/* This file is part of GNUnet. (C) 2001, 2002, 2004, 2005, 2007, 2009, 2010 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 peerinfo/gnunet-service-peerinfo.c * @brief maintains list of known peers * * Code to maintain the list of currently known hosts (in memory * structure of data/hosts/). * * @author Christian Grothoff * * TODO: * - HostEntries are never 'free'd (add expiration, upper bound?) */ #include "platform.h" #include "gnunet_crypto_lib.h" #include "gnunet_container_lib.h" #include "gnunet_disk_lib.h" #include "gnunet_hello_lib.h" #include "gnunet_protocols.h" #include "gnunet_service_lib.h" #include "gnunet_statistics_service.h" #include "peerinfo.h" /** * How often do we scan the HOST_DIR for new entries? */ #define DATA_HOST_FREQ GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 15) /** * How often do we discard old entries in data/hosts/? */ #define DATA_HOST_CLEAN_FREQ GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 60) /** * In-memory cache of known hosts. */ struct HostEntry { /** * Identity of the peer. */ struct GNUNET_PeerIdentity identity; /** * Hello for the peer (can be NULL) */ struct GNUNET_HELLO_Message *hello; }; /** * The in-memory list of known hosts, mapping of * host IDs to 'struct HostEntry*' values. */ static struct GNUNET_CONTAINER_MultiHashMap *hostmap; /** * Clients to immediately notify about all changes. */ static struct GNUNET_SERVER_NotificationContext *notify_list; /** * Directory where the hellos are stored in (data/hosts) */ static char *networkIdDirectory; /** * Handle for reporting statistics. */ static struct GNUNET_STATISTICS_Handle *stats; /** * Notify all clients in the notify list about the * given host entry changing. */ static struct InfoMessage * make_info_message (const struct HostEntry *he) { struct InfoMessage *im; size_t hs; hs = (he->hello == NULL) ? 0 : GNUNET_HELLO_size (he->hello); im = GNUNET_malloc (sizeof (struct InfoMessage) + hs); im->header.size = htons (hs + sizeof (struct InfoMessage)); im->header.type = htons (GNUNET_MESSAGE_TYPE_PEERINFO_INFO); im->peer = he->identity; if (he->hello != NULL) memcpy (&im[1], he->hello, hs); return im; } /** * Address iterator that causes expired entries to be discarded. * * @param cls pointer to the current time * @param tname name of the transport * @param expiration expiration time for the address * @param addr the address * @param addrlen length of addr in bytes * @return GNUNET_NO if expiration smaller than the current time */ static int discard_expired (void *cls, const char *tname, struct GNUNET_TIME_Absolute expiration, const void *addr, uint16_t addrlen) { const struct GNUNET_TIME_Absolute *now = cls; if (now->abs_value > expiration.abs_value) { GNUNET_log (GNUNET_ERROR_TYPE_INFO, _("Removing expired address of transport `%s'\n"), tname); return GNUNET_NO; } return GNUNET_OK; } /** * Get the filename under which we would store the GNUNET_HELLO_Message * for the given host and protocol. * @return filename of the form DIRECTORY/HOSTID */ static char * get_host_filename (const struct GNUNET_PeerIdentity *id) { struct GNUNET_CRYPTO_HashAsciiEncoded fil; char *fn; GNUNET_CRYPTO_hash_to_enc (&id->hashPubKey, &fil); GNUNET_asprintf (&fn, "%s%s%s", networkIdDirectory, DIR_SEPARATOR_STR, &fil); return fn; } /** * Broadcast information about the given entry to all * clients that care. * * @param entry entry to broadcast about */ static void notify_all (struct HostEntry *entry) { struct InfoMessage *msg; msg = make_info_message (entry); GNUNET_SERVER_notification_context_broadcast (notify_list, &msg->header, GNUNET_NO); GNUNET_free (msg); } /** * Add a host to the list. * * @param identity the identity of the host */ static void add_host_to_known_hosts (const struct GNUNET_PeerIdentity *identity) { struct HostEntry *entry; char buffer[GNUNET_SERVER_MAX_MESSAGE_SIZE - 1]; const struct GNUNET_HELLO_Message *hello; struct GNUNET_HELLO_Message *hello_clean; int size; struct GNUNET_TIME_Absolute now; char *fn; entry = GNUNET_CONTAINER_multihashmap_get (hostmap, &identity->hashPubKey); if (entry != NULL) return; GNUNET_STATISTICS_update (stats, gettext_noop ("# peers known"), 1, GNUNET_NO); entry = GNUNET_malloc (sizeof (struct HostEntry)); entry->identity = *identity; fn = get_host_filename (identity); if (GNUNET_DISK_file_test (fn) == GNUNET_YES) { size = GNUNET_DISK_fn_read (fn, buffer, sizeof (buffer)); hello = (const struct GNUNET_HELLO_Message *) buffer; if ((size < sizeof (struct GNUNET_MessageHeader)) || (size != ntohs ((((const struct GNUNET_MessageHeader *) hello)->size))) || (size != GNUNET_HELLO_size (hello))) { GNUNET_break (0); if (0 != UNLINK (fn)) GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING, "unlink", fn); } else { now = GNUNET_TIME_absolute_get (); hello_clean = GNUNET_HELLO_iterate_addresses (hello, GNUNET_YES, &discard_expired, &now); entry->hello = hello_clean; } } GNUNET_free (fn); GNUNET_CONTAINER_multihashmap_put (hostmap, &identity->hashPubKey, entry, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY); notify_all (entry); } /** * Remove a file that should not be there. LOG * success or failure. */ static void remove_garbage (const char *fullname) { if (0 == UNLINK (fullname)) GNUNET_log (GNUNET_ERROR_TYPE_WARNING | GNUNET_ERROR_TYPE_BULK, _ ("File `%s' in directory `%s' does not match naming convention. " "Removed.\n"), fullname, networkIdDirectory); else GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK, "unlink", fullname); } static int hosts_directory_scan_callback (void *cls, const char *fullname) { unsigned int *matched = cls; struct GNUNET_PeerIdentity identity; const char *filename; if (GNUNET_DISK_file_test (fullname) != GNUNET_YES) return GNUNET_OK; /* ignore non-files */ if (strlen (fullname) < sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded)) { remove_garbage (fullname); return GNUNET_OK; } filename = &fullname[strlen (fullname) - sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded) + 1]; if (filename[-1] != DIR_SEPARATOR) { remove_garbage (fullname); return GNUNET_OK; } if (GNUNET_OK != GNUNET_CRYPTO_hash_from_string (filename, &identity.hashPubKey)) { remove_garbage (fullname); return GNUNET_OK; } (*matched)++; add_host_to_known_hosts (&identity); return GNUNET_OK; } /** * Call this method periodically to scan data/hosts for new hosts. */ static void cron_scan_directory_data_hosts (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { static unsigned int retries; unsigned int count; if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)) return; count = 0; if (GNUNET_SYSERR == GNUNET_DISK_directory_create (networkIdDirectory)) { GNUNET_SCHEDULER_add_delayed (DATA_HOST_FREQ, &cron_scan_directory_data_hosts, NULL); return; } GNUNET_DISK_directory_scan (networkIdDirectory, &hosts_directory_scan_callback, &count); if ((0 == count) && (0 == (++retries & 31))) GNUNET_log (GNUNET_ERROR_TYPE_WARNING | GNUNET_ERROR_TYPE_BULK, _("Still no peers found in `%s'!\n"), networkIdDirectory); GNUNET_SCHEDULER_add_delayed (DATA_HOST_FREQ, &cron_scan_directory_data_hosts, NULL); } /** * Bind a host address (hello) to a hostId. * * @param peer the peer for which this is a hello * @param hello the verified (!) hello message */ static void bind_address (const struct GNUNET_PeerIdentity *peer, const struct GNUNET_HELLO_Message *hello) { char *fn; struct HostEntry *host; struct GNUNET_HELLO_Message *mrg; struct GNUNET_TIME_Absolute delta; add_host_to_known_hosts (peer); host = GNUNET_CONTAINER_multihashmap_get (hostmap, &peer->hashPubKey); GNUNET_assert (host != NULL); if (host->hello == NULL) { host->hello = GNUNET_malloc (GNUNET_HELLO_size (hello)); memcpy (host->hello, hello, GNUNET_HELLO_size (hello)); } else { mrg = GNUNET_HELLO_merge (host->hello, hello); delta = GNUNET_HELLO_equals (mrg, host->hello, GNUNET_TIME_absolute_get ()); if (delta.abs_value == GNUNET_TIME_UNIT_FOREVER_ABS.abs_value) { GNUNET_free (mrg); return; } GNUNET_free (host->hello); host->hello = mrg; } fn = get_host_filename (peer); if (GNUNET_OK == GNUNET_DISK_directory_create_for_file (fn)) { if (GNUNET_SYSERR == GNUNET_DISK_fn_write (fn, host->hello, GNUNET_HELLO_size (host->hello), GNUNET_DISK_PERM_USER_READ | GNUNET_DISK_PERM_USER_WRITE | GNUNET_DISK_PERM_GROUP_READ | GNUNET_DISK_PERM_OTHER_READ)) GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING, "write", fn); } GNUNET_free (fn); notify_all (host); } /** * Do transmit info about peer to given host. * * @param cls NULL to hit all hosts, otherwise specifies a particular target * @param key hostID * @param value information to transmit * @return GNUNET_YES (continue to iterate) */ static int add_to_tc (void *cls, const GNUNET_HashCode * key, void *value) { struct GNUNET_SERVER_TransmitContext *tc = cls; struct HostEntry *pos = value; struct InfoMessage *im; uint16_t hs; char buf[GNUNET_SERVER_MAX_MESSAGE_SIZE - 1]; hs = 0; im = (struct InfoMessage *) buf; if (pos->hello != NULL) { hs = GNUNET_HELLO_size (pos->hello); GNUNET_assert (hs < GNUNET_SERVER_MAX_MESSAGE_SIZE - sizeof (struct InfoMessage)); memcpy (&im[1], pos->hello, hs); } im->header.type = htons (GNUNET_MESSAGE_TYPE_PEERINFO_INFO); im->header.size = htons (sizeof (struct InfoMessage) + hs); im->reserved = htonl (0); im->peer = pos->identity; GNUNET_SERVER_transmit_context_append_message (tc, &im->header); return GNUNET_YES; } /** * @brief delete expired HELLO entries in data/hosts/ */ static int discard_hosts_helper (void *cls, const char *fn) { struct GNUNET_TIME_Absolute *now = cls; char buffer[GNUNET_SERVER_MAX_MESSAGE_SIZE - 1]; const struct GNUNET_HELLO_Message *hello; struct GNUNET_HELLO_Message *new_hello; int size; size = GNUNET_DISK_fn_read (fn, buffer, sizeof (buffer)); if (size < sizeof (struct GNUNET_MessageHeader)) { if (0 != UNLINK (fn)) GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING | GNUNET_ERROR_TYPE_BULK, "unlink", fn); return GNUNET_OK; } hello = (const struct GNUNET_HELLO_Message *) buffer; new_hello = GNUNET_HELLO_iterate_addresses (hello, GNUNET_YES, &discard_expired, now); if (new_hello != NULL) { GNUNET_DISK_fn_write (fn, new_hello, GNUNET_HELLO_size (new_hello), GNUNET_DISK_PERM_USER_READ | GNUNET_DISK_PERM_USER_WRITE | GNUNET_DISK_PERM_GROUP_READ | GNUNET_DISK_PERM_OTHER_READ); GNUNET_free (new_hello); } else { if (0 != UNLINK (fn)) GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING | GNUNET_ERROR_TYPE_BULK, "unlink", fn); } return GNUNET_OK; } /** * Call this method periodically to scan data/hosts for new hosts. */ static void cron_clean_data_hosts (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct GNUNET_TIME_Absolute now; if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)) return; now = GNUNET_TIME_absolute_get (); GNUNET_DISK_directory_scan (networkIdDirectory, &discard_hosts_helper, &now); GNUNET_SCHEDULER_add_delayed (DATA_HOST_CLEAN_FREQ, &cron_clean_data_hosts, NULL); } /** * Handle HELLO-message. * * @param cls closure * @param client identification of the client * @param message the actual message */ static void handle_hello (void *cls, struct GNUNET_SERVER_Client *client, const struct GNUNET_MessageHeader *message) { const struct GNUNET_HELLO_Message *hello; struct GNUNET_PeerIdentity pid; hello = (const struct GNUNET_HELLO_Message *) message; if (GNUNET_OK != GNUNET_HELLO_get_id (hello, &pid)) { GNUNET_break (0); GNUNET_SERVER_receive_done (client, GNUNET_SYSERR); return; } #if DEBUG_PEERINFO GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s' message received for peer `%4s'\n", "HELLO", GNUNET_i2s (&pid)); #endif bind_address (&pid, hello); GNUNET_SERVER_receive_done (client, GNUNET_OK); } /** * Handle GET-message. * * @param cls closure * @param client identification of the client * @param message the actual message */ static void handle_get (void *cls, struct GNUNET_SERVER_Client *client, const struct GNUNET_MessageHeader *message) { const struct ListPeerMessage *lpm; struct GNUNET_SERVER_TransmitContext *tc; lpm = (const struct ListPeerMessage *) message; GNUNET_break (0 == ntohl (lpm->reserved)); #if DEBUG_PEERINFO GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s' message received for peer `%4s'\n", "GET", GNUNET_i2s (&lpm->peer)); #endif tc = GNUNET_SERVER_transmit_context_create (client); GNUNET_CONTAINER_multihashmap_get_multiple (hostmap, &lpm->peer.hashPubKey, &add_to_tc, tc); GNUNET_SERVER_transmit_context_append_data (tc, NULL, 