moonbridge

view moonbridge_http.lua @ 326:4379766473ec

Fixed proper errno handling for blocking I/O in localconnect function for connecting to sockets
author jbe
date Tue Jun 23 12:25:58 2020 +0200 (6 weeks ago)
parents 7751e4982916
children
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 "&lt;"
22 elseif char == '>' then
23 return "&gt;"
24 elseif char == '&' then
25 return "&amp;"
26 elseif char == '"' then
27 return "&quot;"
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 while true do
104 key = next(tbl, key)
105 if key == nil then
106 return nil
107 end
108 local value = tbl[key][1]
109 if value ~= nil then
110 return key, value
111 end
112 end
113 end
114 local params_list_metatable = {
115 __index = function(self, key)
116 local tbl = {}
117 self[key] = tbl
118 return tbl
119 end,
120 __pairs = function(self)
121 return nextnonempty, self, nil
122 end
123 }
124 local params_metatable = {
125 __index = function(self, key)
126 return params_list_mapping[self][key][1]
127 end,
128 __newindex = function(self, key, value)
129 params_list_mapping[self][key] = {value}
130 end,
131 __pairs = function(self)
132 return nextvalue, params_list_mapping[self], nil
133 end
134 }
135 -- function that returns a table to store key value-list pairs,
136 -- and a second table automatically mapping keys to the first value
137 -- using the key value-list pairs in the first table:
138 new_params_list = function()
139 local params_list = setmetatable({}, params_list_metatable)
140 local params = setmetatable({}, params_metatable)
141 params_list_mapping[params] = params_list
142 return params_list, params
143 end
144 end
146 -- function parsing URL encoded form data and storing it in
147 -- a key value-list pairs structure that has to be
148 -- previously obtained by calling by new_params_list():
149 local function read_urlencoded_form(tbl, data)
150 for rawkey, rawvalue in string.gmatch(data, "([^?=&]*)=([^?=&]*)") do
151 local subtbl = tbl[decode_uri(rawkey)]
152 subtbl[#subtbl+1] = decode_uri(rawvalue)
153 end
154 end
156 -- function to convert a HTTP request handler to a socket handler:
157 function generate_handler(handler, options)
158 -- swap arguments if necessary (for convenience):
159 if type(handler) ~= "function" and type(options) == "function" then
160 handler, options = options, handler
161 end
162 -- helper function to process options:
163 local function default(name, default_value)
164 local value = options[name]
165 if value == nil then
166 return default_value
167 else
168 return value or nil
169 end
170 end
171 -- process options:
172 options = options or {}
173 local preamble = "" -- preamble sent with every(!) HTTP response
174 do
175 -- named arg "static_headers" is used to create the preamble:
176 local s = options.static_headers
177 local t = {}
178 if s then
179 if type(s) == "string" then
180 for line in string.gmatch(s, "[^\r\n]+") do
181 t[#t+1] = line
182 end
183 else
184 for i, kv in ipairs(s) do
185 if type(kv) == "string" then
186 t[#t+1] = kv
187 else
188 t[#t+1] = kv[1] .. ": " .. kv[2]
189 end
190 end
191 end
192 end
193 t[#t+1] = ""
194 preamble = table.concat(t, "\r\n")
195 end
196 local input_chunk_size = options.maximum_input_chunk_size or options.chunk_size or 16384
197 local output_chunk_size = options.minimum_output_chunk_size or options.chunk_size or 1024
198 local header_size_limit = options.request_header_size_limit or 1024*1024
199 local body_size_limit = options.request_body_size_limit or 64*1024*1024
200 local idle_timeout = default("idle_timeout", 65)
201 local stall_timeout = default("stall_timeout", 60)
202 local request_header_timeout = default("request_header_timeout", 120)
203 local response_timeout = default("response_timeout", 3600)
204 local drain_timeout = default("drain_timeout", 2)
205 local poll = options.poll_function or moonbridge_io.poll
206 -- return socket handler:
207 return function(socket)
208 local socket_set = {[socket] = true} -- used for poll function
209 local survive = true -- set to false if process shall be terminated later
210 local consume -- can be set to function that reads some input if possible
211 -- function that may be used as "consume" function
212 -- and which drains some input if possible:
213 local function drain()
214 local bytes, status = socket:drain_nb(input_chunk_size)
215 if not bytes or status == "eof" then
216 consume = nil
217 end
218 end
219 -- function trying to unblock socket by reading:
220 local function unblock()
