pf_osfp.c revision 126261
1126261Smlaier/* $FreeBSD: head/sys/contrib/pf/net/pf_osfp.c 126261 2004-02-26 02:34:12Z mlaier $ */ 2126258Smlaier/* $OpenBSD: pf_osfp.c,v 1.3 2003/08/27 18:23:36 frantzen Exp $ */ 3126258Smlaier 4126258Smlaier/* 5126258Smlaier * Copyright (c) 2003 Mike Frantzen <frantzen@w4g.org> 6126258Smlaier * 7126258Smlaier * Permission to use, copy, modify, and distribute this software for any 8126258Smlaier * purpose with or without fee is hereby granted, provided that the above 9126258Smlaier * copyright notice and this permission notice appear in all copies. 10126258Smlaier * 11126258Smlaier * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 12126258Smlaier * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 13126258Smlaier * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 14126258Smlaier * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 15126258Smlaier * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 16126258Smlaier * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 17126258Smlaier * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 18126258Smlaier * 19126258Smlaier */ 20126258Smlaier 21126258Smlaier#include <sys/param.h> 22126258Smlaier#include <sys/socket.h> 23126258Smlaier#ifdef _KERNEL 24126258Smlaier# include <sys/systm.h> 25126258Smlaier#endif /* _KERNEL */ 26126258Smlaier#include <sys/mbuf.h> 27126258Smlaier 28126258Smlaier#include <netinet/in.h> 29126258Smlaier#include <netinet/in_systm.h> 30126258Smlaier#include <netinet/ip.h> 31126258Smlaier#include <netinet/tcp.h> 32126258Smlaier 33126258Smlaier#include <net/if.h> 34126258Smlaier#include <net/pfvar.h> 35126258Smlaier 36126258Smlaier#ifdef INET6 37126258Smlaier#include <netinet/ip6.h> 38126258Smlaier#endif /* INET6 */ 39126258Smlaier 40126258Smlaier#ifdef _KERNEL 41126258Smlaier# define DPFPRINTF(format, x...) \ 42126258Smlaier if (pf_status.debug >= PF_DEBUG_NOISY) \ 43126258Smlaier printf(format , ##x) 44126261Smlaier#if defined(__FreeBSD__) 45126261Smlaiertypedef uma_zone_t pool_t; 46126261Smlaier#else 47126258Smlaiertypedef struct pool pool_t; 48126261Smlaier#endif 49126258Smlaier 50126258Smlaier#else 51126258Smlaier/* Userland equivalents so we can lend code to tcpdump et al. */ 52126258Smlaier 53126258Smlaier# include <arpa/inet.h> 54126258Smlaier# include <errno.h> 55126258Smlaier# include <stdio.h> 56126258Smlaier# include <stdlib.h> 57126258Smlaier# define pool_t int 58126258Smlaier# define pool_get(pool, flags) malloc(*(pool)) 59126258Smlaier# define pool_put(pool, item) free(item) 60126258Smlaier# define pool_init(pool, size, a, ao, f, m, p) (*(pool)) = (size) 61126258Smlaier 62126261Smlaier# if defined(__FreeBSD__) 63126261Smlaier# define NTOHS(x) (x) = ntohs((u_int16_t)(x)) 64126261Smlaier# endif 65126261Smlaier 66126258Smlaier# ifdef PFDEBUG 67126258Smlaier# include <stdarg.h> 68126258Smlaier# define DPFPRINTF(format, x...) fprintf(stderr, format , ##x) 69126258Smlaier# else 70126258Smlaier# define