1 /* 2 * Copyright (C) 1995-2003 by Darren Reed. 3 * 4 * See the IPFILTER.LICENCE file for details on licencing. 5 * 6 * Copyright 2007 Sun Microsystems, Inc. All rights reserved. 7 * Use is subject to license terms. 8 */ 9 10 #pragma ident "%Z%%M% %I% %E% SMI" 11 12 #if defined(KERNEL) || defined(_KERNEL) 13 # undef KERNEL 14 # undef _KERNEL 15 # define KERNEL 1 16 # define _KERNEL 1 17 #endif 18 #include <sys/errno.h> 19 #include <sys/types.h> 20 #include <sys/param.h> 21 #include <sys/file.h> 22 #if defined(__NetBSD__) && (NetBSD >= 199905) && !defined(IPFILTER_LKM) && \ 23 defined(_KERNEL) 24 # include "opt_ipfilter_log.h" 25 #endif 26 #if defined(_KERNEL) && defined(__FreeBSD_version) && \ 27 (__FreeBSD_version >= 400000) && !defined(KLD_MODULE) 28 #include "opt_inet6.h" 29 #endif 30 #if !defined(_KERNEL) && !defined(__KERNEL__) 31 # include <stdio.h> 32 # include <stdlib.h> 33 # include <string.h> 34 # define _KERNEL 35 # ifdef __OpenBSD__ 36 struct file; 37 # endif 38 # include <sys/uio.h> 39 # undef _KERNEL 40 #endif 41 #if defined(_KERNEL) && (__FreeBSD_version >= 220000) 42 # include <sys/filio.h> 43 # include <sys/fcntl.h> 44 # if (__FreeBSD_version >= 300000) && !defined(IPFILTER_LKM) 45 # include "opt_ipfilter.h" 46 # endif 47 #else 48 # include <sys/ioctl.h> 49 #endif 50 #include <sys/time.h> 51 #if !defined(linux) 52 # include <sys/protosw.h> 53 #endif 54 #include <sys/socket.h> 55 #if defined(_KERNEL) 56 # include <sys/systm.h> 57 # if !defined(__SVR4) && !defined(__svr4__) 58 # include <sys/mbuf.h> 59 # endif 60 #endif 61 #if defined(__SVR4) || defined(__svr4__) 62 # include <sys/filio.h> 63 # include <sys/byteorder.h> 64 # ifdef _KERNEL 65 # include <sys/dditypes.h> 66 # endif 67 # include <sys/stream.h> 68 # include <sys/kmem.h> 69 #endif 70 71 #include <net/if.h> 72 #ifdef sun 73 # include <net/af.h> 74 #endif 75 #include <net/route.h> 76 #include <netinet/in.h> 77 #include <netinet/in_systm.h> 78 #include <netinet/ip.h> 79 #include <netinet/tcp.h> 80 #if !defined(linux) 81 # include <netinet/ip_var.h> 82 #endif 83 #if !defined(__hpux) && !defined(linux) 84 # include <netinet/tcp_fsm.h> 85 #endif 86 #include <netinet/udp.h> 87 #include <netinet/ip_icmp.h> 88 #include "netinet/ip_compat.h" 89 #include <netinet/tcpip.h> 90 #include "netinet/ip_fil.h" 91 #include "netinet/ip_nat.h" 92 #include "netinet/ip_frag.h" 93 #include "netinet/ip_state.h" 94 #include "netinet/ip_proxy.h" 95 #include "netinet/ipf_stack.h" 96 #ifdef IPFILTER_SYNC 97 #include "netinet/ip_sync.h" 98 #endif 99 #ifdef IPFILTER_SCAN 100 #include "netinet/ip_scan.h" 101 #endif 102 #ifdef USE_INET6 103 #include <netinet/icmp6.h> 104 #endif 105 #if (__FreeBSD_version >= 300000) 106 # include <sys/malloc.h> 107 # if defined(_KERNEL) && !defined(IPFILTER_LKM) 108 # include <sys/libkern.h> 109 # include <sys/systm.h> 110 # endif 111 #endif 112 /* END OF INCLUDES */ 113 114 115 #if !defined(lint) 116 static const char sccsid[] = "@(#)ip_state.c 1.8 6/5/96 (C) 1993-2000 Darren Reed"; 117 static const char rcsid[] = "@(#)$Id: ip_state.c,v 2.186.2.36 2005/08/11 19:58:03 darrenr Exp $"; 118 #endif 119 120 #ifdef USE_INET6 121 static ipstate_t *fr_checkicmp6matchingstate __P((fr_info_t *)); 122 #endif 123 static ipstate_t *fr_matchsrcdst __P((fr_info_t *, ipstate_t *, i6addr_t *, 124 i6addr_t *, tcphdr_t *, u_32_t)); 125 static ipstate_t *fr_checkicmpmatchingstate __P((fr_info_t *)); 126 static int fr_state_flush __P((int, int, ipf_stack_t *)); 127 static ips_stat_t *fr_statetstats __P((ipf_stack_t *)); 128 static void fr_delstate __P((ipstate_t *, int, ipf_stack_t *)); 129 static int fr_state_remove __P((caddr_t, ipf_stack_t *)); 130 static void fr_ipsmove __P((ipstate_t *, u_int, ipf_stack_t *)); 131 static int fr_tcpstate __P((fr_info_t *, tcphdr_t *, ipstate_t *)); 132 static int fr_tcpoptions __P((fr_info_t *, tcphdr_t *, tcpdata_t *)); 133 static ipstate_t *fr_stclone __P((fr_info_t *, tcphdr_t *, ipstate_t *)); 134 static void fr_fixinisn __P((fr_info_t *, ipstate_t *)); 135 static void fr_fixoutisn __P((fr_info_t *, ipstate_t *)); 136 static void fr_checknewisn __P((fr_info_t *, ipstate_t *)); 137 static int fr_stateiter __P((ipftoken_t *, ipfgeniter_t *, ipf_stack_t *)); 138 139 int fr_stputent __P((caddr_t, ipf_stack_t *)); 140 int fr_stgetent __P((caddr_t, ipf_stack_t *)); 141 142 #define ONE_DAY IPF_TTLVAL(1 * 86400) /* 1 day */ 143 #define FIVE_DAYS (5 * ONE_DAY) 144 #define DOUBLE_HASH(x, ifs) \ 145 (((x) + ifs->ifs_ips_seed[(x) % ifs->ifs_fr_statesize]) % ifs->ifs_fr_statesize) 146 147 148 149 /* ------------------------------------------------------------------------ */ 150 /* Function: fr_stateinit */ 151 /* Returns: int - 0 == success, -1 == failure */ 152 /* Parameters: Nil */ 153 /* */ 154 /* Initialise all the global variables used within the state code. */ 155 /* This action also includes initiailising locks. */ 156 /* ------------------------------------------------------------------------ */ 157 int fr_stateinit(ifs) 158 ipf_stack_t *ifs; 159 { 160 int i; 161 162 ifs->ifs_fr_tcpidletimeout = FIVE_DAYS; 163 ifs->ifs_fr_tcpclosewait = IPF_TTLVAL(TCP_MSL); 164 ifs->ifs_fr_tcplastack = IPF_TTLVAL(TCP_MSL); 165 ifs->ifs_fr_tcptimeout = IPF_TTLVAL(TCP_MSL); 166 ifs->ifs_fr_tcpclosed = IPF_TTLVAL(60); 167 ifs->ifs_fr_tcphalfclosed = IPF_TTLVAL(2 * 3600); /* 2 hours */ 168 ifs->ifs_fr_udptimeout = IPF_TTLVAL(120); 169 ifs->ifs_fr_udpacktimeout = IPF_TTLVAL(12); 170 ifs->ifs_fr_icmptimeout = IPF_TTLVAL(60); 171 ifs->ifs_fr_icmpacktimeout = IPF_TTLVAL(6); 172 ifs->ifs_fr_iptimeout = IPF_TTLVAL(60); 173 ifs->ifs_fr_statemax = IPSTATE_MAX; 174 ifs->ifs_fr_statesize = IPSTATE_SIZE; 175 ifs->ifs_fr_state_maxbucket_reset = 1; 176 #ifdef IPFILTER_LOG 177 ifs->ifs_ipstate_logging = 1; 178 #else 179 ifs->ifs_ipstate_logging = 0; 180 #endif 181 182 KMALLOCS(ifs->ifs_ips_table, ipstate_t **, 183 ifs->ifs_fr_statesize * sizeof(ipstate_t *)); 184 if (ifs->ifs_ips_table == NULL) 185 return -1; 186 bzero((char *)ifs->ifs_ips_table, 187 ifs->ifs_fr_statesize * sizeof(ipstate_t *)); 188 189 KMALLOCS(ifs->ifs_ips_seed, u_long *, 190 ifs->ifs_fr_statesize * sizeof(*ifs->ifs_ips_seed)); 191 if (ifs->ifs_ips_seed == NULL) 192 return -2; 193 for (i = 0; i < ifs->ifs_fr_statesize; i++) { 194 /* 195 * XXX - ips_seed[X] should be a random number of sorts. 196 */ 197 #if (__FreeBSD_version >= 400000) 198 ifs->ifs_ips_seed[i] = arc4random(); 199 #else 200 ifs->ifs_ips_seed[i] = ((u_long)ifs->ifs_ips_seed + i) * 201 ifs->ifs_fr_statesize; 202 ifs->ifs_ips_seed[i] ^= 0xa5a55a5a; 203 ifs->ifs_ips_seed[i] *= (u_long)ifs->ifs_ips_seed; 204 ifs->ifs_ips_seed[i] ^= 0x5a5aa5a5; 205 ifs->ifs_ips_seed[i] *= ifs->ifs_fr_statemax; 206 #endif 207 } 208 209 /* fill icmp reply type table */ 210 for (i = 0; i <= ICMP_MAXTYPE; i++) 211 icmpreplytype4[i] = -1; 212 icmpreplytype4[ICMP_ECHO] = ICMP_ECHOREPLY; 213 icmpreplytype4[ICMP_TSTAMP] = ICMP_TSTAMPREPLY; 214 icmpreplytype4[ICMP_IREQ] = ICMP_IREQREPLY; 215 icmpreplytype4[ICMP_MASKREQ] = ICMP_MASKREPLY; 216 #ifdef USE_INET6 217 /* fill icmp reply type table */ 218 for (i = 0; i <= ICMP6_MAXTYPE; i++) 219 icmpreplytype6[i] = -1; 220 icmpreplytype6[ICMP6_ECHO_REQUEST] = ICMP6_ECHO_REPLY; 221 icmpreplytype6[ICMP6_MEMBERSHIP_QUERY] = ICMP6_MEMBERSHIP_REPORT; 222 icmpreplytype6[ICMP6_NI_QUERY] = ICMP6_NI_REPLY; 223 icmpreplytype6[ND_ROUTER_SOLICIT] = ND_ROUTER_ADVERT; 224 icmpreplytype6[ND_NEIGHBOR_SOLICIT] = ND_NEIGHBOR_ADVERT; 225 #endif 226 227 KMALLOCS(ifs->ifs_ips_stats.iss_bucketlen, u_long *, 228 ifs->ifs_fr_statesize * sizeof(u_long)); 229 if (ifs->ifs_ips_stats.iss_bucketlen == NULL) 230 return -1; 231 bzero((char *)ifs->ifs_ips_stats.iss_bucketlen, 232 ifs->ifs_fr_statesize * sizeof(u_long)); 233 234 if (ifs->ifs_fr_state_maxbucket == 0) { 235 for (i = ifs->ifs_fr_statesize; i > 0; i >>= 1) 236 ifs->ifs_fr_state_maxbucket++; 237 ifs->ifs_fr_state_maxbucket *= 2; 238 } 239 240 fr_sttab_init(ifs->ifs_ips_tqtqb, ifs); 241 ifs->ifs_ips_tqtqb[IPF_TCP_NSTATES - 1].ifq_next = &ifs->ifs_ips_udptq; 242 ifs->ifs_ips_udptq.ifq_ttl = (u_long)ifs->ifs_fr_udptimeout; 243 ifs->ifs_ips_udptq.ifq_ref = 1; 244 ifs->ifs_ips_udptq.ifq_head = NULL; 245 ifs->ifs_ips_udptq.ifq_tail = &ifs->ifs_ips_udptq.ifq_head; 246 MUTEX_INIT(&ifs->ifs_ips_udptq.ifq_lock, "ipftq udp tab"); 247 ifs->ifs_ips_udptq.ifq_next = &ifs->ifs_ips_udpacktq; 248 ifs->ifs_ips_udpacktq.ifq_ttl = (u_long)ifs->ifs_fr_udpacktimeout; 249 ifs->ifs_ips_udpacktq.ifq_ref = 1; 250 ifs->ifs_ips_udpacktq.ifq_head = NULL; 251 ifs->ifs_ips_udpacktq.ifq_tail = &ifs->ifs_ips_udpacktq.ifq_head; 252 MUTEX_INIT(&ifs->ifs_ips_udpacktq.ifq_lock, "ipftq udpack tab"); 253 ifs->ifs_ips_udpacktq.ifq_next = &ifs->ifs_ips_icmptq; 254 ifs->ifs_ips_icmptq.ifq_ttl = (u_long)ifs->ifs_fr_icmptimeout; 255 ifs->ifs_ips_icmptq.ifq_ref = 1; 256 ifs->ifs_ips_icmptq.ifq_head = NULL; 257 ifs->ifs_ips_icmptq.ifq_tail = &ifs->ifs_ips_icmptq.ifq_head; 258 MUTEX_INIT(&ifs->ifs_ips_icmptq.ifq_lock, "ipftq icmp tab"); 259 ifs->ifs_ips_icmptq.ifq_next = &ifs->ifs_ips_icmpacktq; 260 ifs->ifs_ips_icmpacktq.ifq_ttl = (u_long)ifs->ifs_fr_icmpacktimeout; 261 ifs->ifs_ips_icmpacktq.ifq_ref = 1; 262 ifs->ifs_ips_icmpacktq.ifq_head = NULL; 263 ifs->ifs_ips_icmpacktq.ifq_tail = &ifs->ifs_ips_icmpacktq.ifq_head; 264 MUTEX_INIT(&ifs->ifs_ips_icmpacktq.ifq_lock, "ipftq icmpack tab"); 265 ifs->ifs_ips_icmpacktq.ifq_next = &ifs->ifs_ips_iptq; 266 ifs->ifs_ips_iptq.ifq_ttl = (u_long)ifs->ifs_fr_iptimeout; 267 ifs->ifs_ips_iptq.ifq_ref = 1; 268 ifs->ifs_ips_iptq.ifq_head = NULL; 269 ifs->ifs_ips_iptq.ifq_tail = &ifs->ifs_ips_iptq.ifq_head; 270 MUTEX_INIT(&ifs->ifs_ips_iptq.ifq_lock, "ipftq ip tab"); 271 ifs->ifs_ips_iptq.ifq_next = NULL; 272 273 RWLOCK_INIT(&ifs->ifs_ipf_state, "ipf IP state rwlock"); 274 MUTEX_INIT(&ifs->ifs_ipf_stinsert, "ipf state insert mutex"); 275 ifs->ifs_fr_state_init = 1; 276 277 ifs->ifs_ips_last_force_flush = ifs->ifs_fr_ticks; 278 return 0; 279 } 280 281 282 /* ------------------------------------------------------------------------ */ 283 /* Function: fr_stateunload */ 284 /* Returns: Nil */ 285 /* Parameters: Nil */ 286 /* */ 287 /* Release and destroy any resources acquired or initialised so that */ 288 /* IPFilter can be unloaded or re-initialised. */ 289 /* ------------------------------------------------------------------------ */ 290 void fr_stateunload(ifs) 291 ipf_stack_t *ifs; 292 { 293 ipftq_t *ifq, *ifqnext; 294 ipstate_t *is; 295 296 while ((is = ifs->ifs_ips_list) != NULL) 297 fr_delstate(is, 0, ifs); 298 299 /* 300 * Proxy timeout queues are not cleaned here because although they 301 * exist on the state list, appr_unload is called after fr_stateunload 302 * and the proxies actually are responsible for them being created. 303 * Should the proxy timeouts have their own list? There's no real 304 * justification as this is the only complicationA 305 */ 306 for (ifq = ifs->ifs_ips_utqe; ifq != NULL; ifq = ifqnext) { 307 ifqnext = ifq->ifq_next; 308 if (((ifq->ifq_flags & IFQF_PROXY) == 0) && 309 (fr_deletetimeoutqueue(ifq) == 0)) 310 fr_freetimeoutqueue(ifq, ifs); 311 } 312 313 ifs->ifs_ips_stats.iss_inuse = 0; 314 ifs->ifs_ips_num = 0; 315 316 if (ifs->ifs_fr_state_init == 1) { 317 fr_sttab_destroy(ifs->ifs_ips_tqtqb); 318 MUTEX_DESTROY(&ifs->ifs_ips_udptq.ifq_lock); 319 MUTEX_DESTROY(&ifs->ifs_ips_icmptq.ifq_lock); 320 MUTEX_DESTROY(&ifs->ifs_ips_udpacktq.ifq_lock); 321 MUTEX_DESTROY(&ifs->ifs_ips_icmpacktq.ifq_lock); 322 MUTEX_DESTROY(&ifs->ifs_ips_iptq.ifq_lock); 323 } 324 325 if (ifs->ifs_ips_table != NULL) { 326 KFREES(ifs->ifs_ips_table, 327 ifs->ifs_fr_statesize * sizeof(*ifs->ifs_ips_table)); 328 ifs->ifs_ips_table = NULL; 329 } 330 331 if (ifs->ifs_ips_seed != NULL) { 332 KFREES(ifs->ifs_ips_seed, 333 ifs->ifs_fr_statesize * sizeof(*ifs->ifs_ips_seed)); 334 ifs->ifs_ips_seed = NULL; 335 } 336 337 if (ifs->ifs_ips_stats.iss_bucketlen != NULL) { 338 KFREES(ifs->ifs_ips_stats.iss_bucketlen, 339 ifs->ifs_fr_statesize * sizeof(u_long)); 340 ifs->ifs_ips_stats.iss_bucketlen = NULL; 341 } 342 343 if (ifs->ifs_fr_state_maxbucket_reset == 1) 344 ifs->ifs_fr_state_maxbucket = 0; 345 346 if (ifs->ifs_fr_state_init == 1) { 347 ifs->ifs_fr_state_init = 0; 348 RW_DESTROY(&ifs->ifs_ipf_state); 349 MUTEX_DESTROY(&ifs->ifs_ipf_stinsert); 350 } 351 } 352 353 354 /* ------------------------------------------------------------------------ */ 355 /* Function: fr_statetstats */ 356 /* Returns: ips_state_t* - pointer to state stats structure */ 357 /* Parameters: Nil */ 358 /* */ 359 /* Put all the current numbers and pointers into a single struct and return */ 360 /* a pointer to it. */ 361 /* ------------------------------------------------------------------------ */ 362 static ips_stat_t *fr_statetstats(ifs) 363 ipf_stack_t *ifs; 364 { 365 ifs->ifs_ips_stats.iss_active = ifs->ifs_ips_num; 366 ifs->ifs_ips_stats.iss_statesize = ifs->ifs_fr_statesize; 367 ifs->ifs_ips_stats.iss_statemax = ifs->ifs_fr_statemax; 368 ifs->ifs_ips_stats.iss_table = ifs->ifs_ips_table; 369 ifs->ifs_ips_stats.iss_list = ifs->ifs_ips_list; 370 ifs->ifs_ips_stats.iss_ticks = ifs->ifs_fr_ticks; 371 return &ifs->ifs_ips_stats; 372 } 373 374 /* ------------------------------------------------------------------------ */ 375 /* Function: fr_state_remove */ 376 /* Returns: int - 0 == success, != 0 == failure */ 377 /* Parameters: data(I) - pointer to state structure to delete from table */ 378 /* */ 379 /* Search for a state structure that matches the one passed, according to */ 380 /* the IP addresses and other protocol specific information. */ 381 /* ------------------------------------------------------------------------ */ 382 static int fr_state_remove(data, ifs) 383 caddr_t data; 384 ipf_stack_t *ifs; 385 { 386 ipstate_t *sp, st; 387 int error; 388 389 sp = &st; 390 error = fr_inobj(data, &st, IPFOBJ_IPSTATE); 391 if (error) 392 return EFAULT; 393 394 WRITE_ENTER(&ifs->ifs_ipf_state); 395 for (sp = ifs->ifs_ips_list; sp; sp = sp->is_next) 396 if ((sp->is_p == st.is_p) && (sp->is_v == st.is_v) && 397 !bcmp((caddr_t)&sp->is_src, (caddr_t)&st.is_src, 398 sizeof(st.is_src)) && 399 !bcmp((caddr_t)&sp->is_dst, (caddr_t)&st.is_src, 400 sizeof(st.is_dst)) && 401 !bcmp((caddr_t)&sp->is_ps, (caddr_t)&st.is_ps, 402 sizeof(st.is_ps))) { 403 fr_delstate(sp, ISL_REMOVE, ifs); 404 RWLOCK_EXIT(&ifs->ifs_ipf_state); 405 return 0; 406 } 407 RWLOCK_EXIT(&ifs->ifs_ipf_state); 408 return ESRCH; 409 } 410 411 412 /* ------------------------------------------------------------------------ */ 413 /* Function: fr_state_ioctl */ 414 /* Returns: int - 0 == success, != 0 == failure */ 415 /* Parameters: data(I) - pointer to ioctl data */ 416 /* cmd(I) - ioctl command integer */ 417 /* mode(I) - file mode bits used with open */ 418 /* */ 419 /* Processes an ioctl call made to operate on the IP Filter state device. */ 420 /* ------------------------------------------------------------------------ */ 421 int fr_state_ioctl(data, cmd, mode, uid, ctx, ifs) 422 caddr_t data; 423 ioctlcmd_t cmd; 424 int mode, uid; 425 void *ctx; 426 ipf_stack_t *ifs; 427 { 428 int arg, ret, error = 0; 429 430 switch (cmd) 431 { 432 /* 433 * Delete an entry from the state table. 