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1.1 nbrk 1: /* $OpenBSD: pf_osfp.c,v 1.12 2006/12/13 18:14:10 itojun 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: #endif /* _KERNEL */
25: #include <sys/mbuf.h>
26:
27: #include <netinet/in.h>
28: #include <netinet/in_systm.h>
29: #include <netinet/ip.h>
30: #include <netinet/tcp.h>
31:
32: #include <net/if.h>
33: #include <net/pfvar.h>
34:
35: #include <netinet/ip6.h>
36: #ifdef _KERNEL
37: #include <netinet6/in6_var.h>
38: #endif
39:
40:
41: #ifdef _KERNEL
42: # define DPFPRINTF(format, x...) \
43: if (pf_status.debug >= PF_DEBUG_NOISY) \
44: printf(format , ##x)
45: typedef struct pool pool_t;
46:
47: #else
48: /* Userland equivalents so we can lend code to tcpdump et al. */
49:
50: # include <arpa/inet.h>
51: # include <errno.h>
52: # include <stdio.h>
53: # include <stdlib.h>
54: # include <string.h>
55: # include <netdb.h>
56: # define pool_t int
57: # define pool_get(pool, flags) malloc(*(pool))
58: # define pool_put(pool, item) free(item)
59: # define pool_init(pool, size, a, ao, f, m, p) (*(pool)) = (size)
60:
61: # ifdef PFDEBUG
62: # include <sys/stdarg.h>
63: # define DPFPRINTF(format, x...) fprintf(stderr, format , ##x)
64: # else
65: # define DPFPRINTF(format, x...) ((void)0)
66: # endif /* PFDEBUG */
67: #endif /* _KERNEL */
68:
69:
70: SLIST_HEAD(pf_osfp_list, pf_os_fingerprint) pf_osfp_list;
71: pool_t pf_osfp_entry_pl;
72: pool_t pf_osfp_pl;
73:
74: struct pf_os_fingerprint *pf_osfp_find(struct pf_osfp_list *,
75: struct pf_os_fingerprint *, u_int8_t);
76: struct pf_os_fingerprint *pf_osfp_find_exact(struct pf_osfp_list *,
77: struct pf_os_fingerprint *);
78: void pf_osfp_insert(struct pf_osfp_list *,
79: struct pf_os_fingerprint *);
80:
81:
82: #ifdef _KERNEL
83: /*
84: * Passively fingerprint the OS of the host (IPv4 TCP SYN packets only)
85: * Returns the list of possible OSes.
86: */
87: struct pf_osfp_enlist *
88: pf_osfp_fingerprint(struct pf_pdesc *pd, struct mbuf *m, int off,
89: const struct tcphdr *tcp)
90: {
91: struct ip *ip;
92: struct ip6_hdr *ip6;
93: char hdr[60];
94:
95: if ((pd->af != PF_INET && pd->af != PF_INET6) ||
96: pd->proto != IPPROTO_TCP || (tcp->th_off << 2) < sizeof(*tcp))
97: return (NULL);
98:
99: if (pd->af == PF_INET) {
100: ip = mtod(m, struct ip *);
101: ip6 = (struct ip6_hdr *)NULL;
102: } else {
103: ip = (struct ip *)NULL;
104: ip6 = mtod(m, struct ip6_hdr *);
105: }
106: if (!pf_pull_hdr(m, off, hdr, tcp->th_off << 2, NULL, NULL,
107: pd->af)) 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, const struct tcphdr *tcp)
115: {
116: struct pf_os_fingerprint fp, *fpresult;
117: int cnt, optlen = 0;
118: const u_int8_t *optp;
119: #ifdef _KERNEL
120: char srcname[128];
121: #else
122: char srcname[NI_MAXHOST];
123: #endif
