smailq

   1 #!/usr/bin/env python3
   2 """A mail queue for lightweight SMTP clients (MSAs) like msmtp."""
   3
   4 __author__ = "Stefan Huber"
   5 __copyright__ = "Copyright 2013"
   6
   7 __license__ = "LGPL-3"
   8 __version__ = "1.0"
   9
  10
  11 from contextlib import contextmanager
  12 import configparser
  13 import fcntl
  14 import getopt
  15 import os
  16 import pickle
  17 import random
  18 import shlex
  19 import subprocess
  20 import sys
  21 import time
  22 import socket
  23 import syslog
  24
  25
  26 verbose = False
  27 quiet = False
  28
  29
  30 class Config:
  31     """Configuration read from a config file"""
  32
  33     class ConfigError(RuntimeError):
  34         """Error when reading config file"""
  35         def __init__(self, value):
  36             self.value = value
  37             self.message = value
  38
  39     def __init__(self, conffn):
  40         self.logdir = None
  41         self.datadir = None
  42         self.nwtesthost = None
  43         self.nwtestport = None
  44         self.nwtesttimeout = None
  45         self.msacmd = None
  46
  47         self.__nwtest = None
  48
  49         self.__read(conffn)
  50
  51     def __read(self, conffn):
  52         conf = configparser.RawConfigParser()
  53         conf.read(conffn)
  54
  55         self.logdir = "~/.smailq/log"
  56         self.datadir = "~/.smailq/data"
  57         self.nwtesthost = "www.google.com"
  58         self.nwtestport = 80
  59         self.nwtesttimeout = 8
  60
  61         self.logdir = conf.get("general", "logdir", fallback=self.logdir)
  62         self.datadir = conf.get("general", "datadir", fallback=self.datadir)
  63         self.nwtesthost = conf.get("nwtest", "host", fallback=self.nwtesthost)
  64         self.nwtestport = conf.getint("nwtest", "port",
  65                                       fallback=self.nwtestport)
  66         self.nwtesttimeout = conf.getint("nwtest", "timeout",
  67                                          fallback=self.nwtesttimeout)
  68
  69         if not conf.has_option("msa", "cmd"):
  70             raise Config.ConfigError("Section 'msa' contains no 'cmd' option.")
  71         self.msacmd = conf.get("msa", "cmd")
  72
  73     def getdatadir(self):
  74         """Returns the directory for the mail data"""
  75         return os.path.expanduser(self.datadir)
  76
  77     def getlogdir(self):
  78         """Returns the directory for the log data"""
  79         return os.path.expanduser(self.logdir)
  80
  81     def getlockfn(self):
  82         """Get a lock filename of the data directory"""
  83         return self.getdatadir() + "/.lock"
  84
  85     def getmailfn(self, id):
  86         return self.getdatadir() + "/" + id + ".eml"
  87
  88     def getmsaargsfn(self, id):
  89         return self.getdatadir() + "/" + id + ".msaargs"
  90
  91     @contextmanager
  92     def aquiredatalock(self):
  93         """Get a lock on the data directory"""
  94         fn = self.getlockfn()
  95
  96         # If lock file exists, wait until it disappears
  97         while os.path.exists(fn):
  98             time.sleep(0.05)
  99
 100         # Use lockf to get exclusive access to file
 101         fp = open(fn, 'w')
 102         fcntl.lockf(fp, fcntl.LOCK_EX)
 103         try:
 104             yield
 105         finally:
 106             fcntl.lockf(fp, fcntl.LOCK_UN)
 107             fp.close()
 108             os.remove(self.getlockfn())
 109
 110     def networktest(self):
 111         """Test if we have connection to the internet."""