434 */ 435 case SIOCDELST : 436 error = fr_state_remove(data, ifs); 437 break; 438 /* 439 * Flush the state table 440 */ 441 case SIOCIPFFL : 442 BCOPYIN(data, (char *)&arg, sizeof(arg)); 443 if (arg == 0 || arg == 1) { 444 WRITE_ENTER(&ifs->ifs_ipf_state); 445 ret = fr_state_flush(arg, 4, ifs); 446 RWLOCK_EXIT(&ifs->ifs_ipf_state); 447 BCOPYOUT((char *)&ret, data, sizeof(ret)); 448 } else 449 error = EINVAL; 450 break; 451 #ifdef USE_INET6 452 case SIOCIPFL6 : 453 BCOPYIN(data, (char *)&arg, sizeof(arg)); 454 if (arg == 0 || arg == 1) { 455 WRITE_ENTER(&ifs->ifs_ipf_state); 456 ret = fr_state_flush(arg, 6, ifs); 457 RWLOCK_EXIT(&ifs->ifs_ipf_state); 458 BCOPYOUT((char *)&ret, data, sizeof(ret)); 459 } else 460 error = EINVAL; 461 break; 462 #endif 463 #ifdef IPFILTER_LOG 464 /* 465 * Flush the state log. 466 */ 467 case SIOCIPFFB : 468 if (!(mode & FWRITE)) 469 error = EPERM; 470 else { 471 int tmp; 472 473 tmp = ipflog_clear(IPL_LOGSTATE, ifs); 474 BCOPYOUT((char *)&tmp, data, sizeof(tmp)); 475 } 476 break; 477 /* 478 * Turn logging of state information on/off. 479 */ 480 case SIOCSETLG : 481 if (!(mode & FWRITE)) 482 error = EPERM; 483 else { 484 BCOPYIN((char *)data, 485 (char *)&ifs->ifs_ipstate_logging, 486 sizeof(ifs->ifs_ipstate_logging)); 487 } 488 break; 489 /* 490 * Return the current state of logging. 491 */ 492 case SIOCGETLG : 493 BCOPYOUT((char *)&ifs->ifs_ipstate_logging, (char *)data, 494 sizeof(ifs->ifs_ipstate_logging)); 495 break; 496 /* 497 * Return the number of bytes currently waiting to be read. 498 */ 499 case FIONREAD : 500 arg = ifs->ifs_iplused[IPL_LOGSTATE]; /* returned in an int */ 501 BCOPYOUT((char *)&arg, data, sizeof(arg)); 502 break; 503 #endif 504 /* 505 * Get the current state statistics. 506 */ 507 case SIOCGETFS : 508 error = fr_outobj(data, fr_statetstats(ifs), IPFOBJ_STATESTAT); 509 break; 510 /* 511 * Lock/Unlock the state table. (Locking prevents any changes, which 512 * means no packets match). 513 */ 514 case SIOCSTLCK : 515 if (!(mode & FWRITE)) { 516 error = EPERM; 517 } else { 518 fr_lock(data, &ifs->ifs_fr_state_lock); 519 } 520 break; 521 /* 522 * Add an entry to the current state table. 523 */ 524 case SIOCSTPUT : 525 if (!ifs->ifs_fr_state_lock || !(mode &FWRITE)) { 526 error = EACCES; 527 break; 528 } 529 error = fr_stputent(data, ifs); 530 break; 531 /* 532 * Get a state table entry. 533 */ 534 case SIOCSTGET : 535 if (!ifs->ifs_fr_state_lock) { 536 error = EACCES; 537 break; 538 } 539 error = fr_stgetent(data, ifs); 540 break; 541 542 case SIOCGENITER : 543 { 544 ipftoken_t *token; 545 ipfgeniter_t iter; 546 547 error = fr_inobj(data, &iter, IPFOBJ_GENITER); 548 if (error != 0) 549 break; 550 551 token = ipf_findtoken(IPFGENITER_STATE, uid, ctx, ifs); 552 if (token != NULL) 553 error = fr_stateiter(token, &iter, ifs); 554 else 555 error = ESRCH; 556 RWLOCK_EXIT(&ifs->ifs_ipf_tokens); 557 break; 558 } 559 560 case SIOCIPFDELTOK : 561 (void) BCOPYIN(data, (char *)&arg, sizeof(arg)); 562 error = ipf_deltoken(arg, uid, ctx, ifs); 563 break; 564 565 default : 566 error = EINVAL; 567 break; 568 } 569 return error; 570 } 571 572 573 /* ------------------------------------------------------------------------ */ 574 /* Function: fr_stgetent */ 575 /* Returns: int - 0 == success, != 0 == failure */ 576 /* Parameters: data(I) - pointer to state structure to retrieve from table */ 577 /* */ 578 /* Copy out state information from the kernel to a user space process. If */ 579 /* there is a filter rule associated with the state entry, copy that out */ 580 /* as well. The entry to copy out is taken from the value of "ips_next" in */ 581 /* the struct passed in and if not null and not found in the list of current*/ 582 /* state entries, the retrieval fails. */ 583 /* ------------------------------------------------------------------------ */ 584 int fr_stgetent(data, ifs) 585 caddr_t data; 586 ipf_stack_t *ifs; 587 { 588 ipstate_t *is, *isn; 589 ipstate_save_t ips; 590 int error; 591 592 error = fr_inobj(data, &ips, IPFOBJ_STATESAVE); 593 if (error) 594 return EFAULT; 595 596 isn = ips.ips_next; 597 if (isn == NULL) { 598 isn = ifs->ifs_ips_list; 599 if (isn == NULL) { 600 if (ips.ips_next == NULL) 601 return ENOENT; 602 return 0; 603 } 604 } else { 605 /* 606 * Make sure the pointer we're copying from exists in the 607 * current list of entries. Security precaution to prevent 608 * copying of random kernel data. 609 */ 610 for (is = ifs->ifs_ips_list; is; is = is->is_next) 611 if (is == isn) 612 break; 613 if (!is) 614 return ESRCH; 615 } 616 ips.ips_next = isn->is_next; 617 bcopy((char *)isn, (char *)&ips.ips_is, sizeof(ips.ips_is)); 618 ips.ips_rule = isn->is_rule; 619 if (isn->is_rule != NULL) 620 bcopy((char *)isn->is_rule, (char *)&ips.ips_fr, 621 sizeof(ips.ips_fr)); 622 error = fr_outobj(data, &ips, IPFOBJ_STATESAVE); 623 if (error) 624 return EFAULT; 625 return 0; 626 } 627 628 629 /* ------------------------------------------------------------------------ */ 630 /* Function: fr_stputent */ 631 /* Returns: int - 0 == success, != 0 == failure */ 632 /* Parameters: data(I) - pointer to state information struct */ 633 /* */ 634 /* This function implements the SIOCSTPUT ioctl: insert a state entry into */ 635 /* the state table. If the state info. includes a pointer to a filter rule */ 636 /* then also add in an orphaned rule (will not show up in any "ipfstat -io" */ 637 /* output. */ 638 /* ------------------------------------------------------------------------ */ 639 int fr_stputent(data, ifs) 640 caddr_t data; 641 ipf_stack_t *ifs; 642 { 643 ipstate_t *is, *isn; 644 ipstate_save_t ips; 645 int error, i; 646 frentry_t *fr; 647 char *name; 648 649 error = fr_inobj(data, &ips, IPFOBJ_STATESAVE); 650 if (error) 651 return EFAULT; 652 653 KMALLOC(isn, ipstate_t *); 654 if (isn == NULL) 655 return ENOMEM; 656 657 bcopy((char *)&ips.ips_is, (char *)isn, sizeof(*isn)); 658 bzero((char *)isn, offsetof(struct ipstate, is_pkts)); 659 isn->is_sti.tqe_pnext = NULL; 660 isn->is_sti.tqe_next = NULL; 661 isn->is_sti.tqe_ifq = NULL; 662 isn->is_sti.tqe_parent = isn; 663 isn->is_ifp[0] = NULL; 664 isn->is_ifp[1] = NULL; 665 isn->is_ifp[2] = NULL; 666 isn->is_ifp[3] = NULL; 667 isn->is_sync = NULL; 668 fr = ips.ips_rule; 669 670 if (fr == NULL) { 671 READ_ENTER(&ifs->ifs_ipf_state); 672 fr_stinsert(isn, 0, ifs); 673 MUTEX_EXIT(&isn->is_lock); 674 RWLOCK_EXIT(&ifs->ifs_ipf_state); 675 return 0; 676 } 677 678 if (isn->is_flags & SI_NEWFR) { 679 KMALLOC(fr, frentry_t *); 680 if (fr == NULL) { 681 KFREE(isn); 682 return ENOMEM; 683 } 684 bcopy((char *)&ips.ips_fr, (char *)fr, sizeof(*fr)); 685 isn->is_rule = fr; 686 ips.ips_is.is_rule = fr; 687 MUTEX_NUKE(&fr->fr_lock); 688 MUTEX_INIT(&fr->fr_lock, "state filter rule lock"); 689 690 /* 691 * Look up all the interface names in the rule. 692 */ 693 for (i = 0; i < 4; i++) { 694 name = fr->fr_ifnames[i]; 695 fr->fr_ifas[i] = fr_resolvenic(name, fr->fr_v, ifs); 696 name = isn->is_ifname[i]; 697 isn->is_ifp[i] = fr_resolvenic(name, isn->is_v, ifs); 698 } 699 700 fr->fr_ref = 0; 701 fr->fr_dsize = 0; 702 fr->fr_data = NULL; 703 704 fr_resolvedest(&fr->fr_tif, fr->fr_v, ifs); 705 fr_resolvedest(&fr->fr_dif, fr->fr_v, ifs); 706 fr_resolvedest(&fr->fr_rif, fr->fr_v, ifs); 707 708 /* 709 * send a copy back to userland of what we ended up 710 * to allow for verification. 711 */ 712 error = fr_outobj(data, &ips, IPFOBJ_STATESAVE); 713 if (error) { 714 KFREE(isn); 715 MUTEX_DESTROY(&fr->fr_lock); 716 KFREE(fr); 717 return EFAULT; 718 } 719 READ_ENTER(&ifs->ifs_ipf_state); 720 fr_stinsert(isn, 0, ifs); 721 MUTEX_EXIT(&isn->is_lock); 722 RWLOCK_EXIT(&ifs->ifs_ipf_state); 723 724 } else { 725 READ_ENTER(&ifs->ifs_ipf_state); 726 for (is = ifs->ifs_ips_list; is; is = is->is_next) 727 if (is->is_rule == fr) { 728 fr_stinsert(isn, 0, ifs); 729 MUTEX_EXIT(&isn->is_lock); 730 break; 731 } 732 733 if (is == NULL) { 734 KFREE(isn); 735 isn = NULL; 736 } 737 RWLOCK_EXIT(&ifs->ifs_ipf_state); 738 739 return (isn == NULL) ? ESRCH : 0; 740 } 741 742 return 0; 743 } 744 745 746 /* ------------------------------------------------------------------------ */ 747 /* Function: fr_stinsert */ 748 /* Returns: Nil */ 749 /* Parameters: is(I) - pointer to state structure */ 750 /* rev(I) - flag indicating forward/reverse direction of packet */ 751 /* */ 752 /* Inserts a state structure into the hash table (for lookups) and the list */ 753 /* of state entries (for enumeration). Resolves all of the interface names */ 754 /* to pointers and adjusts running stats for the hash table as appropriate. */ 755 /* */ 756 /* Locking: it is assumed that some kind of lock on ipf_state is held. */ 757 /* Exits with is_lock initialised and held. */ 758 /* ------------------------------------------------------------------------ */ 759 void fr_stinsert(is, rev, ifs) 760 ipstate_t *is; 761 int rev; 762 ipf_stack_t *ifs; 763 { 764 frentry_t *fr; 765 u_int hv; 766 int i; 767 768 MUTEX_INIT(&is->is_lock, "ipf state entry"); 769 770 fr = is->is_rule; 771 if (fr != NULL) { 772 MUTEX_ENTER(&fr->fr_lock); 773 fr->fr_ref++; 774 fr->fr_statecnt++; 775 MUTEX_EXIT(&fr->fr_lock); 776 } 777 778 /* 779 * Look up all the interface names in the state entry. 780 */ 781 for (i = 0; i < 4; i++) { 782 if (is->is_ifp[i] != NULL) 783 continue; 784 is->is_ifp[i] = fr_resolvenic(is->is_ifname[i], is->is_v, ifs); 785 } 786 787 /* 788 * If we could trust is_hv, then the modulous would not be needed, but 789 * when running with IPFILTER_SYNC, this stops bad values. 790 */ 791 hv = is->is_hv % ifs->ifs_fr_statesize; 792 is->is_hv = hv; 793 794 /* 795 * We need to get both of these locks...the first because it is 796 * possible that once the insert is complete another packet might 797 * come along, match the entry and want to update it. 798 */ 799 MUTEX_ENTER(&is->is_lock); 800 MUTEX_ENTER(&ifs->ifs_ipf_stinsert); 801 802 /* 803 * add into list table. 804 */ 805 if (ifs->ifs_ips_list != NULL) 806 ifs->ifs_ips_list->is_pnext = &is->is_next; 807 is->is_pnext = &ifs->ifs_ips_list; 808 is->is_next = ifs->ifs_ips_list; 809 ifs->ifs_ips_list = is; 810 811 if (ifs->ifs_ips_table[hv] != NULL) 812 ifs->ifs_ips_table[hv]->is_phnext = &is->is_hnext; 813 else 814 ifs->ifs_ips_stats.iss_inuse++; 815 is->is_phnext = ifs->ifs_ips_table + hv; 816 is->is_hnext = ifs->ifs_ips_table[hv]; 817 ifs->ifs_ips_table[hv] = is; 818 ifs->ifs_ips_stats.iss_bucketlen[hv]++; 819 ifs->ifs_ips_num++; 820 MUTEX_EXIT(&ifs->ifs_ipf_stinsert); 821 822 fr_setstatequeue(is, rev, ifs); 823 } 824 825 826 /* ------------------------------------------------------------------------ */ 827 /* Function: fr_addstate */ 828 /* Returns: ipstate_t* - NULL == failure, else pointer to new state */ 829 /* Parameters: fin(I) - pointer to packet information */ 830 /* stsave(O) - pointer to place to save pointer to created */ 831 /* state structure. */ 832 /* flags(I) - flags to use when creating the structure */ 833 /* */ 834 /* Creates a new IP state structure from the packet information collected. */ 835 /* Inserts it into the state table and appends to the bottom of the active */ 836 /* list. If the capacity of the table has reached the maximum allowed then */ 837 /* the call will fail and a flush is scheduled for the next timeout call. */ 838 /* ------------------------------------------------------------------------ */ 839 ipstate_t *fr_addstate(fin, stsave, flags) 840 fr_info_t *fin; 841 ipstate_t **stsave; 842 u_int flags; 843 { 844 ipstate_t *is, ips; 845 struct icmp *ic; 846 u_int pass, hv; 847 frentry_t *fr; 848 tcphdr_t *tcp; 849 grehdr_t *gre; 850 void *ifp; 851 int out; 852 ipf_stack_t *ifs = fin->fin_ifs; 853 854 if (ifs->ifs_fr_state_lock || 855 (fin->fin_flx & (FI_SHORT|FI_STATE|FI_FRAGBODY|FI_BAD))) 856 return NULL; 857 858 if ((fin->fin_flx & FI_OOW) && !(fin->fin_tcpf & TH_SYN)) 859 return NULL; 860 861 /* 862 * If a "keep state" rule has reached the maximum number of references 863 * to it, then schedule an automatic flush in case we can clear out 864 * some "dead old wood". Note that because the lock isn't held on 865 * fr it is possible that we could overflow. The cost of overflowing 866 * is being ignored here as the number by which it can overflow is 867 * a product of the number of simultaneous threads that could be 868 * executing in here, so a limit of 100 won't result in 200, but could 869 * result in 101 or 102. 870 */ 871 fr = fin->fin_fr; 872 if (fr != NULL) { 873 if ((ifs->ifs_ips_num == ifs->ifs_fr_statemax) && (fr->fr_statemax == 0)) { 874 ATOMIC_INCL(ifs->ifs_ips_stats.iss_max); 875 ifs->ifs_fr_state_doflush = 1; 876 return NULL; 877 } 878 if ((fr->fr_statemax != 0) && 879 (fr->fr_statecnt >= fr->fr_statemax)) { 880 ATOMIC_INCL(ifs->ifs_ips_stats.iss_maxref); 881 ifs->ifs_fr_state_doflush = 1; 882 return NULL; 883 } 884 } 885 886 pass = (fr == NULL) ? 0 : fr->fr_flags; 887 888 ic = NULL; 889 tcp = NULL; 890 out = fin->fin_out; 891 is = &ips; 892 bzero((char *)is, sizeof(*is)); 893 is->is_die = 1 + ifs->ifs_fr_ticks; 894 895 /* 896 * Copy and calculate... 897 */ 898 hv = (is->is_p = fin->fin_fi.fi_p); 899 is->is_src = fin->fin_fi.fi_src; 900 hv += is->is_saddr; 901 is->is_dst = fin->fin_fi.fi_dst; 902 hv += is->is_daddr; 903 #ifdef USE_INET6 904 if (fin->fin_v == 6) { 905 /* 906 * For ICMPv6, we check to see if the destination address is 907 * a multicast address. If it is, do not include it in the 908 * calculation of the hash because the correct reply will come 909 * back from a real address, not a multicast address. 910 */ 911 if ((is->is_p == IPPROTO_ICMPV6) && 912 IN6_IS_ADDR_MULTICAST(&is->is_dst.in6)) { 913 /* 914 * So you can do keep state with neighbour discovery. 915 * 916 * Here we could use the address from the neighbour 917 * solicit message to put in the state structure and 918 * we could use that without a wildcard flag too... 919 */ 920 is->is_flags |= SI_W_DADDR; 921 hv -= is->is_daddr; 922 } else { 923 hv += is->is_dst.i6[1]; 924 hv += is->is_dst.i6[2]; 925 hv += is->is_dst.i6[3]; 926 } 927 hv += is->is_src.i6[1]; 928 hv += is->is_src.i6[2]; 929 hv += is->is_src.i6[3]; 930 } 931 #endif 932 933 switch (is->is_p) 934 { 935 #ifdef USE_INET6 936 case IPPROTO_ICMPV6 : 937 ic = fin->fin_dp; 938 939 switch (ic->icmp_type) 940 { 941 case ICMP6_ECHO_REQUEST : 942 is->is_icmp.ici_type = ic->icmp_type; 943 hv += (is->is_icmp.ici_id = ic->icmp_id); 944 break; 945 case ICMP6_MEMBERSHIP_QUERY : 946 case ND_ROUTER_SOLICIT : 947 case ND_NEIGHBOR_SOLICIT : 948 case ICMP6_NI_QUERY : 949 is->is_icmp.ici_type = ic->icmp_type; 950 break; 951 default : 952 return NULL; 953 } 954 ATOMIC_INCL(ifs->ifs_ips_stats.iss_icmp); 955 break; 956 #endif 957 case IPPROTO_ICMP : 958 ic = fin->fin_dp; 959 960 switch (ic->icmp_type) 961 { 962 case ICMP_ECHO : 963 case ICMP_TSTAMP : 964 case ICMP_IREQ : 965 case ICMP_MASKREQ : 966 is->is_icmp.ici_type = ic->icmp_type; 967 hv += (is->is_icmp.ici_id = ic->icmp_id); 968 break; 969 default : 970 return NULL; 971 } 972 ATOMIC_INCL(ifs->ifs_ips_stats.iss_icmp); 973 break; 974 975 case IPPROTO_GRE : 976 gre = fin->fin_dp; 977 978 is->is_gre.gs_flags = gre->gr_flags; 979 is->is_gre.gs_ptype = gre->gr_ptype; 980 if (GRE_REV(is->is_gre.gs_flags) == 1) { 981 is->is_call[0] = fin->fin_data[0]; 982 is->is_call[1] = fin->fin_data[1]; 983 } 984 break; 985 986 case IPPROTO_TCP : 987 tcp = fin->fin_dp; 988 989 if (tcp->th_flags & TH_RST) 990 return NULL; 991 /* 992 * The endian of the ports doesn't matter, but the ack and 993 * sequence numbers do as we do mathematics on them later. 