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 1.1.2.4 2003/07/17 06:03:39 luigi Exp $ 26 */ 27 28#ifndef _IPFW2_H 29#define _IPFW2_H 30 31/* 32 * Define IP Firewall event subclass, and associated events. 33 */ 34 35/*! 36 @defined KEV_IPFW_SUBCLASS 37 @discussion The kernel event subclass for IP Firewall. 38*/ 39#define KEV_IPFW_SUBCLASS 1 40 41/*! 42 @defined KEV_IPFW_ADD 43 @discussion The event code indicating a rule has been added. 44*/ 45#define KEV_IPFW_ADD 1 46 47/*! 48 @defined KEV_IPFW_DEL 49 @discussion The event code indicating a rule has been removed. 50*/ 51#define KEV_IPFW_DEL 2 52 53/*! 54 @defined KEV_IPFW_FLUSH 55 @discussion The event code indicating the rule set has been flushed. 56*/ 57#define KEV_IPFW_FLUSH 3 58 59/*! 60 @defined KEV_IPFW_ENABLE 61 @discussion The event code indicating the enable flag has been changed 62*/ 63#define KEV_IPFW_ENABLE 4 64 65 66 67#if !__LP64__ 68 69/* 70 * The kernel representation of ipfw rules is made of a list of 71 * 'instructions' (for all practical purposes equivalent to BPF 72 * instructions), which specify which fields of the packet 73 * (or its metadata) should be analysed. 74 * 75 * Each instruction is stored in a structure which begins with 76 * "ipfw_insn", and can contain extra fields depending on the 77 * instruction type (listed below). 78 * Note that the code is written so that individual instructions 79 * have a size which is a multiple of 32 bits. This means that, if 80 * such structures contain pointers or other 64-bit entities, 81 * (there is just one instance now) they may end up unaligned on 82 * 64-bit architectures, so the must be handled with care. 83 * 84 * "enum ipfw_opcodes" are the opcodes supported. We can have up 85 * to 256 different opcodes. 86 */ 87 88enum ipfw_opcodes { /* arguments (4 byte each) */ 89 O_NOP, 90 91 O_IP_SRC, /* u32 = IP */ 92 O_IP_SRC_MASK, /* ip = IP/mask */ 93 O_IP_SRC_ME, /* none */ 94 O_IP_SRC_SET, /* u32=base, arg1=len, bitmap */ 95 96 O_IP_DST, /* u32 = IP */ 97 O_IP_DST_MASK, /* ip = IP/mask */ 98 O_IP_DST_ME, /* none */ 99 O_IP_DST_SET, /* u32=base, arg1=len, bitmap */ 100 101 O_IP_SRCPORT, /* (n)port list:mask 4 byte ea */ 102 O_IP_DSTPORT, /* (n)port list:mask 4 byte ea */ 103 O_PROTO, /* arg1=protocol */ 104 105 O_MACADDR2, /* 2 mac addr:mask */ 106 O_MAC_TYPE, /* same as srcport */ 107 108 O_LAYER2, /* none */ 109 O_IN, /* none */ 110 O_FRAG, /* none */ 111 112 O_RECV, /* none */ 113 O_XMIT, /* none */ 114 O_VIA, /* none */ 115 116 O_IPOPT, /* arg1 = 2*u8 bitmap */ 117 O_IPLEN, /* arg1 = len */ 118 O_IPID, /* arg1 = id */ 119 120 O_IPTOS, /* arg1 = id */ 121 O_IPPRECEDENCE, /* arg1 = precedence << 5 */ 122 O_IPTTL, /* arg1 = TTL */ 123 124 O_IPVER, /* arg1 = version */ 125 O_UID, /* u32 = id */ 126 O_GID, /* u32 = id */ 127 O_ESTAB, /* none (tcp established) */ 128 O_TCPFLAGS, /* arg1 = 2*u8 bitmap */ 129 O_TCPWIN, /* arg1 = desired win */ 130 O_TCPSEQ, /* u32 = desired seq. */ 131 O_TCPACK, /* u32 = desired seq. */ 132 O_ICMPTYPE, /* u32 = icmp bitmap */ 133 O_TCPOPTS, /* arg1 = 2*u8 bitmap */ 134 135 O_VERREVPATH, /* 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 */ 161 162 /* 163 * More opcodes. 164 */ 165 O_IPSEC, /* has ipsec history */ 166 167 O_LAST_OPCODE /* not an opcode! */ 168}; 169 170/* 171 * Template for instructions. 