ip_fw.h revision 32330 
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 *	$Id: ip_fw.h,v 1.30 1997/10/28 15:58:45 bde Exp $
15 */
16
17#ifndef _IP_FW_H
18#define _IP_FW_H
19
20/*
21 * This union structure identifies an interface, either explicitly
22 * by name or implicitly by IP address. The flags IP_FW_F_IIFNAME
23 * and IP_FW_F_OIFNAME say how to interpret this structure. An
24 * interface unit number of -1 matches any unit number, while an
25 * IP address of 0.0.0.0 indicates matches any interface.
26 *
27 * The receive and transmit interfaces are only compared against the
28 * the packet if the corresponding bit (IP_FW_F_IIFACE or IP_FW_F_OIFACE)
29 * is set. Note some packets lack a receive or transmit interface
30 * (in which case the missing "interface" never matches).
31 */
32
33union ip_fw_if {
34    struct in_addr fu_via_ip;	/* Specified by IP address */
35    struct {			/* Specified by interface name */
36#define FW_IFNLEN     IFNAMSIZ
37	    char  name[FW_IFNLEN];
38	    short unit;		/* -1 means match any unit */
39    } fu_via_if;
40};
41
42/*
43 * Format of an IP firewall descriptor
44 *
45 * fw_src, fw_dst, fw_smsk, fw_dmsk are always stored in network byte order.
46 * fw_flg and fw_n*p are stored in host byte order (of course).
47 * Port numbers are stored in HOST byte order.
48 * Warning: setsockopt() will fail if sizeof(struct ip_fw) > MLEN (108)
49 */
50
51struct ip_fw {
52    u_int64_t fw_pcnt,fw_bcnt;		/* Packet and byte counters */
53    struct in_addr fw_src, fw_dst;	/* Source and destination IP addr */
54    struct in_addr fw_smsk, fw_dmsk;	/* Mask for src and dest IP addr */
55    u_short fw_number;			/* Rule number */
56    u_short fw_flg;			/* Flags word */
57#define IP_FW_MAX_PORTS	10		/* A reasonable maximum */
58	union {
59	u_short fw_pts[IP_FW_MAX_PORTS];	/* Array of port numbers to match */
60#define IP_FW_ICMPTYPES_MAX	128
61#define IP_FW_ICMPTYPES_DIM	(IP_FW_ICMPTYPES_MAX / (sizeof(unsigned) * 8))
62	unsigned fw_icmptypes[IP_FW_ICMPTYPES_DIM]; /* ICMP types bitmap */
63	} fw_uar;
64    u_char fw_ipopt,fw_ipnopt;		/* IP options set/unset */
65    u_char fw_tcpf,fw_tcpnf;		/* TCP flags set/unset */
66    long timestamp;			/* timestamp (tv_sec) of last match */
67    union ip_fw_if fw_in_if, fw_out_if;	/* Incoming and outgoing interfaces */
68    union {
69	u_short fu_divert_port;		/* Divert/tee port (options IPDIVERT) */
70	u_short fu_skipto_rule;		/* SKIPTO command rule number */
71	u_short fu_reject_code;		/* REJECT response code */
72    } fw_un;
73    u_char fw_prot;			/* IP protocol */
74    u_char fw_nports;			/* N'of src ports and # of dst ports */
75					/* in ports array (dst ports follow */
76					/* src ports; max of 10 ports in all; */
77					/* count of 0 means match all ports) */
78};
79
80#define IP_FW_GETNSRCP(rule)		((rule)->fw_nports & 0x0f)
81#define IP_FW_SETNSRCP(rule, n)		do {				\
82					  (rule)->fw_nports &= ~0x0f;	\
83					  (rule)->fw_nports |= (n);	\
84					} while (0)
85#define IP_FW_GETNDSTP(rule)		((rule)->fw_nports >> 4)
86#define IP_FW_SETNDSTP(rule, n)		do {				\
87					  (rule)->fw_nports &= ~0xf0;	\
88					  (rule)->fw_nports |= (n) << 4;\
89					} while (0)
90
91#define fw_divert_port	fw_un.fu_divert_port
92#define fw_skipto_rule	fw_un.fu_skipto_rule
93#define fw_reject_code	fw_un.fu_reject_code
94
95struct ip_fw_chain {
96        LIST_ENTRY(ip_fw_chain) chain;
97        struct ip_fw    *rule;
98};
99
100/*
101 * Values for "flags" field .
