1 /* $FreeBSD: src/sys/contrib/pf/net/pf_osfp.c,v 1.4 2004/06/16 23:24:00 mlaier Exp $ */ 2 /* $OpenBSD: pf_osfp.c,v 1.9 2004/01/04 20:08:42 pvalchev Exp $ */ 3 /* $DragonFly: src/sys/net/pf/pf_osfp.c,v 1.2 2006/12/22 23:44:57 swildner Exp $ */ 4 5 /* 6 * Copyright (c) 2004 The DragonFly Project. All rights reserved. 7 * 8 * Copyright (c) 2003 Mike Frantzen <frantzen@w4g.org> 9 * 10 * Permission to use, copy, modify, and distribute this software for any 11 * purpose with or without fee is hereby granted, provided that the above 12 * copyright notice and this permission notice appear in all copies. 13 * 14 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 15 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 16 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 17 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 18 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 19 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 20 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 21 * 22 */ 23 24 #include <sys/param.h> 25 #include <sys/socket.h> 26 #ifdef _KERNEL 27 # include <sys/systm.h> 28 # include <vm/vm_zone.h> 29 #endif /* _KERNEL */ 30 #include <sys/mbuf.h> 31 32 #include <netinet/in.h> 33 #include <netinet/in_systm.h> 34 #include <netinet/ip.h> 35 #include <netinet/tcp.h> 36 37 #include <net/if.h> 38 #include <net/pf/pfvar.h> 39 40 #ifdef INET6 41 #include <netinet/ip6.h> 42 #endif /* INET6 */ 43 44 45 #ifdef _KERNEL 46 # define DPFPRINTF(format, x...) \ 47 if (pf_status.debug >= PF_DEBUG_NOISY) \ 48 kprintf(format , ##x) 49 typedef vm_zone_t pool_t; 50 51 #else 52 /* Userland equivalents so we can lend code to tcpdump et al. */ 53 54 # include <arpa/inet.h> 55 # include <errno.h> 56 # include <stdio.h> 57 # include <stdlib.h> 58 # include <string.h> 59 # define pool_t int 60 # define pool_get(pool, flags) malloc(*(pool)) 61 # define pool_put(pool, item) free(item) 62 # define pool_init(pool, size, a, ao, f, m, p) (*(pool)) = (size) 63 64 # ifdef PFDEBUG 65 # include <sys/stdarg.h> 66 # define DPFPRINTF(format, x...) fprintf(stderr, format , ##x) 67 # else 68 # define DPFPRINTF(format, x...) ((void)0) 69 # endif /* PFDEBUG */ 70 #endif /* _KERNEL */ 71 72 73 SLIST_HEAD(pf_osfp_list, pf_os_fingerprint) pf_osfp_list; 74 pool_t pf_osfp_entry_pl; 75 pool_t pf_osfp_pl; 76 77 struct pf_os_fingerprint *pf_osfp_find(struct pf_osfp_list *, 78 struct pf_os_fingerprint *, u_int8_t); 79 struct pf_os_fingerprint *pf_osfp_find_exact(struct pf_osfp_list *, 80 struct pf_os_fingerprint *); 81 void pf_osfp_insert(struct pf_osfp_list *, 82 struct pf_os_fingerprint *); 83 84 85 #ifdef _KERNEL 86 /* 87 * Passively fingerprint the OS of the host (IPv4 TCP SYN packets only) 88 * Returns the list of possible OSes. 89 */ 90 struct pf_osfp_enlist * 91 pf_osfp_fingerprint(struct pf_pdesc *pd, struct mbuf *m, int off, 92 const struct tcphdr *tcp) 93 { 94 struct ip *ip; 95 char hdr[60]; 96 97 /* XXX don't have a fingerprint database for IPv6 :-( */ 98 if (pd->af != PF_INET || pd->proto != IPPROTO_TCP || (tcp->th_off << 2) 99 < sizeof(*tcp)) 100 return (NULL); 101 102 ip = mtod(m, struct ip *); 103 if (!pf_pull_hdr(m, off, hdr, tcp->th_off << 2, NULL, NULL, pd->af)) 104 return (NULL); 105 106 return (pf_osfp_fingerprint_hdr(ip, (struct tcphdr *)hdr)); 107 } 108 #endif /* _KERNEL */ 109 110 struct pf_osfp_enlist * 111 pf_osfp_fingerprint_hdr(const struct ip *ip, const struct tcphdr *tcp) 112 { 113 struct pf_os_fingerprint fp, *fpresult; 114 int cnt, optlen = 0; 115 const u_int8_t *optp; 116 117 if ((tcp->th_flags & (TH_SYN|TH_ACK)) != TH_SYN || (ip->ip_off & 118 IP_OFFMASK)) 119 return (NULL); 120 121 memset(&fp, 0, sizeof(fp)); 122 123 fp.fp_psize = ip->ip_len; 124 fp.fp_ttl = ip->ip_ttl; 125 if (ip->ip_off & IP_DF) 126 fp.fp_flags |= PF_OSFP_DF; 127 fp.fp_wsize = ntohs(tcp->th_win); 128 129 130 cnt = (tcp->th_off << 2) - sizeof(*tcp); 131 optp = (const u_int8_t *)((const char *)tcp + sizeof(*tcp)); 132 for (; cnt > 0; cnt -= optlen, optp += optlen) { 133 if (*optp == TCPOPT_EOL) 134 break; 135 136 fp.fp_optcnt++; 137 if (*optp == TCPOPT_NOP) { 138 fp.fp_tcpopts = (fp.fp_tcpopts << PF_OSFP_TCPOPT_BITS) | 139 PF_OSFP_TCPOPT_NOP; 140 optlen = 1; 141 } else { 142 if (cnt < 2) 143 return (NULL); 144 optlen = optp[1]; 145 if (optlen > cnt || optlen < 2) 146 return (NULL); 147 switch (*optp) { 148 case TCPOPT_MAXSEG: 149 if (optlen >= TCPOLEN_MAXSEG) 150 memcpy(&fp.fp_mss, &optp[2], 151 sizeof(fp.fp_mss)); 152 fp.fp_tcpopts = (fp.fp_tcpopts << 153 PF_OSFP_TCPOPT_BITS) | PF_OSFP_TCPOPT_MSS; 154 fp.fp_mss = ntohs(fp.fp_mss); 155 break; 156 case TCPOPT_WINDOW: 157 if (optlen >= TCPOLEN_WINDOW) 158 memcpy(&fp.fp_wscale, &optp[2], 159 sizeof(fp.fp_wscale)); 160 fp.fp_wscale = ntohs(fp.fp_wscale); 161 fp.fp_tcpopts = (fp.fp_tcpopts << 162 PF_OSFP_TCPOPT_BITS) | 163 PF_OSFP_TCPOPT_WSCALE; 164 break; 165 case TCPOPT_SACK_PERMITTED: 166 fp.fp_tcpopts = (fp.fp_tcpopts << 167 PF_OSFP_TCPOPT_BITS) | PF_OSFP_TCPOPT_SACK; 168 break; 169 case TCPOPT_TIMESTAMP: 170 if (optlen >= TCPOLEN_TIMESTAMP) { 171 u_int32_t ts; 172 memcpy(&ts, &optp[2], sizeof(ts)); 173 if (ts == 0) 174 fp.fp_flags |= PF_OSFP_TS0; 175 176 } 177 fp.fp_tcpopts = (fp.fp_tcpopts << 178 PF_OSFP_TCPOPT_BITS) | PF_OSFP_TCPOPT_TS; 179 break; 180 default: 181 return (NULL); 182 } 183 } 184 optlen = MAX(optlen, 1); /* paranoia */ 185 } 186 187 DPFPRINTF("fingerprinted %s:%d %d:%d:%d:%d:%llx (%d) " 188 "(TS=%s,M=%s%d,W=%s%d)\n", 