Bugfixes to Everest, finalize the terminal API

2024-11-23 10:58:06 +11:00 · 2020-04-01 23:21:36 +01:00 · 2020-04-01 23:21:36 +01:00 · 7c70a1128c
commit 7c70a1128c
parent 5ac8f9ff11
9 changed files with 374 additions and 176 deletions
--- a/claw/code-claw.lua
+++ b/claw/code-claw.lua
@ -55,7 +55,7 @@ return {
 },
 ["neo-everest"] = {
  desc = "KittenOS NEO / Everest (windowing)",
-  v = 5,
+  v = 9,
  deps = {
   "neo"
  },
@ -68,7 +68,7 @@ return {
 },
 ["neo-icecap"] = {
  desc = "KittenOS NEO / Icecap",
-  v = 8,
+  v = 9,
  deps = {
   "neo"
  },
@ -85,7 +85,7 @@ return {
 },
 ["neo-secpolicy"] = {
  desc = "KittenOS NEO / Secpolicy",
-  v = 8,
+  v = 9,
  deps = {
  },
  dirs = {
--- a/code/apps/app-luashell.lua
+++ b/code/apps/app-luashell.lua
@ -3,12 +3,16 @@

 local _, _, termId = ...
 local ok = pcall(function ()
- assert(string.sub(termId, 1, 8) == "x.svc.t/")
+ assert(string.sub(termId, 1, 12) == "x.neo.pub.t/")
 end)
+
+local termClose
+
 if not ok then
 termId = nil
 neo.executeAsync("svc-t", function (res)
  termId = res.access
+  termClose = res.close
  neo.scheduleTimer(0)
 end, "luashell")
 while not termId do
@ -17,7 +21,18 @@ if not ok then
 end
 TERM = neo.requireAccess(termId, "terminal")

-TERM.line("KittenOS NEO Lua Shell")
+-- Using event makes it easier for stuff
+--  within the shell to not spectacularly explode.
+event = require("event")(neo)
+
+local alive = true
+event.listen("k.procdie", function (_, _, pid)
+ if pid == TERM.pid then
+  alive = false
+ end
+end)
+
+TERM.write("KittenOS NEO Lua Shell\r\n")

 print = function (...)
 local n = {}
@ -29,11 +44,9 @@ print = function (...)
  end
  table.insert(n, tostring(v))
 end
- TERM.line(table.concat(n, " "))
+ TERM.write(table.concat(n, " ") .. "\r\n")
 end

-local alive = true
-
 run = function (x, ...)
 local subPid = neo.executeAsync(x, ...)
 if not subPid then
@ -49,40 +62,63 @@ run = function (x, ...)
  error("cannot find " .. x)
 end
 while true do
-  local e = {coroutine.yield()}
+  local e = {event.pull()}
  if e[1] == "k.procdie" then
-   if e[3] == TERM.pid then
-    alive = false
-    return
-   elseif e[3] == subPid then
+   if e[3] == subPid then
    return
   end
  end
 end
 end

-exit = function ()
+local ioBuffer = ""
+
+io = {
+ read = function ()
+  while alive do
+   local pos = ioBuffer:find("\n")
+   if pos then
+    local line = ioBuffer:sub(1, pos):gsub("\r", "")
+    ioBuffer = ioBuffer:sub(pos + 1)
+    return line
+   end
+   local e = {event.pull()}
+   if e[1] == TERM.id then
+    if e[2] == "data" then
+     ioBuffer = ioBuffer .. e[3]
+    end
+   end
+  end
+ end,
+ write = function (s) TERM.write(s) end
+}
+
+local originalOS = os
+os = setmetatable({}, {
+ __index = originalOS
+})
+
+os.exit = function ()
 alive = false
 end

 while alive do
- local e = {coroutine.yield()}
- if e[1] == "k.procdie" then
-  if e[3] == TERM.pid then
-   alive = false
-  end
- elseif e[1] == TERM.id then
-  if e[2] == "line" then
-   TERM.line("> " .. e[3])
+ TERM.write("> ")
+ local code = io.read()
+ if code then
  local ok, err = pcall(function ()
-    if e[3]:sub(1, 1) == "=" then
-     e[3] = "return " .. e[3]:sub(2)
+   if code:sub(1, 1) == "=" then
+    code = "return " .. code:sub(2)
   end
-    print(assert(load(e[3]))())
+   print(assert(load(code))())
  end)
  if not ok then
-    TERM.line(tostring(err))
-   end
+   TERM.write(tostring(err) .. "\r\n")
  end
 end
 end
+
+if termClose then
+ termClose()
+end
+
--- a/code/apps/svc-t.lua
+++ b/code/apps/svc-t.lua
@ -15,66 +15,203 @@ local function rW()
 return string.format("%04x", math.random(0, 65535))
 end