 112
 113         if self.__nwtest is None:
 114             self.__nwtest = False
 115             try:
 116                 host = (self.nwtesthost, self.nwtestport)
 117                 to = self.nwtesttimeout
 118                 with socket.create_connection(host, timeout=to):
 119                     self.__nwtest = True
 120             except OSError as e:
 121                 pass
 122             except Exception as e:
 123                 printerr(e)
 124
 125         return self.__nwtest
 126
 127
 128 class MailQueue:
 129
 130     def __init__(self, conf):
 131         self.conf = conf
 132         self.__mailids = None
 133
 134     def get_mail_ids(self):
 135         """Return a list of all mail IDs"""
 136
 137         # Get mail and msaargs files in datadir
 138         listdir = os.listdir(self.conf.getdatadir())
 139         mailfiles = [f for f in listdir if f.endswith(".eml")]
 140         msaargsfiles = [f for f in listdir if f.endswith(".msaargs")]
 141
 142         # Strip of file endings
 143         mailfiles = [f[:-4] for f in mailfiles]
 144         msaargsfiles = [f[:-8] for f in msaargsfiles]
 145
 146         # Check if symmetric difference is zero
 147         for f in set(mailfiles) - set(msaargsfiles):
 148             printerr("For ID %s an eml file but no msaargs file exists." % f)
 149         for f in set(msaargsfiles) - set(mailfiles):
 150             printerr("For ID %s a msaargs file but no eml file exists." % f)
 151
 152         # Get mail IDs
 153         return set(mailfiles) & set(msaargsfiles)
 154
 155     def getmailinfo(self, id):
 156         """Get some properties of mail with given ID"""
 157         assert(id in self.get_mail_ids())
 158
 159         mailfn = self.conf.getmailfn(id)
 160
 161         info = {}
 162         info['ctime'] = time.ctime(os.path.getctime(mailfn))
 163         info['size'] = os.path.getsize(mailfn)
 164         info['to'] = ""
 165         info['subject'] = ""
 166
 167         with open(mailfn, "rb") as f:
 168             mail = f.read().decode('utf8', 'replace').splitlines()
 169
 170             for l in mail:
 171                 if l.startswith("Subject:"):
 172                     info['subject'] = l[8:].strip()
 173                     break
 174
 175             for l in mail:
 176                 if l.startswith("To:"):
 177                     info['to'] = l[3:].strip()
 178                     break
 179                 if l.startswith("Cc:"):
 180                     info['to'] = l[3:].strip()
 181
 182         return info
 183
 184     def printmailinfo(self, id):
 185         """Print some info on the mail with given ID"""
 186
 187         print("ID %s:" % id)
 188
 189         if not id in self.get_mail_ids():
 190             printerr("ID %s is not in the queue!" % id)
 191             return
 192
 193         info = self.getmailinfo(id)
 194
 195         print("  Time: %s" % info['ctime'])
 196         print("  Size: %s Bytes" % info['size'])
 197         print("  To: %s" % info['to'])
 198         print("  Subject: %s" % info['subject'])
 199
 200     def listqueue(self):
 201         """Print a list of mails in the mail queue"""
 202
 203         ids = self.get_mail_ids()
 204         print("%d mails in the queue.\n" % len(ids))
 205         for id in ids:
 206             self.printmailinfo(id)
 207             print()
 208
 209     def deletemail(self, id):
 210         """Attempt to deliver mail with given ID"""
 211         printinfo("Removing mail with ID " + id)
 212
 213         if not id in self.get_mail_ids():
 214             printerr("ID %s is not in the queue!" % id)
 215             return
 216
 217         os.remove(conf.getmailfn(id))
 218         os.remove(conf.getmsaargsfn(id))
 219         log(conf, "Removed from queue.", id=id)
 220
 221     def delivermail(self, id):
 222         """Attempt to deliver mail with given ID"""
 223         printinfo("Deliver mail with ID " + id)
 224
 225         if not id in self.get_mail_ids():
 226             printerr("ID %s is not in the queue!" % id)
 227             return
 228
 229         if not self.conf.networktest():
 230             printinfo("Network down. Do not deliver mail.")
