path: root/debloat

#!/usr/bin/lua

-- Use of various qdiscs for ethernet and wireless

-- This script expects to be run in /etc/network/if-pre-up.d To run it
-- manually, do a IFACE=yournetworkcard ./debloat

-- For NATTED interfaces, use a NAT=y for a better filter
-- To select QFQ use QMODEL=qfq.

-- Some options currently require a new version of tc. Build a version
-- of iproute2 and stick it somewhere and change the TC variable to
-- suit.

-- These are the possible parameters that can be changed via
-- environment variables.

params = { "MDISC", "BIGDISC", "NORMDISC", "BINS", "MAX_HWQ_BYTES",
	   "QMODEL", "FORCE_SPEED", "FORCE_RING", "QDEBUG", "VERBOSE",
	   "UPLINK", "DOWNLINK", "IFACE", "SPEED", "DEPTH", "DEBLOATLOG",
	   "NAT", "NAT64", "CLAMP_MSS", "SYN_FLOOD", "MTU", "INGRESS",
	   "TC", "TCARG", "ETHTOOL", "INSMOD", "LSMOD", "IPTABLES",
	   "IP6TABLES", "PINGOPT", "FLOWS", "TSO", "BURST", "IPV6",
	   "OVERHEAD", "LINKLAYER", "MPU", "PPPOE", "ADSL",
	   "NOPRIOHOSTSRC","NOPRIOHOSTDST","NOPRIOPORTSRC",
	   "NOPRIOPORTDST", "EST_MIN", "EST_MAX", "HEADDROP", "ECNMASK",
	   "qlen_vo", "qlen_vi", "qlen_be", "qlen_bk", "CODEL_LL_QUANTUM" }

-- Useful defaults

env = { ["TC"] = "/sbin/tc",
	["TCARG"] = "-b",
	["INSMOD"] = "/sbin/modprobe",
        ["ETHTOOL"] = "/sbin/ethtool",
	["LSMOD"] = "/sbin/lsmod",
	["IPTABLES"] = "/sbin/iptables",
	["IP6TABLES"] = "/sbin/ip6tables",
	["MDISC"] = "codel",
	["BIGDISC"] =  "codel",
	["NORMDISC"] = "codel",
	["BINS"] = 2048,
	["DEPTH"] = 24,
	["QMODEL"] = "fq_codel_ll",
	["MAX_HWQ_BYTES"] = 3000,
	["ECNMASK"] = 0xfc,
	["EST_MIN"] = 1,
	["EST_MAX"] = 4,
	["IPV6"] = true,
	["LINKLAYER"] = "ethernet",
	["DEBLOATLOG"] = "/dev/null",
	["qlen_vo"] = 2,
	["qlen_vi"] = 4,
	["qlen_be"] = 12,
	["qlen_bk"] = 12,
	["MTU"] = 1500,
	["CODEL_LL_QUANTUM"] = 1000
	}

wireless_debug = "/sys/kernel/debug/ieee80211/"
qlens = { "qlen_vo", "qlen_vi", "qlen_bk", "qlen_be" }

-- various shortcuts for commonly used functions

local sf=string.format
local exec=os.execute
local popen=io.popen
local open=io.open

-- FIXME, override above to redirect stderr

VO=0x10; VI=0x20; BE=0x30; BK=0x40
local WQUEUES = { BE, VO, VI, BK }

local function usage(s) o=[[

The debloat tool aims for minimal latency (particularly under load) on
the network, for hosts, servers, wireless devices, and routers.

There are various forms of traffic shapers and tools in here because
this is an unsolved problem! Most of the known techniques are in here,
however, and the results can be quite remarkable. At tested rates of
100Mbit and 4Mbit, we see interstream latencies drop by over two
orders of magnitude.

This script expects to be run in /etc/network/if-pre-up.d

To run it manually, do a:

IFACE=yournetworkcard ./this_script

For NATTED interfaces, use a NAT=y for a better filter.

There are many environment variables and at some point will be a conf
file. The one of greatest importance is "QMODEL" to which I keep
adding various models for various circumstances. See the end of this
file for more details.

This script can be run on both debian and openwrt.

Usage of QFQ and the advanced SFQ and SFQRED options currently
requires a patched version of iproute2 and a Linux 3.3 kernel.

Build a version and stick it somewhere and change TC to suit.

Also, if you are interested in seeing the rules being generated,
rather than reconfiguring your system

export QDEBUG=1

is helpful.

* Some general overall design notes:

This started out life as a shell script to exercise qfq,
Now it does a lot more than that and is getting crufty.

FQ_CODEL is now the default. SFQ has been improved significantly
in Linux 3.3 (eliminating a head of line problem), and in this case
no new TC utility is required. Also a bug in red was fixed, and no
new tc utility is required there either. So if you were using either
or both of these qdiscs, you should automagically see your life
improve...

QFQ is too buggy prior to 3.3 to use.

More advanced SFQ options and REDSFQ and QFQ all require a patched
version of TC. Also, most builds for the linux kernel do not
enable QFQ by default. QFQ and SFQ are behaving competitively now
in most circumstances, however.

* Byte Queue Limits is supposed to have a rate limiter that works.

It is not very effective at less than 100Mbit. I get ~32k peak there
and with GSO on, at 100Mbit, I have seen latency spikes of up to 70ms.

   (Not recently tested, however)

A per queue limit of 2 large packets appears to be the best
compromise at 100Mbit and below. So typically I hammer down BQL to
3k at < 100Mbit, and turn GSO/TSO off, and as a result see
ping against load latencies in the 1 to 2ms range, which is about
what you would expect. I have tried 1500 bytes, which limited the top
end performance to about 84Mbit. At 10Mbit, 1514 works on most OSes.

For comparison, you will see PFIFO_FAST doing 130+ms, pre BQL, no
SFQ at 100Mbit.

* A BQL enabled ethernet device driver is helpful

But there is currently no good way to detect if you have one at run
time. 10 of the most major drivers have been convered to BQL, more
remain.

* Wireless still has problems

This stuff helps on wireless stations, desktops, etc, and on P2P
wireless links.

** caveat 1

There remains so much device buffering and retries below the qdisc
layer as to defeat both FQ and and AQM to a large extent. Also packets
tend to be held 'forever' (ping rtts of over 10 seconds have been
observed)

A time in queue optimization at the qdisc layer for the latter problem
has been proposed, but not implemented, and much further work on the
wireless driver portion of the stack remains to be designed and agreed
upon.

BQL has not (and cannot, to a large extent) be implemented on the
wireless portion of the stack as it currently stands.

** caveat 2

There is not a particularly good way to apply much of this to the
wireless interface on an AP as yet. FQ messes with wireless-n packet
aggregation. That said, under home use with a limited number of user,
SFQ+RED does seem to work pretty good.

* Some QFQ related notes:
** QFQ can handle up to 32k bins

Whether you are willing to wait for them to be generated is a better
question.  How this interacts with bittorrent etc is also a good
question. 512 is 4x as many bins as the old SFQ implementation.

I have tested as many as 2048 bins, problems ensue with kernel
memory allocation at various levels higher than that.

The 'bin creation' problem is why this code uses tc in batch mode. It
used to take minutes to create the bins. Now, a split second.  (there
was also a patch that helped this in 3.3)

** Various sub-qdiscs in QFQ

I have tried pfifo_drop_head, SFB, and RED here.  All had bugs until
3.3. And linux RED & SFB, being byte oriented, was often not good.
pfifo_drop_head generates interesting results.

The very new combination of REDSFQ which compensates for both bytes
and packets was very interesting, as it combines everything we have
learned in the past year into one single qdisc which can be brought up
as a shaper in three lines of code.

FQ_Codel is better.

In other news:

I have not tried the new 'adaptive red' implementation as a stand
alone qdisc, nor revisited SFB in light about what I now know about
GSO behavior.

I would like to try QFQ and SFQ in combination to attempt to defeat
the bittorrent problem at some point.

** Calculating a sane per-queue packet limit is an issue, too.

iw10 requires a minimum of 10, and more likely 12 (fin, close) so...
In places we arbitrarily double that, and wave hands.  I almost never
see packet drop with 24, which is far, far better than 1000.  Might
need to be larger on gigE+. Might be wrong headed entirely.

** Multicast

We try to maltreat multicast especially in the QFQ implementation.

When handed to a load balancing filter based on IPs, multicast
addresses are all over the map.  It would be trivial to do a DOS with
this multi-bin setup. So we toss all multicast into a single bin
whenever possible. This is suboptimal, also. It would be good
to get multicast into the VO queue on wireless but bugs exist.

Multicast concerns me also when using SFQ on general purpose ethernet.

** Default Bins

You can do tricks with the DEFAULTB concept, creating a filter to
optimize for ping, for example, which makes tests reproducable. (this
is done for wshaper and QFQ) Another example would be to set aside
bins for voip or dns, etc. Still, it is saner to just let the filter
do all the work of finding a decent bin.

The only sane purpose for DEFAULTB at the moment is to have a safe
place to put QFQ packets until all the filters and bins are setup.

