1 /*- 2 * Copyright (c) 2002-2009 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 * $FreeBSD$ 26 */ 27 28 #ifndef _IPFW2_H 29 #define _IPFW2_H 30 31 /* 32 * The default rule number. By the design of ip_fw, the default rule 33 * is the last one, so its number can also serve as the highest number 34 * allowed for a rule. The ip_fw code relies on both meanings of this 35 * constant. 36 */ 37 #define IPFW_DEFAULT_RULE 65535 38 39 /* 40 * The number of ipfw tables. The maximum allowed table number is the 41 * (IPFW_TABLES_MAX - 1). 42 */ 43 #define IPFW_TABLES_MAX 128 44 45 /* 46 * Most commands (queue, pipe, tag, untag, limit...) can have a 16-bit 47 * argument between 1 and 65534. The value 0 is unused, the value 48 * 65535 (IP_FW_TABLEARG) is used to represent 'tablearg', i.e. the 49 * can be 1..65534, or 65535 to indicate the use of a 'tablearg' 50 * result of the most recent table() lookup. 51 * Note that 16bit is only a historical limit, resulting from 52 * the use of a 16-bit fields for that value. In reality, we can have 53 * 2^32 pipes, queues, tag values and so on, and use 0 as a tablearg. 54 */ 55 #define IPFW_ARG_MIN 1 56 #define IPFW_ARG_MAX 65534 57 #define IP_FW_TABLEARG 65535 /* XXX should use 0 */ 58 59 /* 60 * Number of entries in the call stack of the call/return commands. 61 * Call stack currently is an uint16_t array with rule numbers. 62 */ 63 #define IPFW_CALLSTACK_SIZE 16 64 65 /* 66 * The kernel representation of ipfw rules is made of a list of 67 * 'instructions' (for all practical purposes equivalent to BPF 68 * instructions), which specify which fields of the packet 69 * (or its metadata) should be analysed. 70 * 71 * Each instruction is stored in a structure which begins with 72 * "ipfw_insn", and can contain extra fields depending on the 73 * instruction type (listed below). 74 * Note that the code is written so that individual instructions 75 * have a size which is a multiple of 32 bits. This means that, if 76 * such structures contain pointers or other 64-bit entities, 77 * (there is just one instance now) they may end up unaligned on 78 * 64-bit architectures, so the must be handled with care. 79 * 80 * "enum ipfw_opcodes" are the opcodes supported. We can have up 81 * to 256 different opcodes. When adding new opcodes, they should 82 * be appended to the end of the opcode list before O_LAST_OPCODE, 83 * this will prevent the ABI from being broken, otherwise users 84 * will have to recompile ipfw(8) when they update the kernel. 85 */ 86 87 enum ipfw_opcodes { /* arguments (4 byte each) */ 88 O_NOP, 89 90 O_IP_SRC, /* u32 = IP */ 91 O_IP_SRC_MASK, /* ip = IP/mask */ 92 O_IP_SRC_ME, /* none */ 93 O_IP_SRC_SET, /* u32=base, arg1=len, bitmap */ 94 95 O_IP_DST, /* u32 = IP */ 96 O_IP_DST_MASK, /* ip = IP/mask */ 97 O_IP_DST_ME, /* none */ 98 O_IP_DST_SET, /* u32=base, arg1=len, bitmap */ 99 100 O_IP_SRCPORT, /* (n)port list:mask 4 byte ea */ 101 O_IP_DSTPORT, /* (n)port list:mask 4 