Hi
On Wed, Jun 26, 2024 at 7:53 PM Laurent Vivier <lvivier@redhat.com
<mailto:lvivier@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 <lvivier@redhat.com
<mailto:lvivier@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
<http://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