124:
125: if ((tcp->th_flags & (TH_SYN|TH_ACK)) != TH_SYN)
126: return (NULL);
127: if (ip) {
128: if ((ip->ip_off & htons(IP_OFFMASK)) != 0)
129: return (NULL);
130: }
131:
132: memset(&fp, 0, sizeof(fp));
133:
134: if (ip) {
135: #ifndef _KERNEL
136: struct sockaddr_in sin;
137: #endif
138:
139: fp.fp_psize = ntohs(ip->ip_len);
140: fp.fp_ttl = ip->ip_ttl;
141: if (ip->ip_off & htons(IP_DF))
142: fp.fp_flags |= PF_OSFP_DF;
143: #ifdef _KERNEL
144: strlcpy(srcname, inet_ntoa(ip->ip_src), sizeof(srcname));
145: #else
146: memset(&sin, 0, sizeof(sin));
147: sin.sin_family = AF_INET;
148: sin.sin_len = sizeof(struct sockaddr_in);
149: sin.sin_addr = ip->ip_src;
150: (void)getnameinfo((struct sockaddr *)&sin,
151: sizeof(struct sockaddr_in), srcname, sizeof(srcname),
152: NULL, 0, NI_NUMERICHOST);
153: #endif
154: }
155: #ifdef INET6
156: else if (ip6) {
157: #ifndef _KERNEL
158: struct sockaddr_in6 sin6;
159: #endif
160:
161: /* jumbo payload? */
162: fp.fp_psize = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
163: fp.fp_ttl = ip6->ip6_hlim;
164: fp.fp_flags |= PF_OSFP_DF;
165: fp.fp_flags |= PF_OSFP_INET6;
166: #ifdef _KERNEL
167: strlcpy(srcname, ip6_sprintf((struct in6_addr *)&ip6->ip6_src),
168: sizeof(srcname));
169: #else
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
178: }
179: #endif
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: 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: NTOHS(fp.fp_wscale);
216: fp.fp_tcpopts = (fp.fp_tcpopts <<
217: PF_OSFP_TCPOPT_BITS) |
218: PF_OSFP_TCPOPT_WSCALE;
219: break;
220: case TCPOPT_SACK_PERMITTED:
221: fp.fp_tcpopts = (fp.fp_tcpopts <<
222: PF_OSFP_TCPOPT_BITS) | PF_OSFP_TCPOPT_SACK;
223: break;
224: case TCPOPT_TIMESTAMP:
225: if (optlen >= TCPOLEN_TIMESTAMP) {
226: u_int32_t ts;
227: memcpy(&ts, &optp[2], sizeof(ts));
228: if (ts == 0)
229: fp.fp_flags |= PF_OSFP_TS0;
230:
231: }
232: fp.fp_tcpopts = (fp.fp_tcpopts <<
233: PF_OSFP_TCPOPT_BITS) | PF_OSFP_TCPOPT_TS;
234: break;
235: default:
236: return (NULL);
237: }
238: }
239: optlen = MAX(optlen, 1); /* paranoia */
240: }
241:
242: DPFPRINTF("fingerprinted %s:%d %d:%d:%d:%d:%llx (%d) "
243: "(TS=%s,M=%s%d,W=%s%d)\n",
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("osfp no match against %x\n", 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("osfp matched %s %s %s %x==%x\n",
282: entry->fp_class_nm, entry->fp_version_nm,
283: entry->fp_subtype_nm, os, entry->fp_os);
284: return (1);
285: }
286: }
287: DPFPRINTF("fingerprint 0x%x didn't match\n", os);
288: return (0);
289: }
290:
291: /* Initialize the OS fingerprint system */
292: void
293: pf_osfp_initialize(void)
294: {
295: pool_init(&pf_osfp_entry_pl, sizeof(struct pf_osfp_entry), 0, 0, 0,
296: "pfosfpen", &pool_allocator_nointr);