byte ea */ 102 O_PROTO, /* arg1=protocol */ 103 104 O_MACADDR2, /* 2 mac addr:mask */ 105 O_MAC_TYPE, /* same as srcport */ 106 107 O_LAYER2, /* none */ 108 O_IN, /* none */ 109 O_FRAG, /* none */ 110 111 O_RECV, /* none */ 112 O_XMIT, /* none */ 113 O_VIA, /* none */ 114 115 O_IPOPT, /* arg1 = 2*u8 bitmap */ 116 O_IPLEN, /* arg1 = len */ 117 O_IPID, /* arg1 = id */ 118 119 O_IPTOS, /* arg1 = id */ 120 O_IPPRECEDENCE, /* arg1 = precedence << 5 */ 121 O_IPTTL, /* arg1 = TTL */ 122 123 O_IPVER, /* arg1 = version */ 124 O_UID, /* u32 = id */ 125 O_GID, /* u32 = id */ 126 O_ESTAB, /* none (tcp established) */ 127 O_TCPFLAGS, /* arg1 = 2*u8 bitmap */ 128 O_TCPWIN, /* arg1 = desired win */ 129 O_TCPSEQ, /* u32 = desired seq. */ 130 O_TCPACK, /* u32 = desired seq. */ 131 O_ICMPTYPE, /* u32 = icmp bitmap */ 132 O_TCPOPTS, /* arg1 = 2*u8 bitmap */ 133 134 O_VERREVPATH, /* none */ 135 O_VERSRCREACH, /* none */ 136 137 O_PROBE_STATE, /* none */ 138 O_KEEP_STATE, /* none */ 139 O_LIMIT, /* ipfw_insn_limit */ 140 O_LIMIT_PARENT, /* dyn_type, not an opcode. */ 141 142 /* 143 * These are really 'actions'. 144 */ 145 146 O_LOG, /* ipfw_insn_log */ 147 O_PROB, /* u32 = match probability */ 148 149 O_CHECK_STATE, /* none */ 150 O_ACCEPT, /* none */ 151 O_DENY, /* none */ 152 O_REJECT, /* arg1=icmp arg (same as deny) */ 153 O_COUNT, /* none */ 154 O_SKIPTO, /* arg1=next rule number */ 155 O_PIPE, /* arg1=pipe number */ 156 O_QUEUE, /* arg1=queue number */ 157 O_DIVERT, /* arg1=port number */ 158 O_TEE, /* arg1=port number */ 159 O_FORWARD_IP, /* fwd sockaddr */ 160 O_FORWARD_MAC, /* fwd mac */ 161 O_NAT, /* nope */ 162 O_REASS, /* none */ 163 164 /* 165 * More opcodes. 166 */ 167 O_IPSEC, /* has ipsec history */ 168 O_IP_SRC_LOOKUP, /* arg1=table number, u32=value */ 169 O_IP_DST_LOOKUP, /* arg1=table number, u32=value */ 170 O_ANTISPOOF, /* none */ 171 O_JAIL, /* u32 = id */ 172 O_ALTQ, /* u32 = altq classif. qid */ 173 O_DIVERTED, /* arg1=bitmap (1:loop, 2:out) */ 174 O_TCPDATALEN, /* arg1 = tcp data len */ 175 O_IP6_SRC, /* address without mask */ 176 O_IP6_SRC_ME, /* my addresses */ 177 O_IP6_SRC_MASK, /* address with the mask */ 178 O_IP6_DST, 179 O_IP6_DST_ME, 180 O_IP6_DST_MASK, 181 O_FLOW6ID, /* for flow id tag in the ipv6 pkt */ 182 O_ICMP6TYPE, /* icmp6 packet type filtering */ 183 O_EXT_HDR, /* filtering for ipv6 extension header */ 184 O_IP6, 185 186 /* 187 * actions for ng_ipfw 188 */ 189 O_NETGRAPH, /* send to ng_ipfw */ 190 O_NGTEE, /* copy to ng_ipfw */ 191 192 O_IP4, 193 194 O_UNREACH6, /* arg1=icmpv6 code arg (deny) */ 195 196 O_TAG, /* arg1=tag number */ 197 O_TAGGED, /* arg1=tag number */ 198 199 O_SETFIB, /* arg1=FIB number */ 200 O_FIB, /* arg1=FIB desired fib number */ 201 202 O_SOCKARG, /* socket argument */ 203 204 O_CALLRETURN, /* arg1=called rule number */ 205 206 O_FORWARD_IP6, /* fwd sockaddr_in6 */ 207 208 O_LAST_OPCODE /* not an opcode! */ 209 }; 210 211 212 /* 213 * The extension header are filtered only for presence using a bit 214 * vector with a flag for each header. 