Re: [PATCH v3 09/25] python/aqmp: add AsyncProtocol.accept() method
On Thu, Aug 19, 2021 at 11:48:16AM -0400, John Snow wrote:
> On Thu, Aug 19, 2021 at 10:50 AM Eric Blake wrote:
>
> > On Wed, Aug 18, 2021 at 10:24:52AM -0400, John Snow wrote:
> > > > >
> > > > > +@upper_half
> > > > > +@require(Runstate.IDLE)
> > > > > +async def accept(self, address: Union[str, Tuple[str, int]],
> > > > > + ssl: Optional[SSLContext] = None) -> None:
> > > > > +"""
> > > > > +Accept a connection and begin processing message queues.
> > > > > +
> > > > > +If this call fails, `runstate` is guaranteed to be set back
> > to
> > > > `IDLE`.
> > > > > +
> > > > > +:param address:
> > > > > +Address to listen to; UNIX socket path or TCP
> > address/port.
> > > >
> > > > Can't TCP use a well-known port name instead of an int? But limiting
> > > > clients to just int port for now isn't fatal to the patch.
> > > >
> > > >
> > > The old QMP library didn't support this, and I used the old library as my
> > > template here. I'm willing to change the address format and types to be
> > > more comprehensive, but I was thinking that it should probably try to
> > match
> > > or adhere to some standard; de-facto or otherwise. I wasn't sure which to
> > > pick, and we use a few different ones in QEMU itself. Any recommendations
> > > for me?
> >
> > I asked because I know QAPI specifies TCP as string/string (the
> > hostname as a string makes absolute sense, but the port number as a
> > string is because of the less-used feature of a well-known port name).
> > I'm fine if the initial patch uses an int for the port number here; we
> > can always add support for more formats down the road when someone
> > actually has a use for them.
> >
> >
> https://docs.python.org/3/library/socket.html#socket-families
>
> "A pair (host, port) is used for the AF_INET address family, where host is
> a string representing either a hostname in Internet domain notation like '
> daring.cwi.nl' or an IPv4 address like '100.50.200.5', and port is an
> integer."
>
> The docs seem to suggest that I am actually limited only to integers here.
> Do you have an example of using a string for a port number? I have to admit
> I am not well acquainted with it.
QEMU uses getaddrinfo() at inet_parse_connect_saddr() to translate the
string/string pair to a socket address.
Python equivalent:
>> socket.getaddrinfo('localhost', 'ssh')
[(, , 6, '', ('::1', 22,
0, 0)), (, , 17, '',
('::1', 22, 0, 0)), (, ,
132, '', ('::1', 22, 0, 0)), (, , 132, '', ('::1', 22, 0,
0)), (, , 6, '',
('127.0.0.1', 22)), (, ,
17, '', ('127.0.0.1', 22)), (, , 132, '', ('127.0.0.1', 22)),
(, , 132, '',
('127.0.0.1', 22))]
Translating this to the correct arguments to socket.socket() and
socket.socket.connect() seems overly complicated, though.
--
Eduardo
Re: [PATCH v3 09/25] python/aqmp: add AsyncProtocol.accept() method
On Thu, Aug 19, 2021 at 10:50 AM Eric Blake wrote: > On Wed, Aug 18, 2021 at 10:24:52AM -0400, John Snow wrote: > > > > > > > > +@upper_half > > > > +@require(Runstate.IDLE) > > > > +async def accept(self, address: Union[str, Tuple[str, int]], > > > > + ssl: Optional[SSLContext] = None) -> None: > > > > +""" > > > > +Accept a connection and begin processing message queues. > > > > + > > > > +If this call fails, `runstate` is guaranteed to be set back > to > > > `IDLE`. > > > > + > > > > +:param address: > > > > +Address to listen to; UNIX socket path or TCP > address/port. > > > > > > Can't TCP use a well-known port name instead of an int? But limiting > > > clients to just int port for now isn't fatal to the patch. > > > > > > > > The old QMP library didn't support this, and I used the old library as my > > template here. I'm willing to change the address format and types to be > > more comprehensive, but I was thinking that it should probably try to > match > > or adhere to some standard; de-facto or otherwise. I wasn't sure which to > > pick, and we use a few different ones in QEMU itself. Any recommendations > > for me? > > I asked because I know QAPI specifies TCP as string/string (the > hostname as a string makes absolute sense, but the port number as a > string is because of the less-used feature of a well-known port name). > I'm fine if the initial patch uses an int for the port number here; we > can always add support for more formats down the road when someone > actually has a use for them. > > https://docs.python.org/3/library/socket.html#socket-families "A pair (host, port) is used for the AF_INET address family, where host is a string representing either a hostname in Internet domain notation like ' daring.cwi.nl' or an IPv4 address like '100.50.200.5', and port is an integer." The docs seem to suggest that I am actually limited only to integers here. Do you have an example of using a string for a port number? I have to admit I am not well acquainted with it.
