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
27 #include "gnunet_client_lib.h"
28 #include "gnunet_constants.h"
29 #include "gnunet_container_lib.h"
30 #include "gnunet_arm_service.h"
31 #include "gnunet_hello_lib.h"
32 #include "gnunet_protocols.h"
33 #include "gnunet_server_lib.h"
34 #include "gnunet_time_lib.h"
35 #include "gnunet_nse_service.h"
38 #define LOG(kind,...) GNUNET_log_from (kind, "nse-api",__VA_ARGS__)
41 * Handle for the service.
43 struct GNUNET_NSE_Handle
46 * Configuration to use.
48 const struct GNUNET_CONFIGURATION_Handle *cfg;
51 * Socket (if available).
53 struct GNUNET_CLIENT_Connection *client;
56 * Currently pending transmission request.
58 struct GNUNET_CLIENT_TransmitHandle *th;
61 * Task doing exponential back-off trying to reconnect.
63 GNUNET_SCHEDULER_TaskIdentifier reconnect_task;
66 * Time for next connect retry.
68 struct GNUNET_TIME_Relative reconnect_delay;
71 * Callback function to call when message is received.
73 GNUNET_NSE_Callback recv_cb;
76 * Closure to pass to callback.
84 * Try again to connect to network size estimation service.
86 * @param cls the handle to the transport service
87 * @param tc scheduler context
90 reconnect (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
94 * Type of a function to call when we receive a message
98 * @param msg message received, NULL on timeout or fatal error
101 message_handler (void *cls, const struct GNUNET_MessageHeader *msg)
103 struct GNUNET_NSE_Handle *h = cls;
104 const struct GNUNET_NSE_ClientMessage *client_msg;
108 /* Error, timeout, death */
109 GNUNET_CLIENT_disconnect (h->client, GNUNET_NO);
112 GNUNET_SCHEDULER_add_delayed (h->reconnect_delay, &reconnect, h);
115 if ((ntohs (msg->size) != sizeof (struct GNUNET_NSE_ClientMessage)) ||
116 (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_NSE_ESTIMATE))
121 client_msg = (const struct GNUNET_NSE_ClientMessage *) msg;
122 h->recv_cb (h->recv_cb_cls, GNUNET_TIME_absolute_ntoh (client_msg->timestamp),
123 client_msg->size_estimate, client_msg->std_deviation);
124 GNUNET_CLIENT_receive (h->client, &message_handler, h,
125 GNUNET_TIME_UNIT_FOREVER_REL);
131 * Reschedule a connect attempt to the service.
133 * @param h transport service to reconnect
136 reschedule_connect (struct GNUNET_NSE_Handle *h)
138 GNUNET_assert (h->reconnect_task == GNUNET_SCHEDULER_NO_TASK);
142 GNUNET_CLIENT_notify_transmit_ready_cancel (h->th);
145 if (NULL != h->client)
147 GNUNET_CLIENT_disconnect (h->client, GNUNET_NO);
152 LOG (GNUNET_ERROR_TYPE_DEBUG,
153 "Scheduling task to reconnect to nse service in %llu ms.\n",
154 h->reconnect_delay.rel_value);
157 GNUNET_SCHEDULER_add_delayed (h->reconnect_delay, &reconnect, h);
158 if (h->reconnect_delay.rel_value == 0)
160 h->reconnect_delay = GNUNET_TIME_UNIT_MILLISECONDS;
164 h->reconnect_delay = GNUNET_TIME_relative_multiply (h->reconnect_delay, 2);
166 GNUNET_TIME_relative_min (GNUNET_TIME_UNIT_SECONDS, h->reconnect_delay);
172 * Transmit START message to service.
175 * @param size number of bytes available in buf
176 * @param buf where to copy the message
177 * @return number of bytes copied to buf
180 send_start (void *cls, size_t size, void *buf)
182 struct GNUNET_NSE_Handle *h = cls;
183 struct GNUNET_MessageHeader *msg;
188 /* Connect error... */
190 LOG (GNUNET_ERROR_TYPE_DEBUG,
191 "Shutdown while trying to transmit `%s' request.\n", "START");
193 reschedule_connect (h);
197 LOG (GNUNET_ERROR_TYPE_DEBUG, "Transmitting `%s' request.\n", "START");
199 GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader));
201 msg = (struct GNUNET_MessageHeader *) buf;
202 msg->size = htons (sizeof (struct GNUNET_MessageHeader));
203 msg->type = htons (GNUNET_MESSAGE_TYPE_NSE_START);
204 GNUNET_CLIENT_receive (h->client, &message_handler, h,
205 GNUNET_TIME_UNIT_FOREVER_REL);
206 return sizeof (struct GNUNET_MessageHeader);
211 * Try again to connect to network size estimation service.
213 * @param cls the handle to the transport service
214 * @param tc scheduler context
217 reconnect (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
219 struct GNUNET_NSE_Handle *h = cls;
221 h->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
222 if ((tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0)
224 /* shutdown, just give up */
228 LOG (GNUNET_ERROR_TYPE_DEBUG,
229 "Connecting to network size estimation service.\n");
231 GNUNET_assert (h->client == NULL);
232 h->client = GNUNET_CLIENT_connect ("nse", h->cfg);
233 GNUNET_assert (h->client != NULL);
236 GNUNET_CLIENT_notify_transmit_ready (h->client,
237 sizeof (struct GNUNET_MessageHeader),
238 GNUNET_TIME_UNIT_FOREVER_REL,
239 GNUNET_NO, &send_start, h);
240 GNUNET_assert (h->th != NULL);
245 * Connect to the network size estimation service.
247 * @param cfg the configuration to use
248 * @param func funtion to call with network size estimate
249 * @param func_cls closure to pass for network size estimate callback
251 * @return handle to use
253 struct GNUNET_NSE_Handle *
254 GNUNET_NSE_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
255 GNUNET_NSE_Callback func, void *func_cls)
257 struct GNUNET_NSE_Handle *ret;
259 GNUNET_assert (func != NULL);
260 ret = GNUNET_malloc (sizeof (struct GNUNET_NSE_Handle));
263 ret->recv_cb_cls = func_cls;
264 ret->reconnect_delay = GNUNET_TIME_UNIT_ZERO;
265 ret->reconnect_task = GNUNET_SCHEDULER_add_now (&reconnect, ret);
271 * Disconnect from network size estimation service
273 * @param h handle to destroy
276 GNUNET_NSE_disconnect (struct GNUNET_NSE_Handle *h)
278 GNUNET_assert (h != NULL);
279 if (h->reconnect_task != GNUNET_SCHEDULER_NO_TASK)
281 GNUNET_SCHEDULER_cancel (h->reconnect_task);
282 h->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
286 GNUNET_CLIENT_notify_transmit_ready_cancel (h->th);
289 if (h->client != NULL)
291 GNUNET_CLIENT_disconnect (h->client, GNUNET_NO);
297 /* end of nse_api.c */