Commit a7e38208 authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski
Browse files

inet: ping: avoid skb_clone() dance in ping_rcv() 



ping_rcv() callers currently call skb_free() or consume_skb(),
forcing ping_rcv() to clone the skb.

After this patch ping_rcv() is now 'consuming' the original skb,
either moving to a socket receive queue, or dropping it.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Reviewed-by: default avatarDavid Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20250226183437.1457318-3-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent daeb6a8f

net/ipv4/icmp.c

+3 −2
Original line number Diff line number Diff line
@@ -1274,9 +1274,10 @@ int icmp_rcv(struct sk_buff *skb) 
		}

	}



	if (icmph->type == ICMP_EXT_ECHOREPLY) {

	if (icmph->type == ICMP_EXT_ECHOREPLY ||

	    icmph->type == ICMP_ECHOREPLY) {

		reason = ping_rcv(skb);

		goto reason_check;

		return reason ? NET_RX_DROP : NET_RX_SUCCESS;

	}



	/*

net/ipv4/ping.c

+5 −15
Original line number Diff line number Diff line
@@ -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);

net/ipv6/icmp.c

+2 −5
Original line number Diff line number Diff line
@@ -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