1 /* 2 * Copyright (c) 2002 Luigi Rizzo, Universita` di Pisa 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23 * SUCH DAMAGE. 24 * 25 * $FreeBSD: src/sys/netinet/ip_fw2.c,v 1.6.2.12 2003/04/08 10:42:32 maxim Exp $ 26 */ 27 28 /* 29 * Implement IP packet firewall (new version) 30 */ 31 32 #include "opt_ipfw.h" 33 #include "opt_inet.h" 34 #ifndef INET 35 #error IPFIREWALL requires INET. 36 #endif /* INET */ 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/malloc.h> 41 #include <sys/mbuf.h> 42 #include <sys/kernel.h> 43 #include <sys/proc.h> 44 #include <sys/socket.h> 45 #include <sys/socketvar.h> 46 #include <sys/sysctl.h> 47 #include <sys/syslog.h> 48 #include <sys/ucred.h> 49 #include <sys/in_cksum.h> 50 #include <sys/lock.h> 51 52 #include <net/if.h> 53 #include <net/route.h> 54 #include <net/pfil.h> 55 #include <net/dummynet/ip_dummynet.h> 56 57 #include <sys/thread2.h> 58 #include <sys/mplock2.h> 59 #include <net/netmsg2.h> 60 61 #include <netinet/in.h> 62 #include <netinet/in_systm.h> 63 #include <netinet/in_var.h> 64 #include <netinet/in_pcb.h> 65 #include <netinet/ip.h> 66 #include <netinet/ip_var.h> 67 #include <netinet/ip_icmp.h> 68 #include <netinet/tcp.h> 69 #include <netinet/tcp_timer.h> 70 #include <netinet/tcp_var.h> 71 #include <netinet/tcpip.h> 72 #include <netinet/udp.h> 73 #include <netinet/udp_var.h> 74 #include <netinet/ip_divert.h> 75 #include <netinet/if_ether.h> /* XXX for ETHERTYPE_IP */ 76 77 #include <net/ipfw/ip_fw2.h> 78 79 #ifdef IPFIREWALL_DEBUG 80 #define DPRINTF(fmt, ...) \ 81 do { \ 82 if (fw_debug > 0) \ 83 kprintf(fmt, __VA_ARGS__); \ 84 } while (0) 85 #else 86 #define DPRINTF(fmt, ...) ((void)0) 87 #endif 88 89 /* 90 * Description about per-CPU rule duplication: 91 * 92 * Module loading/unloading and all ioctl operations are serialized 93 * by netisr0, so we don't have any ordering or locking problems. 94 * 95 * Following graph shows how operation on per-CPU rule list is 96 * performed [2 CPU case]: 97 * 98 * CPU0 CPU1 99 * 100 * netisr0 <------------------------------------+ 101 * domsg | 102 * | | 103 * | netmsg | 104 * | | 105 * V | 106 * ifnet0 | 107 * : | netmsg 108 * :(delete/add...) | 109 * : | 110 * : netmsg | 111 * forwardmsg---------->ifnet1 | 112 * : | 113 * :(delete/add...) | 114 * : | 115 * : | 116 * replymsg--------------+ 117 * 118 * 119 * 120 * 121 * Rules which will not create states (dyn rules) [2 CPU case] 122 * 123 * CPU0 CPU1 124 * layer3_chain layer3_chain 125 * | | 126 * V V 127 * +-------+ sibling +-------+ sibling 128 * | rule1 |--------->| rule1 |--------->NULL 129 * +-------+ +-------+ 130 * | | 131 * |next |next 132 * V V 133 * +-------+ sibling +-------+ sibling 134 * | rule2 |--------->| rule2 |--------->NULL 135 * +-------+ +-------+ 136 * 137 * ip_fw.sibling: 138 * 1) Ease statistics calculation during IP_FW_GET. We only need to 139 * iterate layer3_chain on CPU0; the current rule's duplication on 140 * the other CPUs could safely be read-only accessed by using 141 * ip_fw.sibling 142 * 2) Accelerate rule insertion and deletion, e.g. rule insertion: 143 * a) In netisr0 (on CPU0) rule3 is determined to be inserted between 144 * rule1 and rule2. To make this decision we need to iterate the 145 * layer3_chain on CPU0. The netmsg, which is used to insert the 146 * rule, will contain rule1 on CPU0 as prev_rule and rule2 on CPU0 147 * as next_rule 148 * b) After the insertion on CPU0 is done, we will move on to CPU1. 149 * But instead of relocating the rule3's position on CPU1 by 150 * iterating the layer3_chain on CPU1, we set the netmsg's prev_rule 151 * to rule1->sibling and next_rule to rule2->sibling before the 152 * netmsg is forwarded to CPU1 from CPU0 153 * 154 * 155 * 156 * Rules which will create states (dyn rules) [2 CPU case] 157 * (unnecessary parts are omitted; they are same as in the previous figure) 158 * 159 * CPU0 CPU1 160 * 161 * +-------+ +-------+ 162 * | rule1 | | rule1 | 163 * +-------+ +-------+ 164 * ^ | | ^ 165 * | |stub stub| | 166 * | | | | 167 * | +----+ +----+ | 168 * | | | | 169 * | V V | 170 * | +--------------------+ | 171 * | | rule_stub | | 172 * | | (read-only shared) | | 173 * | | | | 174 * | | back pointer array | | 175 * | | (indexed by cpuid) | | 176 * | | | | 177 * +----|---------[0] | | 178 * | [1]--------|----+ 179 * | | 180 * +--------------------+ 181 * ^ ^ 182 * | | 183 * ........|............|............ 184 * : | | : 185 * : |stub |stub : 186 * : | | : 187 * : +---------+ +---------+ : 188 * : | state1a | | state1b | .... : 189 * : +---------+ +---------+ : 190 * : : 191 * : states table : 192 * : (shared) : 193 * : (protected by dyn_lock) : 194 * .................................. 195 * 196 * [state1a and state1b are states created by rule1] 197 * 198 * ip_fw_stub: 199 * This structure is introduced so that shared (locked) state table could 200 * work with per-CPU (duplicated) static rules. It mainly bridges states 201 * and static rules and serves as static rule's place holder (a read-only 202 * shared part of duplicated rules) from states point of view. 203 * 204 * IPFW_RULE_F_STATE (only for rules which create states): 205 * o During rule installation, this flag is turned on after rule's 206 * duplications reach all CPUs, to avoid at least following race: 207 * 1) rule1 is duplicated on CPU0 and is not duplicated on CPU1 yet 208 * 2) rule1 creates state1 209 * 3) state1 is located on CPU1 by check-state 210 * But rule1 is not duplicated on CPU1 yet 211 * o During rule deletion, this flag is turned off before deleting states 212 * created by the rule and before deleting the rule itself, so no 213 * more states will be created by the to-be-deleted rule even when its 214 * duplication on certain CPUs are not eliminated yet. 215 */ 216 217 #define IPFW_AUTOINC_STEP_MIN 1 218 #define IPFW_AUTOINC_STEP_MAX 1000 219 #define IPFW_AUTOINC_STEP_DEF 100 220 221 #define IPFW_DEFAULT_RULE 65535 /* rulenum for the default rule */ 222 #define IPFW_DEFAULT_SET 31 /* set number for the default rule */ 223 224 struct netmsg_ipfw { 225 struct netmsg_base base; 226 const struct ipfw_ioc_rule *ioc_rule; 227 struct ip_fw *next_rule; 228 struct ip_fw *prev_rule; 229 struct ip_fw *sibling; 230 struct ip_fw_stub *stub; 231 }; 232 233 struct netmsg_del { 234 struct netmsg_base base; 235 struct ip_fw *start_rule; 236 struct ip_fw *prev_rule; 237 uint16_t rulenum; 238 uint8_t from_set; 239 uint8_t to_set; 240 }; 241 242 struct netmsg_zent { 243 struct netmsg_base base; 244 struct ip_fw *start_rule; 245 uint16_t rulenum; 246 uint16_t log_only; 247 }; 248 249 struct ipfw_context { 250 struct ip_fw *ipfw_layer3_chain; /* list of rules for layer3 */ 251 struct ip_fw *ipfw_default_rule; /* default rule */ 252 uint64_t ipfw_norule_counter; /* counter for ipfw_log(NULL) */ 253 254 /* 255 * ipfw_set_disable contains one bit per set value (0..31). 256 * If the bit is set, all rules with the corresponding set 257 * are disabled. Set IPDW_DEFAULT_SET is reserved for the 258 * default rule and CANNOT be disabled. 259 */ 260 uint32_t ipfw_set_disable; 261 uint32_t ipfw_gen; /* generation of rule list */ 262 }; 263 264 static struct ipfw_context *ipfw_ctx[MAXCPU]; 265 266 #ifdef KLD_MODULE 267 /* 268 * Module can not be unloaded, if there are references to 269 * certains rules of ipfw(4), e.g. dummynet(4) 270 */ 271 static int ipfw_refcnt; 272 #endif 273 274 MALLOC_DEFINE(M_IPFW, "IpFw/IpAcct", "IpFw/IpAcct chain's"); 275 276 /* 277 * Following two global variables are accessed and 278 * updated only on CPU0 279 */ 280 static uint32_t static_count; /* # of static rules */ 281 static uint32_t static_ioc_len; /* bytes of static rules */ 282 283 /* 284 * If 1, then ipfw static rules are being flushed, 285 * ipfw_chk() will skip to the default rule. 286 */ 287 static int ipfw_flushing; 288 289 static int fw_verbose; 290 static int verbose_limit; 291 292 static int fw_debug; 293 static int autoinc_step = IPFW_AUTOINC_STEP_DEF; 294 295 static int ipfw_sysctl_enable(SYSCTL_HANDLER_ARGS); 296 static int ipfw_sysctl_autoinc_step(SYSCTL_HANDLER_ARGS); 297 static int ipfw_sysctl_dyn_buckets(SYSCTL_HANDLER_ARGS); 298 static int ipfw_sysctl_dyn_fin(SYSCTL_HANDLER_ARGS); 299 static int ipfw_sysctl_dyn_rst(SYSCTL_HANDLER_ARGS); 300 301 SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 302 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, enable, CTLTYPE_INT | CTLFLAG_RW, 303 &fw_enable, 0, ipfw_sysctl_enable, "I", "Enable ipfw"); 304 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, autoinc_step, CTLTYPE_INT | CTLFLAG_RW, 305 &autoinc_step, 0, ipfw_sysctl_autoinc_step, "I", 306 "Rule number autincrement step"); 307 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO,one_pass,CTLFLAG_RW, 308 &fw_one_pass, 0, 309 "Only do a single pass through ipfw when using dummynet(4)"); 310 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, debug, CTLFLAG_RW, 311 &fw_debug, 0, "Enable printing of debug ip_fw statements"); 312 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose, CTLFLAG_RW, 313 &fw_verbose, 0, "Log matches to ipfw rules"); 314 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, CTLFLAG_RW, 315 &verbose_limit, 0, "Set upper limit of matches of ipfw rules logged"); 316 317 /* 318 * Description of dynamic rules. 319 * 320 * Dynamic rules are stored in lists accessed through a hash table 321 * (ipfw_dyn_v) whose size is curr_dyn_buckets. This value can 322 * be modified through the sysctl variable dyn_buckets which is 323 * updated when the table becomes empty. 324 * 325 * XXX currently there is only one list, ipfw_dyn. 326 * 327 * When a packet is received, its address fields are first masked 328 * with the mask defined for the rule, then hashed, then matched 329 * against the entries in the corresponding list. 330 * Dynamic rules can be used for different purposes: 331 * + stateful rules; 332 * + enforcing limits on the number of sessions; 333 * + in-kernel NAT (not implemented yet) 334 * 335 * The lifetime of dynamic rules is regulated by dyn_*_lifetime, 336 * measured in seconds and depending on the flags. 337 * 338 * The total number of dynamic rules is stored in dyn_count. 339 * The max number of dynamic rules is dyn_max. When we reach 340 * the maximum number of rules we do not create anymore. This is 341 * done to avoid consuming too much memory, but also too much 342 * time when searching on each packet (ideally, we should try instead 343 * to put a limit on the length of the list on each bucket...). 344 * 345 * Each dynamic rule holds a pointer to the parent ipfw rule so 346 * we know what action to perform. Dynamic rules are removed when 347 * the parent rule is deleted. XXX we should make them survive. 348 * 349 * There are some limitations with dynamic rules -- we do not 350 * obey the 'randomized match', and we do not do multiple 351 * passes through the firewall. XXX check the latter!!! 352 * 353 * NOTE about the SHARED LOCKMGR LOCK during dynamic rule looking up: 354 * Only TCP state transition will change dynamic rule's state and ack 355 * sequences, while all packets of one TCP connection only goes through 356 * one TCP thread, so it is safe to use shared lockmgr lock during dynamic 357 * rule looking up. The keep alive callout uses exclusive lockmgr lock 358 * when it tries to find suitable dynamic rules to send keep alive, so 359 * it will not see half updated state and ack sequences. Though the expire 360 * field updating looks racy for other protocols, the resolution (second) 361 * of expire field makes this kind of race harmless. 362 * XXX statistics' updating is _not_ MPsafe!!! 363 * XXX once UDP output path is fixed, we could use lockless dynamic rule 364 * hash table 365 */ 366 static ipfw_dyn_rule **ipfw_dyn_v = NULL; 367 static uint32_t dyn_buckets = 256; /* must be power of 2 */ 368 static uint32_t curr_dyn_buckets = 256; /* must be power of 2 */ 369 static uint32_t dyn_buckets_gen; /* generation of dyn buckets array */ 370 static struct lock dyn_lock; /* dynamic rules' hash table lock */ 371 372 static struct netmsg_base ipfw_timeout_netmsg; /* schedule ipfw timeout */ 373 static struct callout ipfw_timeout_h; 374 375 /* 376 * Timeouts for various events in handing dynamic rules. 377 */ 378 static uint32_t dyn_ack_lifetime = 300; 379 static uint32_t dyn_syn_lifetime = 20; 380 static uint32_t dyn_fin_lifetime = 1; 381 static uint32_t dyn_rst_lifetime = 1; 382 static uint32_t dyn_udp_lifetime = 10; 383 static uint32_t dyn_short_lifetime = 5; 384 385 /* 386 * Keepalives are sent if dyn_keepalive is set. They are sent every 387 * dyn_keepalive_period seconds, in the last dyn_keepalive_interval 388 * seconds of lifetime of a rule. 389 * dyn_rst_lifetime and dyn_fin_lifetime should be strictly lower 390 * than dyn_keepalive_period. 391 */ 392 393 static uint32_t dyn_keepalive_interval = 20; 394 static uint32_t dyn_keepalive_period = 5; 395 static uint32_t dyn_keepalive = 1; /* do send keepalives */ 396 397 static uint32_t dyn_count; /* # of dynamic rules */ 398 static uint32_t dyn_max = 4096; /* max # of dynamic rules */ 399 400 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, dyn_buckets, CTLTYPE_INT | CTLFLAG_RW, 401 &dyn_buckets, 0, ipfw_sysctl_dyn_buckets, "I", "Number of dyn. buckets"); 402 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, curr_dyn_buckets, CTLFLAG_RD, 403 &curr_dyn_buckets, 0, "Current Number of dyn. buckets"); 404 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_count, CTLFLAG_RD, 405 &dyn_count, 0, "Number of dyn. rules"); 406 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_max, CTLFLAG_RW, 407 &dyn_max, 0, "Max number of dyn. rules"); 408 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, static_count, CTLFLAG_RD, 409 &static_count, 0, "Number of static rules"); 410 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_ack_lifetime, CTLFLAG_RW, 411 &dyn_ack_lifetime, 0, "Lifetime of dyn. rules for acks"); 412 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_syn_lifetime, CTLFLAG_RW, 413 &dyn_syn_lifetime, 0, "Lifetime of dyn. rules for syn"); 414 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, dyn_fin_lifetime, 415 CTLTYPE_INT | CTLFLAG_RW, &dyn_fin_lifetime, 0, ipfw_sysctl_dyn_fin, "I", 416 "Lifetime of dyn. rules for fin"); 417 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, dyn_rst_lifetime, 418 CTLTYPE_INT | CTLFLAG_RW, &dyn_rst_lifetime, 0, ipfw_sysctl_dyn_rst, "I", 419 "Lifetime of dyn. rules for rst"); 420 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_udp_lifetime, CTLFLAG_RW, 421 &dyn_udp_lifetime, 0, "Lifetime of dyn. rules for UDP"); 422 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_short_lifetime, CTLFLAG_RW, 423 &dyn_short_lifetime, 0, "Lifetime of dyn. rules for other situations"); 424 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_keepalive, CTLFLAG_RW, 425 &dyn_keepalive, 0, "Enable keepalives for dyn. rules"); 426 427 static ip_fw_chk_t ipfw_chk; 428 static void ipfw_tick(void *); 429 430 static __inline int 431 ipfw_free_rule(struct ip_fw *rule) 432 { 433 KASSERT(rule->cpuid == mycpuid, ("rule freed on cpu%d", mycpuid)); 434 KASSERT(rule->refcnt > 0, ("invalid refcnt %u", rule->refcnt)); 435 rule->refcnt--; 436 if (rule->refcnt == 0) { 437 kfree(rule, M_IPFW); 438 return 1; 439 } 440 return 0; 441 } 442 443 static void 444 ipfw_unref_rule(void *priv) 445 { 446 ipfw_free_rule(priv); 447 #ifdef KLD_MODULE 448 atomic_subtract_int(&ipfw_refcnt, 1); 449 #endif 450 } 451 452 static __inline void 453 ipfw_ref_rule(struct ip_fw *rule) 454 { 455 KASSERT(rule->cpuid == mycpuid, ("rule used on cpu%d", mycpuid)); 456 #ifdef KLD_MODULE 457 atomic_add_int(&ipfw_refcnt, 1); 458 #endif 459 rule->refcnt++; 460 } 461 462 /* 463 * This macro maps an ip pointer into a layer3 header pointer of type T 464 */ 465 #define L3HDR(T, ip) ((T *)((uint32_t *)(ip) + (ip)->ip_hl)) 466 467 static __inline int 468 icmptype_match(struct ip *ip, ipfw_insn_u32 *cmd) 469 { 470 int type = L3HDR(struct icmp,ip)->icmp_type; 471 472 return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1 << type))); 473 } 474 475 #define TT ((1 << ICMP_ECHO) | \ 476 (1 << ICMP_ROUTERSOLICIT) | \ 477 (1 << ICMP_TSTAMP) | \ 478 (1 << ICMP_IREQ) | \ 479 (1 << ICMP_MASKREQ)) 480 481 static int 482 is_icmp_query(struct ip *ip) 483 { 484 int type = L3HDR(struct icmp, ip)->icmp_type; 485 486 return (type <= ICMP_MAXTYPE && (TT & (1 << type))); 487 } 488 489 #undef TT 490 491 /* 492 * The following checks use two arrays of 8 or 16 bits to store the 493 * bits that we want set or clear, respectively. They are in the 494 * low and high half of cmd->arg1 or cmd->d[0]. 