221 if consume then
222 if not poll(socket_set, socket_set, stall_timeout) then
223 socket:reset()
224 error("Client connection stalled")
225 end
226 consume()
227 else
228 if not poll(nil, socket_set, stall_timeout) then
229 socket:reset()
230 error("Client connection stalled")
231 end
232 end
233 end
234 -- handle requests in a loop:
235 repeat
236 -- table for caching nil values:
237 local headers_value_nil = {}
238 -- create a new request object (methods are added later):
239 local request -- allow references to local variable
240 request = {
241 -- allow access to underlying socket:
242 socket = socket,
243 -- cookies are simply stored in a table:
244 cookies = {},
245 -- table mapping header field names to value-lists
246 -- (raw access, but case-insensitive):
247 headers = setmetatable({}, {
248 __index = function(self, key)
249 assert(type(key) == "string", "Attempted to index headers table with a non-string key")
250 local lowerkey = string.lower(key)
251 local result = rawget(self, lowerkey)
252 if result == nil then
253 result = {}
254 rawset(self, lowerkey, result)
255 end
256 rawset(self, key, result)
257 return result
258 end
259 }),
260 -- table mapping header field names to value-lists
261 -- (for headers with comma separated values):
262 headers_csv_table = setmetatable({}, {
263 __index = function(self, key)
264 local result = {}
265 for i, line in ipairs(request.headers[key]) do
266 for entry in string.gmatch(line, "[^,]+") do
267 local value = string.match(entry, "^[ \t]*(..-)[ \t]*$")
268 if value then
269 result[#result+1] = value
270 end
271 end
272 end
273 self[key] = result
274 return result
275 end
276 }),
277 -- table mapping header field names to a comma separated string
278 -- (for headers with comma separated values):
279 headers_csv_string = setmetatable({}, {
280 __index = function(self, key)
281 local result = {}
282 for i, line in ipairs(request.headers[key]) do
283 result[#result+1] = line
284 end
285 result = table.concat(result, ", ")
286 self[key] = result
287 return result
288 end
289 }),
290 -- table mapping header field names to a single string value
291 -- (or false if header has been sent multiple times):
292 headers_value = setmetatable({}, {
293 __index = function(self, key)
294 if headers_value_nil[key] then
295 return nil
296 end
297 local values = request.headers_csv_table[key]
298 if #values == 0 then
299 headers_value_nil[key] = true
300 else
301 local result
302 if #values == 1 then
303 result = values[1]
304 else
305 result = false
306 end
307 self[key] = result
308 return result
309 end
310 end
311 }),
312 -- table mapping header field names to a flag table,
313 -- indicating if the comma separated value contains certain entries:
314 headers_flags = setmetatable({}, {
315 __index = function(self, key)
316 local result = setmetatable({}, {
317 __index = function(self, key)
318 assert(type(key) == "string", "Attempted to index header flag table with a non-string key")
319 local lowerkey = string.lower(key)
320 local result = rawget(self, lowerkey) or false
321 self[lowerkey] = result
322 self[key] = result
323 return result
324 end
325 })
326 for i, value in ipairs(request.headers_csv_table[key]) do
327 result[string.lower(value)] = true
328 end
329 self[key] = result
330 return result
331 end
332 })
333 }
334 -- create metatable for request object:
335 local request_mt = {}
336 setmetatable(request, request_mt)
337 -- callback for request body streaming:
338 local process_body_chunk
339 -- function to enable draining:
340 local function enable_drain()
341 consume = drain
342 process_body_chunk = nil -- allow for early garbage collection
343 end
344 -- local variables to track the state:
345 local state = "init" -- one of:
346 -- "init" (initial state)
347 -- "no_status_sent" (request body streaming config complete)
348 -- "info_status_sent" (1xx status code has been sent)
349 -- "bodyless_status_sent" (204/304 status code has been sent)
350 -- "status_sent" (regular status code has been sent)
351 -- "headers_sent" (headers have been terminated)
352 -- "finished" (request has been answered completely)
353 -- "faulty" (I/O or protocaol error)
354 local request_body_content_length -- Content-Length of request body
355 local close_requested = false -- "Connection: close" requested
356 local close_responded = false -- "Connection: close" sent
357 local content_length = nil -- value of Content-Length header sent
358 local bytes_sent = 0 -- number of bytes sent if Content-Length is set
