Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next

Pablo Neira Ayuso says:

====================
The following patchset contains Netfilter updates for your net-next tree,
they are:

* The new SYNPROXY target for iptables, including IPv4 and IPv6 support,
  from Patrick McHardy.

* nf_defrag_ipv6.o should be only linked to nf_defrag_ipv6.ko, from
  Nathan Hintz.

* Fix an old bug in REJECT, which replies with wrong MAC source address
  from the bridge, by Phil Oester.

* Fix uninitialized helper variable in the expectation support over
  nfnetlink_queue, from Florian Westphal.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/netfilter.h

@@ -319,6 +319,7 @@ extern void nf_ct_attach(struct sk_buff *, const struct sk_buff *);
 extern void (*nf_ct_destroy)(struct nf_conntrack *) __rcu;
 
 struct nf_conn;
+enum ip_conntrack_info;
 struct nlattr;
 
 struct nfq_ct_hook {
@@ -327,14 +328,10 @@ struct nfq_ct_hook {
 	int (*parse)(const struct nlattr *attr, struct nf_conn *ct);
 	int (*attach_expect)(const struct nlattr *attr, struct nf_conn *ct,
 			     u32 portid, u32 report);
-};
-extern struct nfq_ct_hook __rcu *nfq_ct_hook;
-
-struct nfq_ct_nat_hook {
 	void (*seq_adjust)(struct sk_buff *skb, struct nf_conn *ct,
-			   u32 ctinfo, s32 off);
+			   enum ip_conntrack_info ctinfo, s32 off);
 };
-extern struct nfq_ct_nat_hook __rcu *nfq_ct_nat_hook;
+extern struct nfq_ct_hook __rcu *nfq_ct_hook;
 #else
 static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {}
 #endif

include/net/netfilter/nf_conntrack_extend.h

@@ -10,6 +10,7 @@ enum nf_ct_ext_id {
 #if defined(CONFIG_NF_NAT) || defined(CONFIG_NF_NAT_MODULE)
 	NF_CT_EXT_NAT,
 #endif
+	NF_CT_EXT_SEQADJ,
 	NF_CT_EXT_ACCT,
 #ifdef CONFIG_NF_CONNTRACK_EVENTS
 	NF_CT_EXT_ECACHE,
@@ -25,18 +26,23 @@ enum nf_ct_ext_id {
 #endif
 #ifdef CONFIG_NF_CONNTRACK_LABELS
 	NF_CT_EXT_LABELS,
+#endif
+#if IS_ENABLED(CONFIG_NETFILTER_SYNPROXY)
+	NF_CT_EXT_SYNPROXY,
 #endif
 	NF_CT_EXT_NUM,
 };
 
 #define NF_CT_EXT_HELPER_TYPE struct nf_conn_help
 #define NF_CT_EXT_NAT_TYPE struct nf_conn_nat
+#define NF_CT_EXT_SEQADJ_TYPE struct nf_conn_seqadj
 #define NF_CT_EXT_ACCT_TYPE struct nf_conn_counter
 #define NF_CT_EXT_ECACHE_TYPE struct nf_conntrack_ecache
 #define NF_CT_EXT_ZONE_TYPE struct nf_conntrack_zone
 #define NF_CT_EXT_TSTAMP_TYPE struct nf_conn_tstamp
 #define NF_CT_EXT_TIMEOUT_TYPE struct nf_conn_timeout
 #define NF_CT_EXT_LABELS_TYPE struct nf_conn_labels
+#define NF_CT_EXT_SYNPROXY_TYPE struct nf_conn_synproxy
 
 /* Extensions: optional stuff which isn't permanently in struct. */
 struct nf_ct_ext {

include/net/netfilter/nf_conntrack_seqadj.h

+#ifndef _NF_CONNTRACK_SEQADJ_H
+#define _NF_CONNTRACK_SEQADJ_H
+
+#include <net/netfilter/nf_conntrack_extend.h>
+
+/**
+ * struct nf_ct_seqadj - sequence number adjustment information
+ *
+ * @correction_pos: position of the last TCP sequence number modification
+ * @offset_before: sequence number offset before last modification
+ * @offset_after: sequence number offset after last modification
+ */
+struct nf_ct_seqadj {
+	u32		correction_pos;
+	s32		offset_before;
+	s32		offset_after;
+};
+
+struct nf_conn_seqadj {
+	struct nf_ct_seqadj	seq[IP_CT_DIR_MAX];
+};
+
+static inline struct nf_conn_seqadj *nfct_seqadj(const struct nf_conn *ct)
+{
+	return nf_ct_ext_find(ct, NF_CT_EXT_SEQADJ);
+}
+
+static inline struct nf_conn_seqadj *nfct_seqadj_ext_add(struct nf_conn *ct)
+{
+	return nf_ct_ext_add(ct, NF_CT_EXT_SEQADJ, GFP_ATOMIC);
+}
+
+extern int nf_ct_seqadj_init(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
+			     s32 off);
+extern int nf_ct_seqadj_set(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
+			    __be32 seq, s32 off);
+extern void nf_ct_tcp_seqadj_set(struct sk_buff *skb,
+				 struct nf_conn *ct,
+				 enum ip_conntrack_info ctinfo,
+				 s32 off);
+
+extern int nf_ct_seq_adjust(struct sk_buff *skb,
+			    struct nf_conn *ct, enum ip_conntrack_info ctinfo,
+			    unsigned int protoff);
+extern s32 nf_ct_seq_offset(const struct nf_conn *ct, enum ip_conntrack_dir,
+			    u32 seq);
+
+extern int nf_conntrack_seqadj_init(void);
+extern void nf_conntrack_seqadj_fini(void);
+
+#endif /* _NF_CONNTRACK_SEQADJ_H */

include/net/netfilter/nf_conntrack_synproxy.h

+#ifndef _NF_CONNTRACK_SYNPROXY_H
+#define _NF_CONNTRACK_SYNPROXY_H
+
+#include <net/netns/generic.h>
+
+struct nf_conn_synproxy {
+	u32	isn;
+	u32	its;
+	u32	tsoff;
+};
+
+static inline struct nf_conn_synproxy *nfct_synproxy(const struct nf_conn *ct)
+{
+#if IS_ENABLED(CONFIG_NETFILTER_SYNPROXY)
+	return nf_ct_ext_find(ct, NF_CT_EXT_SYNPROXY);
+#else
+	return NULL;
+#endif
+}
+
+static inline struct nf_conn_synproxy *nfct_synproxy_ext_add(struct nf_conn *ct)
+{
+#if IS_ENABLED(CONFIG_NETFILTER_SYNPROXY)
+	return nf_ct_ext_add(ct, NF_CT_EXT_SYNPROXY, GFP_ATOMIC);
+#else
+	return NULL;
+#endif
+}
+
+struct synproxy_stats {
+	unsigned int			syn_received;
+	unsigned int			cookie_invalid;
+	unsigned int			cookie_valid;
+	unsigned int			cookie_retrans;
+	unsigned int			conn_reopened;
+};
+
+struct synproxy_net {
+	struct nf_conn			*tmpl;
+	struct synproxy_stats __percpu	*stats;
+};
+
+extern int synproxy_net_id;
+static inline struct synproxy_net *synproxy_pernet(struct net *net)
+{
+	return net_generic(net, synproxy_net_id);
+}
+
+struct synproxy_options {
+	u8				options;
+	u8				wscale;
+	u16				mss;
+	u32				tsval;
+	u32				tsecr;
+};
+
+struct tcphdr;
+struct xt_synproxy_info;
+extern void synproxy_parse_options(const struct sk_buff *skb, unsigned int doff,
+				   const struct tcphdr *th,
+				   struct synproxy_options *opts);
+extern unsigned int synproxy_options_size(const struct synproxy_options *opts);
+extern void synproxy_build_options(struct tcphdr *th,
+				   const struct synproxy_options *opts);
+
+extern void synproxy_init_timestamp_cookie(const struct xt_synproxy_info *info,
+					   struct synproxy_options *opts);
+extern void synproxy_check_timestamp_cookie(struct synproxy_options *opts);
+
+extern unsigned int synproxy_tstamp_adjust(struct sk_buff *skb,
+					   unsigned int protoff,
+					   struct tcphdr *th,
+					   struct nf_conn *ct,
+					   enum ip_conntrack_info ctinfo,
+					   const struct nf_conn_synproxy *synproxy);
+
+#endif /* _NF_CONNTRACK_SYNPROXY_H */

include/net/netfilter/nf_nat.h

@@ -13,15 +13,6 @@ enum nf_nat_manip_type {
 #define HOOK2MANIP(hooknum) ((hooknum) != NF_INET_POST_ROUTING && \
 			     (hooknum) != NF_INET_LOCAL_IN)
 
-/* NAT sequence number modifications */
-struct nf_nat_seq {
-	/* position of the last TCP sequence number modification (if any) */
-	u_int32_t correction_pos;
-
-	/* sequence number offset before and after last modification */
-	int32_t offset_before, offset_after;
-};
-
 #include <linux/list.h>
 #include <linux/netfilter/nf_conntrack_pptp.h>
 #include <net/netfilter/nf_conntrack_extend.h>
@@ -39,7 +30,6 @@ struct nf_conn;
 /* The structure embedded in the conntrack structure. */
 struct nf_conn_nat {
 	struct hlist_node bysource;
-	struct nf_nat_seq seq[IP_CT_DIR_MAX];
 	struct nf_conn *ct;
 	union nf_conntrack_nat_help help;
 #if defined(CONFIG_IP_NF_TARGET_MASQUERADE) || \

include/net/netfilter/nf_nat_helper.h

@@ -39,28 +39,9 @@ extern int nf_nat_mangle_udp_packet(struct sk_buff *skb,
 				    const char *rep_buffer,
 				    unsigned int rep_len);
 
