2 This file is part of GNUnet
3 (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 Christian Grothoff (and other contributing authors)
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13 General Public License for more details.
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22 * @file dv/plugin_transport_dv.c
23 * @brief DV transport service, takes incoming DV requests and deals with
25 * @author Christian Grothoff
31 * As a start, the dv plugin needs to listen for information from the dv
32 * service. The plugin (?) will be notified by core (?) when a tcp/udp/whatever
33 * message comes in that should be for dv. The plugin will then hand off the message
34 * to the dv service which will decrypt/validate the message (?) and then send the
35 * result back to us (the transport) which will then send the message to the transport
38 * Or, core will notify the dv service directly which will validate,
39 * etc. and then just send a message to us.
41 * For starters, this plugin needs to have a client which will listen for messages from
42 * the dv service that need to be sent up to the gnunet-transport-service.
44 * Messages sent from the dv transport get passed to the dv service which deals
45 * with the actual sending (how much state does this transport need? should it know
46 * which peers it is currently connected to and their distances, or just assume that
47 * anything should be passed along to the dv service?).
50 #include "gnunet_protocols.h"
51 #include "gnunet_connection_lib.h"
52 #include "gnunet_server_lib.h"
53 #include "gnunet_service_lib.h"
54 #include "gnunet_statistics_service.h"
55 #include "gnunet_dv_service.h"
56 #include "gnunet_transport_service.h"
57 #include "../transport/plugin_transport.h"
60 #define DEBUG_TEMPLATE GNUNET_NO
63 * Encapsulation of all of the state of the plugin.
69 * Session handle for connections.
75 * Stored in a linked list.
80 * Pointer to the global plugin struct.
82 struct Plugin *plugin;
85 * The client (used to identify this connection)
90 * Continuation function to call once the transmission buffer
91 * has again space available. NULL if there is no
92 * continuation to call.
94 GNUNET_TRANSPORT_TransmitContinuation transmit_cont;
97 * Closure for transmit_cont.
99 void *transmit_cont_cls;
102 * To whom are we talking to (set to our identity
103 * if we are still waiting for the welcome message)
105 struct GNUNET_PeerIdentity sender;
108 * At what time did we reset last_received last?
110 struct GNUNET_TIME_Absolute last_quota_update;
113 * How many bytes have we received since the "last_quota_update"
116 uint64_t last_received;
119 * Number of bytes per ms that this peer is allowed
127 * Encapsulation of all of the state of the plugin.
134 struct GNUNET_TRANSPORT_PluginEnvironment *env;
137 * List of open sessions.
139 struct Session *sessions;
142 * Handle for the statistics service.
144 struct GNUNET_STATISTICS_Handle *statistics;
149 //struct GNUNET_SERVER_Handle *server;
152 * Handle to the running service.
154 //struct GNUNET_SERVICE_Context *service;
157 * Copy of the handler array where the closures are
158 * set to this struct's instance.
160 struct GNUNET_SERVER_MessageHandler *handlers;
163 * Handle to the DV service
165 struct GNUNET_DV_Handle *dv_handle;
170 * Handler for messages received from the DV service.
172 void handle_dv_message_received (void *cls,
173 struct GNUNET_PeerIdentity *sender,
177 char *sender_address,
178 size_t sender_address_len)
180 struct Plugin *plugin = cls;
182 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
183 "plugin_transport_dv",
184 _("PLUGIN Received message from %s of type %d, distance %u!\n"),
185 "DV SERVICE", ntohs(((struct GNUNET_MessageHeader *)msg)->type), distance);
187 plugin->env->receive(plugin->env->cls,
189 (struct GNUNET_MessageHeader *)msg,
191 NULL, /* FIXME: pass session! */
198 /* Question: how does the transport service learn of a newly connected (gossipped about)
199 * DV peer? Should the plugin (here) create a HELLO for that peer and send it along,
200 * or should the DV service create a HELLO and send it to us via the other part?
204 * Function that can be used by the transport service to transmit
205 * a message using the plugin.
208 * @param target who should receive this message
209 * @param priority how important is the message
210 * @param msgbuf the message to transmit
211 * @param msgbuf_size number of bytes in 'msgbuf'
212 * @param timeout when should we time out
213 * @param session the session used
214 * @param addr the address to use (can be NULL if the plugin
215 * is "on its own" (i.e. re-use existing TCP connection))
216 * @param addrlen length of the address in bytes
217 * @param force_address GNUNET_YES if the plugin MUST use the given address,
218 * otherwise the plugin may use other addresses or
219 * existing connections (if available)
220 * @param cont continuation to call once the message has
221 * been transmitted (or if the transport is ready
222 * for the next transmission call; or if the
223 * peer disconnected...)