359 local chunk_parts = {} -- list of chunks to send
360 local chunk_bytes = 0 -- sum of lengths of chunks to send
361 local streamed_post_params = {} -- mapping from POST field name to stream function
362 local streamed_post_param_patterns = {} -- list of POST field pattern and stream function pairs
363 -- function to report an error:
364 local function request_error(throw_error, status, text)
365 local response_sent = false
366 if
367 state == "init" or
368 state == "no_status_sent" or
369 state == "info_status_sent"
370 then
371 local error_response_status, errmsg = pcall(function()
372 request:monologue()
373 request:send_status(status)
374 request:send_header("Content-Type", "text/plain")
375 request:send_data(status, "\n")
376 if text then
377 request:send_data("\n", text, "\n")
378 end
379 request:finish()
380 end)
381 if not error_response_status then
382 if text then
383 error("Error while sending error response (" .. status .. " / " .. text .. "): " .. errmsg)
384 else
385 error("Error while sending error response (" .. status .. "): " .. errmsg)
386 end
387 end
388 response_sent = true
389 end
390 if throw_error then
391 local errmsg
392 if response_sent then
393 errmsg = "Error while reading request from client. Error response: "
394 else
395 errmsg = "Error while reading request from client: "
396 end
397 errmsg = errmsg .. status
398 if text then
399 errmsg = errmsg .. " (" .. text .. ")"
400 end
401 error(errmsg)
402 else
403 return survive
404 end
405 end
406 -- function that enforces consumption of all input:
407 local function consume_all(timeout)
408 local starttime = timeout and moonbridge_io.timeref()
409 while consume do
410 if timeout then
411 -- passed timeout does not get reset but refers to starttime
412 if not poll(socket_set, nil, timeout-moonbridge_io.timeref(starttime)) then
413 return false
414 end
415 else
416 -- stall_timeout gets reset for every poll
417 if not poll(socket_set, nil, stall_timeout) then
418 request_error(true, "408 Request Timeout", "Timeout while waiting for request body")
419 end
420 end
421 consume()
422 end
423 return true
424 end
425 -- function to assert non-faulty handle:
426 local function assert_not_faulty()
427 assert(state ~= "faulty", "Tried to use faulty request handle")
428 end
429 -- functions to send data to the browser:
430 local function send(...)
431 local old_state = state; state = "faulty"
432 local success, errmsg = socket:write_call(unblock, ...)
433 if not success then
434 socket:reset()
435 error("Could not send data to client: " .. errmsg)
436 end
437 state = old_state
438 end
439 local function send_flush(...)
440 local old_state = state; state = "faulty"
441 local success, errmsg = socket:flush_call(unblock, ...)
442 if not success then
443 socket:reset()
444 error("Could not send data to client: " .. errmsg)
445 end
446 state = old_state
447 end
448 -- function to assert proper finish/close/reset:
449 local function assert_close(retval, errmsg)
450 if not retval then
451 error("Could not finish sending data to client: " .. errmsg)
452 end
453 end
454 -- function to finish request:
455 local function finish()
456 if close_responded then
457 -- discard any input:
458 enable_drain()
459 -- close output stream:
460 send_flush()
461 assert_close(socket:finish())
462 -- wait for EOF from peer to avoid immediate TCP RST condition:
463 if consume_all(drain_timeout) then
464 -- fully close socket:
465 assert_close(socket:close())
466 else
467 -- send TCP RST if draining input takes too long:
468 assert_close(socket:reset())
469 end
470 else
471 -- flush outgoing data:
472 send_flush()
473 -- consume incoming data:
474 consume_all()
475 end
476 end
477 -- function that writes out buffered chunks (without flushing the socket):
478 function send_chunk()
479 if chunk_bytes > 0 then
480 local old_state = state; state = "faulty"
481 send(string.format("%x\r\n", chunk_bytes))
482 for i = 1, #chunk_parts do
483 send(chunk_parts[i])
484 chunk_parts[i] = nil
485 end
486 chunk_bytes = 0
487 send("\r\n")
488 state = old_state
489 end
490 end
491 -- read functions
492 local function read(...)
493 local data, status = socket:read_yield(...)
494 if data == nil then
495 request_error(true, "400 Bad Request", "Read error")
496 end
497 if status == "eof" then
498 request_error(true, "400 Bad Request", "Unexpected EOF")
499 end
500 return data
501 end
502 local function read_eof(...)
503 local data, status = socket:read_yield(...)
