1 /* $OpenBSD: pf_osfp.c,v 1.15 2008/06/14 02:22:13 henning 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 #ifdef _KERNEL
21 #include "opt_inet6.h"
22 #endif
23
24 #include <sys/param.h>
25 #include <sys/socket.h>
26 #ifdef _KERNEL
27 #include <sys/systm.h>
28 #include <sys/malloc.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 #include <netinet/ip6.h>
41 #ifdef _KERNEL
42 #include <netinet6/in6_var.h>
43 #endif
44
45
46 #ifdef _KERNEL
47 # define DPFPRINTF(format, x...) \
48 if (pf_status.debug >= PF_DEBUG_NOISY) \
49 kprintf(format , ##x)
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 # include <netdb.h>
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 static MALLOC_DEFINE(M_PFOSFPENTRYPL, "pfospfen", "pf OS finger printing pool list");
70 static MALLOC_DEFINE(M_PFOSFPPL, "pfosfp", "pf OS finger printing pool list");
71
72 SLIST_HEAD(pf_osfp_list, pf_os_fingerprint) pf_osfp_list;
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 *
pf_osfp_fingerprint(struct pf_pdesc * pd,struct mbuf * m,int off,const struct tcphdr * tcp)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 = NULL;
102 } else {
103 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 *
pf_osfp_fingerprint_hdr(const struct ip * ip,const struct ip6_hdr * ip6,const struct tcphdr * tcp)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 kinet_ntoa(ip->ip_src, 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(&ip6->ip6_src), sizeof(srcname));
168 #else
169 memset(&sin6, 0, sizeof(sin6));
170 sin6.sin6_family = AF_INET6;
171 sin6.sin6_len = sizeof(struct sockaddr_in6);
172 sin6.sin6_addr = ip6->ip6_src;
173 (void)getnameinfo((struct sockaddr *)&sin6,
174 sizeof(struct sockaddr_in6), srcname, sizeof(srcname),
175 NULL, 0, NI_NUMERICHOST);
176 #endif
177 }
178 #endif
179 else
180 return (NULL);
181 fp.fp_wsize = ntohs(tcp->th_win);
182
183
184 cnt = (tcp->th_off << 2) - sizeof(*tcp);
185 optp = (const u_int8_t *)((const char *)tcp + sizeof(*tcp));
186 for (; cnt > 0; cnt -= optlen, optp += optlen) {
187 if (*optp == TCPOPT_EOL)
188 break;
189
190 fp.fp_optcnt++;
191 if (*optp == TCPOPT_NOP) {
192 fp.fp_tcpopts = (fp.fp_tcpopts << PF_OSFP_TCPOPT_BITS) |
193 PF_OSFP_TCPOPT_NOP;
194 optlen = 1;
195 } else {
196 if (cnt < 2)
197 return (NULL);
198 optlen = optp[1];
199 if (optlen > cnt || optlen < 2)
200 return (NULL);
201 switch (*optp) {
202 case TCPOPT_MAXSEG:
203 if (optlen >= TCPOLEN_MAXSEG)
204 memcpy(&fp.fp_mss, &optp[2],
205 sizeof(fp.fp_mss));
206 fp.fp_tcpopts = (fp.fp_tcpopts <<
207 PF_OSFP_TCPOPT_BITS) | PF_OSFP_TCPOPT_MSS;
208 fp.fp_mss = ntohs(fp.fp_mss);
209 break;
210 case TCPOPT_WINDOW:
211 if (optlen >= TCPOLEN_WINDOW)
212 memcpy(&fp.fp_wscale, &optp[2],
213 sizeof(fp.fp_wscale));
214 fp.fp_tcpopts = (fp.fp_tcpopts <<
215 PF_OSFP_TCPOPT_BITS) |
216 PF_OSFP_TCPOPT_WSCALE;
217 break;
