split and organize coffee files, improve Cake build tasks

README.md

@@ -49,12 +49,20 @@ At this point the tor client should bootstrap to 100%.
 
 #### Snowflake proxy
 
-Otherwise, to connect through the WebRTC proxy in the browser, start a local
+Otherwise, to connect through the WebRTC proxy in the browser, build with:
-http server in the `proxy/` directory however you wish. For instance:
 ```
 cd proxy/
-python -m http.server
+cake build
 ```
+
+Then start a local http server in the `proxy/build/` however you wish
+For instance:
+
+'''
+cd build/
+python -m http.server
+'''
+
 Open a browser tab to `0.0.0.0:8000/snowflake.html`.
 The page will ask you to input a relay.
 Input your desired relay address, or input nothing/gibberish which will cause

proxy/Cakefile

@@ -1,17 +1,44 @@
 fs = require 'fs'
-
 {exec} = require 'child_process'
 
+# All coffeescript files required.
+FILES = [
+  'shims.coffee'
+  'util.coffee'
+  'proxypair.coffee'
+  'websocket.coffee'
+  'snowflake.coffee'
+]
+OUTFILE = 'build/snowflake.coffee'
+STATIC = 'static'
+
 task 'test', 'snowflake unit tests', ->
   testFile = 'test/snowflake.bundle.coffee'
-  exec 'cat snowflake.coffee snowflake_test.coffee | cat > ' + testFile, (err, stdout, stderr) ->
+  exec 'cat ' + FILES.join(' ') + ' snowflake_test.coffee | cat > ' +
+      testFile, (err, stdout, stderr) ->
     throw err if err
     console.log stdout + stderr
   exec 'coffee ' + testFile + ' -v', (err, stdout, stderr) ->
     throw err if err
     console.log stdout + stderr
 
-task 'build', 'build the snowflake proxy', ->
+concatCoffeeFiles = -> exec 'cat ' + FILES.join(' ') + ' | cat > ' + OUTFILE
-  exec 'coffee -o build -c snowflake.coffee', (err, stdout, stderr) ->
+
+copyStaticFiles = -> exec 'cp ' + STATIC + '/* build/'
+
+compileCoffee = ->
+  exec 'coffee -o build -c build/snowflake.coffee', (err, stdout, stderr) ->
     throw err if err
-    console.log stdout + stderr
+
+task 'build:concat', 'concatenate coffeescript files.', concatCoffeeFiles
+
+task 'build', 'build the snowflake proxy', ->
+  exec 'mkdir build'
+  concatCoffeeFiles()
+  copyStaticFiles()
+  compileCoffee()
+  console.log 'Snowflake prepared.'
+
+task 'clean', 'remove all built files', ->
+  exec 'rm -r build'
+  exec 'rm -r test'

