The size is verified by x_tables and isn't needed by the modules anymore. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
126 lines
3 KiB
C
126 lines
3 KiB
C
/* Kernel module to match ESP parameters. */
|
|
|
|
/* (C) 1999-2000 Yon Uriarte <yon@astaro.de>
|
|
*
|
|
* 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/skbuff.h>
|
|
#include <linux/in.h>
|
|
#include <linux/ip.h>
|
|
|
|
#include <linux/netfilter/xt_esp.h>
|
|
#include <linux/netfilter/x_tables.h>
|
|
|
|
#include <linux/netfilter_ipv4/ip_tables.h>
|
|
#include <linux/netfilter_ipv6/ip6_tables.h>
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Yon Uriarte <yon@astaro.de>");
|
|
MODULE_DESCRIPTION("x_tables ESP SPI match module");
|
|
MODULE_ALIAS("ipt_esp");
|
|
MODULE_ALIAS("ip6t_esp");
|
|
|
|
#if 0
|
|
#define duprintf(format, args...) printk(format , ## args)
|
|
#else
|
|
#define duprintf(format, args...)
|
|
#endif
|
|
|
|
/* Returns 1 if the spi is matched by the range, 0 otherwise */
|
|
static inline int
|
|
spi_match(u_int32_t min, u_int32_t max, u_int32_t spi, int invert)
|
|
{
|
|
int r = 0;
|
|
duprintf("esp spi_match:%c 0x%x <= 0x%x <= 0x%x", invert ? '!' : ' ',
|
|
min, spi, max);
|
|
r = (spi >= min && spi <= max) ^ invert;
|
|
duprintf(" result %s\n", r ? "PASS" : "FAILED");
|
|
return r;
|
|
}
|
|
|
|
static int
|
|
match(const struct sk_buff *skb,
|
|
const struct net_device *in,
|
|
const struct net_device *out,
|
|
const struct xt_match *match,
|
|
const void *matchinfo,
|
|
int offset,
|
|
unsigned int protoff,
|
|
int *hotdrop)
|
|
{
|
|
struct ip_esp_hdr _esp, *eh;
|
|
const struct xt_esp *espinfo = matchinfo;
|
|
|
|
/* Must not be a fragment. */
|
|
if (offset)
|
|
return 0;
|
|
|
|
eh = skb_header_pointer(skb, protoff, sizeof(_esp), &_esp);
|
|
if (eh == NULL) {
|
|
/* We've been asked to examine this packet, and we
|
|
* can't. Hence, no choice but to drop.
|
|
*/
|
|
duprintf("Dropping evil ESP tinygram.\n");
|
|
*hotdrop = 1;
|
|
return 0;
|
|
}
|
|
|
|
return spi_match(espinfo->spis[0], espinfo->spis[1], ntohl(eh->spi),
|
|
!!(espinfo->invflags & XT_ESP_INV_SPI));
|
|
}
|
|
|
|
/* Called when user tries to insert an entry of this type. */
|
|
static int
|
|
checkentry(const char *tablename,
|
|
const void *ip_void,
|
|
const struct xt_match *match,
|
|
void *matchinfo,
|
|
unsigned int hook_mask)
|
|
{
|
|
const struct xt_esp *espinfo = matchinfo;
|
|
|
|
if (espinfo->invflags & ~XT_ESP_INV_MASK) {
|
|
duprintf("xt_esp: unknown flags %X\n", espinfo->invflags);
|
|
return 0;
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
static struct xt_match xt_esp_match[] = {
|
|
{
|
|
.name = "esp",
|
|
.family = AF_INET,
|
|
.checkentry = checkentry,
|
|
.match = match,
|
|
.matchsize = sizeof(struct xt_esp),
|
|
.proto = IPPROTO_ESP,
|
|
.me = THIS_MODULE,
|
|
},
|
|
{
|
|
.name = "esp",
|
|
.family = AF_INET6,
|
|
.checkentry = checkentry,
|
|
.match = match,
|
|
.matchsize = sizeof(struct xt_esp),
|
|
.proto = IPPROTO_ESP,
|
|
.me = THIS_MODULE,
|
|
},
|
|
};
|
|
|
|
static int __init xt_esp_init(void)
|
|
{
|
|
return xt_register_matches(xt_esp_match, ARRAY_SIZE(xt_esp_match));
|
|
}
|
|
|
|
static void __exit xt_esp_cleanup(void)
|
|
{
|
|
xt_unregister_matches(xt_esp_match, ARRAY_SIZE(xt_esp_match));
|
|
}
|
|
|
|
module_init(xt_esp_init);
|
|
module_exit(xt_esp_cleanup);
|