ip_fw.h revision 70826 
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 70826 2001-01-09 03:10:30Z rwatson $
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 */
51
52struct ip_fw {
53    u_int64_t fw_pcnt,fw_bcnt;		/* Packet and byte counters */
54    struct in_addr fw_src, fw_dst;	/* Source and destination IP addr */
55    struct in_addr fw_smsk, fw_dmsk;	/* Mask for src and dest IP addr */
56    u_short fw_number;			/* Rule number */
57    u_int fw_flg;			/* Operational Flags word */
58#define IP_FW_MAX_PORTS	10		/* A reasonable maximum */
59	union {
60	u_short fw_pts[IP_FW_MAX_PORTS];	/* Array of port numbers to match */
61#define IP_FW_ICMPTYPES_MAX	128
62#define IP_FW_ICMPTYPES_DIM	(IP_FW_ICMPTYPES_MAX / (sizeof(unsigned) * 8))
63	unsigned fw_icmptypes[IP_FW_ICMPTYPES_DIM]; /* ICMP types bitmap */
64	} fw_uar;
65    u_int fw_ipflg;			/* IP flags word */
66    u_char fw_ipopt,fw_ipnopt;		/* IP options set/unset */
67    u_short fw_iplen, fw_ipid;		/* IP length, identification */
68    u_char fw_iptos, fw_ipntos;		/* IP type of service set/unset */
69    u_char fw_ipttl;			/* IP time to live */
70    u_int fw_ipver:4;			/* IP version */
71    u_char fw_tcpopt,fw_tcpnopt;	/* TCP options set/unset */
72    u_char fw_tcpf,fw_tcpnf;		/* TCP flags set/unset */
73    u_int32_t fw_tcpseq, fw_tcpack;	/* TCP sequence and acknowledgement */
74    u_short fw_tcpwin;			/* TCP window size */
75    long timestamp;			/* timestamp (tv_sec) of last match */
76    union ip_fw_if fw_in_if, fw_out_if;	/* Incoming and outgoing interfaces */
77    union {
78	u_short fu_divert_port;		/* Divert/tee port (options IPDIVERT) */
79	u_short fu_pipe_nr;		/* queue number (option DUMMYNET) */
80	u_short fu_skipto_rule;		/* SKIPTO command rule number */
81	u_short fu_reject_code;		/* REJECT response code */
82	struct sockaddr_in fu_fwd_ip;
83    } fw_un;
84    u_char fw_prot;			/* IP protocol */
85	/*
86	 * N'of src ports and # of dst ports in ports array (dst ports
87	 * follow src ports; max of 10 ports in all; count of 0 means
88	 * match all ports)
89	 */
90    u_char fw_nports;
91    void *pipe_ptr;                    /* flow_set ptr for dummynet pipe */
92    void *next_rule_ptr ;              /* next rule in case of match */
93    uid_t fw_uid;			/* uid to match */
94    gid_t fw_gid;			/* gid to match */
95    int fw_logamount;			/* amount to log */
96    u_int64_t fw_loghighest;		/* highest number packet to log */
97};
98
99/*
100 * extended ipfw structure... some fields in the original struct
101 * can be used to pass parameters up/down, namely pointers
102 *     void *pipe_ptr
103 *     void *next_rule_ptr
104 * some others can be used to pass parameters down, namely counters etc.
105 *     u_int64_t fw_pcnt,fw_bcnt;
106 *     long timestamp;
107 */
108
109struct ip_fw_ext {             /* extended structure */
110    struct ip_fw rule;      /* must be at offset 0 */
111    long    dont_match_prob;        /* 0x7fffffff means 1.0, always fail */
112    u_int   dyn_type;  /* type for dynamic rule */
113};
114
115#define IP_FW_GETNSRCP(rule)		((rule)->fw_nports & 0x0f)
116#define IP_FW_SETNSRCP(rule, n)		do {				\
117					  (rule)->fw_nports &= ~0x0f;	\
118					  (rule)->fw_nports |= (n);	\
119					} while (0)
120#define IP_FW_GETNDSTP(rule)		((rule)->fw_nports >> 4)
121#define IP_FW_SETNDSTP(rule, n)		do {				\
122					  (rule)->fw_nports &= ~0xf0;	\
123					  (rule)->fw_nports |= (n) << 4;\
124					} while (0)
125
126#define fw_divert_port	fw_un.fu_divert_port
127#define fw_skipto_rule	fw_un.fu_skipto_rule
128#define fw_reject_code	fw_un.fu_reject_code
129#define fw_pipe_nr	fw_un.fu_pipe_nr
130#define fw_fwd_ip	fw_un.fu_fwd_ip
131
132struct ip_fw_chain {
133        LIST_ENTRY(ip_fw_chain) chain;
134        struct ip_fw    *rule;
135};
136
137/*
138 * Flow mask/flow id for each queue.
