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Switch to python f-strings and autopep

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This commit is contained in:
Thomas Oettli
2020-02-28 22:02:23 +01:00
parent d6e2e4a5bb
commit d41978233e
1 changed files with 131 additions and 79 deletions
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210
pyheadermilter/__init__.py
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@@ -2,18 +2,17 @@
# it under the terms of the GNU General Public License as published by # it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or # the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version. # (at your option) any later version.
# #
# PyHeader-Milter is distributed in the hope that it will be useful, # PyHeader-Milter is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of # but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details. # GNU General Public License for more details.
# #
# You should have received a copy of the GNU General Public License # You should have received a copy of the GNU General Public License
# along with PyHeader-Milter. If not, see <http://www.gnu.org/licenses/>. # along with PyHeader-Milter. If not, see <http://www.gnu.org/licenses/>.
# #
__all__ = ["HeaderRule", "HeaderMilter"] __all__ = ["HeaderRule", "HeaderMilter"]
name = "pyheadermilter"
import Milter import Milter
import argparse import argparse
@@ -34,7 +33,8 @@ from netaddr import IPAddress, IPNetwork, AddrFormatError
class HeaderRule: class HeaderRule:
"""HeaderRule to implement a rule to apply on e-mail headers.""" """HeaderRule to implement a rule to apply on e-mail headers."""
def __init__(self, name, action, header, search="", value="", ignore_hosts=[], ignore_envfrom=None, only_hosts=[], log=True): def __init__(self, name, action, header, search="", value="",
ignore_hosts=[], ignore_envfrom=None, only_hosts=[], log=True):
self.logger = logging.getLogger(__name__) self.logger = logging.getLogger(__name__)
self.name = name self.name = name
self.action = action self.action = action
@@ -49,38 +49,46 @@ class HeaderRule:
if action in ["del", "mod"]: if action in ["del", "mod"]:
# compile header regex # compile header regex
try: try:
self.header = re.compile(header, re.MULTILINE + re.DOTALL + re.IGNORECASE) self.header = re.compile(
header, re.MULTILINE + re.DOTALL + re.IGNORECASE)
except re.error as e: except re.error as e:
raise RuntimeError("unable to parse option 'header' of rule '{}': {}".format(name, e)) raise RuntimeError(
f"unable to parse option 'header' of rule '{name}': {e}")
if action == "mod": if action == "mod":
# compile search regex # compile search regex
try: try:
self.search = re.compile(search, re.MULTILINE + re.DOTALL + re.IGNORECASE) self.search = re.compile(
search, re.MULTILINE + re.DOTALL + re.IGNORECASE)
except re.error as e: except re.error as e:
raise RuntimeError("unable to parse option 'search' of rule '{}': {}".format(name, e)) raise RuntimeError(
f"unable to parse option 'search' of rule '{name}': {e}")
if action in ["add", "mod"] and not value: if action in ["add", "mod"] and not value:
raise RuntimeError("value of option 'value' is empty") raise RuntimeError("value of option 'value' is empty")
# replace strings in ignore_hosts and only_hosts with IPNetwork instances # replace strings in ignore_hosts and only_hosts with IPNetwork
# instances
try: try:
for index, ignore in enumerate(ignore_hosts): for index, ignore in enumerate(ignore_hosts):
self.ignore_hosts[index] = IPNetwork(ignore) self.ignore_hosts[index] = IPNetwork(ignore)
except AddrFormatError as e: except AddrFormatError as e:
raise RuntimeError("unable to parse option 'ignore_hosts' of rule '{}': {}".format(name, e)) raise RuntimeError(
f"unable to parse option 'ignore_hosts' of rule '{name}': {e}")
if self.ignore_envfrom: if self.ignore_envfrom:
try: try:
self.ignore_envfrom = re.compile(ignore_envfrom, re.IGNORECASE) self.ignore_envfrom = re.compile(ignore_envfrom, re.IGNORECASE)
except re.error as e: except re.error as e:
raise RuntimeError("unable to parse option 'ignore_envfrom' of rule '{}': {}".format(name, e)) raise RuntimeError(
f"unable to parse option 'ignore_envfrom' of rule '{name}': {e}")