-extern void nf_nat_set_seq_adjust(struct nf_conn *ct,
-				  enum ip_conntrack_info ctinfo,
-				  __be32 seq, s32 off);
-extern int nf_nat_seq_adjust(struct sk_buff *skb,
-			     struct nf_conn *ct,
-			     enum ip_conntrack_info ctinfo,
-			     unsigned int protoff);
-extern int (*nf_nat_seq_adjust_hook)(struct sk_buff *skb,
-				     struct nf_conn *ct,
-				     enum ip_conntrack_info ctinfo,
-				     unsigned int protoff);
-
 /* Setup NAT on this expected conntrack so it follows master, but goes
  * to port ct->master->saved_proto. */
 extern void nf_nat_follow_master(struct nf_conn *ct,
 				 struct nf_conntrack_expect *this);
 
-extern s32 nf_nat_get_offset(const struct nf_conn *ct,
-			     enum ip_conntrack_dir dir,
-			     u32 seq);
-
-extern void nf_nat_tcp_seq_adjust(struct sk_buff *skb, struct nf_conn *ct,
-				  u32 dir, s32 off);
-
 #endif

include/net/tcp.h

@@ -476,9 +476,13 @@ void inet_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb);
 
 /* From syncookies.c */
 extern __u32 syncookie_secret[2][16-4+SHA_DIGEST_WORDS];
+extern int __cookie_v4_check(const struct iphdr *iph, const struct tcphdr *th,
+			     u32 cookie);
 extern struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb, 
 				    struct ip_options *opt);
 #ifdef CONFIG_SYN_COOKIES
+extern u32 __cookie_v4_init_sequence(const struct iphdr *iph,
+				     const struct tcphdr *th, u16 *mssp);
 extern __u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb, 
 				     __u16 *mss);
 #else
@@ -495,8 +499,12 @@ extern bool cookie_check_timestamp(struct tcp_options_received *opt,
 				struct net *net, bool *ecn_ok);
 
 /* From net/ipv6/syncookies.c */
+extern int __cookie_v6_check(const struct ipv6hdr *iph, const struct tcphdr *th,
+			     u32 cookie);
 extern struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb);
 #ifdef CONFIG_SYN_COOKIES
+extern u32 __cookie_v6_init_sequence(const struct ipv6hdr *iph,
+				     const struct tcphdr *th, u16 *mssp);
 extern __u32 cookie_v6_init_sequence(struct sock *sk, const struct sk_buff *skb,
 				     __u16 *mss);
 #else

include/uapi/linux/netfilter/nf_conntrack_common.h

@@ -99,7 +99,8 @@ enum ip_conntrack_events {
 	IPCT_PROTOINFO,		/* protocol information has changed */
 	IPCT_HELPER,		/* new helper has been set */
 	IPCT_MARK,		/* new mark has been set */
-	IPCT_NATSEQADJ,		/* NAT is doing sequence adjustment */
+	IPCT_SEQADJ,		/* sequence adjustment has changed */
+	IPCT_NATSEQADJ = IPCT_SEQADJ,
 	IPCT_SECMARK,		/* new security mark has been set */
 	IPCT_LABEL,		/* new connlabel has been set */
 };

include/uapi/linux/netfilter/nfnetlink_conntrack.h

@@ -42,8 +42,10 @@ enum ctattr_type {
 	CTA_ID,
 	CTA_NAT_DST,
 	CTA_TUPLE_MASTER,
-	CTA_NAT_SEQ_ADJ_ORIG,
-	CTA_NAT_SEQ_ADJ_REPLY,
+	CTA_SEQ_ADJ_ORIG,
+	CTA_NAT_SEQ_ADJ_ORIG	= CTA_SEQ_ADJ_ORIG,
+	CTA_SEQ_ADJ_REPLY,
+	CTA_NAT_SEQ_ADJ_REPLY	= CTA_SEQ_ADJ_REPLY,
 	CTA_SECMARK,		/* obsolete */
 	CTA_ZONE,
 	CTA_SECCTX,
@@ -165,6 +167,15 @@ enum ctattr_protonat {
 };
 #define CTA_PROTONAT_MAX (__CTA_PROTONAT_MAX - 1)
 
+enum ctattr_seqadj {
+	CTA_SEQADJ_UNSPEC,
+	CTA_SEQADJ_CORRECTION_POS,
+	CTA_SEQADJ_OFFSET_BEFORE,
+	CTA_SEQADJ_OFFSET_AFTER,
+	__CTA_SEQADJ_MAX
+};
+#define CTA_SEQADJ_MAX (__CTA_SEQADJ_MAX - 1)
+
 enum ctattr_natseq {
 	CTA_NAT_SEQ_UNSPEC,
 	CTA_NAT_SEQ_CORRECTION_POS,

include/uapi/linux/netfilter/xt_SYNPROXY.h

+#ifndef _XT_SYNPROXY_H
+#define _XT_SYNPROXY_H
+
+#define XT_SYNPROXY_OPT_MSS		0x01
+#define XT_SYNPROXY_OPT_WSCALE		0x02
+#define XT_SYNPROXY_OPT_SACK_PERM	0x04
+#define XT_SYNPROXY_OPT_TIMESTAMP	0x08
+#define XT_SYNPROXY_OPT_ECN		0x10
+
+struct xt_synproxy_info {
+	__u8	options;
+	__u8	wscale;
+	__u16	mss;
+};
+
+#endif /* _XT_SYNPROXY_H */

net/ipv4/netfilter/Kconfig

@@ -110,6 +110,19 @@ config IP_NF_TARGET_REJECT
 
 	  To compile it as a module, choose M here.  If unsure, say N.
 
+config IP_NF_TARGET_SYNPROXY
+	tristate "SYNPROXY target support"
+	depends on NF_CONNTRACK && NETFILTER_ADVANCED
+	select NETFILTER_SYNPROXY
+	select SYN_COOKIES
+	help
+	  The SYNPROXY target allows you to intercept TCP connections and
+	  establish them using syncookies before they are passed on to the
+	  server. This allows to avoid conntrack and server resource usage
+	  during SYN-flood attacks.
+
+	  To compile it as a module, choose M here. If unsure, say N.
+
 config IP_NF_TARGET_ULOG
 	tristate "ULOG target support (obsolete)"
 	default m if NETFILTER_ADVANCED=n

net/ipv4/netfilter/Makefile

@@ -46,6 +46,7 @@ obj-$(CONFIG_IP_NF_TARGET_CLUSTERIP) += ipt_CLUSTERIP.o
 obj-$(CONFIG_IP_NF_TARGET_ECN) += ipt_ECN.o
 obj-$(CONFIG_IP_NF_TARGET_MASQUERADE) += ipt_MASQUERADE.o
 obj-$(CONFIG_IP_NF_TARGET_REJECT) += ipt_REJECT.o
+obj-$(CONFIG_IP_NF_TARGET_SYNPROXY) += ipt_SYNPROXY.o
 obj-$(CONFIG_IP_NF_TARGET_ULOG) += ipt_ULOG.o
 
 # generic ARP tables

net/ipv4/netfilter/ipt_REJECT.c

@@ -119,7 +119,26 @@ static void send_reset(struct sk_buff *oldskb, int hook)
 
 	nf_ct_attach(nskb, oldskb);
 
-	ip_local_out(nskb);
+#ifdef CONFIG_BRIDGE_NETFILTER
+	/* If we use ip_local_out for bridged traffic, the MAC source on
+	 * the RST will be ours, instead of the destination's.  This confuses
+	 * some routers/firewalls, and they drop the packet.  So we need to
+	 * build the eth header using the original destination's MAC as the
+	 * source, and send the RST packet directly.
+	 */
+	if (oldskb->nf_bridge) {
+		struct ethhdr *oeth = eth_hdr(oldskb);
+		nskb->dev = oldskb->nf_bridge->physindev;
+		niph->tot_len = htons(nskb->len);
+		ip_send_check(niph);
+		if (dev_hard_header(nskb, nskb->dev, ntohs(nskb->protocol),
+				    oeth->h_source, oeth->h_dest, nskb->len) < 0)
+			goto free_nskb;
+		dev_queue_xmit(nskb);
+	} else
+#endif
+		ip_local_out(nskb);
+
 	return;
 
  free_nskb:

net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c

@@ -25,6 +25,7 @@
 #include <net/netfilter/nf_conntrack_l3proto.h>
 #include <net/netfilter/nf_conntrack_zones.h>
 #include <net/netfilter/nf_conntrack_core.h>
+#include <net/netfilter/nf_conntrack_seqadj.h>
 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
 #include <net/netfilter/nf_nat_helper.h>
 #include <net/netfilter/ipv4/nf_defrag_ipv4.h>
@@ -136,11 +137,7 @@ static unsigned int ipv4_confirm(unsigned int hooknum,
 	/* adjust seqs for loopback traffic only in outgoing direction */
 	if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&
 	    !nf_is_loopback_packet(skb)) {
-		typeof(nf_nat_seq_adjust_hook) seq_adjust;
-
-		seq_adjust = rcu_dereference(nf_nat_seq_adjust_hook);
-		if (!seq_adjust ||
-		    !seq_adjust(skb, ct, ctinfo, ip_hdrlen(skb))) {
+		if (!nf_ct_seq_adjust(skb, ct, ctinfo, ip_hdrlen(skb))) {
 			NF_CT_STAT_INC_ATOMIC(nf_ct_net(ct), drop);
 			return NF_DROP;
 		}

net/ipv4/syncookies.c

@@ -160,26 +160,33 @@ static __u16 const msstab[] = {
  * Generate a syncookie.  mssp points to the mss, which is returned
  * rounded down to the value encoded in the cookie.
  */
-__u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb, __u16 *mssp)
+u32 __cookie_v4_init_sequence(const struct iphdr *iph, const struct tcphdr *th,
+			      u16 *mssp)
 {
-	const struct iphdr *iph = ip_hdr(skb);
-	const struct tcphdr *th = tcp_hdr(skb);
 	int mssind;
 	const __u16 mss = *mssp;
 