-local id = "svc.t/" .. rW() .. rW() .. rW() .. rW()
+local id = "neo.pub.t/" .. rW() .. rW() .. rW() .. rW()
 local closeNow = false

+-- Terminus Registration State --
+
 local tReg = neo.requireAccess("r." .. id, "registration")
+local sendSigs = {}

-- unicode.safeTextFormat'd lines
+-- Display State --
+-- unicode.safeTextFormat'd lines.
+-- The size of this must not go below 1.
 local console = {}
+-- This must not go below 3.
+local conW = 40
+local conCX, conCY = 1, 1
 for i = 1, 14 do
- console[i] = (" "):rep(40)
+ console[i] = (" "):rep(conW)
 end

-local l15 = ""
--++++++++++++++++++++++++++++++++++++++++
-
-- sW must not go below 3.
-- sH must not go below 2.
-local sW, sH = 40, 15
-local cX = 1
-local windows = neo.requireAccess("x.neo.pub.window", "windows")
-local window = windows(sW, sH, title)
-
-local function fmtLine(s)
- s = unicode.safeTextFormat(s)
- local l = unicode.len(s)
- return unicode.sub(s .. (" "):rep(sW - l), -sW)
+-- Line Editing State --
+-- Nil if line editing is off.
+-- In this case, the console height
+--  must be adjusted accordingly.
+local leText = ""
+-- These are NOT nil'd out,
+--  particularly not the history buffer.
+local leCX = 1
+local leHistory = {
+ -- Size = history buffer size
+ "", "", "", ""
+}
+local function cycleHistoryUp()
+ local backupFirst = leHistory[1]
+ for i = 1, #leHistory - 1 do
+  leHistory[i] = leHistory[i + 1]
+ end
+ leHistory[#leHistory] = backupFirst
+end
+local function cycleHistoryDown()
+ local backup = leHistory[1]
+ for i = 2, #leHistory do
+  backup, leHistory[i] = leHistory[i], backup
+ end
+ leHistory[1] = backup
 end

-local function line(i)
- local l, c = console[i] or l15
- l, c = unicode.safeTextFormat(l, cX)
- l = require("lineedit").draw(sW, l, i == sH and c)
- if i ~= sH then
-  window.span(1, i, l, 0xFFFFFF, 0)
+-- Window --
+
+local window = neo.requireAccess("x.neo.pub.window", "window")(conW, #console + 1, title)
+
+-- Core Terminal Functions --
+
+local function setSize(w, h)
+ conW = w
+ while #console < h do
+  table.insert(console, "")
+ end
+ while #console > h do
+  table.remove(console, 1)
+ end
+ for i = 1, #console do
+  console[i] = unicode.sub(console[i], 1, w) .. (" "):rep(w - unicode.len(console[i]))
+ end
+ if leText then
+  window.setSize(w, h + 1)
 else
-  window.span(1, i, l, 0, 0xFFFFFF)
+  window.setSize(w, h)
+ end
+ conCX, conCY = 1, h
+end
+
+local function setLineEditing(state)
+ if state and not leText then
+  leText = ""
+  leCX = 1
+  setSize(conW, #console)
+ elseif leText and not state then
+  leText = nil
+  setSize(conW, #console)
 end
 end

-local function incoming(s)
- local function shift(f)
+local function draw(i)
+ if console[i] then
+  window.span(1, i, console[i], 0, 0xFFFFFF)
+ elseif leText then
+  window.span(1, i, require("lineedit").draw(conW, unicode.safeTextFormat(leText, leCX)), 0xFFFFFF, 0)
+ end
+end
+local function drawDisplay()
+ for i = 1, #console do draw(i) end
+end
+
+-- Terminal Visual --
+
+local function writeFF()
+ if conCY ~= #console then
+  conCY = conCY + 1
+ else
  for i = 1, #console - 1 do
   console[i] = console[i + 1]
  end
-  console[#console] = f
- end
- -- Need to break this safely.
- shift("")
- for i = 1, unicode.len(s) do
-  local ch = unicode.sub(s, i, i)
-  if unicode.wlen(console[#console] .. ch) > sW then
-   shift(" ")
-  end
-  console[#console] = console[#console] .. ch
- end
- for i = 1, #console do
-  line(i)
+  console[#console] = (" "):rep(conW)
 end
 end

