tests/dummysmtpd.py

interfaces: introduce and use a protocol class for the `mpatch` module

See f2832de2a46c for details when this was done for the `bdiff` module.

Two things worth pointing out-

  1) The `cffi` module "inherits" the `pure` implementation of `patchedsize()`
     because of its wildcard import.
  2) It's odd that the `mpatchError` lives in both `pure` and `cext` modules.

I initially thought to move the exception into the new class, and make the
existing class name an alias to the class in the new location, but the exception
is created in C code by the `cext` module, so that won't work.  I don't think a
protocol class is approriate, because there's nothing special about the class to
distinguish from any other `Exception`.  Fortunately, nobody is catching this
exception in core, so we can kick the can down the road.

#!/usr/bin/env python

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


import optparse
import os
import socket
import ssl
import sys

from mercurial import (
    pycompat,
    server,
    sslutil,
    ui as uimod,
)


if os.environ.get('HGIPV6', '0') == '1':
    family = socket.AF_INET6
else:
    family = socket.AF_INET


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


def mocksmtpserversession(conn, addr):
    conn.send(b'220 smtp.example.com ESMTP\r\n')

    try:
        # Newer versions of OpenSSL raise on EOF
        line = conn.recv(1024)
    except ssl.SSLError:
        log('no hello: EOF\n')
        return

    if not line.lower().startswith(b'ehlo '):
        # Older versions of OpenSSl don't raise
        log('no hello: %s\n' % line)
        return

    conn.send(b'250 Hello\r\n')

    line = conn.recv(1024)
    if not line.lower().startswith(b'mail from:'):
        log('no mail from: %s\n' % line)
        return
    mailfrom = line[10:].decode().rstrip()
    if mailfrom.startswith('<') and mailfrom.endswith('>'):
        mailfrom = mailfrom[1:-1]

    conn.send(b'250 Ok\r\n')

    rcpttos = []
    while True:
        line = conn.recv(1024)
        if not line.lower().startswith(b'rcpt to:'):
            break
        rcptto = line[8:].decode().rstrip()
        if rcptto.startswith('<') and rcptto.endswith('>'):
            rcptto = rcptto[1:-1]
        rcpttos.append(rcptto)

        conn.send(b'250 Ok\r\n')

    if not line.lower().strip() == b'data':
        log('no rcpt to or data: %s' % line)

    conn.send(b'354 Go ahead\r\n')

    data = b''
    while True:
        line = conn.recv(1024)
        if not line:
            log('connection closed before end of data')
            break
        data += line
        if data.endswith(b'\r\n.\r\n'):
            data = data[:-5]
            break

    conn.send(b'250 Ok\r\n')

    log(
        '%s from=%s to=%s\n%s\n'
        % (addr[0], mailfrom, ', '.join(rcpttos), data.decode())
    )


def run(host, port, certificate):
    ui = uimod.ui.load()
    with socket.socket(family, socket.SOCK_STREAM) as s:
        s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        s.bind((host, port))
        # log('listening at %s:%d\n' % (host, port))
        s.listen(1)
        try:
            while True:
                conn, addr = s.accept()
                if certificate:
                    try:
                        conn = sslutil.wrapserversocket(
                            conn, ui, certfile=certificate
                        )
                    except ssl.SSLError as e:
                        log('%s ssl error: %s\n' % (addr[0], e))
                        conn.close()
                        continue
                log("connection from %s:%s\n" % addr)
                mocksmtpserversession(conn, addr)
                conn.close()
        except KeyboardInterrupt:
            pass


def _encodestrsonly(v):
    if isinstance(v, type(u'')):
        return v.encode('ascii')
    return v


def bytesvars(obj):
    unidict = vars(obj)
    bd = {k.encode('ascii'): _encodestrsonly(v) for k, v in unidict.items()}
    if bd[b'daemon_postexec'] is not None:
        bd[b'daemon_postexec'] = [
            _encodestrsonly(v) for v in bd[b'daemon_postexec']
        ]
    return bd


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')
    op.add_option('--logfile', metavar='FILE')

    opts, args = op.parse_args()
    if (opts.tls == 'smtps') != bool(opts.certificate):
        op.error('--certificate must be specified with --tls=smtps')

    server.runservice(
        bytesvars(opts),
        runfn=lambda: run(opts.address, opts.port, opts.certificate),
        runargs=[pycompat.sysexecutable, pycompat.fsencode(__file__)]
        + pycompat.sysargv[1:],
        logfile=opts.logfile,
    )


if __name__ == '__main__':
    main()