aboutsummaryrefslogtreecommitdiffstats
path: root/net/http/parser.lua
blob: 96f17fdb02ef9819a8f315f98f8baa301a08b7b3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
local tonumber = tonumber;
local assert = assert;
local url_parse = require "socket.url".parse;
local urldecode = require "util.http".urldecode;
local dbuffer = require "util.dbuffer";

local function preprocess_path(path)
	path = urldecode((path:gsub("//+", "/")));
	if path:sub(1,1) ~= "/" then
		path = "/"..path;
	end
	local level = 0;
	for component in path:gmatch("([^/]+)/") do
		if component == ".." then
			level = level - 1;
		elseif component ~= "." then
			level = level + 1;
		end
		if level < 0 then
			return nil;
		end
	end
	return path;
end

local httpstream = {};

function httpstream.new(success_cb, error_cb, parser_type, options_cb)
	local client = true;
	if not parser_type or parser_type == "server" then client = false; else assert(parser_type == "client", "Invalid parser type"); end
	local bodylimit = tonumber(options_cb and options_cb().body_size_limit) or 10*1024*1024;
	-- https://stackoverflow.com/a/686243
	-- Indiviual headers can be up to 16k? What madness?
	local headlimit = tonumber(options_cb and options_cb().head_size_limit) or 10*1024;
	local buflimit = tonumber(options_cb and options_cb().buffer_size_limit) or bodylimit * 2;
	local buffer = dbuffer.new(buflimit);
	local chunked;
	local state = nil;
	local packet;
	local len;
	local have_body;
	local error;
	return {
		feed = function(_, data)
			if error then return nil, "parse has failed"; end
			if not data then -- EOF
				if state and client and not len then -- reading client body until EOF
					buffer:collapse();
					packet.body = buffer:read_chunk() or "";
					packet.partial = nil;
					success_cb(packet);
					state = nil;
				elseif buffer:length() ~= 0 then -- unexpected EOF
					error = true; return error_cb("unexpected-eof");
				end
				return;
			end
			if not buffer:write(data) then error = true; return error_cb("max-buffer-size-exceeded"); end
			while buffer:length() > 0 do
				if state == nil then -- read request
					local index = buffer:sub(1, headlimit):find("\r\n\r\n", nil, true);
					if not index then return; end -- not enough data
					-- FIXME was reason_phrase meant to be passed on somewhere?
					local method, path, httpversion, status_code, reason_phrase; -- luacheck: ignore reason_phrase
					local first_line;
					local headers = {};
					for line in buffer:read(index+3):gmatch("([^\r\n]+)\r\n") do -- parse request
						if first_line then
							local key, val = line:match("^([^%s:]+): *(.*)$");
							if not key then error = true; return error_cb("invalid-header-line"); end -- TODO handle multi-line and invalid headers
							key = key:lower();
							headers[key] = headers[key] and headers[key]..","..val or val;
						else
							first_line = line;
							if client then
								httpversion, status_code, reason_phrase = line:match("^HTTP/(1%.[01]) (%d%d%d) (.*)$");
								status_code = tonumber(status_code);
								if not status_code then error = true; return error_cb("invalid-status-line"); end
								have_body = not
									 ( (options_cb and options_cb().method == "HEAD")
									or (status_code == 204 or status_code == 304 or status_code == 301)
									or (status_code >= 100 and status_code < 200) );
							else
								method, path, httpversion = line:match("^(%w+) (%S+) HTTP/(1%.[01])$");
								if not method then error = true; return error_cb("invalid-status-line"); end
							end
						end
					end
					if not first_line then error = true; return error_cb("invalid-status-line"); end
					chunked = have_body and headers["transfer-encoding"] == "chunked";
					len = tonumber(headers["content-length"]); -- TODO check for invalid len
					if client then
						-- FIXME handle '100 Continue' response (by skipping it)
						if not have_body then len = 0; end
						packet = {
							code = status_code;
							httpversion = httpversion;
							headers = headers;
							body = false;
							body_length = len;
							chunked = chunked;
							partial = true;
							-- COMPAT the properties below are deprecated
							responseversion = httpversion;
							responseheaders = headers;
						};
					else
						local parsed_url;
						if path:byte() == 47 then -- starts with /
							local _path, _query = path:match("([^?]*).?(.*)");
							if _query == "" then _query = nil; end
							parsed_url = { path = _path, query = _query };
						else
							parsed_url = url_parse(path);
							if not(parsed_url and parsed_url.path) then error = true; return error_cb("invalid-url"); end
						end
						path = preprocess_path(parsed_url.path);
						headers.host = parsed_url.host or headers.host;

						len = len or 0;
						packet = {
							method = method;
							url = parsed_url;
							path = path;
							httpversion = httpversion;
							headers = headers;
							body = false;
							body_sink = nil;
							chunked = chunked;
							partial = true;
						};
					end
					if len and len > bodylimit then
						-- Early notification, for redirection
						success_cb(packet);
						if not packet.body_sink then error = true; return error_cb("content-length-limit-exceeded"); end
					end
					if chunked and not packet.body_sink then
						success_cb(packet);
						if not packet.body_sink then
							packet.body_buffer = dbuffer.new(buflimit);
						end
					end
					state = true;
				end
				if state then -- read body
					if chunked then
						local chunk_header = buffer:sub(1, 512); -- XXX How large do chunk headers grow?
						local chunk_size, chunk_start = chunk_header:match("^(%x+)[^\r\n]*\r\n()");
						if not chunk_size then return; end
						chunk_size = chunk_size and tonumber(chunk_size, 16);
						if not chunk_size then error = true; return error_cb("invalid-chunk-size"); end
						if chunk_size == 0 and chunk_header:find("\r\n\r\n", chunk_start-2, true) then
							local body_buffer = packet.body_buffer;
							if body_buffer then
								packet.body_buffer = nil;
								body_buffer:collapse();
								packet.body = body_buffer:read_chunk() or "";
							end

							buffer:collapse();
							local buf = buffer:read_chunk();
							buf = buf:gsub("^.-\r\n\r\n", ""); -- This ensure extensions and trailers are stripped
							buffer:write(buf);
							state, chunked = nil, nil;
							packet.partial = nil;
							success_cb(packet);
						elseif buffer:length() - chunk_start - 2 >= chunk_size then -- we have a chunk
							buffer:discard(chunk_start - 1); -- TODO verify that it's not off-by-one
							(packet.body_sink or packet.body_buffer):write(buffer:read(chunk_size));
							buffer:discard(2); -- CRLF
						else -- Partial chunk remaining
							break;
						end
					elseif packet.body_sink then
						local chunk = buffer:read_chunk(len);
						while chunk and len > 0 do
							if packet.body_sink:write(chunk) then
								len = len - #chunk;
								chunk = buffer:read_chunk(len);
							else
								error = true;
								return error_cb("body-sink-write-failure");
							end
						end
						if len == 0 then
							state = nil;
							packet.partial = nil;
							success_cb(packet);
						end
					elseif buffer:length() >= len then
						assert(not chunked)
						packet.body = buffer:read(len) or "";
						state = nil;
						packet.partial = nil;
						success_cb(packet);
					else
						break;
					end
				else
					break;
				end
			end
		end;
	};
end

return httpstream;