1 /* $OpenBSD: pf_osfp.c,v 1.46 2023/05/07 12:45:21 kn 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, NULL, 115 pd->af)) 116 return (NULL); 117 118 return (pf_osfp_fingerprint_hdr(ip, ip6, (struct tcphdr *)hdr)); 119 } 120 #endif /* _KERNEL */ 121 122 struct pf_osfp_enlist * 123 pf_osfp_fingerprint_hdr(const struct ip *ip, const struct ip6_hdr *ip6, 124 const struct tcphdr *tcp) 125 { 126 struct pf_os_fingerprint fp, *fpresult; 127 int cnt, optlen = 0; 128 const u_int8_t *optp; 129 #ifdef _KERNEL 130 char srcname[128]; 131 #else /* !_KERNEL */ 132 char srcname[NI_MAXHOST]; 133 #endif /* _KERNEL */ 134 135 if ((tcp->th_flags & (TH_SYN|TH_ACK)) != TH_SYN) 136 return (NULL); 137 if (ip) { 138 if ((ip->ip_off & htons(IP_OFFMASK)) != 0) 139 return (NULL); 140 } 141 142 memset(&fp, 0, sizeof(fp)); 143 144 if (ip) { 145 #ifndef _KERNEL 146 struct sockaddr_in sin; 147 #endif /* _KERNEL */ 148 149 fp.fp_psize = ntohs(ip->ip_len); 150 fp.fp_ttl = ip->ip_ttl; 151 if (ip->ip_off & htons(IP_DF)) 152 fp.fp_flags |= PF_OSFP_DF; 153 #ifdef _KERNEL 154 inet_ntop(AF_INET, &ip->ip_src, srcname, sizeof(srcname)); 155 #else /* !_KERNEL */ 156 memset(&sin, 0, sizeof(sin)); 157 sin.sin_family = AF_INET; 158 sin.sin_len = sizeof(struct sockaddr_in); 159 sin.sin_addr = ip->ip_src; 160 (void)getnameinfo((struct sockaddr *)&sin, 161 sizeof(struct sockaddr_in), srcname, sizeof(srcname), 162 NULL, 0, NI_NUMERICHOST); 163 #endif /* _KERNEL */ 164 } 165 #ifdef INET6 166 else if (ip6) { 167 #ifndef _KERNEL 168 struct sockaddr_in6 sin6; 169 #endif /* !_KERNEL */ 170 171 /* jumbo payload? */ 172 fp.fp_psize = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen); 173 fp.fp_ttl = ip6->ip6_hlim; 174 fp.fp_flags |= PF_OSFP_DF; 175 fp.fp_flags |= PF_OSFP_INET6; 176 #ifdef _KERNEL 177 inet_ntop(AF_INET6, &ip6->ip6_src, srcname, sizeof(srcname)); 178 #else /* !_KERNEL */ 179 memset(&sin6, 0, sizeof(sin6)); 180 sin6.sin6_family = AF_INET6; 181 sin6.sin6_len = sizeof(struct sockaddr_in6); 182 sin6.sin6_addr = ip6->ip6_src; 183 (void)getnameinfo((struct sockaddr *)&sin6, 184 sizeof(struct sockaddr_in6), srcname, sizeof(srcname), 185 NULL, 0, NI_NUMERICHOST); 186 #endif /* !