495 * 496 * We scan options and store the bits we find set. We succeed if 497 * 498 * (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear 499 * 500 * The code is sometimes optimized not to store additional variables. 501 */ 502 503 static int 504 flags_match(ipfw_insn *cmd, uint8_t bits) 505 { 506 u_char want_clear; 507 bits = ~bits; 508 509 if (((cmd->arg1 & 0xff) & bits) != 0) 510 return 0; /* some bits we want set were clear */ 511 512 want_clear = (cmd->arg1 >> 8) & 0xff; 513 if ((want_clear & bits) != want_clear) 514 return 0; /* some bits we want clear were set */ 515 return 1; 516 } 517 518 static int 519 ipopts_match(struct ip *ip, ipfw_insn *cmd) 520 { 521 int optlen, bits = 0; 522 u_char *cp = (u_char *)(ip + 1); 523 int x = (ip->ip_hl << 2) - sizeof(struct ip); 524 525 for (; x > 0; x -= optlen, cp += optlen) { 526 int opt = cp[IPOPT_OPTVAL]; 527 528 if (opt == IPOPT_EOL) 529 break; 530 531 if (opt == IPOPT_NOP) { 532 optlen = 1; 533 } else { 534 optlen = cp[IPOPT_OLEN]; 535 if (optlen <= 0 || optlen > x) 536 return 0; /* invalid or truncated */ 537 } 538 539 switch (opt) { 540 case IPOPT_LSRR: 541 bits |= IP_FW_IPOPT_LSRR; 542 break; 543 544 case IPOPT_SSRR: 545 bits |= IP_FW_IPOPT_SSRR; 546 break; 547 548 case IPOPT_RR: 549 bits |= IP_FW_IPOPT_RR; 550 break; 551 552 case IPOPT_TS: 553 bits |= IP_FW_IPOPT_TS; 554 break; 555 556 default: 557 break; 558 } 559 } 560 return (flags_match(cmd, bits)); 561 } 562 563 static int 564 tcpopts_match(struct ip *ip, ipfw_insn *cmd) 565 { 566 int optlen, bits = 0; 567 struct tcphdr *tcp = L3HDR(struct tcphdr,ip); 568 u_char *cp = (u_char *)(tcp + 1); 569 int x = (tcp->th_off << 2) - sizeof(struct tcphdr); 570 571 for (; x > 0; x -= optlen, cp += optlen) { 572 int opt = cp[0]; 573 574 if (opt == TCPOPT_EOL) 575 break; 576 577 if (opt == TCPOPT_NOP) { 578 optlen = 1; 579 } else { 580 optlen = cp[1]; 581 if (optlen <= 0) 582 break; 583 } 584 585 switch (opt) { 586 case TCPOPT_MAXSEG: 587 bits |= IP_FW_TCPOPT_MSS; 588 break; 589 590 case TCPOPT_WINDOW: 591 bits |= IP_FW_TCPOPT_WINDOW; 592 break; 593 594 case TCPOPT_SACK_PERMITTED: 595 case TCPOPT_SACK: 596 bits |= IP_FW_TCPOPT_SACK; 597 break; 598 599 case TCPOPT_TIMESTAMP: 600 bits |= IP_FW_TCPOPT_TS; 601 break; 602 603 case TCPOPT_CC: 604 case TCPOPT_CCNEW: 605 case TCPOPT_CCECHO: 606 bits |= IP_FW_TCPOPT_CC; 607 break; 608 609 default: 610 break; 611 } 612 } 613 return (flags_match(cmd, bits)); 614 } 615 616 static int 617 iface_match(struct ifnet *ifp, ipfw_insn_if *cmd) 618 { 619 if (ifp == NULL) /* no iface with this packet, match fails */ 620 return 0; 621 622 /* Check by name or by IP address */ 623 if (cmd->name[0] != '\0') { /* match by name */ 624 /* Check name */ 625 if (cmd->p.glob) { 626 if (kfnmatch(cmd->name, ifp->if_xname, 0) == 0) 627 return(1); 628 } else { 629 if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0) 630 return(1); 631 } 632 } else { 633 struct ifaddr_container *ifac; 634 635 TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) { 636 struct ifaddr *ia = ifac->ifa; 637 638 if (ia->ifa_addr == NULL) 639 continue; 640 if (ia->ifa_addr->sa_family != AF_INET) 641 continue; 642 if (cmd->p.ip.s_addr == ((struct sockaddr_in *) 643 (ia->ifa_addr))->sin_addr.s_addr) 644 return(1); /* match */ 645 } 646 } 647 return(0); /* no match, fail ... */ 648 } 649 650 #define SNPARGS(buf, len) buf + len, sizeof(buf) > len ? sizeof(buf) - len : 0 651 652 /* 653 * We enter here when we have a rule with O_LOG. 654 * XXX this function alone takes about 2Kbytes of code! 655 */ 656 static void 657 ipfw_log(struct ip_fw *f, u_int hlen, struct ether_header *eh, 658 struct mbuf *m, struct ifnet *oif) 659 { 660 char *action; 661 int limit_reached = 0; 662 char action2[40], proto[48], fragment[28]; 663 664 fragment[0] = '\0'; 665 proto[0] = '\0'; 666 667 if (f == NULL) { /* bogus pkt */ 668 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 669 670 if (verbose_limit != 0 && 671 ctx->ipfw_norule_counter >= verbose_limit) 672 return; 673 ctx->ipfw_norule_counter++; 674 if (ctx->ipfw_norule_counter == verbose_limit) 675 limit_reached = verbose_limit; 676 action = "Refuse"; 677 } else { /* O_LOG is the first action, find the real one */ 678 ipfw_insn *cmd = ACTION_PTR(f); 679 ipfw_insn_log *l = (ipfw_insn_log *)cmd; 680 681 if (l->max_log != 0 && l->log_left == 0) 682 return; 683 l->log_left--; 684 if (l->log_left == 0) 685 limit_reached = l->max_log; 686 cmd += F_LEN(cmd); /* point to first action */ 687 if (cmd->opcode == O_PROB) 688 cmd += F_LEN(cmd); 689 690 action = action2; 691 switch (cmd->opcode) { 692 case O_DENY: 693 action = "Deny"; 694 break; 695 696 case O_REJECT: 697 if (cmd->arg1==ICMP_REJECT_RST) { 698 action = "Reset"; 699 } else if (cmd->arg1==ICMP_UNREACH_HOST) { 700 action = "Reject"; 701 } else { 702 ksnprintf(SNPARGS(action2, 0), "Unreach %d", 703 cmd->arg1); 704 } 705 break; 706 707 case O_ACCEPT: 708 action = "Accept"; 709 break; 710 711 case O_COUNT: 712 action = "Count"; 713 break; 714 715 case O_DIVERT: 716 ksnprintf(SNPARGS(action2, 0), "Divert %d", cmd->arg1); 717 break; 718 719 case O_TEE: 720 ksnprintf(SNPARGS(action2, 0), "Tee %d", cmd->arg1); 721 break; 722 723 case O_SKIPTO: 724 ksnprintf(SNPARGS(action2, 0), "SkipTo %d", cmd->arg1); 725 break; 726 727 case O_PIPE: 728 ksnprintf(SNPARGS(action2, 0), "Pipe %d", cmd->arg1); 729 break; 730 731 case O_QUEUE: 732 ksnprintf(SNPARGS(action2, 0), "Queue %d", cmd->arg1); 733 break; 734 735 case O_FORWARD_IP: 736 { 737 ipfw_insn_sa *sa = (ipfw_insn_sa *)cmd; 738 int len; 739 740 len = ksnprintf(SNPARGS(action2, 0), 741 "Forward to %s", 742 inet_ntoa(sa->sa.sin_addr)); 743 if (sa->sa.sin_port) { 744 ksnprintf(SNPARGS(action2, len), ":%d", 745 sa->sa.sin_port); 746 } 747 } 748 break; 749 750 default: 751 action = "UNKNOWN"; 752 break; 753 } 754 } 755 756 if (hlen == 0) { /* non-ip */ 757 ksnprintf(SNPARGS(proto, 0), "MAC"); 758 } else { 759 struct ip *ip = mtod(m, struct ip *); 760 /* these three are all aliases to the same thing */ 761 struct icmp *const icmp = L3HDR(struct icmp, ip); 762 struct tcphdr *const tcp = (struct tcphdr *)icmp; 763 struct udphdr *const udp = (struct udphdr *)icmp; 764 765 int ip_off, offset, ip_len; 766 int len; 767 768 if (eh != NULL) { /* layer 2 packets are as on the wire */ 769 ip_off = ntohs(ip->ip_off); 770 ip_len = ntohs(ip->ip_len); 771 } else { 772 ip_off = ip->ip_off; 773 ip_len = ip->ip_len; 774 } 775 offset = ip_off & IP_OFFMASK; 776 switch (ip->ip_p) { 777 case IPPROTO_TCP: 778 len = ksnprintf(SNPARGS(proto, 0), "TCP %s", 779 inet_ntoa(ip->ip_src)); 780 if (offset == 0) { 781 ksnprintf(SNPARGS(proto, len), ":%d %s:%d", 782 ntohs(tcp->th_sport), 783 inet_ntoa(ip->ip_dst), 784 ntohs(tcp->th_dport)); 785 } else { 786 ksnprintf(SNPARGS(proto, len), " %s", 787 inet_ntoa(ip->ip_dst)); 788 } 789 break; 790 791 case IPPROTO_UDP: 792 len = ksnprintf(SNPARGS(proto, 0), "UDP %s", 793 inet_ntoa(ip->ip_src)); 794 if (offset == 0) { 795 ksnprintf(SNPARGS(proto, len), ":%d %s:%d", 796 ntohs(udp->uh_sport), 797 inet_ntoa(ip->ip_dst), 798 ntohs(udp->uh_dport)); 799 } else { 800 ksnprintf(SNPARGS(proto, len), " %s", 801 inet_ntoa(ip->ip_dst)); 802 } 803 break; 804 805 case IPPROTO_ICMP: 806 if (offset == 0) { 807 len = ksnprintf(SNPARGS(proto, 0), 808 "ICMP:%u.%u ", 809 icmp->icmp_type, 810 icmp->icmp_code); 811 } else { 812 len = ksnprintf(SNPARGS(proto, 0), "ICMP "); 813 } 814 len += ksnprintf(SNPARGS(proto, len), "%s", 815 inet_ntoa(ip->ip_src)); 816 ksnprintf(SNPARGS(proto, len), " %s", 817 inet_ntoa(ip->ip_dst)); 818 break; 819 820 default: 821 len = ksnprintf(SNPARGS(proto, 0), "P:%d %s", ip->ip_p, 822 inet_ntoa(ip->ip_src)); 823 ksnprintf(SNPARGS(proto, len), " %s", 824 inet_ntoa(ip->ip_dst)); 825 break; 826 } 827 828 if (ip_off & (IP_MF | IP_OFFMASK)) { 829 ksnprintf(SNPARGS(fragment, 0), " (frag %d:%d@%d%s)", 830 ntohs(ip->ip_id), ip_len - (ip->ip_hl << 2), 831 offset << 3, (ip_off & IP_MF) ? "+" : ""); 832 } 833 } 834 835 if (oif || m->m_pkthdr.rcvif) { 836 log(LOG_SECURITY | LOG_INFO, 837 "ipfw: %d %s %s %s via %s%s\n", 838 f ? f->rulenum : -1, 839 action, proto, oif ? "out" : "in", 840 oif ? oif->if_xname : m->m_pkthdr.rcvif->if_xname, 841 fragment); 842 } else { 843 log(LOG_SECURITY | LOG_INFO, 844 "ipfw: %d %s %s [no if info]%s\n", 845 f ? f->rulenum : -1, 846 action, proto, fragment); 847 } 848 849 if (limit_reached) { 850 log(LOG_SECURITY | LOG_NOTICE, 851 "ipfw: limit %d reached on entry %d\n", 852 limit_reached, f ? f->rulenum : -1); 853 } 854 } 855 856 #undef SNPARGS 857 858 /* 859 * IMPORTANT: the hash function for dynamic rules must be commutative 860 * in source and destination (ip,port), because rules are bidirectional 861 * and we want to find both in the same bucket. 862 */ 863 static __inline int 864 hash_packet(struct ipfw_flow_id *id) 865 { 866 uint32_t i; 867 868 i = (id->dst_ip) ^ (id->src_ip) ^ (id->dst_port) ^ (id->src_port); 869 i &= (curr_dyn_buckets - 1); 870 return i; 871 } 872 873 /** 874 * unlink a dynamic rule from a chain. prev is a pointer to 875 * the previous one, q is a pointer to the rule to delete, 876 * head is a pointer to the head of the queue. 877 * Modifies q and potentially also head. 878 */ 879 #define UNLINK_DYN_RULE(prev, head, q) \ 880 do { \ 881 ipfw_dyn_rule *old_q = q; \ 882 \ 883 /* remove a refcount to the parent */ \ 884 if (q->dyn_type == O_LIMIT) \ 885 q->parent->count--; \ 886 DPRINTF("-- unlink entry 0x%08x %d -> 0x%08x %d, %d left\n", \ 887 q->id.src_ip, q->id.src_port, \ 888 q->id.dst_ip, q->id.dst_port, dyn_count - 1); \ 889 if (prev != NULL) \ 890 prev->next = q = q->next; \ 891 else \ 892 head = q = q->next; \ 893 KASSERT(dyn_count > 0, ("invalid dyn count %u", dyn_count)); \ 894 dyn_count--; \ 895 kfree(old_q, M_IPFW); \ 896 } while (0) 897 898 #define TIME_LEQ(a, b) ((int)((a) - (b)) <= 0) 899 900 /** 901 * Remove dynamic rules pointing to "rule", or all of them if rule == NULL. 902 * 903 * If keep_me == NULL, rules are deleted even if not expired, 904 * otherwise only expired rules are removed. 905 * 906 * The value of the second parameter is also used to point to identify 907 * a rule we absolutely do not want to remove (e.g. because we are 908 * holding a reference to it -- this is the case with O_LIMIT_PARENT 909 * rules). The pointer is only used for comparison, so any non-null 910 * value will do. 911 */ 912 static void 913 remove_dyn_rule_locked(struct ip_fw *rule, ipfw_dyn_rule *keep_me) 914 { 915 static time_t last_remove = 0; /* XXX */ 916 917 #define FORCE (keep_me == NULL) 918 919 ipfw_dyn_rule *prev, *q; 920 int i, pass = 0, max_pass = 0, unlinked = 0; 921 922 if (ipfw_dyn_v == NULL || dyn_count == 0) 923 return; 924 /* do not expire more than once per second, it is useless */ 925 if (!FORCE && last_remove == time_uptime) 926 return; 927 last_remove = time_uptime; 928 929 /* 930 * because O_LIMIT refer to parent rules, during the first pass only 931 * remove child and mark any pending LIMIT_PARENT, and remove 932 * them in a second pass. 933 */ 934 next_pass: 935 for (i = 0; i < curr_dyn_buckets; i++) { 936 for (prev = NULL, q = ipfw_dyn_v[i]; q;) { 937 /* 938 * Logic can become complex here, so we split tests. 939 */ 940 if (q == keep_me) 941 goto next; 942 if (rule != NULL && rule->stub != q->stub) 943 goto next; /* not the one we are looking for */ 944 if (q->dyn_type == O_LIMIT_PARENT) { 945 /* 946 * handle parent in the second pass, 947 * record we need one. 948 */ 949 max_pass = 1; 950 if (pass == 0) 951 goto next; 952 if (FORCE && q->count != 0) { 953 /* XXX should not happen! */ 954 kprintf("OUCH! cannot remove rule, " 955 "count %d\n", q->count); 956 } 957 } else { 958 if (!FORCE && !TIME_LEQ(q->expire, time_second)) 959 goto next; 960 } 961 unlinked = 1; 962 UNLINK_DYN_RULE(prev, ipfw_dyn_v[i], q); 963 continue; 964 next: 965 prev = q; 966 q = q->next; 967 } 968 } 969 if (pass++ < max_pass) 970 goto next_pass; 971 972 if (unlinked) 973 ++dyn_buckets_gen; 974 975 #undef FORCE 976 } 977 978 /** 979 * lookup a dynamic rule. 980 */ 981 static ipfw_dyn_rule * 982 lookup_dyn_rule(struct ipfw_flow_id *pkt, int *match_direction, 983 struct tcphdr *tcp) 984 { 985 /* 986 * stateful ipfw extensions. 987 * Lookup into dynamic session queue 988 */ 989 #define MATCH_REVERSE 0 990 #define MATCH_FORWARD 1 991 #define MATCH_NONE 2 992 #define MATCH_UNKNOWN 3 993 int i, dir = MATCH_NONE; 994 ipfw_dyn_rule *q=NULL; 995 996 if (ipfw_dyn_v == NULL) 997 goto done; /* not found */ 998 999 i = hash_packet(pkt); 1000 for (q = ipfw_dyn_v[i]; q != NULL;) { 1001 if (q->dyn_type == O_LIMIT_PARENT) 1002 goto next; 1003 1004 if (TIME_LEQ(q->expire, time_second)) { 1005 /* 1006 * Entry expired; skip. 1007 * Let ipfw_tick() take care of it 1008 */ 1009 goto next; 1010 } 1011 1012 if (pkt->proto == q->id.proto) { 1013 if (pkt->src_ip == q->id.src_ip && 1014 pkt->dst_ip == q->id.dst_ip && 1015 pkt->src_port == q->id.src_port && 1016 pkt->dst_port == q->id.dst_port) { 1017 dir = MATCH_FORWARD; 1018 break; 1019 } 1020 if (pkt->src_ip == q->id.dst_ip && 1021 pkt->dst_ip == q->id.src_ip && 1022 pkt->src_port == q->id.dst_port && 1023 pkt->dst_port == q->id.src_port) { 1024 dir = MATCH_REVERSE; 1025 break; 1026 } 1027 } 1028 next: 1029 q = q->next; 1030 } 1031 if (q == NULL) 1032 goto done; /* q = NULL, not found */ 1033 1034 if (pkt->proto == IPPROTO_TCP) { /* update state according to flags */ 1035 u_char flags = pkt->flags & (TH_FIN|TH_SYN|TH_RST); 1036 1037 #define BOTH_SYN (TH_SYN | (TH_SYN << 8)) 1038 #define BOTH_FIN (TH_FIN | (TH_FIN << 8)) 1039 1040 q->state |= (dir == MATCH_FORWARD ) ? flags : (flags << 8); 1041 switch (q->state) { 1042 case TH_SYN: /* opening */ 1043 q->expire = time_second + dyn_syn_lifetime; 1044 break; 1045 1046 case BOTH_SYN: /* move to established */ 1047 case BOTH_SYN | TH_FIN : /* one side tries to close */ 1048 case BOTH_SYN | (TH_FIN << 8) : 1049 if (tcp) { 1050 uint32_t ack = ntohl(tcp->th_ack); 1051 1052 #define _SEQ_GE(a, b) ((int)(a) - (int)(b) >= 0) 1053 1054 if (dir == MATCH_FORWARD) { 1055 if (q->ack_fwd == 0 || 1056 _SEQ_GE(ack, q->ack_fwd)) 1057 q->ack_fwd = ack; 1058 else /* ignore out-of-sequence */ 1059 break; 1060 } else { 1061 if (q->ack_rev == 0 || 1062 _SEQ_GE(ack, q->ack_rev)) 1063 q->ack_rev = ack; 1064 else /* ignore out-of-sequence */ 1065 break; 1066 } 1067 #undef _SEQ_GE 1068 } 1069 q->expire = time_second + dyn_ack_lifetime; 1070 break; 1071 1072 case BOTH_SYN | BOTH_FIN: /* both sides closed */ 1073 KKASSERT(dyn_fin_lifetime < dyn_keepalive_period); 1074 q->expire = time_second + dyn_fin_lifetime; 1075 break; 1076 1077 default: 1078 #if 0 1079 /* 1080 * reset or some invalid combination, but can also 1081 * occur if we use keep-state the wrong way. 1082 */ 1083 if ((q->state & ((TH_RST << 8) | TH_RST)) == 0) 1084 kprintf("invalid state: 0x%x\n", q->state); 1085 #endif 1086 KKASSERT(dyn_rst_lifetime < dyn_keepalive_period); 1087 q->expire = time_second + dyn_rst_lifetime; 1088 break; 1089 } 1090 } else if (pkt->proto == IPPROTO_UDP) { 1091 q->expire = time_second + dyn_udp_lifetime; 1092 } else { 1093 /* other protocols */ 1094 q->expire = time_second + dyn_short_lifetime; 1095 } 1096 done: 1097 if (match_direction) 1098 *match_direction = dir; 1099 return q; 1100 } 1101 1102 static struct ip_fw * 1103 lookup_rule(struct ipfw_flow_id *pkt, int *match_direction, struct tcphdr *tcp, 1104 uint16_t len, int *deny) 1105 { 1106 struct ip_fw *rule = NULL; 1107 ipfw_dyn_rule *q; 1108 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 1109 uint32_t gen; 1110 1111 *deny = 0; 1112 gen = ctx->ipfw_gen; 1113 1114 lockmgr(&dyn_lock, LK_SHARED); 1115 1116 if (ctx->ipfw_gen != gen) { 1117 /* 1118 * Static rules had been change when we were waiting 1119 * for the dynamic hash table lock; deny this packet, 1120 * since it is _not_ known whether it is safe to keep 1121 * iterating the static rules. 