-	tcp_synq_overflow(sk);
-
 	for (mssind = ARRAY_SIZE(msstab) - 1; mssind ; mssind--)
 		if (mss >= msstab[mssind])
 			break;
 	*mssp = msstab[mssind];
 
-	NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_SYNCOOKIESSENT);
-
 	return secure_tcp_syn_cookie(iph->saddr, iph->daddr,
 				     th->source, th->dest, ntohl(th->seq),
 				     jiffies / (HZ * 60), mssind);
 }
+EXPORT_SYMBOL_GPL(__cookie_v4_init_sequence);
+
+__u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb, __u16 *mssp)
+{
+	const struct iphdr *iph = ip_hdr(skb);
+	const struct tcphdr *th = tcp_hdr(skb);
+
+	tcp_synq_overflow(sk);
+	NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_SYNCOOKIESSENT);
+
+	return __cookie_v4_init_sequence(iph, th, mssp);
+}
 
 /*
  * This (misnamed) value is the age of syncookie which is permitted.
@@ -192,10 +199,9 @@ __u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb, __u16 *mssp)
  * Check if a ack sequence number is a valid syncookie.
  * Return the decoded mss if it is, or 0 if not.
  */
-static inline int cookie_check(struct sk_buff *skb, __u32 cookie)
+int __cookie_v4_check(const struct iphdr *iph, const struct tcphdr *th,
+		      u32 cookie)
 {
-	const struct iphdr *iph = ip_hdr(skb);
-	const struct tcphdr *th = tcp_hdr(skb);
 	__u32 seq = ntohl(th->seq) - 1;
 	__u32 mssind = check_tcp_syn_cookie(cookie, iph->saddr, iph->daddr,
 					    th->source, th->dest, seq,
@@ -204,6 +210,7 @@ static inline int cookie_check(struct sk_buff *skb, __u32 cookie)
 
 	return mssind < ARRAY_SIZE(msstab) ? msstab[mssind] : 0;
 }
+EXPORT_SYMBOL_GPL(__cookie_v4_check);
 
 static inline struct sock *get_cookie_sock(struct sock *sk, struct sk_buff *skb,
 					   struct request_sock *req,
@@ -284,7 +291,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
 		goto out;
 
 	if (tcp_synq_no_recent_overflow(sk) ||
-	    (mss = cookie_check(skb, cookie)) == 0) {
+	    (mss = __cookie_v4_check(ip_hdr(skb), th, cookie)) == 0) {
 		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_SYNCOOKIESFAILED);
 		goto out;
 	}

net/ipv6/netfilter/Kconfig

@@ -153,6 +153,19 @@ config IP6_NF_TARGET_REJECT
 
 	  To compile it as a module, choose M here.  If unsure, say N.
 
+config IP6_NF_TARGET_SYNPROXY
+	tristate "SYNPROXY target support"
+	depends on NF_CONNTRACK && NETFILTER_ADVANCED
+	select NETFILTER_SYNPROXY
+	select SYN_COOKIES
+	help
+	  The SYNPROXY target allows you to intercept TCP connections and
+	  establish them using syncookies before they are passed on to the
+	  server. This allows to avoid conntrack and server resource usage
+	  during SYN-flood attacks.
+
+	  To compile it as a module, choose M here. If unsure, say N.
+
 config IP6_NF_MANGLE
 	tristate "Packet mangling"
 	default m if NETFILTER_ADVANCED=n

net/ipv6/netfilter/Makefile

@@ -14,7 +14,7 @@ obj-$(CONFIG_NF_NAT_IPV6) += ip6table_nat.o
 nf_conntrack_ipv6-y  :=  nf_conntrack_l3proto_ipv6.o nf_conntrack_proto_icmpv6.o
 
 # l3 independent conntrack
-obj-$(CONFIG_NF_CONNTRACK_IPV6) += nf_conntrack_ipv6.o nf_defrag_ipv6.o
+obj-$(CONFIG_NF_CONNTRACK_IPV6) += nf_conntrack_ipv6.o
 
 nf_nat_ipv6-y		:= nf_nat_l3proto_ipv6.o nf_nat_proto_icmpv6.o
 obj-$(CONFIG_NF_NAT_IPV6) += nf_nat_ipv6.o
@@ -37,3 +37,4 @@ obj-$(CONFIG_IP6_NF_MATCH_RT) += ip6t_rt.o
 obj-$(CONFIG_IP6_NF_TARGET_MASQUERADE) += ip6t_MASQUERADE.o
 obj-$(CONFIG_IP6_NF_TARGET_NPT) += ip6t_NPT.o
 obj-$(CONFIG_IP6_NF_TARGET_REJECT) += ip6t_REJECT.o
+obj-$(CONFIG_IP6_NF_TARGET_SYNPROXY) += ip6t_SYNPROXY.o

net/ipv6/netfilter/ip6t_REJECT.c

@@ -169,7 +169,25 @@ static void send_reset(struct net *net, struct sk_buff *oldskb)
 
 	nf_ct_attach(nskb, oldskb);
 
-	ip6_local_out(nskb);
+#ifdef CONFIG_BRIDGE_NETFILTER
+	/* If we use ip6_local_out for bridged traffic, the MAC source on
+	 * the RST will be ours, instead of the destination's.  This confuses
+	 * some routers/firewalls, and they drop the packet.  So we need to
+	 * build the eth header using the original destination's MAC as the
+	 * source, and send the RST packet directly.
+	 */
+	if (oldskb->nf_bridge) {
+		struct ethhdr *oeth = eth_hdr(oldskb);
+		nskb->dev = oldskb->nf_bridge->physindev;
+		nskb->protocol = htons(ETH_P_IPV6);
+		ip6h->payload_len = htons(sizeof(struct tcphdr));
+		if (dev_hard_header(nskb, nskb->dev, ntohs(nskb->protocol),
+				    oeth->h_source, oeth->h_dest, nskb->len) < 0)
+			return;
+		dev_queue_xmit(nskb);
+	} else
+#endif
+		ip6_local_out(nskb);
 }
 
 static inline void

net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c

@@ -28,6 +28,7 @@
 #include <net/netfilter/nf_conntrack_l3proto.h>
 #include <net/netfilter/nf_conntrack_core.h>
 #include <net/netfilter/nf_conntrack_zones.h>
+#include <net/netfilter/nf_conntrack_seqadj.h>
 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
 #include <net/netfilter/nf_nat_helper.h>
 #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
@@ -158,11 +159,7 @@ static unsigned int ipv6_confirm(unsigned int hooknum,
 	/* adjust seqs for loopback traffic only in outgoing direction */
 	if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&
 	    !nf_is_loopback_packet(skb)) {
-		typeof(nf_nat_seq_adjust_hook) seq_adjust;
-
-		seq_adjust = rcu_dereference(nf_nat_seq_adjust_hook);
-		if (!seq_adjust ||
-		    !seq_adjust(skb, ct, ctinfo, protoff)) {
+		if (!nf_ct_seq_adjust(skb, ct, ctinfo, protoff)) {
 			NF_CT_STAT_INC_ATOMIC(nf_ct_net(ct), drop);
 			return NF_DROP;
 		}

net/ipv6/syncookies.c

@@ -112,32 +112,38 @@ static __u32 check_tcp_syn_cookie(__u32 cookie, const struct in6_addr *saddr,
 		& COOKIEMASK;
 }
 
-__u32 cookie_v6_init_sequence(struct sock *sk, const struct sk_buff *skb, __u16 *mssp)
+u32 __cookie_v6_init_sequence(const struct ipv6hdr *iph,
+			      const struct tcphdr *th, __u16 *mssp)
 {
-	const struct ipv6hdr *iph = ipv6_hdr(skb);
-	const struct tcphdr *th = tcp_hdr(skb);
 	int mssind;
 	const __u16 mss = *mssp;
 
-	tcp_synq_overflow(sk);
-
 	for (mssind = ARRAY_SIZE(msstab) - 1; mssind ; mssind--)
 		if (mss >= msstab[mssind])
 			break;
 
 	*mssp = msstab[mssind];
 
-	NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_SYNCOOKIESSENT);
-
 	return secure_tcp_syn_cookie(&iph->saddr, &iph->daddr, th->source,
 				     th->dest, ntohl(th->seq),
 				     jiffies / (HZ * 60), mssind);
 }
+EXPORT_SYMBOL_GPL(__cookie_v6_init_sequence);
 
-static inline int cookie_check(const struct sk_buff *skb, __u32 cookie)
+__u32 cookie_v6_init_sequence(struct sock *sk, const struct sk_buff *skb, __u16 *mssp)
 {
 	const struct ipv6hdr *iph = ipv6_hdr(skb);
 	const struct tcphdr *th = tcp_hdr(skb);
+
+	tcp_synq_overflow(sk);
+	NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_SYNCOOKIESSENT);
+
+	return __cookie_v6_init_sequence(iph, th, mssp);
+}
+
+int __cookie_v6_check(const struct ipv6hdr *iph, const struct tcphdr *th,
+		      __u32 cookie)
+{
 	__u32 seq = ntohl(th->seq) - 1;
 	__u32 mssind = check_tcp_syn_cookie(cookie, &iph->saddr, &iph->daddr,
 					    th->source, th->dest, seq,
@@ -145,6 +151,7 @@ static inline int cookie_check(const struct sk_buff *skb, __u32 cookie)
 
 	return mssind < ARRAY_SIZE(msstab) ? msstab[mssind] : 0;
 }
+EXPORT_SYMBOL_GPL(__cookie_v6_check);
 
 struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
 {
@@ -167,7 +174,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
 		goto out;
 
 	if (tcp_synq_no_recent_overflow(sk) ||
-		(mss = cookie_check(skb, cookie)) == 0) {
+		(mss = __cookie_v6_check(ipv6_hdr(skb), th, cookie)) == 0) {
 		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_SYNCOOKIESFAILED);
 		goto out;
 	}

net/netfilter/Kconfig

@@ -408,6 +408,9 @@ config NF_NAT_TFTP
 	depends on NF_CONNTRACK && NF_NAT
 	default NF_NAT && NF_CONNTRACK_TFTP
 
