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
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13 General Public License for more details.
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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_util_lib.h"
28 #include "gnunet_peerinfo_service.h"
29 #include "gnunet_protocols.h"
32 #define LOG(kind,...) GNUNET_log_from (kind, "nse-api",__VA_ARGS__)
35 * Context for the info handler.
37 struct GNUNET_PEERINFO_NotifyContext
41 * Our connection to the PEERINFO service.
43 struct GNUNET_CLIENT_Connection *client;
46 * Function to call with information.
48 GNUNET_PEERINFO_Processor callback;
51 * Closure for callback.
56 * Handle to our initial request for message transmission to
57 * the peerinfo service.
59 struct GNUNET_CLIENT_TransmitHandle *init;
64 const struct GNUNET_CONFIGURATION_Handle *cfg;
67 * Tasked used for delayed re-connection attempt.
69 GNUNET_SCHEDULER_TaskIdentifier task;
72 * Include friend only HELLOs in callbacks
75 int include_friend_only;
80 * Send a request to the peerinfo service to start being
81 * notified about all changes to peer information.
83 * @param nc our context
86 request_notifications (struct GNUNET_PEERINFO_NotifyContext *nc);
90 * Read notifications from the client handle and pass them
93 * @param nc our context
96 receive_notifications (struct GNUNET_PEERINFO_NotifyContext *nc);
100 * Task to re-try connecting to peerinfo.
102 * @param cls the 'struct GNUNET_PEERINFO_NotifyContext'
103 * @param tc scheduler context
106 reconnect (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
108 struct GNUNET_PEERINFO_NotifyContext *nc = cls;
110 nc->task = GNUNET_SCHEDULER_NO_TASK;
111 nc->client = GNUNET_CLIENT_connect ("peerinfo", nc->cfg);
112 if (NULL == nc->client)
116 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS, &reconnect, nc);
119 request_notifications (nc);
124 * Receive a peerinfo information message, process it and
128 * @param msg message received, NULL on timeout or fatal error
131 process_notification (void *cls, const struct GNUNET_MessageHeader *msg)
133 struct GNUNET_PEERINFO_NotifyContext *nc = cls;
134 const struct InfoMessage *im;
135 const struct GNUNET_HELLO_Message *hello;
140 GNUNET_CLIENT_disconnect (nc->client);
141 reconnect (nc, NULL);
144 ms = ntohs (msg->size);
145 if ((ms < sizeof (struct InfoMessage)) ||
146 (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_PEERINFO_INFO))
149 GNUNET_CLIENT_disconnect (nc->client);
150 nc->client = GNUNET_CLIENT_connect ("peerinfo", nc->cfg);
151 request_notifications (nc);
154 im = (const struct InfoMessage *) msg;
156 if (ms > sizeof (struct InfoMessage) + sizeof (struct GNUNET_MessageHeader))
158 hello = (const struct GNUNET_HELLO_Message *) &im[1];
159 if (ms != sizeof (struct InfoMessage) + GNUNET_HELLO_size (hello))
162 GNUNET_CLIENT_disconnect (nc->client);
163 nc->client = GNUNET_CLIENT_connect ("peerinfo", nc->cfg);
164 request_notifications (nc);
169 LOG (GNUNET_ERROR_TYPE_DEBUG,
170 "Received information about peer `%s' from peerinfo database\n",
171 GNUNET_i2s (&im->peer));
172 nc->callback (nc->callback_cls, &im->peer, hello, NULL);
173 receive_notifications (nc);
178 * Read notifications from the client handle and pass them
181 * @param nc our context
184 receive_notifications (struct GNUNET_PEERINFO_NotifyContext *nc)
186 GNUNET_CLIENT_receive (nc->client, &process_notification, nc,
187 GNUNET_TIME_UNIT_FOREVER_REL);
192 * Transmit our init-notify request, start receiving.
194 * @param cls closure (our 'struct GNUNET_PEERINFO_NotifyContext')
195 * @param size number of bytes available in buf
196 * @param buf where the callee should write the message
197 * @return number of bytes written to buf
200 transmit_notify_request (void *cls, size_t size, void *buf)
202 struct GNUNET_PEERINFO_NotifyContext *nc = cls;
203 struct NotifyMessage nm;
208 GNUNET_CLIENT_disconnect (nc->client);
209 nc->client = GNUNET_CLIENT_connect ("peerinfo", nc->cfg);
210 request_notifications (nc);
213 GNUNET_assert (size >= sizeof (struct NotifyMessage));
214 nm.header.type = htons (GNUNET_MESSAGE_TYPE_PEERINFO_NOTIFY);
215 nm.header.size = htons (sizeof (struct NotifyMessage));
216 nm.include_friend_only = htonl (nc->include_friend_only);
217 memcpy (buf, &nm, sizeof (struct NotifyMessage));
218 receive_notifications (nc);
219 return sizeof (struct NotifyMessage);
224 * Send a request to the peerinfo service to start being
225 * notified about all changes to peer information.
227 * @param nc our context
230 request_notifications (struct GNUNET_PEERINFO_NotifyContext *nc)
232 GNUNET_assert (NULL == nc->init);
234 GNUNET_CLIENT_notify_transmit_ready (nc->client,
235 sizeof (struct NotifyMessage),
236 GNUNET_TIME_UNIT_FOREVER_REL,
237 GNUNET_YES, &transmit_notify_request,
243 * Call a method whenever our known information about peers
244 * changes. Initially calls the given function for all known
245 * peers and then only signals changes.
247 * If include_friend_only is set to GNUNET_YES peerinfo will include HELLO
248 * messages which are intended for friend to friend mode and which do not
249 * have to be gossiped. Otherwise these messages are skipped.
251 * @param cfg configuration to use
252 * @param include_friend_only include HELLO messages for friends only
253 * @param callback the method to call for each peer
254 * @param callback_cls closure for callback
255 * @return NULL on error
257 struct GNUNET_PEERINFO_NotifyContext *
258 GNUNET_PEERINFO_notify (const struct GNUNET_CONFIGURATION_Handle *cfg,
259 int include_friend_only,
260 GNUNET_PEERINFO_Processor callback, void *callback_cls)
262 struct GNUNET_PEERINFO_NotifyContext *nc;
263 struct GNUNET_CLIENT_Connection *client;
265 client = GNUNET_CLIENT_connect ("peerinfo", cfg);
268 LOG (GNUNET_ERROR_TYPE_WARNING, _("Could not connect to `%s' service.\n"),
272 nc = GNUNET_malloc (sizeof (struct GNUNET_PEERINFO_NotifyContext));
275 nc->callback = callback;
276 nc->callback_cls = callback_cls;
277 nc->include_friend_only = include_friend_only;
278 request_notifications (nc);
284 * Stop notifying about changes.
286 * @param nc context to stop notifying
289 GNUNET_PEERINFO_notify_cancel (struct GNUNET_PEERINFO_NotifyContext *nc)
291 if (NULL != nc->init)
293 GNUNET_CLIENT_notify_transmit_ready_cancel (nc->init);
296 if (NULL != nc->client)
297 GNUNET_CLIENT_disconnect (nc->client);
298 if (GNUNET_SCHEDULER_NO_TASK != nc->task)
299 GNUNET_SCHEDULER_cancel (nc->task);
303 /* end of peerinfo_api_notify.c */