1122 */ 1123 *deny = 1; 1124 goto back; 1125 } 1126 1127 q = lookup_dyn_rule(pkt, match_direction, tcp); 1128 if (q == NULL) { 1129 rule = NULL; 1130 } else { 1131 rule = q->stub->rule[mycpuid]; 1132 KKASSERT(rule->stub == q->stub && rule->cpuid == mycpuid); 1133 1134 /* XXX */ 1135 q->pcnt++; 1136 q->bcnt += len; 1137 } 1138 back: 1139 lockmgr(&dyn_lock, LK_RELEASE); 1140 return rule; 1141 } 1142 1143 static void 1144 realloc_dynamic_table(void) 1145 { 1146 ipfw_dyn_rule **old_dyn_v; 1147 uint32_t old_curr_dyn_buckets; 1148 1149 KASSERT(dyn_buckets <= 65536 && (dyn_buckets & (dyn_buckets - 1)) == 0, 1150 ("invalid dyn_buckets %d", dyn_buckets)); 1151 1152 /* Save the current buckets array for later error recovery */ 1153 old_dyn_v = ipfw_dyn_v; 1154 old_curr_dyn_buckets = curr_dyn_buckets; 1155 1156 curr_dyn_buckets = dyn_buckets; 1157 for (;;) { 1158 ipfw_dyn_v = kmalloc(curr_dyn_buckets * sizeof(ipfw_dyn_rule *), 1159 M_IPFW, M_NOWAIT | M_ZERO); 1160 if (ipfw_dyn_v != NULL || curr_dyn_buckets <= 2) 1161 break; 1162 1163 curr_dyn_buckets /= 2; 1164 if (curr_dyn_buckets <= old_curr_dyn_buckets && 1165 old_dyn_v != NULL) { 1166 /* 1167 * Don't try allocating smaller buckets array, reuse 1168 * the old one, which alreay contains enough buckets 1169 */ 1170 break; 1171 } 1172 } 1173 1174 if (ipfw_dyn_v != NULL) { 1175 if (old_dyn_v != NULL) 1176 kfree(old_dyn_v, M_IPFW); 1177 } else { 1178 /* Allocation failed, restore old buckets array */ 1179 ipfw_dyn_v = old_dyn_v; 1180 curr_dyn_buckets = old_curr_dyn_buckets; 1181 } 1182 1183 if (ipfw_dyn_v != NULL) 1184 ++dyn_buckets_gen; 1185 } 1186 1187 /** 1188 * Install state of type 'type' for a dynamic session. 1189 * The hash table contains two type of rules: 1190 * - regular rules (O_KEEP_STATE) 1191 * - rules for sessions with limited number of sess per user 1192 * (O_LIMIT). When they are created, the parent is 1193 * increased by 1, and decreased on delete. In this case, 1194 * the third parameter is the parent rule and not the chain. 1195 * - "parent" rules for the above (O_LIMIT_PARENT). 1196 */ 1197 static ipfw_dyn_rule * 1198 add_dyn_rule(struct ipfw_flow_id *id, uint8_t dyn_type, struct ip_fw *rule) 1199 { 1200 ipfw_dyn_rule *r; 1201 int i; 1202 1203 if (ipfw_dyn_v == NULL || 1204 (dyn_count == 0 && dyn_buckets != curr_dyn_buckets)) { 1205 realloc_dynamic_table(); 1206 if (ipfw_dyn_v == NULL) 1207 return NULL; /* failed ! */ 1208 } 1209 i = hash_packet(id); 1210 1211 r = kmalloc(sizeof(*r), M_IPFW, M_NOWAIT | M_ZERO); 1212 if (r == NULL) 1213 return NULL; 1214 1215 /* increase refcount on parent, and set pointer */ 1216 if (dyn_type == O_LIMIT) { 1217 ipfw_dyn_rule *parent = (ipfw_dyn_rule *)rule; 1218 1219 if (parent->dyn_type != O_LIMIT_PARENT) 1220 panic("invalid parent"); 1221 parent->count++; 1222 r->parent = parent; 1223 rule = parent->stub->rule[mycpuid]; 1224 KKASSERT(rule->stub == parent->stub); 1225 } 1226 KKASSERT(rule->cpuid == mycpuid && rule->stub != NULL); 1227 1228 r->id = *id; 1229 r->expire = time_second + dyn_syn_lifetime; 1230 r->stub = rule->stub; 1231 r->dyn_type = dyn_type; 1232 r->pcnt = r->bcnt = 0; 1233 r->count = 0; 1234 1235 r->bucket = i; 1236 r->next = ipfw_dyn_v[i]; 1237 ipfw_dyn_v[i] = r; 1238 dyn_count++; 1239 dyn_buckets_gen++; 1240 DPRINTF("-- add dyn entry ty %d 0x%08x %d -> 0x%08x %d, total %d\n", 1241 dyn_type, 1242 r->id.src_ip, r->id.src_port, 1243 r->id.dst_ip, r->id.dst_port, dyn_count); 1244 return r; 1245 } 1246 1247 /** 1248 * lookup dynamic parent rule using pkt and rule as search keys. 1249 * If the lookup fails, then install one. 1250 */ 1251 static ipfw_dyn_rule * 1252 lookup_dyn_parent(struct ipfw_flow_id *pkt, struct ip_fw *rule) 1253 { 1254 ipfw_dyn_rule *q; 1255 int i; 1256 1257 if (ipfw_dyn_v) { 1258 i = hash_packet(pkt); 1259 for (q = ipfw_dyn_v[i]; q != NULL; q = q->next) { 1260 if (q->dyn_type == O_LIMIT_PARENT && 1261 rule->stub == q->stub && 1262 pkt->proto == q->id.proto && 1263 pkt->src_ip == q->id.src_ip && 1264 pkt->dst_ip == q->id.dst_ip && 1265 pkt->src_port == q->id.src_port && 1266 pkt->dst_port == q->id.dst_port) { 1267 q->expire = time_second + dyn_short_lifetime; 1268 DPRINTF("lookup_dyn_parent found 0x%p\n", q); 1269 return q; 1270 } 1271 } 1272 } 1273 return add_dyn_rule(pkt, O_LIMIT_PARENT, rule); 1274 } 1275 1276 /** 1277 * Install dynamic state for rule type cmd->o.opcode 1278 * 1279 * Returns 1 (failure) if state is not installed because of errors or because 1280 * session limitations are enforced. 1281 */ 1282 static int 1283 install_state_locked(struct ip_fw *rule, ipfw_insn_limit *cmd, 1284 struct ip_fw_args *args) 1285 { 1286 static int last_log; /* XXX */ 1287 1288 ipfw_dyn_rule *q; 1289 1290 DPRINTF("-- install state type %d 0x%08x %u -> 0x%08x %u\n", 1291 cmd->o.opcode, 1292 args->f_id.src_ip, args->f_id.src_port, 1293 args->f_id.dst_ip, args->f_id.dst_port); 1294 1295 q = lookup_dyn_rule(&args->f_id, NULL, NULL); 1296 if (q != NULL) { /* should never occur */ 1297 if (last_log != time_second) { 1298 last_log = time_second; 1299 kprintf(" install_state: entry already present, done\n"); 1300 } 1301 return 0; 1302 } 1303 1304 if (dyn_count >= dyn_max) { 1305 /* 1306 * Run out of slots, try to remove any expired rule. 1307 */ 1308 remove_dyn_rule_locked(NULL, (ipfw_dyn_rule *)1); 1309 if (dyn_count >= dyn_max) { 1310 if (last_log != time_second) { 1311 last_log = time_second; 1312 kprintf("install_state: " 1313 "Too many dynamic rules\n"); 1314 } 1315 return 1; /* cannot install, notify caller */ 1316 } 1317 } 1318 1319 switch (cmd->o.opcode) { 1320 case O_KEEP_STATE: /* bidir rule */ 1321 if (add_dyn_rule(&args->f_id, O_KEEP_STATE, rule) == NULL) 1322 return 1; 1323 break; 1324 1325 case O_LIMIT: /* limit number of sessions */ 1326 { 1327 uint16_t limit_mask = cmd->limit_mask; 1328 struct ipfw_flow_id id; 1329 ipfw_dyn_rule *parent; 1330 1331 DPRINTF("installing dyn-limit rule %d\n", 1332 cmd->conn_limit); 1333 1334 id.dst_ip = id.src_ip = 0; 1335 id.dst_port = id.src_port = 0; 1336 id.proto = args->f_id.proto; 1337 1338 if (limit_mask & DYN_SRC_ADDR) 1339 id.src_ip = args->f_id.src_ip; 1340 if (limit_mask & DYN_DST_ADDR) 1341 id.dst_ip = args->f_id.dst_ip; 1342 if (limit_mask & DYN_SRC_PORT) 1343 id.src_port = args->f_id.src_port; 1344 if (limit_mask & DYN_DST_PORT) 1345 id.dst_port = args->f_id.dst_port; 1346 1347 parent = lookup_dyn_parent(&id, rule); 1348 if (parent == NULL) { 1349 kprintf("add parent failed\n"); 1350 return 1; 1351 } 1352 1353 if (parent->count >= cmd->conn_limit) { 1354 /* 1355 * See if we can remove some expired rule. 1356 */ 1357 remove_dyn_rule_locked(rule, parent); 1358 if (parent->count >= cmd->conn_limit) { 1359 if (fw_verbose && 1360 last_log != time_second) { 1361 last_log = time_second; 1362 log(LOG_SECURITY | LOG_DEBUG, 1363 "drop session, " 1364 "too many entries\n"); 1365 } 1366 return 1; 1367 } 1368 } 1369 if (add_dyn_rule(&args->f_id, O_LIMIT, 1370 (struct ip_fw *)parent) == NULL) 1371 return 1; 1372 } 1373 break; 1374 default: 1375 kprintf("unknown dynamic rule type %u\n", cmd->o.opcode); 1376 return 1; 1377 } 1378 lookup_dyn_rule(&args->f_id, NULL, NULL); /* XXX just set lifetime */ 1379 return 0; 1380 } 1381 1382 static int 1383 install_state(struct ip_fw *rule, ipfw_insn_limit *cmd, 1384 struct ip_fw_args *args, int *deny) 1385 { 1386 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 1387 uint32_t gen; 1388 int ret = 0; 1389 1390 *deny = 0; 1391 gen = ctx->ipfw_gen; 1392 1393 lockmgr(&dyn_lock, LK_EXCLUSIVE); 1394 if (ctx->ipfw_gen != gen) { 1395 /* See the comment in lookup_rule() */ 1396 *deny = 1; 1397 } else { 1398 ret = install_state_locked(rule, cmd, args); 1399 } 1400 lockmgr(&dyn_lock, LK_RELEASE); 1401 1402 return ret; 1403 } 1404 1405 /* 1406 * Transmit a TCP packet, containing either a RST or a keepalive. 1407 * When flags & TH_RST, we are sending a RST packet, because of a 1408 * "reset" action matched the packet. 1409 * Otherwise we are sending a keepalive, and flags & TH_ 1410 */ 1411 static void 1412 send_pkt(struct ipfw_flow_id *id, uint32_t seq, uint32_t ack, int flags) 1413 { 1414 struct mbuf *m; 1415 struct ip *ip; 1416 struct tcphdr *tcp; 1417 struct route sro; /* fake route */ 1418 1419 MGETHDR(m, MB_DONTWAIT, MT_HEADER); 1420 if (m == NULL) 1421 return; 1422 m->m_pkthdr.rcvif = NULL; 1423 m->m_pkthdr.len = m->m_len = sizeof(struct ip) + sizeof(struct tcphdr); 1424 m->m_data += max_linkhdr; 1425 1426 ip = mtod(m, struct ip *); 1427 bzero(ip, m->m_len); 1428 tcp = (struct tcphdr *)(ip + 1); /* no IP options */ 1429 ip->ip_p = IPPROTO_TCP; 1430 tcp->th_off = 5; 1431 1432 /* 1433 * Assume we are sending a RST (or a keepalive in the reverse 1434 * direction), swap src and destination addresses and ports. 1435 */ 1436 ip->ip_src.s_addr = htonl(id->dst_ip); 1437 ip->ip_dst.s_addr = htonl(id->src_ip); 1438 tcp->th_sport = htons(id->dst_port); 1439 tcp->th_dport = htons(id->src_port); 1440 if (flags & TH_RST) { /* we are sending a RST */ 1441 if (flags & TH_ACK) { 1442 tcp->th_seq = htonl(ack); 1443 tcp->th_ack = htonl(0); 1444 tcp->th_flags = TH_RST; 1445 } else { 1446 if (flags & TH_SYN) 1447 seq++; 1448 tcp->th_seq = htonl(0); 1449 tcp->th_ack = htonl(seq); 1450 tcp->th_flags = TH_RST | TH_ACK; 1451 } 1452 } else { 1453 /* 1454 * We are sending a keepalive. flags & TH_SYN determines 1455 * the direction, forward if set, reverse if clear. 1456 * NOTE: seq and ack are always assumed to be correct 1457 * as set by the caller. This may be confusing... 1458 */ 1459 if (flags & TH_SYN) { 1460 /* 1461 * we have to rewrite the correct addresses! 1462 */ 1463 ip->ip_dst.s_addr = htonl(id->dst_ip); 1464 ip->ip_src.s_addr = htonl(id->src_ip); 1465 tcp->th_dport = htons(id->dst_port); 1466 tcp->th_sport = htons(id->src_port); 1467 } 1468 tcp->th_seq = htonl(seq); 1469 tcp->th_ack = htonl(ack); 1470 tcp->th_flags = TH_ACK; 1471 } 1472 1473 /* 1474 * set ip_len to the payload size so we can compute 1475 * the tcp checksum on the pseudoheader 1476 * XXX check this, could save a couple of words ? 1477 */ 1478 ip->ip_len = htons(sizeof(struct tcphdr)); 1479 tcp->th_sum = in_cksum(m, m->m_pkthdr.len); 1480 1481 /* 1482 * now fill fields left out earlier 1483 */ 1484 ip->ip_ttl = ip_defttl; 1485 ip->ip_len = m->m_pkthdr.len; 1486 1487 bzero(&sro, sizeof(sro)); 1488 ip_rtaddr(ip->ip_dst, &sro); 1489 1490 m->m_pkthdr.fw_flags |= IPFW_MBUF_GENERATED; 1491 ip_output(m, NULL, &sro, 0, NULL, NULL); 1492 if (sro.ro_rt) 1493 RTFREE(sro.ro_rt); 1494 } 1495 1496 /* 1497 * sends a reject message, consuming the mbuf passed as an argument. 1498 */ 1499 static void 1500 send_reject(struct ip_fw_args *args, int code, int offset, int ip_len) 1501 { 1502 if (code != ICMP_REJECT_RST) { /* Send an ICMP unreach */ 1503 /* We need the IP header in host order for icmp_error(). */ 1504 if (args->eh != NULL) { 1505 struct ip *ip = mtod(args->m, struct ip *); 1506 1507 ip->ip_len = ntohs(ip->ip_len); 1508 ip->ip_off = ntohs(ip->ip_off); 1509 } 1510 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0); 1511 } else if (offset == 0 && args->f_id.proto == IPPROTO_TCP) { 1512 struct tcphdr *const tcp = 1513 L3HDR(struct tcphdr, mtod(args->m, struct ip *)); 1514 1515 if ((tcp->th_flags & TH_RST) == 0) { 1516 send_pkt(&args->f_id, ntohl(tcp->th_seq), 1517 ntohl(tcp->th_ack), tcp->th_flags | TH_RST); 1518 } 1519 m_freem(args->m); 1520 } else { 1521 m_freem(args->m); 1522 } 1523 args->m = NULL; 1524 } 1525 1526 /** 1527 * 1528 * Given an ip_fw *, lookup_next_rule will return a pointer 1529 * to the next rule, which can be either the jump 1530 * target (for skipto instructions) or the next one in the list (in 1531 * all other cases including a missing jump target). 1532 * The result is also written in the "next_rule" field of the rule. 1533 * Backward jumps are not allowed, so start looking from the next 1534 * rule... 1535 * 1536 * This never returns NULL -- in case we do not have an exact match, 1537 * the next rule is returned. When the ruleset is changed, 1538 * pointers are flushed so we are always correct. 1539 */ 1540 1541 static struct ip_fw * 1542 lookup_next_rule(struct ip_fw *me) 1543 { 1544 struct ip_fw *rule = NULL; 1545 ipfw_insn *cmd; 1546 1547 /* look for action, in case it is a skipto */ 1548 cmd = ACTION_PTR(me); 1549 if (cmd->opcode == O_LOG) 1550 cmd += F_LEN(cmd); 1551 if (cmd->opcode == O_SKIPTO) { 1552 for (rule = me->next; rule; rule = rule->next) { 1553 if (rule->rulenum >= cmd->arg1) 1554 break; 1555 } 1556 } 1557 if (rule == NULL) /* failure or not a skipto */ 1558 rule = me->next; 1559 me->next_rule = rule; 1560 return rule; 1561 } 1562 1563 static int 1564 _ipfw_match_uid(const struct ipfw_flow_id *fid, struct ifnet *oif, 1565 enum ipfw_opcodes opcode, uid_t uid) 1566 { 1567 struct in_addr src_ip, dst_ip; 1568 struct inpcbinfo *pi; 1569 int wildcard; 1570 struct inpcb *pcb; 1571 1572 if (fid->proto == IPPROTO_TCP) { 1573 wildcard = 0; 1574 pi = &tcbinfo[mycpuid]; 1575 } else if (fid->proto == IPPROTO_UDP) { 1576 wildcard = 1; 1577 pi = &udbinfo; 1578 } else { 1579 return 0; 1580 } 1581 1582 /* 1583 * Values in 'fid' are in host byte order 1584 */ 1585 dst_ip.s_addr = htonl(fid->dst_ip); 1586 src_ip.s_addr = htonl(fid->src_ip); 1587 if (oif) { 1588 pcb = in_pcblookup_hash(pi, 1589 dst_ip, htons(fid->dst_port), 1590 src_ip, htons(fid->src_port), 1591 wildcard, oif); 1592 } else { 1593 pcb = in_pcblookup_hash(pi, 1594 src_ip, htons(fid->src_port), 1595 dst_ip, htons(fid->dst_port), 1596 wildcard, NULL); 1597 } 1598 if (pcb == NULL || pcb->inp_socket == NULL) 1599 return 0; 1600 1601 if (opcode == O_UID) { 1602 #define socheckuid(a,b) ((a)->so_cred->cr_uid != (b)) 1603 return !socheckuid(pcb->inp_socket, uid); 1604 #undef socheckuid 1605 } else { 1606 return groupmember(uid, pcb->inp_socket->so_cred); 1607 } 1608 } 1609 1610 static int 1611 ipfw_match_uid(const struct ipfw_flow_id *fid, struct ifnet *oif, 1612 enum ipfw_opcodes opcode, uid_t uid, int *deny) 1613 { 1614 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 1615 uint32_t gen; 1616 int match = 0; 1617 1618 *deny = 0; 1619 gen = ctx->ipfw_gen; 1620 1621 if (gen != ctx->ipfw_gen) { 1622 /* See the comment in lookup_rule() */ 1623 *deny = 1; 1624 } else { 1625 match = _ipfw_match_uid(fid, oif, opcode, uid); 1626 } 1627 return match; 1628 } 1629 1630 /* 1631 * The main check routine for the firewall. 