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diff --git a/src/nat-auto/gnunet-service-nat-auto.c b/src/nat-auto/gnunet-service-nat-auto.c
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1/*
2 This file is part of GNUnet.
3 Copyright (C) 2016, 2017 GNUnet e.V.
4
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
8 option) any later version.
9
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
18 Boston, MA 02110-1301, USA.
19 */
20
21/**
22 * @file nat-auto/gnunet-service-nat-auto.c
23 * @brief NAT autoconfiguration service
24 * @author Christian Grothoff
25 *
26 * TODO:
27 * - merge client handle and autoconfig context
28 * - implement "more" autoconfig:
29 * + re-work gnunet-nat-server & integrate!
30 * + test manually punched NAT (how?)
31 */
32#include "platform.h"
33#include <math.h>
34#include "gnunet_util_lib.h"
35#include "gnunet_protocols.h"
36#include "gnunet_signatures.h"
37#include "gnunet_nat_service.h"
38#include "gnunet_statistics_service.h"
39#include "gnunet_resolver_service.h"
40#include "nat-auto.h"
41#include <gcrypt.h>
42
43
44/**
45 * How long do we wait until we forcefully terminate autoconfiguration?
46 */
47#define AUTOCONFIG_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5)
48
49
50/**
51 * Internal data structure we track for each of our clients.
52 */
53struct ClientHandle
54{
55
56 /**
57 * Kept in a DLL.
58 */
59 struct ClientHandle *next;
60
61 /**
62 * Kept in a DLL.
63 */
64 struct ClientHandle *prev;
65
66 /**
67 * Underlying handle for this client with the service.
68 */
69 struct GNUNET_SERVICE_Client *client;
70
71 /**
72 * Message queue for communicating with the client.
73 */
74 struct GNUNET_MQ_Handle *mq;
75};
76
77
78/**
79 * Context for autoconfiguration operations.
80 */
81struct AutoconfigContext
82{
83 /**
84 * Kept in a DLL.
85 */
86 struct AutoconfigContext *prev;
87
88 /**
89 * Kept in a DLL.
90 */
91 struct AutoconfigContext *next;
92
93 /**
94 * Which client asked the question.
95 */
96 struct ClientHandle *ch;
97
98 /**
99 * Configuration we are creating.
100 */
101 struct GNUNET_CONFIGURATION_Handle *c;
102
103 /**
104 * Original configuration (for diffing).
105 */
106 struct GNUNET_CONFIGURATION_Handle *orig;
107
108 /**
109 * Timeout task to force termination.
110 */
111 struct GNUNET_SCHEDULER_Task *timeout_task;
112
113 /**
114 * #GNUNET_YES if upnpc should be used,
115 * #GNUNET_NO if upnpc should not be used,
116 * #GNUNET_SYSERR if we should simply not change the option.
117 */
118 int enable_upnpc;
119
120 /**
121 * Status code to return to the client.
122 */
123 enum GNUNET_NAT_StatusCode status_code;
124
125 /**
126 * NAT type to return to the client.
127 */
128 enum GNUNET_NAT_Type type;
129};
130
131
132/**
133 * Head of client DLL.
134 */
135static struct ClientHandle *ch_head;
136
137/**
138 * Tail of client DLL.
139 */
140static struct ClientHandle *ch_tail;
141
142/**
143 * DLL of our autoconfiguration operations.
144 */
145static struct AutoconfigContext *ac_head;
146
147/**
148 * DLL of our autoconfiguration operations.
149 */
150static struct AutoconfigContext *ac_tail;
151
152/**
153 * Handle to our current configuration.
154 */
155static const struct GNUNET_CONFIGURATION_Handle *cfg;
156
157/**
158 * Handle to the statistics service.
159 */
160static struct GNUNET_STATISTICS_Handle *stats;
161
162
163/**
164 * Check validity of #GNUNET_MESSAGE_TYPE_NAT_REQUEST_AUTO_CFG message
165 * from client.
166 *
167 * @param cls client who sent the message
168 * @param message the message received
169 * @return #GNUNET_OK if message is well-formed
170 */
171static int
172check_autoconfig_request (void *cls,
173 const struct GNUNET_NAT_AutoconfigRequestMessage *message)
174{
175 return GNUNET_OK; /* checked later */
176}
177
178
179/**
180 * Stop all pending activities with respect to the @a ac
181 *
182 * @param ac autoconfiguration to terminate activities for
183 */
184static void
185terminate_ac_activities (struct AutoconfigContext *ac)
186{
187 if (NULL != ac->timeout_task)
188 {
189 GNUNET_SCHEDULER_cancel (ac->timeout_task);
190 ac->timeout_task = NULL;
191 }
192}
193
194
195/**
196 * Finish handling the autoconfiguration request and send
197 * the response to the client.
