From 1e39d7da21ed904f0344a166c4597708df9463ef Mon Sep 17 00:00:00 2001
From: Javier Guerra <javier@guerrag.com>
Date: Tue, 15 Apr 2014 03:11:26 -0500
Subject: [PATCH 1/4] test framework

---
 src/Makefile                  |   2 +-
 src/apps/basic/basic_apps.lua |  50 +++++++++
 src/apps/intel/intel10g_t.lua | 199 ++++++++++++++++++++++++++++++++++
 src/apps/intel/intel_app.lua  |   1 +
 src/apps/intel/intel_t.lua    |  24 ++++
 src/core/config.lua           |   2 +-
 src/core/lib.lua              |  22 ----
 src/core/packet_t.lua         | 143 ++++++++++++++++++++++++
 src/lib/index_set_t.lua       |  18 +++
 src/lib/macaddress_t.lua      |  16 +++
 src/test.lua                  |  66 +++++++++++
 11 files changed, 519 insertions(+), 24 deletions(-)
 create mode 100644 src/apps/intel/intel10g_t.lua
 create mode 100644 src/apps/intel/intel_t.lua
 create mode 100644 src/core/packet_t.lua
 create mode 100644 src/lib/index_set_t.lua
 create mode 100644 src/lib/macaddress_t.lua
 create mode 100644 src/test.lua

diff --git a/src/Makefile b/src/Makefile
index c8d9c93288..716e347b22 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -7,7 +7,7 @@ E= @echo
 SRCDIR = $(shell find . -type d -not -regex './obj.*' -printf '%P ')
 OBJDIR = $(patsubst %,obj/%,$(SRCDIR))
 
-LUASRC = $(shell find . -regex '[^\#]*\.lua' -printf '%P ')
+LUASRC = $(shell find . -regex '[^\#]*\.lua' ! -name '*_t.lua' -printf '%P ')
 CSRC   = $(shell find . -regex '[^\#]*\.c'   -printf '%P ')
 CHDR   = $(shell find . -regex '[^\#]*\.h'   -printf '%P ')
 ASM    = $(shell find . -regex '[^\#]*\.dasc' -printf '%P ')
diff --git a/src/apps/basic/basic_apps.lua b/src/apps/basic/basic_apps.lua
index 961334ccfc..a5bae08ff9 100644
--- a/src/apps/basic/basic_apps.lua
+++ b/src/apps/basic/basic_apps.lua
@@ -1,5 +1,6 @@
 module(...,package.seeall)
 
+local lib = require("core.lib")
 local app = require("core.app")
 local buffer = require("core.buffer")
 local packet = require("core.packet")
@@ -221,3 +222,52 @@ function Buzz:pull () print "bzzz pull" end
 function Buzz:push () print "bzzz push" end
 