1632 * 1633 * All arguments are in args so we can modify them and return them 1634 * back to the caller. 1635 * 1636 * Parameters: 1637 * 1638 * args->m (in/out) The packet; we set to NULL when/if we nuke it. 1639 * Starts with the IP header. 1640 * args->eh (in) Mac header if present, or NULL for layer3 packet. 1641 * args->oif Outgoing interface, or NULL if packet is incoming. 1642 * The incoming interface is in the mbuf. (in) 1643 * 1644 * args->rule Pointer to the last matching rule (in/out) 1645 * args->f_id Addresses grabbed from the packet (out) 1646 * 1647 * Return value: 1648 * 1649 * If the packet was denied/rejected and has been dropped, *m is equal 1650 * to NULL upon return. 1651 * 1652 * IP_FW_DENY the packet must be dropped. 1653 * IP_FW_PASS The packet is to be accepted and routed normally. 1654 * IP_FW_DIVERT Divert the packet to port (args->cookie) 1655 * IP_FW_TEE Tee the packet to port (args->cookie) 1656 * IP_FW_DUMMYNET Send the packet to pipe/queue (args->cookie) 1657 */ 1658 1659 static int 1660 ipfw_chk(struct ip_fw_args *args) 1661 { 1662 /* 1663 * Local variables hold state during the processing of a packet. 1664 * 1665 * IMPORTANT NOTE: to speed up the processing of rules, there 1666 * are some assumption on the values of the variables, which 1667 * are documented here. Should you change them, please check 1668 * the implementation of the various instructions to make sure 1669 * that they still work. 1670 * 1671 * args->eh The MAC header. It is non-null for a layer2 1672 * packet, it is NULL for a layer-3 packet. 1673 * 1674 * m | args->m Pointer to the mbuf, as received from the caller. 1675 * It may change if ipfw_chk() does an m_pullup, or if it 1676 * consumes the packet because it calls send_reject(). 1677 * XXX This has to change, so that ipfw_chk() never modifies 1678 * or consumes the buffer. 1679 * ip is simply an alias of the value of m, and it is kept 1680 * in sync with it (the packet is supposed to start with 1681 * the ip header). 1682 */ 1683 struct mbuf *m = args->m; 1684 struct ip *ip = mtod(m, struct ip *); 1685 1686 /* 1687 * oif | args->oif If NULL, ipfw_chk has been called on the 1688 * inbound path (ether_input, ip_input). 1689 * If non-NULL, ipfw_chk has been called on the outbound path 1690 * (ether_output, ip_output). 1691 */ 1692 struct ifnet *oif = args->oif; 1693 1694 struct ip_fw *f = NULL; /* matching rule */ 1695 int retval = IP_FW_PASS; 1696 struct m_tag *mtag; 1697 struct divert_info *divinfo; 1698 1699 /* 1700 * hlen The length of the IPv4 header. 1701 * hlen >0 means we have an IPv4 packet. 1702 */ 1703 u_int hlen = 0; /* hlen >0 means we have an IP pkt */ 1704 1705 /* 1706 * offset The offset of a fragment. offset != 0 means that 1707 * we have a fragment at this offset of an IPv4 packet. 1708 * offset == 0 means that (if this is an IPv4 packet) 1709 * this is the first or only fragment. 1710 */ 1711 u_short offset = 0; 1712 1713 /* 1714 * Local copies of addresses. They are only valid if we have 1715 * an IP packet. 1716 * 1717 * proto The protocol. Set to 0 for non-ip packets, 1718 * or to the protocol read from the packet otherwise. 1719 * proto != 0 means that we have an IPv4 packet. 1720 * 1721 * src_port, dst_port port numbers, in HOST format. Only 1722 * valid for TCP and UDP packets. 1723 * 1724 * src_ip, dst_ip ip addresses, in NETWORK format. 1725 * Only valid for IPv4 packets. 1726 */ 1727 uint8_t proto; 1728 uint16_t src_port = 0, dst_port = 0; /* NOTE: host format */ 1729 struct in_addr src_ip, dst_ip; /* NOTE: network format */ 1730 uint16_t ip_len = 0; 1731 1732 /* 1733 * dyn_dir = MATCH_UNKNOWN when rules unchecked, 1734 * MATCH_NONE when checked and not matched (dyn_f = NULL), 1735 * MATCH_FORWARD or MATCH_REVERSE otherwise (dyn_f != NULL) 1736 */ 1737 int dyn_dir = MATCH_UNKNOWN; 1738 struct ip_fw *dyn_f = NULL; 1739 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 1740 1741 if (m->m_pkthdr.fw_flags & IPFW_MBUF_GENERATED) 1742 return IP_FW_PASS; /* accept */ 1743 1744 if (args->eh == NULL || /* layer 3 packet */ 1745 (m->m_pkthdr.len >= sizeof(struct ip) && 1746 ntohs(args->eh->ether_type) == ETHERTYPE_IP)) 1747 hlen = ip->ip_hl << 2; 1748 1749 /* 1750 * Collect parameters into local variables for faster matching. 1751 */ 1752 if (hlen == 0) { /* do not grab addresses for non-ip pkts */ 1753 proto = args->f_id.proto = 0; /* mark f_id invalid */ 1754 goto after_ip_checks; 1755 } 1756 1757 proto = args->f_id.proto = ip->ip_p; 1758 src_ip = ip->ip_src; 1759 dst_ip = ip->ip_dst; 1760 if (args->eh != NULL) { /* layer 2 packets are as on the wire */ 1761 offset = ntohs(ip->ip_off) & IP_OFFMASK; 1762 ip_len = ntohs(ip->ip_len); 1763 } else { 1764 offset = ip->ip_off & IP_OFFMASK; 1765 ip_len = ip->ip_len; 1766 } 1767 1768 #define PULLUP_TO(len) \ 1769 do { \ 1770 if (m->m_len < (len)) { \ 1771 args->m = m = m_pullup(m, (len));\ 1772 if (m == NULL) \ 1773 goto pullup_failed; \ 1774 ip = mtod(m, struct ip *); \ 1775 } \ 1776 } while (0) 1777 1778 if (offset == 0) { 1779 switch (proto) { 1780 case IPPROTO_TCP: 1781 { 1782 struct tcphdr *tcp; 1783 1784 PULLUP_TO(hlen + sizeof(struct tcphdr)); 1785 tcp = L3HDR(struct tcphdr, ip); 1786 dst_port = tcp->th_dport; 1787 src_port = tcp->th_sport; 1788 args->f_id.flags = tcp->th_flags; 1789 } 1790 break; 1791 1792 case IPPROTO_UDP: 1793 { 1794 struct udphdr *udp; 1795 1796 PULLUP_TO(hlen + sizeof(struct udphdr)); 1797 udp = L3HDR(struct udphdr, ip); 1798 dst_port = udp->uh_dport; 1799 src_port = udp->uh_sport; 1800 } 1801 break; 1802 1803 case IPPROTO_ICMP: 1804 PULLUP_TO(hlen + 4); /* type, code and checksum. */ 1805 args->f_id.flags = L3HDR(struct icmp, ip)->icmp_type; 1806 break; 1807 1808 default: 1809 break; 1810 } 1811 } 1812 1813 #undef PULLUP_TO 1814 1815 args->f_id.src_ip = ntohl(src_ip.s_addr); 1816 args->f_id.dst_ip = ntohl(dst_ip.s_addr); 1817 args->f_id.src_port = src_port = ntohs(src_port); 1818 args->f_id.dst_port = dst_port = ntohs(dst_port); 1819 1820 after_ip_checks: 1821 if (args->rule) { 1822 /* 1823 * Packet has already been tagged. Look for the next rule 1824 * to restart processing. 1825 * 1826 * If fw_one_pass != 0 then just accept it. 1827 * XXX should not happen here, but optimized out in 1828 * the caller. 1829 */ 1830 if (fw_one_pass) 1831 return IP_FW_PASS; 1832 1833 /* This rule is being/has been flushed */ 1834 if (ipfw_flushing) 1835 return IP_FW_DENY; 1836 1837 KASSERT(args->rule->cpuid == mycpuid, 1838 ("rule used on cpu%d", mycpuid)); 1839 1840 /* This rule was deleted */ 1841 if (args->rule->rule_flags & IPFW_RULE_F_INVALID) 1842 return IP_FW_DENY; 1843 1844 f = args->rule->next_rule; 1845 if (f == NULL) 1846 f = lookup_next_rule(args->rule); 1847 } else { 1848 /* 1849 * Find the starting rule. It can be either the first 1850 * one, or the one after divert_rule if asked so. 1851 */ 1852 int skipto; 1853 1854 mtag = m_tag_find(m, PACKET_TAG_IPFW_DIVERT, NULL); 1855 if (mtag != NULL) { 1856 divinfo = m_tag_data(mtag); 1857 skipto = divinfo->skipto; 1858 } else { 1859 skipto = 0; 1860 } 1861 1862 f = ctx->ipfw_layer3_chain; 1863 if (args->eh == NULL && skipto != 0) { 1864 /* No skipto during rule flushing */ 1865 if (ipfw_flushing) 1866 return IP_FW_DENY; 1867 1868 if (skipto >= IPFW_DEFAULT_RULE) 1869 return IP_FW_DENY; /* invalid */ 1870 1871 while (f && f->rulenum <= skipto) 1872 f = f->next; 1873 if (f == NULL) /* drop packet */ 1874 return IP_FW_DENY; 1875 } else if (ipfw_flushing) { 1876 /* Rules are being flushed; skip to default rule */ 1877 f = ctx->ipfw_default_rule; 1878 } 1879 } 1880 if ((mtag = m_tag_find(m, PACKET_TAG_IPFW_DIVERT, NULL)) != NULL) 1881 m_tag_delete(m, mtag); 1882 1883 /* 1884 * Now scan the rules, and parse microinstructions for each rule. 1885 */ 1886 for (; f; f = f->next) { 1887 int l, cmdlen; 1888 ipfw_insn *cmd; 1889 int skip_or; /* skip rest of OR block */ 1890 1891 again: 1892 if (ctx->ipfw_set_disable & (1 << f->set)) 1893 continue; 1894 1895 skip_or = 0; 1896 for (l = f->cmd_len, cmd = f->cmd; l > 0; 1897 l -= cmdlen, cmd += cmdlen) { 1898 int match, deny; 1899 1900 /* 1901 * check_body is a jump target used when we find a 1902 * CHECK_STATE, and need to jump to the body of 1903 * the target rule. 1904 */ 1905 1906 check_body: 1907 cmdlen = F_LEN(cmd); 1908 /* 1909 * An OR block (insn_1 || .. || insn_n) has the 1910 * F_OR bit set in all but the last instruction. 1911 * The first match will set "skip_or", and cause 1912 * the following instructions to be skipped until 1913 * past the one with the F_OR bit clear. 1914 */ 1915 if (skip_or) { /* skip this instruction */ 1916 if ((cmd->len & F_OR) == 0) 1917 skip_or = 0; /* next one is good */ 1918 continue; 1919 } 1920 match = 0; /* set to 1 if we succeed */ 1921 1922 switch (cmd->opcode) { 1923 /* 1924 * The first set of opcodes compares the packet's 1925 * fields with some pattern, setting 'match' if a 1926 * match is found. At the end of the loop there is 1927 * logic to deal with F_NOT and F_OR flags associated 1928 * with the opcode. 1929 */ 1930 case O_NOP: 1931 match = 1; 1932 break; 1933 1934 case O_FORWARD_MAC: 1935 kprintf("ipfw: opcode %d unimplemented\n", 1936 cmd->opcode); 1937 break; 1938 1939 case O_GID: 1940 case O_UID: 1941 /* 1942 * We only check offset == 0 && proto != 0, 1943 * as this ensures that we have an IPv4 1944 * packet with the ports info. 1945 */ 1946 if (offset!=0) 1947 break; 1948 1949 match = ipfw_match_uid(&args->f_id, oif, 1950 cmd->opcode, 1951 (uid_t)((ipfw_insn_u32 *)cmd)->d[0], 1952 &deny); 1953 if (deny) 1954 return IP_FW_DENY; 1955 break; 1956 1957 case O_RECV: 1958 match = iface_match(m->m_pkthdr.rcvif, 1959 (ipfw_insn_if *)cmd); 1960 break; 1961 1962 case O_XMIT: 1963 match = iface_match(oif, (ipfw_insn_if *)cmd); 1964 break; 1965 1966 case O_VIA: 1967 match = iface_match(oif ? oif : 1968 m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd); 1969 break; 1970 1971 case O_MACADDR2: 1972 if (args->eh != NULL) { /* have MAC header */ 1973 uint32_t *want = (uint32_t *) 1974 ((ipfw_insn_mac *)cmd)->addr; 1975 uint32_t *mask = (uint32_t *) 1976 ((ipfw_insn_mac *)cmd)->mask; 1977 uint32_t *hdr = (uint32_t *)args->eh; 1978 1979 match = 1980 (want[0] == (hdr[0] & mask[0]) && 1981 want[1] == (hdr[1] & mask[1]) && 1982 want[2] == (hdr[2] & mask[2])); 1983 } 1984 break; 1985 1986 case O_MAC_TYPE: 1987 if (args->eh != NULL) { 1988 uint16_t t = 1989 ntohs(args->eh->ether_type); 1990 uint16_t *p = 1991 ((ipfw_insn_u16 *)cmd)->ports; 1992 int i; 1993 1994 /* Special vlan handling */ 1995 if (m->m_flags & M_VLANTAG) 1996 t = ETHERTYPE_VLAN; 1997 1998 for (i = cmdlen - 1; !match && i > 0; 1999 i--, p += 2) { 2000 match = 2001 (t >= p[0] && t <= p[1]); 2002 } 2003 } 2004 break; 2005 2006 case O_FRAG: 2007 match = (hlen > 0 && offset != 0); 2008 break; 2009 2010 case O_IN: /* "out" is "not in" */ 2011 match = (oif == NULL); 2012 break; 2013 2014 case O_LAYER2: 2015 match = (args->eh != NULL); 2016 break; 2017 2018 case O_PROTO: 2019 /* 2020 * We do not allow an arg of 0 so the 2021 * check of "proto" only suffices. 2022 */ 2023 match = (proto == cmd->arg1); 2024 break; 2025 2026 case O_IP_SRC: 2027 match = (hlen > 0 && 2028 ((ipfw_insn_ip *)cmd)->addr.s_addr == 2029 src_ip.s_addr); 2030 break; 2031 2032 case O_IP_SRC_MASK: 2033 match = (hlen > 0 && 2034 ((ipfw_insn_ip *)cmd)->addr.s_addr == 2035 (src_ip.s_addr & 2036 ((ipfw_insn_ip *)cmd)->mask.s_addr)); 2037 break; 2038 2039 case O_IP_SRC_ME: 2040 if (hlen > 0) { 2041 struct ifnet *tif; 2042 2043 tif = INADDR_TO_IFP(&src_ip); 2044 match = (tif != NULL); 2045 } 2046 break; 2047 2048 case O_IP_DST_SET: 2049 case O_IP_SRC_SET: 2050 if (hlen > 0) { 2051 uint32_t *d = (uint32_t *)(cmd + 1); 2052 uint32_t addr = 2053 cmd->opcode == O_IP_DST_SET ? 2054 args->f_id.dst_ip : 2055 args->f_id.src_ip; 2056 2057 if (addr < d[0]) 2058 break; 2059 addr -= d[0]; /* subtract base */ 2060 match = 2061 (addr < cmd->arg1) && 2062 (d[1 + (addr >> 5)] & 2063 (1 << (addr & 0x1f))); 2064 } 2065 break; 2066 2067 case O_IP_DST: 2068 match = (hlen > 0 && 2069 ((ipfw_insn_ip *)cmd)->addr.s_addr == 2070 dst_ip.s_addr); 2071 break; 2072 2073 case O_IP_DST_MASK: 2074 match = (hlen > 0) && 2075 (((ipfw_insn_ip *)cmd)->addr.s_addr == 2076 (dst_ip.s_addr & 2077 ((ipfw_insn_ip *)cmd)->mask.s_addr)); 2078 break; 2079 2080 case O_IP_DST_ME: 2081 if (hlen > 0) { 2082 struct ifnet *tif; 2083 2084 tif = INADDR_TO_IFP(&dst_ip); 2085 match = (tif != NULL); 2086 } 2087 break; 2088 2089 case O_IP_SRCPORT: 2090 case O_IP_DSTPORT: 2091 /* 2092 * offset == 0 && proto != 0 is enough 2093 * to guarantee that we have an IPv4 2094 * packet with port info. 2095 */ 2096 if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP) 2097 && offset == 0) { 2098 uint16_t x = 2099 (cmd->opcode == O_IP_SRCPORT) ? 2100 src_port : dst_port ; 2101 uint16_t *p = 2102 ((ipfw_insn_u16 *)cmd)->ports; 2103 int i; 2104 2105 for (i = cmdlen - 1; !match && i > 0; 2106 i--, p += 2) { 2107 match = 2108 (x >= p[0] && x <= p[1]); 2109 } 2110 } 2111 break; 2112 2113 case O_ICMPTYPE: 2114 match = (offset == 0 && proto==IPPROTO_ICMP && 2115 icmptype_match(ip, (ipfw_insn_u32 *)cmd)); 2116 break; 2117 2118 case O_IPOPT: 2119 match = (hlen > 0 && ipopts_match(ip, cmd)); 2120 break; 2121 2122 case O_IPVER: 2123 match = (hlen > 0 && cmd->arg1 == ip->ip_v); 2124 break; 2125 2126 case O_IPTTL: 2127 match = (hlen > 0 && cmd->arg1 == ip->ip_ttl); 2128 break; 2129 2130 case O_IPID: 2131 match = (hlen > 0 && 2132 cmd->arg1 == ntohs(ip->ip_id)); 2133 break; 2134 2135 case O_IPLEN: 2136 match = (hlen > 0 && cmd->arg1 == ip_len); 2137 break; 2138 2139 case O_IPPRECEDENCE: 2140 match = (hlen > 0 && 2141 (cmd->arg1 == (ip->ip_tos & 0xe0))); 2142 break; 2143 2144 case O_IPTOS: 2145 match = (hlen > 0 && 2146 flags_match(cmd, ip->ip_tos)); 2147 break; 2148 2149 case O_TCPFLAGS: 2150 match = (proto == IPPROTO_TCP && offset == 0 && 2151 flags_match(cmd, 2152 L3HDR(struct tcphdr,ip)->th_flags)); 2153 break; 2154 2155 case O_TCPOPTS: 2156 match = (proto == IPPROTO_TCP && offset == 0 && 2157 tcpopts_match(ip, cmd)); 2158 break; 2159 2160 case O_TCPSEQ: 2161 match = (proto == IPPROTO_TCP && offset == 0 && 2162 ((ipfw_insn_u32 *)cmd)->d[0] == 2163 L3HDR(struct tcphdr,ip)->th_seq); 2164 break; 2165 2166 case O_TCPACK: 2167 match = (proto == IPPROTO_TCP && offset == 0 && 2168 ((ipfw_insn_u32 *)cmd)->d[0] == 2169 L3HDR(struct tcphdr,ip)->th_ack); 2170 break; 2171 2172 case O_TCPWIN: 2173 match = (proto == IPPROTO_TCP && offset == 0 && 2174 cmd->arg1 == 2175 L3HDR(struct tcphdr,ip)->th_win); 2176 break; 2177 2178 case O_ESTAB: 2179 /* reject packets which have SYN only */ 2180 /* XXX should i also check for TH_ACK ? */ 2181 match = (proto == IPPROTO_TCP && offset == 0 && 2182 (L3HDR(struct tcphdr,ip)->th_flags & 2183 (TH_RST | TH_ACK | TH_SYN)) != TH_SYN); 2184 break; 2185 2186 case O_LOG: 2187 if (fw_verbose) 2188 ipfw_log(f, hlen, args->eh, m, oif); 2189 match = 1; 2190 break; 2191 2192 case O_PROB: 2193 match = (krandom() < 2194 ((ipfw_insn_u32 *)cmd)->d[0]); 2195 break; 2196 2197 /* 2198 * The second set of opcodes represents 'actions', 2199 * i.e. the terminal part of a rule once the packet 2200 * matches all previous patterns. 