 231             return
 232
 233         info = self.getmailinfo(id)
 234         log(conf, "Attempting to deliver mail. To=%s" % info['to'], id=id)
 235
 236         # Read the mail
 237         mailfn = self.conf.getmailfn(id)
 238         mailf = open(mailfn, "rb")
 239
 240         # Read the options
 241         msaargsfn = self.conf.getmsaargsfn(id)
 242         msaargs = None
 243         with open(msaargsfn, "rb") as f:
 244             msaargs = pickle.load(f)
 245
 246         # Build argv for the MSA
 247         msacmd = self.conf.msacmd
 248         msaargv = shlex.split(msacmd)
 249         msaargv += msaargs
 250
 251         # Call the MSA and give it the mail
 252         printinfo("Calling " + " ".join([shlex.quote(m) for m in msaargv]))
 253         ret = subprocess.call(msaargv, stdin=mailf)
 254
 255         if ret == 0:
 256             log(conf, "Delivery successful.", id=id)
 257             self.deletemail(id)
 258         else:
 259             log(conf, "Delivery failed with exit code %d." % ret, id=id)
 260
 261     def delivermails(self):
 262         """Attempt to deliver all mails in the mail queue"""
 263         printinfo("Deliver mails in the queue.")
 264
 265         if not self.conf.networktest():
 266             printinfo("Network down. Do not deliver mails.")
 267             return
 268
 269         for id in self.get_mail_ids():
 270             self.delivermail(id)
 271
 272     def enqueuemail(self, mail, msaargs):
 273         """Insert the given mail into the mail queue"""
 274         # Creeate a new ID
 275         id = None
 276         while True:
 277             nibbles = 8
 278             id = hex(random.getrandbits(4*nibbles))[2:].upper()
 279             while len(id) < nibbles:
 280                 id = '0' + id
 281             if not os.path.exists(self.conf.getmailfn(id)):
 282                 break
 283
 284         log(conf, "Insert into queue.", id=id)
 285
 286         # Write the mail
 287         mailfn = self.conf.getmailfn(id)
 288         with open(mailfn, "wb") as f:
 289             f.write(mail)
 290
 291         # Write the options
 292         msaargsfn = self.conf.getmsaargsfn(id)
 293         with open(msaargsfn, "wb") as f:
 294             pickle.dump(msaargs, f)
 295
 296         return id
 297
 298     def sendmail(self, mail, msaargs):
 299         """Insert a mail in the mail queue, and attempt to deliver mails"""
 300         self.enqueuemail(mail, msaargs)
 301         self.delivermails()
 302
 303
 304 def log(conf, msg, id=None):
 305     """Write message to log file"""
 306     # Prepend ID to msg
 307     if id is not None:
 308         msg = ("ID %s: " % id) + msg
 309
 310     if conf.getlogdir() == 'syslog':
 311         syslog.syslog(msg)
 312         return
 313
 314     fn = conf.getlogdir() + "/smailq.log"
 315
 316     with open(fn, 'a') as f:
 317         fcntl.lockf(f, fcntl.LOCK_EX)
 318
 319         # Prepend time to msg
 320         msg = time.strftime("%Y-%m-%d %H:%M:%S: ", time.localtime()) + msg
 321
 322         # Write msg line
 323         f.write(msg + "\n")
 324         if not quiet:
 325             print(msg)
 326
 327         fcntl.lockf(f, fcntl.LOCK_UN)
 328
 329
 330 def printerr(msg):
 331     """Print an error message"""
 332     print(msg, file=sys.stderr)
 333
 334
 335 def printinfo(msg):
 336     if verbose:
 337         print(msg)
 338
 339
 340 def version():
 341     """Show version info"""
 342
 343     print("smailq " + __version__)
 344     print("Copyright (C) 2013 Stefan Huber")
 345
 346
 347 def usage():
 348     """Print usage text of this program"""
 349
 350     print("""
 351 smailq is a mail queue for lightweight SMTP clients (MSAs) like msmtp that do
 352 not provide a queue. It basically provides the functionality of sendmail and
 353 mailq.
 354
 355 USAGE:
 356
 357   {0} --send [recipient ...] -- [MSA options ...]
 358   {0} --list
 359   {0} --deliver-all
 360   {0} --deliver [ID ...]
 361   {0} --delete [ID ...]
