[PATCH v2] net: fix multicast support with BSD (macOS) socket implementations

[PATCH v2] net: fix multicast support with BSD (macOS) socket implementations

[Vitaly Cheptsov]

Cc: Jason Wang <jasowang@redhat.com>
Cc: Daniel P. Berrange <berrange@redhat.com>
Cc: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Vitaly Cheptsov <cheptsov@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)

Re: [PATCH v2] net: fix multicast support with BSD (macOS) socket implementations

[Vitaly Cheptsov]

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V2 version of the previous patch ensures to keep compatibility with non-Apple platforms to avoid any potential compatibility issues with e.g. Windows mentioned in the review.

> On 18 May 2022, at 10:39, Vitaly Cheptsov <cheptsov@ispras.ru> wrote:
> 
> Cc: Jason Wang <jasowang@redhat.com>
> Cc: Daniel P. Berrange <berrange@redhat.com>
> Cc: Philippe Mathieu-Daudé <f4bug@amsat.org>
> Signed-off-by: Vitaly Cheptsov <cheptsov@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)
> 


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Re: [PATCH v2] net: fix multicast support with BSD (macOS) socket implementations

[Jason Wang]

On Wed, May 18, 2022 at 3:40 PM Vitaly Cheptsov <cheptsov@ispras.ru> wrote:
>

Hi Vitaly:

We need a changelog to describe why we need this.

Thanks

> Cc: Jason Wang <jasowang@redhat.com>
> Cc: Daniel P. Berrange <berrange@redhat.com>
> Cc: Philippe Mathieu-Daudé <f4bug@amsat.org>
> Signed-off-by: Vitaly Cheptsov <cheptsov@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)
>

Re: [PATCH v2] net: fix multicast support with BSD (macOS) socket implementations

[Vitaly Cheptsov]

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 <jasowang@redhat.com> wrote:
> 
> On Wed, May 18, 2022 at 3:40 PM Vitaly Cheptsov <cheptsov@ispras.ru> wrote:
>> 
> 
> Hi Vitaly:
> 
> We need a changelog to describe why we need this.
> 
> Thanks
> 
>> Cc: Jason Wang <jasowang@redhat.com>
>> Cc: Daniel P. Berrange <berrange@redhat.com>
>> Cc: Philippe Mathieu-Daudé <f4bug@amsat.org>
>> Signed-off-by: Vitaly Cheptsov <cheptsov@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)
>> 
> 

Re: [PATCH v2] net: fix multicast support with BSD (macOS) socket implementations

[Jason Wang]

On Tue, May 31, 2022 at 7:28 PM Vitaly Cheptsov <cheptsov@ispras.ru> wrote:
>
> 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

Would you mind resending the patch with the above as the changelog?

Thanks

>
> > On 31 May 2022, at 10:02, Jason Wang <jasowang@redhat.com> wrote:
> >
> > On Wed, May 18, 2022 at 3:40 PM Vitaly Cheptsov <cheptsov@ispras.ru> wrote:
> >>
> >
> > Hi Vitaly:
> >
> > We need a changelog to describe why we need this.
> >
> > Thanks
> >
> >> Cc: Jason Wang <jasowang@redhat.com>
> >> Cc: Daniel P. Berrange <berrange@redhat.com>
> >> Cc: Philippe Mathieu-Daudé <f4bug@amsat.org>
> >> Signed-off-by: Vitaly Cheptsov <cheptsov@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)
> >>
> >
>