summaryrefslogtreecommitdiff
path: root/src/bitz/request_handler.cpp
blob: aa906f9943325d44af3819a0e60cf38677843cde (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
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
/*
 *	bitz-server, An ICAP server implementation in C++
 *	Copyright (C) 2012	Uditha Atukorala
 *
 *	This program 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; either version 3 of the License, or
 *	(at your option) any later version.
 *
 *	This program 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 this program; if not, write to the Free Software
 *	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "request_handler.h"
#include "config.h"
#include "util.h"

#include <dlfcn.h>
#include <icap/util.h>


namespace bitz {

	RequestHandler::RequestHandler( const std::string &method ) {

		// initialise defaults
		_handlers_count = 0;
		_handlers       = NULL;

		// update variables
		_req_handler.method = method;

		// logger
		_logger = spdlog::get( "bitz-server" );

		// load modifier modules
		load_modules();

	}


	RequestHandler::~RequestHandler() {

		// cleanup modifier modules
		cleanup_modules();

		if ( _handlers != NULL ) {
			delete [] _handlers;
		}

		_logger->debug( std::string( "[req] exiting request handler [" ).append( _req_handler.method ).append( "]" ) );

	}


	const std::string &RequestHandler::method() const throw() {
		return _req_handler.method;
	}


	icap::Response * RequestHandler::process( icap::RequestHeader * req_header, psocksxx::iosockstream * socket ) throw() {

		icap::Request  * request;
		icap::Response * response = NULL;


		// request
		request = new icap::Request( req_header );

		// read request data
		if (! icap::util::read_req_data( request, socket ) ) {

			_logger->warn( "[req] failed to read request data" );
			response = new icap::Response( icap::ResponseHeader::SERVER_ERROR );

		} else {

			_logger->debug( std::string( "[req] payload.req-hdr:\r\n").append( request->payload().req_header ) );
			_logger->debug( std::string( "[req] payload.req-body:\r\n").append( request->payload().req_body ) );
			_logger->debug( std::string( "[req] payload.res-hdr:\r\n").append( request->payload().res_header ) );
			_logger->debug( std::string( "[req] payload.res-body:\r\n").append( request->payload().res_body ) );


			// check for message preview
			if ( request->preview_size() >= 0 ) {

				// process preview
				_logger->debug( std::string( "[req] message preview request, preview: " ).append( util::itoa( request->preview_size() ) ) );
				response = process_preview( request, socket );

			}

			/*
			*  When we get here, if the response is NULL then either this is a
			*  pure REQMOD request without message preview or the preview was
			*  inconclusive (i.e. 100 Continue) and we have requested for the full
			*  request.
			*/
			if ( response == NULL ) {

				// process modify
				_logger->debug( "[req] modify request" );
				response = process_modify( request );

			}

		}

		// cleanup
		delete request;

		// sanity check
		if ( response == NULL ) {
			_logger->warn( "[req] no valid response from modifiers, creating a server error (500) response" );
			response = new icap::Response( icap::ResponseHeader::SERVER_ERROR );
		}

		return response;

	}


	bool RequestHandler::load_modifier( const std::string &file, Modifier::symbols_t &symbols ) throw() {

		// vars
		const char* dlsym_error;

		// load the modifier module
		_logger->debug( "[req] loading modifier: " + file );
		symbols.modifier = dlopen( file.c_str(), RTLD_LAZY | RTLD_LOCAL );

		if (! symbols.modifier ) {
			_logger->warn( std::string( "[req] failed to load modifier: " ).append( file ).append( dlerror() ) );
			return false;
		}

		// reset errors
		dlerror();

		// load the symbols
		symbols.create = ( Modifier::create_t * ) dlsym( symbols.modifier, "create" );
		dlsym_error    = dlerror();

		if ( dlsym_error ) {
			_logger->warn( std::string( "[req] failed to load create symbol: " ).append( dlsym_error ) );
			return false;
		}

		symbols.destroy = ( Modifier::destroy_t * ) dlsym( symbols.modifier, "destroy" );
		dlsym_error     = dlerror();

		if ( dlsym_error ) {
			_logger->warn( std::string( "[req] failed to load destroy symbol: " ).append( dlsym_error ) );
			return false;
		}

		return true;

	}


	void RequestHandler::unload_modifier( void * modifier ) throw() {
		// unload the modifier module
		dlclose( modifier );
	}


	void RequestHandler::load_modules() throw() {

		int i = 0;
		int j = 0;
		const bitz::config_t &config = Config::instance().configs();

		// search for request handlers
		for ( i = 0; i < config.req_handlers_count; i++ ) {

