src/include/gnunet_mesh_service.h

   1 /*
   2      This file is part of GNUnet.
   3      (C) 2009, 2010 Christian Grothoff (and other contributing authors)
   4
   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
   8      option) any later version.
   9
  10      GNUnet is distributed in the hope that it will be useful, but
  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.
  14
  15      You should have received a copy of the GNU General Public License
  16      along with GNUnet; see the file COPYING.  If not, write to the
  17      Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18      Boston, MA 02111-1307, USA.
  19 */
  20
  21 /**
  22  * @file include/gnunet_mesh_service.h
  23  * @brief mesh service; establish tunnels to distant peers
  24  * @author Christian Grothoff
  25  */
  26
  27 #ifndef GNUNET_MESH_SERVICE_H
  28 #define GNUNET_MESH_SERVICE_H
  29
  30 #ifdef __cplusplus
  31 extern "C"
  32 {
  33 #if 0                           /* keep Emacsens' auto-indent happy */
  34 }
  35 #endif
  36 #endif
  37
  38 #include "gnunet_util_lib.h"
  39 #include "gnunet_transport_service.h"
  40
  41 /**
  42  * Version number of GNUnet-mesh API.
  43  */
  44 #define GNUNET_MESH_VERSION 0x00000000
  45
  46
  47 /**
  48  * Opaque handle to the service.
  49  */
  50 struct GNUNET_MESH_Handle;
  51
  52 /**
  53  * Opaque handle to a tunnel.
  54  */
  55 struct GNUNET_MESH_Tunnel;
  56
  57 /**
  58  * Functions with this signature are called whenever a message is
  59  * received or transmitted.
  60  *
  61  * @param cls closure (set from GNUNET_MESH_connect)
  62  * @param tunnel connection to the other end
  63  * @param tunnel_ctx place to store local state associated with the tunnel
  64  * @param sender who sent the message
  65  * @param message the actual message
  66  * @param atsi performance data for the connection
  67  * @return GNUNET_OK to keep the connection open,
  68  *         GNUNET_SYSERR to close it (signal serious error)
  69  */
  70 typedef int
  71     (*GNUNET_MESH_MessageCallback) (void *cls,
  72                                     struct GNUNET_MESH_Tunnel * tunnel,
  73                                     void **tunnel_ctx,
  74                                     const struct GNUNET_PeerIdentity * sender,
  75                                     const struct GNUNET_MessageHeader * message,
  76                                     const struct
  77                                     GNUNET_TRANSPORT_ATS_Information * atsi);
  78
  79
  80 /**
  81  * Message handler.  Each struct specifies how to handle on particular
  82  * type of message received.
  83  */
  84 struct GNUNET_MESH_MessageHandler
  85 {
  86   /**
  87    * Function to call for messages of "type".
  88    */
  89   GNUNET_MESH_MessageCallback callback;
  90
  91   /**
  92    * Type of the message this handler covers.
  93    */
  94   uint16_t type;
  95
  96   /**
  97    * Expected size of messages of this type.  Use 0 for variable-size.
  98    * If non-zero, messages of the given type will be discarded if they
  99    * do not have the right size.
 100    */
 101   uint16_t expected_size;
 102
 103 };
 104
 105
 106 /**
 107  * Function called whenever an inbound tunnel is destroyed.  Should clean up
 108  * any associated state.
 109  *
 110  * @param cls closure (set from GNUNET_MESH_connect)
 111  * @param tunnel connection to the other end (henceforth invalid)
 112  * @param tunnel_ctx place where local state associated with the tunnel is stored
 113  */
 114 typedef void (GNUNET_MESH_TunnelEndHandler) (void *cls,
 115                                              const struct GNUNET_MESH_Tunnel *
 116                                              tunnel, void **tunnel_ctx);
 117
 118
 119 /**
 120  * Type for an application.  Values defined in gnunet_applications.h
 121  */
 122 typedef uint32_t GNUNET_MESH_ApplicationType;
 123
 124
 125 /**
 126  * Connect to the mesh service.
