1 /* $OpenBSD: pf_osfp.c,v 1.40 2017/04/23 11:37:11 sthen 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 #ifdef PFDEBUG 64 #include <sys/stdarg.h> /* for DPFPRINTF() */ 65 #endif /* PFDEBUG */ 66 67 #endif /* _KERNEL */ 68 69 SLIST_HEAD(pf_osfp_list, pf_os_fingerprint) pf_osfp_list; 70 pool_t pf_osfp_entry_pl; 71 pool_t pf_osfp_pl; 72 73 struct pf_os_fingerprint *pf_osfp_find(struct pf_osfp_list *, 74 struct pf_os_fingerprint *, u_int8_t); 75 struct pf_os_fingerprint *pf_osfp_find_exact(struct pf_osfp_list *, 76 struct pf_os_fingerprint *); 77 void pf_osfp_insert(struct pf_osfp_list *, 78 struct pf_os_fingerprint *); 79 80 81 #ifdef _KERNEL 82 /* 83 * Passively fingerprint the OS of the host (IPv4 TCP SYN packets only) 84 * Returns the list of possible OSes. 85 */ 86 struct pf_osfp_enlist * 87 pf_osfp_fingerprint(struct pf_pdesc *pd) 88 { 89 struct tcphdr *th = &pd->hdr.tcp; 90 struct ip *ip = NULL; 91 struct ip6_hdr *ip6 = NULL; 92 char hdr[60]; 93 94 if (pd->proto != IPPROTO_TCP) 95 return (NULL); 96 97 switch (pd->af) { 98 case AF_INET: 99 ip = mtod(pd->m, struct ip *); 100 break; 101 case AF_INET6: 102 ip6 = mtod(pd->m, struct ip6_hdr *); 103 break; 104 } 105 if (!pf_pull_hdr(pd->m, pd->off, hdr, th->th_off << 2, NULL, NULL, 106 pd->af)) 107 return (NULL); 108 109 return (pf_osfp_fingerprint_hdr(ip, ip6, (struct tcphdr *)hdr)); 110 } 111 #endif /* _KERNEL */ 112 113 struct pf_osfp_enlist * 114 pf_osfp_fingerprint_hdr(const struct ip *ip, const struct ip6_hdr *ip6, 115 const struct tcphdr *tcp) 116 { 117 struct pf_os_fingerprint fp, *fpresult; 118 int cnt, optlen = 0; 119 const u_int8_t *optp; 120 #ifdef _KERNEL 121 char srcname[128]; 122 #else /* !_KERNEL */ 123 char srcname[NI_MAXHOST]; 124 #endif /* _KERNEL */ 125 126 if ((tcp->th_flags & (TH_SYN|TH_ACK)) != TH_SYN) 127 return (NULL); 128 if (ip) { 129 if ((ip->ip_off & htons(IP_OFFMASK)) != 0) 130 return (NULL); 131 } 132 133 memset(&fp, 0, sizeof(fp)); 134 135 if (ip) { 136 #ifndef _KERNEL 137 struct sockaddr_in sin; 138 #endif /* _KERNEL */ 139 140 fp.fp_psize = ntohs(ip->ip_len); 141 fp.fp_ttl = ip->ip_ttl; 142 if (ip->ip_off & htons(IP_DF)) 143 fp.fp_flags |= PF_OSFP_DF; 144 #ifdef _KERNEL 145 inet_ntop(AF_INET, &ip->ip_src, srcname, sizeof(srcname)); 146 #else /* !_KERNEL */ 147 memset(&sin, 0, sizeof(sin)); 148 sin.sin_family = AF_INET; 149 sin.sin_len = sizeof(struct sockaddr_in); 150 sin.sin_addr = ip->ip_src; 151 (void)getnameinfo((struct sockaddr *)&sin, 152 sizeof(struct sockaddr_in), srcname, sizeof(srcname), 153 NULL, 0, NI_NUMERICHOST); 154 #endif /* _KERNEL */ 155 } 156 #ifdef INET6 157 else if (ip6) { 158 #ifndef _KERNEL 159 struct sockaddr_in6 sin6; 160 #endif /* !