139 */
140struct ipfw_flow_id {
141    u_int32_t dst_ip, src_ip ;
142    u_int16_t dst_port, src_port ;
143    u_int8_t proto ;
144    u_int8_t flags ;    /* protocol-specific flags */
145} ;
146
147/*
148 * dynamic ipfw rule
149 */
150struct ipfw_dyn_rule {
151    struct ipfw_dyn_rule *next ;
152
153    struct ipfw_flow_id id ;
154    struct ipfw_flow_id mask ;
155    struct ip_fw_chain *chain ;		/* pointer to parent rule	*/
156    u_int32_t type ;			/* rule type			*/
157    u_int32_t expire ;			/* expire time			*/
158    u_int64_t pcnt, bcnt;		/* match counters		*/
159    u_int32_t bucket ;			/* which bucket in hash table	*/
160    u_int32_t state ;			/* state of this rule (typ. a   */
161					/* combination of TCP flags)	*/
162} ;
163
164/*
165 * Values for "flags" field .
166 */
167#define IP_FW_F_COMMAND 0x000000ff	/* Mask for type of chain entry:	*/
168#define IP_FW_F_DENY	0x00000000	/* This is a deny rule			*/
169#define IP_FW_F_REJECT	0x00000001	/* Deny and send a response packet	*/
170#define IP_FW_F_ACCEPT	0x00000002	/* This is an accept rule		*/
171#define IP_FW_F_COUNT	0x00000003	/* This is a count rule			*/
172#define IP_FW_F_DIVERT	0x00000004	/* This is a divert rule		*/
173#define IP_FW_F_TEE	0x00000005	/* This is a tee rule			*/
174#define IP_FW_F_SKIPTO	0x00000006	/* This is a skipto rule		*/
175#define IP_FW_F_FWD	0x00000007	/* This is a "change forwarding address" rule */
176#define IP_FW_F_PIPE	0x00000008	/* This is a dummynet rule */
177#define IP_FW_F_QUEUE	0x00000009	/* This is a dummynet queue */
178
179#define IP_FW_F_IN	0x00000100	/* Check inbound packets		*/
180#define IP_FW_F_OUT	0x00000200	/* Check outbound packets		*/
181#define IP_FW_F_IIFACE	0x00000400	/* Apply inbound interface test		*/
182#define IP_FW_F_OIFACE	0x00000800	/* Apply outbound interface test	*/
183
184#define IP_FW_F_PRN	0x00001000	/* Print if this rule matches		*/
185
186#define IP_FW_F_SRNG	0x00002000	/* The first two src ports are a min	*
187					 * and max range (stored in host byte	*
188					 * order).				*/
189
190#define IP_FW_F_DRNG	0x00004000	/* The first two dst ports are a min	*
191					 * and max range (stored in host byte	*
192					 * order).				*/
193
194#define IP_FW_F_FRAG	0x00008000	/* Fragment				*/
195
196#define IP_FW_F_IIFNAME	0x00010000	/* In interface by name/unit (not IP)	*/
197#define IP_FW_F_OIFNAME	0x00020000	/* Out interface by name/unit (not IP)	*/
198
199#define IP_FW_F_INVSRC	0x00040000	/* Invert sense of src check		*/
200#define IP_FW_F_INVDST	0x00080000	/* Invert sense of dst check		*/
201
202#define IP_FW_F_ICMPBIT 0x00100000	/* ICMP type bitmap is valid		*/
203
204#define IP_FW_F_UID	0x00200000	/* filter by uid			*/
205
206#define IP_FW_F_GID	0x00400000	/* filter by gid			*/
207
208#define IP_FW_F_RND_MATCH 0x00800000	/* probabilistic rule match		*/
209#define IP_FW_F_SMSK	0x01000000	/* src-port + mask 			*/
210#define IP_FW_F_DMSK	0x02000000	/* dst-port + mask 			*/
211#define	IP_FW_BRIDGED	0x04000000	/* only match bridged packets		*/
212#define IP_FW_F_KEEP_S	0x08000000	/* keep state	 			*/
213#define IP_FW_F_CHECK_S	0x10000000	/* check state	 			*/
214
215#define IP_FW_F_MASK	0x1FFFFFFF	/* All possible flag bits mask		*/
216
217/*
218 * Flags for the 'fw_ipflg' field, for comparing values of ip and its protocols.
