Hi Jason,
This patch fixes socket communication with QEMU -> host and QEMU <--> QEMU on
macOS, which was originally impossible due to QEMU and host program having to
bind to the same ip/port in a way not supported by BSD sockets. The change was
tested on both Linux and macOS.
Basically after applying this patch one will be able to communicate with QEMU
when using "-nic socket,mcast=230.0.0.1:1234,model=virtio-net-pci" from QEMU or
macOS itself.
Best regards,
Vitaly
> On 31 May 2022, at 10:02, Jason Wang <jasow...@redhat.com> wrote:
>
> On Wed, May 18, 2022 at 3:40 PM Vitaly Cheptsov <chept...@ispras.ru> wrote:
>>
>
> Hi Vitaly:
>
> We need a changelog to describe why we need this.
>
> Thanks
>
>> Cc: Jason Wang <jasow...@redhat.com>
>> Cc: Daniel P. Berrange <berra...@redhat.com>
>> Cc: Philippe Mathieu-Daudé <f4...@amsat.org>
>> Signed-off-by: Vitaly Cheptsov <chept...@ispras.ru>
>> ---
>> net/socket.c | 18 ++++++++++++++++++
>> 1 file changed, 18 insertions(+)
>>
>> diff --git a/net/socket.c b/net/socket.c
>> index bfd8596250..583f788a22 100644
>> --- a/net/socket.c
>> +++ b/net/socket.c
>> @@ -239,6 +239,22 @@ static int net_socket_mcast_create(struct sockaddr_in
>> *mcastaddr,
>> return -1;
>> }
>>
>> +#ifdef __APPLE__
>> + val = 1;
>> + ret = qemu_setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &val, sizeof(val));
>> + if (ret < 0) {
>> + error_setg_errno(errp, errno,
>> + "can't set socket option SO_REUSEPORT");
>> + goto fail;
>> + }
>> +
>> + struct sockaddr_in bindaddr;
>> + memset(&bindaddr, 0, sizeof(bindaddr));
>> + bindaddr.sin_family = AF_INET;
>> + bindaddr.sin_addr.s_addr = htonl(INADDR_ANY);
>> + bindaddr.sin_port = mcastaddr->sin_port;
>> + ret = bind(fd, (struct sockaddr *)&bindaddr, sizeof(bindaddr));
>> +#else
>> /* Allow multiple sockets to bind the same multicast ip and port by
>> setting
>> * SO_REUSEADDR. This is the only situation where SO_REUSEADDR should be
>> set
>> * on windows. Use socket_set_fast_reuse otherwise as it sets
>> SO_REUSEADDR
>> @@ -253,6 +269,8 @@ static int net_socket_mcast_create(struct sockaddr_in
>> *mcastaddr,
>> }
>>
>> ret = bind(fd, (struct sockaddr *)mcastaddr, sizeof(*mcastaddr));
>> +#endif
>> +
>> if (ret < 0) {
>> error_setg_errno(errp, errno, "can't bind ip=%s to socket",
>> inet_ntoa(mcastaddr->sin_addr));
>> --
>> 2.32.1 (Apple Git-133)
>>
>