 
+--- ### Classifier app:
+--- records history of packets
+Classifier = setmetatable({}, {__index = Basic})
+function Classifier:new()
+   return setmetatable(
+      {_patterns={}, _rev={}, _counters={}, _seq={}}, 
+      {__index=Classifier})
+end
+
+function Classifier:setPatterns(pats)
+   self._patterns = pats
+   self._seq = {}
+   self._rev = {}
+   self._counters = {}
+   for k,v in pairs(pats) do
+      self._rev[v] = k
+      self._counters[k] = 0
+   end
+end
+
+function Classifier:count(ln, d)
+   local packet_name = self._rev[d]
+   if packet_name == nil then
+     packet_name = #self._patterns+1
+     self._patterns[packet_name] = d
+     self._rev[d] = packet_name
+   end
+   self._seq[#self._seq+1] = ln..':'..packet_name
+   self._counters[packet_name] = (self._counters[packet_name] or 0) + 1
+end
+
+function Classifier:repConters()
+   return table.concat(self._counters, ',')
+end
+
+function Classifier:repSequence()
+   return table.concat(self._seq, ',')
+end
+
+function Classifier:push ()
+   for ln, l in pairs(self.input) do
+      for _ = 1, link.nreadable(l) do
+        local p = link.receive(l)
+        self:count(ln, packet.tostring(p))
+        packet.deref(p)
+      end
+   end
+end
+
diff --git a/src/apps/intel/intel10g_t.lua b/src/apps/intel/intel10g_t.lua
new file mode 100644
index 0000000000..df3e3d102f
--- /dev/null
+++ b/src/apps/intel/intel10g_t.lua
@@ -0,0 +1,199 @@
+local lib      = require("core.lib")
+local packet = require "core.packet"
+local link     = require("core.link")
+local config = require("core.config")
+local app      = require("core.app")
+local basic_apps = require("apps.basic.basic_apps")
+local Intel82599 = require "apps.intel.intel_app".Intel82599
+
+
+local PCIdevA, PCIdevB = '0000:05:00.0', '0000:8a:00.0'
+
+
+local function _unhex(s)
+   local d = {}
+   for b in s:gmatch('[0-9a-fA-F][0-9a-fA-F]') do
+      d[#d+1] = tonumber(b, 16)
+   end
+   return string.char(unpack(d))
+end
+
+local function pad(s, n)
+   if not n then return s end
+   return (s..('\0'):rep(n)):sub(1, n)
+end
+
+local function make_packet(s, padlen)
+   return packet.from_data(
+      _unhex('FF:FF:FF:FF:FF:FF')..
+      _unhex('52:54:00:01:01:01')..
+      _unhex('08:00')..
+      pad(s, padlen)..
+      _unhex('00 00 00 00')
+   )
+end
+
+local function make_split_packet(s, padlen)
+   return packet.from_data(
+      _unhex('FF:FF:FF:FF:FF:FF')..
+      _unhex('52:54:00:01:01:01')..
+      _unhex('08:00'),
+      pad(s, padlen)..
+      _unhex('00 00 00 00')
+   )
+end
+
+local function _set_dst(p, dst)
+   if #dst ~= 6 then dst = _unhex(dst) end
+   assert(#dst==6, "wrong address length")
+   packet.fill_data(p, dst, 0)
+   return p
+end
+
+local function _set_src(p, src)
+   if #src ~= 6 then src = _unhex(src) end
+   assert(#src==6, "wrong address length")
+   packet.fill_data(p, src, 6)
+   return p
+end
+
+
+return {   
+   sf_to_sf = {
+      __setup = function ()
+         local c = config.new()
+         config.app(c, 'source1', basic_apps.Join)
+--         config.app(c, 'source2', basic_apps.Source)
+         config.app(c, 'nicA', Intel82599, ([[{pciaddr='%s'}]]):format(PCIdevA))
+         config.app(c, 'nicB', Intel82599, ([[{pciaddr='%s'}]]):format(PCIdevB))
+         config.app(c, 'sink', basic_apps.Classifier)
+         config.link(c, 'source1.out -> nicA.rx')
+--         config.link(c, 'source2.out -> nicB.rx')
+         config.link(c, 'nicA.tx -> sink.in1')
+         config.link(c, 'nicB.tx -> sink.in2')
+         app.configure(c)
+      end,
+      
+      t = {
+         single_iovec = {
+            broadcast = function ()
+               local p = make_packet('some payload', 42)
+               _set_dst(p, 'FF:FF:FF:FF:FF:FF')
+               app.app_table.sink:setPatterns({same=packet.tostring(p)})
+               link.transmit(app.app_table.source1.output.out, p)
+               app.main({duration = 1, report={showlinks=false}})
+               assert(app.app_table.sink:repSequence() == 'in2:same')
+            end,
+            unicast = function ()
+               local p = make_packet('some payload', 42)
+               _set_dst(p, '52:54:00:01:01:01')
+               app.app_table.sink:setPatterns({same=packet.tostring(p)})
+               link.transmit(app.app_table.source1.output.out, p)
+               app.main({duration = 1, report={showlinks=false}})
+               assert(app.app_table.sink:repSequence() == 'in2:same')
+            end,
+         },
+         
+         split_header = {
+            broadcast = function ()
+               local p = make_split_packet('some payload', 42)
+               _set_dst(p, 'FF:FF:FF:FF:FF:FF')
+               app.app_table.sink:setPatterns({same=packet.tostring(p)})
+               link.transmit(app.app_table.source1.output.out, p)
+               app.main({duration = 1, report={showlinks=false}})
+               assert(app.app_table.sink:repSequence() == 'in2:same')
+            end,
+            unicast = function ()
+               local p = make_split_packet('some payload', 42)
+               _set_dst(p, '52:54:00:01:01:01')
+               app.app_table.sink:setPatterns({same=packet.tostring(p)})
+               link.transmit(app.app_table.source1.output.out, p)
+               app.main({duration = 1, report={showlinks=false}})
+               assert(app.app_table.sink:repSequence() == 'in2:same')
+            end,
+         },
+      },
+   },
+   
+   sf_to_vf = {
+      __setup = function ()
+         local c = config.new()
+         config.app(c, 'source1', basic_apps.Join)
+         config.app(c, 'nicAs', Intel82599, ([[{
+         -- Single App on NIC A
+            pciaddr = '%s',
+            macaddr = '52:54:00:01:01:01',
+         }]]):format(PCIdevA))
+         config.app(c, 'nicBm0', Intel82599, ([[{
+         -- first VF on NIC B
+            pciaddr = '%s',
+            vmdq = true,
+            macaddr = '52:54:00:02:02:02',
+         }]]):format(PCIdevB))
+         config.app(c, 'nicBm1', Intel82599, ([[{
+         -- second VF on NIC B
+            pciaddr = '%s',
+            vmdq = true,
+            macaddr = '52:54:00:03:03:03',
+         }]]):format(PCIdevB))
+         config.app(c, 'sink', basic_apps.Classifier)
+         config.link(c, 'source1.out -> nicAs.rx')
+         config.link(c, 'nicAs.tx -> sink.in1')
+         config.link(c, 'nicBm0.tx -> sink.in2')
+         config.link(c, 'nicBm1.tx -> sink.in3')
+         app.configure(c)
+      end,
+      t = {
+         single_iovec = {
+            broadcast = function ()
+               local p = make_packet('broadcast content', 42)
+               _set_dst(p, 'FF:FF:FF:FF:FF:FF')
+               app.app_table.sink:setPatterns({same=packet.tostring(p)})
+               link.transmit(app.app_table.source1.output.out, p)
+               app.main({duration = 1, report={showlinks=false}})
+               assert(app.app_table.sink:repSequence() == 'in2:same,in3:same')
+            end,
+            unicast = function ()
+               local p = make_packet('some payload', 42)
+               _set_dst(p, '52:54:00:02:02:02')
+               app.app_table.sink:setPatterns({same=packet.tostring(p)})
+               link.transmit(app.app_table.source1.output.out, p)
+               app.main({duration = 1, report={showlinks=false}})
+               assert(app.app_table.sink:repSequence() == 'in2:same')
+            end,
+         },
+         split_header = {
+            broadcast = function ()
+               local p = make_split_packet('broadcast content', 42)
+               _set_dst(p, 'FF:FF:FF:FF:FF:FF')
+               app.app_table.sink:setPatterns({same=packet.tostring(p)})
+               link.transmit(app.app_table.source1.output.out, p)
+               app.main({duration = 1, report={showlinks=false}})
+               assert(app.app_table.sink:repSequence() == 'in2:same,in3:same')
+            end,
+            unicast = function ()
+               local p = make_split_packet('some payload', 42)
+               _set_dst(p, '52:54:00:02:02:02')
+               app.app_table.sink:setPatterns({same=packet.tostring(p)})
+               link.transmit(app.app_table.source1.output.out, p)
+               app.main({duration = 1, report={showlinks=false}})
+               assert(app.app_table.sink:repSequence() == 'in2:same')
+            end,
+         },
+         
+         
+      },
+   },
+   
+   local_A_dev = {
+      Broadcast = function ()
+         local p = packet.from_data(
+            _unhex('FF:FF:FF:FF:FF:FF')..
+            _unhex('52:54:00:01:01:01')..
+            _unhex('08:00')..
+            'this is the payload'..
+            _unhex('00:00:00:00')
+         )
+      end,
+   },
+}
\ No newline at end of file
diff --git a/src/apps/intel/intel_app.lua b/src/apps/intel/intel_app.lua
index 329c34f3a6..9c427004dd 100644
--- a/src/apps/intel/intel_app.lua
+++ b/src/apps/intel/intel_app.lua
@@ -115,6 +115,7 @@ function selftest ()
 
    mq_sq('0000:05:00.0', '0000:8a:00.0')
    app.main({duration = 1, report={showlinks=true, showapps=false}})
+   require ("test")('src/apps/intel/intel10g_t')
 end
 