-local sendSigs = {}
+local function writeData(data)
+ -- handle data until completion
+ while #data > 0 do
+  local char = unicode.sub(data, 1, 1)
+  data = unicode.sub(data, 2)
+  -- handle character
+  if char == "\r" then
+   conCX = 1
+  elseif char == "\n" then
+   conCX = 1
+   writeFF()
+  elseif char == "\a" then
+   -- Bell (er...)
+  elseif char == "\b" then
+   conCX = math.max(1, conCX - 1)
+  elseif char == "\v" or char == "\f" then
+   writeFF()
+  else
+   local charL = unicode.wlen(char)
+   if (conCX + charL - 1) > conW then
+    conCX = 1
+    writeFF()
+   end
+   local spaces = (" "):rep(charL - 1)
+   console[conCY] = unicode.sub(console[conCY], 1, conCX - 1) .. char .. spaces .. unicode.sub(console[conCY], conCX + charL)
+   conCX = conCX + charL
+  end
+ end
+end
+
+-- The Terminus --
+
+local tvBuildingCmd = ""
+local tvBuildingUTF = ""
+local function incoming(s)
+ tvBuildingCmd = tvBuildingCmd .. s
+ -- Flush Cmd
+ while #tvBuildingCmd > 0 do
+  if tvBuildingCmd:byte() == 255 then
+   -- It's a command. Uhoh.
+   if #tvBuildingCmd < 2 then break end
+   local cmd = tvBuildingCmd:byte(2)
+   local param = tvBuildingCmd:byte(3)
+   local cmdLen = 2
+   -- Command Lengths
+   if cmd >= 251 and cmd <= 254 then cmdLen = 3 end
+   if #tvBuildingCmd < cmdLen then break end
+   if cmd == 251 and param == 1 then
+    -- WILL ECHO (respond with DO ECHO, disable line editing)
+    -- test using io.write("\xFF\xFB\x01")
+    for _, v in pairs(sendSigs) do
+     v("telnet", "\xFF\xFD\x01")
+    end
+    setLineEditing(false)
+   elseif cmd == 252 and param == 1 then
+    -- WON'T ECHO (respond with DON'T ECHO, enable line editing)
+    for _, v in pairs(sendSigs) do
+     v("telnet", "\xFF\xFE\x01")
+    end
+    setLineEditing(true)
+   elseif cmd == 253 or cmd == 254 then
+    -- DO/DON'T (x) (respond with WON'T (X))
+    local res = "\xFF\xFC" .. string.char(param)
+    for _, v in pairs(sendSigs) do
+     v("telnet", res)
+    end
+   elseif cmd == 255 then
+    tvBuildingUTF = tvBuildingUTF .. "\xFF"
+   end
+   tvBuildingCmd = tvBuildingCmd:sub(cmdLen + 1)
+  else
+   tvBuildingUTF = tvBuildingUTF .. tvBuildingCmd:sub(1, 1)
+   tvBuildingCmd = tvBuildingCmd:sub(2)
+  end
+ end
+ -- Flush UTF
+ while #tvBuildingUTF > 0 do
+  local head = tvBuildingUTF:byte()
+  local len = 1
+  if head >= 192 and head < 224 then len = 2 end
+  if head >= 224 and head < 240 then len = 3 end
+  if head >= 240 and head < 248 then len = 4 end
+  if head >= 248 and head < 252 then len = 5 end
+  if head >= 252 and head < 254 then len = 6 end
+  if #tvBuildingUTF < len then break end
+  -- verified one full character...
+  local char = tvBuildingUTF:sub(1, len)
+  tvBuildingUTF = tvBuildingUTF:sub(len + 1)
+  writeData(char)
+ end
+end

 do
 tReg(function (_, pid, sendSig)
@ -82,11 +219,12 @@ do
  return {
   id = "x." .. id,
   pid = neo.pid,
-   line = function (text)
+   write = function (text)
    incoming(tostring(text))
+    drawDisplay()
   end
  }
- end)
+ end, true)

 if retTbl then
  coroutine.resume(coroutine.create(retTbl), {
@ -99,51 +237,45 @@ do
 end
 end