+config NETFILTER_SYNPROXY
+	tristate
+
 endif # NF_CONNTRACK
 
 config NETFILTER_XTABLES

net/netfilter/Makefile

 netfilter-objs := core.o nf_log.o nf_queue.o nf_sockopt.o
 
-nf_conntrack-y	:= nf_conntrack_core.o nf_conntrack_standalone.o nf_conntrack_expect.o nf_conntrack_helper.o nf_conntrack_proto.o nf_conntrack_l3proto_generic.o nf_conntrack_proto_generic.o nf_conntrack_proto_tcp.o nf_conntrack_proto_udp.o nf_conntrack_extend.o nf_conntrack_acct.o
+nf_conntrack-y	:= nf_conntrack_core.o nf_conntrack_standalone.o nf_conntrack_expect.o nf_conntrack_helper.o nf_conntrack_proto.o nf_conntrack_l3proto_generic.o nf_conntrack_proto_generic.o nf_conntrack_proto_tcp.o nf_conntrack_proto_udp.o nf_conntrack_extend.o nf_conntrack_acct.o nf_conntrack_seqadj.o
 nf_conntrack-$(CONFIG_NF_CONNTRACK_TIMEOUT) += nf_conntrack_timeout.o
 nf_conntrack-$(CONFIG_NF_CONNTRACK_TIMESTAMP) += nf_conntrack_timestamp.o
 nf_conntrack-$(CONFIG_NF_CONNTRACK_EVENTS) += nf_conntrack_ecache.o
@@ -61,6 +61,9 @@ obj-$(CONFIG_NF_NAT_IRC) += nf_nat_irc.o
 obj-$(CONFIG_NF_NAT_SIP) += nf_nat_sip.o
 obj-$(CONFIG_NF_NAT_TFTP) += nf_nat_tftp.o
 
+# SYNPROXY
+obj-$(CONFIG_NETFILTER_SYNPROXY) += nf_synproxy_core.o
+
 # generic X tables 
 obj-$(CONFIG_NETFILTER_XTABLES) += x_tables.o xt_tcpudp.o
 

net/netfilter/nf_conntrack_core.c

@@ -39,6 +39,7 @@
 #include <net/netfilter/nf_conntrack_l4proto.h>
 #include <net/netfilter/nf_conntrack_expect.h>
 #include <net/netfilter/nf_conntrack_helper.h>
+#include <net/netfilter/nf_conntrack_seqadj.h>
 #include <net/netfilter/nf_conntrack_core.h>
 #include <net/netfilter/nf_conntrack_extend.h>
 #include <net/netfilter/nf_conntrack_acct.h>
@@ -47,6 +48,7 @@
 #include <net/netfilter/nf_conntrack_timestamp.h>
 #include <net/netfilter/nf_conntrack_timeout.h>
 #include <net/netfilter/nf_conntrack_labels.h>
+#include <net/netfilter/nf_conntrack_synproxy.h>
 #include <net/netfilter/nf_nat.h>
 #include <net/netfilter/nf_nat_core.h>
 #include <net/netfilter/nf_nat_helper.h>
@@ -798,6 +800,11 @@ init_conntrack(struct net *net, struct nf_conn *tmpl,
 	if (IS_ERR(ct))
 		return (struct nf_conntrack_tuple_hash *)ct;
 
+	if (tmpl && nfct_synproxy(tmpl)) {
+		nfct_seqadj_ext_add(ct);
+		nfct_synproxy_ext_add(ct);
+	}
+
 	timeout_ext = tmpl ? nf_ct_timeout_find(tmpl) : NULL;
 	if (timeout_ext)
 		timeouts = NF_CT_TIMEOUT_EXT_DATA(timeout_ext);
@@ -1326,6 +1333,7 @@ void nf_conntrack_cleanup_end(void)
 	nf_ct_extend_unregister(&nf_ct_zone_extend);
 #endif
 	nf_conntrack_proto_fini();
+	nf_conntrack_seqadj_fini();
 	nf_conntrack_labels_fini();
 	nf_conntrack_helper_fini();
 	nf_conntrack_timeout_fini();
@@ -1531,6 +1539,10 @@ int nf_conntrack_init_start(void)
 	if (ret < 0)
 		goto err_labels;
 
+	ret = nf_conntrack_seqadj_init();
+	if (ret < 0)
+		goto err_seqadj;
+
 #ifdef CONFIG_NF_CONNTRACK_ZONES
 	ret = nf_ct_extend_register(&nf_ct_zone_extend);
 	if (ret < 0)
@@ -1555,6 +1567,8 @@ int nf_conntrack_init_start(void)
 	nf_ct_extend_unregister(&nf_ct_zone_extend);
 err_extend:
 #endif
+	nf_conntrack_seqadj_fini();
+err_seqadj:
 	nf_conntrack_labels_fini();
 err_labels:
 	nf_conntrack_helper_fini();
@@ -1577,9 +1591,6 @@ void nf_conntrack_init_end(void)
 	/* For use by REJECT target */
 	RCU_INIT_POINTER(ip_ct_attach, nf_conntrack_attach);
 	RCU_INIT_POINTER(nf_ct_destroy, destroy_conntrack);
-
-	/* Howto get NAT offsets */
-	RCU_INIT_POINTER(nf_ct_nat_offset, NULL);
 }
 
 /*
@@ -1666,8 +1677,3 @@ int nf_conntrack_init_net(struct net *net)
 err_stat:
 	return ret;
 }
-
-s32 (*nf_ct_nat_offset)(const struct nf_conn *ct,
-			enum ip_conntrack_dir dir,
-			u32 seq);
-EXPORT_SYMBOL_GPL(nf_ct_nat_offset);

net/netfilter/nf_conntrack_netlink.c

@@ -37,6 +37,7 @@
 #include <net/netfilter/nf_conntrack_core.h>
 #include <net/netfilter/nf_conntrack_expect.h>
 #include <net/netfilter/nf_conntrack_helper.h>
+#include <net/netfilter/nf_conntrack_seqadj.h>
 #include <net/netfilter/nf_conntrack_l3proto.h>
 #include <net/netfilter/nf_conntrack_l4proto.h>
 #include <net/netfilter/nf_conntrack_tuple.h>
@@ -381,9 +382,8 @@ ctnetlink_dump_master(struct sk_buff *skb, const struct nf_conn *ct)
 	return -1;
 }
 
-#ifdef CONFIG_NF_NAT_NEEDED
 static int
-dump_nat_seq_adj(struct sk_buff *skb, const struct nf_nat_seq *natseq, int type)
+dump_ct_seq_adj(struct sk_buff *skb, const struct nf_ct_seqadj *seq, int type)
 {
 	struct nlattr *nest_parms;
 
@@ -391,12 +391,12 @@ dump_nat_seq_adj(struct sk_buff *skb, const struct nf_nat_seq *natseq, int type)
 	if (!nest_parms)
 		goto nla_put_failure;
 
-	if (nla_put_be32(skb, CTA_NAT_SEQ_CORRECTION_POS,
-			 htonl(natseq->correction_pos)) ||
-	    nla_put_be32(skb, CTA_NAT_SEQ_OFFSET_BEFORE,
-			 htonl(natseq->offset_before)) ||
-	    nla_put_be32(skb, CTA_NAT_SEQ_OFFSET_AFTER,
-			 htonl(natseq->offset_after)))
+	if (nla_put_be32(skb, CTA_SEQADJ_CORRECTION_POS,
+			 htonl(seq->correction_pos)) ||
+	    nla_put_be32(skb, CTA_SEQADJ_OFFSET_BEFORE,
+			 htonl(seq->offset_before)) ||
+	    nla_put_be32(skb, CTA_SEQADJ_OFFSET_AFTER,
+			 htonl(seq->offset_after)))
 		goto nla_put_failure;
 
 	nla_nest_end(skb, nest_parms);
@@ -408,27 +408,24 @@ dump_nat_seq_adj(struct sk_buff *skb, const struct nf_nat_seq *natseq, int type)
 }
 
 static inline int
-ctnetlink_dump_nat_seq_adj(struct sk_buff *skb, const struct nf_conn *ct)
+ctnetlink_dump_ct_seq_adj(struct sk_buff *skb, const struct nf_conn *ct)
 {
-	struct nf_nat_seq *natseq;
-	struct nf_conn_nat *nat = nfct_nat(ct);
+	struct nf_conn_seqadj *seqadj = nfct_seqadj(ct);
+	struct nf_ct_seqadj *seq;
 
-	if (!(ct->status & IPS_SEQ_ADJUST) || !nat)
+	if (!(ct->status & IPS_SEQ_ADJUST) || !seqadj)
 		return 0;
 
