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>"); | |
25 | MODULE_DESCRIPTION("x_tables multiple port match module"); | |
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 |
a89ecb6a YK |
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) | |
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 |
a89ecb6a YK |
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, | |
103 | int offset, | |
104 | unsigned int protoff, | |
cff533ac | 105 | bool *hotdrop) |
a89ecb6a | 106 | { |
98a4a861 | 107 | __be16 _ports[2], *pptr; |
a89ecb6a YK |
108 | const struct xt_multiport *multiinfo = matchinfo; |
109 | ||
110 | if (offset) | |
1d93a9cb | 111 | return false; |
a89ecb6a YK |
112 | |
113 | pptr = skb_header_pointer(skb, protoff, sizeof(_ports), _ports); | |
114 | if (pptr == NULL) { | |
115 | /* We've been asked to examine this packet, and we | |
116 | * can't. Hence, no choice but to drop. | |
117 | */ | |
118 | duprintf("xt_multiport: Dropping evil offset=0 tinygram.\n"); | |
cff533ac | 119 | *hotdrop = true; |
1d93a9cb | 120 | return false; |
a89ecb6a YK |
121 | } |
122 | ||
123 | return ports_match(multiinfo->ports, | |
124 | multiinfo->flags, multiinfo->count, | |
125 | ntohs(pptr[0]), ntohs(pptr[1])); | |
126 | } | |
127 | ||
1d93a9cb | 128 | static bool |
a89ecb6a YK |
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, | |
134 | int offset, | |
135 | unsigned int protoff, | |
cff533ac | 136 | bool *hotdrop) |
a89ecb6a | 137 | { |
98a4a861 | 138 | __be16 _ports[2], *pptr; |
a89ecb6a YK |
139 | const struct xt_multiport_v1 *multiinfo = matchinfo; |
140 | ||
141 | if (offset) | |
1d93a9cb | 142 | return false; |
a89ecb6a YK |
143 | |
144 | pptr = skb_header_pointer(skb, protoff, sizeof(_ports), _ports); | |
145 | if (pptr == NULL) { | |
146 | /* We've been asked to examine this packet, and we | |
147 | * can't. Hence, no choice but to drop. | |
148 | */ | |
149 | duprintf("xt_multiport: Dropping evil offset=0 tinygram.\n"); | |
cff533ac | 150 | *hotdrop = true; |
1d93a9cb | 151 | return false; |
a89ecb6a YK |
152 | } |
153 | ||
154 | return ports_match_v1(multiinfo, ntohs(pptr[0]), ntohs(pptr[1])); | |
155 | } | |
156 | ||
ccb79bdc | 157 | static inline bool |
a89ecb6a YK |
158 | check(u_int16_t proto, |
159 | u_int8_t ip_invflags, | |
160 | u_int8_t match_flags, | |
161 | u_int8_t count) | |
162 | { | |
957dc80a PM |
163 | /* Must specify supported protocol, no unknown flags or bad count */ |
164 | return (proto == IPPROTO_TCP || proto == IPPROTO_UDP | |
ba4e58ec | 165 | || proto == IPPROTO_UDPLITE |
957dc80a | 166 | || proto == IPPROTO_SCTP || proto == IPPROTO_DCCP) |
a89ecb6a YK |
167 | && !(ip_invflags & XT_INV_PROTO) |
168 | && (match_flags == XT_MULTIPORT_SOURCE | |
169 | || match_flags == XT_MULTIPORT_DESTINATION | |
170 | || match_flags == XT_MULTIPORT_EITHER) | |
171 | && count <= XT_MULTI_PORTS; | |
172 | } | |
173 | ||
174 | /* Called when user tries to insert an entry of this type. */ | |
ccb79bdc | 175 | static bool |
a89ecb6a YK |
176 | checkentry(const char *tablename, |
177 | const void *info, | |
178 | const struct xt_match *match, | |
179 | void *matchinfo, | |
a89ecb6a YK |
180 | unsigned int hook_mask) |
181 | { | |
182 | const struct ipt_ip *ip = info; | |
