jbe@0: #!/usr/bin/env lua
jbe@0: 
jbe@0: -- module preamble
jbe@0: local _G, _M = _ENV, {}
jbe@0: _ENV = setmetatable({}, {
jbe@0:   __index = function(self, key)
jbe@0:     local value = _M[key]; if value ~= nil then return value end
jbe@0:     return _G[key]
jbe@0:   end,
jbe@63:   __newindex = _M
jbe@0: })
jbe@0: 
jbe@0: -- function that encodes certain HTML entities:
jbe@0: -- (not used by the library itself)
jbe@0: function encode_html(text)
jbe@0:   return (
jbe@0:     string.gsub(
jbe@0:       text, '[<>&"]',
jbe@0:       function(char)
jbe@0:         if char == '<' then
jbe@0:           return "&lt;"
jbe@0:         elseif char == '>' then
jbe@0:           return "&gt;"
jbe@0:         elseif char == '&' then
jbe@0:           return "&amp;"
jbe@0:         elseif char == '"' then
jbe@0:           return "&quot;"
jbe@0:         end
jbe@0:       end
jbe@0:     )
jbe@0:   )
jbe@0: 
jbe@0: end
jbe@0: 
jbe@0: -- function that encodes special characters for URIs:
jbe@0: -- (not used by the library itself)
jbe@0: function encode_uri(text)
jbe@0:   return (
jbe@0:     string.gsub(text, "[^0-9A-Za-z_%.~-]",
jbe@0:       function (char)
jbe@0:         return string.format("%%%02x", string.byte(char))
jbe@0:       end
jbe@0:     )
jbe@0:   )
jbe@0: end
jbe@0: 
jbe@0: -- function undoing URL encoding:
jbe@0: do
jbe@0:   local b0 = string.byte("0")
jbe@0:   local b9 = string.byte("9")
jbe@0:   local bA = string.byte("A")
jbe@0:   local bF = string.byte("F")
jbe@0:   local ba = string.byte("a")
jbe@0:   local bf = string.byte("f")
jbe@0:   function decode_uri(str)
jbe@0:     return (
jbe@0:       string.gsub(
jbe@0:         string.gsub(str, "%+", " "),
jbe@0:         "%%([0-9A-Fa-f][0-9A-Fa-f])",
jbe@0:         function(hex)
jbe@0:           local n1, n2 = string.byte(hex, 1, 2)
jbe@0:           if n1 >= b0 and n1 <= b9 then n1 = n1 - b0
jbe@0:           elseif n1 >= bA and n1 <= bF then n1 = n1 - bA + 10
jbe@0:           elseif n1 >= ba and n1 <= bf then n1 = n1 - ba + 10
jbe@0:           else error("Assertion failed") end
jbe@0:           if n2 >= b0 and n2 <= b9 then n2 = n2 - b0
jbe@0:           elseif n2 >= bA and n2 <= bF then n2 = n2 - bA + 10
jbe@0:           elseif n2 >= ba and n2 <= bf then n2 = n2 - ba + 10
jbe@0:           else error("Assertion failed") end
jbe@0:           return string.char(n1 * 16 + n2)
jbe@0:         end
jbe@0:       )
jbe@0:     )
jbe@0:   end
jbe@0: end
jbe@0: 
jbe@0: -- status codes that carry no response body (in addition to 1xx):
jbe@0: -- (set to "zero_content_length" if Content-Length header is required)
jbe@0: status_without_response_body = {
jbe@5:   ["101"] = true,  -- list 101 to allow protocol switch
jbe@0:   ["204"] = true,
jbe@0:   ["205"] = "zero_content_length",
jbe@0:   ["304"] = true
jbe@0: }
jbe@0: 
jbe@154: -- parses URL encoded form data:
jbe@154: local function read_urlencoded_form(data)
jbe@154:   local tbl = {}
jbe@154:   for rawkey, rawvalue in string.gmatch(data, "([^?=&]*)=([^?=&]*)") do
jbe@154:     local key = decode_uri(rawkey)
jbe@154:     local value = decode_uri(rawvalue)
jbe@154:     local subtbl = tbl[key]
jbe@154:     if subtbl then
jbe@154:       subtbl[#subtbl+1] = value
jbe@154:     else
jbe@154:       tbl[key] = {value}
jbe@35:     end
jbe@35:   end
jbe@154:   return tbl
jbe@0: end
jbe@0: 
jbe@154: -- extracts first value from each subtable:
jbe@154: local function get_first_values(tbl)
jbe@154:   local newtbl = {}
jbe@154:   for key, subtbl in pairs(tbl) do
jbe@154:     newtbl[key] = subtbl[1]
jbe@0:   end
jbe@154:   return newtbl
jbe@154: end
jbe@154: 
jbe@154: request_pt = {}
jbe@154: request_mt = { __index = request_pt }
jbe@154: 
