"-netdev socket" only supports inet sockets. It's not a complex task to add support for unix sockets, but the socket netdev parameters are not defined to manage well unix socket parameters.
As discussed in: "socket.c added support for unix domain socket datagram transport" https://lore.kernel.org/qemu-devel/1c0e1bc5-904f-46b0-8044-68e43e67b...@gmail.com/ This series adds support of unix socket type using SocketAddress QAPI structure. Two new netdev backends, "stream" and "dgram" are added, that are barely a copy of "socket" backend but they use the SocketAddress QAPI to provide socket parameters. And then they also implement unix sockets (TCP and UDP). Some examples of CLI syntax: for TCP: -netdev stream,id=socket0,addr.type=inet,addr.host=localhost,addr.port=1234 -netdev stream,id=socket0,server=off,addr.type=inet,addr.host=localhost,addr.port=1234 -netdev dgram,id=socket0,\ local.type=inet,local.host=localhost,local.port=1234,\ remote.type=inet,remote.host=localhost,remote.port=1235 for UNIX: -netdev stream,id=socket0,addr.type=unix,addr.path=/tmp/qemu0 -netdev stream,id=socket0,server=off,addr.type=unix,addr.path=/tmp/qemu0 -netdev dgram,id=socket0,\ local.type=unix,local.path=/tmp/qemu0,\ remote.type=unix,remote.path=/tmp/qemu1 for FD: -netdev stream,id=socket0,addr.type=fd,addr.str=4 -netdev stream,id=socket0,server=off,addr.type=fd,addr.str=5 -netdev dgram,id=socket0,local.type=fd,addr.str=4 v9: - add events to report stream connection/disconnection - remove from net/dgram.c send_fn, listen_fd, net_dgram_accept() net_dgram_connect() and net_dgram_send() that are only needed by net/stream.c - remove from net/stream.c send_fn - add Red Hat copyright - add original net/socket.c Stefano's patch (EINVAL) v8: - test ipv4 and ipv6 parameters (stream inet) - test abstract parameter (stream unix) - add SocketAddressInet supported parameters in qemu-options.hx (only stream, supported by the move to QIO) - with qio_channel_writev() replace (ret == -1 && errno == EAGAIN) by (ret == QIO_CHANNEL_ERR_BLOCK) v7: - add qtests - update parameters table in net.json - update socket_uri() and socket_parse() v6: - s/netdev option/-netdev option/ PATCH 4 - s/ / / - update @NetdevStreamOptions and @NetdevDgramOptions comments - update PATCH 4 description message - add missing return in error case for unix stream socket - split socket_uri() patch: move and rename, then change content v5: - remove RFC prefix - put the change of net_client_parse() into its own patch (exit() in the function) - update comments regarding netdev_is_modern() and netdev_parse_modern() - update error case in net_stream_server_init() - update qemu-options.hx with unix type - fix HMP "info network" with unix protocol/server side. v4: - net_client_parse() fails with exit() rather than with return. - keep "{ 'name': 'vmnet-host', 'if': 'CONFIG_VMNET' }" on its own line in qapi/net.json - add a comment in qapi/net.json about parameters usage - move netdev_is_modern() check to qemu_init() - in netdev_is_modern(), check for JSON and use qemu_opts_do_parse() to parse parameters and detect type value. - add a blank line after copyright comment v3: - remove support of "-net" for dgram and stream. They are only supported with "-netdev" option. - use &error_fatal directly in net_client_inits() - update qemu-options.hx - move to QIO for stream socket v2: - use "stream" and "dgram" rather than "socket-ng,mode=stream" and ""socket-ng,mode=dgram" - extract code to bypass qemu_opts_parse_noisily() to a new patch - do not ignore EINVAL (Stefano) - fix "-net" option CC: Ralph Schmieder <ralph.schmie...@gmail.com> CC: Stefano Brivio <sbri...@redhat.com> CC: Daniel P. Berrangé <berra...@redhat.com> CC: Markus Armbruster <arm...@redhat.com> Laurent Vivier (14): net: introduce convert_host_port() net: remove the @errp argument of net_client_inits() net: simplify net_client_parse() error management qapi: net: introduce a way to bypass qemu_opts_parse_noisily() qapi: net: add stream and dgram netdevs net: stream: add unix socket net: dgram: make dgram_dst generic net: dgram: move mcast specific code from net_socket_fd_init_dgram() net: dgram: add unix socket qemu-sockets: move and rename SocketAddress_to_str() qemu-sockets: update socket_uri() and socket_parse() to be consistent net: stream: move to QIO to enable additional parameters tests/qtest: netdev: test stream and dgram backends net: stream: add QAPI events to report connection state Stefano Brivio (2): net: socket: Don't ignore EINVAL on netdev socket connection net: stream: Don't ignore EINVAL on netdev socket connection hmp-commands.hx | 2 +- include/net/net.h | 6 +- include/qemu/sockets.h | 4 +- monitor/hmp-cmds.c | 23 +- net/clients.h | 6 + net/dgram.c | 619 ++++++++++++++++++++++++++++++++++++ net/hub.c | 2 + net/meson.build | 2 + net/net.c | 169 +++++++--- net/socket.c | 3 +- net/stream.c | 384 ++++++++++++++++++++++ qapi/net.json | 109 ++++++- qemu-options.hx | 14 + softmmu/vl.c | 16 +- tests/qtest/meson.build | 1 + tests/qtest/netdev-socket.c | 391 +++++++++++++++++++++++ util/qemu-sockets.c | 25 ++ 17 files changed, 1692 insertions(+), 84 deletions(-) create mode 100644 net/dgram.c create mode 100644 net/stream.c create mode 100644 tests/qtest/netdev-socket.c -- 2.37.3