chriswl · March 12, 2014 20:48 · Sep 20, 2011
diff --git a/proxy_views.py b/proxy_views.py
@@ -0,0 +1,113 @@
+# coding:utf-8
+# Copyright 2011 litl, LLC. All Rights Reserved.
+
+import httplib
+import re
+import urllib
+import urlparse
+
+from flask import Blueprint, request, Response, url_for
+from werkzeug.datastructures import Headers
+from werkzeug.exceptions import NotFound
+
+from jiffy.admin.login import check_login
+
+proxy = Blueprint('proxy', __name__)
+
+proxy.before_request(check_login)
+
+HTML_REGEX = re.compile(r'((?:src|action|href)=["\'])/')
+JQUERY_REGEX = re.compile(r'(\$\.(?:get|post)\(["\'])/')
+JS_LOCATION_REGEX = re.compile(r'((?:window|document)\.location.*=.*["\'])/')
+CSS_REGEX = re.compile(r'(url\(["\']?)/')
+
+REGEXES = [HTML_REGEX, JQUERY_REGEX, JS_LOCATION_REGEX, CSS_REGEX]
+
+
+def iterform(multidict):
+    for key in multidict.keys():
+        for value in multidict.getlist(key):
+            yield (key.encode("utf8"), value.encode("utf8"))
+
+def parse_host_port(h):
+    """Parses strings in the form host[:port]"""
+    host_port = h.split(":", 1)
+    if len(host_port) == 1:
+        return (h, 80)
+    else:
+        host_port[1] = int(host_port[1])
+        return host_port
+
+
+@proxy.route('/proxy/<host>/', methods=["GET", "POST"])
+@proxy.route('/proxy/<host>/<path:file>', methods=["GET", "POST"])
+def proxy_request(host, file=""):
+    hostname, port = parse_host_port(host)
+
+    # Whitelist a few headers to pass on
+    request_headers = {}
+    for h in ["Cookie", "Referer", "X-Csrf-Token"]:
+        if h in request.headers:
+            request_headers[h] = request.headers[h]
+
+    if request.query_string:
+        path = "/%s?%s" % (file, request.query_string)
+    else:
+        path = "/" + file
+
+    if request.method == "POST":
+        form_data = list(iterform(request.form))
+        form_data = urllib.urlencode(form_data)
+        request_headers["Content-Length"] = len(form_data)
+    else:
+        form_data = None
+
+    conn = httplib.HTTPConnection(hostname, port)
+    conn.request(request.method, path, body=form_data, headers=request_headers)
+    resp = conn.getresponse()
+
+    # Clean up response headers for forwarding
+    response_headers = Headers()
+    for key, value in resp.getheaders():
+        if key in ["content-length", "connection", "content-type"]:
+            continue
+
+        if key == "set-cookie":
+            cookies = value.split(",")
+            [response_headers.add(key, c) for c in cookies]
+        else:
+            response_headers.add(key, value)
+
+    # If this is a redirect, munge the Location URL
+    if "location" in response_headers:
+        redirect = response_headers["location"]
+        parsed = urlparse.urlparse(request.url)
+        redirect_parsed = urlparse.urlparse(redirect)
+
+        redirect_host = redirect_parsed.netloc
+        if not redirect_host:
+            redirect_host = "%s:%d" % (hostname, port)
+
+        redirect_path = redirect_parsed.path
+        if redirect_parsed.query:
+            redirect_path += "?" + redirect_parsed.query
+
+        munged_path = url_for(".proxy_request",
+                              host=redirect_host,
+                              file=redirect_path[1:])
+
+        url = "%s://%s%s" % (parsed.scheme, parsed.netloc, munged_path)
+        response_headers["location"] = url
+
+    # Rewrite URLs in the content to point to our URL scheme instead.
+    # Ugly, but seems to mostly work.
+    root = url_for(".proxy_request", host=host)
+    contents = resp.read()
+    for regex in REGEXES:
+        contents = regex.sub(r'\1%s' % root, contents)
+
+    flask_response = Response(response=contents,
+                              status=resp.status,
+                              headers=response_headers,
+                              content_type=resp.getheader('content-type'))
+    return flask_response