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 * $DragonFly: src/sys/net/ipfw/ip_fw2.h,v 1.17 2008/09/26 12:12:36 sephe Exp $ 27 */ 28 29 #ifndef _IPFW2_H 30 #define _IPFW2_H 31 32 /* 33 * The kernel representation of ipfw rules is made of a list of 34 * 'instructions' (for all practical purposes equivalent to BPF 35 * instructions), which specify which fields of the packet 36 * (or its metatada) should be analysed. 37 * 38 * Each instruction is stored in a structure which begins with 39 * "ipfw_insn", and can contain extra fields depending on the 40 * instruction type (listed below). 41 * 42 * "enum ipfw_opcodes" are the opcodes supported. We can have up 43 * to 256 different opcodes. 44 */ 45 46 enum ipfw_opcodes { /* arguments (4 byte each) */ 47 O_NOP, 48 49 O_IP_SRC, /* u32 = IP */ 50 O_IP_SRC_MASK, /* ip = IP/mask */ 51 O_IP_SRC_ME, /* none */ 52 O_IP_SRC_SET, /* u32=base, arg1=len, bitmap */ 53 54 O_IP_DST, /* u32 = IP */ 55 O_IP_DST_MASK, /* ip = IP/mask */ 56 O_IP_DST_ME, /* none */ 57 O_IP_DST_SET, /* u32=base, arg1=len, bitmap */ 58 59 O_IP_SRCPORT, /* (n)port list:mask 4 byte ea */ 60 O_IP_DSTPORT, /* (n)port list:mask 4 byte ea */ 61 O_PROTO, /* arg1=protocol */ 62 63 O_MACADDR2, /* 2 mac addr:mask */ 64 O_MAC_TYPE, /* same as srcport */ 65 66 O_LAYER2, /* none */ 67 O_IN, /* none */ 68 O_FRAG, /* none */ 69 70 O_RECV, /* none */ 71 O_XMIT, /* none */ 72 O_VIA, /* none */ 73 74 O_IPOPT, /* arg1 = 2*u8 bitmap */ 75 O_IPLEN, /* arg1 = len */ 76 O_IPID, /* arg1 = id */ 77 78 O_IPTOS, /* arg1 = id */ 79 O_IPPRECEDENCE, /* arg1 = precedence << 5 */ 80 O_IPTTL, /* arg1 = TTL */ 81 82 O_IPVER, /* arg1 = version */ 83 O_UID, /* u32 = id */ 84 O_GID, /* u32 = id */ 85 O_ESTAB, /* none (tcp established) */ 86 O_TCPFLAGS, /* arg1 = 2*u8 bitmap */ 87 O_TCPWIN, /* arg1 = desired win */ 88 O_TCPSEQ, /* u32 = desired seq. */ 89 O_TCPACK, /* u32 = desired seq. */ 90 O_ICMPTYPE, /* u32 = icmp bitmap */ 91 O_TCPOPTS, /* arg1 = 2*u8 bitmap */ 92 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 * these are really 'actions', and must be last in the list. 99 */ 100 101 O_LOG, /* ipfw_insn_log */ 102 O_PROB, /* u32 = match probability */ 103 104 O_CHECK_STATE, /* none */ 105 O_ACCEPT, /* none */ 106 O_DENY, /* none */ 107 O_REJECT, /* arg1=icmp arg (same as deny) */ 108 O_COUNT, /* none */ 109 O_SKIPTO, /* arg1=next rule number */ 110 O_PIPE, /* arg1=pipe number */ 111 O_QUEUE, /* arg1=queue number */ 112 O_DIVERT, /* arg1=port number */ 113 O_TEE, /* arg1=port number */ 114 O_FORWARD_IP, /* fwd sockaddr */ 115 O_FORWARD_MAC, /* fwd mac */ 116 O_LAST_OPCODE /* not an opcode! */ 117 }; 118 119 /* 120 * Template for instructions. 121 * 122 * ipfw_insn is used for all instructions which require no operands, 123 * a single 16-bit value (arg1), or a couple of 8-bit values. 124 * 125 * For other instructions which require different/larger arguments 126 * we have derived structures, ipfw_insn_*. 127 * 128 * The size of the instruction (in 32-bit words) is in the low 129 * 6 bits of "len". The 2 remaining bits are used to implement 130 * NOT and OR on individual instructions. Given a type, you can 131 * compute the length to be put in "len" using F_INSN_SIZE(t) 132 * 133 * F_NOT negates the match result of the instruction. 134 * 135 * F_OR is used to build or blocks. By default, instructions 136 * are evaluated as part of a logical AND. An "or" block 137 * { X or Y or Z } contains F_OR set in all but the last 138 * instruction of the block. A match will cause the code 139 * to skip past the last instruction of the block. 