2 * Copyright (c) 2002 Luigi Rizzo, Universita` di Pisa
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
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.
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
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 1.4 2005/04/18 14:26:57 joerg Exp $
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.
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).
42 * "enum ipfw_opcodes" are the opcodes supported. We can have up
43 * to 256 different opcodes.
46 enum ipfw_opcodes { /* arguments (4 byte each) */
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 */
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 */
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 */
63 O_MACADDR2, /* 2 mac addr:mask */
64 O_MAC_TYPE, /* same as srcport */
74 O_IPOPT, /* arg1 = 2*u8 bitmap */
75 O_IPLEN, /* arg1 = len */
76 O_IPID, /* arg1 = id */
78 O_IPTOS, /* arg1 = id */
79 O_IPPRECEDENCE, /* arg1 = precedence << 5 */
80 O_IPTTL, /* arg1 = TTL */
82 O_IPVER, /* arg1 = version */
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 */
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. */
98 * these are really 'actions', and must be last in the list.
101 O_LOG, /* ipfw_insn_log */
102 O_PROB, /* u32 = match probability */
104 O_CHECK_STATE, /* none */
107 O_REJECT, /* arg1=icmp arg (same as deny) */
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! */
120 * Template for instructions.
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.
125 * For other instructions which require different/larger arguments
126 * we have derived structures, ipfw_insn_*.
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)
133 * F_NOT negates the match result of the instruction.
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.
141 * NOTA BENE: in a couple of places we assume that
142 * sizeof(ipfw_insn) == sizeof(u_int32_t)
143 * this needs to be fixed.
146 typedef struct _ipfw_insn { /* template for instructions */
147 enum ipfw_opcodes opcode:8;
148 u_int8_t len; /* numer of 32-byte words */
151 #define F_LEN_MASK 0x3f
152 #define F_LEN(cmd) ((cmd)->len & F_LEN_MASK)
158 * The F_INSN_SIZE(type) computes the size, in 4-byte words, of
161 #define F_INSN_SIZE(t) ((sizeof (t))/sizeof(u_int32_t))
164 * This is used to store an array of 16-bit entries (ports etc.)
166 typedef struct _ipfw_insn_u16 {
168 u_int16_t ports[2]; /* there may be more */
172 * This is used to store an array of 32-bit entries
173 * (uid, single IPv4 addresses etc.)
175 typedef struct _ipfw_insn_u32 {
177 u_int32_t d[1]; /* one or more */
181 * This is used to store IP addr-mask pairs.
183 typedef struct _ipfw_insn_ip {
190 * This is used to forward to a given address (ip)
192 typedef struct _ipfw_insn_sa {
194 struct sockaddr_in sa;
198 * This is used for MAC addr-mask pairs.
200 typedef struct _ipfw_insn_mac {
202 u_char addr[12]; /* dst[6] + src[6] */
203 u_char mask[12]; /* dst[6] + src[6] */
207 * This is used for interface match rules (recv xx, xmit xx)
209 typedef struct _ipfw_insn_if {
219 * This is used for pipe and queue actions, which need to store
220 * a single pointer (which can have different size on different
223 typedef struct _ipfw_insn_pipe {
229 * This is used for limit rules.
231 typedef struct _ipfw_insn_limit {
234 u_int8_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
240 u_int16_t conn_limit;
244 * This is used for log instructions
246 typedef struct _ipfw_insn_log {
248 u_int32_t max_log; /* how many do we log -- 0 = all */
249 u_int32_t log_left; /* how many left to log */
253 * Here we have the structure representing an ipfw rule.
255 * It starts with a general area (with link fields and counters)
256 * followed by an array of one or more instructions, which the code
257 * accesses as an array of 32-bit values.
259 * Given a rule pointer r:
261 * r->cmd is the start of the first instruction.
262 * ACTION_PTR(r) is the start of the first action (things to do
263 * once a rule matched).
265 * When assembling instruction, remember the following:
267 * + if a rule has a "keep-state" (or "limit") option, then the
268 * first instruction (at r->cmd) MUST BE an O_PROBE_STATE
269 * + if a rule has a "log" option, then the first action
270 * (at ACTION_PTR(r)) MUST be O_LOG
272 * NOTE: we use a simple linked list of rules because we never need
273 * to delete a rule without scanning the list. We do not use
274 * queue(3) macros for portability and readability.
