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.h,v 1.1.2.2 2002/08/16 11:03:11 luigi Exp $ 26 */ 27 28 #ifndef _IPFW2_H 29 #define _IPFW2_H 30 31 /* 32 * The kernel representation of ipfw rules is made of a list of 33 * 'instructions' (for all practical purposes equivalent to BPF 34 * instructions), which specify which fields of the packet 35 * (or its metatada) should be analysed. 36 * 37 * Each instruction is stored in a structure which begins with 38 * "ipfw_insn", and can contain extra fields depending on the 39 * instruction type (listed below). 40 * 41 * "enum ipfw_opcodes" are the opcodes supported. We can have up 42 * to 256 different opcodes. 43 */ 44 45 enum ipfw_opcodes { /* arguments (4 byte each) */ 46 O_NOP, 47 48 O_IP_SRC, /* u32 = IP */ 49 O_IP_SRC_MASK, /* ip = IP/mask */ 50 O_IP_SRC_ME, /* none */ 51 O_IP_SRC_SET, /* u32=base, arg1=len, bitmap */ 52 53 O_IP_DST, /* u32 = IP */ 54 O_IP_DST_MASK, /* ip = IP/mask */ 55 O_IP_DST_ME, /* none */ 56 O_IP_DST_SET, /* u32=base, arg1=len, bitmap */ 57 58 O_IP_SRCPORT, /* (n)port list:mask 4 byte ea */ 59 O_IP_DSTPORT, /* (n)port list:mask 4 byte ea */ 60 O_PROTO, /* arg1=protocol */ 61 62 O_MACADDR2, /* 2 mac addr:mask */ 63 O_MAC_TYPE, /* same as srcport */ 64 65 O_LAYER2, /* none */ 66 O_IN, /* none */ 67 O_FRAG, /* none */ 68 69 O_RECV, /* none */ 70 O_XMIT, /* none */ 71 O_VIA, /* none */ 72 73 O_IPOPT, /* arg1 = 2*u8 bitmap */ 74 O_IPLEN, /* arg1 = len */ 75 O_IPID, /* arg1 = id */ 76 77 O_IPTOS, /* arg1 = id */ 78 O_IPPRECEDENCE, /* arg1 = precedence << 5 */ 79 O_IPTTL, /* arg1 = TTL */ 80 81 O_IPVER, /* arg1 = version */ 82 O_UID, /* u32 = id */ 83 O_GID, /* u32 = id */ 84 O_ESTAB, /* none (tcp established) */ 85 O_TCPFLAGS, /* arg1 = 2*u8 bitmap */ 86 O_TCPWIN, /* arg1 = desired win */ 87 O_TCPSEQ, /* u32 = desired seq. */ 88 O_TCPACK, /* u32 = desired seq. */ 89 O_ICMPTYPE, /* u32 = icmp bitmap */ 90 O_TCPOPTS, /* arg1 = 2*u8 bitmap */ 91 92 /* States. */ 93 O_PROBE_STATE, /* none */ 94 O_KEEP_STATE, /* none */ 95 O_LIMIT, /* ipfw_insn_limit */ 96 O_LIMIT_PARENT, /* dyn_type, not an opcode. */ 97 98 /* Actions. */ 99 O_LOG, /* ipfw_insn_log */ 100 O_PROB, /* u32 = match probability */ 101 O_CHECK_STATE, /* none */ 102 O_ACCEPT, /* none */ 103 O_DENY, /* none */ 104 O_REJECT, /* arg1=icmp arg (same as deny) */ 105 O_COUNT, /* none */ 106 O_SKIPTO, /* arg1=next rule number */ 107 O_PIPE, /* arg1=pipe number */ 108 O_QUEUE, /* arg1=queue number */ 109 O_DIVERT, /* arg1=port number */ 110 O_TEE, /* arg1=port number */ 111 O_FORWARD_IP, /* fwd sockaddr */ 112 O_FORWARD_MAC, /* fwd mac */ 113 114 /* Table based filters. */ 115 O_IP_SRC_TABLE, /* arg1 = tableid */ 116 O_IP_DST_TABLE, /* arg1 = tableid */ 117 118 /* Action. */ 119 O_DEFRAG, /* none */ 120 121 /* Filters. */ 122 O_IPFRAG, /* none */ 123 O_IP_SRC_IFIP, /* ipfw_insn_ifip */ 124 O_IP_DST_IFIP, /* ipfw_insn_ifip */ 125 126 /* Translates. */ 127 O_REDIRECT, /* ipfw_insn_rdr */ 128 129 O_LAST_OPCODE /* not an opcode! */ 130 }; 131 #ifdef _KERNEL 132 CTASSERT(O_LAST_OPCODE <= 256); 133 #endif 134 135 /* 136 * Template for instructions. 