net/httpserver.lua

   1
   2 local socket = require "socket"
   3 local server = require "net.server"
   4 local url_parse = require "socket.url".parse;
   5
   6 local connlisteners_start = require "net.connlisteners".start;
   7 local connlisteners_get = require "net.connlisteners".get;
   8 local listener;
   9
  10 local t_insert, t_concat = table.insert, table.concat;
  11 local s_match, s_gmatch = string.match, string.gmatch;
  12 local tonumber, tostring, pairs = tonumber, tostring, pairs;
  13
  14 local urlencode = function (s) return s and (s:gsub("%W", function (c) return string.format("%%%x", c:byte()); end)); end
  15
  16 local log = require "util.logger".init("httpserver");
  17
  18 local http_servers = {};
  19
  20 module "httpserver"
  21
  22 local default_handler;
  23
  24 local function expectbody(reqt)
  25     return reqt.method == "POST";
  26 end
  27
  28 local function send_response(request, response)
  29         -- Write status line
  30         local resp;
  31         if response.body then
  32                 log("debug", "Sending response to %s", request.id);
  33                 resp = { "HTTP/1.0 ", response.status or "200 OK", "\r\n"};
  34                 local h = response.headers;
  35                 if h then
  36                         for k, v in pairs(h) do
  37                                 t_insert(resp, k);
  38                                 t_insert(resp, ": ");
  39                                 t_insert(resp, v);
  40                                 t_insert(resp, "\r\n");
  41                         end
  42                 end
  43                 if response.body and not (h and h["Content-Length"]) then
  44                         t_insert(resp, "Content-Length: ");
  45                         t_insert(resp, #response.body);
  46                         t_insert(resp, "\r\n");
  47                 end
  48                 t_insert(resp, "\r\n");
  49
  50                 if response.body and request.method ~= "HEAD" then
  51                         t_insert(resp, response.body);
  52                 end
  53         else
  54                 -- Response we have is just a string (the body)
  55                 log("debug", "Sending response to %s: %s", request.id, response);
  56
  57                 resp = { "HTTP/1.0 200 OK\r\n" };
  58                 t_insert(resp, "Connection: close\r\n");
  59                 t_insert(resp, "Content-Length: ");
  60                 t_insert(resp, #response);
  61                 t_insert(resp, "\r\n\r\n");
  62
  63                 t_insert(resp, response);
  64         end
  65         request.write(t_concat(resp));
  66         if not request.stayopen then
  67                 request:destroy();
  68         end
  69 end
  70
  71 local function call_callback(request, err)
  72         if request.handled then return; end
  73         request.handled = true;
  74         local callback = request.callback;
  75         if not callback and request.path then
  76                 local path = request.url.path;
  77                 local base = path:match("^/([^/?]+)");
  78                 if not base then
  79                         base = path:match("^http://[^/?]+/([^/?]+)");
  80                 end
  81
  82                 callback = (request.server and request.server.handlers[base]) or default_handler;
  83                 if callback == default_handler then
  84                         log("debug", "Default callback for this request (base: "..tostring(base)..")")
  85                 end
  86         end
  87         if callback then
  88                 if err then
  89                         log("debug", "Request error: "..err);
  90                         if not callback(nil, err, request) then
  91                                 destroy_request(request);
  92                         end
  93                         return;
  94                 end
  95
  96                 local response = callback(request.method, request.body and t_concat(request.body), request);
  97                 if response then
  98                         if response == true and not request.destroyed then
  99                                 -- Keep connection open, we will reply later
 100                                 log("warn", "Request %s left open, on_destroy is %s", request.id, tostring(request.on_destroy));
 101                         elseif response ~= true then
 102                                 -- Assume response
 103                                 send_response(request, response);
 104                                 destroy_request(request);
 105                         end
 106                 else
 107                         log("debug", "Request handler provided no response, destroying request...");
 108                         -- No response, close connection
 109                         destroy_request(request);
 110                 end
 111         end
 112 end
 113
 114 local function request_reader(request, data, startpos)
 115         if not data then
 116                 if request.body then
 117                         call_callback(request);
 118                 else
 119                         -- Error.. connection was closed prematurely
 120                         call_callback(request, "connection-closed");
 121                 end
 122                 -- Here we force a destroy... the connection is gone, so we can't reply later
 123                 destroy_request(request);
 124                 return;
 125         end
 126         if request.state == "body" then
 127                 log("debug", "Reading body...")