994 */ 995 is->is_sport = htons(fin->fin_data[0]); 996 is->is_dport = htons(fin->fin_data[1]); 997 if ((flags & (SI_W_DPORT|SI_W_SPORT)) == 0) { 998 hv += is->is_sport; 999 hv += is->is_dport; 1000 } 1001 1002 /* 1003 * If this is a real packet then initialise fields in the 1004 * state information structure from the TCP header information. 1005 */ 1006 1007 is->is_maxdwin = 1; 1008 is->is_maxswin = ntohs(tcp->th_win); 1009 if (is->is_maxswin == 0) 1010 is->is_maxswin = 1; 1011 1012 if ((fin->fin_flx & FI_IGNORE) == 0) { 1013 is->is_send = ntohl(tcp->th_seq) + fin->fin_dlen - 1014 (TCP_OFF(tcp) << 2) + 1015 ((tcp->th_flags & TH_SYN) ? 1 : 0) + 1016 ((tcp->th_flags & TH_FIN) ? 1 : 0); 1017 is->is_maxsend = is->is_send; 1018 1019 /* 1020 * Window scale option is only present in 1021 * SYN/SYN-ACK packet. 1022 */ 1023 if ((tcp->th_flags & ~(TH_FIN|TH_ACK|TH_ECNALL)) == 1024 TH_SYN && 1025 (TCP_OFF(tcp) > (sizeof(tcphdr_t) >> 2))) { 1026 if (fr_tcpoptions(fin, tcp, 1027 &is->is_tcp.ts_data[0])) 1028 is->is_swinflags = TCP_WSCALE_SEEN| 1029 TCP_WSCALE_FIRST; 1030 } 1031 1032 if ((fin->fin_out != 0) && (pass & FR_NEWISN) != 0) { 1033 fr_checknewisn(fin, is); 1034 fr_fixoutisn(fin, is); 1035 } 1036 1037 if ((tcp->th_flags & TH_OPENING) == TH_SYN) 1038 flags |= IS_TCPFSM; 1039 else { 1040 is->is_maxdwin = is->is_maxswin * 2; 1041 is->is_dend = ntohl(tcp->th_ack); 1042 is->is_maxdend = ntohl(tcp->th_ack); 1043 is->is_maxdwin *= 2; 1044 } 1045 } 1046 1047 /* 1048 * If we're creating state for a starting connection, start the 1049 * timer on it as we'll never see an error if it fails to 1050 * connect. 1051 */ 1052 ATOMIC_INCL(ifs->ifs_ips_stats.iss_tcp); 1053 break; 1054 1055 case IPPROTO_UDP : 1056 tcp = fin->fin_dp; 1057 1058 is->is_sport = htons(fin->fin_data[0]); 1059 is->is_dport = htons(fin->fin_data[1]); 1060 if ((flags & (SI_W_DPORT|SI_W_SPORT)) == 0) { 1061 hv += tcp->th_dport; 1062 hv += tcp->th_sport; 1063 } 1064 ATOMIC_INCL(ifs->ifs_ips_stats.iss_udp); 1065 break; 1066 1067 default : 1068 break; 1069 } 1070 hv = DOUBLE_HASH(hv, ifs); 1071 is->is_hv = hv; 1072 is->is_rule = fr; 1073 is->is_flags = flags & IS_INHERITED; 1074 1075 /* 1076 * Look for identical state. 1077 */ 1078 for (is = ifs->ifs_ips_table[is->is_hv % ifs->ifs_fr_statesize]; 1079 is != NULL; 1080 is = is->is_hnext) { 1081 if (bcmp(&ips.is_src, &is->is_src, 1082 offsetof(struct ipstate, is_ps) - 1083 offsetof(struct ipstate, is_src)) == 0) 1084 break; 1085 } 1086 if (is != NULL) 1087 return NULL; 1088 1089 if (ifs->ifs_ips_stats.iss_bucketlen[hv] >= ifs->ifs_fr_state_maxbucket) { 1090 ATOMIC_INCL(ifs->ifs_ips_stats.iss_bucketfull); 1091 return NULL; 1092 } 1093 KMALLOC(is, ipstate_t *); 1094 if (is == NULL) { 1095 ATOMIC_INCL(ifs->ifs_ips_stats.iss_nomem); 1096 return NULL; 1097 } 1098 bcopy((char *)&ips, (char *)is, sizeof(*is)); 1099 /* 1100 * Do not do the modulous here, it is done in fr_stinsert(). 1101 */ 1102 if (fr != NULL) { 1103 (void) strncpy(is->is_group, fr->fr_group, FR_GROUPLEN); 1104 if (fr->fr_age[0] != 0) { 1105 is->is_tqehead[0] = 1106 fr_addtimeoutqueue(&ifs->ifs_ips_utqe, 1107 fr->fr_age[0], ifs); 1108 is->is_sti.tqe_flags |= TQE_RULEBASED; 1109 } 1110 if (fr->fr_age[1] != 0) { 1111 is->is_tqehead[1] = 1112 fr_addtimeoutqueue(&ifs->ifs_ips_utqe, 1113 fr->fr_age[1], ifs); 1114 is->is_sti.tqe_flags |= TQE_RULEBASED; 1115 } 1116 is->is_tag = fr->fr_logtag; 1117 1118 is->is_ifp[(out << 1) + 1] = fr->fr_ifas[1]; 1119 is->is_ifp[(1 - out) << 1] = fr->fr_ifas[2]; 1120 is->is_ifp[((1 - out) << 1) + 1] = fr->fr_ifas[3]; 1121 1122 if (((ifp = fr->fr_ifas[1]) != NULL) && 1123 (ifp != (void *)-1)) { 1124 COPYIFNAME(ifp, is->is_ifname[(out << 1) + 1], fr->fr_v); 1125 } 1126 if (((ifp = fr->fr_ifas[2]) != NULL) && 1127 (ifp != (void *)-1)) { 1128 COPYIFNAME(ifp, is->is_ifname[(1 - out) << 1], fr->fr_v); 1129 } 1130 if (((ifp = fr->fr_ifas[3]) != NULL) && 1131 (ifp != (void *)-1)) { 1132 COPYIFNAME(ifp, is->is_ifname[((1 - out) << 1) + 1], fr->fr_v); 1133 } 1134 } else { 1135 pass = ifs->ifs_fr_flags; 1136 is->is_tag = FR_NOLOGTAG; 1137 } 1138 1139 is->is_ifp[out << 1] = fin->fin_ifp; 1140 if (fin->fin_ifp != NULL) { 1141 COPYIFNAME(fin->fin_ifp, is->is_ifname[out << 1], fr->fr_v); 1142 } 1143 1144 /* 1145 * It may seem strange to set is_ref to 2, but fr_check() will call 1146 * fr_statederef() after calling fr_addstate() and the idea is to 1147 * have it exist at the end of fr_check() with is_ref == 1. 1148 */ 1149 is->is_ref = 2; 1150 is->is_pass = pass; 1151 is->is_pkts[0] = 0, is->is_bytes[0] = 0; 1152 is->is_pkts[1] = 0, is->is_bytes[1] = 0; 1153 is->is_pkts[2] = 0, is->is_bytes[2] = 0; 1154 is->is_pkts[3] = 0, is->is_bytes[3] = 0; 1155 if ((fin->fin_flx & FI_IGNORE) == 0) { 1156 is->is_pkts[out] = 1; 1157 is->is_bytes[out] = fin->fin_plen; 1158 is->is_flx[out][0] = fin->fin_flx & FI_CMP; 1159 is->is_flx[out][0] &= ~FI_OOW; 1160 } 1161 1162 if (pass & FR_STSTRICT) 1163 is->is_flags |= IS_STRICT; 1164 1165 if (pass & FR_STATESYNC) 1166 is->is_flags |= IS_STATESYNC; 1167 1168 /* 1169 * We want to check everything that is a property of this packet, 1170 * but we don't (automatically) care about it's fragment status as 1171 * this may change. 1172 */ 1173 is->is_v = fin->fin_v; 1174 is->is_opt[0] = fin->fin_optmsk; 1175 is->is_optmsk[0] = 0xffffffff; 1176 is->is_optmsk[1] = 0xffffffff; 1177 if (is->is_v == 6) { 1178 is->is_opt[0] &= ~0x8; 1179 is->is_optmsk[0] &= ~0x8; 1180 is->is_optmsk[1] &= ~0x8; 1181 } 1182 is->is_sec = fin->fin_secmsk; 1183 is->is_secmsk = 0xffff; 1184 is->is_auth = fin->fin_auth; 1185 is->is_authmsk = 0xffff; 1186 if (flags & (SI_WILDP|SI_WILDA)) { 1187 ATOMIC_INCL(ifs->ifs_ips_stats.iss_wild); 1188 } 1189 is->is_rulen = fin->fin_rule; 1190 1191 1192 if (pass & FR_LOGFIRST) 1193 is->is_pass &= ~(FR_LOGFIRST|FR_LOG); 1194 1195 READ_ENTER(&ifs->ifs_ipf_state); 1196 is->is_me = stsave; 1197 1198 fr_stinsert(is, fin->fin_rev, ifs); 1199 1200 if (fin->fin_p == IPPROTO_TCP) { 1201 /* 1202 * If we're creating state for a starting connection, start the 1203 * timer on it as we'll never see an error if it fails to 1204 * connect. 1205 */ 1206 (void) fr_tcp_age(&is->is_sti, fin, ifs->ifs_ips_tqtqb, 1207 is->is_flags); 1208 MUTEX_EXIT(&is->is_lock); 1209 #ifdef IPFILTER_SCAN 1210 if ((is->is_flags & SI_CLONE) == 0) 1211 (void) ipsc_attachis(is); 1212 #endif 1213 } else { 1214 MUTEX_EXIT(&is->is_lock); 1215 } 1216 #ifdef IPFILTER_SYNC 1217 if ((is->is_flags & IS_STATESYNC) && ((is->is_flags & SI_CLONE) == 0)) 1218 is->is_sync = ipfsync_new(SMC_STATE, fin, is); 1219 #endif 1220 if (ifs->ifs_ipstate_logging) 1221 ipstate_log(is, ISL_NEW, ifs); 1222 1223 RWLOCK_EXIT(&ifs->ifs_ipf_state); 1224 fin->fin_state = is; 1225 fin->fin_rev = IP6_NEQ(&is->is_dst, &fin->fin_daddr); 1226 fin->fin_flx |= FI_STATE; 1227 if (fin->fin_flx & FI_FRAG) 1228 (void) fr_newfrag(fin, pass ^ FR_KEEPSTATE); 1229 1230 return is; 1231 } 1232 1233 1234 /* ------------------------------------------------------------------------ */ 1235 /* Function: fr_tcpoptions */ 1236 /* Returns: int - 1 == packet matches state entry, 0 == it does not */ 1237 /* Parameters: fin(I) - pointer to packet information */ 1238 /* tcp(I) - pointer to TCP packet header */ 1239 /* td(I) - pointer to TCP data held as part of the state */ 1240 /* */ 1241 /* Look after the TCP header for any options and deal with those that are */ 1242 /* present. Record details about those that we recogise. */ 1243 /* ------------------------------------------------------------------------ */ 1244 static int fr_tcpoptions(fin, tcp, td) 1245 fr_info_t *fin; 1246 tcphdr_t *tcp; 1247 tcpdata_t *td; 1248 { 1249 int off, mlen, ol, i, len, retval; 1250 char buf[64], *s, opt; 1251 mb_t *m = NULL; 1252 1253 len = (TCP_OFF(tcp) << 2); 1254 if (fin->fin_dlen < len) 1255 return 0; 1256 len -= sizeof(*tcp); 1257 1258 off = fin->fin_plen - fin->fin_dlen + sizeof(*tcp) + fin->fin_ipoff; 1259 1260 m = fin->fin_m; 1261 mlen = MSGDSIZE(m) - off; 1262 if (len > mlen) { 1263 len = mlen; 1264 retval = 0; 1265 } else { 1266 retval = 1; 1267 } 1268 1269 COPYDATA(m, off, len, buf); 1270 1271 for (s = buf; len > 0; ) { 1272 opt = *s; 1273 if (opt == TCPOPT_EOL) 1274 break; 1275 else if (opt == TCPOPT_NOP) 1276 ol = 1; 1277 else { 1278 if (len < 2) 1279 break; 1280 ol = (int)*(s + 1); 1281 if (ol < 2 || ol > len) 1282 break; 1283 1284 /* 1285 * Extract the TCP options we are interested in out of 1286 * the header and store them in the the tcpdata struct. 1287 */ 1288 switch (opt) 1289 { 1290 case TCPOPT_WINDOW : 1291 if (ol == TCPOLEN_WINDOW) { 1292 i = (int)*(s + 2); 1293 if (i > TCP_WSCALE_MAX) 1294 i = TCP_WSCALE_MAX; 1295 else if (i < 0) 1296 i = 0; 1297 td->td_winscale = i; 1298 } 1299 break; 1300 case TCPOPT_MAXSEG : 1301 /* 1302 * So, if we wanted to set the TCP MAXSEG, 1303 * it should be done here... 1304 */ 1305 if (ol == TCPOLEN_MAXSEG) { 1306 i = (int)*(s + 2); 1307 i <<= 8; 1308 i += (int)*(s + 3); 1309 td->td_maxseg = i; 1310 } 1311 break; 1312 } 1313 } 1314 len -= ol; 1315 s += ol; 1316 } 1317 return retval; 1318 } 1319 1320 1321 /* ------------------------------------------------------------------------ */ 1322 /* Function: fr_tcpstate */ 1323 /* Returns: int - 1 == packet matches state entry, 0 == it does not */ 1324 /* Parameters: fin(I) - pointer to packet information */ 1325 /* tcp(I) - pointer to TCP packet header */ 1326 /* is(I) - pointer to master state structure */ 1327 /* */ 1328 /* Check to see if a packet with TCP headers fits within the TCP window. */ 1329 /* Change timeout depending on whether new packet is a SYN-ACK returning */ 1330 /* for a SYN or a RST or FIN which indicate time to close up shop. */ 1331 /* ------------------------------------------------------------------------ */ 1332 static int fr_tcpstate(fin, tcp, is) 1333 fr_info_t *fin; 1334 tcphdr_t *tcp; 1335 ipstate_t *is; 1336 { 1337 int source, ret = 0, flags; 1338 tcpdata_t *fdata, *tdata; 1339 ipf_stack_t *ifs = fin->fin_ifs; 1340 1341 source = !fin->fin_rev; 1342 if (((is->is_flags & IS_TCPFSM) != 0) && (source == 1) && 1343 (ntohs(is->is_sport) != fin->fin_data[0])) 1344 source = 0; 1345 fdata = &is->is_tcp.ts_data[!source]; 1346 tdata = &is->is_tcp.ts_data[source]; 1347 1348 MUTEX_ENTER(&is->is_lock); 1349 if (fr_tcpinwindow(fin, fdata, tdata, tcp, is->is_flags)) { 1350 #ifdef IPFILTER_SCAN 1351 if (is->is_flags & (IS_SC_CLIENT|IS_SC_SERVER)) { 1352 ipsc_packet(fin, is); 1353 if (FR_ISBLOCK(is->is_pass)) { 1354 MUTEX_EXIT(&is->is_lock); 1355 return 1; 1356 } 1357 } 1358 #endif 1359 1360 /* 1361 * Nearing end of connection, start timeout. 1362 */ 1363 ret = fr_tcp_age(&is->is_sti, fin, ifs->ifs_ips_tqtqb, 1364 is->is_flags); 1365 if (ret == 0) { 1366 MUTEX_EXIT(&is->is_lock); 1367 return 0; 1368 } 1369 1370 /* 1371 * set s0's as appropriate. Use syn-ack packet as it 1372 * contains both pieces of required information. 1373 */ 1374 /* 1375 * Window scale option is only present in SYN/SYN-ACK packet. 1376 * Compare with ~TH_FIN to mask out T/TCP setups. 1377 */ 1378 flags = tcp->th_flags & ~(TH_FIN|TH_ECNALL); 1379 if (flags == (TH_SYN|TH_ACK)) { 1380 is->is_s0[source] = ntohl(tcp->th_ack); 1381 is->is_s0[!source] = ntohl(tcp->th_seq) + 1; 1382 if ((TCP_OFF(tcp) > (sizeof(tcphdr_t) >> 2)) && 1383 tdata->td_winscale) { 1384 if (fr_tcpoptions(fin, tcp, fdata)) { 1385 fdata->td_winflags = TCP_WSCALE_SEEN| 1386 TCP_WSCALE_FIRST; 1387 } else { 1388 if (!fdata->td_winscale) 1389 tdata->td_winscale = 0; 1390 } 1391 } 1392 if ((fin->fin_out != 0) && (is->is_pass & FR_NEWISN)) 1393 fr_checknewisn(fin, is); 1394 } else if (flags == TH_SYN) { 1395 is->is_s0[source] = ntohl(tcp->th_seq) + 1; 1396 if ((TCP_OFF(tcp) > (sizeof(tcphdr_t) >> 2))) 1397 if (fr_tcpoptions(fin, tcp, tdata)) { 1398 tdata->td_winflags = TCP_WSCALE_SEEN| 1399 TCP_WSCALE_FIRST; 1400 } 1401 1402 if ((fin->fin_out != 0) && (is->is_pass & FR_NEWISN)) 1403 fr_checknewisn(fin, is); 1404 1405 } 1406 ret = 1; 1407 } else 1408 fin->fin_flx |= FI_OOW; 1409 MUTEX_EXIT(&is->is_lock); 1410 return ret; 1411 } 1412 1413 1414 /* ------------------------------------------------------------------------ */ 1415 /* Function: fr_checknewisn */ 1416 /* Returns: Nil */ 1417 /* Parameters: fin(I) - pointer to packet information */ 1418 /* is(I) - pointer to master state structure */ 1419 /* */ 1420 /* Check to see if this TCP connection is expecting and needs a new */ 1421 /* sequence number for a particular direction of the connection. */ 1422 /* */ 1423 /* NOTE: This does not actually change the sequence numbers, only gets new */ 1424 /* one ready. */ 1425 /* ------------------------------------------------------------------------ */ 1426 static void fr_checknewisn(fin, is) 1427 fr_info_t *fin; 1428 ipstate_t *is; 1429 { 1430 u_32_t sumd, old, new; 1431 tcphdr_t *tcp; 1432 int i; 1433 1434 i = fin->fin_rev; 1435 tcp = fin->fin_dp; 1436 1437 if (((i == 0) && !(is->is_flags & IS_ISNSYN)) || 1438 ((i == 1) && !(is->is_flags & IS_ISNACK))) { 1439 old = ntohl(tcp->th_seq); 1440 new = fr_newisn(fin); 1441 is->is_isninc[i] = new - old; 1442 CALC_SUMD(old, new, sumd); 1443 is->is_sumd[i] = (sumd & 0xffff) + (sumd >> 16); 1444 1445 is->is_flags |= ((i == 0) ? IS_ISNSYN : IS_ISNACK); 1446 } 1447 } 1448 1449 1450 /* ------------------------------------------------------------------------ */ 1451 /* Function: fr_tcpinwindow */ 1452 /* Returns: int - 1 == packet inside TCP "window", 0 == not inside. */ 1453 /* Parameters: fin(I) - pointer to packet information */ 1454 /* fdata(I) - pointer to tcp state informatio (forward) */ 1455 /* tdata(I) - pointer to tcp state informatio (reverse) */ 1456 /* tcp(I) - pointer to TCP packet header */ 1457 /* */ 1458 /* Given a packet has matched addresses and ports, check to see if it is */ 1459 /* within the TCP data window. In a show of generosity, allow packets that */ 1460 /* are within the window space behind the current sequence # as well. */ 1461 /* ------------------------------------------------------------------------ */ 1462 int fr_tcpinwindow(fin, fdata, tdata, tcp, flags) 1463 fr_info_t *fin; 1464 tcpdata_t *fdata, *tdata; 1465 tcphdr_t *tcp; 1466 int flags; 1467 { 1468 tcp_seq seq, ack, end; 1469 int ackskew, tcpflags; 1470 u_32_t win, maxwin; 1471 1472 /* 1473 * Find difference between last checked packet and this packet. 