140 * 141 * NOTA BENE: in a couple of places we assume that 142 * sizeof(ipfw_insn) == sizeof(uint32_t) 143 * this needs to be fixed. 144 * 145 */ 146 typedef struct _ipfw_insn { /* template for instructions */ 147 enum ipfw_opcodes opcode:8; 148 uint8_t len; /* numer of 32-byte words */ 149 #define F_NOT 0x80 150 #define F_OR 0x40 151 #define F_LEN_MASK 0x3f 152 #define F_LEN(cmd) ((cmd)->len & F_LEN_MASK) 153 154 uint16_t arg1; 155 } ipfw_insn; 156 157 /* 158 * The F_INSN_SIZE(type) computes the size, in 4-byte words, of 159 * a given type. 160 */ 161 #define F_INSN_SIZE(t) ((sizeof (t))/sizeof(uint32_t)) 162 163 /* 164 * This is used to store an array of 16-bit entries (ports etc.) 165 */ 166 typedef struct _ipfw_insn_u16 { 167 ipfw_insn o; 168 uint16_t ports[2]; /* there may be more */ 169 } ipfw_insn_u16; 170 171 /* 172 * This is used to store an array of 32-bit entries 173 * (uid, single IPv4 addresses etc.) 174 */ 175 typedef struct _ipfw_insn_u32 { 176 ipfw_insn o; 177 uint32_t d[1]; /* one or more */ 178 } ipfw_insn_u32; 179 180 /* 181 * This is used to store IP addr-mask pairs. 182 */ 183 typedef struct _ipfw_insn_ip { 184 ipfw_insn o; 185 struct in_addr addr; 186 struct in_addr mask; 187 } ipfw_insn_ip; 188 189 /* 190 * This is used to forward to a given address (ip) 191 */ 192 typedef struct _ipfw_insn_sa { 193 ipfw_insn o; 194 struct sockaddr_in sa; 195 } ipfw_insn_sa; 196 197 /* 198 * This is used for MAC addr-mask pairs. 199 */ 200 typedef struct _ipfw_insn_mac { 201 ipfw_insn o; 202 u_char addr[12]; /* dst[6] + src[6] */ 203 u_char mask[12]; /* dst[6] + src[6] */ 204 } ipfw_insn_mac; 205 206 /* 207 * This is used for interface match rules (recv xx, xmit xx) 208 */ 209 typedef struct _ipfw_insn_if { 210 ipfw_insn o; 211 union { 212 struct in_addr ip; 213 int glob; 214 } p; 215 char name[IFNAMSIZ]; 216 } ipfw_insn_if; 217 218 /* 219 * This is used for pipe and queue actions, which need to store 220 * a single pointer (which can have different size on different 221 * architectures. 222 */ 223 typedef struct _ipfw_insn_pipe { 224 ipfw_insn o; 225 void *pipe_ptr; 226 } ipfw_insn_pipe; 227 228 /* 229 * This is used for limit rules. 230 */ 231 typedef struct _ipfw_insn_limit { 232 ipfw_insn o; 233 uint8_t _pad; 234 uint8_t limit_mask; /* combination of DYN_* below */ 235 #define DYN_SRC_ADDR 0x1 236 #define DYN_SRC_PORT 0x2 237 #define DYN_DST_ADDR 0x4 238 #define DYN_DST_PORT 0x8 239 240 uint16_t conn_limit; 241 } ipfw_insn_limit; 242 243 /* 244 * This is used for log instructions 245 */ 246 typedef struct _ipfw_insn_log { 247 ipfw_insn o; 248 uint32_t max_log; /* how many do we log -- 0 = all */ 249 uint32_t log_left; /* how many left to log */ 250 } ipfw_insn_log; 251 252 #ifdef _KERNEL 253 254 struct ip_fw; 255 struct ip_fw_stub { 256 struct ip_fw *rule[1]; 257 }; 258 259 /* 260 * Here we have the structure representing an ipfw rule. 261 * 262 * It starts with a general area (with link fields and counters) 263 * followed by an array of one or more instructions, which the code 264 * accesses as an array of 32-bit values. 265 * 266 * Given a rule pointer r: 267 * 268 * r->cmd is the start of the first instruction. 269 * ACTION_PTR(r) is the start of the first action (things to do 270 * once a rule matched). 271 * 272 * When assembling instruction, remember the following: 273 * 274 * + if a rule has a "keep-state" (or "limit") option, then the 275 * first instruction (at r->cmd) MUST BE an O_PROBE_STATE 276 * + if a rule has a "log" option, then the first action 277 * (at ACTION_PTR(r)) MUST be O_LOG 278 * 279 * NOTE: we use a simple linked list of rules because we never need 280 * to delete a rule without scanning the list. We do not use 281 * queue(3) macros for portability and readability. 282 */ 283 284 struct ip_fw { 285 struct ip_fw *next; /* linked list of rules */ 286 struct ip_fw *next_rule; /* ptr to next [skipto] rule */ 287 uint16_t act_ofs; /* offset of action in 32-bit units */ 288 uint16_t cmd_len; /* # of 32-bit words in cmd */ 289 uint16_t rulenum; /* rule number */ 290 uint8_t set; /* rule set (0..31) */ 291 uint8_t usr_flags; /* IPFW_USR_F_ */ 292 293 /* These fields are present in all rules. */ 294 uint64_t pcnt; /* Packet counter */ 295 uint64_t bcnt; /* Byte counter */ 296 uint32_t timestamp; /* tv_sec of last match */ 297 298 struct ip_fw_stub *stub; /* back pointers to clones */ 299 struct ip_fw *sibling; /* clone on next cpu */ 300 int cpuid; /* owner cpu */ 301 302 uint32_t refcnt; /* Ref count for transit pkts */ 303 uint32_t rule_flags; /* IPFW_RULE_F_ */ 304 305 ipfw_insn cmd[1]; /* storage for commands */ 306 }; 307 308 #define IPFW_RULE_F_INVALID 0x1 309 #define IPFW_RULE_F_STATE 0x2 310 311 #define RULESIZE(rule) (sizeof(struct ip_fw) + (rule)->cmd_len * 4 - 4) 312 313 /* 314 * This structure is used as a flow mask and a flow id for various 315 * parts of the code. 316 */ 317 struct ipfw_flow_id { 318 uint32_t dst_ip; 319 uint32_t src_ip; 320 uint16_t dst_port; 321 uint16_t src_port; 322 uint8_t proto; 323 uint8_t flags; /* protocol-specific flags */ 324 }; 325 326 /* 327 * dynamic ipfw rule 328 */ 329 typedef struct _ipfw_dyn_rule ipfw_dyn_rule; 330 331 struct _ipfw_dyn_rule { 332 ipfw_dyn_rule *next; /* linked list of rules. */ 333 struct ipfw_flow_id id; /* (masked) flow id */ 334 #ifdef notyet 335 struct ip_fw *rule; /* pointer to rule */ 336 #else 337 const struct ip_fw_stub *stub; /* pointer to rule's stub */ 338 #endif 339 ipfw_dyn_rule *parent; /* pointer to parent rule */ 340 uint32_t expire; /* expire time */ 341 uint64_t pcnt; /* packet match counter */ 342 uint64_t bcnt; /* byte match counter */ 343 uint32_t bucket; /* which bucket in hash table */ 344 uint32_t state; /* state of this rule (typically a 345 * combination of TCP flags) 346 */ 347 uint32_t ack_fwd; /* most recent ACKs in forward */ 348 uint32_t ack_rev; /* and reverse directions (used */ 349 /* to generate keepalives) */ 350 uint16_t dyn_type; /* rule type */ 351 uint16_t count; /* refcount */ 352 time_t keep_alive; /* last keep-alive sending time */ 353 }; 354 355 /* 356 * Main firewall chains definitions and global var's definitions. 357 */ 358 359 /* ipfw_chk/ip_fw_chk_ptr return values */ 360 #define IP_FW_PASS 0 361 #define IP_FW_DENY 1 362 #define IP_FW_DIVERT 2 363 #define IP_FW_TEE 3 364 #define IP_FW_DUMMYNET 4 365 366 /* 367 * arguments for calling ipfw_chk() and dummynet_io(). We put them 368 * all into a structure because this way it is easier and more 369 * efficient to pass variables around and extend the interface. 