* Other important debloat options

There are many environment variables that can be set. Most
notably - the QMODEL var has various forms of AQM/FQ/shaper available.

Available QMODELS are qfq, sfq, sfqred, efq and various combinations
thereof, as well as a hard coded 4mbit htb_sfq_red model, and emulations
of the original wondershaper and a mildly improved one. See the
tail end of the code for what is available.

Most work on either ethernet or wireless and try to deal with
the problems of each.

Usage of QFQ and the advanced SFQ options currently requires a new
version of iproute2 and a Linux 3.3 kernel and some patches.

A byte Queue limit enabled device driver is required for ethernet,
except for when the HTB rate limiter is used.

In all cases a Linux 3.3 or later kernel is required for best results.

]]

print(o)
-- print("Available Shaper Models Are:")
-- for i,v in pairs (ECALLBACKS) do
--   print(i)
-- end
print(s)
os.exit(-1)
end

pingopt = function(...) return nil end
warn = function(...) return nil end

function file_exists(name)
   local f=open(name,"r")
   if f ~= nil then f:close(); return true else return false end
end

local function is_openwrt()
   if file_exists("/etc/uci-defaults") then
      return true
   else
      return false
   end
end

-- Override various defaults with env vars

if is_openwrt() then
   env.INSMOD = "/sbin/insmod"
   env.ETHTOOL = "/usr/sbin/ethtool"
   env.TC = "/usr/sbin/tc"
end

-- pull params from conf file

local function getconf()
end

-- getenv pulls in everything as strings,
-- so do the conversion here

local function fromenv(v)
   local s = os.getenv(v)
   if s == nil then return nil end
-- FIXME allow .
   local m = string.match(s,"^%d+")
   if m ~= nil then return tonumber(s) end
   if s == "true" then return true end
   if s == "false" then return false end
   return s
end

-- From the possible parameters in t, override o

local function getenvs(t,o)
   for i,v in pairs(t) do
      local s = fromenv(v)
      if s ~= nil then o[v] = s end
   end
   return o
end

env = getenvs(params, env)

if (env["IFACE"] == nil) then
   usage("Error: The IFACE environment variable must be set")
end

IFACE=env.IFACE
QMODEL=env.QMODEL
BINS=env.BINS
MULTICAST=BINS+1
DEFAULTB=BINS+2

PREREQS = { "sch_qfq", "sch_codel", "sch_fq_codel", "cls_u32", "cls_flow",
	    "sch_sfq", "sch_red", "sch_htb", "cls_fw", "sch_efq_codel",
	    "sch_ns2_codel", "sch_nfq_codel" }

-- we can get more complex later

PREREQS2 = {
   ["qfq"] = { "sch_qfq", "cls_u32", "cls_flow" },
   ["sfq"] = { "sch_sfq", "cls_u32", "cls_flow" },
   ["red"] = { "sch_qfq", "sch_red", "cls_u32", "cls_flow" },
   ["ared"] = { "sch_qfq", "sch_red", "cls_u32", "cls_flow" }
}

-- FIXME: Merge multiple tables into one table on values in first
-- return table

function merge(...)
   local t = { }
   for i,v in pairs(...) do
      for i,v in pairs(v) do
	 t[v] = true
      end
   end
   return t
end

-- slurp a file

function slurpf(file)
   local f = open(file,"r")
   if f ~= nil then
      local s = f:read("*all")
      f:close()
      return s
   end
   return nil
end

-- spew output into a command

function spewc(command,s)
   local f = popen(command,"w")
   if f ~= nil then
      local v = f:write(s)
      f:close()
      return v
   end
   return nil
end

-- spew output into a file

function spewf(file,s)
   local f = open(file,"w")
   if f ~= nil then
      local v = f:write(s)
      f:close()
      return v
   end
   return nil
end

-- slurp a file into a table

function tslurpf(file)
   local s = slurpf(file)
   if s ~= nil then return s:split("\n") end
   return nil
end

-- return the output of a command as a big string

function slurpc(command)
   local f = popen(command,"r")
   if f ~= nil then
      local s = f:read("*all")
      f:close()
      return s
   end
   return nil
end

-- return the output of a command as a table

function tslurpc(command)
   local s = slurpc(command)
   if s ~= nil then return s:split("\n") end
   return nil
end

-- Some utility functions

-- can't depend on 'wlan or eth' patterns, so try sysfs
-- FIXME: This needs to be made smarter and detect other forms
-- of tunnel.

function interface_type(iface)
   if iface == 'lo'           then return('localhost') end
   if iface:sub(1,3) == 'ifb' then return('ifb') end
   if iface:find('%.') ~= nil then return('vlan') end
   if iface:sub(1,3) == 'gre' then return('tunnel') end
   if iface:sub(1,2) == 'br'  then return('bridge') end
   if file_exists(sf("/sys/class/net/%s/phy80211/name",iface)) then return ('wireless') end
return ('ethernet')
end

local function ethtool_popen(...)
   return popen(sf("%s %s 2>> %s",env.ETHTOOL,sf(...),env.DEBLOATLOG),"r")
end

local function ethtool(...)
   exec(sf("%s %s 2>> %s",env.ETHTOOL,sf(...),env.DEBLOATLOG))
end

-- lua doesn't have a split function. Grr.

function string:split(sep)
   local sep, fields = sep or ":", {}
   local pattern = string.format("([^%s]+)", sep)
   self:gsub(pattern, function(c) fields[#fields+1] = c end)
   return fields
end

-- return the modules already installed

local function lsmod()
   local t = { }
   local k = { }
   for i,v in pairs(tslurpc(env.LSMOD)) do
      k = v:split(" ")
      if k[1] ~= "Module" then
	 table.insert(t,k[1])
      end
   end
   return t
end

-- take a table of modules to insert

local function insmod(modules)
     for i,v in pairs(modules) do
	exec(sf("%s %s",env.INSMOD,v))
     end
     return true
end

-- there must be a more lua-specific way for this

function exists(t,s)
   for i,v in pairs(t) do
      if v == s then return true end
   end
   return false
end

-- Return pre-reqs not installed

function prereq_check(prereqs)
   s = lsmod()
   local t = { }
   for i,v in pairs(prereqs) do
      if exists(s,v) == false then
	 table.insert(t,v)
      end
   end
   return t
end

-- install pre-reqs if not installed

function kernel_prereqs(prereqs)
   return insmod(prereq_check(prereqs))
end

function round(v)
   return math.ceil(v-.5)
end

function kleinrock(bandwidth, delay, flows)
   return round(math.sqrt(flows)*bandwidth*delay)
end

function bound(v,min,max)
   if max < min then
      local t = max
      max = min
      min = t
   end
   if v > min and v < max then return v end
   if v > max then return max end
   if v < min then return min end
   return v
end

function rbound(v,min,max)
	return round(bound(v,min,max))
end

local function lowrate(rate)
   if rate < 15000 then return true else return false end
end

-- Don't like these side effects

local function htb_est()
   s = " "
   if env.PPPOE then env.OVERHEAD=40 end
   if env.ADSL then env.LINKLAYER="adsl" end
   if lowrate(env.UPLINK) then env.R2Q=1 end
end

-- ADSL overhead calculation for htb

local function overhead(rate)
   local s = " "
   if env.OVERHEAD then s = s .. "OVERHEAD=" .. OVERHEAD .. " " end
   if env.LINKLAYER then s = s .. "LINKLAYER=" .. env.LINKLAYER .. " " end
   if lowrate(rate) then s = s .. "R2Q=1 " end
   return(s)
end

-- Attempt at finding useful values for sfqred
-- FIXME: re-read ared paper

-- Yes, you want a depth=10 (or 15) limit, to cope with the increase
-- of CWND done by Google.

-- Best thing would be to use SFQRED and headdrop, so that there is no
-- assumption on packet lengths.

-- tc qdisc add ... sfq headdrop limit 200 depth 15 redflowlimit 50000
-- min 5000 max 10000 probability 0.15 ecn

-- Another often hidden assumption is that RTTs are 100ms

target = 50

-- The problem with byte oriented red is that it will never
-- kick in or mark acks.

local function redflowlimit(up,down)
   local OVERHEAD=0
   if env.OVERHEAD then OVERHEAD=env.OVERHEAD end
   bytes_per_ms = up / 12.5
   pkt_per_ms_worst = bytes_per_ms/(env.MTU + OVERHEAD)
   pkt_per_ms_best = bytes_per_ms/(64 + OVERHEAD)
   local limit = round(pkt_per_ms_best * target)
   local perflow = round(pkt_per_ms_best)
   local rlimit = rbound(target * bytes_per_ms,1500,15000)
   local depth = 10
   return limit,rlimit,depth,pkt_per_ms_worst
end

--print(redflowlimit(4000,20000))
--print(redflowlimit(2000,20000))
--print(redflowlimit(400,2000))

-- Choke is packet oriented at the UI, but bytes underlie it...

local function chokelimit(up,down)
   local OVERHEAD=0
   if env.OVERHEAD then OVERHEAD=env.OVERHEAD end
   bytes_per_ms = up / 12.5
   pkt_per_ms_worst = bytes_per_ms/(env.MTU + OVERHEAD)
   pkt_per_ms_best = bytes_per_ms/(64 + OVERHEAD)
   local limit = round(pkt_per_ms_best * target)
   local perflow = round(pkt_per_ms_best)
   local rlimit = rbound(target * bytes_per_ms,1500,15000)
   local depth = 10
   return limit,rlimit,depth,pkt_per_ms_worst
end

-- Some htb info that is probably hopelessly out of date

-- Counting packets with quantum can be strange. If we have a low rate
-- class (rate = 5kbit), default quantum = 5000 / 10 = 500 bytes. But
-- most packets are more then 500 bytes. Htb version 1 and 2 uses DRR,
-- so a packet larger then 1000 bytes will be sent and it will
-- remember how much it sent and wait until the packet is paid back
-- before another packet is send. So if you send 1000 byte, next time
-- the class is polled, you will not be allowed to send.

