development environment scripts and helper programs using network nam…

…espaces (WIP: l2tp.lua doesn't work anymore with namespaces, it was working with containers)

src/program/lisper/README.inc

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+README

src/program/lisper/dev-env/l2tp.app1

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+ip netns exec app1 ./l2tp.lua t0 e0 \
+    aa:aa:aa:aa:aa:01 \
+    aa:aa:aa:aa:aa:02 \
+    fd80:0001:0000:0000:0000:0000:0000:0002 \
+    fd80:0002:0000:0000:0000:0000:0000:0002 \
+    00001234 00004321

src/program/lisper/dev-env/l2tp.app2

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+ip netns exec app2 ./l2tp.lua t0 e0 \
+    aa:aa:aa:aa:aa:02 \
+    aa:aa:aa:aa:aa:01 \
+    fd80:0002:0000:0000:0000:0000:0000:0002 \
+    fd80:0001:0000:0000:0000:0000:0000:0002 \
+    00004321 00001234

src/program/lisper/dev-env/l2tp.lua

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+#!/usr/bin/env luajit
+
+--L2TP IP-over-IPv6 tunnelling program for testing.
+
+local ffi    = require'ffi'
+local S      = require'syscall'
+local C      = ffi.C
+local htons  = require'syscall.helpers'.htons
+
+local DEBUG  = true
+
+local function assert(v, ...)
+	if v then return v, ... end
+	error(tostring((...)), 2)
+end
+
+local function hex(s)
+	return (s:gsub('(.)(.?)', function(c1, c2)
+		return c2 and
+			string.format('%02x%02x ', c1:byte(), c2:byte()) or
+			string.format('%02x ', c1:byte())
+	end))
+end
+
+local digits = {}
+for i=0,9 do digits[string.char(('0'):byte()+i)] = i end
+for i=0,5 do digits[string.char(('a'):byte()+i)] = 10+i end
+for i=0,5 do digits[string.char(('A'):byte()+i)] = 10+i end
+local function parsehex(s)
+	return (s:gsub('[%s%:%.]*(%x)(%x)[%s%:%.]*', function(hi, lo)
+		local hi = digits[hi]
+		local lo = digits[lo]
+		return string.char(lo + hi * 16)
+	end))
+end
+
+local function open_tap(name)
+	local fd = assert(S.open('/dev/net/tun', 'rdwr, nonblock'))
+	local ifr = S.t.ifreq{flags = 'tap, no_pi', name = name}
+	assert(fd:ioctl('tunsetiff', ifr))
+	return fd
+end
+
+local function open_raw(name)
+	local fd = assert(S.socket('packet', 'raw, nonblock', htons(S.c.ETH_P.all)))
+	local ifr = S.t.ifreq{name = name}
+	assert(S.ioctl(fd, 'siocgifindex', ifr))
+	assert(S.bind(fd, S.t.sockaddr_ll{
+		ifindex = ifr.ivalue,
+		protocol = 'all'}))
+	return fd
+end
+
+local function can_read(...)
+	return assert(S.select({readfds = {...}}, 0)).count == 1
+end
+
+local function can_write(...)
+	return assert(S.select({writefds = {...}}, 0)).count == 1
+end
+
+local mtu = 1500
+local buf = ffi.new('uint8_t[?]', mtu)
+local function read(fd)
