httpd: add ASN enrichment for worker-reported proxies

Load pyasn database in httpd and look up ASN when workers report
working proxies. Previously ASN was only populated by proxywatchd
which doesn't run independently on the master node, leaving all
worker-reported proxies with asn=null.

httpd.py

@@ -31,6 +31,13 @@ except (ImportError, IOError, ValueError):
     _geodb = None
     _geolite = False
 
+# ASN lookup (optional)
+try:
+    import pyasn
+    _asndb = pyasn.pyasn(os.path.join("data", "ipasn.dat"))
+except (ImportError, IOError):
+    _asndb = None
+
 # Rate limiting configuration
 _rate_limits = defaultdict(list)
 _rate_lock = threading.Lock()
@@ -604,7 +611,7 @@ def submit_proxy_reports(db, worker_id, proxies):
             ''', (proxy_key, ip, port, proto, now_int, now_int, latency, now_int,
                   checktype, target))
 
-            # Geolocate if IP2Location available
+            # Geolocate and ASN lookup
             if _geolite and _geodb:
                 try:
                     rec = _geodb.get_all(ip)
@@ -614,6 +621,15 @@ def submit_proxy_reports(db, worker_id, proxies):
                             (rec.country_short, proxy_key))
                 except Exception:
                     pass
+            if _asndb:
+                try:
+                    asn_result = _asndb.lookup(ip)
+                    if asn_result and asn_result[0]:
+                        db.execute(
+                            'UPDATE proxylist SET asn=? WHERE proxy=?',
+                            (asn_result[0], proxy_key))
+                except Exception:
+                    pass
 
             # Track per-URL working count for working_ratio
             if source_url: