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 uint32_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_second) 926 return; 927 last_remove = time_second; 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 get_mplock(); 1622 if (gen != ctx->ipfw_gen) { 1623 /* See the comment in lookup_rule() */ 1624 *deny = 1; 1625 } else { 1626 match = _ipfw_match_uid(fid, oif, opcode, uid); 1627 } 1628 rel_mplock(); 1629 return match; 1630 } 1631 1632 /* 1633 * The main check routine for the firewall. 1634 * 1635 * All arguments are in args so we can modify them and return them 1636 * back to the caller. 1637 * 1638 * Parameters: 1639 * 1640 * args->m (in/out) The packet; we set to NULL when/if we nuke it. 1641 * Starts with the IP header. 1642 * args->eh (in) Mac header if present, or NULL for layer3 packet. 1643 * args->oif Outgoing interface, or NULL if packet is incoming. 1644 * The incoming interface is in the mbuf. (in) 1645 * 1646 * args->rule Pointer to the last matching rule (in/out) 1647 * args->f_id Addresses grabbed from the packet (out) 1648 * 1649 * Return value: 1650 * 1651 * If the packet was denied/rejected and has been dropped, *m is equal 1652 * to NULL upon return. 1653 * 1654 * IP_FW_DENY the packet must be dropped. 1655 * IP_FW_PASS The packet is to be accepted and routed normally. 1656 * IP_FW_DIVERT Divert the packet to port (args->cookie) 1657 * IP_FW_TEE Tee the packet to port (args->cookie) 1658 * IP_FW_DUMMYNET Send the packet to pipe/queue (args->cookie) 1659 */ 1660 1661 static int 1662 ipfw_chk(struct ip_fw_args *args) 1663 { 1664 /* 1665 * Local variables hold state during the processing of a packet. 1666 * 1667 * IMPORTANT NOTE: to speed up the processing of rules, there 1668 * are some assumption on the values of the variables, which 1669 * are documented here. Should you change them, please check 1670 * the implementation of the various instructions to make sure 1671 * that they still work. 1672 * 1673 * args->eh The MAC header. It is non-null for a layer2 1674 * packet, it is NULL for a layer-3 packet. 1675 * 1676 * m | args->m Pointer to the mbuf, as received from the caller. 1677 * It may change if ipfw_chk() does an m_pullup, or if it 1678 * consumes the packet because it calls send_reject(). 1679 * XXX This has to change, so that ipfw_chk() never modifies 1680 * or consumes the buffer. 1681 * ip is simply an alias of the value of m, and it is kept 1682 * in sync with it (the packet is supposed to start with 1683 * the ip header). 1684 */ 1685 struct mbuf *m = args->m; 1686 struct ip *ip = mtod(m, struct ip *); 1687 1688 /* 1689 * oif | args->oif If NULL, ipfw_chk has been called on the 1690 * inbound path (ether_input, ip_input). 1691 * If non-NULL, ipfw_chk has been called on the outbound path 1692 * (ether_output, ip_output). 1693 */ 1694 struct ifnet *oif = args->oif; 1695 1696 struct ip_fw *f = NULL; /* matching rule */ 1697 int retval = IP_FW_PASS; 1698 struct m_tag *mtag; 1699 struct divert_info *divinfo; 1700 1701 /* 1702 * hlen The length of the IPv4 header. 1703 * hlen >0 means we have an IPv4 packet. 1704 */ 1705 u_int hlen = 0; /* hlen >0 means we have an IP pkt */ 1706 1707 /* 1708 * offset The offset of a fragment. offset != 0 means that 1709 * we have a fragment at this offset of an IPv4 packet. 1710 * offset == 0 means that (if this is an IPv4 packet) 1711 * this is the first or only fragment. 1712 */ 1713 u_short offset = 0; 1714 1715 /* 1716 * Local copies of addresses. They are only valid if we have 1717 * an IP packet. 1718 * 1719 * proto The protocol. Set to 0 for non-ip packets, 1720 * or to the protocol read from the packet otherwise. 1721 * proto != 0 means that we have an IPv4 packet. 1722 * 1723 * src_port, dst_port port numbers, in HOST format. Only 1724 * valid for TCP and UDP packets. 1725 * 1726 * src_ip, dst_ip ip addresses, in NETWORK format. 1727 * Only valid for IPv4 packets. 1728 */ 1729 uint8_t proto; 1730 uint16_t src_port = 0, dst_port = 0; /* NOTE: host format */ 1731 struct in_addr src_ip, dst_ip; /* NOTE: network format */ 1732 uint16_t ip_len = 0; 1733 1734 /* 1735 * dyn_dir = MATCH_UNKNOWN when rules unchecked, 1736 * MATCH_NONE when checked and not matched (dyn_f = NULL), 1737 * MATCH_FORWARD or MATCH_REVERSE otherwise (dyn_f != NULL) 1738 */ 1739 int dyn_dir = MATCH_UNKNOWN; 1740 struct ip_fw *dyn_f = NULL; 1741 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 1742 1743 if (m->m_pkthdr.fw_flags & IPFW_MBUF_GENERATED) 1744 return IP_FW_PASS; /* accept */ 1745 1746 if (args->eh == NULL || /* layer 3 packet */ 1747 (m->m_pkthdr.len >= sizeof(struct ip) && 1748 ntohs(args->eh->ether_type) == ETHERTYPE_IP)) 1749 hlen = ip->ip_hl << 2; 1750 1751 /* 1752 * Collect parameters into local variables for faster matching. 1753 */ 1754 if (hlen == 0) { /* do not grab addresses for non-ip pkts */ 1755 proto = args->f_id.proto = 0; /* mark f_id invalid */ 1756 goto after_ip_checks; 1757 } 1758 1759 proto = args->f_id.proto = ip->ip_p; 1760 src_ip = ip->ip_src; 1761 dst_ip = ip->ip_dst; 1762 if (args->eh != NULL) { /* layer 2 packets are as on the wire */ 1763 offset = ntohs(ip->ip_off) & IP_OFFMASK; 1764 ip_len = ntohs(ip->ip_len); 1765 } else { 1766 offset = ip->ip_off & IP_OFFMASK; 1767 ip_len = ip->ip_len; 1768 } 1769 1770 #define PULLUP_TO(len) \ 1771 do { \ 1772 if (m->m_len < (len)) { \ 1773 args->m = m = m_pullup(m, (len));\ 1774 if (m == NULL) \ 1775 goto pullup_failed; \ 1776 ip = mtod(m, struct ip *); \ 1777 } \ 1778 } while (0) 1779 1780 if (offset == 0) { 1781 switch (proto) { 1782 case IPPROTO_TCP: 1783 { 1784 struct tcphdr *tcp; 1785 1786 PULLUP_TO(hlen + sizeof(struct tcphdr)); 1787 tcp = L3HDR(struct tcphdr, ip); 1788 dst_port = tcp->th_dport; 1789 src_port = tcp->th_sport; 1790 args->f_id.flags = tcp->th_flags; 1791 } 1792 break; 1793 1794 case IPPROTO_UDP: 1795 { 1796 struct udphdr *udp; 1797 1798 PULLUP_TO(hlen + sizeof(struct udphdr)); 1799 udp = L3HDR(struct udphdr, ip); 1800 dst_port = udp->uh_dport; 1801 src_port = udp->uh_sport; 1802 } 1803 break; 1804 1805 case IPPROTO_ICMP: 1806 PULLUP_TO(hlen + 4); /* type, code and checksum. */ 1807 args->f_id.flags = L3HDR(struct icmp, ip)->icmp_type; 1808 break; 1809 1810 default: 1811 break; 1812 } 1813 } 1814 1815 #undef PULLUP_TO 1816 1817 args->f_id.src_ip = ntohl(src_ip.s_addr); 1818 args->f_id.dst_ip = ntohl(dst_ip.s_addr); 1819 args->f_id.src_port = src_port = ntohs(src_port); 1820 args->f_id.dst_port = dst_port = ntohs(dst_port); 1821 1822 after_ip_checks: 1823 if (args->rule) { 1824 /* 1825 * Packet has already been tagged. Look for the next rule 1826 * to restart processing. 1827 * 1828 * If fw_one_pass != 0 then just accept it. 1829 * XXX should not happen here, but optimized out in 1830 * the caller. 1831 */ 1832 if (fw_one_pass) 1833 return IP_FW_PASS; 1834 1835 /* This rule is being/has been flushed */ 1836 if (ipfw_flushing) 1837 return IP_FW_DENY; 1838 1839 KASSERT(args->rule->cpuid == mycpuid, 1840 ("rule used on cpu%d", mycpuid)); 1841 1842 /* This rule was deleted */ 1843 if (args->rule->rule_flags & IPFW_RULE_F_INVALID) 1844 return IP_FW_DENY; 1845 1846 f = args->rule->next_rule; 1847 if (f == NULL) 1848 f = lookup_next_rule(args->rule); 1849 } else { 1850 /* 1851 * Find the starting rule. It can be either the first 1852 * one, or the one after divert_rule if asked so. 1853 */ 1854 int skipto; 1855 1856 mtag = m_tag_find(m, PACKET_TAG_IPFW_DIVERT, NULL); 1857 if (mtag != NULL) { 1858 divinfo = m_tag_data(mtag); 1859 skipto = divinfo->skipto; 1860 } else { 1861 skipto = 0; 1862 } 1863 1864 f = ctx->ipfw_layer3_chain; 1865 if (args->eh == NULL && skipto != 0) { 1866 /* No skipto during rule flushing */ 1867 if (ipfw_flushing) 1868 return IP_FW_DENY; 1869 1870 if (skipto >= IPFW_DEFAULT_RULE) 1871 return IP_FW_DENY; /* invalid */ 1872 1873 while (f && f->rulenum <= skipto) 1874 f = f->next; 1875 if (f == NULL) /* drop packet */ 1876 return IP_FW_DENY; 1877 } else if (ipfw_flushing) { 1878 /* Rules are being flushed; skip to default rule */ 1879 f = ctx->ipfw_default_rule; 1880 } 1881 } 1882 if ((mtag = m_tag_find(m, PACKET_TAG_IPFW_DIVERT, NULL)) != NULL) 1883 m_tag_delete(m, mtag); 1884 1885 /* 1886 * Now scan the rules, and parse microinstructions for each rule. 1887 */ 1888 for (; f; f = f->next) { 1889 int l, cmdlen; 1890 ipfw_insn *cmd; 1891 int skip_or; /* skip rest of OR block */ 1892 1893 again: 1894 if (ctx->ipfw_set_disable & (1 << f->set)) 1895 continue; 1896 1897 skip_or = 0; 1898 for (l = f->cmd_len, cmd = f->cmd; l > 0; 1899 l -= cmdlen, cmd += cmdlen) { 1900 int match, deny; 1901 1902 /* 1903 * check_body is a jump target used when we find a 1904 * CHECK_STATE, and need to jump to the body of 1905 * the target rule. 1906 */ 1907 1908 check_body: 1909 cmdlen = F_LEN(cmd); 1910 /* 1911 * An OR block (insn_1 || .. || insn_n) has the 1912 * F_OR bit set in all but the last instruction. 1913 * The first match will set "skip_or", and cause 1914 * the following instructions to be skipped until 1915 * past the one with the F_OR bit clear. 1916 */ 1917 if (skip_or) { /* skip this instruction */ 1918 if ((cmd->len & F_OR) == 0) 1919 skip_or = 0; /* next one is good */ 1920 continue; 1921 } 1922 match = 0; /* set to 1 if we succeed */ 1923 1924 switch (cmd->opcode) { 1925 /* 1926 * The first set of opcodes compares the packet's 1927 * fields with some pattern, setting 'match' if a 1928 * match is found. At the end of the loop there is 1929 * logic to deal with F_NOT and F_OR flags associated 1930 * with the opcode. 