"-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-46B0-8044-68E43E67BE60@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

v14:
 - move some minor changes from PATCH 17 to 15
 - update PATCH 17 commit message

v13:
  - fix server default in qtest
  - use SocketAddress in event
  - remove unwanted meson update
  - update error message in net_init_dgram()

v12:
  - replace NETDEV_STREAM_EOC by NETDEV_STREAM_DISCONNECTED
  - set server=off by default

v11:
  - use qemu_set_info_str() in hw/net/xen_nic.c
  - fix link_down state in stream client mode
  - cleanup error case in net_stream_receive()
  - update qapi version to 7.2

v10:
  - add Red Hat copyright
  - initialize dgram_dst to NULL in SOCKET_ADDRESS_TYPE_FD
  - remove redundente _stream / _dgram in functions name
  - move net_dgram_init() into net_init_dgram()
  - address Thomas' comments on qtest
  - add a function qemu_set_info_str() to set info string
  - tested stream netdev with fd type using qrap/passt and
    "-netdev stream,addr.type=fd,server=off,addr.str=5,id=netdev0"

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.schmieder@gmail.com>
CC: Stefano Brivio <sbrivio@redhat.com>
CC: Daniel P. Berrangé <berrange@redhat.com>
CC: Markus Armbruster <armbru@redhat.com>

Laurent Vivier (15):
  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()
  net: introduce qemu_set_info_str() function
  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 +-
 hw/net/xen_nic.c            |   5 +-
 include/net/net.h           |   7 +-
 include/qemu/sockets.h      |   4 +-
 monitor/hmp-cmds.c          |  23 +-
 net/clients.h               |   6 +
 net/dgram.c                 | 623 ++++++++++++++++++++++++++++++++++++
 net/hub.c                   |   2 +
 net/l2tpv3.c                |   3 +-
 net/meson.build             |   2 +
 net/net.c                   | 186 ++++++++---
 net/slirp.c                 |   5 +-
 net/socket.c                |  36 +--
 net/stream.c                | 386 ++++++++++++++++++++++
 net/tap-win32.c             |   3 +-
 net/tap.c                   |  13 +-
 net/vde.c                   |   3 +-
 net/vhost-user.c            |   3 +-
 net/vhost-vdpa.c            |   2 +-
 qapi/net.json               | 115 ++++++-
 qemu-options.hx             |  14 +
 softmmu/vl.c                |  16 +-
 tests/qtest/meson.build     |   1 +
 tests/qtest/netdev-socket.c | 420 ++++++++++++++++++++++++
 util/qemu-sockets.c         |  25 ++
 25 files changed, 1774 insertions(+), 131 deletions(-)
 create mode 100644 net/dgram.c
 create mode 100644 net/stream.c
 create mode 100644 tests/qtest/netdev-socket.c

-- 
2.37.3