198 *
199 * @param cls the `struct AutoconfigContext` to conclude
200 */
201static void
202conclude_autoconfig_request (void *cls)
203{
204 struct AutoconfigContext *ac = cls;
205 struct ClientHandle *ch = ac->ch;
206 struct GNUNET_NAT_AutoconfigResultMessage *arm;
207 struct GNUNET_MQ_Envelope *env;
208 size_t c_size;
209 char *buf;
210 struct GNUNET_CONFIGURATION_Handle *diff;
211
212 ac->timeout_task = NULL;
213 terminate_ac_activities (ac);
214
215 /* Send back response */
216 diff = GNUNET_CONFIGURATION_get_diff (ac->orig,
217 ac->c);
218 buf = GNUNET_CONFIGURATION_serialize (diff,
219 &c_size);
220 GNUNET_CONFIGURATION_destroy (diff);
221 env = GNUNET_MQ_msg_extra (arm,
222 c_size,
223 GNUNET_MESSAGE_TYPE_NAT_AUTO_CFG_RESULT);
224 arm->status_code = htonl ((uint32_t) ac->status_code);
225 arm->type = htonl ((uint32_t) ac->type);
226 GNUNET_memcpy (&arm[1],
227 buf,
228 c_size);
229 GNUNET_free (buf);
230 GNUNET_MQ_send (ch->mq,
231 env);
232
233 /* clean up */
234 GNUNET_CONFIGURATION_destroy (ac->orig);
235 GNUNET_CONFIGURATION_destroy (ac->c);
236 GNUNET_CONTAINER_DLL_remove (ac_head,
237 ac_tail,
238 ac);
239 GNUNET_free (ac);
240 GNUNET_SERVICE_client_continue (ch->client);
241}
242
243
244/**
245 * Check if all autoconfiguration operations have concluded,
246 * and if they have, send the result back to the client.
247 *
248 * @param ac autoconfiguation context to check
249 */
250static void
251check_autoconfig_finished (struct AutoconfigContext *ac)
252{
253 GNUNET_SCHEDULER_cancel (ac->timeout_task);
254 ac->timeout_task
255 = GNUNET_SCHEDULER_add_now (&conclude_autoconfig_request,
256 ac);
257}
258
259
260/**
261 * Update ENABLE_UPNPC configuration option.
262 *
263 * @param ac autoconfiguration to update
264 */
265static void
266update_enable_upnpc_option (struct AutoconfigContext *ac)
267{
268 switch (ac->enable_upnpc)
269 {
270 case GNUNET_YES:
271 GNUNET_CONFIGURATION_set_value_string (ac->c,
272 "NAT",
273 "ENABLE_UPNP",
274 "YES");
275 break;
276 case GNUNET_NO:
277 GNUNET_CONFIGURATION_set_value_string (ac->c,
278 "NAT",
279 "ENABLE_UPNP",
280 "NO");
281 break;
282 case GNUNET_SYSERR:
283 /* We are unsure, do not change option */
284 break;
285 }
286}
287
288
289/**
290 * Handler for #GNUNET_MESSAGE_TYPE_NAT_REQUEST_AUTO_CFG message from
291 * client.
292 *
293 * @param cls client who sent the message
294 * @param message the message received
295 */
296static void
297handle_autoconfig_request (void *cls,
298 const struct GNUNET_NAT_AutoconfigRequestMessage *message)
299{
300 struct ClientHandle *ch = cls;
301 size_t left = ntohs (message->header.size) - sizeof (*message);
302 struct AutoconfigContext *ac;
303
304 ac = GNUNET_new (struct AutoconfigContext);
305 ac->status_code = GNUNET_NAT_ERROR_SUCCESS;
306 ac->ch = ch;
307 ac->c = GNUNET_CONFIGURATION_create ();
308 if (GNUNET_OK !=
309 GNUNET_CONFIGURATION_deserialize (ac->c,
310 (const char *) &message[1],
311 left,
312 GNUNET_NO))
313 {
314 GNUNET_break (0);
315 GNUNET_SERVICE_client_drop (ch->client);
316 GNUNET_CONFIGURATION_destroy (ac->c);
317 GNUNET_free (ac);
318 return;
319 }
320 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
321 "Received REQUEST_AUTO_CONFIG message from client\n");
322
323 GNUNET_CONTAINER_DLL_insert (ac_head,
324 ac_tail,
325 ac);
326 ac->orig
327 = GNUNET_CONFIGURATION_dup (ac->c);
328 ac->timeout_task
329 = GNUNET_SCHEDULER_add_delayed (AUTOCONFIG_TIMEOUT,
330 &conclude_autoconfig_request,
331 ac);
332 ac->enable_upnpc = GNUNET_SYSERR; /* undecided */
333
334 /* Probe for upnpc */
335 if (GNUNET_SYSERR ==
336 GNUNET_OS_check_helper_binary ("upnpc",
337 GNUNET_NO,
338 NULL))
339 {
340 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
341 _("UPnP client `upnpc` command not found, disabling UPnP\n"));
342 ac->enable_upnpc = GNUNET_NO;
343 }
344 else
345 {
346 /* We might at some point be behind NAT, try upnpc */
347 ac->enable_upnpc = GNUNET_YES;
348 }
349 update_enable_upnpc_option (ac);
350
351 /* Finally, check if we are already done */
352 check_autoconfig_finished (ac);
353}
354
355
356/**
357 * Task run during shutdown.
