ip_fw.h revision 61413 
1/*
2 * Copyright (c) 1993 Daniel Boulet
3 * Copyright (c) 1994 Ugen J.S.Antsilevich
4 *
5 * Redistribution and use in source forms, with and without modification,
6 * are permitted provided that this entire comment appears intact.
7 *
8 * Redistribution in binary form may occur without any restrictions.
9 * Obviously, it would be nice if you gave credit where credit is due
10 * but requiring it would be too onerous.
11 *
12 * This software is provided ``AS IS'' without any warranties of any kind.
13 *
14 * $FreeBSD: head/sys/netinet/ip_fw.h 61413 2000-06-08 09:45:23Z luigi $
15 */
16
17#ifndef _IP_FW_H
18#define _IP_FW_H
19
20#include <sys/queue.h>
21
22/*
23 * This union structure identifies an interface, either explicitly
24 * by name or implicitly by IP address. The flags IP_FW_F_IIFNAME
25 * and IP_FW_F_OIFNAME say how to interpret this structure. An
26 * interface unit number of -1 matches any unit number, while an
27 * IP address of 0.0.0.0 indicates matches any interface.
28 *
29 * The receive and transmit interfaces are only compared against the
30 * the packet if the corresponding bit (IP_FW_F_IIFACE or IP_FW_F_OIFACE)
31 * is set. Note some packets lack a receive or transmit interface
32 * (in which case the missing "interface" never matches).
33 */
34
35union ip_fw_if {
36    struct in_addr fu_via_ip;	/* Specified by IP address */
37    struct {			/* Specified by interface name */
38#define FW_IFNLEN     10 /* need room ! was IFNAMSIZ */
39	    char  name[FW_IFNLEN];
40	    short unit;		/* -1 means match any unit */
41    } fu_via_if;
42};
43
44/*
45 * Format of an IP firewall descriptor
46 *
47 * fw_src, fw_dst, fw_smsk, fw_dmsk are always stored in network byte order.
48 * fw_flg and fw_n*p are stored in host byte order (of course).
49 * Port numbers are stored in HOST byte order.
50 * Warning: setsockopt() will fail if sizeof(struct ip_fw) > MLEN (108)
51 */
52
53struct ip_fw {
54    u_int64_t fw_pcnt,fw_bcnt;		/* Packet and byte counters */
55    struct in_addr fw_src, fw_dst;	/* Source and destination IP addr */
56    struct in_addr fw_smsk, fw_dmsk;	/* Mask for src and dest IP addr */
57    u_short fw_number;			/* Rule number */
58    u_int fw_flg;			/* Flags word */
59#define IP_FW_MAX_PORTS	10		/* A reasonable maximum */
60	union {
61	u_short fw_pts[IP_FW_MAX_PORTS];	/* Array of port numbers to match */
62#define IP_FW_ICMPTYPES_MAX	128
63#define IP_FW_ICMPTYPES_DIM	(IP_FW_ICMPTYPES_MAX / (sizeof(unsigned) * 8))
64	unsigned fw_icmptypes[IP_FW_ICMPTYPES_DIM]; /* ICMP types bitmap */
65	} fw_uar;
66    u_char fw_ipopt,fw_ipnopt;		/* IP options set/unset */
67    u_char fw_tcpf,fw_tcpnf;		/* TCP flags set/unset */
68    long timestamp;			/* timestamp (tv_sec) of last match */
69    union ip_fw_if fw_in_if, fw_out_if;	/* Incoming and outgoing interfaces */
70    union {
71	u_short fu_divert_port;		/* Divert/tee port (options IPDIVERT) */
72	u_short fu_pipe_nr;		/* queue number (option DUMMYNET) */
73	u_short fu_skipto_rule;		/* SKIPTO command rule number */
74	u_short fu_reject_code;		/* REJECT response code */
75	struct sockaddr_in fu_fwd_ip;
76    } fw_un;
77    u_char fw_prot;			/* IP protocol */
78	/*
79	 * N'of src ports and # of dst ports in ports array (dst ports
80	 * follow src ports; max of 10 ports in all; count of 0 means
81	 * match all ports)
82	 */
83    u_char fw_nports;
84    void *pipe_ptr;                    /* flow_set ptr for dummynet pipe */
85    void *next_rule_ptr ;              /* next rule in case of match */
86    uid_t fw_uid;			/* uid to match */
87    gid_t fw_gid;			/* gid to match */
88    int fw_logamount;			/* amount to log */
89    u_int64_t fw_loghighest;		/* highest number packet to log */
90};
91
92/*
93 * extended ipfw structure... some fields in the original struct
94 * can be used to pass parameters up/down, namely pointers
95 *     void *pipe_ptr
96 *     void *next_rule_ptr
97 * some others can be used to pass parameters down, namely counters etc.
