diff options
| -rw-r--r-- | include/uapi/linux/netfilter/Kbuild | 1 | ||||
| -rw-r--r-- | include/uapi/linux/netfilter/xt_ipcomp.h | 16 | ||||
| -rw-r--r-- | net/netfilter/Kconfig | 9 | ||||
| -rw-r--r-- | net/netfilter/Makefile | 1 | ||||
| -rw-r--r-- | net/netfilter/xt_ipcomp.c | 111 |
5 files changed, 138 insertions, 0 deletions
diff --git a/include/uapi/linux/netfilter/Kbuild b/include/uapi/linux/netfilter/Kbuild index 17c3af2c4bb9..91be8ce623f0 100644 --- a/include/uapi/linux/netfilter/Kbuild +++ b/include/uapi/linux/netfilter/Kbuild @@ -54,6 +54,7 @@ header-y += xt_ecn.h header-y += xt_esp.h header-y += xt_hashlimit.h header-y += xt_helper.h +header-y += xt_ipcomp.h header-y += xt_iprange.h header-y += xt_ipvs.h header-y += xt_length.h diff --git a/include/uapi/linux/netfilter/xt_ipcomp.h b/include/uapi/linux/netfilter/xt_ipcomp.h new file mode 100644 index 000000000000..45c7e40eb8e1 --- /dev/null +++ b/include/uapi/linux/netfilter/xt_ipcomp.h @@ -0,0 +1,16 @@ +#ifndef _XT_IPCOMP_H +#define _XT_IPCOMP_H + +#include <linux/types.h> + +struct xt_ipcomp { + __u32 spis[2]; /* Security Parameter Index */ + __u8 invflags; /* Inverse flags */ + __u8 hdrres; /* Test of the Reserved Filed */ +}; + +/* Values for "invflags" field in struct xt_ipcomp. */ +#define XT_IPCOMP_INV_SPI 0x01 /* Invert the sense of spi. */ +#define XT_IPCOMP_INV_MASK 0x01 /* All possible flags. */ + +#endif /*_XT_IPCOMP_H*/ diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig index c3398cd99b94..6d8e48b376fc 100644 --- a/net/netfilter/Kconfig +++ b/net/netfilter/Kconfig @@ -1035,6 +1035,15 @@ config NETFILTER_XT_MATCH_HL in the IPv6 header, or the time-to-live field in the IPv4 header of the packet. +config NETFILTER_XT_MATCH_IPCOMP + tristate '"ipcomp" match support' + depends on NETFILTER_ADVANCED + help + This match extension allows you to match a range of CPIs(16 bits) + inside IPComp header of IPSec packets. + + To compile it as a module, choose M here. If unsure, say N. + config NETFILTER_XT_MATCH_IPRANGE tristate '"iprange" address range match support' depends on NETFILTER_ADVANCED diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile index 394483b2c193..398cd709aa09 100644 --- a/net/netfilter/Makefile +++ b/net/netfilter/Makefile @@ -133,6 +133,7 @@ obj-$(CONFIG_NETFILTER_XT_MATCH_ESP) += xt_esp.o obj-$(CONFIG_NETFILTER_XT_MATCH_HASHLIMIT) += xt_hashlimit.o obj-$(CONFIG_NETFILTER_XT_MATCH_HELPER) += xt_helper.o obj-$(CONFIG_NETFILTER_XT_MATCH_HL) += xt_hl.o +obj-$(CONFIG_NETFILTER_XT_MATCH_IPCOMP) += xt_ipcomp.o obj-$(CONFIG_NETFILTER_XT_MATCH_IPRANGE) += xt_iprange.o obj-$(CONFIG_NETFILTER_XT_MATCH_IPVS) += xt_ipvs.o obj-$(CONFIG_NETFILTER_XT_MATCH_LENGTH) += xt_length.o diff --git a/net/netfilter/xt_ipcomp.c b/net/netfilter/xt_ipcomp.c new file mode 100644 index 000000000000..a4c7561698c5 --- /dev/null +++ b/net/netfilter/xt_ipcomp.c @@ -0,0 +1,111 @@ +/* Kernel module to match IPComp parameters for IPv4 and IPv6 + * + * Copyright (C) 2013 WindRiver + * + * Author: + * Fan Du <fan.du@windriver.com> + * + * Based on: + * net/netfilter/xt_esp.c + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include <linux/in.h> +#include <linux/module.h> +#include <linux/skbuff.h> +#include <linux/ip.h> + +#include <linux/netfilter/xt_ipcomp.h> +#include <linux/netfilter/x_tables.h> + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Fan Du <fan.du@windriver.com>"); +MODULE_DESCRIPTION("Xtables: IPv4/6 IPsec-IPComp SPI match"); + +/* Returns 1 if the spi is matched by the range, 0 otherwise */ +static inline bool +spi_match(u_int32_t min, u_int32_t max, u_int32_t spi, bool invert) +{ + bool r; + pr_debug("spi_match:%c 0x%x <= 0x%x <= 0x%x\n", + invert ? '!' : ' ', min, spi, max); + r = (spi >= min && spi <= max) ^ invert; + pr_debug(" result %s\n", r ? "PASS" : "FAILED"); + return r; +} + +static bool comp_mt(const struct sk_buff *skb, struct xt_action_param *par) +{ + struct ip_comp_hdr _comphdr; + const struct ip_comp_hdr *chdr; + const struct xt_ipcomp *compinfo = par->matchinfo; + + /* Must not be a fragment. */ + if (par->fragoff != 0) + return false; + + chdr = skb_header_pointer(skb, par->thoff, sizeof(_comphdr), &_comphdr); + if (chdr == NULL) { + /* We've been asked to examine this packet, and we + * can't. Hence, no choice but to drop. + */ + pr_debug("Dropping evil IPComp tinygram.\n"); + par->hotdrop = true; + return 0; + } + + return spi_match(compinfo->spis[0], compinfo->spis[1], + ntohl(chdr->cpi << 16), + !!(compinfo->invflags & XT_IPCOMP_INV_SPI)); +} + +static int comp_mt_check(const struct xt_mtchk_param *par) +{ + const struct xt_ipcomp *compinfo = par->matchinfo; + + /* Must specify no unknown invflags */ + if (compinfo->invflags & ~XT_IPCOMP_INV_MASK) { + pr_err("unknown flags %X\n", compinfo->invflags); + return -EINVAL; + } + return 0; +} + +static struct xt_match comp_mt_reg[] __read_mostly = { + { + .name = "ipcomp", + .family = NFPROTO_IPV4, + .match = comp_mt, + .matchsize = sizeof(struct xt_ipcomp), + .proto = IPPROTO_COMP, + .checkentry = comp_mt_check, + .me = THIS_MODULE, + }, + { + .name = "ipcomp", + .family = NFPROTO_IPV6, + .match = comp_mt, + .matchsize = sizeof(struct xt_ipcomp), + .proto = IPPROTO_COMP, + .checkentry = comp_mt_check, + .me = THIS_MODULE, + }, +}; + +static int __init comp_mt_init(void) +{ + return xt_register_matches(comp_mt_reg, ARRAY_SIZE(comp_mt_reg)); +} + +static void __exit comp_mt_exit(void) +{ + xt_unregister_matches(comp_mt_reg, ARRAY_SIZE(comp_mt_reg)); +} + +module_init(comp_mt_init); +module_exit(comp_mt_exit); |