_KERNEL */ 161 162 /* jumbo payload? */ 163 fp.fp_psize = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen); 164 fp.fp_ttl = ip6->ip6_hlim; 165 fp.fp_flags |= PF_OSFP_DF; 166 fp.fp_flags |= PF_OSFP_INET6; 167 #ifdef _KERNEL 168 inet_ntop(AF_INET6, &ip6->ip6_src, srcname, sizeof(srcname)); 169 #else /* !_KERNEL */ 170 memset(&sin6, 0, sizeof(sin6)); 171 sin6.sin6_family = AF_INET6; 172 sin6.sin6_len = sizeof(struct sockaddr_in6); 173 sin6.sin6_addr = ip6->ip6_src; 174 (void)getnameinfo((struct sockaddr *)&sin6, 175 sizeof(struct sockaddr_in6), srcname, sizeof(srcname), 176 NULL, 0, NI_NUMERICHOST); 177 #endif /* !_KERNEL */ 178 } 179 #endif /* INET6 */ 180 else 181 return (NULL); 182 fp.fp_wsize = ntohs(tcp->th_win); 183 184 185 cnt = (tcp->th_off << 2) - sizeof(*tcp); 186 optp = (const u_int8_t *)((const char *)tcp + sizeof(*tcp)); 187 for (; cnt > 0; cnt -= optlen, optp += optlen) { 188 if (*optp == TCPOPT_EOL) 189 break; 190 191 fp.fp_optcnt++; 192 if (*optp == TCPOPT_NOP) { 193 fp.fp_tcpopts = (fp.fp_tcpopts << PF_OSFP_TCPOPT_BITS) | 194 PF_OSFP_TCPOPT_NOP; 195 optlen = 1; 196 } else { 197 if (cnt < 2) 198 return (NULL); 199 optlen = optp[1]; 200 if (optlen > cnt || optlen < 2) 201 return (NULL); 202 switch (*optp) { 203 case TCPOPT_MAXSEG: 204 if (optlen >= TCPOLEN_MAXSEG) 205 memcpy(&fp.fp_mss, &optp[2], 206 sizeof(fp.fp_mss)); 207 fp.fp_tcpopts = (fp.fp_tcpopts << 208 PF_OSFP_TCPOPT_BITS) | PF_OSFP_TCPOPT_MSS; 209 fp.fp_mss = ntohs(fp.fp_mss); 210 break; 211 case TCPOPT_WINDOW: 212 if (optlen >= TCPOLEN_WINDOW) 213 memcpy(&fp.fp_wscale, &optp[2], 214 sizeof(fp.fp_wscale)); 215 fp.fp_tcpopts = (fp.fp_tcpopts << 216 PF_OSFP_TCPOPT_BITS) | 217 PF_OSFP_TCPOPT_WSCALE; 218 break; 219 case TCPOPT_SACK_PERMITTED: 220 fp.fp_tcpopts = (fp.fp_tcpopts << 221 PF_OSFP_TCPOPT_BITS) | PF_OSFP_TCPOPT_SACK; 222 break; 223 case TCPOPT_TIMESTAMP: 224 if (optlen >= TCPOLEN_TIMESTAMP) { 225 u_int32_t ts; 226 memcpy(&ts, &optp[2], sizeof(ts)); 227 if (ts == 0) 228 fp.fp_flags |= PF_OSFP_TS0; 229 230 } 231 fp.fp_tcpopts = (fp.fp_tcpopts << 232 PF_OSFP_TCPOPT_BITS) | PF_OSFP_TCPOPT_TS; 233 break; 234 default: 235 return (NULL); 236 } 237 } 238 optlen = MAX(optlen, 1); /* paranoia */ 239 } 240 241 DPFPRINTF(LOG_INFO, 242 "fingerprinted %s:%d %d:%d:%d:%d:%llx (%d) " 243 "(TS=%s,M=%s%d,W=%s%d)", 244 srcname, ntohs(tcp->th_sport), 245 fp.fp_wsize, fp.fp_ttl, (fp.fp_flags & PF_OSFP_DF) != 0, 246 fp.fp_psize, (long long int)fp.fp_tcpopts, fp.fp_optcnt, 247 (fp.fp_flags & PF_OSFP_TS0) ? "0" : "", 248 (fp.fp_flags & PF_OSFP_MSS_MOD) ? "%" : 249 (fp.fp_flags & PF_OSFP_MSS_DC) ? "*" : "", 250 fp.fp_mss, 251 (fp.fp_flags & PF_OSFP_WSCALE_MOD) ? "%" : 252 (fp.fp_flags & PF_OSFP_WSCALE_DC) ? "*" : "", 253 fp.fp_wscale); 254 255 if ((fpresult = pf_osfp_find(&pf_osfp_list, &fp, 256 PF_OSFP_MAXTTL_OFFSET))) 257 return (&fpresult->fp_oses); 258 return (NULL); 259 } 260 261 /* Match a fingerprint ID against a list of OSes */ 262 int 263 pf_osfp_match(struct pf_osfp_enlist *list, pf_osfp_t os) 264 { 265 struct pf_osfp_entry *entry; 266 int os_class, os_version, os_subtype; 267 int en_class, en_version, en_subtype; 268 269 if (os == PF_OSFP_ANY) 270 return (1); 271 if (list == NULL) { 272 DPFPRINTF(LOG_INFO, "osfp no match against %x", os); 273 return (os == PF_OSFP_UNKNOWN); 274 } 275 PF_OSFP_UNPACK(os, os_class, os_version, os_subtype); 276 SLIST_FOREACH(entry, list, fp_entry) { 277 PF_OSFP_UNPACK(entry->fp_os, en_class, en_version, en_subtype); 278 if ((os_class == PF_OSFP_ANY || en_class == os_class) && 279 (os_version == PF_OSFP_ANY || en_version == os_version) && 280 (os_subtype == PF_OSFP_ANY || en_subtype == os_subtype)) { 281 DPFPRINTF(LOG_INFO, 282 "osfp matched %s %s %s %x==%x", 283 entry->fp_class_nm, entry->fp_version_nm, 284 entry->fp_subtype_nm, os, entry->fp_os); 285 return (1); 286 } 287 } 288 DPFPRINTF(LOG_INFO, "fingerprint 0x%x didn't match", os); 289 return (0); 290 } 291 292 /* Initialize the OS fingerprint system */ 293 void 294 pf_osfp_initialize(void) 295 { 296 pool_init(&pf_osfp_entry_pl, sizeof(struct pf_osfp_entry), 0, 297 IPL_NONE, PR_WAITOK, "pfosfpen", NULL); 298 pool_init(&pf_osfp_pl, sizeof(struct pf_os_fingerprint), 0, 299 IPL_NONE, PR_WAITOK, "pfosfp", NULL); 300 SLIST_INIT(&pf_osfp_list); 301 } 302 303 /* Flush the fingerprint list */ 304 void 305 pf_osfp_flush(void) 306 { 307 struct pf_os_fingerprint *fp; 308 struct pf_osfp_entry *entry; 309 310 while ((fp = SLIST_FIRST(&pf_osfp_list))) { 311 SLIST_REMOVE_HEAD(&pf_osfp_list, fp_next); 312 while ((entry = SLIST_FIRST(&fp->fp_oses))) { 313 SLIST_REMOVE_HEAD(&fp->fp_oses, fp_entry); 314 pool_put(&pf_osfp_entry_pl, entry); 315 } 316 pool_put(&pf_osfp_pl, fp); 317 } 318 } 319 320 321 /* Add a fingerprint */ 322 int 323 pf_osfp_add(struct pf_osfp_ioctl *fpioc) 324 { 325 struct pf_os_fingerprint *fp, fpadd; 326 struct pf_osfp_entry *entry; 327 328 memset(&fpadd, 0, sizeof(fpadd)); 329 fpadd.fp_tcpopts = fpioc->fp_tcpopts; 330 fpadd.fp_wsize = fpioc->fp_wsize; 331 fpadd.fp_psize = fpioc->fp_psize; 332 fpadd.fp_mss = fpioc->fp_mss; 333 fpadd.fp_flags = fpioc->fp_flags; 334 fpadd.fp_optcnt = fpioc->fp_optcnt; 335 fpadd.fp_wscale = fpioc->fp_wscale; 336 fpadd.fp_ttl = fpioc->fp_ttl; 337 338 DPFPRINTF(LOG_DEBUG, 339 "adding osfp %s %s %s = %s%d:%d:%d:%s%d:0x%llx %d " 340 "(TS=%s,M=%s%d,W=%s%d) %x", 341 fpioc->fp_os.fp_class_nm, fpioc->fp_os.fp_version_nm, 342 fpioc->fp_os.fp_subtype_nm, 343 (fpadd.fp_flags & PF_OSFP_WSIZE_MOD) ? "%" : 344 (fpadd.fp_flags & PF_OSFP_WSIZE_MSS) ? "S" : 345 (fpadd.fp_flags & PF_OSFP_WSIZE_MTU) ? "T" : 346 (fpadd.fp_flags & PF_OSFP_WSIZE_DC) ? "*" : "", 347 fpadd.fp_wsize, 348 fpadd.fp_ttl, 349 (fpadd.fp_flags & PF_OSFP_DF) ? 1 : 0, 350 (fpadd.fp_flags & PF_OSFP_PSIZE_MOD) ? "%" : 351 (fpadd.fp_flags & PF_OSFP_PSIZE_DC) ? "*" : "", 352 fpadd.fp_psize, 353 (long long int)fpadd.fp_tcpopts, fpadd.fp_optcnt, 354 (fpadd.fp_flags & PF_OSFP_TS0) ? "0" : "", 355 (fpadd.fp_flags & PF_OSFP_MSS_MOD) ? "%" : 356 (fpadd.fp_flags & PF_OSFP_MSS_DC) ? "*" : "", 357 fpadd.fp_mss, 358 (fpadd.fp_flags & PF_OSFP_WSCALE_MOD) ? "%" : 359 (fpadd.fp_flags & PF_OSFP_WSCALE_DC) ? "*" : "", 360 fpadd.fp_wscale, 361 fpioc->fp_os.fp_os); 362 363 if ((fp = pf_osfp_find_exact(&pf_osfp_list, &fpadd))) { 364 SLIST_FOREACH(entry, &fp->fp_oses, fp_entry) { 365 if (PF_OSFP_ENTRY_EQ(entry, &fpioc->fp_os)) 366 return (EEXIST); 367 } 368 if ((entry = pool_get(&pf_osfp_entry_pl, 369 PR_WAITOK|PR_LIMITFAIL)) == NULL) 370 return (ENOMEM); 371 } else { 372 if ((fp = pool_get(&pf_osfp_pl, 373 PR_WAITOK|PR_ZERO|PR_LIMITFAIL)) == NULL) 374 return (ENOMEM); 375 fp->fp_tcpopts = fpioc->fp_tcpopts; 376 fp->fp_wsize = fpioc->fp_wsize; 377 fp->fp_psize = fpioc->fp_psize; 378 fp->fp_mss = fpioc->fp_mss; 379 fp->fp_flags = fpioc->fp_flags; 380 fp->fp_optcnt = fpioc->fp_optcnt; 381 fp->fp_wscale = fpioc->fp_wscale; 382 fp->fp_ttl = fpioc->fp_ttl; 383 SLIST_INIT(&fp->fp_oses); 384 if ((entry = pool_get(&pf_osfp_entry_pl, 385 PR_WAITOK|PR_LIMITFAIL)) == NULL) { 386 pool_put(&pf_osfp_pl, fp); 387 return (ENOMEM); 388 } 389 pf_osfp_insert(&pf_osfp_list, fp); 390 } 391 memcpy(entry, &fpioc->fp_os, sizeof(*entry)); 392 393 /* Make sure the strings are NUL terminated */ 394 entry->fp_class_nm[sizeof(entry->fp_class_nm)-1] = '\0'; 395 entry->fp_version_nm[sizeof(entry->fp_version_nm)-1] = '\0'; 396 entry->fp_subtype_nm[sizeof(entry->fp_subtype_nm)-1] = '\0'; 397 398 SLIST_INSERT_HEAD(&fp->fp_oses, entry, fp_entry); 399 400 #ifdef PFDEBUG 401 if ((fp = pf_osfp_validate())) 402 DPFPRINTF(LOG_NOTICE, 403 "Invalid fingerprint list"); 404 #endif /* PFDEBUG */ 405 return (0); 406 } 407 408 409 /* Find a fingerprint in the list */ 410 struct