[IPV6]: Per-interface statistics support.

For IP MIB (RFC4293).

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index 88c96b1..27829cc 100644
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -284,10 +284,12 @@
 #ifdef CONFIG_IPV6_MIP6
 	__u16 dstbuf;
 #endif
+	struct dst_entry *dst;
 
 	if (!pskb_may_pull(skb, (skb->h.raw-skb->data)+8) ||
 	    !pskb_may_pull(skb, (skb->h.raw-skb->data)+((skb->h.raw[1]+1)<<3))) {
-		IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
+		IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
+				 IPSTATS_MIB_INHDRERRORS);
 		kfree_skb(skb);
 		return -1;
 	}
@@ -298,7 +300,9 @@
 	dstbuf = opt->dst1;
 #endif
 
+	dst = dst_clone(skb->dst);
 	if (ip6_parse_tlv(tlvprocdestopt_lst, skbp)) {
+		dst_release(dst);
 		skb = *skbp;
 		skb->h.raw += ((skb->h.raw[1]+1)<<3);
 		opt = IP6CB(skb);
@@ -310,7 +314,8 @@
 		return 1;
 	}
 
-	IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
+	IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS);
+	dst_release(dst);
 	return -1;
 }
 
@@ -365,7 +370,8 @@
 
 	if (!pskb_may_pull(skb, (skb->h.raw-skb->data)+8) ||
 	    !pskb_may_pull(skb, (skb->h.raw-skb->data)+((skb->h.raw[1]+1)<<3))) {
-		IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
+		IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
+				 IPSTATS_MIB_INHDRERRORS);
 		kfree_skb(skb);
 		return -1;
 	}
@@ -374,7 +380,8 @@
 
 	if (ipv6_addr_is_multicast(&skb->nh.ipv6h->daddr) ||
 	    skb->pkt_type != PACKET_HOST) {
-		IP6_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS);
+		IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
+				 IPSTATS_MIB_INADDRERRORS);
 		kfree_skb(skb);
 		return -1;
 	}
@@ -388,7 +395,8 @@
 			 * processed by own
 			 */
 			if (!addr) {
-				IP6_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS);
+				IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
+						 IPSTATS_MIB_INADDRERRORS);
 				kfree_skb(skb);
 				return -1;
 			}
@@ -410,7 +418,8 @@
 	switch (hdr->type) {
 	case IPV6_SRCRT_TYPE_0:
 		if (hdr->hdrlen & 0x01) {
-			IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
+			IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
+					 IPSTATS_MIB_INHDRERRORS);
 			icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, (&hdr->hdrlen) - skb->nh.raw);
 			return -1;
 		}
@@ -419,14 +428,16 @@
 	case IPV6_SRCRT_TYPE_2:
 		/* Silently discard invalid RTH type 2 */
 		if (hdr->hdrlen != 2 || hdr->segments_left != 1) {
-			IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
+			IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
+					 IPSTATS_MIB_INHDRERRORS);
 			kfree_skb(skb);
 			return -1;
 		}
 		break;
 #endif
 	default:
-		IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
+		IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
+				 IPSTATS_MIB_INHDRERRORS);
 		icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, (&hdr->type) - skb->nh.raw);
 		return -1;
 	}
@@ -439,7 +450,8 @@
 	n = hdr->hdrlen >> 1;
 
 	if (hdr->segments_left > n) {
-		IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
+		IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
+				 IPSTATS_MIB_INHDRERRORS);
 		icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, (&hdr->segments_left) - skb->nh.raw);
 		return -1;
 	}
@@ -449,12 +461,14 @@
 	 */
 	if (skb_cloned(skb)) {
 		struct sk_buff *skb2 = skb_copy(skb, GFP_ATOMIC);
-		kfree_skb(skb);
 		/* the copy is a forwarded packet */
 		if (skb2 == NULL) {
-			IP6_INC_STATS_BH(IPSTATS_MIB_OUTDISCARDS);	
+			IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
+					 IPSTATS_MIB_OUTDISCARDS);
+			kfree_skb(skb);
 			return -1;
 		}
+		kfree_skb(skb);
 		*skbp = skb = skb2;
 		opt = IP6CB(skb2);
 		hdr = (struct ipv6_rt_hdr *) skb2->h.raw;
@@ -475,12 +489,14 @@
 		if (xfrm6_input_addr(skb, (xfrm_address_t *)addr,
 				     (xfrm_address_t *)&skb->nh.ipv6h->saddr,
 				     IPPROTO_ROUTING) < 0) {
-			IP6_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS);
+			IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
+					 IPSTATS_MIB_INADDRERRORS);
 			kfree_skb(skb);
 			return -1;
 		}
 		if (!ipv6_chk_home_addr(addr)) {
-			IP6_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS);
+			IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
+					 IPSTATS_MIB_INADDRERRORS);
 			kfree_skb(skb);
 			return -1;
 		}
@@ -491,7 +507,8 @@
 	}
 
 	if (ipv6_addr_is_multicast(addr)) {
-		IP6_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS);
+		IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
+				 IPSTATS_MIB_INADDRERRORS);
 		kfree_skb(skb);
 		return -1;
 	}
@@ -510,7 +527,8 @@
 
 	if (skb->dst->dev->flags&IFF_LOOPBACK) {
 		if (skb->nh.ipv6h->hop_limit <= 1) {
-			IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
+			IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
+					 IPSTATS_MIB_INHDRERRORS);
 			icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
 				    0, skb->dev);
 			kfree_skb(skb);
@@ -632,24 +650,25 @@
 	if (skb->nh.raw[optoff+1] != 4 || (optoff&3) != 2) {
 		LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n",
 		               skb->nh.raw[optoff+1]);
-		IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
+		IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
+				 IPSTATS_MIB_INHDRERRORS);
 		goto drop;
 	}
 
 	pkt_len = ntohl(*(u32*)(skb->nh.raw+optoff+2));
 	if (pkt_len <= IPV6_MAXPLEN) {
-		IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
+		IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_INHDRERRORS);
 		icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff+2);
 		return 0;
 	}
 	if (skb->nh.ipv6h->payload_len) {
-		IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
+		IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_INHDRERRORS);
 		icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff);
 		return 0;
 	}
 
 	if (pkt_len > skb->len - sizeof(struct ipv6hdr)) {
-		IP6_INC_STATS_BH(IPSTATS_MIB_INTRUNCATEDPKTS);
+		IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_INTRUNCATEDPKTS);
 		goto drop;
 	}