diff options
| author | Stefan Hajnoczi <stefanha@redhat.com> | 2013-03-27 10:10:46 +0100 |
|---|---|---|
| committer | Luiz Capitulino <lcapitulino@redhat.com> | 2013-04-02 11:47:37 -0400 |
| commit | 9b938c7262e403f5467110609cb20ef1ae6e9df2 (patch) | |
| tree | a4d062e324c9eaa8a6d9432af65d1c5e40dd05ff | |
| parent | 1a751ebfbb2d7a696b889d8208cb5ffc83c090b1 (diff) | |
chardev: clear O_NONBLOCK on SCM_RIGHTS file descriptors
When we receive a file descriptor over a UNIX domain socket the
O_NONBLOCK flag is preserved. Clear the O_NONBLOCK flag and rely on
QEMU file descriptor users like migration, SPICE, VNC, block layer, and
others to set non-blocking only when necessary.
This change ensures we don't accidentally expose O_NONBLOCK in the QMP
API. QMP clients should not need to get the non-blocking state
"correct".
A recent real-world example was when libvirt passed a non-blocking TCP
socket for migration where we expected a blocking socket. The source
QEMU produced a corrupted migration stream since its code did not cope
with non-blocking sockets.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
| -rw-r--r-- | qemu-char.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/qemu-char.c b/qemu-char.c index 4d8c6cab41..d825b60177 100644 --- a/qemu-char.c +++ b/qemu-char.c @@ -2440,6 +2440,9 @@ static void unix_process_msgfd(CharDriverState *chr, struct msghdr *msg) if (fd < 0) continue; + /* O_NONBLOCK is preserved across SCM_RIGHTS so reset it */ + qemu_set_block(fd); + #ifndef MSG_CMSG_CLOEXEC qemu_set_cloexec(fd); #endif |