testmx.py

#!/usr/bin/env python3
# test MXes
# thread version

# Copyright 2019-2020 Standcore LLC
#
# Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
#
# 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
#
# 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

import dns.resolver
import argparse
import sys
import pymysql
import concurrent.futures
import socket
import struct 
import smtplib

# eai dict indexed by MX addr
# contains (ndoms, name, okeai, ok8bit)

dolist = []
eai = dict()
oldtld = None
clientaddr = None
timeout = 30
replace = False
mx = dict()                             # mx'es we've already tested
dbmx = None                             # mx'es from the database
parallel = None

def process(f):
    """
    process file of the form
    domain exchange v4address
    """

    global oldtld, eai, dolist, mx, dbmx

    for l in f:
        if l.startswith('###'):  # end of tld
            if dolist:
                testmx()
            if eai:
                putaway(replace)
            eai = dict()
            print("end", oldtld)
            oldtld = None
            continue

        (dom, exch, addr) = l.split()[:3]
        #print(dom,addr)
        if dom[-1] == '.':
            dom = dom[:-1]
        if "." not in dom:
            print("mystery domain",dom)
            continue
        tld = dom.rsplit('.', maxsplit=1)[1].lower()
        if tld != oldtld:
            if dolist:
                testmx()
            if eai:
                putaway(replace)
            eai = dict()
            oldtld = tld
            print("start", oldtld)

        if addr in eai:
            eai[addr][0] += 1
            continue

        if addr in mx:
            eai[addr] = [1, exch ] + mx[addr]
            continue

        if dbmx and addr in dbmx:
            eai[addr] = [1, exch ] + dbmx[addr]
            print(addr,exch,"from db")
            continue

        # need to test this one
        eai[addr] = [ 1, exch ]
        dolist.append(addr)
        if len(dolist) >= parallel:
            testmx()

mtas = (b"Postfix", b"Sendmail", b"Exim", b"MailSite", b"protection.outlook", b"Microsoft", b"gsmtp",
    b"Haraka", b"Nemesis", b"Amazon SES", b"bizsmtp", b"MailEnable", b"MDaemon", b"CommuniGate",
    b"hostedemail", b"yahoo.com")

def tmx1(addr):
    """ test one MX in thread
    """
    #print("test", addr)
    if addr in ("0.0.0.0", "1.1.1.1", "127.0.0.1"):
        return (addr, False, False, "Noaddr")

    try:
        if clientaddr:
            sess = smtplib.SMTP(timeout=timeout, source_address=(clientaddr, 0))
        else:
            sess = smtplib.SMTP(timeout=timeout)
        if not sess:
            return (addr, False, False, "Norej")
        ms = sess.connect(addr);
        if ms[0] != 220:
            print("bad greet",ms)
            return (addr, False, False, "Nogreet")
        s = sess.ehlo()
        sess.quit()
        if s[0] != 250:
            print("bad ehlo",s)
            return (addr, False, False, "Nohelo")
        # mta signature
        print("mta sig is", ms[1])
        mta = None
        for mm in mtas:
            if mm in ms[1]:
                mta = mm
                #print("it is",mta)
                break

        #print("text is",s[1])
        r = (addr, b"SMTPUTF8" in s[1], b"8BITMIME" in s[1], mta)
        print("return",r)
        return r
    except (OSError, PermissionError, socket.timeout, TimeoutError, smtplib.SMTPServerDisconnected, ConnectionRefusedError):
        print("fail",addr)
        return (addr, False, False, "Noconn")

def testmx():
    """
    test all the MTAs in dolist
    """

    global dolist, mx

    print("test", oldtld, len(dolist))
    fl = []
    with concurrent.futures.ThreadPoolExecutor(max_workers=parallel) as tex:
        for d in dolist:
            fl.append(tex.submit(tmx1, d))

        for future in concurrent.futures.as_completed(fl):
            try:
                r = future.result()
                if r:
                    (addr,okeai,ok8bit,mtasw) = r
                    #print(addr, okeai, ok8bit,mtasw)
                    oldr = eai[addr]
                    eai[addr] = oldr[:2] + list(r[1:])
                    mx[addr] = list(r[1:])
            except Exception as exc:
                print("thread barf", exc, file=sys.stderr)
    dolist = []
        
def putaway(replace=False):
    """
    store everything in eai
    as tld oldtld
    """

    global eai,oldtld
    
    def aton(s):
        """ ipv4 to unsigned int """
        return struct.unpack(">I", socket.inet_aton(s))[0]

    db = pymysql.connect(user='eaimail',password='x',db='eaimail')
    ex = [ [oldtld, aton(a)]+i for (a,i) in eai.items() if len(i) == 5]
    print("to database",ex)
    with db.cursor() as cur:
        if replace:
            cur.execute("""DELETE FROM eaimail WHERE tld=%s""", (oldtld,))

        cur.executemany("""REPLACE INTO eaimail(tld, mxip, ndomain, mx, neai,n8bit,mtasw,scandate)
            values(%s,%s,%s,%s,%s,%s,%s,DATE(NOW()))""",
            ex)
    db.commit()
            
if __name__ == '__main__':
    parser = argparse.ArgumentParser(description='check whether MX is EAI')
    parser.add_argument('--par', type=int, help="Do this many in parallel (default 10)");
    parser.add_argument('--timeout', type=int, help="connection timeout (default 30)");
    parser.add_argument('--addr', type=str, help="IP client address");
    parser.add_argument('--replace', action='store_true', help="replace current DB entries");
    parser.add_argument('--dbmx', action='store_true', help="use MX info from existing database");
    parser.add_argument('domains', type=str, nargs='*', help="domain exch addr aaaaddr");
    args = parser.parse_args();
    
    parallel = args.par or 10
    clientaddr = args.addr
    timeout = args.timeout or 30
    replace = args.replace
    
    if args.dbmx:
        db = pymysql.connect(host='g4.iecc.com',user='eaimail',password='x',db='eaimail')
        with db.cursor() as cur:
            r = cur.execute("""SELECT inet_ntoa(mxip),neai,n8bit,mtasw FROM eaimail GROUP BY mxip""")
            dbmx = { m[0]: [ bool(m[1]), bool(m[2]), m[3] ] for m in cur.fetchall() }
        print("fetched {} mx from db".format(len(dbmx)))

    eai = dict()
    if args.domains:
        for zf in args.domains:
            try:
                if '.gz' in zf:
                    f = gzip.open(zf, 'r')
                else:
                    f = open(zf, 'r')
            except FileNotFoundError:
                print("Cannot open file", zf)
                continue
            process(f)
            f.close()
    else:
        process(sys.stdin)

    if dolist:
        testmx()

    if eai:
        putaway(replace)