504 if data == nil then
505 return nil -- do not throw error on TCP RST
506 --request_error(true, "400 Bad Request", "Read error")
507 end
508 if status == "eof" then
509 if data == "" then
510 return nil
511 else
512 request_error(true, "400 Bad Request", "Unexpected EOF")
513 end
514 end
515 return data
516 end
517 -- reads a number of bytes from the socket,
518 -- optionally feeding these bytes chunk-wise into
519 -- the "process_body_chunk" callback function:
520 local function read_body_bytes(remaining)
521 while remaining > 0 do
522 coroutine.yield() -- do not read more than necessary
523 local chunklen
524 if remaining > input_chunk_size then
525 chunklen = input_chunk_size
526 else
527 chunklen = remaining
528 end
529 local chunk = read(chunklen)
530 remaining = remaining - chunklen
531 if process_body_chunk then
532 process_body_chunk(chunk)
533 end
534 end
535 end
536 -- coroutine for request body processing:
537 local function read_body()
538 if request.headers_flags["Transfer-Encoding"]["chunked"] then
539 coroutine.yield() -- do not read on first invocation
540 local limit = body_size_limit
541 while true do
542 local line = read(32 + limit, "\n")
543 local zeros, lenstr = string.match(line, "^(0*)([1-9A-Fa-f]+[0-9A-Fa-f]*)\r?\n$")
544 local chunkext
545 if lenstr then
546 chunkext = ""
547 else
548 zeros, lenstr, chunkext = string.match(line, "^(0*)([1-9A-Fa-f]+[0-9A-Fa-f]*)([ \t;].-)\r?\n$")
549 end
550 if not lenstr or #lenstr > 13 then
551 request_error(true, "400 Bad Request", "Encoding error while reading chunk of request body")
552 end
553 local len = tonumber("0x" .. lenstr)
554 limit = limit - (#zeros + #chunkext + len)
555 if limit < 0 then
556 request_error(true, "413 Request Entity Too Large", "Request body size limit exceeded")
557 end
558 if len == 0 then break end
559 read_body_bytes(len)
560 local term = read(2, "\n")
561 if term ~= "\r\n" and term ~= "\n" then
562 request_error(true, "400 Bad Request", "Encoding error while reading chunk of request body")
563 end
564 end
565 while true do
566 local line = read(2 + limit, "\n")
567 if line == "\r\n" or line == "\n" then break end
568 limit = limit - #line
569 if limit < 0 then
570 request_error(true, "413 Request Entity Too Large", "Request body size limit exceeded while reading trailer section of chunked request body")
571 end
572 end
573 elseif request_body_content_length then
574 read_body_bytes(request_body_content_length)
575 end
576 if process_body_chunk then
577 process_body_chunk(nil) -- signal EOF
578 end
579 consume = nil -- avoid further resumes
580 end
581 -- function to setup default request body handling:
582 local function default_request_body_handling()
583 local post_params_list, post_params = new_params_list()
584 local content_type = request.headers_value["Content-Type"]
585 if content_type then
586 if
587 content_type == "application/x-www-form-urlencoded" or
588 string.match(content_type, "^application/x%-www%-form%-urlencoded *;")
589 then
590 read_urlencoded_form(post_params_list, request.body)
591 else
592 local boundary = string.match(
593 content_type,
594 '^multipart/form%-data[ \t]*[;,][ \t]*boundary="([^"]+)"$'
595 ) or string.match(
596 content_type,
597 '^multipart/form%-data[ \t]*[;,][ \t]*boundary=([^"; \t]+)$'
598 )
599 if boundary then
600 local post_metadata_list, post_metadata = new_params_list()
601 boundary = "--" .. boundary
602 local headerdata = ""
603 local streamer
604 local field_name
605 local metadata = {}
606 local value_parts
607 local function default_streamer(chunk)
608 value_parts[#value_parts+1] = chunk
609 end
610 local function stream_part_finish()
611 if streamer == default_streamer then
612 local value = table.concat(value_parts)
613 value_parts = nil
614 if field_name then
615 local values = post_params_list[field_name]
616 values[#values+1] = value
617 local metadata_entries = post_metadata_list[field_name]
618 metadata_entries[#metadata_entries+1] = metadata
619 end
620 else
621 streamer()
622 end
623 headerdata = ""
624 streamer = nil
625 field_name = nil
626 metadata = {}
627 end
628 local function stream_part_chunk(chunk)
629 if streamer then
630 streamer(chunk)
631 else
632 headerdata = headerdata .. chunk
633 while true do
634 local line, remaining = string.match(headerdata, "^(.-)\r?\n(.*)$")
635 if not line then
636 break
637 end
638 if line == "" then
639 streamer = streamed_post_params[field_name]
640 if not streamer then