-	natseq = &nat->seq[IP_CT_DIR_ORIGINAL];
-	if (dump_nat_seq_adj(skb, natseq, CTA_NAT_SEQ_ADJ_ORIG) == -1)
+	seq = &seqadj->seq[IP_CT_DIR_ORIGINAL];
+	if (dump_ct_seq_adj(skb, seq, CTA_SEQ_ADJ_ORIG) == -1)
 		return -1;
 
-	natseq = &nat->seq[IP_CT_DIR_REPLY];
-	if (dump_nat_seq_adj(skb, natseq, CTA_NAT_SEQ_ADJ_REPLY) == -1)
+	seq = &seqadj->seq[IP_CT_DIR_REPLY];
+	if (dump_ct_seq_adj(skb, seq, CTA_SEQ_ADJ_REPLY) == -1)
 		return -1;
 
 	return 0;
 }
-#else
-#define ctnetlink_dump_nat_seq_adj(a, b) (0)
-#endif
 
 static inline int
 ctnetlink_dump_id(struct sk_buff *skb, const struct nf_conn *ct)
@@ -502,7 +499,7 @@ ctnetlink_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
 	    ctnetlink_dump_id(skb, ct) < 0 ||
 	    ctnetlink_dump_use(skb, ct) < 0 ||
 	    ctnetlink_dump_master(skb, ct) < 0 ||
-	    ctnetlink_dump_nat_seq_adj(skb, ct) < 0)
+	    ctnetlink_dump_ct_seq_adj(skb, ct) < 0)
 		goto nla_put_failure;
 
 	nlmsg_end(skb, nlh);
@@ -707,8 +704,8 @@ ctnetlink_conntrack_event(unsigned int events, struct nf_ct_event *item)
 		    ctnetlink_dump_master(skb, ct) < 0)
 			goto nla_put_failure;
 
-		if (events & (1 << IPCT_NATSEQADJ) &&
-		    ctnetlink_dump_nat_seq_adj(skb, ct) < 0)
+		if (events & (1 << IPCT_SEQADJ) &&
+		    ctnetlink_dump_ct_seq_adj(skb, ct) < 0)
 			goto nla_put_failure;
 	}
 
@@ -1439,66 +1436,65 @@ ctnetlink_change_protoinfo(struct nf_conn *ct, const struct nlattr * const cda[]
 	return err;
 }
 
-#ifdef CONFIG_NF_NAT_NEEDED
-static const struct nla_policy nat_seq_policy[CTA_NAT_SEQ_MAX+1] = {
-	[CTA_NAT_SEQ_CORRECTION_POS]	= { .type = NLA_U32 },
-	[CTA_NAT_SEQ_OFFSET_BEFORE]	= { .type = NLA_U32 },
-	[CTA_NAT_SEQ_OFFSET_AFTER]	= { .type = NLA_U32 },
+static const struct nla_policy seqadj_policy[CTA_SEQADJ_MAX+1] = {
+	[CTA_SEQADJ_CORRECTION_POS]	= { .type = NLA_U32 },
+	[CTA_SEQADJ_OFFSET_BEFORE]	= { .type = NLA_U32 },
+	[CTA_SEQADJ_OFFSET_AFTER]	= { .type = NLA_U32 },
 };
 
 static inline int
-change_nat_seq_adj(struct nf_nat_seq *natseq, const struct nlattr * const attr)
+change_seq_adj(struct nf_ct_seqadj *seq, const struct nlattr * const attr)
 {
 	int err;
-	struct nlattr *cda[CTA_NAT_SEQ_MAX+1];
+	struct nlattr *cda[CTA_SEQADJ_MAX+1];
 
-	err = nla_parse_nested(cda, CTA_NAT_SEQ_MAX, attr, nat_seq_policy);
+	err = nla_parse_nested(cda, CTA_SEQADJ_MAX, attr, seqadj_policy);
 	if (err < 0)
 		return err;
 
-	if (!cda[CTA_NAT_SEQ_CORRECTION_POS])
+	if (!cda[CTA_SEQADJ_CORRECTION_POS])
 		return -EINVAL;
 
-	natseq->correction_pos =
-		ntohl(nla_get_be32(cda[CTA_NAT_SEQ_CORRECTION_POS]));
+	seq->correction_pos =
+		ntohl(nla_get_be32(cda[CTA_SEQADJ_CORRECTION_POS]));
 
-	if (!cda[CTA_NAT_SEQ_OFFSET_BEFORE])
+	if (!cda[CTA_SEQADJ_OFFSET_BEFORE])
 		return -EINVAL;
 
-	natseq->offset_before =
-		ntohl(nla_get_be32(cda[CTA_NAT_SEQ_OFFSET_BEFORE]));
+	seq->offset_before =
+		ntohl(nla_get_be32(cda[CTA_SEQADJ_OFFSET_BEFORE]));
 
-	if (!cda[CTA_NAT_SEQ_OFFSET_AFTER])
+	if (!cda[CTA_SEQADJ_OFFSET_AFTER])
 		return -EINVAL;
 
-	natseq->offset_after =
-		ntohl(nla_get_be32(cda[CTA_NAT_SEQ_OFFSET_AFTER]));
+	seq->offset_after =
+		ntohl(nla_get_be32(cda[CTA_SEQADJ_OFFSET_AFTER]));
 
 	return 0;
 }
 
 static int
-ctnetlink_change_nat_seq_adj(struct nf_conn *ct,
-			     const struct nlattr * const cda[])
+ctnetlink_change_seq_adj(struct nf_conn *ct,
+			 const struct nlattr * const cda[])
 {
+	struct nf_conn_seqadj *seqadj = nfct_seqadj(ct);
 	int ret = 0;
-	struct nf_conn_nat *nat = nfct_nat(ct);
 
-	if (!nat)
+	if (!seqadj)
 		return 0;
 
-	if (cda[CTA_NAT_SEQ_ADJ_ORIG]) {
-		ret = change_nat_seq_adj(&nat->seq[IP_CT_DIR_ORIGINAL],
-					 cda[CTA_NAT_SEQ_ADJ_ORIG]);
+	if (cda[CTA_SEQ_ADJ_ORIG]) {
+		ret = change_seq_adj(&seqadj->seq[IP_CT_DIR_ORIGINAL],
+				     cda[CTA_SEQ_ADJ_ORIG]);
 		if (ret < 0)
 			return ret;
 
 		ct->status |= IPS_SEQ_ADJUST;
 	}
 
-	if (cda[CTA_NAT_SEQ_ADJ_REPLY]) {
-		ret = change_nat_seq_adj(&nat->seq[IP_CT_DIR_REPLY],
-					 cda[CTA_NAT_SEQ_ADJ_REPLY]);
+	if (cda[CTA_SEQ_ADJ_REPLY]) {
+		ret = change_seq_adj(&seqadj->seq[IP_CT_DIR_REPLY],
+				     cda[CTA_SEQ_ADJ_REPLY]);
 		if (ret < 0)
 			return ret;
 
@@ -1507,7 +1503,6 @@ ctnetlink_change_nat_seq_adj(struct nf_conn *ct,
 
 	return 0;
 }
-#endif
 
 static int
 ctnetlink_attach_labels(struct nf_conn *ct, const struct nlattr * const cda[])
@@ -1573,13 +1568,12 @@ ctnetlink_change_conntrack(struct nf_conn *ct,
 		ct->mark = ntohl(nla_get_be32(cda[CTA_MARK]));
 #endif
 
-#ifdef CONFIG_NF_NAT_NEEDED
-	if (cda[CTA_NAT_SEQ_ADJ_ORIG] || cda[CTA_NAT_SEQ_ADJ_REPLY]) {
-		err = ctnetlink_change_nat_seq_adj(ct, cda);
+	if (cda[CTA_SEQ_ADJ_ORIG] || cda[CTA_SEQ_ADJ_REPLY]) {
+		err = ctnetlink_change_seq_adj(ct, cda);
 		if (err < 0)
 			return err;
 	}
-#endif
+
 	if (cda[CTA_LABELS]) {
 		err = ctnetlink_attach_labels(ct, cda);
 		if (err < 0)
@@ -1684,13 +1678,11 @@ ctnetlink_create_conntrack(struct net *net, u16 zone,
 			goto err2;
 	}
 
-#ifdef CONFIG_NF_NAT_NEEDED
-	if (cda[CTA_NAT_SEQ_ADJ_ORIG] || cda[CTA_NAT_SEQ_ADJ_REPLY]) {
-		err = ctnetlink_change_nat_seq_adj(ct, cda);
+	if (cda[CTA_SEQ_ADJ_ORIG] || cda[CTA_SEQ_ADJ_REPLY]) {
+		err = ctnetlink_change_seq_adj(ct, cda);
 		if (err < 0)
 			goto err2;
 	}
-#endif
 
 	memset(&ct->proto, 0, sizeof(ct->proto));
 	if (cda[CTA_PROTOINFO]) {
@@ -1804,7 +1796,7 @@ ctnetlink_new_conntrack(struct sock *ctnl, struct sk_buff *skb,
 						      (1 << IPCT_ASSURED) |
 						      (1 << IPCT_HELPER) |
 						      (1 << IPCT_PROTOINFO) |
-						      (1 << IPCT_NATSEQADJ) |
+						      (1 << IPCT_SEQADJ) |
 						      (1 << IPCT_MARK) | events,
 						      ct, NETLINK_CB(skb).portid,
 						      nlmsg_report(nlh));
@@ -1827,7 +1819,7 @@ ctnetlink_new_conntrack(struct sock *ctnl, struct sk_buff *skb,
 						      (1 << IPCT_HELPER) |
 						      (1 << IPCT_LABEL) |
 						      (1 << IPCT_PROTOINFO) |
-						      (1 << IPCT_NATSEQADJ) |
+						      (1 << IPCT_SEQADJ) |
 						      (1 << IPCT_MARK),
 						      ct, NETLINK_CB(skb).portid,
 						      nlmsg_report(nlh));
@@ -2082,7 +2074,7 @@ ctnetlink_nfqueue_build(struct sk_buff *skb, struct nf_conn *ct)
 		goto nla_put_failure;
 
 	if ((ct->status & IPS_SEQ_ADJUST) &&
-	    ctnetlink_dump_nat_seq_adj(skb, ct) < 0)
+	    ctnetlink_dump_ct_seq_adj(skb, ct) < 0)
 		goto nla_put_failure;
 
