From b41649989c9640e54e47001994b7ecb927ea1822 Mon Sep 17 00:00:00 2001 From: Jan Engelhardt Date: Thu, 31 Jan 2008 03:58:24 -0800 Subject: [PATCH] [NETFILTER]: xt_conntrack: add port and direction matching Extend the xt_conntrack match revision 1 by port matching (all four {orig,repl}{src,dst}) and by packet direction matching. Signed-off-by: Jan Engelhardt Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- include/linux/netfilter/xt_conntrack.h | 30 +++++++++------- net/netfilter/xt_conntrack.c | 50 +++++++++++++++++++++++--- 2 files changed, 63 insertions(+), 17 deletions(-) diff --git a/include/linux/netfilter/xt_conntrack.h b/include/linux/netfilter/xt_conntrack.h index d2492a3329be..f3fd83e46bab 100644 --- a/include/linux/netfilter/xt_conntrack.h +++ b/include/linux/netfilter/xt_conntrack.h @@ -6,9 +6,6 @@ #define _XT_CONNTRACK_H #include -#ifdef __KERNEL__ -# include -#endif #define XT_CONNTRACK_STATE_BIT(ctinfo) (1 << ((ctinfo)%IP_CT_IS_REPLY+1)) #define XT_CONNTRACK_STATE_INVALID (1 << 0) @@ -18,14 +15,21 @@ #define XT_CONNTRACK_STATE_UNTRACKED (1 << (IP_CT_NUMBER + 3)) /* flags, invflags: */ -#define XT_CONNTRACK_STATE 0x01 -#define XT_CONNTRACK_PROTO 0x02 -#define XT_CONNTRACK_ORIGSRC 0x04 -#define XT_CONNTRACK_ORIGDST 0x08 -#define XT_CONNTRACK_REPLSRC 0x10 -#define XT_CONNTRACK_REPLDST 0x20 -#define XT_CONNTRACK_STATUS 0x40 -#define XT_CONNTRACK_EXPIRES 0x80 +enum { + XT_CONNTRACK_STATE = 1 << 0, + XT_CONNTRACK_PROTO = 1 << 1, + XT_CONNTRACK_ORIGSRC = 1 << 2, + XT_CONNTRACK_ORIGDST = 1 << 3, + XT_CONNTRACK_REPLSRC = 1 << 4, + XT_CONNTRACK_REPLDST = 1 << 5, + XT_CONNTRACK_STATUS = 1 << 6, + XT_CONNTRACK_EXPIRES = 1 << 7, + XT_CONNTRACK_ORIGSRC_PORT = 1 << 8, + XT_CONNTRACK_ORIGDST_PORT = 1 << 9, + XT_CONNTRACK_REPLSRC_PORT = 1 << 10, + XT_CONNTRACK_REPLDST_PORT = 1 << 11, + XT_CONNTRACK_DIRECTION = 1 << 12, +}; /* This is exposed to userspace, so remains frozen in time. */ struct ip_conntrack_old_tuple @@ -70,8 +74,10 @@ struct xt_conntrack_mtinfo1 { union nf_inet_addr repldst_addr, repldst_mask; u_int32_t expires_min, expires_max; u_int16_t l4proto; + __be16 origsrc_port, origdst_port; + __be16 replsrc_port, repldst_port; + u_int16_t match_flags, invert_flags; u_int8_t state_mask, status_mask; - u_int8_t match_flags, invert_flags; }; #endif /*_XT_CONNTRACK_H*/ diff --git a/net/netfilter/xt_conntrack.c b/net/netfilter/xt_conntrack.c index e92190eafcc5..85330856a29c 100644 --- a/net/netfilter/xt_conntrack.c +++ b/net/netfilter/xt_conntrack.c @@ -4,7 +4,6 @@ * * (C) 2001 Marc Boucher (marc@mbsi.ca). * Copyright © CC Computer Consultants GmbH, 2007 - 2008 - * Jan Engelhardt * * 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 @@ -20,6 +19,7 @@ MODULE_LICENSE("GPL"); MODULE_AUTHOR("Marc Boucher "); +MODULE_AUTHOR("Jan Engelhardt "); MODULE_DESCRIPTION("Xtables: connection tracking state match"); MODULE_ALIAS("ipt_conntrack"); MODULE_ALIAS("ip6t_conntrack"); @@ -166,6 +166,44 @@ conntrack_mt_repldst(const struct nf_conn *ct, &info->repldst_addr, &info->repldst_mask, family); } +static inline bool +ct_proto_port_check(const struct xt_conntrack_mtinfo1 *info, + const struct nf_conn *ct) +{ + const struct nf_conntrack_tuple *tuple; + + tuple = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple; + if ((info->match_flags & XT_CONNTRACK_PROTO) && + (tuple->dst.protonum == info->l4proto) ^ + !(info->invert_flags & XT_CONNTRACK_PROTO)) + return false; + + /* Shortcut to match all recognized protocols by using ->src.all. */ + if ((info->match_flags & XT_CONNTRACK_ORIGSRC_PORT) && + (tuple->src.u.all == info->origsrc_port) ^ + !(info->invert_flags & XT_CONNTRACK_ORIGSRC_PORT)) + return false; + + if ((info->match_flags & XT_CONNTRACK_ORIGDST_PORT) && + (tuple->dst.u.all == info->origdst_port) ^ + !(info->invert_flags & XT_CONNTRACK_ORIGDST_PORT)) + return false; + + tuple = &ct->tuplehash[IP_CT_DIR_REPLY].tuple; + + if ((info->match_flags & XT_CONNTRACK_REPLSRC_PORT) && + (tuple->src.u.all == info->replsrc_port) ^ + !(info->invert_flags & XT_CONNTRACK_REPLSRC_PORT)) + return false; + + if ((info->match_flags & XT_CONNTRACK_REPLDST_PORT) && + (tuple->dst.u.all == info->repldst_port) ^ + !(info->invert_flags & XT_CONNTRACK_REPLDST_PORT)) + return false; + + return true; +} + static bool conntrack_mt(const struct sk_buff *skb, const struct net_device *in, const struct net_device *out, const struct xt_match *match, @@ -200,10 +238,9 @@ conntrack_mt(const struct sk_buff *skb, const struct net_device *in, if (ct == NULL) return info->match_flags & XT_CONNTRACK_STATE; - - if ((info->match_flags & XT_CONNTRACK_PROTO) && - ((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum == - info->l4proto) ^ !(info->invert_flags & XT_CONNTRACK_PROTO))) + if ((info->match_flags & XT_CONNTRACK_DIRECTION) && + (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) ^ + !!(info->invert_flags & XT_CONNTRACK_DIRECTION)) return false; if (info->match_flags & XT_CONNTRACK_ORIGSRC) @@ -226,6 +263,9 @@ conntrack_mt(const struct sk_buff *skb, const struct net_device *in, !(info->invert_flags & XT_CONNTRACK_REPLDST)) return false; + if (!ct_proto_port_check(info, ct)) + return false; + if ((info->match_flags & XT_CONNTRACK_STATUS) && (!!(info->status_mask & ct->status) ^ !(info->invert_flags & XT_CONNTRACK_STATUS))) -- 2.20.1