1931 */ 1932 case O_NOP: 1933 match = 1; 1934 break; 1935 1936 case O_FORWARD_MAC: 1937 kprintf("ipfw: opcode %d unimplemented\n", 1938 cmd->opcode); 1939 break; 1940 1941 case O_GID: 1942 case O_UID: 1943 /* 1944 * We only check offset == 0 && proto != 0, 1945 * as this ensures that we have an IPv4 1946 * packet with the ports info. 1947 */ 1948 if (offset!=0) 1949 break; 1950 1951 match = ipfw_match_uid(&args->f_id, oif, 1952 cmd->opcode, 1953 (uid_t)((ipfw_insn_u32 *)cmd)->d[0], 1954 &deny); 1955 if (deny) 1956 return IP_FW_DENY; 1957 break; 1958 1959 case O_RECV: 1960 match = iface_match(m->m_pkthdr.rcvif, 1961 (ipfw_insn_if *)cmd); 1962 break; 1963 1964 case O_XMIT: 1965 match = iface_match(oif, (ipfw_insn_if *)cmd); 1966 break; 1967 1968 case O_VIA: 1969 match = iface_match(oif ? oif : 1970 m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd); 1971 break; 1972 1973 case O_MACADDR2: 1974 if (args->eh != NULL) { /* have MAC header */ 1975 uint32_t *want = (uint32_t *) 1976 ((ipfw_insn_mac *)cmd)->addr; 1977 uint32_t *mask = (uint32_t *) 1978 ((ipfw_insn_mac *)cmd)->mask; 1979 uint32_t *hdr = (uint32_t *)args->eh; 1980 1981 match = 1982 (want[0] == (hdr[0] & mask[0]) && 1983 want[1] == (hdr[1] & mask[1]) && 1984 want[2] == (hdr[2] & mask[2])); 1985 } 1986 break; 1987 1988 case O_MAC_TYPE: 1989 if (args->eh != NULL) { 1990 uint16_t t = 1991 ntohs(args->eh->ether_type); 1992 uint16_t *p = 1993 ((ipfw_insn_u16 *)cmd)->ports; 1994 int i; 1995 1996 /* Special vlan handling */ 1997 if (m->m_flags & M_VLANTAG) 1998 t = ETHERTYPE_VLAN; 1999 2000 for (i = cmdlen - 1; !match && i > 0; 2001 i--, p += 2) { 2002 match = 2003 (t >= p[0] && t <= p[1]); 2004 } 2005 } 2006 break; 2007 2008 case O_FRAG: 2009 match = (hlen > 0 && offset != 0); 2010 break; 2011 2012 case O_IN: /* "out" is "not in" */ 2013 match = (oif == NULL); 2014 break; 2015 2016 case O_LAYER2: 2017 match = (args->eh != NULL); 2018 break; 2019 2020 case O_PROTO: 2021 /* 2022 * We do not allow an arg of 0 so the 2023 * check of "proto" only suffices. 2024 */ 2025 match = (proto == cmd->arg1); 2026 break; 2027 2028 case O_IP_SRC: 2029 match = (hlen > 0 && 2030 ((ipfw_insn_ip *)cmd)->addr.s_addr == 2031 src_ip.s_addr); 2032 break; 2033 2034 case O_IP_SRC_MASK: 2035 match = (hlen > 0 && 2036 ((ipfw_insn_ip *)cmd)->addr.s_addr == 2037 (src_ip.s_addr & 2038 ((ipfw_insn_ip *)cmd)->mask.s_addr)); 2039 break; 2040 2041 case O_IP_SRC_ME: 2042 if (hlen > 0) { 2043 struct ifnet *tif; 2044 2045 tif = INADDR_TO_IFP(&src_ip); 2046 match = (tif != NULL); 2047 } 2048 break; 2049 2050 case O_IP_DST_SET: 2051 case O_IP_SRC_SET: 2052 if (hlen > 0) { 2053 uint32_t *d = (uint32_t *)(cmd + 1); 2054 uint32_t addr = 2055 cmd->opcode == O_IP_DST_SET ? 2056 args->f_id.dst_ip : 2057 args->f_id.src_ip; 2058 2059 if (addr < d[0]) 2060 break; 2061 addr -= d[0]; /* subtract base */ 2062 match = 2063 (addr < cmd->arg1) && 2064 (d[1 + (addr >> 5)] & 2065 (1 << (addr & 0x1f))); 2066 } 2067 break; 2068 2069 case O_IP_DST: 2070 match = (hlen > 0 && 2071 ((ipfw_insn_ip *)cmd)->addr.s_addr == 2072 dst_ip.s_addr); 2073 break; 2074 2075 case O_IP_DST_MASK: 2076 match = (hlen > 0) && 2077 (((ipfw_insn_ip *)cmd)->addr.s_addr == 2078 (dst_ip.s_addr & 2079 ((ipfw_insn_ip *)cmd)->mask.s_addr)); 2080 break; 2081 2082 case O_IP_DST_ME: 2083 if (hlen > 0) { 2084 struct ifnet *tif; 2085 2086 tif = INADDR_TO_IFP(&dst_ip); 2087 match = (tif != NULL); 2088 } 2089 break; 2090 2091 case O_IP_SRCPORT: 2092 case O_IP_DSTPORT: 2093 /* 2094 * offset == 0 && proto != 0 is enough 2095 * to guarantee that we have an IPv4 2096 * packet with port info. 2097 */ 2098 if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP) 2099 && offset == 0) { 2100 uint16_t x = 2101 (cmd->opcode == O_IP_SRCPORT) ? 2102 src_port : dst_port ; 2103 uint16_t *p = 2104 ((ipfw_insn_u16 *)cmd)->ports; 2105 int i; 2106 2107 for (i = cmdlen - 1; !match && i > 0; 2108 i--, p += 2) { 2109 match = 2110 (x >= p[0] && x <= p[1]); 2111 } 2112 } 2113 break; 2114 2115 case O_ICMPTYPE: 2116 match = (offset == 0 && proto==IPPROTO_ICMP && 2117 icmptype_match(ip, (ipfw_insn_u32 *)cmd)); 2118 break; 2119 2120 case O_IPOPT: 2121 match = (hlen > 0 && ipopts_match(ip, cmd)); 2122 break; 2123 2124 case O_IPVER: 2125 match = (hlen > 0 && cmd->arg1 == ip->ip_v); 2126 break; 2127 2128 case O_IPTTL: 2129 match = (hlen > 0 && cmd->arg1 == ip->ip_ttl); 2130 break; 2131 2132 case O_IPID: 2133 match = (hlen > 0 && 2134 cmd->arg1 == ntohs(ip->ip_id)); 2135 break; 2136 2137 case O_IPLEN: 2138 match = (hlen > 0 && cmd->arg1 == ip_len); 2139 break; 2140 2141 case O_IPPRECEDENCE: 2142 match = (hlen > 0 && 2143 (cmd->arg1 == (ip->ip_tos & 0xe0))); 2144 break; 2145 2146 case O_IPTOS: 2147 match = (hlen > 0 && 2148 flags_match(cmd, ip->ip_tos)); 2149 break; 2150 2151 case O_TCPFLAGS: 2152 match = (proto == IPPROTO_TCP && offset == 0 && 2153 flags_match(cmd, 2154 L3HDR(struct tcphdr,ip)->th_flags)); 2155 break; 2156 2157 case O_TCPOPTS: 2158 match = (proto == IPPROTO_TCP && offset == 0 && 2159 tcpopts_match(ip, cmd)); 2160 break; 2161 2162 case O_TCPSEQ: 2163 match = (proto == IPPROTO_TCP && offset == 0 && 2164 ((ipfw_insn_u32 *)cmd)->d[0] == 2165 L3HDR(struct tcphdr,ip)->th_seq); 2166 break; 2167 2168 case O_TCPACK: 2169 match = (proto == IPPROTO_TCP && offset == 0 && 2170 ((ipfw_insn_u32 *)cmd)->d[0] == 2171 L3HDR(struct tcphdr,ip)->th_ack); 2172 break; 2173 2174 case O_TCPWIN: 2175 match = (proto == IPPROTO_TCP && offset == 0 && 2176 cmd->arg1 == 2177 L3HDR(struct tcphdr,ip)->th_win); 2178 break; 2179 2180 case O_ESTAB: 2181 /* reject packets which have SYN only */ 2182 /* XXX should i also check for TH_ACK ? */ 2183 match = (proto == IPPROTO_TCP && offset == 0 && 2184 (L3HDR(struct tcphdr,ip)->th_flags & 2185 (TH_RST | TH_ACK | TH_SYN)) != TH_SYN); 2186 break; 2187 2188 case O_LOG: 2189 if (fw_verbose) 2190 ipfw_log(f, hlen, args->eh, m, oif); 2191 match = 1; 2192 break; 2193 2194 case O_PROB: 2195 match = (krandom() < 2196 ((ipfw_insn_u32 *)cmd)->d[0]); 2197 break; 2198 2199 /* 2200 * The second set of opcodes represents 'actions', 2201 * i.e. the terminal part of a rule once the packet 2202 * matches all previous patterns. 2203 * Typically there is only one action for each rule, 2204 * and the opcode is stored at the end of the rule 2205 * (but there are exceptions -- see below). 2206 * 2207 * In general, here we set retval and terminate the 2208 * outer loop (would be a 'break 3' in some language, 2209 * but we need to do a 'goto done'). 2210 * 2211 * Exceptions: 2212 * O_COUNT and O_SKIPTO actions: 2213 * instead of terminating, we jump to the next rule 2214 * ('goto next_rule', equivalent to a 'break 2'), 2215 * or to the SKIPTO target ('goto again' after 2216 * having set f, cmd and l), respectively. 2217 * 2218 * O_LIMIT and O_KEEP_STATE: these opcodes are 2219 * not real 'actions', and are stored right 2220 * before the 'action' part of the rule. 2221 * These opcodes try to install an entry in the 2222 * state tables; if successful, we continue with 2223 * the next opcode (match=1; break;), otherwise 2224 * the packet must be dropped ('goto done' after 2225 * setting retval). If static rules are changed 2226 * during the state installation, the packet will 2227 * be dropped and rule's stats will not beupdated 2228 * ('return IP_FW_DENY'). 2229 * 2230 * O_PROBE_STATE and O_CHECK_STATE: these opcodes 2231 * cause a lookup of the state table, and a jump 2232 * to the 'action' part of the parent rule 2233 * ('goto check_body') if an entry is found, or 2234 * (CHECK_STATE only) a jump to the next rule if 2235 * the entry is not found ('goto next_rule'). 2236 * The result of the lookup is cached to make 2237 * further instances of these opcodes are 2238 * effectively NOPs. If static rules are changed 2239 * during the state looking up, the packet will 2240 * be dropped and rule's stats will not be updated 2241 * ('return IP_FW_DENY'). 2242 */ 2243 case O_LIMIT: 2244 case O_KEEP_STATE: 2245 if (!(f->rule_flags & IPFW_RULE_F_STATE)) { 2246 kprintf("%s rule (%d) is not ready " 2247 "on cpu%d\n", 2248 cmd->opcode == O_LIMIT ? 2249 "limit" : "keep state", 2250 f->rulenum, f->cpuid); 2251 goto next_rule; 2252 } 2253 if (install_state(f, 2254 (ipfw_insn_limit *)cmd, args, &deny)) { 2255 if (deny) 2256 return IP_FW_DENY; 2257 2258 retval = IP_FW_DENY; 2259 goto done; /* error/limit violation */ 2260 } 2261 if (deny) 2262 return IP_FW_DENY; 2263 match = 1; 2264 break; 2265 2266 case O_PROBE_STATE: 2267 case O_CHECK_STATE: 2268 /* 2269 * dynamic rules are checked at the first 2270 * keep-state or check-state occurrence, 2271 * with the result being stored in dyn_dir. 2272 * The compiler introduces a PROBE_STATE 2273 * instruction for us when we have a 2274 * KEEP_STATE (because PROBE_STATE needs 2275 * to be run first). 2276 */ 2277 if (dyn_dir == MATCH_UNKNOWN) { 2278 dyn_f = lookup_rule(&args->f_id, 2279 &dyn_dir, 2280 proto == IPPROTO_TCP ? 2281 L3HDR(struct tcphdr, ip) : NULL, 2282 ip_len, &deny); 2283 if (deny) 2284 return IP_FW_DENY; 2285 if (dyn_f != NULL) { 2286 /* 2287 * Found a rule from a dynamic 2288 * entry; jump to the 'action' 2289 * part of the rule. 2290 */ 2291 f = dyn_f; 2292 cmd = ACTION_PTR(f); 2293 l = f->cmd_len - f->act_ofs; 2294 goto check_body; 2295 } 2296 } 2297 /* 2298 * Dynamic entry not found. If CHECK_STATE, 2299 * skip to next rule, if PROBE_STATE just 2300 * ignore and continue with next opcode. 2301 */ 2302 if (cmd->opcode == O_CHECK_STATE) 2303 goto next_rule; 2304 else if (!