jbe@154: function request_pt:_init(handler, options)
jbe@0:   -- process options:
jbe@0:   options = options or {}
jbe@0:   do
jbe@0:     -- named arg "static_headers" is used to create the preamble:
jbe@0:     local s = options.static_headers
jbe@0:     local t = {}
jbe@0:     if s then
jbe@0:       if type(s) == "string" then
jbe@0:         for line in string.gmatch(s, "[^\r\n]+") do
jbe@0:           t[#t+1] = line
jbe@0:         end
jbe@0:       else
jbe@0:         for i, kv in ipairs(options.static_headers) do
jbe@0:           if type(kv) == "string" then
jbe@0:             t[#t+1] = kv
jbe@0:           else
jbe@0:             t[#t+1] = kv[1] .. ": " .. kv[2]
jbe@0:           end
jbe@0:         end
jbe@0:       end
jbe@0:     end
jbe@0:     t[#t+1] = ""
jbe@154:     self._preamble = table.concat(t, "\r\n")  -- preamble sent with every(!) HTTP response
jbe@115:   end
jbe@154:   self._input_chunk_size = options.maximum_input_chunk_size or options.chunk_size or 16384
jbe@154:   self._output_chunk_size = options.minimum_output_chunk_size or options.chunk_size or 1024
jbe@154:   self._header_size_limit = options.header_size_limit or 1024*1024
jbe@154:   local function init_timeout(name, default)
jbe@154:     local value = options[name]
jbe@154:     if value == nil then
jbe@154:       self["_"..name] = default
jbe@154:     else
jbe@154:       self["_"..name] = value or 0
jbe@154:     end
jbe@53:   end
jbe@154:   init_timeout("request_idle_timeout", 330)
jbe@154:   init_timeout("request_header_timeout", 30)
jbe@154:   init_timeout("request_body_timeout", 1800)
jbe@154:   init_timeout("response_timeout", 1830)
jbe@154:   self._poll = options.poll_function or moonbridge_io.poll
jbe@154:   self:_create_closure("_write_yield")
jbe@154:   self:_create_closure("_handler")
jbe@154:   -- table mapping header field names to value-lists:
jbe@154:   self._headers_mt = {
jbe@154:     __index = function(tbl, key)
jbe@154:       local lowerkey = string.lower(key)
jbe@154:       local result = self._headers[lowerkey]
jbe@154:       if result == nil then
jbe@154:         result = {}
jbe@50:       end
jbe@154:       tbl[lowerkey] = result
jbe@154:       tbl[key] = result
jbe@154:       return result
jbe@154:     end
jbe@154:   }
jbe@154:   -- table mapping header field names to value-lists
jbe@154:   -- (for headers with comma separated values):
jbe@154:   self._headers_csv_table_mt = {
jbe@154:     __index = function(tbl, key)
jbe@154:       local result = {}
jbe@154:       for i, line in ipairs(self.headers[key]) do
jbe@154:         for entry in string.gmatch(line, "[^,]+") do
jbe@154:           local value = string.match(entry, "^[ \t]*(..-)[ \t]*$")
jbe@154:           if value then
jbe@154:             result[#result+1] = value
jbe@0:           end
jbe@0:         end
jbe@0:       end
jbe@154:       tbl[key] = result
jbe@154:       return result
jbe@154:     end
jbe@154:   }
jbe@154:   -- table mapping header field names to a comma separated string
jbe@154:   -- (for headers with comma separated values):
jbe@154:   self._headers_csv_string_mt = {
jbe@154:     __index = function(tbl, key)
jbe@154:       local result = {}
jbe@154:       for i, line in ipairs(self.headers[key]) do
jbe@154:         result[#result+1] = line
jbe@154:       end
jbe@154:       result = string.concat(result, ", ")
jbe@154:       tbl[key] = result
jbe@154:       return result
jbe@154:     end
jbe@154:   }
jbe@154:   -- table mapping header field names to a single string value
jbe@154:   -- (or false if header has been sent multiple times):
jbe@154:   self._headers_value_mt = {
jbe@154:     __index = function(tbl, key)
jbe@154:       if self._headers_value_nil[key] then
