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. */
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.
11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12 #include <linux/module.h>
13 #include <linux/types.h>
14 #include <linux/udp.h>
15 #include <linux/skbuff.h>
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>
23 MODULE_LICENSE("GPL");
24 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
25 MODULE_DESCRIPTION("Xtables: multiple port matching for TCP, UDP, UDP-Lite, SCTP and DCCP");
26 MODULE_ALIAS("ipt_multiport");
27 MODULE_ALIAS("ip6t_multiport");
29 /* Returns 1 if the port is matched by the test, 0 otherwise. */
31 ports_match_v1(const struct xt_multiport_v1
*minfo
,
32 u_int16_t src
, u_int16_t dst
)
37 for (i
= 0; i
< minfo
->count
; i
++) {
40 if (minfo
->pflags
[i
]) {
41 /* range port matching */
42 e
= minfo
->ports
[++i
];
43 pr_debug("src or dst matches with %d-%d?\n", s
, e
);
45 switch (minfo
->flags
) {
46 case XT_MULTIPORT_SOURCE
:
47 if (src
>= s
&& src
<= e
)
48 return true ^ minfo
->invert
;
50 case XT_MULTIPORT_DESTINATION
:
51 if (dst
>= s
&& dst
<= e
)
52 return true ^ minfo
->invert
;
54 case XT_MULTIPORT_EITHER
:
55 if ((dst
>= s
&& dst
<= e
) ||
56 (src
>= s
&& src
<= e
))
57 return true ^ minfo
->invert
;
63 /* exact port matching */
64 pr_debug("src or dst matches with %d?\n", s
);
66 switch (minfo
->flags
) {
67 case XT_MULTIPORT_SOURCE
:
69 return true ^ minfo
->invert
;
71 case XT_MULTIPORT_DESTINATION
:
73 return true ^ minfo
->invert
;
75 case XT_MULTIPORT_EITHER
:
76 if (src
== s
|| dst
== s
)
77 return true ^ minfo
->invert
;
89 multiport_mt(const struct sk_buff
*skb
, struct xt_action_param
*par
)
93 const struct xt_multiport_v1
*multiinfo
= par
->matchinfo
;
95 if (par
->fragoff
!= 0)
98 pptr
= skb_header_pointer(skb
, par
->thoff
, sizeof(_ports
), _ports
);
100 /* We've been asked to examine this packet, and we
101 * can't. Hence, no choice but to drop.
103 pr_debug("Dropping evil offset=0 tinygram.\n");
108 return ports_match_v1(multiinfo
, ntohs(pptr
[0]), ntohs(pptr
[1]));
112 check(u_int16_t proto
,
113 u_int8_t ip_invflags
,
114 u_int8_t match_flags
,
117 /* Must specify supported protocol, no unknown flags or bad count */
118 return (proto
== IPPROTO_TCP
|| proto
== IPPROTO_UDP
119 || proto
== IPPROTO_UDPLITE
120 || proto
== IPPROTO_SCTP
|| proto
== IPPROTO_DCCP
)
121 && !(ip_invflags
& XT_INV_PROTO
)
122 && (match_flags
== XT_MULTIPORT_SOURCE
123 || match_flags
== XT_MULTIPORT_DESTINATION
124 || match_flags
== XT_MULTIPORT_EITHER
)
125 && count
<= XT_MULTI_PORTS
;
128 static int multiport_mt_check(const struct xt_mtchk_param
*par
)
130 const struct ipt_ip
*ip
= par
->entryinfo
;
131 const struct xt_multiport_v1
*multiinfo
= par
->matchinfo
;
133 return check(ip
->proto
, ip
->invflags
, multiinfo
->flags
,
134 multiinfo
->count
) ? 0 : -EINVAL
;
137 static int multiport_mt6_check(const struct xt_mtchk_param
*par
)
139 const struct ip6t_ip6
*ip
= par
->entryinfo
;
140 const struct xt_multiport_v1
*multiinfo
= par
->matchinfo
;
142 return check(ip
->proto
, ip
->invflags
, multiinfo
->flags
,
143 multiinfo
->count
) ? 0 : -EINVAL
;
146 static struct xt_match multiport_mt_reg
[] __read_mostly
= {
149 .family
= NFPROTO_IPV4
,
151 .checkentry
= multiport_mt_check
,
152 .match
= multiport_mt
,
153 .matchsize
= sizeof(struct xt_multiport_v1
),
158 .family
= NFPROTO_IPV6
,
160 .checkentry
= multiport_mt6_check
,
161 .match
= multiport_mt
,
162 .matchsize
= sizeof(struct xt_multiport_v1
),
167 static int __init
multiport_mt_init(void)
169 return xt_register_matches(multiport_mt_reg
,
170 ARRAY_SIZE(multiport_mt_reg
));
173 static void __exit
multiport_mt_exit(void)
175 xt_unregister_matches(multiport_mt_reg
, ARRAY_SIZE(multiport_mt_reg
));
178 module_init(multiport_mt_init
);
179 module_exit(multiport_mt_exit
);