218 case TCPOPT_SACK_PERMITTED:
219 fp.fp_tcpopts = (fp.fp_tcpopts <<
220 PF_OSFP_TCPOPT_BITS) | PF_OSFP_TCPOPT_SACK;
221 break;
222 case TCPOPT_TIMESTAMP:
223 if (optlen >= TCPOLEN_TIMESTAMP) {
224 u_int32_t ts;
225 memcpy(&ts, &optp[2], sizeof(ts));
226 if (ts == 0)
227 fp.fp_flags |= PF_OSFP_TS0;
228
229 }
230 fp.fp_tcpopts = (fp.fp_tcpopts <<
231 PF_OSFP_TCPOPT_BITS) | PF_OSFP_TCPOPT_TS;
232 break;
233 default:
234 return (NULL);
235 }
236 }
237 optlen = MAX(optlen, 1); /* paranoia */
238 }
239
240 DPFPRINTF("fingerprinted %s:%d %d:%d:%d:%d:%llx (%d) "
241 "(TS=%s,M=%s%d,W=%s%d)\n",
242 srcname, ntohs(tcp->th_sport),
243 fp.fp_wsize, fp.fp_ttl, (fp.fp_flags & PF_OSFP_DF) != 0,
244 fp.fp_psize, (long long int)fp.fp_tcpopts, fp.fp_optcnt,
245 (fp.fp_flags & PF_OSFP_TS0) ? "0" : "",
246 (fp.fp_flags & PF_OSFP_MSS_MOD) ? "%" :
247 (fp.fp_flags & PF_OSFP_MSS_DC) ? "*" : "",
248 fp.fp_mss,
249 (fp.fp_flags & PF_OSFP_WSCALE_MOD) ? "%" :
250 (fp.fp_flags & PF_OSFP_WSCALE_DC) ? "*" : "",
251 fp.fp_wscale);
252
253 if ((fpresult = pf_osfp_find(&pf_osfp_list, &fp,
254 PF_OSFP_MAXTTL_OFFSET)))
255 return (&fpresult->fp_oses);
256 return (NULL);
257 }
258
259 /* Match a fingerprint ID against a list of OSes */
260 int
pf_osfp_match(struct pf_osfp_enlist * list,pf_osfp_t os)261 pf_osfp_match(struct pf_osfp_enlist *list, pf_osfp_t os)
262 {
263 struct pf_osfp_entry *entry;
264 int os_class, os_version, os_subtype;
265 int en_class, en_version, en_subtype;
266
267 if (os == PF_OSFP_ANY)
268 return (1);
269 if (list == NULL) {
270 DPFPRINTF("osfp no match against %x\n", os);
271 return (os == PF_OSFP_UNKNOWN);
272 }
273 PF_OSFP_UNPACK(os, os_class, os_version, os_subtype);
274 SLIST_FOREACH(entry, list, fp_entry) {
275 PF_OSFP_UNPACK(entry->fp_os, en_class, en_version, en_subtype);
276 if ((os_class == PF_OSFP_ANY || en_class == os_class) &&
277 (os_version == PF_OSFP_ANY || en_version == os_version) &&
278 (os_subtype == PF_OSFP_ANY || en_subtype == os_subtype)) {
279 DPFPRINTF("osfp matched %s %s %s %x==%x\n",
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("fingerprint 0x%x didn't match\n", os);
286 return (0);
287 }
288
289 /* Initialize the OS fingerprint system */
290 void
pf_osfp_initialize(void)291 pf_osfp_initialize(void)
292 {
293 SLIST_INIT(&pf_osfp_list);
294 }
295
296 /* Flush the fingerprint list */
297 void
pf_osfp_flush(void)298 pf_osfp_flush(void)
299 {
300 struct pf_os_fingerprint *fp;
301 struct pf_osfp_entry *entry;
302
303 while ((fp = SLIST_FIRST(&pf_osfp_list))) {
304 SLIST_REMOVE_HEAD(&pf_osfp_list, fp_next);
305 while ((entry = SLIST_FIRST(&fp->fp_oses))) {
306 SLIST_REMOVE_HEAD(&fp->fp_oses, fp_entry);
307 kfree(entry, M_PFOSFPENTRYPL);
308 }
309 kfree(fp, M_PFOSFPPL);
310 }
311 }
312
313
314 /* Add a fingerprint */
315 int
pf_osfp_add(struct pf_osfp_ioctl * fpioc)316 pf_osfp_add(struct pf_osfp_ioctl *fpioc)
