view tests/dummysmtpd.py @ 29859:a1092e2d70a3

help: internals topic for wire protocol

The Mercurial wire protocol is under-documented. This includes a lack
of source docstrings and comments as well as pages on the official
wiki.

This patch adds the beginnings of "internals" documentation on the
wire protocol.

The documentation should have nearly complete coverage on the
lower-level parts of the protocol, such as the different transport
mechanims, how commands and arguments are sent, capabilities, and,
of course, the commands themselves.

As part of writing this documentation, I discovered a number of
deficiencies in the protocol and bugs in the implementation. I've
started sending patches for some of the issues. I hope to send a lot
more.

This patch starts with the scaffolding for a new internals page.

#!/usr/bin/env python

"""dummy SMTP server for use in tests"""

from __future__ import absolute_import

import asyncore
import optparse
import smtpd
import ssl
import sys

from mercurial import (
    cmdutil,
    sslutil,
    ui as uimod,
)

def log(msg):
    sys.stdout.write(msg)
    sys.stdout.flush()

class dummysmtpserver(smtpd.SMTPServer):
    def __init__(self, localaddr):
        smtpd.SMTPServer.__init__(self, localaddr, remoteaddr=None)

    def process_message(self, peer, mailfrom, rcpttos, data):
        log('%s from=%s to=%s\n' % (peer[0], mailfrom, ', '.join(rcpttos)))

class dummysmtpsecureserver(dummysmtpserver):
    def __init__(self, localaddr, certfile):
        dummysmtpserver.__init__(self, localaddr)
        self._certfile = certfile

    def handle_accept(self):
        pair = self.accept()
        if not pair:
            return
        conn, addr = pair
        ui = uimod.ui()
        try:
            # wrap_socket() would block, but we don't care
            conn = sslutil.wrapserversocket(conn, ui, certfile=self._certfile)
        except ssl.SSLError:
            log('%s ssl error\n' % addr[0])
            conn.close()
            return
        smtpd.SMTPChannel(self, conn, addr)

def run():
    try:
        asyncore.loop()
    except KeyboardInterrupt:
        pass

def main():
    op = optparse.OptionParser()
    op.add_option('-d', '--daemon', action='store_true')
    op.add_option('--daemon-postexec', action='append')
    op.add_option('-p', '--port', type=int, default=8025)
    op.add_option('-a', '--address', default='localhost')
    op.add_option('--pid-file', metavar='FILE')
    op.add_option('--tls', choices=['none', 'smtps'], default='none')
    op.add_option('--certificate', metavar='FILE')

    opts, args = op.parse_args()
    if opts.tls == 'smtps' and not opts.certificate:
        op.error('--certificate must be specified')

    addr = (opts.address, opts.port)
    def init():
        if opts.tls == 'none':
            dummysmtpserver(addr)
        else:
            dummysmtpsecureserver(addr, opts.certificate)
        log('listening at %s:%d\n' % addr)

    cmdutil.service(vars(opts), initfn=init, runfn=run,
                    runargs=[sys.executable, __file__] + sys.argv[1:])

if __name__ == '__main__':
    main()