netfilter: add IPv4/6 IPComp extension match support (6a649f33) · Commits · 戴 / test

include/uapi/linux/netfilter/Kbuild

+1 −0

Original line number	Diff line number	Diff line
		@@ -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

include/uapi/linux/netfilter/xt_ipcomp.h

0 → 100644

+16 −0

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		#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/

net/netfilter/Kconfig

+9 −0

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		@@ -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

net/netfilter/Makefile

+1 −0

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		@@ -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

net/netfilter/xt_ipcomp.c

0 → 100644

+111 −0

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		/* 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);

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