172 * 173 * ipfw_insn is used for all instructions which require no operands, 174 * a single 16-bit value (arg1), or a couple of 8-bit values. 175 * 176 * For other instructions which require different/larger arguments 177 * we have derived structures, ipfw_insn_*. 178 * 179 * The size of the instruction (in 32-bit words) is in the low 180 * 6 bits of "len". The 2 remaining bits are used to implement 181 * NOT and OR on individual instructions. Given a type, you can 182 * compute the length to be put in "len" using F_INSN_SIZE(t) 183 * 184 * F_NOT negates the match result of the instruction. 185 * 186 * F_OR is used to build or blocks. By default, instructions 187 * are evaluated as part of a logical AND. An "or" block 188 * { X or Y or Z } contains F_OR set in all but the last 189 * instruction of the block. A match will cause the code 190 * to skip past the last instruction of the block. 191 * 192 * NOTA BENE: in a couple of places we assume that 193 * sizeof(ipfw_insn) == sizeof(u_int32_t) 194 * this needs to be fixed. 195 * 196 */ 197typedef struct _ipfw_insn { /* template for instructions */ 198 enum ipfw_opcodes opcode:8; 199 u_int8_t len; /* numer of 32-byte words */ 200#define F_NOT 0x80 201#define F_OR 0x40 202#define F_LEN_MASK 0x3f 203#define F_LEN(cmd) ((cmd)->len & F_LEN_MASK) 204 205 u_int16_t arg1; 206} ipfw_insn; 207 208/* 209 * The F_INSN_SIZE(type) computes the size, in 4-byte words, of 210 * a given type. 211 */ 212#define F_INSN_SIZE(t) ((sizeof (t))/sizeof(u_int32_t)) 213 214/* 215 * This is used to store an array of 16-bit entries (ports etc.) 216 */ 217typedef struct _ipfw_insn_u16 { 218 ipfw_insn o; 219 u_int16_t ports[2]; /* there may be more */ 220} ipfw_insn_u16; 221 222/* 223 * This is used to store an array of 32-bit entries 224 * (uid, single IPv4 addresses etc.) 225 */ 226typedef struct _ipfw_insn_u32 { 227 ipfw_insn o; 228 u_int32_t d[1]; /* one or more */ 229} ipfw_insn_u32; 230 231/* 232 * This is used to store IP addr-mask pairs. 233 */ 234typedef struct _ipfw_insn_ip { 235 ipfw_insn o; 236 struct in_addr addr; 237 struct in_addr mask; 238} ipfw_insn_ip; 239 240/* 241 * This is used to forward to a given address (ip). 242 */ 243typedef struct _ipfw_insn_sa { 244 ipfw_insn o; 245 struct sockaddr_in sa; 246} ipfw_insn_sa; 247 248/* 249 * This is used for MAC addr-mask pairs. 250 */ 251typedef struct _ipfw_insn_mac { 252 ipfw_insn o; 253 u_char addr[12]; /* dst[6] + src[6] */ 254 u_char mask[12]; /* dst[6] + src[6] */ 255} ipfw_insn_mac; 256 257/* 258 * This is used for interface match rules (recv xx, xmit xx). 259 */ 260typedef struct _ipfw_insn_if { 261 ipfw_insn o; 262 union { 263 struct in_addr ip; 264 int32_t unit; 265 } p; 266 char name[IFNAMSIZ]; 267} ipfw_insn_if; 268 269/* 270 * This is used for pipe and queue actions, which need to store 271 * a single pointer (which can have different size on different 272 * architectures. 273 * Note that, because of previous instructions, pipe_ptr might 274 * be unaligned in the overall structure, so it needs to be 275 * manipulated with care. 276 */ 277typedef struct _ipfw_insn_pipe { 278 ipfw_insn o; 279 void *pipe_ptr; /* XXX */ 280} ipfw_insn_pipe; 281 282/* 283 * This is used for limit rules. 