278 struct ip_fw *next; /* linked list of rules */
279 struct ip_fw *next_rule; /* ptr to next [skipto] rule */
280 u_int16_t act_ofs; /* offset of action in 32-bit units */
281 u_int16_t cmd_len; /* # of 32-bit words in cmd */
282 u_int16_t rulenum; /* rule number */
283 u_int8_t set; /* rule set (0..31) */
284 u_int8_t _pad; /* padding */
286 /* These fields are present in all rules. */
287 u_int64_t pcnt; /* Packet counter */
288 u_int64_t bcnt; /* Byte counter */
289 u_int32_t timestamp; /* tv_sec of last match */
291 ipfw_insn cmd[1]; /* storage for commands */
294 #define ACTION_PTR(rule) \
295 (ipfw_insn *)( (u_int32_t *)((rule)->cmd) + ((rule)->act_ofs) )
297 #define RULESIZE(rule) (sizeof(struct ip_fw) + \
298 ((struct ip_fw *)(rule))->cmd_len * 4 - 4)
301 * This structure is used as a flow mask and a flow id for various
304 struct ipfw_flow_id {
310 u_int8_t flags; /* protocol-specific flags */
316 typedef struct _ipfw_dyn_rule ipfw_dyn_rule;
318 struct _ipfw_dyn_rule {
319 ipfw_dyn_rule *next; /* linked list of rules. */
320 struct ipfw_flow_id id; /* (masked) flow id */
321 struct ip_fw *rule; /* pointer to rule */
322 ipfw_dyn_rule *parent; /* pointer to parent rule */
323 u_int32_t expire; /* expire time */
324 u_int64_t pcnt; /* packet match counter */
325 u_int64_t bcnt; /* byte match counter */
326 u_int32_t bucket; /* which bucket in hash table */
327 u_int32_t state; /* state of this rule (typically a
328 * combination of TCP flags)
330 u_int32_t ack_fwd; /* most recent ACKs in forward */
331 u_int32_t ack_rev; /* and reverse directions (used */
332 /* to generate keepalives) */
333 u_int16_t dyn_type; /* rule type */
334 u_int16_t count; /* refcount */
338 * Definitions for IP option names.
340 #define IP_FW_IPOPT_LSRR 0x01
341 #define IP_FW_IPOPT_SSRR 0x02
342 #define IP_FW_IPOPT_RR 0x04
343 #define IP_FW_IPOPT_TS 0x08
346 * Definitions for TCP option names.
348 #define IP_FW_TCPOPT_MSS 0x01
349 #define IP_FW_TCPOPT_WINDOW 0x02
350 #define IP_FW_TCPOPT_SACK 0x04
351 #define IP_FW_TCPOPT_TS 0x08
352 #define IP_FW_TCPOPT_CC 0x10
354 #define ICMP_REJECT_RST 0x100 /* fake ICMP code (send a TCP RST) */
357 * Main firewall chains definitions and global var's definitions.
361 #define IP_FW_PORT_DYNT_FLAG 0x10000
362 #define IP_FW_PORT_TEE_FLAG 0x20000
363 #define IP_FW_PORT_DENY_FLAG 0x40000
366 * arguments for calling ipfw_chk() and dummynet_io(). We put them
367 * all into a structure because this way it is easier and more
368 * efficient to pass variables around and extend the interface.
371 struct mbuf *m; /* the mbuf chain */
372 struct ifnet *oif; /* output interface */
373 struct sockaddr_in *next_hop; /* forward address */
374 struct ip_fw *rule; /* matching rule */
375 struct ether_header *eh; /* for bridged packets */
377 struct route *ro; /* for dummynet */
378 struct sockaddr_in *dst; /* for dummynet */
379 int flags; /* for dummynet */
381 struct ipfw_flow_id f_id; /* grabbed from IP header */
386 * Function definitions.
393 void flush_pipe_ptrs(struct dn_flow_set *match); /* used by dummynet */
395 typedef int ip_fw_chk_t (struct ip_fw_args *args);
396 typedef int ip_fw_ctl_t (struct sockopt *);
397 extern ip_fw_chk_t *ip_fw_chk_ptr;
398 extern ip_fw_ctl_t *ip_fw_ctl_ptr;
399 extern int fw_one_pass;
400 extern int fw_enable;
401 #define IPFW_LOADED (ip_fw_chk_ptr != NULL)
404 #endif /* _IPFW2_H */