Merge pull request #1183 from mitmproxy/module-imports

use module-level imports only

66 files changed, 618 insertions, 504 deletions

diff --git a/mitmproxy/cmdline.py b/mitmproxy/cmdline.py
index 5ea76e44..a873143d 100644
--- a/mitmproxy/cmdline.py
+++ b/mitmproxy/cmdline.py
@@ -1,15 +1,17 @@
-from __future__ import absolute_import
+from __future__ import absolute_import, print_function, division
+
+import base64
 import os
 import re
-import base64
 
 import configargparse
 
-from netlib.tcp import Address, sslversion_choices
-import netlib.http.url
+from mitmproxy import filt
+from mitmproxy import version
+from mitmproxy.proxy import config
 from netlib import human
-from . import filt, version
-from .proxy import config
+from netlib import tcp
+from netlib.http import url
 
 APP_HOST = "mitm.it"
 APP_PORT = 80
@@ -104,17 +106,17 @@ def parse_setheader(s):
     return _parse_hook(s)
 
 
-def parse_server_spec(url):
+def parse_server_spec(spec):
     try:
-        p = netlib.http.url.parse(url)
+        p = url.parse(spec)
         if p[0] not in ("http", "https"):
             raise ValueError()
     except ValueError:
         raise configargparse.ArgumentTypeError(
-            "Invalid server specification: %s" % url
+            "Invalid server specification: %s" % spec
         )
 
-    address = Address(p[1:3])
+    address = tcp.Address(p[1:3])
     scheme = p[0].lower()
     return config.ServerSpec(scheme, address)
 
@@ -477,14 +479,14 @@ def proxy_ssl_options(parser):
     group.add_argument(
         "--ssl-version-client", dest="ssl_version_client",
         default="secure", action="store",
-        choices=sslversion_choices.keys(),
+        choices=tcp.sslversion_choices.keys(),
         help="Set supported SSL/TLS versions for client connections. "
              "SSLv2, SSLv3 and 'all' are INSECURE. Defaults to secure, which is TLS1.0+."
     )
     group.add_argument(
         "--ssl-version-server", dest="ssl_version_server",
         default="secure", action="store",
-        choices=sslversion_choices.keys(),
+        choices=tcp.sslversion_choices.keys(),
         help="Set supported SSL/TLS versions for server connections. "
              "SSLv2, SSLv3 and 'all' are INSECURE. Defaults to secure, which is TLS1.0+."
     )
diff --git a/mitmproxy/console/__init__.py b/mitmproxy/console/__init__.py
index 1a70157a..00fb4b1b 100644
--- a/mitmproxy/console/__init__.py
+++ b/mitmproxy/console/__init__.py
@@ -1,8 +1,7 @@
-from __future__ import absolute_import, print_function
+from __future__ import absolute_import, print_function, division
 
 import mailcap
 import mimetypes
-import tempfile
 import os
 import os.path
 import shlex
@@ -10,16 +9,28 @@ import signal
 import stat
 import subprocess
 import sys
+import tempfile
 import traceback
-import urwid
 import weakref
 
-from netlib import tcp
+import urwid
 
-from .. import flow, script, contentviews, controller
-from . import flowlist, flowview, help, window, signals, options
-from . import grideditor, palettes, statusbar, palettepicker
-from ..exceptions import FlowReadException, ScriptException
+from mitmproxy import contentviews
+from mitmproxy import controller
+from mitmproxy import exceptions
+from mitmproxy import flow
+from mitmproxy import script
+from mitmproxy.console import flowlist
+from mitmproxy.console import flowview
+from mitmproxy.console import grideditor
+from mitmproxy.console import help
+from mitmproxy.console import options
+from mitmproxy.console import palettepicker
+from mitmproxy.console import palettes
+from mitmproxy.console import signals
+from mitmproxy.console import statusbar
+from mitmproxy.console import window
+from netlib import tcp
 
 EVENTLOG_SIZE = 500
 
@@ -231,7 +242,7 @@ class ConsoleMaster(flow.FlowMaster):
             for i in options.scripts:
                 try:
                     self.load_script(i)
-                except ScriptException as e:
+                except exceptions.ScriptException as e:
                     print("Script load error: {}".format(e), file=sys.stderr)
                     sys.exit(1)
 
@@ -352,7 +363,7 @@ class ConsoleMaster(flow.FlowMaster):
         """
         try:
             return flow.read_flows_from_paths(path)
-        except FlowReadException as e:
+        except exceptions.FlowReadException as e:
             signals.status_message.send(message=e.strerror)
 
     def client_playback_path(self, path):
@@ -636,7 +647,7 @@ class ConsoleMaster(flow.FlowMaster):
         reterr = None
         try:
             flow.FlowMaster.load_flows_file(self, path)
-        except FlowReadException as e:
+        except exceptions.FlowReadException as e:
             reterr = str(e)
         signals.flowlist_change.send(self)
         return reterr
@@ -666,7 +677,7 @@ class ConsoleMaster(flow.FlowMaster):
         for command in commands:
             try:
                 self.load_script(command)
-            except ScriptException as e:
+            except exceptions.ScriptException as e:
                 signals.status_message.send(
                     message='Error loading "{}".'.format(command)
                 )
diff --git a/mitmproxy/console/common.py b/mitmproxy/console/common.py
index a3ed5dc8..acb7fc35 100644
--- a/mitmproxy/console/common.py
+++ b/mitmproxy/console/common.py
@@ -1,18 +1,17 @@
-from __future__ import absolute_import
+from __future__ import absolute_import, print_function, division
+
+import os
 
 import urwid
 import urwid.util
-import os
 
 import netlib
+from mitmproxy import flow
+from mitmproxy import models
+from mitmproxy import utils
+from mitmproxy.console import signals
 from netlib import human
 
-from .. import utils
-from .. import flow
-from ..models import decoded
-from . import signals
-
-
 try:
     import pyperclip
 except:
@@ -260,7 +259,7 @@ def copy_flow_format_data(part, scope, flow):
         if scope in ("q", "a"):
             if flow.request.content is None:
                 return None, "Request content is missing"
-            with decoded(flow.request):
+            with models.decoded(flow.request):
                 if part == "h":
                     data += netlib.http.http1.assemble_request(flow.request)
                 elif part == "c":
@@ -273,7 +272,7 @@ def copy_flow_format_data(part, scope, flow):
         if scope in ("s", "a") and flow.response:
             if flow.response.content is None:
                 return None, "Response content is missing"
-            with decoded(flow.response):
+            with models.decoded(flow.response):
                 if part == "h":
                     data += netlib.http.http1.assemble_response(flow.response)
                 elif part == "c":
diff --git a/mitmproxy/console/flowdetailview.py b/mitmproxy/console/flowdetailview.py
index ca083b10..e2c28e71 100644
--- a/mitmproxy/console/flowdetailview.py
+++ b/mitmproxy/console/flowdetailview.py
@@ -1,7 +1,9 @@
-from __future__ import absolute_import
+from __future__ import absolute_import, print_function, division
+
 import urwid
-from . import common, searchable
-from .. import utils
+
+from mitmproxy import utils
+from mitmproxy.console import common, searchable
 
 
 def maybe_timestamp(base, attr):
diff --git a/mitmproxy/console/flowlist.py b/mitmproxy/console/flowlist.py
index 1e65e3eb..eb1e76fb 100644
--- a/mitmproxy/console/flowlist.py
+++ b/mitmproxy/console/flowlist.py
@@ -1,9 +1,10 @@
-from __future__ import absolute_import
+from __future__ import absolute_import, print_function, division
+
 import urwid
 
 import netlib.http.url
-
-from . import common, signals
+from mitmproxy.console import common
+from mitmproxy.console import signals
 
 
 def _mkhelp():
diff --git a/mitmproxy/console/flowview.py b/mitmproxy/console/flowview.py
index 2010cecd..e9b23176 100644
--- a/mitmproxy/console/flowview.py
+++ b/mitmproxy/console/flowview.py
@@ -1,17 +1,25 @@
-from __future__ import absolute_import, division
+from __future__ import absolute_import, print_function, division
+
+import math
 import os
-import traceback
 import sys
+import traceback
 
-import math
 import urwid
 
-from netlib.http import Headers, status_codes
-from . import common, grideditor, signals, searchable, tabs
-from . import flowdetailview
-from .. import utils, controller, contentviews
-from ..models import HTTPRequest, HTTPResponse, decoded
-from ..exceptions import ContentViewException
+from mitmproxy import contentviews
+from mitmproxy import controller
+from mitmproxy import exceptions
+from mitmproxy import models
+from mitmproxy import utils
+from mitmproxy.console import common
+from mitmproxy.console import flowdetailview
+from mitmproxy.console import grideditor
+from mitmproxy.console import searchable
+from mitmproxy.console import signals
+from mitmproxy.console import tabs
+from netlib.http import Headers
+from netlib.http import status_codes
 
 
 class SearchError(Exception):
@@ -193,12 +201,12 @@ class FlowView(tabs.Tabs):
 
         try:
             query = None
-            if isinstance(message, HTTPRequest):
+            if isinstance(message, models.HTTPRequest):
                 query = message.query
             description, lines = contentviews.get_content_view(
                 viewmode, message.content, headers=message.headers, query=query
             )
-        except ContentViewException:
+        except exceptions.ContentViewException:
             s = "Content viewer failed: \n" + traceback.format_exc()
             signals.add_event(s, "error")
             description, lines = contentviews.get_content_view(
@@ -207,7 +215,7 @@ class FlowView(tabs.Tabs):
             description = description.replace("Raw", "Couldn't parse: falling back to Raw")
 
         # Give hint that you have to tab for the response.
-        if description == "No content" and isinstance(message, HTTPRequest):
+        if description == "No content" and isinstance(message, models.HTTPRequest):
             description = "No request content (press tab to view response)"
 
         # If the users has a wide terminal, he gets fewer lines; this should not be an issue.
@@ -372,7 +380,7 @@ class FlowView(tabs.Tabs):
             message = self.flow.request
         else:
             if not self.flow.response:
-                self.flow.response = HTTPResponse(
+                self.flow.response = models.HTTPResponse(
                     self.flow.request.http_version,
                     200, "OK", Headers(), ""
                 )
@@ -399,7 +407,7 @@ class FlowView(tabs.Tabs):
                 )
             )
         if part == "r":
-            with decoded(message):
+            with models.decoded(message):
                 # Fix an issue caused by some editors when editing a
                 # request/response body. Many editors make it hard to save a
                 # file without a terminating newline on the last line. When
diff --git a/mitmproxy/console/grideditor.py b/mitmproxy/console/grideditor.py
index ea26d966..9fa51ccb 100644
--- a/mitmproxy/console/grideditor.py
+++ b/mitmproxy/console/grideditor.py
@@ -1,15 +1,18 @@
-from __future__ import absolute_import
+from __future__ import absolute_import, print_function, division
 
 import copy
-import re
 import os
-import urwid
-
-from netlib.http import user_agents, cookies
+import re
 
-from . import common, signals
-from .. import utils, filt, script
+import urwid
 
+from mitmproxy import filt
+from mitmproxy import script
+from mitmproxy import utils
+from mitmproxy.console import common
+from mitmproxy.console import signals
+from netlib.http import cookies
+from netlib.http import user_agents
 
 FOOTER = [
     ('heading_key', "enter"), ":edit ",
diff --git a/mitmproxy/console/help.py b/mitmproxy/console/help.py
index 0c264ebf..26cb4ed3 100644
--- a/mitmproxy/console/help.py
+++ b/mitmproxy/console/help.py
@@ -1,9 +1,11 @@
-from __future__ import absolute_import
+from __future__ import absolute_import, print_function, division
 
 import urwid
 
-from . import common, signals
-from .. import filt, version
+from mitmproxy import filt
+from mitmproxy import version
+from mitmproxy.console import common
+from mitmproxy.console import signals
 
 footer = [
     ("heading", 'mitmproxy v%s ' % version.VERSION),
diff --git a/mitmproxy/console/options.py b/mitmproxy/console/options.py
index 5c9e0cc9..5a01c9d5 100644
--- a/mitmproxy/console/options.py
+++ b/mitmproxy/console/options.py
@@ -1,8 +1,13 @@
+from __future__ import absolute_import, print_function, division
+
 import urwid
 
-from .. import contentviews
-from . import common, signals, grideditor
-from . import select, palettes
+from mitmproxy import contentviews
+from mitmproxy.console import common
+from mitmproxy.console import grideditor
+from mitmproxy.console import palettes
+from mitmproxy.console import select
+from mitmproxy.console import signals
 
 footer = [
     ('heading_key', "enter/space"), ":toggle ",
diff --git a/mitmproxy/console/palettepicker.py b/mitmproxy/console/palettepicker.py
index 51ad0606..f2acba0a 100644
--- a/mitmproxy/console/palettepicker.py
+++ b/mitmproxy/console/palettepicker.py
@@ -1,6 +1,11 @@
+from __future__ import absolute_import, print_function, division
+
 import urwid
 
-from . import select, common, palettes, signals
+from mitmproxy.console import common
+from mitmproxy.console import palettes
+from mitmproxy.console import select
+from mitmproxy.console import signals
 
 footer = [
     ('heading_key', "enter/space"), ":select",
diff --git a/mitmproxy/console/palettes.py b/mitmproxy/console/palettes.py
index bd370181..36cc3ac0 100644
--- a/mitmproxy/console/palettes.py
+++ b/mitmproxy/console/palettes.py
@@ -3,6 +3,7 @@
 #
 # http://urwid.org/manual/displayattributes.html
 #
+from __future__ import absolute_import, print_function, division
 
 
 class Palette:
diff --git a/mitmproxy/console/pathedit.py b/mitmproxy/console/pathedit.py
index 4447070b..0eae9123 100644
--- a/mitmproxy/console/pathedit.py
+++ b/mitmproxy/console/pathedit.py
@@ -1,3 +1,5 @@
+from __future__ import absolute_import, print_function, division
+
 import glob
 import os.path
 
diff --git a/mitmproxy/console/searchable.py b/mitmproxy/console/searchable.py
index cff1f0a1..c60d1cd9 100644
--- a/mitmproxy/console/searchable.py
+++ b/mitmproxy/console/searchable.py
@@ -1,6 +1,8 @@
+from __future__ import absolute_import, print_function, division
+
 import urwid
 
