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comparison etc/tftp.lua @ 0:4b915342e2a8

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LuaSocket 2.0.2 + CMake build description.
author Eric Wing <ewing . public |-at-| gmail . com>
date Tue, 26 Aug 2008 18:40:01 -0700
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-1:000000000000 0:4b915342e2a8
1 -----------------------------------------------------------------------------
2 -- TFTP support for the Lua language
3 -- LuaSocket toolkit.
4 -- Author: Diego Nehab
5 -- RCS ID: $Id: tftp.lua,v 1.16 2005/11/22 08:33:29 diego Exp $
6 -----------------------------------------------------------------------------
7
8 -----------------------------------------------------------------------------
9 -- Load required files
10 -----------------------------------------------------------------------------
11 local base = _G
12 local table = require("table")
13 local math = require("math")
14 local string = require("string")
15 local socket = require("socket")
16 local ltn12 = require("ltn12")
17 local url = require("socket.url")
18 module("socket.tftp")
19
20 -----------------------------------------------------------------------------
21 -- Program constants
22 -----------------------------------------------------------------------------
23 local char = string.char
24 local byte = string.byte
25
26 PORT = 69
27 local OP_RRQ = 1
28 local OP_WRQ = 2
29 local OP_DATA = 3
30 local OP_ACK = 4
31 local OP_ERROR = 5
32 local OP_INV = {"RRQ", "WRQ", "DATA", "ACK", "ERROR"}
33
34 -----------------------------------------------------------------------------
35 -- Packet creation functions
36 -----------------------------------------------------------------------------
37 local function RRQ(source, mode)
38 return char(0, OP_RRQ) .. source .. char(0) .. mode .. char(0)
39 end
40
41 local function WRQ(source, mode)
42 return char(0, OP_RRQ) .. source .. char(0) .. mode .. char(0)
43 end
44
45 local function ACK(block)
46 local low, high
47 low = math.mod(block, 256)
48 high = (block - low)/256
49 return char(0, OP_ACK, high, low)
50 end
51
52 local function get_OP(dgram)
53 local op = byte(dgram, 1)*256 + byte(dgram, 2)
54 return op
55 end
56
57 -----------------------------------------------------------------------------
58 -- Packet analysis functions
59 -----------------------------------------------------------------------------
60 local function split_DATA(dgram)
61 local block = byte(dgram, 3)*256 + byte(dgram, 4)
62 local data = string.sub(dgram, 5)
63 return block, data
64 end
65
66 local function get_ERROR(dgram)
67 local code = byte(dgram, 3)*256 + byte(dgram, 4)
68 local msg
69 _,_, msg = string.find(dgram, "(.*)\000", 5)
70 return string.format("error code %d: %s", code, msg)
71 end
72
73 -----------------------------------------------------------------------------
74 -- The real work
75 -----------------------------------------------------------------------------
76 local function tget(gett)
77 local retries, dgram, sent, datahost, dataport, code
78 local last = 0
79 socket.try(gett.host, "missing host")
80 local con = socket.try(socket.udp())
81 local try = socket.newtry(function() con:close() end)
82 -- convert from name to ip if needed
83 gett.host = try(socket.dns.toip(gett.host))
84 con:settimeout(1)
85 -- first packet gives data host/port to be used for data transfers
86 local path = string.gsub(gett.path or "", "^/", "")
87 path = url.unescape(path)
88 retries = 0
89 repeat
90 sent = try(con:sendto(RRQ(path, "octet"), gett.host, gett.port))
91 dgram, datahost, dataport = con:receivefrom()
92 retries = retries + 1
93 until dgram or datahost ~= "timeout" or retries > 5
94 try(dgram, datahost)
95 -- associate socket with data host/port
96 try(con:setpeername(datahost, dataport))
97 -- default sink
98 local sink = gett.sink or ltn12.sink.null()
99 -- process all data packets
100 while 1 do
101 -- decode packet
102 code = get_OP(dgram)
103 try(code ~= OP_ERROR, get_ERROR(dgram))
104 try(code == OP_DATA, "unhandled opcode " .. code)
105 -- get data packet parts
106 local block, data = split_DATA(dgram)
107 -- if not repeated, write
108 if block == last+1 then
109 try(sink(data))
110 last = block
111 end
112 -- last packet brings less than 512 bytes of data
113 if string.len(data) < 512 then
114 try(con:send(ACK(block)))
115 try(con:close())
116 try(sink(nil))
117 return 1
118 end
119 -- get the next packet
120 retries = 0
121 repeat
122 sent = try(con:send(ACK(last)))
123 dgram, err = con:receive()
124 retries = retries + 1
125 until dgram or err ~= "timeout" or retries > 5
126 try(dgram, err)
127 end
128 end
129
130 local default = {
131 port = PORT,
132 path ="/",
133 scheme = "tftp"
134 }
135
136 local function parse(u)
137 local t = socket.try(url.parse(u, default))
138 socket.try(t.scheme == "tftp", "invalid scheme '" .. t.scheme .. "'")
139 socket.try(t.host, "invalid host")
140 return t
141 end
142
143 local function sget(u)
144 local gett = parse(u)
145 local t = {}
146 gett.sink = ltn12.sink.table(t)
147 tget(gett)
148 return table.concat(t)
149 end
150
151 get = socket.protect(function(gett)
152 if base.type(gett) == "string" then return sget(gett)
153 else return tget(gett) end
154 end)
155