2 This file is part of GNUnet.
3 (C) 2009, 2010, 2011 Christian Grothoff (and other contributing authors)
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.
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.
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., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
23 * @brief api to get information from the network size estimation service
24 * @author Nathan Evans
29 #include "gnunet_client_lib.h"
30 #include "gnunet_constants.h"
31 #include "gnunet_container_lib.h"
32 #include "gnunet_arm_service.h"
33 #include "gnunet_hello_lib.h"
34 #include "gnunet_protocols.h"
35 #include "gnunet_server_lib.h"
36 #include "gnunet_time_lib.h"
37 #include "gnunet_nse_service.h"
42 * Handle for the service.
44 struct GNUNET_NSE_Handle
47 * Configuration to use.
49 const struct GNUNET_CONFIGURATION_Handle *cfg;
52 * Socket (if available).
54 struct GNUNET_CLIENT_Connection *client;
57 * Currently pending transmission request.
59 struct GNUNET_CLIENT_TransmitHandle *th;
62 * Task doing exponential back-off trying to reconnect.
64 GNUNET_SCHEDULER_TaskIdentifier reconnect_task;
67 * Time for next connect retry.
69 struct GNUNET_TIME_Relative reconnect_delay;
72 * Should this handle auto-destruct once all actions have
78 * Are we currently receiving from the service?
83 * Callback function to call when message is received.
85 GNUNET_NSE_Callback recv_cb;
88 * Closure to pass to callback.
96 * Type of a function to call when we receive a message
100 * @param msg message received, NULL on timeout or fatal error
102 void message_handler (void *cls,
103 const struct GNUNET_MessageHeader * msg)
105 struct GNUNET_NSE_Handle *h = cls;
106 struct GNUNET_NSE_ClientMessage *client_msg;
108 if (msg == NULL) /* Error, timeout, death */
111 if ((ntohs (msg->size) < sizeof(struct GNUNET_NSE_ClientMessage))
112 || (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_NSE_ESTIMATE))
115 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
116 "%s: received incorrect message (size %d < %d) from service!",
117 "NSE API", ntohs (msg->size),
118 sizeof(struct GNUNET_NSE_ClientMessage));
123 client_msg = (struct GNUNET_NSE_ClientMessage *)msg;
125 h->recv_cb (h->recv_cb_cls, client_msg->size_estimate,
126 client_msg->std_deviation);
128 GNUNET_CLIENT_receive (h->client,
129 &message_handler, h, GNUNET_TIME_UNIT_FOREVER_REL);
133 reconnect (void *cls,
134 const struct GNUNET_SCHEDULER_TaskContext *tc);
137 * Reschedule a connect attempt to the service.
139 * @param h transport service to reconnect
142 reschedule_connect (struct GNUNET_NSE_Handle *h)
144 GNUNET_assert (h->reconnect_task == GNUNET_SCHEDULER_NO_TASK);
148 GNUNET_CLIENT_notify_transmit_ready_cancel (h->th);
151 if (NULL != h->client)
153 GNUNET_CLIENT_disconnect (h->client, GNUNET_NO);
158 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
159 "Scheduling task to reconnect to nse service in %llu ms.\n",
160 h->reconnect_delay.rel_value);
163 = GNUNET_SCHEDULER_add_delayed (h->reconnect_delay,
165 if (h->reconnect_delay.rel_value == 0)
167 h->reconnect_delay = GNUNET_TIME_UNIT_MILLISECONDS;
171 h->reconnect_delay = GNUNET_TIME_relative_multiply (h->reconnect_delay, 2);
172 h->reconnect_delay = GNUNET_TIME_relative_min (GNUNET_TIME_UNIT_SECONDS,
178 * Transmit START message to service.
181 * @param size number of bytes available in buf
182 * @param buf where to copy the message
183 * @return number of bytes copied to buf
186 send_start (void *cls, size_t size, void *buf)
188 struct GNUNET_NSE_Handle *h = cls;
189 struct GNUNET_MessageHeader *msg;
194 /* Connect error... */
196 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
197 "Shutdown while trying to transmit `%s' request.\n",
200 reschedule_connect(h);
204 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
205 "Transmitting `%s' request.\n", "START");
207 GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader));
209 msg = (struct GNUNET_MessageHeader *)buf;
210 msg->size = htons (sizeof (struct GNUNET_MessageHeader));
211 msg->type = htons (GNUNET_MESSAGE_TYPE_NSE_START);
212 GNUNET_CLIENT_receive (h->client,
213 &message_handler, h, GNUNET_TIME_UNIT_FOREVER_REL);
214 return sizeof (struct GNUNET_MessageHeader);
218 * Try again to connect to network size estimation service.
220 * @param cls the handle to the transport service
221 * @param tc scheduler context
224 reconnect (void *cls,
225 const struct GNUNET_SCHEDULER_TaskContext *tc)
227 struct GNUNET_NSE_Handle *h = cls;
229 h->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
230 if ((tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0)
232 /* shutdown, just give up */
236 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
237 "Connecting to network size estimation service.\n");
239 GNUNET_assert (h->client == NULL);
240 h->client = GNUNET_CLIENT_connect ("nse", h->cfg);
241 GNUNET_assert (h->client != NULL);
244 GNUNET_CLIENT_notify_transmit_ready (h->client,
245 sizeof(struct GNUNET_MessageHeader),
246 GNUNET_TIME_UNIT_FOREVER_REL,
250 GNUNET_assert(h->th != NULL);
254 * Connect to the network size estimation service.
256 * @param cfg the configuration to use
257 * @param func funtion to call with network size estimate
258 * @param func_cls closure to pass for network size estimate callback
260 * @return handle to use
262 struct GNUNET_NSE_Handle *
263 GNUNET_NSE_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
264 GNUNET_NSE_Callback func, void *func_cls)
266 struct GNUNET_NSE_Handle *ret;
268 ret = GNUNET_malloc (sizeof (struct GNUNET_NSE_Handle));
275 ret->recv_cb_cls = func_cls;
276 ret->reconnect_delay = GNUNET_TIME_UNIT_ZERO;
277 ret->reconnect_task = GNUNET_SCHEDULER_add_now (&reconnect, ret);
282 * Disconnect from network size estimation service
284 * @param h handle to destroy
288 GNUNET_NSE_disconnect (struct GNUNET_NSE_Handle *h)
290 GNUNET_assert(h != NULL);
291 if (h->reconnect_task != GNUNET_SCHEDULER_NO_TASK)
293 GNUNET_SCHEDULER_cancel(h->reconnect_task);
294 h->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
297 GNUNET_CLIENT_notify_transmit_ready_cancel(h->th);
298 if (h->client != NULL)
299 GNUNET_CLIENT_disconnect(h->client, GNUNET_NO);