DPFPRINTF(format, x...) ((void)0) 71126258Smlaier# endif /* PFDEBUG */ 72126258Smlaier#endif /* _KERNEL */ 73126258Smlaier 74126258Smlaier 75126258SmlaierSLIST_HEAD(pf_osfp_list, pf_os_fingerprint) pf_osfp_list; 76126258Smlaierpool_t pf_osfp_entry_pl; 77126258Smlaierpool_t pf_osfp_pl; 78126258Smlaier 79126258Smlaierstruct pf_os_fingerprint *pf_osfp_find(struct pf_osfp_list *, 80126258Smlaier struct pf_os_fingerprint *, u_int8_t); 81126258Smlaierstruct pf_os_fingerprint *pf_osfp_find_exact(struct pf_osfp_list *, 82126258Smlaier struct pf_os_fingerprint *); 83126258Smlaiervoid pf_osfp_insert(struct pf_osfp_list *, 84126258Smlaier struct pf_os_fingerprint *); 85126258Smlaier 86126258Smlaier 87126258Smlaier#ifdef _KERNEL 88126258Smlaier/* 89126258Smlaier * Passively fingerprint the OS of the host (IPv4 TCP SYN packets only) 90126258Smlaier * Returns the list of possible OSes. 91126258Smlaier */ 92126258Smlaierstruct pf_osfp_enlist * 93126258Smlaierpf_osfp_fingerprint(struct pf_pdesc *pd, struct mbuf *m, int off, 94126258Smlaier const struct tcphdr *tcp) 95126258Smlaier{ 96126258Smlaier struct ip *ip; 97126258Smlaier char hdr[60]; 98126258Smlaier 99126258Smlaier /* XXX don't have a fingerprint database for IPv6 :-( */ 100126258Smlaier if (pd->af != PF_INET || pd->proto != IPPROTO_TCP || (tcp->th_off << 2) 101126258Smlaier < sizeof(*tcp)) 102126258Smlaier return (NULL); 103126258Smlaier 104126258Smlaier ip = mtod(m, struct ip *); 105126258Smlaier if (!pf_pull_hdr(m, off, hdr, tcp->th_off << 2, NULL, NULL, pd->af)) 106126258Smlaier return (NULL); 107126258Smlaier 108126258Smlaier return (pf_osfp_fingerprint_hdr(ip, (struct tcphdr *)hdr)); 109126258Smlaier} 110126258Smlaier#endif /* _KERNEL */ 111126258Smlaier 112126258Smlaierstruct pf_osfp_enlist * 113126258Smlaierpf_osfp_fingerprint_hdr(const struct ip *ip, const struct tcphdr *tcp) 114126258Smlaier{ 115126258Smlaier struct pf_os_fingerprint fp, *fpresult; 116126258Smlaier int cnt, optlen = 0; 117126261Smlaier const u_int8_t *optp; 118126258Smlaier 119126258Smlaier if ((tcp->th_flags & (TH_SYN|TH_ACK)) != TH_SYN || (ip->ip_off & 120126258Smlaier htons(IP_OFFMASK))) 121126258Smlaier return (NULL); 122126258Smlaier 123126258Smlaier memset(&fp, 0, sizeof(fp)); 124126258Smlaier 125126258Smlaier fp.fp_psize = ntohs(ip->ip_len); 126126258Smlaier fp.fp_ttl = ip->ip_ttl; 127126258Smlaier if (ip->ip_off & htons(IP_DF)) 128126258Smlaier fp.fp_flags |= PF_OSFP_DF; 129126258Smlaier fp.fp_wsize = ntohs(tcp->th_win); 130126258Smlaier 131126258Smlaier 132126258Smlaier cnt = (tcp->th_off << 2) - sizeof(*tcp); 133126261Smlaier optp = (const u_int8_t *)((const char *)tcp + sizeof(*tcp)); 134126258Smlaier for (; cnt > 0; cnt -= optlen, optp += optlen) { 135126258Smlaier if (*optp == TCPOPT_EOL) 136126258Smlaier break; 137126258Smlaier 138126258Smlaier fp.fp_optcnt++; 139126258Smlaier if (*optp == TCPOPT_NOP) { 140126258Smlaier fp.fp_tcpopts = (fp.fp_tcpopts << PF_OSFP_TCPOPT_BITS) | 