 127  *
 128  * @param cfg configuration to use
 129  * @param cls closure for the various callbacks that follow (including handlers in the handlers array)
 130  * @param cleaner function called when an *inbound* tunnel is destroyed
 131  * @param handlers callbacks for messages we care about, NULL-terminated
 132  *                note that the mesh is allowed to drop notifications about inbound
 133  *                messages if the client does not process them fast enough (for this
 134  *                notification type, a bounded queue is used)
 135  * @param stypes Application Types the client claims to offer
 136  * @return handle to the mesh service
 137  *           NULL on error (in this case, init is never called)
 138  */
 139 struct GNUNET_MESH_Handle *GNUNET_MESH_connect (const struct
 140                                                 GNUNET_CONFIGURATION_Handle
 141                                                 *cfg, void *cls,
 142                                                 GNUNET_MESH_TunnelEndHandler
 143                                                 cleaner,
 144                                                 const struct
 145                                                 GNUNET_MESH_MessageHandler
 146                                                 *handlers,
 147                                                 const
 148                                                 GNUNET_MESH_ApplicationType
 149                                                 *stypes);
 150
 151 /**
 152  * Get the peer on the other side of this tunnel if it is just one. Return NULL otherwise
 153  *
 154  * @param tunnel the tunnel
 155  * @return the peer or NULL
 156  */
 157 const struct GNUNET_PeerIdentity *GNUNET_MESH_get_peer (const struct
 158                                                         GNUNET_MESH_Tunnel
 159                                                         *tunnel);
 160
 161
 162 /**
 163  * Disconnect from the mesh service.
 164  *
 165  * @param handle connection to mesh to disconnect
 166  */
 167 void GNUNET_MESH_disconnect (struct GNUNET_MESH_Handle *handle);
 168
 169
 170
 171
 172
 173 /**
 174  * Method called whenever a tunnel falls apart.
 175  *
 176  * @param cls closure
 177  * @param peer peer identity the tunnel stopped working with
 178  */
 179 typedef void (*GNUNET_MESH_TunnelDisconnectHandler) (void *cls,
 180                                                      const struct
 181                                                      GNUNET_PeerIdentity *
 182                                                      peer);
 183
 184
 185 /**
 186  * Method called whenever a tunnel is established.
 187  *
 188  * @param cls closure
 189  * @param peer peer identity the tunnel was created to, NULL on timeout
 190  * @param atsi performance data for the connection
 191  */
 192 typedef void (*GNUNET_MESH_TunnelConnectHandler) (void *cls,
 193                                                   const struct
 194                                                   GNUNET_PeerIdentity * peer,
 195                                                   const struct
 196                                                   GNUNET_TRANSPORT_ATS_Information
 197                                                   * atsi);
 198
 199
 200
 201 /**
 202  * Handle for a request to the mesh to connect or disconnect
 203  * from a particular peer.  Can be used to cancel the request
 204  * (before the 'cont'inuation is called).
 205  */
 206 struct GNUNET_MESH_PeerRequestHandle;
 207
 208
 209 /**
 210  * Request that the mesh should try to connect to any of the given peers.
 211  *
 212  * @param h mesh handle
 213  * @param timeout how long to try to establish a connection
 214  * @param num_peers length of the peers array
 215  * @param peers list of candidates to connect to
 216  * @param connect_handler function to call on successful connect (or timeout)
 217  * @param disconnect_handler function to call on disconnect
 218  * @param handler_cls closure for handler
 219  * @return NULL on error (handler will not be called), otherwise handle for cancellation
 220  */
 221 struct GNUNET_MESH_Tunnel *GNUNET_MESH_peer_request_connect_any (struct
 222                                                                  GNUNET_MESH_Handle
 223                                                                  *h,
 224                                                                  struct
 225                                                                  GNUNET_TIME_Relative
 226                                                                  timeout,
 227                                                                  unsigned int
 228                                                                  num_peers,
 229                                                                  const struct
 230                                                                  GNUNET_PeerIdentity
 231                                                                  *peers,
 232                                                                  GNUNET_MESH_TunnelConnectHandler
 233                                                                  connect_handler,
 234                                                                  GNUNET_MESH_TunnelDisconnectHandler
 235                                                                  disconnect_handler,
 236                                                                  void
 237                                                                  *handler_cls);
 238
 239
 240 /**
 241  * Request that the mesh should try to connect to all of the given peers.