297: pool_init(&pf_osfp_pl, sizeof(struct pf_os_fingerprint), 0, 0, 0,
298: "pfosfp", &pool_allocator_nointr);
299: SLIST_INIT(&pf_osfp_list);
300: }
301:
302: /* Flush the fingerprint list */
303: void
304: pf_osfp_flush(void)
305: {
306: struct pf_os_fingerprint *fp;
307: struct pf_osfp_entry *entry;
308:
309: while ((fp = SLIST_FIRST(&pf_osfp_list))) {
310: SLIST_REMOVE_HEAD(&pf_osfp_list, fp_next);
311: while ((entry = SLIST_FIRST(&fp->fp_oses))) {
312: SLIST_REMOVE_HEAD(&fp->fp_oses, fp_entry);
313: pool_put(&pf_osfp_entry_pl, entry);
314: }
315: pool_put(&pf_osfp_pl, fp);
316: }
317: }
318:
319:
320: /* Add a fingerprint */
321: int
322: pf_osfp_add(struct pf_osfp_ioctl *fpioc)
323: {
324: struct pf_os_fingerprint *fp, fpadd;
325: struct pf_osfp_entry *entry;
326:
327: memset(&fpadd, 0, sizeof(fpadd));
328: fpadd.fp_tcpopts = fpioc->fp_tcpopts;
329: fpadd.fp_wsize = fpioc->fp_wsize;
330: fpadd.fp_psize = fpioc->fp_psize;
331: fpadd.fp_mss = fpioc->fp_mss;
332: fpadd.fp_flags = fpioc->fp_flags;
333: fpadd.fp_optcnt = fpioc->fp_optcnt;
334: fpadd.fp_wscale = fpioc->fp_wscale;
335: fpadd.fp_ttl = fpioc->fp_ttl;
336:
337: DPFPRINTF("adding osfp %s %s %s = %s%d:%d:%d:%s%d:0x%llx %d "
338: "(TS=%s,M=%s%d,W=%s%d) %x\n",
339: fpioc->fp_os.fp_class_nm, fpioc->fp_os.fp_version_nm,
340: fpioc->fp_os.fp_subtype_nm,
341: (fpadd.fp_flags & PF_OSFP_WSIZE_MOD) ? "%" :
342: (fpadd.fp_flags & PF_OSFP_WSIZE_MSS) ? "S" :
343: (fpadd.fp_flags & PF_OSFP_WSIZE_MTU) ? "T" :
344: (fpadd.fp_flags & PF_OSFP_WSIZE_DC) ? "*" : "",
345: fpadd.fp_wsize,
346: fpadd.fp_ttl,
347: (fpadd.fp_flags & PF_OSFP_DF) ? 1 : 0,
348: (fpadd.fp_flags & PF_OSFP_PSIZE_MOD) ? "%" :
349: (fpadd.fp_flags & PF_OSFP_PSIZE_DC) ? "*" : "",
350: fpadd.fp_psize,
351: (long long int)fpadd.fp_tcpopts, fpadd.fp_optcnt,
352: (fpadd.fp_flags & PF_OSFP_TS0) ? "0" : "",
353: (fpadd.fp_flags & PF_OSFP_MSS_MOD) ? "%" :
354: (fpadd.fp_flags & PF_OSFP_MSS_DC) ? "*" : "",
355: fpadd.fp_mss,
356: (fpadd.fp_flags & PF_OSFP_WSCALE_MOD) ? "%" :
357: (fpadd.fp_flags & PF_OSFP_WSCALE_DC) ? "*" : "",
358: fpadd.fp_wscale,
359: fpioc->fp_os.fp_os);
360:
361:
362: if ((fp = pf_osfp_find_exact(&pf_osfp_list, &fpadd))) {
363: SLIST_FOREACH(entry, &fp->fp_oses, fp_entry) {
364: if (PF_OSFP_ENTRY_EQ(entry, &fpioc->fp_os))
365: return (EEXIST);
366: }
367: if ((entry = pool_get(&pf_osfp_entry_pl, PR_NOWAIT)) == NULL)
368: return (ENOMEM);
369: } else {
370: if ((fp = pool_get(&pf_osfp_pl, PR_NOWAIT)) == NULL)
371: return (ENOMEM);
372: memset(fp, 0, sizeof(*fp));
373: fp->fp_tcpopts = fpioc->fp_tcpopts;
374: fp->fp_wsize = fpioc->fp_wsize;
375: fp->fp_psize = fpioc->fp_psize;
376: fp->fp_mss = fpioc->fp_mss;
377: fp->fp_flags = fpioc->fp_flags;
378: fp->fp_optcnt = fpioc->fp_optcnt;
379: fp->fp_wscale = fpioc->fp_wscale;