jbe@154:         return nil
jbe@154:       end
jbe@154:       local result = nil
jbe@154:       local values = self.headers_csv_table[key]
jbe@154:       if #values == 0 then
jbe@154:         self._headers_value_nil[key] = true
jbe@154:       elseif #values == 1 then
jbe@154:         result = values[1]
jbe@154:       else
jbe@154:         result = false
jbe@154:       end
jbe@154:       tbl[key] = result
jbe@154:       return result
jbe@154:     end
jbe@154:   }
jbe@154:   -- table mapping header field names to a flag table,
jbe@154:   -- indicating if the comma separated value contains certain entries:
jbe@154:   self._headers_flags_mt = {
jbe@154:     __index = function(tbl, key)
jbe@154:       local result = setmetatable({}, {
jbe@154:         __index = function(tbl, key)
jbe@154:           local lowerkey = string.lower(key)
jbe@154:           local result = rawget(tbl, lowerkey) or false
jbe@154:           tbl[lowerkey] = result
jbe@154:           tbl[key] = result
jbe@154:           return result
jbe@0:         end
jbe@154:       })
jbe@154:       for i, value in ipairs(self.headers_csv_table[key]) do
jbe@154:         result[string.lower(value)] = true
jbe@0:       end
jbe@154:       tbl[key] = result
jbe@154:       return result
jbe@154:     end
jbe@154:   }
jbe@154: end
jbe@154: 
jbe@154: function request_pt:_create_closure(name)
jbe@154:   self[name.."_closure"] = function(...)
jbe@154:     return self[name](self, ...)
jbe@154:   end
jbe@154: end
jbe@154: 
jbe@154: function request_pt:_create_magictable(name)
jbe@154:   self[name] = setmetatable({}, self["_"..name.."_mt"])
jbe@154: end
jbe@154: 
jbe@154: function request_pt:_handler(socket)
jbe@154:   self._socket = socket
jbe@154:   self._survive = true
jbe@154:   self._socket_set = {[socket] = true}
jbe@154:   self._faulty = false
jbe@154:   self._consume_input = self._drain_input
jbe@154:   self._headers = {}
jbe@154:   self._headers_value_nil = {}
jbe@154:   self:_create_magictable("headers")
jbe@154:   self:_create_magictable("headers_csv_table")
jbe@154:   self:_create_magictable("headers_csv_string")
jbe@154:   self:_create_magictable("headers_value")
jbe@154:   self:_create_magictable("headers_flags")
jbe@154:   repeat
jbe@154:     -- wait for input:
jbe@154:     if not moonbridge_io.poll(self._socket_set, nil, self._request_idle_timeout) then
jbe@154:       self:_error("408 Request Timeout", "Idle connection timed out")
jbe@154:       return self._survive
jbe@154:     end
jbe@154:     -- read headers (with timeout):
jbe@154:     do
jbe@154:       local coro = coroutine.wrap(self._read_headers)
jbe@154:       local timeout = self._request_header_timeout
jbe@154:       local starttime = timeout and moonbridge_io.timeref()
jbe@154:       while true do
jbe@154:         local status = coro(self)
jbe@154:         if status == nil then
jbe@154:           local remaining
jbe@154:           if timeout then
jbe@154:             remaining = timeout - moonbridge_io.timeref(starttime)
jbe@0:           end
jbe@154:           if not self._poll(self._socket_set, nil, remaining) then
jbe@154:             self:_error("408 Request Timeout", "Timeout while receiving headers")
jbe@154:             return self._survive
jbe@0:           end
jbe@154:         elseif status == false then
jbe@154:           return self._survive
jbe@154:         elseif status == true then
jbe@154:           break
jbe@154:         else
jbe@154:           error("Unexpected yield value")
jbe@0:         end
jbe@0:       end
jbe@154:     end
jbe@154:   until true
jbe@154: end
jbe@154: 
jbe@154: function request_pt:_error(status, explanation)
jbe@154: end
jbe@154: 
jbe@154: function request_pt:_read(...)