141126258Smlaier PF_OSFP_TCPOPT_NOP; 142126258Smlaier optlen = 1; 143126258Smlaier } else { 144126258Smlaier if (cnt < 2) 145126258Smlaier return (NULL); 146126258Smlaier optlen = optp[1]; 147126258Smlaier if (optlen > cnt || optlen < 2) 148126258Smlaier return (NULL); 149126258Smlaier switch (*optp) { 150126258Smlaier case TCPOPT_MAXSEG: 151126258Smlaier if (optlen >= TCPOLEN_MAXSEG) 152126258Smlaier memcpy(&fp.fp_mss, &optp[2], 153126258Smlaier sizeof(fp.fp_mss)); 154126258Smlaier fp.fp_tcpopts = (fp.fp_tcpopts << 155126258Smlaier PF_OSFP_TCPOPT_BITS) | PF_OSFP_TCPOPT_MSS; 156126258Smlaier NTOHS(fp.fp_mss); 157126258Smlaier break; 158126258Smlaier case TCPOPT_WINDOW: 159126258Smlaier if (optlen >= TCPOLEN_WINDOW) 160126258Smlaier memcpy(&fp.fp_wscale, &optp[2], 161126258Smlaier sizeof(fp.fp_wscale)); 162126258Smlaier NTOHS(fp.fp_wscale); 163126258Smlaier fp.fp_tcpopts = (fp.fp_tcpopts << 164126258Smlaier PF_OSFP_TCPOPT_BITS) | 165126258Smlaier PF_OSFP_TCPOPT_WSCALE; 166126258Smlaier break; 167126258Smlaier case TCPOPT_SACK_PERMITTED: 168126258Smlaier fp.fp_tcpopts = (fp.fp_tcpopts << 169126258Smlaier PF_OSFP_TCPOPT_BITS) | PF_OSFP_TCPOPT_SACK; 170126258Smlaier break; 171126258Smlaier case TCPOPT_TIMESTAMP: 172126258Smlaier if (optlen >= TCPOLEN_TIMESTAMP) { 173126258Smlaier u_int32_t ts; 174126258Smlaier memcpy(&ts, &optp[2], sizeof(ts)); 175126258Smlaier if (ts == 0) 176126258Smlaier fp.fp_flags |= PF_OSFP_TS0; 177126258Smlaier 178126258Smlaier } 179126258Smlaier fp.fp_tcpopts = (fp.fp_tcpopts << 180126258Smlaier PF_OSFP_TCPOPT_BITS) | PF_OSFP_TCPOPT_TS; 181126258Smlaier break; 182126258Smlaier default: 183126258Smlaier return (NULL); 184126258Smlaier } 185126258Smlaier } 186126258Smlaier optlen = MAX(optlen, 1); /* paranoia */ 187126258Smlaier } 188126258Smlaier 189126258Smlaier DPFPRINTF("fingerprinted %s:%d %d:%d:%d:%d:%llx (%d) " 190126258Smlaier "(TS=%s,M=%s%d,W=%s%d)\n", 191126258Smlaier inet_ntoa(ip->ip_src), ntohs(tcp->th_sport), 192126258Smlaier fp.fp_wsize, fp.fp_ttl, (fp.fp_flags & PF_OSFP_DF) != 0, 193126258Smlaier fp.fp_psize, (long long int)fp.fp_tcpopts, fp.fp_optcnt, 194126258Smlaier (fp.fp_flags & PF_OSFP_TS0) ? "0" : "", 195126258Smlaier (fp.fp_flags & PF_OSFP_MSS_MOD) ? "%" : 196126258Smlaier (fp.fp_flags & PF_OSFP_MSS_DC) ? "*" : "", 197126258Smlaier fp.fp_mss, 198126258Smlaier (fp.fp_flags & PF_OSFP_WSCALE_MOD) ? "%" : 199126258Smlaier (fp.fp_flags & PF_OSFP_WSCALE_DC) ? "*" : "", 200126258Smlaier fp.fp_wscale); 201126258Smlaier 202126258Smlaier if ((fpresult = pf_osfp_find(&pf_osfp_list, &fp, 203126258Smlaier PF_OSFP_MAXTTL_OFFSET))) 204126258Smlaier return (&fpresult->fp_oses); 205126258Smlaier return (NULL); 206126258Smlaier} 207126258Smlaier 208126258Smlaier/* Match a fingerprint ID against a list of OSes */ 209126258Smlaierint 210126258Smlaierpf_osfp_match(struct pf_osfp_enlist *list, pf_osfp_t os) 211126258Smlaier{ 212126258Smlaier struct pf_osfp_entry *entry; 213126258Smlaier