 -- open two singlequeue drivers on both ends of the wire
diff --git a/src/apps/intel/intel_t.lua b/src/apps/intel/intel_t.lua
new file mode 100644
index 0000000000..74becbfd98
--- /dev/null
+++ b/src/apps/intel/intel_t.lua
@@ -0,0 +1,24 @@
+return {
+   sum = function()
+      assert(2+2 == 4, "if this fails, there's no hope")
+   end,
+   
+   mult = function()
+      assert(2*2 == 4.1, "missed it by that much")
+   end,
+   
+   strs = {
+      
+      concat = function()
+         assert('a'..'b' == 'ab', "the obvious thing")
+      end,
+      
+      repeated = function()
+         assert(3*'a' == 'aaa', "would this work?")
+      end,
+      
+      good_repeat = function()
+         assert(string.rep('a',3)=='aaa', "this should work")
+      end,
+   },
+}
\ No newline at end of file
diff --git a/src/core/config.lua b/src/core/config.lua
index e7ed6751a9..05dd77e155 100644
--- a/src/core/config.lua
+++ b/src/core/config.lua
@@ -60,7 +60,7 @@ end
 -- Example:
 --   parse_app_arg("{ timeout = 5 * 10 }") => { timeout = 50 }
 function parse_app_arg (s)
-   print("s", type(s), s)
+--   print("s", type(s), s)
    assert(type(s) == 'string')
    return loadstring("return " .. s)()
 end
diff --git a/src/core/lib.lua b/src/core/lib.lua
index 6c417e97ec..92baf3ef1e 100644
--- a/src/core/lib.lua
+++ b/src/core/lib.lua
@@ -277,27 +277,5 @@ function selftest ()
          :match('^45.00.B6.7D.00.FA.40.00.40.11$'), "wrong hex dump")
    assert(hexundump('4500 B67D 00FA400040 11', 10)
          =='\x45\x00\xb6\x7d\x00\xFA\x40\x00\x40\x11', "wrong hex undump")
-
-   local macA = new_mac('00-01-02-0a-0b-0c')
-   local macB = new_mac('0001020A0B0C')
-   local macC = new_mac('0A:0B:0C:00:01:02')
-   print ('macA', macA)
-   assert (tostring(macA) == '00:01:02:0A:0B:0C', "bad canonical MAC")
-   assert (macA == macB, "macA and macB should be equal")
-   assert (macA ~= macC, "macA and macC should be different")
-   assert (macA:subbits(0,31)==0x0a020100, "low A")
-   assert (macA:subbits(32,48)==0x0c0b, ("hi A (%X)"):format(macA:subbits(32,48)))
-   assert (macC:subbits(0,31)==0x000c0b0a, "low C")
-   assert (macC:subbits(32,48)==0x0201," hi C")
-
-   local ndx_set = new_index_set(4, 'test ndx')
-   assert (string.format('%d/%s', ndx_set:add('a'))=='0/true', "indexes start with 0, and is new")
-   assert (string.format('%d/%s', ndx_set:add('b'))=='1/true', "second new index")
-   assert (string.format('%d/%s', ndx_set:add('c'))=='2/true', "third new")
-   assert (string.format('%d/%s', ndx_set:add('b'))=='1/false', "that's an old one")
-   assert (string.format('%d/%s', ndx_set:add('a'))=='0/false', "the very first one")
-   assert (string.format('%d/%s', ndx_set:add('A'))=='3/true', "almost, but new")
-   assert (string.format('%s/%s', pcall(ndx_set.add, ndx_set,'B'))
-         :match('^false/core/lib.lua:%d+: test ndx overflow'), 'should overflow')
 end
 