-- Htb3 uses the WRR scheduler. When a packet with size > quantum is
-- sent, it will be sent and an error that the quantum is too small
-- will be logged. But there is no pay back. The WRR scheduler is
-- faster then the DRR scheduler. So make sure quantum is bigger then
-- the default packet size. For 15 kbyte/s and default r2q, quantum is
-- 1500 and this is exactly the maximum packet size. If you want to
-- tune htb for rates smaller then 15 kbyte/s, you can manually set
-- the r2q and/or quantum.

-- FIXME:
-- We want to capture the characteristics of
-- the interface in a table.
-- So we need to parse the output of ethtool better
-- ["tx-ring"] = X
-- ["speed"] = X
-- etc
-- return a hash of the properties of the interface

-- terrific, this is hard to parse.
-- ethtool -g eth0

-- Ring parameters for eth0:
-- Pre-set maximums:
-- RX:		4096
-- RX Mini:	0
-- RX Jumbo:	0
-- TX:		4096
-- Current hardware settings:
-- RX:		256
-- RX Mini:	0
-- RX Jumbo:	0
-- TX:		64

-- ethtool -g wlan0
-- Ring parameters for wlan0:
-- Pre-set maximums:
-- RX:		0
-- RX Mini:	0
-- RX Jumbo:	0
-- TX:		0
-- Current hardware settings:
-- RX:		0
-- RX Mini:	0
-- RX Jumbo:	0
-- TX:		0

-- -k is easier
-- ethtool -k eth0
-- Offload parameters for eth0:
-- rx-checksumming: on
-- tx-checksumming: on
-- scatter-gather: on
-- tcp-segmentation-offload: off
-- udp-fragmentation-offload: off
-- generic-segmentation-offload: off
-- generic-receive-offload: on
-- large-receive-offload: off
-- rx-vlan-offload: on
-- tx-vlan-offload: on
-- ntuple-filters: off
-- receive-hashing: off

function string:trim ()
   return (string.gsub(self, "^%s*(.-)%s*$", "%1"))
end

function offloads(iface)
   local t = { }
   local s = tslurpc(sf("%s -k %s",env.ETHTOOL,iface))
   if s ~= nil then
      for i,v in ipairs(s) do
	 if v == "no offload info available" then
	    return nil
	 end
      end

      for i,v in ipairs(s) do
	 local h = v:split(":")
	 local j = h[1]:split(" ")
	 if # j > 1 then
	 if j[1] ~= "Offload" then
	 if # h > 1 then
	    t[h[1]:trim()] = h[2]:trim()
	 end
	    -- FIXME: should probably change 'off' and 'on' to false and true
	 end
	 end
      end
   end
   return t
end

-- test the offloads problem
-- we have a wide range of possible inputs to test against as yet

function test_offloads(iface)
   local o = offloads(iface)
   if o ~= nil then
      for i,v in pairs(o) do
	 print(sf("%s %s",i,v))
      end
   end
end

-- test_offloads("eth1")

-- FIXME - could use a little more thought on creating the
-- hash

function ring_params(iface)
   local t = { }
   local state = 0
   for i,v in ipairs(tslurpc(sf("%s -g %s",env.ETHTOOL,iface))) do
      local h = v:split(":")
      local j = h[1]:split(" ")
      if j[1] == "Ring" or j[1] == "Pre-set" then
	 -- do nothing
      elseif j[1] == "Current" then state = 1
      elseif state == 0 then
	 t['max_' .. h[1]:trim()] = h[2]:trim()
      elseif state == 1 then
	 t['cur_' .. h[1]:trim()] = h[2]:trim()
      end
   end
   return t
end

function test_ring_params(iface)
   local o = ring_params(iface)
   for i,v in pairs(o) do
      print(sf("%s %s",i,v))
   end
end

-- test_offloads(IFACE)
-- test_ring_params(IFACE)

function iface_get(iface)
end

-- return number of hardware queues found

local function bql_setup(iface)
   local c = 0
   while spewf(sf("/sys/class/net/%s/queues/tx-%d/byte_queue_limits/limit_max",iface,c),
	       env.MAX_HWQ_BYTES) ~= nil do
      c = c + 1
   end
   return c
end

-- Maybe better done with ethtool

local function speed_set(iface,speed)
   return spewf(sf("/sys/class/net/%s/speed",iface),speed)
end

local function speed_get(iface)
   return slurpf(sf("/sys/class/net/%s/speed",iface))
end

local function rate_quantum(rate)
   if rate < 10000 then return(1500) end
   return(1500)
end

-- Doing this as a lookup table hurt lua
-- FIXME: Not clear how to reset to advertising all
-- Not clear how to reset this parameter from
-- userspace to autonegotiate
-- What to do with non-sensical values that you
-- get before an interface is live?
-- Maybe use ethtool speed option?

local function advertise_speed(s)
   local x = "0x000"
   if s < 10001 then x = "0x1000" end
   if s < 1001 then x = "0x020" end
   if s < 101 then x = "0x008" end
   if s < 11 then x = "0x002" end
   if s == 0 then x = "0x000" end
   return x
end

-- TSO does terrible things to the scheduler
-- GSO does as well
-- UFO is not a feature of most devices

-- In the long run I think we want to disable
-- TSO and GSO entirely below 100Mbit. I'd
-- argue for same for gigE, too, for desktops

local function ethernet_setup(iface)
   local o = offloads(iface)
   local tx = ring_params(iface)

-- for testing, limit ethernet to SPEED

   if env.FORCE_SPEED then
      ethtool(sf("-s %s advertise %s",iface,
		 advertise_speed(env.FORCE_SPEED)))
   end
   if env.FORCE_RING then
	 if env.FORCE_RING < tx['cur_TX'] then
	    ethtool(sf("-G %s tx %d",iface,env.FORCE_RING))
	 end
   end
   local queues = bql_setup(iface)
   if env.TSO == nil then
      ethtool("-K %s gso off",iface)
      ethtool("-K %s tso off",iface)
      ethtool("-K %s ufo off",iface)
      ethtool("-K %s gro off",iface)
   end
   return queues
end

-- Some TC helpers

-- rates are specified as kilobits (xkbits)
-- does this need to be integer?
-- FIXME the effect of rounding really isn't what we want

local function r2s(rate)
   if round(rate) < 1000 then return round(rate) .. "kbit" end
   local r = rate/1000
   if round(r) < 1000 then return round(r) .. "mbit" end
   r = r/1000
   return round(r) .. "gbit"
end

-- print(r2s(10))
-- print(r2s(1001))
-- print(r2s(1050)) -- yea, rounding bad
-- print(r2s(999999.4))
-- print(r2s(10000000.6))
-- print(r2s(1000000))

-- TC tends to be repetitive and hard to read
-- So these function shorten things considerably by doing
-- the "{class,qdisc,filter} add dev %s" for us
-- It also means lua keeps less unique strings around.