215 */ 216 #define EXT_FRAGMENT 0x1 217 #define EXT_HOPOPTS 0x2 218 #define EXT_ROUTING 0x4 219 #define EXT_AH 0x8 220 #define EXT_ESP 0x10 221 #define EXT_DSTOPTS 0x20 222 #define EXT_RTHDR0 0x40 223 #define EXT_RTHDR2 0x80 224 225 /* 226 * Template for instructions. 227 * 228 * ipfw_insn is used for all instructions which require no operands, 229 * a single 16-bit value (arg1), or a couple of 8-bit values. 230 * 231 * For other instructions which require different/larger arguments 232 * we have derived structures, ipfw_insn_*. 233 * 234 * The size of the instruction (in 32-bit words) is in the low 235 * 6 bits of "len". The 2 remaining bits are used to implement 236 * NOT and OR on individual instructions. Given a type, you can 237 * compute the length to be put in "len" using F_INSN_SIZE(t) 238 * 239 * F_NOT negates the match result of the instruction. 240 * 241 * F_OR is used to build or blocks. By default, instructions 242 * are evaluated as part of a logical AND. An "or" block 243 * { X or Y or Z } contains F_OR set in all but the last 244 * instruction of the block. A match will cause the code 245 * to skip past the last instruction of the block. 246 * 247 * NOTA BENE: in a couple of places we assume that 248 * sizeof(ipfw_insn) == sizeof(u_int32_t) 249 * this needs to be fixed. 250 * 251 */ 252 typedef struct _ipfw_insn { /* template for instructions */ 253 u_int8_t opcode; 254 u_int8_t len; /* number of 32-bit words */ 255 #define F_NOT 0x80 256 #define F_OR 0x40 257 #define F_LEN_MASK 0x3f 258 #define F_LEN(cmd) ((cmd)->len & F_LEN_MASK) 259 260 u_int16_t arg1; 261 } ipfw_insn; 262 263 /* 264 * The F_INSN_SIZE(type) computes the size, in 4-byte words, of 265 * a given type. 266 */ 267 #define F_INSN_SIZE(t) ((sizeof (t))/sizeof(u_int32_t)) 268 269 /* 270 * This is used to store an array of 16-bit entries (ports etc.) 271 */ 272 typedef struct _ipfw_insn_u16 { 273 ipfw_insn o; 274 u_int16_t ports[2]; /* there may be more */ 275 } ipfw_insn_u16; 276 277 /* 278 * This is used to store an array of 32-bit entries 279 * (uid, single IPv4 addresses etc.) 280 */ 281 typedef struct _ipfw_insn_u32 { 282 ipfw_insn o; 283 u_int32_t d[1]; /* one or more */ 284 } ipfw_insn_u32; 285 286 /* 287 * This is used to store IP addr-mask pairs. 288 */ 289 typedef struct _ipfw_insn_ip { 290 ipfw_insn o; 291 struct in_addr addr; 292 struct in_addr mask; 293 } ipfw_insn_ip; 294 295 /* 296 * This is used to forward to a given address (ip). 297 */ 298 typedef struct _ipfw_insn_sa { 299 ipfw_insn o; 300 struct sockaddr_in sa; 301 } ipfw_insn_sa; 302 303 /* 304 * This is used to forward to a given address (ipv6). 305 */ 306 typedef struct _ipfw_insn_sa6 { 307 ipfw_insn o; 308 struct sockaddr_in6 sa; 309 } ipfw_insn_sa6; 310 311 /* 312 * This is used for MAC addr-mask pairs. 