189 inet_ntoa(ip->ip_src), ntohs(tcp->th_sport), 190 fp.fp_wsize, fp.fp_ttl, (fp.fp_flags & PF_OSFP_DF) != 0, 191 fp.fp_psize, (long long int)fp.fp_tcpopts, fp.fp_optcnt, 192 (fp.fp_flags & PF_OSFP_TS0) ? "0" : "", 193 (fp.fp_flags & PF_OSFP_MSS_MOD) ? "%" : 194 (fp.fp_flags & PF_OSFP_MSS_DC) ? "*" : "", 195 fp.fp_mss, 196 (fp.fp_flags & PF_OSFP_WSCALE_MOD) ? "%" : 197 (fp.fp_flags & PF_OSFP_WSCALE_DC) ? "*" : "", 198 fp.fp_wscale); 199 200 if ((fpresult = pf_osfp_find(&pf_osfp_list, &fp, 201 PF_OSFP_MAXTTL_OFFSET))) 202 return (&fpresult->fp_oses); 203 return (NULL); 204 } 205 206 /* Match a fingerprint ID against a list of OSes */ 207 int 208 pf_osfp_match(struct pf_osfp_enlist *list, pf_osfp_t os) 209 { 210 struct pf_osfp_entry *entry; 211 int os_class, os_version, os_subtype; 212 int en_class, en_version, en_subtype; 213 214 if (os == PF_OSFP_ANY) 215 return (1); 216 if (list == NULL) { 217 DPFPRINTF("osfp no match against %x\n", os); 218 return (os == PF_OSFP_UNKNOWN); 219 } 220 PF_OSFP_UNPACK(os, os_class, os_version, os_subtype); 221 SLIST_FOREACH(entry, list, fp_entry) { 222 PF_OSFP_UNPACK(entry->fp_os, en_class, en_version, en_subtype); 223 if ((os_class == PF_OSFP_ANY || en_class == os_class) && 224 (os_version == PF_OSFP_ANY || en_version == os_version) && 225 (os_subtype == PF_OSFP_ANY || en_subtype == os_subtype)) { 226 DPFPRINTF("osfp matched %s %s %s %x==%x\n", 227 entry->fp_class_nm, entry->fp_version_nm, 228 entry->fp_subtype_nm, os, entry->fp_os); 229 return (1); 230 } 231 } 232 DPFPRINTF("fingerprint 0x%x didn't match\n", os); 233 return (0); 234 } 235 236 /* Initialize the OS fingerprint system */ 237 int 238 pf_osfp_initialize(void) 239 { 240 int error = 0; 241 242 #ifdef _KERNEL 243 do { 244 error = ENOMEM; 245 pf_osfp_entry_pl = pf_osfp_pl = NULL; 246 ZONE_CREATE(pf_osfp_entry_pl, struct pf_osfp_entry, "pfospfen"); 247 ZONE_CREATE(pf_osfp_pl, struct pf_os_fingerprint, "pfosfp"); 248 error = 0; 249 } while(0); 250 #else 251 pool_init(&pf_osfp_entry_pl, sizeof(struct pf_osfp_entry), 0, 0, 0, 252 "pfosfpen", NULL); 253 pool_init(&pf_osfp_pl, sizeof(struct pf_os_fingerprint), 0, 0, 0, 254 "pfosfp", NULL); 255 #endif 256 SLIST_INIT(&pf_osfp_list); 257 258 return (error); 259 } 260 261 #ifdef _KERNEL 262 void 263 pf_osfp_cleanup(void) 264 { 265 ZONE_DESTROY(pf_osfp_entry_pl); 266 ZONE_DESTROY(pf_osfp_pl); 267 } 268 #endif 269 270 /* Flush the fingerprint list */ 271 void 272 pf_osfp_flush(void) 273 { 274 struct pf_os_fingerprint *fp; 275 struct pf_osfp_entry *entry; 276 277 while ((fp = SLIST_FIRST(&pf_osfp_list))) { 278 SLIST_REMOVE_HEAD(&pf_osfp_list, fp_next); 279 while ((entry = SLIST_FIRST(&fp->fp_oses))) { 280 SLIST_REMOVE_HEAD(&fp->fp_oses, fp_entry); 