 242  * Messages send to the tunnel will be broadcast.
 243  *
 244  * @param h mesh handle
 245  * @param timeout how long to try to establish a connection
 246  * @param num_peers length of the peers array
 247  * @param peers list of candidates to connect to
 248  * @param connect_handler function to call on successful connect (or timeout);
 249  *                will be called for EACH of the peers in the list and
 250  *                once at the end with 'NULL' on timeout or once we've connected
 251  *                to each of the peers in the list
 252  * @param disconnect_handler function called if a peer drops out of the tunnel;
 253  *                the mesh will NOT try to add it back automatically
 254  * @param handler_cls closure for handler
 255  * @return NULL on error (handler will not be called), otherwise handle for cancellation
 256  */
 257 struct GNUNET_MESH_Tunnel *GNUNET_MESH_peer_request_connect_all (struct
 258                                                                  GNUNET_MESH_Handle
 259                                                                  *h,
 260                                                                  struct
 261                                                                  GNUNET_TIME_Relative
 262                                                                  timeout,
 263                                                                  unsigned int
 264                                                                  num_peers,
 265                                                                  const struct
 266                                                                  GNUNET_PeerIdentity
 267                                                                  *peers,
 268                                                                  GNUNET_MESH_TunnelConnectHandler
 269                                                                  connect_handler,
 270                                                                  GNUNET_MESH_TunnelDisconnectHandler
 271                                                                  disconnect_handler,
 272                                                                  void
 273                                                                  *handler_cls);
 274
 275
 276 /**
 277  * Request that a peer should be added to the tunnel.  The existing
 278  * connect handler will be called ONCE with either success or failure.
 279  *
 280  * @param tunnel handle to existing tunnel
 281  * @param timeout how long to try to establish a connection
 282  * @param peer peer to add
 283  */
 284 void
 285 GNUNET_MESH_peer_request_connect_add (struct GNUNET_MESH_Tunnel *tunnel,
 286                                       struct GNUNET_TIME_Relative timeout,
 287                                       const struct GNUNET_PeerIdentity *peer);
 288
 289
 290 /**
 291  * Request that a peer should be removed from the tunnel.  The existing
 292  * disconnect handler will be called ONCE if we were connected.
 293  *
 294  * @param tunnel handle to existing tunnel
 295  * @param peer peer to remove
 296  */
 297 void
 298 GNUNET_MESH_peer_request_connect_del (struct GNUNET_MESH_Tunnel *tunnel,
 299                                       const struct GNUNET_PeerIdentity *peer);
 300
 301
 302 /**
 303  * Request that the mesh should try to connect to a peer supporting the given
 304  * message type.
 305  *
 306  * @param h mesh handle
 307  * @param timeout how long to try to establish a connection
 308  * @param app_type application type that must be supported by the peer (MESH should
 309  *                discover peer in proximity handling this type)
 310  * @param connect_handler function to call on successful connect (or timeout);
 311  *                will be called for EACH of the peers in the list and
 312  *                once at the end with 'NULL' on timeout or once we've connected
 313  *                to each of the peers in the list
 314  * @param disconnect_handler function called if a peer drops out of the tunnel;
 315  *                the mesh will NOT try to add it back automatically
 316  * @param handler_cls closure for handler
 317  * @return NULL on error (handler will not be called), otherwise handle for cancellation
 318  */
 319 struct GNUNET_MESH_Tunnel *GNUNET_MESH_peer_request_connect_by_type (struct
 320                                                                      GNUNET_MESH_Handle
 321                                                                      *h,
 322                                                                      struct
 323                                                                      GNUNET_TIME_Relative
 324                                                                      timeout,
 325                                                                      GNUNET_MESH_ApplicationType
 326                                                                      app_type,
 327                                                                      GNUNET_MESH_TunnelConnectHandler
 328                                                                      connect_handler,
 329                                                                      GNUNET_MESH_TunnelDisconnectHandler
 330                                                                      disconnect_handler,
 331                                                                      void
 332                                                                      *handler_cls);
 333
 334
 335 /**
 336  * Cancel a pending request to connect to a particular peer.  Destroys the
 337  * tunnel.