137 * 138 * ipfw_insn is used for all instructions which require no operands, 139 * a single 16-bit value (arg1), or a couple of 8-bit values. 140 * 141 * For other instructions which require different/larger arguments 142 * we have derived structures, ipfw_insn_*. 143 * 144 * The size of the instruction (in 32-bit words) is in the low 145 * 6 bits of "len". The 2 remaining bits are used to implement 146 * NOT and OR on individual instructions. Given a type, you can 147 * compute the length to be put in "len" using F_INSN_SIZE(t) 148 * 149 * F_NOT negates the match result of the instruction. 150 * 151 * F_OR is used to build or blocks. By default, instructions 152 * are evaluated as part of a logical AND. An "or" block 153 * { X or Y or Z } contains F_OR set in all but the last 154 * instruction of the block. A match will cause the code 155 * to skip past the last instruction of the block. 156 * 157 * NOTA BENE: in a couple of places we assume that 158 * sizeof(ipfw_insn) == sizeof(uint32_t) 159 * this needs to be fixed. 160 * 161 */ 162 typedef struct _ipfw_insn { /* template for instructions */ 163 enum ipfw_opcodes opcode:8; 164 uint8_t len; /* numer of 32-byte words */ 165 #define F_NOT 0x80 166 #define F_OR 0x40 167 #define F_LEN_MASK 0x3f 168 #define F_LEN(cmd) ((cmd)->len & F_LEN_MASK) 169 170 uint16_t arg1; 171 } ipfw_insn; 172 173 #define IPFW_INSN_SIZE_MAX 63 /* unit: uint32_t */ 174 175 /* 176 * The F_INSN_SIZE(type) computes the size, in 4-byte words, of 177 * a given type. 178 */ 179 #define F_INSN_SIZE(t) ((sizeof (t))/sizeof(uint32_t)) 180 181 /* 182 * This is used to store an array of 16-bit entries (ports etc.) 183 */ 184 typedef struct _ipfw_insn_u16 { 185 ipfw_insn o; 186 uint16_t ports[2]; /* there may be more */ 187 } ipfw_insn_u16; 188 189 /* 190 * This is used to store an array of 32-bit entries 191 * (uid, single IPv4 addresses etc.) 192 */ 193 typedef struct _ipfw_insn_u32 { 194 ipfw_insn o; 195 uint32_t d[1]; /* one or more */ 196 } ipfw_insn_u32; 197 198 /* 199 * This is used to store IP addr-mask pairs. 200 */ 201 typedef struct _ipfw_insn_ip { 202 ipfw_insn o; 203 struct in_addr addr; 204 struct in_addr mask; 205 } ipfw_insn_ip; 206 207 /* 208 * This is used to forward to a given address (ip) 209 */ 210 typedef struct _ipfw_insn_sa { 211 ipfw_insn o; 212 struct sockaddr_in sa; 213 } ipfw_insn_sa; 214 215 /* 216 * This is used for MAC addr-mask pairs. 217 */ 218 typedef struct _ipfw_insn_mac { 219 ipfw_insn o; 220 u_char addr[12]; /* dst[6] + src[6] */ 221 u_char mask[12]; /* dst[6] + src[6] */ 222 } ipfw_insn_mac; 223 224 /* 225 * This is used for interface match rules (recv xx, xmit xx) 226 */ 227 typedef struct _ipfw_insn_if { 228 ipfw_insn o; 229 union { 230 struct in_addr ip; 231 int glob; 232 } p; 233 char name[IFNAMSIZ]; 234 } ipfw_insn_if; 235 236 /* 237 * This is used for pipe and queue actions, which need to store 238 * a single pointer (which can have different size on different 239 * architectures. 240 */ 241 typedef struct _ipfw_insn_pipe { 242 ipfw_insn o; 243 void *pipe_ptr; 244 } ipfw_insn_pipe; 245 246 /* 247 * This is used for limit rules. 