/* This file is part of GNUnet. Copyright (C) 2011, 2016 GNUnet e.V. GNUnet is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, 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 Affero General Public License for more details. You should have received a copy of the GNU Affero General Public License along with this program. If not, see . SPDX-License-Identifier: AGPL3.0-or-later */ /** * @file fs/gnunet-service-fs_cp.c * @brief API to handle 'connected peers' * @author Christian Grothoff */ #include "platform.h" #include "gnunet_util_lib.h" #include "gnunet_load_lib.h" #include "gnunet-service-fs.h" #include "gnunet-service-fs_cp.h" #include "gnunet-service-fs_pe.h" #include "gnunet-service-fs_pr.h" #include "gnunet-service-fs_push.h" #include "gnunet_peerstore_service.h" /** * Ratio for moving average delay calculation. The previous * average goes in with a factor of (n-1) into the calculation. * Must be > 0. */ #define RUNAVG_DELAY_N 16 /** * How often do we flush respect values to disk? */ #define RESPECT_FLUSH_FREQ GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 5) /** * After how long do we discard a reply? */ #define REPLY_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 2) /** * Collect an instane number of statistics? May cause excessive IPC. */ #define INSANE_STATISTICS GNUNET_NO /** * Handle to cancel a transmission request. */ struct GSF_PeerTransmitHandle { /** * Kept in a doubly-linked list. */ struct GSF_PeerTransmitHandle *next; /** * Kept in a doubly-linked list. */ struct GSF_PeerTransmitHandle *prev; /** * Time when this transmission request was issued. */ struct GNUNET_TIME_Absolute transmission_request_start_time; /** * Envelope with the actual message. */ struct GNUNET_MQ_Envelope *env; /** * Peer this request targets. */ struct GSF_ConnectedPeer *cp; /** * #GNUNET_YES if this is a query, #GNUNET_NO for content. */ int is_query; /** * Did we get a reservation already? */ int was_reserved; /** * Priority of this request. */ uint32_t priority; }; /** * Handle for an entry in our delay list. */ struct GSF_DelayedHandle { /** * Kept in a doubly-linked list. */ struct GSF_DelayedHandle *next; /** * Kept in a doubly-linked list. */ struct GSF_DelayedHandle *prev; /** * Peer this transmission belongs to. */ struct GSF_ConnectedPeer *cp; /** * Envelope of the message that was delayed. */ struct GNUNET_MQ_Envelope *env; /** * Task for the delay. */ struct GNUNET_SCHEDULER_Task *delay_task; /** * Size of the message. */ size_t msize; }; /** * Information per peer and request. */ struct PeerRequest { /** * Handle to generic request (generic: from peer or local client). */ struct GSF_PendingRequest *pr; /** * Which specific peer issued this request? */ struct GSF_ConnectedPeer *cp; /** * Task for asynchronous stopping of this request. */ struct GNUNET_SCHEDULER_Task *kill_task; }; /** * A connected peer. */ struct GSF_ConnectedPeer { /** * Performance data for this peer. */ struct GSF_PeerPerformanceData ppd; /** * Time until when we blocked this peer from migrating * data to us. */ struct GNUNET_TIME_Absolute last_migration_block; /** * Task scheduled to revive migration to this peer. */ struct GNUNET_SCHEDULER_Task *mig_revive_task; /** * Messages (replies, queries, content migration) we would like to * send to this peer in the near future. Sorted by priority, head. */ struct GSF_PeerTransmitHandle *pth_head; /** * Messages (replies, queries, content migration) we would like to * send to this peer in the near future. Sorted by priority, tail. */ struct GSF_PeerTransmitHandle *pth_tail; /** * Messages (replies, queries, content migration) we would like to * send to this peer in the near future. Sorted by priority, head. */ struct GSF_DelayedHandle *delayed_head; /** * Messages (replies, queries, content migration) we would like to * send to this peer in the near future. Sorted by priority, tail. */ struct GSF_DelayedHandle *delayed_tail; /** * Context of our GNUNET_ATS_reserve_bandwidth call (or NULL). */ struct GNUNET_ATS_ReservationContext *rc; /** * Task scheduled if we need to retry bandwidth reservation later. */ struct GNUNET_SCHEDULER_Task *rc_delay_task; /** * Active requests from this neighbour, map of query to `struct PeerRequest`. */ struct GNUNET_CONTAINER_MultiHashMap *request_map; /** * Handle for an active request for transmission to this * peer. */ struct GNUNET_MQ_Handle *mq; /** * Increase in traffic preference still to be submitted * to the core service for this peer. */ uint64_t inc_preference; /** * Number of entries in @e delayed_head DLL. */ unsigned int delay_queue_size; /** * Respect rating for this peer on disk. */ uint32_t disk_respect; /** * Which offset in @e last_p2p_replies will be updated next? * (we go round-robin). */ unsigned int last_p2p_replies_woff; /** * Which offset in @e last_client_replies will be updated next? * (we go round-robin). */ unsigned int last_client_replies_woff; /** * Current offset into @e last_request_times ring buffer. */ unsigned int last_request_times_off; /** * #GNUNET_YES if we did successfully reserve 32k bandwidth, * #GNUNET_NO if not. */ int did_reserve; /** * Handle to the PEERSTORE iterate request for peer respect value */ struct GNUNET_PEERSTORE_IterateContext *respect_iterate_req; }; /** * Map from peer identities to `struct GSF_ConnectPeer` entries. */ static struct GNUNET_CONTAINER_MultiPeerMap *cp_map; /** * Handle to peerstore service. */ static struct GNUNET_PEERSTORE_Handle *peerstore; /** * Task used to flush respect values to disk. */ static struct GNUNET_SCHEDULER_Task *fr_task; /** * Update the latency information kept for the given peer. * * @param id peer record to update * @param latency current latency value */ void GSF_update_peer_latency_ (const struct GNUNET_PeerIdentity *id, struct GNUNET_TIME_Relative latency) { struct GSF_ConnectedPeer *cp; cp = GSF_peer_get_ (id); if (NULL == cp) return; /* we're not yet connected at the core level, ignore */ GNUNET_LOAD_value_set_decline (cp->ppd.transmission_delay, latency); } /** * Return the performance data record for the given peer * * @param cp peer to query * @return performance data record for the peer */ struct GSF_PeerPerformanceData * GSF_get_peer_performance_data_ (struct GSF_ConnectedPeer *cp) { return &cp->ppd; } /** * Core is ready to transmit to a peer, get the message. * * @param cp which peer to send a message to */ static void peer_transmit (struct GSF_ConnectedPeer *cp); /** * Function called by core upon success or failure of our bandwidth reservation request. * * @param cls the `struct GSF_ConnectedPeer` of the peer for which we made the request * @param peer identifies the peer * @param amount set to the amount that was actually reserved or unreserved; * either the full requested amount or zero (no partial reservations) * @param res_delay if the reservation could not be satisfied (amount was 0), how * long should the client wait until re-trying? */ static void ats_reserve_callback (void *cls, const struct GNUNET_PeerIdentity *peer, int32_t amount, struct GNUNET_TIME_Relative res_delay); /** * If ready (bandwidth reserved), try to schedule transmission via * core for the given handle. * * @param pth transmission handle to schedule */ static void schedule_transmission (struct GSF_PeerTransmitHandle *pth) { struct GSF_ConnectedPeer *cp; struct GNUNET_PeerIdentity target; cp = pth->cp; GNUNET_assert (0 != cp->ppd.pid); GNUNET_PEER_resolve (cp->ppd.pid, &target); if (0 != cp->inc_preference) { GNUNET_ATS_performance_change_preference (GSF_ats, &target, GNUNET_ATS_PREFERENCE_BANDWIDTH, (double) cp->inc_preference, GNUNET_ATS_PREFERENCE_END); cp->inc_preference = 0; } if ( (GNUNET_YES == pth->is_query) && (GNUNET_YES != pth->was_reserved) ) { /* query, need reservation */ if (GNUNET_YES != cp->did_reserve) return; /* not ready */ cp->did_reserve = GNUNET_NO; /* reservation already done! */ pth->was_reserved = GNUNET_YES; cp->rc = GNUNET_ATS_reserve_bandwidth (GSF_ats, &target, DBLOCK_SIZE, &ats_reserve_callback, cp); return; } peer_transmit (cp); } /** * Core is ready to transmit to a peer, get the message. * * @param cp which peer to send a message to */ static void peer_transmit (struct GSF_ConnectedPeer *cp) { struct GSF_PeerTransmitHandle *pth = cp->pth_head; struct GSF_PeerTransmitHandle *pos; if (NULL == pth) return; GNUNET_CONTAINER_DLL_remove (cp->pth_head, cp->pth_tail, pth); if (GNUNET_YES == pth->is_query) { cp->ppd.last_request_times[(cp->last_request_times_off++) % MAX_QUEUE_PER_PEER] = GNUNET_TIME_absolute_get (); GNUNET_assert (0 < cp->ppd.pending_queries--); } else if (GNUNET_NO == pth->is_query) { GNUNET_assert (0 < cp->ppd.pending_replies--); } GNUNET_LOAD_update (cp->ppd.transmission_delay, GNUNET_TIME_absolute_get_duration (pth->transmission_request_start_time).rel_value_us); GNUNET_MQ_send (cp->mq, pth->env); GNUNET_free (pth); if (NULL != (pos = cp->pth_head)) { GNUNET_assert (pos != pth); schedule_transmission (pos); } } /** * (re)try to reserve bandwidth from the given peer. * * @param cls the `struct GSF_ConnectedPeer` to reserve from */ static void retry_reservation (void *cls) { struct GSF_ConnectedPeer *cp = cls; struct GNUNET_PeerIdentity target; GNUNET_PEER_resolve (cp->ppd.pid, &target); cp->rc_delay_task = NULL; cp->rc = GNUNET_ATS_reserve_bandwidth (GSF_ats, &target, DBLOCK_SIZE, &ats_reserve_callback, cp); } /** * Function called by core upon success or failure of our bandwidth reservation request. * * @param cls the `struct GSF_ConnectedPeer` of the peer for which we made the request * @param peer identifies the peer * @param amount set to the amount that was actually reserved or unreserved; * either the full requested amount or zero (no partial reservations) * @param res_delay if the reservation could not be satisfied (amount was 0), how * long should the client wait until re-trying? */ static void ats_reserve_callback (void *cls, const struct GNUNET_PeerIdentity *peer, int32_t amount, struct GNUNET_TIME_Relative res_delay) { struct GSF_ConnectedPeer *cp = cls; struct GSF_PeerTransmitHandle *pth; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Reserved %d bytes / need to wait %s for reservation\n", (int) amount, GNUNET_STRINGS_relative_time_to_string (res_delay, GNUNET_YES)); cp->rc = NULL; if (0 == amount) { cp->rc_delay_task = GNUNET_SCHEDULER_add_delayed (res_delay, &retry_reservation, cp); return; } cp->did_reserve = GNUNET_YES; pth = cp->pth_head; if (NULL != pth) { /* reservation success, try transmission now! */ peer_transmit (cp); } } /** * Function called by PEERSTORE with peer respect record * * @param cls handle to connected peer entry * @param record peerstore record information * @param emsg error message, or NULL if no errors */ static void peer_respect_cb (void *cls, const struct GNUNET_PEERSTORE_Record *record, const char *emsg) { struct GSF_ConnectedPeer *cp = cls; GNUNET_assert (NULL != cp->respect_iterate_req); if ( (NULL != record) && (sizeof (cp->disk_respect) == record->value_size)) { cp->disk_respect = *((uint32_t *)record->value); cp->ppd.respect += *((uint32_t *)record->value); } GSF_push_start_ (cp); if (NULL != record) GNUNET_PEERSTORE_iterate_cancel (cp->respect_iterate_req); cp->respect_iterate_req = NULL; } /** * Function called for each pending request whenever a new * peer connects, giving us a chance to decide about submitting * the existing request to the new peer. * * @param cls the `struct GSF_ConnectedPeer` of the new peer * @param key query for the request * @param pr handle to the pending request * @return #GNUNET_YES to continue to iterate */ static int consider_peer_for_forwarding (void *cls, const struct GNUNET_HashCode *key, struct GSF_PendingRequest *pr) { struct GSF_ConnectedPeer *cp = cls; struct GNUNET_PeerIdentity pid; if (GNUNET_YES != GSF_pending_request_test_active_ (pr)) return GNUNET_YES; /* request is not actually active, skip! */ GSF_connected_peer_get_identity_ (cp, &pid); if (GNUNET_YES != GSF_pending_request_test_target_ (pr, &pid)) { GNUNET_STATISTICS_update (GSF_stats, gettext_noop ("# Loopback routes suppressed"), 1, GNUNET_NO); return GNUNET_YES; } GSF_plan_add_ (cp, pr); return GNUNET_YES; } /** * A peer connected to us. Setup the connected peer * records. * * @param cls NULL * @param peer identity of peer that connected * @param mq message queue for talking to @a peer * @return our internal handle for the peer */ void * GSF_peer_connect_handler (void *cls, const struct GNUNET_PeerIdentity *peer, struct GNUNET_MQ_Handle *mq) { struct GSF_ConnectedPeer *cp; if (0 == GNUNET_memcmp (&GSF_my_id, peer)) return NULL; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Connected to peer %s\n", GNUNET_i2s (peer)); cp = GNUNET_new (struct GSF_ConnectedPeer); cp->ppd.pid = GNUNET_PEER_intern (peer); cp->ppd.peer = peer; cp->mq = mq; cp->ppd.transmission_delay = GNUNET_LOAD_value_init (GNUNET_TIME_UNIT_ZERO); cp->rc = GNUNET_ATS_reserve_bandwidth (GSF_ats, peer, DBLOCK_SIZE, &ats_reserve_callback, cp); cp->request_map = GNUNET_CONTAINER_multihashmap_create (128, GNUNET_YES); GNUNET_break (GNUNET_OK == GNUNET_CONTAINER_multipeermap_put (cp_map, GSF_connected_peer_get_identity2_ (cp), cp, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY)); GNUNET_STATISTICS_set (GSF_stats, gettext_noop ("# peers connected"), GNUNET_CONTAINER_multipeermap_size (cp_map), GNUNET_NO); cp->respect_iterate_req = GNUNET_PEERSTORE_iterate (peerstore, "fs", peer, "respect", &peer_respect_cb, cp); GSF_iterate_pending_requests_ (&consider_peer_for_forwarding, cp); return cp; } /** * It may be time to re-start migrating content to this * peer. Check, and if so, restart migration. * * @param cls the `struct GSF_ConnectedPeer` */ static void revive_migration (void *cls) { struct GSF_ConnectedPeer *cp = cls; struct GNUNET_TIME_Relative bt; cp->mig_revive_task = NULL; bt = GNUNET_TIME_absolute_get_remaining (cp->ppd.migration_blocked_until); if (0 != bt.rel_value_us) { /* still time left... */ cp->mig_revive_task = GNUNET_SCHEDULER_add_delayed (bt, &revive_migration, cp); return; } GSF_push_start_ (cp); } /** * Get a handle for a connected peer. * * @param peer peer's identity * @return NULL if the peer is not currently connected */ struct GSF_ConnectedPeer * GSF_peer_get_ (const struct GNUNET_PeerIdentity *peer) { if (NULL == cp_map) return NULL; return GNUNET_CONTAINER_multipeermap_get (cp_map, peer); } /** * Handle P2P #GNUNET_MESSAGE_TYPE_FS_MIGRATION_STOP message. * * @param cls closure, the `struct GSF_ConnectedPeer` * @param msm the actual message */ void handle_p2p_migration_stop (void *cls, const struct MigrationStopMessage *msm) { struct GSF_ConnectedPeer *cp = cls; struct GNUNET_TIME_Relative bt; GNUNET_STATISTICS_update (GSF_stats, gettext_noop ("# migration stop messages received"), 1, GNUNET_NO); bt = GNUNET_TIME_relative_ntoh (msm->duration); GNUNET_log (GNUNET_ERROR_TYPE_INFO, _("Migration of content to peer `%s' blocked for %s\n"), GNUNET_i2s (cp->ppd.peer), GNUNET_STRINGS_relative_time_to_string (bt, GNUNET_YES)); cp->ppd.migration_blocked_until = GNUNET_TIME_relative_to_absolute (bt); if ( (NULL == cp->mig_revive_task) && (NULL == cp->respect_iterate_req) ) { GSF_push_stop_ (cp); cp->mig_revive_task = GNUNET_SCHEDULER_add_delayed (bt, &revive_migration, cp); } } /** * Free resources associated with the given peer request. * * @param peerreq request to free */ static void free_pending_request (struct PeerRequest *peerreq) { struct GSF_ConnectedPeer *cp = peerreq->cp; struct GSF_PendingRequestData *prd; prd = GSF_pending_request_get_data_ (peerreq->pr); if (NULL != peerreq->kill_task) { GNUNET_SCHEDULER_cancel (peerreq->kill_task); peerreq->kill_task = NULL; } GNUNET_STATISTICS_update (GSF_stats, gettext_noop ("# P2P searches active"), -1, GNUNET_NO); GNUNET_break (GNUNET_YES == GNUNET_CONTAINER_multihashmap_remove (cp->request_map, &prd->query, peerreq)); GNUNET_free (peerreq); } /** * Cancel all requests associated with the peer. * * @param cls unused * @param query hash code of the request * @param value the `struct GSF_PendingRequest` * @return #GNUNET_YES (continue to iterate) */ static int cancel_pending_request (void *cls, const struct GNUNET_HashCode *query, void *value) { struct PeerRequest *peerreq = value; struct GSF_PendingRequest *pr = peerreq->pr; free_pending_request (peerreq); GSF_pending_request_cancel_ (pr, GNUNET_NO); return GNUNET_OK; } /** * Free the given request. * * @param cls the request to free */ static void peer_request_destroy (void *cls) { struct PeerRequest *peerreq = cls; struct GSF_PendingRequest *pr = peerreq->pr; struct GSF_PendingRequestData *prd; peerreq->kill_task = NULL; prd = GSF_pending_request_get_data_ (pr); cancel_pending_request (NULL, &prd->query, peerreq); } /** * The artificial delay is over, transmit the message now. * * @param cls the `struct GSF_DelayedHandle` with the message */ static void transmit_delayed_now (void *cls) { struct GSF_DelayedHandle *dh = cls; struct GSF_ConnectedPeer *cp = dh->cp; GNUNET_CONTAINER_DLL_remove (cp->delayed_head, cp->delayed_tail, dh); cp->delay_queue_size--; GSF_peer_transmit_ (cp, GNUNET_NO, UINT32_MAX, dh->env); GNUNET_free (dh); } /** * Get the randomized delay a response should be subjected to. * * @return desired delay */ static struct GNUNET_TIME_Relative get_randomized_delay () { struct GNUNET_TIME_Relative ret; ret = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, 2 * GSF_avg_latency.rel_value_us + 1)); #if INSANE_STATISTICS GNUNET_STATISTICS_update (GSF_stats, gettext_noop ("# artificial delays introduced (ms)"), ret.rel_value_us / 1000LL, GNUNET_NO); #endif return ret; } /** * Handle a reply to a pending request. Also called if a request * expires (then with data == NULL). The handler may be called * many times (depending on the request type), but will not be * called during or after a call to GSF_pending_request_cancel * and will also not be called anymore after a call signalling * expiration. * * @param cls `struct PeerRequest` this is an answer for * @param eval evaluation of the result * @param pr handle to the original pending request * @param reply_anonymity_level anonymity level for the reply, UINT32_MAX for "unknown" * @param expiration when does @a data expire? * @param last_transmission when did we last transmit a request for this block * @param type type of the block * @param data response data, NULL on request expiration * @param data_len number of bytes in @a data */ static void handle_p2p_reply (void *cls, enum GNUNET_BLOCK_EvaluationResult eval, struct GSF_PendingRequest *pr, uint32_t reply_anonymity_level, struct GNUNET_TIME_Absolute expiration, struct GNUNET_TIME_Absolute last_transmission, enum GNUNET_BLOCK_Type type, const void *data, size_t data_len) { struct PeerRequest *peerreq = cls; struct GSF_ConnectedPeer *cp = peerreq->cp; struct GSF_PendingRequestData *prd; struct GNUNET_MQ_Envelope *env; struct PutMessage *pm; size_t msize; GNUNET_assert (data_len + sizeof (struct PutMessage) < GNUNET_MAX_MESSAGE_SIZE); GNUNET_assert (peerreq->pr == pr); prd = GSF_pending_request_get_data_ (pr); if (NULL == data) { free_pending_request (peerreq); return; } GNUNET_break (GNUNET_BLOCK_TYPE_ANY != type); if ((prd->type != type) && (GNUNET_BLOCK_TYPE_ANY != prd->type)) { GNUNET_STATISTICS_update (GSF_stats, gettext_noop ("# replies dropped due to type mismatch"), 1, GNUNET_NO); return; } GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Transmitting result for query `%s' to peer\n", GNUNET_h2s (&prd->query)); GNUNET_STATISTICS_update (GSF_stats, gettext_noop ("# replies received for other peers"), 1, GNUNET_NO); msize = sizeof (struct PutMessage) + data_len; if (msize >= GNUNET_MAX_MESSAGE_SIZE) { GNUNET_break (0); return; } if ((UINT32_MAX != reply_anonymity_level) && (reply_anonymity_level > 1)) { if (reply_anonymity_level - 1 > GSF_cover_content_count) { GNUNET_STATISTICS_update (GSF_stats, gettext_noop ("# replies dropped due to insufficient cover traffic"), 1, GNUNET_NO); return; } GSF_cover_content_count -= (reply_anonymity_level - 1); } env = GNUNET_MQ_msg_extra (pm, data_len, GNUNET_MESSAGE_TYPE_FS_PUT); pm->type = htonl (type); pm->expiration = GNUNET_TIME_absolute_hton (expiration); GNUNET_memcpy (&pm[1], data, data_len); if ( (UINT32_MAX != reply_anonymity_level) && (0 != reply_anonymity_level) && (GNUNET_YES == GSF_enable_randomized_delays) ) { struct GSF_DelayedHandle *dh; dh = GNUNET_new (struct GSF_DelayedHandle); dh->cp = cp; dh->env = env; dh->msize = msize; GNUNET_CONTAINER_DLL_insert (cp->delayed_head, cp->delayed_tail, dh); cp->delay_queue_size++; dh->delay_task = GNUNET_SCHEDULER_add_delayed (get_randomized_delay (), &transmit_delayed_now, dh); } else { GSF_peer_transmit_ (cp, GNUNET_NO, UINT32_MAX, env); } if (GNUNET_BLOCK_EVALUATION_OK_LAST != eval) return; if (NULL == peerreq->kill_task) { GNUNET_STATISTICS_update (GSF_stats, gettext_noop ("# P2P searches destroyed due to ultimate reply"), 1, GNUNET_NO); peerreq->kill_task = GNUNET_SCHEDULER_add_now (&peer_request_destroy, peerreq); } } /** * Increase