diff --git a/src/core/packet_t.lua b/src/core/packet_t.lua
new file mode 100644
index 0000000000..beceecbc3d
--- /dev/null
+++ b/src/core/packet_t.lua
@@ -0,0 +1,143 @@
+local ffi = require("ffi")
+local C = ffi.C
+local memory = require "core.memory"
+memory.allocate_RAM = C.malloc
+memory.ram_to_io_addr = memory.virtual_to_physical
+local buffer = require "core.buffer"
+local packet = require "core.packet"
+
+
+return {
+   from_data = function ()
+      local p = packet.from_data('abcdefghijklmnopqrstuvwxyz')
+      assert (packet.tostring(p) == 'abcdefghijklmnopqrstuvwxyz')
+   end,
+   
+   add_iovec = {
+      
+      to_empty_packet = function ()
+         local p = packet.allocate()
+         local b = buffer.from_data('abcdefghijklmnopqrstuvwxyz')
+         packet.add_iovec(p, b, 26, 0)
+         assert (p.niovecs == 1)
+         assert (p.length == 26)
+         assert (buffer.tostring(p.iovecs[0].buffer, 26) == 'abcdefghijklmnopqrstuvwxyz')
+         assert (packet.tostring(p) == 'abcdefghijklmnopqrstuvwxyz')
+      end,
+      
+      to_single_iovec_packet = function ()
+         local p = packet.from_data('abcdefghijklm')
+         local b = buffer.from_data('nopqrstuvwxyz')
+         packet.add_iovec(p, b, 13, 0)
+         assert (p.niovecs == 2)
+         assert (p.length == 26)
+         assert (buffer.tostring(p.iovecs[0].buffer, 13) == 'abcdefghijklm')
+         assert (buffer.tostring(p.iovecs[1].buffer, 13) == 'nopqrstuvwxyz')
+         assert (packet.tostring(p) == 'abcdefghijklmnopqrstuvwxyz')
+      end,
+   },
+   
+   prepend_iovec = {
+      
+      to_empty_packet = function ()
+         local p = packet.allocate()
+         local b = buffer.from_data('abcdefghijklmnopqrstuvwxyz')
+         packet.prepend_iovec(p, b, 26, 0)
+         assert (p.niovecs == 1)
+         assert (p.length == 26)
+         assert (buffer.tostring(p.iovecs[0].buffer, 26) == 'abcdefghijklmnopqrstuvwxyz')
+         assert (packet.tostring(p) == 'abcdefghijklmnopqrstuvwxyz')
+      end,
+      
+      to_single_iovec_packet = function ()
+         local p = packet.from_data('nopqrstuvwxyz')
+         local b = buffer.from_data('abcdefghijklm')
+         packet.prepend_iovec(p, b, 13, 0)
+         assert (p.niovecs == 2)
+         assert (p.length == 26)
+         assert (buffer.tostring(p.iovecs[0].buffer, 13) == 'abcdefghijklm')
+         assert (buffer.tostring(p.iovecs[1].buffer, 13) == 'nopqrstuvwxyz')
+         assert (packet.tostring(p) == 'abcdefghijklmnopqrstuvwxyz')
+      end,
+   },
+   
+   coalesce = function ()
+      local p = packet.from_data('abcdefghijklm')
+      local b = buffer.from_data('nopqrstuvwxyz')
+      packet.add_iovec(p, b, 13, 0)
+      assert (p.niovecs == 2)
+      assert (p.length == 26)
+      assert (packet.tostring(p) == 'abcdefghijklmnopqrstuvwxyz')
+      packet.coalesce(p)
+      assert (p.niovecs == 1)
+      assert (p.length == 26)
+      assert (packet.tostring(p) == 'abcdefghijklmnopqrstuvwxyz')
+   end,
+   
+   fill_data = {
+      
+      at_start = {
+         to_single_iovec_packet = function ()
+            local p = packet.from_data('abcdefghijklmnopqrstuvwxyz')
+            packet.fill_data(p, '12345678')
+            assert (packet.tostring(p) == '12345678ijklmnopqrstuvwxyz')
+         end,
+         
+         to_first_of_multi_iovec_packet = function ()
+            local p = packet.allocate()
+            packet.add_iovec(p, buffer.from_data('abcdefghijklm'), 13, 0)
+            packet.add_iovec(p, buffer.from_data('nopqrstuvwxyz'), 13, 0)
+            packet.fill_data(p, '12345678', 0)
+            assert (packet.tostring(p) == '12345678ijklmnopqrstuvwxyz')
+         end,
+         
+         to_two_of_multi_iovec_packet = function ()
+            local p = packet.allocate()
+            packet.add_iovec(p, buffer.from_data('abcdefghijklm'), 13, 0)
+            packet.add_iovec(p, buffer.from_data('nopqrstuvwxyz'), 13, 0)
+            packet.fill_data(p, '12345678', 0)
+            assert (packet.tostring(p) == '12345678ijklmnopqrstuvwxyz')
+         end,
+      },
+      at_offset = {
+         to_single_iovec_packet = function ()
+            local p = packet.from_data('abcdefghijklmnopqrstuvwxyz')
+            packet.fill_data(p, '12345678', 3)
+            assert (packet.tostring(p) == 'abc12345678lmnopqrstuvwxyz')
+         end,
+         
+         to_first_of_multi_iovec_packet = function ()
+            local p = packet.allocate()
+            packet.add_iovec(p, buffer.from_data('abcdefghijklm'), 13, 0)
+            packet.add_iovec(p, buffer.from_data('nopqrstuvwxyz'), 13, 0)
+            packet.fill_data(p, '12345678', 3)
+            assert (packet.tostring(p) == 'abc12345678lmnopqrstuvwxyz')
+         end,
+         
+         to_second_of_multi_iovec_packet = function ()
+            local p = packet.allocate()
+            packet.add_iovec(p, buffer.from_data('abcdefghijklm'), 13, 0)
+            packet.add_iovec(p, buffer.from_data('nopqrstuvwxyz'), 13, 0)
+            packet.fill_data(p, '12345678', 15)
+            assert (packet.tostring(p) == 'abcdefghijklmno12345678xyz')
+         end,
+         
+         to_two_of_multi_iovec_packet = function ()
+            local p = packet.allocate()
+            packet.add_iovec(p, buffer.from_data('abcdefghijklm'), 13, 0)
+            packet.add_iovec(p, buffer.from_data('nopqrstuvwxyz'), 13, 0)
+            packet.fill_data(p, '12345678', 9)
+            assert (packet.tostring(p) == 'abcdefghi12345678rstuvwxyz')
+         end,
+         
+         to_three_of_multi_iovec_packet = function ()
+            local p = packet.allocate()
+            packet.add_iovec(p, buffer.from_data('abcdefghijk'), 11, 0)
+            packet.add_iovec(p, buffer.from_data('lmno'), 4, 0)
+            packet.add_iovec(p, buffer.from_data('pqrstuvwxyz'), 11, 0)
+            packet.fill_data(p, '12345678', 9)
+            assert (packet.tostring(p) == 'abcdefghi12345678rstuvwxyz')
+         end,
+      },
+   },
+}
\ No newline at end of file
diff --git a/src/lib/index_set_t.lua b/src/lib/index_set_t.lua
new file mode 100644
index 0000000000..b1a1dab263
--- /dev/null
+++ b/src/lib/index_set_t.lua
@@ -0,0 +1,18 @@
+local index_set = require "lib.index_set"
+
+local function _t(a, b)
+   return tostring(a)..'/'..tostring(b)
+end
+
+return {
+   basic_handling = function ()
+      local ndx_set = index_set:new(4, 'test ndx')
+      assert (_t(ndx_set:add('a'))=='0/true', "indexes start with 0, and is new")
+      assert (_t(ndx_set:add('b'))=='1/true', "second new index")
+      assert (_t(ndx_set:add('c'))=='2/true', "third new")
+      assert (_t(ndx_set:add('b'))=='1/false', "that's an old one")
+      assert (_t(ndx_set:add('a'))=='0/false', "the very first one")
+      assert (_t(ndx_set:add('A'))=='3/true', "almost, but new")
+      assert (_t(pcall(ndx_set.add, ndx_set,'B'))
+         :match('^false/lib/index_set.lua:%d+: test ndx overflow'), 'should overflow')   end
+}
diff --git a/src/lib/macaddress_t.lua b/src/lib/macaddress_t.lua
new file mode 100644
index 0000000000..2c110cc1ce
--- /dev/null
+++ b/src/lib/macaddress_t.lua
@@ -0,0 +1,16 @@
+local macaddress = require "lib.macaddress"
+
+return {
+   basic_handling = function ()
+      local macA = macaddress:new('00-01-02-0a-0b-0c')
+      local macB = macaddress:new('0001020A0B0C')
+      local macC = macaddress:new('0A:0B:0C:00:01:02')
+      assert (tostring(macA) == '00:01:02:0A:0B:0C', "bad canonical MAC")
+      assert (macA == macB, "macA and macB should be equal")
+      assert (macA ~= macC, "macA and macC should be different")
+      assert (macA:subbits(0,31)==0x0a020100, "low A")
+      assert (macA:subbits(32,48)==0x0c0b, ("hi A (%X)"):format(macA:subbits(32,48)))
+      assert (macC:subbits(0,31)==0x000c0b0a, "low C")
+      assert (macC:subbits(32,48)==0x0201," hi C")
+   end,
+}
diff --git a/src/test.lua b/src/test.lua
new file mode 100644
index 0000000000..65d3052fb7
--- /dev/null
+++ b/src/test.lua
@@ -0,0 +1,66 @@
+local ffi = require("ffi")
+local C   = ffi.C
+local main = require("core.main")
+
+local shortlogs = false
+local results = {fails=0}
+
+local function show_log()
+   io.write(string.format('\n======= %d tests, %d failures\n', #results, results.fails))
+   for _,log in ipairs(results) do
+      if #log.out > 0 then
+         io.write(log.ok and '[Ok]\t' or '[FAIL]\t', log.name, ':\n')
+         for _,line in ipairs(log.out) do
+            io.write(line, '\n')
+         end
+         io.write('------\n')
+      end
+   end
+end
+
+local function log(name, ok, ...)
+   results[#results+1] = {name=name or '---', ok=ok, out={...}}
+   if not ok then results.fails = results.fails+1 end
+   return ok
+end
+
+local function do_test(name, test, showlog)
+   if showlog and name ~= '' then io.write('======= ', name, '\n') end
+   local function gettb(err) 
+      return debug.traceback(err, 2)
+         :gsub('\n[^\n]*xpcall\'%s*test.lua:.*$', '\n\t['..name..']') 
+   end
+   
+   if type(test) == 'function' then      -- perform the test
+--      log(name, xpcall(test, gettb))
+      io.write(log(name, xpcall(test, gettb)) and '[Ok]\t' or '[FAIL]\t', name, '\n')
+      
+   elseif type(test) == 'table' then      -- test every non '_xxx' item
+      for k, v in pairs(test) do
+         if test.__setup then 
+            if not log (nil, xpcall(test.__setup, gettb, test, k, v)) then return end
+         end
+         if string.sub(k, 1, 1) ~= '_' then
+            do_test(name..'.'..((type(k)=='string' or type(v)~='string') and k or v), v, showlog)
+         end
+      end
+      
+   elseif type(test) == 'string' then
+      if io.open(test..'.lua', 'r') then         -- load test(s) from a file
+         do_test(name, assert(loadfile(test..'.lua'))())
+      else                                      -- last resort: a directory
+         for fn in io.popen('ls -1F "'..test..'" 2>/dev/null'):lines() do
+            if fn:match('_t%.lua$') then               -- found a test file
+               do_test(name..'.'..fn:sub(1, -5), test..'/'..fn:sub(1, -5))
+                  
+            elseif fn:sub(-1) == '/' then               -- subdirectory: recurse
+               do_test(name..'.'..fn:sub(1, -2), test..'/'..fn:sub(1, -2))
+            end
+         end
+      end
+   end
+   if showlog and name ~= '' then show_log() end
+end
+
+do_test('', main.parameters, true)
+return function(tn) do_test(tn, tn, true) end
\ No newline at end of file

From 4cd4fdad7914e5fd52288ed4545ccf9957ab6efe Mon Sep 17 00:00:00 2001
From: Javier Guerra <javier@guerrag.com>
Date: Wed, 16 Apr 2014 04:46:42 -0500
Subject: [PATCH 2/4] documentation

---
 src/apps/intel/intel_t.lua    | 24 -------------
 src/core/buffer.lua           | 33 +++++++++++++++---
 src/core/memory.c             |  4 +--
 src/core/packet.h             | 23 ++++++------
 src/core/packet.lua           | 66 +++++++++++++++++++++++------------
 src/doc/genbook.sh            | 39 +++++++++++++--------
 src/doc/test.md               | 61 ++++++++++++++++++++++++++++++++
 src/lib/hardware/register.lua |  8 +++--
 8 files changed, 177 insertions(+), 81 deletions(-)
 delete mode 100644 src/apps/intel/intel_t.lua
 create mode 100644 src/doc/test.md

diff --git a/src/apps/intel/intel_t.lua b/src/apps/intel/intel_t.lua
deleted file mode 100644
index 74becbfd98..0000000000
--- a/src/apps/intel/intel_t.lua
+++ /dev/null
@@ -1,24 +0,0 @@
-return {
-   sum = function()
-      assert(2+2 == 4, "if this fails, there's no hope")
-   end,
-   
-   mult = function()
-      assert(2*2 == 4.1, "missed it by that much")
-   end,
-   
-   strs = {
-      
-      concat = function()
-         assert('a'..'b' == 'ab', "the obvious thing")
-      end,
-      
-      repeated = function()
-         assert(3*'a' == 'aaa', "would this work?")
-      end,
-      
-      good_repeat = function()
-         assert(string.rep('a',3)=='aaa', "this should work")
-      end,
-   },
-}
\ No newline at end of file
diff --git a/src/core/buffer.lua b/src/core/buffer.lua
index b826c7b04f..7df7ac8aad 100644
--- a/src/core/buffer.lua
+++ b/src/core/buffer.lua
@@ -20,12 +20,14 @@ buffer_ptr_t = ffi.typeof("struct buffer *")
 -- This is used to return freed buffers to their devices.
 virtio_devices = {}
 
--- Return a ready-to-use buffer, or nil if none is available.
+--- ### Allocation
+
+--- Return a ready-to-use buffer, or nil if none is available.
 function allocate ()
    return freelist.remove(buffers) or new_buffer()
 end
 
--- Return a newly created buffer, or nil if none can be created.
+--- Return a newly created buffer, or nil if none can be created.
 function new_buffer ()
    assert(allocated < max, "out of buffers")
    allocated = allocated + 1
@@ -35,7 +37,7 @@ function new_buffer ()
    return b
 end
 
--- Free a buffer that is no longer in use.
+--- Free a buffer that is no longer in use.
 function free (b)
    freelist.add(buffers, b)
    if b.origin.type == C.BUFFER_ORIGIN_VIRTIO then
@@ -43,8 +45,8 @@ function free (b)
    end
 end
 
--- Create buffers until at least N are ready for use.
--- This is a way to pay the cost of allocating buffer memory in advance.
+--- Create buffers until at least N are ready for use.
+--- This is a way to pay the cost of allocating buffer memory in advance.
 function preallocate (n)
    while freelist.nfree(buffers) < n do free(new_buffer()) end
 end
@@ -59,3 +61,24 @@ function delete_virtio_device (index)
    virtio_devices[index] = nil
 end
 
+--- ### to/from binary strings
+
+--- copies data from a string to an allocated buffer
+function fill_data (b, d, offset)
+   offset = offset or 0
+   assert (offset+#d <= b.size, "can't fit on buffer")
+   ffi.copy (b.pointer + offset, d, math.min(#d, b.size-offset))
+end
+
+--- creates a buffer from a given binary string
+function from_data (d)
+   local b = allocate()
+   local size = math.min(#d, b.size)
+   fill_data(b, d)
+   return b
+end
+
+--- returns a string with buffer's content
+function tostring(b, size)
+   return ffi.string(b.pointer, size or b.size)
+end
diff --git a/src/core/memory.c b/src/core/memory.c
index c27de86f5e..2163a35853 100644
--- a/src/core/memory.c
+++ b/src/core/memory.c
@@ -9,8 +9,8 @@
 
 /// ### HugeTLB page allocation
 
-// Allocate a HugeTLB memory page of 'size' bytes.
-// Return a pointer to the start of the page, or NULL on failure.
+/// Allocate a HugeTLB memory page of 'size' bytes.
+/// Return a pointer to the start of the page, or NULL on failure.
 void *allocate_huge_page(int size)
 {
   void *ptr = mmap(NULL, size, PROT_READ | PROT_WRITE,
diff --git a/src/core/packet.h b/src/core/packet.h
index 185fb4f356..65e3f7c049 100644
--- a/src/core/packet.h
+++ b/src/core/packet.h
@@ -1,7 +1,7 @@
-// Buffers can be treated specially depending on their origin.
-//
-// For example, buffers belonging to Virtio devices need to be
-// returned to the device when freed.
+/// Buffers can be treated specially depending on their origin.
+///
+/// For example, buffers belonging to Virtio devices need to be
+/// returned to the device when freed.
 
 struct buffer_origin {
   enum buffer_origin_type {
@@ -18,7 +18,7 @@ struct buffer_origin {
   } info;
 };
 
-// A buffer describes a piece of memory with known size and physical address.
+/// A buffer describes a piece of memory with known size and physical address.
 struct buffer {
   char     *pointer; // virtual address in this process
   uint64_t physical; // stable physical address
@@ -26,7 +26,7 @@ struct buffer {
   struct buffer_origin origin;
 };
 
-// A packet_iovec describes a portion of a buffer.
+/// A packet_iovec describes a portion of a buffer.
 struct packet_iovec {
   struct buffer *buffer;
   uint32_t offset;
@@ -36,10 +36,10 @@ struct packet_iovec {
 // Maximum number of packet_iovec's per packet.
 enum { PACKET_IOVEC_MAX = 16 };
 
