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 |
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 | { |
98a4a861 | 103 | __be16 _ports[2], *pptr; |
a89ecb6a YK |
104 | const struct xt_multiport *multiinfo = matchinfo; |
105 | ||
106 | if (offset) | |
1d93a9cb | 107 | return false; |
a89ecb6a YK |
108 | |
109 | pptr = skb_header_pointer(skb, protoff, sizeof(_ports), _ports); | |
110 | if (pptr == NULL) { | |
111 | /* We've been asked to examine this packet, and we | |
112 | * can't. Hence, no choice but to drop. | |
113 | */ | |
114 | duprintf("xt_multiport: Dropping evil offset=0 tinygram.\n"); | |
cff533ac | 115 | *hotdrop = true; |
1d93a9cb | 116 | return false; |
a89ecb6a YK |
117 | } |
118 | ||
d3c5ee6d JE |
119 | return ports_match_v0(multiinfo->ports, multiinfo->flags, |
120 | multiinfo->count, ntohs(pptr[0]), ntohs(pptr[1])); | |
a89ecb6a YK |
121 | } |
122 | ||
1d93a9cb | 123 | static bool |
d3c5ee6d JE |
124 | multiport_mt(const struct sk_buff *skb, const struct net_device *in, |
125 | const struct net_device *out, const struct xt_match *match, | |
126 | const void *matchinfo, int offset, unsigned int protoff, | |
127 | bool *hotdrop) | |
a89ecb6a | 128 | { |
98a4a861 | 129 | __be16 _ports[2], *pptr; |
a89ecb6a YK |
130 | const struct xt_multiport_v1 *multiinfo = matchinfo; |
131 | ||
132 | if (offset) | |
1d93a9cb | 133 | return false; |
a89ecb6a YK |
134 | |
135 | pptr = skb_header_pointer(skb, protoff, sizeof(_ports), _ports); | |
136 | if (pptr == NULL) { | |
137 | /* We've been asked to examine this packet, and we | |
138 | * can't. Hence, no choice but to drop. | |
139 | */ | |
140 | duprintf("xt_multiport: Dropping evil offset=0 tinygram.\n"); | |
cff533ac | 141 | *hotdrop = true; |
1d93a9cb | 142 | return false; |
a89ecb6a YK |
143 | } |
144 | ||
145 | return ports_match_v1(multiinfo, ntohs(pptr[0]), ntohs(pptr[1])); | |
146 | } | |
147 | ||
ccb79bdc | 148 | static inline bool |
a89ecb6a YK |
149 | check(u_int16_t proto, |
150 | u_int8_t ip_invflags, | |
151 | u_int8_t match_flags, | |
152 | u_int8_t count) | |
153 | { | |
957dc80a PM |
154 | /* Must specify supported protocol, no unknown flags or bad count */ |
155 | return (proto == IPPROTO_TCP || proto == IPPROTO_UDP | |
ba4e58ec | 156 | || proto == IPPROTO_UDPLITE |
957dc80a | 157 | || proto == IPPROTO_SCTP || proto == IPPROTO_DCCP) |
a89ecb6a YK |
158 | && !(ip_invflags & XT_INV_PROTO) |
159 | && (match_flags == XT_MULTIPORT_SOURCE | |
160 | || match_flags == XT_MULTIPORT_DESTINATION | |
161 | || match_flags == XT_MULTIPORT_EITHER) | |
162 | && count <= XT_MULTI_PORTS; | |
163 | } | |
164 | ||
165 | /* Called when user tries to insert an entry of this type. */ | |
ccb79bdc | 166 | static bool |
d3c5ee6d JE |
167 | multiport_mt_check_v0(const char *tablename, const void *info, |
168 | const struct xt_match *match, void *matchinfo, | |
169 | unsigned int hook_mask) | |
a89ecb6a YK |
170 | { |
171 | const struct ipt_ip *ip = info; | |
172 | const struct xt_multiport *multiinfo = matchinfo; | |
173 | ||
174 | return check(ip->proto, ip->invflags, multiinfo->flags, | |
175 | multiinfo->count); | |
176 | } | |
177 | ||
ccb79bdc | 178 | static bool |
