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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 | /* Kernel module to match one of a list of TCP/UDP ports: ports are in
the same place so we can treat them as equal. */
/* (C) 1999-2001 Paul `Rusty' Russell
* (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/udp.h>
#include <linux/skbuff.h>
#include <linux/netfilter_ipv4/ipt_multiport.h>
#include <linux/netfilter_ipv4/ip_tables.h>
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
MODULE_DESCRIPTION("iptables multiple port match module");
#if 0
#define duprintf(format, args...) printk(format , ## args)
#else
#define duprintf(format, args...)
#endif
/* Returns 1 if the port is matched by the test, 0 otherwise. */
static inline int
ports_match(const u_int16_t *portlist, enum ipt_multiport_flags flags,
u_int8_t count, u_int16_t src, u_int16_t dst)
{
unsigned int i;
for (i=0; i<count; i++) {
if (flags != IPT_MULTIPORT_DESTINATION
&& portlist[i] == src)
return 1;
if (flags != IPT_MULTIPORT_SOURCE
&& portlist[i] == dst)
return 1;
}
return 0;
}
/* Returns 1 if the port is matched by the test, 0 otherwise. */
static inline int
ports_match_v1(const struct ipt_multiport_v1 *minfo,
u_int16_t src, u_int16_t dst)
{
unsigned int i;
u_int16_t s, e;
for (i=0; i < minfo->count; i++) {
s = minfo->ports[i];
if (minfo->pflags[i]) {
/* range port matching */
e = minfo->ports[++i];
duprintf("src or dst matches with %d-%d?\n", s, e);
if (minfo->flags == IPT_MULTIPORT_SOURCE
&& src >= s && src <= e)
return 1 ^ minfo->invert;
if (minfo->flags == IPT_MULTIPORT_DESTINATION
&& dst >= s && dst <= e)
return 1 ^ minfo->invert;
if (minfo->flags == IPT_MULTIPORT_EITHER
&& ((dst >= s && dst <= e)
|| (src >= s && src <= e)))
return 1 ^ minfo->invert;
} else {
/* exact port matching */
duprintf("src or dst matches with %d?\n", s);
if (minfo->flags == IPT_MULTIPORT_SOURCE
&& src == s)
return 1 ^ minfo->invert;
if (minfo->flags == IPT_MULTIPORT_DESTINATION
&& dst == s)
return 1 ^ minfo->invert;
if (minfo->flags == IPT_MULTIPORT_EITHER
&& (src == s || dst == s))
return 1 ^ minfo->invert;
}
}
return minfo->invert;
}
static int
match(const struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out,
const void *matchinfo,
int offset,
unsigned int protoff,
int *hotdrop)
{
u16 _ports[2], *pptr;
const struct ipt_multiport *multiinfo = matchinfo;
if (offset)
return 0;
pptr = skb_header_pointer(skb, protoff,
sizeof(_ports), _ports);
if (pptr == NULL) {
/* We've been asked to examine this packet, and we
* can't. Hence, no choice but to drop.
*/
duprintf("ipt_multiport:"
" Dropping evil offset=0 tinygram.\n");
*hotdrop = 1;
return 0;
}
return ports_match(multiinfo->ports,
multiinfo->flags, multiinfo->count,
ntohs(pptr[0]), ntohs(pptr[1]));
}
static int
match_v1(const struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out,
const void *matchinfo,
int offset,
unsigned int protoff,
int *hotdrop)
{
u16 _ports[2], *pptr;
const struct ipt_multiport_v1 *multiinfo = matchinfo;
if (offset)
return 0;
pptr = skb_header_pointer(skb, protoff,
sizeof(_ports), _ports);
if (pptr == NULL) {
/* We've been asked to examine this packet, and we
* can't. Hence, no choice but to drop.
*/
duprintf("ipt_multiport:"
" Dropping evil offset=0 tinygram.\n");
*hotdrop = 1;
return 0;
}
return ports_match_v1(multiinfo, ntohs(pptr[0]), ntohs(pptr[1]));
}
/* Called when user tries to insert an entry of this type. */
static int
checkentry(const char *tablename,
const void *ip,
void *matchinfo,
unsigned int matchsize,
unsigned int hook_mask)
{
return (matchsize == IPT_ALIGN(sizeof(struct ipt_multiport)));
}
static int
checkentry_v1(const char *tablename,
const void *ip,
void *matchinfo,
unsigned int matchsize,
unsigned int hook_mask)
{
return (matchsize == IPT_ALIGN(sizeof(struct ipt_multiport_v1)));
}
static struct ipt_match multiport_match = {
.name = "multiport",
.revision = 0,
.match = &match,
.checkentry = &checkentry,
.me = THIS_MODULE,
};
static struct ipt_match multiport_match_v1 = {
.name = "multiport",
.revision = 1,
.match = &match_v1,
.checkentry = &checkentry_v1,
.me = THIS_MODULE,
};
static int __init init(void)
{
int err;
err = ipt_register_match(&multiport_match);
if (!err) {
err = ipt_register_match(&multiport_match_v1);
if (err)
ipt_unregister_match(&multiport_match);
}
return err;
}
static void __exit fini(void)
{
ipt_unregister_match(&multiport_match);
ipt_unregister_match(&multiport_match_v1);
}
module_init(init);
module_exit(fini);
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