proxy/proxypair.coffee

@@ -0,0 +1,142 @@
+###
+Represents a single:
+
+   client <-- webrtc --> snowflake <-- websocket --> relay
+
+###
+
+
+class ProxyPair
+
+  MAX_BUFFER: 10 * 1024 * 1024
+  pc: null
+  c2rSchedule: []
+  r2cSchedule: []
+  client: null  # WebRTC Data channel
+  relay: null   # websocket
+  running: true
+  flush_timeout_id: null
+
+  constructor: (@clientAddr, @relayAddr, @rateLimit) ->
+
+  connectClient: =>
+    @pc = new PeerConnection config, {
+      optional: [
+        { DtlsSrtpKeyAgreement: true }
+        { RtpDataChannels: false }
+      ]}
+    @pc.onicecandidate = (evt) =>
+      # Browser sends a null candidate once the ICE gathering completes.
+      # In this case, it makes sense to send one copy-paste blob.
+      if null == evt.candidate
+        # TODO: Use a promise.all to tell Snowflake about all offers at once,
+        # once multiple proxypairs are supported.
+        log 'Finished gathering ICE candidates.'
+        Signalling.send @pc.localDescription
+    # OnDataChannel triggered remotely from the client when connection succeeds.
+    @pc.ondatachannel = (dc) =>
+      console.log dc;
+      channel = dc.channel
+      log 'Data Channel established...'
+      @prepareDataChannel channel
+      @client = channel
+
+  prepareDataChannel: (channel) =>
+    channel.onopen = =>
+      log 'Data channel opened!'
+      snowflake.state = MODE.WEBRTC_READY
+      $msglog.className = 'active';
+      # This is the point when the WebRTC datachannel is done, so the next step
+      # is to establish websocket to the server.
+      @connectRelay()
+    channel.onclose = =>
+      log 'Data channel closed.'
+      snowflake.state = MODE.INIT;
+      $msglog.className = ''
+    channel.onerror = =>
+      log 'Data channel error!'
+    channel.onmessage = @onClientToRelayMessage
+
+  # Assumes WebRTC datachannel is connected.
+  connectRelay: =>
+    log 'Connecting to relay...'
+    @relay = makeWebsocket @relayAddr
+    @relay.label = 'websocket-relay'
+    @relay.onopen = =>
+      log '\nRelay ' + @relay.label + ' connected!'
+    @relay.onclose = @onClose
+    @relay.onerror = @onError
+    @relay.onmessage = @onRelayToClientMessage
+
+  # WebRTC --> websocket
+  onClientToRelayMessage: (msg) =>
+    line = recv = msg.data
+    console.log msg
+    # Go sends only raw bytes...
+    if '[object ArrayBuffer]' == recv.toString()
+      bytes = new Uint8Array recv
+      line = String.fromCharCode.apply(null, bytes)
+    line = line.trim()
+    console.log 'WebRTC --> websocket data: ' + line
+    @c2rSchedule.push recv
+    @flush()
+
+  # websocket --> WebRTC
+  onRelayToClientMessage: (event) =>
+    @r2cSchedule.push event.data
+    # log 'websocket-->WebRTC data: ' + event.data
+    @flush()
+
+  onClose: (event) =>
+    ws = event.target
+    log(ws.label + ': closed.')
+    @flush()
+    @maybeCleanup()
+
+  onError: (event) =>
+    ws = event.target
+    log ws.label + ': error.'
+    @close()
+    # we can't rely on onclose_callback to cleanup, since one common error
+    # case is when the client fails to connect and the relay never starts.
+    # in that case close() is a NOP and onclose_callback is never called.
+    @maybeCleanup()
+
+  webrtcIsReady: -> null != @client && 'open' == @client.readyState
+  relayIsReady: -> (null != @relay) && (WebSocket.OPEN == @relay.readyState)
+  isClosed: (ws) -> undefined == ws || WebSocket.CLOSED == ws.readyState
+  close: ->
+    @client.close() if @webrtcIsReady()
+    @relay.close() if @relayIsReady()
+    relay = null
+
+  maybeCleanup: =>
+    if @running
+      @running = false
+      # TODO: Call external callback
+      true
+    false
+
+  # Send as much data as the rate limit currently allows.
+  flush: =>
+    clearTimeout @flush_timeout_id if @flush_timeout_id
+    @flush_timeout_id = null
+    busy = true
+    checkChunks = =>
+      busy = false
+      # WebRTC --> websocket
+      if @relayIsReady() && @relay.bufferedAmount < @MAX_BUFFER && @c2rSchedule.length > 0
+        chunk = @c2rSchedule.shift()
+        @rateLimit.update chunk.length
+        @relay.send chunk
+        busy = true
+      # websocket --> WebRTC
+      if @webrtcIsReady() && @client.bufferedAmount < @MAX_BUFFER && @r2cSchedule.length > 0
+        chunk = @r2cSchedule.shift()
+        @rateLimit.update chunk.length
+        @client.send chunk
+        busy = true
+    checkChunks() while busy  && !@rateLimit.isLimited()
+
+    if @r2cSchedule.length > 0 || @c2rSchedule.length > 0 || (@relayIsReady() && @relay.bufferedAmount > 0) || (@webrtcIsReady() && @client.bufferedAmount > 0)
+      @flush_timeout_id = setTimeout @flush,  @rateLimit.when() * 1000

proxy/shims.coffee

@@ -0,0 +1,14 @@
+###
+WebrTC shims for multiple browsers.
+###
+
+if 'undefined' != typeof module && 'undefined' != typeof module.exports
+  console.log 'not in browser.'
+else
+  window.PeerConnection = window.RTCPeerConnection ||
+                          window.mozRTCPeerConnection ||
+                          window.webkitRTCPeerConnection
+  window.RTCIceCandidate = window.RTCIceCandidate || window.mozRTCIceCandidate
+  window.RTCSessionDescription = window.RTCSessionDescription ||
+                                 window.mozRTCSessionDescription
+

proxy/snowflake.coffee

@@ -7,137 +7,16 @@ Uses WebRTC from the client, and websocket to the server.
 Assume that the webrtc client plugin is always the offerer, in which case
 this must always act as the answerer.
 ###
-
 DEFAULT_WEBSOCKET = '192.81.135.242:9901'
+DEFAULT_PORTS =
+  http:  80
+  https: 443
 
