[libvirt] [PATCH v6 1/6] qemu-char: Add MSG_CMSG_CLOEXEC flag to recvmsg

[Corey Bryant]

If these patches are acceptable, I'll resend and get the version history 
out of the commit message.

-- 
Regards,
Corey

On 08/03/2012 01:28 PM, Corey Bryant wrote:
> Set the close-on-exec flag for the file descriptor received
> via SCM_RIGHTS.
>
> v4
>   -This patch is new in v4 (eblake at redhat.com)
>
> v5
>   -Fallback to FD_CLOEXEC if MSG_CMSG_CLOEXEC is not available
>    (eblake at redhat.com, stefanha at linux.vnet.ibm.com)
>
> v6
>   -Set cloexec on correct fd (eblake at redhat.com)
>
> Signed-off-by: Corey Bryant <coreyb at linux.vnet.ibm.com>
> ---
>   qemu-char.c |   12 ++++++++++--
>   1 file changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/qemu-char.c b/qemu-char.c
> index c2aaaee..ab4a928 100644
> --- a/qemu-char.c
> +++ b/qemu-char.c
> @@ -2238,6 +2238,9 @@ static void unix_process_msgfd(CharDriverState *chr, struct msghdr *msg)
>           if (fd < 0)
>               continue;
>
> +#ifndef MSG_CMSG_CLOEXEC
> +        qemu_set_cloexec(fd);
> +#endif
>           if (s->msgfd != -1)
>               close(s->msgfd);
>           s->msgfd = fd;
> @@ -2253,6 +2256,7 @@ static ssize_t tcp_chr_recv(CharDriverState *chr, char *buf, size_t len)
>           struct cmsghdr cmsg;
>           char control[CMSG_SPACE(sizeof(int))];
>       } msg_control;
> +    int flags = 0;
>       ssize_t ret;
>
>       iov[0].iov_base = buf;
> @@ -2263,9 +2267,13 @@ static ssize_t tcp_chr_recv(CharDriverState *chr, char *buf, size_t len)
>       msg.msg_control = &msg_control;
>       msg.msg_controllen = sizeof(msg_control);
>
> -    ret = recvmsg(s->fd, &msg, 0);
> -    if (ret > 0 && s->is_unix)
> +#ifdef MSG_CMSG_CLOEXEC
> +    flags |= MSG_CMSG_CLOEXEC;
> +#endif
> +    ret = recvmsg(s->fd, &msg, flags);
> +    if (ret > 0 && s->is_unix) {
>           unix_process_msgfd(chr, &msg);
> +    }
>
>       return ret;
>   }
>