[v4,1/4] net/socket: Drop the odd 'default' case and comment

In the net_socket_fd_init(), the 'default' case and comment is odd.
If @fd really was a pty, getsockopt() would fail with ENOTSOCK. If
@fd was a socket, but neither SOCK_DGRAM nor SOCK_STREAM. It should
not be treated as if it was SOCK_STREAM.

If there is a genuine reason to support something like SOCK_RAW, it
should be explicitly handled.

So, drop the 'default' case since it is broken already.

Cc: jasowang@redhat.com
Cc: armbru@redhat.com
Cc: berrange@redhat.com
Cc: armbru@redhat.com
Suggested-by: Markus Armbruster <armbru@redhat.com>
Suggested-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Mao Zhongyi <maozy.fnst@cn.fujitsu.com>
---
 net/socket.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Mao Zhongyi <maozy.fnst@cn.fujitsu.com> writes:

> In the net_socket_fd_init(), the 'default' case and comment is odd.
> If @fd really was a pty, getsockopt() would fail with ENOTSOCK. If
> @fd was a socket, but neither SOCK_DGRAM nor SOCK_STREAM. It should
> not be treated as if it was SOCK_STREAM.
>
> If there is a genuine reason to support something like SOCK_RAW, it
> should be explicitly handled.
>
> So, drop the 'default' case since it is broken already.
>
> Cc: jasowang@redhat.com
> Cc: armbru@redhat.com
> Cc: berrange@redhat.com
> Cc: armbru@redhat.com
> Suggested-by: Markus Armbruster <armbru@redhat.com>
> Suggested-by: Daniel P. Berrange <berrange@redhat.com>
> Signed-off-by: Mao Zhongyi <maozy.fnst@cn.fujitsu.com>
> ---
>  net/socket.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/net/socket.c b/net/socket.c
> index dcae1ae..53765bd 100644
> --- a/net/socket.c
> +++ b/net/socket.c
> @@ -449,9 +449,9 @@ static NetSocketState *net_socket_fd_init(NetClientState *peer,
>      case SOCK_STREAM:
>          return net_socket_fd_init_stream(peer, model, name, fd, is_connected);
>      default:
> -        /* who knows ... this could be a eg. a pty, do warn and continue as stream */
> -        fprintf(stderr, "qemu: warning: socket type=%d for fd=%d is not SOCK_DGRAM or SOCK_STREAM\n", so_type, fd);
> -        return net_socket_fd_init_stream(peer, model, name, fd, is_connected);
> +        error_report("qemu: error: socket type=%d for fd=%d is not"
> +                " SOCK_DGRAM or SOCK_STREAM", so_type, fd);
> +        closesocket(fd);
>      }
>      return NULL;
>  }

You don't actually "drop the 'default' case", as your commit message
claims.  Perhaps:

    net/socket: Don't treat odd socket type as SOCK_STREAM

    In net_socket_fd_init(), the 'default' case is odd: it warns, then
    continues as if the socket type was SOCK_STREAM.  The comment
    explains "this could be a eg. a pty", but that makes no sense.  If
    @fd really was a pty, getsockopt() would fail with ENOTSOCK.  If @fd
    was a socket, but neither SOCK_DGRAM nor SOCK_STREAM, it should not
    be treated as if it was SOCK_STREAM.

    Turn this case into an error.  If there is a genuine reason to
    support something like SOCK_RAW, it should be handled explicitly.

With something like that:
Reviewed-by: Markus Armbruster <armbru@redhat.com>

Hi, Markus


On 06/23/2017 09:36 PM, Markus Armbruster wrote:
> Mao Zhongyi <maozy.fnst@cn.fujitsu.com> writes:
>
>> In the net_socket_fd_init(), the 'default' case and comment is odd.
>> If @fd really was a pty, getsockopt() would fail with ENOTSOCK. If
>> @fd was a socket, but neither SOCK_DGRAM nor SOCK_STREAM. It should
>> not be treated as if it was SOCK_STREAM.
>>
>> If there is a genuine reason to support something like SOCK_RAW, it
>> should be explicitly handled.
>>
>> So, drop the 'default' case since it is broken already.
>>
>> Cc: jasowang@redhat.com
>> Cc: armbru@redhat.com
>> Cc: berrange@redhat.com
>> Cc: armbru@redhat.com
>> Suggested-by: Markus Armbruster <armbru@redhat.com>
>> Suggested-by: Daniel P. Berrange <berrange@redhat.com>
>> Signed-off-by: Mao Zhongyi <maozy.fnst@cn.fujitsu.com>
>> ---
>>  net/socket.c | 6 +++---
>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/net/socket.c b/net/socket.c
>> index dcae1ae..53765bd 100644
>> --- a/net/socket.c
>> +++ b/net/socket.c
>> @@ -449,9 +449,9 @@ static NetSocketState *net_socket_fd_init(NetClientState *peer,
>>      case SOCK_STREAM:
>>          return net_socket_fd_init_stream(peer, model, name, fd, is_connected);
>>      default:
>> -        /* who knows ... this could be a eg. a pty, do warn and continue as stream */
>> -        fprintf(stderr, "qemu: warning: socket type=%d for fd=%d is not SOCK_DGRAM or SOCK_STREAM\n", so_type, fd);
>> -        return net_socket_fd_init_stream(peer, model, name, fd, is_connected);
>> +        error_report("qemu: error: socket type=%d for fd=%d is not"
>> +                " SOCK_DGRAM or SOCK_STREAM", so_type, fd);
>> +        closesocket(fd);
>>      }
>>      return NULL;
>>  }
>
> You don't actually "drop the 'default' case", as your commit message
> claims.  Perhaps:
>
>     net/socket: Don't treat odd socket type as SOCK_STREAM
>
>     In net_socket_fd_init(), the 'default' case is odd: it warns, then
>     continues as if the socket type was SOCK_STREAM.  The comment
>     explains "this could be a eg. a pty", but that makes no sense.  If
>     @fd really was a pty, getsockopt() would fail with ENOTSOCK.  If @fd
>     was a socket, but neither SOCK_DGRAM nor SOCK_STREAM, it should not
>     be treated as if it was SOCK_STREAM.
>
>     Turn this case into an error.  If there is a genuine reason to
>     support something like SOCK_RAW, it should be handled explicitly.
>
> With something like that:


Yes, I have noticed that the commit message is really not very match this
patch after read your exact description. I will fix it in the next version.

Thank you very much. :)
Mao

> Reviewed-by: Markus Armbruster <armbru@redhat.com>