317 {
318 struct pf_os_fingerprint *fp, fpadd;
319 struct pf_osfp_entry *entry;
320
321 memset(&fpadd, 0, sizeof(fpadd));
322 fpadd.fp_tcpopts = fpioc->fp_tcpopts;
323 fpadd.fp_wsize = fpioc->fp_wsize;
324 fpadd.fp_psize = fpioc->fp_psize;
325 fpadd.fp_mss = fpioc->fp_mss;
326 fpadd.fp_flags = fpioc->fp_flags;
327 fpadd.fp_optcnt = fpioc->fp_optcnt;
328 fpadd.fp_wscale = fpioc->fp_wscale;
329 fpadd.fp_ttl = fpioc->fp_ttl;
330
331 #if 0 /* XXX RYAN wants to fix logging */
332 DPFPRINTF("adding osfp %s %s %s = %s%d:%d:%d:%s%d:0x%llx %d "
333 "(TS=%s,M=%s%d,W=%s%d) %x\n",
334 fpioc->fp_os.fp_class_nm, fpioc->fp_os.fp_version_nm,
335 fpioc->fp_os.fp_subtype_nm,
336 (fpadd.fp_flags & PF_OSFP_WSIZE_MOD) ? "%" :
337 (fpadd.fp_flags & PF_OSFP_WSIZE_MSS) ? "S" :
338 (fpadd.fp_flags & PF_OSFP_WSIZE_MTU) ? "T" :
339 (fpadd.fp_flags & PF_OSFP_WSIZE_DC) ? "*" : "",
340 fpadd.fp_wsize,
341 fpadd.fp_ttl,
342 (fpadd.fp_flags & PF_OSFP_DF) ? 1 : 0,
343 (fpadd.fp_flags & PF_OSFP_PSIZE_MOD) ? "%" :
344 (fpadd.fp_flags & PF_OSFP_PSIZE_DC) ? "*" : "",
345 fpadd.fp_psize,
346 (long long int)fpadd.fp_tcpopts, fpadd.fp_optcnt,
347 (fpadd.fp_flags & PF_OSFP_TS0) ? "0" : "",
348 (fpadd.fp_flags & PF_OSFP_MSS_MOD) ? "%" :
349 (fpadd.fp_flags & PF_OSFP_MSS_DC) ? "*" : "",
350 fpadd.fp_mss,
351 (fpadd.fp_flags & PF_OSFP_WSCALE_MOD) ? "%" :
352 (fpadd.fp_flags & PF_OSFP_WSCALE_DC) ? "*" : "",
353 fpadd.fp_wscale,
354 fpioc->fp_os.fp_os);
355 #endif
356
357 if ((fp = pf_osfp_find_exact(&pf_osfp_list, &fpadd))) {
358 SLIST_FOREACH(entry, &fp->fp_oses, fp_entry) {
359 if (PF_OSFP_ENTRY_EQ(entry, &fpioc->fp_os))
360 return (EEXIST);
361 }
362 if ((entry = kmalloc(sizeof(struct pf_osfp_entry),
363 M_PFOSFPENTRYPL, M_WAITOK|M_NULLOK)) == NULL)
364 return (ENOMEM);
365 } else {
366 if ((fp = kmalloc(sizeof(struct pf_os_fingerprint),
367 M_PFOSFPPL, M_WAITOK|M_NULLOK)) == NULL)
368 return (ENOMEM);
369 memset(fp, 0, sizeof(*fp));
370 fp->fp_tcpopts = fpioc->fp_tcpopts;
371 fp->fp_wsize = fpioc->fp_wsize;
372 fp->fp_psize = fpioc->fp_psize;
373 fp->fp_mss = fpioc->fp_mss;
374 fp->fp_flags = fpioc->fp_flags;
375 fp->fp_optcnt = fpioc->fp_optcnt;
376 fp->fp_wscale = fpioc->fp_wscale;
377 fp->fp_ttl = fpioc->fp_ttl;
378 SLIST_INIT(&fp->fp_oses);
379 if ((entry = kmalloc(sizeof(struct pf_osfp_entry),
380 M_PFOSFPENTRYPL, M_WAITOK|M_NULLOK)) == NULL) {
381 kfree(fp, M_PFOSFPPL);
382 return (ENOMEM);
383 }
384 pf_osfp_insert(&pf_osfp_list, fp);
385 }
386 memcpy(entry, &fpioc->fp_os, sizeof(*entry));
387
388 /* Make sure the strings are NUL terminated */
389 entry->fp_class_nm[sizeof(entry->fp_class_nm)-1] = '\0';
390 entry->fp_version_nm[sizeof(entry->fp_version_nm)-1] = '\0';
391 entry->fp_subtype_nm[sizeof(entry->fp_subtype_nm)-1] = '\0';
392
393 SLIST_INSERT_HEAD(&fp->fp_oses, entry, fp_entry);
