From 5ed7aedd6006c78f180a2d67da0b38eb3d072db1 Mon Sep 17 00:00:00 2001 From: Kelly Littlepage Date: Fri, 8 May 2020 19:58:46 +0000 Subject: [PATCH] net: tcp: fix rx timestamp behavior for tcp_recvmsg The stated intent of the original commit is to is to "return the timestamp corresponding to the highest sequence number data returned." The current implementation returns the timestamp for the last byte of the last fully read skb, which is not necessarily the last byte in the recv buffer. This patch converts behavior to the original definition, and to the behavior of the previous draft versions of commit 6087a950f640 ("tcp: Extend SOF_TIMESTAMPING_RX_SOFTWARE to TCP recvmsg") which also match this behavior. Fixes: 6087a950f640 ("tcp: Extend SOF_TIMESTAMPING_RX_SOFTWARE to TCP recvmsg") Co-developed-by: Iris Liu Signed-off-by: Iris Liu Signed-off-by: Kelly Littlepage Signed-off-by: Eric Dumazet Acked-by: Soheil Hassas Yeganeh Acked-by: Willem de Bruijn Signed-off-by: Jakub Kicinski --- net/ipv4/tcp.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 6d87de434377e..e72bd651d21ac 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2154,13 +2154,15 @@ skip_copy: tp->urg_data = 0; tcp_fast_path_check(sk); } - if (used + offset < skb->len) - continue; if (TCP_SKB_CB(skb)->has_rxtstamp) { tcp_update_recv_tstamps(skb, &tss); cmsg_flags |= 2; } + + if (used + offset < skb->len) + continue; + if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) goto found_fin_ok; if (!(flags & MSG_PEEK)) -- 2.39.5