-if 'undefined' != typeof module && 'undefined' != typeof module.exports
-  console.log 'not in browser.'
-else
-  window.PeerConnection = window.RTCPeerConnection ||
-                          window.mozRTCPeerConnection ||
-                          window.webkitRTCPeerConnection
-  window.RTCIceCandidate = window.RTCIceCandidate || window.mozRTCIceCandidate
-  window.RTCSessionDescription = window.RTCSessionDescription ||
-                                 window.mozRTCSessionDescription
-
-Query =
-  ###
-  Parse a URL query string or application/x-www-form-urlencoded body. The
-  return type is an object mapping string keys to string values. By design,
-  this function doesn't support multiple values for the same named parameter,
-  for example 'a=1&a=2&a=3'; the first definition always wins. Returns null on
-  error.
-
-  Always decodes from UTF-8, not any other encoding.
-  http://dev.w3.org/html5/spec/Overview.html#url-encoded-form-data
-  ###
-  parse: (qs) ->
-    result = {}
-    strings = []
-    strings = qs.split '&' if qs
-    return result if 0 == strings.length
-    for string in strings
-      j = string.indexOf '='
-      if j == -1
-        name = string
-        value = ''
-      else
-        name = string.substr(0, j)
-        value = string.substr(j + 1)
-      name = decodeURIComponent(name.replace(/\+/g, ' '))
-      value = decodeURIComponent(value.replace(/\+/g, ' '))
-      result[name] = value if name not of result
-    result
-
-  # params is a list of (key, value) 2-tuples.
-  buildString: (params) ->
-    parts = []
-    for param in params
-      parts.push encodeURIComponent(param[0]) + '=' +
-                 encodeURIComponent(param[1])
-    parts.join '&'
-
-Parse =
-  # Parse a cookie data string (usually document.cookie). The return type is an
-  # object mapping cookies names to values. Returns null on error.
-  # http://www.w3.org/TR/DOM-Level-2-HTML/html.html#ID-8747038
-  cookie: (cookies) ->
-    result = {}
-    strings = []
-    strings = cookies.split ';' if cookies
-    for string in strings
-      j = string.indexOf '='
-      return null if -1 == j
-      name  = decodeURIComponent string.substr(0, j).trim()
-      value = decodeURIComponent string.substr(j + 1).trim()
-      result[name] = value if !(name in result)
-    result
-
-  # Parse an address in the form 'host:port'. Returns an Object with keys 'host'
-  # (String) and 'port' (int). Returns null on error.
-  address: (spec) ->
-    m = null
-    # IPv6 syntax.
-    m = spec.match(/^\[([\0-9a-fA-F:.]+)\]:([0-9]+)$/) if !m
-    # IPv4 syntax.
-    m = spec.match(/^([0-9.]+):([0-9]+)$/) if !m
-    return null if !m
-
-    host = m[1]
-    port = parseInt(m[2], 10)
-    if isNaN(port) || port < 0 || port > 65535
-      return null
-    { host: host, port: port }
-
-  # Parse a count of bytes. A suffix of 'k', 'm', or 'g' (or uppercase)
-  # does what you would think. Returns null on error.
-  byteCount: (spec) ->
-    UNITS = {
-      k: 1024, m: 1024 * 1024, g: 1024 * 1024 * 1024
-      K: 1024, M: 1024 * 1024, G: 1024 * 1024 * 1024
-    }
-    matches = spec.match /^(\d+(?:\.\d*)?)(\w*)$/
-    return null if null == matches
-    count = Number matches[1]
-    return null if isNaN count
-    if '' == matches[2]
-      units = 1
-    else
-      units = UNITS[matches[2]]
-      return null if null == units
-    count * Number(units)
-
-Params =
-  getBool: (query, param, defaultValue) ->
-    val = query[param]
-    return defaultValue if undefined == val
-    return true if 'true' == val || '1' == val || '' == val
-    return false if 'false' == val || '0' == val
-    return null
-
-  # Get an object value and parse it as a byte count. Example byte counts are
-  # '100' and '1.3m'. Returns |defaultValue| if param is not a key. Return null on
-  # a parsing error.
-  getByteCount: (query, param, defaultValue) ->
-    spec = query[param]
-    return defaultValue if undefined == spec
-    Parse.byteCount spec
-
-  # Get an object value and parse it as an address spec. Returns |defaultValue|
-  # if param is not a key. Returns null on a parsing error.
-  getAddress: (query, param, defaultValue) ->
-    val = query[param]
-    return defaultValue if undefined == val
-    Parse.address val
-
-
-safe_repr = (s) -> SAFE_LOGGING ? '[scrubbed]' : JSON.stringify(s)
-
-# HEADLESS is true if we are running not in a browser with a DOM.
 DEBUG = false
 if window && window.location
   query = Query.parse(window.location.search.substr(1))
   DEBUG = Params.getBool(query, 'debug', false)
+# HEADLESS is true if we are running not in a browser with a DOM.
 HEADLESS = 'undefined' == typeof(document)
 