 #ifdef CONFIG_NF_CONNTRACK_MARK
@@ -2170,7 +2162,7 @@ ctnetlink_nfqueue_attach_expect(const struct nlattr *attr, struct nf_conn *ct,
 {
 	struct nlattr *cda[CTA_EXPECT_MAX+1];
 	struct nf_conntrack_tuple tuple, mask;
-	struct nf_conntrack_helper *helper;
+	struct nf_conntrack_helper *helper = NULL;
 	struct nf_conntrack_expect *exp;
 	int err;
 
@@ -2211,6 +2203,7 @@ static struct nfq_ct_hook ctnetlink_nfqueue_hook = {
 	.build		= ctnetlink_nfqueue_build,
 	.parse		= ctnetlink_nfqueue_parse,
 	.attach_expect	= ctnetlink_nfqueue_attach_expect,
+	.seq_adjust	= nf_ct_tcp_seqadj_set,
 };
 #endif /* CONFIG_NETFILTER_NETLINK_QUEUE_CT */
 

net/netfilter/nf_conntrack_proto_tcp.c

@@ -27,6 +27,8 @@
 #include <net/netfilter/nf_conntrack.h>
 #include <net/netfilter/nf_conntrack_l4proto.h>
 #include <net/netfilter/nf_conntrack_ecache.h>
+#include <net/netfilter/nf_conntrack_seqadj.h>
+#include <net/netfilter/nf_conntrack_synproxy.h>
 #include <net/netfilter/nf_log.h>
 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
@@ -495,21 +497,6 @@ static void tcp_sack(const struct sk_buff *skb, unsigned int dataoff,
 	}
 }
 
-#ifdef CONFIG_NF_NAT_NEEDED
-static inline s32 nat_offset(const struct nf_conn *ct,
-			     enum ip_conntrack_dir dir,
-			     u32 seq)
-{
-	typeof(nf_ct_nat_offset) get_offset = rcu_dereference(nf_ct_nat_offset);
-
-	return get_offset != NULL ? get_offset(ct, dir, seq) : 0;
-}
-#define NAT_OFFSET(ct, dir, seq) \
-	(nat_offset(ct, dir, seq))
-#else
-#define NAT_OFFSET(ct, dir, seq)	0
-#endif
-
 static bool tcp_in_window(const struct nf_conn *ct,
 			  struct ip_ct_tcp *state,
 			  enum ip_conntrack_dir dir,
@@ -540,7 +527,7 @@ static bool tcp_in_window(const struct nf_conn *ct,
 		tcp_sack(skb, dataoff, tcph, &sack);
 
 	/* Take into account NAT sequence number mangling */
-	receiver_offset = NAT_OFFSET(ct, !dir, ack - 1);
+	receiver_offset = nf_ct_seq_offset(ct, !dir, ack - 1);
 	ack -= receiver_offset;
 	sack -= receiver_offset;
 
@@ -960,6 +947,21 @@ static int tcp_packet(struct nf_conn *ct,
 				  "state %s ", tcp_conntrack_names[old_state]);
 		return NF_ACCEPT;
 	case TCP_CONNTRACK_MAX:
+		/* Special case for SYN proxy: when the SYN to the server or
+		 * the SYN/ACK from the server is lost, the client may transmit
+		 * a keep-alive packet while in SYN_SENT state. This needs to
+		 * be associated with the original conntrack entry in order to
+		 * generate a new SYN with the correct sequence number.
+		 */
+		if (nfct_synproxy(ct) && old_state == TCP_CONNTRACK_SYN_SENT &&
+		    index == TCP_ACK_SET && dir == IP_CT_DIR_ORIGINAL &&
+		    ct->proto.tcp.last_dir == IP_CT_DIR_ORIGINAL &&
+		    ct->proto.tcp.seen[dir].td_end - 1 == ntohl(th->seq)) {
+			pr_debug("nf_ct_tcp: SYN proxy client keep alive\n");
+			spin_unlock_bh(&ct->lock);
+			return NF_ACCEPT;
+		}
+
 		/* Invalid packet */
 		pr_debug("nf_ct_tcp: Invalid dir=%i index=%u ostate=%u\n",
 			 dir, get_conntrack_index(th), old_state);

net/netfilter/nf_conntrack_seqadj.c

+#include <linux/types.h>
+#include <linux/netfilter.h>
+#include <net/tcp.h>
+
+#include <net/netfilter/nf_conntrack.h>
+#include <net/netfilter/nf_conntrack_extend.h>
+#include <net/netfilter/nf_conntrack_seqadj.h>
+
+int nf_ct_seqadj_init(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
+		      s32 off)
+{
+	enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
+	struct nf_conn_seqadj *seqadj;
+	struct nf_ct_seqadj *this_way;
+
+	if (off == 0)
+		return 0;
+
+	set_bit(IPS_SEQ_ADJUST_BIT, &ct->status);
+
+	seqadj = nfct_seqadj(ct);
+	this_way = &seqadj->seq[dir];
+	this_way->offset_before	 = off;
+	this_way->offset_after	 = off;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nf_ct_seqadj_init);
+
+int nf_ct_seqadj_set(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
+		     __be32 seq, s32 off)
+{
+	struct nf_conn_seqadj *seqadj = nfct_seqadj(ct);
+	enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
+	struct nf_ct_seqadj *this_way;
+
+	if (off == 0)
+		return 0;
+
+	set_bit(IPS_SEQ_ADJUST_BIT, &ct->status);
+
+	spin_lock_bh(&ct->lock);
+	this_way = &seqadj->seq[dir];
+	if (this_way->offset_before == this_way->offset_after ||
+	    before(this_way->correction_pos, seq)) {
+		this_way->correction_pos = seq;
+		this_way->offset_before	 = this_way->offset_after;
+		this_way->offset_after	+= off;
+	}
+	spin_unlock_bh(&ct->lock);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nf_ct_seqadj_set);
+
+void nf_ct_tcp_seqadj_set(struct sk_buff *skb,
+			  struct nf_conn *ct, enum ip_conntrack_info ctinfo,
+			  s32 off)
+{
+	const struct tcphdr *th;
+
+	if (nf_ct_protonum(ct) != IPPROTO_TCP)
+		return;
+
+	th = (struct tcphdr *)(skb_network_header(skb) + ip_hdrlen(skb));
+	nf_ct_seqadj_set(ct, ctinfo, th->seq, off);
+}
+EXPORT_SYMBOL_GPL(nf_ct_tcp_seqadj_set);
+
+/* Adjust one found SACK option including checksum correction */
+static void nf_ct_sack_block_adjust(struct sk_buff *skb,
+				    struct tcphdr *tcph,
+				    unsigned int sackoff,
+				    unsigned int sackend,
+				    struct nf_ct_seqadj *seq)
+{
+	while (sackoff < sackend) {
+		struct tcp_sack_block_wire *sack;
+		__be32 new_start_seq, new_end_seq;
+
+		sack = (void *)skb->data + sackoff;
+		if (after(ntohl(sack->start_seq) - seq->offset_before,
+			  seq->correction_pos))
+			new_start_seq = htonl(ntohl(sack->start_seq) -
+					seq->offset_after);
+		else
+			new_start_seq = htonl(ntohl(sack->start_seq) -
+					seq->offset_before);
+
+		if (after(ntohl(sack->end_seq) - seq->offset_before,
+			  seq->correction_pos))
+			new_end_seq = htonl(ntohl(sack->end_seq) -
+				      seq->offset_after);
+		else
+			new_end_seq = htonl(ntohl(sack->end_seq) -
+				      seq->offset_before);
+
+		pr_debug("sack_adjust: start_seq: %d->%d, end_seq: %d->%d\n",
+			 ntohl(sack->start_seq), new_start_seq,
+			 ntohl(sack->end_seq), new_end_seq);
+
+		inet_proto_csum_replace4(&tcph->check, skb,
+					 sack->start_seq, new_start_seq, 0);
+		inet_proto_csum_replace4(&tcph->check, skb,
+					 sack->end_seq, new_end_seq, 0);
+		sack->start_seq = new_start_seq;
+		sack->end_seq = new_end_seq;
+		sackoff += sizeof(*sack);
+	}
+}
+
+/* TCP SACK sequence number adjustment */
+static unsigned int nf_ct_sack_adjust(struct sk_buff *skb,
+				      unsigned int protoff,
+				      struct tcphdr *tcph,
+				      struct nf_conn *ct,
+				      enum ip_conntrack_info ctinfo)
+{
+	unsigned int dir, optoff, optend;
+	struct nf_conn_seqadj *seqadj = nfct_seqadj(ct);
+
+	optoff = protoff + sizeof(struct tcphdr);
+	optend = protoff + tcph->doff * 4;
+
+	if (!skb_make_writable(skb, optend))
+		return 0;
+
+	dir = CTINFO2DIR(ctinfo);
+
+	while (optoff < optend) {
+		/* Usually: option, length. */
+		unsigned char *op = skb->data + optoff;
+
+		switch (op[0]) {
+		case TCPOPT_EOL:
+			return 1;
+		case TCPOPT_NOP:
+			optoff++;
+			continue;
+		default:
+			/* no partial options */
+			if (optoff + 1 == optend ||
+			    optoff + op[1] > optend ||
+			    op[1] < 2)
+				return 0;
+			if (op[0] == TCPOPT_SACK &&
+			    op[1] >= 2+TCPOLEN_SACK_PERBLOCK &&
+			    ((op[1] - 2) % TCPOLEN_SACK_PERBLOCK) == 0)
+				nf_ct_sack_block_adjust(skb, tcph, optoff + 2,
+							optoff+op[1],
+							&seqadj->seq[!dir]);
+			optoff += op[1];
+		}
+	}
+	return 1;
+}
+
+/* TCP sequence number adjustment.  Returns 1 on success, 0 on failure */
+int nf_ct_seq_adjust(struct sk_buff *skb,
+		     struct nf_conn *ct, enum ip_conntrack_info ctinfo,
+		     unsigned int protoff)
+{
+	enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
+	struct tcphdr *tcph;
+	__be32 newseq, newack;
+	s32 seqoff, ackoff;
+	struct nf_conn_seqadj *seqadj = nfct_seqadj(ct);
+	struct nf_ct_seqadj *this_way, *other_way;
+	int res;
+
+	this_way  = &seqadj->seq[dir];
+	other_way = &seqadj->seq[!dir];
+
+	if (!skb_make_writable(skb, protoff + sizeof(*tcph)))
+		return 0;
+
+	tcph = (void *)skb->data + protoff;
+	spin_lock_bh(&ct->lock);
+	if (after(ntohl(tcph->seq), this_way->correction_pos))
+		seqoff = this_way->offset_after;
+	else
+		seqoff = this_way->offset_before;
+
+	if (after(ntohl(tcph->ack_seq) - other_way->offset_before,
+		  other_way->correction_pos))
+		ackoff = other_way->offset_after;
+	else
+		ackoff = other_way->offset_before;
+
+	newseq = htonl(ntohl(tcph->seq) + seqoff);
+	newack = htonl(ntohl(tcph->ack_seq) - ackoff);
+
+	inet_proto_csum_replace4(&tcph->check, skb, tcph->seq, newseq, 0);
+	inet_proto_csum_replace4(&tcph->check, skb, tcph->ack_seq, newack, 0);
+
+	pr_debug("Adjusting sequence number from %u->%u, ack from %u->%u\n",
+		 ntohl(tcph->seq), ntohl(newseq), ntohl(tcph->ack_seq),
+		 ntohl(newack));
+
+	tcph->seq = newseq;
+	tcph->ack_seq = newack;
+
+	res = nf_ct_sack_adjust(skb, protoff, tcph, ct, ctinfo);
+	spin_unlock_bh(&ct->lock);
+
+	return res;
+}
+EXPORT_SYMBOL_GPL(nf_ct_seq_adjust);
+
+s32 nf_ct_seq_offset(const struct nf_conn *ct,
+		     enum ip_conntrack_dir dir,
+		     u32 seq)
+{
+	struct nf_conn_seqadj *seqadj = nfct_seqadj(ct);
+	struct nf_ct_seqadj *this_way;
+
+	if (!seqadj)
+		return 0;
+
+	this_way = &seqadj->seq[dir];
+	return after(seq, this_way->correction_pos) ?
+		 this_way->offset_after : this_way->offset_before;
+}
+EXPORT_SYMBOL_GPL(nf_ct_seq_offset);
+
+static struct nf_ct_ext_type nf_ct_seqadj_extend __read_mostly = {
+	.len	= sizeof(struct nf_conn_seqadj),
+	.align	= __alignof__(struct nf_conn_seqadj),
+	.id	= NF_CT_EXT_SEQADJ,
+};
+
+int nf_conntrack_seqadj_init(void)
+{
+	return nf_ct_extend_register(&nf_ct_seqadj_extend);
+}
+
+void nf_conntrack_seqadj_fini(void)
+{
+	nf_ct_extend_unregister(&nf_ct_seqadj_extend);
+}

