2 This file is part of GNUnet.
3 (C) 2001, 2002, 2004, 2005, 2007, 2009, 2010 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
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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"
34 * Context for the info handler.
36 struct GNUNET_PEERINFO_NotifyContext
40 * Our connection to the PEERINFO service.
42 struct GNUNET_CLIENT_Connection *client;
45 * Function to call with information.
47 GNUNET_PEERINFO_Processor callback;
50 * Closure for callback.
55 * Handle to our initial request for message transmission to
56 * the peerinfo service.
58 struct GNUNET_CLIENT_TransmitHandle *init;
63 const struct GNUNET_CONFIGURATION_Handle *cfg;
69 * Send a request to the peerinfo service to start being
70 * notified about all changes to peer information.
72 * @param nc our context
75 request_notifications (struct GNUNET_PEERINFO_NotifyContext *nc);
79 * Read notifications from the client handle and pass them
82 * @param nc our context
85 receive_notifications (struct GNUNET_PEERINFO_NotifyContext *nc);
89 * Receive a peerinfo information message, process it and
93 * @param msg message received, NULL on timeout or fatal error
96 process_notification (void *cls,
98 GNUNET_MessageHeader * msg)
100 struct GNUNET_PEERINFO_NotifyContext *nc = cls;
101 const struct InfoMessage *im;
102 const struct GNUNET_HELLO_Message *hello;
107 GNUNET_CLIENT_disconnect (nc->client, GNUNET_NO);
108 nc->client = GNUNET_CLIENT_connect ("peerinfo", nc->cfg);
109 request_notifications (nc);
112 ms = ntohs (msg->size);
113 if ((ms < sizeof (struct InfoMessage)) ||
114 (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_PEERINFO_INFO))
117 GNUNET_CLIENT_disconnect (nc->client, GNUNET_NO);
118 nc->client = GNUNET_CLIENT_connect ("peerinfo", nc->cfg);
119 request_notifications (nc);
122 im = (const struct InfoMessage *) msg;
124 if (ms > sizeof (struct InfoMessage) + sizeof (struct GNUNET_MessageHeader))
126 hello = (const struct GNUNET_HELLO_Message *) &im[1];
127 if (ms != sizeof (struct InfoMessage) + GNUNET_HELLO_size (hello))
130 GNUNET_CLIENT_disconnect (nc->client, GNUNET_NO);
131 nc->client = GNUNET_CLIENT_connect ("peerinfo", nc->cfg);
132 request_notifications (nc);
137 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
138 "Received information about peer `%s' from peerinfo database\n",
139 GNUNET_i2s (&im->peer));
141 nc->callback (nc->callback_cls, &im->peer, hello);
142 receive_notifications (nc);
147 * Read notifications from the client handle and pass them
150 * @param nc our context
153 receive_notifications (struct GNUNET_PEERINFO_NotifyContext *nc)
155 GNUNET_CLIENT_receive (nc->client,
156 &process_notification,
158 GNUNET_TIME_UNIT_FOREVER_REL);
163 * Transmit our init-notify request, start receiving.
165 * @param cls closure (our 'struct GNUNET_PEERINFO_NotifyContext')
166 * @param size number of bytes available in buf
167 * @param buf where the callee should write the message
168 * @return number of bytes written to buf
171 transmit_notify_request (void *cls,
175 struct GNUNET_PEERINFO_NotifyContext *nc = cls;
176 struct GNUNET_MessageHeader hdr;
181 GNUNET_CLIENT_disconnect (nc->client, GNUNET_NO);
182 nc->client = GNUNET_CLIENT_connect ("peerinfo", nc->cfg);
183 request_notifications (nc);
186 GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader));
187 hdr.size = htons (sizeof (struct GNUNET_MessageHeader));
188 hdr.type = htons (GNUNET_MESSAGE_TYPE_PEERINFO_NOTIFY);
189 memcpy (buf, &hdr, sizeof (struct GNUNET_MessageHeader));
190 receive_notifications (nc);
191 return sizeof (struct GNUNET_MessageHeader);
196 * Send a request to the peerinfo service to start being
197 * notified about all changes to peer information.
199 * @param nc our context
202 request_notifications (struct GNUNET_PEERINFO_NotifyContext *nc)
204 GNUNET_assert (NULL == nc->init);
205 nc->init =GNUNET_CLIENT_notify_transmit_ready (nc->client,
206 sizeof (struct GNUNET_MessageHeader),
207 GNUNET_TIME_UNIT_FOREVER_REL,
209 &transmit_notify_request,
215 * Call a method whenever our known information about peers
216 * changes. Initially calls the given function for all known
217 * peers and then only signals changes.
219 * @param cfg configuration to use
220 * @param callback the method to call for each peer
221 * @param callback_cls closure for callback
222 * @return NULL on error
224 struct GNUNET_PEERINFO_NotifyContext *
225 GNUNET_PEERINFO_notify (const struct GNUNET_CONFIGURATION_Handle *cfg,
226 GNUNET_PEERINFO_Processor callback,
229 struct GNUNET_PEERINFO_NotifyContext *nc;
230 struct GNUNET_CLIENT_Connection *client;
232 client = GNUNET_CLIENT_connect ("peerinfo", cfg);
235 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
236 _("Could not connect to `%s' service.\n"), "peerinfo");
239 nc = GNUNET_malloc (sizeof (struct GNUNET_PEERINFO_NotifyContext));
242 nc->callback = callback;
243 nc->callback_cls = callback_cls;
244 request_notifications (nc);
250 * Stop notifying about changes.
252 * @param nc context to stop notifying
255 GNUNET_PEERINFO_notify_cancel (struct GNUNET_PEERINFO_NotifyContext *nc)
257 if (NULL != nc->init)
259 GNUNET_CLIENT_notify_transmit_ready_cancel (nc->init);
262 GNUNET_CLIENT_disconnect (nc->client, GNUNET_NO);
266 /* end of peerinfo_api_notify.c */