641 for i, rule in ipairs(streamed_post_param_patterns) do
642 if string.match(field_name, rule[1]) then
643 streamer = rule[2]
644 break
645 end
646 end
647 end
648 if not streamer then
649 value_parts = {}
650 streamer = default_streamer
651 end
652 streamer(remaining, field_name, metadata)
653 return
654 end
655 headerdata = remaining
656 local header_key, header_value = string.match(line, "^([^:]*):[ \t]*(.-)[ \t]*$")
657 if not header_key then
658 request_error(true, "400 Bad Request", "Invalid header in multipart/form-data part")
659 end
660 header_key = string.lower(header_key)
661 if header_key == "content-disposition" then
662 local escaped_header_value = string.gsub(header_value, '"[^"]*"', function(str)
663 return string.gsub(str, "=", "==")
664 end)
665 field_name = string.match(escaped_header_value, ';[ \t]*name="([^"]*)"')
666 if field_name then
667 field_name = string.gsub(field_name, "==", "=")
668 else
669 field_name = string.match(header_value, ';[ \t]*name=([^"; \t]+)')
670 end
671 metadata.file_name = string.match(escaped_header_value, ';[ \t]*filename="([^"]*)"')
672 if metadata.file_name then
673 metadata.file_name = string.gsub(metadata.file_name, "==", "=")
674 else
675 string.match(header_value, ';[ \t]*filename=([^"; \t]+)')
676 end
677 elseif header_key == "content-type" then
678 metadata.content_type = header_value
679 elseif header_key == "content-transfer-encoding" then
680 request_error(true, "400 Bad Request", "Content-transfer-encoding not supported by multipart/form-data parser")
681 end
682 end
683 end
684 end
685 local skippart = true -- ignore data until first boundary
686 local afterbound = false -- interpret 2 bytes after boundary ("\r\n" or "--")
687 local terminated = false -- final boundary read
688 local bigchunk = ""
689 request:stream_request_body(function(chunk)
690 if chunk == nil then
691 if not terminated then
692 request_error(true, "400 Bad Request", "Premature end of multipart/form-data request body")
693 end
694 request.post_params_list, request.post_params = post_params_list, post_params
695 request.post_metadata_list, request.post_metadata = post_metadata_list, post_metadata
696 end
697 if terminated then
698 return
699 end
700 bigchunk = bigchunk .. chunk
701 while true do
702 if afterbound then
703 if #bigchunk <= 2 then
704 return
705 end
706 local terminator = string.sub(bigchunk, 1, 2)
707 if terminator == "\r\n" then
708 afterbound = false
709 bigchunk = string.sub(bigchunk, 3)
710 elseif terminator == "--" then
711 terminated = true
712 bigchunk = nil
713 return
714 else
715 request_error(true, "400 Bad Request", "Error while parsing multipart body (expected CRLF or double minus)")
716 end
717 end
718 local pos1, pos2 = string.find(bigchunk, boundary, 1, true)
719 if not pos1 then
720 if not skippart then
721 local safe = #bigchunk-#boundary
722 if safe > 0 then
723 stream_part_chunk(string.sub(bigchunk, 1, safe))
724 bigchunk = string.sub(bigchunk, safe+1)
725 end
726 end
727 return
728 end
729 if not skippart then
730 stream_part_chunk(string.sub(bigchunk, 1, pos1 - 1))
731 stream_part_finish()
732 else
733 boundary = "\r\n" .. boundary
734 skippart = false
735 end
736 bigchunk = string.sub(bigchunk, pos2 + 1)
737 afterbound = true
738 end
739 end)
740 return -- finalization is executed in stream handler
741 else
742 request_error(true, "415 Unsupported Media Type", "Unknown Content-Type of request body")
743 end
744 end
745 end
746 request.post_params_list, request.post_params = post_params_list, post_params
747 end
748 -- function to prepare body processing:
749 local function prepare()
750 assert_not_faulty()
751 if state ~= "init" then
752 return
753 end
754 if process_body_chunk == nil then
755 default_request_body_handling()
756 end
757 if state ~= "init" then -- re-check if state is still "init"
758 return
759 end
760 consume = coroutine.wrap(read_body)
761 consume() -- call coroutine once to avoid hangup on empty body
762 state = "no_status_sent"
763 if request.headers_flags["Expect"]["100-continue"] then
764 request:send_status("100 Continue")
765 request:finish_headers()
766 end
767 end
768 -- method to ignore input and close connection after response:
769 function request:monologue()
770 assert_not_faulty()
771 if
772 state == "headers_sent" or
773 state == "finished"
774 then
775 error("All HTTP headers have already been sent")
776 end
777 local old_state = state; state = "faulty"
778 enable_drain()
779 close_requested = true