2201 * Typically there is only one action for each rule, 2202 * and the opcode is stored at the end of the rule 2203 * (but there are exceptions -- see below). 2204 * 2205 * In general, here we set retval and terminate the 2206 * outer loop (would be a 'break 3' in some language, 2207 * but we need to do a 'goto done'). 2208 * 2209 * Exceptions: 2210 * O_COUNT and O_SKIPTO actions: 2211 * instead of terminating, we jump to the next rule 2212 * ('goto next_rule', equivalent to a 'break 2'), 2213 * or to the SKIPTO target ('goto again' after 2214 * having set f, cmd and l), respectively. 2215 * 2216 * O_LIMIT and O_KEEP_STATE: these opcodes are 2217 * not real 'actions', and are stored right 2218 * before the 'action' part of the rule. 2219 * These opcodes try to install an entry in the 2220 * state tables; if successful, we continue with 2221 * the next opcode (match=1; break;), otherwise 2222 * the packet must be dropped ('goto done' after 2223 * setting retval). If static rules are changed 2224 * during the state installation, the packet will 2225 * be dropped and rule's stats will not beupdated 2226 * ('return IP_FW_DENY'). 2227 * 2228 * O_PROBE_STATE and O_CHECK_STATE: these opcodes 2229 * cause a lookup of the state table, and a jump 2230 * to the 'action' part of the parent rule 2231 * ('goto check_body') if an entry is found, or 2232 * (CHECK_STATE only) a jump to the next rule if 2233 * the entry is not found ('goto next_rule'). 2234 * The result of the lookup is cached to make 2235 * further instances of these opcodes are 2236 * effectively NOPs. If static rules are changed 2237 * during the state looking up, the packet will 2238 * be dropped and rule's stats will not be updated 2239 * ('return IP_FW_DENY'). 2240 */ 2241 case O_LIMIT: 2242 case O_KEEP_STATE: 2243 if (!(f->rule_flags & IPFW_RULE_F_STATE)) { 2244 kprintf("%s rule (%d) is not ready " 2245 "on cpu%d\n", 2246 cmd->opcode == O_LIMIT ? 2247 "limit" : "keep state", 2248 f->rulenum, f->cpuid); 2249 goto next_rule; 2250 } 2251 if (install_state(f, 2252 (ipfw_insn_limit *)cmd, args, &deny)) { 2253 if (deny) 2254 return IP_FW_DENY; 2255 2256 retval = IP_FW_DENY; 2257 goto done; /* error/limit violation */ 2258 } 2259 if (deny) 2260 return IP_FW_DENY; 2261 match = 1; 2262 break; 2263 2264 case O_PROBE_STATE: 2265 case O_CHECK_STATE: 2266 /* 2267 * dynamic rules are checked at the first 2268 * keep-state or check-state occurrence, 2269 * with the result being stored in dyn_dir. 2270 * The compiler introduces a PROBE_STATE 2271 * instruction for us when we have a 2272 * KEEP_STATE (because PROBE_STATE needs 2273 * to be run first). 2274 */ 2275 if (dyn_dir == MATCH_UNKNOWN) { 2276 dyn_f = lookup_rule(&args->f_id, 2277 &dyn_dir, 2278 proto == IPPROTO_TCP ? 2279 L3HDR(struct tcphdr, ip) : NULL, 2280 ip_len, &deny); 2281 if (deny) 2282 return IP_FW_DENY; 2283 if (dyn_f != NULL) { 2284 /* 2285 * Found a rule from a dynamic 2286 * entry; jump to the 'action' 2287 * part of the rule. 2288 */ 2289 f = dyn_f; 2290 cmd = ACTION_PTR(f); 2291 l = f->cmd_len - f->act_ofs; 2292 goto check_body; 2293 } 2294 } 2295 /* 2296 * Dynamic entry not found. If CHECK_STATE, 2297 * skip to next rule, if PROBE_STATE just 2298 * ignore and continue with next opcode. 2299 */ 2300 if (cmd->opcode == O_CHECK_STATE) 2301 goto next_rule; 2302 else if (!(f->rule_flags & IPFW_RULE_F_STATE)) 2303 goto next_rule; /* not ready yet */ 2304 match = 1; 2305 break; 2306 2307 case O_ACCEPT: 2308 retval = IP_FW_PASS; /* accept */ 2309 goto done; 2310 2311 case O_PIPE: 2312 case O_QUEUE: 2313 args->rule = f; /* report matching rule */ 2314 args->cookie = cmd->arg1; 2315 retval = IP_FW_DUMMYNET; 2316 goto done; 2317 2318 case O_DIVERT: 2319 case O_TEE: 2320 if (args->eh) /* not on layer 2 */ 2321 break; 2322 2323 mtag = m_tag_get(PACKET_TAG_IPFW_DIVERT, 2324 sizeof(*divinfo), MB_DONTWAIT); 2325 if (mtag == NULL) { 2326 retval = IP_FW_DENY; 2327 goto done; 2328 } 2329 divinfo = m_tag_data(mtag); 2330 2331 divinfo->skipto = f->rulenum; 2332 divinfo->port = cmd->arg1; 2333 divinfo->tee = (cmd->opcode == O_TEE); 2334 m_tag_prepend(m, mtag); 2335 2336 args->cookie = cmd->arg1; 2337 retval = (cmd->opcode == O_DIVERT) ? 2338 IP_FW_DIVERT : IP_FW_TEE; 2339 goto done; 2340 2341 case O_COUNT: 2342 case O_SKIPTO: 2343 f->pcnt++; /* update stats */ 2344 f->bcnt += ip_len; 2345 f->timestamp = time_second; 2346 if (cmd->opcode == O_COUNT) 2347 goto next_rule; 2348 /* handle skipto */ 2349 if (f->next_rule == NULL) 2350 lookup_next_rule(f); 2351 f = f->next_rule; 2352 goto again; 2353 2354 case O_REJECT: 2355 /* 2356 * Drop the packet and send a reject notice 2357 * if the packet is not ICMP (or is an ICMP 2358 * query), and it is not multicast/broadcast. 2359 */ 2360 if (hlen > 0 && 2361 (proto != IPPROTO_ICMP || 2362 is_icmp_query(ip)) && 2363 !(m->m_flags & (M_BCAST|M_MCAST)) && 2364 !IN_MULTICAST(ntohl(dst_ip.s_addr))) { 2365 /* 2366 * Update statistics before the possible 2367 * blocking 'send_reject' 2368 */ 2369 f->pcnt++; 2370 f->bcnt += ip_len; 2371 f->timestamp = time_second; 2372 2373 send_reject(args, cmd->arg1, 2374 offset,ip_len); 2375 m = args->m; 2376 2377 /* 2378 * Return directly here, rule stats 2379 * have been updated above. 2380 */ 2381 return IP_FW_DENY; 2382 } 2383 /* FALLTHROUGH */ 2384 case O_DENY: 2385 retval = IP_FW_DENY; 2386 goto done; 2387 2388 case O_FORWARD_IP: 2389 if (args->eh) /* not valid on layer2 pkts */ 2390 break; 2391 if (!dyn_f || dyn_dir == MATCH_FORWARD) { 2392 struct sockaddr_in *sin; 2393 2394 mtag = m_tag_get(PACKET_TAG_IPFORWARD, 2395 sizeof(*sin), MB_DONTWAIT); 2396 if (mtag == NULL) { 2397 retval = IP_FW_DENY; 2398 goto done; 2399 } 2400 sin = m_tag_data(mtag); 2401 2402 /* Structure copy */ 2403 *sin = ((ipfw_insn_sa *)cmd)->sa; 2404 2405 m_tag_prepend(m, mtag); 2406 m->m_pkthdr.fw_flags |= 2407 IPFORWARD_MBUF_TAGGED; 2408 m->m_pkthdr.fw_flags &= 2409 ~BRIDGE_MBUF_TAGGED; 2410 } 2411 retval = IP_FW_PASS; 2412 goto done; 2413 2414 default: 2415 panic("-- unknown opcode %d", cmd->opcode); 2416 } /* end of switch() on opcodes */ 2417 2418 if (cmd->len & F_NOT) 2419 match = !match; 2420 2421 if (match) { 2422 if (cmd->len & F_OR) 2423 skip_or = 1; 2424 } else { 2425 if (!(cmd->len & F_OR)) /* not an OR block, */ 2426 break; /* try next rule */ 2427 } 2428 2429 } /* end of inner for, scan opcodes */ 2430 2431 next_rule:; /* try next rule */ 2432 2433 } /* end of outer for, scan rules */ 2434 kprintf("+++ ipfw: ouch!, skip past end of rules, denying packet\n"); 2435 return IP_FW_DENY; 2436 2437 done: 2438 /* Update statistics */ 2439 f->pcnt++; 2440 f->bcnt += ip_len; 2441 f->timestamp = time_second; 2442 return retval; 2443 2444 pullup_failed: 2445 if (fw_verbose) 2446 kprintf("pullup failed\n"); 2447 return IP_FW_DENY; 2448 } 2449 2450 static void 2451 ipfw_dummynet_io(struct mbuf *m, int pipe_nr, int dir, struct ip_fw_args *fwa) 2452 { 2453 struct m_tag *mtag; 2454 struct dn_pkt *pkt; 2455 ipfw_insn *cmd; 2456 const struct ipfw_flow_id *id; 2457 struct dn_flow_id *fid; 2458 2459 M_ASSERTPKTHDR(m); 2460 2461 mtag = m_tag_get(PACKET_TAG_DUMMYNET, sizeof(*pkt), MB_DONTWAIT); 2462 if (mtag == NULL) { 2463 m_freem(m); 2464 return; 2465 } 2466 m_tag_prepend(m, mtag); 2467 2468 pkt = m_tag_data(mtag); 2469 bzero(pkt, sizeof(*pkt)); 2470 2471 cmd = fwa->rule->cmd + fwa->rule->act_ofs; 2472 if (cmd->opcode == O_LOG) 2473 cmd += F_LEN(cmd); 2474 KASSERT(cmd->opcode == O_PIPE || cmd->opcode == O_QUEUE, 2475 ("Rule is not PIPE or QUEUE, opcode %d", cmd->opcode)); 2476 2477 pkt->dn_m = m; 2478 pkt->dn_flags = (dir & DN_FLAGS_DIR_MASK); 2479 pkt->ifp = fwa->oif; 2480 pkt->pipe_nr = pipe_nr; 2481 2482 pkt->cpuid = mycpuid; 2483 pkt->msgport = netisr_curport(); 2484 2485 id = &fwa->f_id; 2486 fid = &pkt->id; 2487 fid->fid_dst_ip = id->dst_ip; 2488 fid->fid_src_ip = id->src_ip; 2489 fid->fid_dst_port = id->dst_port; 2490 fid->fid_src_port = id->src_port; 2491 fid->fid_proto = id->proto; 2492 fid->fid_flags = id->flags; 2493 2494 ipfw_ref_rule(fwa->rule); 2495 pkt->dn_priv = fwa->rule; 2496 pkt->dn_unref_priv = ipfw_unref_rule; 2497 2498 if (cmd->opcode == O_PIPE) 2499 pkt->dn_flags |= DN_FLAGS_IS_PIPE; 2500 2501 m->m_pkthdr.fw_flags |= DUMMYNET_MBUF_TAGGED; 2502 } 2503 2504 /* 2505 * When a rule is added/deleted, clear the next_rule pointers in all rules. 2506 * These will be reconstructed on the fly as packets are matched. 2507 * Must be called at splimp(). 2508 */ 2509 static void 2510 ipfw_flush_rule_ptrs(struct ipfw_context *ctx) 2511 { 2512 struct ip_fw *rule; 2513 2514 for (rule = ctx->ipfw_layer3_chain; rule; rule = rule->next) 2515 rule->next_rule = NULL; 2516 } 2517 2518 static __inline void 2519 ipfw_inc_static_count(struct ip_fw *rule) 2520 { 2521 /* Static rule's counts are updated only on CPU0 */ 2522 KKASSERT(mycpuid == 0); 2523 2524 static_count++; 2525 static_ioc_len += IOC_RULESIZE(rule); 2526 } 2527 2528 static __inline void 2529 ipfw_dec_static_count(struct ip_fw *rule) 2530 { 2531 int l = IOC_RULESIZE(rule); 2532 2533 /* Static rule's counts are updated only on CPU0 */ 2534 KKASSERT(mycpuid == 0); 2535 2536 KASSERT(static_count > 0, ("invalid static count %u", static_count)); 2537 static_count--; 2538 2539 KASSERT(static_ioc_len >= l, 2540 ("invalid static len %u", static_ioc_len)); 2541 static_ioc_len -= l; 2542 } 2543 2544 static void 2545 ipfw_link_sibling(struct netmsg_ipfw *fwmsg, struct ip_fw *rule) 2546 { 2547 if (fwmsg->sibling != NULL) { 2548 KKASSERT(mycpuid > 0 && fwmsg->sibling->cpuid == mycpuid - 1); 2549 fwmsg->sibling->sibling = rule; 2550 } 2551 fwmsg->sibling = rule; 2552 } 2553 2554 static struct ip_fw * 2555 ipfw_create_rule(const struct ipfw_ioc_rule *ioc_rule, struct ip_fw_stub *stub) 2556 { 2557 struct ip_fw *rule; 2558 2559 rule = kmalloc(RULESIZE(ioc_rule), M_IPFW, M_WAITOK | M_ZERO); 2560 2561 rule->act_ofs = ioc_rule->act_ofs; 2562 rule->cmd_len = ioc_rule->cmd_len; 2563 rule->rulenum = ioc_rule->rulenum; 2564 rule->set = ioc_rule->set; 2565 rule->usr_flags = ioc_rule->usr_flags; 2566 2567 bcopy(ioc_rule->cmd, rule->cmd, rule->cmd_len * 4 /* XXX */); 2568 2569 rule->refcnt = 1; 2570 rule->cpuid = mycpuid; 2571 2572 rule->stub = stub; 2573 if (stub != NULL) 2574 stub->rule[mycpuid] = rule; 2575 2576 return rule; 2577 } 2578 2579 static void 2580 ipfw_add_rule_dispatch(netmsg_t nmsg) 2581 { 2582 struct netmsg_ipfw *fwmsg = (struct netmsg_ipfw *)nmsg; 2583 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 2584 struct ip_fw *rule; 2585 2586 rule = ipfw_create_rule(fwmsg->ioc_rule, fwmsg->stub); 2587 2588 /* 2589 * Bump generation after ipfw_create_rule(), 2590 * since this function is blocking 2591 */ 2592 ctx->ipfw_gen++; 2593 2594 /* 2595 * Insert rule into the pre-determined position 2596 */ 2597 if (fwmsg->prev_rule != NULL) { 2598 struct ip_fw *prev, *next; 2599 2600 prev = fwmsg->prev_rule; 2601 KKASSERT(prev->cpuid == mycpuid); 2602 2603 next = fwmsg->next_rule; 2604 KKASSERT(next->cpuid == mycpuid); 2605 2606 rule->next = next; 2607 prev->next = rule; 2608 2609 /* 2610 * Move to the position on the next CPU 2611 * before the msg is forwarded. 2612 */ 2613 fwmsg->prev_rule = prev->sibling; 2614 fwmsg->next_rule = next->sibling; 2615 } else { 2616 KKASSERT(fwmsg->next_rule == NULL); 2617 rule->next = ctx->ipfw_layer3_chain; 2618 ctx->ipfw_layer3_chain = rule; 2619 } 2620 2621 /* Link rule CPU sibling */ 2622 ipfw_link_sibling(fwmsg, rule); 2623 2624 ipfw_flush_rule_ptrs(ctx); 2625 2626 if (mycpuid == 0) { 2627 /* Statistics only need to be updated once */ 2628 ipfw_inc_static_count(rule); 2629 2630 /* Return the rule on CPU0 */ 2631 nmsg->lmsg.u.ms_resultp = rule; 2632 } 2633 2634 ifnet_forwardmsg(&nmsg->lmsg, mycpuid + 1); 2635 } 2636 2637 static void 2638 ipfw_enable_state_dispatch(netmsg_t nmsg) 2639 { 2640 struct lwkt_msg *lmsg = &nmsg->lmsg; 2641 struct ip_fw *rule = lmsg->u.ms_resultp; 2642 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 2643 2644 ctx->ipfw_gen++; 2645 2646 KKASSERT(rule->cpuid == mycpuid); 2647 KKASSERT(rule->stub != NULL && rule->stub->rule[mycpuid] == rule); 2648 KKASSERT(!(rule->rule_flags & IPFW_RULE_F_STATE)); 2649 rule->rule_flags |= IPFW_RULE_F_STATE; 2650 lmsg->u.ms_resultp = rule->sibling; 2651 2652 ifnet_forwardmsg(lmsg, mycpuid + 1); 2653 } 2654 2655 /* 2656 * Add a new rule to the list. Copy the rule into a malloc'ed area, 2657 * then possibly create a rule number and add the rule to the list. 2658 * Update the rule_number in the input struct so the caller knows 2659 * it as well. 2660 */ 2661 static void 2662 ipfw_add_rule(struct ipfw_ioc_rule *ioc_rule, uint32_t rule_flags) 2663 { 2664 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 2665 struct netmsg_ipfw fwmsg; 2666 struct netmsg_base *nmsg; 2667 struct ip_fw *f, *prev, *rule; 2668 struct ip_fw_stub *stub; 2669 2670 IPFW_ASSERT_CFGPORT(&curthread->td_msgport); 2671 2672 /* 2673 * If rulenum is 0, find highest numbered rule before the 2674 * default rule, and add rule number incremental step. 2675 */ 2676 if (ioc_rule->rulenum == 0) { 2677 int step = autoinc_step; 2678 2679 KKASSERT(step >= IPFW_AUTOINC_STEP_MIN && 2680 step <= IPFW_AUTOINC_STEP_MAX); 2681 2682 /* 2683 * Locate the highest numbered rule before default 2684 */ 2685 for (f = ctx->ipfw_layer3_chain; f; f = f->next) { 2686 if (f->rulenum == IPFW_DEFAULT_RULE) 2687 break; 2688 ioc_rule->rulenum = f->rulenum; 2689 } 2690 if (ioc_rule->rulenum < IPFW_DEFAULT_RULE - step) 2691 ioc_rule->rulenum += step; 2692 } 2693 KASSERT(ioc_rule->rulenum != IPFW_DEFAULT_RULE && 2694 ioc_rule->rulenum != 0, 2695 ("invalid rule num %d", ioc_rule->rulenum)); 2696 2697 /* 2698 * Now find the right place for the new rule in the sorted list. 2699 */ 2700 for (prev = NULL, f = ctx->ipfw_layer3_chain; f; 2701 prev = f, f = f->next) { 2702 if (f->rulenum > ioc_rule->rulenum) { 2703 /* Found the location */ 2704 break; 2705 } 2706 } 2707 KASSERT(f != NULL, ("no default rule?!")); 2708 2709 if (rule_flags & IPFW_RULE_F_STATE) { 2710 int size; 2711 2712 /* 2713 * If the new rule will create states, then allocate 2714 * a rule stub, which will be referenced by states 2715 * (dyn rules) 2716 */ 2717 size = sizeof(*stub) + ((ncpus - 1) * sizeof(struct ip_fw *)); 2718 stub = kmalloc(size, M_IPFW, M_WAITOK | M_ZERO); 2719 } else { 2720 stub = NULL; 2721 } 2722 2723 /* 2724 * Duplicate the rule onto each CPU. 2725 * The rule duplicated on CPU0 will be returned. 