Hi
On Wed, Jun 26, 2024 at 7:53 PM Laurent Vivier <lviv...@redhat.com> wrote:
> Add the description of "-netdev stream" and "-netdev dgram" in the QEMU
> manpage.
>
> Add some examples on how to use them, including a way to use
> "-netdev stream" and "passt" in place of "-netdev user".
> ("passt" is a non privileged translation proxy between layer-2,
> like "-netdev stream", and layer-4 on host, like TCP, UDP,
> ICMP/ICMPv6 echo)
>
> Fixes: 5166fe0ae46d ("qapi: net: add stream and dgram netdevs")
> Fixes: 13c6be96618c ("net: stream: add unix socket")
> Fixes: 784e7a253104 ("net: dgram: add unix socket")
> Fixes: 148fbf0d58a6 ("net: stream: add a new option to automatically
> reconnect"
> Signed-off-by: Laurent Vivier <lviv...@redhat.com>
>
Could be easier to review if this documentation addition is splitted in
various patches.
> ---
> qemu-options.hx | 189 ++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 189 insertions(+)
>
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 8ca7f34ef0c8..b8a1a65f05e7 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -3353,6 +3353,195 @@ SRST
> -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\
> -netdev socket,id=n1,mcast=239.192.168.1:1102
> ,localaddr=1.2.3.4
>
> +``-netdev
> stream,id=str[,server=on|off],addr.type=inet,addr.host=host,addr.port=port[,to=maxport][,numeric=on|off][,keep-alive=on|off][,mptcp=on|off][,addr.ipv4=on|off][,addr.ipv6=on|off][,reconnect=seconds]``
> + Configure a network backend to connect to another QEMU virtual
> machine or a proxy using a TCP/IP socket.
> +
> + ``server=on|off``
> + if ``on`` create a server socket
> +
> + ``addr.host=host,addr.port=port``
> + socket address to listen on (server=on) or connect to (server=off)
> +
> + ``to=maxport``
> + if present, this is range of possible addresses, with port
> between ``port`` and ``maxport``.
> +
> + ``numeric=on|off``
> + if ``on`` ``host`` and ``port`` are guaranteed to be numeric,
> otherwise a name resolution should be attempted (default: ``off``)
> +
> + ``keep-alive=on|off``
> + enable keep-alive when connecting to this socket. Not supported
> for passive sockets.
> +
> + ``mptcp=on|off``
> + enable multipath TCP
> +
> + ``ipv4=on|off``
> + whether to accept IPv4 addresses, default to try both IPv4 and
> IPv6
> +
> + ``ipv6=on|off``
> + whether to accept IPv6 addresses, default to try both IPv4 and
> IPv6
> +
> + ``reconnect=seconds``
> + for a client socket, if a socket is disconnected, then attempt a
> reconnect after the given number of seconds.
> + Setting this to zero disables this function. (default: 0)
> +
> + Example (two guests connected using a TCP/IP socket):
> +
> + .. parsed-literal::
> +
> + # first VM
> + |qemu_system| linux.img \\
> + -device
> virtio-net,netdev=net0,mac=52:54:00:12:34:56 \\
> + -netdev
> stream,id=net0,server=on,addr.type=inet,addr.host=localhost,addr.port=1234
> + # second VM
> + |qemu_system| linux.img \\
> + -device
> virtio-net,netdev=net0,mac=52:54:00:12:34:57 \\
> + -netdev
> stream,id=net0,server=off,addr.type=inet,addr.host=localhost,addr.port=1234,reconnect=5
> +
> +``-netdev
> stream,id=str[,server=on|off],addr.type=unix,addr.path=path[,abstract=on|off][,tight=on|off][,reconnect=seconds]``
> + Configure a network backend to connect to another QEMU virtual
> machine or a proxy using a TCP/UNIX socket.
>
"TCP/UNIX": just UNIX instead?
+
> + ``server=on|off``
> + if ``on`` create a server socket
> +
> + ``addr.path=path``
> + filesystem path to use
> +
> + ``abstract=on|off``
> + if ``on``, this is a Linux abstract socket address.
> +
> + ``tight=on|off``
> + if false, pad an abstract socket address with enough null bytes
> to make it fill struct sockaddr_un member sun_path.
> +
> + ``reconnect=seconds``
> + for a client socket, if a socket is disconnected, then attempt a
> reconnect after the given number of seconds.
> + Setting this to zero disables this function. (default: 0)
> +
> + Example (using passt as a replacement of -netdev user):
> +
> + .. parsed-literal::
> +
> + # start passt server as a non privileged user
> + passt
> + UNIX domain socket bound at /tmp/passt_1.socket
> + # start QEMU to connect to passt
> + |qemu_system| linux.img \\
> + -device virtio-net,netdev=net0 \\
> + -netdev
> stream,id=net0,server=off,addr.type=unix,addr.path=/tmp/passt_1.socket
> +
> + Example (two guests connected using a TCP/UNIX socket):
> +
>
same
> + .. parsed-literal::
> +
> + # first VM
> + |qemu_system| linux.img \\
> + -device
> virtio-net,netdev=net0,mac=52:54:00:12:34:56 \\
> + netdev
> stream,id=net0,server=on,addr.type=unix,addr.path=/tmp/qemu0
> + # second VM
> + |qemu_system| linux.img \\
> + -device
> virtio-net,netdev=net0,mac=52:54:00:12:34:57 \\
> + -netdev
> stream,id=net0,server=off,addr.type=unix,addr.path=/tmp/qemu0,reconnect=5
> +
> +``-netdev
> stream,id=str[,server=on|off],addr.type=fd,addr.str=file-descriptor[,reconnect=seconds]``
> + Configure a network backend to connect to another QEMU virtual
> machine or a proxy using a TCP socket file descriptor.
