Commit | Line | Data |
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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
ba4e58ec GR |
2 | /* Kernel module to match one of a list of TCP/UDP(-Lite)/SCTP/DCCP ports: |
3 | ports are in the same place so we can treat them as equal. */ | |
a89ecb6a YK |
4 | |
5 | /* (C) 1999-2001 Paul `Rusty' Russell | |
6 | * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org> | |
a89ecb6a | 7 | */ |
be91fd5e | 8 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
a89ecb6a YK |
9 | #include <linux/module.h> |
10 | #include <linux/types.h> | |
11 | #include <linux/udp.h> | |
12 | #include <linux/skbuff.h> | |
13 | #include <linux/in.h> | |
14 | ||
15 | #include <linux/netfilter/xt_multiport.h> | |
16 | #include <linux/netfilter/x_tables.h> | |
17 | #include <linux/netfilter_ipv4/ip_tables.h> | |
18 | #include <linux/netfilter_ipv6/ip6_tables.h> | |
19 | ||
20 | MODULE_LICENSE("GPL"); | |
21 | MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); | |
2ae15b64 | 22 | MODULE_DESCRIPTION("Xtables: multiple port matching for TCP, UDP, UDP-Lite, SCTP and DCCP"); |
a89ecb6a YK |
23 | MODULE_ALIAS("ipt_multiport"); |
24 | MODULE_ALIAS("ip6t_multiport"); | |
25 | ||
a89ecb6a | 26 | /* Returns 1 if the port is matched by the test, 0 otherwise. */ |
1d93a9cb | 27 | static inline bool |
a89ecb6a YK |
28 | ports_match_v1(const struct xt_multiport_v1 *minfo, |
29 | u_int16_t src, u_int16_t dst) | |
30 | { | |
31 | unsigned int i; | |
32 | u_int16_t s, e; | |
33 | ||
34 | for (i = 0; i < minfo->count; i++) { | |
35 | s = minfo->ports[i]; | |
36 | ||
37 | if (minfo->pflags[i]) { | |
38 | /* range port matching */ | |
39 | e = minfo->ports[++i]; | |
be91fd5e | 40 | pr_debug("src or dst matches with %d-%d?\n", s, e); |
a89ecb6a | 41 | |
dd2602d0 GF |
42 | switch (minfo->flags) { |
43 | case XT_MULTIPORT_SOURCE: | |
1ed9887e GF |
44 | if (src >= s && src <= e) |
45 | return true ^ minfo->invert; | |
46 | break; | |
dd2602d0 | 47 | case XT_MULTIPORT_DESTINATION: |
1ed9887e GF |
48 | if (dst >= s && dst <= e) |
49 | return true ^ minfo->invert; | |
50 | break; | |
dd2602d0 | 51 | case XT_MULTIPORT_EITHER: |
1ed9887e GF |
52 | if ((dst >= s && dst <= e) || |
53 | (src >= s && src <= e)) | |
54 | return true ^ minfo->invert; | |
55 | break; | |
dd2602d0 GF |
56 | default: |
57 | break; | |
58 | } | |
a89ecb6a YK |
59 | } else { |
60 | /* exact port matching */ | |
be91fd5e | 61 | pr_debug("src or dst matches with %d?\n", s); |
a89ecb6a | 62 | |
dd2602d0 GF |
63 | switch (minfo->flags) { |
64 | case XT_MULTIPORT_SOURCE: | |
1ed9887e GF |
65 | if (src == s) |
66 | return true ^ minfo->invert; | |
67 | break; | |
dd2602d0 | 68 | case XT_MULTIPORT_DESTINATION: |
1ed9887e GF |
69 | if (dst == s) |
70 | return true ^ minfo->invert; | |
71 | break; | |
dd2602d0 | 72 | case XT_MULTIPORT_EITHER: |
1ed9887e GF |
73 | if (src == s || dst == s) |
74 | return true ^ minfo->invert; | |
75 | break; | |
dd2602d0 GF |
76 | default: |
77 | break; | |
78 | } | |
a89ecb6a YK |
79 | } |
80 | } | |
81 | ||
601e68e1 | 82 | return minfo->invert; |
a89ecb6a YK |
83 | } |
84 | ||
1d93a9cb | 85 | static bool |
62fc8051 | 86 | multiport_mt(const struct sk_buff *skb, struct xt_action_param *par) |
a89ecb6a | 87 | { |
3cf93c96 JE |
88 | const __be16 *pptr; |
89 | __be16 _ports[2]; | |
f7108a20 | 90 | const struct xt_multiport_v1 *multiinfo = par->matchinfo; |
a89ecb6a | 91 | |