int os_class, os_version, os_subtype; 214126258Smlaier int en_class, en_version, en_subtype; 215126258Smlaier 216126258Smlaier if (os == PF_OSFP_ANY) 217126258Smlaier return (1); 218126258Smlaier if (list == NULL) { 219126258Smlaier DPFPRINTF("osfp no match against %x\n", os); 220126258Smlaier return (os == PF_OSFP_UNKNOWN); 221126258Smlaier } 222126258Smlaier PF_OSFP_UNPACK(os, os_class, os_version, os_subtype); 223126258Smlaier SLIST_FOREACH(entry, list, fp_entry) { 224126258Smlaier PF_OSFP_UNPACK(entry->fp_os, en_class, en_version, en_subtype); 225126258Smlaier if ((os_class == PF_OSFP_ANY || en_class == os_class) && 226126258Smlaier (os_version == PF_OSFP_ANY || en_version == os_version) && 227126258Smlaier (os_subtype == PF_OSFP_ANY || en_subtype == os_subtype)) { 228126258Smlaier DPFPRINTF("osfp matched %s %s %s %x==%x\n", 229126258Smlaier entry->fp_class_nm, entry->fp_version_nm, 230126258Smlaier entry->fp_subtype_nm, os, entry->fp_os); 231126258Smlaier return (1); 232126258Smlaier } 233126258Smlaier } 234126258Smlaier DPFPRINTF("fingerprint 0x%x didn't match\n", os); 235126258Smlaier return (0); 236126258Smlaier} 237126258Smlaier 238126258Smlaier/* Initialize the OS fingerprint system */ 239126261Smlaier#if defined(__FreeBSD__) 240126261Smlaierint 241126261Smlaier#else 242126258Smlaiervoid 243126261Smlaier#endif 244126258Smlaierpf_osfp_initialize(void) 245126258Smlaier{ 246126261Smlaier#if defined(__FreeBSD__) && defined(_KERNEL) 247126261Smlaier int error = ENOMEM; 248126261Smlaier 249126261Smlaier do { 250126261Smlaier pf_osfp_entry_pl = pf_osfp_pl = NULL; 251126261Smlaier UMA_CREATE(pf_osfp_entry_pl, struct pf_osfp_entry, "pfospfen"); 252126261Smlaier UMA_CREATE(pf_osfp_pl, struct pf_os_fingerprint, "pfosfp"); 253126261Smlaier error = 0; 254126261Smlaier } while(0); 255126261Smlaier#else 256126258Smlaier pool_init(&pf_osfp_entry_pl, sizeof(struct pf_osfp_entry), 0, 0, 0, 257126258Smlaier "pfosfpen", NULL); 258126258Smlaier pool_init(&pf_osfp_pl, sizeof(struct pf_os_fingerprint), 0, 0, 0, 259126258Smlaier "pfosfp", NULL); 260126261Smlaier#endif 261126258Smlaier SLIST_INIT(&pf_osfp_list); 262126261Smlaier#if defined(__FreeBSD__) 263126261Smlaier#if defined(_KERNEL) 264126261Smlaier return (error); 265126261Smlaier#else 266126261Smlaier return (0); 267126261Smlaier#endif 268126261Smlaier#endif 269126258Smlaier} 270126258Smlaier 271126261Smlaier#if defined(__FreeBSD__) && (_KERNEL) 272126261Smlaiervoid 273126261Smlaierpf_osfp_cleanup(void) 274126261Smlaier{ 275126261Smlaier UMA_DESTROY(pf_osfp_entry_pl); 276126261Smlaier UMA_DESTROY(pf_osfp_pl); 277126261Smlaier} 278126261Smlaier#endif 279126261Smlaier 280126258Smlaier/* Flush the fingerprint list */ 281126258Smlaiervoid 282126258Smlaierpf_osfp_flush(void) 283126258Smlaier{ 284126258Smlaier struct pf_os_fingerprint *fp; 285126258Smlaier struct pf_osfp_entry *entry; 286126258Smlaier 287126258Smlaier while ((fp = SLIST_FIRST(&pf_osfp_list))) { 288126258Smlaier