try: try:
for index, only in enumerate(only_hosts): for index, only in enumerate(only_hosts):
self.only_hosts[index] = IPNetwork(only) self.only_hosts[index] = IPNetwork(only)
except AddrFormatError as e: except AddrFormatError as e:
raise RuntimeError("unable to parse option 'only_hosts' of rule '{}': {}".format(name, e)) raise RuntimeError(
f"unable to parse option 'only_hosts' of rule '{name}': {e}")
def ignore_host(self, host): def ignore_host(self, host):
ip = IPAddress(host) ip = IPAddress(host)
@@ -101,7 +109,7 @@ class HeaderRule:
break break
if ignore: if ignore:
self.logger.debug("host {} is ignored by rule {}".format(host, self.name)) self.logger.debug(f"host {host} is ignored by rule {self.name}")
return ignore return ignore
def ignore_from(self, envfrom): def ignore_from(self, envfrom):
@@ -110,7 +118,8 @@ class HeaderRule:
if self.ignore_envfrom: if self.ignore_envfrom:
if self.ignore_envfrom.search(envfrom): if self.ignore_envfrom.search(envfrom):
ignore = True ignore = True
self.logger.debug("envelope-from {} is ignored by rule {}".format(envfrom, self.name)) self.logger.debug(
f"envelope-from {envfrom} is ignored by rule {self.name}")
return ignore return ignore
def execute(self, headers): def execute(self, headers):
@@ -123,25 +132,26 @@ class HeaderRule:
occurrences = {} occurrences = {}
# iterate headers # iterate headers
for name, hdr in headers: for name, header in headers:
# keep track of the occurrence of each header, needed by Milter.Base.chgheader # keep track of the occurrence of each header, needed by
# Milter.Base.chgheader
if name not in occurrences.keys(): if name not in occurrences.keys():
occurrences[name] = 1 occurrences[name] = 1
else: else:
occurrences[name] += 1 occurrences[name] += 1
# check if header line matches regex # check if header line matches regex
value = hdr[name] value = header[name]
if self.header.search("{}: {}".format(name, value)): if self.header.search(f"{name}: {value}"):
if self.action == "del": if self.action == "del":
# set an empty value to delete the header # set an empty value to delete the header
new_value = "" new_value = ""
else: else:
new_value = self.search.sub(self.value, value) new_value = self.search.sub(self.value, value)
if value != new_value: if value != new_value:
hdr = EmailMessage(policy=default_policy) header = EmailMessage(policy=default_policy)
hdr.add_header(name, new_value) header.add_header(name, new_value)
modified.append((name, hdr, index, occurrences[name])) modified.append((name, header, index, occurrences[name]))
index += 1 index += 1
return modified return modified
@@ -161,7 +171,8 @@ class HeaderMilter(Milter.Base):
self.rules = HeaderMilter._rules.copy() self.rules = HeaderMilter._rules.copy()
def connect(self, IPname, family, hostaddr): def connect(self, IPname, family, hostaddr):
self.logger.debug("accepted milter connection from {} port {}".format(*hostaddr)) self.logger.debug(
f"accepted milter connection from {hostaddr[0]} port {hostaddr[1]}")
ip = IPAddress(hostaddr[0]) ip = IPAddress(hostaddr[0])
# remove rules which ignore this host # remove rules which ignore this host
@@ -170,9 +181,10 @@ class HeaderMilter(Milter.Base):
self.rules.remove(rule) self.rules.remove(rule)
if not self.rules: if not self.rules:
self.logger.debug("host {} is ignored by all rules, skip further processing".format(hostaddr[0])) self.logger.debug(
f"host {hostaddr[0]} is ignored by all rules, skip further processing")
return Milter.ACCEPT return Milter.ACCEPT
return Milter.CONTINUE return Milter.CONTINUE
def envfrom(self, mailfrom, *str): def envfrom(self, mailfrom, *str):
mailfrom = "@".join(parse_addr(mailfrom)).lower() mailfrom = "@".join(parse_addr(mailfrom)).lower()
@@ -181,14 +193,15 @@ class HeaderMilter(Milter.Base):
self.rules.remove(rule) self.rules.remove(rule)
if not self.rules: if not self.rules:
self.logger.debug("mail from {} is ignored by all rules, skip further processing".format(mailfrom)) self.logger.debug(
f"mail from {mailfrom} is ignored by all rules, skip further processing")
return Milter.ACCEPT return Milter.ACCEPT
return Milter.CONTINUE return Milter.CONTINUE
@Milter.noreply @Milter.noreply