248 */ 249 typedef struct _ipfw_insn_limit { 250 ipfw_insn o; 251 uint8_t _pad; 252 uint8_t limit_mask; /* combination of DYN_* below */ 253 #define DYN_SRC_ADDR 0x1 254 #define DYN_SRC_PORT 0x2 255 #define DYN_DST_ADDR 0x4 256 #define DYN_DST_PORT 0x8 257 258 uint16_t conn_limit; 259 } ipfw_insn_limit; 260 261 /* 262 * This is used for log instructions 263 */ 264 typedef struct _ipfw_insn_log { 265 ipfw_insn o; 266 uint32_t max_log; /* how many do we log -- 0 = all */ 267 uint32_t log_left; /* how many left to log */ 268 } ipfw_insn_log; 269 270 /* 271 * This is used by O_IP_{SRC,DST}_IFIP. 272 */ 273 typedef struct _ipfw_insn_ifip { 274 ipfw_insn o; /* arg1 & 0x1, addr is valid */ 275 #define IPFW_IFIP_VALID 0x0001 276 #define IPFW_IFIP_NET 0x0002 277 #define IPFW_IFIP_SETTINGS IPFW_IFIP_NET 278 char ifname[IFNAMSIZ]; 279 struct in_addr addr; 280 struct in_addr mask; 281 } ipfw_insn_ifip; 282 283 /* 284 * This is used by O_REDIRECT. 285 */ 286 typedef struct _ipfw_insn_rdr { 287 ipfw_insn o; 288 struct in_addr addr; 289 uint16_t port; /* network byte order, 0 = same port */ 290 uint16_t set; /* reserved for set, 0xffff */ 291 } ipfw_insn_rdr; 292 293 #ifdef _KERNEL 294 295 /* 296 * Here we have the structure representing an ipfw rule. 297 * 298 * It starts with a general area (with link fields and counters) 299 * followed by an array of one or more instructions, which the code 300 * accesses as an array of 32-bit values. 301 * 302 * Given a rule pointer r: 303 * 304 * r->cmd is the start of the first instruction. 305 * ACTION_PTR(r) is the start of the first action (things to do 306 * once a rule matched). 307 * 308 * When assembling instruction, remember the following: 309 * 310 * + if a rule has a "keep-state" (or "limit") option, then the 311 * first instruction (at r->cmd) MUST BE an O_PROBE_STATE 312 * + if a rule has a "log" option, then the first action 313 * (at ACTION_PTR(r)) MUST be O_LOG 314 * 315 * NOTE: we use a simple linked list of rules because we never need 316 * to delete a rule without scanning the list. We do not use 317 * queue(3) macros for portability and readability. 318 */ 319 320 struct ip_fw { 321 struct ip_fw *next; /* linked list of rules */ 322 struct ip_fw *next_rule; /* ptr to next [skipto] rule */ 323 uint16_t act_ofs; /* offset of action in 32-bit units */ 324 uint16_t cmd_len; /* # of 32-bit words in cmd */ 325 uint16_t rulenum; /* rule number */ 326 uint8_t set; /* rule set (0..31) */ 327 uint8_t usr_flags; /* IPFW_USR_F_ */ 328 329 /* These fields are present in all rules. */ 330 uint64_t pcnt; /* Packet counter */ 331 uint64_t bcnt; /* Byte counter */ 332 uint32_t timestamp; /* tv_sec of last match */ 333 334 int cpuid; /* owner cpu */ 335 struct ip_fw *sibling; /* clone on next cpu */ 336 337 struct ip_fw **cross_rules; /* cross referenced rules */ 338 volatile uint64_t cross_refs; /* cross references */ 339 340 uint32_t refcnt; /* Ref count for transit pkts */ 341 uint32_t rule_flags; /* IPFW_RULE_F_ */ 342 uintptr_t track_ruleid; /* ruleid for src/dst tracks */ 343 344 