Commit fe857018 authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski
Browse files

ipv4: use dst4_mtu() instead of dst_mtu() 



When we expect an IPv4 dst, use dst4_mtu() instead of dst_mtu()
to save some code space.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Reviewed-by: default avatarKuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260130210303.3888261-8-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent b40f0130

net/ipv4/icmp.c

+1 −1
Original line number Diff line number Diff line
@@ -945,7 +945,7 @@ void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info, 


	/* RFC says return as much as we can without exceeding 576 bytes. */



	room = dst_mtu(&rt->dst);

	room = dst4_mtu(&rt->dst);

	if (room > 576)

		room = 576;

	room -= sizeof(struct iphdr) + icmp_param->replyopts.opt.optlen;

net/ipv4/ip_output.c

+2 −2
Original line number Diff line number Diff line
@@ -1300,7 +1300,7 @@ static int ip_setup_cork(struct sock *sk, struct inet_cork *cork, 
		return -EFAULT;



	cork->fragsize = ip_sk_use_pmtu(sk) ?

			 dst_mtu(&rt->dst) : READ_ONCE(rt->dst.dev->mtu);

			 dst4_mtu(&rt->dst) : READ_ONCE(rt->dst.dev->mtu);



	if (!inetdev_valid_mtu(cork->fragsize))

		return -ENETUNREACH;
@@ -1439,7 +1439,7 @@ struct sk_buff *__ip_make_skb(struct sock *sk, 
	pmtudisc = READ_ONCE(inet->pmtudisc);

	if (pmtudisc == IP_PMTUDISC_DO ||

	    pmtudisc == IP_PMTUDISC_PROBE ||

	    (skb->len <= dst_mtu(&rt->dst) &&

	    (skb->len <= dst4_mtu(&rt->dst) &&

	     ip_dont_fragment(sk, &rt->dst)))

		df = htons(IP_DF);

net/ipv4/ip_sockglue.c

+1 −1
Original line number Diff line number Diff line
@@ -1634,7 +1634,7 @@ int do_ip_getsockopt(struct sock *sk, int level, int optname, 
		val = 0;

		dst = sk_dst_get(sk);

		if (dst) {

			val = dst_mtu(dst);

			val = dst4_mtu(dst);

			dst_release(dst);

		}

		if (!val)

net/ipv4/ipmr.c

+1 −1
Original line number Diff line number Diff line
@@ -1895,7 +1895,7 @@ static int ipmr_prepare_xmit(struct net *net, struct mr_table *mrt, 
			return -1;

	}



	if (skb->len+encap > dst_mtu(&rt->dst) && (ntohs(iph->frag_off) & IP_DF)) {

	if (skb->len+encap > dst4_mtu(&rt->dst) && (ntohs(iph->frag_off) & IP_DF)) {

		/* Do not fragment multicasts. Alas, IPv4 does not

		 * allow to send ICMP, so that packets will disappear

		 * to blackhole.

net/ipv4/netfilter/nf_reject_ipv4.c

+1 −1
Original line number Diff line number Diff line
@@ -303,7 +303,7 @@ void nf_send_reset(struct net *net, struct sock *sk, struct sk_buff *oldskb, 
		goto free_nskb;



	/* "Never happens" */

	if (nskb->len > dst_mtu(skb_dst(nskb)))

	if (nskb->len > dst4_mtu(skb_dst(nskb)))

		goto free_nskb;



	nf_ct_attach(nskb, oldskb);