-from . import signals
+from mitmproxy.console import signals
 
 
 class Highlight(urwid.AttrMap):
diff --git a/mitmproxy/console/select.py b/mitmproxy/console/select.py
index 7c6d1e96..091f07a2 100644
--- a/mitmproxy/console/select.py
+++ b/mitmproxy/console/select.py
@@ -1,6 +1,8 @@
+from __future__ import absolute_import, print_function, division
+
 import urwid
 
-from . import common
+from mitmproxy.console import common
 
 
 class _OptionWidget(urwid.WidgetWrap):
diff --git a/mitmproxy/console/signals.py b/mitmproxy/console/signals.py
index 6a439bf3..b57ebf0c 100644
--- a/mitmproxy/console/signals.py
+++ b/mitmproxy/console/signals.py
@@ -1,3 +1,5 @@
+from __future__ import absolute_import, print_function, division
+
 import blinker
 
 # Show a status message in the action bar
diff --git a/mitmproxy/console/statusbar.py b/mitmproxy/console/statusbar.py
index d57ac69c..b3e1517f 100644
--- a/mitmproxy/console/statusbar.py
+++ b/mitmproxy/console/statusbar.py
@@ -1,10 +1,14 @@
+from __future__ import absolute_import, print_function, division
+
 import os.path
 
 import urwid
 
 import netlib.utils
+from mitmproxy.console import common
+from mitmproxy.console import pathedit
+from mitmproxy.console import signals
 from netlib import human
-from . import pathedit, signals, common
 
 
 class ActionBar(urwid.WidgetWrap):
diff --git a/mitmproxy/console/tabs.py b/mitmproxy/console/tabs.py
index b5423038..bfcdeba3 100644
--- a/mitmproxy/console/tabs.py
+++ b/mitmproxy/console/tabs.py
@@ -1,3 +1,5 @@
+from __future__ import absolute_import, print_function, division
+
 import urwid
 
 
diff --git a/mitmproxy/console/window.py b/mitmproxy/console/window.py
index 47c284e4..25780daf 100644
--- a/mitmproxy/console/window.py
+++ b/mitmproxy/console/window.py
@@ -1,5 +1,8 @@
+from __future__ import absolute_import, print_function, division
+
 import urwid
-from . import signals
+
+from mitmproxy.console import signals
 
 
 class Window(urwid.Frame):
diff --git a/mitmproxy/contentviews.py b/mitmproxy/contentviews.py
index 373c9514..87cb2aa0 100644
--- a/mitmproxy/contentviews.py
+++ b/mitmproxy/contentviews.py
@@ -12,27 +12,31 @@ use. For HTTP, the message headers are passed as the ``headers`` keyword argumen
 requests, the query parameters are passed as the ``query`` keyword argument.
 
 """
-from __future__ import (absolute_import, print_function, division)
-from six.moves import cStringIO as StringIO
+from __future__ import absolute_import, print_function, division
+
+import datetime
 import json
 import logging
 import subprocess
 import sys
-import lxml.html
-import lxml.etree
-import datetime
-from PIL import Image
-from PIL.ExifTags import TAGS
+
 import html2text
+import lxml.etree
+import lxml.html
 import six
-from netlib.odict import ODict
-from netlib import encoding, http
+from PIL import ExifTags
+from PIL import Image
+from six.moves import cStringIO as StringIO
+
+import mitmproxy.utils
+from mitmproxy import exceptions
+from mitmproxy.contrib import jsbeautifier
+from mitmproxy.contrib.wbxml import ASCommandResponse
+from netlib import encoding
+from netlib import http
+from netlib import odict
 from netlib.http import url
-from netlib.utils import clean_bin, hexdump
-from . import utils
-from .exceptions import ContentViewException
-from .contrib import jsbeautifier
-from .contrib.wbxml.ASCommandResponse import ASCommandResponse
+import netlib.utils
 
 try:
     import pyamf
@@ -125,11 +129,11 @@ class ViewAuto(View):
             ct = "%s/%s" % (ct[0], ct[1])
             if ct in content_types_map:
                 return content_types_map[ct][0](data, **metadata)
-            elif utils.isXML(data):
+            elif mitmproxy.utils.isXML(data):
                 return get("XML")(data, **metadata)
         if metadata.get("query"):
             return get("Query")(data, **metadata)
-        if data and utils.isMostlyBin(data):
+        if data and mitmproxy.utils.isMostlyBin(data):
             return get("Hex")(data)
         if not data:
             return "No content", []
@@ -152,7 +156,7 @@ class ViewHex(View):
 
     @staticmethod
     def _format(data):
-        for offset, hexa, s in hexdump(data):
+        for offset, hexa, s in netlib.utils.hexdump(data):
             yield [
                 ("offset", offset + " "),
                 ("text", hexa + "   "),
@@ -211,7 +215,7 @@ class ViewJSON(View):
     content_types = ["application/json"]
 
     def __call__(self, data, **metadata):
-        pretty_json = utils.pretty_json(data)
+        pretty_json = mitmproxy.utils.pretty_json(data)
         if pretty_json:
             return "JSON", format_text(pretty_json)
 
@@ -222,7 +226,7 @@ class ViewHTML(View):
     content_types = ["text/html"]
 
     def __call__(self, data, **metadata):
-        if utils.isXML(data):
+        if mitmproxy.utils.isXML(data):
             parser = lxml.etree.HTMLParser(
                 strip_cdata=True,
                 remove_blank_text=True
@@ -259,7 +263,7 @@ class ViewURLEncoded(View):
 
     def __call__(self, data, **metadata):
         d = url.decode(data)
-        return "URLEncoded form", format_dict(ODict(d))
+        return "URLEncoded form", format_dict(odict.ODict(d))
 
 
 class ViewMultipart(View):
@@ -270,7 +274,7 @@ class ViewMultipart(View):
     @staticmethod
     def _format(v):
         yield [("highlight", "Form data:\n")]
-        for message in format_dict(ODict(v)):
+        for message in format_dict(odict.ODict(v)):
             yield message
 
     def __call__(self, data, **metadata):
@@ -415,11 +419,11 @@ class ViewImage(View):
             ex = img._getexif()
             if ex:
                 for i in sorted(ex.keys()):
-                    tag = TAGS.get(i, i)
+                    tag = ExifTags.TAGS.get(i, i)
                     parts.append(
                         (str(tag), str(ex[i]))
                     )
-        fmt = format_dict(ODict(parts))
+        fmt = format_dict(odict.ODict(parts))
         return "%s image" % img.format, fmt
 
 
@@ -490,7 +494,7 @@ class ViewWBXML(View):
     def __call__(self, data, **metadata):
 
         try:
-            parser = ASCommandResponse(data)
+            parser = ASCommandResponse.ASCommandResponse(data)
             parsedContent = parser.xmlString
             if parsedContent:
                 return "WBXML", format_text(parsedContent)
@@ -519,12 +523,12 @@ def add(view):
     # TODO: auto-select a different name (append an integer?)
     for i in views:
         if i.name == view.name:
-            raise ContentViewException("Duplicate view: " + view.name)
+            raise exceptions.ContentViewException("Duplicate view: " + view.name)
 
     # TODO: the UI should auto-prompt for a replacement shortcut
     for prompt in view_prompts:
         if prompt[1] == view.prompt[1]:
-            raise ContentViewException("Duplicate view shortcut: " + view.prompt[1])
+            raise exceptions.ContentViewException("Duplicate view shortcut: " + view.prompt[1])
 
     views.append(view)
 
@@ -577,9 +581,9 @@ def safe_to_print(lines, encoding="utf8"):
         clean_line = []
         for (style, text) in line:
             try:
-                text = clean_bin(text.decode(encoding, "strict"))
+                text = netlib.utils.clean_bin(text.decode(encoding, "strict"))
             except UnicodeDecodeError:
-                text = clean_bin(text).decode(encoding, "strict")
+                text = netlib.utils.clean_bin(text).decode(encoding, "strict")
             clean_line.append((style, text))
         yield clean_line
 
@@ -611,8 +615,8 @@ def get_content_view(viewmode, data, **metadata):
     # Third-party viewers can fail in unexpected ways...
     except Exception as e:
         six.reraise(
-            ContentViewException,
-            ContentViewException(str(e)),
+            exceptions.ContentViewException,
+            exceptions.ContentViewException(str(e)),
             sys.exc_info()[2]
         )
     if not ret:
diff --git a/mitmproxy/controller.py b/mitmproxy/controller.py
index a9e101eb..1498c3ad 100644
--- a/mitmproxy/controller.py
+++ b/mitmproxy/controller.py
@@ -1,9 +1,11 @@
-from __future__ import absolute_import
-from six.moves import queue
-import threading
+from __future__ import absolute_import, print_function, division
+
 import functools
+import threading
+
+from six.moves import queue
 
-from . import exceptions
+from mitmproxy import exceptions
 
 Events = frozenset([
     "clientconnect",
diff --git a/mitmproxy/dump.py b/mitmproxy/dump.py
index 0f54b4d4..f5d6725c 100644
--- a/mitmproxy/dump.py
+++ b/mitmproxy/dump.py
@@ -1,13 +1,19 @@
-from __future__ import absolute_import, print_function
-import traceback
+from __future__ import absolute_import, print_function, division
+
+import itertools
 import sys
+import traceback
+
 import click
-import itertools
 
-from netlib import tcp, human
-from netlib.utils import bytes_to_escaped_str
-from . import flow, filt, contentviews, controller
-from .exceptions import ContentViewException, FlowReadException, ScriptException
+from mitmproxy import contentviews
+from mitmproxy import controller
+from mitmproxy import exceptions
+from mitmproxy import filt
+from mitmproxy import flow
+from netlib import human
+from netlib import tcp
+from netlib import utils
 
 
 class DumpError(Exception):
@@ -127,13 +133,13 @@ class DumpMaster(flow.FlowMaster):
         for command in scripts:
             try:
                 self.load_script(command, use_reloader=True)
-            except ScriptException as e:
+            except exceptions.ScriptException as e:
                 raise DumpError(str(e))
 
         if options.rfile:
             try:
                 self.load_flows_file(options.rfile)
-            except FlowReadException as v:
+            except exceptions.FlowReadException as v:
                 self.add_event("Flow file corrupted.", "error")
                 raise DumpError(v)
 
@@ -147,7 +153,7 @@ class DumpMaster(flow.FlowMaster):
         """
         try:
             return flow.read_flows_from_paths(paths)
-        except FlowReadException as e:
+        except exceptions.FlowReadException as e:
             raise DumpError(str(e))
 
     def add_event(self, e, level="info"):
@@ -175,8 +181,8 @@ class DumpMaster(flow.FlowMaster):
         if self.o.flow_detail >= 2:
             headers = "\r\n".join(
                 "{}: {}".format(
-                    click.style(bytes_to_escaped_str(k), fg="blue", bold=True),
-                    click.style(bytes_to_escaped_str(v), fg="blue"))
+                    click.style(utils.bytes_to_escaped_str(k), fg="blue", bold=True),
+                    click.style(utils.bytes_to_escaped_str(v), fg="blue"))
                 for k, v in message.headers.fields
             )
             self.echo(headers, indent=4)
@@ -192,7 +198,7 @@ class DumpMaster(flow.FlowMaster):
                         message.content,
                         headers=message.headers
                     )
-                except ContentViewException:
+                except exceptions.ContentViewException:
                     s = "Content viewer failed: \n" + traceback.format_exc()
                     self.add_event(s, "debug")
                     type, lines = contentviews.get_content_view(
@@ -238,7 +244,7 @@ class DumpMaster(flow.FlowMaster):
             stickycookie = ""
 
         if flow.client_conn:
-            client = click.style(bytes_to_escaped_str(flow.client_conn.address.host), bold=True)
+            client = click.style(utils.bytes_to_escaped_str(flow.client_conn.address.host), bold=True)
         else:
             client = click.style("[replay]", fg="yellow", bold=True)
 
@@ -247,12 +253,12 @@ class DumpMaster(flow.FlowMaster):
             GET="green",
             DELETE="red"
         ).get(method.upper(), "magenta")
-        method = click.style(bytes_to_escaped_str(method), fg=method_color, bold=True)
+        method = click.style(utils.bytes_to_escaped_str(method), fg=method_color, bold=True)
         if self.showhost:
             url = flow.request.pretty_url
         else:
             url = flow.request.url
-        url = click.style(bytes_to_escaped_str(url), bold=True)
+        url = click.style(utils.bytes_to_escaped_str(url), bold=True)
 
         httpversion = ""
         if flow.request.http_version not in ("HTTP/1.1", "HTTP/1.0"):
@@ -282,7 +288,7 @@ class DumpMaster(flow.FlowMaster):
         elif 400 <= code < 600:
             code_color = "red"
         code = click.style(str(code), fg=code_color, bold=True, blink=(code == 418))
-        reason = click.style(bytes_to_escaped_str(flow.response.reason), fg=code_color, bold=True)
+        reason = click.style(utils.bytes_to_escaped_str(flow.response.reason), fg=code_color, bold=True)
 
         if flow.response.content is None:
             size = "(content missing)"
diff --git a/mitmproxy/exceptions.py b/mitmproxy/exceptions.py
index b1d2c03a..d97b9498 100644
--- a/mitmproxy/exceptions.py
+++ b/mitmproxy/exceptions.py
@@ -5,11 +5,10 @@ Every Exception mitmproxy raises shall be a subclass of ProxyException.
 
