improve exception handling

pymodmilter/__init__.py

@@ -154,6 +154,11 @@ class ModifyMilter(Milter.Base):
         self.rules = ModifyMilter._rules.copy()
 
     def connect(self, IPname, family, hostaddr):
+        try:
+            if hostaddr is None:
+                self.logger.error("unable to proceed, host address is None")
+                return Milter.TEMPFAIL
+
             self.logger.debug(
                 f"accepted milter connection from {hostaddr[0]} "
                 f"port {hostaddr[1]}")
@@ -168,10 +173,15 @@ class ModifyMilter(Milter.Base):
                     f"host {hostaddr[0]} is ignored by all rules, "
                     f"skip further processing")
                 return Milter.ACCEPT
+        except Exception as e:
+            self.logger.exception(
+                f"an exception occured in connect function: {e}")
+            return Milter.TEMPFAIL
 
         return Milter.CONTINUE
 
     def envfrom(self, mailfrom, *str):
+        try:
             mailfrom = "@".join(parse_addr(mailfrom)).lower()
             for rule in self.rules.copy():
                 if rule.ignores(envfrom=mailfrom):
@@ -179,16 +189,27 @@ class ModifyMilter(Milter.Base):
 
             if not self.rules:
                 self.logger.debug(
-                f"envelope-from address {mailfrom} is ignored by all rules, "
-                f"skip further processing")
+                    f"envelope-from address {mailfrom} is ignored by "
+                    f"all rules, skip further processing")
                 return Milter.ACCEPT
 
             self.recipients = set()
+        except Exception as e:
+            self.logger.exception(
+                f"an exception occured in envfrom function: {e}")
+            return Milter.TEMPFAIL
+
         return Milter.CONTINUE
 
     @Milter.noreply
     def envrcpt(self, to, *str):
+        try:
             self.recipients.add("@".join(parse_addr(to)).lower())
+        except Exception as e:
+            self.logger.exception(
+                f"an exception occured in envrcpt function: {e}")
+            return Milter.TEMPFAIL
+
         return Milter.CONTINUE
 
     def data(self):