moonbridge
view moonbridge_http.lua @ 167:625ab06babe9
Use old system for GET/POST param tables in new HTTP module implementation
| author | jbe |
|---|---|
| date | Mon Jun 15 00:07:08 2015 +0200 (2015-06-15) |
| parents | 41a44ae5c293 |
| children | d4f5d6a7d401 |
line source
1 #!/usr/bin/env lua
3 -- module preamble
4 local _G, _M = _ENV, {}
5 _ENV = setmetatable({}, {
6 __index = function(self, key)
7 local value = _M[key]; if value ~= nil then return value end
8 return _G[key]
9 end,
10 __newindex = _M
11 })
13 -- function that encodes certain HTML entities:
14 -- (not used by the library itself)
15 function encode_html(text)
16 return (
17 string.gsub(
18 text, '[<>&"]',
19 function(char)
20 if char == '<' then
21 return "<"
22 elseif char == '>' then
23 return ">"
24 elseif char == '&' then
25 return "&"
26 elseif char == '"' then
27 return """
28 end
29 end
30 )
31 )
33 end
35 -- function that encodes special characters for URIs:
36 -- (not used by the library itself)
37 function encode_uri(text)
38 return (
39 string.gsub(text, "[^0-9A-Za-z_%.~-]",
40 function (char)
41 return string.format("%%%02x", string.byte(char))
42 end
43 )
44 )
45 end
47 -- function undoing URL encoding:
48 do
49 local b0 = string.byte("0")
50 local b9 = string.byte("9")
51 local bA = string.byte("A")
52 local bF = string.byte("F")
53 local ba = string.byte("a")
54 local bf = string.byte("f")
55 function decode_uri(str)
56 return (
57 string.gsub(
58 string.gsub(str, "%+", " "),
59 "%%([0-9A-Fa-f][0-9A-Fa-f])",
60 function(hex)
61 local n1, n2 = string.byte(hex, 1, 2)
62 if n1 >= b0 and n1 <= b9 then n1 = n1 - b0
63 elseif n1 >= bA and n1 <= bF then n1 = n1 - bA + 10
64 elseif n1 >= ba and n1 <= bf then n1 = n1 - ba + 10
65 else error("Assertion failed") end
66 if n2 >= b0 and n2 <= b9 then n2 = n2 - b0
67 elseif n2 >= bA and n2 <= bF then n2 = n2 - bA + 10
68 elseif n2 >= ba and n2 <= bf then n2 = n2 - ba + 10
69 else error("Assertion failed") end
70 return string.char(n1 * 16 + n2)
71 end
72 )
73 )
74 end
75 end
77 -- status codes that carry no response body (in addition to 1xx):
78 -- (set to "zero_content_length" if Content-Length header is required)
79 status_without_response_body = {
80 ["101"] = true, -- list 101 to allow protocol switch
81 ["204"] = true,
82 ["205"] = "zero_content_length",
83 ["304"] = true
84 }
86 -- handling of GET/POST param tables:
87 local new_params_list -- defined later
88 do
89 local params_list_mapping = setmetatable({}, {__mode="k"})
90 local function nextnonempty(tbl, key)
91 while true do
92 key = next(tbl, key)
93 if key == nil then
94 return nil
95 end
96 local value = tbl[key]
97 if #value > 0 then
98 return key, value
99 end
100 end
101 end
102 local function nextvalue(tbl, key)
103 key = next(tbl, key)
104 if key == nil then
105 return nil
106 end
107 return key, tbl[key][1]
108 end
109 local params_list_metatable = {
110 __index = function(self, key)
111 local tbl = {}
112 self[key] = tbl
113 return tbl
114 end,
115 __pairs = function(self)
116 return nextnonempty, self, nil
117 end
118 }
119 local params_metatable = {
120 __index = function(self, key)
121 return params_list_mapping[self][key][1]
122 end,
123 __newindex = function(self, key, value)
124 params_list_mapping[self][key] = {value}
125 end,
126 __pairs = function(self)
127 return nextvalue, params_list_mapping[self], nil
128 end
129 }
130 -- returns a table to store key value-list pairs (i.e. multiple values),
131 -- and a second table automatically mapping keys to the first value
132 -- using the key value-list pairs in the first table:
133 new_params_list = function()
134 local params_list = setmetatable({}, params_list_metatable)
135 local params = setmetatable({}, params_metatable)
136 params_list_mapping[params] = params_list
137 return params_list, params
138 end
139 end