 See also: http://lucumr.pocoo.org/2014/10/16/on-error-handling/
 """
-from __future__ import (absolute_import, print_function, division)
-
-import traceback
+from __future__ import absolute_import, print_function, division
 
 import sys
+import traceback
 
 
 class ProxyException(Exception):
diff --git a/mitmproxy/filt.py b/mitmproxy/filt.py
index 6228d364..d98e3749 100644
--- a/mitmproxy/filt.py
+++ b/mitmproxy/filt.py
@@ -31,9 +31,11 @@
         ~c CODE     Response code.
         rex         Equivalent to ~u rex
 """
-from __future__ import absolute_import, print_function
+from __future__ import absolute_import, print_function, division
+
 import re
 import sys
+
 import pyparsing as pp
 
 
diff --git a/mitmproxy/flow/export.py b/mitmproxy/flow/export.py
index d71ac609..97cee984 100644
--- a/mitmproxy/flow/export.py
+++ b/mitmproxy/flow/export.py
@@ -1,3 +1,5 @@
+from __future__ import absolute_import, print_function, division
+
 import json
 import re
 from textwrap import dedent
diff --git a/mitmproxy/flow/io.py b/mitmproxy/flow/io.py
index f31c8e5b..cd3d9986 100644
--- a/mitmproxy/flow/io.py
+++ b/mitmproxy/flow/io.py
@@ -1,7 +1,10 @@
+from __future__ import absolute_import, print_function, division
+
 import os
 
-from mitmproxy import tnetstring, models
-from mitmproxy.exceptions import FlowReadException
+from mitmproxy import exceptions
+from mitmproxy import models
+from mitmproxy import tnetstring
 from mitmproxy.flow import io_compat
 
 
@@ -38,17 +41,17 @@ class FlowReader:
                 try:
                     data = io_compat.migrate_flow(data)
                 except ValueError as e:
-                    raise FlowReadException(str(e))
+                    raise exceptions.FlowReadException(str(e))
                 if can_tell:
                     off = self.fo.tell()
                 if data["type"] not in models.FLOW_TYPES:
-                    raise FlowReadException("Unknown flow type: {}".format(data["type"]))
+                    raise exceptions.FlowReadException("Unknown flow type: {}".format(data["type"]))
                 yield models.FLOW_TYPES[data["type"]].from_state(data)
         except ValueError:
             # Error is due to EOF
             if can_tell and self.fo.tell() == off and self.fo.read() == '':
                 return
-            raise FlowReadException("Invalid data format.")
+            raise exceptions.FlowReadException("Invalid data format.")
 
 
 class FilteredFlowWriter:
@@ -79,5 +82,5 @@ def read_flows_from_paths(paths):
             with open(path, "rb") as f:
                 flows.extend(FlowReader(f).stream())
     except IOError as e:
-        raise FlowReadException(e.strerror)
+        raise exceptions.FlowReadException(e.strerror)
     return flows
diff --git a/mitmproxy/flow/master.py b/mitmproxy/flow/master.py
index e0d2c51e..a198018e 100644
--- a/mitmproxy/flow/master.py
+++ b/mitmproxy/flow/master.py
@@ -1,16 +1,22 @@
+from __future__ import absolute_import, print_function, division
+
 import os
 import sys
 
 from typing import List, Optional, Set  # noqa
 
-from mitmproxy import controller, script, filt, models
-from mitmproxy.exceptions import FlowReadException, Kill
-from mitmproxy.flow import io, modules
+import netlib.exceptions
+from mitmproxy import controller
+from mitmproxy import exceptions
+from mitmproxy import filt
+from mitmproxy import models
+from mitmproxy import script
+from mitmproxy.flow import io
+from mitmproxy.flow import modules
 from mitmproxy.onboarding import app
-from mitmproxy.protocol.http_replay import RequestReplayThread
+from mitmproxy.protocol import http_replay
 from mitmproxy.proxy.config import HostMatcher
 from netlib import utils
-from netlib.exceptions import HttpException
 
 
 class FlowMaster(controller.Master):
@@ -311,7 +317,7 @@ class FlowMaster(controller.Master):
                     freader = io.FlowReader(f)
                     return self.load_flows(freader)
         except IOError as v:
-            raise FlowReadException(v.strerror)
+            raise exceptions.FlowReadException(v.strerror)
 
     def process_new_request(self, f):
         if self.stickycookie_state:
@@ -351,7 +357,7 @@ class FlowMaster(controller.Master):
             f.response = None
             f.error = None
             self.process_new_request(f)
-            rt = RequestReplayThread(
+            rt = http_replay.RequestReplayThread(
                 self.server.config,
                 f,
                 self.event_queue if run_scripthooks else False,
@@ -405,7 +411,7 @@ class FlowMaster(controller.Master):
                 )
                 if err:
                     self.add_event("Error in wsgi app. %s" % err, "error")
-                f.reply(Kill)
+                f.reply(exceptions.Kill)
                 return
         if f not in self.state.flows:  # don't add again on replay
             self.state.add_flow(f)
@@ -421,8 +427,8 @@ class FlowMaster(controller.Master):
         try:
             if self.stream_large_bodies:
                 self.stream_large_bodies.run(f, False)
-        except HttpException:
-            f.reply(Kill)
+        except netlib.exceptions.HttpException:
+            f.reply(exceptions.Kill)
             return
         self.run_script_hook("responseheaders", f)
         return f
diff --git a/mitmproxy/flow/modules.py b/mitmproxy/flow/modules.py
index 438c5a21..601ebfce 100644
--- a/mitmproxy/flow/modules.py
+++ b/mitmproxy/flow/modules.py
@@ -1,3 +1,5 @@
+from __future__ import absolute_import, print_function, division
+
 import collections
 import hashlib
 import re
@@ -5,9 +7,12 @@ import re
 from six.moves import http_cookiejar
 from six.moves import urllib
 
-from mitmproxy import version, filt, controller
+from mitmproxy import controller
+from mitmproxy import filt
+from mitmproxy import version
 from netlib import wsgi
-from netlib.http import http1, cookies
+from netlib.http import cookies
+from netlib.http import http1
 
 
 class AppRegistry:
diff --git a/mitmproxy/flow/state.py b/mitmproxy/flow/state.py
index 16e79542..4287d77b 100644
--- a/mitmproxy/flow/state.py
+++ b/mitmproxy/flow/state.py
@@ -1,9 +1,12 @@
+from __future__ import absolute_import, print_function, division
+
 from abc import abstractmethod, ABCMeta
 
 import six
 from typing import List  # noqa
 
-from mitmproxy import models, filt  # noqa
+from mitmproxy import filt
+from mitmproxy import models  # noqa
 
 
 @six.add_metaclass(ABCMeta)
diff --git a/mitmproxy/main.py b/mitmproxy/main.py
index d44c257e..b73966ba 100644
--- a/mitmproxy/main.py
+++ b/mitmproxy/main.py
@@ -1,13 +1,16 @@
-from __future__ import print_function, absolute_import
+from __future__ import absolute_import, print_function, division
+
 import os
 import signal
 import sys
+
 from six.moves import _thread  # PY3: We only need _thread.error, which is an alias of RuntimeError in 3.3+
-from netlib.version_check import check_pyopenssl_version
-from . import cmdline
-from .exceptions import ServerException
-from .proxy.server import DummyServer, ProxyServer
-from .proxy.config import process_proxy_options
+
+from mitmproxy import cmdline
+from mitmproxy import exceptions
+from mitmproxy.proxy import config
+from mitmproxy.proxy import server
+from netlib import version_check
 
 
 def assert_utf8_env():
@@ -28,11 +31,11 @@ def assert_utf8_env():
 
 def get_server(dummy_server, options):
     if dummy_server:
-        return DummyServer(options)
+        return server.DummyServer(options)
     else:
         try:
-            return ProxyServer(options)
-        except ServerException as v:
+            return server.ProxyServer(options)
+        except exceptions.ServerException as v:
             print(str(v), file=sys.stderr)
             sys.exit(1)
 
@@ -44,7 +47,7 @@ def mitmproxy(args=None):  # pragma: no cover
         sys.exit(1)
     from . import console
 
-    check_pyopenssl_version()
+    version_check.check_pyopenssl_version()
     assert_utf8_env()
 
     parser = cmdline.mitmproxy()
@@ -52,7 +55,7 @@ def mitmproxy(args=None):  # pragma: no cover
     if options.quiet:
         options.verbose = 0
 
-    proxy_config = process_proxy_options(parser, options)
+    proxy_config = cmdline.process_proxy_options(parser, options)
     console_options = console.Options(**cmdline.get_common_options(options))
     console_options.palette = options.palette
     console_options.palette_transparent = options.palette_transparent
@@ -74,7 +77,7 @@ def mitmproxy(args=None):  # pragma: no cover
 def mitmdump(args=None):  # pragma: no cover
     from . import dump
 
-    check_pyopenssl_version()
+    version_check.check_pyopenssl_version()
 
     parser = cmdline.mitmdump()
     options = parser.parse_args(args)
@@ -82,7 +85,7 @@ def mitmdump(args=None):  # pragma: no cover
         options.verbose = 0
         options.flow_detail = 0
 
-    proxy_config = process_proxy_options(parser, options)
+    proxy_config = config.process_proxy_options(parser, options)
     dump_options = dump.Options(**cmdline.get_common_options(options))
     dump_options.flow_detail = options.flow_detail
     dump_options.keepserving = options.keepserving
@@ -108,7 +111,7 @@ def mitmdump(args=None):  # pragma: no cover
 def mitmweb(args=None):  # pragma: no cover
     from . import web
 
-    check_pyopenssl_version()
+    version_check.check_pyopenssl_version()
 
     parser = cmdline.mitmweb()
 
@@ -116,7 +119,7 @@ def mitmweb(args=None):  # pragma: no cover
     if options.quiet:
         options.verbose = 0
 
-    proxy_config = process_proxy_options(parser, options)
+    proxy_config = config.process_proxy_options(parser, options)
     web_options = web.Options(**cmdline.get_common_options(options))
     web_options.intercept = options.intercept
     web_options.wdebug = options.wdebug
diff --git a/mitmproxy/models/__init__.py b/mitmproxy/models/__init__.py
index 3d9d9dae..ca813567 100644
--- a/mitmproxy/models/__init__.py
+++ b/mitmproxy/models/__init__.py
@@ -1,12 +1,12 @@
-from __future__ import (absolute_import, print_function, division)
+from __future__ import absolute_import, print_function, division
 
+from netlib.http import decoded
+from .connections import ClientConnection, ServerConnection
+from .flow import Flow, Error
 from .http import (
     HTTPFlow, HTTPRequest, HTTPResponse, Headers,
     make_error_response, make_connect_request, make_connect_response, expect_continue_response
 )
-from netlib.http import decoded
-from .connections import ClientConnection, ServerConnection
-from .flow import Flow, Error
 from .tcp import TCPFlow
 
 FLOW_TYPES = dict(
diff --git a/mitmproxy/models/connections.py b/mitmproxy/models/connections.py
index 24cdff74..6347f488 100644
--- a/mitmproxy/models/connections.py
+++ b/mitmproxy/models/connections.py
@@ -1,12 +1,14 @@
-from __future__ import (absolute_import, print_function, division)
+from __future__ import absolute_import, print_function, division
 
 import copy
 import os
 
 import six
 
-from netlib import tcp, certutils
-from .. import stateobject, utils
+from mitmproxy import stateobject
+from mitmproxy import utils
+from netlib import certutils
+from netlib import tcp
 
 
 class ClientConnection(tcp.BaseHandler, stateobject.StateObject):
diff --git a/mitmproxy/models/flow.py b/mitmproxy/models/flow.py
index 8797fcd8..7b9ec030 100644
--- a/mitmproxy/models/flow.py
+++ b/mitmproxy/models/flow.py
@@ -1,10 +1,14 @@
-from __future__ import (absolute_import, print_function, division)
+from __future__ import absolute_import, print_function, division
+
 import copy
 import uuid
 
-from .. import stateobject, utils, version
-from .connections import ClientConnection, ServerConnection
-from ..exceptions import Kill
+from mitmproxy import exceptions
+from mitmproxy import stateobject
+from mitmproxy import utils
+from mitmproxy import version
+from mitmproxy.models.connections import ClientConnection
+from mitmproxy.models.connections import ServerConnection
 
 
 class Error(stateobject.StateObject):
@@ -151,7 +155,7 @@ class Flow(stateobject.StateObject):
         """
         self.error = Error("Connection killed")
         self.intercepted = False
-        self.reply(Kill)
+        self.reply(exceptions.Kill)
         master.error(self)
 
     def intercept(self, master):
diff --git a/mitmproxy/models/http.py b/mitmproxy/models/http.py
index 43618ef8..a32124ac 100644
--- a/mitmproxy/models/http.py
+++ b/mitmproxy/models/http.py
@@ -1,11 +1,15 @@
-from __future__ import (absolute_import, print_function, division)
+from __future__ import absolute_import, print_function, division
+
 import cgi
 
+from mitmproxy import version
+from mitmproxy.models.flow import Flow
 from netlib import encoding
-from netlib.http import status_codes, Headers, Request, Response
+from netlib.http import Headers
+from netlib.http import Request
+from netlib.http import Response
+from netlib.http import status_codes
 from netlib.tcp import Address
-from .. import version
-from .flow import Flow
 
 
 class MessageMixin(object):
diff --git a/mitmproxy/models/tcp.py b/mitmproxy/models/tcp.py
index c7cfb9f8..e33475c2 100644
--- a/mitmproxy/models/tcp.py
+++ b/mitmproxy/models/tcp.py
@@ -1,8 +1,11 @@
+from __future__ import absolute_import, print_function, division
+
 import time
+
 from typing import List
 
 import netlib.basetypes
-from .flow import Flow
+from mitmproxy.models.flow import Flow
 
 
 class TCPMessage(netlib.basetypes.Serializable):
diff --git a/mitmproxy/onboarding/app.py b/mitmproxy/onboarding/app.py
index ff5ed63c..f93b9982 100644
--- a/mitmproxy/onboarding/app.py
+++ b/mitmproxy/onboarding/app.py
@@ -1,12 +1,13 @@
-from __future__ import absolute_import
+from __future__ import absolute_import, print_function, division
+
 import os
+
+import tornado.template
 import tornado.web
 import tornado.wsgi
-import tornado.template
-
-from .. import utils
-from ..proxy import config
 
+from mitmproxy import utils
+from mitmproxy.proxy import config
 
 loader = tornado.template.Loader(utils.pkg_data.path("onboarding/templates"))
 
diff --git a/mitmproxy/platform/osx.py b/mitmproxy/platform/osx.py
index 3cd4bc66..b16c1861 100644
--- a/mitmproxy/platform/osx.py
+++ b/mitmproxy/platform/osx.py
@@ -1,4 +1,5 @@
 import subprocess
+
 import pf
 