284 */ 285typedef struct _ipfw_insn_limit { 286 ipfw_insn o; 287 u_int8_t _pad; 288 u_int8_t limit_mask; /* combination of DYN_* below */ 289#define DYN_SRC_ADDR 0x1 290#define DYN_SRC_PORT 0x2 291#define DYN_DST_ADDR 0x4 292#define DYN_DST_PORT 0x8 293 294 u_int16_t conn_limit; 295} ipfw_insn_limit; 296 297/* 298 * This is used for log instructions. 299 */ 300typedef struct _ipfw_insn_log { 301 ipfw_insn o; 302 u_int32_t max_log; /* how many do we log -- 0 = all */ 303 u_int32_t log_left; /* how many left to log */ 304} ipfw_insn_log; 305 306/* Version of this API */ 307#define IP_FW_VERSION_NONE 0 308#define IP_FW_VERSION_0 10 /* old ipfw */ 309#define IP_FW_VERSION_1 20 /* ipfw in Jaguar/Panther */ 310#define IP_FW_VERSION_2 30 /* ipfw2 */ 311#define IP_FW_CURRENT_API_VERSION IP_FW_VERSION_2 312 313/* 314 * Here we have the structure representing an ipfw rule. 315 * 316 * It starts with a general area (with link fields and counters) 317 * followed by an array of one or more instructions, which the code 318 * accesses as an array of 32-bit values. 319 * 320 * Given a rule pointer r: 321 * 322 * r->cmd is the start of the first instruction. 323 * ACTION_PTR(r) is the start of the first action (things to do 324 * once a rule matched). 325 * 326 * When assembling instruction, remember the following: 327 * 328 * + if a rule has a "keep-state" (or "limit") option, then the 329 * first instruction (at r->cmd) MUST BE an O_PROBE_STATE 330 * + if a rule has a "log" option, then the first action 331 * (at ACTION_PTR(r)) MUST be O_LOG 332 * 333 * NOTE: we use a simple linked list of rules because we never need 334 * to delete a rule without scanning the list. We do not use 335 * queue(3) macros for portability and readability. 336 */ 337 338struct ip_fw { 339 u_int32_t version; /* Version of this structure. MUST be set */ 340 /* by clients. Should always be */ 341 /* set to IP_FW_CURRENT_API_VERSION. */ 342 void *context; /* Context that is usable by user processes to */ 343 /* identify this rule. */ 344 struct ip_fw *next; /* linked list of rules */ 345 struct ip_fw *next_rule; /* ptr to next [skipto] rule */ 346 /* 'next_rule' is used to pass up 'set_disable' status */ 347 348 u_int16_t act_ofs; /* offset of action in 32-bit units */ 349 u_int16_t cmd_len; /* # of 32-bit words in cmd */ 350 u_int16_t rulenum; /* rule number */ 351 u_int8_t set; /* rule set (0..31) */ 352 u_int32_t set_masks[2]; /* masks for manipulating sets atomically */ 353#define RESVD_SET 31 /* set for default and persistent rules */ 354 u_int8_t _pad; /* padding */ 355 356 /* These fields are present in all rules. */ 357 u_int64_t pcnt; /* Packet counter */ 358 u_int64_t bcnt; /* Byte counter */ 359 u_int32_t timestamp; /* tv_sec of last match */ 360 361 u_int32_t reserved_1; /* reserved - set to 0 */ 362 u_int32_t reserved_2; /* reserved - set to 0 */ 363 364 ipfw_insn cmd[1]; /* storage for commands */ 365}; 366 367#define ACTION_PTR(rule) \ 368 (ipfw_insn *)( (u_int32_t *)((rule)->cmd) + ((rule)->act_ofs) ) 369 370#define RULESIZE(rule) (sizeof(struct ip_fw) + \ 371 ((struct ip_fw *)(rule))->cmd_len * 4 - 4) 372 373/* 374 * This structure is used as a flow mask and a flow id for various 375 * parts of the code. 376 */ 377struct ipfw_flow_id { 378 