141 -- parses URL encoded form data and stores it in
142 -- a key value-list pairs structure that has to be
143 -- previously obtained by calling by new_params_list():
144 local function read_urlencoded_form(tbl, data)
145 for rawkey, rawvalue in string.gmatch(data, "([^?=&]*)=([^?=&]*)") do
146 local subtbl = tbl[decode_uri(rawkey)]
147 subtbl[#subtbl+1] = decode_uri(rawvalue)
148 end
149 end
151 -- extracts first value from each subtable:
152 local function get_first_values(tbl)
153 local newtbl = {}
154 for key, subtbl in pairs(tbl) do
155 newtbl[key] = subtbl[1]
156 end
157 return newtbl
158 end
160 function generate_handler(handler, options)
161 -- swap arguments if necessary (for convenience):
162 if type(handler) ~= "function" and type(options) == "function" then
163 handler, options = options, handler
164 end
165 -- helper function to process options:
166 local function default(name, default_value)
167 local value = options[name]
168 if value == nil then
169 return default_value
170 else
171 return value or nil
172 end
173 end
174 -- process options:
175 options = options or {}
176 local preamble = "" -- preamble sent with every(!) HTTP response
177 do
178 -- named arg "static_headers" is used to create the preamble:
179 local s = options.static_headers
180 local t = {}
181 if s then
182 if type(s) == "string" then
183 for line in string.gmatch(s, "[^\r\n]+") do
184 t[#t+1] = line
185 end
186 else
187 for i, kv in ipairs(options.static_headers) do
188 if type(kv) == "string" then
189 t[#t+1] = kv
190 else
191 t[#t+1] = kv[1] .. ": " .. kv[2]
192 end
193 end
194 end
195 end
196 t[#t+1] = ""
197 preamble = table.concat(t, "\r\n")
198 end
199 local input_chunk_size = options.maximum_input_chunk_size or options.chunk_size or 16384
200 local output_chunk_size = options.minimum_output_chunk_size or options.chunk_size or 1024
201 local header_size_limit = options.header_size_limit or 1024*1024
202 local body_size_limit = options.body_size_limit or 64*1024*1024
203 local request_idle_timeout = default("request_idle_timeout", 330)
204 local request_header_timeout = default("request_header_timeout", 30)
205 local request_body_timeout = default("request_body_timeout", 60)
206 local request_response_timeout = default("request_response_timeout", 1800)
207 local poll = options.poll_function or moonbridge_io.poll
208 -- return socket handler:
209 return function(socket)
210 local socket_set = {[socket] = true} -- used for poll function
211 local survive = true -- set to false if process shall be terminated later
212 local consume -- function that reads some input if possible
213 -- function that drains some input if possible:
214 local function drain()
215 local bytes, status = socket:drain_nb(input_chunk_size)
216 if not bytes or status == "eof" then
217 consume = nil
218 end
219 end
220 -- function trying to unblock socket by reading:
221 local function unblock()
222 if consume then
223 poll(socket_set, socket_set)
224 consume()
225 else
226 poll(nil, socket_set)
227 end
228 end
229 -- function that enforces consumption of all input:
230 local function consume_all()
231 while consume do
232 poll(socket_set, nil)
233 consume()
234 end
235 end
236 -- handle requests in a loop:
237 repeat
238 -- table for caching nil values:
239 local headers_value_nil = {}
240 -- create a new request object:
241 local request -- allow references to local variable
242 request = {
243 -- allow access to underlying socket:
244 socket = socket,
245 -- cookies are simply stored in a table:
246 cookies = {},
247 -- table mapping header field names to value-lists
248 -- (raw access, but case-insensitive):
249 headers = setmetatable({}, {
250 __index = function(self, key)
251 local lowerkey = string.lower(key)
252 if lowerkey == key then
253 return
254 end
255 local result = rawget(self, lowerkey)
256 if result == nil then