net/netfilter/nf_nat_core.c

@@ -25,6 +25,7 @@
 #include <net/netfilter/nf_nat_core.h>
 #include <net/netfilter/nf_nat_helper.h>
 #include <net/netfilter/nf_conntrack_helper.h>
+#include <net/netfilter/nf_conntrack_seqadj.h>
 #include <net/netfilter/nf_conntrack_l3proto.h>
 #include <net/netfilter/nf_conntrack_zones.h>
 #include <linux/netfilter/nf_nat.h>
@@ -402,6 +403,9 @@ nf_nat_setup_info(struct nf_conn *ct,
 			ct->status |= IPS_SRC_NAT;
 		else
 			ct->status |= IPS_DST_NAT;
+
+		if (nfct_help(ct))
+			nfct_seqadj_ext_add(ct);
 	}
 
 	if (maniptype == NF_NAT_MANIP_SRC) {
@@ -764,10 +768,6 @@ static struct nf_ct_helper_expectfn follow_master_nat = {
 	.expectfn	= nf_nat_follow_master,
 };
 
-static struct nfq_ct_nat_hook nfq_ct_nat = {
-	.seq_adjust	= nf_nat_tcp_seq_adjust,
-};
-
 static int __init nf_nat_init(void)
 {
 	int ret;
@@ -787,14 +787,9 @@ static int __init nf_nat_init(void)
 	/* Initialize fake conntrack so that NAT will skip it */
 	nf_ct_untracked_status_or(IPS_NAT_DONE_MASK);
 
-	BUG_ON(nf_nat_seq_adjust_hook != NULL);
-	RCU_INIT_POINTER(nf_nat_seq_adjust_hook, nf_nat_seq_adjust);
 	BUG_ON(nfnetlink_parse_nat_setup_hook != NULL);
 	RCU_INIT_POINTER(nfnetlink_parse_nat_setup_hook,
 			   nfnetlink_parse_nat_setup);
-	BUG_ON(nf_ct_nat_offset != NULL);
-	RCU_INIT_POINTER(nf_ct_nat_offset, nf_nat_get_offset);
-	RCU_INIT_POINTER(nfq_ct_nat_hook, &nfq_ct_nat);
 #ifdef CONFIG_XFRM
 	BUG_ON(nf_nat_decode_session_hook != NULL);
 	RCU_INIT_POINTER(nf_nat_decode_session_hook, __nf_nat_decode_session);
@@ -813,10 +808,7 @@ static void __exit nf_nat_cleanup(void)
 	unregister_pernet_subsys(&nf_nat_net_ops);
 	nf_ct_extend_unregister(&nat_extend);
 	nf_ct_helper_expectfn_unregister(&follow_master_nat);
-	RCU_INIT_POINTER(nf_nat_seq_adjust_hook, NULL);
 	RCU_INIT_POINTER(nfnetlink_parse_nat_setup_hook, NULL);
-	RCU_INIT_POINTER(nf_ct_nat_offset, NULL);
-	RCU_INIT_POINTER(nfq_ct_nat_hook, NULL);
 #ifdef CONFIG_XFRM
 	RCU_INIT_POINTER(nf_nat_decode_session_hook, NULL);
 #endif

net/netfilter/nf_nat_helper.c

@@ -20,67 +20,13 @@
 #include <net/netfilter/nf_conntrack_helper.h>
 #include <net/netfilter/nf_conntrack_ecache.h>
 #include <net/netfilter/nf_conntrack_expect.h>
+#include <net/netfilter/nf_conntrack_seqadj.h>
 #include <net/netfilter/nf_nat.h>
 #include <net/netfilter/nf_nat_l3proto.h>
 #include <net/netfilter/nf_nat_l4proto.h>
 #include <net/netfilter/nf_nat_core.h>
 #include <net/netfilter/nf_nat_helper.h>
 
-#define DUMP_OFFSET(x) \
-	pr_debug("offset_before=%d, offset_after=%d, correction_pos=%u\n", \
-		 x->offset_before, x->offset_after, x->correction_pos);
-
-/* Setup TCP sequence correction given this change at this sequence */
-static inline void
-adjust_tcp_sequence(u32 seq,
-		    int sizediff,
-		    struct nf_conn *ct,
-		    enum ip_conntrack_info ctinfo)
-{
-	enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
-	struct nf_conn_nat *nat = nfct_nat(ct);
-	struct nf_nat_seq *this_way = &nat->seq[dir];
-
-	pr_debug("adjust_tcp_sequence: seq = %u, sizediff = %d\n",
-		 seq, sizediff);
-
-	pr_debug("adjust_tcp_sequence: Seq_offset before: ");
-	DUMP_OFFSET(this_way);
-
-	spin_lock_bh(&ct->lock);
-
-	/* SYN adjust. If it's uninitialized, or this is after last
-	 * correction, record it: we don't handle more than one
-	 * adjustment in the window, but do deal with common case of a
-	 * retransmit */
-	if (this_way->offset_before == this_way->offset_after ||
-	    before(this_way->correction_pos, seq)) {
-		this_way->correction_pos = seq;
-		this_way->offset_before = this_way->offset_after;
-		this_way->offset_after += sizediff;
-	}
-	spin_unlock_bh(&ct->lock);
-
-	pr_debug("adjust_tcp_sequence: Seq_offset after: ");
-	DUMP_OFFSET(this_way);
-}
-
-/* Get the offset value, for conntrack. Caller must have the conntrack locked */
-s32 nf_nat_get_offset(const struct nf_conn *ct,
-		      enum ip_conntrack_dir dir,
-		      u32 seq)
-{
-	struct nf_conn_nat *nat = nfct_nat(ct);
-	struct nf_nat_seq *this_way;
-
-	if (!nat)
-		return 0;
-
-	this_way = &nat->seq[dir];
-	return after(seq, this_way->correction_pos)
-		 ? this_way->offset_after : this_way->offset_before;
-}
-
 /* Frobs data inside this packet, which is linear. */
 static void mangle_contents(struct sk_buff *skb,
 			    unsigned int dataoff,
@@ -135,30 +81,6 @@ static int enlarge_skb(struct sk_buff *skb, unsigned int extra)
 	return 1;
 }
 