(f->rule_flags & IPFW_RULE_F_STATE)) 2305 goto next_rule; /* not ready yet */ 2306 match = 1; 2307 break; 2308 2309 case O_ACCEPT: 2310 retval = IP_FW_PASS; /* accept */ 2311 goto done; 2312 2313 case O_PIPE: 2314 case O_QUEUE: 2315 args->rule = f; /* report matching rule */ 2316 args->cookie = cmd->arg1; 2317 retval = IP_FW_DUMMYNET; 2318 goto done; 2319 2320 case O_DIVERT: 2321 case O_TEE: 2322 if (args->eh) /* not on layer 2 */ 2323 break; 2324 2325 mtag = m_tag_get(PACKET_TAG_IPFW_DIVERT, 2326 sizeof(*divinfo), MB_DONTWAIT); 2327 if (mtag == NULL) { 2328 retval = IP_FW_DENY; 2329 goto done; 2330 } 2331 divinfo = m_tag_data(mtag); 2332 2333 divinfo->skipto = f->rulenum; 2334 divinfo->port = cmd->arg1; 2335 divinfo->tee = (cmd->opcode == O_TEE); 2336 m_tag_prepend(m, mtag); 2337 2338 args->cookie = cmd->arg1; 2339 retval = (cmd->opcode == O_DIVERT) ? 2340 IP_FW_DIVERT : IP_FW_TEE; 2341 goto done; 2342 2343 case O_COUNT: 2344 case O_SKIPTO: 2345 f->pcnt++; /* update stats */ 2346 f->bcnt += ip_len; 2347 f->timestamp = time_second; 2348 if (cmd->opcode == O_COUNT) 2349 goto next_rule; 2350 /* handle skipto */ 2351 if (f->next_rule == NULL) 2352 lookup_next_rule(f); 2353 f = f->next_rule; 2354 goto again; 2355 2356 case O_REJECT: 2357 /* 2358 * Drop the packet and send a reject notice 2359 * if the packet is not ICMP (or is an ICMP 2360 * query), and it is not multicast/broadcast. 2361 */ 2362 if (hlen > 0 && 2363 (proto != IPPROTO_ICMP || 2364 is_icmp_query(ip)) && 2365 !(m->m_flags & (M_BCAST|M_MCAST)) && 2366 !IN_MULTICAST(ntohl(dst_ip.s_addr))) { 2367 /* 2368 * Update statistics before the possible 2369 * blocking 'send_reject' 2370 */ 2371 f->pcnt++; 2372 f->bcnt += ip_len; 2373 f->timestamp = time_second; 2374 2375 send_reject(args, cmd->arg1, 2376 offset,ip_len); 2377 m = args->m; 2378 2379 /* 2380 * Return directly here, rule stats 2381 * have been updated above. 2382 */ 2383 return IP_FW_DENY; 2384 } 2385 /* FALLTHROUGH */ 2386 case O_DENY: 2387 retval = IP_FW_DENY; 2388 goto done; 2389 2390 case O_FORWARD_IP: 2391 if (args->eh) /* not valid on layer2 pkts */ 2392 break; 2393 if (!dyn_f || dyn_dir == MATCH_FORWARD) { 2394 struct sockaddr_in *sin; 2395 2396 mtag = m_tag_get(PACKET_TAG_IPFORWARD, 2397 sizeof(*sin), MB_DONTWAIT); 2398 if (mtag == NULL) { 2399 retval = IP_FW_DENY; 2400 goto done; 2401 } 2402 sin = m_tag_data(mtag); 2403 2404 /* Structure copy */ 2405 *sin = ((ipfw_insn_sa *)cmd)->sa; 2406 2407 m_tag_prepend(m, mtag); 2408 m->m_pkthdr.fw_flags |= 2409 IPFORWARD_MBUF_TAGGED; 2410 m->m_pkthdr.fw_flags &= 2411 ~BRIDGE_MBUF_TAGGED; 2412 } 2413 retval = IP_FW_PASS; 2414 goto done; 2415 2416 default: 2417 panic("-- unknown opcode %d", cmd->opcode); 2418 } /* end of switch() on opcodes */ 2419 2420 if (cmd->len & F_NOT) 2421 match = !match; 2422 2423 if (match) { 2424 if (cmd->len & F_OR) 2425 skip_or = 1; 2426 } else { 2427 if (!(cmd->len & F_OR)) /* not an OR block, */ 2428 break; /* try next rule */ 2429 } 2430 2431 } /* end of inner for, scan opcodes */ 2432 2433 next_rule:; /* try next rule */ 2434 2435 } /* end of outer for, scan rules */ 2436 kprintf("+++ ipfw: ouch!, skip past end of rules, denying packet\n"); 2437 return IP_FW_DENY; 2438 2439 done: 2440 /* Update statistics */ 2441 f->pcnt++; 2442 f->bcnt += ip_len; 2443 f->timestamp = time_second; 2444 return retval; 2445 2446 pullup_failed: 2447 if (fw_verbose) 2448 kprintf("pullup failed\n"); 2449 return IP_FW_DENY; 2450 } 2451 2452 static void 2453 ipfw_dummynet_io(struct mbuf *m, int pipe_nr, int dir, struct ip_fw_args *fwa) 2454 { 2455 struct m_tag *mtag; 2456 struct dn_pkt *pkt; 2457 ipfw_insn *cmd; 2458 const struct ipfw_flow_id *id; 2459 struct dn_flow_id *fid; 2460 2461 M_ASSERTPKTHDR(m); 2462 2463 mtag = m_tag_get(PACKET_TAG_DUMMYNET, sizeof(*pkt), MB_DONTWAIT); 2464 if (mtag == NULL) { 2465 m_freem(m); 2466 return; 2467 } 2468 m_tag_prepend(m, mtag); 2469 2470 pkt = m_tag_data(mtag); 2471 bzero(pkt, sizeof(*pkt)); 2472 2473 cmd = fwa->rule->cmd + fwa->rule->act_ofs; 2474 if (cmd->opcode == O_LOG) 2475 cmd += F_LEN(cmd); 2476 KASSERT(cmd->opcode == O_PIPE || cmd->opcode == O_QUEUE, 2477 ("Rule is not PIPE or QUEUE, opcode %d", cmd->opcode)); 2478 2479 pkt->dn_m = m; 2480 pkt->dn_flags = (dir & DN_FLAGS_DIR_MASK); 2481 pkt->ifp = fwa->oif; 2482 pkt->pipe_nr = pipe_nr; 2483 2484 pkt->cpuid = mycpuid; 2485 pkt->msgport = cur_netport(); 2486 2487 id = &fwa->f_id; 2488 fid = &pkt->id; 2489 fid->fid_dst_ip = id->dst_ip; 2490 fid->fid_src_ip = id->src_ip; 2491 fid->fid_dst_port = id->dst_port; 2492 fid->fid_src_port = id->src_port; 2493 fid->fid_proto = id->proto; 2494 fid->fid_flags = id->flags; 2495 2496 ipfw_ref_rule(fwa->rule); 2497 pkt->dn_priv = fwa->rule; 2498 pkt->dn_unref_priv = ipfw_unref_rule; 2499 2500 if (cmd->opcode == O_PIPE) 2501 pkt->dn_flags |= DN_FLAGS_IS_PIPE; 2502 2503 m->m_pkthdr.fw_flags |= DUMMYNET_MBUF_TAGGED; 2504 } 2505 2506 /* 2507 * When a rule is added/deleted, clear the next_rule pointers in all rules. 2508 * These will be reconstructed on the fly as packets are matched. 2509 * Must be called at splimp(). 2510 */ 2511 static void 2512 ipfw_flush_rule_ptrs(struct ipfw_context *ctx) 2513 { 2514 struct ip_fw *rule; 2515 2516 for (rule = ctx->ipfw_layer3_chain; rule; rule = rule->next) 2517 rule->next_rule = NULL; 2518 } 2519 2520 static __inline void 2521 ipfw_inc_static_count(struct ip_fw *rule) 2522 { 2523 /* Static rule's counts are updated only on CPU0 */ 2524 KKASSERT(mycpuid == 0); 2525 2526 static_count++; 2527 static_ioc_len += IOC_RULESIZE(rule); 2528 } 2529 2530 static __inline void 2531 ipfw_dec_static_count(struct ip_fw *rule) 2532 { 2533 int l = IOC_RULESIZE(rule); 2534 2535 /* Static rule's counts are updated only on CPU0 */ 2536 KKASSERT(mycpuid == 0); 2537 2538 KASSERT(static_count > 0, ("invalid static count %u", static_count)); 2539 static_count--; 2540 2541 KASSERT(static_ioc_len >= l, 2542 ("invalid static len %u", static_ioc_len)); 2543 static_ioc_len -= l; 2544 } 2545 2546 static void 2547 ipfw_link_sibling(struct netmsg_ipfw *fwmsg, struct ip_fw *rule) 2548 { 2549 if (fwmsg->sibling != NULL) { 2550 KKASSERT(mycpuid > 0 && fwmsg->sibling->cpuid == mycpuid - 1); 2551 fwmsg->sibling->sibling = rule; 2552 } 2553 fwmsg->sibling = rule; 2554 } 2555 2556 static struct ip_fw * 2557 ipfw_create_rule(const struct ipfw_ioc_rule *ioc_rule, struct ip_fw_stub *stub) 2558 { 2559 struct ip_fw *rule; 2560 2561 rule = kmalloc(RULESIZE(ioc_rule), M_IPFW, M_WAITOK | M_ZERO); 2562 2563 rule->act_ofs = ioc_rule->act_ofs; 2564 rule->cmd_len = ioc_rule->cmd_len; 2565 rule->rulenum = ioc_rule->rulenum; 2566 rule->set = ioc_rule->set; 2567 rule->usr_flags = ioc_rule->usr_flags; 2568 2569 bcopy(ioc_rule->cmd, rule->cmd, rule->cmd_len * 4 /* XXX */); 2570 2571 rule->refcnt = 1; 2572 rule->cpuid = mycpuid; 2573 2574 rule->stub = stub; 2575 if (stub != NULL) 2576 stub->rule[mycpuid] = rule; 2577 2578 return rule; 2579 } 2580 2581 static void 2582 ipfw_add_rule_dispatch(netmsg_t nmsg) 2583 { 2584 struct netmsg_ipfw *fwmsg = (struct netmsg_ipfw *)nmsg; 2585 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 2586 struct ip_fw *rule; 2587 2588 rule = ipfw_create_rule(fwmsg->ioc_rule, fwmsg->stub); 2589 2590 /* 2591 * Bump generation after ipfw_create_rule(), 2592 * since this function is blocking 2593 */ 2594 ctx->ipfw_gen++; 2595 2596 /* 2597 * Insert rule into the pre-determined position 2598 */ 2599 if (fwmsg->prev_rule != NULL) { 2600 struct ip_fw *prev, *next; 2601 2602 prev = fwmsg->prev_rule; 2603 KKASSERT(prev->cpuid == mycpuid); 2604 2605 next = fwmsg->next_rule; 2606 KKASSERT(next->cpuid == mycpuid); 2607 2608 rule->next = next; 2609 prev->next = rule; 2610 2611 /* 2612 * Move to the position on the next CPU 2613 * before the msg is forwarded. 2614 */ 2615 fwmsg->prev_rule = prev->sibling; 2616 fwmsg->next_rule = next->sibling; 2617 } else { 2618 KKASSERT(fwmsg->next_rule == NULL); 2619 rule->next = ctx->ipfw_layer3_chain; 2620 ctx->ipfw_layer3_chain = rule; 2621 } 2622 2623 /* Link rule CPU sibling */ 2624 ipfw_link_sibling(fwmsg, rule); 2625 2626 ipfw_flush_rule_ptrs(ctx); 2627 2628 if (mycpuid == 0) { 2629 /* Statistics only need to be updated once */ 2630 ipfw_inc_static_count(rule); 2631 2632 /* Return the rule on CPU0 */ 2633 nmsg->lmsg.u.ms_resultp = rule; 2634 } 2635 2636 ifnet_forwardmsg(&nmsg->lmsg, mycpuid + 1); 2637 } 2638 2639 static void 2640 ipfw_enable_state_dispatch(netmsg_t nmsg) 2641 { 2642 struct lwkt_msg *lmsg = &nmsg->lmsg; 2643 struct ip_fw *rule = lmsg->u.ms_resultp; 2644 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 2645 2646 ctx->ipfw_gen++; 2647 2648 KKASSERT(rule->cpuid == mycpuid); 2649 KKASSERT(rule->stub != NULL && rule->stub->rule[mycpuid] == rule); 2650 KKASSERT(!