257 result = {}
258 end
259 self[lowerkey] = result
260 self[key] = result
261 return result
262 end
263 }),
264 -- table mapping header field names to value-lists
265 -- (for headers with comma separated values):
266 headers_csv_table = setmetatable({}, {
267 __index = function(self, key)
268 local result = {}
269 for i, line in ipairs(request.headers[key]) do
270 for entry in string.gmatch(line, "[^,]+") do
271 local value = string.match(entry, "^[ \t]*(..-)[ \t]*$")
272 if value then
273 result[#result+1] = value
274 end
275 end
276 end
277 self[key] = result
278 return result
279 end
280 }),
281 -- table mapping header field names to a comma separated string
282 -- (for headers with comma separated values):
283 headers_csv_string = setmetatable({}, {
284 __index = function(self, key)
285 local result = {}
286 for i, line in ipairs(request.headers[key]) do
287 result[#result+1] = line
288 end
289 result = string.concat(result, ", ")
290 self[key] = result
291 return result
292 end
293 }),
294 -- table mapping header field names to a single string value
295 -- (or false if header has been sent multiple times):
296 headers_value = setmetatable({}, {
297 __index = function(self, key)
298 if headers_value_nil[key] then
299 return nil
300 end
301 local result = nil
302 local values = request.headers_csv_table[key]
303 if #values == 0 then
304 headers_value_nil[key] = true
305 elseif #values == 1 then
306 result = values[1]
307 else
308 result = false
309 end
310 self[key] = result
311 return result
312 end
313 }),
314 -- table mapping header field names to a flag table,
315 -- indicating if the comma separated value contains certain entries:
316 headers_flags = setmetatable({}, {
317 __index = function(self, key)
318 local result = setmetatable({}, {
319 __index = function(self, key)
320 local lowerkey = string.lower(key)
321 local result = rawget(self, lowerkey) or false
322 self[lowerkey] = result
323 self[key] = result
324 return result
325 end
326 })
327 for i, value in ipairs(request.headers_csv_table[key]) do
328 result[string.lower(value)] = true
329 end
330 self[key] = result
331 return result
332 end
333 })
334 }
335 -- local variables to track the state:
336 local state = "init" -- one of:
337 -- "init" (initial state)
338 -- "prepare" (configureation in preparation)
339 -- "no_status_sent" (configuration complete)
340 -- "info_status_sent" (1xx status code has been sent)
341 -- "bodyless_status_sent" (204/304 status code has been sent)
342 -- "status_sent" (regular status code has been sent)
343 -- "headers_sent" (headers have been terminated)
344 -- "finished" (request has been answered completely)
345 -- "faulty" (I/O or protocaol error)
346 local close_requested = false -- "Connection: close" requested
347 local close_responded = false -- "Connection: close" sent
348 local content_length = nil -- value of Content-Length header sent
349 local chunk_parts = {} -- list of chunks to send
350 local chunk_bytes = 0 -- sum of lengths of chunks to send
351 -- functions to assert proper output/closing:
352 local function assert_output(...)
353 local retval, errmsg = ...
354 if retval then return ... end
355 state = "faulty"
356 socket:reset()
357 error("Could not send data to client: " .. errmsg)
358 end
359 local function assert_close(...)
360 local retval, errmsg = ...
361 if retval then return ... end
362 state = "faulty"
363 error("Could not finish sending data to client: " .. errmsg)
364 end
365 -- function to assert non-faulty handle:
366 local function assert_not_faulty()
367 assert(state ~= "faulty", "Tried to use faulty request handle")
368 end
369 -- functions to send data to the browser:
370 local function send(...)
371 assert_output(socket:write_call(unblock, ...))
372 end
373 local function send_flush(...)
374 assert_output(socket:flush_call(unblock, ...))