1474 */ 1475 tcpflags = tcp->th_flags; 1476 seq = ntohl(tcp->th_seq); 1477 ack = ntohl(tcp->th_ack); 1478 if (tcpflags & TH_SYN) 1479 win = ntohs(tcp->th_win); 1480 else 1481 win = ntohs(tcp->th_win) << fdata->td_winscale; 1482 if (win == 0) 1483 win = 1; 1484 1485 /* 1486 * if window scaling is present, the scaling is only allowed 1487 * for windows not in the first SYN packet. In that packet the 1488 * window is 65535 to specify the largest window possible 1489 * for receivers not implementing the window scale option. 1490 * Currently, we do not assume TTCP here. That means that 1491 * if we see a second packet from a host (after the initial 1492 * SYN), we can assume that the receiver of the SYN did 1493 * already send back the SYN/ACK (and thus that we know if 1494 * the receiver also does window scaling) 1495 */ 1496 if (!(tcpflags & TH_SYN) && (fdata->td_winflags & TCP_WSCALE_FIRST)) { 1497 if (tdata->td_winflags & TCP_WSCALE_SEEN) { 1498 fdata->td_winflags &= ~TCP_WSCALE_FIRST; 1499 fdata->td_maxwin = win; 1500 } else { 1501 fdata->td_winscale = 0; 1502 fdata->td_winflags = 0; 1503 tdata->td_winscale = 0; 1504 tdata->td_winflags = 0; 1505 } 1506 } 1507 1508 end = seq + fin->fin_dlen - (TCP_OFF(tcp) << 2) + 1509 ((tcpflags & TH_SYN) ? 1 : 0) + ((tcpflags & TH_FIN) ? 1 : 0); 1510 1511 if ((fdata->td_end == 0) && 1512 (!(flags & IS_TCPFSM) || 1513 ((tcpflags & TH_OPENING) == TH_OPENING))) { 1514 /* 1515 * Must be a (outgoing) SYN-ACK in reply to a SYN. 1516 */ 1517 fdata->td_end = end; 1518 fdata->td_maxwin = 1; 1519 fdata->td_maxend = end + win; 1520 } 1521 1522 if (!(tcpflags & TH_ACK)) { /* Pretend an ack was sent */ 1523 ack = tdata->td_end; 1524 } else if (((tcpflags & (TH_ACK|TH_RST)) == (TH_ACK|TH_RST)) && 1525 (ack == 0)) { 1526 /* gross hack to get around certain broken tcp stacks */ 1527 ack = tdata->td_end; 1528 } 1529 1530 if (seq == end) 1531 seq = end = fdata->td_end; 1532 1533 maxwin = tdata->td_maxwin; 1534 ackskew = tdata->td_end - ack; 1535 1536 /* 1537 * Strict sequencing only allows in-order delivery. 1538 */ 1539 if ((flags & IS_STRICT) != 0) { 1540 if (seq != fdata->td_end) { 1541 return 0; 1542 } 1543 } 1544 1545 #define SEQ_GE(a,b) ((int)((a) - (b)) >= 0) 1546 #define SEQ_GT(a,b) ((int)((a) - (b)) > 0) 1547 if ( 1548 #if defined(_KERNEL) 1549 (SEQ_GE(fdata->td_maxend, end)) && 1550 (SEQ_GE(seq, fdata->td_end - maxwin)) && 1551 #endif 1552 /* XXX what about big packets */ 1553 #define MAXACKWINDOW 66000 1554 (-ackskew <= (MAXACKWINDOW << fdata->td_winscale)) && 1555 ( ackskew <= (MAXACKWINDOW << fdata->td_winscale))) { 1556 1557 /* if ackskew < 0 then this should be due to fragmented 1558 * packets. There is no way to know the length of the 1559 * total packet in advance. 1560 * We do know the total length from the fragment cache though. 1561 * Note however that there might be more sessions with 1562 * exactly the same source and destination parameters in the 1563 * state cache (and source and destination is the only stuff 1564 * that is saved in the fragment cache). Note further that 1565 * some TCP connections in the state cache are hashed with 1566 * sport and dport as well which makes it not worthwhile to 1567 * look for them. 1568 * Thus, when ackskew is negative but still seems to belong 1569 * to this session, we bump up the destinations end value. 1570 */ 1571 if (ackskew < 0) 1572 tdata->td_end = ack; 1573 1574 /* update max window seen */ 1575 if (fdata->td_maxwin < win) 1576 fdata->td_maxwin = win; 1577 if (SEQ_GT(end, fdata->td_end)) 1578 fdata->td_end = end; 1579 if (SEQ_GE(ack + win, tdata->td_maxend)) 1580 tdata->td_maxend = ack + win; 1581 return 1; 1582 } 1583 return 0; 1584 } 1585 1586 1587 /* ------------------------------------------------------------------------ */ 1588 /* Function: fr_stclone */ 1589 /* Returns: ipstate_t* - NULL == cloning failed, */ 1590 /* else pointer to new state structure */ 1591 /* Parameters: fin(I) - pointer to packet information */ 1592 /* tcp(I) - pointer to TCP/UDP header */ 1593 /* is(I) - pointer to master state structure */ 1594 /* */ 1595 /* Create a "duplcate" state table entry from the master. */ 1596 /* ------------------------------------------------------------------------ */ 1597 static ipstate_t *fr_stclone(fin, tcp, is) 1598 fr_info_t *fin; 1599 tcphdr_t *tcp; 1600 ipstate_t *is; 1601 { 1602 ipstate_t *clone; 1603 u_32_t send; 1604 ipf_stack_t *ifs = fin->fin_ifs; 1605 1606 if (ifs->ifs_ips_num == ifs->ifs_fr_statemax) { 1607 ATOMIC_INCL(ifs->ifs_ips_stats.iss_max); 1608 ifs->ifs_fr_state_doflush = 1; 1609 return NULL; 1610 } 1611 KMALLOC(clone, ipstate_t *); 1612 if (clone == NULL) 1613 return NULL; 1614 bcopy((char *)is, (char *)clone, sizeof(*clone)); 1615 1616 MUTEX_NUKE(&clone->is_lock); 1617 1618 clone->is_die = ONE_DAY + ifs->ifs_fr_ticks; 1619 clone->is_state[0] = 0; 1620 clone->is_state[1] = 0; 1621 send = ntohl(tcp->th_seq) + fin->fin_dlen - (TCP_OFF(tcp) << 2) + 1622 ((tcp->th_flags & TH_SYN) ? 1 : 0) + 1623 ((tcp->th_flags & TH_FIN) ? 1 : 0); 1624 1625 if (fin->fin_rev == 1) { 1626 clone->is_dend = send; 1627 clone->is_maxdend = send; 1628 clone->is_send = 0; 1629 clone->is_maxswin = 1; 1630 clone->is_maxdwin = ntohs(tcp->th_win); 1631 if (clone->is_maxdwin == 0) 1632 clone->is_maxdwin = 1; 1633 } else { 1634 clone->is_send = send; 1635 clone->is_maxsend = send; 1636 clone->is_dend = 0; 1637 clone->is_maxdwin = 1; 1638 clone->is_maxswin = ntohs(tcp->th_win); 1639 if (clone->is_maxswin == 0) 1640 clone->is_maxswin = 1; 1641 } 1642 1643 clone->is_flags &= ~SI_CLONE; 1644 clone->is_flags |= SI_CLONED; 1645 fr_stinsert(clone, fin->fin_rev, ifs); 1646 clone->is_ref = 2; 1647 if (clone->is_p == IPPROTO_TCP) { 1648 (void) fr_tcp_age(&clone->is_sti, fin, ifs->ifs_ips_tqtqb, 1649 clone->is_flags); 1650 } 1651 MUTEX_EXIT(&clone->is_lock); 1652 #ifdef IPFILTER_SCAN 1653 (void) ipsc_attachis(is); 1654 #endif 1655 #ifdef IPFILTER_SYNC 1656 if (is->is_flags & IS_STATESYNC) 1657 clone->is_sync = ipfsync_new(SMC_STATE, fin, clone); 1658 #endif 1659 return clone; 1660 } 1661 1662 1663 /* ------------------------------------------------------------------------ */ 1664 /* Function: fr_matchsrcdst */ 1665 /* Returns: Nil */ 1666 /* Parameters: fin(I) - pointer to packet information */ 1667 /* is(I) - pointer to state structure */ 1668 /* src(I) - pointer to source address */ 1669 /* dst(I) - pointer to destination address */ 1670 /* tcp(I) - pointer to TCP/UDP header */ 1671 /* */ 1672 /* Match a state table entry against an IP packet. The logic below is that */ 1673 /* ret gets set to one if the match succeeds, else remains 0. If it is */ 1674 /* still 0 after the test. no match. */ 1675 /* ------------------------------------------------------------------------ */ 1676 static ipstate_t *fr_matchsrcdst(fin, is, src, dst, tcp, cmask) 1677 fr_info_t *fin; 1678 ipstate_t *is; 1679 i6addr_t *src, *dst; 1680 tcphdr_t *tcp; 1681 u_32_t cmask; 1682 { 1683 int ret = 0, rev, out, flags, flx = 0, idx; 1684 u_short sp, dp; 1685 u_32_t cflx; 1686 void *ifp; 1687 ipf_stack_t *ifs = fin->fin_ifs; 1688 1689 rev = IP6_NEQ(&is->is_dst, dst); 1690 ifp = fin->fin_ifp; 1691 out = fin->fin_out; 1692 flags = is->is_flags; 1693 sp = 0; 1694 dp = 0; 1695 1696 if (tcp != NULL) { 1697 sp = htons(fin->fin_sport); 1698 dp = ntohs(fin->fin_dport); 1699 } 1700 if (!rev) { 1701 if (tcp != NULL) { 1702 if (!(flags & SI_W_SPORT) && (sp != is->is_sport)) 1703 rev = 1; 1704 else if (!(flags & SI_W_DPORT) && (dp != is->is_dport)) 1705 rev = 1; 1706 } 1707 } 1708 1709 idx = (out << 1) + rev; 1710 1711 /* 1712 * If the interface for this 'direction' is set, make sure it matches. 1713 * An interface name that is not set matches any, as does a name of *. 1714 */ 1715 if ((is->is_ifp[idx] == NULL && 1716 (*is->is_ifname[idx] == '\0' || *is->is_ifname[idx] == '*')) || 1717 is->is_ifp[idx] == ifp) 1718 ret = 1; 1719 1720 if (ret == 0) 1721 return NULL; 1722 ret = 0; 1723 1724 /* 1725 * Match addresses and ports. 1726 */ 1727 if (rev == 0) { 1728 if ((IP6_EQ(&is->is_dst, dst) || (flags & SI_W_DADDR)) && 1729 (IP6_EQ(&is->is_src, src) || (flags & SI_W_SADDR))) { 1730 if (tcp) { 1731 if ((sp == is->is_sport || flags & SI_W_SPORT)&& 1732 (dp == is->is_dport || flags & SI_W_DPORT)) 1733 ret = 1; 1734 } else { 1735 ret = 1; 1736 } 1737 } 1738 } else { 1739 if ((IP6_EQ(&is->is_dst, src) || (flags & SI_W_DADDR)) && 1740 (IP6_EQ(&is->is_src, dst) || (flags & SI_W_SADDR))) { 1741 if (tcp) { 1742 if ((dp == is->is_sport || flags & SI_W_SPORT)&& 1743 (sp == is->is_dport || flags & SI_W_DPORT)) 1744 ret = 1; 1745 } else { 1746 ret = 1; 1747 } 1748 } 1749 } 1750 1751 if (ret == 0) 1752 return NULL; 1753 1754 /* 1755 * Whether or not this should be here, is questionable, but the aim 1756 * is to get this out of the main line. 1757 */ 1758 if (tcp == NULL) 1759 flags = is->is_flags & ~(SI_WILDP|SI_NEWFR|SI_CLONE|SI_CLONED); 1760 1761 /* 1762 * Only one of the source or destination address can be flaged as a 1763 * wildcard. Fill in the missing address, if set. 1764 * For IPv6, if the address being copied in is multicast, then 1765 * don't reset the wild flag - multicast causes it to be set in the 1766 * first place! 1767 */ 1768 if ((flags & (SI_W_SADDR|SI_W_DADDR))) { 1769 fr_ip_t *fi = &fin->fin_fi; 1770 1771 if ((flags & SI_W_SADDR) != 0) { 1772 if (rev == 0) { 1773 #ifdef USE_INET6 1774 if (is->is_v == 6 && 1775 IN6_IS_ADDR_MULTICAST(&fi->fi_src.in6)) 1776 /*EMPTY*/; 1777 else 1778 #endif 1779 { 1780 is->is_src = fi->fi_src; 1781 is->is_flags &= ~SI_W_SADDR; 1782 } 1783 } else { 1784 #ifdef USE_INET6 1785 if (is->is_v == 6 && 1786 IN6_IS_ADDR_MULTICAST(&fi->fi_dst.in6)) 1787 /*EMPTY*/; 1788 else 1789 #endif 1790 { 1791 is->is_src = fi->fi_dst; 1792 is->is_flags &= ~SI_W_SADDR; 1793 } 1794 } 1795 } else if ((flags & SI_W_DADDR) != 0) { 1796 if (rev == 0) { 1797 #ifdef USE_INET6 1798 if (is->is_v == 6 && 1799 IN6_IS_ADDR_MULTICAST(&fi->fi_dst.in6)) 1800 /*EMPTY*/; 1801 else 1802 #endif 1803 { 1804 is->is_dst = fi->fi_dst; 1805 is->is_flags &= ~SI_W_DADDR; 1806 } 1807 } else { 1808 #ifdef USE_INET6 1809 if (is->is_v == 6 && 1810 IN6_IS_ADDR_MULTICAST(&fi->fi_src.in6)) 1811 /*EMPTY*/; 1812 else 1813 #endif 1814 { 1815 is->is_dst = fi->fi_src; 1816 is->is_flags &= ~SI_W_DADDR; 1817 } 1818 } 1819 } 1820 if ((is->is_flags & (SI_WILDA|SI_WILDP)) == 0) { 1821 ATOMIC_DECL(ifs->ifs_ips_stats.iss_wild); 1822 } 1823 } 1824 1825 flx = fin->fin_flx & cmask; 1826 cflx = is->is_flx[out][rev]; 1827 1828 /* 1829 * Match up any flags set from IP options. 1830 */ 1831 if ((cflx && (flx != (cflx & cmask))) || 1832 ((fin->fin_optmsk & is->is_optmsk[rev]) != is->is_opt[rev]) || 1833 ((fin->fin_secmsk & is->is_secmsk) != is->is_sec) || 1834 ((fin->fin_auth & is->is_authmsk) != is->is_auth)) 1835 return NULL; 1836 1837 /* 1838 * Only one of the source or destination port can be flagged as a 1839 * wildcard. When filling it in, fill in a copy of the matched entry 1840 * if it has the cloning flag set. 1841 */ 1842 if ((fin->fin_flx & FI_IGNORE) != 0) { 1843 fin->fin_rev = rev; 1844 return is; 1845 } 1846 1847 if ((flags & (SI_W_SPORT|SI_W_DPORT))) { 1848 if ((flags & SI_CLONE) != 0) { 1849 ipstate_t *clone; 1850 1851 clone = fr_stclone(fin, tcp, is); 1852 if (clone == NULL) 1853 return NULL; 1854 is = clone; 1855 } else { 1856 ATOMIC_DECL(ifs->ifs_ips_stats.iss_wild); 1857 } 1858 1859 if ((flags & SI_W_SPORT) != 0) { 1860 if (rev == 0) { 1861 is->is_sport = sp; 1862 is->is_send = ntohl(tcp->th_seq); 1863 } else { 1864 is->is_sport = dp; 1865 is->is_send = ntohl(tcp->th_ack); 1866 } 1867 is->is_maxsend = is->is_send + 1; 1868 } else if ((flags & SI_W_DPORT) != 0) { 1869 if (rev == 0) { 1870 is->is_dport = dp; 1871 is->is_dend = ntohl(tcp->th_ack); 1872 } else { 1873 is->is_dport = sp; 1874 is->is_dend = ntohl(tcp->th_seq); 1875 } 1876 is->is_maxdend = is->is_dend + 1; 1877 } 1878 is->is_flags &= ~(SI_W_SPORT|SI_W_DPORT); 1879 if ((flags & SI_CLONED) && ifs->ifs_ipstate_logging) 1880 ipstate_log(is, ISL_CLONE, ifs); 1881 } 1882 1883 ret = -1; 1884 1885 if (is->is_flx[out][rev] == 0) { 1886 is->is_flx[out][rev] = flx; 1887 is->is_opt[rev] = fin->fin_optmsk; 1888 if (is->is_v == 6) { 1889 is->is_opt[rev] &= ~0x8; 1890 is->is_optmsk[rev] &= ~0x8; 1891 } 1892 } 1893 1894 /* 1895 * Check if the interface name for this "direction" is set and if not, 1896 * fill it in. 1897 */ 1898 if (is->is_ifp[idx] == NULL && 1899 (*is->is_ifname[idx] == '\0' || *is->is_ifname[idx] == '*')) { 1900 is->is_ifp[idx] = ifp; 1901 COPYIFNAME(ifp, is->is_ifname[idx], fin->fin_v); 1902 } 1903 fin->fin_rev = rev; 1904 return is; 1905 } 1906 1907 1908 /* ------------------------------------------------------------------------ */ 1909 /* Function: fr_checkicmpmatchingstate */ 1910 /* Returns: Nil */ 1911 /* Parameters: fin(I) - pointer to packet information */ 1912 /* */ 1913 /* If we've got an ICMP error message, using the information stored in the */ 1914 /* ICMP packet, look for a matching state table entry. */ 1915 /* */ 1916 /* If we return NULL then no lock on ipf_state is held. */ 1917 /* If we return non-null then a read-lock on ipf_state is held. */ 1918 /* ------------------------------------------------------------------------ */ 1919 static ipstate_t *fr_checkicmpmatchingstate(fin) 1920 fr_info_t *fin; 1921 { 1922 ipstate_t *is, **isp; 1923 u_short sport, dport; 1924 u_char pr; 1925 int backward, i, oi; 1926 i6addr_t dst, src; 1927 struct icmp *ic; 1928 u_short savelen; 1929 icmphdr_t *icmp; 1930 fr_info_t ofin; 1931 tcphdr_t *tcp; 1932 int len; 1933 ip_t *oip; 1934 u_int hv; 1935 ipf_stack_t *ifs = fin->fin_ifs; 1936 1937 /* 1938 * Does it at least have the return (basic) IP header ? 1939 * Is it an actual recognised ICMP error type? 1940 * Only a basic IP header (no options) should be with 1941 * an ICMP error header. 1942 */ 1943 if ((fin->fin_v != 4) || (fin->fin_hlen != sizeof(ip_t)) || 1944 (fin->fin_plen < ICMPERR_MINPKTLEN) || 1945 !(fin->fin_flx & FI_ICMPERR)) 1946 return NULL; 1947 ic = fin->fin_dp; 1948 1949 oip = (ip_t *)((char *)ic + ICMPERR_ICMPHLEN); 1950 /* 1951 * Check if the at least the old IP header (with options) and 1952 * 8 bytes of payload is present. 1953 */ 1954 if (fin->fin_plen < ICMPERR_MAXPKTLEN + ((IP_HL(oip) - 5) << 2)) 1955 return NULL; 1956 1957 /* 1958 * Sanity Checks. 1959 */ 1960 len = fin->fin_dlen - ICMPERR_ICMPHLEN; 1961 if ((len <= 0) || ((IP_HL(oip) << 2) > len)) 1962 return NULL; 1963 1964 /* 1965 * Is the buffer big enough for all of it ? It's the size of the IP 1966 * header claimed in the encapsulated part which is of concern. It 1967 * may be too big to be in this buffer but not so big that it's 1968 * outside the ICMP packet, leading to TCP deref's causing problems. 