313 */ 314 typedef struct _ipfw_insn_mac { 315 ipfw_insn o; 316 u_char addr[12]; /* dst[6] + src[6] */ 317 u_char mask[12]; /* dst[6] + src[6] */ 318 } ipfw_insn_mac; 319 320 /* 321 * This is used for interface match rules (recv xx, xmit xx). 322 */ 323 typedef struct _ipfw_insn_if { 324 ipfw_insn o; 325 union { 326 struct in_addr ip; 327 int glob; 328 } p; 329 char name[IFNAMSIZ]; 330 } ipfw_insn_if; 331 332 /* 333 * This is used for storing an altq queue id number. 334 */ 335 typedef struct _ipfw_insn_altq { 336 ipfw_insn o; 337 u_int32_t qid; 338 } ipfw_insn_altq; 339 340 /* 341 * This is used for limit rules. 342 */ 343 typedef struct _ipfw_insn_limit { 344 ipfw_insn o; 345 u_int8_t _pad; 346 u_int8_t limit_mask; /* combination of DYN_* below */ 347 #define DYN_SRC_ADDR 0x1 348 #define DYN_SRC_PORT 0x2 349 #define DYN_DST_ADDR 0x4 350 #define DYN_DST_PORT 0x8 351 352 u_int16_t conn_limit; 353 } ipfw_insn_limit; 354 355 /* 356 * This is used for log instructions. 357 */ 358 typedef struct _ipfw_insn_log { 359 ipfw_insn o; 360 u_int32_t max_log; /* how many do we log -- 0 = all */ 361 u_int32_t log_left; /* how many left to log */ 362 } ipfw_insn_log; 363 364 /* 365 * Data structures required by both ipfw(8) and ipfw(4) but not part of the 366 * management API are protected by IPFW_INTERNAL. 367 */ 368 #ifdef IPFW_INTERNAL 369 /* Server pool support (LSNAT). */ 370 struct cfg_spool { 371 LIST_ENTRY(cfg_spool) _next; /* chain of spool instances */ 372 struct in_addr addr; 373 u_short port; 374 }; 375 #endif 376 377 /* Redirect modes id. */ 378 #define REDIR_ADDR 0x01 379 #define REDIR_PORT 0x02 380 #define REDIR_PROTO 0x04 381 382 #ifdef IPFW_INTERNAL 383 /* Nat redirect configuration. */ 384 struct cfg_redir { 385 LIST_ENTRY(cfg_redir) _next; /* chain of redir instances */ 386 u_int16_t mode; /* type of redirect mode */ 387 struct in_addr laddr; /* local ip address */ 388 struct in_addr paddr; /* public ip address */ 389 struct in_addr raddr; /* remote ip address */ 390 u_short lport; /* local port */ 391 u_short pport; /* public port */ 392 u_short rport; /* remote port */ 393 u_short pport_cnt; /* number of public ports */ 394 u_short rport_cnt; /* number of remote ports */ 395 int proto; /* protocol: tcp/udp */ 396 struct alias_link **alink; 397 /* num of entry in spool chain */ 398 u_int16_t spool_cnt; 399 /* chain of spool instances */ 400 LIST_HEAD(spool_chain, cfg_spool) spool_chain; 401 }; 402 #endif 403 404 #ifdef IPFW_INTERNAL 405 /* Nat configuration data struct. */ 406 struct cfg_nat { 407 /* chain of nat instances */ 408 LIST_ENTRY(cfg_nat) _next; 409 int id; /* nat id */ 410 struct in_addr ip; /* nat ip address */ 411 char if_name[IF_NAMESIZE]; /* interface name */ 412 int mode; /* aliasing mode */ 413 struct libalias *lib; /* libalias instance */ 414 /* number of entry in spool chain */ 415 int redir_cnt; 416 /* chain of redir instances */ 417 LIST_HEAD(redir_chain, cfg_redir) redir_chain; 418 }; 419 #endif 420 421 #define SOF_NAT sizeof(struct cfg_nat) 422 #define SOF_REDIR sizeof(struct cfg_redir) 423 #define SOF_SPOOL sizeof(struct cfg_spool) 424 425 /* Nat command. */ 426 typedef struct _ipfw_insn_nat { 427 ipfw_insn o; 428 struct cfg_nat *nat; 429 } ipfw_insn_nat; 430 431 /* Apply ipv6 mask on ipv6 addr */ 432 #define APPLY_MASK(addr,mask) \ 433 (addr)->__u6_addr.