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