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Diffstat (limited to 'src/transport/gnunet-service-transport_hello.c')
| -rw-r--r-- | src/transport/gnunet-service-transport_hello.c | 318 |
1 files changed, 318 insertions, 0 deletions
diff --git a/src/transport/gnunet-service-transport_hello.c b/src/transport/gnunet-service-transport_hello.c new file mode 100644 index 0000000..120f176 --- /dev/null +++ b/src/transport/gnunet-service-transport_hello.c @@ -0,0 +1,318 @@ +/* + This file is part of GNUnet. + (C) 2010,2011 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/gnunet-service-transport_hello.c + * @brief hello management implementation + * @author Christian Grothoff + */ +#include "platform.h" +#include "gnunet_constants.h" +#include "gnunet_hello_lib.h" +#include "gnunet_peerinfo_service.h" +#include "gnunet_statistics_service.h" +#include "gnunet-service-transport_hello.h" +#include "gnunet-service-transport.h" +#include "gnunet-service-transport_plugins.h" + + +/** + * How often do we refresh our HELLO (due to expiration concerns)? + */ +#define HELLO_REFRESH_PERIOD GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_HOURS, 6) + + +/** + * Entry in linked list of network addresses for ourselves. Also + * includes a cached signature for 'struct TransportPongMessage's. + */ +struct OwnAddressList +{ + /** + * This is a doubly-linked list. + */ + struct OwnAddressList *next; + + /** + * This is a doubly-linked list. + */ + struct OwnAddressList *prev; + + /** + * The address. + */ + struct GNUNET_HELLO_Address *address; + + /** + * How long until the current signature expires? (ZERO if the + * signature was never created). + */ + struct GNUNET_TIME_Absolute pong_sig_expires; + + /** + * Signature for a 'struct TransportPongMessage' for this address. + */ + struct GNUNET_CRYPTO_RsaSignature pong_signature; + +}; + + +/** + * Our HELLO message. + */ +static struct GNUNET_HELLO_Message *our_hello; + +/** + * Function to call on HELLO changes. + */ +static GST_HelloCallback hello_cb; + +/** + * Closure for 'hello_cb'. + */ +static void *hello_cb_cls; + +/** + * Head of my addresses. + */ +struct OwnAddressList *oal_head; + +/** + * Tail of my addresses. + */ +struct OwnAddressList *oal_tail; + +/** + * Identifier of 'refresh_hello' task. + */ +static GNUNET_SCHEDULER_TaskIdentifier hello_task; + + +/** + * Closure for 'address_generator'. + */ +struct GeneratorContext +{ + /** + * Where are we in the DLL? + */ + struct OwnAddressList *addr_pos; + + /** + * When do addresses expire? + */ + struct GNUNET_TIME_Absolute expiration; +}; + + +/** + * Add an address from the 'OwnAddressList' to the buffer. + * + * @param cls the 'struct GeneratorContext' + * @param max maximum number of bytes left + * @param buf where to write the address + */ +static size_t +address_generator (void *cls, size_t max, void *buf) +{ + struct GeneratorContext *gc = cls; + size_t ret; + + if (NULL == gc->addr_pos) + return 0; + ret = + GNUNET_HELLO_add_address (gc->addr_pos->address, gc->expiration, buf, + max); + gc->addr_pos = gc->addr_pos->next; + return ret; +} + + +/** + * Construct our HELLO message from all of the addresses of + * all of the transports. + * + * @param cls unused + * @param tc scheduler context + */ +static void +refresh_hello_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) +{ + struct GeneratorContext gc; + + hello_task = GNUNET_SCHEDULER_NO_TASK; + gc.addr_pos = oal_head; + gc.expiration = + GNUNET_TIME_relative_to_absolute + (GNUNET_CONSTANTS_HELLO_ADDRESS_EXPIRATION); + GNUNET_free (our_hello); + our_hello = GNUNET_HELLO_create (&GST_my_public_key, &address_generator, &gc); +#if DEBUG_TRANSPORT + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG | GNUNET_ERROR_TYPE_BULK, + "Refreshed my `%s', new size is %d\n", "HELLO", + GNUNET_HELLO_size (our_hello)); +#endif + GNUNET_STATISTICS_update (GST_stats, gettext_noop ("# refreshed my HELLO"), 1, + GNUNET_NO); + if (NULL != hello_cb) + hello_cb (hello_cb_cls, GST_hello_get ()); + GNUNET_PEERINFO_add_peer (GST_peerinfo, our_hello); + hello_task = + GNUNET_SCHEDULER_add_delayed (HELLO_REFRESH_PERIOD, &refresh_hello_task, + NULL); + +} + + +/** + * Schedule task to refresh hello (unless such a + * task exists already). + */ +static void +refresh_hello () +{ + if (hello_task != GNUNET_SCHEDULER_NO_TASK) + GNUNET_SCHEDULER_cancel (hello_task); + hello_task = GNUNET_SCHEDULER_add_now (&refresh_hello_task, NULL); +} + + +/** + * Initialize the HELLO module. + * + * @param cb function to call whenever our HELLO changes + * @param cb_cls closure for cb + */ +void +GST_hello_start (GST_HelloCallback cb, void *cb_cls) +{ + hello_cb = cb; + hello_cb_cls = cb_cls; + our_hello = GNUNET_HELLO_create (&GST_my_public_key, NULL, NULL); + refresh_hello (); +} + + +/** + * Shutdown the HELLO module. + */ +void +GST_hello_stop () +{ + hello_cb = NULL; + hello_cb_cls = NULL; + if (GNUNET_SCHEDULER_NO_TASK != hello_task) + { + GNUNET_SCHEDULER_cancel (hello_task); + hello_task = GNUNET_SCHEDULER_NO_TASK; + } + if (NULL != our_hello) + { + GNUNET_free (our_hello); + our_hello = NULL; + } +} + + +/** + * Obtain this peers HELLO message. + * + * @return our HELLO message + */ +const struct GNUNET_MessageHeader * +GST_hello_get () +{ + return (struct GNUNET_MessageHeader *) our_hello; +} + + +/** + * Add or remove an address from this peer's HELLO message. + * + * @param addremove GNUNET_YES to add, GNUNET_NO to remove + * @param address address to add or remove + */ +void +GST_hello_modify_addresses (int addremove, + const struct GNUNET_HELLO_Address *address) +{ + struct OwnAddressList *al; + +#if DEBUG_TRANSPORT + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, + (add_remove == + GNUNET_YES) ? "Adding `%s':%s to the set of our addresses\n" : + "Removing `%s':%s from the set of our addresses\n", + GST_plugins_a2s (address), p->short_name); +#endif + GNUNET_assert (address != NULL); + if (GNUNET_NO == addremove) + { + for (al = oal_head; al != NULL; al = al->next) + if (0 == GNUNET_HELLO_address_cmp (address, al->address)) + { + GNUNET_CONTAINER_DLL_remove (oal_head, oal_tail, al); + GNUNET_HELLO_address_free (al->address); + GNUNET_free (al); + refresh_hello (); + return; + } + /* address to be removed not found!? */ + GNUNET_break (0); + return; + } + al = GNUNET_malloc (sizeof (struct OwnAddressList)); + GNUNET_CONTAINER_DLL_insert (oal_head, oal_tail, al); + al->address = GNUNET_HELLO_address_copy (address); + refresh_hello (); +} + + +/** + * Test if a particular address is one of ours. + * + * @param address address to test + * @param sig location where to cache PONG signatures for this address [set] + * @param sig_expiration how long until the current 'sig' expires? + * (ZERO if sig was never created) [set] + * @return GNUNET_YES if this is one of our addresses, + * GNUNET_NO if not + */ +int +GST_hello_test_address (const struct GNUNET_HELLO_Address *address, + struct GNUNET_CRYPTO_RsaSignature **sig, + struct GNUNET_TIME_Absolute **sig_expiration) +{ + struct OwnAddressList *al; + + for (al = oal_head; al != NULL; al = al->next) + if (0 == GNUNET_HELLO_address_cmp (address, al->address)) + { + *sig = &al->pong_signature; + *sig_expiration = &al->pong_sig_expires; + return GNUNET_YES; + } + *sig = NULL; + *sig_expiration = NULL; + return GNUNET_NO; +} + + +/* end of file gnunet-service-transport_hello.c */ |