394
395 #ifdef PFDEBUG
396 if ((fp = pf_osfp_validate()))
397 kprintf("Invalid fingerprint list\n");
398 #endif /* PFDEBUG */
399 return (0);
400 }
401
402
403 /* Find a fingerprint in the list */
404 struct pf_os_fingerprint *
pf_osfp_find(struct pf_osfp_list * list,struct pf_os_fingerprint * find,u_int8_t ttldiff)405 pf_osfp_find(struct pf_osfp_list *list, struct pf_os_fingerprint *find,
406 u_int8_t ttldiff)
407 {
408 struct pf_os_fingerprint *f;
409
410 #define MATCH_INT(_MOD, _DC, _field) \
411 if ((f->fp_flags & _DC) == 0) { \
412 if ((f->fp_flags & _MOD) == 0) { \
413 if (f->_field != find->_field) \
414 continue; \
415 } else { \
416 if (f->_field == 0 || find->_field % f->_field) \
417 continue; \
418 } \
419 }
420
421 SLIST_FOREACH(f, list, fp_next) {
422 if (f->fp_tcpopts != find->fp_tcpopts ||
423 f->fp_optcnt != find->fp_optcnt ||
424 f->fp_ttl < find->fp_ttl ||
425 f->fp_ttl - find->fp_ttl > ttldiff ||
426 (f->fp_flags & (PF_OSFP_DF|PF_OSFP_TS0)) !=
427 (find->fp_flags & (PF_OSFP_DF|PF_OSFP_TS0)))
428 continue;
429
430 MATCH_INT(PF_OSFP_PSIZE_MOD, PF_OSFP_PSIZE_DC, fp_psize)
431 MATCH_INT(PF_OSFP_MSS_MOD, PF_OSFP_MSS_DC, fp_mss)
432 MATCH_INT(PF_OSFP_WSCALE_MOD, PF_OSFP_WSCALE_DC, fp_wscale)
433 if ((f->fp_flags & PF_OSFP_WSIZE_DC) == 0) {
434 if (f->fp_flags & PF_OSFP_WSIZE_MSS) {
435 if (find->fp_mss == 0)
436 continue;
437
438 /* Some "smart" NAT devices and DSL routers will tweak the MSS size and
439 * will set it to whatever is suitable for the link type.
440 */
441 #define SMART_MSS 1460
442 if ((find->fp_wsize % find->fp_mss ||
443 find->fp_wsize / find->fp_mss !=
444 f->fp_wsize) &&
445 (find->fp_wsize % SMART_MSS ||
446 find->fp_wsize / SMART_MSS !=
447 f->fp_wsize))
448 continue;
449 } else if (f->fp_flags & PF_OSFP_WSIZE_MTU) {
450 if (find->fp_mss == 0)
451 continue;
452
453 #define MTUOFF (sizeof(struct ip) + sizeof(struct tcphdr))
454 #define SMART_MTU (SMART_MSS + MTUOFF)
455 if ((find->fp_wsize % (find->fp_mss + MTUOFF) ||
456 find->fp_wsize / (find->fp_mss + MTUOFF) !=
457 f->fp_wsize) &&
458 (find->fp_wsize % SMART_MTU ||
459 find->fp_wsize / SMART_MTU !=
460 f->fp_wsize))
461 continue;
462 } else if (f->fp_flags & PF_OSFP_WSIZE_MOD) {
463 if (f->fp_wsize == 0 || find->fp_wsize %
464 f->fp_wsize)
465 continue;
466 } else {
467 if (f->fp_wsize != find->fp_wsize)
468 continue;
469 }
470 }
471 return (f);
472 }
473
474 return (NULL);
475 }
476
477 /* Find an exact fingerprint in the list */
478 struct pf_os_fingerprint *
pf_osfp_find_exact(struct pf_osfp_list * list,struct pf_os_fingerprint * find)479 pf_osfp_find_exact(struct pf_osfp_list *list, struct pf_os_fingerprint *find)
480 {
481 struct pf_os_fingerprint *f;
482
483 SLIST_FOREACH(f, list, fp_next) {
484 if (f->fp_tcpopts == find->fp_tcpopts &&
485 f->fp_wsize == find->fp_wsize &&