281 pool_put(&pf_osfp_entry_pl, entry); 282 } 283 pool_put(&pf_osfp_pl, fp); 284 } 285 } 286 287 288 /* Add a fingerprint */ 289 int 290 pf_osfp_add(struct pf_osfp_ioctl *fpioc) 291 { 292 struct pf_os_fingerprint *fp, fpadd; 293 struct pf_osfp_entry *entry; 294 295 memset(&fpadd, 0, sizeof(fpadd)); 296 fpadd.fp_tcpopts = fpioc->fp_tcpopts; 297 fpadd.fp_wsize = fpioc->fp_wsize; 298 fpadd.fp_psize = fpioc->fp_psize; 299 fpadd.fp_mss = fpioc->fp_mss; 300 fpadd.fp_flags = fpioc->fp_flags; 301 fpadd.fp_optcnt = fpioc->fp_optcnt; 302 fpadd.fp_wscale = fpioc->fp_wscale; 303 fpadd.fp_ttl = fpioc->fp_ttl; 304 305 DPFPRINTF("adding osfp %s %s %s = %s%d:%d:%d:%s%d:0x%llx %d " 306 "(TS=%s,M=%s%d,W=%s%d) %x\n", 307 fpioc->fp_os.fp_class_nm, fpioc->fp_os.fp_version_nm, 308 fpioc->fp_os.fp_subtype_nm, 309 (fpadd.fp_flags & PF_OSFP_WSIZE_MOD) ? "%" : 310 (fpadd.fp_flags & PF_OSFP_WSIZE_MSS) ? "S" : 311 (fpadd.fp_flags & PF_OSFP_WSIZE_MTU) ? "T" : 312 (fpadd.fp_flags & PF_OSFP_WSIZE_DC) ? "*" : "", 313 fpadd.fp_wsize, 314 fpadd.fp_ttl, 315 (fpadd.fp_flags & PF_OSFP_DF) ? 1 : 0, 316 (fpadd.fp_flags & PF_OSFP_PSIZE_MOD) ? "%" : 317 (fpadd.fp_flags & PF_OSFP_PSIZE_DC) ? "*" : "", 318 fpadd.fp_psize, 319 (long long int)fpadd.fp_tcpopts, fpadd.fp_optcnt, 320 (fpadd.fp_flags & PF_OSFP_TS0) ? "0" : "", 321 (fpadd.fp_flags & PF_OSFP_MSS_MOD) ? "%" : 322 (fpadd.fp_flags & PF_OSFP_MSS_DC) ? "*" : "", 323 fpadd.fp_mss, 324 (fpadd.fp_flags & PF_OSFP_WSCALE_MOD) ? "%" : 325 (fpadd.fp_flags & PF_OSFP_WSCALE_DC) ? "*" : "", 326 fpadd.fp_wscale, 327 fpioc->fp_os.fp_os); 328 329 330 if ((fp = pf_osfp_find_exact(&pf_osfp_list, &fpadd))) { 331 SLIST_FOREACH(entry, &fp->fp_oses, fp_entry) { 332 if (PF_OSFP_ENTRY_EQ(entry, &fpioc->fp_os)) 333 return (EEXIST); 334 } 335 if ((entry = pool_get(&pf_osfp_entry_pl, PR_NOWAIT)) == NULL) 336 return (ENOMEM); 337 } else { 338 if ((fp = pool_get(&pf_osfp_pl, PR_NOWAIT)) == NULL) 339 return (ENOMEM); 340 memset(fp, 0, sizeof(*fp)); 341 fp->fp_tcpopts = fpioc->fp_tcpopts; 342 fp->fp_wsize = fpioc->fp_wsize; 343 fp->fp_psize = fpioc->fp_psize; 344 fp->fp_mss = fpioc->fp_mss; 345 fp->fp_flags = fpioc->fp_flags; 346 fp->fp_optcnt = fpioc->fp_optcnt; 347 fp->fp_wscale = fpioc->fp_wscale; 348 fp->fp_ttl = fpioc->fp_ttl; 349 SLIST_INIT(&fp->fp_oses); 350 if ((entry = pool_get(&pf_osfp_entry_pl, PR_NOWAIT)) == NULL) { 351 pool_put(&pf_osfp_pl, fp); 352 return (ENOMEM); 353 } 354 pf_osfp_insert(&pf_osfp_list, fp); 355 } 356 memcpy(entry, &fpioc->fp_os, sizeof(*entry)); 357 358 /* Make sure the strings are NUL terminated */ 359 entry->fp_class_nm[sizeof(entry->fp_class_nm)-1] = '\0'; 360 entry->fp_version_nm[sizeof(entry->fp_version_nm)-1] = '\0'; 361 entry->fp_subtype_nm[sizeof(entry->fp_subtype_nm)-1] = '\0'; 