-void nf_nat_set_seq_adjust(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
-			   __be32 seq, s32 off)
-{
-	if (!off)
-		return;
-	set_bit(IPS_SEQ_ADJUST_BIT, &ct->status);
-	adjust_tcp_sequence(ntohl(seq), off, ct, ctinfo);
-	nf_conntrack_event_cache(IPCT_NATSEQADJ, ct);
-}
-EXPORT_SYMBOL_GPL(nf_nat_set_seq_adjust);
-
-void nf_nat_tcp_seq_adjust(struct sk_buff *skb, struct nf_conn *ct,
-			   u32 ctinfo, int off)
-{
-	const struct tcphdr *th;
-
-	if (nf_ct_protonum(ct) != IPPROTO_TCP)
-		return;
-
-	th = (struct tcphdr *)(skb_network_header(skb)+ ip_hdrlen(skb));
-	nf_nat_set_seq_adjust(ct, ctinfo, th->seq, off);
-}
-EXPORT_SYMBOL_GPL(nf_nat_tcp_seq_adjust);
-
 /* Generic function for mangling variable-length address changes inside
  * NATed TCP connections (like the PORT XXX,XXX,XXX,XXX,XXX,XXX
  * command in FTP).
@@ -203,8 +125,8 @@ int __nf_nat_mangle_tcp_packet(struct sk_buff *skb,
 			     datalen, oldlen);
 
 	if (adjust && rep_len != match_len)
-		nf_nat_set_seq_adjust(ct, ctinfo, tcph->seq,
-				      (int)rep_len - (int)match_len);
+		nf_ct_seqadj_set(ct, ctinfo, tcph->seq,
+				 (int)rep_len - (int)match_len);
 
 	return 1;
 }
@@ -264,150 +186,6 @@ nf_nat_mangle_udp_packet(struct sk_buff *skb,
 }
 EXPORT_SYMBOL(nf_nat_mangle_udp_packet);
 
-/* Adjust one found SACK option including checksum correction */
-static void
-sack_adjust(struct sk_buff *skb,
-	    struct tcphdr *tcph,
-	    unsigned int sackoff,
-	    unsigned int sackend,
-	    struct nf_nat_seq *natseq)
-{
-	while (sackoff < sackend) {
-		struct tcp_sack_block_wire *sack;
-		__be32 new_start_seq, new_end_seq;
-
-		sack = (void *)skb->data + sackoff;
-		if (after(ntohl(sack->start_seq) - natseq->offset_before,
-			  natseq->correction_pos))
-			new_start_seq = htonl(ntohl(sack->start_seq)
-					- natseq->offset_after);
-		else
-			new_start_seq = htonl(ntohl(sack->start_seq)
-					- natseq->offset_before);
-
-		if (after(ntohl(sack->end_seq) - natseq->offset_before,
-			  natseq->correction_pos))
-			new_end_seq = htonl(ntohl(sack->end_seq)
-				      - natseq->offset_after);
-		else
-			new_end_seq = htonl(ntohl(sack->end_seq)
-				      - natseq->offset_before);
-
-		pr_debug("sack_adjust: start_seq: %d->%d, end_seq: %d->%d\n",
-			 ntohl(sack->start_seq), new_start_seq,
-			 ntohl(sack->end_seq), new_end_seq);
-
-		inet_proto_csum_replace4(&tcph->check, skb,
-					 sack->start_seq, new_start_seq, 0);
-		inet_proto_csum_replace4(&tcph->check, skb,
-					 sack->end_seq, new_end_seq, 0);
-		sack->start_seq = new_start_seq;
-		sack->end_seq = new_end_seq;
-		sackoff += sizeof(*sack);
-	}
-}
-
-/* TCP SACK sequence number adjustment */
-static inline unsigned int
-nf_nat_sack_adjust(struct sk_buff *skb,
-		   unsigned int protoff,
-		   struct tcphdr *tcph,
-		   struct nf_conn *ct,
-		   enum ip_conntrack_info ctinfo)
-{
-	unsigned int dir, optoff, optend;
-	struct nf_conn_nat *nat = nfct_nat(ct);
-
-	optoff = protoff + sizeof(struct tcphdr);
-	optend = protoff + tcph->doff * 4;
-
-	if (!skb_make_writable(skb, optend))
-		return 0;
-
-	dir = CTINFO2DIR(ctinfo);
-
-	while (optoff < optend) {
-		/* Usually: option, length. */
-		unsigned char *op = skb->data + optoff;
-
-		switch (op[0]) {
-		case TCPOPT_EOL:
-			return 1;
-		case TCPOPT_NOP:
-			optoff++;
-			continue;
-		default:
-			/* no partial options */
-			if (optoff + 1 == optend ||
-			    optoff + op[1] > optend ||
-			    op[1] < 2)
-				return 0;
-			if (op[0] == TCPOPT_SACK &&
-			    op[1] >= 2+TCPOLEN_SACK_PERBLOCK &&
-			    ((op[1] - 2) % TCPOLEN_SACK_PERBLOCK) == 0)
-				sack_adjust(skb, tcph, optoff+2,
-					    optoff+op[1], &nat->seq[!dir]);
-			optoff += op[1];
-		}
-	}
-	return 1;
-}
-
-/* TCP sequence number adjustment.  Returns 1 on success, 0 on failure */
-int
-nf_nat_seq_adjust(struct sk_buff *skb,
-		  struct nf_conn *ct,
-		  enum ip_conntrack_info ctinfo,
-		  unsigned int protoff)
-{
-	struct tcphdr *tcph;
-	int dir;
-	__be32 newseq, newack;
-	s32 seqoff, ackoff;
-	struct nf_conn_nat *nat = nfct_nat(ct);
-	struct nf_nat_seq *this_way, *other_way;
-	int res;
-
-	dir = CTINFO2DIR(ctinfo);
-
-	this_way = &nat->seq[dir];
-	other_way = &nat->seq[!dir];
-
-	if (!skb_make_writable(skb, protoff + sizeof(*tcph)))
-		return 0;
-
-	tcph = (void *)skb->data + protoff;
-	spin_lock_bh(&ct->lock);
-	if (after(ntohl(tcph->seq), this_way->correction_pos))
-		seqoff = this_way->offset_after;
-	else
-		seqoff = this_way->offset_before;
-
-	if (after(ntohl(tcph->ack_seq) - other_way->offset_before,
-		  other_way->correction_pos))
-		ackoff = other_way->offset_after;
-	else
-		ackoff = other_way->offset_before;
-
-	newseq = htonl(ntohl(tcph->seq) + seqoff);
-	newack = htonl(ntohl(tcph->ack_seq) - ackoff);
-
-	inet_proto_csum_replace4(&tcph->check, skb, tcph->seq, newseq, 0);
-	inet_proto_csum_replace4(&tcph->check, skb, tcph->ack_seq, newack, 0);
-
-	pr_debug("Adjusting sequence number from %u->%u, ack from %u->%u\n",
-		 ntohl(tcph->seq), ntohl(newseq), ntohl(tcph->ack_seq),
-		 ntohl(newack));
-
-	tcph->seq = newseq;
-	tcph->ack_seq = newack;
-
-	res = nf_nat_sack_adjust(skb, protoff, tcph, ct, ctinfo);
-	spin_unlock_bh(&ct->lock);
-
-	return res;
-}
-
 /* Setup NAT on this expected conntrack so it follows master. */
 /* If we fail to get a free NAT slot, we'll get dropped on confirm */
 void nf_nat_follow_master(struct nf_conn *ct,

net/netfilter/nf_nat_sip.c

@@ -20,6 +20,7 @@
 #include <net/netfilter/nf_nat_helper.h>
 #include <net/netfilter/nf_conntrack_helper.h>
 #include <net/netfilter/nf_conntrack_expect.h>
+#include <net/netfilter/nf_conntrack_seqadj.h>
 #include <linux/netfilter/nf_conntrack_sip.h>
 
 MODULE_LICENSE("GPL");
@@ -308,7 +309,7 @@ static void nf_nat_sip_seq_adjust(struct sk_buff *skb, unsigned int protoff,
 		return;
 
 	th = (struct tcphdr *)(skb->data + protoff);
-	nf_nat_set_seq_adjust(ct, ctinfo, th->seq, off);
+	nf_ct_seqadj_set(ct, ctinfo, th->seq, off);
 }
 
 /* Handles expected signalling connections and media streams */

net/netfilter/nfnetlink_queue_ct.c

@@ -87,14 +87,14 @@ int nfqnl_ct_put(struct sk_buff *skb, struct nf_conn *ct,
 void nfqnl_ct_seq_adjust(struct sk_buff *skb, struct nf_conn *ct,
 			 enum ip_conntrack_info ctinfo, int diff)
 {
-	struct nfq_ct_nat_hook *nfq_nat_ct;
+	struct nfq_ct_hook *nfq_ct;
 
-	nfq_nat_ct = rcu_dereference(nfq_ct_nat_hook);
-	if (nfq_nat_ct == NULL)
+	nfq_ct = rcu_dereference(nfq_ct_hook);
+	if (nfq_ct == NULL)
 		return;
 
 	if ((ct->status & IPS_NAT_MASK) && diff)
-		nfq_nat_ct->seq_adjust(skb, ct, ctinfo, diff);
+		nfq_ct->seq_adjust(skb, ct, ctinfo, diff);
 }
 
 int nfqnl_attach_expect(struct nf_conn *ct, const struct nlattr *attr,