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Commit | Line | Data |
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ba4e58ec GR |
1 | /* Kernel module to match one of a list of TCP/UDP(-Lite)/SCTP/DCCP ports: |
2 | ports are in the same place so we can treat them as equal. */ | |
a89ecb6a YK |
3 | |
4 | /* (C) 1999-2001 Paul `Rusty' Russell | |
5 | * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org> | |
6 | * | |
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. | |
10 | */ | |
11 | ||
12 | #include <linux/module.h> | |
13 | #include <linux/types.h> | |
14 | #include <linux/udp.h> | |
15 | #include <linux/skbuff.h> | |
16 | #include <linux/in.h> | |
17 | ||
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> | |
22 | ||
23 | MODULE_LICENSE("GPL"); | |
24 | MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); | |
2ae15b64 | 25 | MODULE_DESCRIPTION("Xtables: multiple port matching for TCP, UDP, UDP-Lite, SCTP and DCCP"); |
a89ecb6a YK |
26 | MODULE_ALIAS("ipt_multiport"); |
27 | MODULE_ALIAS("ip6t_multiport"); | |
28 | ||
29 | #if 0 | |
30 | #define duprintf(format, args...) printk(format , ## args) | |
31 | #else | |
32 | #define duprintf(format, args...) | |
33 | #endif | |
34 | ||
35 | /* Returns 1 if the port is matched by the test, 0 otherwise. */ | |
1d93a9cb | 36 | static inline bool |
d3c5ee6d JE |
37 | ports_match_v0(const u_int16_t *portlist, enum xt_multiport_flags flags, |
38 | u_int8_t count, u_int16_t src, u_int16_t dst) | |
a89ecb6a YK |
39 | { |
40 | unsigned int i; | |
41 | for (i = 0; i < count; i++) { | |
42 | if (flags != XT_MULTIPORT_DESTINATION && portlist[i] == src) | |
1d93a9cb | 43 | return true; |
a89ecb6a YK |
44 | |
45 | if (flags != XT_MULTIPORT_SOURCE && portlist[i] == dst) | |
1d93a9cb | 46 | return true; |
a89ecb6a YK |
47 | } |
48 | ||
1d93a9cb | 49 | return false; |
a89ecb6a YK |
50 | } |
51 | ||
52 | /* Returns 1 if the port is matched by the test, 0 otherwise. */ | |
1d93a9cb | 53 | static inline bool |
a89ecb6a YK |
54 | ports_match_v1(const struct xt_multiport_v1 *minfo, |
55 | u_int16_t src, u_int16_t dst) | |
56 | { | |
57 | unsigned int i; | |
58 | u_int16_t s, e; | |
59 | ||
60 | for (i = 0; i < minfo->count; i++) { | |
61 | s = minfo->ports[i]; | |
62 | ||
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); | |
67 | ||
68 | if (minfo->flags == XT_MULTIPORT_SOURCE | |
69 | && src >= s && src <= e) | |
1d93a9cb | 70 | return true ^ minfo->invert; |
a89ecb6a YK |
71 | if (minfo->flags == XT_MULTIPORT_DESTINATION |
72 | && dst >= s && dst <= e) | |
1d93a9cb | 73 | return true ^ minfo->invert; |
a89ecb6a YK |
74 | if (minfo->flags == XT_MULTIPORT_EITHER |
75 | && ((dst >= s && dst <= e) | |
76 | || (src >= s && src <= e))) | |
1d93a9cb | 77 | return true ^ minfo->invert; |
a89ecb6a YK |
78 | } else { |
79 | /* exact port matching */ | |
80 | duprintf("src or dst matches with %d?\n", s); | |
81 | ||
82 | if (minfo->flags == XT_MULTIPORT_SOURCE | |
83 | && src == s) | |
1d93a9cb | 84 | return true ^ minfo->invert; |
a89ecb6a YK |
85 | if (minfo->flags == XT_MULTIPORT_DESTINATION |
86 | && dst == s) | |
1d93a9cb | 87 | return true ^ minfo->invert; |
a89ecb6a YK |
88 | if (minfo->flags == XT_MULTIPORT_EITHER |
89 | && (src == s || dst == s)) | |
1d93a9cb | 90 | return true ^ minfo->invert; |
a89ecb6a YK |
91 | } |
92 | } | |