> +
>
I guess it would work with either a TCP or UNIX socket. Perhaps just say "a
socket file descriptor" ?
> + ``server=on|off``
> + if ``on`` create a server socket
> +
> + ``addr.str=file-descriptor``
> + file descriptor number to use as a socket
> +
> + ``reconnect=seconds``
> + for a client socket, if a socket is disconnected, then attempt a
> reconnect after the given number of seconds.
> + Setting this to zero disables this function. (default: 0)
> +
> +``-netdev
> dgram,id=str,remote.type=inet,remote.host=maddr,remote.port=port[,local.type=inet,local.host=addr]``
> + Configure a network backend to connect to a multicast address.
> +
> + ``remote.host=maddr,remote.port=port``
> + multicast address
> +
> + ``local.host=addr``
> + specify the host address to send packets from
> +
> + Example:
> +
> + .. parsed-literal::
> +
> + # launch one QEMU instance
> + |qemu_system| linux.img \\
> + -device
> virtio-net,netdev=net0,mac=52:54:00:12:34:56 \\
> + -netdev
> dgram,id=net0,remote.type=inet,remote.host=224.0.0.1,remote.port=1234
> + # launch another QEMU instance on same "bus"
> + |qemu_system| linux.img \\
> + -device
> virtio-net,netdev=net0,mac=52:54:00:12:34:57 \\
> + -netdev
> dgram,id=net0,remote.type=inet,remote.host=224.0.0.1,remote.port=1234
> + # launch yet another QEMU instance on same "bus"
> + |qemu_system| linux.img \\
> + -device
> virtio-net,netdev=net0,mac=52:54:00:12:34:58 \\
> + -netdev
> dgram,id=net0,remote.type=inet,remote.host=224.0.0.1,remote.port=1234
> +
> +``-netdev
> dgram,id=str,remote.type=inet,remote.host=maddr,remote.port=port[,local.type=fd,local.str=file-descriptor]``
> + Configure a network backend to connect to a multicast address using a
> UDP socket file descriptor.
> +
> + ``remote.host=maddr,remote.port=port``
> + multicast address
> +
> + ``local.str=file-descriptor``
> + File descriptor to use to send packets
> +
> +``-netdev
> dgram,id=str,local.type=inet,local.host=addr,local.port=port[,remote.type=inet,remote.host=addr,remote.port=port]``
> + Configure a network backend to connect to another QEMU virtual
> + machine or a proxy using an UDP/IP socket.
> +
> + ``local.host=addr,local.port=port``
> + IP address to use to send the packets from
> +
> + ``remote.host=addr,remote.port=port``
> + Destination IP address
> +
> + Example (two guests connected using an UDP/IP socket):
> +
> + .. parsed-literal::
> +
> + # first VM
> + |qemu_system| linux.img \\
> + -device
> virtio-net,netdev=net0,mac=52:54:00:12:34:56 \\
> + -netdev
> dgram,id=net0,local.type=inet,local.host=localhost,local.port=1234,remote.type=inet,remote.host=localhost,remote.port=1235
> + # second VM
> + |qemu_system| linux.img \\
> + -device
> virtio-net,netdev=net0,mac=52:54:00:12:34:56 \\
> + -netdev
> dgram,id=net0,local.type=inet,local.host=localhost,local.port=1235,remote.type=inet,remote.host=localhost,remote.port=1234
> +
> +``-netdev
> dgram,id=str,local.type=unix,local.path=path[,remote.type=unix,remote.path=path]``
> + Configure a network backend to connect to another QEMU virtual
> + machine or a proxy using an UDP/UNIX socket.
>
Here also, that kind of notation is confusing. What's the use case, since
afaik there is no multicast with UNIX socket? Perhaps this shouldn't be
allowed at all.
+
> + ``local.path=path``
> + filesystem path to use to bind the socket
> +
> + ``remote.path=path``
> + filesystem path to use as a destination (see sendto(2))
> +
> + Example (two guests connected using an UDP/UNIX socket):
> +
> + .. parsed-literal::
> +
> + # first VM
> + |qemu_system| linux.img \\
> + -device
> virtio-net,netdev=net0,mac=52:54:00:12:34:56 \\
> + -netdev
> dgram,id=net0,local.type=unix,local.path=/tmp/qemu0,remote.type=unix,remote.path=/tmp/qemu1
> + # second VM
> + |qemu_system| linux.img \\
> + -device
> virtio-net,netdev=net0,mac=52:54:00:12:34:57 \\
> + -netdev
> dgram,id=net0,local.type=unix,local.path=/tmp/qemu1,remote.type=unix,remote.path=/tmp/qemu0
> +
> +``-netdev dgram,id=str,local.type=fd,local.str=file-descriptor``
> + Configure a network backend to connect to another QEMU virtual
> + machine or a proxy using an UDP socket file descriptor.
> +
> + ``local.str=file-descriptor``
> + File descriptor to use to send packets
> +
> ``-netdev
> l2tpv3,id=id,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport],txsession=txsession[,rxsession=rxsession][,ipv6=on|off][,udp=on|off][,cookie64][,counter][,pincounter][,txcookie=txcookie][,rxcookie=rxcookie][,offset=offset]``
> Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3931)
> is a popular protocol to transport Ethernet (and other Layer 2) data
> --
> 2.45.2
>
>
>
--
Marc-André Lureau
