diff options
author | Dmitry Torokhov <dtor_core@ameritech.net> | 2006-04-29 01:11:23 -0400 |
---|---|---|
committer | Dmitry Torokhov <dtor_core@ameritech.net> | 2006-04-29 01:11:23 -0400 |
commit | 7b7e394185014e0f3bd8989cac937003f20ef9ce (patch) | |
tree | 3beda5f979bba0aa9822534e239cf1b45f3be69c /net/netfilter/xt_esp.c | |
parent | ddc5d3414593e4d7ad7fbd33e7f7517fcc234544 (diff) | |
parent | 693f7d362055261882659475d2ef022e32edbff1 (diff) |
Merge rsync://rsync.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Diffstat (limited to 'net/netfilter/xt_esp.c')
-rw-r--r-- | net/netfilter/xt_esp.c | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/net/netfilter/xt_esp.c b/net/netfilter/xt_esp.c new file mode 100644 index 00000000000..9dad6281e0c --- /dev/null +++ b/net/netfilter/xt_esp.c @@ -0,0 +1,136 @@ +/* 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 matchinfosize, + 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 esp_match = { + .name = "esp", + .family = AF_INET, + .proto = IPPROTO_ESP, + .match = &match, + .matchsize = sizeof(struct xt_esp), + .checkentry = &checkentry, + .me = THIS_MODULE, +}; + +static struct xt_match esp6_match = { + .name = "esp", + .family = AF_INET6, + .proto = IPPROTO_ESP, + .match = &match, + .matchsize = sizeof(struct xt_esp), + .checkentry = &checkentry, + .me = THIS_MODULE, +}; + +static int __init xt_esp_init(void) +{ + int ret; + ret = xt_register_match(&esp_match); + if (ret) + return ret; + + ret = xt_register_match(&esp6_match); + if (ret) + xt_unregister_match(&esp_match); + + return ret; +} + +static void __exit xt_esp_cleanup(void) +{ + xt_unregister_match(&esp_match); + xt_unregister_match(&esp6_match); +} + +module_init(xt_esp_init); +module_exit(xt_esp_cleanup); |