2726 */ 2727 bzero(&fwmsg, sizeof(fwmsg)); 2728 nmsg = &fwmsg.base; 2729 netmsg_init(nmsg, NULL, &curthread->td_msgport, 2730 0, ipfw_add_rule_dispatch); 2731 fwmsg.ioc_rule = ioc_rule; 2732 fwmsg.prev_rule = prev; 2733 fwmsg.next_rule = prev == NULL ? NULL : f; 2734 fwmsg.stub = stub; 2735 2736 ifnet_domsg(&nmsg->lmsg, 0); 2737 KKASSERT(fwmsg.prev_rule == NULL && fwmsg.next_rule == NULL); 2738 2739 rule = nmsg->lmsg.u.ms_resultp; 2740 KKASSERT(rule != NULL && rule->cpuid == mycpuid); 2741 2742 if (rule_flags & IPFW_RULE_F_STATE) { 2743 /* 2744 * Turn on state flag, _after_ everything on all 2745 * CPUs have been setup. 2746 */ 2747 bzero(nmsg, sizeof(*nmsg)); 2748 netmsg_init(nmsg, NULL, &curthread->td_msgport, 2749 0, ipfw_enable_state_dispatch); 2750 nmsg->lmsg.u.ms_resultp = rule; 2751 2752 ifnet_domsg(&nmsg->lmsg, 0); 2753 KKASSERT(nmsg->lmsg.u.ms_resultp == NULL); 2754 } 2755 2756 DPRINTF("++ installed rule %d, static count now %d\n", 2757 rule->rulenum, static_count); 2758 } 2759 2760 /** 2761 * Free storage associated with a static rule (including derived 2762 * dynamic rules). 2763 * The caller is in charge of clearing rule pointers to avoid 2764 * dangling pointers. 2765 * @return a pointer to the next entry. 2766 * Arguments are not checked, so they better be correct. 2767 * Must be called at splimp(). 2768 */ 2769 static struct ip_fw * 2770 ipfw_delete_rule(struct ipfw_context *ctx, 2771 struct ip_fw *prev, struct ip_fw *rule) 2772 { 2773 struct ip_fw *n; 2774 struct ip_fw_stub *stub; 2775 2776 ctx->ipfw_gen++; 2777 2778 /* STATE flag should have been cleared before we reach here */ 2779 KKASSERT((rule->rule_flags & IPFW_RULE_F_STATE) == 0); 2780 2781 stub = rule->stub; 2782 n = rule->next; 2783 if (prev == NULL) 2784 ctx->ipfw_layer3_chain = n; 2785 else 2786 prev->next = n; 2787 2788 /* Mark the rule as invalid */ 2789 rule->rule_flags |= IPFW_RULE_F_INVALID; 2790 rule->next_rule = NULL; 2791 rule->sibling = NULL; 2792 rule->stub = NULL; 2793 #ifdef foo 2794 /* Don't reset cpuid here; keep various assertion working */ 2795 rule->cpuid = -1; 2796 #endif 2797 2798 /* Statistics only need to be updated once */ 2799 if (mycpuid == 0) 2800 ipfw_dec_static_count(rule); 2801 2802 /* Free 'stub' on the last CPU */ 2803 if (stub != NULL && mycpuid == ncpus - 1) 2804 kfree(stub, M_IPFW); 2805 2806 /* Try to free this rule */ 2807 ipfw_free_rule(rule); 2808 2809 /* Return the next rule */ 2810 return n; 2811 } 2812 2813 static void 2814 ipfw_flush_dispatch(netmsg_t nmsg) 2815 { 2816 struct lwkt_msg *lmsg = &nmsg->lmsg; 2817 int kill_default = lmsg->u.ms_result; 2818 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 2819 struct ip_fw *rule; 2820 2821 ipfw_flush_rule_ptrs(ctx); /* more efficient to do outside the loop */ 2822 2823 while ((rule = ctx->ipfw_layer3_chain) != NULL && 2824 (kill_default || rule->rulenum != IPFW_DEFAULT_RULE)) 2825 ipfw_delete_rule(ctx, NULL, rule); 2826 2827 ifnet_forwardmsg(lmsg, mycpuid + 1); 2828 } 2829 2830 static void 2831 ipfw_disable_rule_state_dispatch(netmsg_t nmsg) 2832 { 2833 struct netmsg_del *dmsg = (struct netmsg_del *)nmsg; 2834 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 2835 struct ip_fw *rule; 2836 2837 ctx->ipfw_gen++; 2838 2839 rule = dmsg->start_rule; 2840 if (rule != NULL) { 2841 KKASSERT(rule->cpuid == mycpuid); 2842 2843 /* 2844 * Move to the position on the next CPU 2845 * before the msg is forwarded. 2846 */ 2847 dmsg->start_rule = rule->sibling; 2848 } else { 2849 KKASSERT(dmsg->rulenum == 0); 2850 rule = ctx->ipfw_layer3_chain; 2851 } 2852 2853 while (rule != NULL) { 2854 if (dmsg->rulenum && rule->rulenum != dmsg->rulenum) 2855 break; 2856 rule->rule_flags &= ~IPFW_RULE_F_STATE; 2857 rule = rule->next; 2858 } 2859 2860 ifnet_forwardmsg(&nmsg->lmsg, mycpuid + 1); 2861 } 2862 2863 /* 2864 * Deletes all rules from a chain (including the default rule 2865 * if the second argument is set). 2866 * Must be called at splimp(). 2867 */ 2868 static void 2869 ipfw_flush(int kill_default) 2870 { 2871 struct netmsg_del dmsg; 2872 struct netmsg_base nmsg; 2873 struct lwkt_msg *lmsg; 2874 struct ip_fw *rule; 2875 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 2876 2877 IPFW_ASSERT_CFGPORT(&curthread->td_msgport); 2878 2879 /* 2880 * If 'kill_default' then caller has done the necessary 2881 * msgport syncing; unnecessary to do it again. 2882 */ 2883 if (!kill_default) { 2884 /* 2885 * Let ipfw_chk() know the rules are going to 2886 * be flushed, so it could jump directly to 2887 * the default rule. 2888 */ 2889 ipfw_flushing = 1; 2890 netmsg_service_sync(); 2891 } 2892 2893 /* 2894 * Clear STATE flag on rules, so no more states (dyn rules) 2895 * will be created. 2896 */ 2897 bzero(&dmsg, sizeof(dmsg)); 2898 netmsg_init(&dmsg.base, NULL, &curthread->td_msgport, 2899 0, ipfw_disable_rule_state_dispatch); 2900 ifnet_domsg(&dmsg.base.lmsg, 0); 2901 2902 /* 2903 * This actually nukes all states (dyn rules) 2904 */ 2905 lockmgr(&dyn_lock, LK_EXCLUSIVE); 2906 for (rule = ctx->ipfw_layer3_chain; rule != NULL; rule = rule->next) { 2907 /* 2908 * Can't check IPFW_RULE_F_STATE here, 2909 * since it has been cleared previously. 2910 * Check 'stub' instead. 2911 */ 2912 if (rule->stub != NULL) { 2913 /* Force removal */ 2914 remove_dyn_rule_locked(rule, NULL); 2915 } 2916 } 2917 lockmgr(&dyn_lock, LK_RELEASE); 2918 2919 /* 2920 * Press the 'flush' button 2921 */ 2922 bzero(&nmsg, sizeof(nmsg)); 2923 netmsg_init(&nmsg, NULL, &curthread->td_msgport, 2924 0, ipfw_flush_dispatch); 2925 lmsg = &nmsg.lmsg; 2926 lmsg->u.ms_result = kill_default; 2927 ifnet_domsg(lmsg, 0); 2928 2929 KASSERT(dyn_count == 0, ("%u dyn rule remains", dyn_count)); 2930 2931 if (kill_default) { 2932 if (ipfw_dyn_v != NULL) { 2933 /* 2934 * Free dynamic rules(state) hash table 2935 */ 2936 kfree(ipfw_dyn_v, M_IPFW); 2937 ipfw_dyn_v = NULL; 2938 } 2939 2940 KASSERT(static_count == 0, 2941 ("%u static rules remain", static_count)); 2942 KASSERT(static_ioc_len == 0, 2943 ("%u bytes of static rules remain", static_ioc_len)); 2944 } else { 2945 KASSERT(static_count == 1, 2946 ("%u static rules remain", static_count)); 2947 KASSERT(static_ioc_len == IOC_RULESIZE(ctx->ipfw_default_rule), 2948 ("%u bytes of static rules remain, should be %lu", 2949 static_ioc_len, 2950 (u_long)IOC_RULESIZE(ctx->ipfw_default_rule))); 2951 } 2952 2953 /* Flush is done */ 2954 ipfw_flushing = 0; 2955 } 2956 2957 static void 2958 ipfw_alt_delete_rule_dispatch(netmsg_t nmsg) 2959 { 2960 struct netmsg_del *dmsg = (struct netmsg_del *)nmsg; 2961 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 2962 struct ip_fw *rule, *prev; 2963 2964 rule = dmsg->start_rule; 2965 KKASSERT(rule->cpuid == mycpuid); 2966 dmsg->start_rule = rule->sibling; 2967 2968 prev = dmsg->prev_rule; 2969 if (prev != NULL) { 2970 KKASSERT(prev->cpuid == mycpuid); 2971 2972 /* 2973 * Move to the position on the next CPU 2974 * before the msg is forwarded. 2975 */ 2976 dmsg->prev_rule = prev->sibling; 2977 } 2978 2979 /* 2980 * flush pointers outside the loop, then delete all matching 2981 * rules. 'prev' remains the same throughout the cycle. 2982 */ 2983 ipfw_flush_rule_ptrs(ctx); 2984 while (rule && rule->rulenum == dmsg->rulenum) 2985 rule = ipfw_delete_rule(ctx, prev, rule); 2986 2987 ifnet_forwardmsg(&nmsg->lmsg, mycpuid + 1); 2988 } 2989 2990 static int 2991 ipfw_alt_delete_rule(uint16_t rulenum) 2992 { 2993 struct ip_fw *prev, *rule, *f; 2994 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 2995 struct netmsg_del dmsg; 2996 struct netmsg_base *nmsg; 2997 int state; 2998 2999 /* 3000 * Locate first rule to delete 3001 */ 3002 for (prev = NULL, rule = ctx->ipfw_layer3_chain; 3003 rule && rule->rulenum < rulenum; 3004 prev = rule, rule = rule->next) 3005 ; /* EMPTY */ 3006 if (rule->rulenum != rulenum) 3007 return EINVAL; 3008 3009 /* 3010 * Check whether any rules with the given number will 3011 * create states. 3012 */ 3013 state = 0; 3014 for (f = rule; f && f->rulenum == rulenum; f = f->next) { 3015 if (f->rule_flags & IPFW_RULE_F_STATE) { 3016 state = 1; 3017 break; 3018 } 3019 } 3020 3021 if (state) { 3022 /* 3023 * Clear the STATE flag, so no more states will be 3024 * created based the rules numbered 'rulenum'. 3025 */ 3026 bzero(&dmsg, sizeof(dmsg)); 3027 nmsg = &dmsg.base; 3028 netmsg_init(nmsg, NULL, &curthread->td_msgport, 3029 0, ipfw_disable_rule_state_dispatch); 3030 dmsg.start_rule = rule; 3031 dmsg.rulenum = rulenum; 3032 3033 ifnet_domsg(&nmsg->lmsg, 0); 3034 KKASSERT(dmsg.start_rule == NULL); 3035 3036 /* 3037 * Nuke all related states 3038 */ 3039 lockmgr(&dyn_lock, LK_EXCLUSIVE); 3040 for (f = rule; f && f->rulenum == rulenum; f = f->next) { 3041 /* 3042 * Can't check IPFW_RULE_F_STATE here, 3043 * since it has been cleared previously. 3044 * Check 'stub' instead. 3045 */ 3046 if (f->stub != NULL) { 3047 /* Force removal */ 3048 remove_dyn_rule_locked(f, NULL); 3049 } 3050 } 3051 lockmgr(&dyn_lock, LK_RELEASE); 3052 } 3053 3054 /* 3055 * Get rid of the rule duplications on all CPUs 3056 */ 3057 bzero(&dmsg, sizeof(dmsg)); 3058 nmsg = &dmsg.base; 3059 netmsg_init(nmsg, NULL, &curthread->td_msgport, 3060 0, ipfw_alt_delete_rule_dispatch); 3061 dmsg.prev_rule = prev; 3062 dmsg.start_rule = rule; 3063 dmsg.rulenum = rulenum; 3064 3065 ifnet_domsg(&nmsg->lmsg, 0); 3066 KKASSERT(dmsg.prev_rule == NULL && dmsg.start_rule == NULL); 3067 return 0; 3068 } 3069 3070 static void 3071 ipfw_alt_delete_ruleset_dispatch(netmsg_t nmsg) 3072 { 3073 struct netmsg_del *dmsg = (struct netmsg_del *)nmsg; 3074 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 3075 struct ip_fw *prev, *rule; 3076 #ifdef INVARIANTS 3077 int del = 0; 3078 #endif 3079 3080 ipfw_flush_rule_ptrs(ctx); 3081 3082 prev = NULL; 3083 rule = ctx->ipfw_layer3_chain; 3084 while (rule != NULL) { 3085 if (rule->set == dmsg->from_set) { 3086 rule = ipfw_delete_rule(ctx, prev, rule); 3087 #ifdef INVARIANTS 3088 del = 1; 3089 #endif 3090 } else { 3091 prev = rule; 3092 rule = rule->next; 3093 } 3094 } 3095 KASSERT(del, ("no match set?!")); 3096 3097 ifnet_forwardmsg(&nmsg->lmsg, mycpuid + 1); 3098 } 3099 3100 static void 3101 ipfw_disable_ruleset_state_dispatch(netmsg_t nmsg) 3102 { 3103 struct netmsg_del *dmsg = (struct netmsg_del *)nmsg; 3104 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 3105 struct ip_fw *rule; 3106 #ifdef INVARIANTS 3107 int cleared = 0; 3108 #endif 3109 3110 ctx->ipfw_gen++; 3111 3112 for (rule = ctx->ipfw_layer3_chain; rule; rule = rule->next) { 3113 if (rule->set == dmsg->from_set) { 3114 #ifdef INVARIANTS 3115 cleared = 1; 3116 #endif 3117 rule->rule_flags &= ~IPFW_RULE_F_STATE; 3118 } 3119 } 3120 KASSERT(cleared, ("no match set?!")); 3121 3122 ifnet_forwardmsg(&nmsg->lmsg, mycpuid + 1); 3123 } 3124 3125 static int 3126 ipfw_alt_delete_ruleset(uint8_t set) 3127 { 3128 struct netmsg_del dmsg; 3129 struct netmsg_base *nmsg; 3130 int state, del; 3131 struct ip_fw *rule; 3132 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 3133 3134 /* 3135 * Check whether the 'set' exists. If it exists, 3136 * then check whether any rules within the set will 3137 * try to create states. 3138 */ 3139 state = 0; 3140 del = 0; 3141 for (rule = ctx->ipfw_layer3_chain; rule; rule = rule->next) { 3142 if (rule->set == set) { 3143 del = 1; 3144 if (rule->rule_flags & IPFW_RULE_F_STATE) { 3145 state = 1; 3146 break; 3147 } 3148 } 3149 } 3150 if (!del) 3151 return 0; /* XXX EINVAL? */ 3152 3153 if (state) { 3154 /* 3155 * Clear the STATE flag, so no more states will be 3156 * created based the rules in this set. 3157 */ 3158 bzero(&dmsg, sizeof(dmsg)); 3159 nmsg = &dmsg.base; 3160 netmsg_init(nmsg, NULL, &curthread->td_msgport, 3161 0, ipfw_disable_ruleset_state_dispatch); 3162 dmsg.from_set = set; 3163 3164 ifnet_domsg(&nmsg->lmsg, 0); 3165 3166 /* 3167 * Nuke all related states 3168 */ 3169 lockmgr(&dyn_lock, LK_EXCLUSIVE); 3170 for (rule = ctx->ipfw_layer3_chain; rule; rule = rule->next) { 3171 if (rule->set != set) 3172 continue; 3173 3174 /* 3175 * Can't check IPFW_RULE_F_STATE here, 3176 * since it has been cleared previously. 3177 * Check 'stub' instead. 3178 */ 3179 if (rule->stub != NULL) { 3180 /* Force removal */ 3181 remove_dyn_rule_locked(rule, NULL); 3182 } 3183 } 3184 lockmgr(&dyn_lock, LK_RELEASE); 3185 } 3186 3187 /* 3188 * Delete this set 3189 */ 3190 bzero(&dmsg, sizeof(dmsg)); 3191 nmsg = &dmsg.base; 3192 netmsg_init(nmsg, NULL, &curthread->td_msgport, 3193 0, ipfw_alt_delete_ruleset_dispatch); 3194 dmsg.from_set = set; 3195 3196 ifnet_domsg(&nmsg->lmsg, 0); 3197 return 0; 3198 } 3199 3200 static void 3201 ipfw_alt_move_rule_dispatch(netmsg_t nmsg) 3202 { 3203 struct netmsg_del *dmsg = (struct netmsg_del *)nmsg; 3204 struct ip_fw *rule; 3205 3206 rule = dmsg->start_rule; 3207 KKASSERT(rule->cpuid == mycpuid); 3208 3209 /* 3210 * Move to the position on the next CPU 3211 * before the msg is forwarded. 3212 */ 3213 dmsg->start_rule = rule->sibling; 3214 3215 while (rule && rule->rulenum <= dmsg->rulenum) { 3216 if (rule->rulenum == dmsg->rulenum) 3217 rule->set = dmsg->to_set; 3218 rule = rule->next; 3219 } 3220 ifnet_forwardmsg(&nmsg->lmsg, mycpuid + 1); 3221 } 3222 3223 static int 3224 ipfw_alt_move_rule(uint16_t rulenum, uint8_t set) 3225 { 3226 struct netmsg_del dmsg; 3227 struct netmsg_base *nmsg; 3228 struct ip_fw *rule; 3229 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 3230 3231 /* 3232 * Locate first rule to move 3233 */ 3234 for (rule = ctx->ipfw_layer3_chain; rule && rule->rulenum <= rulenum; 3235 rule = rule->next) { 3236 if (rule->rulenum == rulenum && rule->set != set) 3237 break; 3238 } 3239 if (rule == NULL || rule->rulenum > rulenum) 3240 return 0; /* XXX error? */ 3241 3242 bzero(&dmsg, sizeof(dmsg)); 3243 nmsg = &dmsg.base; 3244 netmsg_init(nmsg, NULL, &curthread->td_msgport, 3245 0, ipfw_alt_move_rule_dispatch); 3246 dmsg.start_rule = rule; 3247 dmsg.rulenum = rulenum; 3248 dmsg.to_set = set; 3249 3250 ifnet_domsg(&nmsg->lmsg, 0); 3251 KKASSERT(dmsg.start_rule == NULL); 3252 return 0; 3253 } 3254 3255 static void 3256 ipfw_alt_move_ruleset_dispatch(netmsg_t nmsg) 3257 { 3258 struct netmsg_del *dmsg = (struct netmsg_del *)nmsg; 3259 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 3260 struct ip_fw *rule; 3261 3262 for (rule = ctx->ipfw_layer3_chain; rule; rule = rule->next) { 3263 if (rule->set == dmsg->from_set) 3264 rule->set = dmsg->to_set; 3265 } 3266 ifnet_forwardmsg(&nmsg->lmsg, mycpuid + 1); 3267 } 3268 3269 static int 3270 ipfw_alt_move_ruleset(uint8_t from_set, uint8_t to_set) 3271 { 3272 struct netmsg_del dmsg; 3273 struct netmsg_base *nmsg; 3274 3275 bzero(&dmsg, sizeof(dmsg)); 3276 nmsg = &dmsg.base; 3277 netmsg_init(nmsg, NULL, &curthread->td_msgport, 3278 0, ipfw_alt_move_ruleset_dispatch); 3279 dmsg.from_set = from_set; 3280 dmsg.to_set = to_set; 3281 3282 ifnet_domsg(&nmsg->lmsg, 0); 3283 return 0; 3284 } 3285 3286 static void 3287 ipfw_alt_swap_ruleset_dispatch(netmsg_t nmsg) 3288 { 3289 struct netmsg_del *dmsg = (struct netmsg_del *)nmsg; 3290 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 3291 struct ip_fw *rule; 3292 3293 for (rule = ctx->ipfw_layer3_chain; rule; rule = rule->next) { 3294 if (rule->set == dmsg->from_set) 3295 rule->set = dmsg->to_set; 3296 else if (rule->set == dmsg->to_set) 3297 rule->set = dmsg->from_set; 3298 } 3299 ifnet_forwardmsg(&nmsg->lmsg, mycpuid + 1); 3300 } 3301 3302 static int 3303 ipfw_alt_swap_ruleset(uint8_t set1, uint8_t set2) 3304 { 3305 struct netmsg_del dmsg; 3306 struct netmsg_base *nmsg; 3307 3308 bzero(&dmsg, sizeof(dmsg)); 3309 nmsg = &dmsg.base; 3310 netmsg_init(nmsg, NULL, &curthread->td_msgport, 3311 0, ipfw_alt_swap_ruleset_dispatch); 3312 dmsg.from_set = set1; 3313 dmsg.to_set = set2; 3314 3315 ifnet_domsg(&nmsg->lmsg, 0); 3316 return 0; 3317 } 3318 3319 /** 3320 * Remove all rules with given number, and also do set manipulation. 