370 */ 371 struct ip_fw_args { 372 struct mbuf *m; /* the mbuf chain */ 373 struct ifnet *oif; /* output interface */ 374 struct ip_fw *rule; /* matching rule */ 375 struct ether_header *eh; /* for bridged packets */ 376 377 struct ipfw_flow_id f_id; /* grabbed from IP header */ 378 379 /* 380 * Depend on the return value of ipfw_chk/ip_fw_chk_ptr 381 * 'cookie' field may save following information: 382 * 383 * IP_FW_TEE or IP_FW_DIVERT 384 * The divert port number 385 * 386 * IP_FW_DUMMYNET 387 * The pipe or queue number 388 */ 389 uint32_t cookie; 390 }; 391 392 /* 393 * Function definitions. 394 */ 395 int ip_fw_sockopt(struct sockopt *); 396 397 /* Firewall hooks */ 398 struct sockopt; 399 struct dn_flow_set; 400 401 typedef int ip_fw_chk_t(struct ip_fw_args *); 402 typedef int ip_fw_ctl_t(struct sockopt *); 403 typedef void ip_fw_dn_io_t(struct mbuf *, int, int, struct ip_fw_args *); 404 405 extern ip_fw_chk_t *ip_fw_chk_ptr; 406 extern ip_fw_ctl_t *ip_fw_ctl_ptr; 407 extern ip_fw_dn_io_t *ip_fw_dn_io_ptr; 408 409 extern int fw_one_pass; 410 extern int fw_enable; 411 412 extern int ip_fw_loaded; 413 #define IPFW_LOADED (ip_fw_loaded) 414 415 #define IPFW_CFGCPUID 0 416 #define IPFW_CFGPORT netisr_portfn(IPFW_CFGCPUID) 417 #define IPFW_ASSERT_CFGPORT(msgport) \ 418 KASSERT((msgport) == IPFW_CFGPORT, ("not IPFW CFGPORT")) 419 420 #endif /* _KERNEL */ 421 422 #define ACTION_PTR(rule) \ 423 (ipfw_insn *)((uint32_t *)((rule)->cmd) + ((rule)->act_ofs)) 424 425 struct ipfw_ioc_rule { 426 uint16_t act_ofs; /* offset of action in 32-bit units */ 427 uint16_t cmd_len; /* # of 32-bit words in cmd */ 428 uint16_t rulenum; /* rule number */ 429 uint8_t set; /* rule set (0..31) */ 430 uint8_t usr_flags; /* IPFW_USR_F_ */ 431 432 /* Rule set information */ 433 uint32_t set_disable; /* disabled rule sets */ 434 uint32_t static_count; /* # of static rules */ 435 uint32_t static_len; /* total length of static rules */ 436 437 /* Statistics */ 438 uint64_t pcnt; /* Packet counter */ 439 uint64_t bcnt; /* Byte counter */ 440 uint32_t timestamp; /* tv_sec of last match */ 441 442 uint8_t reserved[16]; 443 444 ipfw_insn cmd[1]; /* storage for commands */ 445 }; 446 447 #define IPFW_USR_F_NORULE 0x01 448 449 #define IPFW_RULE_SIZE_MAX 255 /* unit: uint32_t */ 450 451 #define IOC_RULESIZE(rule) \ 452 (sizeof(struct ipfw_ioc_rule) + (rule)->cmd_len * 4 - 4) 453 454 struct ipfw_ioc_flowid { 455 uint16_t type; /* ETHERTYPE_ */ 456 uint16_t pad; 457 union { 458 struct { 459 uint32_t dst_ip; 460 uint32_t src_ip; 461 uint16_t dst_port; 462 uint16_t src_port; 463 uint8_t proto; 464 } ip; 465 uint8_t pad[64]; 466 } u; 467 }; 468 469 struct ipfw_ioc_state { 470 uint32_t expire; /* expire time */ 471 uint64_t pcnt; /* packet match counter */ 472 uint64_t bcnt; /* byte match counter */ 473 474 uint16_t dyn_type; /* rule type */ 475 uint16_t count; /* refcount */ 476 477 uint16_t rulenum; 478 uint16_t pad; 479 480 int cpu; /* reserved */ 481 482 struct ipfw_ioc_flowid id; /* (masked) flow id */ 483 uint8_t reserved[16]; 484 }; 485 486 /* 487 * Definitions for IP option names. 488 */ 489 #define IP_FW_IPOPT_LSRR 0x01 490 #define IP_FW_IPOPT_SSRR 0x02 491 #define IP_FW_IPOPT_RR 0x04 492 #define IP_FW_IPOPT_TS 0x08 493 494 /* 495 * Definitions for TCP option names. 496 */ 497 #define IP_FW_TCPOPT_MSS 0x01 498 #define IP_FW_TCPOPT_WINDOW 0x02 499 #define IP_FW_TCPOPT_SACK 0x04 500 #define IP_FW_TCPOPT_TS 0x08 501 #define IP_FW_TCPOPT_CC 0x10 502 503 #define ICMP_REJECT_RST 0x100 /* fake ICMP code (send a TCP RST) */ 504 505 #endif /* _IPFW2_H */ 506