netdev - [PATCH net-next] net-timestamp: support TCP GSO case for a few missing flags

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-Id: <20250228164904.47511-1-kerneljasonxing@gmail.com>
Date: Sat,  1 Mar 2025 00:49:04 +0800
From: Jason Xing <kerneljasonxing@...il.com>
To: davem@...emloft.net,
	edumazet@...gle.com,
	kuba@...nel.org,
	pabeni@...hat.com,
	ncardwell@...gle.com,
	kuniyu@...zon.com,
	dsahern@...nel.org,
	willemb@...gle.com,
	willemdebruijn.kernel@...il.com,
	horms@...nel.org
Cc: netdev@...r.kernel.org,
	Jason Xing <kerneljasonxing@...il.com>
Subject: [PATCH net-next] net-timestamp: support TCP GSO case for a few missing flags

When I read through the TSO codes, I found out that we probably
miss initializing the tx_flags of last seg when TSO is turned
off, which means at the following points no more timestamp
(for this last one) will be generated. There are three flags
to be handled in this patch:
1. SKBTX_HW_TSTAMP
2. SKBTX_HW_TSTAMP_USE_CYCLES
3. SKBTX_BPF

This patch initializes the tx_flags to SKBTX_ANY_TSTAMP like what
the UDP GSO does. But flag like SKBTX_SCHED_TSTAMP is not useful
and will not be used in the remaining path since the skb has already
passed the QDisc layer.

Signed-off-by: Jason Xing <kerneljasonxing@...il.com>
---
 net/ipv4/tcp_offload.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c
index 2308665b51c5..886582002425 100644
--- a/net/ipv4/tcp_offload.c
+++ b/net/ipv4/tcp_offload.c
@@ -13,12 +13,15 @@
 #include <net/tcp.h>
 #include <net/protocol.h>
 
-static void tcp_gso_tstamp(struct sk_buff *skb, unsigned int ts_seq,
+static void tcp_gso_tstamp(struct sk_buff *skb, struct sk_buff *gso_skb,
 			   unsigned int seq, unsigned int mss)
 {
+	u32 flags = skb_shinfo(gso_skb)->tx_flags & SKBTX_ANY_TSTAMP;
+	u32 ts_seq = skb_shinfo(gso_skb)->tskey;
+
 	while (skb) {
 		if (before(ts_seq, seq + mss)) {
-			skb_shinfo(skb)->tx_flags |= SKBTX_SW_TSTAMP;
+			skb_shinfo(skb)->tx_flags |= flags;
 			skb_shinfo(skb)->tskey = ts_seq;
 			return;
 		}
@@ -193,8 +196,8 @@ struct sk_buff *tcp_gso_segment(struct sk_buff *skb,
 	th = tcp_hdr(skb);
 	seq = ntohl(th->seq);
 
-	if (unlikely(skb_shinfo(gso_skb)->tx_flags & SKBTX_SW_TSTAMP))
-		tcp_gso_tstamp(segs, skb_shinfo(gso_skb)->tskey, seq, mss);
+	if (unlikely(skb_shinfo(gso_skb)->tx_flags & (SKBTX_ANY_TSTAMP)))
+		tcp_gso_tstamp(segs, gso_skb, seq, mss);
 
 	newcheck = ~csum_fold(csum_add(csum_unfold(th->check), delta));
 
-- 
2.43.5