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         info['to'] = ""
 164         info['subject'] = ""
 165
 166         with open(mailfn, "rb") as f:
 167             mail = f.read().decode('utf8', 'replace').splitlines()
 168
 169             for l in mail:
 170                 if l.startswith("Subject:"):
 171                     info['subject'] = l[8:].strip()
 172                     break
 173
 174             for l in mail:
 175                 if l.startswith("To:"):
 176                     info['to'] = l[3:].strip()
 177                     break
 178                 if l.startswith("Cc:"):
 179                     info['to'] = l[3:].strip()
 180
 181         return info
 182
 183     def printmailinfo(self, id):
 184         """Print some info on the mail with given ID"""
 185
 186         print("ID %s:" % id)
 187
 188         if not id in self.get_mail_ids():
 189             printerr("ID %s is not in the queue!" % id)
 190             return
 191
 192         info = self.getmailinfo(id)
 193
 194         print("  Time: %s" % info['ctime'])
 195         print("  Size: %s Bytes" % info['size'])
 196         print("  To: %s" % info['to'])
 197         print("  Subject: %s" % info['subject'])
 198
 199     def listqueue(self):
 200         """Print a list of mails in the mail queue"""
 201
 202         ids = self.get_mail_ids()
 203         print("%d mails in the queue.\n" % len(ids))
 204         for id in ids:
 205             self.printmailinfo(id)
 206             print()
 207
 208     def deletemail(self, id):
 209         """Attempt to deliver mail with given ID"""
 210         printinfo("Removing mail with ID " + id)
 211
 212         if not id in self.get_mail_ids():
 213             printerr("ID %s is not in the queue!" % id)
 214             return
 215
 216         os.remove(conf.getmailfn(id))
 217         os.remove(conf.getmsaargsfn(id))
 218         log(conf, "Removed from queue.", id=id)
 219
 220     def delivermail(self, id):
 221         """Attempt to deliver mail with given ID"""
 222         printinfo("Deliver mail with ID " + id)
 223
 224         if not id in self.get_mail_ids():
 225             printerr("ID %s is not in the queue!" % id)
 226             return
 227
 228         if not self.conf.networktest():
 229             printinfo("Network down. Do not deliver mail.")
 230             return
 231
 232         info = self.getmailinfo(id)
 233         log(conf, "Attempting to deliver mail. To=%s" % info['to'], id=id)
 234
 235         # Read the mail
 236         mailfn = self.conf.getmailfn(id)
 237         mailf = open(mailfn, "rb")
 238
 239         # Read the options
 240         msaargsfn = self.conf.getmsaargsfn(id)
 241         msaargs = None
 242         with open(msaargsfn, "rb") as f:
 243             msaargs = pickle.load(f)
 244
 245         # Build argv for the MSA
 246         msacmd = self.conf.msacmd
 247         msaargv = shlex.split(msacmd)
 248         msaargv += msaargs
 249
 250         # Call the MSA and give it the mail
 251         printinfo("Calling " + " ".join([shlex.quote(m) for m in msaargv]))
 252         ret = subprocess.call(msaargv, stdin=mailf)
 253
 254         if ret == 0:
 255             log(conf, "Delivery successful.", id=id)
 256             self.deletemail(id)
 257         else:
 258             log(conf, "Delivery failed with exit code %d." % ret, id=id)
 259
 260     def delivermails(self):
 261         """Attempt to deliver all mails in the mail queue"""
 262         printinfo("Deliver mails in the queue.")
 263
 264         if not self.conf.networktest():
 265             printinfo("Network down. Do not deliver mails.")
 266             return
 267
 268         for id in self.get_mail_ids():
 269             self.delivermail(id)
 270
 271     def enqueuemail(self, mail, msaargs):
 272         """Insert the given mail into the mail queue"""
 273         # Creeate a new ID
 274         id = None
 275         while True:
 276             nibbles = 8
 277             id = hex(random.getrandbits(4*nibbles))[2:].upper()
 278             while len(id) < nibbles:
 279                 id = '0' + id
 280             if not os.path.exists(self.conf.getmailfn(id)):
 281                 break
 282
 283         log(conf, "Insert into queue.", id=id)
 284
 285         # Write the mail
 286         mailfn = self.conf.getmailfn(id)
 287         with open(mailfn, "wb") as f:
 288             f.write(mail)
 289
 290         # Write the options
 291         msaargsfn = self.conf.getmsaargsfn(id)
 292         with open(msaargsfn, "wb") as f:
 293             pickle.dump(msaargs, f)
 294
 295         return id
 296
 297     def sendmail(self, mail, msaargs):
 298         """Insert a mail in the mail queue, and attempt to deliver mails"""
 299         self.enqueuemail(mail, msaargs)
 300         self.delivermails()
 301
 302
 303 def log(conf, msg, id=None):
 304     """Write message to log file"""
 305     fn = conf.getlogdir() + "/smailq.log"
 306
 307     with open(fn, 'a') as f:
 308         fcntl.lockf(f, fcntl.LOCK_EX)
 309         # Prepend ID to msg
 310         if id is not None:
 311             msg = ("ID %s: " % id) + msg
 312         # Prepend time to msg
 313         msg = time.strftime("%Y-%m-%d %H:%M:%S: ", time.localtime()) + msg
 314
 315         # Write msg line
 316         f.write(msg + "\n")
 317         if not quiet:
 318             print(msg)
 319
 320         fcntl.lockf(f, fcntl.LOCK_UN)
 321
 322
 323 def printerr(msg):
 324     """Print an error message"""
 325     print(msg, file=sys.stderr)
 326
 327
 328 def printinfo(msg):
 329     if verbose:
 330         print(msg)
 331
 332
 333 def version():
 334     """Show version info"""
 335
 336     print("smailq " + __version__)
 337     print("Copyright (C) 2013 Stefan Huber")
 338
 339
 340 def usage():
 341     """Print usage text of this program"""
 342
 343     print("""
 344 smailq is a mail queue for lightweight SMTP clients (MSAs) like msmtp that do
 345 not provide a queue. It basically provides the functionality of sendmail and
 346 mailq.