SLIST_REMOVE_HEAD(&pf_osfp_list, fp_next); 289126258Smlaier while ((entry = SLIST_FIRST(&fp->fp_oses))) { 290126258Smlaier SLIST_REMOVE_HEAD(&fp->fp_oses, fp_entry); 291126258Smlaier pool_put(&pf_osfp_entry_pl, entry); 292126258Smlaier } 293126258Smlaier pool_put(&pf_osfp_pl, fp); 294126258Smlaier } 295126258Smlaier} 296126258Smlaier 297126258Smlaier 298126258Smlaier/* Add a fingerprint */ 299126258Smlaierint 300126258Smlaierpf_osfp_add(struct pf_osfp_ioctl *fpioc) 301126258Smlaier{ 302126258Smlaier struct pf_os_fingerprint *fp, fpadd; 303126258Smlaier struct pf_osfp_entry *entry; 304126258Smlaier 305126258Smlaier memset(&fpadd, 0, sizeof(fpadd)); 306126258Smlaier fpadd.fp_tcpopts = fpioc->fp_tcpopts; 307126258Smlaier fpadd.fp_wsize = fpioc->fp_wsize; 308126258Smlaier fpadd.fp_psize = fpioc->fp_psize; 309126258Smlaier fpadd.fp_mss = fpioc->fp_mss; 310126258Smlaier fpadd.fp_flags = fpioc->fp_flags; 311126258Smlaier fpadd.fp_optcnt = fpioc->fp_optcnt; 312126258Smlaier fpadd.fp_wscale = fpioc->fp_wscale; 313126258Smlaier fpadd.fp_ttl = fpioc->fp_ttl; 314126258Smlaier 315126258Smlaier DPFPRINTF("adding osfp %s %s %s = %s%d:%d:%d:%s%d:0x%llx %d " 316126258Smlaier "(TS=%s,M=%s%d,W=%s%d) %x\n", 317126258Smlaier fpioc->fp_os.fp_class_nm, fpioc->fp_os.fp_version_nm, 318126258Smlaier fpioc->fp_os.fp_subtype_nm, 319126258Smlaier (fpadd.fp_flags & PF_OSFP_WSIZE_MOD) ? "%" : 320126258Smlaier (fpadd.fp_flags & PF_OSFP_WSIZE_MSS) ? "S" : 321126258Smlaier (fpadd.fp_flags & PF_OSFP_WSIZE_MTU) ? "T" : 322126258Smlaier (fpadd.fp_flags & PF_OSFP_WSIZE_DC) ? "*" : "", 323126258Smlaier fpadd.fp_wsize, 324126258Smlaier fpadd.fp_ttl, 325126258Smlaier (fpadd.fp_flags & PF_OSFP_DF) ? 1 : 0, 326126258Smlaier (fpadd.fp_flags & PF_OSFP_PSIZE_MOD) ? "%" : 327126258Smlaier (fpadd.fp_flags & PF_OSFP_PSIZE_DC) ? "*" : "", 328126258Smlaier fpadd.fp_psize, 329126258Smlaier (long long int)fpadd.fp_tcpopts, fpadd.fp_optcnt, 330126258Smlaier (fpadd.fp_flags & PF_OSFP_TS0) ? "0" : "", 331126258Smlaier (fpadd.fp_flags & PF_OSFP_MSS_MOD) ? "%" : 332126258Smlaier (fpadd.fp_flags & PF_OSFP_MSS_DC) ? "*" : "", 333126258Smlaier fpadd.fp_mss, 334126258Smlaier (fpadd.fp_flags & PF_OSFP_WSCALE_MOD) ? "%" : 335126258Smlaier (fpadd.fp_flags & PF_OSFP_WSCALE_DC) ? "*" : "", 336126258Smlaier fpadd.fp_wscale, 337126258Smlaier fpioc->fp_os.fp_os); 338126258Smlaier 339126258Smlaier 340126258Smlaier if ((fp = pf_osfp_find_exact(&pf_osfp_list, &fpadd))) { 341126258Smlaier SLIST_FOREACH(entry, &fp->fp_oses, fp_entry) { 342126258Smlaier if (PF_OSFP_ENTRY_EQ(entry, &fpioc->fp_os)) 343126258Smlaier return (EEXIST); 344126258Smlaier } 345126258Smlaier if ((entry = pool_get(&pf_osfp_entry_pl, PR_NOWAIT)) == NULL) 346126258Smlaier return (ENOMEM); 347126258Smlaier } else { 348126258Smlaier if ((fp = pool_get(&pf_osfp_pl, PR_NOWAIT)) == NULL) 349126258Smlaier return (ENOMEM); 350126258Smlaier memset(fp, 0, sizeof(*fp)); 351126258Smlaier fp->fp_tcpopts = fpioc->fp_tcpopts; 