-- Constructing something that was ** reversible **
-- and cleaner to express would be better that this

local castring=sf("class add dev %s ", env.IFACE)
local fastring=sf("filter add dev %s ",env.IFACE)
local qastring=sf("qdisc add dev %s ", env.IFACE)

-- Similarly, the 'parent' string is often used

local capstring=sf("class add dev %s parent ", env.IFACE)
local fapstring=sf("filter add dev %s parent ",env.IFACE)
local qapstring=sf("qdisc add dev %s parent ", env.IFACE)

local function ca(...)
   return tc:write(castring,sf(...),"\n")
end

local function cap(...)
   return tc:write(capstring,sf(...),"\n")
end

local function fa(...)
   return tc:write(fastring,sf(...),"\n")
end

local function fap(...)
   return tc:write(fapstring,sf(...),"\n")
end

local function qa(...)
   return tc:write(qastring,sf(...),"\n")
end

local function qap(...)
   return tc:write(qapstring,sf(...),"\n")
end

-- FIXME sanely calculate htb rate, overhead, etc, etc

local function hap(parent,child,rate,str)
   cap("%x: classid %x:%x %s htb rate %skibit mtu %d mpu 64 quantum %d %s",
	  parent,parent,child,est,rate,env.MTU,quantum,str)
end

local function opentc()
   return popen(sf("%s %s",env.TC, env.TCARG),'w')
end

function ingress()
   if env.INGRESS then
      kernel_prereqs({"sch_ingress"})
      local tc = opentc()
      tc:write(sf("qdisc del dev %s ingress\n",IFACE))
      tc:close()
   end
end

function resettc()
   local tc=opentc()
   tc:write(sf("qdisc del dev %s root\n",IFACE))
   tc:close()
   return opentc()
end

-- QFQ: Create a bin attached to the parent class

local function cb(base,bin,disc)
   cap("%x classid %x:%x qfq",base,base,bin)
   qap("%x:%x %s",base,bin,disc)
end

-- FIXME: It would be nice to have a cleaner way to match all multicast

local function fa_mcast(parent)
   fap("%x: protocol ip prio 5 u32 match u8 0x01 0x01 at -14 flowid %x:%x",parent,parent,MULTICAST)
   fap("%x: protocol ipv6 prio 6 u32 match u8 0x01 0x01 at -14 flowid %x:%x",parent,parent,MULTICAST)
   fap("%x: protocol arp prio 7 u32 match u8 0x01 0x01 at -14 flowid %x:%x",parent,parent,MULTICAST)
end

local function fa_defb(parent)
   fap("%x: protocol all prio 999 u32 match ip protocol 0 0x00 flowid %x:%x",parent,parent,DEFAULTB)
end

-- FIXME: This needs a correct hash for natted sources when NAT=y and ipv6
-- handle 3 repeated bad?

local function fa_bins(parent)
if env.NAT then
   fap("%x: handle 3 protocol ipv6 prio 94 flow hash keys proto-dst,rxhash divisor %d",parent,env.BINS)
   fap("%x: handle 4 protocol all prio 97 flow hash keys proto-dst,nfct-src divisor %d",parent,env.BINS)
else
   fap("%x: handle 3 protocol all prio 97 flow hash keys proto-dst,rxhash divisor %d",parent,env.BINS)
end
pingopt(sf("%x:",parent),sf("%x:%x",parent,DEFAULTB))
-- At one point I was trying to handle ipv6 separately
-- fa("protocol ipv6 parent %x: handle 4 prio 98 flow hash keys proto-dst,rxhash divisor %d",parent,env.BINS)
end

local function faip_bins(parent)
if env.NAT then
   fap("%x: handle 3 protocol ipv6 prio 94 flow hash keys src divisor %d",parent,env.BINS)
   fap("%x: handle 4 protocol all prio 97 flow hash keys nfct-src divisor %d",parent,env.BINS)
else
   fap("%x: handle 3 protocol all prio 97 flow hash keys src divisor %d",parent,env.BINS)
end

pingopt(sf("%x:",parent),sf("%x:%x",parent,DEFAULTB))
-- At one point I was trying to handle ipv6 separately
-- fa("protocol ipv6 parent %x: handle 4 prio 98 flow hash keys proto-dst,rxhash divisor %d",parent,env.BINS)
end

local function q_bins(parent)
   for i=0,env.BINS
   do
      cap("%x: classid %x:%x qfq",parent,parent,i)
      qap("%x:%x %s",parent,i,env.BIGDISC)
   end
end

-- We can do simple per-stream load balancing across multiple hardware
-- queues thusly. This assumes your IPv6 isn't natted....

local function mqprio_bins(parent,queues)
if env.NAT then
   fap("%x: handle 3 protocol ipv6 prio 94 flow hash keys proto-dst,rxhash divisor %d",parent,queues)
   fap("%x: handle 4 protocol all prio 97 flow hash keys proto-dst,nfct-src divisor %d",parent,queues)
else
   fap("%x: handle 3 protocol all prio 97 flow hash keys proto-dst,rxhash divisor %d",parent,queues)
end
-- At one point I was trying to handle ipv6 separately
-- fa("protocol ipv6 parent %x: handle 4 prio 98 flow hash keys proto-dst,rxhash divisor %d",parent,BINS)
end

-- Eric's Enhanced SFQ

-- FIXME: originally hard coded for 200Mbit
-- I'm going to argue that depth, flows, speed all need to be
-- done via something kleinrock-like. The problem is that
-- we don't know the delay without hitting the next hop
-- And we can't get the next hop until after the interface is
-- up. And even then we can only measure RTT, which is off
-- by a factor of three on the two different systems I've looked at

-- FIXME: I don't think I should be measuring speed in megabits

-- Eric's original code had a mtu of 40000, which I assume is needed
-- for TSO/GSO to work.  These quantums are way too large for lower
-- speeds

--[[ FIXME: Add ADSL support
My crude hack was adding:
tc_stab_string="stab overhead 18 mtu 2048 mpu 53 linklayer atm"
to generate.sh; and then modifying the addition of root disc like the following
tc qdisc add dev $dev root handle 1: ${tc_stab_string} hfsc default ${class_default}0
Then I only needed to reduce the uplink and downlink speed marginally (5%) and got good and stable ping latencies even in the lieu of massive uploads and opening 100 browser tabs at the same time. Without the stab option I had to reduce nominal speeds to around 65%-70% of the line rate and still got worse ping latencies than with the stab option.
--]]

local function htb_sfq(speed,flows)
   qa("root handle 1: est 1sec 8sec htb default 1")
   cap("1: classid 1:1 est 1sec 8sec htb rate 200Mbit mtu 1500 quantum 80000")
   qap("1:1 handle 10: est 1sec 8sec sfq limit 2000 depth 10 headdrop flows 1000 divisor 16384")
end

-- local function htb_sfq_red(speed,flows)
-- hard coded, no math, reasonable for ~4Mbit

local function htb_sfq_red(queues)
   qa("root handle 1: est 1sec 8sec htb default 1")
   cap("1: classid 1:1 est 1sec 8sec htb rate %dkibit mtu 1500 quantum 1514",env.UPLINK)
   qap("1:1 handle 10: est 1sec 4sec sfq limit 200 headdrop flows 500 divisor 16384 redflowlimit 24000 min 3000 max 18000 depth 16 probability 0.12 ecn harddrop")
end

-- This simplified model is intended to work best with the out of tree
-- sfq that has enqueuing to head. It merely looks for background traffic
-- and tosses that into a separate bucket.

-- Rate and ceil

local function htb_sfq_red2(queues)
   BKTRAFFIC=rbound(env.UPLINK *.05, 32, env.UPLINK*.90)
   BKTRAFFIC_MAX=rbound(env.UPLINK*.85,32,env.UPLINK*.90)
   MAXTRAFFIC=round(env.UPLINK-BKTRAFFIC)
   qa("root handle 1:0 est 1sec 8sec htb default 1")
   cap("1:0 classid 10:1 est 1sec 8sec htb prio 1 rate %dkbps ceil %dkbps mtu 1500 quantum 1514",
	env.UPLINK, env.UPLINK)
   cap("10:1 classid 11:1 est 1sec 8sec htb prio 2 rate %dkbps ceil %dkbps mtu 1500 quantum 1514",
	BKTRAFFIC,BKTRAFFIC_MAX)
   cap("10:1 classid 12:1 est 1sec 8sec htb prio 2 rate %dkbps ceil %dkbps mtu 1500 quantum 1514",
	BKTRAFFIC,BKTRAFFIC_MAX)
   qap("10:1 handle 12:0 est 1sec 4sec sfq limit 300 headdrop flows 2000 divisor 16384 redflowlimit 24000 min 3000 max 18000 depth 43 probability 0.12 ecn harddrop")
   qap("11:1 handle 20:0 est 1sec 4sec sfq limit 300 headdrop flows 2000 divisor 16384 redflowlimit 64000 min 3000 max 18000 depth 43 probability 0.12 ecn harddrop")
   fap("1:1 prio 10 u32 match ip tos 0x08 0xff flowid 11:1")
--   fap("1:0 prio 11 u32 match ipv6 tos 0x08 0xfc flowid 1:2")

end

local function htb_sfq_red_cero(queues)
   qa("root handle 1: est 1sec 8sec htb default 1")
   cap("1: classid 1:1 est 1sec 8sec htb rate 4Mbit mtu 1500 quantum 4500")
   qap("1:1 handle 10: est 1sec 4sec sfq limit 120 perturb 60000")
end

local function efq(parent, handle, speed, flows)
   qap(sf("%s handle %x: est 1sec 8sec sfq limit 2000 depth 12 headdrop flows %d divisor 16384",
	 parent,handle,flows))
end

local function efqr(parent, handle, speed, flows)
   qap("%s handle %x: est 1sec 4sec sfq limit 200 quantum 3028 perturb 600 headdrop flows %d depth 24 divisor 16384 redflowlimit 40000 min 4500 max 18000 probability 0.20 ecn",parent,handle,flows)
end

function iptables4(...)
   exec(sf("iptables %s",...))
end

function iptables6(...)
   exec(sf("ip6tables %s",...))
end

function iptables(...)
   iptables4(...)
   iptables6(...)
end

function recreate_filter(t)
   assert(t.chain, "ERROR: chain parameter is missing!")
   assert(t.table, "ERROR: table parameter is missing!")
   iptables(sf("-t %s -F %s", t.table, t.chain))
   iptables(sf("-t %s -X %s", t.table,t.chain))
   iptables(sf("-t %s -N %s", t.table,t.chain))
end