the peer's respect by a value. * * @param cp which peer to change the respect value on * @param value is the int value by which the * peer's credit is to be increased or decreased * @returns the actual change in respect (positive or negative) */ static int change_peer_respect (struct GSF_ConnectedPeer *cp, int value) { if (0 == value) return 0; GNUNET_assert (NULL != cp); if (value > 0) { if (cp->ppd.respect + value < cp->ppd.respect) { value = UINT32_MAX - cp->ppd.respect; cp->ppd.respect = UINT32_MAX; } else cp->ppd.respect += value; } else { if (cp->ppd.respect < -value) { value = -cp->ppd.respect; cp->ppd.respect = 0; } else cp->ppd.respect += value; } return value; } /** * We've received a request with the specified priority. Bound it * according to how much we respect the given peer. * * @param prio_in requested priority * @param cp the peer making the request * @return effective priority */ static int32_t bound_priority (uint32_t prio_in, struct GSF_ConnectedPeer *cp) { #define N ((double)128.0) uint32_t ret; double rret; int ld; ld = GSF_test_get_load_too_high_ (0); if (GNUNET_SYSERR == ld) { #if INSANE_STATISTICS GNUNET_STATISTICS_update (GSF_stats, gettext_noop ("# requests done for free (low load)"), 1, GNUNET_NO); #endif return 0; /* excess resources */ } if (prio_in > INT32_MAX) prio_in = INT32_MAX; ret = -change_peer_respect (cp, -(int) prio_in); if (ret > 0) { if (ret > GSF_current_priorities + N) rret = GSF_current_priorities + N; else rret = ret; GSF_current_priorities = (GSF_current_priorities * (N - 1) + rret) / N; } if ((GNUNET_YES == ld) && (ret > 0)) { /* try with charging */ ld = GSF_test_get_load_too_high_ (ret); } if (GNUNET_YES == ld) { GNUNET_STATISTICS_update (GSF_stats, gettext_noop ("# request dropped, priority insufficient"), 1, GNUNET_NO); /* undo charge */ change_peer_respect (cp, (int) ret); return -1; /* not enough resources */ } else { GNUNET_STATISTICS_update (GSF_stats, gettext_noop ("# requests done for a price (normal load)"), 1, GNUNET_NO); } #undef N return ret; } /** * The priority level imposes a bound on the maximum * value for the ttl that can be requested. * * @param ttl_in requested ttl * @param prio given priority * @return @a ttl_in if @a ttl_in is below the limit, * otherwise the ttl-limit for the given @a prio */ static int32_t bound_ttl (int32_t ttl_in, uint32_t prio) { unsigned long long allowed; if (ttl_in <= 0) return ttl_in; allowed = ((unsigned long long) prio) * TTL_DECREMENT / 1000; if (ttl_in > allowed) { if (allowed >= (1 << 30)) return 1 << 30; return allowed; } return ttl_in; } /** * Closure for #test_exist_cb(). */ struct TestExistClosure { /** * Priority of the incoming request. */ int32_t priority; /** * Relative TTL of the incoming request. */ int32_t ttl; /** * Type of the incoming request. */ enum GNUNET_BLOCK_Type type; /** * Set to #GNUNET_YES if we are done handling the query. */ int finished; }; /** * Test if the query already exists. If so, merge it, otherwise * keep `finished` at #GNUNET_NO. * * @param cls our `struct TestExistClosure` * @param hc the key of the query * @param value the existing `struct PeerRequest`. * @return #GNUNET_YES to continue to iterate, * #GNUNET_NO if we successfully merged */ static int test_exist_cb (void *cls, const struct GNUNET_HashCode *hc, void *value) { struct TestExistClosure *tec = cls; struct PeerRequest *peerreq = value; struct GSF_PendingRequest *pr; struct GSF_PendingRequestData *prd; pr = peerreq->pr; prd = GSF_pending_request_get_data_ (pr); if (prd->type != tec->type) return GNUNET_YES; if (prd->ttl.abs_value_us >= GNUNET_TIME_absolute_get ().abs_value_us + tec->ttl * 1000LL) { /* existing request has higher TTL, drop new one! */ prd->priority += tec->priority; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Have existing request with higher TTL, dropping new request.\n"); GNUNET_STATISTICS_update (GSF_stats, gettext_noop ("# requests dropped due to higher-TTL request"), 1, GNUNET_NO); tec->finished = GNUNET_YES; return GNUNET_NO; } /* existing request has lower TTL, drop old one! */ tec->priority += prd->priority; free_pending_request (peerreq); GSF_pending_request_cancel_ (pr, GNUNET_YES); return GNUNET_NO; } /** * Handle P2P "QUERY" message. Creates the pending request entry * and sets up all of the data structures to that we will * process replies properly. Does not initiate forwarding or * local database lookups. * * @param cls the other peer involved (sender of the message) * @param gm the GET message */ void handle_p2p_get (void *cls, const struct GetMessage *gm) { struct GSF_ConnectedPeer *cps = cls; struct PeerRequest *peerreq; struct GSF_PendingRequest *pr; struct GSF_ConnectedPeer *cp; const struct GNUNET_PeerIdentity *target; enum GSF_PendingRequestOptions options; uint16_t msize; unsigned int bits; const struct GNUNET_PeerIdentity *opt; uint32_t bm; size_t bfsize; uint32_t ttl_decrement; struct TestExistClosure tec; GNUNET_PEER_Id spid; const struct GSF_PendingRequestData *prd; msize = ntohs (gm->header.size); tec.type = ntohl (gm->type); bm = ntohl (gm->hash_bitmap); bits = 0; while (bm > 0) { if (1 == (bm & 1)) bits++; bm >>= 1; } opt = (const struct GNUNET_PeerIdentity *) &gm[1]; bfsize = msize - sizeof (struct GetMessage) - bits * sizeof (struct GNUNET_PeerIdentity); GNUNET_STATISTICS_update (GSF_stats, gettext_noop ("# GET requests received (from other peers)"), 1, GNUNET_NO); GSF_cover_query_count++; bm = ntohl (gm->hash_bitmap); bits = 0; if (0 != (bm & GET_MESSAGE_BIT_RETURN_TO)) cp = GSF_peer_get_ (&opt[bits++]); else cp = cps; if (NULL == cp) { if (0 != (bm & GET_MESSAGE_BIT_RETURN_TO)) GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Failed to find RETURN-TO peer `%s' in connection set. Dropping query.