/* This file is part of GNUnet (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 Christian Grothoff (and other contributing authors) GNUnet is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. GNUnet is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNUnet; see the file COPYING. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /** * @file transport/plugin_transport_template.c * @brief template for a new transport service * @author Christian Grothoff */ #include "platform.h" #include "gnunet_protocols.h" #include "gnunet_connection_lib.h" #include "gnunet_server_lib.h" #include "gnunet_service_lib.h" #include "gnunet_statistics_service.h" #include "gnunet_transport_service.h" #include "gnunet_transport_plugin.h" #define DEBUG_TEMPLATE GNUNET_EXTRA_LOGGING /** * After how long do we expire an address that we * learned from another peer if it is not reconfirmed * by anyone? */ #define LEARNED_ADDRESS_EXPIRATION GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_HOURS, 6) /** * Encapsulation of all of the state of the plugin. */ struct Plugin; /** * Session handle for connections. */ struct Session { /** * To whom are we talking to (set to our identity * if we are still waiting for the welcome message) */ struct GNUNET_PeerIdentity sender; /** * Stored in a linked list. */ struct Session *next; /** * Pointer to the global plugin struct. */ struct Plugin *plugin; /** * The client (used to identify this connection) */ /* void *client; */ /** * Continuation function to call once the transmission buffer * has again space available. NULL if there is no * continuation to call. */ GNUNET_TRANSPORT_TransmitContinuation transmit_cont; /** * Closure for transmit_cont. */ void *transmit_cont_cls; /** * At what time did we reset last_received last? */ struct GNUNET_TIME_Absolute last_quota_update; /** * How many bytes have we received since the "last_quota_update" * timestamp? */ uint64_t last_received; /** * Number of bytes per ms that this peer is allowed * to send to us. */ uint32_t quota; }; /** * Encapsulation of all of the state of the plugin. */ struct Plugin { /** * Our environment. */ struct GNUNET_TRANSPORT_PluginEnvironment *env; /** * List of open sessions. */ struct Session *sessions; }; /** * Function that can be used by the transport service to transmit * a message using the plugin. Note that in the case of a * peer disconnecting, the continuation MUST be called * prior to the disconnect notification itself. This function * will be called with this peer's HELLO message to initiate * a fresh connection to another peer. * * @param cls closure * @param session which session must be used * @param msgbuf the message to transmit * @param msgbuf_size number of bytes in 'msgbuf' * @param priority how important is the message (most plugins will * ignore message priority and just FIFO) * @param to how long to wait at most for the transmission (does not * require plugins to discard the message after the timeout, * just advisory for the desired delay; most plugins will ignore * this as well) * @param cont continuation to call once the message has * been transmitted (or if the transport is ready * for the next transmission call; or if the * peer disconnected...); can be NULL * @param cont_cls closure for cont * @return number of bytes used (on the physical network, with overheads); * -1 on hard errors (i.e. address invalid); 0 is a legal value * and does NOT mean that the message was not transmitted (DV) */ static ssize_t template_plugin_send (void *cls, struct Session *session, const char *msgbuf, size_t msgbuf_size, unsigned int priority, struct GNUNET_TIME_Relative to, GNUNET_TRANSPORT_TransmitContinuation cont, void *cont_cls) { struct Plugin *plugin = cls; int bytes_sent = 0; GNUNET_assert (plugin != NULL); GNUNET_assert (session != NULL); /* struct Plugin *plugin = cls; */ return bytes_sent; } /** * Function that can be used to force the plugin to disconnect * from the given peer and cancel all previous transmissions * (and their continuationc). * * @param cls closure * @param target peer from which to disconnect */ static void template_plugin_disconnect (void *cls, const struct GNUNET_PeerIdentity *target) { // struct Plugin *plugin = cls; // FIXME } /** * Convert the transports address to a nice, human-readable * format. * * @param cls closure * @param type name of the transport that generated the address * @param addr one of the addresses of the host, NULL for the last address * the specific address format depends on the transport * @param addrlen length of the address * @param numeric should (IP) addresses be displayed in numeric form? * @param timeout after how long should we give up? * @param asc function to call on each string * @param asc_cls closure for asc */ static void template_plugin_address_pretty_printer (void *cls, const char *type, const void *addr, size_t addrlen, int numeric, struct GNUNET_TIME_Relative timeout, GNUNET_TRANSPORT_AddressStringCallback asc, void *asc_cls) { asc (asc_cls, NULL); } /** * Another peer has suggested an address for this * peer and transport plugin. Check that this could be a valid * address. If so, consider adding it to the list * of addresses. * * @param cls closure * @param addr pointer to the address * @param addrlen length of addr * @return GNUNET_OK if this is a plausible address for this peer * and transport */ static int template_plugin_address_suggested (void *cls, const void *addr, size_t addrlen) { /* struct Plugin *plugin = cls; */ /* check if the address is plausible; if so, * add it to our list! */ return GNUNET_OK; } /** * Function called for a quick conversion of the binary address to * a numeric address. Note that the caller must not free the * address and that the next call to this function is allowed * to override the address again. * * @param cls closure * @param addr binary address * @param addrlen length of the address * @return string representing the same address */ static const char * template_plugin_address_to_string (void *cls, const void *addr, size_t addrlen) { GNUNET_break (0); return NULL; } /** * Entry point for the plugin. */ void * gnunet_plugin_transport_template_init (void *cls) { struct GNUNET_TRANSPORT_PluginEnvironment *env = cls; struct GNUNET_TRANSPORT_PluginFunctions *api; struct Plugin *plugin; plugin = GNUNET_malloc (sizeof (struct Plugin)); plugin->env = env; api = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_PluginFunctions)); api->cls = plugin; api->send = &template_plugin_send; api->disconnect = &template_plugin_disconnect; api->address_pretty_printer = &template_plugin_address_pretty_printer; api->check_address = &template_plugin_address_suggested; api->address_to_string = &template_plugin_address_to_string; return api; } /** * Exit point from the plugin. */ void * gnunet_plugin_transport_template_done (void *cls) { struct GNUNET_TRANSPORT_PluginFunctions *api = cls; struct Plugin *plugin = api->cls; GNUNET_free (plugin); GNUNET_free (api); return NULL; } /* end of plugin_transport_template.c */