375 end
376 -- function to finish request:
377 local function finish()
378 if close_responded then
379 -- discard any input:
380 consume = drain
381 -- close output stream:
382 send_flush()
383 assert_close(socket:finish())
384 -- wait for EOF of peer to avoid immediate TCP RST condition:
385 consume_all()
386 -- fully close socket:
387 assert_close(socket:close())
388 else
389 send_flush()
390 consume_all()
391 end
392 end
393 -- function that writes out buffered chunks (without flushing the socket):
394 function send_chunk()
395 if chunk_bytes > 0 then
396 assert_output(socket:write(string.format("%x\r\n", chunk_bytes)))
397 for i = 1, #chunk_parts do -- TODO: evaluated only once?
398 send(chunk_parts[i])
399 chunk_parts[i] = nil
400 end
401 chunk_bytes = 0
402 send("\r\n")
403 end
404 end
405 -- function to prepare (or skip) body processing:
406 local function prepare()
407 assert_not_faulty()
408 if state == "prepare" then
409 error("Unexpected internal status in HTTP engine (recursive prepare)")
410 elseif state ~= "init" then
411 return
412 end
413 state = "prepare"
414 -- TODO
415 state = "no_status_sent"
416 end
417 -- method to ignore input and close connection after response:
418 function request:monologue()
419 assert_not_faulty()
420 if
421 state == "headers_sent" or
422 state == "finished"
423 then
424 error("All HTTP headers have already been sent")
425 end
426 local old_state = state
427 state = "faulty"
428 consume = drain
429 close_requested = true
430 if old_state == "init" or old_state == "prepare" then -- TODO: ok?
431 state = "no_status_sent"
432 else
433 state = old_state
434 end
435 end
436 --
437 -- method to send a HTTP response status (e.g. "200 OK"):
438 function request:send_status(status)
439 prepare()
440 local old_state = state
441 state = "faulty"
442 if old_state == "info_status_sent" then
443 send_flush("\r\n")
444 elseif old_state ~= "no_status_sent" then
445 error("HTTP status has already been sent")
446 end
447 local status1 = string.sub(status, 1, 1)
448 local status3 = string.sub(status, 1, 3)
449 send("HTTP/1.1 ", status, "\r\n", preamble)
450 local wrb = status_without_response_body[status3]
451 if wrb then
452 state = "bodyless_status_sent"
453 if wrb == "zero_content_length" then
454 request:send_header("Content-Length", 0)
455 end
456 elseif status1 == "1" then
457 state = "info_status_sent"
458 else
459 state = "status_sent"
460 end
461 end
462 -- method to send a HTTP response header:
463 -- (key and value must be provided as separate args)
464 function request:send_header(key, value)
465 assert_not_faulty()
466 if
467 state == "init" or
468 state == "prepare" or
469 state == "no_status_sent"
470 then
471 error("HTTP status has not been sent yet")
472 elseif
473 state == "headers_sent" or
474 state == "finished"
475 then
476 error("All HTTP headers have already been sent")
477 end
478 local key_lower = string.lower(key)
479 if key_lower == "content-length" then
480 if state == "info_status_sent" then
481 error("Cannot set Content-Length for informational status response")
482 end
483 local cl = assert(tonumber(value), "Invalid content-length")
484 if content_length == nil then
485 content_length = cl
486 elseif content_length == cl then
487 return
488 else
489 error("Content-Length has been set multiple times with different values")
490 end
491 elseif key_lower == "connection" then
492 for entry in string.gmatch(string.lower(value), "[^,]+") do
493 if string.match(entry, "^[ \t]*close[ \t]*$") then
494 if state == "info_status_sent" then
495 error("Cannot set \"Connection: close\" for informational status response")
496 end
497 close_responded = true
498 break
499 end
500 end
501 end
502 assert_output(socket:write(key, ": ", value, "\r\n"))
503 end
504 -- function to terminate header section in response, optionally flushing:
505 -- (may be called multiple times unless response is finished)
506 local function finish_headers(with_flush)
507 if state == "finished" then
508 error("Response has already been finished")
509 elseif state == "info_status_sent" then
510 send_flush("\r\n")
511 state = "no_status_sent"
512 elseif state == "bodyless_status_sent" then
513 if close_requested and not close_responded then
514 request:send_header("Connection", "close")
515 end
516 send("\r\n")
517 finish()
518 state = "finished"
519 elseif state == "status_sent" then
520 if not content_length then
521 request:send_header("Transfer-Encoding", "chunked")
522 end
523 if close_requested and not close_responded then
524 request:send_header("Connection", "close")
525 end
526 send("\r\n")
527 if request.method == "HEAD" then
528 finish()
529 elseif with_flush then
530 send_flush()
531 end
532 state = "headers_sent"
533 elseif state ~= "headers_sent" then
534 error("HTTP status has not been sent yet")
535 end
536 end
537 -- method to finish and flush headers:
538 function request:finish_headers()
539 assert_not_faulty()
540 finish_headers(true)
541 end
542 -- method to send body data:
543 function request:send_data(...)