f7108a20 | 92 | if (par->fragoff != 0) |
1d93a9cb | 93 | return false; |
a89ecb6a | 94 | |
f7108a20 | 95 | pptr = skb_header_pointer(skb, par->thoff, sizeof(_ports), _ports); |
a89ecb6a YK |
96 | if (pptr == NULL) { |
97 | /* We've been asked to examine this packet, and we | |
98 | * can't. Hence, no choice but to drop. | |
99 | */ | |
be91fd5e | 100 | pr_debug("Dropping evil offset=0 tinygram.\n"); |
b4ba2611 | 101 | par->hotdrop = true; |
1d93a9cb | 102 | return false; |
a89ecb6a YK |
103 | } |
104 | ||
105 | return ports_match_v1(multiinfo, ntohs(pptr[0]), ntohs(pptr[1])); | |
106 | } | |
107 | ||
ccb79bdc | 108 | static inline bool |
a89ecb6a YK |
109 | check(u_int16_t proto, |
110 | u_int8_t ip_invflags, | |
111 | u_int8_t match_flags, | |
112 | u_int8_t count) | |
113 | { | |
957dc80a PM |
114 | /* Must specify supported protocol, no unknown flags or bad count */ |
115 | return (proto == IPPROTO_TCP || proto == IPPROTO_UDP | |
ba4e58ec | 116 | || proto == IPPROTO_UDPLITE |
957dc80a | 117 | || proto == IPPROTO_SCTP || proto == IPPROTO_DCCP) |
a89ecb6a YK |
118 | && !(ip_invflags & XT_INV_PROTO) |
119 | && (match_flags == XT_MULTIPORT_SOURCE | |
120 | || match_flags == XT_MULTIPORT_DESTINATION | |
121 | || match_flags == XT_MULTIPORT_EITHER) | |
122 | && count <= XT_MULTI_PORTS; | |
123 | } | |
124 | ||
b0f38452 | 125 | static int multiport_mt_check(const struct xt_mtchk_param *par) |
a89ecb6a | 126 | { |
9b4fce7a JE |
127 | const struct ipt_ip *ip = par->entryinfo; |
128 | const struct xt_multiport_v1 *multiinfo = par->matchinfo; | |
a89ecb6a YK |
129 | |
130 | return check(ip->proto, ip->invflags, multiinfo->flags, | |
c29c9492 | 131 | multiinfo->count) ? 0 : -EINVAL; |
a89ecb6a YK |
132 | } |
133 | ||
b0f38452 | 134 | static int multiport_mt6_check(const struct xt_mtchk_param *par) |
a89ecb6a | 135 | { |
9b4fce7a JE |
136 | const struct ip6t_ip6 *ip = par->entryinfo; |
137 | const struct xt_multiport_v1 *multiinfo = par->matchinfo; | |
a89ecb6a YK |
138 | |
139 | return check(ip->proto, ip->invflags, multiinfo->flags, | |
c29c9492 | 140 | multiinfo->count) ? 0 : -EINVAL; |
a89ecb6a YK |
141 | } |
142 | ||
d3c5ee6d | 143 | static struct xt_match multiport_mt_reg[] __read_mostly = { |
4470bbc7 PM |
144 | { |
145 | .name = "multiport", | |
ee999d8b | 146 | .family = NFPROTO_IPV4, |
4470bbc7 | 147 | .revision = 1, |
d3c5ee6d JE |
148 | .checkentry = multiport_mt_check, |
149 | .match = multiport_mt, | |
4470bbc7 PM |
150 | .matchsize = sizeof(struct xt_multiport_v1), |
151 | .me = THIS_MODULE, | |
152 | }, | |
4470bbc7 PM |
153 | { |
154 | .name = "multiport", | |
ee999d8b | 155 | .family = NFPROTO_IPV6, |
4470bbc7 | 156 | .revision = 1, |
d3c5ee6d JE |
157 | .checkentry = multiport_mt6_check, |
158 | .match = multiport_mt, | |
4470bbc7 PM |
159 | .matchsize = sizeof(struct xt_multiport_v1), |
160 | .me = THIS_MODULE, | |
161 | }, | |
a89ecb6a YK |
162 | }; |
163 | ||
d3c5ee6d | 164 | static int __init multiport_mt_init(void) |
a89ecb6a | 165 | { |
d3c5ee6d JE |
166 | return xt_register_matches(multiport_mt_reg, |
167 | ARRAY_SIZE(multiport_mt_reg)); | |
a89ecb6a YK |
168 | } |
169 | ||
d3c5ee6d | 170 | static void __exit multiport_mt_exit(void) |
a89ecb6a | 171 | { |
d3c5ee6d | 172 | xt_unregister_matches(multiport_mt_reg, ARRAY_SIZE(multiport_mt_reg)); |
a89ecb6a YK |
173 | } |
174 | ||
d3c5ee6d JE |
175 | module_init(multiport_mt_init); |
176 | module_exit(multiport_mt_exit); |