2 This file is part of GNUnet.
3 (C) 2001, 2002, 2004, 2005, 2007, 2009, 2010 Christian Grothoff (and other contributing authors)
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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
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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.
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16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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22 * @file peerinfo/peerinfo_api_notify.c
23 * @brief notify API to access peerinfo service
24 * @author Christian Grothoff
27 #include "gnunet_client_lib.h"
28 #include "gnunet_peerinfo_service.h"
29 #include "gnunet_protocols.h"
30 #include "gnunet_time_lib.h"
33 #define LOG(kind,...) GNUNET_log_from (kind, "nse-api",__VA_ARGS__)
36 * Context for the info handler.
38 struct GNUNET_PEERINFO_NotifyContext
42 * Our connection to the PEERINFO service.
44 struct GNUNET_CLIENT_Connection *client;
47 * Function to call with information.
49 GNUNET_PEERINFO_Processor callback;
52 * Closure for callback.
57 * Handle to our initial request for message transmission to
58 * the peerinfo service.
60 struct GNUNET_CLIENT_TransmitHandle *init;
65 const struct GNUNET_CONFIGURATION_Handle *cfg;
68 * Tasked used for delayed re-connection attempt.
70 GNUNET_SCHEDULER_TaskIdentifier task;
76 * Send a request to the peerinfo service to start being
77 * notified about all changes to peer information.
79 * @param nc our context
82 request_notifications (struct GNUNET_PEERINFO_NotifyContext *nc);
86 * Read notifications from the client handle and pass them
89 * @param nc our context
92 receive_notifications (struct GNUNET_PEERINFO_NotifyContext *nc);
96 * Task to re-try connecting to peerinfo.
98 * @param cls the 'struct GNUNET_PEERINFO_NotifyContext'
99 * @param tc scheduler context
102 reconnect (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
104 struct GNUNET_PEERINFO_NotifyContext *nc = cls;
106 nc->task = GNUNET_SCHEDULER_NO_TASK;
107 nc->client = GNUNET_CLIENT_connect ("peerinfo", nc->cfg);
108 if (NULL == nc->client)
112 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS, &reconnect, nc);
115 request_notifications (nc);
120 * Receive a peerinfo information message, process it and
124 * @param msg message received, NULL on timeout or fatal error
127 process_notification (void *cls, const struct GNUNET_MessageHeader *msg)
129 struct GNUNET_PEERINFO_NotifyContext *nc = cls;
130 const struct InfoMessage *im;
131 const struct GNUNET_HELLO_Message *hello;
136 GNUNET_CLIENT_disconnect (nc->client);
137 reconnect (nc, NULL);
140 ms = ntohs (msg->size);
141 if ((ms < sizeof (struct InfoMessage)) ||
142 (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_PEERINFO_INFO))
145 GNUNET_CLIENT_disconnect (nc->client);
146 nc->client = GNUNET_CLIENT_connect ("peerinfo", nc->cfg);
147 request_notifications (nc);
150 im = (const struct InfoMessage *) msg;
152 if (ms > sizeof (struct InfoMessage) + sizeof (struct GNUNET_MessageHeader))
154 hello = (const struct GNUNET_HELLO_Message *) &im[1];
155 if (ms != sizeof (struct InfoMessage) + GNUNET_HELLO_size (hello))
158 GNUNET_CLIENT_disconnect (nc->client);
159 nc->client = GNUNET_CLIENT_connect ("peerinfo", nc->cfg);
160 request_notifications (nc);
164 LOG (GNUNET_ERROR_TYPE_DEBUG,
165 "Received information about peer `%s' from peerinfo database\n",
166 GNUNET_i2s (&im->peer));
167 nc->callback (nc->callback_cls, &im->peer, hello, NULL);
168 receive_notifications (nc);
173 * Read notifications from the client handle and pass them
176 * @param nc our context
179 receive_notifications (struct GNUNET_PEERINFO_NotifyContext *nc)
181 GNUNET_CLIENT_receive (nc->client, &process_notification, nc,
182 GNUNET_TIME_UNIT_FOREVER_REL);
187 * Transmit our init-notify request, start receiving.
189 * @param cls closure (our 'struct GNUNET_PEERINFO_NotifyContext')
190 * @param size number of bytes available in buf
191 * @param buf where the callee should write the message
192 * @return number of bytes written to buf
195 transmit_notify_request (void *cls, size_t size, void *buf)
197 struct GNUNET_PEERINFO_NotifyContext *nc = cls;
198 struct GNUNET_MessageHeader hdr;
203 GNUNET_CLIENT_disconnect (nc->client);
204 nc->client = GNUNET_CLIENT_connect ("peerinfo", nc->cfg);
205 request_notifications (nc);
208 GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader));
209 hdr.size = htons (sizeof (struct GNUNET_MessageHeader));
210 hdr.type = htons (GNUNET_MESSAGE_TYPE_PEERINFO_NOTIFY);
211 memcpy (buf, &hdr, sizeof (struct GNUNET_MessageHeader));
212 receive_notifications (nc);
213 return sizeof (struct GNUNET_MessageHeader);
218 * Send a request to the peerinfo service to start being
219 * notified about all changes to peer information.
221 * @param nc our context
224 request_notifications (struct GNUNET_PEERINFO_NotifyContext *nc)
226 GNUNET_assert (NULL == nc->init);
228 GNUNET_CLIENT_notify_transmit_ready (nc->client,
229 sizeof (struct GNUNET_MessageHeader),
230 GNUNET_TIME_UNIT_FOREVER_REL,
231 GNUNET_YES, &transmit_notify_request,
237 * Call a method whenever our known information about peers
238 * changes. Initially calls the given function for all known
239 * peers and then only signals changes.
241 * @param cfg configuration to use
242 * @param callback the method to call for each peer
243 * @param callback_cls closure for callback
244 * @return NULL on error
246 struct GNUNET_PEERINFO_NotifyContext *
247 GNUNET_PEERINFO_notify (const struct GNUNET_CONFIGURATION_Handle *cfg,
248 GNUNET_PEERINFO_Processor callback, void *callback_cls)
250 struct GNUNET_PEERINFO_NotifyContext *nc;
251 struct GNUNET_CLIENT_Connection *client;
253 client = GNUNET_CLIENT_connect ("peerinfo", cfg);
256 LOG (GNUNET_ERROR_TYPE_WARNING, _("Could not connect to `%s' service.\n"),
260 nc = GNUNET_malloc (sizeof (struct GNUNET_PEERINFO_NotifyContext));
263 nc->callback = callback;
264 nc->callback_cls = callback_cls;
265 request_notifications (nc);
271 * Stop notifying about changes.
273 * @param nc context to stop notifying
276 GNUNET_PEERINFO_notify_cancel (struct GNUNET_PEERINFO_NotifyContext *nc)
278 if (NULL != nc->init)
280 GNUNET_CLIENT_notify_transmit_ready_cancel (nc->init);
283 if (NULL != nc->client)
284 GNUNET_CLIENT_disconnect (nc->client);
285 if (GNUNET_SCHEDULER_NO_TASK != nc->task)
286 GNUNET_SCHEDULER_cancel (nc->task);
290 /* end of peerinfo_api_notify.c */