ipfw_insn cmd[1]; /* storage for commands */ 345 }; 346 347 #define IPFW_RULE_F_INVALID 0x1 348 /* unused 0x2 */ 349 #define IPFW_RULE_F_GENSTATE 0x4 350 #define IPFW_RULE_F_GENTRACK 0x8 351 #define IPFW_RULE_F_CROSSREF 0x10 352 #define IPFW_RULE_F_DYNIFADDR 0x20 353 354 #define RULESIZE(rule) (sizeof(struct ip_fw) + (rule)->cmd_len * 4 - 4) 355 356 /* 357 * This structure is used as a flow mask and a flow id for various 358 * parts of the code. 359 */ 360 struct ipfw_flow_id { 361 uint32_t dst_ip; /* host byte order */ 362 uint32_t src_ip; /* host byte order */ 363 uint16_t dst_port; /* host byte order */ 364 uint16_t src_port; /* host byte order */ 365 uint8_t proto; 366 uint8_t flags; /* protocol-specific flags */ 367 }; 368 369 /* 370 * Main firewall chains definitions and global var's definitions. 371 */ 372 373 /* ipfw_chk/ip_fw_chk_ptr return values */ 374 #define IP_FW_PASS 0 375 #define IP_FW_DENY 1 376 #define IP_FW_DIVERT 2 377 #define IP_FW_TEE 3 378 #define IP_FW_DUMMYNET 4 379 #define IP_FW_REDISPATCH 6 380 381 /* 382 * arguments for calling ipfw_chk() and dummynet_io(). We put them 383 * all into a structure because this way it is easier and more 384 * efficient to pass variables around and extend the interface. 385 */ 386 struct ip_fw_args { 387 struct mbuf *m; /* the mbuf chain */ 388 struct ifnet *oif; /* output interface */ 389 struct ip_fw *rule; /* matching rule */ 390 struct ipfw_xlat *xlat; /* matching xlate */ 391 struct ether_header *eh; /* for bridged packets */ 392 393 struct ipfw_flow_id f_id; /* grabbed from IP header */ 394 uint8_t flags; 395 #define IP_FWARG_F_CONT 0x01 396 #define IP_FWARG_F_XLATINS 0x02 397 #define IP_FWARG_F_XLATFWD 0x04 398 399 /* 400 * Depend on the return value of ipfw_chk/ip_fw_chk_ptr 401 * 'cookie' field may save following information: 402 * 403 * IP_FW_TEE or IP_FW_DIVERT 404 * The divert port number 405 * 406 * IP_FW_DUMMYNET 407 * The pipe or queue number 408 */ 409 uint32_t cookie; 410 }; 411 412 /* 413 * Function definitions. 414 */ 415 int ip_fw_sockopt(struct sockopt *); 416 417 /* Firewall hooks */ 418 struct sockopt; 419 struct dn_flow_set; 420 421 typedef int ip_fw_chk_t(struct ip_fw_args *); 422 typedef int ip_fw_ctl_t(struct sockopt *); 423 typedef struct mbuf 424 *ip_fw_dn_io_t(struct mbuf *, int, int, struct ip_fw_args *); 425 426 extern ip_fw_chk_t *ip_fw_chk_ptr; 427 extern ip_fw_ctl_t *ip_fw_ctl_ptr; 428 extern ip_fw_dn_io_t *ip_fw_dn_io_ptr; 429 430 extern int fw_one_pass; 431 extern int fw_enable; 432 433 extern int ip_fw_loaded; 434 #define IPFW_LOADED (ip_fw_loaded) 435 436 #endif /* _KERNEL */ 437 438 #define ACTION_PTR(rule) \ 439 (ipfw_insn *)((uint32_t *)((rule)->cmd) + ((rule)->act_ofs)) 440 441 struct ipfw_ioc_rule { 442 uint16_t act_ofs; /* offset of action in 32-bit units */ 443 uint16_t cmd_len; /* # of 32-bit words in cmd */ 444 uint16_t rulenum; /* rule number */ 445 uint8_t set; /* rule set (0..31) */ 446 uint8_t usr_flags; /* IPFW_USR_F_ */ 447 448 /* Rule set information */ 449 uint32_t set_disable; /* disabled rule sets */ 450 uint32_t static_count; /* # of static