(rule->rule_flags & IPFW_RULE_F_STATE)); 2651 rule->rule_flags |= IPFW_RULE_F_STATE; 2652 lmsg->u.ms_resultp = rule->sibling; 2653 2654 ifnet_forwardmsg(lmsg, mycpuid + 1); 2655 } 2656 2657 /* 2658 * Add a new rule to the list. Copy the rule into a malloc'ed area, 2659 * then possibly create a rule number and add the rule to the list. 2660 * Update the rule_number in the input struct so the caller knows 2661 * it as well. 2662 */ 2663 static void 2664 ipfw_add_rule(struct ipfw_ioc_rule *ioc_rule, uint32_t rule_flags) 2665 { 2666 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 2667 struct netmsg_ipfw fwmsg; 2668 struct netmsg_base *nmsg; 2669 struct ip_fw *f, *prev, *rule; 2670 struct ip_fw_stub *stub; 2671 2672 IPFW_ASSERT_CFGPORT(&curthread->td_msgport); 2673 2674 /* 2675 * If rulenum is 0, find highest numbered rule before the 2676 * default rule, and add rule number incremental step. 2677 */ 2678 if (ioc_rule->rulenum == 0) { 2679 int step = autoinc_step; 2680 2681 KKASSERT(step >= IPFW_AUTOINC_STEP_MIN && 2682 step <= IPFW_AUTOINC_STEP_MAX); 2683 2684 /* 2685 * Locate the highest numbered rule before default 2686 */ 2687 for (f = ctx->ipfw_layer3_chain; f; f = f->next) { 2688 if (f->rulenum == IPFW_DEFAULT_RULE) 2689 break; 2690 ioc_rule->rulenum = f->rulenum; 2691 } 2692 if (ioc_rule->rulenum < IPFW_DEFAULT_RULE - step) 2693 ioc_rule->rulenum += step; 2694 } 2695 KASSERT(ioc_rule->rulenum != IPFW_DEFAULT_RULE && 2696 ioc_rule->rulenum != 0, 2697 ("invalid rule num %d", ioc_rule->rulenum)); 2698 2699 /* 2700 * Now find the right place for the new rule in the sorted list. 2701 */ 2702 for (prev = NULL, f = ctx->ipfw_layer3_chain; f; 2703 prev = f, f = f->next) { 2704 if (f->rulenum > ioc_rule->rulenum) { 2705 /* Found the location */ 2706 break; 2707 } 2708 } 2709 KASSERT(f != NULL, ("no default rule?!")); 2710 2711 if (rule_flags & IPFW_RULE_F_STATE) { 2712 int size; 2713 2714 /* 2715 * If the new rule will create states, then allocate 2716 * a rule stub, which will be referenced by states 2717 * (dyn rules) 2718 */ 2719 size = sizeof(*stub) + ((ncpus - 1) * sizeof(struct ip_fw *)); 2720 stub = kmalloc(size, M_IPFW, M_WAITOK | M_ZERO); 2721 } else { 2722 stub = NULL; 2723 } 2724 2725 /* 2726 * Duplicate the rule onto each CPU. 2727 * The rule duplicated on CPU0 will be returned. 2728 */ 2729 bzero(&fwmsg, sizeof(fwmsg)); 2730 nmsg = &fwmsg.base; 2731 netmsg_init(nmsg, NULL, &curthread->td_msgport, 2732 0, ipfw_add_rule_dispatch); 2733 fwmsg.ioc_rule = ioc_rule; 2734 fwmsg.prev_rule = prev; 2735 fwmsg.next_rule = prev == NULL ? NULL : f; 2736 fwmsg.stub = stub; 2737 2738 ifnet_domsg(&nmsg->lmsg, 0); 2739 KKASSERT(fwmsg.prev_rule == NULL && fwmsg.next_rule == NULL); 2740 2741 rule = nmsg->lmsg.u.ms_resultp; 2742 KKASSERT(rule != NULL && rule->cpuid == mycpuid); 2743 2744 if (rule_flags & IPFW_RULE_F_STATE) { 2745 /* 2746 * Turn on state flag, _after_ everything on all 2747 * CPUs have been setup. 2748 */ 2749 bzero(nmsg, sizeof(*nmsg)); 2750 netmsg_init(nmsg, NULL, &curthread->td_msgport, 2751 0, ipfw_enable_state_dispatch); 2752 nmsg->lmsg.u.ms_resultp = rule; 2753 2754 ifnet_domsg(&nmsg->lmsg, 0); 2755 KKASSERT(nmsg->lmsg.u.ms_resultp == NULL); 2756 } 2757 2758 DPRINTF("++ installed rule %d, static count now %d\n", 2759 rule->rulenum, static_count); 2760 } 2761 2762 /** 2763 * Free storage associated with a static rule (including derived 2764 * dynamic rules). 2765 * The caller is in charge of clearing rule pointers to avoid 2766 * dangling pointers. 2767 * @return a pointer to the next entry. 2768 * Arguments are not checked, so they better be correct. 2769 * Must be called at splimp(). 2770 */ 2771 static struct ip_fw * 2772 ipfw_delete_rule(struct ipfw_context *ctx, 2773 struct ip_fw *prev, struct ip_fw *rule) 2774 { 2775 struct ip_fw *n; 2776 struct ip_fw_stub *stub; 2777 2778 ctx->ipfw_gen++; 2779 2780 /* STATE flag should have been cleared before we reach here */ 2781 KKASSERT((rule->rule_flags & IPFW_RULE_F_STATE) == 0); 2782 2783 stub = rule->stub; 2784 n = rule->next; 2785 if (prev == NULL) 2786 ctx->ipfw_layer3_chain = n; 2787 else 2788 prev->next = n; 2789 2790 /* Mark the rule as invalid */ 2791 rule->rule_flags |= IPFW_RULE_F_INVALID; 2792 rule->next_rule = NULL; 2793 rule->sibling = NULL; 2794 rule->stub = NULL; 2795 #ifdef foo 2796 /* Don't reset cpuid here; keep various assertion working */ 2797 rule->cpuid = -1; 2798 #endif 2799 2800 /* Statistics only need to be updated once */ 2801 if (mycpuid == 0) 2802 ipfw_dec_static_count(rule); 2803 2804 /* Free 'stub' on the last CPU */ 2805 if (stub != NULL && mycpuid == ncpus - 1) 2806 kfree(stub, M_IPFW); 2807 2808 /* Try to free this rule */ 2809 ipfw_free_rule(rule); 2810 2811 /* Return the next rule */ 2812 return n; 2813 } 2814 2815 static void 2816 ipfw_flush_dispatch(netmsg_t nmsg) 2817 { 2818 struct lwkt_msg *lmsg = &nmsg->lmsg; 2819 int kill_default = lmsg->u.ms_result; 2820 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 2821 struct ip_fw *rule; 2822 2823 ipfw_flush_rule_ptrs(ctx); /* more efficient to do outside the loop */ 2824 2825 while ((rule = ctx->ipfw_layer3_chain) != NULL && 2826 (kill_default || rule->rulenum != IPFW_DEFAULT_RULE)) 2827 ipfw_delete_rule(ctx, NULL, rule); 2828 2829 ifnet_forwardmsg(lmsg, mycpuid + 1); 2830 } 2831 2832 static void 2833 ipfw_disable_rule_state_dispatch(netmsg_t nmsg) 2834 { 2835 struct netmsg_del *dmsg = (struct netmsg_del *)nmsg; 2836 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 2837 struct ip_fw *rule; 2838 2839 ctx->ipfw_gen++; 2840 2841 rule = dmsg->start_rule; 2842 if (rule != NULL) { 2843 KKASSERT(rule->cpuid == mycpuid); 2844 2845 /* 2846 * Move to the position on the next CPU 2847 * before the msg is forwarded. 2848 */ 2849 dmsg->start_rule = rule->sibling; 2850 } else { 2851 KKASSERT(dmsg->rulenum == 0); 2852 rule = ctx->ipfw_layer3_chain; 2853 } 2854 2855 while (rule != NULL) { 2856 if (dmsg->rulenum && rule->rulenum != dmsg->rulenum) 2857 break; 2858 rule->rule_flags &= ~IPFW_RULE_F_STATE; 2859 rule = rule->next; 2860 } 2861 2862 ifnet_forwardmsg(&nmsg->lmsg, mycpuid + 1); 2863 } 2864 2865 /* 2866 * Deletes all rules from a chain (including the default rule 2867 * if the second argument is set). 2868 * Must be called at splimp(). 2869 */ 2870 static void 2871 ipfw_flush(int kill_default) 2872 { 2873 struct netmsg_del dmsg; 2874 struct netmsg_base nmsg; 2875 struct lwkt_msg *lmsg; 2876 struct ip_fw *rule; 2877 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 2878 2879 IPFW_ASSERT_CFGPORT(&curthread->td_msgport); 2880 2881 /* 2882 * If 'kill_default' then caller has done the necessary 2883 * msgport syncing; unnecessary to do it again. 2884 */ 2885 if (!kill_default) { 2886 /* 2887 * Let ipfw_chk() know the rules are going to 2888 * be flushed, so it could jump directly to 2889 * the default rule. 2890 */ 2891 ipfw_flushing = 1; 2892 netmsg_service_sync(); 2893 } 2894 2895 /* 2896 * Clear STATE flag on rules, so no more states (dyn rules) 2897 * will be created. 2898 */ 2899 bzero(&dmsg, sizeof(dmsg)); 2900 netmsg_init(&dmsg.base, NULL, &curthread->td_msgport, 2901 0, ipfw_disable_rule_state_dispatch); 2902 ifnet_domsg(&dmsg.base.lmsg, 0); 2903 2904 /* 2905 * This actually nukes all states (dyn rules) 2906 */ 2907 lockmgr(&dyn_lock, LK_EXCLUSIVE); 2908 for (rule = ctx->ipfw_layer3_chain; rule != NULL; rule = rule->next) { 2909 /* 2910 * Can't check IPFW_RULE_F_STATE here, 2911 * since it has been cleared previously. 2912 * Check 'stub' instead. 2913 */ 2914 if (rule->stub != NULL) { 2915 /* Force removal */ 2916 remove_dyn_rule_locked(rule, NULL); 2917 } 2918 } 2919 lockmgr(&dyn_lock, LK_RELEASE); 2920 2921 /* 2922 * Press the 'flush' button 2923 */ 2924 bzero(&nmsg, sizeof(nmsg)); 2925 netmsg_init(&nmsg, NULL, &curthread->td_msgport, 2926 0, ipfw_flush_dispatch); 2927 lmsg = &nmsg.lmsg; 2928 lmsg->u.ms_result = kill_default; 2929 ifnet_domsg(lmsg, 0); 2930 2931 KASSERT(dyn_count == 0, ("%u dyn rule remains", dyn_count)); 2932 2933 if (kill_default) { 2934 if (ipfw_dyn_v != NULL) { 2935 /* 2936 * Free dynamic rules(state) hash table 2937 */ 2938 kfree(ipfw_dyn_v, M_IPFW); 2939 ipfw_dyn_v = NULL; 2940 } 2941 2942 KASSERT(static_count == 0, 2943 ("%u static rules remain", static_count)); 2944 KASSERT(static_ioc_len == 0, 2945 ("%u bytes of static rules remain", static_ioc_len)); 2946 } else { 2947 KASSERT(static_count == 1, 2948 ("%u static rules remain", static_count)); 2949 KASSERT(static_ioc_len == IOC_RULESIZE(ctx->ipfw_default_rule), 2950 ("%u bytes of static rules remain, should be %lu", 2951 static_ioc_len, 2952 (u_long)IOC_RULESIZE(ctx->ipfw_default_rule))); 2953 } 2954 2955 /* Flush is done */ 2956 ipfw_flushing = 0; 2957 } 2958 2959 static void 2960 ipfw_alt_delete_rule_dispatch(netmsg_t nmsg) 2961 { 2962 struct netmsg_del *dmsg = (struct netmsg_del *)nmsg; 2963 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 2964 struct ip_fw *rule, *prev; 2965 2966 rule = dmsg->start_rule; 2967 KKASSERT(rule->cpuid == mycpuid); 2968 dmsg->start_rule = rule->sibling; 2969 2970 prev = dmsg->prev_rule; 2971 if (prev != NULL) { 2972 KKASSERT(prev->cpuid == mycpuid); 2973 2974 /* 2975 * Move to the position on the next CPU 2976 * before the msg is forwarded. 2977 */ 2978 dmsg->prev_rule = prev->sibling; 2979 } 2980 2981 /* 2982 * flush pointers outside the loop, then delete all matching 2983 * rules. 'prev' remains the same throughout the cycle. 2984 */ 2985 ipfw_flush_rule_ptrs(ctx); 2986 while (rule && rule->rulenum == dmsg->rulenum) 2987 rule = ipfw_delete_rule(ctx, prev, rule); 2988 2989 ifnet_forwardmsg(&nmsg->lmsg, mycpuid + 1); 2990 } 2991 2992 static int 2993 ipfw_alt_delete_rule(uint16_t rulenum) 2994 { 2995 struct ip_fw *prev, *rule, *f; 2996 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 2997 struct netmsg_del dmsg; 2998 struct netmsg_base *nmsg; 2999 int state; 3000 3001 /* 3002 * Locate first rule to delete 3003 */ 3004 for (prev = NULL, rule = ctx->ipfw_layer3_chain; 3005 rule && rule->rulenum < rulenum; 3006 prev = rule, rule = rule->next) 3007 ; /* EMPTY */ 3008 if (rule->rulenum != rulenum) 3009 return EINVAL; 3010 3011 /* 3012 * Check whether any rules with the given number will 3013 * create states. 3014 */ 3015 state = 0; 3016 for (f = rule; f && f->rulenum == rulenum; f = f->next) { 3017 if (f->rule_flags & IPFW_RULE_F_STATE) { 3018 state = 1; 3019 break; 3020 } 3021 } 3022 3023 if (state) { 3024 /* 3025 * Clear the STATE flag, so no more states will be 3026 * created based the rules numbered 'rulenum'. 