jbe@154:   local line, status = self._socket:read_yield(...)
jbe@154:   if line == nil then
jbe@154:     self._faulty = true
jbe@154:     error(status)
jbe@154:   else
jbe@154:     return line, status
jbe@154:   end
jbe@154: end
jbe@154: 
jbe@154: function request_pt:_read_headers()
jbe@154:   local remaining = self._header_size_limit
jbe@154:   -- read and parse request line:
jbe@154:   local target, proto
jbe@154:   do
jbe@154:     local line, status = self:_read(remaining-2, "\n")
jbe@154:     if status == "maxlen" then
jbe@154:       self:_error("414 Request-URI Too Long")
jbe@154:       return false
jbe@154:     elseif status == "eof" then
jbe@154:       if line ~= "" then
jbe@154:         self:_error("400 Bad Request", "Unexpected EOF in request-URI line")
jbe@115:       end
jbe@154:       return false
jbe@154:     end
jbe@154:     remaining = remaining - #line
jbe@154:     self.method, target, proto =
jbe@154:       line:match("^([^ \t\r]+)[ \t]+([^ \t\r]+)[ \t]*([^ \t\r]*)[ \t]*\r?\n$")
jbe@154:     if not request.method then
jbe@154:       self:_error("400 Bad Request", "Invalid request-URI line")
jbe@154:       return false
jbe@154:     elseif proto ~= "HTTP/1.1" then
jbe@154:       self:_error("505 HTTP Version Not Supported")
jbe@154:       return false
jbe@154:     end
jbe@154:   end
jbe@154:   -- read and parse headers:
jbe@154:   while true do
jbe@154:     local line, status = self:_read(remaining, "\n");
jbe@154:     if status == "maxlen" then
jbe@154:       self:_error("431 Request Header Fields Too Large")
jbe@154:       return false
jbe@154:     elseif status == "eof" then
jbe@154:       self:_error("400 Bad Request", "Unexpected EOF in request headers")
jbe@154:       return false
jbe@154:     end
jbe@154:     remaining = remaining - #line
jbe@154:     if line == "\r\n" or line == "\n" then
jbe@154:       break
jbe@154:     end
jbe@154:     local key, value = string.match(line, "^([^ \t\r]+):[ \t]*(.-)[ \t]*\r?\n$")
jbe@154:     if not key then
jbe@154:       self:_error("400 Bad Request", "Invalid header line")
jbe@154:       return false
jbe@154:     end
jbe@154:     local lowerkey = key:lower()
jbe@154:     local values = self._headers[lowerkey]
jbe@154:     if values then
jbe@154:       values[#values+1] = value
jbe@154:     else
jbe@154:       self._headers[lowerkey] = {value}
jbe@154:     end
jbe@154:   end
jbe@154:   -- process "Connection: close" header if existent:
jbe@154:   self._connection_close_requested = self.headers_flags["Connection"]["close"]
jbe@154:   -- process "Content-Length" header if existent:
jbe@154:   do
jbe@154:     local values = self.headers_csv_table["Content-Length"]
jbe@154:     if #values > 0 then
jbe@154:       self._request_body_content_length = tonumber(values[1])
jbe@154:       local proper_value = tostring(request_body_content_length)
jbe@154:       for i, value in ipairs(values) do
jbe@154:         value = string.match(value, "^0*(.*)")
jbe@154:         if value ~= proper_value then
jbe@154:           self:_error("400 Bad Request", "Content-Length header(s) invalid")
jbe@154:           return false
jbe@0:         end
jbe@38:       end
jbe@154:       if request_body_content_length > self._body_size_limit then
jbe@154:         self:_error("413 Request Entity Too Large", "Announced request body size is too big")
jbe@154:         return false
jbe@38:       end
jbe@154:     end
jbe@154:   end