780 if old_state == "init" then
781 state = "no_status_sent"
782 else
783 state = old_state
784 end
785 end
786 -- method to send a HTTP response status (e.g. "200 OK"):
787 function request:send_status(status)
788 prepare()
789 local old_state = state; state = "faulty"
790 if old_state == "info_status_sent" then
791 send_flush("\r\n")
792 elseif old_state ~= "no_status_sent" then
793 state = old_state
794 error("HTTP status has already been sent")
795 end
796 local status1 = string.sub(status, 1, 1)
797 local status3 = string.sub(status, 1, 3)
798 send("HTTP/1.1 ", status, "\r\n", preamble)
799 local wrb = status_without_response_body[status3]
800 if wrb then
801 state = "bodyless_status_sent"
802 if wrb == "zero_content_length" then
803 request:send_header("Content-Length", 0)
804 end
805 elseif status1 == "1" then
806 state = "info_status_sent"
807 else
808 state = "status_sent"
809 end
810 end
811 -- method to send a HTTP response header:
812 -- (key and value must be provided as separate args)
813 function request:send_header(key, value)
814 assert_not_faulty()
815 if state == "init" or state == "no_status_sent" then
816 error("HTTP status has not been sent yet")
817 elseif
818 state == "headers_sent" or
819 state == "finished"
820 then
821 error("All HTTP headers have already been sent")
822 end
823 local old_state = state; state = "faulty"
824 local key_lower = string.lower(key)
825 if key_lower == "content-length" then
826 if old_state == "info_status_sent" then
827 state = old_state
828 error("Cannot set Content-Length for informational status response")
829 end
830 local cl = assert(tonumber(value), "Invalid content-length")
831 if content_length == nil then
832 content_length = cl
833 elseif content_length == cl then
834 return
835 else
836 error("Content-Length has been set multiple times with different values")
837 end
838 elseif key_lower == "connection" then
839 for entry in string.gmatch(string.lower(value), "[^,]+") do
840 if string.match(entry, "^[ \t]*close[ \t]*$") then
841 if old_state == "info_status_sent" then
842 state = old_state
843 error("Cannot set \"Connection: close\" for informational status response")
844 end
845 close_responded = true
846 break
847 end
848 end
849 end
850 send(key, ": ", value, "\r\n")
851 state = old_state
852 end
853 -- method to announce (and enforce) connection close after sending the
854 -- response:
855 function request:close_after_finish()
856 assert_not_faulty()
857 if state == "headers_sent" or state == "finished" then
858 error("All HTTP headers have already been sent")
859 end
860 close_requested = true
861 end
862 -- function to terminate header section in response, optionally flushing:
863 -- (may be called multiple times unless response is finished)
864 local function finish_headers(with_flush)
865 if state == "finished" then
866 error("Response has already been finished")
867 elseif state == "info_status_sent" then
868 state = "faulty"
869 send_flush("\r\n")
870 state = "no_status_sent"
871 elseif state == "bodyless_status_sent" then
872 if close_requested and not close_responded then
873 request:send_header("Connection", "close")
874 end
875 state = "faulty"
876 send("\r\n")
877 finish()
878 state = "finished"
879 elseif state == "status_sent" then
880 if not content_length then
881 request:send_header("Transfer-Encoding", "chunked")
882 end
883 if close_requested and not close_responded then
884 request:send_header("Connection", "close")
885 end
886 state = "faulty"
887 send("\r\n")
888 if request.method == "HEAD" then
889 finish()
890 elseif with_flush then
891 send_flush()
892 end
893 state = "headers_sent"
894 elseif state ~= "headers_sent" then
895 error("HTTP status has not been sent yet")
896 end
897 end
898 -- method to finish and flush headers:
899 function request:finish_headers()
900 assert_not_faulty()
901 finish_headers(true)
902 end
903 -- method to send body data:
904 function request:send_data(...)
905 assert_not_faulty()
906 if state == "info_status_sent" then
907 error("No (non-informational) HTTP status has been sent yet")
908 elseif state == "bodyless_status_sent" then
909 error("Cannot send response data for body-less status message")
910 end
911 finish_headers(false)
912 if state ~= "headers_sent" then
913 error("Unexpected internal status in HTTP engine")
914 end
915 if request.method == "HEAD" then
916 return
917 end
918 state = "faulty"
919 for i = 1, select("#", ...) do
920 local str = tostring(select(i, ...))
