ipv6: Count interface receive statistics on the ingress netdev

The statistics such as InHdrErrors should be counted on the ingress
netdev rather than on the dev from the dst, which is the egress.

Signed-off-by: Stephen Suryaputra <ssuryaextr@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/addrconf.h b/include/net/addrconf.h
index 378d601..8312cc2 100644
--- a/include/net/addrconf.h
+++ b/include/net/addrconf.h
@@ -308,6 +308,20 @@ static inline struct inet6_dev *__in6_dev_get(const struct net_device *dev)
 }
 
 /**
+ * __in6_dev_get_safely - get inet6_dev pointer from netdevice
+ * @dev: network device
+ *
+ * This is a safer version of __in6_dev_get
+ */
+static inline struct inet6_dev *__in6_dev_get_safely(const struct net_device *dev)
+{
+	if (likely(dev))
+		return rcu_dereference_rtnl(dev->ip6_ptr);
+	else
+		return NULL;
+}
+
+/**
  * in6_dev_get - get inet6_dev pointer from netdevice
  * @dev: network device
  *
diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index bc68eb6..5bc2bf3 100644
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -280,6 +280,7 @@ static const struct tlvtype_proc tlvprocdestopt_lst[] = {
 
 static int ipv6_destopt_rcv(struct sk_buff *skb)
 {
+	struct inet6_dev *idev = __in6_dev_get(skb->dev);
 	struct inet6_skb_parm *opt = IP6CB(skb);
 #if IS_ENABLED(CONFIG_IPV6_MIP6)
 	__u16 dstbuf;
@@ -291,7 +292,7 @@ static int ipv6_destopt_rcv(struct sk_buff *skb)
 	if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
 	    !pskb_may_pull(skb, (skb_transport_offset(skb) +
 				 ((skb_transport_header(skb)[1] + 1) << 3)))) {
-		__IP6_INC_STATS(dev_net(dst->dev), ip6_dst_idev(dst),
+		__IP6_INC_STATS(dev_net(dst->dev), idev,
 				IPSTATS_MIB_INHDRERRORS);
 fail_and_free:
 		kfree_skb(skb);
@@ -319,8 +320,7 @@ static int ipv6_destopt_rcv(struct sk_buff *skb)
 		return 1;
 	}
 
-	__IP6_INC_STATS(dev_net(dst->dev),
-			ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS);
+	__IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
 	return -1;
 }
 
@@ -416,8 +416,7 @@ static int ipv6_srh_rcv(struct sk_buff *skb)
 	}
 
 	if (hdr->segments_left >= (hdr->hdrlen >> 1)) {
-		__IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
-				IPSTATS_MIB_INHDRERRORS);
+		__IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
 		icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
 				  ((&hdr->segments_left) -
 				   skb_network_header(skb)));
@@ -456,8 +455,7 @@ static int ipv6_srh_rcv(struct sk_buff *skb)
 
 	if (skb_dst(skb)->dev->flags & IFF_LOOPBACK) {
 		if (ipv6_hdr(skb)->hop_limit <= 1) {
-			__IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
-					IPSTATS_MIB_INHDRERRORS);
+			__IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
 			icmpv6_send(skb, ICMPV6_TIME_EXCEED,
 				    ICMPV6_EXC_HOPLIMIT, 0);
 			kfree_skb(skb);
@@ -481,10 +479,10 @@ static int ipv6_srh_rcv(struct sk_buff *skb)
 /* called with rcu_read_lock() */
 static int ipv6_rthdr_rcv(struct sk_buff *skb)
 {
+	struct inet6_dev *idev = __in6_dev_get(skb->dev);
 	struct inet6_skb_parm *opt = IP6CB(skb);
 	struct in6_addr *addr = NULL;
 	struct in6_addr daddr;
-	struct inet6_dev *idev;
 	int n, i;
 	struct ipv6_rt_hdr *hdr;
 	struct rt0_hdr *rthdr;
@@ -498,8 +496,7 @@ static int ipv6_rthdr_rcv(struct sk_buff *skb)
 	if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
 	    !pskb_may_pull(skb, (skb_transport_offset(skb) +
 				 ((skb_transport_header(skb)[1] + 1) << 3)))) {
-		__IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
-				IPSTATS_MIB_INHDRERRORS);
+		__IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
 		kfree_skb(skb);
 		return -1;
 	}
@@ -508,8 +505,7 @@ static int ipv6_rthdr_rcv(struct sk_buff *skb)
 
 	if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) ||
 	    skb->pkt_type != PACKET_HOST) {
-		__IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
-				IPSTATS_MIB_INADDRERRORS);
+		__IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
 		kfree_skb(skb);
 		return -1;
 	}
@@ -527,7 +523,7 @@ static int ipv6_rthdr_rcv(struct sk_buff *skb)
 			 * processed by own
 			 */
 			if (!addr) {
-				__IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
+				__IP6_INC_STATS(net, idev,
 						IPSTATS_MIB_INADDRERRORS);
 				kfree_skb(skb);
 				return -1;
@@ -553,8 +549,7 @@ static int ipv6_rthdr_rcv(struct sk_buff *skb)
 			goto unknown_rh;
 		/* Silently discard invalid RTH type 2 */
 		if (hdr->hdrlen != 2 || hdr->segments_left != 1) {
-			__IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
-					IPSTATS_MIB_INHDRERRORS);
+			__IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
 			kfree_skb(skb);
 			return -1;
 		}
@@ -572,8 +567,7 @@ static int ipv6_rthdr_rcv(struct sk_buff *skb)
 	n = hdr->hdrlen >> 1;
 
