summaryrefslogtreecommitdiff
path: root/src/network/core/tcp_http.cpp
blob: f11722ae38c2662afc4136854924a2ffe7965e54 (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
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */

/**
 * @file tcp_http.cpp Basic functions to receive and send HTTP TCP packets.
 */

#include "../../stdafx.h"
#include "../../debug.h"
#include "../../rev.h"
#include "../network_internal.h"
#include "game_info.h"

#include "tcp_http.h"

#include "../../safeguards.h"

/** List of open HTTP connections. */
static std::vector<NetworkHTTPSocketHandler *> _http_connections;

/**
 * Start the querying
 * @param s        the socket of this connection
 * @param callback the callback for HTTP retrieval
 * @param host     the hostname of the server to connect to
 * @param url      the url at the server
 * @param data     the data to send
 * @param depth    the depth (redirect recursion) of the queries
 */
NetworkHTTPSocketHandler::NetworkHTTPSocketHandler(SOCKET s,
		HTTPCallback *callback, const char *host, const char *url,
		const char *data, int depth) :
	NetworkSocketHandler(),
	recv_pos(0),
	recv_length(0),
	callback(callback),
	data(data),
	redirect_depth(depth),
	sock(s)
{
	size_t bufferSize = strlen(url) + strlen(host) + strlen(GetNetworkRevisionString()) + (data == nullptr ? 0 : strlen(data)) + 128;
	char *buffer = AllocaM(char, bufferSize);

	DEBUG(net, 5, "[tcp/http] Requesting %s%s", host, url);
	if (data != nullptr) {
		seprintf(buffer, buffer + bufferSize - 1, "POST %s HTTP/1.0\r\nHost: %s\r\nUser-Agent: OpenTTD/%s\r\nContent-Type: text/plain\r\nContent-Length: %d\r\n\r\n%s\r\n", url, host, GetNetworkRevisionString(), (int)strlen(data), data);
	} else {
		seprintf(buffer, buffer + bufferSize - 1, "GET %s HTTP/1.0\r\nHost: %s\r\nUser-Agent: OpenTTD/%s\r\n\r\n", url, host, GetNetworkRevisionString());
	}

	ssize_t size = strlen(buffer);
	ssize_t res = send(this->sock, (const char*)buffer, size, 0);
	if (res != size) {
		/* Sending all data failed. Socket can't handle this little bit
		 * of information? Just fall back to the old system! */
		this->callback->OnFailure();
		delete this;
		return;
	}

	_http_connections.push_back(this);
}

/** Free whatever needs to be freed. */
NetworkHTTPSocketHandler::~NetworkHTTPSocketHandler()
{
	this->CloseSocket();

	free(this->data);
}

/**
 * Close the actual socket of the connection.
 */
void NetworkHTTPSocketHandler::CloseSocket()
{
	if (this->sock != INVALID_SOCKET) closesocket(this->sock);
	this->sock = INVALID_SOCKET;
}

/**
 * Helper to simplify the error handling.
 * @param msg the error message to show.
 */
#define return_error(msg) { DEBUG(net, 1, msg); return -1; }

static const char * const NEWLINE        = "\r\n";             ///< End of line marker
static const char * const END_OF_HEADER  = "\r\n\r\n";         ///< End of header marker
static const char * const HTTP_1_0       = "HTTP/1.0 ";        ///< Preamble for HTTP 1.0 servers
static const char * const HTTP_1_1       = "HTTP/1.1 ";        ///< Preamble for HTTP 1.1 servers
static const char * const CONTENT_LENGTH = "Content-Length: "; ///< Header for the length of the content
static const char * const LOCATION       = "Location: ";       ///< Header for location

/**
 * Handle the header of a HTTP reply.
 * @return amount of data to continue downloading.
 *         > 0: we need to download N bytes.
 *         = 0: we're being redirected.
 *         < 0: an error occurred. Downloading failed.
 * @note if an error occurred the header might not be in its
 *       original state. No effort is undertaken to bring
 *       the header in its original state.
 */
int NetworkHTTPSocketHandler::HandleHeader()
{
	assert(strlen(HTTP_1_0) == strlen(HTTP_1_1));
	assert(strstr(this->recv_buffer, END_OF_HEADER) != nullptr);

	/* We expect a HTTP/1.[01] reply */
	if (strncmp(this->recv_buffer, HTTP_1_0, strlen(HTTP_1_0)) != 0 &&
			strncmp(this->recv_buffer, HTTP_1_1, strlen(HTTP_1_1)) != 0) {
		return_error("[tcp/http] Received invalid HTTP reply");
	}

	char *status = this->recv_buffer + strlen(HTTP_1_0);
	if (strncmp(status, "200", 3) == 0) {
		/* We are going to receive a document. */

		/* Get the length of the document to receive */
		char *length = strcasestr(this->recv_buffer, CONTENT_LENGTH);
		if (length == nullptr) return_error("[tcp/http] Missing 'content-length' header");

		/* Skip the header */
		length += strlen(CONTENT_LENGTH);

		/* Search the end of the line. This is safe because the header will
		 * always end with two newlines. */
		char *end_of_line = strstr(length, NEWLINE);

		/* Read the length */
		*end_of_line = '\0';
		int len = atoi(length);
		/* Restore the header. */
		*end_of_line = '\r';

		/* Make sure we're going to download at least something;
		 * zero sized files are, for OpenTTD's purposes, always
		 * wrong. You can't have gzips of 0 bytes! */
		if (len == 0) return_error("[tcp/http] Refusing to download 0 bytes");