pf_os_fingerprint * 411 pf_osfp_find(struct pf_osfp_list *list, struct pf_os_fingerprint *find, 412 u_int8_t ttldiff) 413 { 414 struct pf_os_fingerprint *f; 415 416 #define MATCH_INT(_MOD, _DC, _field) \ 417 if ((f->fp_flags & _DC) == 0) { \ 418 if ((f->fp_flags & _MOD) == 0) { \ 419 if (f->_field != find->_field) \ 420 continue; \ 421 } else { \ 422 if (f->_field == 0 || find->_field % f->_field) \ 423 continue; \ 424 } \ 425 } 426 427 SLIST_FOREACH(f, list, fp_next) { 428 if (f->fp_tcpopts != find->fp_tcpopts || 429 f->fp_optcnt != find->fp_optcnt || 430 f->fp_ttl < find->fp_ttl || 431 f->fp_ttl - find->fp_ttl > ttldiff || 432 (f->fp_flags & (PF_OSFP_DF|PF_OSFP_TS0)) != 433 (find->fp_flags & (PF_OSFP_DF|PF_OSFP_TS0))) 434 continue; 435 436 MATCH_INT(PF_OSFP_PSIZE_MOD, PF_OSFP_PSIZE_DC, fp_psize) 437 MATCH_INT(PF_OSFP_MSS_MOD, PF_OSFP_MSS_DC, fp_mss) 438 MATCH_INT(PF_OSFP_WSCALE_MOD, PF_OSFP_WSCALE_DC, fp_wscale) 439 if ((f->fp_flags & PF_OSFP_WSIZE_DC) == 0) { 440 if (f->fp_flags & PF_OSFP_WSIZE_MSS) { 441 if (find->fp_mss == 0) 442 continue; 443 444 /* Some "smart" NAT devices and DSL routers will tweak the MSS size and 445 * will set it to whatever is suitable for the link type. 446 */ 447 #define SMART_MSS 1460 448 if ((find->fp_wsize % find->fp_mss || 449 find->fp_wsize / find->fp_mss != 450 f->fp_wsize) && 451 (find->fp_wsize % SMART_MSS || 452 find->fp_wsize / SMART_MSS != 453 f->fp_wsize)) 454 continue; 455 } else if (f->fp_flags & PF_OSFP_WSIZE_MTU) { 456 if (find->fp_mss == 0) 457 continue; 458 459 #define MTUOFF (sizeof(struct ip) + sizeof(struct tcphdr)) 460 #define SMART_MTU (SMART_MSS + MTUOFF) 461 if ((find->fp_wsize % (find->fp_mss + MTUOFF) || 462 find->fp_wsize / (find->fp_mss + MTUOFF) != 463 f->fp_wsize) && 464 (find->fp_wsize % SMART_MTU || 465 find->fp_wsize / SMART_MTU != 466 f->fp_wsize)) 467 continue; 468 } else if (f->fp_flags & PF_OSFP_WSIZE_MOD) { 469 if (f->fp_wsize == 0 || find->fp_wsize % 470 f->fp_wsize) 471 continue; 472 } else { 473 if (f->fp_wsize != find->fp_wsize) 474 continue; 475 } 476 } 477 return (f); 478 } 479 480 return (NULL); 481 } 482 483 /* Find an exact fingerprint in the list */ 484 struct pf_os_fingerprint * 485 pf_osfp_find_exact(struct pf_osfp_list *list, struct pf_os_fingerprint *find) 486 { 487 struct pf_os_fingerprint *f; 488 489 SLIST_FOREACH(f, list, fp_next) { 490 if (f->fp_tcpopts == find->fp_tcpopts && 491 f->fp_wsize == find->fp_wsize && 492 f->fp_psize == find->fp_psize && 493 f->fp_mss == find->fp_mss && 494 f->fp_flags == find->fp_flags && 495 f->fp_optcnt == find->fp_optcnt && 496 f->fp_wscale == find->fp_wscale && 497 f->fp_ttl == find->fp_ttl) 498 return (f); 499 } 500 501 return (NULL); 502 } 503 504 /* Insert a fingerprint into the list */ 505 void 506 pf_osfp_insert(struct pf_osfp_list *list, struct pf_os_fingerprint *ins) 507 { 508 struct pf_os_fingerprint *f, *prev = NULL; 509 510 /* XXX need to go semi tree based. can key on tcp options */ 511 512 SLIST_FOREACH(f, list, fp_next) 513 prev = f; 514 if (prev) 515 SLIST_INSERT_AFTER(prev, ins, fp_next); 516 else 517 SLIST_INSERT_HEAD(list, ins, fp_next); 518 } 519 520 /* Fill a fingerprint by its number (from an ioctl) */ 521 int 522 pf_osfp_get(struct pf_osfp_ioctl *fpioc) 523 { 524 struct pf_os_fingerprint *fp; 525 struct pf_osfp_entry *entry; 526 int num = fpioc->fp_getnum; 527 int i = 0; 528 529 530 memset(fpioc, 0, sizeof(*fpioc)); 531 SLIST_FOREACH(fp, &pf_osfp_list, fp_next) { 532 SLIST_FOREACH(entry, &fp->fp_oses, fp_entry) { 533 if (i++ == num) { 534 fpioc->fp_mss = fp->fp_mss; 535 fpioc->fp_wsize = fp->fp_wsize; 536 fpioc->fp_flags = fp->fp_flags; 537 fpioc->fp_psize = fp->fp_psize; 538 fpioc->fp_ttl = fp->fp_ttl; 539 fpioc->fp_wscale = fp->fp_wscale; 540 fpioc->fp_getnum = num; 541 memcpy(&fpioc->fp_os, entry, 542 sizeof(fpioc->fp_os)); 543 return (0); 544 } 545 } 546 } 547 548 return (EBUSY); 549 } 550 551 552 /* Validate that each signature is reachable */ 553 struct pf_os_fingerprint * 554 pf_osfp_validate(void) 555 { 556 struct pf_os_fingerprint *f, *f2, find; 557 558 SLIST_FOREACH(f, &pf_osfp_list, fp_next) { 559 memcpy(&find, f, sizeof(find)); 560 561 /* We do a few MSS/th_win percolations to make things unique */ 562 if (find.fp_mss == 0) 563 find.fp_mss = 128; 564 if (f->fp_flags & PF_OSFP_WSIZE_MSS) 565 find.fp_wsize *= find.fp_mss; 566 else if (f->fp_flags & PF_OSFP_WSIZE_MTU) 567 find.fp_wsize *= (find.fp_mss + 40); 568 else if (f->fp_flags & PF_OSFP_WSIZE_MOD) 569 find.fp_wsize *= 2; 570 if (f != (f2 = pf_osfp_find(&pf_osfp_list, &find, 0))) { 571 if (f2) 572 DPFPRINTF(LOG_NOTICE, 573 "Found \"%s %s %s\" instead of " 574 "\"%s %s %s\"\n", 575 SLIST_FIRST(&f2->fp_oses)->fp_class_nm, 576 SLIST_FIRST(&f2->fp_oses)->fp_version_nm, 577 SLIST_FIRST(&f2->fp_oses)->fp_subtype_nm, 578 SLIST_FIRST(&f->fp_oses)->fp_class_nm, 579 SLIST_FIRST(&f->fp_oses)->fp_version_nm, 580 SLIST_FIRST(&f->fp_oses)->fp_subtype_nm); 581 else 582 DPFPRINTF(LOG_NOTICE, 583 "Couldn't find \"%s %s %s\"\n", 584 SLIST_FIRST(&f->fp_oses)->fp_class_nm, 585 SLIST_FIRST(&f->fp_oses)->fp_version_nm, 586 SLIST_FIRST(&f->fp_oses)->fp_subtype_nm); 587 return (f); 588 } 589 } 590 return (NULL); 591 } 592