93 | ||
601e68e1 | 94 | return minfo->invert; |
a89ecb6a YK |
95 | } |
96 | ||
1d93a9cb | 97 | static bool |
d3c5ee6d JE |
98 | multiport_mt_v0(const struct sk_buff *skb, const struct net_device *in, |
99 | const struct net_device *out, const struct xt_match *match, | |
100 | const void *matchinfo, int offset, unsigned int protoff, | |
101 | bool *hotdrop) | |
a89ecb6a | 102 | { |
3cf93c96 JE |
103 | const __be16 *pptr; |
104 | __be16 _ports[2]; | |
a89ecb6a YK |
105 | const struct xt_multiport *multiinfo = matchinfo; |
106 | ||
107 | if (offset) | |
1d93a9cb | 108 | return false; |
a89ecb6a YK |
109 | |
110 | pptr = skb_header_pointer(skb, protoff, sizeof(_ports), _ports); | |
111 | if (pptr == NULL) { | |
112 | /* We've been asked to examine this packet, and we | |
113 | * can't. Hence, no choice but to drop. | |
114 | */ | |
115 | duprintf("xt_multiport: Dropping evil offset=0 tinygram.\n"); | |
cff533ac | 116 | *hotdrop = true; |
1d93a9cb | 117 | return false; |
a89ecb6a YK |
118 | } |
119 | ||
d3c5ee6d JE |
120 | return ports_match_v0(multiinfo->ports, multiinfo->flags, |
121 | multiinfo->count, ntohs(pptr[0]), ntohs(pptr[1])); | |
a89ecb6a YK |
122 | } |
123 | ||
1d93a9cb | 124 | static bool |
d3c5ee6d JE |
125 | multiport_mt(const struct sk_buff *skb, const struct net_device *in, |
126 | const struct net_device *out, const struct xt_match *match, | |
127 | const void *matchinfo, int offset, unsigned int protoff, | |
128 | bool *hotdrop) | |
a89ecb6a | 129 | { |
3cf93c96 JE |
130 | const __be16 *pptr; |
131 | __be16 _ports[2]; | |
a89ecb6a YK |
132 | const struct xt_multiport_v1 *multiinfo = matchinfo; |
133 | ||
134 | if (offset) | |
1d93a9cb | 135 | return false; |
a89ecb6a YK |
136 | |
137 | pptr = skb_header_pointer(skb, protoff, sizeof(_ports), _ports); | |
138 | if (pptr == NULL) { | |
139 | /* We've been asked to examine this packet, and we | |
140 | * can't. Hence, no choice but to drop. | |
141 | */ | |
142 | duprintf("xt_multiport: Dropping evil offset=0 tinygram.\n"); | |
cff533ac | 143 | *hotdrop = true; |
1d93a9cb | 144 | return false; |
a89ecb6a YK |
145 | } |
146 | ||
147 | return ports_match_v1(multiinfo, ntohs(pptr[0]), ntohs(pptr[1])); | |
148 | } | |
149 | ||
ccb79bdc | 150 | static inline bool |
a89ecb6a YK |
151 | check(u_int16_t proto, |
152 | u_int8_t ip_invflags, | |
153 | u_int8_t match_flags, | |
154 | u_int8_t count) | |
155 | { | |
957dc80a PM |
156 | /* Must specify supported protocol, no unknown flags or bad count */ |
157 | return (proto == IPPROTO_TCP || proto == IPPROTO_UDP | |
ba4e58ec | 158 | || proto == IPPROTO_UDPLITE |
957dc80a | 159 | || proto == IPPROTO_SCTP || proto == IPPROTO_DCCP) |
a89ecb6a YK |
160 | && !(ip_invflags & XT_INV_PROTO) |
161 | && (match_flags == XT_MULTIPORT_SOURCE | |
162 | || match_flags == XT_MULTIPORT_DESTINATION | |
163 | || match_flags == XT_MULTIPORT_EITHER) | |
164 | && count <= XT_MULTI_PORTS; | |
165 | } | |
166 | ||
167 | /* Called when user tries to insert an entry of this type. */ | |
ccb79bdc | 168 | static bool |
d3c5ee6d JE |
169 | multiport_mt_check_v0(const char *tablename, const void *info, |
170 | const struct xt_match *match, void *matchinfo, | |
171 | unsigned int hook_mask) | |
a89ecb6a YK |
172 | { |
173 | const struct ipt_ip *ip = info; | |
174 | const struct xt_multiport *multiinfo = matchinfo; | |
