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, /* 1*u32 = icmp type 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 O_RESERVED1, /* reserved for NAT */ 129 130 O_ICMPCODE, /* 1*u32 = icmp code bitmap */ 131 132 O_LAST_OPCODE /* not an opcode! */ 133 }; 134 #ifdef _KERNEL 135 CTASSERT(O_LAST_OPCODE <= 256); 136 #endif 137 138 /* 139 * Template for instructions. 140 * 141 * ipfw_insn is used for all instructions which require no operands, 142 * a single 16-bit value (arg1), or a couple of 8-bit values. 143 * 144 * For other instructions which require different/larger arguments 145 * we have derived structures, ipfw_insn_*. 146 * 147 * The size of the instruction (in 32-bit words) is in the low 148 * 6 bits of "len". The 2 remaining bits are used to implement 149 * NOT and OR on individual instructions. Given a type, you can 150 * compute the length to be put in "len" using F_INSN_SIZE(t) 151 * 152 * F_NOT negates the match result of the instruction. 153 * 154 * F_OR is used to build or blocks. By default, instructions 155 * are evaluated as part of a logical AND. An "or" block 156 * { X or Y or Z } contains F_OR set in all but the last 157 * instruction of the block. A match will cause the code 158 * to skip past the last instruction of the block. 159 * 160 * NOTA BENE: in a couple of places we assume that 161 * sizeof(ipfw_insn) == sizeof(uint32_t) 162 * this needs to be fixed. 163 * 164 */ 165 typedef struct _ipfw_insn { /* template for instructions */ 166 enum ipfw_opcodes opcode:8; 167 uint8_t len; /* numer of 32-byte words */ 168 #define F_NOT 0x80 169 #define F_OR 0x40 170 #define F_LEN_MASK 0x3f 171 #define F_LEN(cmd) ((cmd)->len & F_LEN_MASK) 172 173 uint16_t arg1; 174 } ipfw_insn; 175 176 #define IPFW_INSN_SIZE_MAX 63 /* unit: uint32_t */ 177 178 /* 179 * The F_INSN_SIZE(type) computes the size, in 4-byte words, of 180 * a given type. 181 */ 182 #define F_INSN_SIZE(t) ((sizeof (t))/sizeof(uint32_t)) 183 184 /* 185 * This is used to store an array of 16-bit entries (ports etc.) 186 */ 187 typedef struct _ipfw_insn_u16 { 188 ipfw_insn o; 189 uint16_t ports[2]; /* there may be more */ 190 } ipfw_insn_u16; 191 192 /* 193 * This is used to store an array of 32-bit entries 194 * (uid, single IPv4 addresses etc.) 195 */ 196 typedef struct _ipfw_insn_u32 { 197 ipfw_insn o; 198 uint32_t d[1]; /* one or more */ 199 } ipfw_insn_u32; 200 201 /* 202 * This is used to store IP addr-mask pairs. 203 */ 204 typedef struct _ipfw_insn_ip { 205 ipfw_insn o; 206 struct in_addr addr; 207 struct in_addr mask; 208 } ipfw_insn_ip; 209 210 /* 211 * This is used to forward to a given address (ip) 212 */ 213 typedef struct _ipfw_insn_sa { 214 ipfw_insn o; 215 struct sockaddr_in sa; 216 } ipfw_insn_sa; 217 218 /* 219 * This is used for MAC addr-mask pairs. 220 */ 221 typedef struct _ipfw_insn_mac { 222 ipfw_insn o; 223 u_char addr[12]; /* dst[6] + src[6] */ 224 u_char mask[12]; /* dst[6] + src[6] */ 225 } ipfw_insn_mac; 226 227 /* 228 * This is used for interface match rules (recv xx, xmit xx) 229 */ 230 typedef struct _ipfw_insn_if { 231 ipfw_insn o; 232 union { 233 struct in_addr ip; 234 int glob; 235 } p; 236 char name[IFNAMSIZ]; 237 } ipfw_insn_if; 238 239 /* 240 * This is used for pipe and queue actions, which need to store 241 * a single pointer (which can have different size on different 242 * architectures. 