-// Packet info (metadata) for checksum and segmentation offload.
-//
-// This is intentionally bit-compatible with the Virtio structure
-// 'virtio_net_hdr' because that seems a reasonable starting point.
+/// Packet info (metadata) for checksum and segmentation offload.
+///
+/// This is intentionally bit-compatible with the Virtio structure
+/// 'virtio_net_hdr' because that seems a reasonable starting point.
 struct packet_info {
   uint8_t flags;        // see below
   uint8_t gso_flags;    // see below
@@ -64,6 +64,9 @@ enum {
   PACKET_GSO_ECN   = 0x80  // TCP has ECN set
 };
 
+/// Packet data structure.
+///
+/// Holds a number of iovecs, reference counting and other housekeeping info
 struct packet {
   int32_t refcount;
   // How much "fuel" does this packet have left before it's dropped?
diff --git a/src/core/packet.lua b/src/core/packet.lua
index 72fd19e790..e70fa4204b 100644
--- a/src/core/packet.lua
+++ b/src/core/packet.lua
@@ -27,7 +27,7 @@ function allocate ()
    return freelist.remove(packets_fl) or error("out of packets")
 end
 
--- Append data to a packet.
+--- Append data to a packet.
 function add_iovec (p, b, length,  offset)
    if debug then assert(p.niovecs < C.PACKET_IOVEC_MAX, "packet iovec overflow") end
    offset = offset or 0
@@ -77,25 +77,9 @@ function coalesce (p)
    add_iovec(p, b, length)
 end
 
--- fill's an allocated packet with data from a string
-function fill_data (p, d, offset)
-   offset = offset or 0
-   local iovec = p.iovecs[0]
-   assert (offset+#d <= iovec.length, "can't fit on first iovec")       -- TODO: handle more iovecs
-   ffi.copy (iovec.buffer.pointer + iovec.offset + offset, d, #d)
-end
+--- ### Refcounting
 
--- creates a packet from a given binary string
-function from_data (d)
-   local p = allocate()
-   local b = buffer.allocate()
-   local size = math.min(#d, b.size)
-   add_iovec(p, b, size)
-   fill_data(p, d)
-   return p
-end
-
--- Increase the reference count for packet p by n (default n=1).
+--- Increase the reference count for packet p by n (default n=1).
 function ref (p,  n)
    if p.refcount > 0 then
       p.refcount = p.refcount + (n or 1)
@@ -103,8 +87,8 @@ function ref (p,  n)
    return p
 end
 
--- Decrease the reference count for packet p.
--- The packet will be recycled if the reference count reaches 0.
+--- Decrease the reference count for packet p.
+--- The packet will be recycled if the reference count reaches 0.
 function deref (p,  n)
    n = n or 1
    if p.refcount > 0 then
@@ -117,12 +101,12 @@ function deref (p,  n)
    end
 end
 
--- Tenured packets are not reused by defref().
+--- Tenured packets are not reused by defref().
 function tenure (p)
    p.refcount = 0
 end
 
--- Free a packet and all of its buffers.
+--- Free a packet and all of its buffers.
 function free (p)
    for i = 0, p.niovecs-1 do
       buffer.free(p.iovecs[i].buffer)
@@ -133,6 +117,42 @@ function free (p)
    freelist.add(packets_fl, p)
 end
 
+--- ### to/from binary strings
+
+--- Returns a Lua binary string with the whole contents of the packet
+function tostring(p)
+   local out = {}
+   for i = 0, p.niovecs-1 do
+      local iovec = p.iovecs[i]
+      out[i] = ffi.string(iovec.buffer.pointer + iovec.offset, iovec.length)
+   end
+   return table.concat(out, '', 0)
+end
+
+--- Writes data from a string into an existing packet at a specified offset
+function fill_data (p, d, offset)
+   offset = offset or 0
+   for i = 0, p.niovecs-1 do
+      local iovec = p.iovecs[i]
+      if iovec.length > offset then
+         ffi.copy(iovec.buffer.pointer + offset, d, math.min(#d, iovec.length - offset))
+         d = d:sub(iovec.length - offset + 1)
+         if d == '' then return end
+         offset = 0
+      else
+         offset = offset - iovec.length
+      end
+   end
+   error("didn't find given offset")
+end
+
+--- Creates a packet from a given binary string
+function from_data (d)
+   local p = allocate()
+   add_iovec(p, buffer.from_data(d), #d)
+   return p
+end
+
 function iovec_dump (iovec)
    local b = iovec.buffer
    local l = math.min(iovec.length, b.size-iovec.offset)
diff --git a/src/doc/genbook.sh b/src/doc/genbook.sh
index 20afebee2e..c388596474 100755
--- a/src/doc/genbook.sh
+++ b/src/doc/genbook.sh
@@ -14,30 +14,36 @@ cat <<EOF
         awk 'NR > 1 { printf("; ") } { printf("%s", $0) } END { print("") }')
 
 # Memory
-$(cat memory.md)
+$(cat $(find . -name memory.md))
 ## \`memory.c\`: Operating system support
-$(cat obj/memory.c.md)
+$(cat obj/core/memory.c.md)
 ## \`memory.lua\`: Allocate physical memory in Lua
-$(cat obj/memory.lua.md)
+$(cat obj/core/memory.lua.md)
 ## \`buffer.lua\`: Allocate packet buffers from a pool
-$(cat obj/buffer.lua.md)
+$(cat obj/core/buffer.lua.md)
 
 # PCI
 ## \`pci.c\`: Operating system support
-$(cat obj/pci.c.md)
+$(cat obj/lib/hardware/pci.c.md)
 ## \`pci.lua\`: PCI access in Lua
-$(cat obj/pci.lua.md)
+$(cat obj/lib/hardware/pci.lua.md)
+
+# Packets and datagrams
+## \`packet.h\` low level structures
+$(cat obj/core/packet.h.md)
+## \`packet.lua\` basic handling operations
+$(cat obj/core/packet.lua.md)
 
 # Hardware ethernet I/O
 ## Hardware device register access
-$(cat obj/register.lua.md)
+$(cat obj/lib/hardware/register.lua.md)
 ## Intel 82599 (10-Gigabit) ethernet device driver
-$(cat obj/intel10g.lua.md)
+$(cat obj/apps/intel/intel10g.lua.md)
 
 # Software ethernet I/O (virtio)
 $(cat virtio.md)
 ## \`virtio_vring.h\`: vring DMA ring buffer data structure
-$(cat obj/virtio_vring.h.md)
+$(cat obj/lib/virtio/virtio_vring.h.md)
 ## \`virtio_vhost.h\`: vhost Linux kernel `ioctl` data structures
 $(cat obj/virtio_vhost.h.md)
 ## \`virtio_vhost_client.c\`: Linux \`/dev/vhost-net\` vhost client
@@ -52,21 +58,26 @@ $(cat kvm.md)
 $(cat obj/port.lua.md)
 ## \`hub2.lua\`: 2-port ethernet hub
 $(cat obj/hub2.lua.md)
+$(cat core/buffer.lua.md)
 
