Re: [Qemu-devel] [PATCH v2 1/4] linux-user: SOCK_PACKET uses network endian to encode protocol in socket()

[Peter Maydell]

On 28 October 2015 at 19:13, Laurent Vivier <address@hidden> wrote:
> in PACKET(7) :
>
>   packet_socket = socket(AF_PACKET, int socket_type, int protocol);
> [...]
>                                    protocol is the  IEEE  802.3 protocol
>   number in network order.  See the <linux/if_ether.h> include file for a
>   list of allowed protocols.  When protocol is  set  to htons(ETH_P_ALL)
>   then all protocols are received.  All incoming packets of that protocol
>   type will be passed to the packet socket before they are passed to the
>   protocols implemented in the kernel.
> [...]
> Compatibility
>
>   In Linux 2.0, the only way to  get  a  packet  socket  was  by  calling
>   socket(AF_INET,  SOCK_PACKET,  protocol).
>
> We need to tswap16() the protocol because on big-endian, the ABI is
> waiting for, for instance for ETH_P_ALL, 0x0003 (big endian ==
> network order), whereas on little-endian it is waiting for 0x0300.
>
> Signed-off-by: Laurent Vivier <address@hidden>
> ---

Reviewed-by: Peter Maydell <address@hidden>

thanks
-- PMM