+	local len = assert(S.read(fd, buf, mtu))
+	return ffi.string(buf, len)
+end
+
+local function write(fd, s, len)
+	assert(S.write(fd, s, len or #s))
+end
+
+local function close(fd)
+	S.close(fd)
+end
+
+local tapname, ethname, smac, dmac, sip, dip, sid, did = ...
+if not (tapname and ethname and smac and dmac and sip and dip and sid and did) then
+	print('Usage: '..arg[0]..' TAP ETH SMAC DMAC SIP DIP SID DID')
+	os.exit(1)
+end
+smac = parsehex(smac)
+dmac = parsehex(dmac)
+sip  = parsehex(sip)
+dip  = parsehex(dip)
+sid  = parsehex(sid)
+did  = parsehex(did)
+
+local tap = open_tap(tapname)
+local raw = open_raw(ethname)
+
+print('tap  ', tapname)
+print('raw  ', ethname)
+print('smac ', hex(smac))
+print('dmac ', hex(dmac))
+print('sip  ', hex(sip))
+print('dip  ', hex(dip))
+print('sid  ', hex(sid))
+print('did  ', hex(did))
+
+local function decap_l2tp(s)
+	local dmac = s:sub(1, 6)
+	local smac = s:sub(1+6, 1+6+6-1)
+	local sip = s:sub(23, 23+16-1)
+	local dip = s:sub(23+16, 23+16+16-1)
+	local sid = s:sub(55, 55+4-1)
+	local payload = s:sub(63)
+	return smac, dmac, sip, dip, sid, payload
+end
+
+local function encap_l2tp(smac, dmac, sip, dip, did, payload)
+	local l2tp = did..'\0\0\0\0'
+	local len = #payload + #l2tp
+	local len = string.char(bit.rshift(len, 8)) .. string.char(bit.band(len, 0xff))
+	local ipv6_proto = '\115' --l2tp
+	local maxhops = '\64'
+	local ipv6 = '\x60\0\0\0'..len..ipv6_proto..maxhops..sip..dip
+	local eth_proto = '\x86\xdd' --ipv6
+	local eth = dmac..smac..eth_proto
+	return eth..ipv6..l2tp..payload
+end
+
+while true do
+	if can_read(tap, raw) then
+		if can_read(raw) then
+			local s = read(raw)
+			local smac1, dmac1, sip1, dip1, did1, payload = decap_l2tp(s)
+			local accept =
+				smac1 == dmac
+				and dmac1 == smac
+				and dip1 == sip
+				and sip1 == dip
+				and did1 == sid
+			if DEBUG then
+				print('read   ', accept and 'accepted' or 'rejected')
+				print('  smac ', hex(smac1))
+				print('  dmac ', hex(dmac1))
+				print('  sip  ', hex(sip1))
+				print('  dip  ', hex(dip1))
+				print('  did  ', hex(did1))
+				print('  #    ', #payload)
+			end
+			if accept then
+				write(tap, payload)
+			end
+		end
+		if can_read(tap) then
+			local payload = read(tap)
+			local s = encap_l2tp(smac, dmac, sip, dip, did, payload)
+			if DEBUG then
+				print('write')
+				print('  smac ', hex(smac))
+				print('  dmac ', hex(dmac))
+				print('  sip  ', hex(sip))
+				print('  dip  ', hex(dip))
+				print('  did  ', hex(did))
+				print('  #    ', #payload)
+				print(hex(s))
+			end
+			write(raw, s)
+		end
+	end
+end
+
+tap:close()
+raw:close()

