From 64eb12f9972d45f3b9b0f0a33a966e311c3d5275 Mon Sep 17 00:00:00 2001 From: Jan Engelhardt Date: Mon, 14 Jan 2008 23:40:53 -0800 Subject: [PATCH] [NETFILTER]: xt_conntrack match, revision 1 Introduces the xt_conntrack match revision 1. It uses fixed types, the new nf_inet_addr and comes with IPv6 support, thereby completely superseding xt_state. Signed-off-by: Jan Engelhardt Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- include/linux/netfilter/xt_conntrack.h | 16 +- net/netfilter/xt_conntrack.c | 207 ++++++++++++++++++++++--- 2 files changed, 197 insertions(+), 26 deletions(-) diff --git a/include/linux/netfilter/xt_conntrack.h b/include/linux/netfilter/xt_conntrack.h index 70b6f718cf4c..d2492a3329be 100644 --- a/include/linux/netfilter/xt_conntrack.h +++ b/include/linux/netfilter/xt_conntrack.h @@ -6,7 +6,9 @@ #define _XT_CONNTRACK_H #include -#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) @@ -60,4 +62,16 @@ struct xt_conntrack_info /* Inverse flags */ u_int8_t invflags; }; + +struct xt_conntrack_mtinfo1 { + union nf_inet_addr origsrc_addr, origsrc_mask; + union nf_inet_addr origdst_addr, origdst_mask; + union nf_inet_addr replsrc_addr, replsrc_mask; + union nf_inet_addr repldst_addr, repldst_mask; + u_int32_t expires_min, expires_max; + u_int16_t l4proto; + 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 3f8bfbaa9b19..dc9e73786864 100644 --- a/net/netfilter/xt_conntrack.c +++ b/net/netfilter/xt_conntrack.c @@ -1,15 +1,19 @@ -/* Kernel module to match connection tracking information. - * Superset of Rusty's minimalistic state match. +/* + * xt_conntrack - Netfilter module to match connection tracking + * information. (Superset of Rusty's minimalistic state match.) * - * (C) 2001 Marc Boucher (marc@mbsi.ca). + * (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 - * published by the Free Software Foundation. + * 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 #include +#include #include #include #include @@ -18,12 +22,13 @@ MODULE_LICENSE("GPL"); MODULE_AUTHOR("Marc Boucher "); MODULE_DESCRIPTION("iptables connection tracking match module"); MODULE_ALIAS("ipt_conntrack"); +MODULE_ALIAS("ip6t_conntrack"); static bool -conntrack_mt(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, - bool *hotdrop) +conntrack_mt_v0(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, + bool *hotdrop) { const struct xt_conntrack_info *sinfo = matchinfo; const struct nf_conn *ct; @@ -111,6 +116,134 @@ conntrack_mt(const struct sk_buff *skb, const struct net_device *in, #undef FWINV } +static bool +conntrack_addrcmp(const union nf_inet_addr *kaddr, + const union nf_inet_addr *uaddr, + const union nf_inet_addr *umask, unsigned int l3proto) +{ + if (l3proto == AF_INET) + return (kaddr->ip & umask->ip) == uaddr->ip; + else if (l3proto == AF_INET6) + return ipv6_masked_addr_cmp(&kaddr->in6, &umask->in6, + &uaddr->in6) == 0; + else + return false; +} + +static inline bool +conntrack_mt_origsrc(const struct nf_conn *ct, + const struct xt_conntrack_mtinfo1 *info, + unsigned int family) +{ + return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3, + &info->origsrc_addr, &info->origsrc_mask, family); +} + +static inline bool +conntrack_mt_origdst(const struct nf_conn *ct, + const struct xt_conntrack_mtinfo1 *info, + unsigned int family) +{ + return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3, + &info->origdst_addr, &info->origdst_mask, family); +} + +static inline bool +conntrack_mt_replsrc(const struct nf_conn *ct, + const struct xt_conntrack_mtinfo1 *info, + unsigned int family) +{ + return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3, + &info->replsrc_addr, &info->replsrc_mask, family); +} + +static inline bool +conntrack_mt_repldst(const struct nf_conn *ct, + const struct xt_conntrack_mtinfo1 *info, + unsigned int family) +{ + return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3, + &info->repldst_addr, &info->repldst_mask, family); +} + +static bool +conntrack_mt(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, + bool *hotdrop) +{ + const struct xt_conntrack_mtinfo1 *info = matchinfo; + enum ip_conntrack_info ctinfo; + const struct nf_conn *ct; + unsigned int statebit; + + ct = nf_ct_get(skb, &ctinfo); + + if (ct == &nf_conntrack_untracked) + statebit = XT_CONNTRACK_STATE_UNTRACKED; + else if (ct != NULL) + statebit = XT_CONNTRACK_STATE_BIT(ctinfo); + else + statebit = XT_CONNTRACK_STATE_INVALID; + + if (info->match_flags & XT_CONNTRACK_STATE) { + if (ct != NULL) { + if (test_bit(IPS_SRC_NAT_BIT, &ct->status)) + statebit |= XT_CONNTRACK_STATE_SNAT; + if (test_bit(IPS_DST_NAT_BIT, &ct->status)) + statebit |= XT_CONNTRACK_STATE_DNAT; + } + if ((info->state_mask & statebit) ^ + !