1 files changed, 46 insertions, 41 deletions

diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index fe9ead9ee863..19d3141dad1f 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -141,6 +141,8 @@
 #include <linux/mroute.h>
 #include <linux/netlink.h>
 #include <net/dst_metadata.h>
+#include <net/udp.h>
+#include <net/tcp.h>
 
 /*
  *	Process Router Attention IP option (RFC 2113)
@@ -226,6 +228,12 @@ resubmit:
 
 static int ip_local_deliver_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
 {
+	if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC))) {
+		__IP_INC_STATS(net, IPSTATS_MIB_INDISCARDS);
+		kfree_skb_reason(skb, SKB_DROP_REASON_NOMEM);
+		return 0;
+	}
+
 	skb_clear_delivery_time(skb);
 	__skb_pull(skb, skb_network_header_len(skb));
 
@@ -257,10 +265,11 @@ int ip_local_deliver(struct sk_buff *skb)
 }
 EXPORT_SYMBOL(ip_local_deliver);
 
-static inline bool ip_rcv_options(struct sk_buff *skb, struct net_device *dev)
+static inline enum skb_drop_reason
+ip_rcv_options(struct sk_buff *skb, struct net_device *dev)
 {
-	struct ip_options *opt;
 	const struct iphdr *iph;
+	struct ip_options *opt;
 
 	/* It looks as overkill, because not all
 	   IP options require packet mangling.
@@ -271,7 +280,7 @@ static inline bool ip_rcv_options(struct sk_buff *skb, struct net_device *dev)
 	*/
 	if (skb_cow(skb, skb_headroom(skb))) {
 		__IP_INC_STATS(dev_net(dev), IPSTATS_MIB_INDISCARDS);
-		goto drop;
+		return SKB_DROP_REASON_NOMEM;
 	}
 
 	iph = ip_hdr(skb);
@@ -280,7 +289,7 @@ static inline bool ip_rcv_options(struct sk_buff *skb, struct net_device *dev)
 
 	if (ip_options_compile(dev_net(dev), opt, skb)) {
 		__IP_INC_STATS(dev_net(dev), IPSTATS_MIB_INHDRERRORS);
-		goto drop;
+		return SKB_DROP_REASON_IP_INHDR;
 	}
 
 	if (unlikely(opt->srr)) {
@@ -292,17 +301,15 @@ static inline bool ip_rcv_options(struct sk_buff *skb, struct net_device *dev)
 					net_info_ratelimited("source route option %pI4 -> %pI4\n",
 							     &iph->saddr,
 							     &iph->daddr);
-				goto drop;
+				return SKB_DROP_REASON_NOT_SPECIFIED;
 			}
 		}
 
 		if (ip_options_rcv_srr(skb, dev))
-			goto drop;
+			return SKB_DROP_REASON_NOT_SPECIFIED;
 	}
 
-	return false;
-drop:
-	return true;
+	return SKB_NOT_DROPPED_YET;
 }
 
 static bool ip_can_use_hint(const struct sk_buff *skb, const struct iphdr *iph,
@@ -312,22 +319,18 @@ static bool ip_can_use_hint(const struct sk_buff *skb, const struct iphdr *iph,
 	       ip_hdr(hint)->tos == iph->tos;
 }
 
-int tcp_v4_early_demux(struct sk_buff *skb);
-int udp_v4_early_demux(struct sk_buff *skb);
-static int ip_rcv_finish_core(struct net *net, struct sock *sk,
+static int ip_rcv_finish_core(struct net *net,
 			      struct sk_buff *skb, struct net_device *dev,
 			      const struct sk_buff *hint)
 {
 	const struct iphdr *iph = ip_hdr(skb);
-	int err, drop_reason;
 	struct rtable *rt;
-
-	drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
+	int drop_reason;
 
 	if (ip_can_use_hint(skb, iph, hint)) {
-		err = ip_route_use_hint(skb, iph->daddr, iph->saddr, iph->tos,
-					dev, hint);
-		if (unlikely(err))
+		drop_reason = ip_route_use_hint(skb, iph->daddr, iph->saddr,
+						ip4h_dscp(iph), dev, hint);
+		if (unlikely(drop_reason))
 			goto drop_error;
 	}
 
@@ -346,8 +349,8 @@ static int ip_rcv_finish_core(struct net *net, struct sock *sk,
 			break;
 		case IPPROTO_UDP:
 			if (READ_ONCE(net->ipv4.sysctl_udp_early_demux)) {
-				err = udp_v4_early_demux(skb);
-				if (unlikely(err))
+				drop_reason = udp_v4_early_demux(skb);
+				if (unlikely(drop_reason))
 					goto drop_error;
 
