[IPV6]: Per-interface statistics support.

For IP MIB (RFC4293).

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 1bde3ac..85f8892 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -88,7 +88,7 @@
 	} else if (dst->neighbour)
 		return dst->neighbour->output(skb);
 
-	IP6_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
+	IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
 	kfree_skb(skb);
 	return -EINVAL;
 
@@ -118,6 +118,7 @@
 
 	if (ipv6_addr_is_multicast(&skb->nh.ipv6h->daddr)) {
 		struct ipv6_pinfo* np = skb->sk ? inet6_sk(skb->sk) : NULL;
+		struct inet6_dev *idev = ip6_dst_idev(skb->dst);
 
 		if (!(dev->flags & IFF_LOOPBACK) && (!np || np->mc_loop) &&
 		    ipv6_chk_mcast_addr(dev, &skb->nh.ipv6h->daddr,
@@ -133,13 +134,13 @@
 					ip6_dev_loopback_xmit);
 
 			if (skb->nh.ipv6h->hop_limit == 0) {
-				IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
+				IP6_INC_STATS(idev, IPSTATS_MIB_OUTDISCARDS);
 				kfree_skb(skb);
 				return 0;
 			}
 		}
 
-		IP6_INC_STATS(IPSTATS_MIB_OUTMCASTPKTS);
+		IP6_INC_STATS(idev, IPSTATS_MIB_OUTMCASTPKTS);
 	}
 
 	return NF_HOOK(PF_INET6, NF_IP6_POST_ROUTING, skb,NULL, skb->dev,ip6_output_finish);
@@ -182,12 +183,14 @@
 
 		if (skb_headroom(skb) < head_room) {
 			struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room);
-			kfree_skb(skb);
-			skb = skb2;
-			if (skb == NULL) {	
-				IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
+			if (skb2 == NULL) {
+				IP6_INC_STATS(ip6_dst_idev(skb->dst),
+					      IPSTATS_MIB_OUTDISCARDS);
+				kfree_skb(skb);
 				return -ENOBUFS;
 			}
+			kfree_skb(skb);
+			skb = skb2;
 			if (sk)
 				skb_set_owner_w(skb, sk);
 		}
@@ -230,7 +233,8 @@
 
 	mtu = dst_mtu(dst);
 	if ((skb->len <= mtu) || ipfragok || skb_is_gso(skb)) {
-		IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
+		IP6_INC_STATS(ip6_dst_idev(skb->dst),
+			      IPSTATS_MIB_OUTREQUESTS);
 		return NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev,
 				dst_output);
 	}
@@ -239,7 +243,7 @@
 		printk(KERN_DEBUG "IPv6: sending pkt_too_big to self\n");
 	skb->dev = dst->dev;
 	icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
-	IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
+	IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_FRAGFAILS);
 	kfree_skb(skb);
 	return -EMSGSIZE;
 }
@@ -373,7 +377,7 @@
 		goto error;
 
 	if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
-		IP6_INC_STATS(IPSTATS_MIB_INDISCARDS);
+		IP6_INC_STATS(ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS);
 		goto drop;
 	}
 
@@ -406,7 +410,7 @@
 		skb->dev = dst->dev;
 		icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
 			    0, skb->dev);
-		IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
+		IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS);
 
 		kfree_skb(skb);
 		return -ETIMEDOUT;
@@ -419,13 +423,13 @@
 		if (proxied > 0)
 			return ip6_input(skb);
 		else if (proxied < 0) {
-			IP6_INC_STATS(IPSTATS_MIB_INDISCARDS);
+			IP6_INC_STATS(ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS);
 			goto drop;
 		}
 	}
 
 	if (!xfrm6_route_forward(skb)) {
-		IP6_INC_STATS(IPSTATS_MIB_INDISCARDS);
+		IP6_INC_STATS(ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS);
 		goto drop;
 	}
 	dst = skb->dst;
@@ -464,14 +468,14 @@
 		/* Again, force OUTPUT device used as source address */
 		skb->dev = dst->dev;
 		icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, dst_mtu(dst), skb->dev);
-		IP6_INC_STATS_BH(IPSTATS_MIB_INTOOBIGERRORS);
-		IP6_INC_STATS_BH(IPSTATS_MIB_FRAGFAILS);
+		IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_INTOOBIGERRORS);
+		IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_FRAGFAILS);
 		kfree_skb(skb);
 		return -EMSGSIZE;
 	}
 
 	if (skb_cow(skb, dst->dev->hard_header_len)) {
-		IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
+		IP6_INC_STATS(ip6_dst_idev(dst), IPSTATS_MIB_OUTDISCARDS);
 		goto drop;
 	}
 