-- Builds up a list of iptables commands to flush the qos_* chains,
-- remove rules referring to them, then delete them

-- Print rules in the mangle table, like iptables-save
-- Find rules for the qos_* chains
-- Exclude rules in qos_* chains (inter-qos_* refs)
      -- Replace -N with -X and hold, with -F and print
-- Replace -A with -D
-- Print held lines at the end (note leading newline)
-- Make into proper iptables calls
-- Note:  awkward in previous call due to hold space usage
-- Magic borrowed from openwrt generate.sh

function iptables_aqm_clean()
   tstr="-t mangle -S | grep '^-N qos_\|-j qos_' | grep -v '^-A qos_' | sed -e '/^-N/{s/^-N/-X/;H;s/^-X/-F/}' -e 's/^-A/-D/' -e '${p;g}' | sed -n -e 's/^./iptables -t mangle &/p'"
   iptables4(tstr)
   tstr="-t mangle -S | grep '^-N qos_\|-j qos_' | grep -v '^-A qos_' | sed -e '/^-N/{s/^-N/-X/;H;s/^-X/-F/}' -e 's/^-A/-D/' -e '${p;g}' | sed -n -e 's/^./ip6tables -t mangle &/p'"
   iptables6(tstr)
end

-- ${iptrules:+${iptrules}${N}iptables -t mangle -A qos_${cg}_ct -j CONNMARK --save-mark --mask 0xff}
-- iptables -t mangle -A qos_${cg} -j CONNMARK --restore-mark --mask 0xff
-- iptables -t mangle -A qos_${cg} -m mark --mark 0/0xff -j qos_${cg}_ct
-- $pktrules
-- $up$N${down:+${down}$N}

FW_PREREQ = { "ipt_multiport", "ipt_CONNMARK" }
DL_PREREQ = { "cls_u32", "em_u32", "act_connmark", "act_mirred", "sch_ingress" }
OWRT_PREREQ = { "cls_fw", "sch_hfsc","sch_sfq", "sch_red" }

function iptm(...)
   iptables(sf("-t mangle %s", sf(...)))
end

function aqm_init(cg)
   iptm("-N qos_%s",cg)
   iptm("-N qos_%s_ct",cg)
   iptm("-A qos_%s_ct -j CONNMARK --save-mark --mask 0xff",cg)
   iptm("-A qos_%s -j CONNMARK --restore-mark --mask 0xff",cg)
   iptm("-A qos_%s -m mark --mark 0/0xff -j qos_%s_ct",cg,cg)
-- $pktrules
-- $up$N${down:+${down}$N}
end

local function mcast_classify(chain,class)
   iptables(sf("-t mangle -A %s -m pkttype ! --pkt-type unicast -j CLASSIFY --set-class %s",chain,class))
end

local ds = { ["BE"]=0, ["AF11"]=10, ["AF12"]=12, ["AF13"]=14,
	     ["AF21"]=18, ["AF22"]=20, ["AF23"]=22, ["AF31"]=26,
	     ["AF32"]=28,["AF33"]=30, ["AF41"]=34, ["AF42"]=36,
	     ["AF43"]=38, ["EF"]=46, ["CS1"]=8, ["CS2"]=16,
	     ["CS3"]=24, ["CS4"]=32, ["CS5"]=40, ["CS6"]=48,
	     ["CS7"]=56, ["BOFH"]=4, ["ANT"]=42, ["LB"]=63, ["P2P"]=9
	     }

-- No matter what I try I get this wrong. You would think 1:1,2,3,4
-- was the right thing. Nope.
-- So 1:1 doesn't work. 1:10 doesn't work. Trying 1:101 etc because
-- that's a magic value and....
-- And IPv6 multicast is never matched.

local function mac80211e()

   local t = "-t mangle -A W80211e -m dscp --dscp %d -j CLASSIFY --set-class 0:%d -m comment --comment '%s'"
   local function f(...)
      iptables(sf(t,...))
   end

   recreate_filter({table="mangle",chain="W80211e"})

   iptables("-t mangle -A W80211e -j CLASSIFY --set-class 0:103 -m comment --comment 'Reclassify BE'")
   f(ds.EF,  106,'Voice (EF)')
   f(ds.CS6, 106,'Critical (VO)')
   f(ds.ANT, 105,'Ants(VI)')
   f(ds.BOFH,105,'Typing (VI)')
   f(ds.AF41,105,'Net Radio(VI)')
   f(ds.CS3, 105,'Video (VI)')
   f(ds.CS1, 101,'Background (BK)')
   f(ds.CS5, 101,'General Stuff (BK)')
   f(ds.P2P, 101,'P2P (BK)')
   f(ds.CS2, 101,'Background (BK)')
   f(ds.AF33,101,'Background (AF33)')
   mcast_classify("W80211e","0:103")
end

-- Iptables wrappers that we need due to lack of filters. Maybe use a
-- DEBLOAT chain. It would be good to have a universal number to
-- reduce the number of match rules iptables -t mangle -o iface -I
-- POSTROUTING -m multicast ! unicast --classify 1:1

local function iptables_probe(iface,rule)
end

local function iptables_remove(iface,rule)
end

local function iptables_insert(iface,rule)
   iptables(sf("-t mangle -o %s -A POSTROUTING -j %s",iface,rule))
end

-- Basic SFQ on wireless

-- FIXME: We must get ALL multicast out of the other queues
-- and into the VO queue. Always. Somehow.

-- It also makes sense to do EF into the VO queue and match the
-- default behavior inside of the MAC80211 code for scheduling
-- purposes.

local function wireless_filters()
-- FIXME: We need filters to use the various queues
-- The only way to get them is to use iptables presently
-- and even that's not working
end

local function wireless_setup(queuetype)
   qa("handle 1 root mq")
   qap("1:1 handle %x %s",VO, queuetype)
   qap("1:2 handle %x %s ",VI, queuetype)
   qap("1:3 handle %x %s ",BE, queuetype)
   qap("1:4 handle %x %s",BK, queuetype)
   wireless_filters()
end


local function wireless_qlen_change(base)
	for i=1, # qlens do
		q = qlens[i]
		d =  sf("%s/%s",base,q)
		qlen = slurpf(d)
		if qlen ~= nill and qlen ~= env[q] then
			spewf(d,env[q])
		end
	end
end

local function wireless_qlen()
-- Sure we could inspect things here but whatever
	wireless_qlen_change(sf("%s/%s",wireless_debug,"phy0/ath9k"))
	wireless_qlen_change(sf("%s/%s",wireless_debug,"phy1/ath9k"))
	wireless_qlen_change(sf("%s/%s",wireless_debug,"phy2/ath9k"))
end

local function wireless_setup_ll(queuetype)
   qa("handle 1 root mq")
   qap("1:1 handle %x %s limit 800 noecn target 10ms quantum 500",VO, queuetype)
   qap("1:2 handle %x %s limit 800 ecn quantum %d",VI, queuetype, env.CODEL_LL_QUANTUM)
   qap("1:3 handle %x %s limit 1000 ecn quantum %d",BE, queuetype, env.CODEL_LL_QUANTUM)
   qap("1:4 handle %x %s limit 1000 noecn ",BK, queuetype)
   wireless_filters()
end

-- ingress model
-- this is why I wanted my tc things
-- to be objects, e.g:
-- dev = tc.new()
-- dev:qa ifb:qa

local function sfqred_ingress()
      RATE=env.DOWNLINK
      if RATE == nil then return end
      kernel_prereqs({"sch_cbq","act_mirred","cls_fw"})
      IFB="ifb0"
      ALLOT=1524 -- not needed?
      ingress()
      qa("ingress")
      fap("ffff: protocol all u32 match u32 0 0 flowid 1:1 action mirred egress redirect dev %s",IFB)
    -- Lets say our NIC is 100Mbit
    tc:write(sf("qdisc add dev %s root handle 1: cbq avpkt 1000 rate 100Mbit bandwidth 100Mbit\n",IFB))
-- FIXME: allocate bandwidth from underlying interface
    tc:write(sf("class add dev %s parent 1: classid 1:1 cbq allot 1524 mpu 64 rate 100Mbit prio 1 bandwidth 100Mbit maxburst 150 avpkt 1500 bounded\n", IFB))

-- Class for traffic coming from Internet : limited to X Mbits

 tc:write(sf("class add dev %s parent 1:1 classid 1:11 cbq allot %d mpu 64 rate %dkbit bandwidth %dkbit maxburst 80 minburst 40 prio 2 avpkt 1400 bounded\n", IFB, ALLOT, RATE, RATE))

  tc:write(sf("qdisc add dev %s parent 1:11 handle 11: sfq limit 300 quantum 1500 headdrop flows 2048 divisor 16384 redflowlimit 60000 min 9000 max 27000 probability 0.20 ecn harddrop\n", IFB))