380: fp->fp_ttl = fpioc->fp_ttl;
381: SLIST_INIT(&fp->fp_oses);
382: if ((entry = pool_get(&pf_osfp_entry_pl, PR_NOWAIT)) == 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: printf("Invalid fingerprint list\n");
400: #endif /* PFDEBUG */
401: return (0);
402: }
403:
404:
405: /* Find a fingerprint in the list */
406: struct pf_os_fingerprint *
407: pf_osfp_find(struct pf_osfp_list *list, struct pf_os_fingerprint *find,
408: u_int8_t ttldiff)
409: {
410: struct pf_os_fingerprint *f;
411:
412: #define MATCH_INT(_MOD, _DC, _field) \
413: if ((f->fp_flags & _DC) == 0) { \
414: if ((f->fp_flags & _MOD) == 0) { \
415: if (f->_field != find->_field) \
416: continue; \
417: } else { \
418: if (f->_field == 0 || find->_field % f->_field) \
419: continue; \
420: } \
421: }
422:
423: SLIST_FOREACH(f, list, fp_next) {
424: if (f->fp_tcpopts != find->fp_tcpopts ||
425: f->fp_optcnt != find->fp_optcnt ||
426: f->fp_ttl < find->fp_ttl ||
427: f->fp_ttl - find->fp_ttl > ttldiff ||
428: (f->fp_flags & (PF_OSFP_DF|PF_OSFP_TS0)) !=
429: (find->fp_flags & (PF_OSFP_DF|PF_OSFP_TS0)))
430: continue;
431:
432: MATCH_INT(PF_OSFP_PSIZE_MOD, PF_OSFP_PSIZE_DC, fp_psize)
433: MATCH_INT(PF_OSFP_MSS_MOD, PF_OSFP_MSS_DC, fp_mss)
434: MATCH_INT(PF_OSFP_WSCALE_MOD, PF_OSFP_WSCALE_DC, fp_wscale)
435: if ((f->fp_flags & PF_OSFP_WSIZE_DC) == 0) {
436: if (f->fp_flags & PF_OSFP_WSIZE_MSS) {
437: if (find->fp_mss == 0)
438: continue;
439:
440: /* Some "smart" NAT devices and DSL routers will tweak the MSS size and
441: * will set it to whatever is suitable for the link type.
442: */
443: #define SMART_MSS 1460
444: if ((find->fp_wsize % find->fp_mss ||
445: find->fp_wsize / find->fp_mss !=
446: f->fp_wsize) &&
447: (find->fp_wsize % SMART_MSS ||
448: find->fp_wsize / SMART_MSS !=
449: f->fp_wsize))
450: continue;
451: } else if (f->fp_flags & PF_OSFP_WSIZE_MTU) {
452: if (find->fp_mss == 0)
453: continue;
454:
455: #define MTUOFF (sizeof(struct ip) + sizeof(struct tcphdr))
456: #define SMART_MTU (SMART_MSS + MTUOFF)
457: if ((find->fp_wsize % (find->fp_mss + MTUOFF) ||
458: find->fp_wsize / (find->fp_mss + MTUOFF) !=
459: f->fp_wsize) &&
460: (find->fp_wsize % SMART_MTU ||
461: find->fp_wsize / SMART_MTU !=
462: f->fp_wsize))
463: continue;
464: } else if (f->fp_flags & PF_OSFP_WSIZE_MOD) {
465: if (f->fp_wsize == 0 || find->fp_wsize %
466: f->fp_wsize)
467: continue;
468: } else {
469: if (f->fp_wsize != find->fp_wsize)
470: continue;
471: }
472: }
473: return (f);
474: }
475:
476: return (NULL);
477: }
478:
479: /* Find an exact fingerprint in the list */
480: struct pf_os_fingerprint *
481: pf_osfp_find_exact(struct pf_osfp_list *list, struct pf_os_fingerprint *find)
482: {
483: struct pf_os_fingerprint *f;
484:
485: SLIST_FOREACH(f, list, fp_next) {
486: if (f->fp_tcpopts == find->fp_tcpopts &&