 $(cat openstack.md)
 
 # *DRAFT* Library
-## \`clib.h\`: Standard C function prototypes
-$(cat obj/clib.h.md)
+## \`lib.h\`: Standard C function prototypes
+$(cat obj/core/lib.h.md)
+## \`lib.c\`:
+$(cat obj/core/lib.c.md)
 ## \`lib.lua\`: Lua library routines
-$(cat obj/lib.lua.md)
+$(cat obj/core/lib.lua.md)
 
 # Startup
 ## \`snabbswitch.c\`: C \`main()\` entry point
-$(cat obj/snabbswitch.c.md)
+$(cat obj/core/snabbswitch.c.md)
 ## \`main.lua\`: Lua entry point
-$(cat obj/main.lua.md)
+$(cat obj/core/main.lua.md)
 ## \`snabb_lib_init.c\`: Customized Lua initialization
 $(cat obj/snabb_lib_init.c.md)
 
+$(cat test.md)
+
 EOF
diff --git a/src/doc/test.md b/src/doc/test.md
new file mode 100644
index 0000000000..10849a4766
--- /dev/null
+++ b/src/doc/test.md
@@ -0,0 +1,61 @@
+# Testing
+
+A very simple test framework is included.  Invoke it as `snabbswitch test [tests...]`, where the optional test specifications can be either Lua test files (without the `.lua` extension) or directories to be recursively walked, picking `*_t.lua` files.
+
+Each should return a table of named test functions and subtables.  Test functions are tried if their names don't begin with a `_`.
+
+If a table (or subtable) defines a `__setup()` function, it is executed before each function and subtable in the same table, but not each function in a subtable.  It receives four parameters: the table it's defined in, it's full name, the name of the function (or subtable) to be executed, and the function (or subtable) itself.
+
+The test code should be straightforward, finishing the function (or the testfile) is considered a passed test, failing with `error()` or `assert()` signals test failure.  Any return value or error message is stored to be displayed in the final summary.
+
+Example:
+
+    return {
+        sum = function ()
+            assert(2+2 == 4, "if this fails, there's no hope")
+        end,
+
+        mult = function ()
+            assert(2*2 == 4.1, "missed it by that much")
+        end,
+
+        strs = {
+            concat = function ()
+                assert('a'..'b' == 'ab', "the obvious thing")
+            end,
+
+            repeated = function ()
+                assert(3*'a' == 'aaa', "would this work?")
+            end,
+
+            good_repeat = function ()
+                assert(string.rep('a',3)=='aaa', "this should work")
+            end,
+        },
+    }
+
+output:
+
+    ======= testsample_t
+    [Ok]    testsample_t.sum
+    [FAIL]  testsample_t.strs.repeated
+    [Ok]    testsample_t.strs.concat
+    [Ok]    testsample_t.strs.good_repeat
+    [FAIL]  testsample_t.mult
+
+    ======= 5 tests, 2 failures
+    [FAIL]  testsample_t.strs.repeated:
+    testsample_t.lua:17: attempt to perform arithmetic on a string value
+    stack traceback:
+            testsample_t.lua:17: in function <testsample_t.lua:16>
+            [testsample_t.strs.repeated]
+    ------
+    [FAIL]  testsample_t.mult:
+    testsample_t.lua:7: missed it by that much
+    stack traceback:
+            [C]: in function 'assert'
+            testsample_t.lua:7: in function <testsample_t.lua:6>
+            [testsample_t.mult]
+    ------
+
+note that there's no guaranteed order.  I see it as a feature.
diff --git a/src/lib/hardware/register.lua b/src/lib/hardware/register.lua
index 7dbc803bc0..f01ce1f4b3 100644
--- a/src/lib/hardware/register.lua
+++ b/src/lib/hardware/register.lua
@@ -131,9 +131,11 @@ end
 --- The register objects become named entries in `table`.
 ---
 --- This is an example line for a register description:
+---
 ---     TXDCTL    0x06028 +0x40*0..127 (RW) Transmit Descriptor Control
 ---
 --- and this is the grammar:
+---
 ---     Register   ::= Name Offset Indexing Mode Longname
 ---     Name       ::= <identifier>
 ---     Indexing   ::= "-"
@@ -155,9 +157,9 @@ function define (description, table, base_ptr, n)
    end
 end
 
--- registers of the form '+0xXX*j..k' are converted to
--- an array of registers.
--- naïve implementation: actually create the whole array
+--- registers of the form `+0xXX*j..k` are converted to
+--- an array of registers.
+--- naïve implementation: actually create the whole array
 function define_array (description, table, base_ptr)
    local pattern = [[ *(%S+) +(%S+) +(%S+) +(%S+) (.-)
 ]]

From aeff0847a14f4ead066653fbd0f8b21c9535f755 Mon Sep 17 00:00:00 2001
From: Javier Guerra <javier@guerrag.com>
Date: Thu, 17 Apr 2014 22:31:35 -0500
Subject: [PATCH 3/4] packet manipulation

---
 src/apps/intel/intel10g.lua |  8 ++------
 src/core/buffer.lua         |  7 ++-----
 src/core/packet.lua         | 40 ++++++++++++++++++++++++++++---------
 src/core/packet_t.lua       | 24 +++++++++++++++++-----
 4 files changed, 54 insertions(+), 25 deletions(-)

diff --git a/src/apps/intel/intel10g.lua b/src/apps/intel/intel10g.lua
index 0b0dba04ac..ddc6e62718 100644
--- a/src/apps/intel/intel10g.lua
+++ b/src/apps/intel/intel10g.lua
@@ -168,21 +168,17 @@ end
 
 --- See datasheet section 7.1 "Inline Functions -- Transmit Functionality."
 
-txdesc_flags = bits{eop=24,ifcs=25, dext=29, dtyp0=20, dtyp1=21}
+txdesc_flags = bits{ifcs=25, dext=29, dtyp0=20, dtyp1=21}
 txdesc_flags_last = bits({eop=24}, txdesc_flags)
 function M_sf:transmit (p)
-   if p.niovecs > 1 then
-      packet.coalesce(p)
-   end
    for i = 0, p.niovecs - 1 do
       local iov = p.iovecs[i]
       local flags = (i + 1 < p.niovecs) and txdesc_flags or txdesc_flags_last
       self.txdesc[self.tdt].address = iov.buffer.physical + iov.offset
       self.txdesc[self.tdt].options = bit.bor(iov.length, flags, bit.lshift(p.length+0ULL, 46))
-      self.txpackets[self.tdt] = p
+      self.txpackets[self.tdt] = packet.ref(p)
       self.tdt = (self.tdt + 1) % num_descriptors
    end
-   return packet.ref(p)
 end
 
 function M_sf:sync_transmit ()
diff --git a/src/core/buffer.lua b/src/core/buffer.lua
index 7df7ac8aad..9071f0a342 100644
--- a/src/core/buffer.lua
+++ b/src/core/buffer.lua
@@ -61,16 +61,14 @@ function delete_virtio_device (index)
    virtio_devices[index] = nil
 end
 