3027 */ 3028 bzero(&dmsg, sizeof(dmsg)); 3029 nmsg = &dmsg.base; 3030 netmsg_init(nmsg, NULL, &curthread->td_msgport, 3031 0, ipfw_disable_rule_state_dispatch); 3032 dmsg.start_rule = rule; 3033 dmsg.rulenum = rulenum; 3034 3035 ifnet_domsg(&nmsg->lmsg, 0); 3036 KKASSERT(dmsg.start_rule == NULL); 3037 3038 /* 3039 * Nuke all related states 3040 */ 3041 lockmgr(&dyn_lock, LK_EXCLUSIVE); 3042 for (f = rule; f && f->rulenum == rulenum; f = f->next) { 3043 /* 3044 * Can't check IPFW_RULE_F_STATE here, 3045 * since it has been cleared previously. 3046 * Check 'stub' instead. 3047 */ 3048 if (f->stub != NULL) { 3049 /* Force removal */ 3050 remove_dyn_rule_locked(f, NULL); 3051 } 3052 } 3053 lockmgr(&dyn_lock, LK_RELEASE); 3054 } 3055 3056 /* 3057 * Get rid of the rule duplications on all CPUs 3058 */ 3059 bzero(&dmsg, sizeof(dmsg)); 3060 nmsg = &dmsg.base; 3061 netmsg_init(nmsg, NULL, &curthread->td_msgport, 3062 0, ipfw_alt_delete_rule_dispatch); 3063 dmsg.prev_rule = prev; 3064 dmsg.start_rule = rule; 3065 dmsg.rulenum = rulenum; 3066 3067 ifnet_domsg(&nmsg->lmsg, 0); 3068 KKASSERT(dmsg.prev_rule == NULL && dmsg.start_rule == NULL); 3069 return 0; 3070 } 3071 3072 static void 3073 ipfw_alt_delete_ruleset_dispatch(netmsg_t nmsg) 3074 { 3075 struct netmsg_del *dmsg = (struct netmsg_del *)nmsg; 3076 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 3077 struct ip_fw *prev, *rule; 3078 #ifdef INVARIANTS 3079 int del = 0; 3080 #endif 3081 3082 ipfw_flush_rule_ptrs(ctx); 3083 3084 prev = NULL; 3085 rule = ctx->ipfw_layer3_chain; 3086 while (rule != NULL) { 3087 if (rule->set == dmsg->from_set) { 3088 rule = ipfw_delete_rule(ctx, prev, rule); 3089 #ifdef INVARIANTS 3090 del = 1; 3091 #endif 3092 } else { 3093 prev = rule; 3094 rule = rule->next; 3095 } 3096 } 3097 KASSERT(del, ("no match set?!")); 3098 3099 ifnet_forwardmsg(&nmsg->lmsg, mycpuid + 1); 3100 } 3101 3102 static void 3103 ipfw_disable_ruleset_state_dispatch(netmsg_t nmsg) 3104 { 3105 struct netmsg_del *dmsg = (struct netmsg_del *)nmsg; 3106 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 3107 struct ip_fw *rule; 3108 #ifdef INVARIANTS 3109 int cleared = 0; 3110 #endif 3111 3112 ctx->ipfw_gen++; 3113 3114 for (rule = ctx->ipfw_layer3_chain; rule; rule = rule->next) { 3115 if (rule->set == dmsg->from_set) { 3116 #ifdef INVARIANTS 3117 cleared = 1; 3118 #endif 3119 rule->rule_flags &= ~IPFW_RULE_F_STATE; 3120 } 3121 } 3122 KASSERT(cleared, ("no match set?!")); 3123 3124 ifnet_forwardmsg(&nmsg->lmsg, mycpuid + 1); 3125 } 3126 3127 static int 3128 ipfw_alt_delete_ruleset(uint8_t set) 3129 { 3130 struct netmsg_del dmsg; 3131 struct netmsg_base *nmsg; 3132 int state, del; 3133 struct ip_fw *rule; 3134 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 3135 3136 /* 3137 * Check whether the 'set' exists. If it exists, 3138 * then check whether any rules within the set will 3139 * try to create states. 3140 */ 3141 state = 0; 3142 del = 0; 3143 for (rule = ctx->ipfw_layer3_chain; rule; rule = rule->next) { 3144 if (rule->set == set) { 3145 del = 1; 3146 if (rule->rule_flags & IPFW_RULE_F_STATE) { 3147 state = 1; 3148 break; 3149 } 3150 } 3151 } 3152 if (!del) 3153 return 0; /* XXX EINVAL? */ 3154 3155 if (state) { 3156 /* 3157 * Clear the STATE flag, so no more states will be 3158 * created based the rules in this set. 3159 */ 3160 bzero(&dmsg, sizeof(dmsg)); 3161 nmsg = &dmsg.base; 3162 netmsg_init(nmsg, NULL, &curthread->td_msgport, 3163 0, ipfw_disable_ruleset_state_dispatch); 3164 dmsg.from_set = set; 3165 3166 ifnet_domsg(&nmsg->lmsg, 0); 3167 3168 /* 3169 * Nuke all related states 3170 */ 3171 lockmgr(&dyn_lock, LK_EXCLUSIVE); 3172 for (rule = ctx->ipfw_layer3_chain; rule; rule = rule->next) { 3173 if (rule->set != set) 3174 continue; 3175 3176 /* 3177 * Can't check IPFW_RULE_F_STATE here, 3178 * since it has been cleared previously. 3179 * Check 'stub' instead. 3180 */ 3181 if (rule->stub != NULL) { 3182 /* Force removal */ 3183 remove_dyn_rule_locked(rule, NULL); 3184 } 3185 } 3186 lockmgr(&dyn_lock, LK_RELEASE); 3187 } 3188 3189 /* 3190 * Delete this set 3191 */ 3192 bzero(&dmsg, sizeof(dmsg)); 3193 nmsg = &dmsg.base; 3194 netmsg_init(nmsg, NULL, &curthread->td_msgport, 3195 0, ipfw_alt_delete_ruleset_dispatch); 3196 dmsg.from_set = set; 3197 3198 ifnet_domsg(&nmsg->lmsg, 0); 3199 return 0; 3200 } 3201 3202 static void 3203 ipfw_alt_move_rule_dispatch(netmsg_t nmsg) 3204 { 3205 struct netmsg_del *dmsg = (struct netmsg_del *)nmsg; 3206 struct ip_fw *rule; 3207 3208 rule = dmsg->start_rule; 3209 KKASSERT(rule->cpuid == mycpuid); 3210 3211 /* 3212 * Move to the position on the next CPU 3213 * before the msg is forwarded. 3214 */ 3215 dmsg->start_rule = rule->sibling; 3216 3217 while (rule && rule->rulenum <= dmsg->rulenum) { 3218 if (rule->rulenum == dmsg->rulenum) 3219 rule->set = dmsg->to_set; 3220 rule = rule->next; 3221 } 3222 ifnet_forwardmsg(&nmsg->lmsg, mycpuid + 1); 3223 } 3224 3225 static int 3226 ipfw_alt_move_rule(uint16_t rulenum, uint8_t set) 3227 { 3228 struct netmsg_del dmsg; 3229 struct netmsg_base *nmsg; 3230 struct ip_fw *rule; 3231 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 3232 3233 /* 3234 * Locate first rule to move 3235 */ 3236 for (rule = ctx->ipfw_layer3_chain; rule && rule->rulenum <= rulenum; 3237 rule = rule->next) { 3238 if (rule->rulenum == rulenum && rule->set != set) 3239 break; 3240 } 3241 if (rule == NULL || rule->rulenum > rulenum) 3242 return 0; /* XXX error? */ 3243 3244 bzero(&dmsg, sizeof(dmsg)); 3245 nmsg = &dmsg.base; 3246 netmsg_init(nmsg, NULL, &curthread->td_msgport, 3247 0, ipfw_alt_move_rule_dispatch); 3248 dmsg.start_rule = rule; 3249 dmsg.rulenum = rulenum; 3250 dmsg.to_set = set; 3251 3252 ifnet_domsg(&nmsg->lmsg, 0); 3253 KKASSERT(dmsg.start_rule == NULL); 3254 return 0; 3255 } 3256 3257 static void 3258 ipfw_alt_move_ruleset_dispatch(netmsg_t nmsg) 3259 { 3260 struct netmsg_del *dmsg = (struct netmsg_del *)nmsg; 3261 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 3262 struct ip_fw *rule; 3263 3264 for (rule = ctx->ipfw_layer3_chain; rule; rule = rule->next) { 3265 if (rule->set == dmsg->from_set) 3266 rule->set = dmsg->to_set; 3267 } 3268 ifnet_forwardmsg(&nmsg->lmsg, mycpuid + 1); 3269 } 3270 3271 static int 3272 ipfw_alt_move_ruleset(uint8_t from_set, uint8_t to_set) 3273 { 3274 struct netmsg_del dmsg; 3275 struct netmsg_base *nmsg; 3276 3277 bzero(&dmsg, sizeof(dmsg)); 3278 nmsg = &dmsg.base; 3279 netmsg_init(nmsg, NULL, &curthread->td_msgport, 3280 0, ipfw_alt_move_ruleset_dispatch); 3281 dmsg.from_set = from_set; 3282 dmsg.to_set = to_set; 3283 3284 ifnet_domsg(&nmsg->lmsg, 0); 3285 return 0; 3286 } 3287 3288 static void 3289 ipfw_alt_swap_ruleset_dispatch(netmsg_t nmsg) 3290 { 3291 struct netmsg_del *dmsg = (struct netmsg_del *)nmsg; 3292 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 3293 struct ip_fw *rule; 3294 3295 for (rule = ctx->ipfw_layer3_chain; rule; rule = rule->next) { 3296 if (rule->set == dmsg->from_set) 3297 rule->set = dmsg->to_set; 3298 else if (rule->set == dmsg->to_set) 3299 rule->set = dmsg->from_set; 3300 } 3301 ifnet_forwardmsg(&nmsg->lmsg, mycpuid + 1); 3302 } 3303 3304 static int 3305 ipfw_alt_swap_ruleset(uint8_t set1, uint8_t set2) 3306 { 3307 struct netmsg_del dmsg; 3308 struct netmsg_base *nmsg; 3309 3310 bzero(&dmsg, sizeof(dmsg)); 3311 nmsg = &dmsg.base; 3312 netmsg_init(nmsg, NULL, &curthread->td_msgport, 3313 0, ipfw_alt_swap_ruleset_dispatch); 3314 dmsg.from_set = set1; 3315 dmsg.to_set = set2; 3316 3317 ifnet_domsg(&nmsg->lmsg, 0); 3318 return 0; 3319 } 3320 3321 /** 3322 * Remove all rules with given number, and also do set manipulation. 3323 * 3324 * The argument is an uint32_t. The low 16 bit are the rule or set number, 3325 * the next 8 bits are the new set, the top 8 bits are the command: 3326 * 3327 * 0 delete rules with given number 3328 * 1 delete rules with given set number 3329 * 2 move rules with given number to new set 3330 * 3 move rules with given set number to new set 3331 * 4 swap sets with given numbers 3332 */ 3333 static int 3334 ipfw_ctl_alter(uint32_t arg) 3335 { 3336 uint16_t rulenum; 3337 uint8_t cmd, new_set; 3338 int error = 0; 3339 3340 rulenum = arg & 0xffff; 3341 cmd = (arg >> 24) & 0xff; 3342 new_set = (arg >> 16) & 0xff; 3343 3344 if (cmd > 4) 3345 return EINVAL; 3346 if (new_set >= IPFW_DEFAULT_SET) 3347 return EINVAL; 3348 if (cmd == 0 || cmd == 2) { 3349 if (rulenum == IPFW_DEFAULT_RULE) 3350 return EINVAL; 3351 } else { 3352 if (rulenum >= IPFW_DEFAULT_SET) 3353 return EINVAL; 3354 } 3355 3356 switch (cmd) { 3357 case 0: /* delete rules with given number */ 3358 error = ipfw_alt_delete_rule(rulenum); 3359 break; 3360 3361 case 1: /* delete all rules with given set number */ 3362 error = ipfw_alt_delete_ruleset(rulenum); 3363 break; 3364 3365 case 2: /* move rules with given number to new set */ 3366 error = ipfw_alt_move_rule(rulenum, new_set); 3367 break; 3368 3369 case 3: /* move rules with given set number to new set */ 3370 error = ipfw_alt_move_ruleset(rulenum, new_set); 3371 break; 3372 3373 case 4: /* swap two sets */ 3374 error = ipfw_alt_swap_ruleset(rulenum, new_set); 3375 break; 3376 } 3377 return error; 3378 } 3379 3380 /* 3381 * Clear counters for a specific rule. 3382 */ 3383 static void 3384 clear_counters(struct ip_fw *rule, int log_only) 3385 { 3386 ipfw_insn_log *l = (ipfw_insn_log *)ACTION_PTR(rule); 3387 3388 if (log_only == 0) { 3389 rule->bcnt = rule->pcnt = 0; 3390 rule->timestamp = 0; 3391 } 3392 if (l->o.opcode == O_LOG) 3393 l->log_left = l->max_log; 3394 } 3395 3396 static void 3397 ipfw_zero_entry_dispatch(netmsg_t nmsg) 3398 { 3399 struct netmsg_zent *zmsg = (struct netmsg_zent *)nmsg; 3400 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 3401 struct ip_fw *rule; 3402 3403 if (zmsg->rulenum == 0) { 3404 KKASSERT(zmsg->start_rule == NULL); 3405 3406 ctx->ipfw_norule_counter = 0; 3407 for (rule = ctx->ipfw_layer3_chain; rule; rule = rule->next) 3408 clear_counters(rule, zmsg->log_only); 3409 } else { 3410 struct ip_fw *start = zmsg->start_rule; 3411 3412 KKASSERT(start->cpuid == mycpuid); 3413 KKASSERT(start->rulenum == zmsg->rulenum); 3414 3415 /* 3416 * We can have multiple rules with the same number, so we 3417 * need to clear them all. 3418 */ 3419 for (rule = start; rule && rule->rulenum == zmsg->rulenum; 3420 rule = rule->next) 3421 clear_counters(rule, zmsg->log_only); 3422 3423 /* 3424 * Move to the position on the next CPU 3425 * before the msg is forwarded. 