_KERNEL */ 187 } 188 #endif /* INET6 */ 189 else 190 return (NULL); 191 fp.fp_wsize = ntohs(tcp->th_win); 192 193 194 cnt = (tcp->th_off << 2) - sizeof(*tcp); 195 optp = (const u_int8_t *)((const char *)tcp + sizeof(*tcp)); 196 for (; cnt > 0; cnt -= optlen, optp += optlen) { 197 if (*optp == TCPOPT_EOL) 198 break; 199 200 fp.fp_optcnt++; 201 if (*optp == TCPOPT_NOP) { 202 fp.fp_tcpopts = (fp.fp_tcpopts << PF_OSFP_TCPOPT_BITS) | 203 PF_OSFP_TCPOPT_NOP; 204 optlen = 1; 205 } else { 206 if (cnt < 2) 207 return (NULL); 208 optlen = optp[1]; 209 if (optlen > cnt || optlen < 2) 210 return (NULL); 211 switch (*optp) { 212 case TCPOPT_MAXSEG: 213 if (optlen >= TCPOLEN_MAXSEG) 214 memcpy(&fp.fp_mss, &optp[2], 215 sizeof(fp.fp_mss)); 216 fp.fp_tcpopts = (fp.fp_tcpopts << 217 PF_OSFP_TCPOPT_BITS) | PF_OSFP_TCPOPT_MSS; 218 fp.fp_mss = ntohs(fp.fp_mss); 219 break; 220 case TCPOPT_WINDOW: 221 if (optlen >= TCPOLEN_WINDOW) 222 memcpy(&fp.fp_wscale, &optp[2], 223 sizeof(fp.fp_wscale)); 224 fp.fp_tcpopts = (fp.fp_tcpopts << 225 PF_OSFP_TCPOPT_BITS) | 226 PF_OSFP_TCPOPT_WSCALE; 227 break; 228 case TCPOPT_SACK_PERMITTED: 229 fp.fp_tcpopts = (fp.fp_tcpopts << 230 PF_OSFP_TCPOPT_BITS) | PF_OSFP_TCPOPT_SACK; 231 break; 232 case TCPOPT_TIMESTAMP: 233 if (optlen >= TCPOLEN_TIMESTAMP) { 234 u_int32_t ts; 235 memcpy(&ts, &optp[2], sizeof(ts)); 236 if (ts == 0) 237 fp.fp_flags |= PF_OSFP_TS0; 238 239 } 240 fp.fp_tcpopts = (fp.fp_tcpopts << 241 PF_OSFP_TCPOPT_BITS) | PF_OSFP_TCPOPT_TS; 242 break; 243 default: 244 return (NULL); 245 } 246 } 247 optlen = MAX(optlen, 1); /* paranoia */ 248 } 249 250 DPFPRINTF(LOG_INFO, 251 "fingerprinted %s:%d %d:%d:%d:%d:%llx (%d) " 252 "(TS=%s,M=%s%d,W=%s%d)", 253 srcname, ntohs(tcp->th_sport), 254 fp.fp_wsize, fp.fp_ttl, (fp.fp_flags & PF_OSFP_DF) != 0, 255 fp.fp_psize, (long long int)fp.fp_tcpopts, fp.fp_optcnt, 256 (fp.fp_flags & PF_OSFP_TS0) ? "0" : "", 257 (fp.fp_flags & PF_OSFP_MSS_MOD) ? "%" : 258 (fp.fp_flags & PF_OSFP_MSS_DC) ? "*" : "", 259 fp.fp_mss, 260 (fp.fp_flags & PF_OSFP_WSCALE_MOD) ? "%" : 261 (fp.fp_flags & PF_OSFP_WSCALE_DC) ? "*" : "", 262 fp.fp_wscale); 263 264 if ((fpresult = pf_osfp_find(&fp, PF_OSFP_MAXTTL_OFFSET))) 265 return (&fpresult->fp_oses); 266 return (NULL); 267 } 268 269 /* Match a fingerprint ID against a list of OSes */ 270 int 271 pf_osfp_match(struct pf_osfp_enlist *list, pf_osfp_t os) 272 { 273 struct pf_osfp_entry *entry; 274 int os_class, os_version, os_subtype; 275 int en_class, en_version, en_subtype; 276 277 if (os == PF_OSFP_ANY) 278 return (1); 279 if (list == NULL) { 280 DPFPRINTF(LOG_INFO, "osfp no match against %x", os); 281 return (os == PF_OSFP_UNKNOWN); 282 } 283 PF_OSFP_UNPACK(os, os_class, os_version, os_subtype); 284 