[PATCH net 1/2] socket: fix option SO_TIMESTAMPING_NEW

From: Christian Eggers
Date: Fri Oct 09 2020 - 06:32:20 EST


The comparison of optname with SO_TIMESTAMPING_NEW is wrong way around,
so SOCK_TSTAMP_NEW will first be set and than reset again. Additionally
move it out of the test for SOF_TIMESTAMPING_RX_SOFTWARE as this seems
unrelated.

This problem happens on 32 bit platforms were the libc has already
switched to struct timespec64 (from SO_TIMExxx_OLD to SO_TIMExxx_NEW
socket options). ptp4l complains with "missing timestamp on transmitted
peer delay request" because the wrong format is received (and
discarded).

Fixes: 9718475e6908 ("socket: Add SO_TIMESTAMPING_NEW")
Signed-off-by: Christian Eggers <ceggers@xxxxxxx>
---
net/core/sock.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/net/core/sock.c b/net/core/sock.c
index 34a8d12e38d7..3926804702c1 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1024,16 +1024,15 @@ int sock_setsockopt(struct socket *sock, int level, int optname,
}

sk->sk_tsflags = val;
+ if (optname != SO_TIMESTAMPING_NEW)
+ sock_reset_flag(sk, SOCK_TSTAMP_NEW);
+
if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
sock_enable_timestamp(sk,
SOCK_TIMESTAMPING_RX_SOFTWARE);
- else {
- if (optname == SO_TIMESTAMPING_NEW)
- sock_reset_flag(sk, SOCK_TSTAMP_NEW);
-
+ else
sock_disable_timestamp(sk,
(1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
- }
break;

case SO_RCVLOWAT:
--
Christian Eggers
Embedded software developer

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