175 | ||
176 | return check(ip->proto, ip->invflags, multiinfo->flags, | |
177 | multiinfo->count); | |
178 | } | |
179 | ||
ccb79bdc | 180 | static bool |
d3c5ee6d JE |
181 | multiport_mt_check(const char *tablename, const void *info, |
182 | const struct xt_match *match, void *matchinfo, | |
183 | unsigned int hook_mask) | |
a89ecb6a YK |
184 | { |
185 | const struct ipt_ip *ip = info; | |
186 | const struct xt_multiport_v1 *multiinfo = matchinfo; | |
187 | ||
188 | return check(ip->proto, ip->invflags, multiinfo->flags, | |
189 | multiinfo->count); | |
190 | } | |
191 | ||
ccb79bdc | 192 | static bool |
d3c5ee6d JE |
193 | multiport_mt6_check_v0(const char *tablename, const void *info, |
194 | const struct xt_match *match, void *matchinfo, | |
195 | unsigned int hook_mask) | |
a89ecb6a YK |
196 | { |
197 | const struct ip6t_ip6 *ip = info; | |
198 | const struct xt_multiport *multiinfo = matchinfo; | |
199 | ||
200 | return check(ip->proto, ip->invflags, multiinfo->flags, | |
201 | multiinfo->count); | |
202 | } | |
203 | ||
ccb79bdc | 204 | static bool |
d3c5ee6d JE |
205 | multiport_mt6_check(const char *tablename, const void *info, |
206 | const struct xt_match *match, void *matchinfo, | |
207 | unsigned int hook_mask) | |
a89ecb6a YK |
208 | { |
209 | const struct ip6t_ip6 *ip = info; | |
210 | const struct xt_multiport_v1 *multiinfo = matchinfo; | |
211 | ||
212 | return check(ip->proto, ip->invflags, multiinfo->flags, | |
213 | multiinfo->count); | |
214 | } | |
215 | ||
d3c5ee6d | 216 | static struct xt_match multiport_mt_reg[] __read_mostly = { |
4470bbc7 PM |
217 | { |
218 | .name = "multiport", | |
219 | .family = AF_INET, | |
220 | .revision = 0, | |
d3c5ee6d JE |
221 | .checkentry = multiport_mt_check_v0, |
222 | .match = multiport_mt_v0, | |
4470bbc7 PM |
223 | .matchsize = sizeof(struct xt_multiport), |
224 | .me = THIS_MODULE, | |
225 | }, | |
226 | { | |
227 | .name = "multiport", | |
228 | .family = AF_INET, | |
229 | .revision = 1, | |
d3c5ee6d JE |
230 | .checkentry = multiport_mt_check, |
231 | .match = multiport_mt, | |
4470bbc7 PM |
232 | .matchsize = sizeof(struct xt_multiport_v1), |
233 | .me = THIS_MODULE, | |
234 | }, | |
235 | { | |
236 | .name = "multiport", | |
237 | .family = AF_INET6, | |
238 | .revision = 0, | |
d3c5ee6d JE |
239 | .checkentry = multiport_mt6_check_v0, |
240 | .match = multiport_mt_v0, | |
4470bbc7 PM |
241 | .matchsize = sizeof(struct xt_multiport), |
242 | .me = THIS_MODULE, | |
243 | }, | |
244 | { | |
245 | .name = "multiport", | |
246 | .family = AF_INET6, | |
247 | .revision = 1, | |
d3c5ee6d JE |
248 | .checkentry = multiport_mt6_check, |
249 | .match = multiport_mt, | |
4470bbc7 PM |
250 | .matchsize = sizeof(struct xt_multiport_v1), |
251 | .me = THIS_MODULE, | |
252 | }, | |
a89ecb6a YK |
253 | }; |
254 | ||
d3c5ee6d | 255 | static int __init multiport_mt_init(void) |
a89ecb6a | 256 | { |
d3c5ee6d JE |
257 | return xt_register_matches(multiport_mt_reg, |
258 | ARRAY_SIZE(multiport_mt_reg)); | |
a89ecb6a YK |
259 | } |
260 | ||
d3c5ee6d | 261 | static void __exit multiport_mt_exit(void) |
a89ecb6a | 262 | { |
d3c5ee6d | 263 | xt_unregister_matches(multiport_mt_reg, ARRAY_SIZE(multiport_mt_reg)); |
a89ecb6a YK |
264 | } |
265 | ||
d3c5ee6d JE |
266 | module_init(multiport_mt_init); |
267 | module_exit(multiport_mt_exit); |