wireprotoserver: move SSH server operation to a standalone function
The server-side processing logic will soon get a bit more complicated
in order to handle protocol switches. We will use a state machine
to help make the transitions clearer.
To prepare for this, we move SSH server operation into a standalone
function. We structure it as a very simple state machine. It only
has two states for now, with one state containing the bulk of the
logic. But things will evolve shortly.
Differential Revision: https://phab.mercurial-scm.org/D2203
--- a/mercurial/wireprotoserver.py Wed Feb 14 17:35:13 2018 -0700
+++ b/mercurial/wireprotoserver.py Thu Feb 08 15:09:59 2018 -0800
@@ -409,6 +409,56 @@
client = encoding.environ.get('SSH_CLIENT', '').split(' ', 1)[0]
return 'remote:ssh:' + client
+def _runsshserver(ui, repo, fin, fout):
+ state = 'protov1-serving'
+ proto = sshv1protocolhandler(ui, fin, fout)
+
+ while True:
+ if state == 'protov1-serving':
+ # Commands are issued on new lines.
+ request = fin.readline()[:-1]
+
+ # Empty lines signal to terminate the connection.
+ if not request:
+ state = 'shutdown'
+ continue
+
+ available = wireproto.commands.commandavailable(request, proto)
+
+ # This command isn't available. Send an empty response and go
+ # back to waiting for a new command.
+ if not available:
+ _sshv1respondbytes(fout, b'')
+ continue
+
+ rsp = wireproto.dispatch(repo, proto, request)
+
+ if isinstance(rsp, bytes):
+ _sshv1respondbytes(fout, rsp)
+ elif isinstance(rsp, wireprototypes.bytesresponse):
+ _sshv1respondbytes(fout, rsp.data)
+ elif isinstance(rsp, wireprototypes.streamres):
+ _sshv1respondstream(fout, rsp)
+ elif isinstance(rsp, wireprototypes.streamreslegacy):
+ _sshv1respondstream(fout, rsp)
+ elif isinstance(rsp, wireprototypes.pushres):
+ _sshv1respondbytes(fout, b'')
+ _sshv1respondbytes(fout, b'%d' % rsp.res)
+ elif isinstance(rsp, wireprototypes.pusherr):
+ _sshv1respondbytes(fout, rsp.res)
+ elif isinstance(rsp, wireprototypes.ooberror):
+ _sshv1respondooberror(fout, ui.ferr, rsp.message)
+ else:
+ raise error.ProgrammingError('unhandled response type from '
+ 'wire protocol command: %s' % rsp)
+
+ elif state == 'shutdown':
+ break
+
+ else:
+ raise error.ProgrammingError('unhandled ssh server state: %s' %
+ state)
+
class sshserver(object):
def __init__(self, ui, repo):
self._ui = ui
@@ -423,36 +473,6 @@
util.setbinary(self._fin)
util.setbinary(self._fout)
- self._proto = sshv1protocolhandler(self._ui, self._fin, self._fout)
-
def serve_forever(self):
- while self.serve_one():
- pass
+ _runsshserver(self._ui, self._repo, self._fin, self._fout)
sys.exit(0)
-
- def serve_one(self):
- cmd = self._fin.readline()[:-1]
- if cmd and wireproto.commands.commandavailable(cmd, self._proto):
- rsp = wireproto.dispatch(self._repo, self._proto, cmd)
-
- if isinstance(rsp, bytes):
- _sshv1respondbytes(self._fout, rsp)
- elif isinstance(rsp, wireprototypes.bytesresponse):
- _sshv1respondbytes(self._fout, rsp.data)
- elif isinstance(rsp, wireprototypes.streamres):
- _sshv1respondstream(self._fout, rsp)
- elif isinstance(rsp, wireprototypes.streamreslegacy):
- _sshv1respondstream(self._fout, rsp)
- elif isinstance(rsp, wireprototypes.pushres):
- _sshv1respondbytes(self._fout, b'')
- _sshv1respondbytes(self._fout, b'%d' % rsp.res)
- elif isinstance(rsp, wireprototypes.pusherr):
- _sshv1respondbytes(self._fout, rsp.res)
- elif isinstance(rsp, wireprototypes.ooberror):
- _sshv1respondooberror(self._fout, self._ui.ferr, rsp.message)
- else:
- raise error.ProgrammingError('unhandled response type from '
- 'wire protocol command: %s' % rsp)
- elif cmd:
- _sshv1respondbytes(self._fout, b'')
- return cmd != ''
--- a/tests/sshprotoext.py Wed Feb 14 17:35:13 2018 -0700
+++ b/tests/sshprotoext.py Thu Feb 08 15:09:59 2018 -0800
@@ -48,7 +48,9 @@
wireprotoserver._sshv1respondbytes(self._fout, b'')
l = self._fin.readline()
assert l == b'between\n'
- rsp = wireproto.dispatch(self._repo, self._proto, b'between')
+ proto = wireprotoserver.sshv1protocolhandler(self._ui, self._fin,
+ self._fout)
+ rsp = wireproto.dispatch(self._repo, proto, b'between')
wireprotoserver._sshv1respondbytes(self._fout, rsp.data)
super(prehelloserver, self).serve_forever()
@@ -72,8 +74,10 @@
self._fin.read(81)
# Send the upgrade response.
+ proto = wireprotoserver.sshv1protocolhandler(self._ui, self._fin,
+ self._fout)
self._fout.write(b'upgraded %s %s\n' % (token, name))
- servercaps = wireproto.capabilities(self._repo, self._proto)
+ servercaps = wireproto.capabilities(self._repo, proto)
rsp = b'capabilities: %s' % servercaps.data
self._fout.write(b'%d\n' % len(rsp))
self._fout.write(rsp)
--- a/tests/test-sshserver.py Wed Feb 14 17:35:13 2018 -0700
+++ b/tests/test-sshserver.py Thu Feb 08 15:09:59 2018 -0800
@@ -23,8 +23,11 @@
def assertparse(self, cmd, input, expected):
server = mockserver(input)
+ proto = wireprotoserver.sshv1protocolhandler(server._ui,
+ server._fin,
+ server._fout)
_func, spec = wireproto.commands[cmd]
- self.assertEqual(server._proto.getargs(spec), expected)
+ self.assertEqual(proto.getargs(spec), expected)
def mockserver(inbytes):
ui = mockui(inbytes)