352126258Smlaier fp->fp_wsize = fpioc->fp_wsize; 353126258Smlaier fp->fp_psize = fpioc->fp_psize; 354126258Smlaier fp->fp_mss = fpioc->fp_mss; 355126258Smlaier fp->fp_flags = fpioc->fp_flags; 356126258Smlaier fp->fp_optcnt = fpioc->fp_optcnt; 357126258Smlaier fp->fp_wscale = fpioc->fp_wscale; 358126258Smlaier fp->fp_ttl = fpioc->fp_ttl; 359126258Smlaier SLIST_INIT(&fp->fp_oses); 360126258Smlaier if ((entry = pool_get(&pf_osfp_entry_pl, PR_NOWAIT)) == NULL) { 361126258Smlaier pool_put(&pf_osfp_pl, fp); 362126258Smlaier return (ENOMEM); 363126258Smlaier } 364126258Smlaier pf_osfp_insert(&pf_osfp_list, fp); 365126258Smlaier } 366126258Smlaier memcpy(entry, &fpioc->fp_os, sizeof(*entry)); 367126258Smlaier 368126258Smlaier /* Make sure the strings are NUL terminated */ 369126258Smlaier entry->fp_class_nm[sizeof(entry->fp_class_nm)-1] = '\0'; 370126258Smlaier entry->fp_version_nm[sizeof(entry->fp_version_nm)-1] = '\0'; 371126258Smlaier entry->fp_subtype_nm[sizeof(entry->fp_subtype_nm)-1] = '\0'; 372126258Smlaier 373126258Smlaier SLIST_INSERT_HEAD(&fp->fp_oses, entry, fp_entry); 374126258Smlaier 375126258Smlaier#ifdef PFDEBUG 376126258Smlaier if ((fp = pf_osfp_validate())) 377126258Smlaier printf("Invalid fingerprint list\n"); 378126258Smlaier#endif /* PFDEBUG */ 379126258Smlaier return (0); 380126258Smlaier} 381126258Smlaier 382126258Smlaier 383126258Smlaier/* Find a fingerprint in the list */ 384126258Smlaierstruct pf_os_fingerprint * 385126258Smlaierpf_osfp_find(struct pf_osfp_list *list, struct pf_os_fingerprint *find, 386126258Smlaier u_int8_t ttldiff) 387126258Smlaier{ 388126258Smlaier struct pf_os_fingerprint *f; 389126258Smlaier 390126258Smlaier#define MATCH_INT(_MOD, _DC, _field) \ 391126258Smlaier if ((f->fp_flags & _DC) == 0) { \ 392126258Smlaier if ((f->fp_flags & _MOD) == 0) { \ 393126258Smlaier if (f->_field != find->_field) \ 394126258Smlaier continue; \ 395126258Smlaier } else { \ 396126258Smlaier if (f->_field == 0 || find->_field % f->_field) \ 397126258Smlaier continue; \ 398126258Smlaier } \ 399126258Smlaier } 400126258Smlaier 401126258Smlaier SLIST_FOREACH(f, list, fp_next) { 402126258Smlaier if (f->fp_tcpopts != find->fp_tcpopts || 403126258Smlaier f->fp_optcnt != find->fp_optcnt || 404126258Smlaier f->fp_ttl < find->fp_ttl || 405126258Smlaier f->fp_ttl - find->fp_ttl > ttldiff || 406126258Smlaier (f->fp_flags & (PF_OSFP_DF|PF_OSFP_TS0)) != 407126258Smlaier (find->fp_flags & (PF_OSFP_DF|PF_OSFP_TS0))) 408126258Smlaier continue; 409126258Smlaier 410126258Smlaier MATCH_INT(PF_OSFP_PSIZE_MOD, PF_OSFP_PSIZE_DC, fp_psize) 411126258Smlaier MATCH_INT(PF_OSFP_MSS_MOD, PF_OSFP_MSS_DC, fp_mss) 412126258Smlaier MATCH_INT(PF_OSFP_WSCALE_MOD, PF_OSFP_WSCALE_DC, fp_wscale) 413126258Smlaier if ((f->fp_flags & PF_OSFP_WSIZE_DC) == 0) { 414126258Smlaier if (f->fp_flags & PF_OSFP_WSIZE_MSS) { 415126258Smlaier if (find->fp_mss == 0) 416126258Smlaier continue; 417126258Smlaier 418126258Smlaier/* Some "smart" NAT