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