@@ -481,11 +485,11 @@
  
 	hdr->hop_limit--;
 
-	IP6_INC_STATS_BH(IPSTATS_MIB_OUTFORWDATAGRAMS);
+	IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS);
 	return NF_HOOK(PF_INET6,NF_IP6_FORWARD, skb, skb->dev, dst->dev, ip6_forward_finish);
 
 error:
-	IP6_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS);
+	IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_INADDRERRORS);
 drop:
 	kfree_skb(skb);
 	return -EINVAL;
@@ -622,7 +626,7 @@
 
 		tmp_hdr = kmalloc(hlen, GFP_ATOMIC);
 		if (!tmp_hdr) {
-			IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
+			IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_FRAGFAILS);
 			return -ENOMEM;
 		}
 
@@ -643,7 +647,8 @@
 		skb->data_len = first_len - skb_headlen(skb);
 		skb->len = first_len;
 		skb->nh.ipv6h->payload_len = htons(first_len - sizeof(struct ipv6hdr));
- 
+
+		dst_hold(&rt->u.dst);
 
 		for (;;) {
 			/* Prepare header of the next frame,
@@ -667,7 +672,7 @@
 			
 			err = output(skb);
 			if(!err)
-				IP6_INC_STATS(IPSTATS_MIB_FRAGCREATES);
+				IP6_INC_STATS(ip6_dst_idev(&rt->u.dst), IPSTATS_MIB_FRAGCREATES);
 
 			if (err || !frag)
 				break;
@@ -680,7 +685,8 @@
 		kfree(tmp_hdr);
 
 		if (err == 0) {
-			IP6_INC_STATS(IPSTATS_MIB_FRAGOKS);
+			IP6_INC_STATS(ip6_dst_idev(&rt->u.dst), IPSTATS_MIB_FRAGOKS);
+			dst_release(&rt->u.dst);
 			return 0;
 		}
 
@@ -690,7 +696,8 @@
 			frag = skb;
 		}
 
-		IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
+		IP6_INC_STATS(ip6_dst_idev(&rt->u.dst), IPSTATS_MIB_FRAGFAILS);
+		dst_release(&rt->u.dst);
 		return err;
 	}
 
@@ -723,7 +730,8 @@
 
 		if ((frag = alloc_skb(len+hlen+sizeof(struct frag_hdr)+LL_RESERVED_SPACE(rt->u.dst.dev), GFP_ATOMIC)) == NULL) {
 			NETDEBUG(KERN_INFO "IPv6: frag: no memory for new fragment!\n");
-			IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
+			IP6_INC_STATS(ip6_dst_idev(skb->dst),
+				      IPSTATS_MIB_FRAGFAILS);
 			err = -ENOMEM;
 			goto fail;
 		}
@@ -784,15 +792,17 @@
 		if (err)
 			goto fail;
 
-		IP6_INC_STATS(IPSTATS_MIB_FRAGCREATES);
+		IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_FRAGCREATES);
 	}
+	IP6_INC_STATS(ip6_dst_idev(skb->dst),
+		      IPSTATS_MIB_FRAGOKS);
 	kfree_skb(skb);
-	IP6_INC_STATS(IPSTATS_MIB_FRAGOKS);
 	return err;
 
 fail:
+	IP6_INC_STATS(ip6_dst_idev(skb->dst),
+		      IPSTATS_MIB_FRAGFAILS);
 	kfree_skb(skb); 
-	IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
 	return err;
 }
 
@@ -1265,7 +1275,7 @@
 	return 0;
 error:
 	inet->cork.length -= length;
-	IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
+	IP6_INC_STATS(rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
 	return err;
 }
 
@@ -1326,7 +1336,7 @@
 	skb->priority = sk->sk_priority;
 
 	skb->dst = dst_clone(&rt->u.dst);
-	IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS);	
+	IP6_INC_STATS(rt->rt6i_idev, IPSTATS_MIB_OUTREQUESTS);
 	err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, skb->dst->dev, dst_output);
 	if (err) {
 		if (err > 0)
@@ -1357,7 +1367,8 @@
 	struct sk_buff *skb;
 
 	while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) {
-		IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
+		IP6_INC_STATS(ip6_dst_idev(skb->dst),
+			      IPSTATS_MIB_OUTDISCARDS);
 		kfree_skb(skb);
 	}