1 /* $OpenBSD: pf_osfp.c,v 1.21 2010/10/18 15:55:28 deraadt 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/mbuf.h> 27 #include <sys/syslog.h> 28 29 #include <netinet/in.h> 30 #include <netinet/in_systm.h> 31 #include <netinet/ip.h> 32 #include <netinet/tcp.h> 33 34 #include <net/if.h> 35 #include <net/pfvar.h> 36 37 #include <netinet/ip6.h> 38 #ifdef _KERNEL 39 #include <netinet6/in6_var.h> 40 #endif 41 42 43 #ifdef _KERNEL 44 typedef struct pool pool_t; 45 46 #else 47 /* Userland equivalents so we can lend code to tcpdump et al. */ 48 49 # include <arpa/inet.h> 50 # include <errno.h> 51 # include <stdio.h> 52 # include <stdlib.h> 53 # include <string.h> 54 # include <netdb.h> 55 # define pool_t int 56 # define pool_get(pool, flags) malloc(*(pool)) 57 # define pool_put(pool, item) free(item) 58 # define pool_init(pool, size, a, ao, f, m, p) (*(pool)) = (size) 59 60 # ifdef PFDEBUG 61 # include <sys/stdarg.h> /* for DPFPRINTF() */ 62 # endif /* PFDEBUG */ 63 64 #endif /* _KERNEL */ 65 66 67 SLIST_HEAD(pf_osfp_list, pf_os_fingerprint) pf_osfp_list; 68 pool_t pf_osfp_entry_pl; 69 pool_t pf_osfp_pl; 70 71 struct pf_os_fingerprint *pf_osfp_find(struct pf_osfp_list *, 72 struct pf_os_fingerprint *, u_int8_t); 73 struct pf_os_fingerprint *pf_osfp_find_exact(struct pf_osfp_list *, 74 struct pf_os_fingerprint *); 75 void pf_osfp_insert(struct pf_osfp_list *, 76 struct pf_os_fingerprint *); 77 78 79 #ifdef _KERNEL 80 /* 81 * Passively fingerprint the OS of the host (IPv4 TCP SYN packets only) 82 * Returns the list of possible OSes. 83 */ 84 struct pf_osfp_enlist * 85 pf_osfp_fingerprint(struct pf_pdesc *pd, struct mbuf *m, int off, 86 const struct tcphdr *tcp) 87 { 88 struct ip *ip; 89 struct ip6_hdr *ip6; 90 char hdr[60]; 91 92 if ((pd->af != PF_INET && pd->af != PF_INET6) || 93 pd->proto != IPPROTO_TCP || (tcp->th_off << 2) < sizeof(*tcp)) 94 return (NULL); 95 96 if (pd->af == PF_INET) { 97 ip = mtod(m, struct ip *); 98 ip6 = (struct ip6_hdr *)NULL; 99 } else { 100 ip = (struct ip *)NULL; 101 ip6 = mtod(m, struct ip6_hdr *); 102 } 103 if (!pf_pull_hdr(m, off, hdr, tcp->th_off << 2, NULL, NULL, 104 pd->af)) return (NULL); 105 106 return (pf_osfp_fingerprint_hdr(ip, ip6, (struct tcphdr *)hdr)); 107 } 108 #endif /* _KERNEL */ 109 110 struct pf_osfp_enlist * 111 pf_osfp_fingerprint_hdr(const struct ip *ip, const struct ip6_hdr *ip6, const struct tcphdr *tcp) 112 { 113 struct pf_os_fingerprint fp, *fpresult; 114 int cnt, optlen = 0; 115 const u_int8_t *optp; 116 #ifdef _KERNEL 117 char srcname[128]; 118 #else 119 char srcname[NI_MAXHOST]; 120 #endif 121 122 if ((tcp->th_flags & (TH_SYN|TH_ACK)) != TH_SYN) 123 return (NULL); 124 if (ip) { 125 if ((ip->ip_off & htons(IP_OFFMASK)) != 