src/program/lisper/dev-env/lisp.lua

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+#!/usr/bin/env luajit
+
+--LISP controller mock-up program for testing.
+
+local ffi = require("ffi")
+local S   = require("syscall")
+
+CONTROL_SOCK = "/var/tmp/ctrl.socket"
+CONTROL_DATA = [[
+[5]  08:00:27:7f:05:37 fd80:1::1,fd80:1::2
+[7]  4a:86:5c:50:33:5a fd80:2::1
+[2]  00:16:3e:01:01:02 fd80:3::1
+]]
+
+local sock = assert(S.socket("unix", "stream, nonblock"))
+local sa = S.t.sockaddr_un(CONTROL_SOCK)
+
+::retry::
+local ok, err = sock:connect(sa)
+if not ok then
+	if err.CONNREFUSED or err.AGAIN then
+		S.sleep(1)
+		print'retrying...'
+		goto retry
+	end
+	assert(nil, err)
+end
+print'connected'
+
+while assert(S.select({writefds = {sock}}, 0)).count == 1 do
+	print'sending...'
+	assert(S.write(sock, CONTROL_DATA, #CONTROL_DATA))
+	S.sleep(1)
+end
+

src/program/lisper/dev-env/net-bringup

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+#!/bin/bash
+
+# This creates a virtual network of 3 machines in 3 different subnets
+# connected to a router. Besides that, app1 and app2 machines create
+# two static l2tp tunnels which connect _to the same endpoint_ in the
+# lisp machine where lisper responds back.
+
+bringup() {
+ip netns add r2
+ip netns add app1
+ip netns add app2
+ip netns add lisp
+
+ip link add netns app1 e0 address aa:aa:aa:aa:aa:01 type veth peer name e1 netns r2
+ip link add netns app2 e0 address aa:aa:aa:aa:aa:02 type veth peer name e2 netns r2
+ip link add netns lisp e0 address aa:aa:aa:aa:aa:04 type veth peer name e4 netns r2
+
+ip netns exec r2 ip addr add fd80:1::1/56 dev e1
+ip netns exec r2 ip addr add fd80:2::1/56 dev e2
+ip netns exec r2 ip addr add fd80:4::1/56 dev e4
+
+ip netns exec app1 ip addr add fd80:1::2/56 dev e0
+ip netns exec app2 ip addr add fd80:2::2/56 dev e0
+ip netns exec lisp ip addr add fd80:4::2/56 dev e0
+
+ip netns exec app1 ip -6 route add default via fd80:1::1
+ip netns exec app2 ip -6 route add default via fd80:2::1
+ip netns exec lisp ip -6 route add default via fd80:4::1
+
+ip netns exec app1 ip link set e0 up
+ip netns exec app2 ip link set e0 up
+ip netns exec lisp ip link set e0 up
+
+ip netns exec r2 sysctl -wq net.ipv6.conf.all.forwarding=1
+
+ip netns exec r2 ip link set e1 up
+ip netns exec r2 ip link set e2 up
+ip netns exec r2 ip link set e4 up
+
+if false; then
+# NOTE: l2tp ip-over-ipv6 encapsulation doesn't work with namespaces.
+# Hence we're using our own little Lua script which does the same thing in userspace.
+modprobe l2tp_ip6
+modprobe l2tp_eth
+modprobe l2tp_core
+modprobe l2tp_netlink
+ip netns exec app1 ip l2tp add tunnel tunnel_id 1 peer_tunnel_id 1 encap ip local fd80:1::2 remote fd80:4::2
+ip netns exec app2 ip l2tp add tunnel tunnel_id 1 peer_tunnel_id 1 encap ip local fd80:2::2 remote fd80:4::2
+ip netns exec app1 ip l2tp add session name t0 tunnel_id 1 session_id 4660 peer_session_id 17185
+ip netns exec app2 ip l2tp add session name t0 tunnel_id 1 session_id 4660 peer_session_id 17185
+ip netns exec app1 ip link set t0 up
+ip netns exec app2 ip link set t0 up
+ip netns exec lisp ip l2tp add tunnel tunnel_id 1 peer_tunnel_id 1 encap ip local fd80:4::2 remote fd80:1::2
+ip netns exec lisp ip l2tp add session name t0 tunnel_id 1 session_id 17185 peer_session_id 4660
+ip netns exec lisp ip link set t0 up
+else
+./l2tp.app1 &
+echo $! > l2tp.app1.pid
+./l2tp.app2 &
+echo $! > l2tp.app2.pid
+sleep 0.2
+ip netns exec app1 ifconfig t0 10.0.0.1/24 up
+ip netns exec app2 ifconfig t0 10.0.0.2/24 up
+fi
+}
+
+
+teardown() {
+kill -9 `cat l2tp.app1.pid`; rm l2tp.app1.pid
+kill -9 `cat l2tp.app2.pid`; rm l2tp.app2.pid
+ip netns del r2
+ip netns del app1
+ip netns del app2
+ip netns del lisp
+}
+
+
+action=$1; [ "$action" ] || action=bringup
+$action

src/program/lisper/dev-env/net-teardown

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+./net-bringup teardown

src/program/lisper/dev-env/syscall

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+../../../syscall

src/program/lisper/dev-env/syscall.lua

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+../../../syscall.lua