224 * @param cont_cls closure for cont
225 * @return number of bytes used (on the physical network, with overheads);
226 * -1 on hard errors (i.e. address invalid); 0 is a legal value
227 * and does NOT mean that the message was not transmitted (DV)
230 dv_plugin_send (void *cls,
231 const struct GNUNET_PeerIdentity *target,
234 unsigned int priority,
235 struct GNUNET_TIME_Relative timeout,
236 struct Session *session,
240 GNUNET_TRANSPORT_TransmitContinuation
241 cont, void *cont_cls)
244 struct Plugin *plugin = cls;
246 /* FIXME: do we want the dv plugin to remember sent messages to call continuation once message actually goes out?
247 * Or do we just call the continuation once we've notified the plugin?
249 // FIXME: does it make sense for us to use sessions?
251 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "DV API: Received send request from transport, calling GNUNET_DV_send\n");
253 ret = GNUNET_DV_send(plugin->dv_handle,
270 * Function that can be used to force the plugin to disconnect
271 * from the given peer and cancel all previous transmissions
272 * (and their continuations).
275 * @param target peer from which to disconnect
278 dv_plugin_disconnect (void *cls,
279 const struct GNUNET_PeerIdentity *target)
281 // struct Plugin *plugin = cls;
282 // TODO: Add message type to send to dv service to "disconnect" a peer
287 * Convert the transports address to a nice, human-readable
291 * @param type name of the transport that generated the address
292 * @param addr one of the addresses of the host, NULL for the last address
293 * the specific address format depends on the transport
294 * @param addrlen length of the address
295 * @param numeric should (IP) addresses be displayed in numeric form?
296 * @param timeout after how long should we give up?
297 * @param asc function to call on each string
298 * @param asc_cls closure for asc
301 dv_plugin_address_pretty_printer (void *cls,
306 struct GNUNET_TIME_Relative timeout,
307 GNUNET_TRANSPORT_AddressStringCallback
314 * Convert the DV address to a pretty string.
317 * @param addr the (hopefully) DV address
318 * @param addrlen the length of the address
320 * @return string representing the DV address
322 static const char *address_to_string (void *cls,
326 static char return_buffer[2 * 4 + 2]; // Two four character peer identity prefixes a ':' and '\0'
328 struct GNUNET_CRYPTO_HashAsciiEncoded peer_hash;
329 struct GNUNET_CRYPTO_HashAsciiEncoded via_hash;
330 struct GNUNET_PeerIdentity *peer;
331 struct GNUNET_PeerIdentity *via;
332 char *addr_buf = (char *)addr;
334 if (addrlen == (2 * sizeof(struct GNUNET_PeerIdentity)))
336 peer = (struct GNUNET_PeerIdentity *)addr_buf;
337 via = (struct GNUNET_PeerIdentity *)&addr_buf[sizeof(struct GNUNET_PeerIdentity)];
339 GNUNET_CRYPTO_hash_to_enc (&peer->hashPubKey, &peer_hash);
340 peer_hash.encoding[4] = '\0';
341 GNUNET_CRYPTO_hash_to_enc (&via->hashPubKey, &via_hash);
342 via_hash.encoding[4] = '\0';
343 GNUNET_snprintf (return_buffer,
344 sizeof (return_buffer),
352 return return_buffer;
356 * Another peer has suggested an address for this
357 * peer and transport plugin. Check that this could be a valid
358 * address. If so, consider adding it to the list
362 * @param addr pointer to the address
363 * @param addrlen length of addr
364 * @return GNUNET_OK if this is a plausible address for this peer
367 * FIXME: does this mean anything for the DV plugin?
370 dv_plugin_address_suggested (void *cls,
371 void *addr, size_t addrlen)
373 /* struct Plugin *plugin = cls; */
375 /* check if the address is plausible; if so,
376 add it to our list! */
382 * Entry point for the plugin.
385 libgnunet_plugin_transport_dv_init (void *cls)
387 struct GNUNET_TRANSPORT_PluginEnvironment *env = cls;
388 struct GNUNET_TRANSPORT_PluginFunctions *api;
389 struct Plugin *plugin;
391 plugin = GNUNET_malloc (sizeof (struct Plugin));
393 plugin->statistics = NULL;
394 //plugin->service = service;
395 //plugin->server = GNUNET_SERVICE_get_server (service);
397 plugin->dv_handle = GNUNET_DV_connect(env->sched, env->cfg, &handle_dv_message_received, plugin);
399 if (plugin->dv_handle == NULL)
405 api = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_PluginFunctions));
407 api->send = &dv_plugin_send;
408 api->disconnect = &dv_plugin_disconnect;
409 api->address_pretty_printer = &dv_plugin_address_pretty_printer;
410 api->check_address = &dv_plugin_address_suggested;
411 api->address_to_string = &address_to_string;
417 * Exit point from the plugin.
420 libgnunet_plugin_transport_dv_done (void *cls)
422 struct GNUNET_TRANSPORT_PluginFunctions *api = cls;
423 struct Plugin *plugin = api->cls;
425 GNUNET_free (plugin);
430 /* end of plugin_transport_template.c */