 # Bytes per second. Set to undefined to disable limit.
@@ -145,102 +24,8 @@ DEFAULT_RATE_LIMIT = DEFAULT_RATE_LIMIT || undefined
 MIN_RATE_LIMIT = 10 * 1024
 RATE_LIMIT_HISTORY = 5.0
 
-DEFAULT_PORTS =
+MAX_NUM_CLIENTS = 1
-  http:  80
+CONNECTIONS_PER_CLIENT = 1
-  https: 443
-
-# DOM elements.
-$msglog = null
-$send = null
-$input = null
-
-# Build an escaped URL string from unescaped components. Only scheme and host
-# are required. See RFC 3986, section 3.
-buildUrl = (scheme, host, port, path, params) ->
-  parts = []
-  parts.push(encodeURIComponent scheme)
-  parts.push '://'
-
-  # If it contains a colon but no square brackets, treat it as IPv6.
-  if host.match(/:/) && !host.match(/[[\]]/)
-    parts.push '['
-    parts.push host
-    parts.push ']'
-  else
-    parts.push(encodeURIComponent host)
-
-  if undefined != port && DEFAULT_PORTS[scheme] != port
-    parts.push ':'
-    parts.push(encodeURIComponent port.toString())
-
-  if undefined != path && '' != path
-    if !path.match(/^\//)
-      path = '/' + path
-    ###
-    Slash is significant so we must protect it from encodeURIComponent, while
-    still encoding question mark and number sign. RFC 3986, section 3.3: 'The
-    path is terminated by the first question mark ('?') or number sign ('#')
-    character, or by the end of the URI. ... A path consists of a sequence of
-    path segments separated by a slash ('/') character.'
-    ###
-    path = path.replace /[^\/]+/, (m) ->
-      encodeURIComponent m
-    parts.push path
-
-  if undefined != params
-    parts.push '?'
-    parts.push Query.buildString params
-
-  parts.join ''
-
-makeWebsocket = (addr) ->
-  url = buildUrl 'ws', addr.host, addr.port, '/'
-  # if have_websocket_binary_frames()
-  ws = new WebSocket url
-  # else
-    # ws = new WebSocket url 'base64'
-  ###
-  'User agents can use this as a hint for how to handle incoming binary data: if
-  the attribute is set to 'blob', it is safe to spool it to disk, and if it is
-  set to 'arraybuffer', it is likely more efficient to keep the data in memory.'
-  ###
-  ws.binaryType = 'arraybuffer'
-  ws
-
-class BucketRateLimit
-  amount: 0.0
-  lastUpdate: new Date()
-
-  constructor: (@capacity, @time) ->
-
-  age: ->
-    now = new Date()
-    delta = (now - @lastUpdate) / 1000.0
-    @lastUpdate = now
-    @amount -= delta * @capacity / @time
-    @amount = 0.0 if @amount < 0.0
-
-  update: (n) ->
-    @age()
-    @amount += n
-    @amount <= @capacity
-
-  # How many seconds in the future will the limit expire?
-  when: ->
-    age()
-    (@amount - @capacity) / (@capacity / @time)
-
-  isLimited: ->
-    @age()
-    @amount > @capacity
-
-# A rate limiter that never limits.
-class DummyRateLimit
-  constructor: (@capacity, @time) ->
-  update: (n) -> true
-  when: -> 0.0
-  isLimited: -> false
-
 
 # TODO: Different ICE servers.
 config = {
@@ -249,7 +34,6 @@ config = {
   ]
 }
 
-
 # TODO: Implement
 class Badge
 
@@ -262,9 +46,6 @@ MODE =
 # Minimum viable snowflake for now - just 1 client.
 class Snowflake
 