\n", GNUNET_i2s (&opt[bits - 1])); else GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Failed to find peer `%s' in connection set. Dropping query.\n", GNUNET_i2s (cps->ppd.peer)); GNUNET_STATISTICS_update (GSF_stats, gettext_noop ("# requests dropped due to missing reverse route"), 1, GNUNET_NO); return; } unsigned int queue_size = GNUNET_MQ_get_length (cp->mq); queue_size += cp->ppd.pending_replies + cp->delay_queue_size; if (queue_size > MAX_QUEUE_PER_PEER) { GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Peer `%s' has too many replies queued already. Dropping query.\n", GNUNET_i2s (cps->ppd.peer)); GNUNET_STATISTICS_update (GSF_stats, gettext_noop ("# requests dropped due to full reply queue"), 1, GNUNET_NO); return; } /* note that we can really only check load here since otherwise * peers could find out that we are overloaded by not being * disconnected after sending us a malformed query... */ tec.priority = bound_priority (ntohl (gm->priority), cps); if (tec.priority < 0) { GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Dropping query from `%s', this peer is too busy.\n", GNUNET_i2s (cps->ppd.peer)); return; } GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received request for `%s' of type %u from peer `%s' with flags %u\n", GNUNET_h2s (&gm->query), (unsigned int) tec.type, GNUNET_i2s (cps->ppd.peer), (unsigned int) bm); target = (0 != (bm & GET_MESSAGE_BIT_TRANSMIT_TO)) ? (&opt[bits++]) : NULL; options = GSF_PRO_DEFAULTS; spid = 0; if ((GNUNET_LOAD_get_load (cp->ppd.transmission_delay) > 3 * (1 + tec.priority)) || (GNUNET_LOAD_get_average (cp->ppd.transmission_delay) > GNUNET_CONSTANTS_MAX_CORK_DELAY.rel_value_us * 2 + GNUNET_LOAD_get_average (GSF_rt_entry_lifetime))) { /* don't have BW to send to peer, or would likely take longer than we have for it, * so at best indirect the query */ tec.priority = 0; options |= GSF_PRO_FORWARD_ONLY; spid = GNUNET_PEER_intern (cps->ppd.peer); GNUNET_assert (0 != spid); } tec.ttl = bound_ttl (ntohl (gm->ttl), tec.priority); /* decrement ttl (always) */ ttl_decrement = 2 * TTL_DECREMENT + GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, TTL_DECREMENT); if ( (tec.ttl < 0) && (((int32_t) (tec.ttl - ttl_decrement)) > 0) ) { GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Dropping query from `%s' due to TTL underflow (%d - %u).\n", GNUNET_i2s (cps->ppd.peer), tec.ttl, ttl_decrement); GNUNET_STATISTICS_update (GSF_stats, gettext_noop ("# requests dropped due TTL underflow"), 1, GNUNET_NO); /* integer underflow => drop (should be very rare)! */ return; } tec.ttl -= ttl_decrement; /* test if the request already exists */ tec.finished = GNUNET_NO; GNUNET_CONTAINER_multihashmap_get_multiple (cp->request_map, &gm->query, &test_exist_cb, &tec); if (GNUNET_YES == tec.finished) return; /* merged into existing request, we're done */ peerreq = GNUNET_new (struct PeerRequest); peerreq->cp = cp; pr = GSF_pending_request_create_ (options, tec.type, &gm->query, target, (bfsize > 0) ? (const char *) &opt[bits] : NULL, bfsize, ntohl (gm->filter_mutator), 1 /* anonymity */, (uint32_t) tec.priority, tec.ttl, spid, GNUNET_PEER_intern (cps->ppd.peer), NULL, 0, /* replies_seen */ &handle_p2p_reply, peerreq); GNUNET_assert (NULL != pr); prd = GSF_pending_request_get_data_ (pr); peerreq->pr = pr; GNUNET_break (GNUNET_OK == GNUNET_CONTAINER_multihashmap_put (cp->request_map, &prd->query, peerreq, GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE)); GNUNET_STATISTICS_update (GSF_stats, gettext_noop ("# P2P query messages received and processed"), 1, GNUNET_NO); GNUNET_STATISTICS_update (GSF_stats, gettext_noop ("# P2P searches active"), 1, GNUNET_NO); GSF_pending_request_get_data_ (pr)->has_started = GNUNET_YES; GSF_local_lookup_ (pr, &GSF_consider_forwarding, NULL); } /** * Transmit a message to the given peer as soon as possible. * If the peer disconnects before the transmission can happen, * the callback is invoked with a `NULL` @a buffer. * * @param cp target peer * @param is_query is this a query (#GNUNET_YES) or content (#GNUNET_NO) or neither (#GNUNET_SYSERR) * @param priority how important is this request? * @param timeout when does this request timeout * @param size number of bytes we would like to send to the peer * @param env message to send */ void GSF_peer_transmit_ (struct GSF_ConnectedPeer *cp, int is_query, uint32_t priority, struct GNUNET_MQ_Envelope *env) { struct GSF_PeerTransmitHandle *pth; struct GSF_PeerTransmitHandle *pos; struct GSF_PeerTransmitHandle *prev; pth = GNUNET_new (struct GSF_PeerTransmitHandle); pth->transmission_request_start_time = GNUNET_TIME_absolute_get (); pth->env = env; pth->is_query = is_query; pth->priority = priority; pth->cp = cp; /* insertion sort (by