def data(self): def data(self):
self.queueid = self.getsymval('i') self.qid = self.getsymval('i')
self.logger.debug("{}: received queue-id from MTA".format(self.queueid)) self.logger.debug(f"{self.qid}: received queue-id from MTA")
self.headers = [] self.headers = []
return Milter.CONTINUE return Milter.CONTINUE
@@ -196,64 +209,89 @@ class HeaderMilter(Milter.Base):
def header(self, name, value): def header(self, name, value):
# remove surrogates from value # remove surrogates from value
value = value.encode(errors="surrogateescape").decode(errors="replace") value = value.encode(errors="surrogateescape").decode(errors="replace")
self.logger.debug(f"{self.queueid}: received header: {name}: {value}") self.logger.debug(f"{self.qid}: received header: {name}: {value}")
hdr = HeaderParser(policy=default_policy).parsestr(f"{name}: {value}") header = HeaderParser(
self.logger.debug(f"{self.queueid}: decoded header: {name}: {hdr[name]}") policy=default_policy).parsestr(f"{name}: {value}")
self.headers.append((name, hdr)) self.logger.debug(
f"{self.qid}: decoded header: {name}: {header[name]}")
self.headers.append((name, header))
return Milter.CONTINUE return Milter.CONTINUE
def eom(self): def eom(self):
try: try:
for rule in self.rules: for rule in self.rules:
self.logger.debug("{}: executing rule '{}'".format(self.queueid, rule.name)) self.logger.debug(f"{self.qid}: executing rule '{rule.name}'")
modified = rule.execute(self.headers) modified = rule.execute(self.headers)
for name, hdr, index, occurrence in modified: for name, header, index, occurrence in modified:
value = hdr[name] value = header[name]
# remove illegal characters, pymilter does not like them # remove illegal characters, pymilter does not like them
encoded_value = hdr.as_string().replace("\r", "").replace("\n", "").replace("\x00", "").split(":", 1)[1].strip() enc_value = header.as_string().replace(
mod_header = "{}: {}".format(name, value) "\r", "").replace(
"\n", "").replace(
"\x00", "").split(
":", 1)[1].strip()
mod_header = f"{name}: {value}"
if rule.action == "add": if rule.action == "add":
if rule.log: if rule.log:
self.logger.info("{}: add: header: {}".format(self.queueid, mod_header[0:70])) self.logger.info(
f"{self.qid}: add: header: {mod_header[0:70]}")
else: else:
self.logger.debug("{}: add: header: {}".format(self.queueid, mod_header)) self.logger.debug(
self.headers.insert(0, (name, hdr)) f"{self.qid}: add: header: {mod_header}")
self.addheader(name, encoded_value, 1) self.headers.insert(0, (name, header))
self.addheader(name, enc_value, 1)
else: else:
if rule.action == "mod": if rule.action == "mod":
old_value = self.headers[index][1][name] old_value = self.headers[index][1][name]
old_header = "{}: {}".format(name, old_value) old_header = f"{name}: {old_value}"
if rule.log: if rule.log:
self.logger.info("{}: modify: header: {}: {}".format( self.logger.info(f"{self.qid}: modify: header: {old_header[0:70]}: {mod_header[0:70]}")
self.queueid, old_header[0:70], mod_header[0:70]))
else: else:
self.logger.debug("{}: modify: header (occ. {}): {}: {}".format( self.logger.debug(
self.queueid, occurrence, old_header, mod_header)) f"{self.qid}: modify: header (occ. {occurrence}): {old_header}: {mod_header}")
self.headers[index] = (name, hdr) self.headers[index] = (name, header)
elif rule.action == "del": elif rule.action == "del":
if rule.log: if rule.log:
self.logger.info("{}: delete: header: {}".format(self.queueid, mod_header[0:70])) self.logger.info(
f"{self.qid}: delete: header: {mod_header[0:70]}")
else: else:
self.logger.debug("{}: delete: header (occ. {}): {}".format(self.queueid, occurrence, mod_header)) self.logger.debug(
f"{self.qid}: delete: header (occ. {occurrence}): {mod_header}")
del self.headers[index] del self.headers[index]
self.chgheader(name, occurrence, encoded_value) self.chgheader(name, occurrence, enc_value)
return Milter.ACCEPT return Milter.ACCEPT
except Exception as e: except Exception as e:
self.logger.exception("an exception occured in eom function: {}".format(e)) self.logger.exception(f"an exception occured in eom function: {e}")
return Milter.TEMPFAIL return Milter.TEMPFAIL
def main(): def main():
"Run PyHeader-Milter." "Run PyHeader-Milter."