-  MAX_NUM_CLIENTS = 1
-  CONNECTIONS_PER_CLIENT = 1
-
   relayAddr: null
   # TODO: Actually support multiple ProxyPairs. (makes more sense once meek-
   # signalling is ready)
@@ -295,7 +76,7 @@ class Snowflake
       @rateLimit = new BucketRateLimit(rateLimitBytes * RATE_LIMIT_HISTORY,
                                        RATE_LIMIT_HISTORY)
 
-  # TODO: User-supplied for now, but should fetch from facilitator later.
+  # TODO: Should fetch from facilitator later.
   setRelayAddr: (relayAddr) ->
     addr = Parse.address relayAddr
     if !addr
@@ -323,7 +104,7 @@ class Snowflake
     catch e
       log 'Invalid SDP message.'
       return false
-    log('SDP ' + sdp.type + ' successfully received.')
+    log 'SDP ' + sdp.type + ' successfully received.'
     @sendAnswer() if 'offer' == sdp.type
     true
 
@@ -336,7 +117,7 @@ class Snowflake
 
   # Poll facilitator when this snowflake can support more clients.
   proxyMain: ->
-    if @proxyPairs.length >= @MAX_NUM_CLIENTS * @CONNECTIONS_PER_CLIENT
+    if @proxyPairs.length >= MAX_NUM_CLIENTS * CONNECTIONS_PER_CLIENT
       setTimeout(@proxyMain, @facilitator_poll_interval * 1000)
       return
     params = [['r', '1']]
@@ -372,159 +153,16 @@ class Snowflake
     @cease()
     @badge.die() if @badge
 
-###
-Represents: client <-- webrtc --> snowflake <-- websocket --> relay
-###
-class ProxyPair
-  MAX_BUFFER: 10 * 1024 * 1024
-  pc: null
-  c2rSchedule: []
-  r2cSchedule: []
-  client: null  # WebRTC Data channel
-  relay: null   # websocket
-  running: true
-  flush_timeout_id: null
-
-  constructor: (@clientAddr, @relayAddr, @rateLimit) ->
-
-  connectClient: =>
-    @pc = new PeerConnection config, {
-      optional: [
-        { DtlsSrtpKeyAgreement: true }
-        { RtpDataChannels: false }
-      ]}
-    @pc.onicecandidate = (evt) =>
-      # Browser sends a null candidate once the ICE gathering completes.
-      # In this case, it makes sense to send one copy-paste blob.
-      if null == evt.candidate
-        # TODO: Use a promise.all to tell Snowflake about all offers at once,
-        # once multiple proxypairs are supported.
-        log 'Finished gathering ICE candidates.'
-        Signalling.send @pc.localDescription
-    # OnDataChannel triggered remotely from the client when connection succeeds.
-    @pc.ondatachannel = (dc) =>
-      console.log dc;
-      channel = dc.channel
-      log 'Data Channel established...'
-      @prepareDataChannel channel
-      @client = channel
-
-  prepareDataChannel: (channel) =>
-    channel.onopen = =>
-      log 'Data channel opened!'
-      snowflake.state = MODE.WEBRTC_READY
-      $msglog.className = 'active';
-      # This is the point when the WebRTC datachannel is done, so the next step
-      # is to establish websocket to the server.
-      @connectRelay()
-    channel.onclose = =>
-      log 'Data channel closed.'
-      snowflake.state = MODE.INIT;
-      $msglog.className = ''
-    channel.onerror = =>
-      log 'Data channel error!'
-    channel.onmessage = @onClientToRelayMessage
-
-  # Assumes WebRTC datachannel is connected.
-  connectRelay: =>
-    log 'Connecting to relay...'
-    @relay = makeWebsocket @relayAddr
-    @relay.label = 'websocket-relay'
-    @relay.onopen = =>
-      log '\nRelay ' + @relay.label + ' connected!'
-    @relay.onclose = @onClose
-    @relay.onerror = @onError
-    @relay.onmessage = @onRelayToClientMessage
-
-  # WebRTC --> websocket
-  onClientToRelayMessage: (msg) =>
-    line = recv = msg.data
-    console.log msg
-    # Go sends only raw bytes...
-    if '[object ArrayBuffer]' == recv.toString()
-      bytes = new Uint8Array recv
-      line = String.fromCharCode.apply(null, bytes)
-    line = line.trim()
-    console.log 'WebRTC --> websocket data: ' + line
-    @c2rSchedule.push recv
-    @flush()
-
-  # websocket --> WebRTC
-  onRelayToClientMessage: (event) =>
-    @r2cSchedule.push event.data
-    # log 'websocket-->WebRTC data: ' + event.data
-    @flush()
-
-  onClose: (event) =>
-    ws = event.target
-    log(ws.label + ': closed.')
-    @flush()
-    @maybeCleanup()
-
-  onError: (event) =>
-    ws = event.target
-    log ws.label + ': error.'
-    @close()
-    # we can't rely on onclose_callback to cleanup, since one common error
-    # case is when the client fails to connect and the relay never starts.
-    # in that case close() is a NOP and onclose_callback is never called.
-    @maybeCleanup()
-
-  webrtcIsReady: -> null != @client && 'open' == @client.readyState
-  relayIsReady: -> (null != @relay) && (WebSocket.OPEN == @relay.readyState)
-  isClosed: (ws) -> undefined == ws || WebSocket.CLOSED == ws.readyState
-  close: ->
-    @client.close() if @webrtcIsReady()
-    @relay.close() if @relayIsReady()
-    relay = null
-
-  maybeCleanup: =>
-    if @running
-      @running = false
-      # TODO: Call external callback
-      true
-    false
-
-  # Send as much data as the rate limit currently allows.
-  flush: =>
-    clearTimeout @flush_timeout_id if @flush_timeout_id
-    @flush_timeout_id = null
-    busy = true
-    checkChunks = =>
-      busy = false
-      # WebRTC --> websocket
-      if @relayIsReady() && @relay.bufferedAmount < @MAX_BUFFER && @c2rSchedule.length > 0
-        chunk = @c2rSchedule.shift()
-        @rateLimit.update chunk.length
-        @relay.send chunk
-        busy = true
-      # websocket --> WebRTC
-      if @webrtcIsReady() && @client.bufferedAmount < @MAX_BUFFER && @r2cSchedule.length > 0
-        chunk = @r2cSchedule.shift()
-        @rateLimit.update chunk.length
-        @client.send chunk
-        busy = true
-    checkChunks() while busy  && !@rateLimit.isLimited()
-
-    if @r2cSchedule.length > 0 || @c2rSchedule.length > 0 || (@relayIsReady() && @relay.bufferedAmount > 0) || (@webrtcIsReady() && @client.bufferedAmount > 0)
-      @flush_timeout_id = setTimeout @flush,  @rateLimit.when() * 1000
-
-#
-## -- DOM & Input Functionality -- ##
-#
 snowflake = null
 
