[NETFILTER]: nf_conntrack: attach conntrack to locally generated ICMPv6 error

Locally generated ICMPv6 errors should be associated with the conntrack
of the original packet. Since the conntrack entry may not be in the hash
tables (for the first packet), it must be manually attached.

Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/icmp.c

@@ -42,6 +42,7 @@
 #include <linux/net.h>
 #include <linux/skbuff.h>
 #include <linux/init.h>
+#include <linux/netfilter.h>
 
 #ifdef CONFIG_SYSCTL
 #include <linux/sysctl.h>
@@ -255,6 +256,7 @@ out:
 struct icmpv6_msg {
 	struct sk_buff	*skb;
 	int		offset;
+	uint8_t		type;
 };
 
 static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb)
@@ -266,6 +268,8 @@ static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, st
 	csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset,
 				      to, len, csum);
 	skb->csum = csum_block_add(skb->csum, csum, odd);
+	if (!(msg->type & ICMPV6_INFOMSG_MASK))
+		nf_ct_attach(skb, org_skb);
 	return 0;
 }
 
@@ -403,6 +407,7 @@ void icmpv6_send(struct sk_buff *skb, int type, int code, __u32 info,
 
 	msg.skb = skb;
 	msg.offset = skb->nh.raw - skb->data;
+	msg.type = type;
 
 	len = skb->len - msg.offset;
 	len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) -sizeof(struct icmp6hdr));
@@ -500,6 +505,7 @@ static void icmpv6_echo_reply(struct sk_buff *skb)
 
 	msg.skb = skb;
 	msg.offset = 0;
+	msg.type = ICMPV6_ECHO_REPLY;
 
 	err = ip6_append_data(sk, icmpv6_getfrag, &msg, skb->len + sizeof(struct icmp6hdr),
 				sizeof(struct icmp6hdr), hlimit, tclass, NULL, &fl,