3426 */ 3427 zmsg->start_rule = start->sibling; 3428 } 3429 ifnet_forwardmsg(&nmsg->lmsg, mycpuid + 1); 3430 } 3431 3432 /** 3433 * Reset some or all counters on firewall rules. 3434 * @arg frwl is null to clear all entries, or contains a specific 3435 * rule number. 3436 * @arg log_only is 1 if we only want to reset logs, zero otherwise. 3437 */ 3438 static int 3439 ipfw_ctl_zero_entry(int rulenum, int log_only) 3440 { 3441 struct netmsg_zent zmsg; 3442 struct netmsg_base *nmsg; 3443 const char *msg; 3444 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 3445 3446 bzero(&zmsg, sizeof(zmsg)); 3447 nmsg = &zmsg.base; 3448 netmsg_init(nmsg, NULL, &curthread->td_msgport, 3449 0, ipfw_zero_entry_dispatch); 3450 zmsg.log_only = log_only; 3451 3452 if (rulenum == 0) { 3453 msg = log_only ? "ipfw: All logging counts reset.\n" 3454 : "ipfw: Accounting cleared.\n"; 3455 } else { 3456 struct ip_fw *rule; 3457 3458 /* 3459 * Locate the first rule with 'rulenum' 3460 */ 3461 for (rule = ctx->ipfw_layer3_chain; rule; rule = rule->next) { 3462 if (rule->rulenum == rulenum) 3463 break; 3464 } 3465 if (rule == NULL) /* we did not find any matching rules */ 3466 return (EINVAL); 3467 zmsg.start_rule = rule; 3468 zmsg.rulenum = rulenum; 3469 3470 msg = log_only ? "ipfw: Entry %d logging count reset.\n" 3471 : "ipfw: Entry %d cleared.\n"; 3472 } 3473 ifnet_domsg(&nmsg->lmsg, 0); 3474 KKASSERT(zmsg.start_rule == NULL); 3475 3476 if (fw_verbose) 3477 log(LOG_SECURITY | LOG_NOTICE, msg, rulenum); 3478 return (0); 3479 } 3480 3481 /* 3482 * Check validity of the structure before insert. 3483 * Fortunately rules are simple, so this mostly need to check rule sizes. 3484 */ 3485 static int 3486 ipfw_check_ioc_rule(struct ipfw_ioc_rule *rule, int size, uint32_t *rule_flags) 3487 { 3488 int l, cmdlen = 0; 3489 int have_action = 0; 3490 ipfw_insn *cmd; 3491 3492 *rule_flags = 0; 3493 3494 /* Check for valid size */ 3495 if (size < sizeof(*rule)) { 3496 kprintf("ipfw: rule too short\n"); 3497 return EINVAL; 3498 } 3499 l = IOC_RULESIZE(rule); 3500 if (l != size) { 3501 kprintf("ipfw: size mismatch (have %d want %d)\n", size, l); 3502 return EINVAL; 3503 } 3504 3505 /* Check rule number */ 3506 if (rule->rulenum == IPFW_DEFAULT_RULE) { 3507 kprintf("ipfw: invalid rule number\n"); 3508 return EINVAL; 3509 } 3510 3511 /* 3512 * Now go for the individual checks. Very simple ones, basically only 3513 * instruction sizes. 3514 */ 3515 for (l = rule->cmd_len, cmd = rule->cmd; l > 0; 3516 l -= cmdlen, cmd += cmdlen) { 3517 cmdlen = F_LEN(cmd); 3518 if (cmdlen > l) { 3519 kprintf("ipfw: opcode %d size truncated\n", 3520 cmd->opcode); 3521 return EINVAL; 3522 } 3523 3524 DPRINTF("ipfw: opcode %d\n", cmd->opcode); 3525 3526 if (cmd->opcode == O_KEEP_STATE || cmd->opcode == O_LIMIT) { 3527 /* This rule will create states */ 3528 *rule_flags |= IPFW_RULE_F_STATE; 3529 } 3530 3531 switch (cmd->opcode) { 3532 case O_NOP: 3533 case O_PROBE_STATE: 3534 case O_KEEP_STATE: 3535 case O_PROTO: 3536 case O_IP_SRC_ME: 3537 case O_IP_DST_ME: 3538 case O_LAYER2: 3539 case O_IN: 3540 case O_FRAG: 3541 case O_IPOPT: 3542 case O_IPLEN: 3543 case O_IPID: 3544 case O_IPTOS: 3545 case O_IPPRECEDENCE: 3546 case O_IPTTL: 3547 case O_IPVER: 3548 case O_TCPWIN: 3549 case O_TCPFLAGS: 3550 case O_TCPOPTS: 3551 case O_ESTAB: 3552 if (cmdlen != F_INSN_SIZE(ipfw_insn)) 3553 goto bad_size; 3554 break; 3555 3556 case O_UID: 3557 case O_GID: 3558 case O_IP_SRC: 3559 case O_IP_DST: 3560 case O_TCPSEQ: 3561 case O_TCPACK: 3562 case O_PROB: 3563 case O_ICMPTYPE: 3564 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32)) 3565 goto bad_size; 3566 break; 3567 3568 case O_LIMIT: 3569 if (cmdlen != F_INSN_SIZE(ipfw_insn_limit)) 3570 goto bad_size; 3571 break; 3572 3573 case O_LOG: 3574 if (cmdlen != F_INSN_SIZE(ipfw_insn_log)) 3575 goto bad_size; 3576 3577 ((ipfw_insn_log *)cmd)->log_left = 3578 ((ipfw_insn_log *)cmd)->max_log; 3579 3580 break; 3581 3582 case O_IP_SRC_MASK: 3583 case O_IP_DST_MASK: 3584 if (cmdlen != F_INSN_SIZE(ipfw_insn_ip)) 3585 goto bad_size; 3586 if (((ipfw_insn_ip *)cmd)->mask.s_addr == 0) { 3587 kprintf("ipfw: opcode %d, useless rule\n", 3588 cmd->opcode); 3589 return EINVAL; 3590 } 3591 break; 3592 3593 case O_IP_SRC_SET: 3594 case O_IP_DST_SET: 3595 if (cmd->arg1 == 0 || cmd->arg1 > 256) { 3596 kprintf("ipfw: invalid set size %d\n", 3597 cmd->arg1); 3598 return EINVAL; 3599 } 3600 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32) + 3601 (cmd->arg1+31)/32 ) 3602 goto bad_size; 3603 break; 3604 3605 case O_MACADDR2: 3606 if (cmdlen != F_INSN_SIZE(ipfw_insn_mac)) 3607 goto bad_size; 3608 break; 3609 3610 case O_MAC_TYPE: 3611 case O_IP_SRCPORT: 3612 case O_IP_DSTPORT: /* XXX artificial limit, 30 port pairs */ 3613 if (cmdlen < 2 || cmdlen > 31) 3614 goto bad_size; 3615 break; 3616 3617 case O_RECV: 3618 case O_XMIT: 3619 case O_VIA: 3620 if (cmdlen != F_INSN_SIZE(ipfw_insn_if)) 3621 goto bad_size; 3622 break; 3623 3624 case O_PIPE: 3625 case O_QUEUE: 3626 if (cmdlen != F_INSN_SIZE(ipfw_insn_pipe)) 3627 goto bad_size; 3628 goto check_action; 3629 3630 case O_FORWARD_IP: 3631 if (cmdlen != F_INSN_SIZE(ipfw_insn_sa)) { 3632 goto bad_size; 3633 } else { 3634 in_addr_t fwd_addr; 3635 3636 fwd_addr = ((ipfw_insn_sa *)cmd)-> 3637 sa.sin_addr.s_addr; 3638 if (IN_MULTICAST(ntohl(fwd_addr))) { 3639 kprintf("ipfw: try forwarding to " 3640 "multicast address\n"); 3641 return EINVAL; 3642 } 3643 } 3644 goto check_action; 3645 3646 case O_FORWARD_MAC: /* XXX not implemented yet */ 3647 case O_CHECK_STATE: 3648 case O_COUNT: 3649 case O_ACCEPT: 3650 case O_DENY: 3651 case O_REJECT: 3652 case O_SKIPTO: 3653 case O_DIVERT: 3654 case O_TEE: 3655 if (cmdlen != F_INSN_SIZE(ipfw_insn)) 3656 goto bad_size; 3657 check_action: 3658 if (have_action) { 3659 kprintf("ipfw: opcode %d, multiple actions" 3660 " not allowed\n", 3661 cmd->opcode); 3662 return EINVAL; 3663 } 3664 have_action = 1; 3665 if (l != cmdlen) { 3666 kprintf("ipfw: opcode %d, action must be" 3667 " last opcode\n", 3668 cmd->opcode); 3669 return EINVAL; 3670 } 3671 break; 3672 default: 3673 kprintf("ipfw: opcode %d, unknown opcode\n", 3674 cmd->opcode); 3675 return EINVAL; 3676 } 3677 } 3678 if (have_action == 0) { 3679 kprintf("ipfw: missing action\n"); 3680 return EINVAL; 3681 } 3682 return 0; 3683 3684 bad_size: 3685 kprintf("ipfw: opcode %d size %d wrong\n", 3686 cmd->opcode, cmdlen); 3687 return EINVAL; 3688 } 3689 3690 static int 3691 ipfw_ctl_add_rule(struct sockopt *sopt) 3692 { 3693 struct ipfw_ioc_rule *ioc_rule; 3694 size_t size; 3695 uint32_t rule_flags; 3696 int error; 3697 3698 size = sopt->sopt_valsize; 3699 if (size > (sizeof(uint32_t) * IPFW_RULE_SIZE_MAX) || 3700 size < sizeof(*ioc_rule)) { 3701 return EINVAL; 3702 } 3703 if (size != (sizeof(uint32_t) * IPFW_RULE_SIZE_MAX)) { 3704 sopt->sopt_val = krealloc(sopt->sopt_val, sizeof(uint32_t) * 3705 IPFW_RULE_SIZE_MAX, M_TEMP, M_WAITOK); 3706 } 3707 ioc_rule = sopt->sopt_val; 3708 3709 error = ipfw_check_ioc_rule(ioc_rule, size, &rule_flags); 3710 if (error) 3711 return error; 3712 3713 ipfw_add_rule(ioc_rule, rule_flags); 3714 3715 if (sopt->sopt_dir == SOPT_GET) 3716 sopt->sopt_valsize = IOC_RULESIZE(ioc_rule); 3717 return 0; 3718 } 3719 3720 static void * 3721 ipfw_copy_rule(const struct ip_fw *rule, struct ipfw_ioc_rule *ioc_rule) 3722 { 3723 const struct ip_fw *sibling; 3724 #ifdef INVARIANTS 3725 int i; 3726 #endif 3727 3728 KKASSERT(rule->cpuid == IPFW_CFGCPUID); 3729 3730 ioc_rule->act_ofs = rule->act_ofs; 3731 ioc_rule->cmd_len = rule->cmd_len; 3732 ioc_rule->rulenum = rule->rulenum; 3733 ioc_rule->set = rule->set; 3734 ioc_rule->usr_flags = rule->usr_flags; 3735 3736 ioc_rule->set_disable = ipfw_ctx[mycpuid]->ipfw_set_disable; 3737 ioc_rule->static_count = static_count; 3738 ioc_rule->static_len = static_ioc_len; 3739 3740 /* 3741 * Visit (read-only) all of the rule's duplications to get 3742 * the necessary statistics 3743 */ 3744 #ifdef INVARIANTS 3745 i = 0; 3746 #endif 3747 ioc_rule->pcnt = 0; 3748 ioc_rule->bcnt = 0; 3749 ioc_rule->timestamp = 0; 3750 for (sibling = rule; sibling != NULL; sibling = sibling->sibling) { 3751 ioc_rule->pcnt += sibling->pcnt; 3752 ioc_rule->bcnt += sibling->bcnt; 3753 if (sibling->timestamp > ioc_rule->timestamp) 3754 ioc_rule->timestamp = sibling->timestamp; 3755 #ifdef INVARIANTS 3756 ++i; 3757 #endif 3758 } 3759 KASSERT(i == ncpus, ("static rule is not duplicated on every cpu")); 3760 3761 bcopy(rule->cmd, ioc_rule->cmd, ioc_rule->cmd_len * 4 /* XXX */); 3762 3763 return ((uint8_t *)ioc_rule + IOC_RULESIZE(ioc_rule)); 3764 } 3765 3766 static void 3767 ipfw_copy_state(const ipfw_dyn_rule *dyn_rule, 3768 struct ipfw_ioc_state *ioc_state) 3769 { 3770 const struct ipfw_flow_id *id; 3771 struct ipfw_ioc_flowid *ioc_id; 3772 3773 ioc_state->expire = TIME_LEQ(dyn_rule->expire, time_second) ? 