net: qdisc_pkt_len_segs_init() cleanup

Reduce indentation level by returning early if the transport header
was not set.

Add an unlikely() clause as this is not the common case.

No functional change.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Joe Damato <joe@dama.to>
Link: https://patch.msgid.link/20260403221540.3297753-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/core/dev.c b/net/core/dev.c
index 4519f0e59beb695fffb69a0a9cf89a7b75fe209f..3eb2f50f516564c6a6465c19a6d802c136e0ddde 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4104,6 +4104,7 @@ EXPORT_SYMBOL_GPL(validate_xmit_skb_list);
 static void qdisc_pkt_len_segs_init(struct sk_buff *skb)
 {
        struct skb_shared_info *shinfo = skb_shinfo(skb);
+       unsigned int hdr_len;
        u16 gso_segs;
 
        qdisc_skb_cb(skb)->pkt_len = skb->len;
@@ -4117,44 +4118,43 @@ static void qdisc_pkt_len_segs_init(struct sk_buff *skb)
        /* To get more precise estimation of bytes sent on wire,
         * we add to pkt_len the headers size of all segments
         */
-       if (skb_transport_header_was_set(skb)) {
-               unsigned int hdr_len;
+       if (unlikely(!skb_transport_header_was_set(skb)))
+               return;
 
-               /* mac layer + network layer */
-               if (!skb->encapsulation)
-                       hdr_len = skb_transport_offset(skb);
-               else
-                       hdr_len = skb_inner_transport_offset(skb);
+       /* mac layer + network layer */
+       if (!skb->encapsulation)
+               hdr_len = skb_transport_offset(skb);
+       else
+               hdr_len = skb_inner_transport_offset(skb);
 
-               /* + transport layer */
-               if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))) {
-                       const struct tcphdr *th;
-                       struct tcphdr _tcphdr;
+       /* + transport layer */
+       if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))) {
+               const struct tcphdr *th;
+               struct tcphdr _tcphdr;
 
-                       th = skb_header_pointer(skb, hdr_len,
-                                               sizeof(_tcphdr), &_tcphdr);
-                       if (likely(th))
-                               hdr_len += __tcp_hdrlen(th);
-               } else if (shinfo->gso_type & SKB_GSO_UDP_L4) {
-                       struct udphdr _udphdr;
+               th = skb_header_pointer(skb, hdr_len,
+                                       sizeof(_tcphdr), &_tcphdr);
+               if (likely(th))
+                       hdr_len += __tcp_hdrlen(th);
+       } else if (shinfo->gso_type & SKB_GSO_UDP_L4) {
+               struct udphdr _udphdr;
 
-                       if (skb_header_pointer(skb, hdr_len,
-                                              sizeof(_udphdr), &_udphdr))
-                               hdr_len += sizeof(struct udphdr);
-               }
+               if (skb_header_pointer(skb, hdr_len,
+                                      sizeof(_udphdr), &_udphdr))
+                       hdr_len += sizeof(struct udphdr);
+       }
 
-               if (unlikely(shinfo->gso_type & SKB_GSO_DODGY)) {
-                       int payload = skb->len - hdr_len;
+       if (unlikely(shinfo->gso_type & SKB_GSO_DODGY)) {
+               int payload = skb->len - hdr_len;
 
-                       /* Malicious packet. */
-                       if (payload <= 0)
-                               return;
-                       gso_segs = DIV_ROUND_UP(payload, shinfo->gso_size);
-                       shinfo->gso_segs = gso_segs;
-                       qdisc_skb_cb(skb)->pkt_segs = gso_segs;
-               }
-               qdisc_skb_cb(skb)->pkt_len += (gso_segs - 1) * hdr_len;
+               /* Malicious packet. */
+               if (payload <= 0)
+                       return;
+               gso_segs = DIV_ROUND_UP(payload, shinfo->gso_size);
+               shinfo->gso_segs = gso_segs;
+               qdisc_skb_cb(skb)->pkt_segs = gso_segs;
        }
+       qdisc_skb_cb(skb)->pkt_len += (gso_segs - 1) * hdr_len;
 }
 
 static int dev_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *q,