-- Traffic from machines in our LAN : no limit

--for i,privnet in pairs(LOCALNETS) do
--       tc:write(sf("filter add dev %s parent 1: protocol ip prio 2 u32 match ip src %s flowid 1:1\n", IFB, privnet))
-- end

   tc:write(sf("filter add dev %s parent 1: protocol all prio 2 u32 match ip protocol 0 0x00 flowid 1:11\n", IFB))
end

-- Various models

local function wireless_efq_codel()
   wireless_setup("efq_codel limit 1000 quantum 1000")
end

local function wireless_efq_codel_ll()
   wireless_setup_ll("efq_codel")
end

local function wireless_nfq_codel()
   wireless_setup("nfq_codel limit 1000 quantum 1000")
end

local function wireless_nfq_codel_ll()
   wireless_setup_ll("nfq_codel")
end

local function wireless_fq_codel()
   wireless_setup("fq_codel limit 1000 quantum 1000")
end

local function wireless_fq_codel_ll()
   wireless_setup_ll("fq_codel")
end

local function wireless_codel()
   wireless_setup("codel limit 1000")
end

local function wireless_ns2_codel()
   wireless_setup("ns2_codel limit 1000")
end

local function wireless_sfq()
   wireless_setup("sfq limit 40 perturb 6000")
end

-- erics sfq and erics sfqred with
-- some arbitrary speeds and bandwidths (unused)
-- TiQ would be better

local function wireless_efq()
   qa("handle 1 root mq")
   efq("1:1",VO,20,30)
   efq("1:2",VI,50,20)
   efq("1:3",BE,150,100)
   efq("1:4",BK,30,10)
   wireless_filters()
end

local function wireless_efqr()
   qa("handle 1 root mq")
   efqr("1:1",VO,20,30)
   efqr("1:2",VI,50,20)
   efqr("1:3",BE,150,2000)
   efqr("1:4",BK,30,10)
   wireless_filters()
end

-- FIXME: add HTB rate limiter support for a hm gateway
-- What we want are various models expressed object orientedly
-- so we can tie them together eventually
-- This is not that. We ARE trying to get to where the numbering
-- schemes are consistent enough to tie everything together
-- sanely...

local function model_qfq_subdisc(base)
   cb(base,MULTICAST,env.MDISC)
   cb(base,DEFAULTB,env.NORMDISC)
   fa_defb(base)
   fa_mcast(base);
   q_bins(base);
   fa_bins(base);
end

local function model_choke_subdisc(base)
   env.BIGDISC=sf("choke bandwidth %dkbit limit 24 min 4 max 12 probability .2 ecn",env.UPLINK)
   model_qfq_subdisc(base)
end

local function one_over_ip(base)
   cb(base,MULTICAST,env.MDISC)
   cb(base,DEFAULTB,env.NORMDISC)
   fa_defb(base)
   fa_mcast(base);
   q_bins(base);
   faip_bins(base);
end

-- DRR

local function drr(queues)
   kernel_prereqs({"sch_drr"})
   qa("root handle 1: drr")
   cap("1: classid 1:%x drr",env.BINS+1)
   cap("1: classid 1:%x drr",env.BINS+2)
   qap("1:%x pfifo_head_drop limit 16",env.BINS+1)
   qap("1:%x pfifo_head_drop limit 16",env.BINS+2)
   fa_defb(1)
   fa_mcast(1)
   for i=1,env.BINS do
      cap("1: classid 1:%x drr",i)
      qap("1:%x pfifo_head_drop limit 16",i)
   end
   fap("%x: handle 10 protocol all prio 10 flow hash keys proto-src,dst divisor %d perturb 10", 1, env.BINS);
end

-- Choke

local function choke(queues)
   kernel_prereqs({"sch_choke"})
   if env.UPLINK ~= nil then
      local up=env.UPLINK
      local quantum = rate_quantum(up)
      local est = sf("est %dsec %dsec", env.EST_MIN, env.EST_MAX)
      local mtu = env.MTU
--      local limit,min,max = chokelimit(up,env.DOWNLINK)
      qa("root handle 1: choke bandwidth %dkbit limit 32 min 4 max 12 probability .2 ecn",
	 up)
   end

end

-- hap

-- Using the same parameters as in Section V, we can estimate , queue
-- size oscillates the minimal N to be 8.08. When packets, constantly
-- turning CHOKe on and off, around as shown in Fig. 9 (compare with
-- Fig. 8). When is small, the equilibrium model in Section II no
-- longer holds. The same phenomenon is observed when increases (with
-- fixed ). The lower bound on dropping probability when CHOKe is
-- active, , eventually prevents TCP flows from making full use of the
-- available capacity. A positive effect is that the queue length is
-- controlled to stay around 20.  We have also simulated with more th


local function htb_choke(queues)
   kernel_prereqs({"sch_choke", "sch_htb"})
   if env.UPLINK ~= nil then
      local up=env.UPLINK
      local quantum = rate_quantum(up)
      local est = sf("est %dsec %dsec", env.EST_MIN, env.EST_MAX)
      local mtu = env.MTU
      qa("root handle 1: %s htb default 1", est)
      cap("1: classid 1:1 %s htb burst 64 rate %dkibit mtu 1500 mpu 64", est, up)
--      qap("1:1 handle 10: choke bandwidth %dkbit limit 32 min 4 max 16 probability .2 ecn",
--	 up)
--      at 4Mbit, choke will keep 2 .. 8 packets for min, max if
--      you just set the bandwidth
      -- at 40mbit choke will keep 4..12
-- from the doc, this is bytes. From the code, this turns pkts into avpkts??
      qap("1:1 handle 10: choke bandwidth %dkbit limit 24 min 2 max 12 probability .2 ecn", up)
    end
end

-- SFB

local function sfb(queues)
   kernel_prereqs({"sch_sfb"})
   qa("root handle 1: sfb")
end

local function htb_sfb(queues)
   kernel_prereqs({"sch_sfb","sch_htb"})
   if env.UPLINK ~= nil then
      local up=env.UPLINK
      local quantum = rate_quantum(up)
      local est = sf("est %dsec %dsec", env.EST_MIN, env.EST_MAX)
      local mtu = env.MTU
      qa("root handle 1: %s htb default 1", est)
      cap("1: classid 1:1 %s htb burst 64 rate %dkibit mtu 1500 mpu 64 quantum 1500", est, up)
      qap("1:1 handle 10: sfb limit 40")
   end
end

local function tbf(queues)
   kernel_prereqs({"sch_tbf"})
   if env.UPLINK ~= nil then
      local up=env.UPLINK
      local quantum = rate_quantum(up)
      local est = sf("est %dsec %dsec", env.EST_MIN, env.EST_MAX)
      local mtu = env.MTU

   qa("root handle 1: %s tbf rate %dkbit burst 5k latency 5ms minburst 1540", est, up)
   end
end

local function htb_qfq_sfqred(queues)
   kernel_prereqs({"sch_sfq","sch_qfq"})
   if env.UPLINK ~= nil then
      local up=env.UPLINK
      local quantum = rate_quantum(up)
      local est = sf("est %dsec %dsec", env.EST_MIN, env.EST_MAX)
      local mtu = env.MTU

   qa("root handle 1: est 1sec 2sec htb default 1")
   cap("1: classid 1:1 est 1sec 2sec htb burst 64 rate %dkibit mtu 1500 mpu 64 quantum 1500",up)
   qap("1:1 handle %x qfq",10)
   -- FIXME, do the calculation for the bandwidth
   env.BIGDISC="sfq limit 80 headdrop quantum 1500 flows 200 divisor 16384 redflowlimit 9000 min 1500 max 4500 depth 12 probability 0.2 ecn harddrop"
--   env.BIGDISC="sfq limit 80"

   one_over_ip(10)
   end
end

local function htb_qfq_drop_head(queues)
   if env.UPLINK ~= nil then
      local up=env.UPLINK
      local quantum = rate_quantum(up)
      local est = sf("est %dsec %dsec", env.EST_MIN, env.EST_MAX)
      local mtu = env.MTU

   qa("root handle 1: est 1sec 8sec htb default 1")
   cap("1: classid 1:1 est 1sec 8sec htb rate %dkbit mtu 1500 quantum 1500",up)
   qap("1:1 handle %x qfq",10)
   model_qfq_subdisc(10)

   end
end

local function htb_qfq_choke(queues)
   if env.UPLINK ~= nil then
      local up=env.UPLINK
      local quantum = rate_quantum(up)
      local est = sf("est %dsec %dsec", env.EST_MIN, env.EST_MAX)
      local mtu = env.MTU

   qa("root handle 1: est 1sec 8sec htb default 1")
   cap("1: classid 1:1 est 1sec 8sec htb rate %dkbit mtu 1500 quantum 1500",up)
   qap("1:1 handle %x qfq",10)
   model_choke_subdisc(10)

   end
end

-- FIXME: Finish this up

local function model_qfq_ared(base)
   cb(base,MULTICAST,env.MDISC)
   cb(base,DEFAULTB,env.NORMDISC)
   fa_defb(base)
   fa_mcast(base);
   q_bins(base);
   fa_bins(base);
end

local function model_qfq_red(base)
   cb(base,MULTICAST,env.MDISC)
   cb(base,DEFAULTB,env.NORMDISC)
   fa_defb(base)
   fa_mcast(base);
   q_bins(base);
   fa_bins(base);
end

local function model_sfq(base)
   qa("parent %x sfq",base)
end

-- Wireless devices are multi-queued - BUT the hardware
-- enforces differences in behavior vs the queues
-- (actually hostapd does that)
-- FIXME: get a grip on lua iterators

local function wireless_qfq()
   wireless_setup("qfq")
   for i,v in ipairs(WQUEUES) do
      model_qfq_subdisc(v)
   end
end

local function wireless_qfqr()
   wireless_setup("qfq")
   for i,v in ipairs(WQUEUES) do
      model_qfq_ared(v)
   end
end

