From: Eric Dumazet <edumazet@google.com>
Date: Fri, 3 Apr 2026 22:15:39 +0000 (+0000)
Subject: net: qdisc_pkt_len_segs_init() cleanup
X-Git-Url: http://git.ipfire.org/index.cgi?a=commitdiff_plain;h=30e02ec3b4b6bd429a4824f125eb843a291dcccf;p=thirdparty%2Fkernel%2Flinux.git

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 4519f0e59beb6..3eb2f50f51656 100644
--- 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,