1 /* Kernel module to match one of a list of TCP/UDP ports: ports are in
2 the same place so we can treat them as equal. */
4 /* (C) 1999-2001 Paul `Rusty' Russell
5 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
12 #include <linux/module.h>
13 #include <linux/types.h>
14 #include <linux/udp.h>
15 #include <linux/skbuff.h>
18 #include <linux/netfilter/xt_multiport.h>
19 #include <linux/netfilter/x_tables.h>
20 #include <linux/netfilter_ipv4/ip_tables.h>
21 #include <linux/netfilter_ipv6/ip6_tables.h>
23 MODULE_LICENSE("GPL");
24 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
25 MODULE_DESCRIPTION("x_tables multiple port match module");
26 MODULE_ALIAS("ipt_multiport");
27 MODULE_ALIAS("ip6t_multiport");
30 #define duprintf(format, args...) printk(format , ## args)
32 #define duprintf(format, args...)
35 /* Returns 1 if the port is matched by the test, 0 otherwise. */
37 ports_match(const u_int16_t *portlist, enum xt_multiport_flags flags,
38 u_int8_t count, u_int16_t src, u_int16_t dst)
41 for (i = 0; i < count; i++) {
42 if (flags != XT_MULTIPORT_DESTINATION && portlist[i] == src)
45 if (flags != XT_MULTIPORT_SOURCE && portlist[i] == dst)
52 /* Returns 1 if the port is matched by the test, 0 otherwise. */
54 ports_match_v1(const struct xt_multiport_v1 *minfo,
55 u_int16_t src, u_int16_t dst)
60 for (i = 0; i < minfo->count; i++) {
63 if (minfo->pflags[i]) {
64 /* range port matching */
65 e = minfo->ports[++i];
66 duprintf("src or dst matches with %d-%d?\n", s, e);
68 if (minfo->flags == XT_MULTIPORT_SOURCE
69 && src >= s && src <= e)
70 return 1 ^ minfo->invert;
71 if (minfo->flags == XT_MULTIPORT_DESTINATION
72 && dst >= s && dst <= e)
73 return 1 ^ minfo->invert;
74 if (minfo->flags == XT_MULTIPORT_EITHER
75 && ((dst >= s && dst <= e)
76 || (src >= s && src <= e)))
77 return 1 ^ minfo->invert;
79 /* exact port matching */
80 duprintf("src or dst matches with %d?\n", s);
82 if (minfo->flags == XT_MULTIPORT_SOURCE
84 return 1 ^ minfo->invert;
85 if (minfo->flags == XT_MULTIPORT_DESTINATION
87 return 1 ^ minfo->invert;
88 if (minfo->flags == XT_MULTIPORT_EITHER
89 && (src == s || dst == s))
90 return 1 ^ minfo->invert;
98 match(const struct sk_buff *skb,
99 const struct net_device *in,
100 const struct net_device *out,
101 const struct xt_match *match,
102 const void *matchinfo,
104 unsigned int protoff,
107 u16 _ports[2], *pptr;
108 const struct xt_multiport *multiinfo = matchinfo;
113 pptr = skb_header_pointer(skb, protoff, sizeof(_ports), _ports);
115 /* We've been asked to examine this packet, and we
116 * can't. Hence, no choice but to drop.
118 duprintf("xt_multiport: Dropping evil offset=0 tinygram.\n");
123 return ports_match(multiinfo->ports,
124 multiinfo->flags, multiinfo->count,
125 ntohs(pptr[0]), ntohs(pptr[1]));
129 match_v1(const struct sk_buff *skb,
130 const struct net_device *in,
131 const struct net_device *out,
132 const struct xt_match *match,
133 const void *matchinfo,
135 unsigned int protoff,
138 u16 _ports[2], *pptr;
139 const struct xt_multiport_v1 *multiinfo = matchinfo;
144 pptr = skb_header_pointer(skb, protoff, sizeof(_ports), _ports);
146 /* We've been asked to examine this packet, and we
147 * can't. Hence, no choice but to drop.
149 duprintf("xt_multiport: Dropping evil offset=0 tinygram.\n");
154 return ports_match_v1(multiinfo, ntohs(pptr[0]), ntohs(pptr[1]));
158 check(u_int16_t proto,
159 u_int8_t ip_invflags,
160 u_int8_t match_flags,
163 /* Must specify proto == TCP/UDP, no unknown flags or bad count */
164 return (proto == IPPROTO_TCP || proto == IPPROTO_UDP)
165 && !(ip_invflags & XT_INV_PROTO)
166 && (match_flags == XT_MULTIPORT_SOURCE
167 || match_flags == XT_MULTIPORT_DESTINATION
168 || match_flags == XT_MULTIPORT_EITHER)
169 && count <= XT_MULTI_PORTS;
172 /* Called when user tries to insert an entry of this type. */
174 checkentry(const char *tablename,
176 const struct xt_match *match,
178 unsigned int matchsize,
179 unsigned int hook_mask)
181 const struct ipt_ip *ip = info;
182 const struct xt_multiport *multiinfo = matchinfo;
184 return check(ip->proto, ip->invflags, multiinfo->flags,
189 checkentry_v1(const char *tablename,
191 const struct xt_match *match,
193 unsigned int matchsize,
194 unsigned int hook_mask)
196 const struct ipt_ip *ip = info;
197 const struct xt_multiport_v1 *multiinfo = matchinfo;
199 return check(ip->proto, ip->invflags, multiinfo->flags,
204 checkentry6(const char *tablename,
206 const struct xt_match *match,
208 unsigned int matchsize,
209 unsigned int hook_mask)
211 const struct ip6t_ip6 *ip = info;
212 const struct xt_multiport *multiinfo = matchinfo;
214 return check(ip->proto, ip->invflags, multiinfo->flags,
219 checkentry6_v1(const char *tablename,
221 const struct xt_match *match,
223 unsigned int matchsize,
224 unsigned int hook_mask)
226 const struct ip6t_ip6 *ip = info;
227 const struct xt_multiport_v1 *multiinfo = matchinfo;
229 return check(ip->proto, ip->invflags, multiinfo->flags,
233 static struct xt_match multiport_match = {
236 .matchsize = sizeof(struct xt_multiport),
238 .checkentry = &checkentry,
243 static struct xt_match multiport_match_v1 = {
246 .matchsize = sizeof(struct xt_multiport_v1),
248 .checkentry = &checkentry_v1,
253 static struct xt_match multiport6_match = {
256 .matchsize = sizeof(struct xt_multiport),
258 .checkentry = &checkentry6,
263 static struct xt_match multiport6_match_v1 = {
266 .matchsize = sizeof(struct xt_multiport_v1),
268 .checkentry = &checkentry6_v1,
273 static int __init xt_multiport_init(void)
277 ret = xt_register_match(&multiport_match);
281 ret = xt_register_match(&multiport_match_v1);
283 goto out_unreg_multi_v0;
285 ret = xt_register_match(&multiport6_match);
287 goto out_unreg_multi_v1;
289 ret = xt_register_match(&multiport6_match_v1);
291 goto out_unreg_multi6_v0;
296 xt_unregister_match(&multiport6_match);
298 xt_unregister_match(&multiport_match_v1);
300 xt_unregister_match(&multiport_match);
305 static void __exit xt_multiport_fini(void)
307 xt_unregister_match(&multiport_match);
308 xt_unregister_match(&multiport_match_v1);
309 xt_unregister_match(&multiport6_match);
310 xt_unregister_match(&multiport6_match_v1);
313 module_init(xt_multiport_init);
314 module_exit(xt_multiport_fini);