-- This decides the history buffer size.
-local history = {
- "", "", "", ""
-}
-
-local function cycleHistoryUp()
- local backupFirst = history[1]
- for i = 1, #history - 1 do
-  history[i] = history[i + 1]
- end
- history[#history] = backupFirst
-end
-local function cycleHistoryDown()
- local backup = history[1]
- for i = 2, #history do
-  backup, history[i] = history[i], backup
- end
- history[1] = backup
-end
-
 local function key(a, c)
- if c == 200 then
+ if not leText then
+  for _, v in pairs(sendSigs) do
+   if a == "\r" then
+    v("data", "\r\n")
+   elseif a then
+    v("data", a)
+   end
+  end
+ else
+  -- Line Editing active
+  if c == 200 or c == 208 then
   -- History cursor up (history down)
-  l15 = history[#history]
-  cX = 1
-  cycleHistoryDown()
-  return
- elseif c == 208 then
-  -- History cursor down (history up)
-  l15 = history[#history]
-  cX = 1
+   leText = leHistory[#leHistory]
+   leCX = unicode.len(leText)
+   if c == 208 then
    cycleHistoryUp()
+   else
+    cycleHistoryDown()
+   end
   return
  end
- local lT, lC, lX = require("lineedit").key(a, c, l15, cX)
- l15 = lT or l15
- cX = lC or cX
+  local lT, lC, lX = require("lineedit").key(a, c, leText, leCX)
+  leText = lT or leText
+  leCX = lC or leCX
  if lX == "nl" then
   cycleHistoryUp()
-  history[#history] = l15
+   leHistory[#leHistory] = leText
+   -- the whole thing {
+   local fullText = leText .. "\r\n"
+   writeData(fullText)
+   drawDisplay()
   for _, v in pairs(sendSigs) do
-   v("line", l15)
+    v("data", fullText)
+   end
+   -- }
+   leText = ""
+   leCX = 1
  end
-  l15 = ""
-  cX = 1
 end
 end

@ -165,32 +297,26 @@ while not closeNow do
     key(c, 0)
    end
   end
-   line(sH)
+   draw(#console + 1)
  elseif e[3] == "key" then
   if e[5] == 29 or e[5] == 157 then
    control = e[6]
   elseif e[6] then
    if not control then
     key(e[4] ~= 0 and unicode.char(e[4]), e[5])
-     line(sH)
+     draw(#console + 1)
    elseif e[5] == 203 and sW > 8 then
-     sW = sW - 1
-     window.setSize(sW, sH)
-    elseif e[5] == 200 and sH > 2 then
-     sH = sH - 1
-     table.remove(console, 1)
-     window.setSize(sW, sH)
+     setSize(conW - 1, #console)
+    elseif e[5] == 200 and #console > 1 then
+     setSize(conW, #console - 1)
    elseif e[5] == 205 then
-     sW = sW + 1
-     window.setSize(sW, sH)
+     setSize(conW + 1, #console)
    elseif e[5] == 208 then
-     sH = sH + 1
-     table.insert(console, 1, "")
-     window.setSize(sW, sH)
+     setSize(conW, #console + 1)
    end
   end
  elseif e[3] == "line" then
-   line(e[4])
+   draw(e[4])
  end
 end
 end
--- a/code/apps/sys-everest.lua
+++ b/code/apps/sys-everest.lua
@ -616,7 +616,7 @@ local function key(ku, ka, kc, down)
 elseif kc == 56 then
  isAltDown = down
 end
- if isAltDown and kc == 122 then
+ if isAltDown and ka == 122 then
  if focus and down then
   local n = table.remove(surfaces, 1)
   table.insert(surfaces, n)
--- a/code/apps/sys-icecap.lua
+++ b/code/apps/sys-icecap.lua
@ -81,20 +81,12 @@ local function getPfx(xd, pkg)
 end
 end