219 */
220#define IP_FW_IF_TCPOPT	0x00000001      /* tcp options			*/
221#define IP_FW_IF_TCPFLG	0x00000002      /* tcp flags			*/
222#define IP_FW_IF_TCPSEQ	0x00000004      /* tcp sequence number		*/
223#define IP_FW_IF_TCPACK	0x00000008      /* tcp acknowledgement number	*/
224#define IP_FW_IF_TCPWIN	0x00000010      /* tcp window size		*/
225#define	IP_FW_IF_TCPEST 0x00000020	/* established TCP connection	*/
226#define	IP_FW_IF_TCPMSK	0x0000003f	/* mask of all tcp values	*/
227
228#define IP_FW_IF_IPOPT	0x00000100	/* ip options			*/
229#define IP_FW_IF_IPLEN	0x00000200	/* ip length			*/
230#define IP_FW_IF_IPID	0x00000400	/* ip identification		*/
231#define IP_FW_IF_IPTOS	0x00000800	/* ip type of service		*/
232#define IP_FW_IF_IPTTL	0x00001000	/* ip time to live		*/
233#define IP_FW_IF_IPVER	0x00002000	/* ip version			*/
234#define IP_FW_IF_IPMSK	0x00003f00	/* mask of all ip values	*/
235
236#define IP_FW_IF_MSK	0x0000ffff	/* All possible bits mask	*/
237
238/*
239 * For backwards compatibility with rules specifying "via iface" but
240 * not restricted to only "in" or "out" packets, we define this combination
241 * of bits to represent this configuration.
242 */
243
244#define IF_FW_F_VIAHACK	(IP_FW_F_IN|IP_FW_F_OUT|IP_FW_F_IIFACE|IP_FW_F_OIFACE)
245
246/*
247 * Definitions for REJECT response codes.
248 * Values less than 256 correspond to ICMP unreachable codes.
249 */
250#define IP_FW_REJECT_RST	0x0100		/* TCP packets: send RST */
251
252/*
253 * Definitions for IP option names.
254 */
255#define IP_FW_IPOPT_LSRR	0x01
256#define IP_FW_IPOPT_SSRR	0x02
257#define IP_FW_IPOPT_RR		0x04
258#define IP_FW_IPOPT_TS		0x08
259
260/*
261 * Definitions for TCP option names.
262 */
263#define IP_FW_TCPOPT_MSS	0x01
264#define IP_FW_TCPOPT_WINDOW	0x02
265#define IP_FW_TCPOPT_SACK	0x04
266#define IP_FW_TCPOPT_TS		0x08
267#define IP_FW_TCPOPT_CC		0x10
268
269/*
270 * Definitions for TCP flags.
271 */
272#define IP_FW_TCPF_FIN		TH_FIN
273#define IP_FW_TCPF_SYN		TH_SYN
274#define IP_FW_TCPF_RST		TH_RST
275#define IP_FW_TCPF_PSH		TH_PUSH
276#define IP_FW_TCPF_ACK		TH_ACK
277#define IP_FW_TCPF_URG		TH_URG
278
279/*
280 * Main firewall chains definitions and global var's definitions.
281 */
282#ifdef _KERNEL
283
284#define IP_FW_PORT_DYNT_FLAG	0x10000
285#define IP_FW_PORT_TEE_FLAG	0x20000
286
287/*
288 * Function definitions.
289 */
290void ip_fw_init __P((void));
291
292/* Firewall hooks */
293struct ip;
294struct sockopt;
295typedef	int ip_fw_chk_t __P((struct ip **, int, struct ifnet *, u_int16_t *,
296	     struct mbuf **, struct ip_fw_chain **, struct sockaddr_in **));
297typedef	int ip_fw_ctl_t __P((struct sockopt *));
298extern	ip_fw_chk_t *ip_fw_chk_ptr;
299extern	ip_fw_ctl_t *ip_fw_ctl_ptr;
300extern int fw_one_pass;
301extern int fw_enable;
302extern struct ipfw_flow_id last_pkt ;
303#endif /* _KERNEL */
304
305#endif /* _IP_FW_H */
306