-- FIXME: just stubs for now

local function wireless_ared()
   qa("handle 1 root mq")
   for i,v in ipairs(WQUEUES) do
      model_qfq_ared(v)
   end
   wireless_filters()
end

-- FIXME: just stubs for now

local function wireless_red()
   qa("handle 1 root mq")
   for i,v in ipairs(WQUEUES) do
      model_qfq_red(v)
   end
   wireless_filters()
end

-- FIXME - mqprio might not be available
-- FIXME - rethink multi-queue idea

local function ethernet_qfq(queues)
   c = queues
--   for i=0,c do
   if queues > 1 then
      qa("handle %x root qfq",10)
   else
      qa("handle %x root qfq",10)
   end
   model_qfq_subdisc(10)
end

local function ethernet_efq_codel(queues)
	 qa("handle %x root efq_codel limit 1000 ",10)
end

local function ethernet_efq_codel_ll(queues)
	 qa("handle %x root efq_codel limit 1000 quantum 1000 ",10)
end

local function ethernet_nfq_codel(queues)
	 qa("handle %x root nfq_codel limit 1000 ",10)
end

local function ethernet_nfq_codel_ll(queues)
	 qa("handle %x root nfq_codel limit 1000 quantum 1000 ",10)
end

local function ethernet_fq_codel(queues)
	 qa("handle %x root fq_codel",10)
end

local function ethernet_fq_codel_ll(queues)
	 qa("handle %x root fq_codel limit 1000 quantum 1000 ",10)
end

local function ethernet_codel(queues)
	 qa("handle %x root codel",10)
end
local function ethernet_ns2_codel(queues)
	 qa("handle %x root ns2_codel",10)
end
local function ethernet_sfq(queues)
	 qa("handle %x root sfq",10)
end

local function ethernet_efq(queues)
	 qa("root handle %x est 1sec 8sec sfq limit 2000 depth 24 headdrop flows %d divisor 16384",10, 150)
end

local function ethernet_efqr(queues)
-- FIXME, we can do sane things with speed here
	 qa("root handle %x: est 1sec 4sec sfq limit 300 depth 20 headdrop perturb 60000 flows %d divisor 16384 redflowlimit 32000 min 4500 max 18000 probability 0.20 ecn harddrop",10,2000)
end

-- FIXME: just stubs for now

local function ethernet_ared(queues)
	 qa("handle %x root red",10)
end

local function ethernet_red(queues)
	 qa("handle %x root red",10)
end

-- I don't know when a good time to have a larger quantum would be good


-- Proto all makes more sense maybe
local function fw_fap(parent, class, v, pref)
   local mask = 0xff
-- tc filter add dev ge00 parent 1: prio 4 protocol ip handle 4/0xff fw flowid 1:40

--   fap("%s protocol ip pref %d fw 0x%x/0x%x classid %s", parent,pref, v, mask, class )
--   fap("%s protocol ipv6 pref %d fw 0x%x/0x%x classid %s", parent,pref, v, mask, class
   fap("%s protocol all pref %d handle %x/0x%x fw flowid %s", parent, pref, v, mask, class )
end

-- return min, max

local function uplink_to_red(uplink)

end

local function wireless_sfqr(queues)
   --      local quantum = rate_quantum(up) -- convert to number
      local quantum = rate_quantum(4000)
      local mtu = env.MTU
--      local mtu = 1500

-- trying to find an operating point that does useful stuff on
-- wireless yet lets packet agg work better


      local function red2(parent,handle,prio,mark)
	 qap("1:%x handle %x: sfq limit 120 headdrop perturb 60000 flows %d divisor 16384 quantum 3000 depth 24 redflowlimit 60000 min 18000 max 50000 probability 0.20 ecn harddrop", parent, handle, 2000)
--	 qap("1:%x handle %x: sfq limit 120 headdrop perturb 60000 flows %d divisor 16384 quantum 4500 depth 24 redflowlimit 30000 min 6000 max 18000 probability 0.20 ecn harddrop", parent, handle, 2000)
--	 fw_fap("1:",sf("1:%x",handle),prio,mark)
      end

      qa("root handle 1: mq ")
      red(1,10,1,1)
      red(2,20,2,2)
      red(3,30,3,3)
      red(4,40,4,4)

end

local function fourtier(queues)
   kernel_prereqs({"sch_sfq",
		   "ifb",
		   "act_mirred"})
   if env.UPLINK ~= nil then
      local up=env.UPLINK
      local quantum = rate_quantum(up)
      local est = sf("est %dsec %dsec", env.EST_MIN, env.EST_MAX)
      local mtu = env.MTU

-- just straight sfq

      local function red4(parent,handle,prio,mark)
	 cap("1: classid 1:%x %s htb rate %skibit mtu %d mpu 64 quantum %d",
	     parent, est, up, mtu, quantum)
	 qap("1:%x handle %x: %s sfq limit 200",
	     parent, handle, est)
	 fw_fap("1:",sf("1:%x",handle),prio,mark)
      end

-- Hammered down on the defaults

      local function red(parent,handle,prio,mark)
	 cap("1: classid 1:%x %s htb rate %skibit mtu %d mpu 64 quantum %d",
	     parent, est, up, mtu, quantum)
	 qap("1:%x handle %x: %s sfq limit 200 headdrop quantum 1524 perturb 60000 flows %d divisor 16384 depth 24 redflowlimit 9000 min 1500 max 4500 probability 0.20 ecn harddrop",
	     parent, handle, est, 2000)
	 fw_fap("1:",sf("1:%x",handle),prio,mark)
      end

-- still trying to find a useful operating point

      local function red2(parent,handle,prio,mark)
	 cap("1: classid 1:%x %s htb rate %skibit mtu %d mpu 64 quantum %d",
	     parent, est, up, mtu, quantum)
	 qap("1:%x handle %x: %s sfq limit 200 headdrop quantum 1524 perturb 60000 flows %d divisor 16384 depth 24 redflowlimit 40000 min 4500 max 9000 probability 0.20 ecn harddrop",
	     parent, handle, est, 2000)
	 fw_fap("1:",sf("1:%x",handle),prio,mark)
      end

      qa("root handle 1: %s htb default 1", est)
      red(1,10,1,1)
      red(2,20,2,2)
      red(3,30,3,3)
      red(4,40,4,4)
      if env.DOWNLINK ~= nil and env.INGRESS ~= nil then sfqred_ingress() end
   end
end

-- Openwrt emulation
-- The current openwrt shaper uses a combination of
-- HFSC, SFQ, and RED

function tcrules(cstr,rate)
   dir="/usr/lib/aqm"
   if file(sf("%s/tcrules.awk")) then
      spewc(sf("awk -v device=\"%s\" -v linespeed=\"%s\" -f %s/tcrules.awk",env.IFACE,rate,dir), cstr)
   end
end

function oopenwrt(queues)
   if env.UPLINK == nil or env.DOWNLINK == nil then
      usage("UPLINK and DOWNLINK environment variables are required")
   end
   local ul = env.UPLINK
   qa("root handle 1: hfsc default 3")
   cap("1: classid 1:1 hfsc sc rate %dkbit ul rate %dkbit",ul,ul)
   usage("Not complete yet")
   if env.DOWNLOAD then
      qa("ingress")
      fap("ffff: protocol ip prio 1 u32 match u32 0 0 flowid 1:1 action connmark action mirred egress redirect dev ifb%d",ifbdev,n)
   end
end

-- Wondershaper emulation

local function unsupported_shaper(queues)
   usage("Shaper not supported for wireless")
end

-- The wondershaper
-- This is improved over the original wondershaper with
-- Correct ECN support
-- FIXME: IPv6 support