-local endAcPattern = "/[a-z0-9/%.]*$"
-
-local function matchesSvc(xd, pkg, perm)
- local pfx = getPfx(xd, pkg)
- if pfx then
-  local permAct = perm
-  local paP = permAct:match(endAcPattern)
-  if paP then
-   permAct = permAct:sub(1, #permAct - #paP)
-  end
-  if permAct == pfx then
-   return "allow"
-  end
+local function splitAC(ac)
+ local sb = ac:match("/[a-z0-9/%.]*$")
+ if sb then
+  return ac:sub(1, #ac - #sb), sb
 end
+ return ac
 end

 donkonitDFProvider(function (pkg, pid, sendSig)
@ -130,7 +122,8 @@ donkonitDFProvider(function (pkg, pid, sendSig)
  myApi = getPfx("", pkg),
  lockPerm = function (perm)
   -- Are we allowed to?
-   if not matchesSvc("x.", pkg, perm) then
+   local permPfx, detail = splitAC(perm)
+   if getPfx("x.", pkg) ~= permPfx then
    return false, "You don't own this permission."
   end
   local set = "perm|*|" .. perm
@ -223,7 +216,11 @@ local function secPolicyStage2(pid, proc, perm, req)
 -- Push to ICECAP thread to avoid deadlock b/c wrong event-pull context
 neo.scheduleTimer(0)
 table.insert(todo, function ()
-  local ok, err = pcall(secpol, nexus, settings, proc.pkg, pid, perm, req, matchesSvc)
+  local fPerm = perm
+  if fPerm:sub(1, 2) == "r." then
+   fPerm = splitAC(fPerm)
+  end
+  local ok, err = pcall(secpol, nexus, settings, proc.pkg, pid, fPerm, req, getPfx("", proc.pkg))
  if not ok then
   neo.emergency("Used fallback policy because of run-err: " .. err)
   req(def)
@ -243,11 +240,7 @@ rootAccess.securityPolicy = function (pid, proc, perm, req)
 end
 -- Do we need to start it?
 if perm:sub(1, 6) == "x.svc." and not neo.usAccessExists(perm) then
-  local appAct = perm:sub(7)
-  local paP = appAct:match(endAcPattern)
-  if paP then
-   appAct = appAct:sub(1, #appAct - #paP)
-  end
+  local appAct = splitAC(perm:sub(3))
  -- Prepare for success
  onReg[perm] = onReg[perm] or {}
  local orp = onReg[perm]
--- a/code/init.lua
+++ b/code/init.lua
@ -459,7 +459,7 @@ function retrieveAccess(perm, pkg, pid)
  accesses[uid] = function (pkg, pid)
   return nil
  end
-  return function (f)
+  return function (f, secret)
   -- Registration function
   ensureType(f, "function")
   local accessObjectCache = {}
@ -481,8 +481,10 @@ function retrieveAccess(perm, pkg, pid)
    end
    -- returns nil and fails
   end
+   if not secret then
    -- Announce registration
    distEvent(nil, "k.registration", uid)
+   end
  end, function ()
   -- Registration becomes null (access is held but other processes cannot retrieve object)
   if accesses[uid] then
--- a/code/libs/sys-secpolicy.lua
+++ b/code/libs/sys-secpolicy.lua
@ -11,13 +11,19 @@
 -- IRC is usually pretty safe, but no guarantees.

 -- Returns "allow", "deny", or "ask".
-local function actualPolicy(pkg, pid, perm, matchesSvc)
+local function actualPolicy(pkg, pid, perm, pkgSvcPfx)
 -- System stuff is allowed.
 if pkg:sub(1, 4) == "sys-" then
  return "allow"
 end
+ -- svc-t's job is solely to emulate terminals
+ -- TO INSTALL YOUR OWN TERMINAL EMULATOR:
+ -- perm|app-yourterm|r.neo.t
+ if pkg == "svc-t" and perm == "r.neo.pub.t" then
+  return "allow"
+ end
 -- <The following is for apps & services>
- -- x.neo.pub (aka Icecap) is open to all
+ -- x.neo.pub.* is open to all
 if perm:sub(1, 10) == "x.neo.pub." then
  return "allow"
 end
@ -25,7 +31,8 @@ local function actualPolicy(pkg, pid, perm, matchesSvc)
 if perm == "s.h.component_added" or perm == "s.h.component_removed" or perm == "s.h.tablet_use" or perm == "c.tablet" then
  return "allow"
 end
- if matchesSvc("r.", pkg, perm) then
+ -- Userlevel can register for itself
+ if perm == "r." .. pkgSvcPfx then
  return "allow"
 end
 -- Userlevel has no other registration rights
@ -44,8 +51,8 @@ local function actualPolicy(pkg, pid, perm, matchesSvc)
 return "ask"
 end