 347
 348 USAGE:
 349
 350   {0} --send [recipient ...] -- [MSA options ...]
 351   {0} --list
 352   {0} --deliver-all
 353   {0} --deliver [ID ...]
 354   {0} --delete [ID ...]
 355   {0} --help
 356   {0} --version
 357
 358 COMMANDS:
 359
 360       --delete
 361           Remove the mails with given IDs from the queue.
 362
 363       --deliver
 364           Attempt to deliver the mails with given IDs only.
 365
 366       --deliver-all
 367           Attempt to deliver all mails in the queue.
 368
 369   -h, --help
 370           Print this usage text.
 371
 372       --list
 373           List all mails in the queue. This is the default
 374
 375       --send
 376           Read a mail from stdin, insert it into the queue, and attempt to
 377           deliver all mails in the queue. Options after "--" are passed forward
 378           to the MSA for this particular mail.
 379
 380   -V, --version
 381           Show version info.
 382
 383 OPTIONS:
 384
 385   -C, --config=FILE
 386           Use the given configuration file instead of "$HOME/.smailq.conf".
 387
 388   -q, --quiet
 389           Do not print info messages.
 390
 391   -v, --verbose
 392           Increase output verbosity.
 393 """.format(sys.argv[0]))
 394
 395
 396 if __name__ == "__main__":
 397
 398     conffn_list = [os.path.expanduser("~/.smailq.conf"), "/etc/smailq.conf"]
 399     cmd = "--list"
 400     nooptargs = []
 401
 402     try:
 403
 404         longopts = ["config=", "delete", "deliver-all", "deliver", "help",
 405                     "list", "send", "verbose", "version", "quiet"]
 406         opts, nooptargs = getopt.gnu_getopt(sys.argv[1:], "hC:vVq", longopts)
 407
 408         for opt, arg in opts:
 409             if opt in ['-h', '--help']:
 410                 usage()
 411                 sys.exit(os.EX_OK)
 412             elif opt in ['-V', '--version']:
 413                 version()
 414                 sys.exit(os.EX_OK)
 415             elif opt in ['--list', '--send', '--delete', '--deliver-all',
 416                          '--deliver']:
 417                 cmd = opt
 418             elif opt in ['-C', '--config']:
 419                 conffn_list = [arg]
 420             elif opt in ['-v', '--verbose']:
 421                 verbose = True
 422                 quiet = False
 423             elif opt in ['-q', '--quiet']:
 424                 quiet = True
 425                 verbose = False
 426             else:
 427                 assert(False)
 428
 429     except getopt.GetoptError as e:
 430         printerr("Error parsing arguments:", e)
 431         usage()
 432         sys.exit(os.EX_USAGE)
 433
 434     # Reading config file
 435     conffn = next((f for f in conffn_list if os.path.isfile(f)), None)
 436     if conffn is None:
 437         printerr("No config file found: " + str(conffn_list))
 438         sys.exit(os.EX_IOERR)
 439     conf = None
 440     try:
 441         conf = Config(conffn)
 442
 443         if not os.path.isdir(conf.getdatadir()):
 444             printerr("Data directory does not exist: " + conf.getdatadir())
 445             sys.exit(os.EX_IOERR)
 446
 447         if not os.path.isdir(conf.getlogdir()):
 448             printerr("Log directory does not exist: " + conf.getlogdir())
 449             sys.exit(os.EX_IOERR)
 450
 451     except Exception as e:
 452         printerr("Error reading config file:", e)
 453         sys.exit(os.EX_IOERR)
 454
 455     try:
 456         with conf.aquiredatalock():
 457
 458             printinfo("Aquired the lock.")
 459
 460             mq = MailQueue(conf)
 461             if cmd == "--send":
 462                 mail = sys.stdin.buffer.read()
 463                 mq.sendmail(mail, nooptargs)
 464             elif cmd == "--list":
 465                 mq.listqueue()
 466             elif cmd == "--deliver-all":
 467                 mq.delivermails()
 468             elif cmd == "--deliver":
 469                 for id in nooptargs:
 470                     mq.delivermail(id)
 471             elif cmd == "--delete":
 472                 for id in nooptargs:
 473                     mq.deletemail(id)
 474
 475     except OSError as e:
 476         printerr(e)
 477         sys.exit(os.EX_IOERR)