0) 126 return (NULL); 127 } 128 129 memset(&fp, 0, sizeof(fp)); 130 131 if (ip) { 132 #ifndef _KERNEL 133 struct sockaddr_in sin; 134 #endif 135 136 fp.fp_psize = ntohs(ip->ip_len); 137 fp.fp_ttl = ip->ip_ttl; 138 if (ip->ip_off & htons(IP_DF)) 139 fp.fp_flags |= PF_OSFP_DF; 140 #ifdef _KERNEL 141 strlcpy(srcname, inet_ntoa(ip->ip_src), sizeof(srcname)); 142 #else 143 memset(&sin, 0, sizeof(sin)); 144 sin.sin_family = AF_INET; 145 sin.sin_len = sizeof(struct sockaddr_in); 146 sin.sin_addr = ip->ip_src; 147 (void)getnameinfo((struct sockaddr *)&sin, 148 sizeof(struct sockaddr_in), srcname, sizeof(srcname), 149 NULL, 0, NI_NUMERICHOST); 150 #endif 151 } 152 #ifdef INET6 153 else if (ip6) { 154 #ifndef _KERNEL 155 struct sockaddr_in6 sin6; 156 #endif 157 158 /* jumbo payload? */ 159 fp.fp_psize = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen); 160 fp.fp_ttl = ip6->ip6_hlim; 161 fp.fp_flags |= PF_OSFP_DF; 162 fp.fp_flags |= PF_OSFP_INET6; 163 #ifdef _KERNEL 164 strlcpy(srcname, ip6_sprintf((struct in6_addr *)&ip6->ip6_src), 165 sizeof(srcname)); 166 #else 167 memset(&sin6, 0, sizeof(sin6)); 168 sin6.sin6_family = AF_INET6; 169 sin6.sin6_len = sizeof(struct sockaddr_in6); 170 sin6.sin6_addr = ip6->ip6_src; 171 (void)getnameinfo((struct sockaddr *)&sin6, 172 sizeof(struct sockaddr_in6), srcname, sizeof(srcname), 173 NULL, 0, NI_NUMERICHOST); 174 #endif 175 } 176 #endif 177 else 178 return (NULL); 179 fp.fp_wsize = ntohs(tcp->th_win); 180 181 182 cnt = (tcp->th_off << 2) - sizeof(*tcp); 183 optp = (const u_int8_t *)((const char *)tcp + sizeof(*tcp)); 184 for (; cnt > 0; cnt -= optlen, optp += optlen) { 185 if (*optp == TCPOPT_EOL) 186 break; 187 188 fp.fp_optcnt++; 189 if (*optp == TCPOPT_NOP) { 190 fp.fp_tcpopts = (fp.fp_tcpopts << PF_OSFP_TCPOPT_BITS) | 191 PF_OSFP_TCPOPT_NOP; 192 optlen = 1; 193 } else { 194 if (cnt < 2) 195 return (NULL); 196 optlen = optp[1]; 197 if (optlen > cnt || optlen < 2) 198 return (NULL); 199 switch (*optp) { 200 case TCPOPT_MAXSEG: 201 if (optlen >= TCPOLEN_MAXSEG) 202 memcpy(&fp.fp_mss, &optp[2], 203 sizeof(fp.fp_mss)); 204 fp.fp_tcpopts = (fp.fp_tcpopts << 205 PF_OSFP_TCPOPT_BITS) | PF_OSFP_TCPOPT_MSS; 206 NTOHS(fp.fp_mss); 207 break; 208 case TCPOPT_WINDOW: 209 if (optlen >= TCPOLEN_WINDOW) 210 memcpy(&fp.fp_wscale, &optp[2], 211 sizeof(fp.fp_wscale)); 212 fp.fp_tcpopts = (fp.fp_tcpopts << 213 PF_OSFP_TCPOPT_BITS) | 214 PF_OSFP_TCPOPT_WSCALE; 215 break; 216 case TCPOPT_SACK_PERMITTED: 217 fp.fp_tcpopts = (fp.fp_tcpopts << 218 PF_OSFP_TCPOPT_BITS) | PF_OSFP_TCPOPT_SACK; 219 break; 220 case TCPOPT_TIMESTAMP: 221 if (optlen >= TCPOLEN_TIMESTAMP) { 222 u_int32_t ts; 223 memcpy(&ts, &optp[2], sizeof(ts)); 224 if (ts == 0) 225 fp.fp_flags |= PF_OSFP_TS0; 226 227 } 228 fp.fp_tcpopts = (fp.fp_tcpopts << 229 PF_OSFP_TCPOPT_BITS) | PF_OSFP_TCPOPT_TS; 230 break; 231 default: 232 return (NULL); 233 } 234 } 235 optlen = MAX(optlen, 1); /* paranoia */ 236 } 237 238 DPFPRINTF(LOG_NOTICE, 239 "fingerprinted %s:%d %d:%d:%d:%d:%llx (%d) " 240 "(TS=%s,M=%s%d,W=%s%d)", 241 srcname, ntohs(tcp->th_sport), 242 fp.fp_wsize, fp.fp_ttl, (fp.fp_flags & PF_OSFP_DF) != 0, 243 fp.fp_psize, (long long int)fp.fp_tcpopts, fp.fp_optcnt, 244 (fp.fp_flags & PF_OSFP_TS0) ? "0" : "", 245 (fp.fp_flags & PF_OSFP_MSS_MOD) ? "%" : 246 (fp.fp_flags & PF_OSFP_MSS_DC) ? "*" : "", 247 fp.fp_mss, 248 (fp.fp_flags & PF_OSFP_WSCALE_MOD) ? "%" : 249 (fp.fp_flags & PF_OSFP_WSCALE_DC) ? "*" : "", 250 fp.fp_wscale); 251 252 if ((fpresult = pf_osfp_find(&pf_osfp_list, &fp, 253 PF_OSFP_MAXTTL_OFFSET))) 254 return (&fpresult->fp_oses); 255 return (NULL); 256 } 257 258 /* Match a fingerprint ID against a list of OSes */ 259 int 260 pf_osfp_match(struct pf_osfp_enlist *list, pf_osfp_t os) 261 { 262 struct pf_osfp_entry *entry; 263 int os_class, os_version, os_subtype; 264 int en_class, en_version, en_subtype; 265 266 if (os == PF_OSFP_ANY) 267 return (1); 268 if (list == NULL) { 269 DPFPRINTF(LOG_NOTICE, "osfp no match against %x", os); 270 return (os == PF_OSFP_UNKNOWN); 271 } 272 PF_OSFP_UNPACK(os, os_class, os_version, os_subtype); 273 SLIST_FOREACH(entry, list, fp_entry) { 274 PF_OSFP_UNPACK(entry->fp_os, en_class, en_version, en_subtype); 275 if ((os_class == PF_OSFP_ANY || en_class == os_class) && 276 (os_version == PF_OSFP_ANY || en_version == os_version) && 277 (os_subtype == PF_OSFP_ANY || en_subtype == os_subtype)) { 278 DPFPRINTF(LOG_NOTICE, 279 "osfp matched %s %s %s %x==%x", 280 entry->fp_class_nm, entry->fp_version_nm, 281 entry->fp_subtype_nm, os, entry->fp_os); 282 return (1); 283 } 284 } 285 DPFPRINTF(LOG_NOTICE, "fingerprint 0x%x didn't match", os); 286 return (0); 287 } 288 289 /* Initialize the OS fingerprint system */ 290 void 291 pf_osfp_initialize(void) 292 { 293 pool_init(&pf_osfp_entry_pl, sizeof(struct pf_osfp_entry), 0, 0, 0, 294 "pfosfpen", &pool_allocator_nointr); 295 pool_init(&pf_osfp_pl, sizeof(struct pf_os_fingerprint), 0, 0, 0, 296 "pfosfp", &pool_allocator_nointr); 297 SLIST_INIT(&pf_osfp_list); 298 } 299 300 /* Flush the fingerprint list */ 301 void 302 pf_osfp_flush(void) 303 { 304 struct pf_os_fingerprint *fp; 305 struct pf_osfp_entry *entry; 306 307 while ((fp = SLIST_FIRST(&pf_osfp_list))) { 308 SLIST_REMOVE_HEAD(&pf_osfp_list, fp_next); 309 while ((entry = SLIST_FIRST(&fp->fp_oses))) { 310 SLIST_REMOVE_HEAD(&fp->fp_oses, fp_entry); 311 pool_put(&pf_osfp_entry_pl, entry); 312 } 313 pool_put(&pf_osfp_pl, fp); 314 } 315 } 316 317 