183 | const struct xt_multiport *multiinfo = matchinfo; | |
184 | ||
185 | return check(ip->proto, ip->invflags, multiinfo->flags, | |
186 | multiinfo->count); | |
187 | } | |
188 | ||
ccb79bdc | 189 | static bool |
a89ecb6a YK |
190 | checkentry_v1(const char *tablename, |
191 | const void *info, | |
192 | const struct xt_match *match, | |
193 | void *matchinfo, | |
a89ecb6a YK |
194 | unsigned int hook_mask) |
195 | { | |
196 | const struct ipt_ip *ip = info; | |
197 | const struct xt_multiport_v1 *multiinfo = matchinfo; | |
198 | ||
199 | return check(ip->proto, ip->invflags, multiinfo->flags, | |
200 | multiinfo->count); | |
201 | } | |
202 | ||
ccb79bdc | 203 | static bool |
a89ecb6a YK |
204 | checkentry6(const char *tablename, |
205 | const void *info, | |
206 | const struct xt_match *match, | |
207 | void *matchinfo, | |
a89ecb6a YK |
208 | unsigned int hook_mask) |
209 | { | |
210 | const struct ip6t_ip6 *ip = info; | |
211 | const struct xt_multiport *multiinfo = matchinfo; | |
212 | ||
213 | return check(ip->proto, ip->invflags, multiinfo->flags, | |
214 | multiinfo->count); | |
215 | } | |
216 | ||
ccb79bdc | 217 | static bool |
a89ecb6a YK |
218 | checkentry6_v1(const char *tablename, |
219 | const void *info, | |
220 | const struct xt_match *match, | |
221 | void *matchinfo, | |
a89ecb6a YK |
222 | unsigned int hook_mask) |
223 | { | |
224 | const struct ip6t_ip6 *ip = info; | |
225 | const struct xt_multiport_v1 *multiinfo = matchinfo; | |
226 | ||
227 | return check(ip->proto, ip->invflags, multiinfo->flags, | |
228 | multiinfo->count); | |
229 | } | |
230 | ||
9f15c530 | 231 | static struct xt_match xt_multiport_match[] __read_mostly = { |
4470bbc7 PM |
232 | { |
233 | .name = "multiport", | |
234 | .family = AF_INET, | |
235 | .revision = 0, | |
236 | .checkentry = checkentry, | |
237 | .match = match, | |
238 | .matchsize = sizeof(struct xt_multiport), | |
239 | .me = THIS_MODULE, | |
240 | }, | |
241 | { | |
242 | .name = "multiport", | |
243 | .family = AF_INET, | |
244 | .revision = 1, | |
245 | .checkentry = checkentry_v1, | |
246 | .match = match_v1, | |
247 | .matchsize = sizeof(struct xt_multiport_v1), | |
248 | .me = THIS_MODULE, | |
249 | }, | |
250 | { | |
251 | .name = "multiport", | |
252 | .family = AF_INET6, | |
253 | .revision = 0, | |
254 | .checkentry = checkentry6, | |
255 | .match = match, | |
256 | .matchsize = sizeof(struct xt_multiport), | |
257 | .me = THIS_MODULE, | |
258 | }, | |
259 | { | |
260 | .name = "multiport", | |
261 | .family = AF_INET6, | |
262 | .revision = 1, | |
263 | .checkentry = checkentry6_v1, | |
264 | .match = match_v1, | |
265 | .matchsize = sizeof(struct xt_multiport_v1), | |
266 | .me = THIS_MODULE, | |
267 | }, | |
a89ecb6a YK |
268 | }; |
269 | ||
270 | static int __init xt_multiport_init(void) | |
271 | { | |
4470bbc7 PM |
272 | return xt_register_matches(xt_multiport_match, |
273 | ARRAY_SIZE(xt_multiport_match)); | |
a89ecb6a YK |
274 | } |
275 | ||
276 | static void __exit xt_multiport_fini(void) | |
277 | { | |
4470bbc7 PM |
278 | xt_unregister_matches(xt_multiport_match, |
279 | ARRAY_SIZE(xt_multiport_match)); | |
a89ecb6a YK |
280 | } |
281 | ||
282 | module_init(xt_multiport_init); | |
283 | module_exit(xt_multiport_fini); |