d3c5ee6d JE |
179 | multiport_mt_check(const char *tablename, const void *info, |
180 | const struct xt_match *match, void *matchinfo, | |
181 | unsigned int hook_mask) | |
a89ecb6a YK |
182 | { |
183 | const struct ipt_ip *ip = info; | |
184 | const struct xt_multiport_v1 *multiinfo = matchinfo; | |
185 | ||
186 | return check(ip->proto, ip->invflags, multiinfo->flags, | |
187 | multiinfo->count); | |
188 | } | |
189 | ||
ccb79bdc | 190 | static bool |
d3c5ee6d JE |
191 | multiport_mt6_check_v0(const char *tablename, const void *info, |
192 | const struct xt_match *match, void *matchinfo, | |
193 | unsigned int hook_mask) | |
a89ecb6a YK |
194 | { |
195 | const struct ip6t_ip6 *ip = info; | |
196 | const struct xt_multiport *multiinfo = matchinfo; | |
197 | ||
198 | return check(ip->proto, ip->invflags, multiinfo->flags, | |
199 | multiinfo->count); | |
200 | } | |
201 | ||
ccb79bdc | 202 | static bool |
d3c5ee6d JE |
203 | multiport_mt6_check(const char *tablename, const void *info, |
204 | const struct xt_match *match, void *matchinfo, | |
205 | unsigned int hook_mask) | |
a89ecb6a YK |
206 | { |
207 | const struct ip6t_ip6 *ip = info; | |
208 | const struct xt_multiport_v1 *multiinfo = matchinfo; | |
209 | ||
210 | return check(ip->proto, ip->invflags, multiinfo->flags, | |
211 | multiinfo->count); | |
212 | } | |
213 | ||
d3c5ee6d | 214 | static struct xt_match multiport_mt_reg[] __read_mostly = { |
4470bbc7 PM |
215 | { |
216 | .name = "multiport", | |
217 | .family = AF_INET, | |
218 | .revision = 0, | |
d3c5ee6d JE |
219 | .checkentry = multiport_mt_check_v0, |
220 | .match = multiport_mt_v0, | |
4470bbc7 PM |
221 | .matchsize = sizeof(struct xt_multiport), |
222 | .me = THIS_MODULE, | |
223 | }, | |
224 | { | |
225 | .name = "multiport", | |
226 | .family = AF_INET, | |
227 | .revision = 1, | |
d3c5ee6d JE |
228 | .checkentry = multiport_mt_check, |
229 | .match = multiport_mt, | |
4470bbc7 PM |
230 | .matchsize = sizeof(struct xt_multiport_v1), |
231 | .me = THIS_MODULE, | |
232 | }, | |
233 | { | |
234 | .name = "multiport", | |
235 | .family = AF_INET6, | |
236 | .revision = 0, | |
d3c5ee6d JE |
237 | .checkentry = multiport_mt6_check_v0, |
238 | .match = multiport_mt_v0, | |
4470bbc7 PM |
239 | .matchsize = sizeof(struct xt_multiport), |
240 | .me = THIS_MODULE, | |
241 | }, | |
242 | { | |
243 | .name = "multiport", | |
244 | .family = AF_INET6, | |
245 | .revision = 1, | |
d3c5ee6d JE |
246 | .checkentry = multiport_mt6_check, |
247 | .match = multiport_mt, | |
4470bbc7 PM |
248 | .matchsize = sizeof(struct xt_multiport_v1), |
249 | .me = THIS_MODULE, | |
250 | }, | |
a89ecb6a YK |
251 | }; |
252 | ||
d3c5ee6d | 253 | static int __init multiport_mt_init(void) |
a89ecb6a | 254 | { |
d3c5ee6d JE |
255 | return xt_register_matches(multiport_mt_reg, |
256 | ARRAY_SIZE(multiport_mt_reg)); | |
a89ecb6a YK |
257 | } |
258 | ||
d3c5ee6d | 259 | static void __exit multiport_mt_exit(void) |
a89ecb6a | 260 | { |
d3c5ee6d | 261 | xt_unregister_matches(multiport_mt_reg, ARRAY_SIZE(multiport_mt_reg)); |
a89ecb6a YK |
262 | } |
263 | ||
d3c5ee6d JE |
264 | module_init(multiport_mt_init); |
265 | module_exit(multiport_mt_exit); |