SLIST_FOREACH(entry, list, fp_entry) { 285 PF_OSFP_UNPACK(entry->fp_os, en_class, en_version, en_subtype); 286 if ((os_class == PF_OSFP_ANY || en_class == os_class) && 287 (os_version == PF_OSFP_ANY || en_version == os_version) && 288 (os_subtype == PF_OSFP_ANY || en_subtype == os_subtype)) { 289 DPFPRINTF(LOG_INFO, 290 "osfp matched %s %s %s %x==%x", 291 entry->fp_class_nm, entry->fp_version_nm, 292 entry->fp_subtype_nm, os, entry->fp_os); 293 return (1); 294 } 295 } 296 DPFPRINTF(LOG_INFO, "fingerprint 0x%x didn't match", os); 297 return (0); 298 } 299 300 /* Initialize the OS fingerprint system */ 301 void 302 pf_osfp_initialize(void) 303 { 304 pool_init(&pf_osfp_entry_pl, sizeof(struct pf_osfp_entry), 0, 305 IPL_NONE, PR_WAITOK, "pfosfpen", NULL); 306 pool_init(&pf_osfp_pl, sizeof(struct pf_os_fingerprint), 0, 307 IPL_NONE, PR_WAITOK, "pfosfp", NULL); 308 } 309 310 /* Flush the fingerprint list */ 311 void 312 pf_osfp_flush(void) 313 { 314 struct pf_os_fingerprint *fp; 315 struct pf_osfp_entry *entry; 316 317 PF_LOCK(); 318 while ((fp = SLIST_FIRST(&pf_osfp_list))) { 319 SLIST_REMOVE_HEAD(&pf_osfp_list, fp_next); 320 while ((entry = SLIST_FIRST(&fp->fp_oses))) { 321 SLIST_REMOVE_HEAD(&fp->fp_oses, fp_entry); 322 pool_put(&pf_osfp_entry_pl, entry); 323 } 324 pool_put(&pf_osfp_pl, fp); 325 } 326 PF_UNLOCK(); 327 } 328 329 330 /* Add a fingerprint */ 331 int 332 pf_osfp_add(struct pf_osfp_ioctl *fpioc) 333 { 334 struct pf_os_fingerprint *fp, *fp_prealloc, fpadd; 335 struct pf_osfp_entry *entry; 336 337 memset(&fpadd, 0, sizeof(fpadd)); 338 fpadd.fp_tcpopts = fpioc->fp_tcpopts; 339 fpadd.fp_wsize = fpioc->fp_wsize; 340 fpadd.fp_psize = fpioc->fp_psize; 341 fpadd.fp_mss = fpioc->fp_mss; 342 fpadd.fp_flags = fpioc->fp_flags; 343 fpadd.fp_optcnt = fpioc->fp_optcnt; 344 fpadd.fp_wscale = fpioc->fp_wscale; 345 fpadd.fp_ttl = fpioc->fp_ttl; 346 347 DPFPRINTF(LOG_DEBUG, 348 "adding osfp %s %s %s = %s%d:%d:%d:%s%d:0x%llx %d " 349 "(TS=%s,M=%s%d,W=%s%d) %x", 350 fpioc->fp_os.fp_class_nm, fpioc->fp_os.fp_version_nm, 351 fpioc->fp_os.fp_subtype_nm, 352 (fpadd.fp_flags & PF_OSFP_WSIZE_MOD) ? "%" : 353 (fpadd.fp_flags & PF_OSFP_WSIZE_MSS) ? "S" : 354 (fpadd.fp_flags & PF_OSFP_WSIZE_MTU) ? "T" : 355 (fpadd.fp_flags & PF_OSFP_WSIZE_DC) ? "*" : "", 356 fpadd.fp_wsize, 357 fpadd.fp_ttl, 358 (fpadd.fp_flags & PF_OSFP_DF) ? 