-return function (nexus, settings, pkg, pid, perm, rsp, matchesSvc)
- local res = actualPolicy(pkg, pid, perm, matchesSvc)
+return function (nexus, settings, pkg, pid, perm, rsp, pkgSvcPfx)
+ local res = actualPolicy(pkg, pid, perm, pkgSvcPfx)
 if settings then
  res = settings.getSetting("perm|" .. pkg .. "|" .. perm) or
        settings.getSetting("perm|*|" .. perm) or res
--- a/repository/docs/kn-perms
+++ b/repository/docs/kn-perms
@ -63,7 +63,8 @@ The security check may be aliased to
 "r.*": Registers a service's API for
 retrieval via the "x." mechanism.
 Returns a:
- function (function (pkg, pid, send))
+ function (function (pkg, pid, send),
+  secret)
 While the registration is locked on
  success, attempting to use it will
  fail, as no handler has been given.
@ -71,6 +72,11 @@ The security check may be aliased to
  registration with a callback used
  for when a process tries to use the
  registered API.
+ Unless 'secret' is truthy, a
+  k.registration event is sent to all
+  processes; using the secret flag is
+  useful for a more ad-hoc security
+  approach.
 What that API returns goes to the
  target process.
 The given "sendSig" function can be
--- a/repository/docs/us-termi
+++ b/repository/docs/us-termi
@ -5,20 +5,34 @@ The "svc-t" program / "x.svc.t"
 --- THEORETICAL TERMINALS MODEL ---

 The theoretical model for terminals
- in KittenOS NEO is that of a stack
- of processes controlling a player's
- connection to a MUD, where text is
- provided to the server and to the
- player in a line-by-line format,
- with no "flow control"/ttyattrs.
+ in KittenOS NEO is a TELNET client
+ that only supports the ECHO option,
+ and uses the non-standard behavior
+ of treating ECHO ON as 'enable local
+ line editing'.
+
+To prevent code size going too far,
+ the client is extremely restricted
+ in capabilities.
+
+If you really want full support,
+ write a better terminal application.
+
+Features that get added will be added
+ in accordance with ANSI/TELNET where
+ reasonable or in a compatible-ish
+ fashion where unreasonable.
+
+The defaults will be set based on
+ whatever app-luashell requires, as
+ this is what is expected of modern
+ terminal systems regardless of what
+ the standards may have to say.

 A process starting another process
 connected to the same terminal is
 advised to wait for that process to
- die before continuing in terminal
- activities, unless some sort of
- 'in-band notification' functionality
- is intended.
+ die before continuing reading input.

 The controlling process is whichever
 process is supposed to be accepting
@ -32,8 +46,8 @@ The controlling process should show
 acknowledgement that user input has
 been received.

-User input IS NOT automatically
- echoed by the terminal.
+For convenience, terminal echo is on
+ by default; this is easily remedied.

  --- ACTUAL USAGE OF TERMINALS ---

@ -42,12 +56,15 @@ Access control on terminals is looser
 to be able to be 'sublet' in some
 cases, including events.

+As such, the secret flag is set for
+ terminal registration.
+
 A terminal program is given a string
 argument for the ID of the terminal
 to connect to.

 A terminal always has an ID beginning
- with "x.svc.t/". ALWAYS CHECK THIS.
+ with "x.neo.pub.t/". ALWAYS CHECK.

 Requiring the responsible access
 connects to the terminal. All
@ -80,11 +97,22 @@ In either case, when the access has

 id = "x.svc.t/<...>"
 pid = <The terminal's PID.>
-line = function (text): Shows a line.
+write = function (text): Writes the
+ TELNET data to the terminal.

-When the user sends a line, an event
- of: <id>, "line", <text>
- is provided.
+User input is provided in events:
+ <id>, "data", <data>
+
+TELNET commands are provided in:
+ <id>, "telnet", <data>
+
+There is a total of one TELNET
+ command per event, unpadded.
+
+Notably, intermixing the data part
+ of the data/telnet events in order
+ produces the full terminal-to-server
+ TELNET stream.

 -- This is released into
 the public domain.