354 lines
12 KiB
Lua
354 lines
12 KiB
Lua
-----------------------------------------------------------------------------
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-- HTTP/1.1 client support for the Lua language.
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-- LuaSocket toolkit.
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-- Author: Diego Nehab
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-----------------------------------------------------------------------------
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-----------------------------------------------------------------------------
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-- Declare module and import dependencies
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-------------------------------------------------------------------------------
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local socket = require("socket")
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local url = require("socket.url")
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local ltn12 = require("ltn12")
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local mime = require("mime")
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local string = require("string")
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local headers = require("socket.headers")
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local base = _G
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local table = require("table")
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socket.http = {}
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local _M = socket.http
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-----------------------------------------------------------------------------
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-- Program constants
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-----------------------------------------------------------------------------
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-- connection timeout in seconds
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TIMEOUT = 60
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-- default port for document retrieval
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_M.PORT = 80
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-- user agent field sent in request
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_M.USERAGENT = socket._VERSION
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-----------------------------------------------------------------------------
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-- Reads MIME headers from a connection, unfolding where needed
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-----------------------------------------------------------------------------
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local function receiveheaders(sock, headers)
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local line, name, value, err
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headers = headers or {}
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-- get first line
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line, err = sock:receive()
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if err then return nil, err end
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-- headers go until a blank line is found
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while line ~= "" do
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-- get field-name and value
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name, value = socket.skip(2, string.find(line, "^(.-):%s*(.*)"))
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if not (name and value) then return nil, "malformed reponse headers" end
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name = string.lower(name)
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-- get next line (value might be folded)
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line, err = sock:receive()
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if err then return nil, err end
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-- unfold any folded values
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while string.find(line, "^%s") do
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value = value .. line
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line = sock:receive()
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if err then return nil, err end
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end
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-- save pair in table
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if headers[name] then headers[name] = headers[name] .. ", " .. value
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else headers[name] = value end
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end
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return headers
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end
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-----------------------------------------------------------------------------
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-- Extra sources and sinks
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-----------------------------------------------------------------------------
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socket.sourcet["http-chunked"] = function(sock, headers)
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return base.setmetatable({
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getfd = function() return sock:getfd() end,
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dirty = function() return sock:dirty() end
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}, {
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__call = function()
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-- get chunk size, skip extention
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local line, err = sock:receive()
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if err then return nil, err end
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local size = base.tonumber(string.gsub(line, ";.*", ""), 16)
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if not size then return nil, "invalid chunk size" end
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-- was it the last chunk?
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if size > 0 then
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-- if not, get chunk and skip terminating CRLF
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local chunk, err, part = sock:receive(size)
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if chunk then sock:receive() end
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return chunk, err
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else
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-- if it was, read trailers into headers table
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headers, err = receiveheaders(sock, headers)
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if not headers then return nil, err end
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end
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end
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})
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end
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socket.sinkt["http-chunked"] = function(sock)
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return base.setmetatable({
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getfd = function() return sock:getfd() end,
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dirty = function() return sock:dirty() end
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}, {
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__call = function(self, chunk, err)
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if not chunk then return sock:send("0\r\n\r\n") end
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local size = string.format("%X\r\n", string.len(chunk))
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return sock:send(size .. chunk .. "\r\n")
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end
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})
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end
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-----------------------------------------------------------------------------
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-- Low level HTTP API
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-----------------------------------------------------------------------------
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local metat = { __index = {} }
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function _M.open(host, port, create)
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-- create socket with user connect function, or with default
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local c = socket.try((create or socket.tcp)())
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local h = base.setmetatable({ c = c }, metat)
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-- create finalized try
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h.try = socket.newtry(function() h:close() end)
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-- set timeout before connecting
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h.try(c:settimeout(_M.TIMEOUT))
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h.try(c:connect(host, port or _M.PORT))
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-- here everything worked
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return h
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end
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function metat.__index:sendrequestline(method, uri)
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local reqline = string.format("%s %s HTTP/1.1\r\n", method or "GET", uri)
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return self.try(self.c:send(reqline))
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end
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function metat.__index:sendheaders(tosend)
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local canonic = headers.canonic
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local h = "\r\n"
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for f, v in base.pairs(tosend) do
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h = (canonic[f] or f) .. ": " .. v .. "\r\n" .. h
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end
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self.try(self.c:send(h))
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return 1
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end
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function metat.__index:sendbody(headers, source, step)
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source = source or ltn12.source.empty()
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step = step or ltn12.pump.step
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-- if we don't know the size in advance, send chunked and hope for the best
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local mode = "http-chunked"
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if headers["content-length"] then mode = "keep-open" end
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return self.try(ltn12.pump.all(source, socket.sink(mode, self.c), step))
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end
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function metat.__index:receivestatusline()
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local status = self.try(self.c:receive(5))
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-- identify HTTP/0.9 responses, which do not contain a status line
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-- this is just a heuristic, but is what the RFC recommends
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if status ~= "HTTP/" then return nil, status end
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-- otherwise proceed reading a status line
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status = self.try(self.c:receive("*l", status))
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local code = socket.skip(2, string.find(status, "HTTP/%d*%.%d* (%d%d%d)"))
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return self.try(base.tonumber(code), status)
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end
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function metat.__index:receiveheaders()
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return self.try(receiveheaders(self.c))
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end
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function metat.__index:receivebody(headers, sink, step)
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sink = sink or ltn12.sink.null()
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step = step or ltn12.pump.step
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local length = base.tonumber(headers["content-length"])
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local t = headers["transfer-encoding"] -- shortcut
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local mode = "default" -- connection close
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if t and t ~= "identity" then mode = "http-chunked"
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elseif base.tonumber(headers["content-length"]) then mode = "by-length" end
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return self.try(ltn12.pump.all(socket.source(mode, self.c, length),
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sink, step))
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end
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function metat.__index:receive09body(status, sink, step)
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local source = ltn12.source.rewind(socket.source("until-closed", self.c))
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source(status)
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return self.try(ltn12.pump.all(source, sink, step))
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end
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function metat.__index:close()
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return self.c:close()
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end
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-----------------------------------------------------------------------------
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-- High level HTTP API
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-----------------------------------------------------------------------------
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local function adjusturi(reqt)
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local u = reqt
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-- if there is a proxy, we need the full url. otherwise, just a part.
