diff options
Diffstat (limited to 'src/peerinfo/gnunet-service-peerinfo.c')
| -rw-r--r-- | src/peerinfo/gnunet-service-peerinfo.c | 671 |
1 files changed, 671 insertions, 0 deletions
diff --git a/src/peerinfo/gnunet-service-peerinfo.c b/src/peerinfo/gnunet-service-peerinfo.c new file mode 100644 index 0000000..d6e52d4 --- /dev/null +++ b/src/peerinfo/gnunet-service-peerinfo.c @@ -0,0 +1,671 @@ +/* + 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 address the address + * @param expiration expiration time for the address + * @return GNUNET_NO if expiration smaller than the current time + */ +static int +discard_expired (void *cls, const struct GNUNET_HELLO_Address *address, + struct GNUNET_TIME_Absolute expiration) +{ + 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"), + address->transport_name); + 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_with_priority (DATA_HOST_FREQ, + GNUNET_SCHEDULER_PRIORITY_IDLE, + &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_with_priority (DATA_HOST_FREQ, + GNUNET_SCHEDULER_PRIORITY_IDLE, + &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 */ |