3774 0 : dyn_rule->expire - time_second; 3775 ioc_state->pcnt = dyn_rule->pcnt; 3776 ioc_state->bcnt = dyn_rule->bcnt; 3777 3778 ioc_state->dyn_type = dyn_rule->dyn_type; 3779 ioc_state->count = dyn_rule->count; 3780 3781 ioc_state->rulenum = dyn_rule->stub->rule[mycpuid]->rulenum; 3782 3783 id = &dyn_rule->id; 3784 ioc_id = &ioc_state->id; 3785 3786 ioc_id->type = ETHERTYPE_IP; 3787 ioc_id->u.ip.dst_ip = id->dst_ip; 3788 ioc_id->u.ip.src_ip = id->src_ip; 3789 ioc_id->u.ip.dst_port = id->dst_port; 3790 ioc_id->u.ip.src_port = id->src_port; 3791 ioc_id->u.ip.proto = id->proto; 3792 } 3793 3794 static int 3795 ipfw_ctl_get_rules(struct sockopt *sopt) 3796 { 3797 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 3798 struct ip_fw *rule; 3799 void *bp; 3800 size_t size; 3801 uint32_t dcount = 0; 3802 3803 /* 3804 * pass up a copy of the current rules. Static rules 3805 * come first (the last of which has number IPFW_DEFAULT_RULE), 3806 * followed by a possibly empty list of dynamic rule. 3807 */ 3808 3809 size = static_ioc_len; /* size of static rules */ 3810 if (ipfw_dyn_v) { /* add size of dyn.rules */ 3811 dcount = dyn_count; 3812 size += dcount * sizeof(struct ipfw_ioc_state); 3813 } 3814 3815 if (sopt->sopt_valsize < size) { 3816 /* short length, no need to return incomplete rules */ 3817 /* XXX: if superuser, no need to zero buffer */ 3818 bzero(sopt->sopt_val, sopt->sopt_valsize); 3819 return 0; 3820 } 3821 bp = sopt->sopt_val; 3822 3823 for (rule = ctx->ipfw_layer3_chain; rule; rule = rule->next) 3824 bp = ipfw_copy_rule(rule, bp); 3825 3826 if (ipfw_dyn_v && dcount != 0) { 3827 struct ipfw_ioc_state *ioc_state = bp; 3828 uint32_t dcount2 = 0; 3829 #ifdef INVARIANTS 3830 size_t old_size = size; 3831 #endif 3832 int i; 3833 3834 lockmgr(&dyn_lock, LK_SHARED); 3835 3836 /* Check 'ipfw_dyn_v' again with lock held */ 3837 if (ipfw_dyn_v == NULL) 3838 goto skip; 3839 3840 for (i = 0; i < curr_dyn_buckets; i++) { 3841 ipfw_dyn_rule *p; 3842 3843 /* 3844 * The # of dynamic rules may have grown after the 3845 * snapshot of 'dyn_count' was taken, so we will have 3846 * to check 'dcount' (snapshot of dyn_count) here to 3847 * make sure that we don't overflow the pre-allocated 3848 * buffer. 3849 */ 3850 for (p = ipfw_dyn_v[i]; p != NULL && dcount != 0; 3851 p = p->next, ioc_state++, dcount--, dcount2++) 3852 ipfw_copy_state(p, ioc_state); 3853 } 3854 skip: 3855 lockmgr(&dyn_lock, LK_RELEASE); 3856 3857 /* 3858 * The # of dynamic rules may be shrinked after the 3859 * snapshot of 'dyn_count' was taken. To give user a 3860 * correct dynamic rule count, we use the 'dcount2' 3861 * calculated above (with shared lockmgr lock held). 3862 */ 3863 size = static_ioc_len + 3864 (dcount2 * sizeof(struct ipfw_ioc_state)); 3865 KKASSERT(size <= old_size); 3866 } 3867 3868 sopt->sopt_valsize = size; 3869 return 0; 3870 } 3871 3872 static void 3873 ipfw_set_disable_dispatch(netmsg_t nmsg) 3874 { 3875 struct lwkt_msg *lmsg = &nmsg->lmsg; 3876 struct ipfw_context *ctx = ipfw_ctx[mycpuid]; 3877 3878 ctx->ipfw_gen++; 3879 ctx->ipfw_set_disable = lmsg->u.ms_result32; 3880 3881 ifnet_forwardmsg(lmsg, mycpuid + 1); 3882 } 3883 3884 static void 3885 ipfw_ctl_set_disable(uint32_t disable, uint32_t enable) 3886 { 3887 struct netmsg_base nmsg; 3888 struct lwkt_msg *lmsg; 3889 uint32_t set_disable; 3890 3891 /* IPFW_DEFAULT_SET is always enabled */ 3892 enable |= (1 << IPFW_DEFAULT_SET); 3893 set_disable = (ipfw_ctx[mycpuid]->ipfw_set_disable | disable) & ~enable; 3894 3895 bzero(&nmsg, sizeof(nmsg)); 3896 netmsg_init(&nmsg, NULL, &curthread->td_msgport, 3897 0, ipfw_set_disable_dispatch); 3898 lmsg = &nmsg.lmsg; 3899 lmsg->u.ms_result32 = set_disable; 3900 3901 ifnet_domsg(lmsg, 0); 3902 } 3903 3904 /** 3905 * {set|get}sockopt parser. 3906 */ 3907 static int 3908 ipfw_ctl(struct sockopt *sopt) 3909 { 3910 int error, rulenum; 3911 uint32_t *masks; 3912 size_t size; 3913 3914 error = 0; 3915 3916 switch (sopt->sopt_name) { 3917 case IP_FW_GET: 3918 error = ipfw_ctl_get_rules(sopt); 3919 break; 3920 3921 case IP_FW_FLUSH: 3922 ipfw_flush(0 /* keep default rule */); 3923 break; 3924 3925 case IP_FW_ADD: 3926 error = ipfw_ctl_add_rule(sopt); 3927 break; 3928 3929 case IP_FW_DEL: 3930 /* 3931 * IP_FW_DEL is used for deleting single rules or sets, 3932 * and (ab)used to atomically manipulate sets. 3933 * Argument size is used to distinguish between the two: 3934 * sizeof(uint32_t) 3935 * delete single rule or set of rules, 3936 * or reassign rules (or sets) to a different set. 3937 * 2 * sizeof(uint32_t) 3938 * atomic disable/enable sets. 3939 * first uint32_t contains sets to be disabled, 3940 * second uint32_t contains sets to be enabled. 3941 */ 3942 masks = sopt->sopt_val; 3943 size = sopt->sopt_valsize; 3944 if (size == sizeof(*masks)) { 3945 /* 3946 * Delete or reassign static rule 3947 */ 3948 error = ipfw_ctl_alter(masks[0]); 3949 } else if (size == (2 * sizeof(*masks))) { 3950 /* 3951 * Set enable/disable 3952 */ 3953 ipfw_ctl_set_disable(masks[0], masks[1]); 3954 } else { 3955 error = EINVAL; 3956 } 3957 break; 3958 3959 case IP_FW_ZERO: 3960 case IP_FW_RESETLOG: /* argument is an int, the rule number */ 3961 rulenum = 0; 3962 3963 if (sopt->sopt_val != 0) { 3964 error = soopt_to_kbuf(sopt, &rulenum, 3965 sizeof(int), sizeof(int)); 3966 if (error) 3967 break; 3968 } 3969 error = ipfw_ctl_zero_entry(rulenum, 3970 sopt->sopt_name == IP_FW_RESETLOG); 3971 break; 3972 3973 default: 3974 kprintf("ipfw_ctl invalid option %d\n", sopt->sopt_name); 3975 error = EINVAL; 3976 } 3977 return error; 3978 } 3979 3980 /* 3981 * This procedure is only used to handle keepalives. It is invoked 3982 * every dyn_keepalive_period 3983 */ 3984 static void 3985 ipfw_tick_dispatch(netmsg_t nmsg) 3986 { 3987 time_t keep_alive; 3988 uint32_t gen; 3989 int i; 3990 3991 IPFW_ASSERT_CFGPORT(&curthread->td_msgport); 3992 KKASSERT(IPFW_LOADED); 3993 3994 /* Reply ASAP */ 3995 crit_enter(); 3996 lwkt_replymsg(&nmsg->lmsg, 0); 3997 crit_exit(); 3998 3999 if (ipfw_dyn_v == NULL || dyn_count == 0) 4000 goto done; 4001 4002 keep_alive = time_second; 4003 4004 lockmgr(&dyn_lock, LK_EXCLUSIVE); 4005 again: 4006 if (ipfw_dyn_v == NULL || dyn_count == 0) { 4007 lockmgr(&dyn_lock, LK_RELEASE); 4008 goto done; 4009 } 4010 gen = dyn_buckets_gen; 4011 4012 for (i = 0; i < curr_dyn_buckets; i++) { 4013 ipfw_dyn_rule *q, *prev; 4014 4015 for (prev = NULL, q = ipfw_dyn_v[i]; q != NULL;) { 4016 uint32_t ack_rev, ack_fwd; 4017 struct ipfw_flow_id id; 4018 4019 if (q->dyn_type == O_LIMIT_PARENT) 4020 goto next; 4021 4022 if (TIME_LEQ(q->expire, time_second)) { 4023 /* State expired */ 4024 UNLINK_DYN_RULE(prev, ipfw_dyn_v[i], q); 4025 continue; 4026 } 4027 4028 /* 4029 * Keep alive processing 4030 */ 4031 4032 if (!dyn_keepalive) 4033 goto next; 4034 if (q->id.proto != IPPROTO_TCP) 4035 goto next; 4036 if ((q->state & BOTH_SYN) != BOTH_SYN) 4037 goto next; 4038 if (TIME_LEQ(time_second + dyn_keepalive_interval, 4039 q->expire)) 4040 goto next; /* too early */ 4041 if (q->keep_alive == keep_alive) 4042 goto next; /* alreay done */ 4043 4044 /* 4045 * Save necessary information, so that they could 4046 * survive after possible blocking in send_pkt() 4047 */ 4048 id = q->id; 4049 ack_rev = q->ack_rev; 4050 ack_fwd = q->ack_fwd; 4051 4052 /* Sending has been started */ 4053 q->keep_alive = keep_alive; 4054 4055 /* Release lock to avoid possible dead lock */ 4056 lockmgr(&dyn_lock, LK_RELEASE); 4057 send_pkt(&id, ack_rev - 1, ack_fwd, TH_SYN); 4058 send_pkt(&id, ack_fwd - 1, ack_rev, 0); 4059 lockmgr(&dyn_lock, LK_EXCLUSIVE); 4060 4061 if (gen != dyn_buckets_gen) { 4062 /* 4063 * Dyn bucket array has been changed during 4064 * the above two sending; reiterate. 4065 */ 4066 goto again; 4067 } 4068 next: 4069 prev = q; 4070 q = q->next; 4071 } 4072 } 4073 lockmgr(&dyn_lock, LK_RELEASE); 4074 done: 4075 callout_reset(&ipfw_timeout_h, dyn_keepalive_period * hz, 4076 ipfw_tick, NULL); 4077 } 4078 4079 /* 4080 * This procedure is only used to handle keepalives. It is invoked 4081 * every dyn_keepalive_period 4082 */ 4083 static void 4084 ipfw_tick(void *dummy __unused) 4085 { 4086 struct lwkt_msg *lmsg = &ipfw_timeout_netmsg.lmsg; 4087 4088 KKASSERT(mycpuid == IPFW_CFGCPUID); 4089 4090 crit_enter(); 4091 4092 KKASSERT(lmsg->ms_flags & MSGF_DONE); 4093 if (IPFW_LOADED) { 4094 lwkt_sendmsg(IPFW_CFGPORT, lmsg); 4095 /* ipfw_timeout_netmsg's handler reset this callout */ 4096 } 4097 4098 crit_exit(); 4099 } 4100 4101 static int 4102 ipfw_check_in(void *arg, struct mbuf **m0, struct ifnet *ifp, int dir) 4103 { 4104 struct ip_fw_args args; 4105 struct mbuf *m = *m0; 4106 struct m_tag *mtag; 4107 int tee = 0, error = 0, ret; 4108 4109 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) { 4110 /* Extract info from dummynet tag */ 4111 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL); 4112 KKASSERT(mtag != NULL); 4113 args.rule = ((struct dn_pkt *)m_tag_data(mtag))->dn_priv; 4114 KKASSERT(args.rule != NULL); 4115 4116 m_tag_delete(m, mtag); 4117 m->m_pkthdr.fw_flags &= ~DUMMYNET_MBUF_TAGGED; 4118 } else { 4119 args.rule = NULL; 4120 } 4121 4122 args.eh = NULL; 4123 args.oif = NULL; 4124 args.m = m; 4125 ret = ipfw_chk(&args); 4126 m = args.m; 4127 4128 if (m == NULL) { 4129 error = EACCES; 4130 goto back; 4131 } 4132 4133 switch (ret) { 4134 case IP_FW_PASS: 4135 break; 4136 4137 case