1969 * This is possible because we don't know how big oip_hl is when we 1970 * do the pullup early in fr_check() and thus can't guarantee it is 1971 * all here now. 1972 */ 1973 #ifdef _KERNEL 1974 { 1975 mb_t *m; 1976 1977 m = fin->fin_m; 1978 # if defined(MENTAT) 1979 if ((char *)oip + len > (char *)m->b_wptr) 1980 return NULL; 1981 # else 1982 if ((char *)oip + len > (char *)fin->fin_ip + m->m_len) 1983 return NULL; 1984 # endif 1985 } 1986 #endif 1987 bcopy((char *)fin, (char *)&ofin, sizeof(*fin)); 1988 1989 /* 1990 * in the IPv4 case we must zero the i6addr union otherwise 1991 * the IP6_EQ and IP6_NEQ macros produce the wrong results because 1992 * of the 'junk' in the unused part of the union 1993 */ 1994 bzero((char *)&src, sizeof(src)); 1995 bzero((char *)&dst, sizeof(dst)); 1996 1997 /* 1998 * we make an fin entry to be able to feed it to 1999 * matchsrcdst note that not all fields are encessary 2000 * but this is the cleanest way. Note further we fill 2001 * in fin_mp such that if someone uses it we'll get 2002 * a kernel panic. fr_matchsrcdst does not use this. 2003 * 2004 * watch out here, as ip is in host order and oip in network 2005 * order. Any change we make must be undone afterwards, like 2006 * oip->ip_off - it is still in network byte order so fix it. 2007 */ 2008 savelen = oip->ip_len; 2009 oip->ip_len = len; 2010 oip->ip_off = ntohs(oip->ip_off); 2011 2012 ofin.fin_flx = FI_NOCKSUM; 2013 ofin.fin_v = 4; 2014 ofin.fin_ip = oip; 2015 ofin.fin_m = NULL; /* if dereferenced, panic XXX */ 2016 ofin.fin_mp = NULL; /* if dereferenced, panic XXX */ 2017 ofin.fin_plen = fin->fin_dlen - ICMPERR_ICMPHLEN; 2018 (void) fr_makefrip(IP_HL(oip) << 2, oip, &ofin); 2019 ofin.fin_ifp = fin->fin_ifp; 2020 ofin.fin_out = !fin->fin_out; 2021 /* 2022 * Reset the short and bad flag here because in fr_matchsrcdst() 2023 * the flags for the current packet (fin_flx) are compared against 2024 * those for the existing session. 2025 */ 2026 ofin.fin_flx &= ~(FI_BAD|FI_SHORT); 2027 2028 /* 2029 * Put old values of ip_len and ip_off back as we don't know 2030 * if we have to forward the packet (or process it again. 2031 */ 2032 oip->ip_len = savelen; 2033 oip->ip_off = htons(oip->ip_off); 2034 2035 switch (oip->ip_p) 2036 { 2037 case IPPROTO_ICMP : 2038 /* 2039 * an ICMP error can only be generated as a result of an 2040 * ICMP query, not as the response on an ICMP error 2041 * 2042 * XXX theoretically ICMP_ECHOREP and the other reply's are 2043 * ICMP query's as well, but adding them here seems strange XXX 2044 */ 2045 if ((ofin.fin_flx & FI_ICMPERR) != 0) 2046 return NULL; 2047 2048 /* 2049 * perform a lookup of the ICMP packet in the state table 2050 */ 2051 icmp = (icmphdr_t *)((char *)oip + (IP_HL(oip) << 2)); 2052 hv = (pr = oip->ip_p); 2053 src.in4 = oip->ip_src; 2054 hv += src.in4.s_addr; 2055 dst.in4 = oip->ip_dst; 2056 hv += dst.in4.s_addr; 2057 hv += icmp->icmp_id; 2058 hv = DOUBLE_HASH(hv, ifs); 2059 2060 READ_ENTER(&ifs->ifs_ipf_state); 2061 for (isp = &ifs->ifs_ips_table[hv]; ((is = *isp) != NULL); ) { 2062 isp = &is->is_hnext; 2063 if ((is->is_p != pr) || (is->is_v != 4)) 2064 continue; 2065 if (is->is_pass & FR_NOICMPERR) 2066 continue; 2067 is = fr_matchsrcdst(&ofin, is, &src, &dst, 2068 NULL, FI_ICMPCMP); 2069 if (is != NULL) { 2070 if ((is->is_pass & FR_NOICMPERR) != 0) { 2071 RWLOCK_EXIT(&ifs->ifs_ipf_state); 2072 return NULL; 2073 } 2074 /* 2075 * i : the index of this packet (the icmp 2076 * unreachable) 2077 * oi : the index of the original packet found 2078 * in the icmp header (i.e. the packet 2079 * causing this icmp) 2080 * backward : original packet was backward 2081 * compared to the state 2082 */ 2083 backward = IP6_NEQ(&is->is_src, &src); 2084 fin->fin_rev = !backward; 2085 i = (!backward << 1) + fin->fin_out; 2086 oi = (backward << 1) + ofin.fin_out; 2087 if (is->is_icmppkts[i] > is->is_pkts[oi]) 2088 continue; 2089 ifs->ifs_ips_stats.iss_hits++; 2090 is->is_icmppkts[i]++; 2091 return is; 2092 } 2093 } 2094 RWLOCK_EXIT(&ifs->ifs_ipf_state); 2095 return NULL; 2096 case IPPROTO_TCP : 2097 case IPPROTO_UDP : 2098 break; 2099 default : 2100 return NULL; 2101 } 2102 2103 tcp = (tcphdr_t *)((char *)oip + (IP_HL(oip) << 2)); 2104 dport = tcp->th_dport; 2105 sport = tcp->th_sport; 2106 2107 hv = (pr = oip->ip_p); 2108 src.in4 = oip->ip_src; 2109 hv += src.in4.s_addr; 2110 dst.in4 = oip->ip_dst; 2111 hv += dst.in4.s_addr; 2112 hv += dport; 2113 hv += sport; 2114 hv = DOUBLE_HASH(hv, ifs); 2115 2116 READ_ENTER(&ifs->ifs_ipf_state); 2117 for (isp = &ifs->ifs_ips_table[hv]; ((is = *isp) != NULL); ) { 2118 isp = &is->is_hnext; 2119 /* 2120 * Only allow this icmp though if the 2121 * encapsulated packet was allowed through the 2122 * other way around. Note that the minimal amount 2123 * of info present does not allow for checking against 2124 * tcp internals such as seq and ack numbers. Only the 2125 * ports are known to be present and can be even if the 2126 * short flag is set. 2127 */ 2128 if ((is->is_p == pr) && (is->is_v == 4) && 2129 (is = fr_matchsrcdst(&ofin, is, &src, &dst, 2130 tcp, FI_ICMPCMP))) { 2131 /* 2132 * i : the index of this packet (the icmp unreachable) 2133 * oi : the index of the original packet found in the 2134 * icmp header (i.e. the packet causing this icmp) 2135 * backward : original packet was backward compared to 2136 * the state 2137 */ 2138 backward = IP6_NEQ(&is->is_src, &src); 2139 fin->fin_rev = !backward; 2140 i = (!backward << 1) + fin->fin_out; 2141 oi = (backward << 1) + ofin.fin_out; 2142 2143 if (((is->is_pass & FR_NOICMPERR) != 0) || 2144 (is->is_icmppkts[i] > is->is_pkts[oi])) 2145 break; 2146 ifs->ifs_ips_stats.iss_hits++; 2147 is->is_icmppkts[i]++; 2148 /* 2149 * we deliberately do not touch the timeouts 2150 * for the accompanying state table entry. 2151 * It remains to be seen if that is correct. XXX 2152 */ 2153 return is; 2154 } 2155 } 2156 RWLOCK_EXIT(&ifs->ifs_ipf_state); 2157 return NULL; 2158 } 2159 2160 2161 /* ------------------------------------------------------------------------ */ 2162 /* Function: fr_ipsmove */ 2163 /* Returns: Nil */ 2164 /* Parameters: is(I) - pointer to state table entry */ 2165 /* hv(I) - new hash value for state table entry */ 2166 /* Write Locks: ipf_state */ 2167 /* */ 2168 /* Move a state entry from one position in the hash table to another. */ 2169 /* ------------------------------------------------------------------------ */ 2170 static void fr_ipsmove(is, hv, ifs) 2171 ipstate_t *is; 2172 u_int hv; 2173 ipf_stack_t *ifs; 2174 { 2175 ipstate_t **isp; 2176 u_int hvm; 2177 2178 ASSERT(rw_read_locked(&ifs->ifs_ipf_state.ipf_lk) == 0); 2179 2180 hvm = is->is_hv; 2181 /* 2182 * Remove the hash from the old location... 2183 */ 2184 isp = is->is_phnext; 2185 if (is->is_hnext) 2186 is->is_hnext->is_phnext = isp; 2187 *isp = is->is_hnext; 2188 if (ifs->ifs_ips_table[hvm] == NULL) 2189 ifs->ifs_ips_stats.iss_inuse--; 2190 ifs->ifs_ips_stats.iss_bucketlen[hvm]--; 2191 2192 /* 2193 * ...and put the hash in the new one. 2194 */ 2195 hvm = DOUBLE_HASH(hv, ifs); 2196 is->is_hv = hvm; 2197 isp = &ifs->ifs_ips_table[hvm]; 2198 if (*isp) 2199 (*isp)->is_phnext = &is->is_hnext; 2200 else 2201 ifs->ifs_ips_stats.iss_inuse++; 2202 ifs->ifs_ips_stats.iss_bucketlen[hvm]++; 2203 is->is_phnext = isp; 2204 is->is_hnext = *isp; 2205 *isp = is; 2206 } 2207 2208 2209 /* ------------------------------------------------------------------------ */ 2210 /* Function: fr_stlookup */ 2211 /* Returns: ipstate_t* - NULL == no matching state found, */ 2212 /* else pointer to state information is returned */ 2213 /* Parameters: fin(I) - pointer to packet information */ 2214 /* tcp(I) - pointer to TCP/UDP header. */ 2215 /* */ 2216 /* Search the state table for a matching entry to the packet described by */ 2217 /* the contents of *fin. */ 2218 /* */ 2219 /* If we return NULL then no lock on ipf_state is held. */ 2220 /* If we return non-null then a read-lock on ipf_state is held. */ 2221 /* ------------------------------------------------------------------------ */ 2222 ipstate_t *fr_stlookup(fin, tcp, ifqp) 2223 fr_info_t *fin; 2224 tcphdr_t *tcp; 2225 ipftq_t **ifqp; 2226 { 2227 u_int hv, hvm, pr, v, tryagain; 2228 ipstate_t *is, **isp; 2229 u_short dport, sport; 2230 i6addr_t src, dst; 2231 struct icmp *ic; 2232 ipftq_t *ifq; 2233 int oow; 2234 ipf_stack_t *ifs = fin->fin_ifs; 2235 2236 is = NULL; 2237 ifq = NULL; 2238 tcp = fin->fin_dp; 2239 ic = (struct icmp *)tcp; 2240 hv = (pr = fin->fin_fi.fi_p); 2241 src = fin->fin_fi.fi_src; 2242 dst = fin->fin_fi.fi_dst; 2243 hv += src.in4.s_addr; 2244 hv += dst.in4.s_addr; 2245 2246 v = fin->fin_fi.fi_v; 2247 #ifdef USE_INET6 2248 if (v == 6) { 2249 hv += fin->fin_fi.fi_src.i6[1]; 2250 hv += fin->fin_fi.fi_src.i6[2]; 2251 hv += fin->fin_fi.fi_src.i6[3]; 2252 2253 if ((fin->fin_p == IPPROTO_ICMPV6) && 2254 IN6_IS_ADDR_MULTICAST(&fin->fin_fi.fi_dst.in6)) { 2255 hv -= dst.in4.s_addr; 2256 } else { 2257 hv += fin->fin_fi.fi_dst.i6[1]; 2258 hv += fin->fin_fi.fi_dst.i6[2]; 2259 hv += fin->fin_fi.fi_dst.i6[3]; 2260 } 2261 } 2262 #endif 2263 2264 /* 2265 * Search the hash table for matching packet header info. 2266 */ 2267 switch (pr) 2268 { 2269 #ifdef USE_INET6 2270 case IPPROTO_ICMPV6 : 2271 tryagain = 0; 2272 if (v == 6) { 2273 if ((ic->icmp_type == ICMP6_ECHO_REQUEST) || 2274 (ic->icmp_type == ICMP6_ECHO_REPLY)) { 2275 hv += ic->icmp_id; 2276 } 2277 } 2278 READ_ENTER(&ifs->ifs_ipf_state); 2279 icmp6again: 2280 hvm = DOUBLE_HASH(hv, ifs); 2281 for (isp = &ifs->ifs_ips_table[hvm]; ((is = *isp) != NULL); ) { 2282 isp = &is->is_hnext; 2283 if ((is->is_p != pr) || (is->is_v != v)) 2284 continue; 2285 is = fr_matchsrcdst(fin, is, &src, &dst, NULL, FI_CMP); 2286 if (is != NULL && 2287 fr_matchicmpqueryreply(v, &is->is_icmp, 2288 ic, fin->fin_rev)) { 2289 if (fin->fin_rev) 2290 ifq = &ifs->ifs_ips_icmpacktq; 2291 else 2292 ifq = &ifs->ifs_ips_icmptq; 2293 break; 2294 } 2295 } 2296 2297 if (is != NULL) { 2298 if ((tryagain != 0) && !(is->is_flags & SI_W_DADDR)) { 2299 hv += fin->fin_fi.fi_src.i6[0]; 2300 hv += fin->fin_fi.fi_src.i6[1]; 2301 hv += fin->fin_fi.fi_src.i6[2]; 2302 hv += fin->fin_fi.fi_src.i6[3]; 2303 fr_ipsmove(is, hv, ifs); 2304 MUTEX_DOWNGRADE(&ifs->ifs_ipf_state); 2305 } 2306 break; 2307 } 2308 RWLOCK_EXIT(&ifs->ifs_ipf_state); 2309 2310 /* 2311 * No matching icmp state entry. Perhaps this is a 2312 * response to another state entry. 2313 * 2314 * XXX With some ICMP6 packets, the "other" address is already 2315 * in the packet, after the ICMP6 header, and this could be 2316 * used in place of the multicast address. However, taking 2317 * advantage of this requires some significant code changes 2318 * to handle the specific types where that is the case. 2319 */ 2320 if ((ifs->ifs_ips_stats.iss_wild != 0) && (v == 6) && (tryagain == 0) && 2321 !IN6_IS_ADDR_MULTICAST(&fin->fin_fi.fi_src.in6)) { 2322 hv -= fin->fin_fi.fi_src.i6[0]; 2323 hv -= fin->fin_fi.fi_src.i6[1]; 2324 hv -= fin->fin_fi.fi_src.i6[2]; 2325 hv -= fin->fin_fi.fi_src.i6[3]; 2326 tryagain = 1; 2327 WRITE_ENTER(&ifs->ifs_ipf_state); 2328 goto icmp6again; 2329 } 2330 2331 is = fr_checkicmp6matchingstate(fin); 2332 if (is != NULL) 2333 return is; 2334 break; 2335 #endif 2336 2337 case IPPROTO_ICMP : 2338 if (v == 4) { 2339 hv += ic->icmp_id; 2340 } 2341 hv = DOUBLE_HASH(hv, ifs); 2342 READ_ENTER(&ifs->ifs_ipf_state); 2343 for (isp = &ifs->ifs_ips_table[hv]; ((is = *isp) != NULL); ) { 2344 isp = &is->is_hnext; 2345 if ((is->is_p != pr) || (is->is_v != v)) 2346 continue; 2347 is = fr_matchsrcdst(fin, is, &src, &dst, NULL, FI_CMP); 2348 if (is != NULL && 2349 fr_matchicmpqueryreply(v, &is->is_icmp, 2350 ic, fin->fin_rev)) { 2351 if (fin->fin_rev) 2352 ifq = &ifs->ifs_ips_icmpacktq; 2353 else 2354 ifq = &ifs->ifs_ips_icmptq; 2355 break; 2356 } 2357 } 2358 if (is == NULL) { 2359 RWLOCK_EXIT(&ifs->ifs_ipf_state); 2360 } 2361 break; 2362 2363 case IPPROTO_TCP : 2364 case IPPROTO_UDP : 2365 ifqp = NULL; 2366 sport = htons(fin->fin_data[0]); 2367 hv += sport; 2368 dport = htons(fin->fin_data[1]); 2369 hv += dport; 2370 oow = 0; 2371 tryagain = 0; 2372 READ_ENTER(&ifs->ifs_ipf_state); 2373 retry_tcpudp: 2374 hvm = DOUBLE_HASH(hv, ifs); 2375 for (isp = &ifs->ifs_ips_table[hvm]; ((is = *isp) != NULL); ) { 2376 isp = &is->is_hnext; 2377 if ((is->is_p != pr) || (is->is_v != v)) 2378 continue; 2379 fin->fin_flx &= ~FI_OOW; 2380 is = fr_matchsrcdst(fin, is, &src, &dst, tcp, FI_CMP); 2381 if (is != NULL) { 2382 if (pr == IPPROTO_TCP) { 2383 if (!fr_tcpstate(fin, tcp, is)) { 2384 oow |= fin->fin_flx & FI_OOW; 2385 continue; 2386 } 2387 } 2388 break; 2389 } 2390 } 2391 if (is != NULL) { 2392 if (tryagain && 2393 !(is->is_flags & (SI_CLONE|SI_WILDP|SI_WILDA))) { 2394 hv += dport; 2395 hv += sport; 2396 fr_ipsmove(is, hv, ifs); 2397 MUTEX_DOWNGRADE(&ifs->ifs_ipf_state); 2398 } 2399 break; 2400 } 2401 RWLOCK_EXIT(&ifs->ifs_ipf_state); 2402 2403 if (!tryagain && ifs->ifs_ips_stats.iss_wild) { 2404 hv -= dport; 2405 hv -= sport; 2406 tryagain = 1; 2407 WRITE_ENTER(&ifs->ifs_ipf_state); 2408 goto retry_tcpudp; 2409 } 2410 fin->fin_flx |= oow; 2411 break; 2412 2413 #if 0 2414 case IPPROTO_GRE : 2415 gre = fin->fin_dp; 2416 if (GRE_REV(gre->gr_flags) == 1) { 2417 hv += gre->gr_call; 2418 } 2419 /* FALLTHROUGH */ 2420 #endif 2421 default : 2422 ifqp = NULL; 2423 hvm = DOUBLE_HASH(hv, ifs); 2424 READ_ENTER(&ifs->ifs_ipf_state); 2425 for (isp = &ifs->ifs_ips_table[hvm]; ((is = *isp) != NULL); ) { 2426 isp = &is->is_hnext; 2427 if ((is->is_p != pr) || (is->is_v != v)) 2428 continue; 2429 is = fr_matchsrcdst(fin, is, &src, &dst, NULL, FI_CMP); 2430 if (is != NULL) { 2431 ifq = &ifs->ifs_ips_iptq; 2432 break; 2433 } 2434 } 2435 if (is == NULL) { 2436 RWLOCK_EXIT(&ifs->ifs_ipf_state); 2437 } 2438 break; 2439 } 2440 2441 if ((is != NULL) && ((is->is_sti.tqe_flags & TQE_RULEBASED) != 0) && 2442 (is->is_tqehead[fin->fin_rev] != NULL)) 2443 ifq = is->is_tqehead[fin->fin_rev]; 2444 if (ifq != NULL && ifqp != NULL) 2445 *ifqp = ifq; 2446 return is; 2447 } 2448 2449 2450 /* ------------------------------------------------------------------------ */ 2451 /* Function: fr_updatestate */ 2452 /* Returns: Nil */ 2453 /* Parameters: fin(I) - pointer to packet information */ 2454 /* is(I) - pointer to state table entry */ 2455 /* Read Locks: ipf_state */ 2456 /* */ 2457 /* Updates packet and byte counters for a newly received packet. Seeds the */ 2458 /* fragment cache with a new entry as required. */ 2459 /* ------------------------------------------------------------------------ */ 2460 void fr_updatestate(fin, is, ifq) 2461 fr_info_t *fin; 2462 ipstate_t *is; 2463 ipftq_t *ifq; 2464 { 2465 ipftqent_t *tqe; 2466 int i, pass; 2467 ipf_stack_t *ifs = fin->fin_ifs; 2468 2469 i = (fin->fin_rev << 1) + fin->fin_out; 2470 2471 /* 2472 * For TCP packets, ifq == NULL. For all others, check if this new 2473 * queue is different to the last one it was on and move it if so. 2474 */ 2475 tqe = &is->is_sti; 2476 MUTEX_ENTER(&is->is_lock); 2477 if ((tqe->tqe_flags & TQE_RULEBASED) != 0) 2478 ifq = is->is_tqehead[fin->fin_rev]; 2479 2480 if (ifq != NULL) 2481 fr_movequeue(tqe, tqe->tqe_ifq, ifq, ifs); 2482 2483 is->is_pkts[i]++; 2484 is->is_bytes[i] += fin->fin_plen; 2485 MUTEX_EXIT(&is->is_lock); 2486 2487 #ifdef IPFILTER_SYNC 2488 if (is->is_flags & IS_STATESYNC) 2489 ipfsync_update(SMC_STATE, fin, is->is_sync); 2490 #endif 2491 2492 ATOMIC_INCL(ifs->ifs_ips_stats.iss_hits); 2493 2494 fin->fin_fr = is->is_rule; 2495 2496 /* 2497 * If this packet is a fragment and the rule says to track fragments, 2498 * then create a new fragment cache entry. 