0, GNUNET_MESSAGE_TYPE_PEERINFO_INFO_END); GNUNET_SERVER_transmit_context_run (tc, GNUNET_TIME_UNIT_FOREVER_REL); } /** * Handle GET-ALL-message. * * @param cls closure * @param client identification of the client * @param message the actual message */ static void handle_get_all (void *cls, struct GNUNET_SERVER_Client *client, const struct GNUNET_MessageHeader *message) { struct GNUNET_SERVER_TransmitContext *tc; #if DEBUG_PEERINFO GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s' message received\n", "GET_ALL"); #endif tc = GNUNET_SERVER_transmit_context_create (client); GNUNET_CONTAINER_multihashmap_iterate (hostmap, &add_to_tc, tc); GNUNET_SERVER_transmit_context_append_data (tc, NULL, 0, GNUNET_MESSAGE_TYPE_PEERINFO_INFO_END); GNUNET_SERVER_transmit_context_run (tc, GNUNET_TIME_UNIT_FOREVER_REL); } static int do_notify_entry (void *cls, const GNUNET_HashCode * key, void *value) { struct GNUNET_SERVER_Client *client = cls; struct HostEntry *he = value; struct InfoMessage *msg; msg = make_info_message (he); GNUNET_SERVER_notification_context_unicast (notify_list, client, &msg->header, GNUNET_NO); GNUNET_free (msg); return GNUNET_YES; } /** * Handle NOTIFY-message. * * @param cls closure * @param client identification of the client * @param message the actual message */ static void handle_notify (void *cls, struct GNUNET_SERVER_Client *client, const struct GNUNET_MessageHeader *message) { #if DEBUG_PEERINFO GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s' message received\n", "NOTIFY"); #endif GNUNET_SERVER_notification_context_add (notify_list, client); GNUNET_CONTAINER_multihashmap_iterate (hostmap, &do_notify_entry, client); GNUNET_SERVER_receive_done (client, GNUNET_OK); } static int free_host_entry (void *cls, const GNUNET_HashCode * key, void *value) { struct HostEntry *he = value; GNUNET_free_non_null (he->hello); GNUNET_free (he); return GNUNET_YES; } /** * Clean up our state. Called during shutdown. * * @param cls unused * @param tc scheduler task context, unused */ static void shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { GNUNET_SERVER_notification_context_destroy (notify_list); notify_list = NULL; GNUNET_CONTAINER_multihashmap_iterate (hostmap, &free_host_entry, NULL); GNUNET_CONTAINER_multihashmap_destroy (hostmap); if (stats != NULL) { GNUNET_STATISTICS_destroy (stats, GNUNET_NO); stats = NULL; } } /** * Process statistics requests. * * @param cls closure * @param server the initialized server * @param cfg configuration to use */ static void run (void *cls, struct GNUNET_SERVER_Handle *server, const struct GNUNET_CONFIGURATION_Handle *cfg) { static const struct GNUNET_SERVER_MessageHandler handlers[] = { {&handle_hello, NULL, GNUNET_MESSAGE_TYPE_HELLO, 0}, {&handle_get, NULL, GNUNET_MESSAGE_TYPE_PEERINFO_GET, sizeof (struct ListPeerMessage)}, {&handle_get_all, NULL, GNUNET_MESSAGE_TYPE_PEERINFO_GET_ALL, sizeof (struct GNUNET_MessageHeader)}, {&handle_notify, NULL, GNUNET_MESSAGE_TYPE_PEERINFO_NOTIFY, sizeof (struct GNUNET_MessageHeader)}, {NULL, NULL, 0, 0} }; hostmap = GNUNET_CONTAINER_multihashmap_create (1024); stats = GNUNET_STATISTICS_create ("peerinfo", cfg); notify_list = GNUNET_SERVER_notification_context_create (server, 0); GNUNET_assert (GNUNET_OK == GNUNET_CONFIGURATION_get_value_filename (cfg, "peerinfo", "HOSTS", &networkIdDirectory)); GNUNET_DISK_directory_create (networkIdDirectory); GNUNET_SCHEDULER_add_with_priority (GNUNET_SCHEDULER_PRIORITY_IDLE, &cron_scan_directory_data_hosts, NULL); GNUNET_SCHEDULER_add_with_priority (GNUNET_SCHEDULER_PRIORITY_IDLE, &cron_clean_data_hosts, NULL); GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL, &shutdown_task, NULL); GNUNET_SERVER_add_handlers (server, handlers); } /** * The main function for the statistics service. * * @param argc number of arguments from the command line * @param argv command line arguments * @return 0 ok, 1 on error */ int main (int argc, char *const *argv) { int ret; ret = (GNUNET_OK == GNUNET_SERVICE_run (argc, argv, "peerinfo", GNUNET_SERVICE_OPTION_NONE, &run, NULL)) ? 0 : 1; GNUNET_free_non_null (networkIdDirectory); return ret; } /* end of gnunet-service-peerinfo.c */