Re: [PATCH] ws2_32: Handle more IGMP socket options

[Hans Leidekker]

On Fri, 2019-10-18 at 15:27 +0200, Fabian Maurer wrote:
> @@ -6011,6 +6015,20 @@ int WINAPI WS_setsockopt(SOCKET s, int level, int optname,
>      case WS_IPPROTO_IP:
>          switch(optname)
>          {
> -
>    case WS_IP_ADD_SOURCE_MEMBERSHIP:
> -
>    case WS_IP_DROP_SOURCE_MEMBERSHIP:
> -
>    case WS_IP_BLOCK_SOURCE:
> -
>    case WS_IP_UNBLOCK_SOURCE:
> -
>    {
> -
>        /* ip_mreq_source is different on Windows, we need to switch source and interface */
> -
>        struct ip_mreq_source * val = (void*)optval;
> -
>        struct in_addr temp_addr = val->imr_sourceaddr;
> -
>        val->imr_sourceaddr = val->imr_interface;
> -
>        val->imr_interface = temp_addr;

You are modifying a structure owned by the caller. Look at how we build
a local copy for WS_SO_LINGER, for example.