netpoll: factor out IPv6 header setup into push_ipv6() helper

Move IPv6 header construction from netpoll_send_udp() into a new
static helper function, push_ipv6(). This refactoring reduces code
duplication and improves readability in netpoll_send_udp().

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250702-netpoll_untagle_ip-v2-3-13cf3db24e2b@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index 24e6ad2da80967604f48de6bbc3a74f3aadda3fd..247a73762fc2cc513e566fa9e0e54c6dad99da5f 100644 (file)
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -414,6 +414,33 @@ netdev_tx_t netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
 }
 EXPORT_SYMBOL(netpoll_send_skb);
 
+static void push_ipv6(struct netpoll *np, struct sk_buff *skb, int len)
+{
+       struct ipv6hdr *ip6h;
+       struct ethhdr *eth;
+
+       skb_push(skb, sizeof(struct ipv6hdr));
+       skb_reset_network_header(skb);
+       ip6h = ipv6_hdr(skb);
+
+       /* ip6h->version = 6; ip6h->priority = 0; */
+       *(unsigned char *)ip6h = 0x60;
+       ip6h->flow_lbl[0] = 0;
+       ip6h->flow_lbl[1] = 0;
+       ip6h->flow_lbl[2] = 0;
+
+       ip6h->payload_len = htons(sizeof(struct udphdr) + len);
+       ip6h->nexthdr = IPPROTO_UDP;
+       ip6h->hop_limit = 32;
+       ip6h->saddr = np->local_ip.in6;
+       ip6h->daddr = np->remote_ip.in6;
+
+       eth = skb_push(skb, ETH_HLEN);
+       skb_reset_mac_header(skb);
+       skb->protocol = htons(ETH_P_IPV6);
+       eth->h_proto = htons(ETH_P_IPV6);
+}
+
 int netpoll_send_udp(struct netpoll *np, const char *msg, int len)
 {
        int total_len, ip_len, udp_len;
@@ -422,7 +449,6 @@ int netpoll_send_udp(struct netpoll *np, const char *msg, int len)
        struct iphdr *iph;
        struct ethhdr *eth;
        static atomic_t ip_ident;
-       struct ipv6hdr *ip6h;
 
        if (!IS_ENABLED(CONFIG_PREEMPT_RT))
                WARN_ON_ONCE(!irqs_disabled());
@@ -452,25 +478,8 @@ int netpoll_send_udp(struct netpoll *np, const char *msg, int len)
 
        netpoll_udp_checksum(np, skb, len);
        if (np->ipv6) {
-               skb_push(skb, sizeof(struct ipv6hdr));
-               skb_reset_network_header(skb);
-               ip6h = ipv6_hdr(skb);
-
-               /* ip6h->version = 6; ip6h->priority = 0; */
-               *(unsigned char *)ip6h = 0x60;
-               ip6h->flow_lbl[0] = 0;
-               ip6h->flow_lbl[1] = 0;
-               ip6h->flow_lbl[2] = 0;
-
-               ip6h->payload_len = htons(sizeof(struct udphdr) + len);
-               ip6h->nexthdr = IPPROTO_UDP;
-               ip6h->hop_limit = 32;
-               ip6h->saddr = np->local_ip.in6;
-               ip6h->daddr = np->remote_ip.in6;
-
-               eth = skb_push(skb, ETH_HLEN);
-               skb_reset_mac_header(skb);
-               skb->protocol = eth->h_proto = htons(ETH_P_IPV6);
+               push_ipv6(np, skb, len);
+               eth = eth_hdr(skb);
        } else {
                skb_push(skb, sizeof(struct iphdr));
                skb_reset_network_header(skb);