		DEBUG(net, 7, "[tcp/http] Downloading %i bytes", len);
		return len;
	}

	if (strncmp(status, "301", 3) != 0 &&
			strncmp(status, "302", 3) != 0 &&
			strncmp(status, "303", 3) != 0 &&
			strncmp(status, "307", 3) != 0) {
		/* We are not going to be redirected :(. */

		/* Search the end of the line. This is safe because the header will
		 * always end with two newlines. */
		*strstr(status, NEWLINE) = '\0';
		DEBUG(net, 1, "[tcp/http] Unhandled status reply %s", status);
		return -1;
	}

	if (this->redirect_depth == 5) return_error("[tcp/http] Too many redirects, looping redirects?");

	/* Redirect to other URL */
	char *uri = strcasestr(this->recv_buffer, LOCATION);
	if (uri == nullptr) return_error("[tcp/http] Missing 'location' header for redirect");

	uri += strlen(LOCATION);

	/* Search the end of the line. This is safe because the header will
	 * always end with two newlines. */
	char *end_of_line = strstr(uri, NEWLINE);
	*end_of_line = '\0';

	DEBUG(net, 7, "[tcp/http] Redirecting to %s", uri);

	int ret = NetworkHTTPSocketHandler::Connect(uri, this->callback, this->data, this->redirect_depth + 1);
	if (ret != 0) return ret;

	/* We've relinquished control of data now. */
	this->data = nullptr;

	/* Restore the header. */
	*end_of_line = '\r';
	return 0;
}

/**
 * Connect to the given URI.
 * @param uri      the URI to connect to.
 * @param callback the callback to send data back on.
 * @param data     the data we want to send (as POST).
 * @param depth    the recursion/redirect depth.
 */
/* static */ int NetworkHTTPSocketHandler::Connect(char *uri, HTTPCallback *callback, const char *data, int depth)
{
	char *hname = strstr(uri, "://");
	if (hname == nullptr) return_error("[tcp/http] Invalid location");

	hname += 3;

	char *url = strchr(hname, '/');
	if (url == nullptr) return_error("[tcp/http] Invalid location");

	*url = '\0';

	std::string hostname = std::string(hname);

	/* Restore the URL. */
	*url = '/';
	new NetworkHTTPContentConnecter(hostname, callback, url, data, depth);
	return 0;
}

#undef return_error

/**
 * Handle receiving of HTTP data.
 * @return state of the receival of HTTP data.
 *         > 0: we need more cycles for downloading
 *         = 0: we are done downloading
 *         < 0: we have hit an error
 */
int NetworkHTTPSocketHandler::Receive()
{
	for (;;) {
		ssize_t res = recv(this->sock, (char *)this->recv_buffer + this->recv_pos, lengthof(this->recv_buffer) - this->recv_pos, 0);
		if (res == -1) {
			NetworkError err = NetworkError::GetLast();
			if (!err.WouldBlock()) {
				/* Something went wrong... */
				if (!err.IsConnectionReset()) DEBUG(net, 0, "Recv failed: %s", err.AsString());
				return -1;
			}
			/* Connection would block, so stop for now */
			return 1;
		}

		/* No more data... did we get everything we wanted? */
		if (res == 0) {
			if (this->recv_length != 0) return -1;

			this->callback->OnReceiveData(nullptr, 0);
			return 0;
		}

		/* Wait till we read the end-of-header identifier */
		if (this->recv_length == 0) {
			ssize_t read = this->recv_pos + res;
			ssize_t end = std::min<ssize_t>(read, lengthof(this->recv_buffer) - 1);

			/* Do a 'safe' search for the end of the header. */
			char prev = this->recv_buffer[end];
			this->recv_buffer[end] = '\0';
			char *end_of_header = strstr(this->recv_buffer, END_OF_HEADER);
			this->recv_buffer[end] = prev;

			if (end_of_header == nullptr) {
				if (read == lengthof(this->recv_buffer)) {
					DEBUG(net, 1, "[tcp/http] Header too big");
					return -1;
				}
				this->recv_pos = read;
			} else {
				int ret = this->HandleHeader();
				if (ret <= 0) return ret;

				this->recv_length = ret;

				end_of_header += strlen(END_OF_HEADER);
				int len = std::min(read - (end_of_header - this->recv_buffer), res);
				if (len != 0) {
					this->callback->OnReceiveData(end_of_header, len);
					this->recv_length -= len;
				}

				this->recv_pos = 0;
			}
		} else {
			res = std::min<ssize_t>(this->recv_length, res);
			/* Receive whatever we're expecting. */
			this->callback->OnReceiveData(this->recv_buffer, res);
			this->recv_length -= res;
		}
	}
}

/**
 * Do the receiving for all HTTP connections.
 */
/* static */ void NetworkHTTPSocketHandler::HTTPReceive()
{
	/* No connections, just bail out. */
	if (_http_connections.size() == 0) return;

	fd_set read_fd;
	struct timeval tv;

	FD_ZERO(&read_fd);
	for (NetworkHTTPSocketHandler *handler : _http_connections) {
		FD_SET(handler->sock, &read_fd);
	}

	tv.tv_sec = tv.tv_usec = 0; // don't block at all.
	int n = select(FD_SETSIZE, &read_fd, nullptr, nullptr, &tv);
	if (n == -1) return;

	for (auto iter = _http_connections.begin(); iter < _http_connections.end(); /* nothing */) {
		NetworkHTTPSocketHandler *cur = *iter;

		if (FD_ISSET(cur->sock, &read_fd)) {
			int ret = cur->Receive();
			/* First send the failure. */
			if (ret < 0) cur->callback->OnFailure();
			if (ret <= 0) {
				/* Then... the connection can be closed */
				cur->CloseSocket();
				iter = _http_connections.erase(iter);
				delete cur;
				continue;
			}
		}
		iter++;
	}
}