			// we are only interested in handlers for the current method (e.g. REQMOD, RESPMOD)
			if ( config.req_handlers[i].name == method() ) {

				if ( config.req_handlers[i].modules_count > 0 ) {

					_handlers_count = config.req_handlers[i].modules_count;
					_handlers       = new handler_t[_handlers_count];

					// search for request handler modules
					for (j = 0; j < _handlers_count; j++ ) {

						// load module
						if ( load_modifier( config.req_handlers[i].modules[j].module, _handlers[j].symbols ) ) {
							_handlers[j].name = config.req_handlers[i].modules[j].name;
						} else {
							_handlers[j].name = "";
							// FIXME: error handling
						}

					}

				}

				// not interested in duplicate config entries
				break;
			}

		}


	}


	void RequestHandler::cleanup_modules() throw() {

		int i = 0;

		for ( i = 0; i < _handlers_count; i++ ) {

			_logger->debug( std::string( "[req] unloading module: " ).append( _handlers[i].name ) );

			// unload
			unload_modifier( _handlers[i].symbols.modifier );

		}

	}


	icap::Response * RequestHandler::process_preview( icap::Request * request, psocksxx::iosockstream * socket ) throw() {

		icap::Response * response = NULL;
		Modifier       * modifier;

		int i = 0;
		bool continue_status = false;


		/*
		*  Loop through loaded modifier modules and grab responses
		*
		*  We will only get a chance to get a response from the first
		*  module. But if the first module returns a '100 Continue' response
		*  then we read the rest of the request here before returning a NULL
		*  response.
		*/
		for ( i = 0 ; i < _handlers_count; i++ ) {

			// sanity check
			if ( _handlers[i].name == "" ) {
				_logger->info( "[req] modifier not loaded, not trying to get a response" );
				continue;
			}

			// grab the response from modifier
			_logger->debug( std::string( "[req] getting preview response from modifier: " ).append( _handlers[i].name ) );
			modifier = _handlers[i].symbols.create();
			response = modifier->preview( request );

			// cleanup
			_logger->debug( std::string( "[req] cleaning up modifier: " ).append( _handlers[i].name ) );
			_handlers[i].symbols.destroy( modifier );

			// check response status
			if ( ( response->header()->status() == icap::ResponseHeader::NO_CONTENT )
					|| ( response->header()->status() == icap::ResponseHeader::OK ) ) {
				// no further action needed, break out of the loop
				break;
			}

			if ( response->header()->status() == icap::ResponseHeader::CONTINUE ) {

				// read the full response
				continue_status = preview_continue( response, request, socket );

				// cleanup
				delete response;

				// sanity check
				if ( continue_status ) {

					// success - set the response to NULL
					response = NULL;

				} else {

					// something went wrong, server error
					response = new icap::Response( icap::ResponseHeader::SERVER_ERROR );

				}

				// exit the loop
				break;

			}

			// we shouldn't have got this far
			_logger->info( std::string( "[req] unrecognised preview response from modifier: " ).append( _handlers[i].name ) );

		}

		return response;

	}


	icap::Response * RequestHandler::process_modify( icap::Request * request ) throw() {

		icap::Response * response = NULL;
		Modifier       * modifier;

		int i = 0;


		/*
		*  Loop through loaded modifier modules and grab responses
		*
		*  We will only return the response from the last module
		*  unless a icap::ResponseHeader::OK is received
		*/
		for ( i = 0 ; i < _handlers_count; i++ ) {

			// sanity check
			if ( _handlers[i].name == "" ) {
				_logger->info( "[req] modifier not loaded, not trying to get a response" );
				continue;
			}

			// grab the response from modifier
			_logger->debug( std::string( "[req] getting modify response from modifier: " ).append( _handlers[i].name ) );
			modifier = _handlers[i].symbols.create();
			response = modifier->modify( request );

			// cleanup
			_logger->debug( std::string( "[req] cleaning up modifier: " ).append( _handlers[i].name ) );
			_handlers[i].symbols.destroy( modifier );

			// status 200 OK means content modified
			if ( response->header()->status() == icap::ResponseHeader::OK ) {
				_logger->debug( "[req] OK response received, not getting responses from other modifiers" );
				break;
			}

		}

		return response;

	}


	bool RequestHandler::preview_continue( icap::Response * response, icap::Request * request, psocksxx::iosockstream * socket ) throw() {

		bool status = false;

		// sanity check
		if ( request->payload().ieof ) {

			// we can process a '100 Continue' only if an 'ieof' is not received
			_logger->warn( "[req] illegal '100 Continue' response" );

		} else {

			/* read the full request */

			// send back the response first
			if ( icap::util::send_response( response, socket ) ) {

				// read the rest of the request
				status = icap::util::read_req_continue_data( request, socket );

			}

		}

		return status;

	}

} /* end of namespace bitz */