// SPDX-License-Identifier: GPL-2.0-or-later /* RxRPC individual remote procedure call handling * * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include "ar-internal.h" const char *const rxrpc_call_states[NR__RXRPC_CALL_STATES] = { [RXRPC_CALL_UNINITIALISED] = "Uninit ", [RXRPC_CALL_CLIENT_AWAIT_CONN] = "ClWtConn", [RXRPC_CALL_CLIENT_SEND_REQUEST] = "ClSndReq", [RXRPC_CALL_CLIENT_AWAIT_REPLY] = "ClAwtRpl", [RXRPC_CALL_CLIENT_RECV_REPLY] = "ClRcvRpl", [RXRPC_CALL_SERVER_PREALLOC] = "SvPrealc", [RXRPC_CALL_SERVER_SECURING] = "SvSecure", [RXRPC_CALL_SERVER_RECV_REQUEST] = "SvRcvReq", [RXRPC_CALL_SERVER_ACK_REQUEST] = "SvAckReq", [RXRPC_CALL_SERVER_SEND_REPLY] = "SvSndRpl", [RXRPC_CALL_SERVER_AWAIT_ACK] = "SvAwtACK", [RXRPC_CALL_COMPLETE] = "Complete", }; const char *const rxrpc_call_completions[NR__RXRPC_CALL_COMPLETIONS] = { [RXRPC_CALL_SUCCEEDED] = "Complete", [RXRPC_CALL_REMOTELY_ABORTED] = "RmtAbort", [RXRPC_CALL_LOCALLY_ABORTED] = "LocAbort", [RXRPC_CALL_LOCAL_ERROR] = "LocError", [RXRPC_CALL_NETWORK_ERROR] = "NetError", }; struct kmem_cache *rxrpc_call_jar; static DEFINE_SEMAPHORE(rxrpc_call_limiter, 1000); static DEFINE_SEMAPHORE(rxrpc_kernel_call_limiter, 1000); void rxrpc_poke_call(struct rxrpc_call *call, enum rxrpc_call_poke_trace what) { struct rxrpc_local *local = call->local; bool busy; if (!test_bit(RXRPC_CALL_DISCONNECTED, &call->flags)) { spin_lock_bh(&local->lock); busy = !list_empty(&call->attend_link); trace_rxrpc_poke_call(call, busy, what); if (!busy && !rxrpc_try_get_call(call, rxrpc_call_get_poke)) busy = true; if (!busy) { list_add_tail(&call->attend_link, &local->call_attend_q); } spin_unlock_bh(&local->lock); if (!busy) rxrpc_wake_up_io_thread(local); } } static void rxrpc_call_timer_expired(struct timer_list *t) { struct rxrpc_call *call = from_timer(call, t, timer); _enter("%d", call->debug_id); if (!__rxrpc_call_is_complete(call)) { trace_rxrpc_timer_expired(call, jiffies); rxrpc_poke_call(call, rxrpc_call_poke_timer); } } void rxrpc_reduce_call_timer(struct rxrpc_call *call, unsigned long expire_at, unsigned long now, enum rxrpc_timer_trace why) { trace_rxrpc_timer(call, why, now); timer_reduce(&call->timer, expire_at); } static struct lock_class_key rxrpc_call_user_mutex_lock_class_key; static void rxrpc_destroy_call(struct work_struct *); /* * find an extant server call * - called in process context with IRQs enabled */ struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *rx, unsigned long user_call_ID) { struct rxrpc_call *call; struct rb_node *p; _enter("%p,%lx", rx, user_call_ID); read_lock(&rx->call_lock); p = rx->calls.rb_node; while (p) { call = rb_entry(p, struct rxrpc_call, sock_node); if (user_call_ID < call->user_call_ID) p = p->rb_left; else if (user_call_ID > call->user_call_ID) p = p->rb_right; else goto found_extant_call; } read_unlock(&rx->call_lock); _leave(" = NULL"); return NULL; found_extant_call: rxrpc_get_call(call, rxrpc_call_get_sendmsg); read_unlock(&rx->call_lock); _leave(" = %p [%d]", call, refcount_read(&call->ref)); return call; } /* * allocate a new call */ struct rxrpc_call *rxrpc_alloc_call(struct rxrpc_sock *rx, gfp_t gfp, unsigned int debug_id) { struct rxrpc_call *call; struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk)); call = kmem_cache_zalloc(rxrpc_call_jar, gfp); if (!call) return NULL; mutex_init(&call->user_mutex); /* Prevent lockdep reporting a deadlock false positive between the afs * filesystem and sys_sendmsg() via the mmap sem. */ if (rx->sk.sk_kern_sock) lockdep_set_class(&call->user_mutex, &rxrpc_call_user_mutex_lock_class_key); timer_setup(&call->timer, rxrpc_call_timer_expired, 0); INIT_WORK(&call->destroyer, rxrpc_destroy_call); INIT_LIST_HEAD(&call->link); INIT_LIST_HEAD(&call->wait_link); INIT_LIST_HEAD(&call->accept_link); INIT_LIST_HEAD(&call->recvmsg_link); INIT_LIST_HEAD(&call->sock_link); INIT_LIST_HEAD(&call->attend_link); INIT_LIST_HEAD(&call->tx_sendmsg); INIT_LIST_HEAD(&call->tx_buffer); skb_queue_head_init(&call->recvmsg_queue); skb_queue_head_init(&call->rx_oos_queue); init_waitqueue_head(&call->waitq); spin_lock_init(&call->notify_lock); spin_lock_init(&call->tx_lock); refcount_set(&call->ref, 1); call->debug_id = debug_id; call->tx_total_len = -1; call->next_rx_timo = 20 * HZ; call->next_req_timo = 1 * HZ; call->ackr_window = 1; call->ackr_wtop = 1; memset(&call->sock_node, 0xed, sizeof(call->sock_node)); call->rx_winsize = rxrpc_rx_window_size; call->tx_winsize = 16; if (RXRPC_TX_SMSS > 2190) call->cong_cwnd = 2; else if (RXRPC_TX_SMSS > 1095) call->cong_cwnd = 3; else call->cong_cwnd = 4; call->cong_ssthresh = RXRPC_TX_MAX_WINDOW; call->rxnet = rxnet; call->rtt_avail = RXRPC_CALL_RTT_AVAIL_MASK; atomic_inc(&rxnet->nr_calls); return call; } /* * Allocate a new client call. */ static struct rxrpc_call *rxrpc_alloc_client_call(struct rxrpc_sock *rx, struct rxrpc_conn_parameters *cp, struct rxrpc_call_params *p, gfp_t gfp, unsigned int debug_id) { struct rxrpc_call *call; ktime_t now; int ret; _enter(""); call = rxrpc_alloc_call(rx, gfp, debug_id); if (!call) return ERR_PTR(-ENOMEM); now = ktime_get_real(); call->acks_latest_ts = now; call->cong_tstamp = now; call->dest_srx = cp->peer->srx; call->dest_srx.srx_service = cp->service_id; call->interruptibility = p->interruptibility; call->tx_total_len = p->tx_total_len; call->key = key_get(cp->key); call->peer = rxrpc_get_peer(cp->peer, rxrpc_peer_get_call); call->local = rxrpc_get_local(cp->local, rxrpc_local_get_call); call->security_level = cp->security_level; if (p->kernel) __set_bit(RXRPC_CALL_KERNEL, &call->flags); if (cp->upgrade) __set_bit(RXRPC_CALL_UPGRADE, &call->flags); if (cp->exclusive) __set_bit(RXRPC_CALL_EXCLUSIVE, &call->flags); if (p->timeouts.normal) call->next_rx_timo = min(msecs_to_jiffies(p->timeouts.normal), 1UL); if (p->timeouts.idle) call->next_req_timo = min(msecs_to_jiffies(p->timeouts.idle), 1UL); if (p->timeouts.hard) call->hard_timo = p->timeouts.hard * HZ; ret = rxrpc_init_client_call_security(call); if (ret < 0) { rxrpc_prefail_call(call, RXRPC_CALL_LOCAL_ERROR, ret); rxrpc_put_call(call, rxrpc_call_put_discard_error); return ERR_PTR(ret); } rxrpc_set_call_state(call, RXRPC_CALL_CLIENT_AWAIT_CONN); trace_rxrpc_call(call->debug_id, refcount_read(&call->ref), p->user_call_ID, rxrpc_call_new_client); _leave(" = %p", call); return call; } /* * Initiate the call ack/resend/expiry timer. */ void rxrpc_start_call_timer(struct rxrpc_call *call) { unsigned long now = jiffies; unsigned long j = now + MAX_JIFFY_OFFSET; call->delay_ack_at = j; call->ack_lost_at = j; call->resend_at = j; call->ping_at = j; call->keepalive_at = j; call->expect_rx_by = j; call->expect_req_by = j; call->expect_term_by = j + call->hard_timo; call->timer.expires = now; } /* * Wait for a call slot to become available. */ static struct semaphore *rxrpc_get_call_slot(struct rxrpc_call_params *p, gfp_t gfp) { struct semaphore *limiter = &rxrpc_call_limiter; if (p->kernel) limiter = &rxrpc_kernel_call_limiter; if (p->interruptibility == RXRPC_UNINTERRUPTIBLE) { down(limiter); return limiter; } return down_interruptible(limiter) < 0 ? NULL : limiter; } /* * Release a call slot. */ static void rxrpc_put_call_slot(struct rxrpc_call *call) { struct semaphore *limiter = &rxrpc_call_limiter; if (test_bit(RXRPC_CALL_KERNEL, &call->flags)) limiter = &rxrpc_kernel_call_limiter; up(limiter); } /* * Start the process of connecting a call. We obtain a peer and a connection * bundle, but the actual association of a call with a connection is offloaded * to the I/O thread to simplify locking. */ static int rxrpc_connect_call(struct rxrpc_call *call, gfp_t gfp) { struct rxrpc_local *local = call->local; int ret = -ENOMEM; _enter("{%d,%lx},", call->debug_id, call->user_call_ID); ret = rxrpc_look_up_bundle(call, gfp); if (ret < 0) goto error; trace_rxrpc_client(NULL, -1, rxrpc_client_queue_new_call); rxrpc_get_call(call, rxrpc_call_get_io_thread); spin_lock(&local->client_call_lock); list_add_tail(&call->wait_link, &local->new_client_calls); spin_unlock(&local->client_call_lock); rxrpc_wake_up_io_thread(local); return 0; error: __set_bit(RXRPC_CALL_DISCONNECTED, &call->flags); return ret; } /* * Set up a call for the given parameters. * - Called with the socket lock held, which it must release. * - If it returns a call, the call's lock will need releasing by the caller. */ struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx, struct rxrpc_conn_parameters *cp, struct rxrpc_call_params *p, gfp_t gfp, unsigned int debug_id) __releases(&rx->sk.sk_lock.slock) __acquires(&call->user_mutex) { struct rxrpc_call *call, *xcall; struct rxrpc_net *rxnet; struct semaphore *limiter; struct rb_node *parent, **pp; int ret; _enter("%p,%lx", rx, p->user_call_ID); if (WARN_ON_ONCE(!cp->peer)) { release_sock(&rx->sk); return ERR_PTR(-EIO); } limiter = rxrpc_get_call_slot(p, gfp); if (!limiter) { release_sock(&rx->sk); return ERR_PTR(-ERESTARTSYS); } call = rxrpc_alloc_client_call(rx, cp, p, gfp, debug_id); if (IS_ERR(call)) { release_sock(&rx->sk); up(limiter); _leave(" = %ld", PTR_ERR(call)); return call; } /* We need to protect a partially set up call against the user as we * will be acting outside the socket lock. */ mutex_lock(&call->user_mutex); /* Publish the call, even though it is incompletely set up as yet */ write_lock(&rx->call_lock); pp = &rx->calls.rb_node; parent = NULL; while (*pp) { parent = *pp; xcall = rb_entry(parent, struct rxrpc_call, sock_node); if (p->user_call_ID < xcall->user_call_ID) pp = &(*pp)->rb_left; else if (p->user_call_ID > xcall->user_call_ID) pp = &(*pp)->rb_right; else goto error_dup_user_ID; } rcu_assign_pointer(call->socket, rx); call->user_call_ID = p->user_call_ID; __set_bit(RXRPC_CALL_HAS_USERID, &call->flags); rxrpc_get_call(call, rxrpc_call_get_userid); rb_link_node(&call->sock_node, parent, pp); rb_insert_color(&call->sock_node, &rx->calls); list_add(&call->sock_link, &rx->sock_calls); write_unlock(&rx->call_lock); rxnet = call->rxnet; spin_lock(&rxnet->call_lock); list_add_tail_rcu(&call->link, &rxnet->calls); spin_unlock(&rxnet->call_lock); /* From this point on, the call is protected by its own lock. */ release_sock(&rx->sk); /* Set up or get a connection record and set the protocol parameters, * including channel number and call ID. */ ret = rxrpc_connect_call(call, gfp); if (ret < 0) goto error_attached_to_socket; _leave(" = %p [new]", call); return call; /* We unexpectedly found the user ID in the list after taking * the call_lock. This shouldn't happen unless the user races * with itself and tries to add the same user ID twice at the * same time in different threads. */ error_dup_user_ID: write_unlock(&rx->call_lock); release_sock(&rx->sk); rxrpc_prefail_call(call, RXRPC_CALL_LOCAL_ERROR, -EEXIST); trace_rxrpc_call(call->debug_id, refcount_read(&call->ref), 0, rxrpc_call_see_userid_exists); mutex_unlock(&call->user_mutex); rxrpc_put_call(call, rxrpc_call_put_userid_exists); _leave(" = -EEXIST"); return ERR_PTR(-EEXIST); /* We got an error, but the call is attached to the socket and is in * need of release. However, we might now race with recvmsg() when it * completion notifies the socket. Return 0 from sys_sendmsg() and * leave the error to recvmsg() to deal with. */ error_attached_to_socket: trace_rxrpc_call(call->debug_id, refcount_read(&call->ref), ret, rxrpc_call_see_connect_failed); rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR, 0, ret); _leave(" = c=%08x [err]", call->debug_id); return call; } /* * Set up an incoming call. call->conn points to the connection. * This is called in BH context and isn't allowed to fail. */ void rxrpc_incoming_call(struct rxrpc_sock *rx, struct rxrpc_call *call, struct sk_buff *skb) { struct rxrpc_connection *conn = call->conn; struct rxrpc_skb_priv *sp = rxrpc_skb(skb); u32 chan; _enter(",%d", call->conn->debug_id); rcu_assign_pointer(call->socket, rx); call->call_id = sp->hdr.callNumber; call->dest_srx.srx_service = sp->hdr.serviceId; call->cid = sp->hdr.cid; call->cong_tstamp = skb->tstamp; __set_bit(RXRPC_CALL_EXPOSED, &call->flags); rxrpc_set_call_state(call, RXRPC_CALL_SERVER_SECURING); spin_lock(&conn->state_lock); switch (conn->state) { case RXRPC_CONN_SERVICE_UNSECURED: case RXRPC_CONN_SERVICE_CHALLENGING: rxrpc_set_call_state(call, RXRPC_CALL_SERVER_SECURING); break; case RXRPC_CONN_SERVICE: rxrpc_set_call_state(call, RXRPC_CALL_SERVER_RECV_REQUEST); break; case RXRPC_CONN_ABORTED: rxrpc_set_call_completion(call, conn->completion, conn->abort_code, conn->error); break; default: BUG(); } rxrpc_get_call(call, rxrpc_call_get_io_thread); /* Set the channel for this call. We don't get channel_lock as we're * only defending against the data_ready handler (which we're called * from) and the RESPONSE packet parser (which is only really * interested in call_counter and can cope with a disagreement with the * call pointer). */ chan = sp->hdr.cid & RXRPC_CHANNELMASK; conn->channels[chan].call_counter = call->call_id; conn->channels[chan].call_id = call->call_id; conn->channels[chan].call = call; spin_unlock(&conn->state_lock); spin_lock(&conn->peer->lock); hlist_add_head(&call->error_link, &conn->peer->error_targets); spin_unlock(&conn->peer->lock); rxrpc_start_call_timer(call); _leave(""); } /* * Note the re-emergence of a call. */ void rxrpc_see_call(struct rxrpc_call *call, enum rxrpc_call_trace why) { if (call) { int r = refcount_read(&call->ref); trace_rxrpc_call(call->debug_id, r, 0, why); } } struct rxrpc_call *rxrpc_try_get_call(struct rxrpc_call *call, enum rxrpc_call_trace why) { int r; if (!call || !__refcount_inc_not_zero(&call->ref, &r)) return NULL; trace_rxrpc_call(call->debug_id, r + 1, 0, why); return call; } /* * Note the addition of a ref on a call. */ void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace why) { int r; __refcount_inc(&call->ref, &r); trace_rxrpc_call(call->debug_id, r + 1, 0, why); } /* * Clean up the Rx skb ring. */ static void rxrpc_cleanup_ring(struct rxrpc_call *call) { rxrpc_purge_queue(&call->recvmsg_queue); rxrpc_purge_queue(&call->rx_oos_queue); } /* * Detach a call from its owning socket. */ void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call) { struct rxrpc_connection *conn = call->conn; bool put = false, putu = false; _enter("{%d,%d}", call->debug_id, refcount_read(&call->ref)); trace_rxrpc_call(call->debug_id, refcount_read(&call->ref), call->flags, rxrpc_call_see_release); if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags)) BUG(); rxrpc_put_call_slot(call); /* Make sure we don't get any more notifications */ spin_lock(&rx->recvmsg_lock); if (!list_empty(&call->recvmsg_link)) { _debug("unlinking once-pending call %p { e=%lx f=%lx }", call, call->events, call->flags); list_del(&call->recvmsg_link); put = true; } /* list_empty() must return false in rxrpc_notify_socket() */ call->recvmsg_link.next = NULL; call->recvmsg_link.prev = NULL; spin_unlock(&rx->recvmsg_lock); if (put) rxrpc_put_call(call, rxrpc_call_put_unnotify); write_lock(&rx->call_lock); if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) { rb_erase(&call->sock_node, &rx->calls); memset(&call->sock_node, 0xdd, sizeof(call->sock_node)); putu = true; } list_del(&call->sock_link); write_unlock(&rx->call_lock); _debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn); if (putu) rxrpc_put_call(call, rxrpc_call_put_userid); _leave(""); } /* * release all the calls associated with a socket */ void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx) { struct rxrpc_call *call; _enter("%p", rx); while (!list_empty(&rx->to_be_accepted)) { call = list_entry(rx->to_be_accepted.next, struct rxrpc_call, accept_link); list_del(&call->accept_link); rxrpc_propose_abort(call, RX_CALL_DEAD, -ECONNRESET, rxrpc_abort_call_sock_release_tba); rxrpc_put_call(call, rxrpc_call_put_release_sock_tba); } while (!list_empty(&rx->sock_calls)) { call = list_entry(rx->sock_calls.next, struct rxrpc_call, sock_link); rxrpc_get_call(call, rxrpc_call_get_release_sock); rxrpc_propose_abort(call, RX_CALL_DEAD, -ECONNRESET, rxrpc_abort_call_sock_release); rxrpc_release_call(rx, call); rxrpc_put_call(call, rxrpc_call_put_release_sock); } _leave(""); } /* * release a call */ void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace why) { struct rxrpc_net *rxnet = call->rxnet; unsigned int debug_id = call->debug_id; bool dead; int r; ASSERT(call != NULL); dead = __refcount_dec_and_test(&call->ref, &r); trace_rxrpc_call(debug_id, r - 1, 0, why); if (dead) { ASSERTCMP(__rxrpc_call_state(call), ==, RXRPC_CALL_COMPLETE); if (!list_empty(&call->link)) { spin_lock(&rxnet->call_lock); list_del_init(&call->link); spin_unlock(&rxnet->call_lock); } rxrpc_cleanup_call(call); } } /* * Free up the call under RCU. */ static void rxrpc_rcu_free_call(struct rcu_head *rcu) { struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu); struct rxrpc_net *rxnet = READ_ONCE(call->rxnet); kmem_cache_free(rxrpc_call_jar, call); if (atomic_dec_and_test(&rxnet->nr_calls)) wake_up_var(&rxnet->nr_calls); } /* * Final call destruction - but must be done in process context. */ static void rxrpc_destroy_call(struct work_struct *work) { struct rxrpc_call *call = container_of(work, struct rxrpc_call, destroyer); struct rxrpc_txbuf *txb; del_timer_sync(&call->timer); rxrpc_free_skb(call->cong_last_nack, rxrpc_skb_put_last_nack); rxrpc_cleanup_ring(call); while ((txb = list_first_entry_or_null(&call->tx_sendmsg, struct rxrpc_txbuf, call_link))) { list_del(&txb->call_link); rxrpc_put_txbuf(txb, rxrpc_txbuf_put_cleaned); } while ((txb = list_first_entry_or_null(&call->tx_buffer, struct rxrpc_txbuf, call_link))) { list_del(&txb->call_link); rxrpc_put_txbuf(txb, rxrpc_txbuf_put_cleaned); } rxrpc_put_txbuf(call->tx_pending, rxrpc_txbuf_put_cleaned); rxrpc_put_connection(call->conn, rxrpc_conn_put_call); rxrpc_deactivate_bundle(call->bundle); rxrpc_put_bundle(call->bundle, rxrpc_bundle_put_call); rxrpc_put_peer(call->peer, rxrpc_peer_put_call); rxrpc_put_local(call->local, rxrpc_local_put_call); call_rcu(&call->rcu, rxrpc_rcu_free_call); } /* * clean up a call */ void rxrpc_cleanup_call(struct rxrpc_call *call) { memset(&call->sock_node, 0xcd, sizeof(call->sock_node)); ASSERTCMP(__rxrpc_call_state(call), ==, RXRPC_CALL_COMPLETE); ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags)); del_timer(&call->timer); if (rcu_read_lock_held()) /* Can't use the rxrpc workqueue as we need to cancel/flush * something that may be running/waiting there. */ schedule_work(&call->destroyer); else rxrpc_destroy_call(&call->destroyer); } /* * Make sure that all calls are gone from a network namespace. To reach this * point, any open UDP sockets in that namespace must have been closed, so any * outstanding calls cannot be doing I/O. */ void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet) { struct rxrpc_call *call; _enter(""); if (!list_empty(&rxnet->calls)) { spin_lock(&rxnet->call_lock); while (!list_empty(&rxnet->calls)) { call = list_entry(rxnet->calls.next, struct rxrpc_call, link); _debug("Zapping call %p", call); rxrpc_see_call(call, rxrpc_call_see_zap); list_del_init(&call->link); pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n", call, refcount_read(&call->ref), rxrpc_call_states[__rxrpc_call_state(call)], call->flags, call->events); spin_unlock(&rxnet->call_lock); cond_resched(); spin_lock(&rxnet->call_lock); } spin_unlock(&rxnet->call_lock); } atomic_dec(&rxnet->nr_calls); wait_var_event(&rxnet->nr_calls, !atomic_read(&rxnet->nr_calls)); }