u_int32_t dst_ip; 379 u_int32_t src_ip; 380 u_int16_t dst_port; 381 u_int16_t src_port; 382 u_int8_t proto; 383 u_int8_t flags; /* protocol-specific flags */ 384}; 385 386/* 387 * Dynamic ipfw rule. 388 */ 389typedef struct _ipfw_dyn_rule ipfw_dyn_rule; 390 391struct _ipfw_dyn_rule { 392 ipfw_dyn_rule *next; /* linked list of rules. */ 393 struct ip_fw *rule; /* pointer to rule */ 394 /* 'rule' is used to pass up the rule number (from the parent) */ 395 396 ipfw_dyn_rule *parent; /* pointer to parent rule */ 397 u_int64_t pcnt; /* packet match counter */ 398 u_int64_t bcnt; /* byte match counter */ 399 struct ipfw_flow_id id; /* (masked) flow id */ 400 u_int32_t expire; /* expire time */ 401 u_int32_t bucket; /* which bucket in hash table */ 402 u_int32_t state; /* state of this rule (typically a 403 * combination of TCP flags) 404 */ 405 u_int32_t ack_fwd; /* most recent ACKs in forward */ 406 u_int32_t ack_rev; /* and reverse directions (used */ 407 /* to generate keepalives) */ 408 u_int16_t dyn_type; /* rule type */ 409 u_int16_t count; /* refcount */ 410}; 411 412/* 413 * Definitions for IP option names. 414 */ 415#define IP_FW_IPOPT_LSRR 0x01 416#define IP_FW_IPOPT_SSRR 0x02 417#define IP_FW_IPOPT_RR 0x04 418#define IP_FW_IPOPT_TS 0x08 419 420/* 421 * Definitions for TCP option names. 422 */ 423#define IP_FW_TCPOPT_MSS 0x01 424#define IP_FW_TCPOPT_WINDOW 0x02 425#define IP_FW_TCPOPT_SACK 0x04 426#define IP_FW_TCPOPT_TS 0x08 427#define IP_FW_TCPOPT_CC 0x10 428 429#define ICMP_REJECT_RST 0x100 /* fake ICMP code (send a TCP RST) */ 430 431/* 432 * Main firewall chains definitions and global var's definitions. 433 */ 434#ifdef KERNEL 435#if IPFIREWALL 436 437#define IP_FW_PORT_DYNT_FLAG 0x10000 438#define IP_FW_PORT_TEE_FLAG 0x20000 439#define IP_FW_PORT_DENY_FLAG 0x40000 440 441/* 442 * Arguments for calling ipfw_chk() and dummynet_io(). We put them 443 * all into a structure because this way it is easier and more 444 * efficient to pass variables around and extend the interface. 445 */ 446struct ip_fw_args { 447 struct mbuf *m; /* the mbuf chain */ 448 struct ifnet *oif; /* output interface */ 449 struct sockaddr_in *next_hop; /* forward address */ 450 struct ip_fw *rule; /* matching rule */ 451 struct ether_header *eh; /* for bridged packets */ 452 453 struct route *ro; /* for dummynet */ 454 struct sockaddr_in *dst; /* for dummynet */ 455 int flags; /* for dummynet */ 456 struct ip_out_args *ipoa; /* for dummynet */ 457 458 struct ipfw_flow_id f_id; /* grabbed from IP header */ 459 u_int16_t divert_rule; /* divert cookie */ 460 u_int32_t retval; 461}; 462//struct ip_fw_args; 463 464/* 465 * Function definitions. 466 */ 467 468/* Firewall hooks */ 469struct sockopt; 470struct dn_flow_set; 471 472void flush_pipe_ptrs(struct dn_flow_set *match); /* used by dummynet */ 473void ipfw_init(void); /* called from raw_ip.c: load_ipfw() */ 474 475typedef int ip_fw_chk_t (struct ip_fw_args *args); 476typedef int ip_fw_ctl_t (struct sockopt *); 477extern ip_fw_chk_t *ip_fw_chk_ptr; 478extern ip_fw_ctl_t *ip_fw_ctl_ptr; 479extern int fw_one_pass; 480extern int fw_enable; 481#define IPFW_LOADED (ip_fw_chk_ptr != NULL) 482#endif /* IPFIREWALL */ 483#endif /* KERNEL */ 484 485#endif /* !__LP64__ */ 486#endif /* _IPFW2_H */ 487