-- low priority source netmasks
-- NOPRIOHOSTSRC=
-- low priority destination netmasks
-- NOPRIOHOSTDST=
-- low priority source ports
-- NOPRIOPORTSRC=
-- low priority destination ports
-- NOPRIOPORTDST="21"

local function wshaper(queues)
   if env.UPLINK == nil or env.DOWNLINK == nil then
      usage("UPLINK and DOWNLINK environment variables are required")
   end

   local UPLINK = env.UPLINK
   local DOWNLINK = env.DOWNLINK
   local v6 = env.IPV6

   qa("root handle 1: htb default 20")

-- shape everything at UPLINK speed - this prevents huge queues in
-- your next hop gateway which destroy latency:

   cap("1: classid 1:1 htb rate %skbit burst 6k",UPLINK)
   cap("1:1 classid 1:10 htb rate %dkbit burst 6k prio 1",UPLINK)
   cap("1:1 classid 1:20 htb rate %dkbit burst 6k prio 2",round(9*UPLINK/10))
   cap("1:1 classid 1:30 htb rate %dkbit burst 6k prio 2",round(8*UPLINK/10))

-- all get Stochastic Fairness:
-- Note the perturb option is rather excessive now

   qap("1:10 handle 10: sfq perturb 10")
   qap("1:20 handle 20: sfq perturb 10")
   qap("1:30 handle 30: sfq perturb 10")

-- TOS Minimum Delay (ssh, NOT scp) in 1:10:

   fap("1:0 protocol ip prio 10 u32 match ip tos 0x10 0x%x flowid 1:10",env.ECNMASK)

-- ICMP (ip protocol 1) in the interactive class 1:10 so we
-- can do measurements & impress our friends:

   pingopt("1:0","1:10")

-- This is just so wrong in so many cases:

-- To speed up downloads while an upload is going on, put ACK packets
-- in the interactive class:

fap([[1: protocol ip prio 10 u32 \
               match ip protocol 6 0xff \
	       match u8 0x05 0x0f at 0 \
	       match u16 0x0000 0xffc0 at 2 \
	       match u8 0x10 0xff at 33 flowid 1:10]])

-- There is no IPv6 support in old wondershaper
-- FIXME - figure out how to find acks in ipv6

-- some traffic however suffers a worse fate

local function np(args,prio,match,h)
   for i,v in pairs(args:split(" ")) do
   fap("1: protocol ip prio %d u32 \
        match ip %s %s %s flowid 1:30",prio,match,v, h)
   if v6 then
--   fap("1: protocol ipv6 prio %d u32 \
--        match ip %s %s %s flowid 1:30",prio,match,v, h)
   end
   end
end

if env.NOPRIOPORTDST ~= nil then
   np(env.NOPRIOPORTDST,14,"dport","0xffff")
end

if env.NOPRIOPORTSRC ~= nil  then
   np(env.NOPRIOPORTSRC,15,"sport", "0xffff")
end

if env.NOPRIOHOSTSRC ~= nil then
   np(env.NOPRIOHOSTSRC,16,"src"," ")
end

if env.NOPRIOHOSTDST ~= nil then
   np(env.NOPRIOHOSTDST,17,"dst"," ")
end

-- rest is 'non-interactive' ie 'bulk' and ends up in 1:20

fap("1: protocol ip prio 18 u32 match ip dst 0.0.0.0/0 flowid 1:20")

-------------------- downlink --------------------------

-- slow downloads down to somewhat less than the real speed to prevent
-- queuing at our ISP. Tune to see how high you can set it.  ISPs tend
-- to have *huge* queues to make sure big downloads are fast
--
-- attach ingress policer:

   qa("handle ffff: ingress")

-- filter *everything* to it (0.0.0.0/0), drop everything that's
-- coming in too fast:

   fap("ffff: protocol ip prio 50 u32 match ip src 0.0.0.0/0 police rate %dkbit burst 10k drop flowid :1",DOWNLINK)

end

-- For reference, this is a slavish re-implementation of the original
-- wondershaper, bugs with ecn, and ipv6 included

-- The new SFQ should also improve it.

-- That said, it is seriously flawed and I'd
-- like to be able to fully model it's behavior,
-- hence this implementation.

local function owshaper(queues)
   env.ECNMASK = 0xff -- original wshaper screws up on ecn
   env.IPV6 = false
   return wshaper(queues)
end

-- I have to think about the calculations for 100Mbit and below...

-- FIXME: Think on the architecture and models harder
-- first. Need to also be able to stick HSFC, netem, or HTB
-- on top of this

WCALLBACKS = { ["qfq"] = wireless_qfq,
	       ["qfqred"] = wireless_qfqr,
	       ["red"] = wireless_red,
	       ["ared"] = wireless_ared,
	       ["sfq"] = wireless_sfq,
	       ["efq"] = wireless_efq,
	       ["sfqred"] = wireless_efqr,
	       ["sfqr"] = wireless_sfqr,
	       ["codel"] = wireless_codel,
	       ["fq_codel"] = wireless_fq_codel,
	       ["fq_codel_ll"] = wireless_fq_codel_ll,
	       ["nfq_codel"] = wireless_nfq_codel,
	       ["nfq_codel_ll"] = wireless_nfq_codel_ll,
	       ["efq_codel"] = wireless_efq_codel,
	       ["efq_codel_ll"] = wireless_efq_codel_ll,
	       ["ns2_codel"] = wireless_ns2_codel,
	       ["ns2_codel_ll"] = wireless_ns2_codel_ll,
	       ["htb_sfq_red"] = unsupported_shaper,
	       ["oopenwrt"] = unsupported_shaper,
	       ["owshaper"] = unsupported_shaper,
	       ["wshaper"] = wireless_wshaper,
	       ["twotier"] = unsupported_shaper,
	       ["fourtier"] = unsupported_shaper
}

ECALLBACKS = { ["qfq"] = ethernet_qfq,
	       ["qfqred"] = ethernet_qfqr,
	       ["red"] = ethernet_red,
	       ["ared"] = ethernet_ared,
	       ["sfq"] = ethernet_sfq,
	       ["codel"] = ethernet_codel,
	       ["ns2_codel"] = ethernet_ns2_codel,
	       ["fq_codel"] = ethernet_fq_codel,
	       ["fq_codel_ll"] = ethernet_fq_codel_ll,
	       ["nfq_codel"] = ethernet_nfq_codel,
	       ["nfq_codel_ll"] = ethernet_nfq_codel_ll,
	       ["efq_codel"] = ethernet_efq_codel,
	       ["efq_codel_ll"] = ethernet_efq_codel_ll,
	       ["efq"] = ethernet_efq,
	       ["sfqred"] = ethernet_efqr,
	       ["htb_qfq_sfqred"] = htb_qfq_sfqred,
	       ["htb_qfq_drop_head"] = htb_qfq_drop_head,
	       ["htb_sfq_red"] = htb_sfq_red,
	       ["htb_sfq_red2"] = htb_sfq_red2,
	       ["htb_sfq_red_cero"] = htb_sfq_red_cero,
	       ["tbf"] = tbf,
	       ["htb_sfb"] = htb_sfb,
	       ["choke"] = choke,
	       ["htb_choke"] = htb_choke,
	       ["htb_qfq_choke"] = htb_qfq_choke,
	       ["sfb"] = sfb,
	       ["drr"] = drr,
	       ["oopenwrt"] = oopenwrt,
	       ["wshaper"] = wshaper,
	       ["owshaper"] = owshaper,
	       ["owshaper"] = owshaper,
	       ["twotier"] = twotier,
	       ["fourtier"] = fourtier,
}

-- couple other models - dsl, wshaper, etc, needed
-- pingopt and argv processing too

local function wireless(model)
   print(model)
   if WCALLBACKS[model] ~= nil then
      wireless_qlen()
      return WCALLBACKS[model]()
   else
      usage("AQM model not found")
   end
   return nil
end

local function ethernet(model)
   if ECALLBACKS[model] ~= nil then
      return ECALLBACKS[model](ethernet_setup(IFACE))
   else
      usage("AQM model not found")
   end
   return nil
end

-- It's annoying to get deletion as an error
-- And confusing to the user

if env.PINGOPT then
   pingopt = function(parent,flow)
		fap("%s protocol ip prio 10 u32 match ip protocol 1 0xff flowid %s",parent,flow)
		if(env.IPV6) then
		   -- arguably we should only match echo and echo reply but...
		fap("%s protocol ipv6 prio 10 u32 match ip protocol 1 0xff flowid %s",parent,flow)
		end
	     end
end

if env.QDEBUG then
   env.TC="/bin/cat"
   env.TCARG=" "
   env.DEBLOATLOG="/tmp/debloat.log"
end

-- FIXME - do something intelligent when faced with a bridge or vlan

itype=interface_type(IFACE)

if itype == 'wireless' or itype == 'ethernet' then
   kernel_prereqs(PREREQS)
   tc = resettc()

   if itype == 'wireless' then
      wireless(env.QMODEL)
--     FIXME: you watch this code set the class, then not show up in tc
--     mac80211e()
--     iptables_insert(IFACE,"W80211e")
   end
   if itype == 'ethernet' then ethernet(env.QMODEL) end
end