243 */ 244 typedef struct _ipfw_insn_pipe { 245 ipfw_insn o; 246 void *pipe_ptr; 247 } ipfw_insn_pipe; 248 249 /* 250 * This is used for limit rules. 251 */ 252 typedef struct _ipfw_insn_limit { 253 ipfw_insn o; 254 uint8_t _pad; 255 uint8_t limit_mask; /* combination of DYN_* below */ 256 #define DYN_SRC_ADDR 0x1 257 #define DYN_SRC_PORT 0x2 258 #define DYN_DST_ADDR 0x4 259 #define DYN_DST_PORT 0x8 260 261 uint16_t conn_limit; 262 } ipfw_insn_limit; 263 264 /* 265 * This is used for log instructions 266 */ 267 typedef struct _ipfw_insn_log { 268 ipfw_insn o; 269 uint32_t max_log; /* how many do we log -- 0 = all */ 270 uint32_t log_left; /* how many left to log */ 271 } ipfw_insn_log; 272 273 /* 274 * This is used by O_IP_{SRC,DST}_IFIP. 275 */ 276 typedef struct _ipfw_insn_ifip { 277 ipfw_insn o; /* arg1 & 0x1, addr is valid */ 278 #define IPFW_IFIP_VALID 0x0001 279 #define IPFW_IFIP_NET 0x0002 280 #define IPFW_IFIP_SETTINGS IPFW_IFIP_NET 281 char ifname[IFNAMSIZ]; 282 struct in_addr addr; 283 struct in_addr mask; 284 } ipfw_insn_ifip; 285 286 /* 287 * This is used by O_REDIRECT. 288 */ 289 typedef struct _ipfw_insn_rdr { 290 ipfw_insn o; 291 struct in_addr addr; 292 uint16_t port; /* network byte order, 0 = same port */ 293 uint16_t set; /* reserved for set, 0xffff */ 294 } ipfw_insn_rdr; 295 296 #ifdef _KERNEL 297 298 /* 299 * Here we have the structure representing an ipfw rule. 300 * 301 * It starts with a general area (with link fields and counters) 302 * followed by an array of one or more instructions, which the code 303 * accesses as an array of 32-bit values. 304 * 305 * Given a rule pointer r: 306 * 307 * r->cmd is the start of the first instruction. 308 * ACTION_PTR(r) is the start of the first action (things to do 309 * once a rule matched). 310 * 311 * When assembling instruction, remember the following: 312 * 313 * + if a rule has a "keep-state" (or "limit") option, then the 314 * first instruction (at r->cmd) MUST BE an O_PROBE_STATE 315 * + if a rule has a "log" option, then the first action 316 * (at ACTION_PTR(r)) MUST be O_LOG 317 * 318 * NOTE: we use a simple linked list of rules because we never need 319 * to delete a rule without scanning the list. We do not use 320 * queue(3) macros for portability and readability. 321 */ 322 323 struct ip_fw { 324 struct ip_fw *next; /* linked list of rules */ 325 struct ip_fw *next_rule; /* ptr to next [skipto] rule */ 326 uint16_t act_ofs; /* offset of action in 32-bit units */ 327 uint16_t cmd_len; /* # of 32-bit words in cmd */ 328 uint16_t rulenum; /* rule number */ 329 uint8_t set; /* rule set (0..31) */ 330 uint8_t usr_flags; /* IPFW_USR_F_ */ 331 332 /* These fields are present in all rules. */ 333 uint64_t pcnt; /* Packet counter */ 334 uint64_t bcnt; /* Byte counter */ 335 uint32_t timestamp; /* tv_sec of last match */ 336 337 int cpuid; /* owner cpu */ 338 struct ip_fw *sibling; /* clone on next cpu */ 339 340 struct ip_fw **cross_rules; /* cross referenced rules */ 341 volatile uint64_t cross_refs; /* cross