921 if #str > 0 then
922 if content_length then
923 local bytes_to_send = #str
924 if bytes_sent + bytes_to_send > content_length then
925 error("Content length exceeded")
926 else
927 send(str)
928 bytes_sent = bytes_sent + bytes_to_send
929 end
930 else
931 chunk_bytes = chunk_bytes + #str
932 chunk_parts[#chunk_parts+1] = str
933 end
934 end
935 end
936 if chunk_bytes >= output_chunk_size then
937 send_chunk()
938 end
939 state = "headers_sent"
940 end
941 -- method to flush output buffer:
942 function request:flush()
943 assert_not_faulty()
944 send_chunk()
945 send_flush()
946 end
947 -- method to finish response:
948 function request:finish()
949 assert_not_faulty()
950 if state == "finished" then
951 return
952 elseif state == "info_status_sent" then
953 error("Informational HTTP response can be finished with :finish_headers() method")
954 end
955 finish_headers(false)
956 if state == "headers_sent" then
957 if request.method ~= "HEAD" then
958 state = "faulty"
959 if content_length then
960 if bytes_sent ~= content_length then
961 error("Content length not used")
962 end
963 else
964 send_chunk()
965 send("0\r\n\r\n")
966 end
967 finish()
968 end
969 state = "finished"
970 elseif state ~= "finished" then
971 error("Unexpected internal status in HTTP engine")
972 end
973 end
974 -- method to register POST param stream handler for a single field name:
975 function request:stream_post_param(field_name, callback)
976 if state ~= "init" then
977 error("Cannot setup request body streamer at this stage anymore")
978 end
979 streamed_post_params[field_name] = callback
980 end
981 -- method to register POST param stream handler for a field name pattern:
982 function request:stream_post_params(pattern, callback)
983 if state ~= "init" then
984 error("Cannot setup request body streamer at this stage anymore")
985 end
986 streamed_post_param_patterns[#streamed_post_param_patterns+1] = {pattern, callback}
987 end
988 -- method to register request body stream handler
989 function request:stream_request_body(callback)
990 if state ~= "init" then
991 error("Cannot setup request body streamer at this stage anymore")
992 end
993 local inprogress = false
994 local eof = false
995 local buffer = {}
996 process_body_chunk = function(chunk)
997 if inprogress then
998 if chunk == nil then
999 eof = true
1000 else
1001 buffer[#buffer+1] = chunk
1002 end
1003 else
1004 inprogress = true
1005 callback(chunk)
1006 while #buffer > 0 do
1007 chunk = table.concat(buffer)
1008 buffer = {}
1009 callback(chunk)
1010 end
1011 if eof then
1012 callback() -- signal EOF
1013 end
1014 inprogress = false
1015 end
1016 end
1017 end
1018 -- method to start reading request body
1019 function request:consume_input()
1020 prepare()
1021 consume_all()
1022 end
1023 -- method to stream request body
1024 function request:stream_request_body_now(callback)
1025 request:stream_request_body(function(chunk)
1026 if chunk ~= nil then
1027 callback(chunk)
1028 end
1029 end)
1030 request:consume_input()
1031 end
1032 -- metamethod to read special attibutes of request object:
1033 function request_mt:__index(key, value)
1034 if key == "faulty" then
1035 return state == "faulty"
1036 elseif key == "fresh" then
1037 return state == "init" and process_body_chunk == nil
1038 elseif key == "body" then
1039 local chunks = {}
1040 request:stream_request_body_now(function(chunk)
1041 chunks[#chunks+1] = chunk
1042 end)
1043 self.body = table.concat(chunks)
1044 return self.body
1045 elseif
1046 key == "post_params_list" or key == "post_params" or
1047 key == "post_metadata_list" or key == "post_metadata"
1048 then
1049 prepare()
1050 consume_all()
1051 return rawget(self, key)
1052 end
1053 end
1054 -- variable to store request target
1055 local target
1056 -- coroutine for reading headers:
1057 local function read_headers()
1058 -- initialize limit:
1059 local limit = header_size_limit
1060 -- read and parse request line:
1061 local line = read_eof(limit, "\n")
1062 if not line then
1063 return false, survive
1064 end
1065 limit = limit - #line
1066 if limit == 0 then
1067 return false, request_error(false, "414 Request-URI Too Long")
1068 end
1069 local proto
1070 request.method, target, proto =
1071 line:match("^([^ \t\r]+)[ \t]+([^ \t\r]+)[ \t]*([^ \t\r]*)[ \t]*\r?\n$")
1072 if not request.method then
1073 return false, request_error(false, "400 Bad Request")
1074 elseif proto ~= "HTTP/1.1" then
1075 return false, request_error(false, "505 HTTP Version Not Supported")
1076 end
1077 -- read and parse headers:
1078 while true do
1079 local line = read(limit, "\n");
1080 limit = limit - #line
1081 if line == "\r\n" or line == "\n" then
1082 break
1083 end
1084 if limit == 0 then
