Re: [Qemu-devel] [PATCH v1 20/21] osdep: remove direct use of qemu_socket & qemu_accept

[Paolo Bonzini <pbonzini@redhat.com>]

On 09/03/2016 18:28, Daniel P. Berrange wrote:
> The qemu_socket & qemu_accept wrappers exist to ensure
> the O_CLOEXEC flag is always set on new sockets. All
> code is supposed to use these methods instead of the
> normal POSIX socket/accept methods. This proves rather
> error prone though with a number of places forgetting
> to call the QEMU specific wrappers.
> 
> QEMU is already using a technique to transparently
> wrap sockets APIs on Win32, avoiding the need for callers
> to remember to use QEMU specific wrappers. This switches
> over to that technique for socket/accept on POSIX platforms,
> removing the need for callers to use the qemu_socket and
> qemu_accept methods directly.
> 
> Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
> ---
>  contrib/ivshmem-server/ivshmem-server.c |  4 ++--
>  include/qemu/sockets.h                  |  2 --
>  include/sysemu/os-posix.h               | 11 +++++++++
>  migration/tcp.c                         |  2 +-
>  migration/unix.c                        |  2 +-
>  net/socket.c                            | 10 ++++----
>  qga/channel-posix.c                     |  4 ++--
>  slirp/ip_icmp.c                         |  2 +-
>  slirp/misc.c                            |  4 ++--
>  slirp/socket.c                          |  2 +-
>  slirp/tcp_subr.c                        |  2 +-
>  slirp/udp.c                             |  4 ++--
>  util/osdep.c                            | 42 ---------------------------------
>  util/oslib-posix.c                      | 39 ++++++++++++++++++++++++++++++
>  util/oslib-win32.c                      |  4 ++++
>  util/qemu-sockets.c                     | 10 ++++----
>  16 files changed, 77 insertions(+), 67 deletions(-)
> 
> diff --git a/contrib/ivshmem-server/ivshmem-server.c b/contrib/ivshmem-server/ivshmem-server.c
> index bfd0fad..1b72ca0 100644
> --- a/contrib/ivshmem-server/ivshmem-server.c
> +++ b/contrib/ivshmem-server/ivshmem-server.c
> @@ -142,8 +142,8 @@ ivshmem_server_handle_new_conn(IvshmemServer *server)
>  
>      /* accept the incoming connection */
>      unaddr_len = sizeof(unaddr);
> -    newfd = qemu_accept(server->sock_fd,
> -                        (struct sockaddr *)&unaddr, &unaddr_len);
> +    newfd = accept(server->sock_fd,
> +                   (struct sockaddr *)&unaddr, &unaddr_len);
>  
>      if (newfd < 0) {
>          IVSHMEM_SERVER_DEBUG(server, "cannot accept() %s\n", strerror(errno));

I disagree with this change, it adds too much magic.  Someone may see a

   fcntl(fd, F_SETFD, 0);

after a socket() call and think it's unnecessary.

Paolo