 362   {0} --help
 363   {0} --version
 364
 365 COMMANDS:
 366
 367       --delete
 368           Remove the mails with given IDs from the queue.
 369
 370       --deliver
 371           Attempt to deliver the mails with given IDs only.
 372
 373       --deliver-all
 374           Attempt to deliver all mails in the queue.
 375
 376   -h, --help
 377           Print this usage text.
 378
 379       --list
 380           List all mails in the queue. This is the default
 381
 382       --send
 383           Read a mail from stdin, insert it into the queue, and attempt to
 384           deliver all mails in the queue. Options after "--" are passed forward
 385           to the MSA for this particular mail.
 386
 387   -V, --version
 388           Show version info.
 389
 390 OPTIONS:
 391
 392   -C, --config=FILE
 393           Use the given configuration file.
 394
 395   -q, --quiet
 396           Do not print info messages.
 397
 398   -v, --verbose
 399           Increase output verbosity.
 400 """.format(sys.argv[0]))
 401
 402
 403 if __name__ == "__main__":
 404
 405     conffn_list = [os.path.expanduser("~/.smailq.conf"), "/etc/smailq.conf"]
 406     cmd = "--list"
 407     nooptargs = []
 408
 409     try:
 410
 411         longopts = ["config=", "delete", "deliver-all", "deliver", "help",
 412                     "list", "send", "verbose", "version", "quiet"]
 413         opts, nooptargs = getopt.gnu_getopt(sys.argv[1:], "hC:vVq", longopts)
 414
 415         for opt, arg in opts:
 416             if opt in ['-h', '--help']:
 417                 usage()
 418                 sys.exit(os.EX_OK)
 419             elif opt in ['-V', '--version']:
 420                 version()
 421                 sys.exit(os.EX_OK)
 422             elif opt in ['--list', '--send', '--delete', '--deliver-all',
 423                          '--deliver']:
 424                 cmd = opt
 425             elif opt in ['-C', '--config']:
 426                 conffn_list = [arg]
 427             elif opt in ['-v', '--verbose']:
 428                 verbose = True
 429                 quiet = False
 430             elif opt in ['-q', '--quiet']:
 431                 quiet = True
 432                 verbose = False
 433             else:
 434                 assert(False)
 435
 436     except getopt.GetoptError as e:
 437         printerr("Error parsing arguments: " + str(e))
 438         usage()
 439         sys.exit(os.EX_USAGE)
 440
 441     # Reading config file
 442     conffn = next((f for f in conffn_list if os.path.isfile(f)), None)
 443     if conffn is None:
 444         printerr("No config file found: " + str(conffn_list))
 445         sys.exit(os.EX_IOERR)
 446     conf = None
 447     try:
 448         conf = Config(conffn)
 449
 450         if not os.path.isdir(conf.getdatadir()):
 451             printerr("Data directory does not exist: " + conf.getdatadir())
 452             sys.exit(os.EX_IOERR)
 453
 454         if conf.getlogdir() == 'syslog':
 455             syslog.openlog('smailq', 0, syslog.LOG_MAIL)
 456         elif not os.path.isdir(conf.getlogdir()):
 457             printinfo('Creating logdir: ' + conf.getlogdir())
 458             os.mkdir(conf.getlogdir())
 459
 460     except Exception as e:
 461         printerr("Error reading config file: " + str(e))
 462         sys.exit(os.EX_IOERR)
 463
 464     try:
 465         with conf.aquiredatalock():
 466
 467             printinfo("Aquired the lock.")
 468
 469             mq = MailQueue(conf)
 470             if cmd == "--send":
 471                 mail = sys.stdin.buffer.read()
 472                 mq.sendmail(mail, nooptargs)
 473             elif cmd == "--list":
 474                 mq.listqueue()
 475             elif cmd == "--deliver-all":
 476                 mq.delivermails()
 477             elif cmd == "--deliver":
 478                 for id in nooptargs:
 479                     mq.delivermail(id)
 480             elif cmd == "--delete":
 481                 for id in nooptargs:
 482                     mq.deletemail(id)
 483
 484     except OSError as e:
 485         printerr(e)
 486         sys.exit(os.EX_IOERR)