318 /* Add a fingerprint */ 319 int 320 pf_osfp_add(struct pf_osfp_ioctl *fpioc) 321 { 322 struct pf_os_fingerprint *fp, fpadd; 323 struct pf_osfp_entry *entry; 324 325 memset(&fpadd, 0, sizeof(fpadd)); 326 fpadd.fp_tcpopts = fpioc->fp_tcpopts; 327 fpadd.fp_wsize = fpioc->fp_wsize; 328 fpadd.fp_psize = fpioc->fp_psize; 329 fpadd.fp_mss = fpioc->fp_mss; 330 fpadd.fp_flags = fpioc->fp_flags; 331 fpadd.fp_optcnt = fpioc->fp_optcnt; 332 fpadd.fp_wscale = fpioc->fp_wscale; 333 fpadd.fp_ttl = fpioc->fp_ttl; 334 335 DPFPRINTF(LOG_DEBUG, 336 "adding osfp %s %s %s = %s%d:%d:%d:%s%d:0x%llx %d " 337 "(TS=%s,M=%s%d,W=%s%d) %x", 338 fpioc->fp_os.fp_class_nm, fpioc->fp_os.fp_version_nm, 339 fpioc->fp_os.fp_subtype_nm, 340 (fpadd.fp_flags & PF_OSFP_WSIZE_MOD) ? "%" : 341 (fpadd.fp_flags & PF_OSFP_WSIZE_MSS) ? "S" : 342 (fpadd.fp_flags & PF_OSFP_WSIZE_MTU) ? "T" : 343 (fpadd.fp_flags & PF_OSFP_WSIZE_DC) ? "*" : "", 344 fpadd.fp_wsize, 345 fpadd.fp_ttl, 346 (fpadd.fp_flags & PF_OSFP_DF) ? 1 : 0, 347 (fpadd.fp_flags & PF_OSFP_PSIZE_MOD) ? "%" : 348 (fpadd.fp_flags & PF_OSFP_PSIZE_DC) ? "*" : "", 349 fpadd.fp_psize, 350 (long long int)fpadd.fp_tcpopts, fpadd.fp_optcnt, 351 (fpadd.fp_flags & PF_OSFP_TS0) ? "0" : "", 352 (fpadd.fp_flags & PF_OSFP_MSS_MOD) ? "%" : 353 (fpadd.fp_flags & PF_OSFP_MSS_DC) ? "*" : "", 354 fpadd.fp_mss, 355 (fpadd.fp_flags & PF_OSFP_WSCALE_MOD) ? "%" : 356 (fpadd.fp_flags & PF_OSFP_WSCALE_DC) ? "*" : "", 357 fpadd.fp_wscale, 358 fpioc->fp_os.fp_os); 359 360 if ((fp = pf_osfp_find_exact(&pf_osfp_list, &fpadd))) { 361 SLIST_FOREACH(entry, &fp->fp_oses, fp_entry) { 362 if (PF_OSFP_ENTRY_EQ(entry, &fpioc->fp_os)) 363 return (EEXIST); 364 } 365 if ((entry = pool_get(&pf_osfp_entry_pl, 366 PR_WAITOK|PR_LIMITFAIL)) == NULL) 367 return (ENOMEM); 368 } else { 369 if ((fp = pool_get(&pf_osfp_pl, 370 PR_WAITOK|PR_ZERO|PR_LIMITFAIL)) == NULL) 371 return (ENOMEM); 372 fp->fp_tcpopts = fpioc->fp_tcpopts; 373 fp->fp_wsize = fpioc->fp_wsize; 374 fp->fp_psize = fpioc->fp_psize; 375 fp->fp_mss = fpioc->fp_mss; 376 fp->fp_flags = fpioc->fp_flags; 377 fp->fp_optcnt = fpioc->fp_optcnt; 378 fp->fp_wscale = fpioc->fp_wscale; 379 fp->fp_ttl = fpioc->fp_ttl; 380 SLIST_INIT(&fp->fp_oses); 381 if ((entry = pool_get(&pf_osfp_entry_pl, 382 PR_WAITOK|PR_LIMITFAIL)) == NULL) { 383 pool_put(&pf_osfp_pl, fp); 384 return (ENOMEM); 385 } 386 pf_osfp_insert(&pf_osfp_list, fp); 387 } 388 memcpy(entry, &fpioc->fp_os, sizeof(*entry)); 389 390 /* Make sure the strings are NUL terminated */ 391 entry->fp_class_nm[sizeof(entry->fp_class_nm)-1] = '\0'; 392 entry->fp_version_nm[sizeof(entry->fp_version_nm)-1] = '\0'; 393 entry->fp_subtype_nm[sizeof(entry->fp_subtype_nm)-1] = '\0'; 394 395 