98 *     u_int64_t fw_pcnt,fw_bcnt;
99 *     long timestamp;
100 */
101
102struct ip_fw_ext {             /* extended structure */
103    struct ip_fw rule;      /* must be at offset 0 */
104    long    dont_match_prob;        /* 0x7fffffff means 1.0, always fail */
105    u_int   dyn_type;  /* type for dynamic rule */
106};
107
108#define IP_FW_GETNSRCP(rule)		((rule)->fw_nports & 0x0f)
109#define IP_FW_SETNSRCP(rule, n)		do {				\
110					  (rule)->fw_nports &= ~0x0f;	\
111					  (rule)->fw_nports |= (n);	\
112					} while (0)
113#define IP_FW_GETNDSTP(rule)		((rule)->fw_nports >> 4)
114#define IP_FW_SETNDSTP(rule, n)		do {				\
115					  (rule)->fw_nports &= ~0xf0;	\
116					  (rule)->fw_nports |= (n) << 4;\
117					} while (0)
118
119#define fw_divert_port	fw_un.fu_divert_port
120#define fw_skipto_rule	fw_un.fu_skipto_rule
121#define fw_reject_code	fw_un.fu_reject_code
122#define fw_pipe_nr	fw_un.fu_pipe_nr
123#define fw_fwd_ip	fw_un.fu_fwd_ip
124
125struct ip_fw_chain {
126        LIST_ENTRY(ip_fw_chain) chain;
127        struct ip_fw    *rule;
128};
129
130/*
131 * Flow mask/flow id for each queue.
132 */
133struct ipfw_flow_id {
134    u_int32_t dst_ip, src_ip ;
135    u_int16_t dst_port, src_port ;
136    u_int8_t proto ;
137    u_int8_t flags ;    /* protocol-specific flags */
138} ;
139
140/*
141 * dynamic ipfw rule
142 */
143struct ipfw_dyn_rule {
144    struct ipfw_dyn_rule *next ;
145
146    struct ipfw_flow_id id ;
147    struct ipfw_flow_id mask ;
148    struct ip_fw_chain *chain ;		/* pointer to parent rule	*/
149    u_int32_t type ;			/* rule type			*/
150    u_int32_t expire ;			/* expire time			*/
151    u_int64_t pcnt, bcnt;		/* match counters		*/
152    u_int32_t bucket ;			/* which bucket in hash table	*/
153    u_int32_t state ;			/* state of this rule (typ. a   */
154					/* combination of TCP flags)	*/
155} ;
156
157/*
158 * Values for "flags" field .
159 */
160#define IP_FW_F_COMMAND 0x000000ff	/* Mask for type of chain entry:	*/
161#define IP_FW_F_DENY	0x00000000	/* This is a deny rule			*/
162#define IP_FW_F_REJECT	0x00000001	/* Deny and send a response packet	*/
163#define IP_FW_F_ACCEPT	0x00000002	/* This is an accept rule		*/
164#define IP_FW_F_COUNT	0x00000003	/* This is a count rule			*/
165#define IP_FW_F_DIVERT	0x00000004	/* This is a divert rule		*/
166#define IP_FW_F_TEE	0x00000005	/* This is a tee rule			*/
167#define IP_FW_F_SKIPTO	0x00000006	/* This is a skipto rule		*/
168#define IP_FW_F_FWD	0x00000007	/* This is a "change forwarding address" rule */
169#define IP_FW_F_PIPE	0x00000008	/* This is a dummynet rule */
170#define IP_FW_F_QUEUE	0x00000009	/* This is a dummynet queue */
171
172#define IP_FW_F_IN	0x00000100	/* Check inbound packets		*/
173#define IP_FW_F_OUT	0x00000200	/* Check outbound packets		*/
174#define IP_FW_F_IIFACE	0x00000400	/* Apply inbound interface test		*/
175#define IP_FW_F_OIFACE	0x00000800	/* Apply outbound interface test	*/
176
177#define IP_FW_F_PRN	0x00001000	/* Print if this rule matches		*/
178