1085 return false, request_error(false, "431 Request Header Fields Too Large")
1086 end
1087 local key, value = string.match(line, "^([^ \t\r]+):[ \t]*(.-)[ \t]*\r?\n$")
1088 if not key then
1089 return false, request_error(false, "400 Bad Request")
1090 end
1091 local values = request.headers[key]
1092 values[#values+1] = value
1093 end
1094 return true -- success
1095 end
1096 -- wait for input:
1097 local ready, pollmsg, quit = poll(socket_set, nil, idle_timeout, true)
1098 if not ready then
1099 if quit then
1100 return request_error(false, "408 Request Timeout", "Server shutdown")
1101 else
1102 return request_error(false, "408 Request Timeout", "Idle connection timed out")
1103 end
1104 end
1105 -- read headers (with timeout):
1106 do
1107 local coro = coroutine.wrap(read_headers)
1108 local starttime = request_header_timeout and moonbridge_io.timeref()
1109 while true do
1110 local status, retval = coro()
1111 if status == nil then
1112 local timeout
1113 if request_header_timeout then
1114 timeout = request_header_timeout - moonbridge_io.timeref(starttime)
1115 if stall_timeout and timeout > stall_timeout then
1116 timeout = stall_timeout
1117 end
1118 else
1119 timeout = stall_timeout
1120 end
1121 if not poll(socket_set, nil, timeout) then
1122 return request_error(false, "408 Request Timeout", "Timeout while receiving headers")
1123 end
1124 elseif status == false then
1125 return retval
1126 elseif status == true then
1127 break
1128 else
1129 error("Unexpected yield value")
1130 end
1131 end
1132 end
1133 -- process "Connection: close" header if existent:
1134 connection_close_requested = request.headers_flags["Connection"]["close"]
1135 -- process "Content-Length" header if existent:
1136 do
1137 local values = request.headers_csv_table["Content-Length"]
1138 if #values > 0 then
1139 request_body_content_length = tonumber(values[1])
1140 local proper_value = tostring(request_body_content_length)
1141 for i, value in ipairs(values) do
1142 value = string.match(value, "^0*(.*)")
1143 if value == "" then value = "0" end
1144 if value ~= proper_value then
1145 return request_error(false, "400 Bad Request", "Content-Length header(s) invalid")
1146 end
1147 end
1148 if request_body_content_length > body_size_limit then
1149 return request_error(false, "413 Request Entity Too Large", "Announced request body size is too big")
1150 end
1151 end
1152 end
1153 -- process "Transfer-Encoding" header if existent:
1154 do
1155 local flag = request.headers_flags["Transfer-Encoding"]["chunked"]
1156 local list = request.headers_csv_table["Transfer-Encoding"]
1157 if (flag and #list ~= 1) or (not flag and #list ~= 0) then
1158 return request_error(false, "400 Bad Request", "Unexpected Transfer-Encoding")
1159 end
1160 end
1161 -- process "Expect" header if existent:
1162 for i, value in ipairs(request.headers_csv_table["Expect"]) do
1163 if string.lower(value) ~= "100-continue" then
1164 return request_error(false, "417 Expectation Failed", "Unexpected Expect header")
1165 end
1166 end
1167 -- get mandatory Host header according to RFC 7230:
1168 request.host = request.headers_value["Host"]
1169 if not request.host then
1170 return request_error(false, "400 Bad Request", "No valid host header")
1171 end
1172 -- parse request target:
1173 request.path, request.query = string.match(target, "^/([^?]*)(.*)$")
1174 if not request.path then
1175 local host2
1176 host2, request.path, request.query = string.match(target, "^[Hh][Tt][Tt][Pp]://([^/?]+)/?([^?]*)(.*)$")
1177 if host2 then
1178 if request.host ~= host2 then
1179 return request_error(false, "400 Bad Request", "No valid host header")
1180 end
1181 elseif not (target == "*" and request.method == "OPTIONS") then
1182 return request_error(false, "400 Bad Request", "Invalid request target")
1183 end
1184 end
1185 -- parse GET params:
1186 request.get_params_list, request.get_params = new_params_list()
1187 if request.query then
1188 read_urlencoded_form(request.get_params_list, request.query)
1189 end
1190 -- parse cookies:
1191 for i, line in ipairs(request.headers["Cookie"]) do
1192 for rawkey, rawvalue in
1193 string.gmatch(line, "([^=; ]*)=([^=; ]*)")
1194 do
1195 request.cookies[decode_uri(rawkey)] = decode_uri(rawvalue)
1196 end
1197 end
1198 -- (re)set timeout for handler:
1199 timeout(response_timeout or 0)
1200 -- call underlying handler and remember boolean result:
1201 if handler(request) ~= true then survive = false end
1202 -- finish request (unless already done by underlying handler):
1203 request:finish()
1204 -- stop timeout timer:
1205 timeout(0)
1206 until close_responded
1207 return survive
1208 end
1209 end
1211 return _M

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