Merge branch 'dev-fix-server-ipv6'. Close #158.

analyzer/python/ikos/http.py

@@ -50,3 +50,36 @@
     from urlparse import parse_qs
     from urllib import urlencode
     from urllib2 import urlopen
+
+from errno import EAFNOSUPPORT
+from socket import AF_INET, AF_INET6
+import os
+
+class HTTPServerIPv6(HTTPServer):
+    '''
+    HTTP server that listens on IPv6 when available.
+
+    In systems with dual stack, this also listens on IPv4.
+
+    This class tries to listen on IPv6 first (and IPv4 if available). If that
+    is not supported, then it tries IPv4 only.
+    '''
+
+    address_family = AF_INET6
+
+    def __init__(self, server_address, RequestHandlerClass, bind_and_activate=True):
+        try:
+            # Initially try to open the server with IPv6. This will also select
+            # IPv4 on systems with dual stack.
+            super().__init__(server_address, RequestHandlerClass, bind_and_activate)
+
+        except OSError as e:
+            if e.errno == EAFNOSUPPORT:
+                # If the exception is due to IPv6 not being supported, we
+                # select IPv4 only and try to re-open the server again.
+                self.address_family = AF_INET
+                super().__init__(server_address, RequestHandlerClass, bind_and_activate)
+            else:
+                # If the exception is for any other reason other than IPv6 not
+                # being supported, then we cannot do anything about it.
+                raise e

analyzer/python/ikos/scan.py

@@ -641,8 +641,8 @@ def __init__(self):
             try:
                 # try to start the http server on a random port
                 self.port = random.randint(8000, 9000)
-                self.httpd = http.HTTPServer(('', self.port),
-                                             ScanServerRequestHandler)
+                self.httpd = http.HTTPServerIPv6(('', self.port),
+                                                 ScanServerRequestHandler)
             except (OSError, IOError):
                 self.port = None  # port already in use
 

analyzer/python/ikos/view.py

@@ -62,7 +62,7 @@
 from ikos import settings
 from ikos.enums import Result, CheckKind
 from ikos.highlight import CppLexer, HtmlFormatter, highlight
-from ikos.http import HTTPServer, BaseHTTPRequestHandler
+from ikos.http import HTTPServerIPv6, BaseHTTPRequestHandler
 from ikos.log import printf
 from ikos.output_db import OutputDatabase
 
@@ -337,7 +337,7 @@ def __init__(self, db, port=8080):
         self.report = ViewReport(self.db)
 
         try:
-            self.httpd = HTTPServer(('', self.port), RequestHandler)
+            self.httpd = HTTPServerIPv6(('', self.port), RequestHandler)
         except (OSError, IOError) as e:
             log.error("Could not start the HTTP server: %s" % e)
             sys.exit(1)