102 */
103#define IP_FW_F_IN	0x0001	/* Check inbound packets		*/
104#define IP_FW_F_OUT	0x0002	/* Check outbound packets		*/
105#define IP_FW_F_IIFACE	0x0004	/* Apply inbound interface test		*/
106#define IP_FW_F_OIFACE	0x0008	/* Apply outbound interface test	*/
107
108#define IP_FW_F_COMMAND 0x0070	/* Mask for type of chain entry:	*/
109#define IP_FW_F_DENY	0x0000	/* This is a deny rule			*/
110#define IP_FW_F_REJECT	0x0010	/* Deny and send a response packet	*/
111#define IP_FW_F_ACCEPT	0x0020	/* This is an accept rule		*/
112#define IP_FW_F_COUNT	0x0030	/* This is a count rule			*/
113#define IP_FW_F_DIVERT	0x0040	/* This is a divert rule		*/
114#define IP_FW_F_TEE	0x0050	/* This is a tee rule			*/
115#define IP_FW_F_SKIPTO	0x0060	/* This is a skipto rule		*/
116
117#define IP_FW_F_PRN	0x0080	/* Print if this rule matches		*/
118
119#define IP_FW_F_SRNG	0x0100	/* The first two src ports are a min	*
120				 * and max range (stored in host byte	*
121				 * order).				*/
122
123#define IP_FW_F_DRNG	0x0200	/* The first two dst ports are a min	*
124				 * and max range (stored in host byte	*
125				 * order).				*/
126
127#define IP_FW_F_IIFNAME	0x0400	/* In interface by name/unit (not IP)	*/
128#define IP_FW_F_OIFNAME	0x0800	/* Out interface by name/unit (not IP)	*/
129
130#define IP_FW_F_INVSRC	0x1000	/* Invert sense of src check		*/
131#define IP_FW_F_INVDST	0x2000	/* Invert sense of dst check		*/
132
133#define IP_FW_F_FRAG	0x4000	/* Fragment				*/
134
135#define IP_FW_F_ICMPBIT 0x8000	/* ICMP type bitmap is valid		*/
136
137#define IP_FW_F_MASK	0xFFFF	/* All possible flag bits mask		*/
138
139/*
140 * For backwards compatibility with rules specifying "via iface" but
141 * not restricted to only "in" or "out" packets, we define this combination
142 * of bits to represent this configuration.
143 */
144
145#define IF_FW_F_VIAHACK	(IP_FW_F_IN|IP_FW_F_OUT|IP_FW_F_IIFACE|IP_FW_F_OIFACE)
146
147/*
148 * Definitions for REJECT response codes.
149 * Values less than 256 correspond to ICMP unreachable codes.
150 */
151#define IP_FW_REJECT_RST	0x0100		/* TCP packets: send RST */
152
153/*
154 * Definitions for IP option names.
155 */
156#define IP_FW_IPOPT_LSRR	0x01
157#define IP_FW_IPOPT_SSRR	0x02
158#define IP_FW_IPOPT_RR		0x04
159#define IP_FW_IPOPT_TS		0x08
160
161/*
162 * Definitions for TCP flags.
163 */
164#define IP_FW_TCPF_FIN		TH_FIN
165#define IP_FW_TCPF_SYN		TH_SYN
166#define IP_FW_TCPF_RST		TH_RST
167#define IP_FW_TCPF_PSH		TH_PUSH
168#define IP_FW_TCPF_ACK		TH_ACK
169#define IP_FW_TCPF_URG		TH_URG
170#define IP_FW_TCPF_ESTAB	0x40
171
172/*
173 * Main firewall chains definitions and global var's definitions.
174 */
175#ifdef KERNEL
176
177/*
178 * Function definitions.
179 */
180void ip_fw_init __P((void));
181
182#endif /* KERNEL */
183
184#endif /* _IP_FW_H */
185