544 assert_not_faulty()
545 if output_state == "info_status_sent" then
546 error("No (non-informational) HTTP status has been sent yet")
547 elseif output_state == "bodyless_status_sent" then
548 error("Cannot send response data for body-less status message")
549 end
550 finish_headers(false)
551 if output_state ~= "headers_sent" then
552 error("Unexpected internal status in HTTP engine")
553 end
554 if request.method == "HEAD" then
555 return
556 end
557 for i = 1, select("#", ...) do
558 local str = tostring(select(i, ...))
559 if #str > 0 then
560 if content_length then
561 local bytes_to_send = #str
562 if bytes_sent + bytes_to_send > content_length then
563 error("Content length exceeded")
564 else
565 send(str)
566 bytes_sent = bytes_sent + bytes_to_send
567 end
568 else
569 chunk_bytes = chunk_bytes + #str
570 chunk_parts[#chunk_parts+1] = str
571 end
572 end
573 end
574 if chunk_bytes >= output_chunk_size then
575 send_chunk()
576 end
577 end
578 -- method to flush output buffer:
579 function request:flush()
580 assert_not_faulty()
581 send_chunk()
582 send_flush()
583 end
584 -- method to finish response:
585 function request:finish()
586 assert_not_faulty()
587 if state == "finished" then
588 return
589 elseif state == "info_status_sent" then
590 error("Informational HTTP response can be finished with :finish_headers() method")
591 end
592 finish_headers(false)
593 if state == "headers_sent" then
594 if request.method ~= "HEAD" then
595 state = "faulty"
596 if content_length then
597 if bytes_sent ~= content_length then
598 error("Content length not used")
599 end
600 else
601 send_chunk()
602 send("0\r\n\r\n")
603 end
604 finish()
605 end
606 state = "finished"
607 elseif state ~= "finished" then
608 error("Unexpected internal status in HTTP engine")
609 end
610 end
611 -- function to report an error:
612 local function request_error(throw_error, status, text)
613 local errmsg = "Error while reading request from client. Error response: " .. status
614 if text then
615 errmsg = errmsg .. " (" .. text .. ")"
616 end
617 if
618 state == "init" or
619 state == "prepare" or
620 state == "no_status_sent" or
621 state == "info_status_sent"
622 then
623 local error_response_status, errmsg2 = pcall(function()
624 request:monologue()
625 request:send_status(status)
626 request:send_header("Content-Type", "text/plain")
627 request:send_data(status, "\n")
628 if text then
629 request:send_data("\n", text, "\n")
630 end
631 request:finish()
632 end)
633 if not error_response_status then
634 error("Unexpected error while sending error response: " .. errmsg2)
635 end
636 elseif state ~= "faulty" then
637 assert_close(socket:reset())
638 end
639 if throw_error then
640 error(errmsg)
641 else
642 return survive
643 end
644 end
645 -- wait for input:
646 if not poll(socket_set, nil, request_idle_timeout) then
647 return request_error(false, "408 Request Timeout", "Idle connection timed out")
648 end
649 until close_responded
650 return survive
651 end
652 end
654 return _M