IP_FW_DENY: 4138 m_freem(m); 4139 m = NULL; 4140 error = EACCES; 4141 break; 4142 4143 case IP_FW_DUMMYNET: 4144 /* Send packet to the appropriate pipe */ 4145 ipfw_dummynet_io(m, args.cookie, DN_TO_IP_IN, &args); 4146 break; 4147 4148 case IP_FW_TEE: 4149 tee = 1; 4150 /* FALL THROUGH */ 4151 4152 case IP_FW_DIVERT: 4153 /* 4154 * Must clear bridge tag when changing 4155 */ 4156 m->m_pkthdr.fw_flags &= ~BRIDGE_MBUF_TAGGED; 4157 if (ip_divert_p != NULL) { 4158 m = ip_divert_p(m, tee, 1); 4159 } else { 4160 m_freem(m); 4161 m = NULL; 4162 /* not sure this is the right error msg */ 4163 error = EACCES; 4164 } 4165 break; 4166 4167 default: 4168 panic("unknown ipfw return value: %d", ret); 4169 } 4170 back: 4171 *m0 = m; 4172 return error; 4173 } 4174 4175 static int 4176 ipfw_check_out(void *arg, struct mbuf **m0, struct ifnet *ifp, int dir) 4177 { 4178 struct ip_fw_args args; 4179 struct mbuf *m = *m0; 4180 struct m_tag *mtag; 4181 int tee = 0, error = 0, ret; 4182 4183 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) { 4184 /* Extract info from dummynet tag */ 4185 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL); 4186 KKASSERT(mtag != NULL); 4187 args.rule = ((struct dn_pkt *)m_tag_data(mtag))->dn_priv; 4188 KKASSERT(args.rule != NULL); 4189 4190 m_tag_delete(m, mtag); 4191 m->m_pkthdr.fw_flags &= ~DUMMYNET_MBUF_TAGGED; 4192 } else { 4193 args.rule = NULL; 4194 } 4195 4196 args.eh = NULL; 4197 args.m = m; 4198 args.oif = ifp; 4199 ret = ipfw_chk(&args); 4200 m = args.m; 4201 4202 if (m == NULL) { 4203 error = EACCES; 4204 goto back; 4205 } 4206 4207 switch (ret) { 4208 case IP_FW_PASS: 4209 break; 4210 4211 case IP_FW_DENY: 4212 m_freem(m); 4213 m = NULL; 4214 error = EACCES; 4215 break; 4216 4217 case IP_FW_DUMMYNET: 4218 ipfw_dummynet_io(m, args.cookie, DN_TO_IP_OUT, &args); 4219 break; 4220 4221 case IP_FW_TEE: 4222 tee = 1; 4223 /* FALL THROUGH */ 4224 4225 case IP_FW_DIVERT: 4226 if (ip_divert_p != NULL) { 4227 m = ip_divert_p(m, tee, 0); 4228 } else { 4229 m_freem(m); 4230 m = NULL; 4231 /* not sure this is the right error msg */ 4232 error = EACCES; 4233 } 4234 break; 4235 4236 default: 4237 panic("unknown ipfw return value: %d", ret); 4238 } 4239 back: 4240 *m0 = m; 4241 return error; 4242 } 4243 4244 static void 4245 ipfw_hook(void) 4246 { 4247 struct pfil_head *pfh; 4248 4249 IPFW_ASSERT_CFGPORT(&curthread->td_msgport); 4250 4251 pfh = pfil_head_get(PFIL_TYPE_AF, AF_INET); 4252 if (pfh == NULL) 4253 return; 4254 4255 pfil_add_hook(ipfw_check_in, NULL, PFIL_IN | PFIL_MPSAFE, pfh); 4256 pfil_add_hook(ipfw_check_out, NULL, PFIL_OUT | PFIL_MPSAFE, pfh); 4257 } 4258 4259 static void 4260 ipfw_dehook(void) 4261 { 4262 struct pfil_head *pfh; 4263 4264 IPFW_ASSERT_CFGPORT(&curthread->td_msgport); 4265 4266 pfh = pfil_head_get(PFIL_TYPE_AF, AF_INET); 4267 if (pfh == NULL) 4268 return; 4269 4270 pfil_remove_hook(ipfw_check_in, NULL, PFIL_IN, pfh); 4271 pfil_remove_hook(ipfw_check_out, NULL, PFIL_OUT, pfh); 4272 } 4273 4274 static void 4275 ipfw_sysctl_enable_dispatch(netmsg_t nmsg) 4276 { 4277 struct lwkt_msg *lmsg = &nmsg->lmsg; 4278 int enable = lmsg->u.ms_result; 4279 4280 if (fw_enable == enable) 4281 goto reply; 4282 4283 fw_enable = enable; 4284 if (fw_enable) 4285 ipfw_hook(); 4286 else 4287 ipfw_dehook(); 4288 reply: 4289 lwkt_replymsg(lmsg, 0); 4290 } 4291 4292 static int 4293 ipfw_sysctl_enable(SYSCTL_HANDLER_ARGS) 4294 { 4295 struct netmsg_base nmsg; 4296 struct lwkt_msg *lmsg; 4297 int enable, error; 4298 4299 enable = fw_enable; 4300 error = sysctl_handle_int(oidp, &enable, 0, req); 4301 if (error || req->newptr == NULL) 4302 return error; 4303 4304 netmsg_init(&nmsg, NULL, &curthread->td_msgport, 4305 0, ipfw_sysctl_enable_dispatch); 4306 lmsg = &nmsg.lmsg; 4307 lmsg->u.ms_result = enable; 4308 4309 return lwkt_domsg(IPFW_CFGPORT, lmsg, 0); 4310 } 4311 4312 static int 4313 ipfw_sysctl_autoinc_step(SYSCTL_HANDLER_ARGS) 4314 { 4315 return sysctl_int_range(oidp, arg1, arg2, req, 4316 IPFW_AUTOINC_STEP_MIN, IPFW_AUTOINC_STEP_MAX); 4317 } 4318 4319 static int 4320 ipfw_sysctl_dyn_buckets(SYSCTL_HANDLER_ARGS) 4321 { 4322 int error, value; 4323 4324 lockmgr(&dyn_lock, LK_EXCLUSIVE); 4325 4326 value = dyn_buckets; 4327 error = sysctl_handle_int(oidp, &value, 0, req); 4328 if (error || !req->newptr) 4329 goto back; 4330 4331 /* 4332 * Make sure we have a power of 2 and 4333 * do not allow more than 64k entries. 4334 */ 4335 error = EINVAL; 4336 if (value <= 1 || value > 65536) 4337 goto back; 4338 if ((value & (value - 1)) != 0) 4339 goto back; 4340 4341 error = 0; 4342 dyn_buckets = value; 4343 back: 4344 lockmgr(&dyn_lock, LK_RELEASE); 4345 return error; 4346 } 4347 4348 static int 4349 ipfw_sysctl_dyn_fin(SYSCTL_HANDLER_ARGS) 4350 { 4351 return sysctl_int_range(oidp, arg1, arg2, req, 4352 1, dyn_keepalive_period - 1); 4353 } 4354 4355 static int 4356 ipfw_sysctl_dyn_rst(SYSCTL_HANDLER_ARGS) 4357 { 4358 return sysctl_int_range(oidp, arg1, arg2, req, 4359 1, dyn_keepalive_period - 1); 4360 } 4361 4362 static void 4363 ipfw_ctx_init_dispatch(netmsg_t nmsg) 4364 { 4365 struct netmsg_ipfw *fwmsg = (struct netmsg_ipfw *)nmsg; 4366 struct ipfw_context *ctx; 4367 struct ip_fw *def_rule; 4368 4369 ctx = kmalloc(sizeof(*ctx), M_IPFW, M_WAITOK | M_ZERO); 4370 ipfw_ctx[mycpuid] = ctx; 4371 4372 def_rule = kmalloc(sizeof(*def_rule), M_IPFW, M_WAITOK | M_ZERO); 4373 4374 def_rule->act_ofs = 0; 4375 def_rule->rulenum = IPFW_DEFAULT_RULE; 4376 def_rule->cmd_len = 1; 4377 def_rule->set = IPFW_DEFAULT_SET; 4378 4379 def_rule->cmd[0].len = 1; 4380 #ifdef IPFIREWALL_DEFAULT_TO_ACCEPT 4381 def_rule->cmd[0].opcode = O_ACCEPT; 4382 #else 4383 def_rule->cmd[0].opcode = O_DENY; 4384 #endif 4385 4386 def_rule->refcnt = 1; 4387 def_rule->cpuid = mycpuid; 4388 4389 /* Install the default rule */ 4390 ctx->ipfw_default_rule = def_rule; 4391 ctx->ipfw_layer3_chain = def_rule; 4392 4393 /* Link rule CPU sibling */ 4394 ipfw_link_sibling(fwmsg, def_rule); 4395 4396 /* Statistics only need to be updated once */ 4397 if (mycpuid == 0) 4398 ipfw_inc_static_count(def_rule); 4399 4400 ifnet_forwardmsg(&nmsg->lmsg, mycpuid + 1); 4401 } 4402 4403 static void 4404 ipfw_init_dispatch(netmsg_t nmsg) 4405 { 4406 struct netmsg_ipfw fwmsg; 4407 int error = 0; 4408 4409 if (IPFW_LOADED) { 4410 kprintf("IP firewall already loaded\n"); 4411 error = EEXIST; 4412 goto reply; 4413 } 4414 4415 bzero(&fwmsg, sizeof(fwmsg)); 4416 netmsg_init(&fwmsg.base, NULL, &curthread->td_msgport, 4417 0, ipfw_ctx_init_dispatch); 4418 ifnet_domsg(&fwmsg.base.lmsg, 0); 4419 4420 ip_fw_chk_ptr = ipfw_chk; 4421 ip_fw_ctl_ptr = ipfw_ctl; 4422 ip_fw_dn_io_ptr = ipfw_dummynet_io; 4423 4424 kprintf("ipfw2 initialized, default to %s, logging ", 4425 ipfw_ctx[mycpuid]->ipfw_default_rule->cmd[0].opcode == 4426 O_ACCEPT ? "accept" : "deny"); 4427 4428 #ifdef IPFIREWALL_VERBOSE 4429 fw_verbose = 1; 4430 #endif 4431 #ifdef IPFIREWALL_VERBOSE_LIMIT 4432 verbose_limit = IPFIREWALL_VERBOSE_LIMIT; 4433 #endif 4434 if (fw_verbose == 0) { 4435 kprintf("disabled\n"); 4436 } else if (verbose_limit == 0) { 4437 kprintf("unlimited\n"); 4438 } else { 4439 kprintf("limited to %d packets/entry by default\n", 4440 verbose_limit); 4441 } 4442 4443 callout_init_mp(&ipfw_timeout_h); 4444 netmsg_init(&ipfw_timeout_netmsg, NULL, &netisr_adone_rport, 4445 MSGF_DROPABLE | MSGF_PRIORITY, 4446 ipfw_tick_dispatch); 4447 lockinit(&dyn_lock, "ipfw_dyn", 0, 0); 4448 4449 ip_fw_loaded = 1; 4450 callout_reset(&ipfw_timeout_h, hz, ipfw_tick, NULL); 4451 4452 if (fw_enable) 4453 ipfw_hook(); 4454 reply: 4455 lwkt_replymsg(&nmsg->lmsg, error); 4456 } 4457 4458 static int 4459 ipfw_init(void) 4460 { 4461 struct netmsg_base smsg; 4462 4463 netmsg_init(&smsg, NULL, &curthread->td_msgport, 4464 0, ipfw_init_dispatch); 4465 return lwkt_domsg(IPFW_CFGPORT, &smsg.lmsg, 0); 4466 } 4467 4468 #ifdef KLD_MODULE 4469 4470 static void 4471 ipfw_fini_dispatch(netmsg_t nmsg) 4472 { 4473 int error = 0, cpu; 4474 4475 if (ipfw_refcnt != 0) { 4476 error = EBUSY; 4477 goto reply; 4478 } 4479 4480 ip_fw_loaded = 0; 4481 4482 ipfw_dehook(); 4483 callout_stop(&ipfw_timeout_h); 4484 4485 netmsg_service_sync(); 4486 4487 crit_enter(); 4488 if ((ipfw_timeout_netmsg.lmsg.ms_flags & MSGF_DONE) == 0) { 4489 /* 4490 * Callout message is pending; drop it 4491 */ 4492 lwkt_dropmsg(&ipfw_timeout_netmsg.lmsg); 4493 } 4494 crit_exit(); 4495 4496 ip_fw_chk_ptr = NULL; 4497 ip_fw_ctl_ptr = NULL; 4498 ip_fw_dn_io_ptr = NULL; 4499 ipfw_flush(1 /* kill default rule */); 4500 4501 /* Free pre-cpu context */ 4502 for (cpu = 0; cpu < ncpus; ++cpu) 4503 kfree(ipfw_ctx[cpu], M_IPFW); 4504 4505 kprintf("IP firewall unloaded\n"); 4506 reply: 4507 lwkt_replymsg(&nmsg->lmsg, error); 4508 } 4509 4510 static int 4511 ipfw_fini(void) 4512 { 4513 struct netmsg_base smsg; 4514 4515 netmsg_init(&smsg, NULL, &curthread->td_msgport, 4516 0, ipfw_fini_dispatch); 4517 return lwkt_domsg(IPFW_CFGPORT, &smsg.lmsg, 0); 4518 } 4519 4520 #endif /* KLD_MODULE */ 4521 4522 static int 4523 ipfw_modevent(module_t mod, int type, void *unused) 4524 { 4525 int err = 0; 4526 4527 switch (type) { 4528 case MOD_LOAD: 4529 err = ipfw_init(); 4530 break; 4531 4532 case MOD_UNLOAD: 4533 #ifndef KLD_MODULE 4534 kprintf("ipfw statically compiled, cannot unload\n"); 4535 err = EBUSY; 4536 #else 4537 err = ipfw_fini(); 4538 #endif 4539 break; 4540 default: 4541 break; 4542 } 4543 return err; 4544 } 4545 4546 static moduledata_t ipfwmod = { 4547 "ipfw", 4548 ipfw_modevent, 4549 0 4550 }; 4551 DECLARE_MODULE(ipfw, ipfwmod, SI_SUB_PROTO_END, SI_ORDER_ANY); 4552 MODULE_VERSION(ipfw, 1); 4553