references */ 342 343 uint32_t refcnt; /* Ref count for transit pkts */ 344 uint32_t rule_flags; /* IPFW_RULE_F_ */ 345 uintptr_t track_ruleid; /* ruleid for src/dst tracks */ 346 347 ipfw_insn cmd[1]; /* storage for commands */ 348 }; 349 350 #define IPFW_RULE_F_INVALID 0x1 351 /* unused 0x2 */ 352 #define IPFW_RULE_F_GENSTATE 0x4 353 #define IPFW_RULE_F_GENTRACK 0x8 354 #define IPFW_RULE_F_CROSSREF 0x10 355 #define IPFW_RULE_F_DYNIFADDR 0x20 356 357 #define RULESIZE(rule) (sizeof(struct ip_fw) + (rule)->cmd_len * 4 - 4) 358 359 /* 360 * This structure is used as a flow mask and a flow id for various 361 * parts of the code. 362 */ 363 struct ipfw_flow_id { 364 uint32_t dst_ip; /* host byte order */ 365 uint32_t src_ip; /* host byte order */ 366 uint16_t dst_port; /* host byte order */ 367 uint16_t src_port; /* host byte order */ 368 uint8_t proto; 369 uint8_t flags; /* protocol-specific flags */ 370 }; 371 372 /* 373 * Main firewall chains definitions and global var's definitions. 374 */ 375 376 /* ipfw_chk/ip_fw_chk_ptr return values */ 377 #define IP_FW_PASS 0 378 #define IP_FW_DENY 1 379 #define IP_FW_DIVERT 2 380 #define IP_FW_TEE 3 381 #define IP_FW_DUMMYNET 4 382 #define IP_FW_REDISPATCH 6 383 384 /* 385 * arguments for calling ipfw_chk() and dummynet_io(). We put them 386 * all into a structure because this way it is easier and more 387 * efficient to pass variables around and extend the interface. 388 */ 389 struct ip_fw_args { 390 struct mbuf *m; /* the mbuf chain */ 391 struct ifnet *oif; /* output interface */ 392 struct ip_fw *rule; /* matching rule */ 393 struct ipfw_xlat *xlat; /* matching xlate */ 394 struct ether_header *eh; /* for bridged packets */ 395 396 struct ipfw_flow_id f_id; /* grabbed from IP header */ 397 uint8_t flags; 398 #define IP_FWARG_F_CONT 0x01 399 #define IP_FWARG_F_XLATINS 0x02 400 #define IP_FWARG_F_XLATFWD 0x04 401 402 /* 403 * Depend on the return value of ipfw_chk/ip_fw_chk_ptr 404 * 'cookie' field may save following information: 405 * 406 * IP_FW_TEE or IP_FW_DIVERT 407 * The divert port number 408 * 409 * IP_FW_DUMMYNET 410 * The pipe or queue number 411 */ 412 uint32_t cookie; 413 }; 414 415 /* 416 * Function definitions. 417 */ 418 int ip_fw_sockopt(struct sockopt *); 419 420 /* Firewall hooks */ 421 struct sockopt; 422 struct dn_flow_set; 423 424 typedef int ip_fw_chk_t(struct ip_fw_args *); 425 typedef int ip_fw_ctl_t(struct sockopt *); 426 typedef struct mbuf 427 *ip_fw_dn_io_t(struct mbuf *, int, int, struct ip_fw_args *); 428 429 extern ip_fw_chk_t *ip_fw_chk_ptr; 430 extern ip_fw_ctl_t *ip_fw_ctl_ptr; 431 extern ip_fw_dn_io_t *ip_fw_dn_io_ptr; 432 433 extern int fw_one_pass; 434 extern int fw_enable; 435 436 extern int ip_fw_loaded; 437 #define IPFW_LOADED (ip_fw_loaded) 438 439 #endif /* _KERNEL */ 440 441 #define ACTION_PTR(rule) \ 442 (ipfw_insn *)((uint32_t *)((rule)->cmd) + ((rule)->act_ofs)) 443 444 struct ipfw_ioc_rule { 445 uint16_t act_ofs; /* offset of action in 32-bit units */ 446 uint16_t cmd_len; /* # of 32-bit words in cmd */ 447 uint16_t rulenum; /* rule number */ 448 uint8_t set; /* rule set (0..31) */ 449 uint8_t usr_flags; /* IPFW_USR_F_ */ 450 451 /* Rule set information */ 452 uint32_t set_disable; /* disabled rule sets */ 453 uint32_t static_count; /* # of static rules */ 454 uint32_t static_len; /* total length of static rules */ 455 456 /* Statistics */ 457 uint64_t pcnt; /* Packet counter */ 458 uint64_t bcnt; /* Byte counter */ 459 uint32_t timestamp; /* tv_sec of last match */ 460 461 uint8_t reserved[16]; 462 463 ipfw_insn cmd[1]; /* storage for commands */ 464 }; 465 466 #define IPFW_USR_F_NORULE 0x01 467 468 #define IPFW_RULE_SIZE_MAX 255 /* unit: uint32_t */ 469 470 #define IOC_RULESIZE(rule) \ 471 (sizeof(struct ipfw_ioc_rule) + (rule)->cmd_len * 4 - 4) 472 473 struct ipfw_ioc_flowid { 474 uint16_t type; /* ETHERTYPE_ */ 475 uint16_t pad; 476 union { 477 struct { 478 uint32_t dst_ip; /* host byte order */ 479 uint32_t src_ip; /* host byte order */ 480 uint16_t dst_port; /* host byte order */ 481 uint16_t src_port; /* host byte order */ 482 uint8_t proto; 483 } ip; 484 uint8_t pad[64]; 485 } u; 486 }; 487 488 struct ipfw_ioc_state { 489 uint32_t expire; /* expire time */ 490 uint64_t pcnt; /* packet match counter */ 491 uint64_t bcnt; /* byte match counter */ 492 493 uint16_t dyn_type; /* rule type */ 494 uint16_t count; /* refcount */ 495 496 uint16_t rulenum; /* rule number */ 497 498 uint16_t xlat_port; /* xlate port, host byte order */ 499 uint32_t xlat_addr; /* xlate addr, host byte order */ 500 501 struct ipfw_ioc_flowid id; /* (masked) flow id */ 502 uint8_t reserved[16]; 503 }; 504 505 /* 506 * Definitions for IP option names. 507 */ 508 #define IP_FW_IPOPT_LSRR 0x01 509 #define IP_FW_IPOPT_SSRR 0x02 510 #define IP_FW_IPOPT_RR 0x04 511 #define IP_FW_IPOPT_TS 0x08 512 513 /* 514 * Definitions for TCP option names. 515 */ 516 #define IP_FW_TCPOPT_MSS 0x01 517 #define IP_FW_TCPOPT_WINDOW 0x02 518 #define IP_FW_TCPOPT_SACK 0x04 519 #define IP_FW_TCPOPT_TS 0x08 520 #define IP_FW_TCPOPT_CC 0x10 521 522 #define ICMP_REJECT_RST 0x100 /* fake ICMP code (send a TCP RST) */ 523 524 /* 525 * IP_FW_TBL_CREATE, tableid >= 0. 526 * IP_FW_TBL_FLUSH, tableid >= 0. 527 * IP_FW_TBL_FLUSH, tableid < 0, flush all tables. 528 * IP_FW_TBL_DESTROY, tableid >= 0. 529 * IP_FW_TBL_ZERO, tableid >= 0. 530 * IP_FW_TBL_ZERO, tableid < 0, zero all tables' counters. 531 */ 532 struct ipfw_ioc_table { 533 int tableid; 534 }; 535 536 struct ipfw_ioc_tblent { 537 struct sockaddr_in key; 538 struct sockaddr_in netmask; 539 u_long use; 540 time_t last_used; 541 long unused[2]; 542 }; 543 544 /* 545 * IP_FW_TBL_GET, tableid < 0, list of all tables. 546 */ 547 struct ipfw_ioc_tbllist { 548 int tableid; /* MUST be the first field */ 549 int tablecnt; 550 uint16_t tables[]; 551 }; 552 553 /* 554 * IP_FW_TBL_GET, tableid >= 0, entries in the table. 555 * IP_FW_TBL_ADD, tableid >= 0, entcnt == 1. 556 * IP_FW_TBL_DEL, tableid >= 0, entcnt == 1. 557 */ 558 struct ipfw_ioc_tblcont { 559 int tableid; /* MUST be the first field */ 560 int entcnt; 561 struct ipfw_ioc_tblent ent[1]; 562 }; 563 564 /* 565 * IP_FW_TBL_EXPIRE, tableid < 0, expire all tables. 566 * IP_FW_TBL_EXPIRE, tableid >= 0. 567 */ 568 struct ipfw_ioc_tblexp { 569 int tableid; 570 int expcnt; 571 time_t expire; 572 u_long unused1[2]; 573 }; 574 575 #endif /* _IPFW2_H */ 576