1 : 0, 359 (fpadd.fp_flags & PF_OSFP_PSIZE_MOD) ? "%" : 360 (fpadd.fp_flags & PF_OSFP_PSIZE_DC) ? "*" : "", 361 fpadd.fp_psize, 362 (long long int)fpadd.fp_tcpopts, fpadd.fp_optcnt, 363 (fpadd.fp_flags & PF_OSFP_TS0) ? "0" : "", 364 (fpadd.fp_flags & PF_OSFP_MSS_MOD) ? "%" : 365 (fpadd.fp_flags & PF_OSFP_MSS_DC) ? "*" : "", 366 fpadd.fp_mss, 367 (fpadd.fp_flags & PF_OSFP_WSCALE_MOD) ? "%" : 368 (fpadd.fp_flags & PF_OSFP_WSCALE_DC) ? "*" : "", 369 fpadd.fp_wscale, 370 fpioc->fp_os.fp_os); 371 372 entry = pool_get(&pf_osfp_entry_pl, PR_WAITOK|PR_LIMITFAIL); 373 if (entry == NULL) 374 return (ENOMEM); 375 376 fp_prealloc = pool_get(&pf_osfp_pl, PR_WAITOK|PR_ZERO|PR_LIMITFAIL); 377 if (fp_prealloc == NULL) { 378 pool_put(&pf_osfp_entry_pl, entry); 379 return (ENOMEM); 380 } 381 382 PF_LOCK(); 383 if ((fp = pf_osfp_find_exact(&fpadd))) { 384 struct pf_osfp_entry *tentry; 385 386 SLIST_FOREACH(tentry, &fp->fp_oses, fp_entry) { 387 if (PF_OSFP_ENTRY_EQ(tentry, &fpioc->fp_os)) { 388 PF_UNLOCK(); 389 pool_put(&pf_osfp_entry_pl, entry); 390 pool_put(&pf_osfp_pl, fp_prealloc); 391 return (EEXIST); 392 } 393 } 394 } else { 395 fp = fp_prealloc; 396 fp_prealloc = NULL; 397 fp->fp_tcpopts = fpioc->fp_tcpopts; 398 fp->fp_wsize = fpioc->fp_wsize; 399 fp->fp_psize = fpioc->fp_psize; 400 fp->fp_mss = fpioc->fp_mss; 401 fp->fp_flags = fpioc->fp_flags; 402 fp->fp_optcnt = fpioc->fp_optcnt; 403 fp->fp_wscale = fpioc->fp_wscale; 404 fp->fp_ttl = fpioc->fp_ttl; 405 SLIST_INIT(&fp->fp_oses); 406 pf_osfp_insert(fp); 407 } 408 memcpy(entry, &fpioc->fp_os, sizeof(*entry)); 409 410 /* Make sure the strings are NUL terminated */ 411 entry->fp_class_nm[sizeof(entry->fp_class_nm)-1] = '\0'; 412 entry->fp_version_nm[sizeof(entry->fp_version_nm)-1] = '\0'; 413 entry->fp_subtype_nm[sizeof(entry->fp_subtype_nm)-1] = '\0'; 414 415 SLIST_INSERT_HEAD(&fp->fp_oses, entry, fp_entry); 416 PF_UNLOCK(); 417 418 #ifdef PFDEBUG 419 if ((fp = pf_osfp_validate())) 420 DPFPRINTF(LOG_NOTICE, 421 "Invalid fingerprint list"); 422 #endif /* PFDEBUG */ 423 424 if (fp_prealloc != NULL) 425 pool_put(&pf_osfp_pl, fp_prealloc); 426 427 return (0); 428 } 429 430 431 /* Find a fingerprint in the list */ 432 struct pf_os_fingerprint * 433 pf_osfp_find(struct pf_os_fingerprint *find, u_int8_t ttldiff) 434 { 435 struct pf_os_fingerprint *f; 436 437 PF_ASSERT_LOCKED(); 438 439 #define MATCH_INT(_MOD, _DC, _field) \ 440 if ((f->fp_flags & _DC) == 0) { \ 441 if ((f->fp_flags & _MOD) == 0) { \ 442 if (f->_field != find->_field) \ 443 continue; \ 444 } else { \ 445 if (f->_field == 0 || find->_field % f->_field) \ 446 continue; \ 447 } \ 448 } 449 450 SLIST_FOREACH(f, &pf_osfp_list, fp_next) { 451 if (f->fp_tcpopts != find->fp_tcpopts || 452 f->fp_optcnt != find->fp_optcnt || 453 f->fp_ttl < find->fp_ttl || 454 f->fp_ttl - find->fp_ttl > ttldiff || 455 (f->fp_flags & (PF_OSFP_DF|PF_OSFP_TS0)) != 456 (find->fp_flags & (PF_OSFP_DF|PF_OSFP_TS0))) 457 continue; 458 459 MATCH_INT(PF_OSFP_PSIZE_MOD, PF_OSFP_PSIZE_DC, fp_psize) 460 MATCH_INT(PF_OSFP_MSS_MOD, PF_OSFP_MSS_DC, fp_mss) 461 MATCH_INT(PF_OSFP_WSCALE_MOD, PF_OSFP_WSCALE_DC, fp_wscale) 462 if ((f->fp_flags & PF_OSFP_WSIZE_DC) == 0) { 463 if (f->fp_flags & PF_OSFP_WSIZE_MSS) { 464 if (find->fp_mss == 0) 465 continue; 466 467 /* Some "smart" NAT devices and DSL routers will tweak the MSS size and 468 * will set it to whatever is suitable for the link type. 469 */ 470 #define SMART_MSS 1460 471 if ((find->fp_wsize % find->fp_mss || 472 find->fp_wsize / find->fp_mss != 473 f->fp_wsize) && 474 (find->fp_wsize % SMART_MSS || 475 find->fp_wsize / SMART_MSS != 476 f->fp_wsize)) 477 continue; 478 } else if (f->fp_flags & PF_OSFP_WSIZE_MTU) { 479 if (find->fp_mss == 0) 480 continue; 481 482 #define MTUOFF (sizeof(struct ip) + sizeof(struct tcphdr)) 483 #define SMART_MTU (SMART_MSS + MTUOFF) 484 if ((find->fp_wsize % (find->fp_mss + MTUOFF) || 485 find->fp_wsize / (find->fp_mss + MTUOFF) != 486 f->fp_wsize) && 487 (find->fp_wsize % SMART_MTU || 488 find->fp_wsize / SMART_MTU != 489 f->fp_wsize)) 490 continue; 491 } else if (f->fp_flags & PF_OSFP_WSIZE_MOD) { 492 if (f->fp_wsize == 0 || find->fp_wsize % 493 f->fp_wsize) 494 continue; 495 } else { 496 if (f->fp_wsize != find->fp_wsize) 497 continue; 498 } 499 } 500 return (f); 501 } 502 503 return (NULL); 504 } 505 506 /* Find an exact fingerprint in the list */ 507 struct pf_os_fingerprint * 508 pf_osfp_find_exact(struct pf_os_fingerprint *find) 509 { 510 struct pf_os_fingerprint *f; 511 512 PF_ASSERT_LOCKED(); 513 514 SLIST_FOREACH(f, &pf_osfp_list, fp_next) { 515 if (f->fp_tcpopts == find->fp_tcpopts && 516 f->fp_wsize == find->fp_wsize && 517 f->fp_psize == find->fp_psize && 518 f->fp_mss == find->fp_mss && 519 f->fp_flags == find->fp_flags && 520 f->fp_optcnt == find->fp_optcnt && 521 f->fp_wscale == find->fp_wscale && 522 f->fp_ttl == find->fp_ttl) 523 return (f); 524 } 525 526 return (NULL); 527 } 528 529 /* Insert a fingerprint into the list */ 530 void 531 pf_osfp_insert(struct pf_os_fingerprint *ins) 