---- ### to/from binary strings
-
---- copies data from a string to an allocated buffer
+-- fill's an allocated buffer with data from a string
 function fill_data (b, d, offset)
    offset = offset or 0
    assert (offset+#d <= b.size, "can't fit on buffer")
    ffi.copy (b.pointer + offset, d, math.min(#d, b.size-offset))
 end
 
---- creates a buffer from a given binary string
+-- creates a buffer from a given binary string
 function from_data (d)
    local b = allocate()
    local size = math.min(#d, b.size)
@@ -78,7 +76,6 @@ function from_data (d)
    return b
 end
 
---- returns a string with buffer's content
 function tostring(b, size)
    return ffi.string(b.pointer, size or b.size)
 end
diff --git a/src/core/packet.lua b/src/core/packet.lua
index e70fa4204b..6986c4b412 100644
--- a/src/core/packet.lua
+++ b/src/core/packet.lua
@@ -77,7 +77,29 @@ function coalesce (p)
    add_iovec(p, b, length)
 end
 
---- ### Refcounting
+-- fill's an allocated packet with data from a string
+function fill_data (p, d, offset)
+   offset = offset or 0
+   for i = 0, p.niovecs-1 do
+      local iovec = p.iovecs[i]
+      if iovec.length > offset then
+         ffi.copy(iovec.buffer.pointer + offset, d, math.min(#d, iovec.length - offset))
+         d = d:sub(iovec.length - offset + 1)
+         if d == '' then return end
+         offset = 0
+      else
+         offset = offset - iovec.length
+      end
+   end
+   error("didn't find given offset")
+end
+
+-- creates a packet from a given binary string
+function from_data (d)
+   local p = allocate()
+   add_iovec(p, buffer.from_data(d), #d)
+   return p
+end
 
 --- Increase the reference count for packet p by n (default n=1).
 function ref (p,  n)
@@ -117,16 +139,13 @@ function free (p)
    freelist.add(packets_fl, p)
 end
 
---- ### to/from binary strings
-
---- Returns a Lua binary string with the whole contents of the packet
 function tostring(p)
    local out = {}
-   for i = 0, p.niovecs-1 do
-      local iovec = p.iovecs[i]
+   for i = 1, p.niovecs do
+      local iovec = p.iovecs[i-1]
       out[i] = ffi.string(iovec.buffer.pointer + iovec.offset, iovec.length)
    end
-   return table.concat(out, '', 0)
+   return table.concat(out, '')
 end
 
 --- Writes data from a string into an existing packet at a specified offset
@@ -147,9 +166,12 @@ function fill_data (p, d, offset)
 end
 
 --- Creates a packet from a given binary string
-function from_data (d)
+function from_data (...)
    local p = allocate()
-   add_iovec(p, buffer.from_data(d), #d)
+   for i = 1, select('#', ...) do
+      local d = select(i, ...)
+      add_iovec(p, buffer.from_data(d), #d)
+   end
    return p
 end
 
diff --git a/src/core/packet_t.lua b/src/core/packet_t.lua
index beceecbc3d..96cd585ccb 100644
--- a/src/core/packet_t.lua
+++ b/src/core/packet_t.lua
@@ -8,11 +8,25 @@ local packet = require "core.packet"
 
 
 return {
-   from_data = function ()
-      local p = packet.from_data('abcdefghijklmnopqrstuvwxyz')
-      assert (packet.tostring(p) == 'abcdefghijklmnopqrstuvwxyz')
-   end,
-   
+   from_data = {
+      no_parts = function ()
+         local p = packet.from_data()
+         assert (p.niovecs == 0)
+         assert (packet.tostring(p) == '')
+      end,
+      
+      single_part = function ()
+         local p = packet.from_data('abcdefghijklmnopqrstuvwxyz')
+         assert (p.niovecs == 1)
+         assert (packet.tostring(p) == 'abcdefghijklmnopqrstuvwxyz')
+      end,
+         
+      multiple_parts = function ()
+         local p = packet.from_data('abcdef','ghijklmnopqr','stuvwx','yz')
+         assert (p.niovecs == 4)
+         assert (packet.tostring(p) == 'abcdefghijklmnopqrstuvwxyz')
+      end,
+   },
    add_iovec = {
       
       to_empty_packet = function ()

From a1b16d0c758590955597bb0898b08091736e2d4b Mon Sep 17 00:00:00 2001
From: Javier Guerra <javier@guerrag.com>
Date: Sat, 19 Apr 2014 02:39:42 -0500
Subject: [PATCH 4/4] fix indentation

---
 src/core/main.lua | 34 +++++++++++++++++-----------------
 1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/src/core/main.lua b/src/core/main.lua
index d130df9536..45e256e68d 100644
--- a/src/core/main.lua
+++ b/src/core/main.lua
@@ -40,28 +40,28 @@ function main ()
    local i = 1
    while i <= #args do
       if args[i] == '-l' and i < #args then
-	 require(args[i+1])
-	 i = i + 2
+         require(args[i+1])
+         i = i + 2
       elseif args[i] == '-t' and i < #args then
          require(args[i+1]).selftest()
          i = i + 2
       elseif args[i] == '-e' and i < #args then
-	 local thunk, error = loadstring(args[i+1])
-	 if thunk then thunk() else print(error) end
-	 i = i + 2
+         local thunk, error = loadstring(args[i+1])
+         if thunk then thunk() else print(error) end
+         i = i + 2
       elseif args[i] == '-d' then
-	 debug_on_error = true
-	 i = i + 1
+         debug_on_error = true
+         i = i + 1
       elseif (args[i]):match("-jp") then
-	 local pargs, poutput = (args[i]):gmatch("-jp=(%w*),?(.*)")()
-	 if poutput == '' then poutput = nil end
-	 require("jit.p").start(pargs, poutput)
-	 profiling = true
-	 i = i + 1
+         local pargs, poutput = (args[i]):gmatch("-jp=(%w*),?(.*)")()
+         if poutput == '' then poutput = nil end
+         require("jit.p").start(pargs, poutput)
+         profiling = true
+         i = i + 1
       elseif args[i] == '-jdump' and i < #args then
-	 local jit_dump = require "jit.dump"
-	 jit_dump.start("", args[i+1])
-	 i = i + 2
+         local jit_dump = require "jit.dump"
+         jit_dump.start("", args[i+1])
+         i = i + 2
       elseif i <= #args then
          -- Syntax: <module> [args...]
          local module = args[i]
@@ -73,8 +73,8 @@ function main ()
          require(module)
          exit(0)
       else
-	 print(usage)
-	 os.exit(1)
+         print(usage)
+         os.exit(1)
       end
    end
    exit(0)