-welcome = ->
+#
-  log '== snowflake browser proxy =='
+## -- DOM & Inputs -- #
-  log 'Input desired relay address:'
+#
 
-# Log to the message window.
+# DOM elements references.
-log = (msg) ->
+$msglog = null
-  console.log msg
+$send = null
-  # Scroll to latest
+$input = null
-  if $msglog
-    $msglog.value += msg + '\n'
-    $msglog.scrollTop = $msglog.scrollHeight
 
 Interface =
   # Local input from keyboard into message window.
@@ -550,7 +188,7 @@ Interface =
 Signalling =
   send: (msg) ->
     log '---- Please copy the below to peer ----\n'
-    log JSON.stringify(msg)
+    log JSON.stringify msg
     log '\n'
 
   receive: (msg) ->
@@ -566,8 +204,18 @@ Signalling =
       return false
     snowflake.receiveOffer recv if desc
 
-init = ->
+log = (msg) ->  # Log to the message window.
+  console.log msg
+  # Scroll to latest
+  if $msglog
+    $msglog.value += msg + '\n'
+    $msglog.scrollTop = $msglog.scrollHeight
 
+welcome = ->
+  log '== snowflake browser proxy =='
+  log 'Input desired relay address:'
+
+init = ->
   $msglog = document.getElementById('msglog')
   $msglog.value = ''
 
@@ -576,9 +224,8 @@ init = ->
 
   $input = document.getElementById('input')
   $input.focus()
-  $input.onkeydown = (e) =>
+  $input.onkeydown = (e) => $send.onclick() if 13 == e.keyCode  # enter
-    if 13 == e.keyCode  # enter
+
-      $send.onclick()
   snowflake = new Snowflake()
   window.snowflake = snowflake
   welcome()