 """
diff --git a/mitmproxy/platform/windows.py b/mitmproxy/platform/windows.py
index 0a810908..576516e2 100644
--- a/mitmproxy/platform/windows.py
+++ b/mitmproxy/platform/windows.py
@@ -1,18 +1,17 @@
-import configargparse
-from six.moves import cPickle as pickle
-from ctypes import byref, windll, Structure
-from ctypes.wintypes import DWORD
+import collections
+import ctypes
+import ctypes.wintypes
 import os
 import socket
-from six.moves import socketserver
 import struct
 import threading
 import time
-from collections import OrderedDict
-
-from pydivert.windivert import WinDivert
-from pydivert.enum import Direction, Layer, Flag
 
+import configargparse
+from pydivert import enum
+from pydivert import windivert
+from six.moves import cPickle as pickle
+from six.moves import socketserver
 
 PROXY_API_PORT = 8085
 
@@ -91,22 +90,22 @@ ERROR_INSUFFICIENT_BUFFER = 0x7A
 
 
 # http://msdn.microsoft.com/en-us/library/windows/desktop/bb485761(v=vs.85).aspx
-class MIB_TCPROW2(Structure):
+class MIB_TCPROW2(ctypes.Structure):
     _fields_ = [
-        ('dwState', DWORD),
-        ('dwLocalAddr', DWORD),
-        ('dwLocalPort', DWORD),
-        ('dwRemoteAddr', DWORD),
-        ('dwRemotePort', DWORD),
-        ('dwOwningPid', DWORD),
-        ('dwOffloadState', DWORD)
+        ('dwState', ctypes.wintypes.DWORD),
+        ('dwLocalAddr', ctypes.wintypes.DWORD),
+        ('dwLocalPort', ctypes.wintypes.DWORD),
+        ('dwRemoteAddr', ctypes.wintypes.DWORD),
+        ('dwRemotePort', ctypes.wintypes.DWORD),
+        ('dwOwningPid', ctypes.wintypes.DWORD),
+        ('dwOffloadState', ctypes.wintypes.DWORD)
     ]
 
 
 # http://msdn.microsoft.com/en-us/library/windows/desktop/bb485772(v=vs.85).aspx
 def MIB_TCPTABLE2(size):
-    class _MIB_TCPTABLE2(Structure):
-        _fields_ = [('dwNumEntries', DWORD),
+    class _MIB_TCPTABLE2(ctypes.Structure):
+        _fields_ = [('dwNumEntries', ctypes.wintypes.DWORD),
                     ('table', MIB_TCPROW2 * size)]
 
     return _MIB_TCPTABLE2()
@@ -192,13 +191,13 @@ class TransparentProxy(object):
         self.proxy_addr, self.proxy_port = proxy_addr, proxy_port
         self.connection_cache_size = cache_size
 
-        self.client_server_map = OrderedDict()
+        self.client_server_map = collections.OrderedDict()
 
         self.api = APIServer(self, (api_host, api_port), APIRequestHandler)
         self.api_thread = threading.Thread(target=self.api.serve_forever)
         self.api_thread.daemon = True
 
-        self.driver = WinDivert()
+        self.driver = windivert.WinDivert()
         self.driver.register()
 
         self.request_filter = custom_filter or " or ".join(
@@ -212,7 +211,7 @@ class TransparentProxy(object):
         self.addr_pid_map = dict()
         self.trusted_pids = set()
         self.tcptable2 = MIB_TCPTABLE2(0)
-        self.tcptable2_size = DWORD(0)
+        self.tcptable2_size = ctypes.wintypes.DWORD(0)
         self.request_local_handle = None
         self.request_local_thread = threading.Thread(target=self.request_local)
         self.request_local_thread.daemon = True
@@ -244,23 +243,23 @@ class TransparentProxy(object):
         # real gateway if they are on the same network.
         self.icmp_handle = self.driver.open_handle(
             filter="icmp",
-            layer=Layer.NETWORK,
-            flags=Flag.DROP)
+            layer=enum.Layer.NETWORK,
+            flags=enum.Flag.DROP)
 
         self.response_handle = self.driver.open_handle(
             filter=self.response_filter,
-            layer=Layer.NETWORK)
+            layer=enum.Layer.NETWORK)
         self.response_thread.start()
 
         if self.mode == "forward" or self.mode == "both":
             self.request_forward_handle = self.driver.open_handle(
                 filter=self.request_filter,
-                layer=Layer.NETWORK_FORWARD)
+                layer=enum.Layer.NETWORK_FORWARD)
             self.request_forward_thread.start()
         if self.mode == "local" or self.mode == "both":
             self.request_local_handle = self.driver.open_handle(
                 filter=self.request_filter,
-                layer=Layer.NETWORK)
+                layer=enum.Layer.NETWORK)
             self.request_local_thread.start()
 
     def shutdown(self):
@@ -288,9 +287,9 @@ class TransparentProxy(object):
                 raise
 
     def fetch_pids(self):
-        ret = windll.iphlpapi.GetTcpTable2(
-            byref(
-                self.tcptable2), byref(
+        ret = ctypes.windll.iphlpapi.GetTcpTable2(
+            ctypes.byref(
+                self.tcptable2), ctypes.byref(
                 self.tcptable2_size), 0)
         if ret == ERROR_INSUFFICIENT_BUFFER:
             self.tcptable2 = MIB_TCPTABLE2(self.tcptable2_size.value)
@@ -352,7 +351,7 @@ class TransparentProxy(object):
         self.client_server_map[client] = server
 
         packet.dst_addr, packet.dst_port = self.proxy_addr, self.proxy_port
-        metadata.direction = Direction.INBOUND
+        metadata.direction = enum.Direction.INBOUND
 
         packet = self.driver.update_packet_checksums(packet)
         # Use any handle thats on the NETWORK layer - request_local may be
diff --git a/mitmproxy/protocol/__init__.py b/mitmproxy/protocol/__init__.py
index 3d9fa7d4..510cd195 100644
--- a/mitmproxy/protocol/__init__.py
+++ b/mitmproxy/protocol/__init__.py
@@ -25,15 +25,16 @@ Another subtle design goal of this architecture is that upstream connections sho
 as late as possible; this makes server replay without any outgoing connections possible.
 """
 
-from __future__ import (absolute_import, print_function, division)
+from __future__ import absolute_import, print_function, division
+
 from .base import Layer, ServerConnectionMixin
-from .tls import TlsLayer
-from .tls import is_tls_record_magic
-from .tls import TlsClientHello
 from .http import UpstreamConnectLayer
 from .http1 import Http1Layer
 from .http2 import Http2Layer
 from .rawtcp import RawTCPLayer
+from .tls import TlsClientHello
+from .tls import TlsLayer
+from .tls import is_tls_record_magic
 
 __all__ = [
     "Layer", "ServerConnectionMixin",
diff --git a/mitmproxy/protocol/base.py b/mitmproxy/protocol/base.py
index c8e58d1b..11773385 100644
--- a/mitmproxy/protocol/base.py
+++ b/mitmproxy/protocol/base.py
@@ -1,11 +1,12 @@
-from __future__ import (absolute_import, print_function, division)
+from __future__ import absolute_import, print_function, division
+
 import sys
 
 import six
 
-from ..models import ServerConnection
-from ..exceptions import ProtocolException
-from netlib.exceptions import TcpException
+import netlib.exceptions
+from mitmproxy import exceptions
+from mitmproxy import models
 
 
 class _LayerCodeCompletion(object):
@@ -113,7 +114,7 @@ class ServerConnectionMixin(object):
 
     def __init__(self, server_address=None):
         super(ServerConnectionMixin, self).__init__()
-        self.server_conn = ServerConnection(server_address, (self.config.host, 0))
+        self.server_conn = models.ServerConnection(server_address, (self.config.host, 0))
         self.__check_self_connect()
 
     def __check_self_connect(self):
@@ -128,7 +129,7 @@ class ServerConnectionMixin(object):
                 address.host in ("localhost", "127.0.0.1", "::1")
             )
             if self_connect:
-                raise ProtocolException(
+                raise exceptions.ProtocolException(
                     "Invalid server address: {}\r\n"
                     "The proxy shall not connect to itself.".format(repr(address))
                 )
@@ -154,7 +155,7 @@ class ServerConnectionMixin(object):
         self.server_conn.finish()
         self.server_conn.close()
         self.channel.tell("serverdisconnect", self.server_conn)
-        self.server_conn = ServerConnection(address, (source_address.host, 0))
+        self.server_conn = models.ServerConnection(address, (source_address.host, 0))
 
     def connect(self):
         """
@@ -165,15 +166,15 @@ class ServerConnectionMixin(object):
             ~mitmproxy.exceptions.ProtocolException: if the connection could not be established.
         """
         if not self.server_conn.address:
-            raise ProtocolException("Cannot connect to server, no server address given.")
+            raise exceptions.ProtocolException("Cannot connect to server, no server address given.")
         self.log("serverconnect", "debug", [repr(self.server_conn.address)])
         self.channel.ask("serverconnect", self.server_conn)
         try:
             self.server_conn.connect()
-        except TcpException as e:
+        except netlib.exceptions.TcpException as e:
             six.reraise(
-                ProtocolException,
-                ProtocolException(
+                exceptions.ProtocolException,
+                exceptions.ProtocolException(
                     "Server connection to {} failed: {}".format(
                         repr(self.server_conn.address), str(e)
                     )
diff --git a/mitmproxy/protocol/http.py b/mitmproxy/protocol/http.py
index d9111303..ae03ab7f 100644
--- a/mitmproxy/protocol/http.py
+++ b/mitmproxy/protocol/http.py
@@ -1,30 +1,21 @@
-from __future__ import (absolute_import, print_function, division)
+from __future__ import absolute_import, print_function, division
 
 import sys
 import traceback
+
+import h2.exceptions
 import six
 
+import netlib.exceptions
+from mitmproxy import exceptions
+from mitmproxy import models
+from mitmproxy import utils
+from mitmproxy.protocol import base
+from netlib import http
 from netlib import tcp
-from netlib.exceptions import HttpException, HttpReadDisconnect, NetlibException
-from netlib.http import Headers
-
-from h2.exceptions import H2Error
-
-from .. import utils
-from ..exceptions import HttpProtocolException, Http2ProtocolException, ProtocolException
-from ..models import (
-    HTTPFlow,
-    HTTPResponse,
-    make_error_response,
-    make_connect_response,
-    Error,
-    expect_continue_response
-)
-
-from .base import Layer
 
 
-class _HttpTransmissionLayer(Layer):
+class _HttpTransmissionLayer(base.Layer):
 
     def read_request(self):
         raise NotImplementedError()
@@ -51,7 +42,7 @@ class _HttpTransmissionLayer(Layer):
 
     def send_response(self, response):
         if response.content is None:
-            raise HttpException("Cannot assemble flow with missing content")
+            raise netlib.exceptions.HttpException("Cannot assemble flow with missing content")
         self.send_response_headers(response)
         self.send_response_body(response, [response.content])
 
@@ -89,7 +80,7 @@ class ConnectServerConnection(object):
         __nonzero__ = __bool__
 
 
-class UpstreamConnectLayer(Layer):
+class UpstreamConnectLayer(base.Layer):
 
     def __init__(self, ctx, connect_request):
         super(UpstreamConnectLayer, self).__init__(ctx)
@@ -107,7 +98,7 @@ class UpstreamConnectLayer(Layer):
         self.send_request(self.connect_request)
         resp = self.read_response(self.connect_request)
         if resp.status_code != 200:
-            raise ProtocolException("Reconnect: Upstream server refuses CONNECT request")
+            raise exceptions.ProtocolException("Reconnect: Upstream server refuses CONNECT request")
 
     def connect(self):
         if not self.server_conn:
@@ -129,7 +120,7 @@ class UpstreamConnectLayer(Layer):
         self.server_conn.address = address
 
 
-class HttpLayer(Layer):
+class HttpLayer(base.Layer):
 
     def __init__(self, ctx, mode):
         super(HttpLayer, self).__init__(ctx)
@@ -166,16 +157,16 @@ class HttpLayer(Layer):
                     self.handle_regular_mode_connect(request)
                     return
 
-            except HttpReadDisconnect:
+            except netlib.exceptions.HttpReadDisconnect:
                 # don't throw an error for disconnects that happen before/between requests.
                 return
-            except NetlibException as e:
+            except netlib.exceptions.NetlibException as e:
                 self.send_error_response(400, repr(e))
-                six.reraise(ProtocolException, ProtocolException(
+                six.reraise(exceptions.ProtocolException, exceptions.ProtocolException(
                     "Error in HTTP connection: %s" % repr(e)), sys.exc_info()[2])
 
             try:
-                flow = HTTPFlow(self.client_conn, self.server_conn, live=self)
+                flow = models.HTTPFlow(self.client_conn, self.server_conn, live=self)
                 flow.request = request
                 # set upstream auth
                 if self.mode == "upstream" and self.config.upstream_auth is not None:
@@ -210,16 +201,16 @@ class HttpLayer(Layer):
                     self.handle_upstream_mode_connect(flow.request.copy())
                     return
 
-            except (ProtocolException, NetlibException) as e:
+            except (exceptions.ProtocolException, netlib.exceptions.NetlibException) as e:
                 self.send_error_response(502, repr(e))
 
                 if not flow.response:
-                    flow.error = Error(str(e))
+                    flow.error = models.Error(str(e))
                     self.channel.ask("error", flow)
                     self.log(traceback.format_exc(), "debug")
                     return
                 else:
-                    six.reraise(ProtocolException, ProtocolException(
+                    six.reraise(exceptions.ProtocolException, exceptions.ProtocolException(
                         "Error in HTTP connection: %s" % repr(e)), sys.exc_info()[2])
             finally:
                 if flow:
@@ -229,16 +220,16 @@ class HttpLayer(Layer):
         request = self.read_request()
         if request.headers.get("expect", "").lower() == "100-continue":
             # TODO: We may have to use send_response_headers for HTTP2 here.
-            self.send_response(expect_continue_response)
+            self.send_response(models.expect_continue_response)
             request.headers.pop("expect")
             request.body = b"".join(self.read_request_body(request))
         return request
 
     def send_error_response(self, code, message):
         try:
-            response = make_error_response(code, message)
+            response = models.make_error_response(code, message)
             self.send_response(response)
-        except (NetlibException, H2Error, Http2ProtocolException):
+        except (netlib.exceptions.NetlibException, h2.exceptions.H2Error, exceptions.Http2ProtocolException):
             self.log(traceback.format_exc(), "debug")
 
     def change_upstream_proxy_server(self, address):
@@ -249,7 +240,7 @@ class HttpLayer(Layer):
 
     def handle_regular_mode_connect(self, request):
         self.set_server((request.host, request.port))
-        self.send_response(make_connect_response(request.data.http_version))
+        self.send_response(models.make_connect_response(request.data.http_version))
         layer = self.ctx.next_layer(self)
         layer()
 