2499 */ 2500 pass = is->is_pass; 2501 if ((fin->fin_flx & FI_FRAG) && FR_ISPASS(pass)) 2502 (void) fr_newfrag(fin, pass ^ FR_KEEPSTATE); 2503 } 2504 2505 2506 /* ------------------------------------------------------------------------ */ 2507 /* Function: fr_checkstate */ 2508 /* Returns: frentry_t* - NULL == search failed, */ 2509 /* else pointer to rule for matching state */ 2510 /* Parameters: ifp(I) - pointer to interface */ 2511 /* passp(I) - pointer to filtering result flags */ 2512 /* */ 2513 /* Check if a packet is associated with an entry in the state table. */ 2514 /* ------------------------------------------------------------------------ */ 2515 frentry_t *fr_checkstate(fin, passp) 2516 fr_info_t *fin; 2517 u_32_t *passp; 2518 { 2519 ipstate_t *is; 2520 frentry_t *fr; 2521 tcphdr_t *tcp; 2522 ipftq_t *ifq; 2523 u_int pass; 2524 ipf_stack_t *ifs = fin->fin_ifs; 2525 2526 if (ifs->ifs_fr_state_lock || (ifs->ifs_ips_list == NULL) || 2527 (fin->fin_flx & (FI_SHORT|FI_STATE|FI_FRAGBODY|FI_BAD))) 2528 return NULL; 2529 2530 is = NULL; 2531 if ((fin->fin_flx & FI_TCPUDP) || 2532 (fin->fin_fi.fi_p == IPPROTO_ICMP) 2533 #ifdef USE_INET6 2534 || (fin->fin_fi.fi_p == IPPROTO_ICMPV6) 2535 #endif 2536 ) 2537 tcp = fin->fin_dp; 2538 else 2539 tcp = NULL; 2540 2541 /* 2542 * Search the hash table for matching packet header info. 2543 */ 2544 ifq = NULL; 2545 is = fin->fin_state; 2546 if (is == NULL) 2547 is = fr_stlookup(fin, tcp, &ifq); 2548 switch (fin->fin_p) 2549 { 2550 #ifdef USE_INET6 2551 case IPPROTO_ICMPV6 : 2552 if (is != NULL) 2553 break; 2554 if (fin->fin_v == 6) { 2555 is = fr_checkicmp6matchingstate(fin); 2556 if (is != NULL) 2557 goto matched; 2558 } 2559 break; 2560 #endif 2561 case IPPROTO_ICMP : 2562 if (is != NULL) 2563 break; 2564 /* 2565 * No matching icmp state entry. Perhaps this is a 2566 * response to another state entry. 2567 */ 2568 is = fr_checkicmpmatchingstate(fin); 2569 if (is != NULL) 2570 goto matched; 2571 break; 2572 case IPPROTO_TCP : 2573 if (is == NULL) 2574 break; 2575 2576 if (is->is_pass & FR_NEWISN) { 2577 if (fin->fin_out == 0) 2578 fr_fixinisn(fin, is); 2579 else if (fin->fin_out == 1) 2580 fr_fixoutisn(fin, is); 2581 } 2582 break; 2583 default : 2584 if (fin->fin_rev) 2585 ifq = &ifs->ifs_ips_udpacktq; 2586 else 2587 ifq = &ifs->ifs_ips_udptq; 2588 break; 2589 } 2590 if (is == NULL) { 2591 ATOMIC_INCL(ifs->ifs_ips_stats.iss_miss); 2592 return NULL; 2593 } 2594 2595 matched: 2596 fr = is->is_rule; 2597 if (fr != NULL) { 2598 if ((fin->fin_out == 0) && (fr->fr_nattag.ipt_num[0] != 0)) { 2599 if (fin->fin_nattag == NULL) 2600 return NULL; 2601 if (fr_matchtag(&fr->fr_nattag, fin->fin_nattag) != 0) 2602 return NULL; 2603 } 2604 (void) strncpy(fin->fin_group, fr->fr_group, FR_GROUPLEN); 2605 fin->fin_icode = fr->fr_icode; 2606 } 2607 2608 fin->fin_rule = is->is_rulen; 2609 pass = is->is_pass; 2610 fr_updatestate(fin, is, ifq); 2611 if (fin->fin_out == 1) 2612 fin->fin_nat = is->is_nat[fin->fin_rev]; 2613 2614 fin->fin_state = is; 2615 is->is_touched = ifs->ifs_fr_ticks; 2616 MUTEX_ENTER(&is->is_lock); 2617 is->is_ref++; 2618 MUTEX_EXIT(&is->is_lock); 2619 RWLOCK_EXIT(&ifs->ifs_ipf_state); 2620 fin->fin_flx |= FI_STATE; 2621 if ((pass & FR_LOGFIRST) != 0) 2622 pass &= ~(FR_LOGFIRST|FR_LOG); 2623 *passp = pass; 2624 return fr; 2625 } 2626 2627 2628 /* ------------------------------------------------------------------------ */ 2629 /* Function: fr_fixoutisn */ 2630 /* Returns: Nil */ 2631 /* Parameters: fin(I) - pointer to packet information */ 2632 /* is(I) - pointer to master state structure */ 2633 /* */ 2634 /* Called only for outbound packets, adjusts the sequence number and the */ 2635 /* TCP checksum to match that change. */ 2636 /* ------------------------------------------------------------------------ */ 2637 static void fr_fixoutisn(fin, is) 2638 fr_info_t *fin; 2639 ipstate_t *is; 2640 { 2641 tcphdr_t *tcp; 2642 int rev; 2643 u_32_t seq; 2644 2645 tcp = fin->fin_dp; 2646 rev = fin->fin_rev; 2647 if ((is->is_flags & IS_ISNSYN) != 0) { 2648 if (rev == 0) { 2649 seq = ntohl(tcp->th_seq); 2650 seq += is->is_isninc[0]; 2651 tcp->th_seq = htonl(seq); 2652 fix_outcksum(&tcp->th_sum, is->is_sumd[0]); 2653 } 2654 } 2655 if ((is->is_flags & IS_ISNACK) != 0) { 2656 if (rev == 1) { 2657 seq = ntohl(tcp->th_seq); 2658 seq += is->is_isninc[1]; 2659 tcp->th_seq = htonl(seq); 2660 fix_outcksum(&tcp->th_sum, is->is_sumd[1]); 2661 } 2662 } 2663 } 2664 2665 2666 /* ------------------------------------------------------------------------ */ 2667 /* Function: fr_fixinisn */ 2668 /* Returns: Nil */ 2669 /* Parameters: fin(I) - pointer to packet information */ 2670 /* is(I) - pointer to master state structure */ 2671 /* */ 2672 /* Called only for inbound packets, adjusts the acknowledge number and the */ 2673 /* TCP checksum to match that change. */ 2674 /* ------------------------------------------------------------------------ */ 2675 static void fr_fixinisn(fin, is) 2676 fr_info_t *fin; 2677 ipstate_t *is; 2678 { 2679 tcphdr_t *tcp; 2680 int rev; 2681 u_32_t ack; 2682 2683 tcp = fin->fin_dp; 2684 rev = fin->fin_rev; 2685 if ((is->is_flags & IS_ISNSYN) != 0) { 2686 if (rev == 1) { 2687 ack = ntohl(tcp->th_ack); 2688 ack -= is->is_isninc[0]; 2689 tcp->th_ack = htonl(ack); 2690 fix_incksum(&tcp->th_sum, is->is_sumd[0]); 2691 } 2692 } 2693 if ((is->is_flags & IS_ISNACK) != 0) { 2694 if (rev == 0) { 2695 ack = ntohl(tcp->th_ack); 2696 ack -= is->is_isninc[1]; 2697 tcp->th_ack = htonl(ack); 2698 fix_incksum(&tcp->th_sum, is->is_sumd[1]); 2699 } 2700 } 2701 } 2702 2703 2704 /* ------------------------------------------------------------------------ */ 2705 /* Function: fr_statesync */ 2706 /* Returns: Nil */ 2707 /* Parameters: action(I) - type of synchronisation to do */ 2708 /* v(I) - IP version being sync'd (v4 or v6) */ 2709 /* ifp(I) - interface identifier associated with action */ 2710 /* name(I) - name associated with ifp parameter */ 2711 /* */ 2712 /* Walk through all state entries and if an interface pointer match is */ 2713 /* found then look it up again, based on its name in case the pointer has */ 2714 /* changed since last time. */ 2715 /* */ 2716 /* If ifp is passed in as being non-null then we are only doing updates for */ 2717 /* existing, matching, uses of it. */ 2718 /* ------------------------------------------------------------------------ */ 2719 void fr_statesync(action, v, ifp, name, ifs) 2720 int action, v; 2721 void *ifp; 2722 char *name; 2723 ipf_stack_t *ifs; 2724 { 2725 ipstate_t *is; 2726 int i; 2727 2728 if (ifs->ifs_fr_running <= 0) 2729 return; 2730 2731 WRITE_ENTER(&ifs->ifs_ipf_state); 2732 2733 if (ifs->ifs_fr_running <= 0) { 2734 RWLOCK_EXIT(&ifs->ifs_ipf_state); 2735 return; 2736 } 2737 2738 switch (action) 2739 { 2740 case IPFSYNC_RESYNC : 2741 for (is = ifs->ifs_ips_list; is; is = is->is_next) { 2742 if (v != 0 && is->is_v != v) 2743 continue; 2744 /* 2745 * Look up all the interface names in the state entry. 2746 */ 2747 for (i = 0; i < 4; i++) { 2748 is->is_ifp[i] = fr_resolvenic(is->is_ifname[i], 2749 is->is_v, ifs); 2750 } 2751 } 2752 break; 2753 case IPFSYNC_NEWIFP : 2754 for (is = ifs->ifs_ips_list; is; is = is->is_next) { 2755 if (v != 0 && is->is_v != v) 2756 continue; 2757 /* 2758 * Look up all the interface names in the state entry. 2759 */ 2760 for (i = 0; i < 4; i++) { 2761 if (!strncmp(is->is_ifname[i], name, 2762 sizeof(is->is_ifname[i]))) 2763 is->is_ifp[i] = ifp; 2764 } 2765 } 2766 break; 2767 case IPFSYNC_OLDIFP : 2768 for (is = ifs->ifs_ips_list; is; is = is->is_next) { 2769 if (v != 0 && is->is_v != v) 2770 continue; 2771 /* 2772 * Look up all the interface names in the state entry. 2773 */ 2774 for (i = 0; i < 4; i++) { 2775 if (is->is_ifp[i] == ifp) 2776 is->is_ifp[i] = (void *)-1; 2777 } 2778 } 2779 break; 2780 } 2781 RWLOCK_EXIT(&ifs->ifs_ipf_state); 2782 } 2783 2784 2785 /* ------------------------------------------------------------------------ */ 2786 /* Function: fr_delstate */ 2787 /* Returns: Nil */ 2788 /* Parameters: is(I) - pointer to state structure to delete */ 2789 /* why(I) - if not 0, log reason why it was deleted */ 2790 /* Write Locks: ipf_state/ipf_global */ 2791 /* */ 2792 /* Deletes a state entry from the enumerated list as well as the hash table */ 2793 /* and timeout queue lists. Make adjustments to hash table statistics and */ 2794 /* global counters as required. */ 2795 /* ------------------------------------------------------------------------ */ 2796 static void fr_delstate(is, why, ifs) 2797 ipstate_t *is; 2798 int why; 2799 ipf_stack_t *ifs; 2800 { 2801 2802 ASSERT(rw_write_held(&ifs->ifs_ipf_global.ipf_lk) == 0 || 2803 rw_write_held(&ifs->ifs_ipf_state.ipf_lk) == 0); 2804 2805 /* 2806 * Since we want to delete this, remove it from the state table, 2807 * where it can be found & used, first. 2808 */ 2809 if (is->is_pnext != NULL) { 2810 *is->is_pnext = is->is_next; 2811 2812 if (is->is_next != NULL) 2813 is->is_next->is_pnext = is->is_pnext; 2814 2815 is->is_pnext = NULL; 2816 is->is_next = NULL; 2817 } 2818 2819 if (is->is_phnext != NULL) { 2820 *is->is_phnext = is->is_hnext; 2821 if (is->is_hnext != NULL) 2822 is->is_hnext->is_phnext = is->is_phnext; 2823 if (ifs->ifs_ips_table[is->is_hv] == NULL) 2824 ifs->ifs_ips_stats.iss_inuse--; 2825 ifs->ifs_ips_stats.iss_bucketlen[is->is_hv]--; 2826 2827 is->is_phnext = NULL; 2828 is->is_hnext = NULL; 2829 } 2830 2831 /* 2832 * Because ifs->ifs_ips_stats.iss_wild is a count of entries in the state 2833 * table that have wildcard flags set, only decerement it once 2834 * and do it here. 2835 */ 2836 if (is->is_flags & (SI_WILDP|SI_WILDA)) { 2837 if (!(is->is_flags & SI_CLONED)) { 2838 ATOMIC_DECL(ifs->ifs_ips_stats.iss_wild); 2839 } 2840 is->is_flags &= ~(SI_WILDP|SI_WILDA); 2841 } 2842 2843 /* 2844 * Next, remove it from the timeout queue it is in. 2845 */ 2846 fr_deletequeueentry(&is->is_sti); 2847 2848 is->is_me = NULL; 2849 2850 /* 2851 * If it is still in use by something else, do not go any further, 2852 * but note that at this point it is now an orphan. 2853 */ 2854 is->is_ref--; 2855 if (is->is_ref > 0) 2856 return; 2857 2858 if (is->is_tqehead[0] != NULL) { 2859 if (fr_deletetimeoutqueue(is->is_tqehead[0]) == 0) 2860 fr_freetimeoutqueue(is->is_tqehead[0], ifs); 2861 } 2862 if (is->is_tqehead[1] != NULL) { 2863 if (fr_deletetimeoutqueue(is->is_tqehead[1]) == 0) 2864 fr_freetimeoutqueue(is->is_tqehead[1], ifs); 2865 } 2866 2867 #ifdef IPFILTER_SYNC 2868 if (is->is_sync) 2869 ipfsync_del(is->is_sync); 2870 #endif 2871 #ifdef IPFILTER_SCAN 2872 (void) ipsc_detachis(is); 2873 #endif 2874 2875 if (ifs->ifs_ipstate_logging != 0 && why != 0) 2876 ipstate_log(is, why, ifs); 2877 2878 if (is->is_rule != NULL) { 2879 is->is_rule->fr_statecnt--; 2880 (void)fr_derefrule(&is->is_rule, ifs); 2881 } 2882 2883 MUTEX_DESTROY(&is->is_lock); 2884 KFREE(is); 2885 ifs->ifs_ips_num--; 2886 } 2887 2888 2889 /* ------------------------------------------------------------------------ */ 2890 /* Function: fr_timeoutstate */ 2891 /* Returns: Nil */ 2892 /* Parameters: Nil */ 2893 /* */ 2894 /* Slowly expire held state for thingslike UDP and ICMP. The algorithm */ 2895 /* used here is to keep the queue sorted with the oldest things at the top */ 2896 /* and the youngest at the bottom. So if the top one doesn't need to be */ 2897 /* expired then neither will any under it. */ 2898 /* ------------------------------------------------------------------------ */ 2899 void fr_timeoutstate(ifs) 2900 ipf_stack_t *ifs; 2901 { 2902 ipftq_t *ifq, *ifqnext; 2903 ipftqent_t *tqe, *tqn; 2904 ipstate_t *is; 2905 SPL_INT(s); 2906 2907 SPL_NET(s); 2908 WRITE_ENTER(&ifs->ifs_ipf_state); 2909 for (ifq = ifs->ifs_ips_tqtqb; ifq != NULL; ifq = ifq->ifq_next) 2910 for (tqn = ifq->ifq_head; ((tqe = tqn) != NULL); ) { 2911 if (tqe->tqe_die > ifs->ifs_fr_ticks) 2912 break; 2913 tqn = tqe->tqe_next; 2914 is = tqe->tqe_parent; 2915 fr_delstate(is, ISL_EXPIRE, ifs); 2916 } 2917 2918 for (ifq = ifs->ifs_ips_utqe; ifq != NULL; ifq = ifqnext) { 2919 ifqnext = ifq->ifq_next; 2920 2921 for (tqn = ifq->ifq_head; ((tqe = tqn) != NULL); ) { 2922 if (tqe->tqe_die > ifs->ifs_fr_ticks) 2923 break; 2924 tqn = tqe->tqe_next; 2925 is = tqe->tqe_parent; 2926 fr_delstate(is, ISL_EXPIRE, ifs); 2927 } 2928 } 2929 2930 for (ifq = ifs->ifs_ips_utqe; ifq != NULL; ifq = ifqnext) { 2931 ifqnext = ifq->ifq_next; 2932 2933 if (((ifq->ifq_flags & IFQF_DELETE) != 0) && 2934 (ifq->ifq_ref == 0)) { 2935 fr_freetimeoutqueue(ifq, ifs); 2936 } 2937 } 2938 2939 if (ifs->ifs_fr_state_doflush) { 2940 (void) fr_state_flush(2, 0, ifs); 2941 ifs->ifs_fr_state_doflush = 0; 2942 } 2943 RWLOCK_EXIT(&ifs->ifs_ipf_state); 2944 SPL_X(s); 2945 } 2946 2947 2948 /* ------------------------------------------------------------------------ */ 2949 /* Function: fr_state_flush */ 2950 /* Returns: int - 0 == success, -1 == failure */ 2951 /* Parameters: Nil */ 2952 /* Write Locks: ipf_state */ 2953 /* */ 2954 /* Flush state tables. Three actions currently defined: */ 2955 /* which == 0 : flush all state table entries */ 2956 /* which == 1 : flush TCP connections which have started to close but are */ 2957 /* stuck for some reason. */ 2958 /* which == 2 : flush TCP connections which have been idle for a long time, */ 2959 /* starting at > 4 days idle and working back in successive half-*/ 2960 /* days to at most 12 hours old. If this fails to free enough */ 2961 /* slots then work backwards in half hour slots to 30 minutes. */ 2962 /* If that too fails, then work backwards in 30 second intervals */ 2963 /* for the last 30 minutes to at worst 30 seconds idle. */ 2964 /* ------------------------------------------------------------------------ */ 2965 static int fr_state_flush(which, proto, ifs) 2966 int which, proto; 2967 ipf_stack_t *ifs; 2968 { 2969 ipftq_t *ifq, *ifqnext; 2970 ipftqent_t *tqe, *tqn; 2971 ipstate_t *is, **isp; 2972 int delete, removed; 2973 long try, maxtick; 2974 u_long interval; 2975 SPL_INT(s); 2976 2977 removed = 0; 2978 2979 SPL_NET(s); 2980 for (isp = &ifs->ifs_ips_list; ((is = *isp) != NULL); ) { 2981 delete = 0; 2982 