# parse command line # parse command line
parser = argparse.ArgumentParser(description="PyHeader milter daemon", parser = argparse.ArgumentParser(
formatter_class=lambda prog: argparse.HelpFormatter(prog, max_help_position=45, width=140)) description="PyHeader milter daemon",
parser.add_argument("-c", "--config", help="Config file to read.", default="/etc/pyheader-milter.conf") formatter_class=lambda prog: argparse.HelpFormatter(
parser.add_argument("-s", "--socket", help="Socket used to communicate with the MTA.", required=True) prog, max_help_position=45, width=140))
parser.add_argument("-d", "--debug", help="Log debugging messages.", action="store_true") parser.add_argument(
parser.add_argument("-t", "--test", help="Check configuration.", action="store_true") "-c", "--config", help="Config file to read.",
default="/etc/pyheader-milter.conf")
parser.add_argument(
"-s",
"--socket",
help="Socket used to communicate with the MTA.",
required=True)
parser.add_argument(
"-d",
"--debug",
help="Log debugging messages.",
action="store_true")
parser.add_argument(
"-t",
"--test",
help="Check configuration.",
action="store_true")
args = parser.parse_args() args = parser.parse_args()
# setup logging # setup logging
@@ -262,8 +300,8 @@ def main():
syslog_name = logname syslog_name = logname
if args.debug: if args.debug:
loglevel = logging.DEBUG loglevel = logging.DEBUG
logname = "{}[%(name)s]".format(logname) logname = f"{logname}[%(name)s]"
syslog_name = "{}: [%(name)s] %(levelname)s".format(syslog_name) syslog_name = f"{syslog_name}: [%(name)s] %(levelname)s"
# set config files for milter class # set config files for milter class
root_logger = logging.getLogger() root_logger = logging.getLogger()
@@ -272,11 +310,11 @@ def main():
# setup console log # setup console log
stdouthandler = logging.StreamHandler(sys.stdout) stdouthandler = logging.StreamHandler(sys.stdout)
stdouthandler.setLevel(logging.DEBUG) stdouthandler.setLevel(logging.DEBUG)
formatter = logging.Formatter("%(message)s".format(logname)) formatter = logging.Formatter("%(message)s")
stdouthandler.setFormatter(formatter) stdouthandler.setFormatter(formatter)
root_logger.addHandler(stdouthandler) root_logger.addHandler(stdouthandler)
logger = logging.getLogger(__name__) logger = logging.getLogger(__name__)
try: try:
# read config file # read config file
parser = configparser.ConfigParser() parser = configparser.ConfigParser()
@@ -285,21 +323,25 @@ def main():
# check if mandatory config options in global section are present # check if mandatory config options in global section are present
if "global" not in parser.sections(): if "global" not in parser.sections():
raise RuntimeError("mandatory section 'global' not present in config file") raise RuntimeError(
"mandatory section 'global' not present in config file")
for option in ["rules"]: for option in ["rules"]:
if not parser.has_option("global", option): if not parser.has_option("global", option):
raise RuntimeError("mandatory option '{}' not present in config section 'global'".format(option)) raise RuntimeError(
f"mandatory option '{option}' not present in config section 'global'")
# read global config section # read global config section
global_config = dict(parser.items("global")) global_config = dict(parser.items("global"))
# read active rules # read active rules
active_rules = [ r.strip() for r in global_config["rules"].split(",") ] active_rules = [r.strip() for r in global_config["rules"].split(",")]
if len(active_rules) != len(set(active_rules)): if len(active_rules) != len(set(active_rules)):
raise RuntimeError("at least one rule is specified multiple times in 'rules' option") raise RuntimeError(
"at least one rule is specified multiple times in 'rules' option")
if "global" in active_rules: if "global" in active_rules:
active_rules.remove("global") active_rules.remove("global")
logger.warning("removed illegal rule name 'global' from list of active rules") logger.warning(
"removed illegal rule name 'global' from list of active rules")
if not active_rules: if not active_rules:
raise RuntimeError("no rules configured") raise RuntimeError("no rules configured")
@@ -307,9 +349,10 @@ def main():
rules = [] rules = []
# iterate active rules # iterate active rules
for rule_name in active_rules: for rule_name in active_rules:
