Commit 01dae7a6 authored by Breno Leitao's avatar Breno Leitao Committed by Jakub Kicinski
Browse files

netpoll: factor out UDP checksum calculation into helper 



Extract UDP checksum calculation logic from netpoll_send_udp()
into a new static helper function netpoll_udp_checksum(). This
reduces code duplication and improves readability for both IPv4
and IPv6 cases.

No functional change intended.

Signed-off-by: default avatarBreno Leitao <leitao@debian.org>
Reviewed-by: default avatarSimon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250702-netpoll_untagle_ip-v2-2-13cf3db24e2b@debian.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 4b52cdfc

net/core/netpoll.c

+26 −15
Original line number Diff line number Diff line
@@ -372,6 +372,31 @@ static netdev_tx_t __netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) 
	return ret;

}



static void netpoll_udp_checksum(struct netpoll *np, struct sk_buff *skb,

				 int len)

{

	struct udphdr *udph;

	int udp_len;



	udp_len = len + sizeof(struct udphdr);

	udph = udp_hdr(skb);



	/* check needs to be set, since it will be consumed in csum_partial */

	udph->check = 0;

	if (np->ipv6)

		udph->check = csum_ipv6_magic(&np->local_ip.in6,

					      &np->remote_ip.in6,

					      udp_len, IPPROTO_UDP,

					      csum_partial(udph, udp_len, 0));

	else

		udph->check = csum_tcpudp_magic(np->local_ip.ip,

						np->remote_ip.ip,

						udp_len, IPPROTO_UDP,

						csum_partial(udph, udp_len, 0));

	if (udph->check == 0)

		udph->check = CSUM_MANGLED_0;

}



netdev_tx_t netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)

{

	unsigned long flags;
@@ -425,15 +450,8 @@ int netpoll_send_udp(struct netpoll *np, const char *msg, int len) 
	udph->dest = htons(np->remote_port);

	udph->len = htons(udp_len);



	udph->check = 0;

	netpoll_udp_checksum(np, skb, len);

	if (np->ipv6) {

		udph->check = csum_ipv6_magic(&np->local_ip.in6,

					      &np->remote_ip.in6,

					      udp_len, IPPROTO_UDP,

					      csum_partial(udph, udp_len, 0));

		if (udph->check == 0)

			udph->check = CSUM_MANGLED_0;



		skb_push(skb, sizeof(struct ipv6hdr));

		skb_reset_network_header(skb);

		ip6h = ipv6_hdr(skb);
@@ -454,13 +472,6 @@ int netpoll_send_udp(struct netpoll *np, const char *msg, int len) 
		skb_reset_mac_header(skb);

		skb->protocol = eth->h_proto = htons(ETH_P_IPV6);

	} else {

		udph->check = csum_tcpudp_magic(np->local_ip.ip,

						np->remote_ip.ip,

						udp_len, IPPROTO_UDP,

						csum_partial(udph, udp_len, 0));

		if (udph->check == 0)

			udph->check = CSUM_MANGLED_0;



		skb_push(skb, sizeof(struct iphdr));

		skb_reset_network_header(skb);

		iph = ip_hdr(skb);