486 f->fp_psize == find->fp_psize &&
487 f->fp_mss == find->fp_mss &&
488 f->fp_flags == find->fp_flags &&
489 f->fp_optcnt == find->fp_optcnt &&
490 f->fp_wscale == find->fp_wscale &&
491 f->fp_ttl == find->fp_ttl)
492 return (f);
493 }
494
495 return (NULL);
496 }
497
498 /* Insert a fingerprint into the list */
499 void
pf_osfp_insert(struct pf_osfp_list * list,struct pf_os_fingerprint * ins)500 pf_osfp_insert(struct pf_osfp_list *list, struct pf_os_fingerprint *ins)
501 {
502 struct pf_os_fingerprint *f, *prev = NULL;
503
504 /* XXX need to go semi tree based. can key on tcp options */
505
506 SLIST_FOREACH(f, list, fp_next)
507 prev = f;
508 if (prev)
509 SLIST_INSERT_AFTER(prev, ins, fp_next);
510 else
511 SLIST_INSERT_HEAD(list, ins, fp_next);
512 }
513
514 /* Fill a fingerprint by its number (from an ioctl) */
515 int
pf_osfp_get(struct pf_osfp_ioctl * fpioc)516 pf_osfp_get(struct pf_osfp_ioctl *fpioc)
517 {
518 struct pf_os_fingerprint *fp;
519 struct pf_osfp_entry *entry;
520 int num = fpioc->fp_getnum;
521 int i = 0;
522
523
524 memset(fpioc, 0, sizeof(*fpioc));
525 SLIST_FOREACH(fp, &pf_osfp_list, fp_next) {
526 SLIST_FOREACH(entry, &fp->fp_oses, fp_entry) {
527 if (i++ == num) {
528 fpioc->fp_mss = fp->fp_mss;
529 fpioc->fp_wsize = fp->fp_wsize;
530 fpioc->fp_flags = fp->fp_flags;
531 fpioc->fp_psize = fp->fp_psize;
532 fpioc->fp_ttl = fp->fp_ttl;
533 fpioc->fp_wscale = fp->fp_wscale;
534 fpioc->fp_getnum = num;
535 memcpy(&fpioc->fp_os, entry,
536 sizeof(fpioc->fp_os));
537 return (0);
538 }
539 }
540 }
541
542 return (EBUSY);
543 }
544
545
546 /* Validate that each signature is reachable */
547 struct pf_os_fingerprint *
pf_osfp_validate(void)548 pf_osfp_validate(void)
549 {
550 struct pf_os_fingerprint *f, *f2, find;
551
552 SLIST_FOREACH(f, &pf_osfp_list, fp_next) {
553 memcpy(&find, f, sizeof(find));
554
555 /* We do a few MSS/th_win percolations to make things unique */
556 if (find.fp_mss == 0)
557 find.fp_mss = 128;
558 if (f->fp_flags & PF_OSFP_WSIZE_MSS)
559 find.fp_wsize *= find.fp_mss;
560 else if (f->fp_flags & PF_OSFP_WSIZE_MTU)
561 find.fp_wsize *= (find.fp_mss + 40);
562 else if (f->fp_flags & PF_OSFP_WSIZE_MOD)
563 find.fp_wsize *= 2;
564 if (f != (f2 = pf_osfp_find(&pf_osfp_list, &find, 0))) {
565 if (f2)
566 kprintf("Found \"%s %s %s\" instead of "
567 "\"%s %s %s\"\n",
568 SLIST_FIRST(&f2->fp_oses)->fp_class_nm,
569 SLIST_FIRST(&f2->fp_oses)->fp_version_nm,
570 SLIST_FIRST(&f2->fp_oses)->fp_subtype_nm,
571 SLIST_FIRST(&f->fp_oses)->fp_class_nm,
572 SLIST_FIRST(&f->fp_oses)->fp_version_nm,
573 SLIST_FIRST(&f->fp_oses)->fp_subtype_nm);
574 else
575 kprintf("Couldn't find \"%s %s %s\"\n",
576 SLIST_FIRST(&f->fp_oses)->fp_class_nm,
577 SLIST_FIRST(&f->fp_oses)->fp_version_nm,
578 SLIST_FIRST(&f->fp_oses)->fp_subtype_nm);
579 return (f);
580 }
581 }
582 return (NULL);
583 }
584