2983 if ((proto != 0) && (is->is_v != proto)) { 2984 isp = &is->is_next; 2985 continue; 2986 } 2987 2988 switch (which) 2989 { 2990 case 0 : 2991 delete = 1; 2992 break; 2993 case 1 : 2994 case 2 : 2995 if (is->is_p != IPPROTO_TCP) 2996 break; 2997 if ((is->is_state[0] != IPF_TCPS_ESTABLISHED) || 2998 (is->is_state[1] != IPF_TCPS_ESTABLISHED)) 2999 delete = 1; 3000 break; 3001 } 3002 3003 if (delete) { 3004 if (is->is_p == IPPROTO_TCP) 3005 ifs->ifs_ips_stats.iss_fin++; 3006 else 3007 ifs->ifs_ips_stats.iss_expire++; 3008 fr_delstate(is, ISL_FLUSH, ifs); 3009 removed++; 3010 } else 3011 isp = &is->is_next; 3012 } 3013 3014 if (which != 2) { 3015 SPL_X(s); 3016 return removed; 3017 } 3018 3019 /* 3020 * Asked to remove inactive entries because the table is full, try 3021 * again, 3 times, if first attempt failed with a different criteria 3022 * each time. The order tried in must be in decreasing age. 3023 * Another alternative is to implement random drop and drop N entries 3024 * at random until N have been freed up. 3025 */ 3026 if (ifs->ifs_fr_ticks - ifs->ifs_ips_last_force_flush < IPF_TTLVAL(5)) 3027 goto force_flush_skipped; 3028 ifs->ifs_ips_last_force_flush = ifs->ifs_fr_ticks; 3029 3030 if (ifs->ifs_fr_ticks > IPF_TTLVAL(43200)) 3031 interval = IPF_TTLVAL(43200); 3032 else if (ifs->ifs_fr_ticks > IPF_TTLVAL(1800)) 3033 interval = IPF_TTLVAL(1800); 3034 else if (ifs->ifs_fr_ticks > IPF_TTLVAL(30)) 3035 interval = IPF_TTLVAL(30); 3036 else 3037 interval = IPF_TTLVAL(10); 3038 try = ifs->ifs_fr_ticks - (ifs->ifs_fr_ticks - interval); 3039 if (try < 0) 3040 goto force_flush_skipped; 3041 3042 while (removed == 0) { 3043 maxtick = ifs->ifs_fr_ticks - interval; 3044 if (maxtick < 0) 3045 break; 3046 3047 while (try < maxtick) { 3048 for (ifq = ifs->ifs_ips_tqtqb; ifq != NULL; 3049 ifq = ifq->ifq_next) { 3050 for (tqn = ifq->ifq_head; 3051 ((tqe = tqn) != NULL); ) { 3052 if (tqe->tqe_die > try) 3053 break; 3054 tqn = tqe->tqe_next; 3055 is = tqe->tqe_parent; 3056 fr_delstate(is, ISL_EXPIRE, ifs); 3057 removed++; 3058 } 3059 } 3060 3061 for (ifq = ifs->ifs_ips_utqe; ifq != NULL; ifq = ifqnext) { 3062 ifqnext = ifq->ifq_next; 3063 3064 for (tqn = ifq->ifq_head; 3065 ((tqe = tqn) != NULL); ) { 3066 if (tqe->tqe_die > try) 3067 break; 3068 tqn = tqe->tqe_next; 3069 is = tqe->tqe_parent; 3070 fr_delstate(is, ISL_EXPIRE, ifs); 3071 removed++; 3072 } 3073 } 3074 if (try + interval > maxtick) 3075 break; 3076 try += interval; 3077 } 3078 3079 if (removed == 0) { 3080 if (interval == IPF_TTLVAL(43200)) { 3081 interval = IPF_TTLVAL(1800); 3082 } else if (interval == IPF_TTLVAL(1800)) { 3083 interval = IPF_TTLVAL(30); 3084 } else if (interval == IPF_TTLVAL(30)) { 3085 interval = IPF_TTLVAL(10); 3086 } else { 3087 break; 3088 } 3089 } 3090 } 3091 force_flush_skipped: 3092 SPL_X(s); 3093 return removed; 3094 } 3095 3096 3097 3098 /* ------------------------------------------------------------------------ */ 3099 /* Function: fr_tcp_age */ 3100 /* Returns: int - 1 == state transition made, 0 == no change (rejected) */ 3101 /* Parameters: tq(I) - pointer to timeout queue information */ 3102 /* fin(I) - pointer to packet information */ 3103 /* tqtab(I) - TCP timeout queue table this is in */ 3104 /* flags(I) - flags from state/NAT entry */ 3105 /* */ 3106 /* Rewritten by Arjan de Vet <Arjan.deVet@adv.iae.nl>, 2000-07-29: */ 3107 /* */ 3108 /* - (try to) base state transitions on real evidence only, */ 3109 /* i.e. packets that are sent and have been received by ipfilter; */ 3110 /* diagram 18.12 of TCP/IP volume 1 by W. Richard Stevens was used. */ 3111 /* */ 3112 /* - deal with half-closed connections correctly; */ 3113 /* */ 3114 /* - store the state of the source in state[0] such that ipfstat */ 3115 /* displays the state as source/dest instead of dest/source; the calls */ 3116 /* to fr_tcp_age have been changed accordingly. */ 3117 /* */ 3118 /* Internal Parameters: */ 3119 /* */ 3120 /* state[0] = state of source (host that initiated connection) */ 3121 /* state[1] = state of dest (host that accepted the connection) */ 3122 /* */ 3123 /* dir == 0 : a packet from source to dest */ 3124 /* dir == 1 : a packet from dest to source */ 3125 /* */ 3126 /* Locking: it is assumed that the parent of the tqe structure is locked. */ 3127 /* ------------------------------------------------------------------------ */ 3128 int fr_tcp_age(tqe, fin, tqtab, flags) 3129 ipftqent_t *tqe; 3130 fr_info_t *fin; 3131 ipftq_t *tqtab; 3132 int flags; 3133 { 3134 int dlen, ostate, nstate, rval, dir; 3135 u_char tcpflags; 3136 tcphdr_t *tcp; 3137 ipf_stack_t *ifs = fin->fin_ifs; 3138 3139 tcp = fin->fin_dp; 3140 3141 rval = 0; 3142 dir = fin->fin_rev; 3143 tcpflags = tcp->th_flags; 3144 dlen = fin->fin_dlen - (TCP_OFF(tcp) << 2); 3145 3146 if (tcpflags & TH_RST) { 3147 if (!(tcpflags & TH_PUSH) && !dlen) 3148 nstate = IPF_TCPS_CLOSED; 3149 else 3150 nstate = IPF_TCPS_CLOSE_WAIT; 3151 rval = 1; 3152 } else { 3153 ostate = tqe->tqe_state[1 - dir]; 3154 nstate = tqe->tqe_state[dir]; 3155 3156 switch (nstate) 3157 { 3158 case IPF_TCPS_CLOSED: /* 0 */ 3159 if ((tcpflags & TH_OPENING) == TH_OPENING) { 3160 /* 3161 * 'dir' received an S and sends SA in 3162 * response, CLOSED -> SYN_RECEIVED 3163 */ 3164 nstate = IPF_TCPS_SYN_RECEIVED; 3165 rval = 1; 3166 } else if ((tcpflags & TH_OPENING) == TH_SYN) { 3167 /* 'dir' sent S, CLOSED -> SYN_SENT */ 3168 nstate = IPF_TCPS_SYN_SENT; 3169 rval = 1; 3170 } 3171 /* 3172 * the next piece of code makes it possible to get 3173 * already established connections into the state table 3174 * after a restart or reload of the filter rules; this 3175 * does not work when a strict 'flags S keep state' is 3176 * used for tcp connections of course 3177 */ 3178 if (((flags & IS_TCPFSM) == 0) && 3179 ((tcpflags & TH_ACKMASK) == TH_ACK)) { 3180 /* 3181 * we saw an A, guess 'dir' is in ESTABLISHED 3182 * mode 3183 */ 3184 switch (ostate) 3185 { 3186 case IPF_TCPS_CLOSED : 3187 case IPF_TCPS_SYN_RECEIVED : 3188 nstate = IPF_TCPS_HALF_ESTAB; 3189 rval = 1; 3190 break; 3191 case IPF_TCPS_HALF_ESTAB : 3192 case IPF_TCPS_ESTABLISHED : 3193 nstate = IPF_TCPS_ESTABLISHED; 3194 rval = 1; 3195 break; 3196 default : 3197 break; 3198 } 3199 } 3200 /* 3201 * TODO: besides regular ACK packets we can have other 3202 * packets as well; it is yet to be determined how we 3203 * should initialize the states in those cases 3204 */ 3205 break; 3206 3207 case IPF_TCPS_LISTEN: /* 1 */ 3208 /* NOT USED */ 3209 break; 3210 3211 case IPF_TCPS_SYN_SENT: /* 2 */ 3212 if ((tcpflags & ~(TH_ECN|TH_CWR)) == TH_SYN) { 3213 /* 3214 * A retransmitted SYN packet. We do not reset 3215 * the timeout here to fr_tcptimeout because a 3216 * connection connect timeout does not renew 3217 * after every packet that is sent. We need to 3218 * set rval so as to indicate the packet has 3219 * passed the check for its flags being valid 3220 * in the TCP FSM. Setting rval to 2 has the 3221 * result of not resetting the timeout. 3222 */ 3223 rval = 2; 3224 } else if ((tcpflags & (TH_SYN|TH_FIN|TH_ACK)) == 3225 TH_ACK) { 3226 /* 3227 * we see an A from 'dir' which is in SYN_SENT 3228 * state: 'dir' sent an A in response to an SA 3229 * which it received, SYN_SENT -> ESTABLISHED 3230 */ 3231 nstate = IPF_TCPS_ESTABLISHED; 3232 rval = 1; 3233 } else if (tcpflags & TH_FIN) { 3234 /* 3235 * we see an F from 'dir' which is in SYN_SENT 3236 * state and wants to close its side of the 3237 * connection; SYN_SENT -> FIN_WAIT_1 3238 */ 3239 nstate = IPF_TCPS_FIN_WAIT_1; 3240 rval = 1; 3241 } else if ((tcpflags & TH_OPENING) == TH_OPENING) { 3242 /* 3243 * we see an SA from 'dir' which is already in 3244 * SYN_SENT state, this means we have a 3245 * simultaneous open; SYN_SENT -> SYN_RECEIVED 3246 */ 3247 nstate = IPF_TCPS_SYN_RECEIVED; 3248 rval = 1; 3249 } 3250 break; 3251 3252 case IPF_TCPS_SYN_RECEIVED: /* 3 */ 3253 if ((tcpflags & (TH_SYN|TH_FIN|TH_ACK)) == TH_ACK) { 3254 /* 3255 * we see an A from 'dir' which was in 3256 * SYN_RECEIVED state so it must now be in 3257 * established state, SYN_RECEIVED -> 3258 * ESTABLISHED 3259 */ 3260 nstate = IPF_TCPS_ESTABLISHED; 3261 rval = 1; 3262 } else if ((tcpflags & ~(TH_ECN|TH_CWR)) == 3263 TH_OPENING) { 3264 /* 3265 * We see an SA from 'dir' which is already in 3266 * SYN_RECEIVED state. 3267 */ 3268 rval = 2; 3269 } else if (tcpflags & TH_FIN) { 3270 /* 3271 * we see an F from 'dir' which is in 3272 * SYN_RECEIVED state and wants to close its 3273 * side of the connection; SYN_RECEIVED -> 3274 * FIN_WAIT_1 3275 */ 3276 nstate = IPF_TCPS_FIN_WAIT_1; 3277 rval = 1; 3278 } 3279 break; 3280 3281 case IPF_TCPS_HALF_ESTAB: /* 4 */ 3282 if (ostate >= IPF_TCPS_HALF_ESTAB) { 3283 if ((tcpflags & TH_ACKMASK) == TH_ACK) { 3284 nstate = IPF_TCPS_ESTABLISHED; 3285 rval = 1; 3286 } 3287 } 3288 3289 break; 3290 3291 case IPF_TCPS_ESTABLISHED: /* 5 */ 3292 rval = 1; 3293 if (tcpflags & TH_FIN) { 3294 /* 3295 * 'dir' closed its side of the connection; 3296 * this gives us a half-closed connection; 3297 * ESTABLISHED -> FIN_WAIT_1 3298 */ 3299 nstate = IPF_TCPS_FIN_WAIT_1; 3300 } else if (tcpflags & TH_ACK) { 3301 /* 3302 * an ACK, should we exclude other flags here? 3303 */ 3304 if (ostate == IPF_TCPS_FIN_WAIT_1) { 3305 /* 3306 * We know the other side did an active 3307 * close, so we are ACKing the recvd 3308 * FIN packet (does the window matching 3309 * code guarantee this?) and go into 3310 * CLOSE_WAIT state; this gives us a 3311 * half-closed connection 3312 */ 3313 nstate = IPF_TCPS_CLOSE_WAIT; 3314 } else if (ostate < IPF_TCPS_CLOSE_WAIT) { 3315 /* 3316 * still a fully established 3317 * connection reset timeout 3318 */ 3319 nstate = IPF_TCPS_ESTABLISHED; 3320 } 3321 } 3322 break; 3323 3324 case IPF_TCPS_CLOSE_WAIT: /* 6 */ 3325 rval = 1; 3326 if (tcpflags & TH_FIN) { 3327 /* 3328 * application closed and 'dir' sent a FIN, 3329 * we're now going into LAST_ACK state 3330 */ 3331 nstate = IPF_TCPS_LAST_ACK; 3332 } else { 3333 /* 3334 * we remain in CLOSE_WAIT because the other 3335 * side has closed already and we did not 3336 * close our side yet; reset timeout 3337 */ 3338 nstate = IPF_TCPS_CLOSE_WAIT; 3339 } 3340 break; 3341 3342 case IPF_TCPS_FIN_WAIT_1: /* 7 */ 3343 rval = 1; 3344 if ((tcpflags & TH_ACK) && 3345 ostate > IPF_TCPS_CLOSE_WAIT) { 3346 /* 3347 * if the other side is not active anymore 3348 * it has sent us a FIN packet that we are 3349 * ack'ing now with an ACK; this means both 3350 * sides have now closed the connection and 3351 * we go into TIME_WAIT 3352 */ 3353 /* 3354 * XXX: how do we know we really are ACKing 3355 * the FIN packet here? does the window code 3356 * guarantee that? 3357 */ 3358 nstate = IPF_TCPS_TIME_WAIT; 3359 } else { 3360 /* 3361 * we closed our side of the connection 3362 * already but the other side is still active 3363 * (ESTABLISHED/CLOSE_WAIT); continue with 3364 * this half-closed connection 3365 */ 3366 nstate = IPF_TCPS_FIN_WAIT_1; 3367 } 3368 break; 3369 3370 case IPF_TCPS_CLOSING: /* 8 */ 3371 /* NOT USED */ 3372 break; 3373 3374 case IPF_TCPS_LAST_ACK: /* 9 */ 3375 if (tcpflags & TH_ACK) { 3376 if ((tcpflags & TH_PUSH) || dlen) 3377 /* 3378 * there is still data to be delivered, 3379 * reset timeout 3380 */ 3381 rval = 1; 3382 else 3383 rval = 2; 3384 } 3385 /* 3386 * we cannot detect when we go out of LAST_ACK state to 3387 * CLOSED because that is based on the reception of ACK 3388 * packets; ipfilter can only detect that a packet 3389 * has been sent by a host 3390 */ 3391 break; 3392 3393 case IPF_TCPS_FIN_WAIT_2: /* 10 */ 3394 rval = 1; 3395 if ((tcpflags & TH_OPENING) == TH_OPENING) 3396 nstate = IPF_TCPS_SYN_RECEIVED; 3397 else if (tcpflags & TH_SYN) 3398 nstate = IPF_TCPS_SYN_SENT; 3399 break; 3400 3401 case IPF_TCPS_TIME_WAIT: /* 11 */ 3402 /* we're in 2MSL timeout now */ 3403 rval = 1; 3404 break; 3405 3406 default : 3407 #if defined(_KERNEL) 3408 # if SOLARIS 3409 cmn_err(CE_NOTE, 3410 "tcp %lx flags %x si %lx nstate %d ostate %d\n", 3411 (u_long)tcp, tcpflags, (u_long)tqe, 3412 nstate, ostate); 3413 # else 3414 printf("tcp %lx flags %x si %lx nstate %d ostate %d\n", 3415 (u_long)tcp, tcpflags, (u_long)tqe, 3416 nstate, ostate); 3417 # endif 3418 #else 3419 abort(); 3420 #endif 3421 break; 3422 } 3423 } 3424 3425 /* 3426 * If rval == 2 then do not update the queue position, but treat the 3427 * packet as being ok. 3428 */ 3429 if (rval == 2) 3430 rval = 1; 3431 else if (rval == 1) { 3432 tqe->tqe_state[dir] = nstate; 3433 if ((tqe->tqe_flags & TQE_RULEBASED) == 0) 3434 fr_movequeue(tqe, tqe->tqe_ifq, tqtab + nstate, ifs); 3435 } 3436 3437 return rval; 3438 } 3439 3440 3441 /* ------------------------------------------------------------------------ */ 3442 /* Function: ipstate_log */ 3443 /* Returns: Nil */ 3444 /* Parameters: is(I) - pointer to state structure */ 3445 /* type(I) - type of log entry to create */ 3446 /* */ 3447 /* Creates a state table log entry using the state structure and type info. */ 3448 /* passed in. Log packet/byte counts, source/destination address and other */ 3449 /* protocol specific information. */ 3450 /* ------------------------------------------------------------------------ */ 3451 void ipstate_log(is, type, ifs) 3452 struct ipstate *is; 3453 u_int type; 3454 ipf_stack_t *ifs; 3455 { 3456 #ifdef IPFILTER_LOG 3457 struct ipslog ipsl; 3458 size_t sizes[1]; 3459 void *items[1]; 3460 int types[1]; 3461 3462 /* 3463 * Copy information out of the ipstate_t structure and into the 3464 * structure used for logging. 3465 */ 3466 ipsl.isl_type = type; 3467 ipsl.isl_pkts[0] = is->is_pkts[0] + is->is_icmppkts[0]; 3468 ipsl.isl_bytes[0] = is->is_bytes[0]; 3469 ipsl.isl_pkts[1] = is->is_pkts[1] + is->is_icmppkts[1]; 3470 ipsl.isl_bytes[1] = is->is_bytes[1]; 3471 ipsl.isl_pkts[2] = is->is_pkts[2] + is->is_icmppkts[2]; 3472 ipsl.isl_bytes[2] = is->is_bytes[2]; 3473 ipsl.isl_pkts[3] = is->is_pkts[3] + is->is_icmppkts[3]; 3474 ipsl.isl_bytes[3] = is->is_bytes[3]; 3475 ipsl.isl_src = is->is_src; 3476 ipsl.isl_dst = is->is_dst; 3477 ipsl.isl_p = is->is_p; 3478 ipsl.isl_v = is->is_v; 3479 ipsl.isl_flags = is->is_flags; 3480 ipsl.isl_tag = is->is_tag; 3481 ipsl.isl_rulen = is->is_rulen; 3482 (void) strncpy(ipsl.isl_group, is->is_group, FR_GROUPLEN); 3483 3484 if (ipsl.isl_p == IPPROTO_TCP || ipsl.isl_p == IPPROTO_UDP) { 3485 ipsl.isl_sport = is->is_sport; 3486 ipsl.isl_dport = is->is_dport; 3487 if (ipsl.isl_p == IPPROTO_TCP) { 3488 ipsl.isl_state[0] = is->is_state[0]; 3489 ipsl.isl_state[1] = is->is_state[1]; 3490 } 3491 } else if (ipsl.isl_p == IPPROTO_ICMP) { 3492 ipsl.isl_itype = is->is_icmp.ici_type; 3493 } else if (ipsl.isl_p == IPPROTO_ICMPV6) { 3494 ipsl.isl_itype = is->is_icmp.ici_type; 3495 } else { 3496 ipsl.isl_ps.isl_filler[0] = 0; 3497 ipsl.isl_ps.isl_filler[1] = 0; 3498 } 3499 3500 items[0] = &ipsl; 3501 sizes[0] = sizeof(ipsl); 3502 types[0] = 0; 3503 3504 if (ipllog(IPL_LOGSTATE, NULL, items, sizes, types, 1, ifs)) { 3505 ATOMIC_INCL(ifs->ifs_ips_stats.iss_logged); 3506 } else { 3507 ATOMIC_INCL(ifs->ifs_ips_stats.iss_logfail); 3508 } 3509 #endif 3510 } 3511 3512 3513 #ifdef USE_INET6 3514 /* ------------------------------------------------------------------------ */ 3515 /* Function: fr_checkicmp6matchingstate */ 3516 /* Returns: ipstate_t* - NULL == no match found, */ 3517 /* else pointer to matching state entry */ 3518 /* Parameters: fin(I) - pointer to packet information */ 3519 /* Locks: NULL == no locks, else Read Lock on ipf_state */ 3520 /* */ 3521 /* If we've got an ICMPv6 error message, using the information stored in */ 3522 /* the ICMPv6 packet, look for a matching state table entry. */ 3523 /* ------------------------------------------------------------------------ */ 3524 static ipstate_t *fr_checkicmp6matchingstate(fin) 3525 fr_info_t *fin; 3526 { 3527 struct icmp6_hdr *ic6, *oic; 3528 int backward, i; 3529 ipstate_t *is, **isp; 3530 u_short sport, dport; 3531 i6addr_t dst, src; 3532 u_short savelen; 3533 icmpinfo_t *ic; 3534 fr_info_t ofin; 3535 tcphdr_t *tcp; 3536 ip6_t *oip6; 3537 u_char pr; 3538 u_int hv; 3539 ipf_stack_t *ifs = fin->fin_ifs; 3540 3541 /* 3542 * Does it at least have the return (basic) IP header ? 