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>
17 #include <linux/netfilter_ipv4/ipt_multiport.h>
18 #include <linux/netfilter_ipv4/ip_tables.h>
20 MODULE_LICENSE("GPL");
21 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
22 MODULE_DESCRIPTION("iptables multiple port match module");
25 #define duprintf(format, args...) printk(format , ## args)
27 #define duprintf(format, args...)
30 /* Returns 1 if the port is matched by the test, 0 otherwise. */
32 ports_match(const u_int16_t *portlist, enum ipt_multiport_flags flags,
33 u_int8_t count, u_int16_t src, u_int16_t dst)
36 for (i=0; i<count; i++) {
37 if (flags != IPT_MULTIPORT_DESTINATION
38 && portlist[i] == src)
41 if (flags != IPT_MULTIPORT_SOURCE
42 && portlist[i] == dst)
49 /* Returns 1 if the port is matched by the test, 0 otherwise. */
51 ports_match_v1(const struct ipt_multiport_v1 *minfo,
52 u_int16_t src, u_int16_t dst)
57 for (i=0; i < minfo->count; i++) {
60 if (minfo->pflags[i]) {
61 /* range port matching */
62 e = minfo->ports[++i];
63 duprintf("src or dst matches with %d-%d?\n", s, e);
65 if (minfo->flags == IPT_MULTIPORT_SOURCE
66 && src >= s && src <= e)
67 return 1 ^ minfo->invert;
68 if (minfo->flags == IPT_MULTIPORT_DESTINATION
69 && dst >= s && dst <= e)
70 return 1 ^ minfo->invert;
71 if (minfo->flags == IPT_MULTIPORT_EITHER
72 && ((dst >= s && dst <= e)
73 || (src >= s && src <= e)))
74 return 1 ^ minfo->invert;
76 /* exact port matching */
77 duprintf("src or dst matches with %d?\n", s);
79 if (minfo->flags == IPT_MULTIPORT_SOURCE
81 return 1 ^ minfo->invert;
82 if (minfo->flags == IPT_MULTIPORT_DESTINATION
84 return 1 ^ minfo->invert;
85 if (minfo->flags == IPT_MULTIPORT_EITHER
86 && (src == s || dst == s))
87 return 1 ^ minfo->invert;
95 match(const struct sk_buff *skb,
96 const struct net_device *in,
97 const struct net_device *out,
98 const void *matchinfo,
102 u16 _ports[2], *pptr;
103 const struct ipt_multiport *multiinfo = matchinfo;
108 pptr = skb_header_pointer(skb, skb->nh.iph->ihl * 4,
109 sizeof(_ports), _ports);
111 /* We've been asked to examine this packet, and we
112 * can't. Hence, no choice but to drop.
114 duprintf("ipt_multiport:"
115 " Dropping evil offset=0 tinygram.\n");
120 return ports_match(multiinfo->ports,
121 multiinfo->flags, multiinfo->count,
122 ntohs(pptr[0]), ntohs(pptr[1]));
126 match_v1(const struct sk_buff *skb,
127 const struct net_device *in,
128 const struct net_device *out,
129 const void *matchinfo,
133 u16 _ports[2], *pptr;
134 const struct ipt_multiport_v1 *multiinfo = matchinfo;
139 pptr = skb_header_pointer(skb, skb->nh.iph->ihl * 4,
140 sizeof(_ports), _ports);
142 /* We've been asked to examine this packet, and we
143 * can't. Hence, no choice but to drop.
145 duprintf("ipt_multiport:"
146 " Dropping evil offset=0 tinygram.\n");
151 return ports_match_v1(multiinfo, ntohs(pptr[0]), ntohs(pptr[1]));
154 /* Called when user tries to insert an entry of this type. */
156 checkentry(const char *tablename,
157 const struct ipt_ip *ip,
159 unsigned int matchsize,
160 unsigned int hook_mask)
162 return (matchsize == IPT_ALIGN(sizeof(struct ipt_multiport)));
166 checkentry_v1(const char *tablename,
167 const struct ipt_ip *ip,
169 unsigned int matchsize,
170 unsigned int hook_mask)
172 return (matchsize == IPT_ALIGN(sizeof(struct ipt_multiport_v1)));
175 static struct ipt_match multiport_match = {
179 .checkentry = &checkentry,
183 static struct ipt_match multiport_match_v1 = {
187 .checkentry = &checkentry_v1,
191 static int __init init(void)
195 err = ipt_register_match(&multiport_match);
197 err = ipt_register_match(&multiport_match_v1);
199 ipt_unregister_match(&multiport_match);
205 static void __exit fini(void)
207 ipt_unregister_match(&multiport_match);
208 ipt_unregister_match(&multiport_match_v1);