487: f->fp_wsize == find->fp_wsize &&
488: f->fp_psize == find->fp_psize &&
489: f->fp_mss == find->fp_mss &&
490: f->fp_flags == find->fp_flags &&
491: f->fp_optcnt == find->fp_optcnt &&
492: f->fp_wscale == find->fp_wscale &&
493: f->fp_ttl == find->fp_ttl)
494: return (f);
495: }
496:
497: return (NULL);
498: }
499:
500: /* Insert a fingerprint into the list */
501: void
502: pf_osfp_insert(struct pf_osfp_list *list, struct pf_os_fingerprint *ins)
503: {
504: struct pf_os_fingerprint *f, *prev = NULL;
505:
506: /* XXX need to go semi tree based. can key on tcp options */
507:
508: SLIST_FOREACH(f, list, fp_next)
509: prev = f;
510: if (prev)
511: SLIST_INSERT_AFTER(prev, ins, fp_next);
512: else
513: SLIST_INSERT_HEAD(list, ins, fp_next);
514: }
515:
516: /* Fill a fingerprint by its number (from an ioctl) */
517: int
518: pf_osfp_get(struct pf_osfp_ioctl *fpioc)
519: {
520: struct pf_os_fingerprint *fp;
521: struct pf_osfp_entry *entry;
522: int num = fpioc->fp_getnum;
523: int i = 0;
524:
525:
526: memset(fpioc, 0, sizeof(*fpioc));
527: SLIST_FOREACH(fp, &pf_osfp_list, fp_next) {
528: SLIST_FOREACH(entry, &fp->fp_oses, fp_entry) {
529: if (i++ == num) {
530: fpioc->fp_mss = fp->fp_mss;
531: fpioc->fp_wsize = fp->fp_wsize;
532: fpioc->fp_flags = fp->fp_flags;
533: fpioc->fp_psize = fp->fp_psize;
534: fpioc->fp_ttl = fp->fp_ttl;
535: fpioc->fp_wscale = fp->fp_wscale;
536: fpioc->fp_getnum = num;
537: memcpy(&fpioc->fp_os, entry,
538: sizeof(fpioc->fp_os));
539: return (0);
540: }
541: }
542: }
543:
544: return (EBUSY);
545: }
546:
547:
548: /* Validate that each signature is reachable */
549: struct pf_os_fingerprint *
550: pf_osfp_validate(void)
551: {
552: struct pf_os_fingerprint *f, *f2, find;
553:
554: SLIST_FOREACH(f, &pf_osfp_list, fp_next) {
555: memcpy(&find, f, sizeof(find));
556:
557: /* We do a few MSS/th_win percolations to make things unique */
558: if (find.fp_mss == 0)
559: find.fp_mss = 128;
560: if (f->fp_flags & PF_OSFP_WSIZE_MSS)
561: find.fp_wsize *= find.fp_mss, 1;
562: else if (f->fp_flags & PF_OSFP_WSIZE_MTU)
563: find.fp_wsize *= (find.fp_mss + 40);
564: else if (f->fp_flags & PF_OSFP_WSIZE_MOD)
565: find.fp_wsize *= 2;
566: if (f != (f2 = pf_osfp_find(&pf_osfp_list, &find, 0))) {
567: if (f2)
568: printf("Found \"%s %s %s\" instead of "
569: "\"%s %s %s\"\n",
570: SLIST_FIRST(&f2->fp_oses)->fp_class_nm,
571: SLIST_FIRST(&f2->fp_oses)->fp_version_nm,
572: SLIST_FIRST(&f2->fp_oses)->fp_subtype_nm,
573: SLIST_FIRST(&f->fp_oses)->fp_class_nm,
574: SLIST_FIRST(&f->fp_oses)->fp_version_nm,
575: SLIST_FIRST(&f->fp_oses)->fp_subtype_nm);
576: else
577: printf("Couldn't find \"%s %s %s\"\n",
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: return (f);
582: }
583: }
584: return (NULL);
585: }