179#define IP_FW_F_SRNG	0x00002000	/* The first two src ports are a min	*
180					 * and max range (stored in host byte	*
181					 * order).				*/
182
183#define IP_FW_F_DRNG	0x00004000	/* The first two dst ports are a min	*
184					 * and max range (stored in host byte	*
185					 * order).				*/
186
187#define IP_FW_F_FRAG	0x00008000	/* Fragment				*/
188
189#define IP_FW_F_IIFNAME	0x00010000	/* In interface by name/unit (not IP)	*/
190#define IP_FW_F_OIFNAME	0x00020000	/* Out interface by name/unit (not IP)	*/
191
192#define IP_FW_F_INVSRC	0x00040000	/* Invert sense of src check		*/
193#define IP_FW_F_INVDST	0x00080000	/* Invert sense of dst check		*/
194
195#define IP_FW_F_ICMPBIT 0x00100000	/* ICMP type bitmap is valid		*/
196
197#define IP_FW_F_UID	0x00200000	/* filter by uid			*/
198
199#define IP_FW_F_GID	0x00400000	/* filter by gid			*/
200
201#define IP_FW_F_RND_MATCH 0x00800000	/* probabilistic rule match		*/
202#define IP_FW_F_SMSK	0x01000000	/* src-port + mask 			*/
203#define IP_FW_F_DMSK	0x02000000	/* dst-port + mask 			*/
204#define	IP_FW_BRIDGED	0x04000000	/* only match bridged packets		*/
205#define IP_FW_F_KEEP_S	0x08000000	/* keep state	 			*/
206#define IP_FW_F_CHECK_S	0x10000000	/* check state	 			*/
207
208#define IP_FW_F_MASK	0x1FFFFFFF	/* All possible flag bits mask		*/
209
210/*
211 * For backwards compatibility with rules specifying "via iface" but
212 * not restricted to only "in" or "out" packets, we define this combination
213 * of bits to represent this configuration.
214 */
215
216#define IF_FW_F_VIAHACK	(IP_FW_F_IN|IP_FW_F_OUT|IP_FW_F_IIFACE|IP_FW_F_OIFACE)
217
218/*
219 * Definitions for REJECT response codes.
220 * Values less than 256 correspond to ICMP unreachable codes.
221 */
222#define IP_FW_REJECT_RST	0x0100		/* TCP packets: send RST */
223
224/*
225 * Definitions for IP option names.
226 */
227#define IP_FW_IPOPT_LSRR	0x01
228#define IP_FW_IPOPT_SSRR	0x02
229#define IP_FW_IPOPT_RR		0x04
230#define IP_FW_IPOPT_TS		0x08
231
232/*
233 * Definitions for TCP flags.
234 */
235#define IP_FW_TCPF_FIN		TH_FIN
236#define IP_FW_TCPF_SYN		TH_SYN
237#define IP_FW_TCPF_RST		TH_RST
238#define IP_FW_TCPF_PSH		TH_PUSH
239#define IP_FW_TCPF_ACK		TH_ACK
240#define IP_FW_TCPF_URG		TH_URG
241#define IP_FW_TCPF_ESTAB	0x40
242
243/*
244 * Main firewall chains definitions and global var's definitions.
245 */
246#ifdef _KERNEL
247
248#define IP_FW_PORT_DYNT_FLAG	0x10000
249#define IP_FW_PORT_TEE_FLAG	0x20000
250
251/*
252 * Function definitions.
253 */
254void ip_fw_init __P((void));
255
256/* Firewall hooks */
257struct ip;
258struct sockopt;
259typedef	int ip_fw_chk_t __P((struct ip **, int, struct ifnet *, u_int16_t *,
260	     struct mbuf **, struct ip_fw_chain **, struct sockaddr_in **));
261typedef	int ip_fw_ctl_t __P((struct sockopt *));
262extern	ip_fw_chk_t *ip_fw_chk_ptr;
263extern	ip_fw_ctl_t *ip_fw_ctl_ptr;
264extern int fw_one_pass;
265extern int fw_enable;
266extern struct ipfw_flow_id last_pkt ;
267#endif /* _KERNEL */
268
269#endif /* _IP_FW_H */
270