3321 * 3322 * The argument is an uint32_t. The low 16 bit are the rule or set number, 3323 * the next 8 bits are the new set, the top 8 bits are the command: 3324 * 3325 * 0 delete rules with given number 3326 * 1 delete rules with given set number 3327 * 2 move rules with given number to new set 3328 * 3 move rules with given set number to new set 3329 * 4 swap sets with given numbers 3330 */ 3331 static int 3332 ipfw_ctl_alter(uint32_t arg) 3333 { 3334 uint16_t rulenum; 3335 uint8_t cmd, new_set; 3336 int error = 0; 3337 3338 rulenum = arg & 0xffff; 3339 cmd = (arg >> 24) & 0xff; 3340 new_set = (arg >> 16) & 0xff; 3341 3342 if (cmd > 4) 3343 return EINVAL; 3344 if (new_set >= IPFW_DEFAULT_SET) 3345 return EINVAL; 3346 if (cmd == 0 || cmd == 2) { 3347 if (rulenum == IPFW_DEFAULT_RULE) 3348 return EINVAL; 3349 } else { 3350 if (rulenum >= IPFW_DEFAULT_SET) 3351 return EINVAL; 3352 } 3353 3354 switch (cmd) { 3355 case 0: /* delete rules with given number */ 3356 error = ipfw_alt_delete_rule(rulenum); 3357 break; 3358 3359 case 1: /* delete all rules with given set number */ 3360 error = ipfw_alt_delete_ruleset(rulenum); 3361 break; 3362 3363 case 2: /* move rules with given number to new set */ 3364 error = ipfw_alt_move_rule(rulenum, new_set); 3365 break; 3366 3367 case 3: /* move rules with given set number to new set */ 3368 error = ipfw_alt_move_ruleset(rulenum, new_set); 3369 break; 3370 3371 case 4: /* swap two sets */ 3372 error = ipfw_alt_swap_ruleset(rulenum, new_set); 3373 break; 3374 } 3375 return error; 3376 } 3377 3378 /* 3379 * Clear counters for a specific rule. 3380 */ 3381 static void 3382 clear_counters(struct ip_fw *rule, int log_only) 3383 { 3384 ipfw_insn_log *l = (ipfw_insn_log *)ACTION_PTR(rule); 3385 3386 if (log_only == 0) { 3387 rule->bcnt = rule->pcnt = 0; 3388 rule->timestamp = 0; 3389 } 3390 if (l->o.opcode == O_LOG) 3391 l->log_left = l->max_log; 3392 } 3393 3394 static void 3395 ipfw_zero_entry_dispatch(netmsg_t nmsg) 3396 { 3397 struct netmsg_zent *zmsg = (struct netmsg_zent *)nmsg; 3398 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 3399 struct ip_fw *rule; 3400 3401 if (zmsg->rulenum == 0) { 3402 KKASSERT(zmsg->start_rule == NULL); 3403 3404 ctx->ipfw_norule_counter = 0; 3405 for (rule = ctx->ipfw_layer3_chain; rule; rule = rule->next) 3406 clear_counters(rule, zmsg->log_only); 3407 } else { 3408 struct ip_fw *start = zmsg->start_rule; 3409 3410 KKASSERT(start->cpuid == mycpuid); 3411 KKASSERT(start->rulenum == zmsg->rulenum); 3412 3413 /* 3414 * We can have multiple rules with the same number, so we 3415 * need to clear them all. 3416 */ 3417 for (rule = start; rule && rule->rulenum == zmsg->rulenum; 3418 rule = rule->next) 3419 clear_counters(rule, zmsg->log_only); 3420 3421 /* 3422 * Move to the position on the next CPU 3423 * before the msg is forwarded. 3424 */ 3425 zmsg->start_rule = start->sibling; 3426 } 3427 ifnet_forwardmsg(&nmsg->lmsg, mycpuid + 1); 3428 } 3429 3430 /** 3431 * Reset some or all counters on firewall rules. 3432 * @arg frwl is null to clear all entries, or contains a specific 3433 * rule number. 3434 * @arg log_only is 1 if we only want to reset logs, zero otherwise. 3435 */ 3436 static int 3437 ipfw_ctl_zero_entry(int rulenum, int log_only) 3438 { 3439 struct netmsg_zent zmsg; 3440 struct netmsg_base *nmsg; 3441 const char *msg; 3442 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 3443 3444 bzero(&zmsg, sizeof(zmsg)); 3445 nmsg = &zmsg.base; 3446 netmsg_init(nmsg, NULL, &curthread->td_msgport, 3447 0, ipfw_zero_entry_dispatch); 3448 zmsg.log_only = log_only; 3449 3450 if (rulenum == 0) { 3451 msg = log_only ? "ipfw: All logging counts reset.\n" 3452 : "ipfw: Accounting cleared.\n"; 3453 } else { 3454 struct ip_fw *rule; 3455 3456 /* 3457 * Locate the first rule with 'rulenum' 3458 */ 3459 for (rule = ctx->ipfw_layer3_chain; rule; rule = rule->next) { 3460 if (rule->rulenum == rulenum) 3461 break; 3462 } 3463 if (rule == NULL) /* we did not find any matching rules */ 3464 return (EINVAL); 3465 zmsg.start_rule = rule; 3466 zmsg.rulenum = rulenum; 3467 3468 msg = log_only ? "ipfw: Entry %d logging count reset.\n" 3469 : "ipfw: Entry %d cleared.\n"; 3470 } 3471 ifnet_domsg(&nmsg->lmsg, 0); 3472 KKASSERT(zmsg.start_rule == NULL); 3473 3474 if (fw_verbose) 3475 log(LOG_SECURITY | LOG_NOTICE, msg, rulenum); 3476 return (0); 3477 } 3478 3479 /* 3480 * Check validity of the structure before insert. 3481 * Fortunately rules are simple, so this mostly need to check rule sizes. 3482 */ 3483 static int 3484 ipfw_check_ioc_rule(struct ipfw_ioc_rule *rule, int size, uint32_t *rule_flags) 3485 { 3486 int l, cmdlen = 0; 3487 int have_action = 0; 3488 ipfw_insn *cmd; 3489 3490 *rule_flags = 0; 3491 3492 /* Check for valid size */ 3493 if (size < sizeof(*rule)) { 3494 kprintf("ipfw: rule too short\n"); 3495 return EINVAL; 3496 } 3497 l = IOC_RULESIZE(rule); 3498 if (l != size) { 3499 kprintf("ipfw: size mismatch (have %d want %d)\n", size, l); 3500 return EINVAL; 3501 } 3502 3503 /* Check rule number */ 3504 if (rule->rulenum == IPFW_DEFAULT_RULE) { 3505 kprintf("ipfw: invalid rule number\n"); 3506 return EINVAL; 3507 } 3508 3509 /* 3510 * Now go for the individual checks. Very simple ones, basically only 3511 * instruction sizes. 3512 */ 3513 for (l = rule->cmd_len, cmd = rule->cmd; l > 0; 3514 l -= cmdlen, cmd += cmdlen) { 3515 cmdlen = F_LEN(cmd); 3516 if (cmdlen > l) { 3517 kprintf("ipfw: opcode %d size truncated\n", 3518 cmd->opcode); 3519 return EINVAL; 3520 } 3521 3522 DPRINTF("ipfw: opcode %d\n", cmd->opcode); 3523 3524 if (cmd->opcode == O_KEEP_STATE || cmd->opcode == O_LIMIT) { 3525 /* This rule will create states */ 3526 *rule_flags |= IPFW_RULE_F_STATE; 3527 } 3528 3529 switch (cmd->opcode) { 3530 case O_NOP: 3531 case O_PROBE_STATE: 3532 case O_KEEP_STATE: 3533 case O_PROTO: 3534 case O_IP_SRC_ME: 3535 case O_IP_DST_ME: 3536 case O_LAYER2: 3537 case O_IN: 3538 case O_FRAG: 3539 case O_IPOPT: 3540 case O_IPLEN: 3541 case O_IPID: 3542 case O_IPTOS: 3543 case O_IPPRECEDENCE: 3544 case O_IPTTL: 3545 case O_IPVER: 3546 case O_TCPWIN: 3547 case O_TCPFLAGS: 3548 case O_TCPOPTS: 3549 case O_ESTAB: 3550 if (cmdlen != F_INSN_SIZE(ipfw_insn)) 3551 goto bad_size; 3552 break; 3553 3554 case O_UID: 3555 case O_GID: 3556 case O_IP_SRC: 3557 case O_IP_DST: 3558 case O_TCPSEQ: 3559 case O_TCPACK: 3560 case O_PROB: 3561 case O_ICMPTYPE: 3562 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32)) 3563 goto bad_size; 3564 break; 3565 3566 case O_LIMIT: 3567 if (cmdlen != F_INSN_SIZE(ipfw_insn_limit)) 3568 goto bad_size; 3569 break; 3570 3571 case O_LOG: 3572 if (cmdlen != F_INSN_SIZE(ipfw_insn_log)) 3573 goto bad_size; 3574 3575 ((ipfw_insn_log *)cmd)->log_left = 3576 ((ipfw_insn_log *)cmd)->max_log; 3577 3578 break; 3579 3580 case O_IP_SRC_MASK: 3581 case O_IP_DST_MASK: 3582 if (cmdlen != F_INSN_SIZE(ipfw_insn_ip)) 3583 goto bad_size; 3584 if (((ipfw_insn_ip *)cmd)->mask.s_addr == 0) { 3585 kprintf("ipfw: opcode %d, useless rule\n", 3586 cmd->opcode); 3587 return EINVAL; 3588 } 3589 break; 3590 3591 case O_IP_SRC_SET: 3592 case O_IP_DST_SET: 3593 if (cmd->arg1 == 0 || cmd->arg1 > 256) { 3594 kprintf("ipfw: invalid set size %d\n", 3595 cmd->arg1); 3596 return EINVAL; 3597 } 3598 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32) + 3599 (cmd->arg1+31)/32 ) 3600 goto bad_size; 3601 break; 3602 3603 case O_MACADDR2: 3604 if (cmdlen != F_INSN_SIZE(ipfw_insn_mac)) 3605 goto bad_size; 3606 break; 3607 3608 case O_MAC_TYPE: 3609 case O_IP_SRCPORT: 3610 case O_IP_DSTPORT: /* XXX artificial limit, 30 port pairs */ 3611 if (cmdlen < 2 || cmdlen > 31) 3612 goto bad_size; 3613 break; 3614 3615 case O_RECV: 3616 case O_XMIT: 3617 case O_VIA: 3618 if (cmdlen != F_INSN_SIZE(ipfw_insn_if)) 3619 goto bad_size; 3620 break; 3621 3622 case O_PIPE: 3623 case O_QUEUE: 3624 if (cmdlen != F_INSN_SIZE(ipfw_insn_pipe)) 3625 goto bad_size; 3626 goto check_action; 3627 3628 case O_FORWARD_IP: 3629 if (cmdlen != F_INSN_SIZE(ipfw_insn_sa)) { 3630 goto bad_size; 3631 } else { 3632 in_addr_t fwd_addr; 3633 3634 fwd_addr = ((ipfw_insn_sa *)cmd)-> 3635 sa.sin_addr.s_addr; 3636 if (IN_MULTICAST(ntohl(fwd_addr))) { 3637 kprintf("ipfw: try forwarding to " 3638 "multicast address\n"); 3639 return EINVAL; 3640 } 3641 } 3642 goto check_action; 3643 3644 case O_FORWARD_MAC: /* XXX not implemented yet */ 3645 case O_CHECK_STATE: 3646 case O_COUNT: 3647 case O_ACCEPT: 3648 case O_DENY: 3649 case O_REJECT: 3650 case O_SKIPTO: 3651 case O_DIVERT: 3652 case O_TEE: 3653 if (cmdlen != F_INSN_SIZE(ipfw_insn)) 3654 goto bad_size; 3655 check_action: 3656 if (have_action) { 3657 kprintf("ipfw: opcode %d, multiple actions" 3658 " not allowed\n", 3659 cmd->opcode); 3660 return EINVAL; 3661 } 3662 have_action = 1; 3663 if (l != cmdlen) { 3664 kprintf("ipfw: opcode %d, action must be" 3665 " last opcode\n", 3666 cmd->opcode); 3667 return EINVAL; 3668 } 3669 break; 3670 default: 3671 kprintf("ipfw: opcode %d, unknown opcode\n", 3672 cmd->opcode); 3673 return EINVAL; 3674 } 3675 } 3676 if (have_action == 0) { 3677 kprintf("ipfw: missing action\n"); 3678 return EINVAL; 3679 } 3680 return 0; 3681 3682 bad_size: 3683 kprintf("ipfw: opcode %d size %d wrong\n", 3684 cmd->opcode, cmdlen); 3685 return EINVAL; 3686 } 3687 3688 static int 3689 ipfw_ctl_add_rule(struct sockopt *sopt) 3690 { 3691 struct ipfw_ioc_rule *ioc_rule; 3692 size_t size; 3693 uint32_t rule_flags; 3694 int error; 3695 3696 size = sopt->sopt_valsize; 3697 if (size > (sizeof(uint32_t) * IPFW_RULE_SIZE_MAX) || 3698 size < sizeof(*ioc_rule)) { 3699 return EINVAL; 3700 } 3701 if (size != (sizeof(uint32_t) * IPFW_RULE_SIZE_MAX)) { 3702 sopt->sopt_val = krealloc(sopt->sopt_val, sizeof(uint32_t) * 3703 IPFW_RULE_SIZE_MAX, M_TEMP, M_WAITOK); 3704 } 3705 ioc_rule = sopt->sopt_val; 3706 3707 error = ipfw_check_ioc_rule(ioc_rule, size, &rule_flags); 3708 if (error) 3709 return error; 3710 3711 ipfw_add_rule(ioc_rule, rule_flags); 3712 3713 if (sopt->sopt_dir == SOPT_GET) 3714 sopt->sopt_valsize = IOC_RULESIZE(ioc_rule); 3715 return 0; 3716 } 3717 3718 static void * 3719 ipfw_copy_rule(const struct ip_fw *rule, struct ipfw_ioc_rule *ioc_rule) 3720 { 3721 const struct ip_fw *sibling; 3722 #ifdef INVARIANTS 3723 int i; 3724 #endif 3725 3726 KKASSERT(rule->cpuid == IPFW_CFGCPUID); 3727 3728 ioc_rule->act_ofs = rule->act_ofs; 3729 ioc_rule->cmd_len = rule->cmd_len; 3730 ioc_rule->rulenum = rule->rulenum; 3731 ioc_rule->set = rule->set; 3732 ioc_rule->usr_flags = rule->usr_flags; 3733 3734 ioc_rule->set_disable = ipfw_ctx[mycpuid]->ipfw_set_disable; 3735 ioc_rule->static_count = static_count; 3736 ioc_rule->static_len = static_ioc_len; 3737 3738 /* 3739 * Visit (read-only) all of the rule's duplications to get 3740 * the necessary statistics 3741 */ 3742 #ifdef INVARIANTS 3743 i = 0; 3744 #endif 3745 ioc_rule->pcnt = 0; 3746 ioc_rule->bcnt = 0; 3747 ioc_rule->timestamp = 0; 3748 for (sibling = rule; sibling != NULL; sibling = sibling->sibling) { 3749 ioc_rule->pcnt += sibling->pcnt; 3750 ioc_rule->bcnt += sibling->bcnt; 3751 if (sibling->timestamp > ioc_rule->timestamp) 3752 ioc_rule->timestamp = sibling->timestamp; 3753 #ifdef INVARIANTS 3754 ++i; 3755 #endif 3756 } 3757 KASSERT(i == ncpus, ("static rule is not duplicated on every cpu")); 3758 3759 bcopy(rule->cmd, ioc_rule->cmd, ioc_rule->cmd_len * 4 /* XXX */); 3760 3761 return ((uint8_t *)ioc_rule + IOC_RULESIZE(ioc_rule)); 3762 } 3763 3764 static void 3765 ipfw_copy_state(const ipfw_dyn_rule *dyn_rule, 3766 struct ipfw_ioc_state *ioc_state) 3767 { 3768 const struct ipfw_flow_id *id; 3769 struct ipfw_ioc_flowid *ioc_id; 3770 3771 ioc_state->expire = TIME_LEQ(dyn_rule->expire, time_second) ? 3772 0 : dyn_rule->expire - time_second; 3773 ioc_state->pcnt = dyn_rule->pcnt; 3774 ioc_state->bcnt = dyn_rule->bcnt; 3775 3776 ioc_state->dyn_type = dyn_rule->dyn_type; 3777 ioc_state->count = dyn_rule->count; 3778 3779 ioc_state->rulenum = dyn_rule->stub->rule[mycpuid]->rulenum; 3780 3781 id = &dyn_rule->id; 3782 ioc_id = &ioc_state->id; 3783 3784 ioc_id->type = ETHERTYPE_IP; 3785 ioc_id->u.ip.dst_ip = id->dst_ip; 3786 ioc_id->u.ip.src_ip = id->src_ip; 3787 ioc_id->u.ip.dst_port = id->dst_port; 3788 ioc_id->u.ip.src_port = id->src_port; 3789 ioc_id->u.ip.proto = id->proto; 3790 } 3791 3792 static int 3793 ipfw_ctl_get_rules(struct sockopt *sopt) 3794 { 3795 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 3796 struct ip_fw *rule; 3797 void *bp; 3798 size_t size; 3799 uint32_t dcount = 0; 3800 3801 /* 3802 * pass up a copy of the current rules. Static rules 3803 * come first (the last of which has number IPFW_DEFAULT_RULE), 3804 * followed by a possibly empty list of dynamic rule. 3805 */ 3806 3807 size = static_ioc_len; /* size of static rules */ 3808 if (ipfw_dyn_v) { /* add size of dyn.rules */ 3809 dcount = dyn_count; 3810 size += dcount * sizeof(struct ipfw_ioc_state); 3811 } 3812 3813 if (sopt->sopt_valsize < size) { 3814 /* short length, no need to return incomplete rules */ 3815 /* XXX: if superuser, no need to zero buffer */ 3816 bzero(sopt->sopt_val, sopt->sopt_valsize); 3817 return 0; 3818 } 3819 bp = sopt->sopt_val; 3820 3821 for (rule = ctx->ipfw_layer3_chain; rule; rule = rule->next) 3822 bp = ipfw_copy_rule(rule, bp); 3823 3824 if (ipfw_dyn_v && dcount != 0) { 3825 struct ipfw_ioc_state *ioc_state = bp; 3826 uint32_t dcount2 = 0; 3827 #ifdef INVARIANTS 3828 size_t old_size = size; 3829 #endif 3830 int i; 3831 3832 lockmgr(&dyn_lock, LK_SHARED); 3833 3834 /* Check 'ipfw_dyn_v' again with lock held */ 3835 if (ipfw_dyn_v == NULL) 3836 goto skip; 3837 3838 for (i = 0; i < curr_dyn_buckets; i++) { 3839 ipfw_dyn_rule *p; 3840 3841 /* 3842 * The # of dynamic rules may have grown after the 3843 * snapshot of 'dyn_count' was taken, so we will have 3844 * to check 'dcount' (snapshot of dyn_count) here to 3845 * make sure that we don't overflow the pre-allocated 3846 * buffer. 3847 */ 3848 for (p = ipfw_dyn_v[i]; p != NULL && dcount != 0; 3849 p = p->next, ioc_state++, dcount--, dcount2++) 3850 ipfw_copy_state(p, ioc_state); 3851 } 3852 skip: 3853 lockmgr(&dyn_lock, LK_RELEASE); 3854 3855 /* 3856 * The # of dynamic rules may be shrinked after the 3857 * snapshot of 'dyn_count' was taken. To give user a 3858 * correct dynamic rule count, we use the 'dcount2' 3859 * calculated above (with shared lockmgr lock held). 3860 */ 3861 size = static_ioc_len + 3862 (dcount2 * sizeof(struct ipfw_ioc_state)); 3863 KKASSERT(size <= old_size); 3864 } 3865 3866 sopt->sopt_valsize = size; 3867 return 0; 3868 } 3869 3870 static void 3871 ipfw_set_disable_dispatch(netmsg_t nmsg) 3872 { 3873 struct lwkt_msg *lmsg = &nmsg->lmsg; 3874 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 3875 3876 ctx->ipfw_gen++; 3877 ctx->ipfw_set_disable = lmsg->u.ms_result32; 3878 3879 ifnet_forwardmsg(lmsg, mycpuid + 1); 3880 } 3881 3882 static void 3883 ipfw_ctl_set_disable(uint32_t disable, uint32_t enable) 3884 { 3885 struct netmsg_base nmsg; 3886 struct lwkt_msg *lmsg; 3887 uint32_t set_disable; 3888 3889 /* IPFW_DEFAULT_SET is always enabled */ 3890 enable |= (1 << IPFW_DEFAULT_SET); 3891 set_disable = (ipfw_ctx[mycpuid]->ipfw_set_disable | disable) & ~enable; 3892 3893 bzero(&nmsg, sizeof(nmsg)); 3894 netmsg_init(&nmsg, NULL, &curthread->td_msgport, 3895 0, ipfw_set_disable_dispatch); 3896 lmsg = &nmsg.lmsg; 3897 lmsg->u.ms_result32 = set_disable; 3898 3899 ifnet_domsg(lmsg, 0); 3900 } 3901 3902 /** 3903 * {set|get}sockopt parser. 