358 *
359 * @param cls unused
360 */
361static void
362shutdown_task (void *cls)
363{
364 struct AutoconfigContext *ac;
365
366 while (NULL != (ac = ac_head))
367 {
368 GNUNET_CONTAINER_DLL_remove (ac_head,
369 ac_tail,
370 ac);
371 terminate_ac_activities (ac);
372 GNUNET_free (ac);
373 }
374 if (NULL != stats)
375 {
376 GNUNET_STATISTICS_destroy (stats,
377 GNUNET_NO);
378 stats = NULL;
379 }
380}
381
382
383/**
384 * Setup NAT service.
385 *
386 * @param cls closure
387 * @param c configuration to use
388 * @param service the initialized service
389 */
390static void
391run (void *cls,
392 const struct GNUNET_CONFIGURATION_Handle *c,
393 struct GNUNET_SERVICE_Handle *service)
394{
395 cfg = c;
396 GNUNET_SCHEDULER_add_shutdown (&shutdown_task,
397 NULL);
398 stats = GNUNET_STATISTICS_create ("nat-auto",
399 cfg);
400}
401
402
403/**
404 * Callback called when a client connects to the service.
405 *
406 * @param cls closure for the service
407 * @param c the new client that connected to the service
408 * @param mq the message queue used to send messages to the client
409 * @return a `struct ClientHandle`
410 */
411static void *
412client_connect_cb (void *cls,
413 struct GNUNET_SERVICE_Client *c,
414 struct GNUNET_MQ_Handle *mq)
415{
416 struct ClientHandle *ch;
417
418 ch = GNUNET_new (struct ClientHandle);
419 ch->mq = mq;
420 ch->client = c;
421 GNUNET_CONTAINER_DLL_insert (ch_head,
422 ch_tail,
423 ch);
424 return ch;
425}
426
427
428/**
429 * Callback called when a client disconnected from the service
430 *
431 * @param cls closure for the service
432 * @param c the client that disconnected
433 * @param internal_cls a `struct ClientHandle *`
434 */
435static void
436client_disconnect_cb (void *cls,
437 struct GNUNET_SERVICE_Client *c,
438 void *internal_cls)
439{
440 struct ClientHandle *ch = internal_cls;
441
442 GNUNET_CONTAINER_DLL_remove (ch_head,
443 ch_tail,
444 ch);
445 GNUNET_free (ch);
446}
447
448
449/**
450 * Define "main" method using service macro.
451 */
452GNUNET_SERVICE_MAIN
453("nat",
454 GNUNET_SERVICE_OPTION_NONE,
455 &run,
456 &client_connect_cb,
457 &client_disconnect_cb,
458 NULL,
459 GNUNET_MQ_hd_var_size (autoconfig_request,
460 GNUNET_MESSAGE_TYPE_NAT_AUTO_REQUEST_CFG,
461 struct GNUNET_NAT_AutoconfigRequestMessage,
462 NULL),
463 GNUNET_MQ_handler_end ());
464
465
466#if defined(LINUX) && defined(__GLIBC__)
467#include <malloc.h>
468
469/**
470 * MINIMIZE heap size (way below 128k) since this process doesn't need much.
471 */
472void __attribute__ ((constructor))
473GNUNET_ARM_memory_init ()
474{
475 mallopt (M_TRIM_THRESHOLD, 4 * 1024);
476 mallopt (M_TOP_PAD, 1 * 1024);
477 malloc_trim (0);
478}
479#endif
480
481/* end of gnunet-service-nat.c */
generated by cgit v1.2.3 (git 2.39.1) at 2024-04-19 12:49:52 +0000