summaryrefslogtreecommitdiffstats
path: root/sys/netinet/ip_fw.h
blob: ffd1d040522158feefc77f69311a2ec99944b112 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
/*
 * Copyright (c) 1993 Daniel Boulet
 * Copyright (c) 1994 Ugen J.S.Antsilevich
 *
 * Redistribution and use in source forms, with and without modification,
 * are permitted provided that this entire comment appears intact.
 *
 * Redistribution in binary form may occur without any restrictions.
 * Obviously, it would be nice if you gave credit where credit is due
 * but requiring it would be too onerous.
 *
 * This software is provided ``AS IS'' without any warranties of any kind.
 *
 * $FreeBSD$
 */

#ifndef _IP_FW_H
#define _IP_FW_H

#include <sys/queue.h>

/*
 * This union structure identifies an interface, either explicitly
 * by name or implicitly by IP address. The flags IP_FW_F_IIFNAME
 * and IP_FW_F_OIFNAME say how to interpret this structure. An
 * interface unit number of -1 matches any unit number, while an
 * IP address of 0.0.0.0 indicates matches any interface.
 *
 * The receive and transmit interfaces are only compared against the
 * the packet if the corresponding bit (IP_FW_F_IIFACE or IP_FW_F_OIFACE)
 * is set. Note some packets lack a receive or transmit interface
 * (in which case the missing "interface" never matches).
 */

union ip_fw_if {
    struct in_addr fu_via_ip;	/* Specified by IP address */
    struct {			/* Specified by interface name */
#define FW_IFNLEN     10 /* need room ! was IFNAMSIZ */
	    char  name[FW_IFNLEN];
	    short unit;		/* -1 means match any unit */
    } fu_via_if;
};

/*
 * Format of an IP firewall descriptor
 *
 * fw_src, fw_dst, fw_smsk, fw_dmsk are always stored in network byte order.
 * fw_flg and fw_n*p are stored in host byte order (of course).
 * Port numbers are stored in HOST byte order.
 * Warning: setsockopt() will fail if sizeof(struct ip_fw) > MLEN (108)
 */

struct ip_fw {
    u_int64_t fw_pcnt,fw_bcnt;		/* Packet and byte counters */
    struct in_addr fw_src, fw_dst;	/* Source and destination IP addr */
    struct in_addr fw_smsk, fw_dmsk;	/* Mask for src and dest IP addr */
    u_short fw_number;			/* Rule number */
    u_int fw_flg;			/* Flags word */
#define IP_FW_MAX_PORTS	10		/* A reasonable maximum */
	union {
	u_short fw_pts[IP_FW_MAX_PORTS];	/* Array of port numbers to match */
#define IP_FW_ICMPTYPES_MAX	128
#define IP_FW_ICMPTYPES_DIM	(IP_FW_ICMPTYPES_MAX / (sizeof(unsigned) * 8))
	unsigned fw_icmptypes[IP_FW_ICMPTYPES_DIM]; /* ICMP types bitmap */
	} fw_uar;
    u_char fw_ipopt,fw_ipnopt;		/* IP options set/unset */
    u_char fw_tcpf,fw_tcpnf;		/* TCP flags set/unset */
    long timestamp;			/* timestamp (tv_sec) of last match */
    union ip_fw_if fw_in_if, fw_out_if;	/* Incoming and outgoing interfaces */
    union {
	u_short fu_divert_port;		/* Divert/tee port (options IPDIVERT) */
	u_short fu_pipe_nr;		/* pipe number (option DUMMYNET) */
	u_short fu_skipto_rule;		/* SKIPTO command rule number */
	u_short fu_reject_code;		/* REJECT response code */
	struct sockaddr_in fu_fwd_ip;
    } fw_un;
    u_char fw_prot;			/* IP protocol */
	/*
	 * N'of src ports and # of dst ports in ports array (dst ports
	 * follow src ports; max of 10 ports in all; count of 0 means
	 * match all ports)
	 */
    u_char fw_nports;
    void *pipe_ptr;                    /* Pipe ptr in case of dummynet pipe */
    void *next_rule_ptr ;              /* next rule in case of match */
    uid_t fw_uid;			/* uid to match */
    gid_t fw_gid;			/* gid to match */
    int fw_logamount;			/* amount to log */
    u_int64_t fw_loghighest;		/* highest number packet to log */
};

/*
 * extended ipfw structure... some fields in the original struct
 * can be used to pass parameters up/down, namely pointers
 *     void *pipe_ptr
 *     void *next_rule_ptr 
 * some others can be used to pass parameters down, namely counters etc.
 *     u_int64_t fw_pcnt,fw_bcnt;
 *     long timestamp;
 */

struct ip_fw_ext {             /* extended structure */
    struct ip_fw rule;      /* must be at offset 0 */
    long    dont_match_prob;        /* 0x7fffffff means 1.0, always fail */
    u_int   param1;         /* unused at the moment */
};

#define IP_FW_GETNSRCP(rule)		((rule)->fw_nports & 0x0f)
#define IP_FW_SETNSRCP(rule, n)		do {				\
					  (rule)->fw_nports &= ~0x0f;	\
					  (rule)->fw_nports |= (n);	\
					} while (0)
#define IP_FW_GETNDSTP(rule)		((rule)->fw_nports >> 4)
#define IP_FW_SETNDSTP(rule, n)		do {				\
					  (rule)->fw_nports &= ~0xf0;	\
					  (rule)->fw_nports |= (n) << 4;\
					} while (0)

