Merge branch 'inet-ping-remove-extra-skb_clone-consume_skb'

Eric Dumazet says:

====================
inet: ping: remove extra skb_clone()/consume_skb()

First patch in the series moves ICMP_EXT_ECHOREPLY handling in icmp_rcv()
to prepare the second patch.

The second patch removes one skb_clone()/consume_skb() pair
when processing ICMP_EXT_REPLY packets. Some people
use hundreds of "ping -fq ..." to stress hosts :)
====================

Link: https://patch.msgid.link/20250226183437.1457318-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

3 files changed, 24 insertions, 36 deletions

diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 799775ba97d4..717cb7d3607a 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -1248,22 +1248,6 @@ int icmp_rcv(struct sk_buff *skb)
 		goto reason_check;
 	}
 
-	if (icmph->type == ICMP_EXT_ECHOREPLY) {
-		reason = ping_rcv(skb);
-		goto reason_check;
-	}
-
-	/*
-	 *	18 is the highest 'known' ICMP type. Anything else is a mystery
-	 *
-	 *	RFC 1122: 3.2.2  Unknown ICMP messages types MUST be silently
-	 *		  discarded.
-	 */
-	if (icmph->type > NR_ICMP_TYPES) {
-		reason = SKB_DROP_REASON_UNHANDLED_PROTO;
-		goto error;
-	}
-
 	/*
 	 *	Parse the ICMP message
 	 */
@@ -1290,6 +1274,23 @@ int icmp_rcv(struct sk_buff *skb)
 		}
 	}
 
+	if (icmph->type == ICMP_EXT_ECHOREPLY ||
+	    icmph->type == ICMP_ECHOREPLY) {
+		reason = ping_rcv(skb);
+		return reason ? NET_RX_DROP : NET_RX_SUCCESS;
+	}
+
+	/*
+	 *	18 is the highest 'known' ICMP type. Anything else is a mystery
+	 *
+	 *	RFC 1122: 3.2.2  Unknown ICMP messages types MUST be silently
+	 *		  discarded.
+	 */
+	if (icmph->type > NR_ICMP_TYPES) {
+		reason = SKB_DROP_REASON_UNHANDLED_PROTO;
+		goto error;
+	}
+
 	reason = icmp_pointers[icmph->type].handler(skb);
 reason_check:
 	if (!reason)  {
diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
index 85d09f2ecadc..c14baa6589c7 100644
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -966,10 +966,9 @@ EXPORT_SYMBOL_GPL(ping_queue_rcv_skb);
 
 enum skb_drop_reason ping_rcv(struct sk_buff *skb)
 {
-	enum skb_drop_reason reason = SKB_DROP_REASON_NO_SOCKET;
-	struct sock *sk;
 	struct net *net = dev_net(skb->dev);
 	struct icmphdr *icmph = icmp_hdr(skb);
+	struct sock *sk;
 
 	/* We assume the packet has already been checked by icmp_rcv */
 
@@ -980,20 +979,11 @@ enum skb_drop_reason ping_rcv(struct sk_buff *skb)
 	skb_push(skb, skb->data - (u8 *)icmph);
 
 	sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
-	if (sk) {
-		struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
-
-		pr_debug("rcv on socket %p\n", sk);
-		if (skb2)
-			reason = __ping_queue_rcv_skb(sk, skb2);
-		else
-			reason = SKB_DROP_REASON_NOMEM;
-	}
-
-	if (reason)
-		pr_debug("no socket, dropping\n");
+	if (sk)
+		return __ping_queue_rcv_skb(sk, skb);
 
-	return reason;
+	kfree_skb_reason(skb, SKB_DROP_REASON_NO_SOCKET);
+	return SKB_DROP_REASON_NO_SOCKET;
 }
 EXPORT_SYMBOL_GPL(ping_rcv);
 
diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index 4d14ab7f7e99..3fd19a84b358 100644
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -957,12 +957,9 @@ static int icmpv6_rcv(struct sk_buff *skb)
 		break;
 
 	case ICMPV6_ECHO_REPLY:
-		reason = ping_rcv(skb);
-		break;
-
 	case ICMPV6_EXT_ECHO_REPLY:
-		reason = ping_rcv(skb);
-		break;
+		ping_rcv(skb);
+		return 0;
 
 	case ICMPV6_PKT_TOOBIG:
 		/* BUGGG_FUTURE: if packet contains rthdr, we cannot update