3543 * Is it an actual recognised ICMP error type? 3544 * Only a basic IP header (no options) should be with 3545 * an ICMP error header. 3546 */ 3547 if ((fin->fin_v != 6) || (fin->fin_plen < ICMP6ERR_MINPKTLEN) || 3548 !(fin->fin_flx & FI_ICMPERR)) 3549 return NULL; 3550 3551 ic6 = fin->fin_dp; 3552 3553 oip6 = (ip6_t *)((char *)ic6 + ICMPERR_ICMPHLEN); 3554 if (fin->fin_plen < sizeof(*oip6)) 3555 return NULL; 3556 3557 bcopy((char *)fin, (char *)&ofin, sizeof(*fin)); 3558 ofin.fin_v = 6; 3559 ofin.fin_ifp = fin->fin_ifp; 3560 ofin.fin_out = !fin->fin_out; 3561 ofin.fin_m = NULL; /* if dereferenced, panic XXX */ 3562 ofin.fin_mp = NULL; /* if dereferenced, panic XXX */ 3563 3564 /* 3565 * We make a fin entry to be able to feed it to 3566 * matchsrcdst. Note that not all fields are necessary 3567 * but this is the cleanest way. Note further we fill 3568 * in fin_mp such that if someone uses it we'll get 3569 * a kernel panic. fr_matchsrcdst does not use this. 3570 * 3571 * watch out here, as ip is in host order and oip6 in network 3572 * order. Any change we make must be undone afterwards. 3573 */ 3574 savelen = oip6->ip6_plen; 3575 oip6->ip6_plen = fin->fin_dlen - ICMPERR_ICMPHLEN; 3576 ofin.fin_flx = FI_NOCKSUM; 3577 ofin.fin_ip = (ip_t *)oip6; 3578 ofin.fin_plen = oip6->ip6_plen; 3579 (void) fr_makefrip(sizeof(*oip6), (ip_t *)oip6, &ofin); 3580 ofin.fin_flx &= ~(FI_BAD|FI_SHORT); 3581 oip6->ip6_plen = savelen; 3582 3583 if (oip6->ip6_nxt == IPPROTO_ICMPV6) { 3584 oic = (struct icmp6_hdr *)(oip6 + 1); 3585 /* 3586 * an ICMP error can only be generated as a result of an 3587 * ICMP query, not as the response on an ICMP error 3588 * 3589 * XXX theoretically ICMP_ECHOREP and the other reply's are 3590 * ICMP query's as well, but adding them here seems strange XXX 3591 */ 3592 if (!(oic->icmp6_type & ICMP6_INFOMSG_MASK)) 3593 return NULL; 3594 3595 /* 3596 * perform a lookup of the ICMP packet in the state table 3597 */ 3598 hv = (pr = oip6->ip6_nxt); 3599 src.in6 = oip6->ip6_src; 3600 hv += src.in4.s_addr; 3601 dst.in6 = oip6->ip6_dst; 3602 hv += dst.in4.s_addr; 3603 hv += oic->icmp6_id; 3604 hv += oic->icmp6_seq; 3605 hv = DOUBLE_HASH(hv, ifs); 3606 3607 READ_ENTER(&ifs->ifs_ipf_state); 3608 for (isp = &ifs->ifs_ips_table[hv]; ((is = *isp) != NULL); ) { 3609 ic = &is->is_icmp; 3610 isp = &is->is_hnext; 3611 if ((is->is_p == pr) && 3612 !(is->is_pass & FR_NOICMPERR) && 3613 (oic->icmp6_id == ic->ici_id) && 3614 (oic->icmp6_seq == ic->ici_seq) && 3615 (is = fr_matchsrcdst(&ofin, is, &src, 3616 &dst, NULL, FI_ICMPCMP))) { 3617 /* 3618 * in the state table ICMP query's are stored 3619 * with the type of the corresponding ICMP 3620 * response. Correct here 3621 */ 3622 if (((ic->ici_type == ICMP6_ECHO_REPLY) && 3623 (oic->icmp6_type == ICMP6_ECHO_REQUEST)) || 3624 (ic->ici_type - 1 == oic->icmp6_type )) { 3625 ifs->ifs_ips_stats.iss_hits++; 3626 backward = IP6_NEQ(&is->is_dst, &src); 3627 fin->fin_rev = !backward; 3628 i = (backward << 1) + fin->fin_out; 3629 is->is_icmppkts[i]++; 3630 return is; 3631 } 3632 } 3633 } 3634 RWLOCK_EXIT(&ifs->ifs_ipf_state); 3635 return NULL; 3636 } 3637 3638 hv = (pr = oip6->ip6_nxt); 3639 src.in6 = oip6->ip6_src; 3640 hv += src.i6[0]; 3641 hv += src.i6[1]; 3642 hv += src.i6[2]; 3643 hv += src.i6[3]; 3644 dst.in6 = oip6->ip6_dst; 3645 hv += dst.i6[0]; 3646 hv += dst.i6[1]; 3647 hv += dst.i6[2]; 3648 hv += dst.i6[3]; 3649 3650 if ((oip6->ip6_nxt == IPPROTO_TCP) || (oip6->ip6_nxt == IPPROTO_UDP)) { 3651 tcp = (tcphdr_t *)(oip6 + 1); 3652 dport = tcp->th_dport; 3653 sport = tcp->th_sport; 3654 hv += dport; 3655 hv += sport; 3656 } else 3657 tcp = NULL; 3658 hv = DOUBLE_HASH(hv, ifs); 3659 3660 READ_ENTER(&ifs->ifs_ipf_state); 3661 for (isp = &ifs->ifs_ips_table[hv]; ((is = *isp) != NULL); ) { 3662 isp = &is->is_hnext; 3663 /* 3664 * Only allow this icmp though if the 3665 * encapsulated packet was allowed through the 3666 * other way around. Note that the minimal amount 3667 * of info present does not allow for checking against 3668 * tcp internals such as seq and ack numbers. 3669 */ 3670 if ((is->is_p != pr) || (is->is_v != 6) || 3671 (is->is_pass & FR_NOICMPERR)) 3672 continue; 3673 is = fr_matchsrcdst(&ofin, is, &src, &dst, tcp, FI_ICMPCMP); 3674 if (is != NULL) { 3675 ifs->ifs_ips_stats.iss_hits++; 3676 backward = IP6_NEQ(&is->is_dst, &src); 3677 fin->fin_rev = !backward; 3678 i = (backward << 1) + fin->fin_out; 3679 is->is_icmppkts[i]++; 3680 /* 3681 * we deliberately do not touch the timeouts 3682 * for the accompanying state table entry. 3683 * It remains to be seen if that is correct. XXX 3684 */ 3685 return is; 3686 } 3687 } 3688 RWLOCK_EXIT(&ifs->ifs_ipf_state); 3689 return NULL; 3690 } 3691 #endif 3692 3693 3694 /* ------------------------------------------------------------------------ */ 3695 /* Function: fr_sttab_init */ 3696 /* Returns: Nil */ 3697 /* Parameters: tqp(I) - pointer to an array of timeout queues for TCP */ 3698 /* */ 3699 /* Initialise the array of timeout queues for TCP. */ 3700 /* ------------------------------------------------------------------------ */ 3701 void fr_sttab_init(tqp, ifs) 3702 ipftq_t *tqp; 3703 ipf_stack_t *ifs; 3704 { 3705 int i; 3706 3707 for (i = IPF_TCP_NSTATES - 1; i >= 0; i--) { 3708 tqp[i].ifq_ttl = 0; 3709 tqp[i].ifq_ref = 1; 3710 tqp[i].ifq_head = NULL; 3711 tqp[i].ifq_tail = &tqp[i].ifq_head; 3712 tqp[i].ifq_next = tqp + i + 1; 3713 MUTEX_INIT(&tqp[i].ifq_lock, "ipftq tcp tab"); 3714 } 3715 tqp[IPF_TCP_NSTATES - 1].ifq_next = NULL; 3716 tqp[IPF_TCPS_CLOSED].ifq_ttl = ifs->ifs_fr_tcpclosed; 3717 tqp[IPF_TCPS_LISTEN].ifq_ttl = ifs->ifs_fr_tcptimeout; 3718 tqp[IPF_TCPS_SYN_SENT].ifq_ttl = ifs->ifs_fr_tcptimeout; 3719 tqp[IPF_TCPS_SYN_RECEIVED].ifq_ttl = ifs->ifs_fr_tcptimeout; 3720 tqp[IPF_TCPS_ESTABLISHED].ifq_ttl = ifs->ifs_fr_tcpidletimeout; 3721 tqp[IPF_TCPS_CLOSE_WAIT].ifq_ttl = ifs->ifs_fr_tcphalfclosed; 3722 tqp[IPF_TCPS_FIN_WAIT_1].ifq_ttl = ifs->ifs_fr_tcphalfclosed; 3723 tqp[IPF_TCPS_CLOSING].ifq_ttl = ifs->ifs_fr_tcptimeout; 3724 tqp[IPF_TCPS_LAST_ACK].ifq_ttl = ifs->ifs_fr_tcplastack; 3725 tqp[IPF_TCPS_FIN_WAIT_2].ifq_ttl = ifs->ifs_fr_tcpclosewait; 3726 tqp[IPF_TCPS_TIME_WAIT].ifq_ttl = ifs->ifs_fr_tcptimeout; 3727 tqp[IPF_TCPS_HALF_ESTAB].ifq_ttl = ifs->ifs_fr_tcptimeout; 3728 } 3729 3730 3731 /* ------------------------------------------------------------------------ */ 3732 /* Function: fr_sttab_destroy */ 3733 /* Returns: Nil */ 3734 /* Parameters: tqp(I) - pointer to an array of timeout queues for TCP */ 3735 /* */ 3736 /* Do whatever is necessary to "destroy" each of the entries in the array */ 3737 /* of timeout queues for TCP. */ 3738 /* ------------------------------------------------------------------------ */ 3739 void fr_sttab_destroy(tqp) 3740 ipftq_t *tqp; 3741 { 3742 int i; 3743 3744 for (i = IPF_TCP_NSTATES - 1; i >= 0; i--) 3745 MUTEX_DESTROY(&tqp[i].ifq_lock); 3746 } 3747 3748 3749 /* ------------------------------------------------------------------------ */ 3750 /* Function: fr_statederef */ 3751 /* Returns: Nil */ 3752 /* Parameters: isp(I) - pointer to pointer to state table entry */ 3753 /* */ 3754 /* Decrement the reference counter for this state table entry and free it */ 3755 /* if there are no more things using it. */ 3756 /* */ 3757 /* When operating in userland (ipftest), we have no timers to clear a state */ 3758 /* entry. Therefore, we make a few simple tests before deleting an entry */ 3759 /* outright. We compare states on each side looking for a combination of */ 3760 /* TIME_WAIT (should really be FIN_WAIT_2?) and LAST_ACK. Then we factor */ 3761 /* in packet direction with the interface list to make sure we don't */ 3762 /* prematurely delete an entry on a final inbound packet that's we're also */ 3763 /* supposed to route elsewhere. */ 3764 /* */ 3765 /* Internal parameters: */ 3766 /* state[0] = state of source (host that initiated connection) */ 3767 /* state[1] = state of dest (host that accepted the connection) */ 3768 /* */ 3769 /* dir == 0 : a packet from source to dest */ 3770 /* dir == 1 : a packet from dest to source */ 3771 /* ------------------------------------------------------------------------ */ 3772 void fr_statederef(fin, isp, ifs) 3773 fr_info_t *fin; 3774 ipstate_t **isp; 3775 ipf_stack_t *ifs; 3776 { 3777 ipstate_t *is = *isp; 3778 #if 0 3779 int nstate, ostate, dir, eol; 3780 3781 eol = 0; /* End-of-the-line flag. */ 3782 dir = fin->fin_rev; 3783 ostate = is->is_state[1 - dir]; 3784 nstate = is->is_state[dir]; 3785 /* 3786 * Determine whether this packet is local or routed. State entries 3787 * with us as the destination will have an interface list of 3788 * int1,-,-,int1. Entries with us as the origin run as -,int1,int1,-. 3789 */ 3790 if ((fin->fin_p == IPPROTO_TCP) && (fin->fin_out == 0)) { 3791 if ((strcmp(is->is_ifname[0], is->is_ifname[3]) == 0) && 3792 (strcmp(is->is_ifname[1], is->is_ifname[2]) == 0)) { 3793 if ((dir == 0) && 3794 (strcmp(is->is_ifname[1], "-") == 0) && 3795 (strcmp(is->is_ifname[0], "-") != 0)) { 3796 eol = 1; 3797 } else if ((dir == 1) && 3798 (strcmp(is->is_ifname[0], "-") == 0) && 3799 (strcmp(is->is_ifname[1], "-") != 0)) { 3800 eol = 1; 3801 } 3802 } 3803 } 3804 #endif 3805 3806 fin = fin; /* LINT */ 3807 is = *isp; 3808 *isp = NULL; 3809 WRITE_ENTER(&ifs->ifs_ipf_state); 3810 is->is_ref--; 3811 if (is->is_ref == 0) { 3812 is->is_ref++; /* To counter ref-- in fr_delstate() */ 3813 fr_delstate(is, ISL_EXPIRE, ifs); 3814 #ifndef _KERNEL 3815 #if 0 3816 } else if (((fin->fin_out == 1) || (eol == 1)) && 3817 ((ostate == IPF_TCPS_LAST_ACK) && 3818 (nstate == IPF_TCPS_TIME_WAIT))) { 3819 ; 3820 #else 3821 } else if ((is->is_sti.tqe_state[0] > IPF_TCPS_ESTABLISHED) || 3822 (is->is_sti.tqe_state[1] > IPF_TCPS_ESTABLISHED)) { 3823 #endif 3824 fr_delstate(is, ISL_ORPHAN, ifs); 3825 #endif 3826 } 3827 RWLOCK_EXIT(&ifs->ifs_ipf_state); 3828 } 3829 3830 3831 /* ------------------------------------------------------------------------ */ 3832 /* Function: fr_setstatequeue */ 3833 /* Returns: Nil */ 3834 /* Parameters: is(I) - pointer to state structure */ 3835 /* rev(I) - forward(0) or reverse(1) direction */ 3836 /* Locks: ipf_state (read or write) */ 3837 /* */ 3838 /* Put the state entry on its default queue entry, using rev as a helped in */ 3839 /* determining which queue it should be placed on. */ 3840 /* ------------------------------------------------------------------------ */ 3841 void fr_setstatequeue(is, rev, ifs) 3842 ipstate_t *is; 3843 int rev; 3844 ipf_stack_t *ifs; 3845 { 3846 ipftq_t *oifq, *nifq; 3847 3848 3849 if ((is->is_sti.tqe_flags & TQE_RULEBASED) != 0) 3850 nifq = is->is_tqehead[rev]; 3851 else 3852 nifq = NULL; 3853 3854 if (nifq == NULL) { 3855 switch (is->is_p) 3856 { 3857 #ifdef USE_INET6 3858 case IPPROTO_ICMPV6 : 3859 if (rev == 1) 3860 nifq = &ifs->ifs_ips_icmpacktq; 3861 else 3862 nifq = &ifs->ifs_ips_icmptq; 3863 break; 3864 #endif 3865 case IPPROTO_ICMP : 3866 if (rev == 1) 3867 nifq = &ifs->ifs_ips_icmpacktq; 3868 else 3869 nifq = &ifs->ifs_ips_icmptq; 3870 break; 3871 case IPPROTO_TCP : 3872 nifq = ifs->ifs_ips_tqtqb + is->is_state[rev]; 3873 break; 3874 3875 case IPPROTO_UDP : 3876 if (rev == 1) 3877 nifq = &ifs->ifs_ips_udpacktq; 3878 else 3879 nifq = &ifs->ifs_ips_udptq; 3880 break; 3881 3882 default : 3883 nifq = &ifs->ifs_ips_iptq; 3884 break; 3885 } 3886 } 3887 3888 oifq = is->is_sti.tqe_ifq; 3889 /* 3890 * If it's currently on a timeout queue, move it from one queue to 3891 * another, else put it on the end of the newly determined queue. 3892 */ 3893 if (oifq != NULL) 3894 fr_movequeue(&is->is_sti, oifq, nifq, ifs); 3895 else 3896 fr_queueappend(&is->is_sti, nifq, is, ifs); 3897 return; 3898 } 3899 3900 3901 /* ------------------------------------------------------------------------ */ 3902 /* Function: fr_stateiter */ 3903 /* Returns: int - 0 == success, else error */ 3904 /* Parameters: token(I) - pointer to ipftoken structure */ 3905 /* itp(I) - pointer to ipfgeniter structure */ 3906 /* */ 3907 /* This function handles the SIOCGENITER ioctl for the state tables and */ 3908 /* walks through the list of entries in the state table list (ips_list.) */ 3909 /* ------------------------------------------------------------------------ */ 3910 static int fr_stateiter(token, itp, ifs) 3911 ipftoken_t *token; 3912 ipfgeniter_t *itp; 3913 ipf_stack_t *ifs; 3914 { 3915 ipstate_t *is, *next, zero; 3916 int error; 3917 3918 if (itp->igi_data == NULL) 3919 return EFAULT; 3920 3921 if (itp->igi_type != IPFGENITER_STATE) 3922 return EINVAL; 3923 3924 is = token->ipt_data; 3925 if (is == (void *)-1) { 3926 ipf_freetoken(token, ifs); 3927 return ESRCH; 3928 } 3929 3930 READ_ENTER(&ifs->ifs_ipf_state); 3931 if (is == NULL) { 3932 next = ifs->ifs_ips_list; 3933 } else { 3934 next = is->is_next; 3935 } 3936 3937 if (next != NULL) { 3938 /* 3939 * If we find a state entry to use, bump its reference count 3940 * so that it can be used for is_next when we come back. 3941 */ 3942 MUTEX_ENTER(&next->is_lock); 3943 next->is_ref++; 3944 MUTEX_EXIT(&next->is_lock); 3945 token->ipt_data = next; 3946 } else { 3947 bzero(&zero, sizeof(zero)); 3948 next = &zero; 3949 token->ipt_data = (void *)-1; 3950 } 3951 RWLOCK_EXIT(&ifs->ifs_ipf_state); 3952 3953 /* 3954 * If we had a prior pointer to a state entry, release it. 3955 */ 3956 if (is != NULL) { 3957 fr_statederef(NULL, &is, ifs); 3958 } 3959 3960 /* 3961 * This should arguably be via fr_outobj() so that the state 3962 * structure can (if required) be massaged going out. 3963 */ 3964 error = COPYOUT(next, itp->igi_data, sizeof(*next)); 3965 if (error != 0) 3966 error = EFAULT; 3967 3968 return error; 3969 } 3970 3971