532 { 533 struct pf_os_fingerprint *f, *prev = NULL; 534 535 PF_ASSERT_LOCKED(); 536 537 /* XXX need to go semi tree based. can key on tcp options */ 538 539 SLIST_FOREACH(f, &pf_osfp_list, fp_next) 540 prev = f; 541 if (prev) 542 SLIST_INSERT_AFTER(prev, ins, fp_next); 543 else 544 SLIST_INSERT_HEAD(&pf_osfp_list, ins, fp_next); 545 } 546 547 /* Fill a fingerprint by its number (from an ioctl) */ 548 int 549 pf_osfp_get(struct pf_osfp_ioctl *fpioc) 550 { 551 struct pf_os_fingerprint *fp; 552 struct pf_osfp_entry *entry; 553 int num = fpioc->fp_getnum; 554 int i = 0; 555 556 memset(fpioc, 0, sizeof(*fpioc)); 557 PF_LOCK(); 558 SLIST_FOREACH(fp, &pf_osfp_list, fp_next) { 559 SLIST_FOREACH(entry, &fp->fp_oses, fp_entry) { 560 if (i++ == num) { 561 fpioc->fp_mss = fp->fp_mss; 562 fpioc->fp_wsize = fp->fp_wsize; 563 fpioc->fp_flags = fp->fp_flags; 564 fpioc->fp_psize = fp->fp_psize; 565 fpioc->fp_ttl = fp->fp_ttl; 566 fpioc->fp_wscale = fp->fp_wscale; 567 fpioc->fp_getnum = num; 568 memcpy(&fpioc->fp_os, entry, 569 sizeof(fpioc->fp_os)); 570 PF_UNLOCK(); 571 return (0); 572 } 573 } 574 } 575 PF_UNLOCK(); 576 577 return (EBUSY); 578 } 579 580 581 /* Validate that each signature is reachable */ 582 struct pf_os_fingerprint * 583 pf_osfp_validate(void) 584 { 585 struct pf_os_fingerprint *f, *f2, find; 586 587 PF_ASSERT_LOCKED(); 588 589 SLIST_FOREACH(f, &pf_osfp_list, fp_next) { 590 memcpy(&find, f, sizeof(find)); 591 592 /* We do a few MSS/th_win percolations to make things unique */ 593 if (find.fp_mss == 0) 594 find.fp_mss = 128; 595 if (f->fp_flags & PF_OSFP_WSIZE_MSS) 596 find.fp_wsize *= find.fp_mss; 597 else if (f->fp_flags & PF_OSFP_WSIZE_MTU) 598 find.fp_wsize *= (find.fp_mss + 40); 599 else if (f->fp_flags & PF_OSFP_WSIZE_MOD) 600 find.fp_wsize *= 2; 601 if (f != (f2 = pf_osfp_find(&find, 0))) { 602 if (f2) 603 DPFPRINTF(LOG_NOTICE, 604 "Found \"%s %s %s\" instead of " 605 "\"%s %s %s\"\n", 606 SLIST_FIRST(&f2->fp_oses)->fp_class_nm, 607 SLIST_FIRST(&f2->fp_oses)->fp_version_nm, 608 SLIST_FIRST(&f2->fp_oses)->fp_subtype_nm, 609 SLIST_FIRST(&f->fp_oses)->fp_class_nm, 610 SLIST_FIRST(&f->fp_oses)->fp_version_nm, 611 SLIST_FIRST(&f->fp_oses)->fp_subtype_nm); 612 else 613 DPFPRINTF(LOG_NOTICE, 614 "Couldn't find \"%s %s %s\"\n", 615 SLIST_FIRST(&f->fp_oses)->fp_class_nm, 616 SLIST_FIRST(&f->fp_oses)->fp_version_nm, 617 SLIST_FIRST(&f->fp_oses)->fp_subtype_nm); 618 return (f); 619 } 620 } 621 return (NULL); 622 } 623