proxy/static/snowflake.html

@@ -0,0 +1,78 @@
+<!doctype html>
+<html>
+<head>
+  <meta content="text/html;charset=utf-8" http-equiv="Content-Type">
+  <script type="text/javascript" src="snowflake.js"></script>
+  <style>
+  * {
+    box-sizing: border-box;
+    -webkit-transition: all 0.3s;
+    -moz-transition: all 0.3s;
+    transition: all 0.3s;
+  }
+  body {
+    position: absolute;
+    width: 100%; height: 100%; top: 0; margin: 0 auto;
+    background-color: #424;
+    color: #000;
+    text-align: center;
+    font-size: 24px;
+    font-family: monospace;
+    background-image: url('koch.jpg');
+  }
+  textarea {
+    background-color: rgba(0,0,0,0.8);
+    color: #fff;
+    resize: none;
+  }
+  .chatarea {
+    position: relative; border: none;
+    width: 50%; min-width: 40em;
+    padding: 0.5em; margin: auto;
+  }
+  .active { background-color: rgba(0,50,0,0.8); }
+  #msglog {
+    display: block;
+    width: 100%;
+    min-height: 40em;
+    margin-bottom: 1em;
+    padding: 8px;
+  }
+  .inputarea {
+    position: relative;
+    width: 100%;
+    height: 3em;
+    display: block;
+  }
+  #input {
+    display: inline-block;
+    position: absolute; left: 0;
+    width: 89%; height: 100%;
+    padding: 8px 30px;
+    font-size: 80%;
+    color: #fff;
+    background-color: rgba(0,0,0,0.9);
+    border: 1px solid #999;
+  }
+  #send {
+    display: inline-block; position: absolute;
+    right: 0; top: 0;  height: 100%; width: 10%;
+    background-color: #202; color: #f8f;
+    font-variant: small-caps; font-size: 100%;
+    border: none; // box-shadow: 0 2px 5px #000;
+  }
+  #send:hover { background-color: #636; }
+  </style>
+</head>
+<body>
+  <div class="chatarea">
+    <textarea id="msglog" readonly>
+    </textarea>
+    <div class="inputarea">
+      <input type="text" id="input">
+      <input type="submit" id="send" value="send">
+    </div>
+  </div>
+
+</body>
+</html>

proxy/util.coffee

@@ -0,0 +1,154 @@
+###
+A Coffeescript WebRTC snowflake proxy
+
+Contains helpers for parsing query strings and other utilities.
+###
+
+
+Query =
+  ###
+  Parse a URL query string or application/x-www-form-urlencoded body. The
+  return type is an object mapping string keys to string values. By design,
+  this function doesn't support multiple values for the same named parameter,
+  for example 'a=1&a=2&a=3'; the first definition always wins. Returns null on
+  error.
+
+  Always decodes from UTF-8, not any other encoding.
+  http://dev.w3.org/html5/spec/Overview.html#url-encoded-form-data
+  ###
+  parse: (qs) ->
+    result = {}
+    strings = []
+    strings = qs.split '&' if qs
+    return result if 0 == strings.length
+    for string in strings
+      j = string.indexOf '='
+      if j == -1
+        name = string
+        value = ''
+      else
+        name = string.substr(0, j)
+        value = string.substr(j + 1)
+      name = decodeURIComponent(name.replace(/\+/g, ' '))
+      value = decodeURIComponent(value.replace(/\+/g, ' '))
+      result[name] = value if name not of result
+    result
+
+  # params is a list of (key, value) 2-tuples.
+  buildString: (params) ->
+    parts = []
+    for param in params
+      parts.push encodeURIComponent(param[0]) + '=' +
+                 encodeURIComponent(param[1])
+    parts.join '&'
+
+
+Parse =
+  # Parse a cookie data string (usually document.cookie). The return type is an
+  # object mapping cookies names to values. Returns null on error.
+  # http://www.w3.org/TR/DOM-Level-2-HTML/html.html#ID-8747038
+  cookie: (cookies) ->
+    result = {}
+    strings = []
+    strings = cookies.split ';' if cookies
+    for string in strings
+      j = string.indexOf '='
+      return null if -1 == j
+      name  = decodeURIComponent string.substr(0, j).trim()
+      value = decodeURIComponent string.substr(j + 1).trim()
+      result[name] = value if !(name in result)
+    result
+
+  # Parse an address in the form 'host:port'. Returns an Object with keys 'host'
+  # (String) and 'port' (int). Returns null on error.
+  address: (spec) ->
+    m = null
+    # IPv6 syntax.
+    m = spec.match(/^\[([\0-9a-fA-F:.]+)\]:([0-9]+)$/) if !m
+    # IPv4 syntax.
+    m = spec.match(/^([0-9.]+):([0-9]+)$/) if !m
+    return null if !m
+
+    host = m[1]
+    port = parseInt(m[2], 10)
+    if isNaN(port) || port < 0 || port > 65535
+      return null
+    { host: host, port: port }
+
+  # Parse a count of bytes. A suffix of 'k', 'm', or 'g' (or uppercase)
+  # does what you would think. Returns null on error.
+  byteCount: (spec) ->
+    UNITS = {
+      k: 1024, m: 1024 * 1024, g: 1024 * 1024 * 1024
+      K: 1024, M: 1024 * 1024, G: 1024 * 1024 * 1024
+    }
+    matches = spec.match /^(\d+(?:\.\d*)?)(\w*)$/
+    return null if null == matches
+    count = Number matches[1]
+    return null if isNaN count
+    if '' == matches[2]
+      units = 1
+    else
+      units = UNITS[matches[2]]
+      return null if null == units
+    count * Number(units)
+
+
+Params =
+  getBool: (query, param, defaultValue) ->
+    val = query[param]
+    return defaultValue if undefined == val
+    return true if 'true' == val || '1' == val || '' == val
+    return false if 'false' == val || '0' == val
+    return null
+
+  # Get an object value and parse it as a byte count. Example byte counts are
+  # '100' and '1.3m'. Returns |defaultValue| if param is not a key. Return null on
+  # a parsing error.
+  getByteCount: (query, param, defaultValue) ->
+    spec = query[param]
+    return defaultValue if undefined == spec
+    Parse.byteCount spec
+
+  # Get an object value and parse it as an address spec. Returns |defaultValue|
+  # if param is not a key. Returns null on a parsing error.
+  getAddress: (query, param, defaultValue) ->
+    val = query[param]
+    return defaultValue if undefined == val
+    Parse.address val
+
+
+class BucketRateLimit
+  amount: 0.0
+  lastUpdate: new Date()
+
+  constructor: (@capacity, @time) ->
+
+  age: ->
+    now = new Date()
+    delta = (now - @lastUpdate) / 1000.0
+    @lastUpdate = now
+    @amount -= delta * @capacity / @time
+    @amount = 0.0 if @amount < 0.0
+
+  update: (n) ->
+    @age()
+    @amount += n
+    @amount <= @capacity
+
+  # How many seconds in the future will the limit expire?
+  when: ->
+    age()
+    (@amount - @capacity) / (@capacity / @time)
+
+  isLimited: ->
+    @age()
+    @amount > @capacity
+
+
+# A rate limiter that never limits.
+class DummyRateLimit
+  constructor: (@capacity, @time) ->
+  update: (n) -> true
+  when: -> 0.0
+  isLimited: -> false