#define fw_divert_port	fw_un.fu_divert_port
#define fw_skipto_rule	fw_un.fu_skipto_rule
#define fw_reject_code	fw_un.fu_reject_code
#define fw_pipe_nr	fw_un.fu_pipe_nr
#define fw_fwd_ip	fw_un.fu_fwd_ip

struct ip_fw_chain {
        LIST_ENTRY(ip_fw_chain) chain;
        struct ip_fw    *rule;
};

/*
 * Values for "flags" field .
 */
#define IP_FW_F_COMMAND 0x000000ff	/* Mask for type of chain entry:	*/
#define IP_FW_F_DENY	0x00000000	/* This is a deny rule			*/
#define IP_FW_F_REJECT	0x00000001	/* Deny and send a response packet	*/
#define IP_FW_F_ACCEPT	0x00000002	/* This is an accept rule		*/
#define IP_FW_F_COUNT	0x00000003	/* This is a count rule			*/
#define IP_FW_F_DIVERT	0x00000004	/* This is a divert rule		*/
#define IP_FW_F_TEE	0x00000005	/* This is a tee rule			*/
#define IP_FW_F_SKIPTO	0x00000006	/* This is a skipto rule		*/
#define IP_FW_F_FWD	0x00000007	/* This is a "change forwarding address" rule */
#define IP_FW_F_PIPE	0x00000008	/* This is a dummynet rule */

#define IP_FW_F_IN	0x00000100	/* Check inbound packets		*/
#define IP_FW_F_OUT	0x00000200	/* Check outbound packets		*/
#define IP_FW_F_IIFACE	0x00000400	/* Apply inbound interface test		*/
#define IP_FW_F_OIFACE	0x00000800	/* Apply outbound interface test	*/

#define IP_FW_F_PRN	0x00001000	/* Print if this rule matches		*/

#define IP_FW_F_SRNG	0x00002000	/* The first two src ports are a min	*
					 * and max range (stored in host byte	*
					 * order).				*/

#define IP_FW_F_DRNG	0x00004000	/* The first two dst ports are a min	*
					 * and max range (stored in host byte	*
					 * order).				*/

#define IP_FW_F_FRAG	0x00008000	/* Fragment				*/

#define IP_FW_F_IIFNAME	0x00010000	/* In interface by name/unit (not IP)	*/
#define IP_FW_F_OIFNAME	0x00020000	/* Out interface by name/unit (not IP)	*/

#define IP_FW_F_INVSRC	0x00040000	/* Invert sense of src check		*/
#define IP_FW_F_INVDST	0x00080000	/* Invert sense of dst check		*/

#define IP_FW_F_ICMPBIT 0x00100000	/* ICMP type bitmap is valid		*/

#define IP_FW_F_UID	0x00200000	/* filter by uid			*/

#define IP_FW_F_GID	0x00400000	/* filter by gid			*/

#define IP_FW_F_RND_MATCH 0x00800000	/* probabilistic rule match		*/
#define IP_FW_F_SMSK	0x01000000	/* src-port + mask 			*/
#define IP_FW_F_DMSK	0x02000000	/* dst-port + mask 			*/
#define IP_FW_F_KEEP_S	0x04000000	/* keep state	 			*/

#define IP_FW_F_MASK	0x03FFFFFF	/* All possible flag bits mask		*/

/*
 * For backwards compatibility with rules specifying "via iface" but
 * not restricted to only "in" or "out" packets, we define this combination
 * of bits to represent this configuration.
 */

#define IF_FW_F_VIAHACK	(IP_FW_F_IN|IP_FW_F_OUT|IP_FW_F_IIFACE|IP_FW_F_OIFACE)

/*
 * Definitions for REJECT response codes.
 * Values less than 256 correspond to ICMP unreachable codes.
 */
#define IP_FW_REJECT_RST	0x0100		/* TCP packets: send RST */

/*
 * Definitions for IP option names.
 */
#define IP_FW_IPOPT_LSRR	0x01
#define IP_FW_IPOPT_SSRR	0x02
#define IP_FW_IPOPT_RR		0x04
#define IP_FW_IPOPT_TS		0x08

/*
 * Definitions for TCP flags.
 */
#define IP_FW_TCPF_FIN		TH_FIN
#define IP_FW_TCPF_SYN		TH_SYN
#define IP_FW_TCPF_RST		TH_RST
#define IP_FW_TCPF_PSH		TH_PUSH
#define IP_FW_TCPF_ACK		TH_ACK
#define IP_FW_TCPF_URG		TH_URG
#define IP_FW_TCPF_ESTAB	0x40

/*
 * Main firewall chains definitions and global var's definitions.
 */
#ifdef _KERNEL

#define IP_FW_PORT_DYNT_FLAG	0x10000
#define IP_FW_PORT_TEE_FLAG	0x20000

/*
 * Function definitions.
 */
void ip_fw_init __P((void));

/* Firewall hooks */
struct ip;
struct sockopt;
typedef	int ip_fw_chk_t __P((struct ip **, int, struct ifnet *, u_int16_t *,
	     struct mbuf **, struct ip_fw_chain **, struct sockaddr_in **));
typedef	int ip_fw_ctl_t __P((struct sockopt *));
extern	ip_fw_chk_t *ip_fw_chk_ptr;
extern	ip_fw_ctl_t *ip_fw_ctl_ptr;

#endif /* _KERNEL */

#endif /* _IP_FW_H */
OpenPOWER on IntegriCloud