rules */ 451 uint32_t static_len; /* total length of static rules */ 452 453 /* Statistics */ 454 uint64_t pcnt; /* Packet counter */ 455 uint64_t bcnt; /* Byte counter */ 456 uint32_t timestamp; /* tv_sec of last match */ 457 458 uint8_t reserved[16]; 459 460 ipfw_insn cmd[1]; /* storage for commands */ 461 }; 462 463 #define IPFW_USR_F_NORULE 0x01 464 465 #define IPFW_RULE_SIZE_MAX 255 /* unit: uint32_t */ 466 467 #define IOC_RULESIZE(rule) \ 468 (sizeof(struct ipfw_ioc_rule) + (rule)->cmd_len * 4 - 4) 469 470 struct ipfw_ioc_flowid { 471 uint16_t type; /* ETHERTYPE_ */ 472 uint16_t pad; 473 union { 474 struct { 475 uint32_t dst_ip; /* host byte order */ 476 uint32_t src_ip; /* host byte order */ 477 uint16_t dst_port; /* host byte order */ 478 uint16_t src_port; /* host byte order */ 479 uint8_t proto; 480 } ip; 481 uint8_t pad[64]; 482 } u; 483 }; 484 485 struct ipfw_ioc_state { 486 uint32_t expire; /* expire time */ 487 uint64_t pcnt; /* packet match counter */ 488 uint64_t bcnt; /* byte match counter */ 489 490 uint16_t dyn_type; /* rule type */ 491 uint16_t count; /* refcount */ 492 493 uint16_t rulenum; /* rule number */ 494 495 uint16_t xlat_port; /* xlate port, host byte order */ 496 uint32_t xlat_addr; /* xlate addr, host byte order */ 497 498 struct ipfw_ioc_flowid id; /* (masked) flow id */ 499 uint8_t reserved[16]; 500 }; 501 502 /* 503 * Definitions for IP option names. 504 */ 505 #define IP_FW_IPOPT_LSRR 0x01 506 #define IP_FW_IPOPT_SSRR 0x02 507 #define IP_FW_IPOPT_RR 0x04 508 #define IP_FW_IPOPT_TS 0x08 509 510 /* 511 * Definitions for TCP option names. 512 */ 513 #define IP_FW_TCPOPT_MSS 0x01 514 #define IP_FW_TCPOPT_WINDOW 0x02 515 #define IP_FW_TCPOPT_SACK 0x04 516 #define IP_FW_TCPOPT_TS 0x08 517 #define IP_FW_TCPOPT_CC 0x10 518 519 #define ICMP_REJECT_RST 0x100 /* fake ICMP code (send a TCP RST) */ 520 521 /* 522 * IP_FW_TBL_CREATE, tableid >= 0. 523 * IP_FW_TBL_FLUSH, tableid >= 0. 524 * IP_FW_TBL_FLUSH, tableid < 0, flush all tables. 525 * IP_FW_TBL_DESTROY, tableid >= 0. 526 * IP_FW_TBL_ZERO, tableid >= 0. 527 * IP_FW_TBL_ZERO, tableid < 0, zero all tables' counters. 528 */ 529 struct ipfw_ioc_table { 530 int tableid; 531 }; 532 533 struct ipfw_ioc_tblent { 534 struct sockaddr_in key; 535 struct sockaddr_in netmask; 536 u_long use; 537 time_t last_used; 538 long unused[2]; 539 }; 540 541 /* 542 * IP_FW_TBL_GET, tableid < 0, list of all tables. 543 */ 544 struct ipfw_ioc_tbllist { 545 int tableid; /* MUST be the first field */ 546 int tablecnt; 547 uint16_t tables[]; 548 }; 549 550 /* 551 * IP_FW_TBL_GET, tableid >= 0, entries in the table. 552 * IP_FW_TBL_ADD, tableid >= 0, entcnt == 1. 553 * IP_FW_TBL_DEL, tableid >= 0, entcnt == 1. 554 */ 555 struct ipfw_ioc_tblcont { 556 int tableid; /* MUST be the first field */ 557 int entcnt; 558 struct ipfw_ioc_tblent ent[1]; 559 }; 560 561 /* 562 * IP_FW_TBL_EXPIRE, tableid < 0, expire all tables. 563 * IP_FW_TBL_EXPIRE, tableid >= 0. 564 */ 565 struct ipfw_ioc_tblexp { 566 int tableid; 567 int expcnt; 568 time_t expire; 569 u_long unused1[2]; 570 }; 571 572 #endif /* _IPFW2_H */ 573