osfp_entry), 0, 304 IPL_NONE, PR_WAITOK, "pfosfpen", NULL); 305 pool_init(&pf_osfp_pl, sizeof(struct pf_os_fingerprint), 0, 306 IPL_NONE, PR_WAITOK, "pfosfp", NULL); 307 } 308 309 /* Flush the fingerprint list */ 310 void 311 pf_osfp_flush(void) 312 { 313 struct pf_os_fingerprint *fp; 314 struct pf_osfp_entry *entry; 315 316 PF_LOCK(); 317 while ((fp = SLIST_FIRST(&pf_osfp_list))) { 318 SLIST_REMOVE_HEAD(&pf_osfp_list, fp_next); 319 while ((entry = SLIST_FIRST(&fp->fp_oses))) { 320 SLIST_REMOVE_HEAD(&fp->fp_oses, fp_entry); 321 pool_put(&pf_osfp_entry_pl, entry); 322 } 323 pool_put(&pf_osfp_pl, fp); 324 } 325 PF_UNLOCK(); 326 } 327 328 329 /* Add a fingerprint */ 330 int 331 pf_osfp_add(struct pf_osfp_ioctl *fpioc) 332 { 333 struct pf_os_fingerprint *fp, *fp_prealloc, fpadd; 334 struct pf_osfp_entry *entry; 335 336 memset(&fpadd, 0, sizeof(fpadd)); 337 fpadd.fp_tcpopts = fpioc->fp_tcpopts; 338 fpadd.fp_wsize = fpioc->fp_wsize; 339 fpadd.fp_psize = fpioc->fp_psize; 340 fpadd.fp_mss = fpioc->fp_mss; 341 fpadd.fp_flags = fpioc->fp_flags; 342 fpadd.fp_optcnt = fpioc->fp_optcnt; 343 fpadd.fp_wscale = fpioc->fp_wscale; 344 fpadd.fp_ttl = fpioc->fp_ttl; 345 346 DPFPRINTF(LOG_DEBUG, 347 "adding osfp %s %s %s = %s%d:%d:%d:%s%d:0x%llx %d " 348 "(TS=%s,M=%s%d,W=%s%d) %x", 349 fpioc->fp_os.fp_class_nm, fpioc->fp_os.fp_version_nm, 350 fpioc->fp_os.fp_subtype_nm, 351 (fpadd.fp_flags & PF_OSFP_WSIZE_MOD) ? "%" : 352 (fpadd.fp_flags & PF_OSFP_WSIZE_MSS) ? "S" : 353 (fpadd.fp_flags & PF_OSFP_WSIZE_MTU) ? "T" : 354 (fpadd.fp_flags & PF_OSFP_WSIZE_DC) ? "*" : "", 355 fpadd.fp_wsize, 356 fpadd.fp_ttl, 357 (fpadd.fp_flags & PF_OSFP_DF) ? 1 : 0, 358 (fpadd.fp_flags & PF_OSFP_PSIZE_MOD) ? "%" : 359 (fpadd.fp_flags & PF_OSFP_PSIZE_DC) ? "*" : "", 360 fpadd.fp_psize, 361 (long long int)fpadd.fp_tcpopts, fpadd.fp_optcnt, 362 (fpadd.fp_flags & PF_OSFP_TS0) ? "0" : "", 363 (fpadd.fp_flags & PF_OSFP_MSS_MOD) ? "%" : 364 (fpadd.fp_flags & PF_OSFP_MSS_DC) ? "*" : "", 365 fpadd.fp_mss, 366 (fpadd.fp_flags & PF_OSFP_WSCALE_MOD) ? "%" : 367 (fpadd.fp_flags & PF_OSFP_WSCALE_DC) ? "*" : "", 368 fpadd.fp_wscale, 369 fpioc->fp_os.fp_os); 370 371 entry = pool_get(&pf_osfp_entry_pl, PR_WAITOK|PR_LIMITFAIL); 372 if (entry == NULL) 373 return (ENOMEM); 374 375 fp_prealloc = pool_get(&pf_osfp_pl, PR_WAITOK|PR_ZERO|PR_LIMITFAIL); 376 if (fp_prealloc == NULL) { 377 pool_put(&pf_osfp_entry_pl, entry); 378 return (ENOMEM); 379 } 380 381 PF_LOCK(); 382 if ((fp = pf_osfp_find_exact(&fpadd))) { 383 struct pf_osfp_entry *tentry; 384 385 SLIST_FOREACH(tentry, &fp->fp_oses, fp_entry) { 386 if (PF_OSFP_ENTRY_EQ(tentry, &fpioc->fp_os)) { 387 PF_UNLOCK(); 388 pool_put(&pf_osfp_entry_pl, entry); 389 pool_put(&pf_osfp_pl, fp_prealloc); 390 return (EEXIST); 391 } 392 } 393 } else { 394 fp = fp_prealloc; 395 fp_prealloc = NULL; 396 fp->fp_tcpopts = fpioc->fp_tcpopts; 397 fp->fp_wsize = fpioc->fp_wsize; 398 fp->fp_psize = fpioc->fp_psize; 399 fp->fp_mss = fpioc->fp_mss; 400 fp->fp_flags = fpioc->fp_flags; 401 fp->fp_optcnt = fpioc->fp_optcnt; 402 