 	if (hdr->segments_left > n) {
-		__IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
-				IPSTATS_MIB_INHDRERRORS);
+		__IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
 		icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
 				  ((&hdr->segments_left) -
 				   skb_network_header(skb)));
@@ -609,14 +603,12 @@ static int ipv6_rthdr_rcv(struct sk_buff *skb)
 		if (xfrm6_input_addr(skb, (xfrm_address_t *)addr,
 				     (xfrm_address_t *)&ipv6_hdr(skb)->saddr,
 				     IPPROTO_ROUTING) < 0) {
-			__IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
-					IPSTATS_MIB_INADDRERRORS);
+			__IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
 			kfree_skb(skb);
 			return -1;
 		}
 		if (!ipv6_chk_home_addr(dev_net(skb_dst(skb)->dev), addr)) {
-			__IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
-					IPSTATS_MIB_INADDRERRORS);
+			__IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
 			kfree_skb(skb);
 			return -1;
 		}
@@ -627,8 +619,7 @@ static int ipv6_rthdr_rcv(struct sk_buff *skb)
 	}
 
 	if (ipv6_addr_is_multicast(addr)) {
-		__IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
-				IPSTATS_MIB_INADDRERRORS);
+		__IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
 		kfree_skb(skb);
 		return -1;
 	}
@@ -647,8 +638,7 @@ static int ipv6_rthdr_rcv(struct sk_buff *skb)
 
 	if (skb_dst(skb)->dev->flags&IFF_LOOPBACK) {
 		if (ipv6_hdr(skb)->hop_limit <= 1) {
-			__IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
-					IPSTATS_MIB_INHDRERRORS);
+			__IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
 			icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
 				    0);
 			kfree_skb(skb);
@@ -663,7 +653,7 @@ static int ipv6_rthdr_rcv(struct sk_buff *skb)
 	return -1;
 
 unknown_rh:
-	__IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INHDRERRORS);
+	__IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
 	icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
 			  (&hdr->type) - skb_network_header(skb));
 	return -1;
@@ -755,34 +745,31 @@ static bool ipv6_hop_ra(struct sk_buff *skb, int optoff)
 static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff)
 {
 	const unsigned char *nh = skb_network_header(skb);
+	struct inet6_dev *idev = __in6_dev_get_safely(skb->dev);
 	struct net *net = ipv6_skb_net(skb);
 	u32 pkt_len;
 
 	if (nh[optoff + 1] != 4 || (optoff & 3) != 2) {
 		net_dbg_ratelimited("ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n",
 				    nh[optoff+1]);
-		__IP6_INC_STATS(net, ipv6_skb_idev(skb),
-				IPSTATS_MIB_INHDRERRORS);
+		__IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
 		goto drop;
 	}
 
 	pkt_len = ntohl(*(__be32 *)(nh + optoff + 2));
 	if (pkt_len <= IPV6_MAXPLEN) {
-		__IP6_INC_STATS(net, ipv6_skb_idev(skb),
-				IPSTATS_MIB_INHDRERRORS);
+		__IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
 		icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff+2);
 		return false;
 	}
 	if (ipv6_hdr(skb)->payload_len) {
-		__IP6_INC_STATS(net, ipv6_skb_idev(skb),
-				IPSTATS_MIB_INHDRERRORS);
+		__IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
 		icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff);
 		return false;
 	}
 
 	if (pkt_len > skb->len - sizeof(struct ipv6hdr)) {
-		__IP6_INC_STATS(net, ipv6_skb_idev(skb),
-				IPSTATS_MIB_INTRUNCATEDPKTS);
+		__IP6_INC_STATS(net, idev, IPSTATS_MIB_INTRUNCATEDPKTS);
 		goto drop;
 	}
 
diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
index 9ee208a..f08d344 100644
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c
@@ -336,7 +336,7 @@ int ip6_mc_input(struct sk_buff *skb)
 	bool deliver;
 
 	__IP6_UPD_PO_STATS(dev_net(skb_dst(skb)->dev),
-			 ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INMCAST,
+			 __in6_dev_get_safely(skb->dev), IPSTATS_MIB_INMCAST,
 			 skb->len);
 
 	hdr = ipv6_hdr(skb);
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 2e891d2..a39b04f9 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -425,6 +425,7 @@ static bool ip6_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
 
 int ip6_forward(struct sk_buff *skb)
 {
+	struct inet6_dev *idev = __in6_dev_get_safely(skb->dev);
 	struct dst_entry *dst = skb_dst(skb);
 	struct ipv6hdr *hdr = ipv6_hdr(skb);
 	struct inet6_skb_parm *opt = IP6CB(skb);
@@ -444,8 +445,7 @@ int ip6_forward(struct sk_buff *skb)
 		goto drop;
 
 	if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
-		__IP6_INC_STATS(net, ip6_dst_idev(dst),
-				IPSTATS_MIB_INDISCARDS);
+		__IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS);
 		goto drop;
 	}
 