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if not reqt.proxy and not PROXY then
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u = {
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path = socket.try(reqt.path, "invalid path 'nil'"),
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params = reqt.params,
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query = reqt.query,
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fragment = reqt.fragment
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}
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end
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return url.build(u)
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end
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local function adjustproxy(reqt)
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local proxy = reqt.proxy or PROXY
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if proxy then
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proxy = url.parse(proxy)
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return proxy.host, proxy.port or 3128
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else
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return reqt.host, reqt.port
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end
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end
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local function adjustheaders(reqt)
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-- default headers
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local lower = {
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["user-agent"] = _M.USERAGENT,
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["host"] = reqt.host,
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["connection"] = "close, TE",
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["te"] = "trailers"
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}
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-- if we have authentication information, pass it along
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if reqt.user and reqt.password then
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lower["authorization"] =
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"Basic " .. (mime.b64(reqt.user .. ":" .. reqt.password))
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end
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-- override with user headers
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for i,v in base.pairs(reqt.headers or lower) do
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lower[string.lower(i)] = v
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end
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return lower
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end
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-- default url parts
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local default = {
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host = "",
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port = _M.PORT,
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path ="/",
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scheme = "http"
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}
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local function adjustrequest(reqt)
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-- parse url if provided
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local nreqt = reqt.url and url.parse(reqt.url, default) or {}
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-- explicit components override url
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for i,v in base.pairs(reqt) do nreqt[i] = v end
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if nreqt.port == "" then nreqt.port = 80 end
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socket.try(nreqt.host and nreqt.host ~= "",
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"invalid host '" .. base.tostring(nreqt.host) .. "'")
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-- compute uri if user hasn't overriden
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nreqt.uri = reqt.uri or adjusturi(nreqt)
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-- ajust host and port if there is a proxy
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nreqt.host, nreqt.port = adjustproxy(nreqt)
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-- adjust headers in request
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nreqt.headers = adjustheaders(nreqt)
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return nreqt
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end
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local function shouldredirect(reqt, code, headers)
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return headers.location and
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string.gsub(headers.location, "%s", "") ~= "" and
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(reqt.redirect ~= false) and
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(code == 301 or code == 302 or code == 303 or code == 307) and
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(not reqt.method or reqt.method == "GET" or reqt.method == "HEAD")
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and (not reqt.nredirects or reqt.nredirects < 5)
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end
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local function shouldreceivebody(reqt, code)
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if reqt.method == "HEAD" then return nil end
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if code == 204 or code == 304 then return nil end
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if code >= 100 and code < 200 then return nil end
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return 1
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end
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-- forward declarations
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local trequest, tredirect
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--[[local]] function tredirect(reqt, location)
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local result, code, headers, status = trequest {
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-- the RFC says the redirect URL has to be absolute, but some
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-- servers do not respect that
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url = url.absolute(reqt.url, location),
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source = reqt.source,
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sink = reqt.sink,
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headers = reqt.headers,
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proxy = reqt.proxy,
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nredirects = (reqt.nredirects or 0) + 1,
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create = reqt.create
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}
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-- pass location header back as a hint we redirected
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headers = headers or {}
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headers.location = headers.location or location
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return result, code, headers, status
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end
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--[[local]] function trequest(reqt)
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-- we loop until we get what we want, or
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-- until we are sure there is no way to get it
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local nreqt = adjustrequest(reqt)
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local h = _M.open(nreqt.host, nreqt.port, nreqt.create)
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-- send request line and headers
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h:sendrequestline(nreqt.method, nreqt.uri)
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h:sendheaders(nreqt.headers)
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-- if there is a body, send it
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if nreqt.source then
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h:sendbody(nreqt.headers, nreqt.source, nreqt.step)
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end
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local code, status = h:receivestatusline()
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-- if it is an HTTP/0.9 server, simply get the body and we are done
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if not code then
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h:receive09body(status, nreqt.sink, nreqt.step)
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return 1, 200
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end
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local headers
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-- ignore any 100-continue messages
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while code == 100 do
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headers = h:receiveheaders()
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code, status = h:receivestatusline()
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end
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headers = h:receiveheaders()
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-- at this point we should have a honest reply from the server
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-- we can't redirect if we already used the source, so we report the error
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if shouldredirect(nreqt, code, headers) and not nreqt.source then
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h:close()
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return tredirect(reqt, headers.location)
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end
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-- here we are finally done
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if shouldreceivebody(nreqt, code) then
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h:receivebody(headers, nreqt.sink, nreqt.step)
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end
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h:close()
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return 1, code, headers, status
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end
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local function srequest(u, b)
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local t = {}
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local reqt = {
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url = u,
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sink = ltn12.sink.table(t)
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}
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if b then
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reqt.source = ltn12.source.string(b)
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reqt.headers = {
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["content-length"] = string.len(b),
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["content-type"] = "application/x-www-form-urlencoded"
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}
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reqt.method = "POST"
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end
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local code, headers, status = socket.skip(1, trequest(reqt))
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return table.concat(t), code, headers, status
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end
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_M.request = socket.protect(function(reqt, body)
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if base.type(reqt) == "string" then return srequest(reqt, body)
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else return trequest(reqt) end
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end)
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return _M |