3904 */ 3905 static int 3906 ipfw_ctl(struct sockopt *sopt) 3907 { 3908 int error, rulenum; 3909 uint32_t *masks; 3910 size_t size; 3911 3912 error = 0; 3913 3914 switch (sopt->sopt_name) { 3915 case IP_FW_GET: 3916 error = ipfw_ctl_get_rules(sopt); 3917 break; 3918 3919 case IP_FW_FLUSH: 3920 ipfw_flush(0 /* keep default rule */); 3921 break; 3922 3923 case IP_FW_ADD: 3924 error = ipfw_ctl_add_rule(sopt); 3925 break; 3926 3927 case IP_FW_DEL: 3928 /* 3929 * IP_FW_DEL is used for deleting single rules or sets, 3930 * and (ab)used to atomically manipulate sets. 3931 * Argument size is used to distinguish between the two: 3932 * sizeof(uint32_t) 3933 * delete single rule or set of rules, 3934 * or reassign rules (or sets) to a different set. 3935 * 2 * sizeof(uint32_t) 3936 * atomic disable/enable sets. 3937 * first uint32_t contains sets to be disabled, 3938 * second uint32_t contains sets to be enabled. 3939 */ 3940 masks = sopt->sopt_val; 3941 size = sopt->sopt_valsize; 3942 if (size == sizeof(*masks)) { 3943 /* 3944 * Delete or reassign static rule 3945 */ 3946 error = ipfw_ctl_alter(masks[0]); 3947 } else if (size == (2 * sizeof(*masks))) { 3948 /* 3949 * Set enable/disable 3950 */ 3951 ipfw_ctl_set_disable(masks[0], masks[1]); 3952 } else { 3953 error = EINVAL; 3954 } 3955 break; 3956 3957 case IP_FW_ZERO: 3958 case IP_FW_RESETLOG: /* argument is an int, the rule number */ 3959 rulenum = 0; 3960 3961 if (sopt->sopt_val != 0) { 3962 error = soopt_to_kbuf(sopt, &rulenum, 3963 sizeof(int), sizeof(int)); 3964 if (error) 3965 break; 3966 } 3967 error = ipfw_ctl_zero_entry(rulenum, 3968 sopt->sopt_name == IP_FW_RESETLOG); 3969 break; 3970 3971 default: 3972 kprintf("ipfw_ctl invalid option %d\n", sopt->sopt_name); 3973 error = EINVAL; 3974 } 3975 return error; 3976 } 3977 3978 /* 3979 * This procedure is only used to handle keepalives. It is invoked 3980 * every dyn_keepalive_period 3981 */ 3982 static void 3983 ipfw_tick_dispatch(netmsg_t nmsg) 3984 { 3985 time_t keep_alive; 3986 uint32_t gen; 3987 int i; 3988 3989 IPFW_ASSERT_CFGPORT(&curthread->td_msgport); 3990 KKASSERT(IPFW_LOADED); 3991 3992 /* Reply ASAP */ 3993 crit_enter(); 3994 lwkt_replymsg(&nmsg->lmsg, 0); 3995 crit_exit(); 3996 3997 if (ipfw_dyn_v == NULL || dyn_count == 0) 3998 goto done; 3999 4000 keep_alive = time_second; 4001 4002 lockmgr(&dyn_lock, LK_EXCLUSIVE); 4003 again: 4004 if (ipfw_dyn_v == NULL || dyn_count == 0) { 4005 lockmgr(&dyn_lock, LK_RELEASE); 4006 goto done; 4007 } 4008 gen = dyn_buckets_gen; 4009 4010 for (i = 0; i < curr_dyn_buckets; i++) { 4011 ipfw_dyn_rule *q, *prev; 4012 4013 for (prev = NULL, q = ipfw_dyn_v[i]; q != NULL;) { 4014 uint32_t ack_rev, ack_fwd; 4015 struct ipfw_flow_id id; 4016 4017 if (q->dyn_type == O_LIMIT_PARENT) 4018 goto next; 4019 4020 if (TIME_LEQ(q->expire, time_second)) { 4021 /* State expired */ 4022 UNLINK_DYN_RULE(prev, ipfw_dyn_v[i], q); 4023 continue; 4024 } 4025 4026 /* 4027 * Keep alive processing 4028 */ 4029 4030 if (!dyn_keepalive) 4031 goto next; 4032 if (q->id.proto != IPPROTO_TCP) 4033 goto next; 4034 if ((q->state & BOTH_SYN) != BOTH_SYN) 4035 goto next; 4036 if (TIME_LEQ(time_second + dyn_keepalive_interval, 4037 q->expire)) 4038 goto next; /* too early */ 4039 if (q->keep_alive == keep_alive) 4040 goto next; /* alreay done */ 4041 4042 /* 4043 * Save necessary information, so that they could 4044 * survive after possible blocking in send_pkt() 4045 */ 4046 id = q->id; 4047 ack_rev = q->ack_rev; 4048 ack_fwd = q->ack_fwd; 4049 4050 /* Sending has been started */ 4051 q->keep_alive = keep_alive; 4052 4053 /* Release lock to avoid possible dead lock */ 4054 lockmgr(&dyn_lock, LK_RELEASE); 4055 send_pkt(&id, ack_rev - 1, ack_fwd, TH_SYN); 4056 send_pkt(&id, ack_fwd - 1, ack_rev, 0); 4057 lockmgr(&dyn_lock, LK_EXCLUSIVE); 4058 4059 if (gen != dyn_buckets_gen) { 4060 /* 4061 * Dyn bucket array has been changed during 4062 * the above two sending; reiterate. 4063 */ 4064 goto again; 4065 } 4066 next: 4067 prev = q; 4068 q = q->next; 4069 } 4070 } 4071 lockmgr(&dyn_lock, LK_RELEASE); 4072 done: 4073 callout_reset(&ipfw_timeout_h, dyn_keepalive_period * hz, 4074 ipfw_tick, NULL); 4075 } 4076 4077 /* 4078 * This procedure is only used to handle keepalives. It is invoked 4079 * every dyn_keepalive_period 4080 */ 4081 static void 4082 ipfw_tick(void *dummy __unused) 4083 { 4084 struct lwkt_msg *lmsg = &ipfw_timeout_netmsg.lmsg; 4085 4086 KKASSERT(mycpuid == IPFW_CFGCPUID); 4087 4088 crit_enter(); 4089 4090 KKASSERT(lmsg->ms_flags & MSGF_DONE); 4091 if (IPFW_LOADED) { 4092 lwkt_sendmsg_oncpu(IPFW_CFGPORT, lmsg); 4093 /* ipfw_timeout_netmsg's handler reset this callout */ 4094 } 4095 4096 crit_exit(); 4097 } 4098 4099 static int 4100 ipfw_check_in(void *arg, struct mbuf **m0, struct ifnet *ifp, int dir) 4101 { 4102 struct ip_fw_args args; 4103 struct mbuf *m = *m0; 4104 struct m_tag *mtag; 4105 int tee = 0, error = 0, ret; 4106 4107 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) { 4108 /* Extract info from dummynet tag */ 4109 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL); 4110 KKASSERT(mtag != NULL); 4111 args.rule = ((struct dn_pkt *)m_tag_data(mtag))->dn_priv; 4112 KKASSERT(args.rule != NULL); 4113 4114 m_tag_delete(m, mtag); 4115 m->m_pkthdr.fw_flags &= ~DUMMYNET_MBUF_TAGGED; 4116 } else { 4117 args.rule = NULL; 4118 } 4119 4120 args.eh = NULL; 4121 args.oif = NULL; 4122 args.m = m; 4123 ret = ipfw_chk(&args); 4124 m = args.m; 4125 4126 if (m == NULL) { 4127 error = EACCES; 4128 goto back; 4129 } 4130 4131 switch (ret) { 4132 case IP_FW_PASS: 4133 break; 4134 4135 case IP_FW_DENY: 4136 m_freem(m); 4137 m = NULL; 4138 error = EACCES; 4139 break; 4140 4141 case IP_FW_DUMMYNET: 4142 /* Send packet to the appropriate pipe */ 4143 ipfw_dummynet_io(m, args.cookie, DN_TO_IP_IN, &args); 4144 break; 4145 4146 case IP_FW_TEE: 4147 tee = 1; 4148 /* FALL THROUGH */ 4149 4150 case IP_FW_DIVERT: 4151 /* 4152 * Must clear bridge tag when changing 4153 */ 4154 m->m_pkthdr.fw_flags &= ~BRIDGE_MBUF_TAGGED; 4155 if (ip_divert_p != NULL) { 4156 m = ip_divert_p(m, tee, 1); 4157 } else { 4158 m_freem(m); 4159 m = NULL; 4160 /* not sure this is the right error msg */ 4161 error = EACCES; 4162 } 4163 break; 4164 4165 default: 4166 panic("unknown ipfw return value: %d", ret); 4167 } 4168 back: 4169 *m0 = m; 4170 return error; 4171 } 4172 4173 static int 4174 ipfw_check_out(void *arg, struct mbuf **m0, struct ifnet *ifp, int dir) 4175 { 4176 struct ip_fw_args args; 4177 struct mbuf *m = *m0; 4178 struct m_tag *mtag; 4179 int tee = 0, error = 0, ret; 4180 4181 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) { 4182 /* Extract info from dummynet tag */ 4183 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL); 4184 KKASSERT(mtag != NULL); 4185 args.rule = ((struct dn_pkt *)m_tag_data(mtag))->dn_priv; 4186 KKASSERT(args.rule != NULL); 4187 4188 m_tag_delete(m, mtag); 4189 m->m_pkthdr.fw_flags &= ~DUMMYNET_MBUF_TAGGED; 4190 } else { 4191 args.rule = NULL; 4192 } 4193 4194 args.eh = NULL; 4195 args.m = m; 4196 args.oif = ifp; 4197 ret = ipfw_chk(&args); 4198 m = args.m; 4199 4200 if (m == NULL) { 4201 error = EACCES; 4202 goto back; 4203 } 4204 4205 switch (ret) { 4206 case IP_FW_PASS: 4207 break; 4208 4209 case IP_FW_DENY: 4210 m_freem(m); 4211 m = NULL; 4212 error = EACCES; 4213 break; 4214 4215 case IP_FW_DUMMYNET: 4216 ipfw_dummynet_io(m, args.cookie, DN_TO_IP_OUT, &args); 4217 break; 4218 4219 case IP_FW_TEE: 4220 tee = 1; 4221 /* FALL THROUGH */ 4222 4223 case IP_FW_DIVERT: 4224 if (ip_divert_p != NULL) { 4225 m = ip_divert_p(m, tee, 0); 4226 } else { 4227 m_freem(m); 4228 m = NULL; 4229 /* not sure this is the right error msg */ 4230 error = EACCES; 4231 } 4232 break; 4233 4234 default: 4235 panic("unknown ipfw return value: %d", ret); 4236 } 4237 back: 4238 *m0 = m; 4239 return error; 4240 } 4241 4242 static void 4243 ipfw_hook(void) 4244 { 4245 struct pfil_head *pfh; 4246 4247 IPFW_ASSERT_CFGPORT(&curthread->td_msgport); 4248 4249 pfh = pfil_head_get(PFIL_TYPE_AF, AF_INET); 4250 if (pfh == NULL) 4251 return; 4252 4253 pfil_add_hook(ipfw_check_in, NULL, PFIL_IN | PFIL_MPSAFE, pfh); 4254 pfil_add_hook(ipfw_check_out, NULL, PFIL_OUT | PFIL_MPSAFE, pfh); 4255 } 4256 4257 static void 4258 ipfw_dehook(void) 4259 { 4260 struct pfil_head *pfh; 4261 4262 IPFW_ASSERT_CFGPORT(&curthread->td_msgport); 4263 4264 pfh = pfil_head_get(PFIL_TYPE_AF, AF_INET); 4265 if (pfh == NULL) 4266 return; 4267 4268 pfil_remove_hook(ipfw_check_in, NULL, PFIL_IN, pfh); 4269 pfil_remove_hook(ipfw_check_out, NULL, PFIL_OUT, pfh); 4270 } 4271 4272 static void 4273 ipfw_sysctl_enable_dispatch(netmsg_t nmsg) 4274 { 4275 struct lwkt_msg *lmsg = &nmsg->lmsg; 4276 int enable = lmsg->u.ms_result; 4277 4278 if (fw_enable == enable) 4279 goto reply; 4280 4281 fw_enable = enable; 4282 if (fw_enable) 4283 ipfw_hook(); 4284 else 4285 ipfw_dehook(); 4286 reply: 4287 lwkt_replymsg(lmsg, 0); 4288 } 4289 4290 static int 4291 ipfw_sysctl_enable(SYSCTL_HANDLER_ARGS) 4292 { 4293 struct netmsg_base nmsg; 4294 struct lwkt_msg *lmsg; 4295 int enable, error; 4296 4297 enable = fw_enable; 4298 error = sysctl_handle_int(oidp, &enable, 0, req); 4299 if (error || req->newptr == NULL) 4300 return error; 4301 4302 netmsg_init(&nmsg, NULL, &curthread->td_msgport, 4303 0, ipfw_sysctl_enable_dispatch); 4304 lmsg = &nmsg.lmsg; 4305 lmsg->u.ms_result = enable; 4306 4307 return lwkt_domsg(IPFW_CFGPORT, lmsg, 0); 4308 } 4309 4310 static int 4311 ipfw_sysctl_autoinc_step(SYSCTL_HANDLER_ARGS) 4312 { 4313 return sysctl_int_range(oidp, arg1, arg2, req, 4314 IPFW_AUTOINC_STEP_MIN, IPFW_AUTOINC_STEP_MAX); 4315 } 4316 4317 static int 4318 ipfw_sysctl_dyn_buckets(SYSCTL_HANDLER_ARGS) 4319 { 4320 int error, value; 4321 4322 lockmgr(&dyn_lock, LK_EXCLUSIVE); 4323 4324 value = dyn_buckets; 4325 error = sysctl_handle_int(oidp, &value, 0, req); 4326 if (error || !req->newptr) 4327 goto back; 4328 4329 /* 4330 * Make sure we have a power of 2 and 4331 * do not allow more than 64k entries. 4332 */ 4333 error = EINVAL; 4334 if (value <= 1 || value > 65536) 4335 goto back; 4336 if ((value & (value - 1)) != 0) 4337 goto back; 4338 4339 error = 0; 4340 dyn_buckets = value; 4341 back: 4342 lockmgr(&dyn_lock, LK_RELEASE); 4343 return error; 4344 } 4345 4346 static int 4347 ipfw_sysctl_dyn_fin(SYSCTL_HANDLER_ARGS) 4348 { 4349 return sysctl_int_range(oidp, arg1, arg2, req, 4350 1, dyn_keepalive_period - 1); 4351 } 4352 4353 static int 4354 ipfw_sysctl_dyn_rst(SYSCTL_HANDLER_ARGS) 4355 { 4356 return sysctl_int_range(oidp, arg1, arg2, req, 4357 1, dyn_keepalive_period - 1); 4358 } 4359 4360 static void 4361 ipfw_ctx_init_dispatch(netmsg_t nmsg) 4362 { 4363 struct netmsg_ipfw *fwmsg = (struct netmsg_ipfw *)nmsg; 4364 struct ipfw_context *ctx; 4365 struct ip_fw *def_rule; 4366 4367 ctx = kmalloc(sizeof(*ctx), M_IPFW, M_WAITOK | M_ZERO); 4368 ipfw_ctx[mycpuid] = ctx; 4369 4370 def_rule = kmalloc(sizeof(*def_rule), M_IPFW, M_WAITOK | M_ZERO); 4371 4372 def_rule->act_ofs = 0; 4373 def_rule->rulenum = IPFW_DEFAULT_RULE; 4374 def_rule->cmd_len = 1; 4375 def_rule->set = IPFW_DEFAULT_SET; 4376 4377 def_rule->cmd[0].len = 1; 4378 #ifdef IPFIREWALL_DEFAULT_TO_ACCEPT 4379 def_rule->cmd[0].opcode = O_ACCEPT; 4380 #else 4381 def_rule->cmd[0].opcode = O_DENY; 4382 #endif 4383 4384 def_rule->refcnt = 1; 4385 def_rule->cpuid = mycpuid; 4386 4387 /* Install the default rule */ 4388 ctx->ipfw_default_rule = def_rule; 4389 ctx->ipfw_layer3_chain = def_rule; 4390 4391 /* Link rule CPU sibling */ 4392 ipfw_link_sibling(fwmsg, def_rule); 4393 4394 /* Statistics only need to be updated once */ 4395 if (mycpuid == 0) 4396 ipfw_inc_static_count(def_rule); 4397 4398 ifnet_forwardmsg(&nmsg->lmsg, mycpuid + 1); 4399 } 4400 4401 static void 4402 ipfw_init_dispatch(netmsg_t nmsg) 4403 { 4404 struct netmsg_ipfw fwmsg; 4405 int error = 0; 4406 4407 if (IPFW_LOADED) { 4408 kprintf("IP firewall already loaded\n"); 4409 error = EEXIST; 4410 goto reply; 4411 } 4412 4413 bzero(&fwmsg, sizeof(fwmsg)); 4414 netmsg_init(&fwmsg.base, NULL, &curthread->td_msgport, 4415 0, ipfw_ctx_init_dispatch); 4416 ifnet_domsg(&fwmsg.base.lmsg, 0); 4417 4418 ip_fw_chk_ptr = ipfw_chk; 4419 ip_fw_ctl_ptr = ipfw_ctl; 4420 ip_fw_dn_io_ptr = ipfw_dummynet_io; 4421 4422 kprintf("ipfw2 initialized, default to %s, logging ", 4423 ipfw_ctx[mycpuid]->ipfw_default_rule->cmd[0].opcode == 4424 O_ACCEPT ? "accept" : "deny"); 4425 4426 #ifdef IPFIREWALL_VERBOSE 4427 fw_verbose = 1; 4428 #endif 4429 #ifdef IPFIREWALL_VERBOSE_LIMIT 4430 verbose_limit = IPFIREWALL_VERBOSE_LIMIT; 4431 #endif 4432 if (fw_verbose == 0) { 4433 kprintf("disabled\n"); 4434 } else if (verbose_limit == 0) { 4435 kprintf("unlimited\n"); 4436 } else { 4437 kprintf("limited to %d packets/entry by default\n", 4438 verbose_limit); 4439 } 4440 4441 callout_init_mp(&ipfw_timeout_h); 4442 netmsg_init(&ipfw_timeout_netmsg, NULL, &netisr_adone_rport, 4443 MSGF_DROPABLE | MSGF_PRIORITY, 4444 ipfw_tick_dispatch); 4445 lockinit(&dyn_lock, "ipfw_dyn", 0, 0); 4446 4447 ip_fw_loaded = 1; 4448 callout_reset(&ipfw_timeout_h, hz, ipfw_tick, NULL); 4449 4450 if (fw_enable) 4451 ipfw_hook(); 4452 reply: 4453 lwkt_replymsg(&nmsg->lmsg, error); 4454 } 4455 4456 static int 4457 ipfw_init(void) 4458 { 4459 struct netmsg_base smsg; 4460 4461 netmsg_init(&smsg, NULL, &curthread->td_msgport, 4462 0, ipfw_init_dispatch); 4463 return lwkt_domsg(IPFW_CFGPORT, &smsg.lmsg, 0); 4464 } 4465 4466 #ifdef KLD_MODULE 4467 4468 static void 4469 ipfw_fini_dispatch(netmsg_t nmsg) 4470 { 4471 int error = 0, cpu; 4472 4473 if (ipfw_refcnt != 0) { 4474 error = EBUSY; 4475 goto reply; 4476 } 4477 4478 ip_fw_loaded = 0; 4479 4480 ipfw_dehook(); 4481 callout_stop(&ipfw_timeout_h); 4482 4483 netmsg_service_sync(); 4484 4485 crit_enter(); 4486 lwkt_dropmsg(&ipfw_timeout_netmsg.lmsg); 4487 crit_exit(); 4488 4489 ip_fw_chk_ptr = NULL; 4490 ip_fw_ctl_ptr = NULL; 4491 ip_fw_dn_io_ptr = NULL; 4492 ipfw_flush(1 /* kill default rule */); 4493 4494 /* Free pre-cpu context */ 4495 for (cpu = 0; cpu < ncpus; ++cpu) 4496 kfree(ipfw_ctx[cpu], M_IPFW); 4497 4498 kprintf("IP firewall unloaded\n"); 4499 reply: 4500 lwkt_replymsg(&nmsg->lmsg, error); 4501 } 4502 4503 static int 4504 ipfw_fini(void) 4505 { 4506 struct netmsg_base smsg; 4507 4508 netmsg_init(&smsg, NULL, &curthread->td_msgport, 4509 0, ipfw_fini_dispatch); 4510 return lwkt_domsg(IPFW_CFGPORT, &smsg.lmsg, 0); 4511 } 4512 4513 #endif /* KLD_MODULE */ 4514 4515 static int 4516 ipfw_modevent(module_t mod, int type, void *unused) 4517 { 4518 int err = 0; 4519 4520 switch (type) { 4521 case MOD_LOAD: 4522 err = ipfw_init(); 4523 break; 4524 4525 case MOD_UNLOAD: 4526 #ifndef KLD_MODULE 4527 kprintf("ipfw statically compiled, cannot unload\n"); 4528 err = EBUSY; 4529 #else 4530 err = ipfw_fini(); 4531 #endif 4532 break; 4533 default: 4534 break; 4535 } 4536 return err; 4537 } 4538 4539 static moduledata_t ipfwmod = { 4540 "ipfw", 4541 ipfw_modevent, 4542 0 4543 }; 4544 DECLARE_MODULE(ipfw, ipfwmod, SI_SUB_PROTO_END, SI_ORDER_ANY); 4545 MODULE_VERSION(ipfw, 1); 4546