@@ -476,8 +476,7 @@ int ip6_forward(struct sk_buff *skb)
 		/* Force OUTPUT device used as source address */
 		skb->dev = dst->dev;
 		icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 0);
-		__IP6_INC_STATS(net, ip6_dst_idev(dst),
-				IPSTATS_MIB_INHDRERRORS);
+		__IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
 
 		kfree_skb(skb);
 		return -ETIMEDOUT;
@@ -490,15 +489,13 @@ int ip6_forward(struct sk_buff *skb)
 		if (proxied > 0)
 			return ip6_input(skb);
 		else if (proxied < 0) {
-			__IP6_INC_STATS(net, ip6_dst_idev(dst),
-					IPSTATS_MIB_INDISCARDS);
+			__IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS);
 			goto drop;
 		}
 	}
 
 	if (!xfrm6_route_forward(skb)) {
-		__IP6_INC_STATS(net, ip6_dst_idev(dst),
-				IPSTATS_MIB_INDISCARDS);
+		__IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS);
 		goto drop;
 	}
 	dst = skb_dst(skb);
@@ -554,8 +551,7 @@ int ip6_forward(struct sk_buff *skb)
 		/* Again, force OUTPUT device used as source address */
 		skb->dev = dst->dev;
 		icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
-		__IP6_INC_STATS(net, ip6_dst_idev(dst),
-				IPSTATS_MIB_INTOOBIGERRORS);
+		__IP6_INC_STATS(net, idev, IPSTATS_MIB_INTOOBIGERRORS);
 		__IP6_INC_STATS(net, ip6_dst_idev(dst),
 				IPSTATS_MIB_FRAGFAILS);
 		kfree_skb(skb);
@@ -579,7 +575,7 @@ int ip6_forward(struct sk_buff *skb)
 		       ip6_forward_finish);
 
 error:
-	__IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_INADDRERRORS);
+	__IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
 drop:
 	kfree_skb(skb);
 	return -EINVAL;
diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index 4979610..2cdf3dc 100644
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -179,7 +179,7 @@ static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
 			((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1)));
 
 	if ((unsigned int)end > IPV6_MAXPLEN) {
-		__IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
+		__IP6_INC_STATS(net, __in6_dev_get_safely(skb->dev),
 				IPSTATS_MIB_INHDRERRORS);
 		icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
 				  ((u8 *)&fhdr->frag_off -
@@ -214,7 +214,7 @@ static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
 			/* RFC2460 says always send parameter problem in
 			 * this case. -DaveM
 			 */
-			__IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
+			__IP6_INC_STATS(net, __in6_dev_get_safely(skb->dev),
 					IPSTATS_MIB_INHDRERRORS);
 			icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
 					  offsetof(struct ipv6hdr, payload_len));
@@ -536,7 +536,7 @@ static int ipv6_frag_rcv(struct sk_buff *skb)
 	return -1;
 
 fail_hdr:
-	__IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
+	__IP6_INC_STATS(net, __in6_dev_get_safely(skb->dev),
 			IPSTATS_MIB_INHDRERRORS);
 	icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb_network_header_len(skb));
 	return -1;
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 49b954d..1d738bf 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -3541,7 +3541,8 @@ static int ip6_pkt_drop(struct sk_buff *skb, u8 code, int ipstats_mib_noroutes)
 	case IPSTATS_MIB_INNOROUTES:
 		type = ipv6_addr_type(&ipv6_hdr(skb)->daddr);
 		if (type == IPV6_ADDR_ANY) {
-			IP6_INC_STATS(dev_net(dst->dev), ip6_dst_idev(dst),
+			IP6_INC_STATS(dev_net(dst->dev),
+				      __in6_dev_get_safely(skb->dev),
 				      IPSTATS_MIB_INADDRERRORS);
 			break;
 		}
diff --git a/net/netfilter/ipvs/ip_vs_xmit.c b/net/netfilter/ipvs/ip_vs_xmit.c
index 4527921..ba0a0fd 100644
--- a/net/netfilter/ipvs/ip_vs_xmit.c
+++ b/net/netfilter/ipvs/ip_vs_xmit.c
@@ -266,12 +266,13 @@ static inline bool decrement_ttl(struct netns_ipvs *ipvs,
 
 		/* check and decrement ttl */
 		if (ipv6_hdr(skb)->hop_limit <= 1) {
+			struct inet6_dev *idev = __in6_dev_get_safely(skb->dev);
+
 			/* Force OUTPUT device used as source address */
 			skb->dev = dst->dev;
 			icmpv6_send(skb, ICMPV6_TIME_EXCEED,
 				    ICMPV6_EXC_HOPLIMIT, 0);
-			__IP6_INC_STATS(net, ip6_dst_idev(dst),
-					IPSTATS_MIB_INHDRERRORS);
+			__IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
 
 			return false;
 		}