 				/* must reload iph, skb->head might have changed */
@@ -362,9 +365,9 @@ static int ip_rcv_finish_core(struct net *net, struct sock *sk,
 	 *	how the packet travels inside Linux networking.
 	 */
 	if (!skb_valid_dst(skb)) {
-		err = ip_route_input_noref(skb, iph->daddr, iph->saddr,
-					   iph->tos, dev);
-		if (unlikely(err))
+		drop_reason = ip_route_input_noref(skb, iph->daddr, iph->saddr,
+						   ip4h_dscp(iph), dev);
+		if (unlikely(drop_reason))
 			goto drop_error;
 	} else {
 		struct in_device *in_dev = __in_dev_get_rcu(dev);
@@ -384,8 +387,11 @@ static int ip_rcv_finish_core(struct net *net, struct sock *sk,
 	}
 #endif
 
-	if (iph->ihl > 5 && ip_rcv_options(skb, dev))
-		goto drop;
+	if (iph->ihl > 5) {
+		drop_reason = ip_rcv_options(skb, dev);
+		if (drop_reason)
+			goto drop;
+	}
 
 	rt = skb_rtable(skb);
 	if (rt->rt_type == RTN_MULTICAST) {
@@ -425,10 +431,8 @@ drop:
 	return NET_RX_DROP;
 
 drop_error:
-	if (err == -EXDEV) {
-		drop_reason = SKB_DROP_REASON_IP_RPFILTER;
+	if (drop_reason == SKB_DROP_REASON_IP_RPFILTER)
 		__NET_INC_STATS(net, LINUX_MIB_IPRPFILTER);
-	}
 	goto drop;
 }
 
@@ -444,7 +448,7 @@ static int ip_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
 	if (!skb)
 		return NET_RX_SUCCESS;
 
-	ret = ip_rcv_finish_core(net, sk, skb, dev, NULL);
+	ret = ip_rcv_finish_core(net, skb, dev, NULL);
 	if (ret != NET_RX_DROP)
 		ret = dst_input(skb);
 	return ret;
@@ -582,22 +586,25 @@ static void ip_sublist_rcv_finish(struct list_head *head)
 }
 
 static struct sk_buff *ip_extract_route_hint(const struct net *net,
-					     struct sk_buff *skb, int rt_type)
+					     struct sk_buff *skb)
 {
-	if (fib4_has_custom_rules(net) || rt_type == RTN_BROADCAST)
+	const struct iphdr *iph = ip_hdr(skb);
+
+	if (fib4_has_custom_rules(net) ||
+	    ipv4_is_lbcast(iph->daddr) ||
+	    ipv4_is_zeronet(iph->daddr) ||
+	    IPCB(skb)->flags & IPSKB_MULTIPATH)
 		return NULL;
 
 	return skb;
 }
 
-static void ip_list_rcv_finish(struct net *net, struct sock *sk,
-			       struct list_head *head)
+static void ip_list_rcv_finish(struct net *net, struct list_head *head)
 {
 	struct sk_buff *skb, *next, *hint = NULL;
 	struct dst_entry *curr_dst = NULL;
-	struct list_head sublist;
+	LIST_HEAD(sublist);
 
-	INIT_LIST_HEAD(&sublist);
 	list_for_each_entry_safe(skb, next, head, list) {
 		struct net_device *dev = skb->dev;
 		struct dst_entry *dst;
@@ -609,13 +616,12 @@ static void ip_list_rcv_finish(struct net *net, struct sock *sk,
 		skb = l3mdev_ip_rcv(skb);
 		if (!skb)
 			continue;
-		if (ip_rcv_finish_core(net, sk, skb, dev, hint) == NET_RX_DROP)
+		if (ip_rcv_finish_core(net, skb, dev, hint) == NET_RX_DROP)
 			continue;
 
 		dst = skb_dst(skb);
 		if (curr_dst != dst) {
-			hint = ip_extract_route_hint(net, skb,
-					       ((struct rtable *)dst)->rt_type);
+			hint = ip_extract_route_hint(net, skb);
 
 			/* dispatch old sublist */
 			if (!list_empty(&sublist))
@@ -635,7 +641,7 @@ static void ip_sublist_rcv(struct list_head *head, struct net_device *dev,
 {
 	NF_HOOK_LIST(NFPROTO_IPV4, NF_INET_PRE_ROUTING, net, NULL,
 		     head, dev, NULL, ip_rcv_finish);
-	ip_list_rcv_finish(net, NULL, head);
+	ip_list_rcv_finish(net, head);
 }
 
 /* Receive a list of IP packets */
@@ -645,9 +651,8 @@ void ip_list_rcv(struct list_head *head, struct packet_type *pt,
 	struct net_device *curr_dev = NULL;
 	struct net *curr_net = NULL;
 	struct sk_buff *skb, *next;
-	struct list_head sublist;
+	LIST_HEAD(sublist);
 
-	INIT_LIST_HEAD(&sublist);
 	list_for_each_entry_safe(skb, next, head, list) {
 		struct net_device *dev = skb->dev;
 		struct net *net = dev_net(dev);