362 363 SLIST_INSERT_HEAD(&fp->fp_oses, entry, fp_entry); 364 365 #ifdef PFDEBUG 366 if ((fp = pf_osfp_validate())) 367 kprintf("Invalid fingerprint list\n"); 368 #endif /* PFDEBUG */ 369 return (0); 370 } 371 372 373 /* Find a fingerprint in the list */ 374 struct pf_os_fingerprint * 375 pf_osfp_find(struct pf_osfp_list *list, struct pf_os_fingerprint *find, 376 u_int8_t ttldiff) 377 { 378 struct pf_os_fingerprint *f; 379 380 #define MATCH_INT(_MOD, _DC, _field) \ 381 if ((f->fp_flags & _DC) == 0) { \ 382 if ((f->fp_flags & _MOD) == 0) { \ 383 if (f->_field != find->_field) \ 384 continue; \ 385 } else { \ 386 if (f->_field == 0 || find->_field % f->_field) \ 387 continue; \ 388 } \ 389 } 390 391 SLIST_FOREACH(f, list, fp_next) { 392 if (f->fp_tcpopts != find->fp_tcpopts || 393 f->fp_optcnt != find->fp_optcnt || 394 f->fp_ttl < find->fp_ttl || 395 f->fp_ttl - find->fp_ttl > ttldiff || 396 (f->fp_flags & (PF_OSFP_DF|PF_OSFP_TS0)) != 397 (find->fp_flags & (PF_OSFP_DF|PF_OSFP_TS0))) 398 continue; 399 400 MATCH_INT(PF_OSFP_PSIZE_MOD, PF_OSFP_PSIZE_DC, fp_psize) 401 MATCH_INT(PF_OSFP_MSS_MOD, PF_OSFP_MSS_DC, fp_mss) 402 MATCH_INT(PF_OSFP_WSCALE_MOD, PF_OSFP_WSCALE_DC, fp_wscale) 403 if ((f->fp_flags & PF_OSFP_WSIZE_DC) == 0) { 404 if (f->fp_flags & PF_OSFP_WSIZE_MSS) { 405 if (find->fp_mss == 0) 406 continue; 407 408 /* Some "smart" NAT devices and DSL routers will tweak the MSS size and 409 * will set it to whatever is suitable for the link type. 410 */ 411 #define SMART_MSS 1460 412 if ((find->fp_wsize % find->fp_mss || 413 find->fp_wsize / find->fp_mss != 414 f->fp_wsize) && 415 (find->fp_wsize % SMART_MSS || 416 find->fp_wsize / SMART_MSS != 417 f->fp_wsize)) 418 continue; 419 } else if (f->fp_flags & PF_OSFP_WSIZE_MTU) { 420 if (find->fp_mss == 0) 421 continue; 422 423 #define MTUOFF (sizeof(struct ip) + sizeof(struct tcphdr)) 424 #define SMART_MTU (SMART_MSS + MTUOFF) 425 if ((find->fp_wsize % (find->fp_mss + MTUOFF) || 426 find->fp_wsize / (find->fp_mss + MTUOFF) != 427 f->fp_wsize) && 428 (find->fp_wsize % SMART_MTU || 429 find->fp_wsize / SMART_MTU != 430 f->fp_wsize)) 431 continue; 432 } else if (f->fp_flags & PF_OSFP_WSIZE_MOD) { 433 if (f->fp_wsize == 0 || find->fp_wsize % 434 f->fp_wsize) 435 continue; 436 } else { 437 if (f->fp_wsize != find->fp_wsize) 438 continue; 439 } 440 } 441 return (f); 442 } 443 444 return (NULL); 445 } 446 447 /* Find an exact fingerprint in the list */ 448 struct pf_os_fingerprint * 449 pf_osfp_find_exact(struct pf_osfp_list *list, struct pf_os_fingerprint *find) 450 { 451 struct pf_os_fingerprint *f; 452 453 SLIST_FOREACH(f, list, fp_next) { 454 if (f->fp_tcpopts == find->fp_tcpopts && 455 f->fp_wsize == find->fp_wsize && 456 f->fp_psize == find->fp_psize && 457 f->fp_mss == find->fp_mss && 458 f->fp_flags == find->fp_flags && 459 f->fp_optcnt == find->fp_optcnt && 460 f->fp_wscale == find->fp_wscale && 461 f->fp_ttl == find->fp_ttl) 462 return (f); 463 } 464 465 return (NULL); 466 } 467 468 /* Insert a fingerprint into the list */ 469 void 470 pf_osfp_insert(struct pf_osfp_list *list, struct pf_os_fingerprint *ins) 471 { 472 struct pf_os_fingerprint *f, *prev = NULL; 473 474 /* XXX need to go semi tree based. can key on tcp options */ 475 476 SLIST_FOREACH(f, list, fp_next) 477 prev = f; 478 if (prev) 479 SLIST_INSERT_AFTER(prev, ins, fp_next); 480 else 481 SLIST_INSERT_HEAD(list, ins, fp_next); 482 } 483 484 /* Fill a fingerprint by its number (from an ioctl) */ 485 int 486 pf_osfp_get(struct pf_osfp_ioctl *fpioc) 487 { 488 struct pf_os_fingerprint *fp; 489 struct pf_osfp_entry *entry; 490 int num = fpioc->fp_getnum; 491 int i = 0; 492 493 494 memset(fpioc, 0, sizeof(*fpioc)); 495 SLIST_FOREACH(fp, &pf_osfp_list, fp_next) { 496 SLIST_FOREACH(entry, &fp->fp_oses, fp_entry) { 497 if (i++ == num) { 498 fpioc->fp_mss = fp->fp_mss; 499 fpioc->fp_wsize = fp->fp_wsize; 500 fpioc->fp_flags = fp->fp_flags; 501 fpioc->fp_psize = fp->fp_psize; 502 fpioc->fp_ttl = fp->fp_ttl; 503 fpioc->fp_wscale = fp->fp_wscale; 504 fpioc->fp_getnum = num; 505 memcpy(&fpioc->fp_os, entry, 506 sizeof(fpioc->fp_os)); 507 return (0); 508 } 509 } 510 } 511 512 return (EBUSY); 513 } 514 515 516 /* Validate that each signature is reachable */ 517 struct pf_os_fingerprint * 518 pf_osfp_validate(void) 519 { 520 struct pf_os_fingerprint *f, *f2, find; 521 522 SLIST_FOREACH(f, &pf_osfp_list, fp_next) { 523 memcpy(&find, f, sizeof(find)); 524 525 /* We do a few MSS/th_win percolations to make things unique */ 526 if (find.fp_mss == 0) 527 find.fp_mss = 128; 528 if (f->fp_flags & PF_OSFP_WSIZE_MSS) 529 find.fp_wsize *= find.fp_mss, 1; 530 else if (f->fp_flags & PF_OSFP_WSIZE_MTU) 531 find.fp_wsize *= (find.fp_mss + 40); 532 else if (f->fp_flags & PF_OSFP_WSIZE_MOD) 533 find.fp_wsize *= 2; 534 if (f != (f2 = pf_osfp_find(&pf_osfp_list, &find, 0))) { 535 if (f2) 536 kprintf("Found \"%s %s %s\" instead of " 537 "\"%s %s %s\"\n", 538 SLIST_FIRST(&f2->fp_oses)->fp_class_nm, 539 SLIST_FIRST(&f2->fp_oses)->fp_version_nm, 540 SLIST_FIRST(&f2->fp_oses)->fp_subtype_nm, 541 SLIST_FIRST(&f->fp_oses)->fp_class_nm, 542 SLIST_FIRST(&f->fp_oses)->fp_version_nm, 543 SLIST_FIRST(&f->fp_oses)->fp_subtype_nm); 544 else 545 kprintf("Couldn't find \"%s %s %s\"\n", 546 SLIST_FIRST(&f->fp_oses)->fp_class_nm, 547 SLIST_FIRST(&f->fp_oses)->fp_version_nm, 548 SLIST_FIRST(&f->fp_oses)->fp_subtype_nm); 549 return (f); 550 } 551 } 552 return (NULL); 553 } 554