From f2a2241b6ba0c192c12b077fbde2f860f5a432f6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C4=93teris=20Caune?= <cuu508@gmail.com>
Date: Wed, 1 Nov 2017 19:20:12 +0200
Subject: [PATCH] Email listener: "./manage.py smtpd"

---
 hc/api/management/commands/smtpd.py | 50 +++++++++++++++++++++++++++++
 hc/api/models.py                    | 20 ++++++++++++
 hc/api/views.py                     | 28 +++++-----------
 3 files changed, 78 insertions(+), 20 deletions(-)
 create mode 100644 hc/api/management/commands/smtpd.py

diff --git a/hc/api/management/commands/smtpd.py b/hc/api/management/commands/smtpd.py
new file mode 100644
index 00000000..35d10f8c
--- /dev/null
+++ b/hc/api/management/commands/smtpd.py
@@ -0,0 +1,50 @@
+import asyncore
+import re
+from smtpd import SMTPServer
+
+from django.core.management.base import BaseCommand
+from hc.api.models import Check
+
+RE_UUID = re.compile("^[a-fA-F0-9]{8}-[a-fA-F0-9]{4}-4[a-fA-F0-9]{3}-[8|9|aA|bB][a-fA-F0-9]{3}-[a-fA-F0-9]{12}$")
+
+
+class Listener(SMTPServer):
+    def __init__(self, localaddr, stdout):
+        self.stdout = stdout
+        super(Listener, self).__init__(localaddr, None)
+
+    def process_message(self, peer, mailfrom, rcpttos, data):
+        to_parts = rcpttos[0].split("@")
+        code = to_parts[0]
+
+        if not RE_UUID.match(code):
+            self.stdout.write("Not an UUID: %s" % code)
+            return
+
+        try:
+            check = Check.objects.get(code=code)
+        except Check.DoesNotExist:
+            self.stdout.write("Check not found: %s" % code)
+            return
+
+        ua = "Email from %s" % mailfrom
+        check.ping(peer[0], "email", "", ua, data)
+        self.stdout.write("Processed ping for %s" % code)
+
+
+class Command(BaseCommand):
+    help = "Listen for ping emails"
+
+    def add_arguments(self, parser):
+        parser.add_argument("--host",
+                            help="ip address to listen on, default 0.0.0.0",
+                            default="0.0.0.0")
+        parser.add_argument('--port',
+                            help="port to listen on, default 25",
+                            type=int,
+                            default=25)
+
+    def handle(self, host, port, *args, **options):
+        listener = Listener((host, port), self.stdout)
+        print("Starting SMTP listener on %s:%d ..." % (host, port))
+        asyncore.loop()
diff --git a/hc/api/models.py b/hc/api/models.py
index 4439abd5..3fa9d2ca 100644
--- a/hc/api/models.py
+++ b/hc/api/models.py
@@ -188,6 +188,26 @@ class Check(models.Model):
     def has_confirmation_link(self):
         return "confirm" in self.last_ping_body.lower()
 
+    def ping(self, remote_addr, scheme, method, ua, body):
+        self.n_pings = models.F("n_pings") + 1
+        self.last_ping = timezone.now()
+        self.last_ping_body = body[:10000]
+        self.alert_after = self.get_alert_after()
+        if self.status in ("new", "paused"):
+            self.status = "up"
+
+        self.save()
+        self.refresh_from_db()
+
+        ping = Ping(owner=self)
+        ping.n = self.n_pings
+        ping.remote_addr = remote_addr
+        ping.scheme = scheme
+        ping.method = method
+        # If User-Agent is longer than 200 characters, truncate it:
+        ping.ua = ua[:200]
+        ping.save()
+
 
 class Ping(models.Model):
     n = models.IntegerField(null=True)
diff --git a/hc/api/views.py b/hc/api/views.py
index 04844c0b..6f18e853 100644
--- a/hc/api/views.py
+++ b/hc/api/views.py
@@ -1,7 +1,6 @@
 from datetime import timedelta as td
 
 from django.db import connection
-from django.db.models import F
 from django.http import (HttpResponse, HttpResponseForbidden,
                          HttpResponseNotFound, JsonResponse)
 from django.shortcuts import get_object_or_404
@@ -12,7 +11,7 @@ from django.views.decorators.http import require_POST
 
 from hc.api import schemas
 from hc.api.decorators import check_api_key, uuid_or_400, validate_json
-from hc.api.models import Check, Notification, Ping
+from hc.api.models import Check, Notification
 from hc.lib.badges import check_signature, get_badge_svg
 
 
@@ -22,26 +21,15 @@ from hc.lib.badges import check_signature, get_badge_svg
 def ping(request, code):
     check = get_object_or_404(Check, code=code)
 
-    check.n_pings = F("n_pings") + 1
-    check.last_ping = timezone.now()
-    check.last_ping_body = request.body[:10000]
-    check.alert_after = check.get_alert_after()
-    if check.status in ("new", "paused"):
-        check.status = "up"
-
-    check.save()
-    check.refresh_from_db()
-
-    ping = Ping(owner=check)
     headers = request.META
-    ping.n = check.n_pings
     remote_addr = headers.get("HTTP_X_FORWARDED_FOR", headers["REMOTE_ADDR"])
-    ping.remote_addr = remote_addr.split(",")[0]
-    ping.scheme = headers.get("HTTP_X_FORWARDED_PROTO", "http")
-    ping.method = headers["REQUEST_METHOD"]
-    # If User-Agent is longer than 200 characters, truncate it:
-    ping.ua = headers.get("HTTP_USER_AGENT", "")[:200]
-    ping.save()
+    remote_addr = remote_addr.split(",")[0]
+    scheme = headers.get("HTTP_X_FORWARDED_PROTO", "http")
+    method = headers["REQUEST_METHOD"]
+    ua = headers.get("HTTP_USER_AGENT", "")
+    body = request.body[:10000]
+
+    check.ping(remote_addr, scheme, method, ua, body)
 
     response = HttpResponse("OK")
     response["Access-Control-Allow-Origin"] = "*"