From a0ca215a730b2c4d5024143e64b0d80d50858667 Mon Sep 17 00:00:00 2001 From: Masahide NAKAMURA Date: Wed, 7 Feb 2007 15:12:57 -0800 Subject: [PATCH] [NETFILTER]: ip6_tables: support MH match This introduces match for Mobility Header (MH) described by Mobile IPv6 specification (RFC3775). User can specify the MH type or its range to be matched. Signed-off-by: Masahide NAKAMURA Signed-off-by: Yasuyuki Kozakai Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- include/linux/netfilter_ipv6/ip6t_mh.h | 15 ++++ net/ipv6/netfilter/Kconfig | 8 ++ net/ipv6/netfilter/Makefile | 1 + net/ipv6/netfilter/ip6t_mh.c | 108 +++++++++++++++++++++++++ 4 files changed, 132 insertions(+) create mode 100644 include/linux/netfilter_ipv6/ip6t_mh.h create mode 100644 net/ipv6/netfilter/ip6t_mh.c diff --git a/include/linux/netfilter_ipv6/ip6t_mh.h b/include/linux/netfilter_ipv6/ip6t_mh.h new file mode 100644 index 000000000000..b9ca9a5f74d0 --- /dev/null +++ b/include/linux/netfilter_ipv6/ip6t_mh.h @@ -0,0 +1,15 @@ +#ifndef _IP6T_MH_H +#define _IP6T_MH_H + +/* MH matching stuff */ +struct ip6t_mh +{ + u_int8_t types[2]; /* MH type range */ + u_int8_t invflags; /* Inverse flags */ +}; + +/* Values for "invflags" field in struct ip6t_mh. */ +#define IP6T_MH_INV_TYPE 0x01 /* Invert the sense of type. */ +#define IP6T_MH_INV_MASK 0x01 /* All possible flags. */ + +#endif /*_IP6T_MH_H*/ diff --git a/net/ipv6/netfilter/Kconfig b/net/ipv6/netfilter/Kconfig index adcd6131df2a..cd549aea84f0 100644 --- a/net/ipv6/netfilter/Kconfig +++ b/net/ipv6/netfilter/Kconfig @@ -114,6 +114,14 @@ config IP6_NF_MATCH_AH To compile it as a module, choose M here. If unsure, say N. +config IP6_NF_MATCH_MH + tristate "MH match support" + depends on IP6_NF_IPTABLES + help + This module allows one to match MH packets. + + To compile it as a module, choose M here. If unsure, say N. + config IP6_NF_MATCH_EUI64 tristate "EUI64 address check" depends on IP6_NF_IPTABLES diff --git a/net/ipv6/netfilter/Makefile b/net/ipv6/netfilter/Makefile index ac1dfebde175..4513eab77397 100644 --- a/net/ipv6/netfilter/Makefile +++ b/net/ipv6/netfilter/Makefile @@ -19,6 +19,7 @@ obj-$(CONFIG_IP6_NF_TARGET_LOG) += ip6t_LOG.o obj-$(CONFIG_IP6_NF_RAW) += ip6table_raw.o obj-$(CONFIG_IP6_NF_MATCH_HL) += ip6t_hl.o obj-$(CONFIG_IP6_NF_TARGET_REJECT) += ip6t_REJECT.o +obj-$(CONFIG_IP6_NF_MATCH_MH) += ip6t_mh.o # objects for l3 independent conntrack nf_conntrack_ipv6-objs := nf_conntrack_l3proto_ipv6.o nf_conntrack_proto_icmpv6.o nf_conntrack_reasm.o diff --git a/net/ipv6/netfilter/ip6t_mh.c b/net/ipv6/netfilter/ip6t_mh.c new file mode 100644 index 000000000000..2c7efc6a506d --- /dev/null +++ b/net/ipv6/netfilter/ip6t_mh.c @@ -0,0 +1,108 @@ +/* + * Copyright (C)2006 USAGI/WIDE Project + * + * 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. + * + * Author: + * Masahide NAKAMURA @USAGI + * + * Based on net/netfilter/xt_tcpudp.c + * + */ +#include +#include +#include +#include +#include +#include + +#include +#include + +MODULE_DESCRIPTION("ip6t_tables match for MH"); +MODULE_LICENSE("GPL"); + +#ifdef DEBUG_IP_FIREWALL_USER +#define duprintf(format, args...) printk(format , ## args) +#else +#define duprintf(format, args...) +#endif + +/* Returns 1 if the type is matched by the range, 0 otherwise */ +static inline int +type_match(u_int8_t min, u_int8_t max, u_int8_t type, int invert) +{ + int ret; + + ret = (type >= min && type <= max) ^ invert; + return ret; +} + +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 ip6_mh _mh, *mh; + const struct ip6t_mh *mhinfo = matchinfo; + + /* Must not be a fragment. */ + if (offset) + return 0; + + mh = skb_header_pointer(skb, protoff, sizeof(_mh), &_mh); + if (mh == NULL) { + /* We've been asked to examine this packet, and we + can't. Hence, no choice but to drop. */ + duprintf("Dropping evil MH tinygram.\n"); + *hotdrop = 1; + return 0; + } + + return type_match(mhinfo->types[0], mhinfo->types[1], mh->ip6mh_type, + !!(mhinfo->invflags & IP6T_MH_INV_TYPE)); +} + +/* Called when user tries to insert an entry of this type. */ +static int +mh_checkentry(const char *tablename, + const void *entry, + const struct xt_match *match, + void *matchinfo, + unsigned int hook_mask) +{ + const struct ip6t_mh *mhinfo = matchinfo; + + /* Must specify no unknown invflags */ + return !(mhinfo->invflags & ~IP6T_MH_INV_MASK); +} + +static struct xt_match mh_match = { + .name = "mh", + .family = AF_INET6, + .checkentry = mh_checkentry, + .match = match, + .matchsize = sizeof(struct ip6t_mh), + .proto = IPPROTO_MH, + .me = THIS_MODULE, +}; + +static int __init ip6t_mh_init(void) +{ + return xt_register_match(&mh_match); +} + +static void __exit ip6t_mh_fini(void) +{ + xt_unregister_match(&mh_match); +} + +module_init(ip6t_mh_init); +module_exit(ip6t_mh_fini); -- 2.20.1