Re: [PATCH v3 09/25] python/aqmp: add AsyncProtocol.accept() method
On Wed, Aug 18, 2021 at 10:24:52AM -0400, John Snow wrote: > > > > > > +@upper_half > > > +@require(Runstate.IDLE) > > > +async def accept(self, address: Union[str, Tuple[str, int]], > > > + ssl: Optional[SSLContext] = None) -> None: > > > +""" > > > +Accept a connection and begin processing message queues. > > > + > > > +If this call fails, `runstate` is guaranteed to be set back to > > `IDLE`. > > > + > > > +:param address: > > > +Address to listen to; UNIX socket path or TCP address/port. > > > > Can't TCP use a well-known port name instead of an int? But limiting > > clients to just int port for now isn't fatal to the patch. > > > > > The old QMP library didn't support this, and I used the old library as my > template here. I'm willing to change the address format and types to be > more comprehensive, but I was thinking that it should probably try to match > or adhere to some standard; de-facto or otherwise. I wasn't sure which to > pick, and we use a few different ones in QEMU itself. Any recommendations > for me? I asked because I know QAPI specifies TCP as string/string (the hostname as a string makes absolute sense, but the port number as a string is because of the less-used feature of a well-known port name). I'm fine if the initial patch uses an int for the port number here; we can always add support for more formats down the road when someone actually has a use for them. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org
Re: [PATCH v3 09/25] python/aqmp: add AsyncProtocol.accept() method
On Tue, Aug 17, 2021 at 3:30 PM Eric Blake wrote: > On Tue, Aug 03, 2021 at 02:29:25PM -0400, John Snow wrote: > > It's a little messier than connect, because it wasn't designed to accept > > *precisely one* connection. Such is life. > > > > Signed-off-by: John Snow > > --- > > python/qemu/aqmp/protocol.py | 89 ++-- > > 1 file changed, 85 insertions(+), 4 deletions(-) > > > > diff --git a/python/qemu/aqmp/protocol.py b/python/qemu/aqmp/protocol.py > > index 77b330627b3..7eca65aa265 100644 > > --- a/python/qemu/aqmp/protocol.py > > +++ b/python/qemu/aqmp/protocol.py > > @@ -243,6 +243,24 @@ async def runstate_changed(self) -> Runstate: > > await self._runstate_event.wait() > > return self.runstate > > > > +@upper_half > > +@require(Runstate.IDLE) > > +async def accept(self, address: Union[str, Tuple[str, int]], > > + ssl: Optional[SSLContext] = None) -> None: > > +""" > > +Accept a connection and begin processing message queues. > > + > > +If this call fails, `runstate` is guaranteed to be set back to > `IDLE`. > > + > > +:param address: > > +Address to listen to; UNIX socket path or TCP address/port. > > Can't TCP use a well-known port name instead of an int? But limiting > clients to just int port for now isn't fatal to the patch. > > The old QMP library didn't support this, and I used the old library as my template here. I'm willing to change the address format and types to be more comprehensive, but I was thinking that it should probably try to match or adhere to some standard; de-facto or otherwise. I wasn't sure which to pick, and we use a few different ones in QEMU itself. Any recommendations for me? > > +:param ssl: SSL context to use, if any. > > + > > +:raise StateError: When the `Runstate` is not `IDLE`. > > +:raise ConnectError: If a connection could not be accepted. > > +""" > > +await self._new_session(address, ssl, accept=True) > > + > > Reviewed-by: Eric Blake > > -- > Eric Blake, Principal Software Engineer > Red Hat, Inc. +1-919-301-3266 > Virtualization: qemu.org | libvirt.org > >
Re: [PATCH v3 09/25] python/aqmp: add AsyncProtocol.accept() method
On Tue, Aug 03, 2021 at 02:29:25PM -0400, John Snow wrote: > It's a little messier than connect, because it wasn't designed to accept > *precisely one* connection. Such is life. > > Signed-off-by: John Snow > --- > python/qemu/aqmp/protocol.py | 89 ++-- > 1 file changed, 85 insertions(+), 4 deletions(-) > > diff --git a/python/qemu/aqmp/protocol.py b/python/qemu/aqmp/protocol.py > index 77b330627b3..7eca65aa265 100644 > --- a/python/qemu/aqmp/protocol.py > +++ b/python/qemu/aqmp/protocol.py > @@ -243,6 +243,24 @@ async def runstate_changed(self) -> Runstate: > await self._runstate_event.wait() > return self.runstate > > +@upper_half > +@require(Runstate.IDLE) > +async def accept(self, address: Union[str, Tuple[str, int]], > + ssl: Optional[SSLContext] = None) -> None: > +""" > +Accept a connection and begin processing message queues. > + > +If this call fails, `runstate` is guaranteed to be set back to > `IDLE`. > + > +:param address: > +Address to listen to; UNIX socket path or TCP address/port. Can't TCP use a well-known port name instead of an int? But limiting clients to just int port for now isn't fatal to the patch. > +:param ssl: SSL context to use, if any. > + > +:raise StateError: When the `Runstate` is not `IDLE`. > +:raise ConnectError: If a connection could not be accepted. > +""" > +await self._new_session(address, ssl, accept=True) > + Reviewed-by: Eric Blake -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org
[PATCH v3 09/25] python/aqmp: add AsyncProtocol.accept() method
It's a little messier than connect, because it wasn't designed to accept
*precisely one* connection. Such is life.