SLIST_INSERT_HEAD(&fp->fp_oses, entry, fp_entry); 396 397 #ifdef PFDEBUG 398 if ((fp = pf_osfp_validate())) 399 DPFPRINTF(LOG_NOTICE, 400 "Invalid fingerprint list"); 401 #endif /* PFDEBUG */ 402 return (0); 403 } 404 405 406 /* Find a fingerprint in the list */ 407 struct pf_os_fingerprint * 408 pf_osfp_find(struct pf_osfp_list *list, struct pf_os_fingerprint *find, 409 u_int8_t ttldiff) 410 { 411 struct pf_os_fingerprint *f; 412 413 #define MATCH_INT(_MOD, _DC, _field) \ 414 if ((f->fp_flags & _DC) == 0) { \ 415 if ((f->fp_flags & _MOD) == 0) { \ 416 if (f->_field != find->_field) \ 417 continue; \ 418 } else { \ 419 if (f->_field == 0 || find->_field % f->_field) \ 420 continue; \ 421 } \ 422 } 423 424 SLIST_FOREACH(f, list, fp_next) { 425 if (f->fp_tcpopts != find->fp_tcpopts || 426 f->fp_optcnt != find->fp_optcnt || 427 f->fp_ttl < find->fp_ttl || 428 f->fp_ttl - find->fp_ttl > ttldiff || 429 (f->fp_flags & (PF_OSFP_DF|PF_OSFP_TS0)) != 430 (find->fp_flags & (PF_OSFP_DF|PF_OSFP_TS0))) 431 continue; 432 433 MATCH_INT(PF_OSFP_PSIZE_MOD, PF_OSFP_PSIZE_DC, fp_psize) 434 MATCH_INT(PF_OSFP_MSS_MOD, PF_OSFP_MSS_DC, fp_mss) 435 MATCH_INT(PF_OSFP_WSCALE_MOD, PF_OSFP_WSCALE_DC, fp_wscale) 436 if ((f->fp_flags & PF_OSFP_WSIZE_DC) == 0) { 437 if (f->fp_flags & PF_OSFP_WSIZE_MSS) { 438 if (find->fp_mss == 0) 439 continue; 440 441 /* Some "smart" NAT devices and DSL routers will tweak the MSS size and 442 * will set it to whatever is suitable for the link type. 443 */ 444 #define SMART_MSS 1460 445 if ((find->fp_wsize % find->fp_mss || 446 find->fp_wsize / find->fp_mss != 447 f->fp_wsize) && 448 (find->fp_wsize % SMART_MSS || 449 find->fp_wsize / SMART_MSS != 450 f->fp_wsize)) 451 continue; 452 } else if (f->fp_flags & PF_OSFP_WSIZE_MTU) { 453 if (find->fp_mss == 0) 454 continue; 455 456 #define MTUOFF (sizeof(struct ip) + sizeof(struct tcphdr)) 457 #define SMART_MTU (SMART_MSS + MTUOFF) 458 if ((find->fp_wsize % (find->fp_mss + MTUOFF) || 459 find->fp_wsize / (find->fp_mss + MTUOFF) != 460 f->fp_wsize) && 461 (find->fp_wsize % SMART_MTU || 462 find->fp_wsize / SMART_MTU != 463 f->fp_wsize)) 464 continue; 465 } else if (f->fp_flags & PF_OSFP_WSIZE_MOD) { 466 if (f->fp_wsize == 0 || find->fp_wsize % 467 f->fp_wsize) 468 continue; 469 } else { 470 if (f->fp_wsize != find->fp_wsize) 471 continue; 472 } 473 } 474 return (f); 475 } 476 477 return (NULL); 478 } 479 480 /* Find an exact fingerprint in the list */ 481 struct pf_os_fingerprint * 482 pf_osfp_find_exact(struct pf_osfp_list *list, struct pf_os_fingerprint *find) 483 { 484 struct pf_os_fingerprint *f; 485 486 SLIST_FOREACH(f, list, fp_next) { 487 if (f->fp_tcpopts == find->fp_tcpopts && 488 f->fp_wsize == find->fp_wsize && 489 f->fp_psize == find->fp_psize && 490 f->fp_mss == find->fp_mss && 491 f->fp_flags == find->fp_flags && 492 f->fp_optcnt == find->fp_optcnt && 493 f->fp_wscale == find->fp_wscale && 494 f->fp_ttl == find->fp_ttl) 495 return (f); 496 } 497 498 return (NULL); 499 } 500 501 /* Insert a fingerprint into the list */ 502 void 503 pf_osfp_insert(struct pf_osfp_list *list, struct pf_os_fingerprint *ins) 504 { 505 struct pf_os_fingerprint *f, *prev = NULL; 506 507 /* XXX need to go semi tree based. can key on tcp options */ 508 509 SLIST_FOREACH(f, list, fp_next) 510 prev = f; 511 if (prev) 512 SLIST_INSERT_AFTER(prev, ins, fp_next); 513 else 514 SLIST_INSERT_HEAD(list, ins, fp_next); 515 } 516 517 /* Fill a fingerprint by its number (from an ioctl) */ 518 int 519 pf_osfp_get(struct pf_osfp_ioctl *fpioc) 520 { 521 struct pf_os_fingerprint *fp; 522 struct pf_osfp_entry *entry; 523 int num = fpioc->fp_getnum; 524 int i = 0; 525 526 527 memset(fpioc, 0, sizeof(*fpioc)); 528 SLIST_FOREACH(fp, &pf_osfp_list, fp_next) { 529 SLIST_FOREACH(entry, &fp->fp_oses, fp_entry) { 530 if (i++ == num) { 531 fpioc->fp_mss = fp->fp_mss; 532 fpioc->fp_wsize = fp->fp_wsize; 533 fpioc->fp_flags = fp->fp_flags; 534 fpioc->fp_psize = fp->fp_psize; 535 fpioc->fp_ttl = fp->fp_ttl; 536 fpioc->fp_wscale = fp->fp_wscale; 537 fpioc->fp_getnum = num; 538 memcpy(&fpioc->fp_os, entry, 539 sizeof(fpioc->fp_os)); 540 return (0); 541 } 542 } 543 } 544 545 return (EBUSY); 546 } 547 548 549 /* Validate that each signature is reachable */ 550 struct pf_os_fingerprint * 551 pf_osfp_validate(void) 552 { 553 struct pf_os_fingerprint *f, *f2, find; 554 555 SLIST_FOREACH(f, &pf_osfp_list, fp_next) { 556 memcpy(&find, f, sizeof(find)); 557 558 /* We do a few MSS/th_win percolations to make things unique */ 559 if (find.fp_mss == 0) 560 find.fp_mss = 128; 561 if (f->fp_flags & PF_OSFP_WSIZE_MSS) 562 find.fp_wsize *= find.fp_mss; 563 else if (f->fp_flags & PF_OSFP_WSIZE_MTU) 564 find.fp_wsize *= (find.fp_mss + 40); 565 else if (f->fp_flags & PF_OSFP_WSIZE_MOD) 566 find.fp_wsize *= 2; 567 if (f != (f2 = pf_osfp_find(&pf_osfp_list, &find, 0))) { 568 if (f2) 569 DPFPRINTF(LOG_NOTICE, 570 "Found \"%s %s %s\" instead of " 571 "\"%s %s %s\"\n", 572 SLIST_FIRST(&f2->fp_oses)->fp_class_nm, 573 SLIST_FIRST(&f2->fp_oses)->fp_version_nm, 574 SLIST_FIRST(&f2->fp_oses)->fp_subtype_nm, 575 SLIST_FIRST(&f->fp_oses)->fp_class_nm, 576 SLIST_FIRST(&f->fp_oses)->fp_version_nm, 577 SLIST_FIRST(&f->fp_oses)->fp_subtype_nm); 578 else 579 DPFPRINTF(LOG_NOTICE, 580 "Couldn't find \"%s %s %s\"\n", 581 SLIST_FIRST(&f->fp_oses)->fp_class_nm, 582 SLIST_FIRST(&f->fp_oses)->fp_version_nm, 583 SLIST_FIRST(&f->fp_oses)->fp_subtype_nm); 584 return (f); 585 } 586 } 587 return (NULL); 588 } 589