devices and DSL routers will tweak the MSS size and 419126258Smlaier * will set it to whatever is suitable for the link type. 420126258Smlaier */ 421126258Smlaier#define SMART_MSS 1460 422126258Smlaier if ((find->fp_wsize % find->fp_mss || 423126258Smlaier find->fp_wsize / find->fp_mss != 424126258Smlaier f->fp_wsize) && 425126258Smlaier (find->fp_wsize % SMART_MSS || 426126258Smlaier find->fp_wsize / SMART_MSS != 427126258Smlaier f->fp_wsize)) 428126258Smlaier continue; 429126258Smlaier } else if (f->fp_flags & PF_OSFP_WSIZE_MTU) { 430126258Smlaier if (find->fp_mss == 0) 431126258Smlaier continue; 432126258Smlaier 433126258Smlaier#define MTUOFF (sizeof(struct ip) + sizeof(struct tcphdr)) 434126258Smlaier#define SMART_MTU (SMART_MSS + MTUOFF) 435126258Smlaier if ((find->fp_wsize % (find->fp_mss + MTUOFF) || 436126258Smlaier find->fp_wsize / (find->fp_mss + MTUOFF) != 437126258Smlaier f->fp_wsize) && 438126258Smlaier (find->fp_wsize % SMART_MTU || 439126258Smlaier find->fp_wsize / SMART_MTU != 440126258Smlaier f->fp_wsize)) 441126258Smlaier continue; 442126258Smlaier } else if (f->fp_flags & PF_OSFP_WSIZE_MOD) { 443126258Smlaier if (f->fp_wsize == 0 || find->fp_wsize % 444126258Smlaier f->fp_wsize) 445126258Smlaier continue; 446126258Smlaier } else { 447126258Smlaier if (f->fp_wsize != find->fp_wsize) 448126258Smlaier continue; 449126258Smlaier } 450126258Smlaier } 451126258Smlaier return (f); 452126258Smlaier } 453126258Smlaier 454126258Smlaier return (NULL); 455126258Smlaier} 456126258Smlaier 457126258Smlaier/* Find an exact fingerprint in the list */ 458126258Smlaierstruct pf_os_fingerprint * 459126258Smlaierpf_osfp_find_exact(struct pf_osfp_list *list, struct pf_os_fingerprint *find) 460126258Smlaier{ 461126258Smlaier struct pf_os_fingerprint *f; 462126258Smlaier 463126258Smlaier SLIST_FOREACH(f, list, fp_next) { 464126258Smlaier if (f->fp_tcpopts == find->fp_tcpopts && 465126258Smlaier f->fp_wsize == find->fp_wsize && 466126258Smlaier f->fp_psize == find->fp_psize && 467126258Smlaier f->fp_mss == find->fp_mss && 468126258Smlaier f->fp_flags == find->fp_flags && 469126258Smlaier f->fp_optcnt == find->fp_optcnt && 470126258Smlaier f->fp_wscale == find->fp_wscale && 471126258Smlaier f->fp_ttl == find->fp_ttl) 472126258Smlaier return (f); 473126258Smlaier } 474126258Smlaier 475126258Smlaier return (NULL); 476126258Smlaier} 477126258Smlaier 478126258Smlaier/* Insert a fingerprint into the list */ 479126258Smlaiervoid 480126258Smlaierpf_osfp_insert(struct pf_osfp_list *list, struct pf_os_fingerprint *ins) 481126258Smlaier{ 482126258Smlaier struct pf_os_fingerprint *f, *prev = NULL; 483126258Smlaier 484126258Smlaier /* XXX need to go semi tree based. can key on tcp options */ 485126258Smlaier 486126258Smlaier SLIST_FOREACH(f, list, fp_next) 487126258Smlaier prev = f; 488126258Smlaier if (prev) 489126258Smlaier SLIST_INSERT_AFTER(prev, ins, fp_next); 490126258Smlaier else 491126258Smlaier SLIST_INSERT_HEAD(list, ins, fp_next); 