@@ -283,7 +274,7 @@ class HttpLayer(Layer):
 
         try:
             get_response()
-        except NetlibException as e:
+        except netlib.exceptions.NetlibException as e:
             self.log(
                 "server communication error: %s" % repr(e),
                 level="debug"
@@ -300,9 +291,9 @@ class HttpLayer(Layer):
             # > read (100-n)% of large request
             # > send large request upstream
 
-            if isinstance(e, Http2ProtocolException):
+            if isinstance(e, exceptions.Http2ProtocolException):
                 # do not try to reconnect for HTTP2
-                raise ProtocolException("First and only attempt to get response via HTTP2 failed.")
+                raise exceptions.ProtocolException("First and only attempt to get response via HTTP2 failed.")
 
             self.disconnect()
             self.connect()
@@ -345,7 +336,7 @@ class HttpLayer(Layer):
             flow.request.scheme = "https" if self.__initial_server_tls else "http"
 
         request_reply = self.channel.ask("request", flow)
-        if isinstance(request_reply, HTTPResponse):
+        if isinstance(request_reply, models.HTTPResponse):
             flow.response = request_reply
             return
 
@@ -365,7 +356,7 @@ class HttpLayer(Layer):
             if not self.server_conn:
                 self.connect()
             if tls:
-                raise HttpProtocolException("Cannot change scheme in upstream proxy mode.")
+                raise exceptions.HttpProtocolException("Cannot change scheme in upstream proxy mode.")
             """
             # This is a very ugly (untested) workaround to solve a very ugly problem.
             if self.server_conn and self.server_conn.tls_established and not ssl:
@@ -383,7 +374,7 @@ class HttpLayer(Layer):
 
     def validate_request(self, request):
         if request.first_line_format == "absolute" and request.scheme != "http":
-            raise HttpException("Invalid request scheme: %s" % request.scheme)
+            raise netlib.exceptions.HttpException("Invalid request scheme: %s" % request.scheme)
 
         expected_request_forms = {
             "regular": ("authority", "absolute",),
@@ -396,7 +387,7 @@ class HttpLayer(Layer):
             err_message = "Invalid HTTP request form (expected: %s, got: %s)" % (
                 " or ".join(allowed_request_forms), request.first_line_format
             )
-            raise HttpException(err_message)
+            raise netlib.exceptions.HttpException(err_message)
 
         if self.mode == "regular" and request.first_line_format == "absolute":
             request.first_line_format = "relative"
@@ -406,10 +397,10 @@ class HttpLayer(Layer):
             if self.config.authenticator.authenticate(request.headers):
                 self.config.authenticator.clean(request.headers)
             else:
-                self.send_response(make_error_response(
+                self.send_response(models.make_error_response(
                     407,
                     "Proxy Authentication Required",
-                    Headers(**self.config.authenticator.auth_challenge_headers())
+                    http.Headers(**self.config.authenticator.auth_challenge_headers())
                 ))
                 return False
         return True
diff --git a/mitmproxy/protocol/http1.py b/mitmproxy/protocol/http1.py
index 940a4c98..7055a7fd 100644
--- a/mitmproxy/protocol/http1.py
+++ b/mitmproxy/protocol/http1.py
@@ -1,13 +1,11 @@
-from __future__ import (absolute_import, print_function, division)
-
+from __future__ import absolute_import, print_function, division
 
+from mitmproxy import models
+from mitmproxy.protocol import http
 from netlib.http import http1
 
-from .http import _HttpTransmissionLayer, HttpLayer
-from ..models import HTTPRequest, HTTPResponse
-
 
-class Http1Layer(_HttpTransmissionLayer):
+class Http1Layer(http._HttpTransmissionLayer):
 
     def __init__(self, ctx, mode):
         super(Http1Layer, self).__init__(ctx)
@@ -15,7 +13,7 @@ class Http1Layer(_HttpTransmissionLayer):
 
     def read_request(self):
         req = http1.read_request(self.client_conn.rfile, body_size_limit=self.config.body_size_limit)
-        return HTTPRequest.wrap(req)
+        return models.HTTPRequest.wrap(req)
 
     def read_request_body(self, request):
         expected_size = http1.expected_http_body_size(request)
@@ -27,7 +25,7 @@ class Http1Layer(_HttpTransmissionLayer):
 
     def read_response_headers(self):
         resp = http1.read_response_head(self.server_conn.rfile)
-        return HTTPResponse.wrap(resp)
+        return models.HTTPResponse.wrap(resp)
 
     def read_response_body(self, request, response):
         expected_size = http1.expected_http_body_size(request, response)
@@ -63,5 +61,5 @@ class Http1Layer(_HttpTransmissionLayer):
         return close_connection
 
     def __call__(self):
-        layer = HttpLayer(self, self.mode)
+        layer = http.HttpLayer(self, self.mode)
         layer()
diff --git a/mitmproxy/protocol/http2.py b/mitmproxy/protocol/http2.py
index 6ca78347..39512c8f 100644
--- a/mitmproxy/protocol/http2.py
+++ b/mitmproxy/protocol/http2.py
@@ -1,29 +1,27 @@
-from __future__ import (absolute_import, print_function, division)
+from __future__ import absolute_import, print_function, division
 
 import threading
 import time
-from six.moves import queue
-
 import traceback
+
+import h2.exceptions
+import hyperframe
 import six
-from h2.connection import H2Connection
-from h2.exceptions import StreamClosedError
+from h2 import connection
 from h2 import events
-from hyperframe.frame import PriorityFrame
-
-from netlib.tcp import ssl_read_select
-from netlib.exceptions import HttpException
-from netlib.http import Headers
-from netlib.http.http2 import framereader
-import netlib.http.url
+from six.moves import queue
 
-from .base import Layer
-from .http import _HttpTransmissionLayer, HttpLayer
-from ..exceptions import ProtocolException, Http2ProtocolException
-from ..models import HTTPRequest, HTTPResponse
+import netlib.exceptions
+from mitmproxy import exceptions
+from mitmproxy import models
+from mitmproxy.protocol import base
+from mitmproxy.protocol import http
+import netlib.http
+from netlib import tcp
+from netlib.http import http2
 
 
-class SafeH2Connection(H2Connection):
+class SafeH2Connection(connection.H2Connection):
 
     def __init__(self, conn, *args, **kwargs):
         super(SafeH2Connection, self).__init__(*args, **kwargs)
@@ -46,7 +44,7 @@ class SafeH2Connection(H2Connection):
         with self.lock:
             try:
                 self.reset_stream(stream_id, error_code)
-            except StreamClosedError:  # pragma: no cover
+            except h2.exceptions.StreamClosedError:  # pragma: no cover
                 # stream is already closed - good
                 pass
             self.conn.send(self.data_to_send())
@@ -59,7 +57,7 @@ class SafeH2Connection(H2Connection):
     def safe_send_headers(self, is_zombie, stream_id, headers):
         with self.lock:
             if is_zombie():  # pragma: no cover
-                raise Http2ProtocolException("Zombie Stream")
+                raise exceptions.Http2ProtocolException("Zombie Stream")
             self.send_headers(stream_id, headers.fields)
             self.conn.send(self.data_to_send())
 
@@ -70,7 +68,7 @@ class SafeH2Connection(H2Connection):
                 self.lock.acquire()
                 if is_zombie():  # pragma: no cover
                     self.lock.release()
-                    raise Http2ProtocolException("Zombie Stream")
+                    raise exceptions.Http2ProtocolException("Zombie Stream")
                 max_outbound_frame_size = self.max_outbound_frame_size
                 frame_chunk = chunk[position:position + max_outbound_frame_size]
                 if self.local_flow_control_window(stream_id) < len(frame_chunk):
@@ -83,12 +81,12 @@ class SafeH2Connection(H2Connection):
                 position += max_outbound_frame_size
         with self.lock:
             if is_zombie():  # pragma: no cover
-                raise Http2ProtocolException("Zombie Stream")
+                raise exceptions.Http2ProtocolException("Zombie Stream")
             self.end_stream(stream_id)
             self.conn.send(self.data_to_send())
 
 
-class Http2Layer(Layer):
+class Http2Layer(base.Layer):
 
     def __init__(self, ctx, mode):
         super(Http2Layer, self).__init__(ctx)
@@ -108,13 +106,13 @@ class Http2Layer(Layer):
         self.active_conns.append(self.server_conn.connection)
 
     def connect(self):  # pragma: no cover
-        raise Http2ProtocolException("HTTP2 layer should already have a connection.")
+        raise exceptions.Http2ProtocolException("HTTP2 layer should already have a connection.")
 
     def set_server(self):  # pragma: no cover
-        raise Http2ProtocolException("Cannot change server for HTTP2 connections.")
+        raise exceptions.Http2ProtocolException("Cannot change server for HTTP2 connections.")
 
     def disconnect(self):  # pragma: no cover
-        raise Http2ProtocolException("Cannot dis- or reconnect in HTTP2 connections.")
+        raise exceptions.Http2ProtocolException("Cannot dis- or reconnect in HTTP2 connections.")
 
     def next_layer(self):  # pragma: no cover
         # WebSockets over HTTP/2?
@@ -135,19 +133,19 @@ class Http2Layer(Layer):
                 eid = event.stream_id
 
         if isinstance(event, events.RequestReceived):
-            headers = Headers([[k, v] for k, v in event.headers])
+            headers = netlib.http.Headers([[k, v] for k, v in event.headers])
             self.streams[eid] = Http2SingleStreamLayer(self, eid, headers)
             self.streams[eid].timestamp_start = time.time()
             self.streams[eid].start()
         elif isinstance(event, events.ResponseReceived):
-            headers = Headers([[k, v] for k, v in event.headers])
+            headers = netlib.http.Headers([[k, v] for k, v in event.headers])
             self.streams[eid].queued_data_length = 0
             self.streams[eid].timestamp_start = time.time()
             self.streams[eid].response_headers = headers
             self.streams[eid].response_arrived.set()
         elif isinstance(event, events.DataReceived):
             if self.config.body_size_limit and self.streams[eid].queued_data_length > self.config.body_size_limit:
-                raise HttpException("HTTP body too large. Limit is {}.".format(self.config.body_size_limit))
+                raise netlib.exceptions.HttpException("HTTP body too large. Limit is {}.".format(self.config.body_size_limit))
             self.streams[eid].data_queue.put(event.data)
             self.streams[eid].queued_data_length += len(event.data)
             source_conn.h2.safe_increment_flow_control(event.stream_id, event.flow_controlled_length)
@@ -178,7 +176,7 @@ class Http2Layer(Layer):
                 self.client_conn.h2.push_stream(parent_eid, event.pushed_stream_id, event.headers)
                 self.client_conn.send(self.client_conn.h2.data_to_send())
 
-            headers = Headers([[str(k), str(v)] for k, v in event.headers])
+            headers = netlib.http.Headers([[str(k), str(v)] for k, v in event.headers])
             headers['x-mitmproxy-pushed'] = 'true'
             self.streams[event.pushed_stream_id] = Http2SingleStreamLayer(self, event.pushed_stream_id, headers)
             self.streams[event.pushed_stream_id].timestamp_start = time.time()
@@ -197,7 +195,7 @@ class Http2Layer(Layer):
                 depends_on = self.streams[depends_on].server_stream_id
 
             # weight is between 1 and 256 (inclusive), but represented as uint8 (0 to 255)
-            frame = PriorityFrame(stream_id, depends_on, event.weight - 1, event.exclusive)
+            frame = hyperframe.frame.PriorityFrame(stream_id, depends_on, event.weight - 1, event.exclusive)
             self.server_conn.send(frame.serialize())
         elif isinstance(event, events.TrailersReceived):
             raise NotImplementedError()
@@ -226,7 +224,7 @@ class Http2Layer(Layer):
         self.client_conn.send(self.client_conn.h2.data_to_send())
 
         while True:
-            r = ssl_read_select(self.active_conns, 1)
+            r = tcp.ssl_read_select(self.active_conns, 1)
             for conn in r:
                 source_conn = self.client_conn if conn == self.client_conn.connection else self.server_conn
                 other_conn = self.server_conn if conn == self.client_conn.connection else self.client_conn
@@ -234,7 +232,7 @@ class Http2Layer(Layer):
 
                 with source_conn.h2.lock:
                     try:
-                        raw_frame = b''.join(framereader.http2_read_raw_frame(source_conn.rfile))
+                        raw_frame = b''.join(http2.framereader.http2_read_raw_frame(source_conn.rfile))
                     except:
                         # read frame failed: connection closed
                         self._kill_all_streams()
@@ -252,7 +250,7 @@ class Http2Layer(Layer):
             self._cleanup_streams()
 
 
-class Http2SingleStreamLayer(_HttpTransmissionLayer, threading.Thread):
+class Http2SingleStreamLayer(http._HttpTransmissionLayer, threading.Thread):
 
     def __init__(self, ctx, stream_id, request_headers):
         super(Http2SingleStreamLayer, self).__init__(ctx, name="Thread-Http2SingleStreamLayer-{}".format(stream_id))
@@ -336,7 +334,7 @@ class Http2SingleStreamLayer(_HttpTransmissionLayer, threading.Thread):
             data.append(self.request_data_queue.get())
         data = b"".join(data)
 
