1 /* $NetBSD: pf_osfp.c,v 1.7 2007/12/11 11:08:21 lukem Exp $ */ 2 /* $OpenBSD: pf_osfp.c,v 1.10 2004/04/09 19:30:41 frantzen Exp $ */ 3 4 /* 5 * Copyright (c) 2003 Mike Frantzen <frantzen@w4g.org> 6 * 7 * Permission to use, copy, modify, and distribute this software for any 8 * purpose with or without fee is hereby granted, provided that the above 9 * copyright notice and this permission notice appear in all copies. 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 18 * 19 */ 20 21 #include <sys/cdefs.h> 22 __KERNEL_RCSID(0, "$NetBSD: pf_osfp.c,v 1.7 2007/12/11 11:08:21 lukem Exp $"); 23 24 #ifdef _KERNEL_OPT 25 #include "opt_inet.h" 26 #endif 27 28 #include <sys/param.h> 29 #include <sys/socket.h> 30 #ifdef _KERNEL 31 # include <sys/systm.h> 32 #endif /* _KERNEL */ 33 #include <sys/mbuf.h> 34 35 #include <netinet/in.h> 36 #include <netinet/in_systm.h> 37 #include <netinet/ip.h> 38 #include <netinet/tcp.h> 39 40 #include <net/if.h> 41 #include <net/pfvar.h> 42 43 #ifdef INET6 44 #include <netinet/ip6.h> 45 #endif /* INET6 */ 46 47 48 #ifdef _KERNEL 49 # define DPFPRINTF(format, x...) \ 50 if (pf_status.debug >= PF_DEBUG_NOISY) \ 51 printf(format , ##x) 52 typedef struct pool pool_t; 53 54 #else 55 /* Userland equivalents so we can lend code to tcpdump et al. */ 56 57 # include <arpa/inet.h> 58 # include <errno.h> 59 # include <stdio.h> 60 # include <stdlib.h> 61 # include <string.h> 62 # define pool_t int 63 # define pool_get(pool, flags) malloc(*(pool)) 64 # define pool_put(pool, item) free(item) 65 # define pool_init(pool, size, a, ao, f, m, p) (*(pool)) = (size) 66 67 # ifdef PFDEBUG 68 # include <sys/stdarg.h> 69 # define DPFPRINTF(format, x...) fprintf(stderr, format , ##x) 70 # else 71 # define DPFPRINTF(format, x...) ((void)0) 72 # endif /* PFDEBUG */ 73 #endif /* _KERNEL */ 74 75 76 SLIST_HEAD(pf_osfp_list, pf_os_fingerprint) pf_osfp_list; 77 pool_t pf_osfp_entry_pl; 78 pool_t pf_osfp_pl; 79 80 struct pf_os_fingerprint *pf_osfp_find(struct pf_osfp_list *, 81 struct pf_os_fingerprint *, u_int8_t); 82 struct pf_os_fingerprint *pf_osfp_find_exact(struct pf_osfp_list *, 83 struct pf_os_fingerprint *); 84 void pf_osfp_insert(struct pf_osfp_list *, 85 struct pf_os_fingerprint *); 86 87 88 #ifdef _KERNEL 89 /* 90 * Passively fingerprint the OS of the host (IPv4 TCP SYN packets only) 91 * Returns the list of possible OSes. 92 */ 93 struct pf_osfp_enlist * 94 pf_osfp_fingerprint(struct pf_pdesc *pd, struct mbuf *m, int off, 95 const struct tcphdr *tcp) 96 { 97 struct ip *ip; 98 char hdr[60]; 99 100 /* XXX don't have a fingerprint database for IPv6 :-( */ 101 if (pd->af != PF_INET || pd->proto != IPPROTO_TCP || (tcp->th_off << 2) 102 < sizeof(*tcp)) 103 return (NULL); 104 105 ip = mtod(m, struct ip *); 106 if (!pf_pull_hdr(m, off, hdr, tcp->th_off << 2, NULL, NULL, pd->af)) 107 return (NULL); 108 109 return (pf_osfp_fingerprint_hdr(ip, (struct tcphdr *)hdr)); 110 } 111 #endif /* _KERNEL */ 112 113 struct pf_osfp_enlist * 114 pf_osfp_fingerprint_hdr(const struct ip *ip, const struct tcphdr *tcp) 115 { 116 struct pf_os_fingerprint fp, *fpresult; 117 int cnt, optlen = 0; 118 const u_int8_t *optp; 119 120 if ((tcp->th_flags & (TH_SYN|TH_ACK)) != TH_SYN || (ip->ip_off & 121 htons(IP_OFFMASK))) 122 return (NULL); 123 124 memset(&fp, 0, sizeof(fp)); 125 126 fp.fp_psize = ntohs(ip->ip_len); 127 fp.fp_ttl = ip->ip_ttl; 128 if (ip->ip_off & htons(IP_DF)) 129 fp.fp_flags |= PF_OSFP_DF; 130 fp.fp_wsize = ntohs(tcp->th_win); 131 132 133 cnt = (tcp->th_off << 2) - sizeof(*tcp); 134 optp = (const u_int8_t *)((const char *)tcp + sizeof(*tcp)); 135 for (; cnt > 0; cnt -= optlen, optp += optlen) { 136 if (*optp == TCPOPT_EOL) 137 break; 138 139 fp.fp_optcnt++; 140 if (*optp == TCPOPT_NOP) { 141 fp.fp_tcpopts = (fp.fp_tcpopts << PF_OSFP_TCPOPT_BITS) | 142 PF_OSFP_TCPOPT_NOP; 143 optlen = 1; 144 } else { 145 if (cnt < 2) 146 return (NULL); 147 optlen = optp[1]; 148 if (optlen > cnt || optlen < 2) 149 return (NULL); 150 switch (*optp) { 151 case TCPOPT_MAXSEG: 152 if (optlen >= TCPOLEN_MAXSEG) 153 memcpy(&fp.fp_mss, &optp[2], 154 sizeof(fp.fp_mss)); 155 fp.fp_tcpopts = (fp.fp_tcpopts << 156 PF_OSFP_TCPOPT_BITS) | PF_OSFP_TCPOPT_MSS; 157 NTOHS(fp.fp_mss); 158 break; 159 case TCPOPT_WINDOW: 160 if (optlen >= TCPOLEN_WINDOW) 161 memcpy(&fp.fp_wscale, &optp[2], 162 sizeof(fp.fp_wscale)); 163 NTOHS(fp.fp_wscale); 164 fp.fp_tcpopts = (fp.fp_tcpopts << 165 PF_OSFP_TCPOPT_BITS) | 166 PF_OSFP_TCPOPT_WSCALE; 167 break; 168 case TCPOPT_SACK_PERMITTED: 169 fp.fp_tcpopts = (fp.fp_tcpopts << 170 PF_OSFP_TCPOPT_BITS) | PF_OSFP_TCPOPT_SACK; 171 break; 172 case TCPOPT_TIMESTAMP: 173 if (optlen >= TCPOLEN_TIMESTAMP) { 174 u_int32_t ts; 175 memcpy(&ts, &optp[2], sizeof(ts)); 176 if (ts == 0) 177 fp.fp_flags |= PF_OSFP_TS0; 178 179 } 180 fp.fp_tcpopts = (fp.fp_tcpopts << 181 PF_OSFP_TCPOPT_BITS) | PF_OSFP_TCPOPT_TS; 182 break; 183 default: 184 return (NULL); 185 } 186 } 187 optlen = MAX(optlen, 1); /* paranoia */ 188 } 189 190 DPFPRINTF("fingerprinted %s:%d %d:%d:%d:%d:%llx (%d) " 191 "(TS=%s,M=%s%d,W=%s%d)\n", 192 inet_ntoa(ip->ip_src), ntohs(tcp->th_sport), 193 fp.fp_wsize, fp.fp_ttl, (fp.fp_flags & PF_OSFP_DF) != 0, 194 fp.fp_psize, (long long int)fp.fp_tcpopts, fp.fp_optcnt, 195 (fp.fp_flags & PF_OSFP_TS0) ? "0" : "", 196 (fp.fp_flags & PF_OSFP_MSS_MOD) ? "%" : 197 (fp.fp_flags & PF_OSFP_MSS_DC) ? "*" : "", 198 fp.fp_mss, 199 (fp.fp_flags & PF_OSFP_WSCALE_MOD) ? "%" : 200 (fp.fp_flags & PF_OSFP_WSCALE_DC) ? "*" : "", 201 fp.fp_wscale); 202 203 if ((fpresult = pf_osfp_find(&pf_osfp_list, &fp, 204 PF_OSFP_MAXTTL_OFFSET))) 205 return (&fpresult->fp_oses); 206 return (NULL); 207 } 208 209 /* Match a fingerprint ID against a list of OSes */ 210 int 211 pf_osfp_match(struct pf_osfp_enlist *list, pf_osfp_t os) 212 { 213 struct pf_osfp_entry *entry; 214 int os_class, os_version, os_subtype; 215 int en_class, en_version, en_subtype; 216 217 if (os == PF_OSFP_ANY) 218 return (1); 219 if (list == NULL) { 220 DPFPRINTF("osfp no match against %x\n", os); 221 return (os == PF_OSFP_UNKNOWN); 222 } 223 PF_OSFP_UNPACK(os, os_class, os_version, os_subtype); 224 SLIST_FOREACH(entry, list, fp_entry) { 225 PF_OSFP_UNPACK(entry->fp_os, en_class, en_version, en_subtype); 226 if ((os_class == PF_OSFP_ANY || en_class == os_class) && 227 (os_version == PF_OSFP_ANY || en_version == os_version) && 228 (os_subtype == PF_OSFP_ANY || en_subtype == os_subtype)) { 229 DPFPRINTF("osfp matched %s %s %s %x==%x\n", 230 entry->fp_class_nm, entry->fp_version_nm, 231 entry->fp_subtype_nm, os, entry->fp_os); 232 return (1); 233 } 234 } 235 DPFPRINTF("fingerprint 0x%x didn't match\n", os); 236 return (0); 237 } 238 239 /* Initialize the OS fingerprint system */ 240 void 241 pf_osfp_initialize(void) 242 { 243 #ifdef __NetBSD__ 244 pool_init(&pf_osfp_entry_pl, sizeof(struct pf_osfp_entry), 0, 0, 0, 245 "pfosfpen", &pool_allocator_nointr, IPL_NONE); 246 pool_init(&pf_osfp_pl, sizeof(struct pf_os_fingerprint), 0, 0, 0, 247 "pfosfp", &pool_allocator_nointr, IPL_NONE); 248 #else 249 pool_init(&pf_osfp_entry_pl, sizeof(struct pf_osfp_entry), 0, 0, 0, 250 "pfosfpen", &pool_allocator_nointr); 251 pool_init(&pf_osfp_pl, sizeof(struct pf_os_fingerprint), 0, 0, 0, 252 "pfosfp", &pool_allocator_nointr); 253 #endif 254 SLIST_INIT(&pf_osfp_list); 255 } 256 257 #ifdef _LKM 258 void 259 pf_osfp_destroy(void) 260 { 261 pf_osfp_flush(); 262 263 pool_destroy(&pf_osfp_pl); 264 pool_destroy(&pf_osfp_entry_pl); 265 } 266 #endif 267 268 /* Flush the fingerprint list */ 269 void 270 pf_osfp_flush(void) 271 { 272 struct pf_os_fingerprint *fp; 273 struct pf_osfp_entry *entry; 274 275 while ((fp = SLIST_FIRST(&pf_osfp_list))) { 276 SLIST_REMOVE_HEAD(&pf_osfp_list, fp_next); 277 while ((entry = SLIST_FIRST(&fp->fp_oses))) { 278 SLIST_REMOVE_HEAD(&fp->fp_oses, fp_entry); 279 pool_put(&pf_osfp_entry_pl, entry); 280 } 281 pool_put(&pf_osfp_pl, fp); 282 } 283 } 284 285 286 /* Add a fingerprint */ 287 int 288 pf_osfp_add(struct pf_osfp_ioctl *fpioc) 289 { 290 struct pf_os_fingerprint *fp, fpadd; 291 struct pf_osfp_entry *entry; 292 293 memset(&fpadd, 0, sizeof(fpadd)); 294 fpadd.fp_tcpopts = fpioc->fp_tcpopts; 295 fpadd.fp_wsize = fpioc->fp_wsize; 296 fpadd.fp_psize = fpioc->fp_psize; 297 fpadd.fp_mss = fpioc->fp_mss; 298 fpadd.fp_flags = fpioc->fp_flags; 299 fpadd.fp_optcnt = fpioc->fp_optcnt; 300 fpadd.fp_wscale = fpioc->fp_wscale; 301 fpadd.fp_ttl = fpioc->fp_ttl; 302 303 DPFPRINTF("adding osfp %s %s %s = %s%d:%d:%d:%s%d:0x%llx %d " 304 "(TS=%s,M=%s%d,W=%s%d) %x\n", 305 fpioc->fp_os.fp_class_nm, fpioc->fp_os.fp_version_nm, 306 fpioc->fp_os.fp_subtype_nm, 307 (fpadd.fp_flags & PF_OSFP_WSIZE_MOD) ? "%" : 308 (fpadd.fp_flags & PF_OSFP_WSIZE_MSS) ? "S" : 309 (fpadd.fp_flags & PF_OSFP_WSIZE_MTU) ? "T" : 310 (fpadd.fp_flags & PF_OSFP_WSIZE_DC) ? "*" : "", 311 fpadd.fp_wsize, 312 fpadd.fp_ttl, 313 (fpadd.fp_flags & PF_OSFP_DF) ? 1 : 0, 314 (fpadd.fp_flags & PF_OSFP_PSIZE_MOD) ? "%" : 315 (fpadd.fp_flags & PF_OSFP_PSIZE_DC) ? "*" : "", 316 fpadd.fp_psize, 317 (long long int)fpadd.fp_tcpopts, fpadd.fp_optcnt, 318 (fpadd.fp_flags & PF_OSFP_TS0) ? "0" : "", 319 (fpadd.fp_flags & PF_OSFP_MSS_MOD) ? "%" : 320 (fpadd.fp_flags & PF_OSFP_MSS_DC) ? "*" : "", 321 fpadd.fp_mss, 322 (fpadd.fp_flags & PF_OSFP_WSCALE_MOD) ? "%" : 323 (fpadd.fp_flags & PF_OSFP_WSCALE_DC) ? "*" : "", 324 fpadd.fp_wscale, 325 fpioc->fp_os.fp_os); 326 327 328 if ((fp = pf_osfp_find_exact(&pf_osfp_list, &fpadd))) { 329 SLIST_FOREACH(entry, &fp->fp_oses, fp_entry) { 330 if (PF_OSFP_ENTRY_EQ(entry, &fpioc->fp_os)) 331 return (EEXIST); 332 } 333 if ((entry = pool_get(&pf_osfp_entry_pl, PR_NOWAIT)) == NULL) 334 return (ENOMEM); 335 } else { 336 if ((fp = pool_get(&pf_osfp_pl, PR_NOWAIT)) == NULL) 337 return (ENOMEM); 338 memset(fp, 0, sizeof(*fp)); 339 fp->fp_tcpopts = fpioc->fp_tcpopts; 340 fp->fp_wsize = fpioc->fp_wsize; 341 fp->fp_psize = fpioc->fp_psize; 342 fp->fp_mss = fpioc->fp_mss; 343 fp->fp_flags = fpioc->fp_flags; 344 fp->fp_optcnt = fpioc->fp_optcnt; 345 fp->fp_wscale = fpioc->fp_wscale; 346 fp->fp_ttl = fpioc->fp_ttl; 347 SLIST_INIT(&fp->fp_oses); 348 if ((entry = pool_get(&pf_osfp_entry_pl, PR_NOWAIT)) == NULL) { 349 pool_put(&pf_osfp_pl, fp); 350 return (ENOMEM); 351 } 352 pf_osfp_insert(&pf_osfp_list, fp); 353 } 354 memcpy(entry, &fpioc->fp_os, sizeof(*entry)); 355 356 /* Make sure the strings are NUL terminated */ 357 entry->fp_class_nm[sizeof(entry->fp_class_nm)-1] = '\0'; 358 entry->fp_version_nm[sizeof(entry->fp_version_nm)-1] = '\0'; 359 entry->fp_subtype_nm[sizeof(entry->fp_subtype_nm)-1] = '\0'; 360 361 SLIST_INSERT_HEAD(&fp->fp_oses, entry, fp_entry); 362 363 #ifdef PFDEBUG 364 if ((fp = pf_osfp_validate())) 365 printf("Invalid fingerprint list\n"); 366 #endif /* PFDEBUG */ 367 return (0); 368 } 369 370 371 /* Find a fingerprint in the list */ 372 struct pf_os_fingerprint * 373 pf_osfp_find(struct pf_osfp_list *list, struct pf_os_fingerprint *find, 374 u_int8_t ttldiff) 375 { 376 struct pf_os_fingerprint *f; 377 378 #define MATCH_INT(_MOD, _DC, _field) \ 379 if ((f->fp_flags & _DC) == 0) { \ 380 if ((f->fp_flags & _MOD) == 0) { \ 381 if (f->_field != find->_field) \ 382 continue; \ 383 } else { \ 384 if (f->_field == 0 || find->_field % f->_field) \ 385 continue; \ 386 } \ 387 } 388 389 SLIST_FOREACH(f, list, fp_next) { 390 if (f->fp_tcpopts != find->fp_tcpopts || 391 f->fp_optcnt != find->fp_optcnt || 392 f->fp_ttl < find->fp_ttl || 393 f->fp_ttl - find->fp_ttl > ttldiff || 394 (f->fp_flags & (PF_OSFP_DF|PF_OSFP_TS0)) != 395 (find->fp_flags & (PF_OSFP_DF|PF_OSFP_TS0))) 396 continue; 397 398 MATCH_INT(PF_OSFP_PSIZE_MOD, PF_OSFP_PSIZE_DC, fp_psize) 399 MATCH_INT(PF_OSFP_MSS_MOD, PF_OSFP_MSS_DC, fp_mss) 400 MATCH_INT(PF_OSFP_WSCALE_MOD, PF_OSFP_WSCALE_DC, fp_wscale) 401 if ((f->fp_flags & PF_OSFP_WSIZE_DC) == 0) { 402 if (f->fp_flags & PF_OSFP_WSIZE_MSS) { 403 if (find->fp_mss == 0) 404 continue; 405 406 /* Some "smart" NAT devices and DSL routers will tweak the MSS size and 407 * will set it to whatever is suitable for the link type. 408 */ 409 #define SMART_MSS 1460 410 if ((find->fp_wsize % find->fp_mss || 411 find->fp_wsize / find->fp_mss != 412 f->fp_wsize) && 413 (find->fp_wsize % SMART_MSS || 414 find->fp_wsize / SMART_MSS != 415 f->fp_wsize)) 416 continue; 417 } else if (f->fp_flags & PF_OSFP_WSIZE_MTU) { 418 if (find->fp_mss == 0) 419 continue; 420 421 #define MTUOFF (sizeof(struct ip) + sizeof(struct tcphdr)) 422 #define SMART_MTU (SMART_MSS + MTUOFF) 423 if ((find->fp_wsize % (find->fp_mss + MTUOFF) || 424 find->fp_wsize / (find->fp_mss + MTUOFF) != 425 f->fp_wsize) && 426 (find->fp_wsize % SMART_MTU || 427 find->fp_wsize / SMART_MTU != 428 f->fp_wsize)) 429 continue; 430 } else if (f->fp_flags & PF_OSFP_WSIZE_MOD) { 431 if (f->fp_wsize == 0 || find->fp_wsize % 432 f->fp_wsize) 433 continue; 434 } else { 435 if (f->fp_wsize != find->fp_wsize) 436 continue; 437 } 438 } 439 return (f); 440 } 441 442 return (NULL); 443 } 444 445 /* Find an exact fingerprint in the list */ 446 struct pf_os_fingerprint * 447 pf_osfp_find_exact(struct pf_osfp_list *list, struct pf_os_fingerprint *find) 448 { 449 struct pf_os_fingerprint *f; 450 451 SLIST_FOREACH(f, list, fp_next) { 452 if (f->fp_tcpopts == find->fp_tcpopts && 453 f->fp_wsize == find->fp_wsize && 454 f->fp_psize == find->fp_psize && 455 f->fp_mss == find->fp_mss && 456 f->fp_flags == find->fp_flags && 457 f->fp_optcnt == find->fp_optcnt && 458 f->fp_wscale == find->fp_wscale && 459 f->fp_ttl == find->fp_ttl) 460 return (f); 461 } 462 463 return (NULL); 464 } 465 466 /* Insert a fingerprint into the list */ 467 void 468 pf_osfp_insert(struct pf_osfp_list *list, struct pf_os_fingerprint *ins) 469 { 470 struct pf_os_fingerprint *f, *prev = NULL; 471 472 /* XXX need to go semi tree based. can key on tcp options */ 473 474 SLIST_FOREACH(f, list, fp_next) 475 prev = f; 476 if (prev) 477 SLIST_INSERT_AFTER(prev, ins, fp_next); 478 else 479 SLIST_INSERT_HEAD(list, ins, fp_next); 480 } 481 482 /* Fill a fingerprint by its number (from an ioctl) */ 483 int 484 pf_osfp_get(struct pf_osfp_ioctl *fpioc) 485 { 486 struct pf_os_fingerprint *fp; 487 struct pf_osfp_entry *entry; 488 int num = fpioc->fp_getnum; 489 int i = 0; 490 491 492 memset(fpioc, 0, sizeof(*fpioc)); 493 SLIST_FOREACH(fp, &pf_osfp_list, fp_next) { 494 SLIST_FOREACH(entry, &fp->fp_oses, fp_entry) { 495 if (i++ == num) { 496 fpioc->fp_mss = fp->fp_mss; 497 fpioc->fp_wsize = fp->fp_wsize; 498 fpioc->fp_flags = fp->fp_flags; 499 fpioc->fp_psize = fp->fp_psize; 500 fpioc->fp_ttl = fp->fp_ttl; 501 fpioc->fp_wscale = fp->fp_wscale; 502 fpioc->fp_getnum = num; 503 memcpy(&fpioc->fp_os, entry, 504 sizeof(fpioc->fp_os)); 505 return (0); 506 } 507 } 508 } 509 510 return (EBUSY); 511 } 512 513 514 /* Validate that each signature is reachable */ 515 struct pf_os_fingerprint * 516 pf_osfp_validate(void) 517 { 518 struct pf_os_fingerprint *f, *f2, find; 519 520 SLIST_FOREACH(f, &pf_osfp_list, fp_next) { 521 memcpy(&find, f, sizeof(find)); 522 523 /* We do a few MSS/th_win percolations to make things unique */ 524 if (find.fp_mss == 0) 525 find.fp_mss = 128; 526 if (f->fp_flags & PF_OSFP_WSIZE_MSS) 527 find.fp_wsize *= find.fp_mss, 1; 528 else if (f->fp_flags & PF_OSFP_WSIZE_MTU) 529 find.fp_wsize *= (find.fp_mss + 40); 530 else if (f->fp_flags & PF_OSFP_WSIZE_MOD) 531 find.fp_wsize *= 2; 532 if (f != (f2 = pf_osfp_find(&pf_osfp_list, &find, 0))) { 533 if (f2) 534 printf("Found \"%s %s %s\" instead of " 535 "\"%s %s %s\"\n", 536 SLIST_FIRST(&f2->fp_oses)->fp_class_nm, 537 SLIST_FIRST(&f2->fp_oses)->fp_version_nm, 538 SLIST_FIRST(&f2->fp_oses)->fp_subtype_nm, 539 SLIST_FIRST(&f->fp_oses)->fp_class_nm, 540 SLIST_FIRST(&f->fp_oses)->fp_version_nm, 541 SLIST_FIRST(&f->fp_oses)->fp_subtype_nm); 542 else 543 printf("Couldn't find \"%s %s %s\"\n", 544 SLIST_FIRST(&f->fp_oses)->fp_class_nm, 545 SLIST_FIRST(&f->fp_oses)->fp_version_nm, 546 SLIST_FIRST(&f->fp_oses)->fp_subtype_nm); 547 return (f); 548 } 549 } 550 return (NULL); 551 } 552