492126258Smlaier} 493126258Smlaier 494126258Smlaier/* Fill a fingerprint by its number (from an ioctl) */ 495126258Smlaierint 496126258Smlaierpf_osfp_get(struct pf_osfp_ioctl *fpioc) 497126258Smlaier{ 498126258Smlaier struct pf_os_fingerprint *fp; 499126258Smlaier struct pf_osfp_entry *entry; 500126258Smlaier int num = fpioc->fp_getnum; 501126258Smlaier int i = 0; 502126258Smlaier 503126258Smlaier 504126258Smlaier memset(fpioc, 0, sizeof(*fpioc)); 505126258Smlaier SLIST_FOREACH(fp, &pf_osfp_list, fp_next) { 506126258Smlaier SLIST_FOREACH(entry, &fp->fp_oses, fp_entry) { 507126258Smlaier if (i++ == num) { 508126258Smlaier fpioc->fp_mss = fp->fp_mss; 509126258Smlaier fpioc->fp_wsize = fp->fp_wsize; 510126258Smlaier fpioc->fp_flags = fp->fp_flags; 511126258Smlaier fpioc->fp_psize = fp->fp_psize; 512126258Smlaier fpioc->fp_ttl = fp->fp_ttl; 513126258Smlaier fpioc->fp_wscale = fp->fp_wscale; 514126258Smlaier fpioc->fp_getnum = num; 515126258Smlaier memcpy(&fpioc->fp_os, entry, 516126258Smlaier sizeof(fpioc->fp_os)); 517126258Smlaier return (0); 518126258Smlaier } 519126258Smlaier } 520126258Smlaier } 521126258Smlaier 522126258Smlaier return (EBUSY); 523126258Smlaier} 524126258Smlaier 525126258Smlaier 526126258Smlaier/* Validate that each signature is reachable */ 527126258Smlaierstruct pf_os_fingerprint * 528126258Smlaierpf_osfp_validate(void) 529126258Smlaier{ 530126258Smlaier struct pf_os_fingerprint *f, *f2, find; 531126258Smlaier 532126258Smlaier SLIST_FOREACH(f, &pf_osfp_list, fp_next) { 533126258Smlaier memcpy(&find, f, sizeof(find)); 534126258Smlaier 535126258Smlaier /* We do a few MSS/th_win percolations to make things unique */ 536126258Smlaier if (find.fp_mss == 0) 537126258Smlaier find.fp_mss = 128; 538126258Smlaier if (f->fp_flags & PF_OSFP_WSIZE_MSS) 539126258Smlaier find.fp_wsize *= find.fp_mss, 1; 540126258Smlaier else if (f->fp_flags & PF_OSFP_WSIZE_MTU) 541126258Smlaier find.fp_wsize *= (find.fp_mss + 40); 542126258Smlaier else if (f->fp_flags & PF_OSFP_WSIZE_MOD) 543126258Smlaier find.fp_wsize *= 2; 544126258Smlaier if (f != (f2 = pf_osfp_find(&pf_osfp_list, &find, 0))) { 545126258Smlaier if (f2) 546126258Smlaier printf("Found \"%s %s %s\" instead of " 547126258Smlaier "\"%s %s %s\"\n", 548126258Smlaier SLIST_FIRST(&f2->fp_oses)->fp_class_nm, 549126258Smlaier SLIST_FIRST(&f2->fp_oses)->fp_version_nm, 550126258Smlaier SLIST_FIRST(&f2->fp_oses)->fp_subtype_nm, 551126258Smlaier SLIST_FIRST(&f->fp_oses)->fp_class_nm, 552126258Smlaier SLIST_FIRST(&f->fp_oses)->fp_version_nm, 553126258Smlaier SLIST_FIRST(&f->fp_oses)->fp_subtype_nm); 554126258Smlaier else 555126258Smlaier printf("Couldn't find \"%s %s %s\"\n", 556126258Smlaier SLIST_FIRST(&f->fp_oses)->fp_class_nm, 557126258Smlaier SLIST_FIRST(&f->fp_oses)->fp_version_nm, 558126258Smlaier SLIST_FIRST(&f->fp_oses)->fp_subtype_nm); 559126258Smlaier return (f); 560126258Smlaier } 561126258Smlaier } 562126258Smlaier return (NULL); 563126258Smlaier} 564