__u6_addr32[0] &= (mask)->__u6_addr.__u6_addr32[0]; \ 434 (addr)->__u6_addr.__u6_addr32[1] &= (mask)->__u6_addr.__u6_addr32[1]; \ 435 (addr)->__u6_addr.__u6_addr32[2] &= (mask)->__u6_addr.__u6_addr32[2]; \ 436 (addr)->__u6_addr.__u6_addr32[3] &= (mask)->__u6_addr.__u6_addr32[3]; 437 438 /* Structure for ipv6 */ 439 typedef struct _ipfw_insn_ip6 { 440 ipfw_insn o; 441 struct in6_addr addr6; 442 struct in6_addr mask6; 443 } ipfw_insn_ip6; 444 445 /* Used to support icmp6 types */ 446 typedef struct _ipfw_insn_icmp6 { 447 ipfw_insn o; 448 uint32_t d[7]; /* XXX This number si related to the netinet/icmp6.h 449 * define ICMP6_MAXTYPE 450 * as follows: n = ICMP6_MAXTYPE/32 + 1 451 * Actually is 203 452 */ 453 } ipfw_insn_icmp6; 454 455 /* 456 * Here we have the structure representing an ipfw rule. 457 * 458 * It starts with a general area (with link fields and counters) 459 * followed by an array of one or more instructions, which the code 460 * accesses as an array of 32-bit values. 461 * 462 * Given a rule pointer r: 463 * 464 * r->cmd is the start of the first instruction. 465 * ACTION_PTR(r) is the start of the first action (things to do 466 * once a rule matched). 467 * 468 * When assembling instruction, remember the following: 469 * 470 * + if a rule has a "keep-state" (or "limit") option, then the 471 * first instruction (at r->cmd) MUST BE an O_PROBE_STATE 472 * + if a rule has a "log" option, then the first action 473 * (at ACTION_PTR(r)) MUST be O_LOG 474 * + if a rule has an "altq" option, it comes after "log" 475 * + if a rule has an O_TAG option, it comes after "log" and "altq" 476 * 477 * NOTE: we use a simple linked list of rules because we never need 478 * to delete a rule without scanning the list. We do not use 479 * queue(3) macros for portability and readability. 480 */ 481 482 struct ip_fw { 483 struct ip_fw *x_next; /* linked list of rules */ 484 struct ip_fw *next_rule; /* ptr to next [skipto] rule */ 485 /* 'next_rule' is used to pass up 'set_disable' status */ 486 487 uint16_t act_ofs; /* offset of action in 32-bit units */ 488 uint16_t cmd_len; /* # of 32-bit words in cmd */ 489 uint16_t rulenum; /* rule number */ 490 uint8_t set; /* rule set (0..31) */ 491 #define RESVD_SET 31 /* set for default and persistent rules */ 492 uint8_t _pad; /* padding */ 493 uint32_t id; /* rule id */ 494 495 /* These fields are present in all rules. */ 496 uint64_t pcnt; /* Packet counter */ 497 uint64_t bcnt; /* Byte counter */ 498 uint32_t timestamp; /* tv_sec of last match */ 499 500 ipfw_insn cmd[1]; /* storage for commands */ 501 }; 502 503 #define ACTION_PTR(rule) \ 504 (ipfw_insn *)( (u_int32_t *)((rule)->cmd) + ((rule)->act_ofs) ) 505 506 #define RULESIZE(rule) (sizeof(struct ip_fw) + \ 507 ((struct ip_fw *)(rule))->cmd_len * 4 - 4) 508 509 #if 1 // should be moved to in.h 510 /* 511 * This structure is used as a flow mask and a flow id for various 512 * parts of the code. 513 * addr_type is used in userland and kernel to mark the address type. 514 * fib is used in the kernel to record the fib in use. 515 * _flags is used in the kernel to store tcp flags for dynamic rules. 516 */ 517 struct ipfw_flow_id { 518 uint32_t dst_ip; 519 uint32_t src_ip; 520 uint16_t dst_port; 521 uint16_t src_port; 522 uint8_t fib; 523 uint8_t proto; 524 uint8_t _flags; /* protocol-specific flags */ 525 uint8_t addr_type; /* 4=ip4, 6=ip6, 1=ether ? */ 526 struct in6_addr dst_ip6; 527 struct in6_addr src_ip6; 528 uint32_t flow_id6; 529 uint32_t extra; /* queue/pipe or frag_id */ 530 }; 531 #endif 532 533 #define IS_IP6_FLOW_ID(id) ((id)->addr_type == 6) 534 535 /* 536 * Dynamic ipfw rule. 537 */ 538 typedef struct _ipfw_dyn_rule ipfw_dyn_rule; 539 540 struct _ipfw_dyn_rule { 541 ipfw_dyn_rule *next; /* linked list of rules. */ 542 struct ip_fw *rule; /* pointer to rule */ 543 /* 'rule' is used to pass up the rule number (from the parent) */ 544 545 ipfw_dyn_rule *parent; /* pointer to parent rule */ 546 u_int64_t pcnt; /* packet match counter */ 547 u_int64_t bcnt; /* byte match counter */ 548 struct ipfw_flow_id id; /* (masked) flow id */ 549 u_int32_t expire; /* expire time */ 550 u_int32_t bucket; /* which bucket in hash table */ 551 u_int32_t state; /* state of this rule (typically a 552 * combination of TCP flags) 553 */ 554 u_int32_t ack_fwd; /* most recent ACKs in forward */ 555 u_int32_t ack_rev; /* and reverse directions (used */ 556 /* to generate keepalives) */ 557 u_int16_t dyn_type; /* rule type */ 558 u_int16_t count; /* refcount */ 559 }; 560 561 /* 562 * Definitions for IP option names. 563 */ 564 #define IP_FW_IPOPT_LSRR 0x01 565 #define IP_FW_IPOPT_SSRR 0x02 566 #define IP_FW_IPOPT_RR 0x04 567 #define IP_FW_IPOPT_TS 0x08 568 569 /* 570 * Definitions for TCP option names. 571 */ 572 #define IP_FW_TCPOPT_MSS 0x01 573 #define IP_FW_TCPOPT_WINDOW 0x02 574 #define IP_FW_TCPOPT_SACK 0x04 575 #define IP_FW_TCPOPT_TS 0x08 576 #define IP_FW_TCPOPT_CC 0x10 577 578 #define ICMP_REJECT_RST 0x100 /* fake ICMP code (send a TCP RST) */ 579 #define ICMP6_UNREACH_RST 0x100 /* fake ICMPv6 code (send a TCP RST) */ 580 581 /* 582 * These are used for lookup tables. 583 */ 584 typedef struct _ipfw_table_entry { 585 in_addr_t addr; /* network address */ 586 u_int32_t value; /* value */ 587 u_int16_t tbl; /* table number */ 588 u_int8_t masklen; /* mask length */ 589 } ipfw_table_entry; 590 591 typedef struct _ipfw_table { 592 u_int32_t size; /* size of entries in bytes */ 593 u_int32_t cnt; /* # of entries */ 594 u_int16_t tbl; /* table number */ 595 ipfw_table_entry ent[0]; /* entries */ 596 } ipfw_table; 597 598 #endif /* _IPFW2_H */ 599