 338  *
 339  * @param req request handle that was returned for the original request
 340  */
 341 void GNUNET_MESH_peer_request_connect_cancel (struct GNUNET_MESH_Tunnel *req);
 342
 343
 344 /**
 345  * Handle for a transmission request.
 346  */
 347 struct GNUNET_MESH_TransmitHandle;
 348
 349
 350 /**
 351  * Ask the mesh to call "notify" once it is ready to transmit the
 352  * given number of bytes to the specified "target".  If we are not yet
 353  * connected to the specified peer, a call to this function will cause
 354  * us to try to establish a connection.
 355  *
 356  * @param tunnel tunnel to use for transmission
 357  * @param cork is corking allowed for this transmission?
 358  * @param priority how important is the message?
 359  * @param maxdelay how long can the message wait?
 360  * @param target destination for the message, NULL for multicast to all tunnel targets
 361  * @param notify_size how many bytes of buffer space does notify want?
 362  * @param notify function to call when buffer space is available;
 363  *        will be called with NULL on timeout or if the overall queue
 364  *        for this peer is larger than queue_size and this is currently
 365  *        the message with the lowest priority
 366  * @param notify_cls closure for notify
 367  * @return non-NULL if the notify callback was queued,
 368  *         NULL if we can not even queue the request (insufficient
 369  *         memory); if NULL is returned, "notify" will NOT be called.
 370  */
 371 struct GNUNET_MESH_TransmitHandle *GNUNET_MESH_notify_transmit_ready (struct
 372                                                                       GNUNET_MESH_Tunnel
 373                                                                       *tunnel,
 374                                                                       int cork,
 375                                                                       uint32_t
 376                                                                       priority,
 377                                                                       struct
 378                                                                       GNUNET_TIME_Relative
 379                                                                       maxdelay,
 380                                                                       const
 381                                                                       struct
 382                                                                       GNUNET_PeerIdentity
 383                                                                       *target,
 384                                                                       size_t
 385                                                                       notify_size,
 386                                                                       GNUNET_CONNECTION_TransmitReadyNotify
 387                                                                       notify,
 388                                                                       void
 389                                                                       *notify_cls);
 390
 391
 392 /**
 393  * Cancel the specified transmission-ready notification.
 394  *
 395  * @param th handle that was returned by "notify_transmit_ready".
 396  */
 397 void
 398 GNUNET_MESH_notify_transmit_ready_cancel (struct GNUNET_MESH_TransmitHandle
 399                                           *th);
 400
 401 void GNUNET_MESH_tunnel_set_head (struct GNUNET_MESH_Tunnel *tunnel,
 402                                   void *head);
 403 void GNUNET_MESH_tunnel_set_tail (struct GNUNET_MESH_Tunnel *tunnel,
 404                                   void *tail);
 405 void *GNUNET_MESH_tunnel_get_head (struct GNUNET_MESH_Tunnel *tunnel);
 406 void *GNUNET_MESH_tunnel_get_tail (struct GNUNET_MESH_Tunnel *tunnel);
 407
 408 void GNUNET_MESH_tunnel_set_data (struct GNUNET_MESH_Tunnel *tunnel,
 409                                   void *data);
 410 void *GNUNET_MESH_tunnel_get_data (struct GNUNET_MESH_Tunnel *tunnel);
 411
 412 #if 0                           /* keep Emacsens' auto-indent happy */
 413 {
 414 #endif
 415 #ifdef __cplusplus
 416 }
 417 #endif
 418
 419 /* ifndef GNUNET_MESH_SERVICE_H */
 420 #endif
 421 /* end of gnunet_mesh_service.h */