Signed-off-by: John Snow
---
python/qemu/aqmp/protocol.py | 89 ++--
1 file changed, 85 insertions(+), 4 deletions(-)
diff --git a/python/qemu/aqmp/protocol.py b/python/qemu/aqmp/protocol.py
index 77b330627b3..7eca65aa265 100644
--- a/python/qemu/aqmp/protocol.py
+++ b/python/qemu/aqmp/protocol.py
@@ -243,6 +243,24 @@ async def runstate_changed(self) -> Runstate:
await self._runstate_event.wait()
return self.runstate
+@upper_half
+@require(Runstate.IDLE)
+async def accept(self, address: Union[str, Tuple[str, int]],
+ ssl: Optional[SSLContext] = None) -> None:
+"""
+Accept a connection and begin processing message queues.
+
+If this call fails, `runstate` is guaranteed to be set back to `IDLE`.
+
+:param address:
+Address to listen to; UNIX socket path or TCP address/port.
+:param ssl: SSL context to use, if any.
+
+:raise StateError: When the `Runstate` is not `IDLE`.
+:raise ConnectError: If a connection could not be accepted.
+"""
+await self._new_session(address, ssl, accept=True)
+
@upper_half
@require(Runstate.IDLE)
async def connect(self, address: Union[str, Tuple[str, int]],
@@ -308,7 +326,8 @@ def _set_state(self, state: Runstate) -> None:
@upper_half
async def _new_session(self,
address: Union[str, Tuple[str, int]],
- ssl: Optional[SSLContext] = None) -> None:
+ ssl: Optional[SSLContext] = None,
+ accept: bool = False) -> None:
"""
Establish a new connection and initialize the session.
@@ -317,9 +336,10 @@ async def _new_session(self,
to be set back to `IDLE`.
:param address:
-Address to connect to;
+Address to connect to/listen on;
UNIX socket path or TCP address/port.
:param ssl: SSL context to use, if any.
+:param accept: Accept a connection instead of connecting when `True`.
:raise ConnectError:
When a connection or session cannot be established.
@@ -333,7 +353,7 @@ async def _new_session(self,
try:
phase = "connection"
-await self._establish_connection(address, ssl)
+await self._establish_connection(address, ssl, accept)
phase = "session"
await self._establish_session()
@@ -367,6 +387,7 @@ async def _establish_connection(
self,
address: Union[str, Tuple[str, int]],
ssl: Optional[SSLContext] = None,
+accept: bool = False
) -> None:
"""
Establish a new connection.
@@ -375,6 +396,7 @@ async def _establish_connection(
Address to connect to/listen on;
UNIX socket path or TCP address/port.
:param ssl: SSL context to use, if any.
+:param accept: Accept a connection instead of connecting when `True`.
"""
assert self.runstate == Runstate.IDLE
self._set_state(Runstate.CONNECTING)
@@ -384,7 +406,66 @@ async def _establish_connection(
# otherwise yield.
await asyncio.sleep(0)
-await self._do_connect(address, ssl)
+if accept:
+await self._do_accept(address, ssl)
+else:
+await self._do_connect(address, ssl)
+
+@upper_half
+async def _do_accept(self, address: Union[str, Tuple[str, int]],
+ ssl: Optional[SSLContext] = None) -> None:
+"""
+Acting as the transport server, accept a single connection.
+
+:param address:
+Address to listen on; UNIX socket path or TCP address/port.
+:param ssl: SSL context to use, if any.
+
+:raise OSError: For stream-related errors.
+"""
+self.logger.debug("Awaiting connection on %s ...", address)
+connected = asyncio.Event()
+server: Optional[asyncio.AbstractServer] = None
+
+async def _client_connected_cb(reader: asyncio.StreamReader,
+ writer: asyncio.StreamWriter) -> None:
+"""Used to accept a single incoming connection, see below."""
+nonlocal server
+nonlocal connected
+
+# A connection has been accepted; stop listening for new ones.
+assert server is not None
+server.close()
+await server.wait_closed()
+server = None
+
+# Register this client as being connected
+self._reader, self._writer = (reader, writer)
+
+# Signal back: We've accepted a client!
+connected.set()
+
+if isinstance(address, tuple):
+coro = asyncio.start_server(
+