jbe@154:   -- process "Transfer-Encoding" header if existent:
jbe@154:   do
jbe@154:     local flag = self.headers_flags["Transfer-Encoding"]["chunked"]
jbe@154:     local list = self.headers_csv_table["Transfer-Encoding"]
jbe@154:     if (flag and #list ~= 1) or (not flag and #list ~= 0) then
jbe@154:       self:_error("400 Bad Request", "Unexpected Transfer-Encoding")
jbe@154:       return false
jbe@154:     end
jbe@154:   end
jbe@154:   -- process "Expect" header if existent:
jbe@154:   for i, value in ipairs(self.headers_csv_table["Expect"]) do
jbe@154:     if string.lower(value) ~= "100-continue" then
jbe@154:       self:_error("417 Expectation Failed", "Unexpected Expect header")
jbe@154:       return false
jbe@154:     end
jbe@154:   end
jbe@154:   -- get mandatory Host header according to RFC 7230:
jbe@154:   self.host = self.headers_value["Host"]
jbe@154:   if not self.host then
jbe@154:     self:_error("400 Bad Request", "No valid host header")
jbe@154:     return false
jbe@154:   end
jbe@154:   -- parse request target:
jbe@154:   self.path, self.query = string.match(target, "^/([^?]*)(.*)$")
jbe@154:   if not self.path then
jbe@154:     local host2
jbe@154:     host2, self.path, self.query = string.match(target, "^[Hh][Tt][Tt][Pp]://([^/?]+)/?([^?]*)(.*)$")
jbe@154:     if host2 then
jbe@154:       if self.host ~= host2 then
jbe@154:         self:_error("400 Bad Request", "No valid host header")
jbe@154:         return false
jbe@38:       end
jbe@154:     elseif not (target == "*" and self.method == "OPTIONS") then
jbe@154:       self:_error("400 Bad Request", "Invalid request target")
jbe@154:     end
jbe@154:   end
jbe@154:   -- parse GET params:
jbe@154:   if self.query then
jbe@154:     self.get_params_list = read_urlencoded_form(request.query)
jbe@154:     self.get_params = get_first_values(self.get_params_list)
jbe@154:   end
jbe@154:   -- parse cookies:
jbe@154:   for i, line in ipairs(self.headers["Cookie"]) do
jbe@154:     for rawkey, rawvalue in
jbe@154:       string.gmatch(line, "([^=; ]*)=([^=; ]*)")
jbe@154:     do
jbe@154:       self.cookies[decode_uri(rawkey)] = decode_uri(rawvalue)
jbe@154:     end
jbe@0:   end
jbe@0: end
jbe@0: 
jbe@154: function request_pt:_assert_not_faulty()
jbe@154:   assert(not self._faulty, "Tried to use faulty request handle")
jbe@154: end
jbe@154: 
jbe@154: function request_pt:_write_yield()
jbe@154:   self:_consume_input()
jbe@154:   self._poll(self._socket_set, self._socket_set)
jbe@154: end
jbe@154: 
jbe@154: function request_pt:_write(...)
jbe@154:   assert(self._socket:write_call(self._write_yield_closure, ...))
jbe@154: end
jbe@154: 
jbe@154: function request_pt:_flush(...)
jbe@154:   assert(self._socket:write_call(self._write_yield_closure, ...))
jbe@154: end
jbe@154: 
jbe@154: function request_pt:_drain_input()
jbe@154:   socket:drain_nb(self._input_chunk_size)
jbe@154: end
jbe@154: 
jbe@154: 
jbe@154: -- function creating a HTTP handler:
jbe@154: function generate_handler(handler, options)
jbe@154:   -- swap arguments if necessary (for convenience):
jbe@154:   if type(handler) ~= "function" and type(options) == "function" then
jbe@154:     handler, options = options, handler
jbe@154:   end
jbe@154:   local request = setmetatable({}, request_mt)
jbe@154:   request:_init(handler, options)
jbe@154:   return request._handler_closure
jbe@154: end
jbe@154: 
jbe@0: return _M
jbe@0: