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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 struct GNUNET_SCHEDULER_Task * 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 *`
105 reconnect (void *cls)
107 struct GNUNET_PEERINFO_NotifyContext *nc = cls;
110 nc->client = GNUNET_CLIENT_connect ("peerinfo", nc->cfg);
111 if (NULL == nc->client)
115 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS, &reconnect, nc);
118 request_notifications (nc);
123 * Receive a peerinfo information message, process it and
127 * @param msg message received, NULL on timeout or fatal error
130 process_notification (void *cls, const struct GNUNET_MessageHeader *msg)
132 struct GNUNET_PEERINFO_NotifyContext *nc = cls;
133 const struct InfoMessage *im;
134 const struct GNUNET_HELLO_Message *hello;
139 GNUNET_CLIENT_disconnect (nc->client);
143 ms = ntohs (msg->size);
144 if ((ms < sizeof (struct InfoMessage)) ||
145 (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_PEERINFO_INFO))
148 GNUNET_CLIENT_disconnect (nc->client);
149 nc->client = GNUNET_CLIENT_connect ("peerinfo", nc->cfg);
150 request_notifications (nc);
153 im = (const struct InfoMessage *) msg;
155 if (ms > sizeof (struct InfoMessage) + sizeof (struct GNUNET_MessageHeader))
157 hello = (const struct GNUNET_HELLO_Message *) &im[1];
158 if (ms != sizeof (struct InfoMessage) + GNUNET_HELLO_size (hello))
161 GNUNET_CLIENT_disconnect (nc->client);
162 nc->client = GNUNET_CLIENT_connect ("peerinfo", nc->cfg);
163 request_notifications (nc);
168 LOG (GNUNET_ERROR_TYPE_DEBUG,
169 "Received information about peer `%s' from peerinfo database\n",
170 GNUNET_i2s (&im->peer));
171 nc->callback (nc->callback_cls, &im->peer, hello, NULL);
172 receive_notifications (nc);
177 * Read notifications from the client handle and pass them
180 * @param nc our context
183 receive_notifications (struct GNUNET_PEERINFO_NotifyContext *nc)
185 GNUNET_CLIENT_receive (nc->client, &process_notification, nc,
186 GNUNET_TIME_UNIT_FOREVER_REL);
191 * Transmit our init-notify request, start receiving.
193 * @param cls closure (our 'struct GNUNET_PEERINFO_NotifyContext')
194 * @param size number of bytes available in buf
195 * @param buf where the callee should write the message
196 * @return number of bytes written to buf
199 transmit_notify_request (void *cls, size_t size, void *buf)
201 struct GNUNET_PEERINFO_NotifyContext *nc = cls;
202 struct NotifyMessage nm;
207 GNUNET_CLIENT_disconnect (nc->client);
208 nc->client = GNUNET_CLIENT_connect ("peerinfo", nc->cfg);
209 request_notifications (nc);
212 GNUNET_assert (size >= sizeof (struct NotifyMessage));
213 nm.header.type = htons (GNUNET_MESSAGE_TYPE_PEERINFO_NOTIFY);
214 nm.header.size = htons (sizeof (struct NotifyMessage));
215 nm.include_friend_only = htonl (nc->include_friend_only);
216 memcpy (buf, &nm, sizeof (struct NotifyMessage));
217 receive_notifications (nc);
218 return sizeof (struct NotifyMessage);
223 * Send a request to the peerinfo service to start being
224 * notified about all changes to peer information.
226 * @param nc our context
229 request_notifications (struct GNUNET_PEERINFO_NotifyContext *nc)
231 GNUNET_assert (NULL == nc->init);
233 GNUNET_CLIENT_notify_transmit_ready (nc->client,
234 sizeof (struct NotifyMessage),
235 GNUNET_TIME_UNIT_FOREVER_REL,
236 GNUNET_YES, &transmit_notify_request,
242 * Call a method whenever our known information about peers
243 * changes. Initially calls the given function for all known
244 * peers and then only signals changes.
246 * If include_friend_only is set to GNUNET_YES peerinfo will include HELLO
247 * messages which are intended for friend to friend mode and which do not
248 * have to be gossiped. Otherwise these messages are skipped.
250 * @param cfg configuration to use
251 * @param include_friend_only include HELLO messages for friends only
252 * @param callback the method to call for each peer
253 * @param callback_cls closure for callback
254 * @return NULL on error
256 struct GNUNET_PEERINFO_NotifyContext *
257 GNUNET_PEERINFO_notify (const struct GNUNET_CONFIGURATION_Handle *cfg,
258 int include_friend_only,
259 GNUNET_PEERINFO_Processor callback, void *callback_cls)
261 struct GNUNET_PEERINFO_NotifyContext *nc;
262 struct GNUNET_CLIENT_Connection *client;
264 client = GNUNET_CLIENT_connect ("peerinfo", cfg);
267 LOG (GNUNET_ERROR_TYPE_WARNING, _("Could not connect to `%s' service.\n"),
271 nc = GNUNET_new (struct GNUNET_PEERINFO_NotifyContext);
274 nc->callback = callback;
275 nc->callback_cls = callback_cls;
276 nc->include_friend_only = include_friend_only;
277 request_notifications (nc);
283 * Stop notifying about changes.
285 * @param nc context to stop notifying
288 GNUNET_PEERINFO_notify_cancel (struct GNUNET_PEERINFO_NotifyContext *nc)
290 if (NULL != nc->init)
292 GNUNET_CLIENT_notify_transmit_ready_cancel (nc->init);
295 if (NULL != nc->client)
296 GNUNET_CLIENT_disconnect (nc->client);
297 if (NULL != nc->task)
298 GNUNET_SCHEDULER_cancel (nc->task);
302 /* end of peerinfo_api_notify.c */