[NETFILTER]: add IPv6-capable TCPMSS target

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/netfilter/Kbuild

@@ -33,6 +33,7 @@ header-y += xt_tcpmss.h
 header-y += xt_tcpudp.h
 header-y += xt_SECMARK.h
 header-y += xt_CONNSECMARK.h
+header-y += xt_TCPMSS.h
 
 unifdef-y += nf_conntrack_common.h
 unifdef-y += nf_conntrack_ftp.h

include/linux/netfilter/xt_TCPMSS.h

@@ -0,0 +1,10 @@
+#ifndef _XT_TCPMSS_H
+#define _XT_TCPMSS_H
+
+struct xt_tcpmss_info {
+	u_int16_t mss;
+};
+
+#define XT_TCPMSS_CLAMP_PMTU 0xffff
+
+#endif /* _XT_TCPMSS_H */

include/linux/netfilter_ipv4/ipt_TCPMSS.h

@@ -1,10 +1,9 @@
 #ifndef _IPT_TCPMSS_H
 #define _IPT_TCPMSS_H
 
-struct ipt_tcpmss_info {
-	u_int16_t mss;
-};
+#include <linux/netfilter/xt_TCPMSS.h>
 
-#define IPT_TCPMSS_CLAMP_PMTU 0xffff
+#define ipt_tcpmss_info		xt_tcpmss_info
+#define IPT_TCPMSS_CLAMP_PMTU	XT_TCPMSS_CLAMP_PMTU
 
 #endif /*_IPT_TCPMSS_H*/

net/ipv4/netfilter/Kconfig

@@ -361,32 +361,6 @@ config IP_NF_TARGET_ULOG
 
 	  To compile it as a module, choose M here.  If unsure, say N.
 
-config IP_NF_TARGET_TCPMSS
-	tristate "TCPMSS target support"
-	depends on IP_NF_IPTABLES
-	---help---
-	  This option adds a `TCPMSS' target, which allows you to alter the
-	  MSS value of TCP SYN packets, to control the maximum size for that
-	  connection (usually limiting it to your outgoing interface's MTU
-	  minus 40).
-
-	  This is used to overcome criminally braindead ISPs or servers which
-	  block ICMP Fragmentation Needed packets.  The symptoms of this
-	  problem are that everything works fine from your Linux
-	  firewall/router, but machines behind it can never exchange large
-	  packets:
-	  	1) Web browsers connect, then hang with no data received.
-	  	2) Small mail works fine, but large emails hang.
-	  	3) ssh works fine, but scp hangs after initial handshaking.
-
-	  Workaround: activate this option and add a rule to your firewall
-	  configuration like:
-
-	  iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN \
-	  		 -j TCPMSS --clamp-mss-to-pmtu
-
-	  To compile it as a module, choose M here.  If unsure, say N.
-
 # NAT + specific targets: ip_conntrack
 config IP_NF_NAT
 	tristate "Full NAT"

net/ipv4/netfilter/Makefile

@@ -103,7 +103,6 @@ obj-$(CONFIG_IP_NF_TARGET_SAME) += ipt_SAME.o
 obj-$(CONFIG_IP_NF_NAT_SNMP_BASIC) += ip_nat_snmp_basic.o
 obj-$(CONFIG_IP_NF_TARGET_LOG) += ipt_LOG.o
 obj-$(CONFIG_IP_NF_TARGET_ULOG) += ipt_ULOG.o
-obj-$(CONFIG_IP_NF_TARGET_TCPMSS) += ipt_TCPMSS.o
 obj-$(CONFIG_IP_NF_TARGET_CLUSTERIP) += ipt_CLUSTERIP.o
 obj-$(CONFIG_IP_NF_TARGET_TTL) += ipt_TTL.o
 

net/netfilter/Kconfig

@@ -395,6 +395,32 @@ config NETFILTER_XT_TARGET_CONNSECMARK
 
 	  To compile it as a module, choose M here.  If unsure, say N.
 
+config NETFILTER_XT_TARGET_TCPMSS
+	tristate '"TCPMSS" target support'
+	depends on NETFILTER_XTABLES && (IPV6 || IPV6=n)
+	---help---
+	  This option adds a `TCPMSS' target, which allows you to alter the
+	  MSS value of TCP SYN packets, to control the maximum size for that
+	  connection (usually limiting it to your outgoing interface's MTU
+	  minus 40).
+
+	  This is used to overcome criminally braindead ISPs or servers which
+	  block ICMP Fragmentation Needed packets.  The symptoms of this
+	  problem are that everything works fine from your Linux
+	  firewall/router, but machines behind it can never exchange large
+	  packets:
+	        1) Web browsers connect, then hang with no data received.
+	        2) Small mail works fine, but large emails hang.
+	        3) ssh works fine, but scp hangs after initial handshaking.
+
+	  Workaround: activate this option and add a rule to your firewall
+	  configuration like:
+
+	  iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN \
+	                 -j TCPMSS --clamp-mss-to-pmtu
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
 config NETFILTER_XT_MATCH_COMMENT
 	tristate  '"comment" match support'
 	depends on NETFILTER_XTABLES

net/netfilter/Makefile

@@ -45,6 +45,7 @@ obj-$(CONFIG_NETFILTER_XT_TARGET_NFQUEUE) += xt_NFQUEUE.o
 obj-$(CONFIG_NETFILTER_XT_TARGET_NFLOG) += xt_NFLOG.o
 obj-$(CONFIG_NETFILTER_XT_TARGET_NOTRACK) += xt_NOTRACK.o
 obj-$(CONFIG_NETFILTER_XT_TARGET_SECMARK) += xt_SECMARK.o
+obj-$(CONFIG_NETFILTER_XT_TARGET_TCPMSS) += xt_TCPMSS.o
 obj-$(CONFIG_NETFILTER_XT_TARGET_CONNSECMARK) += xt_CONNSECMARK.o
 
 # matches