# check if config section exists # check if config section exists
if rule_name not in parser.sections(): if rule_name not in parser.sections():
raise RuntimeError("config section '{}' does not exist".format(rule_name)) raise RuntimeError(
f"config section '{rule_name}' does not exist")
config = dict(parser.items(rule_name)) config = dict(parser.items(rule_name))
# check if mandatory option action is present in config # check if mandatory option action is present in config
@@ -318,10 +361,12 @@ def main():
option in global_config.keys(): option in global_config.keys():
config[option] = global_config[option] config[option] = global_config[option]
if option not in config.keys(): if option not in config.keys():
raise RuntimeError("mandatory option '{}' not specified for rule '{}'".format(option, rule_name)) raise RuntimeError(
f"mandatory option '{option}' not specified for rule '{rule_name}'")
config["action"] = config["action"].lower() config["action"] = config["action"].lower()
if config["action"] not in ["add", "del", "mod"]: if config["action"] not in ["add", "del", "mod"]:
raise RuntimeError("invalid action specified for rule '{}'".format(rule_name)) raise RuntimeError(
f"invalid action specified for rule '{rule_name}'")
# check if mandatory options are present in config # check if mandatory options are present in config
mandatory = ["header"] mandatory = ["header"]
@@ -334,7 +379,8 @@ def main():
option in global_config.keys(): option in global_config.keys():
config[option] = global_config[option] config[option] = global_config[option]
if option not in config.keys(): if option not in config.keys():
raise RuntimeError("mandatory option '{}' not specified for rule '{}'".format(option, rule_name)) raise RuntimeError(
f"mandatory option '{option}' not specified for rule '{rule_name}'")
# check if optional config options are present in config # check if optional config options are present in config
defaults = { defaults = {
@@ -350,19 +396,22 @@ def main():
if option not in config.keys(): if option not in config.keys():
config[option] = defaults[option] config[option] = defaults[option]
if config["ignore_hosts"]: if config["ignore_hosts"]:
config["ignore_hosts"] = [ h.strip() for h in config["ignore_hosts"].split(",") ] config["ignore_hosts"] = [h.strip()
for h in config["ignore_hosts"].split(",")]
if config["only_hosts"]: if config["only_hosts"]:
config["only_hosts"] = [ h.strip() for h in config["only_hosts"].split(",") ] config["only_hosts"] = [h.strip()
for h in config["only_hosts"].split(",")]
config["log"] = config["log"].lower() config["log"] = config["log"].lower()
if config["log"] == "true": if config["log"] == "true":
config["log"] = True config["log"] = True
elif config["log"] == "false": elif config["log"] == "false":
config["log"] = False config["log"] = False
else: else:
raise RuntimeError("invalid value specified for option 'log' for rule '{}'".format(rule_name)) raise RuntimeError(
f"invalid value specified for option 'log' for rule '{rule_name}'")
# add rule # add rule
logging.debug("adding rule '{}'".format(rule_name)) logging.debug(f"adding rule '{rule_name}'")
rules.append(HeaderRule(name=rule_name, **config)) rules.append(HeaderRule(name=rule_name, **config))
except RuntimeError as e: except RuntimeError as e:
@@ -374,13 +423,16 @@ def main():
sys.exit(0) sys.exit(0)
# change log format for runtime # change log format for runtime
formatter = logging.Formatter("%(asctime)s {}: [%(levelname)s] %(message)s".format(logname), datefmt="%Y-%m-%d %H:%M:%S") formatter = logging.Formatter(
f"%(asctime)s {logname}: [%(levelname)s] %(message)s",
datefmt="%Y-%m-%d %H:%M:%S")
stdouthandler.setFormatter(formatter) stdouthandler.setFormatter(formatter)
# setup syslog # setup syslog
sysloghandler = logging.handlers.SysLogHandler(address="/dev/log", facility=logging.handlers.SysLogHandler.LOG_MAIL) sysloghandler = logging.handlers.SysLogHandler(
address="/dev/log", facility=logging.handlers.SysLogHandler.LOG_MAIL)
sysloghandler.setLevel(loglevel) sysloghandler.setLevel(loglevel)
formatter = logging.Formatter("{}: %(message)s".format(syslog_name)) formatter = logging.Formatter(f"{syslog_name}: %(message)s")
sysloghandler.setFormatter(formatter) sysloghandler.setFormatter(formatter)
root_logger.addHandler(sysloghandler) root_logger.addHandler(sysloghandler)