fp->fp_wscale = fpioc->fp_wscale; 403 fp->fp_ttl = fpioc->fp_ttl; 404 SLIST_INIT(&fp->fp_oses); 405 pf_osfp_insert(fp); 406 } 407 memcpy(entry, &fpioc->fp_os, sizeof(*entry)); 408 409 /* Make sure the strings are NUL terminated */ 410 entry->fp_class_nm[sizeof(entry->fp_class_nm)-1] = '\0'; 411 entry->fp_version_nm[sizeof(entry->fp_version_nm)-1] = '\0'; 412 entry->fp_subtype_nm[sizeof(entry->fp_subtype_nm)-1] = '\0'; 413 414 SLIST_INSERT_HEAD(&fp->fp_oses, entry, fp_entry); 415 PF_UNLOCK(); 416 417 #ifdef PFDEBUG 418 if ((fp = pf_osfp_validate())) 419 DPFPRINTF(LOG_NOTICE, 420 "Invalid fingerprint list"); 421 #endif /* PFDEBUG */ 422 423 if (fp_prealloc != NULL) 424 pool_put(&pf_osfp_pl, fp_prealloc); 425 426 return (0); 427 } 428 429 430 /* Find a fingerprint in the list */ 431 struct pf_os_fingerprint * 432 pf_osfp_find(struct pf_os_fingerprint *find, u_int8_t ttldiff) 433 { 434 struct pf_os_fingerprint *f; 435 436 PF_ASSERT_LOCKED(); 437 438 #define MATCH_INT(_MOD, _DC, _field) \ 439 if ((f->fp_flags & _DC) == 0) { \ 440 if ((f->fp_flags & _MOD) == 0) { \ 441 if (f->_field != find->_field) \ 442 continue; \ 443 } else { \ 444 if (f->_field == 0 || find->_field % f->_field) \ 445 continue; \ 446 } \ 447 } 448 449 SLIST_FOREACH(f, &pf_osfp_list, fp_next) { 450 if (f->fp_tcpopts != find->fp_tcpopts || 451 f->fp_optcnt != find->fp_optcnt || 452 f->fp_ttl < find->fp_ttl || 453 f->fp_ttl - find->fp_ttl > ttldiff || 454 (f->fp_flags & (PF_OSFP_DF|PF_OSFP_TS0)) != 455 (find->fp_flags & (PF_OSFP_DF|PF_OSFP_TS0))) 456 continue; 457 458 MATCH_INT(PF_OSFP_PSIZE_MOD, PF_OSFP_PSIZE_DC, fp_psize) 459 MATCH_INT(PF_OSFP_MSS_MOD, PF_OSFP_MSS_DC, fp_mss) 460 MATCH_INT(PF_OSFP_WSCALE_MOD, PF_OSFP_WSCALE_DC, fp_wscale) 461 if ((f->fp_flags & PF_OSFP_WSIZE_DC) == 0) { 462 if (f->fp_flags & PF_OSFP_WSIZE_MSS) { 463 if (find->fp_mss == 0) 464 continue; 465 466 /* Some "smart" NAT devices and DSL routers will tweak the MSS size and 467 * will set it to whatever is suitable for the link type. 468 */ 469 #define SMART_MSS 1460 470 if ((find->fp_wsize % find->fp_mss || 471 find->fp_wsize / find->fp_mss != 472 f->fp_wsize) && 473 (find->fp_wsize % SMART_MSS || 474 find->fp_wsize / SMART_MSS != 475 f->fp_wsize)) 476 continue; 477 } else if (f->fp_flags & PF_OSFP_WSIZE_MTU) { 478 if (find->fp_mss == 0) 479 continue; 480 481 #define MTUOFF (sizeof(struct ip) + sizeof(struct tcphdr)) 482 #define SMART_MTU (SMART_MSS + MTUOFF) 483 if ((find->fp_wsize % (find->fp_mss + MTUOFF) || 484 find->fp_wsize / (find->fp_mss + MTUOFF) != 485 f->fp_wsize) && 486 (find->fp_wsize % SMART_MTU || 487 find->fp_wsize / SMART_MTU != 488 f->fp_wsize)) 489 continue; 490 } else if (f->fp_flags & PF_OSFP_WSIZE_MOD) { 491 if (f->fp_wsize == 0 || find->fp_wsize % 492 f->fp_wsize) 493 continue; 494 } else { 495 if (f->fp_wsize != find->fp_wsize) 496 continue; 497 } 498 } 499 return (f); 500 } 501 502 return (NULL); 503 } 504 505 /* Find an exact fingerprint in the list */ 506 struct pf_os_fingerprint * 507 pf_osfp_find_exact(struct pf_os_fingerprint *find) 508 { 509 struct pf_os_fingerprint *f; 510 511 PF_ASSERT_LOCKED(); 512 513 SLIST_FOREACH(f, &pf_osfp_list, fp_next) { 514 if (f->fp_tcpopts == find->fp_tcpopts && 515 f->fp_wsize == find->fp_wsize && 516 f->fp_psize == find->fp_psize && 517 f->fp_mss == find->fp_mss && 518 f->fp_flags == find->fp_flags && 519 f->fp_optcnt == find->fp_optcnt && 520 f->fp_wscale == find->fp_wscale && 521 f->fp_ttl == find->fp_ttl) 522 return (f); 523 } 524 525 return (NULL); 526 } 527 528 /* Insert a fingerprint into the list */ 529 void 530 pf_osfp_insert(struct pf_os_fingerprint *ins) 531 { 532 struct pf_os_fingerprint *f, *prev = NULL; 533 534 PF_ASSERT_LOCKED(); 535 536 /* XXX need to go semi tree based. can key on tcp options */ 537 538 SLIST_FOREACH(f, &pf_osfp_list, fp_next) 539 prev = f; 540 if (prev) 541 SLIST_INSERT_AFTER(prev, ins, fp_next); 542 else 543 SLIST_INSERT_HEAD(&pf_osfp_list, ins, fp_next); 544 } 545 546 /* Fill a fingerprint by its number (from an ioctl) */ 547 int 548 pf_osfp_get(struct pf_osfp_ioctl *fpioc) 549 { 550 struct pf_os_fingerprint *fp; 551 struct pf_osfp_entry *entry; 552 int num = fpioc->fp_getnum; 553 int i = 0; 554 555 memset(fpioc, 0, sizeof(*fpioc)); 556 PF_LOCK(); 557 SLIST_FOREACH(fp, &pf_osfp_list, fp_next) { 558 SLIST_FOREACH(entry, &fp->fp_oses, fp_entry) { 559 if (i++ == num) { 560 fpioc->fp_mss = fp->fp_mss; 561 fpioc->fp_wsize = fp->fp_wsize; 562 fpioc->fp_flags = fp->fp_flags; 563 fpioc->fp_psize = fp->fp_psize; 564 fpioc->fp_ttl = fp->fp_ttl; 565 fpioc->fp_wscale = fp->fp_wscale; 566 fpioc->fp_getnum = num; 567 memcpy(&fpioc->fp_os, entry, 568 sizeof(fpioc->fp_os)); 569 PF_UNLOCK(); 570 return (0); 571 } 572 } 573 } 574 PF_UNLOCK(); 575 576 return (EBUSY); 577 } 578 579 580 /* Validate that each signature is reachable */ 581 struct pf_os_fingerprint * 582 pf_osfp_validate(void) 583 { 584 struct pf_os_fingerprint *f, *f2, find; 585 586 PF_ASSERT_LOCKED(); 587 588 SLIST_FOREACH(f, &pf_osfp_list, fp_next) { 589 memcpy(&find, f, sizeof(find)); 590 591 /* We do a few MSS/th_win percolations to make things unique */ 592 if (find.fp_mss == 0) 593 find.fp_mss = 128; 594 if (f->fp_flags & PF_OSFP_WSIZE_MSS) 595 find.fp_wsize *= find.fp_mss; 596 else if (f->fp_flags & PF_OSFP_WSIZE_MTU) 597 find.fp_wsize *= (find.fp_mss + 40); 598 else if (f->fp_flags & PF_OSFP_WSIZE_MOD) 599 find.fp_wsize *= 2; 600 if (f != (f2 = pf_osfp_find(&find, 0))) { 601 if (f2) 602 DPFPRINTF(LOG_NOTICE, 603 "Found \"%s %s %s\" instead of " 604 "\"%s %s %s\"\n", 605 SLIST_FIRST(&f2->fp_oses)->fp_class_nm, 606 SLIST_FIRST(&f2->fp_oses)->fp_version_nm, 607 SLIST_FIRST(&f2->fp_oses)->fp_subtype_nm, 608 SLIST_FIRST(&f->fp_oses)->fp_class_nm, 609 SLIST_FIRST(&f->fp_oses)->fp_version_nm, 610 SLIST_FIRST(&f->fp_oses)->fp_subtype_nm); 611 else 612 DPFPRINTF(LOG_NOTICE, 613 "Couldn't find \"%s %s %s\"\n", 614 SLIST_FIRST(&f->fp_oses)->fp_class_nm, 615 SLIST_FIRST(&f->fp_oses)->fp_version_nm, 616 SLIST_FIRST(&f->fp_oses)->fp_subtype_nm); 617 return (f); 618 } 619 } 620 return (NULL); 621 } 622