priority, descending) */ prev = NULL; pos = cp->pth_head; while ((NULL != pos) && (pos->priority > priority)) { prev = pos; pos = pos->next; } GNUNET_CONTAINER_DLL_insert_after (cp->pth_head, cp->pth_tail, prev, pth); if (GNUNET_YES == is_query) cp->ppd.pending_queries++; else if (GNUNET_NO == is_query) cp->ppd.pending_replies++; schedule_transmission (pth); } /** * Report on receiving a reply; update the performance record of the given peer. * * @param cp responding peer (will be updated) * @param request_time time at which the original query was transmitted * @param request_priority priority of the original request */ void GSF_peer_update_performance_ (struct GSF_ConnectedPeer *cp, struct GNUNET_TIME_Absolute request_time, uint32_t request_priority) { struct GNUNET_TIME_Relative delay; delay = GNUNET_TIME_absolute_get_duration (request_time); cp->ppd.avg_reply_delay.rel_value_us = (cp->ppd.avg_reply_delay.rel_value_us * (RUNAVG_DELAY_N - 1) + delay.rel_value_us) / RUNAVG_DELAY_N; cp->ppd.avg_priority = (cp->ppd.avg_priority * (RUNAVG_DELAY_N - 1) + request_priority) / RUNAVG_DELAY_N; } /** * Report on receiving a reply in response to an initiating client. * Remember that this peer is good for this client. * * @param cp responding peer (will be updated) * @param initiator_client local client on responsible for query */ void GSF_peer_update_responder_client_ (struct GSF_ConnectedPeer *cp, struct GSF_LocalClient *initiator_client) { cp->ppd.last_client_replies[cp->last_client_replies_woff++ % CS2P_SUCCESS_LIST_SIZE] = initiator_client; } /** * Report on receiving a reply in response to an initiating peer. * Remember that this peer is good for this initiating peer. * * @param cp responding peer (will be updated) * @param initiator_peer other peer responsible for query */ void GSF_peer_update_responder_peer_ (struct GSF_ConnectedPeer *cp, const struct GSF_ConnectedPeer *initiator_peer) { unsigned int woff; woff = cp->last_p2p_replies_woff % P2P_SUCCESS_LIST_SIZE; GNUNET_PEER_change_rc (cp->ppd.last_p2p_replies[woff], -1); cp->ppd.last_p2p_replies[woff] = initiator_peer->ppd.pid; GNUNET_PEER_change_rc (initiator_peer->ppd.pid, 1); cp->last_p2p_replies_woff = (woff + 1) % P2P_SUCCESS_LIST_SIZE; } /** * Write peer-respect information to a file - flush the buffer entry! * * @param cls unused * @param key peer identity * @param value the `struct GSF_ConnectedPeer` to flush * @return #GNUNET_OK to continue iteration */ static int flush_respect (void *cls, const struct GNUNET_PeerIdentity *key, void *value) { struct GSF_ConnectedPeer *cp = value; struct GNUNET_PeerIdentity pid; if (cp->ppd.respect == cp->disk_respect) return GNUNET_OK; /* unchanged */ GNUNET_assert (0 != cp->ppd.pid); GNUNET_PEER_resolve (cp->ppd.pid, &pid); GNUNET_PEERSTORE_store (peerstore, "fs", &pid, "respect", &cp->ppd.respect, sizeof (cp->ppd.respect), GNUNET_TIME_UNIT_FOREVER_ABS, GNUNET_PEERSTORE_STOREOPTION_REPLACE, NULL, NULL); return GNUNET_OK; } /** * A peer disconnected from us. Tear down the connected peer * record. * * @param cls unused * @param peer identity of peer that disconnected * @param internal_cls the corresponding `struct GSF_ConnectedPeer` */ void GSF_peer_disconnect_handler (void *cls, const struct GNUNET_PeerIdentity *peer, void *internal_cls) { struct GSF_ConnectedPeer *cp = internal_cls; struct GSF_PeerTransmitHandle *pth; struct GSF_DelayedHandle *dh; if (NULL == cp) return; /* must have been disconnect from core with * 'peer' == my_id, ignore */ flush_respect (NULL, peer, cp); GNUNET_assert (GNUNET_YES == GNUNET_CONTAINER_multipeermap_remove (cp_map, peer, cp)); GNUNET_STATISTICS_set (GSF_stats, gettext_noop ("# peers connected"), GNUNET_CONTAINER_multipeermap_size (cp_map), GNUNET_NO); if (NULL != cp->respect_iterate_req) { GNUNET_PEERSTORE_iterate_cancel (cp->respect_iterate_req); cp->respect_iterate_req = NULL; } if (NULL != cp->rc) { GNUNET_ATS_reserve_bandwidth_cancel (cp->rc); cp->rc = NULL; } if (NULL != cp->rc_delay_task) { GNUNET_SCHEDULER_cancel (cp->rc_delay_task); cp->rc_delay_task = NULL; } GNUNET_CONTAINER_multihashmap_iterate (cp->request_map, &cancel_pending_request, cp); GNUNET_CONTAINER_multihashmap_destroy (cp->request_map); cp->request_map = NULL; GSF_plan_notify_peer_disconnect_ (cp); GNUNET_LOAD_value_free (cp->ppd.transmission_delay); GNUNET_PEER_decrement_rcs (cp->ppd.last_p2p_replies, P2P_SUCCESS_LIST_SIZE); memset (cp->ppd.last_p2p_replies, 0, sizeof (cp->ppd.last_p2p_replies)); GSF_push_stop_ (cp); while (NULL != (pth = cp->pth_head)) { GNUNET_CONTAINER_DLL_remove (cp->pth_head, cp->pth_tail, pth); if (GNUNET_YES == pth->is_query) GNUNET_assert (0 < cp->ppd.pending_queries--); else if (GNUNET_NO == pth->is_query) GNUNET_assert (0 < cp->ppd.pending_replies--); GNUNET_free (pth); } while (NULL != (dh = cp->delayed_head)) { GNUNET_CONTAINER_DLL_remove (cp->delayed_head, cp->delayed_tail, dh); GNUNET_MQ_discard (dh->env); cp->delay_queue_size--; GNUNET_SCHEDULER_cancel (dh->delay_task); GNUNET_free (dh); } GNUNET_PEER_change_rc (cp->ppd.pid, -1); if (NULL != cp->mig_revive_task) { GNUNET_SCHEDULER_cancel (cp->mig_revive_task); cp->mig_revive_task = NULL; } GNUNET_break (0 == cp->ppd.pending_queries); GNUNET_break (0 == cp->ppd.pending_replies); GNUNET_free (cp); } /** * Closure for #call_iterator(). */ struct IterationContext { /** * Function to call on each entry. */ GSF_ConnectedPeerIterator it; /** * Closure for @e it. */ void *it_cls; }; /** * Function that calls the callback for each peer. * * @param cls the `struct IterationContext *` * @param key identity of the peer * @param value the `struct GSF_ConnectedPeer *` * @return #GNUNET_YES to continue iteration */ static int call_iterator (void *cls, const struct GNUNET_PeerIdentity *key, void *value) { struct IterationContext *ic = cls; struct GSF_ConnectedPeer *cp = value; ic->it (ic->it_cls, key, cp, &cp->ppd); return GNUNET_YES; } /** * Iterate over all connected peers. * * @param it function to call for each peer * @param it_cls closure for @a it */ void GSF_iterate_connected_peers_ (GSF_ConnectedPeerIterator it, void *it_cls) { struct IterationContext ic; ic.it = it; ic.it_cls = it_cls; GNUNET_CONTAINER_multipeermap_iterate (cp_map, &call_iterator, &ic); } /** * Obtain the identity of a connected peer. * * @param cp peer to get identity of * @param id identity to set (written to) */ void GSF_connected_peer_get_identity_ (const struct GSF_ConnectedPeer *cp, struct GNUNET_PeerIdentity *id) { GNUNET_assert (0 != cp->ppd.pid); GNUNET_PEER_resolve (cp->ppd.pid, id); } /** * Obtain the identity of a connected peer. * * @param cp peer to get identity of * @return reference to peer identity, valid until peer disconnects (!) */ const struct GNUNET_PeerIdentity * GSF_connected_peer_get_identity2_ (const struct GSF_ConnectedPeer *cp) { GNUNET_assert (0 != cp->ppd.pid); return GNUNET_PEER_resolve2 (cp->ppd.pid); } /** * Ask a peer to stop migrating data to us until the given point * in time. * * @param cp peer to ask * @param block_time until when to block */ void GSF_block_peer_migration_ (struct GSF_ConnectedPeer *cp, struct GNUNET_TIME_Absolute block_time) { struct GNUNET_MQ_Envelope *env; struct MigrationStopMessage *msm; if (cp->last_migration_block.abs_value_us > block_time.abs_value_us) { GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Migration already blocked for another %s\n", GNUNET_STRINGS_relative_time_to_string (GNUNET_TIME_absolute_get_remaining (cp->last_migration_block), GNUNET_YES)); return; /* already blocked */ } GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Asking to stop migration for %s\n", GNUNET_STRINGS_relative_time_to_string (GNUNET_TIME_absolute_get_remaining (block_time), GNUNET_YES)); cp->last_migration_block = block_time; env = GNUNET_MQ_msg (msm, GNUNET_MESSAGE_TYPE_FS_MIGRATION_STOP); msm->reserved = htonl (0); msm->duration = GNUNET_TIME_relative_hton (GNUNET_TIME_absolute_get_remaining (cp->last_migration_block)); GNUNET_STATISTICS_update (GSF_stats, gettext_noop ("# migration stop messages sent"), 1, GNUNET_NO); GSF_peer_transmit_ (cp, GNUNET_SYSERR, UINT32_MAX, env); } /** * Notify core about a preference we have for the given peer * (to allocate more resources towards it). The change will * be communicated the next time we reserve bandwidth with * core (not instantly). * * @param cp peer to reserve bandwidth from * @param pref preference change */ void GSF_connected_peer_change_preference_ (struct GSF_ConnectedPeer *cp, uint64_t pref) { cp->inc_preference += pref; } /** * Call this method periodically to flush respect information to disk. * * @param cls closure, not used */ static void cron_flush_respect (void *cls) { fr_task = NULL; GNUNET_CONTAINER_multipeermap_iterate (cp_map, &flush_respect, NULL); fr_task = GNUNET_SCHEDULER_add_delayed_with_priority (RESPECT_FLUSH_FREQ, GNUNET_SCHEDULER_PRIORITY_HIGH, &cron_flush_respect, NULL); } /** * Initialize peer management subsystem. */ void GSF_connected_peer_init_ () { cp_map = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES); peerstore = GNUNET_PEERSTORE_connect (GSF_cfg); fr_task = GNUNET_SCHEDULER_add_with_priority (GNUNET_SCHEDULER_PRIORITY_HIGH, &cron_flush_respect, NULL); } /** * Shutdown peer management subsystem. */ void GSF_connected_peer_done_ () { GNUNET_CONTAINER_multipeermap_iterate (cp_map, &flush_respect, NULL); GNUNET_SCHEDULER_cancel (fr_task); fr_task = NULL; GNUNET_CONTAINER_multipeermap_destroy (cp_map); cp_map = NULL; GNUNET_PEERSTORE_disconnect (peerstore, GNUNET_YES); } /** * Iterator to remove references to LC entry. * * @param cls the `struct GSF_LocalClient *` to look for * @param key current key code * @param value value in the hash map (peer entry) * @return #GNUNET_YES (we should continue to iterate) */ static int clean_local_client (void *cls, const struct GNUNET_PeerIdentity *key, void *value) { const struct GSF_LocalClient *lc = cls; struct GSF_ConnectedPeer *cp = value; unsigned int i; for (i = 0; i < CS2P_SUCCESS_LIST_SIZE; i++) if (cp->ppd.last_client_replies[i] == lc) cp->ppd.last_client_replies[i] = NULL; return GNUNET_YES; } /** * Notification that a local client disconnected. Clean up all of our * references to the given handle. * * @param lc handle to the local client (henceforth invalid) */ void GSF_handle_local_client_disconnect_ (const struct GSF_LocalClient *lc) { if (NULL == cp_map) return; /* already cleaned up */ GNUNET_CONTAINER_multipeermap_iterate (cp_map, &clean_local_client, (void *) lc); } /* end of gnunet-service-fs_cp.c */