proxy/websocket.coffee

@@ -0,0 +1,56 @@
+###
+Only websocket-specific stuff.
+###
+
+
+# Build an escaped URL string from unescaped components. Only scheme and host
+# are required. See RFC 3986, section 3.
+buildUrl = (scheme, host, port, path, params) ->
+  parts = []
+  parts.push(encodeURIComponent scheme)
+  parts.push '://'
+
+  # If it contains a colon but no square brackets, treat it as IPv6.
+  if host.match(/:/) && !host.match(/[[\]]/)
+    parts.push '['
+    parts.push host
+    parts.push ']'
+  else
+    parts.push(encodeURIComponent host)
+
+  if undefined != port && DEFAULT_PORTS[scheme] != port
+    parts.push ':'
+    parts.push(encodeURIComponent port.toString())
+
+  if undefined != path && '' != path
+    if !path.match(/^\//)
+      path = '/' + path
+    ###
+    Slash is significant so we must protect it from encodeURIComponent, while
+    still encoding question mark and number sign. RFC 3986, section 3.3: 'The
+    path is terminated by the first question mark ('?') or number sign ('#')
+    character, or by the end of the URI. ... A path consists of a sequence of
+    path segments separated by a slash ('/') character.'
+    ###
+    path = path.replace /[^\/]+/, (m) ->
+      encodeURIComponent m
+    parts.push path
+
+  if undefined != params
+    parts.push '?'
+    parts.push Query.buildString params
+
+  parts.join ''
+
+makeWebsocket = (addr) ->
+  url = buildUrl 'ws', addr.host, addr.port, '/'
+  # TODO: Do we need to worry about the base64 version?
+  ws = new WebSocket url
+  ###
+  'User agents can use this as a hint for how to handle incoming binary data: if
+  the attribute is set to 'blob', it is safe to spool it to disk, and if it is
+  set to 'arraybuffer', it is likely more efficient to keep the data in memory.'
+  ###
+  ws.binaryType = 'arraybuffer'
+  ws
+