From: Soheil Hassas Yeganeh <soh...@google.com>
Sergei Trofimovich reported that pulse audio sends SCM_CREDENTIALS
as a control message to TCP. Since __sock_cmsg_send does not
support SCM_RIGHTS and SCM_CREDENTIALS, it returns an error and
hence breaks pulse audio over TCP.
SCM_RIGHTS and SCM_CREDENTIALS are sent on the SOL_SOCKET layer
but they semantically belong to SOL_UNIX. Since all
cmsg-processing functions including sock_cmsg_send ignore control
messages of other layers, it is best to ignore SCM_RIGHTS
and SCM_CREDENTIALS for consistency (and also for fixing pulse
audio over TCP).
Fixes: c14ac9451c34 ("sock: enable timestamping using control messages")
Signed-off-by: Soheil Hassas Yeganeh <soh...@google.com>
Reported-by: Sergei Trofimovich <sly...@gentoo.org>
Tested-by: Sergei Trofimovich <sly...@gentoo.org>
Cc: Eric Dumazet <eduma...@google.com>
Cc: Willem de Bruijn <will...@google.com>
---
net/core/sock.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/net/core/sock.c b/net/core/sock.c
index 08bf97e..b7f1263 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1938,6 +1938,10 @@ int __sock_cmsg_send(struct sock *sk, struct msghdr
*msg, struct cmsghdr *cmsg,
sockc->tsflags &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
sockc->tsflags |= tsflags;
break;
+ /* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
+ case SCM_RIGHTS:
+ case SCM_CREDENTIALS:
+ break;
default:
return -EINVAL;
}
--
2.8.0.rc3.226.g39d4020