(info->invert_flags & XT_CONNTRACK_STATE)) + return false; + } + + 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))) + return false; + + if (info->match_flags & XT_CONNTRACK_ORIGSRC) + if (conntrack_mt_origsrc(ct, info, match->family) ^ + !(info->invert_flags & XT_CONNTRACK_ORIGSRC)) + return false; + + if (info->match_flags & XT_CONNTRACK_ORIGDST) + if (conntrack_mt_origdst(ct, info, match->family) ^ + !(info->invert_flags & XT_CONNTRACK_ORIGDST)) + return false; + + if (info->match_flags & XT_CONNTRACK_REPLSRC) + if (conntrack_mt_replsrc(ct, info, match->family) ^ + !(info->invert_flags & XT_CONNTRACK_REPLSRC)) + return false; + + if (info->match_flags & XT_CONNTRACK_REPLDST) + if (conntrack_mt_repldst(ct, info, match->family) ^ + !(info->invert_flags & XT_CONNTRACK_REPLDST)) + return false; + + if ((info->match_flags & XT_CONNTRACK_STATUS) && + (!!(info->status_mask & ct->status) ^ + !(info->invert_flags & XT_CONNTRACK_STATUS))) + return false; + + if (info->match_flags & XT_CONNTRACK_EXPIRES) { + unsigned long expires = 0; + + if (timer_pending(&ct->timeout)) + expires = (ct->timeout.expires - jiffies) / HZ; + if ((expires >= info->expires_min && + expires <= info->expires_max) ^ + !(info->invert_flags & XT_CONNTRACK_EXPIRES)) + return false; + } + return true; +} + static bool conntrack_mt_check(const char *tablename, const void *ip, const struct xt_match *match, void *matchinfo, @@ -144,7 +277,7 @@ struct compat_xt_conntrack_info u_int8_t invflags; }; -static void conntrack_mt_compat_from_user(void *dst, void *src) +static void conntrack_mt_compat_from_user_v0(void *dst, void *src) { const struct compat_xt_conntrack_info *cm = src; struct xt_conntrack_info m = { @@ -161,7 +294,7 @@ static void conntrack_mt_compat_from_user(void *dst, void *src) memcpy(dst, &m, sizeof(m)); } -static int conntrack_mt_compat_to_user(void __user *dst, void *src) +static int conntrack_mt_compat_to_user_v0(void __user *dst, void *src) { const struct xt_conntrack_info *m = src; struct compat_xt_conntrack_info cm = { @@ -179,29 +312,53 @@ static int conntrack_mt_compat_to_user(void __user *dst, void *src) } #endif -static struct xt_match conntrack_mt_reg __read_mostly = { - .name = "conntrack", - .match = conntrack_mt, - .checkentry = conntrack_mt_check, - .destroy = conntrack_mt_destroy, - .matchsize = sizeof(struct xt_conntrack_info), +static struct xt_match conntrack_mt_reg[] __read_mostly = { + { + .name = "conntrack", + .revision = 0, + .family = AF_INET, + .match = conntrack_mt_v0, + .checkentry = conntrack_mt_check, + .destroy = conntrack_mt_destroy, + .matchsize = sizeof(struct xt_conntrack_info), + .me = THIS_MODULE, #ifdef CONFIG_COMPAT - .compatsize = sizeof(struct compat_xt_conntrack_info), - .compat_from_user = conntrack_mt_compat_from_user, - .compat_to_user = conntrack_mt_compat_to_user, + .compatsize = sizeof(struct compat_xt_conntrack_info), + .compat_from_user = conntrack_mt_compat_from_user_v0, + .compat_to_user = conntrack_mt_compat_to_user_v0, #endif - .family = AF_INET, - .me = THIS_MODULE, + }, + { + .name = "conntrack", + .revision = 1, + .family = AF_INET, + .matchsize = sizeof(struct xt_conntrack_mtinfo1), + .match = conntrack_mt, + .checkentry = conntrack_mt_check, + .destroy = conntrack_mt_destroy, + .me = THIS_MODULE, + }, + { + .name = "conntrack", + .revision = 1, + .family = AF_INET6, + .matchsize = sizeof(struct xt_conntrack_mtinfo1), + .match = conntrack_mt, + .checkentry = conntrack_mt_check, + .destroy = conntrack_mt_destroy, + .me = THIS_MODULE, + }, }; static int __init conntrack_mt_init(void) { - return xt_register_match(&conntrack_mt_reg); + return xt_register_matches(conntrack_mt_reg, + ARRAY_SIZE(conntrack_mt_reg)); } static void __exit conntrack_mt_exit(void) { - xt_unregister_match(&conntrack_mt_reg); + xt_unregister_matches(conntrack_mt_reg, ARRAY_SIZE(conntrack_mt_reg)); } module_init(conntrack_mt_init); -- 2.20.1