 128                 if not request.body then request.body = {}; request.havebodylength, request.bodylength = 0, tonumber(request.headers["content-length"]); end
 129                 if startpos then
 130                         data = data:sub(startpos, -1)
 131                 end
 132                 t_insert(request.body, data);
 133                 if request.bodylength then
 134                         request.havebodylength = request.havebodylength + #data;
 135                         if request.havebodylength >= request.bodylength then
 136                                 -- We have the body
 137                                 call_callback(request);
 138                         end
 139                 end
 140         elseif request.state == "headers" then
 141                 log("debug", "Reading headers...")
 142                 local pos = startpos;
 143                 local headers = request.headers or {};
 144                 for line in data:gmatch("(.-)\r\n") do
 145                         startpos = (startpos or 1) + #line + 2;
 146                         local k, v = line:match("(%S+): (.+)");
 147                         if k and v then
 148                                 headers[k:lower()] = v;
 149 --                              log("debug", "Header: "..k:lower().." = "..v);
 150                         elseif #line == 0 then
 151                                 request.headers = headers;
 152                                 break;
 153                         else
 154                                 log("debug", "Unhandled header line: "..line);
 155                         end
 156                 end
 157
 158                 if not expectbody(request) then
 159                         call_callback(request);
 160                         return;
 161                 end
 162
 163                 -- Reached the end of the headers
 164                 request.state = "body";
 165                 if #data > startpos then
 166                         return request_reader(request, data:sub(startpos, -1));
 167                 end
 168         elseif request.state == "request" then
 169                 log("debug", "Reading request line...")
 170                 local method, path, http, linelen = data:match("^(%S+) (%S+) HTTP/(%S+)\r\n()", startpos);
 171                 if not method then
 172                         return call_callback(request, "invalid-status-line");
 173                 end
 174
 175                 request.method, request.path, request.httpversion = method, path, http;
 176
 177                 request.url = url_parse(request.path);
 178
 179                 log("debug", method.." request for "..tostring(request.path) .. " on port "..request.handler.serverport());
 180
 181                 if request.onlystatus then
 182                         if not call_callback(request) then
 183                                 return;
 184                         end
 185                 end
 186
 187                 request.state = "headers";
 188
 189                 if #data > linelen then
 190                         return request_reader(request, data:sub(linelen, -1));
 191                 end
 192         end
 193 end
 194
 195 -- The default handler for requests
 196 default_handler = function (method, body, request)
 197         log("debug", method.." request for "..tostring(request.path) .. " on port "..request.handler.serverport());
 198         return { status = "404 Not Found",
 199                         headers = { ["Content-Type"] = "text/html" },
 200                         body = "<html><head><title>Page Not Found</title></head><body>Not here :(</body></html>" };
 201 end
 202
 203
 204 function new_request(handler)
 205         return { handler = handler, conn = handler.socket,
 206                         write = handler.write, state = "request",
 207                         server = http_servers[handler.serverport()],
 208                         send = send_response,
 209                         destroy = destroy_request,
 210                         id = tostring{}:match("%x+$")
 211                          };
 212 end
 213
 214 function destroy_request(request)
 215         log("debug", "Destroying request %s", request.id);
 216         listener = listener or connlisteners_get("httpserver");
 217         if not request.destroyed then
 218                 request.destroyed = true;
 219                 if request.on_destroy then
 220                         log("debug", "Request has destroy callback");
 221                         request.on_destroy(request);
 222                 else
 223                         log("debug", "Request has no destroy callback");
 224                 end
 225                 request.handler.close()
 226                 if request.conn then
 227                         listener.disconnect(request.conn, "closed");
 228                 end
 229         end
 230 end
 231
 232 function new(params)
 233         local http_server = http_servers[params.port];
 234         if not http_server then
 235                 http_server = { handlers = {} };
 236                 http_servers[params.port] = http_server;
 237                 -- We weren't already listening on this port, so start now
 238                 connlisteners_start("httpserver", params);
 239         end
 240         if params.base then
 241                 http_server.handlers[params.base] = params.handler;
 242         end
 243 end
 244
 245 _M.request_reader = request_reader;
 246 _M.send_response = send_response;
 247 _M.urlencode = urlencode;
 248
 249 return _M;