-        return HTTPRequest(
+        return models.HTTPRequest(
             first_line_format,
             method,
             scheme,
@@ -361,7 +359,7 @@ class Http2SingleStreamLayer(_HttpTransmissionLayer, threading.Thread):
         with self.server_conn.h2.lock:
             # We must not assign a stream id if we are already a zombie.
             if self.zombie:  # pragma: no cover
-                raise Http2ProtocolException("Zombie Stream")
+                raise exceptions.Http2ProtocolException("Zombie Stream")
 
             self.server_stream_id = self.server_conn.h2.get_next_available_stream_id()
             self.server_to_client_stream_ids[self.server_stream_id] = self.client_stream_id
@@ -382,7 +380,7 @@ class Http2SingleStreamLayer(_HttpTransmissionLayer, threading.Thread):
             message.body
         )
         if self.zombie:  # pragma: no cover
-            raise Http2ProtocolException("Zombie Stream")
+            raise exceptions.Http2ProtocolException("Zombie Stream")
 
     def read_response_headers(self):
         self.response_arrived.wait()
@@ -391,7 +389,7 @@ class Http2SingleStreamLayer(_HttpTransmissionLayer, threading.Thread):
         headers = self.response_headers.copy()
         headers.clear(":status")
 
-        return HTTPResponse(
+        return models.HTTPResponse(
             http_version=b"HTTP/2.0",
             status_code=status_code,
             reason='',
@@ -412,7 +410,7 @@ class Http2SingleStreamLayer(_HttpTransmissionLayer, threading.Thread):
                     yield self.response_data_queue.get()
                 return
             if self.zombie:  # pragma: no cover
-                raise Http2ProtocolException("Zombie Stream")
+                raise exceptions.Http2ProtocolException("Zombie Stream")
 
     def send_response_headers(self, response):
         headers = response.headers.copy()
@@ -423,7 +421,7 @@ class Http2SingleStreamLayer(_HttpTransmissionLayer, threading.Thread):
             headers
         )
         if self.zombie:  # pragma: no cover
-            raise Http2ProtocolException("Zombie Stream")
+            raise exceptions.Http2ProtocolException("Zombie Stream")
 
     def send_response_body(self, _response, chunks):
         self.client_conn.h2.safe_send_body(
@@ -432,7 +430,7 @@ class Http2SingleStreamLayer(_HttpTransmissionLayer, threading.Thread):
             chunks
         )
         if self.zombie:  # pragma: no cover
-            raise Http2ProtocolException("Zombie Stream")
+            raise exceptions.Http2ProtocolException("Zombie Stream")
 
     def check_close_connection(self, flow):
         # This layer only handles a single stream.
@@ -447,11 +445,11 @@ class Http2SingleStreamLayer(_HttpTransmissionLayer, threading.Thread):
         self()
 
     def __call__(self):
-        layer = HttpLayer(self, self.mode)
+        layer = http.HttpLayer(self, self.mode)
 
         try:
             layer()
-        except ProtocolException as e:
+        except exceptions.ProtocolException as e:
             self.log(repr(e), "info")
             self.log(traceback.format_exc(), "debug")
 
diff --git a/mitmproxy/protocol/http_replay.py b/mitmproxy/protocol/http_replay.py
index f7f27148..5928c0af 100644
--- a/mitmproxy/protocol/http_replay.py
+++ b/mitmproxy/protocol/http_replay.py
@@ -1,13 +1,14 @@
-from __future__ import (absolute_import, print_function, division)
+from __future__ import absolute_import, print_function, division
+
 import threading
 import traceback
-from mitmproxy.exceptions import ReplayException
-from netlib.exceptions import HttpException, TcpException
+
+import netlib.exceptions
+from mitmproxy import controller
+from mitmproxy import exceptions
+from mitmproxy import models
 from netlib.http import http1
 
-from ..controller import Channel
-from ..models import Error, HTTPResponse, ServerConnection, make_connect_request
-from ..exceptions import Kill
 
 # TODO: Doesn't really belong into mitmproxy.protocol...
 
@@ -22,7 +23,7 @@ class RequestReplayThread(threading.Thread):
         """
         self.config, self.flow = config, flow
         if event_queue:
-            self.channel = Channel(event_queue, should_exit)
+            self.channel = controller.Channel(event_queue, should_exit)
         else:
             self.channel = None
         super(RequestReplayThread, self).__init__()
@@ -36,17 +37,17 @@ class RequestReplayThread(threading.Thread):
             # If we have a channel, run script hooks.
             if self.channel:
                 request_reply = self.channel.ask("request", self.flow)
-                if isinstance(request_reply, HTTPResponse):
+                if isinstance(request_reply, models.HTTPResponse):
                     self.flow.response = request_reply
 
             if not self.flow.response:
                 # In all modes, we directly connect to the server displayed
                 if self.config.mode == "upstream":
                     server_address = self.config.upstream_server.address
-                    server = ServerConnection(server_address, (self.config.host, 0))
+                    server = models.ServerConnection(server_address, (self.config.host, 0))
                     server.connect()
                     if r.scheme == "https":
-                        connect_request = make_connect_request((r.host, r.port))
+                        connect_request = models.make_connect_request((r.host, r.port))
                         server.wfile.write(http1.assemble_request(connect_request))
                         server.wfile.flush()
                         resp = http1.read_response(
@@ -55,7 +56,7 @@ class RequestReplayThread(threading.Thread):
                             body_size_limit=self.config.body_size_limit
                         )
                         if resp.status_code != 200:
-                            raise ReplayException("Upstream server refuses CONNECT request")
+                            raise exceptions.ReplayException("Upstream server refuses CONNECT request")
                         server.establish_ssl(
                             self.config.clientcerts,
                             sni=self.flow.server_conn.sni
@@ -65,7 +66,7 @@ class RequestReplayThread(threading.Thread):
                         r.first_line_format = "absolute"
                 else:
                     server_address = (r.host, r.port)
-                    server = ServerConnection(server_address, (self.config.host, 0))
+                    server = models.ServerConnection(server_address, (self.config.host, 0))
                     server.connect()
                     if r.scheme == "https":
                         server.establish_ssl(
@@ -77,20 +78,20 @@ class RequestReplayThread(threading.Thread):
                 server.wfile.write(http1.assemble_request(r))
                 server.wfile.flush()
                 self.flow.server_conn = server
-                self.flow.response = HTTPResponse.wrap(http1.read_response(
+                self.flow.response = models.HTTPResponse.wrap(http1.read_response(
                     server.rfile,
                     r,
                     body_size_limit=self.config.body_size_limit
                 ))
             if self.channel:
                 response_reply = self.channel.ask("response", self.flow)
-                if response_reply == Kill:
-                    raise Kill()
-        except (ReplayException, HttpException, TcpException) as e:
-            self.flow.error = Error(str(e))
+                if response_reply == exceptions.Kill:
+                    raise exceptions.Kill()
+        except (exceptions.ReplayException, netlib.exceptions.NetlibException) as e:
+            self.flow.error = models.Error(str(e))
             if self.channel:
                 self.channel.ask("error", self.flow)
-        except Kill:
+        except exceptions.Kill:
             # Kill should only be raised if there's a channel in the
             # first place.
             from ..proxy.root_context import Log
diff --git a/mitmproxy/protocol/rawtcp.py b/mitmproxy/protocol/rawtcp.py
index 05342844..70486cc4 100644
--- a/mitmproxy/protocol/rawtcp.py
+++ b/mitmproxy/protocol/rawtcp.py
@@ -1,17 +1,17 @@
-from __future__ import (absolute_import, print_function, division)
+from __future__ import absolute_import, print_function, division
+
 import socket
 
 from OpenSSL import SSL
-from netlib.exceptions import TcpException
-
-from netlib.tcp import ssl_read_select
-from ..models import Error
-from ..models.tcp import TCPFlow, TCPMessage
 
-from .base import Layer
+import netlib.exceptions
+import netlib.tcp
+from mitmproxy import models
+from mitmproxy.models import tcp
+from mitmproxy.protocol import base
 
 
-class RawTCPLayer(Layer):
+class RawTCPLayer(base.Layer):
     chunk_size = 4096
 
     def __init__(self, ctx, ignore=False):
@@ -22,7 +22,7 @@ class RawTCPLayer(Layer):
         self.connect()
 
         if not self.ignore:
-            flow = TCPFlow(self.client_conn, self.server_conn, self)
+            flow = models.TCPFlow(self.client_conn, self.server_conn, self)
             self.channel.ask("tcp_open", flow)
 
         buf = memoryview(bytearray(self.chunk_size))
@@ -33,7 +33,7 @@ class RawTCPLayer(Layer):
 
         try:
             while not self.channel.should_exit.is_set():
-                r = ssl_read_select(conns, 10)
+                r = netlib.tcp.ssl_read_select(conns, 10)
                 for conn in r:
                     dst = server if conn == client else client
 
@@ -52,15 +52,15 @@ class RawTCPLayer(Layer):
                             return
                         continue
 
-                    tcp_message = TCPMessage(dst == server, buf[:size].tobytes())
+                    tcp_message = tcp.TCPMessage(dst == server, buf[:size].tobytes())
                     if not self.ignore:
                         flow.messages.append(tcp_message)
                         self.channel.ask("tcp_message", flow)
                     dst.sendall(tcp_message.content)
 
-        except (socket.error, TcpException, SSL.Error) as e:
+        except (socket.error, netlib.exceptions.TcpException, SSL.Error) as e:
             if not self.ignore:
-                flow.error = Error("TCP connection closed unexpectedly: {}".format(repr(e)))
+                flow.error = models.Error("TCP connection closed unexpectedly: {}".format(repr(e)))
                 self.channel.tell("tcp_error", flow)
         finally:
             if not self.ignore:
diff --git a/mitmproxy/protocol/tls.py b/mitmproxy/protocol/tls.py
index e0699562..9f883b2b 100644
--- a/mitmproxy/protocol/tls.py
+++ b/mitmproxy/protocol/tls.py
@@ -1,16 +1,15 @@
-from __future__ import (absolute_import, print_function, division)
+from __future__ import absolute_import, print_function, division
 
 import struct
 import sys
 
-from construct import ConstructError
+import construct
 import six
-from netlib.exceptions import InvalidCertificateException
-from netlib.exceptions import TlsException
 
-from ..contrib.tls._constructs import ClientHello
-from ..exceptions import ProtocolException, TlsProtocolException, ClientHandshakeException
-from .base import Layer
+import netlib.exceptions
+from mitmproxy import exceptions
+from mitmproxy.contrib.tls import _constructs
+from mitmproxy.protocol import base
 
 
 # taken from https://testssl.sh/openssl-rfc.mappping.html
@@ -246,11 +245,11 @@ def get_client_hello(client_conn):
     while len(client_hello) < client_hello_size:
         record_header = client_conn.rfile.peek(offset + 5)[offset:]
         if not is_tls_record_magic(record_header) or len(record_header) != 5:
-            raise TlsProtocolException('Expected TLS record, got "%s" instead.' % record_header)
+            raise exceptions.TlsProtocolException('Expected TLS record, got "%s" instead.' % record_header)
         record_size = struct.unpack("!H", record_header[3:])[0] + 5
         record_body = client_conn.rfile.peek(offset + record_size)[offset + 5:]
         if len(record_body) != record_size - 5:
-            raise TlsProtocolException("Unexpected EOF in TLS handshake: %s" % record_body)
+            raise exceptions.TlsProtocolException("Unexpected EOF in TLS handshake: %s" % record_body)
         client_hello += record_body
         offset += record_size
         client_hello_size = struct.unpack("!I", b'\x00' + client_hello[1:4])[0] + 4
@@ -260,7 +259,7 @@ def get_client_hello(client_conn):
 class TlsClientHello(object):
 
     def __init__(self, raw_client_hello):
-        self._client_hello = ClientHello.parse(raw_client_hello)
+        self._client_hello = _constructs.ClientHello.parse(raw_client_hello)
 
     def raw(self):
         return self._client_hello
@@ -297,21 +296,23 @@ class TlsClientHello(object):
         """
         try:
             raw_client_hello = get_client_hello(client_conn)[4:]  # exclude handshake header.
-        except ProtocolException as e:
-            raise TlsProtocolException('Cannot read raw Client Hello: %s' % repr(e))
+        except exceptions.ProtocolException as e:
+            raise exceptions.TlsProtocolException('Cannot read raw Client Hello: %s' % repr(e))
 
         try:
             return cls(raw_client_hello)
-        except ConstructError as e:
-            raise TlsProtocolException('Cannot parse Client Hello: %s, Raw Client Hello: %s' %
-                                       (repr(e), raw_client_hello.encode("hex")))
+        except construct.ConstructError as e:
+            raise exceptions.TlsProtocolException(
+                'Cannot parse Client Hello: %s, Raw Client Hello: %s' %
+                (repr(e), raw_client_hello.encode("hex"))
+            )
 
     def __repr__(self):
         return "TlsClientHello( sni: %s alpn_protocols: %s,  cipher_suites: %s)" % \
             (self.sni, self.alpn_protocols, self.cipher_suites)
 
 
-class TlsLayer(Layer):
+class TlsLayer(base.Layer):
 
     """
     The TLS layer implements transparent TLS connections.
@@ -345,7 +346,7 @@ class TlsLayer(Layer):
             # Peek into the connection, read the initial client hello and parse it to obtain SNI and ALPN values.
             try:
                 self._client_hello = TlsClientHello.from_client_conn(self.client_conn)
-            except TlsProtocolException as e:
+            except exceptions.TlsProtocolException as e:
                 self.log("Cannot parse Client Hello: %s" % repr(e), "error")
 
         # Do we need to do a server handshake now?
@@ -490,10 +491,10 @@ class TlsLayer(Layer):
             # The reason for this might be difficult to find, so we try to peek here to see if it
             # raises ann error.
             self.client_conn.rfile.peek(1)
-        except TlsException as e:
+        except netlib.exceptions.TlsException as e:
             six.reraise(
-                ClientHandshakeException,
-                ClientHandshakeException(
+                exceptions.ClientHandshakeException,
+                exceptions.ClientHandshakeException(
                     "Cannot establish TLS with client (sni: {sni}): {e}".format(
                         sni=self._client_hello.sni, e=repr(e)
                     ),
@@ -544,7 +545,7 @@ class TlsLayer(Layer):
                     (tls_cert_err['depth'], tls_cert_err['errno']),
                     "error")
                 self.log("Ignoring server verification error, continuing with connection", "error")
-        except InvalidCertificateException as e:
+        except netlib.exceptions.InvalidCertificateException as e:
             tls_cert_err = self.server_conn.ssl_verification_error
             self.log(
                 "TLS verification failed for upstream server at depth %s with error: %s" %
@@ -552,18 +553,18 @@ class TlsLayer(Layer):
                 "error")
             self.log("Aborting connection attempt", "error")
             six.reraise(
-                TlsProtocolException,
-                TlsProtocolException("Cannot establish TLS with {address} (sni: {sni}): {e}".format(
+                exceptions.TlsProtocolException,
+                exceptions.TlsProtocolException("Cannot establish TLS with {address} (sni: {sni}): {e}".format(
                     address=repr(self.server_conn.address),
                     sni=self.server_sni,
                     e=repr(e),
                 )),
                 sys.exc_info()[2]
             )
-        except TlsException as e:
+        except netlib.exceptions.TlsException as e:
             six.reraise(
-                TlsProtocolException,
-                TlsProtocolException("Cannot establish TLS with {address} (sni: {sni}): {e}".format(
+                exceptions.TlsProtocolException,
+                exceptions.TlsProtocolException("Cannot establish TLS with {address} (sni: {sni}): {e}".format(
                     address=repr(self.server_conn.address),
                     sni=self.server_sni,
                     e=repr(e),
diff --git a/mitmproxy/proxy/__init__.py b/mitmproxy/proxy/__init__.py
index be7f5207..ada9fa12 100644
--- a/mitmproxy/proxy/__init__.py
+++ b/mitmproxy/proxy/__init__.py
@@ -1,8 +1,8 @@
-from __future__ import (absolute_import, print_function, division)
+from __future__ import absolute_import, print_function, division
 
-from .server import ProxyServer, DummyServer
 from .config import ProxyConfig
 from .root_context import RootContext, Log
+from .server import ProxyServer, DummyServer
 
 __all__ = [
     "ProxyServer", "DummyServer",
diff --git a/mitmproxy/proxy/config.py b/mitmproxy/proxy/config.py
index 163e92dd..9246fe04 100644
--- a/mitmproxy/proxy/config.py
+++ b/mitmproxy/proxy/config.py
@@ -1,4 +1,5 @@
-from __future__ import (absolute_import, print_function, division)
+from __future__ import absolute_import, print_function, division
+
 import collections
 import os
 import re
@@ -6,11 +7,11 @@ import re
 import six
 from OpenSSL import SSL
 
-from netlib import certutils, tcp, human
+from mitmproxy import platform
+from netlib import certutils
+from netlib import human
+from netlib import tcp
 from netlib.http import authentication
-from netlib.tcp import Address, sslversion_choices
-
-from .. import platform
 
 CONF_BASENAME = "mitmproxy"
 CA_DIR = "~/.mitmproxy"
@@ -91,7 +92,7 @@ class ProxyConfig:
         self.body_size_limit = body_size_limit
         self.mode = mode
         if upstream_server:
-            self.upstream_server = ServerSpec(upstream_server[0], Address.wrap(upstream_server[1]))
+            self.upstream_server = ServerSpec(upstream_server[0], tcp.Address.wrap(upstream_server[1]))
             self.upstream_auth = upstream_auth
         else:
             self.upstream_server = None
@@ -111,9 +112,9 @@ class ProxyConfig:
             self.certstore.add_cert_file(spec, cert)
 
         self.openssl_method_client, self.openssl_options_client = \
-            sslversion_choices[ssl_version_client]
+            tcp.sslversion_choices[ssl_version_client]
         self.openssl_method_server, self.openssl_options_server = \
-            sslversion_choices[ssl_version_server]
+            tcp.sslversion_choices[ssl_version_server]
 
         if ssl_verify_upstream_cert:
             self.openssl_verification_mode_server = SSL.VERIFY_PEER
diff --git a/mitmproxy/proxy/modes/__init__.py b/mitmproxy/proxy/modes/__init__.py
index f014ed98..fa62570c 100644
--- a/mitmproxy/proxy/modes/__init__.py
+++ b/mitmproxy/proxy/modes/__init__.py
@@ -1,4 +1,5 @@
-from __future__ import (absolute_import, print_function, division)
+from __future__ import absolute_import, print_function, division
+
 from .http_proxy import HttpProxy, HttpUpstreamProxy
 from .reverse_proxy import ReverseProxy
 from .socks_proxy import Socks5Proxy
diff --git a/mitmproxy/proxy/modes/http_proxy.py b/mitmproxy/proxy/modes/http_proxy.py
index e19062b9..bc64ccd2 100644
--- a/mitmproxy/proxy/modes/http_proxy.py
+++ b/mitmproxy/proxy/modes/http_proxy.py
@@ -1,9 +1,9 @@
-from __future__ import (absolute_import, print_function, division)
+from __future__ import absolute_import, print_function, division
 
-from ...protocol import Layer, ServerConnectionMixin
+from mitmproxy import protocol
 
 
-class HttpProxy(Layer, ServerConnectionMixin):
+class HttpProxy(protocol.Layer, protocol.ServerConnectionMixin):
 
     def __call__(self):
         layer = self.ctx.next_layer(self)
@@ -14,7 +14,7 @@ class HttpProxy(Layer, ServerConnectionMixin):
                 self.disconnect()
 
 
-class HttpUpstreamProxy(Layer, ServerConnectionMixin):
+class HttpUpstreamProxy(protocol.Layer, protocol.ServerConnectionMixin):
 
     def __init__(self, ctx, server_address):
         super(HttpUpstreamProxy, self).__init__(ctx, server_address=server_address)
diff --git a/mitmproxy/proxy/modes/reverse_proxy.py b/mitmproxy/proxy/modes/reverse_proxy.py
index c8e80a10..3739ac0e 100644
--- a/mitmproxy/proxy/modes/reverse_proxy.py
+++ b/mitmproxy/proxy/modes/reverse_proxy.py
@@ -1,9 +1,9 @@
-from __future__ import (absolute_import, print_function, division)
+from __future__ import absolute_import, print_function, division
 
-from ...protocol import Layer, ServerConnectionMixin
+from mitmproxy import protocol
 
 
-class ReverseProxy(Layer, ServerConnectionMixin):
+class ReverseProxy(protocol.Layer, protocol.ServerConnectionMixin):
 
     def __init__(self, ctx, server_address, server_tls):
         super(ReverseProxy, self).__init__(ctx, server_address=server_address)
diff --git a/mitmproxy/proxy/modes/socks_proxy.py b/mitmproxy/proxy/modes/socks_proxy.py
index e2ce44ae..19437835 100644
--- a/mitmproxy/proxy/modes/socks_proxy.py
+++ b/mitmproxy/proxy/modes/socks_proxy.py
@@ -1,13 +1,13 @@
-from __future__ import (absolute_import, print_function, division)
+from __future__ import absolute_import, print_function, division
 
-from netlib import socks, tcp
-from netlib.exceptions import TcpException
+import netlib.exceptions
+from mitmproxy import exceptions
+from mitmproxy import protocol
+from netlib import socks
+from netlib import tcp
 
-from ...exceptions import Socks5ProtocolException
-from ...protocol import Layer, ServerConnectionMixin
 
-
-class Socks5Proxy(Layer, ServerConnectionMixin):
+class Socks5Proxy(protocol.Layer, protocol.ServerConnectionMixin):
 
     def __init__(self, ctx):
         super(Socks5Proxy, self).__init__(ctx)
@@ -51,8 +51,8 @@ class Socks5Proxy(Layer, ServerConnectionMixin):
             connect_reply.to_file(self.client_conn.wfile)
             self.client_conn.wfile.flush()
 
-        except (socks.SocksError, TcpException) as e:
-            raise Socks5ProtocolException("SOCKS5 mode failure: %s" % repr(e))
+        except (socks.SocksError, netlib.exceptions.TcpException) as e:
+            raise exceptions.Socks5ProtocolException("SOCKS5 mode failure: %s" % repr(e))
 
         # https://github.com/mitmproxy/mitmproxy/issues/839
         address_bytes = (connect_request.addr.host.encode("idna"), connect_request.addr.port)
diff --git a/mitmproxy/proxy/modes/transparent_proxy.py b/mitmproxy/proxy/modes/transparent_proxy.py
index 3fdda656..c7df7900 100644
--- a/mitmproxy/proxy/modes/transparent_proxy.py
+++ b/mitmproxy/proxy/modes/transparent_proxy.py
@@ -1,11 +1,11 @@
-from __future__ import (absolute_import, print_function, division)
+from __future__ import absolute_import, print_function, division
 
-from ... import platform
-from ...exceptions import ProtocolException
-from ...protocol import Layer, ServerConnectionMixin
+from mitmproxy import exceptions
+from mitmproxy import platform
+from mitmproxy import protocol
 
 
-class TransparentProxy(Layer, ServerConnectionMixin):
+class TransparentProxy(protocol.Layer, protocol.ServerConnectionMixin):
 
     def __init__(self, ctx):
         super(TransparentProxy, self).__init__(ctx)
@@ -15,7 +15,7 @@ class TransparentProxy(Layer, ServerConnectionMixin):
         try:
             self.server_conn.address = self.resolver.original_addr(self.client_conn.connection)
         except Exception as e:
-            raise ProtocolException("Transparent mode failure: %s" % repr(e))
+            raise exceptions.ProtocolException("Transparent mode failure: %s" % repr(e))
 
         layer = self.ctx.next_layer(self)
         try:
diff --git a/mitmproxy/proxy/root_context.py b/mitmproxy/proxy/root_context.py
index 9b4e2963..57183c7e 100644
--- a/mitmproxy/proxy/root_context.py
+++ b/mitmproxy/proxy/root_context.py
@@ -1,15 +1,13 @@
-from __future__ import (absolute_import, print_function, division)
+from __future__ import absolute_import, print_function, division
+
 import sys
 
 import six
 
-from mitmproxy.exceptions import ProtocolException, TlsProtocolException
-from netlib.exceptions import TcpException
-from ..protocol import (
-    RawTCPLayer, TlsLayer, Http1Layer, Http2Layer, is_tls_record_magic, ServerConnectionMixin,
-    UpstreamConnectLayer, TlsClientHello
-)
-from .modes import HttpProxy, HttpUpstreamProxy, ReverseProxy
+import netlib.exceptions
+from mitmproxy import exceptions
+from mitmproxy import protocol
+from mitmproxy.proxy import modes
 
 
 class RootContext(object):
@@ -50,53 +48,53 @@ class RootContext(object):
     def _next_layer(self, top_layer):
         try:
             d = top_layer.client_conn.rfile.peek(3)
-        except TcpException as e:
-            six.reraise(ProtocolException, ProtocolException(str(e)), sys.exc_info()[2])
-        client_tls = is_tls_record_magic(d)
+        except netlib.exceptions.TcpException as e:
+            six.reraise(exceptions.ProtocolException, exceptions.ProtocolException(str(e)), sys.exc_info()[2])
+        client_tls = protocol.is_tls_record_magic(d)
 
         # 1. check for --ignore
         if self.config.check_ignore:
             ignore = self.config.check_ignore(top_layer.server_conn.address)
             if not ignore and client_tls:
                 try:
-                    client_hello = TlsClientHello.from_client_conn(self.client_conn)
-                except TlsProtocolException as e:
+                    client_hello = protocol.TlsClientHello.from_client_conn(self.client_conn)
+                except exceptions.TlsProtocolException as e:
                     self.log("Cannot parse Client Hello: %s" % repr(e), "error")
                 else:
                     ignore = self.config.check_ignore((client_hello.sni, 443))
             if ignore:
-                return RawTCPLayer(top_layer, ignore=True)
+                return protocol.RawTCPLayer(top_layer, ignore=True)
 
         # 2. Always insert a TLS layer, even if there's neither client nor server tls.
         # An inline script may upgrade from http to https,
         # in which case we need some form of TLS layer.
-        if isinstance(top_layer, ReverseProxy):
-            return TlsLayer(top_layer, client_tls, top_layer.server_tls)
-        if isinstance(top_layer, ServerConnectionMixin) or isinstance(top_layer, UpstreamConnectLayer):
-            return TlsLayer(top_layer, client_tls, client_tls)
+        if isinstance(top_layer, modes.ReverseProxy):
+            return protocol.TlsLayer(top_layer, client_tls, top_layer.server_tls)
+        if isinstance(top_layer, protocol.ServerConnectionMixin) or isinstance(top_layer, protocol.UpstreamConnectLayer):
+            return protocol.TlsLayer(top_layer, client_tls, client_tls)
 
         # 3. In Http Proxy mode and Upstream Proxy mode, the next layer is fixed.
-        if isinstance(top_layer, TlsLayer):
-            if isinstance(top_layer.ctx, HttpProxy):
-                return Http1Layer(top_layer, "regular")
-            if isinstance(top_layer.ctx, HttpUpstreamProxy):
-                return Http1Layer(top_layer, "upstream")
+        if isinstance(top_layer, protocol.TlsLayer):
+            if isinstance(top_layer.ctx, modes.HttpProxy):
+                return protocol.Http1Layer(top_layer, "regular")
+            if isinstance(top_layer.ctx, modes.HttpUpstreamProxy):
+                return protocol.Http1Layer(top_layer, "upstream")
 
         # 4. Check for other TLS cases (e.g. after CONNECT).
         if client_tls:
-            return TlsLayer(top_layer, True, True)
+            return protocol.TlsLayer(top_layer, True, True)
 
         # 4. Check for --tcp
         if self.config.check_tcp(top_layer.server_conn.address):
-            return RawTCPLayer(top_layer)
+            return protocol.RawTCPLayer(top_layer)
 
         # 5. Check for TLS ALPN (HTTP1/HTTP2)
-        if isinstance(top_layer, TlsLayer):
+        if isinstance(top_layer, protocol.TlsLayer):
             alpn = top_layer.client_conn.get_alpn_proto_negotiated()
             if alpn == b'h2':
-                return Http2Layer(top_layer, 'transparent')
+                return protocol.Http2Layer(top_layer, 'transparent')
             if alpn == b'http/1.1':
-                return Http1Layer(top_layer, 'transparent')
+                return protocol.Http1Layer(top_layer, 'transparent')
 
         # 6. Check for raw tcp mode
         is_ascii = (
@@ -105,10 +103,10 @@ class RootContext(object):
             all(65 <= x <= 90 and 97 <= x <= 122 for x in six.iterbytes(d))
         )
         if self.config.rawtcp and not is_ascii:
-            return RawTCPLayer(top_layer)
+            return protocol.RawTCPLayer(top_layer)
 
         # 7. Assume HTTP1 by default
-        return Http1Layer(top_layer, 'transparent')
+        return protocol.Http1Layer(top_layer, 'transparent')
 
     def log(self, msg, level, subs=()):
         """
diff --git a/mitmproxy/proxy/server.py b/mitmproxy/proxy/server.py
index 8483d3df..7e96911a 100644
--- a/mitmproxy/proxy/server.py
+++ b/mitmproxy/proxy/server.py
@@ -1,17 +1,18 @@
-from __future__ import (absolute_import, print_function, division)
+from __future__ import absolute_import, print_function, division
 
-import traceback
-import sys
 import socket
+import sys
+import traceback
+
 import six
 
+import netlib.exceptions
+from mitmproxy import exceptions
+from mitmproxy import models
+from mitmproxy.proxy import modes
+from mitmproxy.proxy import root_context
 from netlib import tcp
-from netlib.exceptions import TcpException
-from netlib.http.http1 import assemble_response
-from ..exceptions import ProtocolException, ServerException, ClientHandshakeException, Kill
-from ..models import ClientConnection, make_error_response
-from .modes import HttpUpstreamProxy, HttpProxy, ReverseProxy, TransparentProxy, Socks5Proxy
-from .root_context import RootContext, Log
+from netlib.http import http1
 
 
 class DummyServer:
@@ -43,8 +44,8 @@ class ProxyServer(tcp.TCPServer):
             super(ProxyServer, self).__init__((config.host, config.port))
         except socket.error as e:
             six.reraise(
-                ServerException,
-                ServerException('Error starting proxy server: ' + repr(e)),
+                exceptions.ServerException,
+                exceptions.ServerException('Error starting proxy server: ' + repr(e)),
                 sys.exc_info()[2]
             )
         self.channel = None
@@ -67,7 +68,7 @@ class ConnectionHandler(object):
     def __init__(self, client_conn, client_address, config, channel):
         self.config = config
         """@type: mitmproxy.proxy.config.ProxyConfig"""
-        self.client_conn = ClientConnection(
+        self.client_conn = models.ClientConnection(
             client_conn,
             client_address,
             None)
@@ -76,7 +77,7 @@ class ConnectionHandler(object):
         """@type: mitmproxy.controller.Channel"""
 
     def _create_root_layer(self):
-        root_context = RootContext(
+        root_ctx = root_context.RootContext(
             self.client_conn,
             self.config,
             self.channel
@@ -84,25 +85,25 @@ class ConnectionHandler(object):
 
         mode = self.config.mode
         if mode == "upstream":
-            return HttpUpstreamProxy(
-                root_context,
+            return modes.HttpUpstreamProxy(
+                root_ctx,
                 self.config.upstream_server.address
             )
         elif mode == "transparent":
-            return TransparentProxy(root_context)
+            return modes.TransparentProxy(root_ctx)
         elif mode == "reverse":
             server_tls = self.config.upstream_server.scheme == "https"
-            return ReverseProxy(
-                root_context,
+            return modes.ReverseProxy(
+                root_ctx,
                 self.config.upstream_server.address,
                 server_tls
             )
         elif mode == "socks5":
-            return Socks5Proxy(root_context)
+            return modes.Socks5Proxy(root_ctx)
         elif mode == "regular":
-            return HttpProxy(root_context)
+            return modes.HttpProxy(root_ctx)
         elif callable(mode):  # pragma: no cover
-            return mode(root_context)
+            return mode(root_ctx)
         else:  # pragma: no cover
             raise ValueError("Unknown proxy mode: %s" % mode)
 
@@ -114,11 +115,11 @@ class ConnectionHandler(object):
         try:
             root_layer = self.channel.ask("clientconnect", root_layer)
             root_layer()
-        except Kill:
+        except exceptions.Kill:
             self.log("Connection killed", "info")
-        except ProtocolException as e:
+        except exceptions.ProtocolException as e:
 
-            if isinstance(e, ClientHandshakeException):
+            if isinstance(e, exceptions.ClientHandshakeException):
                 self.log(
                     "Client Handshake failed. "
                     "The client may not trust the proxy's certificate for {}.".format(e.server),
@@ -133,9 +134,9 @@ class ConnectionHandler(object):
             # we send an HTTP error response, which is both
             # understandable by HTTP clients and humans.
             try:
-                error_response = make_error_response(502, repr(e))
-                self.client_conn.send(assemble_response(error_response))
-            except TcpException:
+                error_response = models.make_error_response(502, repr(e))
+                self.client_conn.send(http1.assemble_response(error_response))
+            except netlib.exceptions.TcpException:
                 pass
         except Exception:
             self.log(traceback.format_exc(), "error")
@@ -149,4 +150,4 @@ class ConnectionHandler(object):
 
     def log(self, msg, level):
         msg = "{}: {}".format(repr(self.client_conn.address), msg)
-        self.channel.tell("log", Log(msg, level))
+        self.channel.tell("log", root_context.Log(msg, level))
diff --git a/mitmproxy/script/__init__.py b/mitmproxy/script/__init__.py
index 3ee19b04..d6bff4c7 100644
--- a/mitmproxy/script/__init__.py
+++ b/mitmproxy/script/__init__.py
@@ -1,8 +1,8 @@
+from . import reloader
+from .concurrent import concurrent
 from .script import Script
 from .script_context import ScriptContext
-from .concurrent import concurrent
 from ..exceptions import ScriptException
-from . import reloader
 
 __all__ = [
     "Script",
diff --git a/mitmproxy/script/concurrent.py b/mitmproxy/script/concurrent.py
index 2f25e78c..43d0d328 100644
--- a/mitmproxy/script/concurrent.py
+++ b/mitmproxy/script/concurrent.py
@@ -3,6 +3,7 @@ This module provides a @concurrent decorator primitive to
 offload computations from mitmproxy's main master thread.
 """
 from __future__ import absolute_import, print_function, division
+
 import threading
 
 
diff --git a/mitmproxy/script/reloader.py b/mitmproxy/script/reloader.py
index 99ce7f60..f5470bbf 100644
--- a/mitmproxy/script/reloader.py
+++ b/mitmproxy/script/reloader.py
@@ -1,6 +1,10 @@
+from __future__ import absolute_import, print_function, division
+
 import os
 import sys
+
 from watchdog.events import RegexMatchingEventHandler
+
 if sys.platform == 'darwin':  # pragma: no cover
     from watchdog.observers.polling import PollingObserver as Observer
 else:
diff --git a/mitmproxy/script/script.py b/mitmproxy/script/script.py
index 9bf05f27..70f74817 100644
--- a/mitmproxy/script/script.py
+++ b/mitmproxy/script/script.py
@@ -4,13 +4,15 @@ Script objects know nothing about mitmproxy or mitmproxy's API - this knowledge
 by the mitmproxy-specific ScriptContext.
 """
 # Do not import __future__ here, this would apply transitively to the inline scripts.
+from __future__ import absolute_import, print_function, division
+
 import os
 import shlex
 import sys
 
 import six
 
-from ..exceptions import ScriptException
+from mitmproxy import exceptions
 
 
 class Script(object):
@@ -41,7 +43,7 @@ class Script(object):
     @staticmethod
     def parse_command(command):
         if not command or not command.strip():
-            raise ScriptException("Empty script command.")
+            raise exceptions.ScriptException("Empty script command.")
         # Windows: escape all backslashes in the path.
         if os.name == "nt":  # pragma: no cover
             backslashes = shlex.split(command, posix=False)[0].count("\\")
@@ -49,13 +51,13 @@ class Script(object):
         args = shlex.split(command)  # pragma: no cover
         args[0] = os.path.expanduser(args[0])
         if not os.path.exists(args[0]):
-            raise ScriptException(
+            raise exceptions.ScriptException(
                 ("Script file not found: %s.\r\n"
                  "If your script path contains spaces, "
                  "make sure to wrap it in additional quotes, e.g. -s \"'./foo bar/baz.py' --args\".") %
                 args[0])
         elif os.path.isdir(args[0]):
-            raise ScriptException("Not a file: %s" % args[0])
+            raise exceptions.ScriptException("Not a file: %s" % args[0])
         return args
 
     def load(self):
@@ -69,7 +71,7 @@ class Script(object):
                 ScriptException on failure
         """
         if self.ns is not None:
-            raise ScriptException("Script is already loaded")
+            raise exceptions.ScriptException("Script is already loaded")
         script_dir = os.path.dirname(os.path.abspath(self.args[0]))
         self.ns = {'__file__': os.path.abspath(self.args[0])}
         sys.path.append(script_dir)
@@ -80,8 +82,8 @@ class Script(object):
                 exec(code, self.ns, self.ns)
         except Exception:
             six.reraise(
-                ScriptException,
-                ScriptException.from_exception_context(),
+                exceptions.ScriptException,
+                exceptions.ScriptException.from_exception_context(),
                 sys.exc_info()[2]
             )
         finally:
@@ -107,15 +109,15 @@ class Script(object):
                 ScriptException if there was an exception.
         """
         if self.ns is None:
-            raise ScriptException("Script not loaded.")
+            raise exceptions.ScriptException("Script not loaded.")
         f = self.ns.get(name)
         if f:
             try:
                 return f(self.ctx, *args, **kwargs)
             except Exception:
                 six.reraise(
-                    ScriptException,
-                    ScriptException.from_exception_context(),
+                    exceptions.ScriptException,
+                    exceptions.ScriptException.from_exception_context(),
                     sys.exc_info()[2]
                 )
         else:
diff --git a/mitmproxy/script/script_context.py b/mitmproxy/script/script_context.py
index cd5d4b61..44e2736b 100644
--- a/mitmproxy/script/script_context.py
+++ b/mitmproxy/script/script_context.py
@@ -2,7 +2,8 @@
 The mitmproxy script context provides an API to inline scripts.
 """
 from __future__ import absolute_import, print_function, division
-from .. import contentviews
+
+from mitmproxy import contentviews
 
 
 class ScriptContext(object):
diff --git a/mitmproxy/stateobject.py b/mitmproxy/stateobject.py
index eb57fa00..6283d845 100644
--- a/mitmproxy/stateobject.py
+++ b/mitmproxy/stateobject.py
@@ -1,7 +1,8 @@
-from __future__ import absolute_import
+from __future__ import absolute_import, print_function, division
 
 import six
-from typing import List, Any
+from typing import Any
+from typing import List
 
 import netlib.basetypes
 
diff --git a/mitmproxy/tnetstring.py b/mitmproxy/tnetstring.py
index acf563ac..6b1c117a 100644
--- a/mitmproxy/tnetstring.py
+++ b/mitmproxy/tnetstring.py
@@ -67,9 +67,10 @@ like so::
     u'\u03b1'
 
 """
-import six
 from collections import deque
 
+import six
+
 __ver_major__ = 0
 __ver_minor__ = 2
 __ver_patch__ = 0
diff --git a/mitmproxy/utils.py b/mitmproxy/utils.py
index 05342500..672805d0 100644
--- a/mitmproxy/utils.py
+++ b/mitmproxy/utils.py
@@ -1,7 +1,8 @@
-from __future__ import (absolute_import, print_function, division)
+from __future__ import absolute_import, print_function, division
+
 import datetime
-import time
 import json
+import time
 
 import netlib.utils
 
diff --git a/mitmproxy/version.py b/mitmproxy/version.py
index 02b0d900..0ebb0829 100644
--- a/mitmproxy/version.py
+++ b/mitmproxy/version.py
@@ -1,4 +1,4 @@
-from __future__ import (absolute_import, print_function, division)
+from __future__ import absolute_import, print_function, division
 
 from netlib.version import VERSION, IVERSION
 
diff --git a/mitmproxy/web/__init__.py b/mitmproxy/web/__init__.py
index 79c81687..80a65886 100644
--- a/mitmproxy/web/__init__.py
+++ b/mitmproxy/web/__init__.py
@@ -1,14 +1,16 @@
-from __future__ import absolute_import, print_function
+from __future__ import absolute_import, print_function, division
+
 import collections
-import tornado.ioloop
-import tornado.httpserver
 import sys
 
-from netlib.http import authentication
+import tornado.httpserver
+import tornado.ioloop
 
-from .. import flow, controller
-from ..exceptions import FlowReadException
-from . import app
+from mitmproxy import controller
+from mitmproxy import exceptions
+from mitmproxy import flow
+from mitmproxy.web import app
+from netlib.http import authentication
 
 
 class Stop(Exception):
@@ -156,7 +158,7 @@ class WebMaster(flow.FlowMaster):
         if options.rfile:
             try:
                 self.load_flows_file(options.rfile)
-            except FlowReadException as v:
+            except exceptions.FlowReadException as v:
                 self.add_event(
                     "Could not read flow file: %s" % v,
                     "error"
diff --git a/mitmproxy/web/app.py b/mitmproxy/web/app.py
index e25c9086..43b2bad1 100644
--- a/mitmproxy/web/app.py
+++ b/mitmproxy/web/app.py
@@ -1,14 +1,16 @@
+from __future__ import absolute_import, print_function, division
+
+import base64
+import json
+import logging
 import os.path
 import re
 
 import six
-import tornado.web
 import tornado.websocket
-import logging
-import json
-import base64
 
-from .. import version, filt
+from mitmproxy import filt
+from mitmproxy import version
 
 
 def _strip_content(flow_state):
diff --git a/netlib/http/http2/__init__.py b/netlib/http/http2/__init__.py
index 7043d36f..633e6a20 100644
--- a/netlib/http/http2/__init__.py
+++ b/netlib/http/http2/__init__.py
@@ -1,6 +1,8 @@
 from __future__ import absolute_import, print_function, division
 from .connections import HTTP2Protocol
+from netlib.http.http2 import framereader
 
 __all__ = [
-    "HTTP2Protocol"
+    "HTTP2Protocol",
+    "framereader",
 ]