/* RxRPC individual remote procedure call handling * * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program 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 * 2 of the License, or (at your option) any later version. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/slab.h> #include <linux/module.h> #include <linux/circ_buf.h> #include <linux/spinlock_types.h> #include <net/sock.h> #include <net/af_rxrpc.h> #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_ACCEPTING] = "SvAccept", [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; LIST_HEAD(rxrpc_calls); DEFINE_RWLOCK(rxrpc_call_lock); static void rxrpc_call_timer_expired(unsigned long _call) { struct rxrpc_call *call = (struct rxrpc_call *)_call; _enter("%d", call->debug_id); if (call->state < RXRPC_CALL_COMPLETE) rxrpc_set_timer(call, rxrpc_timer_expired, ktime_get_real()); } /* * 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_got); read_unlock(&rx->call_lock); _leave(" = %p [%d]", call, atomic_read(&call->usage)); return call; } /* * allocate a new call */ struct rxrpc_call *rxrpc_alloc_call(gfp_t gfp) { struct rxrpc_call *call; call = kmem_cache_zalloc(rxrpc_call_jar, gfp); if (!call) return NULL; call->rxtx_buffer = kcalloc(RXRPC_RXTX_BUFF_SIZE, sizeof(struct sk_buff *), gfp); if (!call->rxtx_buffer) goto nomem; call->rxtx_annotations = kcalloc(RXRPC_RXTX_BUFF_SIZE, sizeof(u8), gfp); if (!call->rxtx_annotations) goto nomem_2; setup_timer(&call->timer, rxrpc_call_timer_expired, (unsigned long)call); INIT_WORK(&call->processor, &rxrpc_process_call); INIT_LIST_HEAD(&call->link); INIT_LIST_HEAD(&call->chan_wait_link); INIT_LIST_HEAD(&call->accept_link); INIT_LIST_HEAD(&call->recvmsg_link); INIT_LIST_HEAD(&call->sock_link); init_waitqueue_head(&call->waitq); spin_lock_init(&call->lock); rwlock_init(&call->state_lock); atomic_set(&call->usage, 1); call->debug_id = atomic_inc_return(&rxrpc_debug_id); memset(&call->sock_node, 0xed, sizeof(call->sock_node)); /* Leave space in the ring to handle a maxed-out jumbo packet */ call->rx_winsize = rxrpc_rx_window_size; call->tx_winsize = 16; call->rx_expect_next = 1; 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_RXTX_BUFF_SIZE - 1; return call; nomem_2: kfree(call->rxtx_buffer); nomem: kmem_cache_free(rxrpc_call_jar, call); return NULL; } /* * Allocate a new client call. */ static struct rxrpc_call *rxrpc_alloc_client_call(struct sockaddr_rxrpc *srx, gfp_t gfp) { struct rxrpc_call *call; ktime_t now; _enter(""); call = rxrpc_alloc_call(gfp); if (!call) return ERR_PTR(-ENOMEM); call->state = RXRPC_CALL_CLIENT_AWAIT_CONN; call->service_id = srx->srx_service; call->tx_phase = true; now = ktime_get_real(); call->acks_latest_ts = now; call->cong_tstamp = now; _leave(" = %p", call); return call; } /* * Initiate the call ack/resend/expiry timer. */ static void rxrpc_start_call_timer(struct rxrpc_call *call) { ktime_t now = ktime_get_real(), expire_at; expire_at = ktime_add_ms(now, rxrpc_max_call_lifetime); call->expire_at = expire_at; call->ack_at = expire_at; call->ping_at = expire_at; call->resend_at = expire_at; call->timer.expires = jiffies + LONG_MAX / 2; rxrpc_set_timer(call, rxrpc_timer_begin, now); } /* * set up a call for the given data * - called in process context with IRQs enabled */ struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx, struct rxrpc_conn_parameters *cp, struct sockaddr_rxrpc *srx, unsigned long user_call_ID, gfp_t gfp) { struct rxrpc_call *call, *xcall; struct rb_node *parent, **pp; const void *here = __builtin_return_address(0); int ret; _enter("%p,%lx", rx, user_call_ID); call = rxrpc_alloc_client_call(srx, gfp); if (IS_ERR(call)) { _leave(" = %ld", PTR_ERR(call)); return call; } trace_rxrpc_call(call, rxrpc_call_new_client, atomic_read(&call->usage), here, (const void *)user_call_ID); /* 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 (user_call_ID < xcall->user_call_ID) pp = &(*pp)->rb_left; else if (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 = user_call_ID; __set_bit(RXRPC_CALL_HAS_USERID, &call->flags); rxrpc_get_call(call, rxrpc_call_got_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); write_lock(&rxrpc_call_lock); list_add_tail(&call->link, &rxrpc_calls); write_unlock(&rxrpc_call_lock); /* Set up or get a connection record and set the protocol parameters, * including channel number and call ID. */ ret = rxrpc_connect_call(call, cp, srx, gfp); if (ret < 0) goto error; trace_rxrpc_call(call, rxrpc_call_connected, atomic_read(&call->usage), here, NULL); spin_lock_bh(&call->conn->params.peer->lock); hlist_add_head(&call->error_link, &call->conn->params.peer->error_targets); spin_unlock_bh(&call->conn->params.peer->lock); rxrpc_start_call_timer(call); _net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id); _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); ret = -EEXIST; error: __rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR, RX_CALL_DEAD, ret); trace_rxrpc_call(call, rxrpc_call_error, atomic_read(&call->usage), here, ERR_PTR(ret)); rxrpc_release_call(rx, call); rxrpc_put_call(call, rxrpc_call_put); _leave(" = %d", ret); return ERR_PTR(ret); } /* * 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->service_id = sp->hdr.serviceId; call->cid = sp->hdr.cid; call->state = RXRPC_CALL_SERVER_ACCEPTING; if (sp->hdr.securityIndex > 0) call->state = RXRPC_CALL_SERVER_SECURING; call->cong_tstamp = skb->tstamp; /* 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; rcu_assign_pointer(conn->channels[chan].call, call); spin_lock(&conn->params.peer->lock); hlist_add_head(&call->error_link, &conn->params.peer->error_targets); spin_unlock(&conn->params.peer->lock); _net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id); rxrpc_start_call_timer(call); _leave(""); } /* * Queue a call's work processor, getting a ref to pass to the work queue. */ bool rxrpc_queue_call(struct rxrpc_call *call) { const void *here = __builtin_return_address(0); int n = __atomic_add_unless(&call->usage, 1, 0); if (n == 0) return false; if (rxrpc_queue_work(&call->processor)) trace_rxrpc_call(call, rxrpc_call_queued, n + 1, here, NULL); else rxrpc_put_call(call, rxrpc_call_put_noqueue); return true; } /* * Queue a call's work processor, passing the callers ref to the work queue. */ bool __rxrpc_queue_call(struct rxrpc_call *call) { const void *here = __builtin_return_address(0); int n = atomic_read(&call->usage); ASSERTCMP(n, >=, 1); if (rxrpc_queue_work(&call->processor)) trace_rxrpc_call(call, rxrpc_call_queued_ref, n, here, NULL); else rxrpc_put_call(call, rxrpc_call_put_noqueue); return true; } /* * Note the re-emergence of a call. */ void rxrpc_see_call(struct rxrpc_call *call) { const void *here = __builtin_return_address(0); if (call) { int n = atomic_read(&call->usage); trace_rxrpc_call(call, rxrpc_call_seen, n, here, NULL); } } /* * Note the addition of a ref on a call. */ void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op) { const void *here = __builtin_return_address(0); int n = atomic_inc_return(&call->usage); trace_rxrpc_call(call, op, n, here, NULL); } /* * Detach a call from its owning socket. */ void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call) { const void *here = __builtin_return_address(0); struct rxrpc_connection *conn = call->conn; bool put = false; int i; _enter("{%d,%d}", call->debug_id, atomic_read(&call->usage)); trace_rxrpc_call(call, rxrpc_call_release, atomic_read(&call->usage), here, (const void *)call->flags); ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE); spin_lock_bh(&call->lock); if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags)) BUG(); spin_unlock_bh(&call->lock); del_timer_sync(&call->timer); /* Make sure we don't get any more notifications */ write_lock_bh(&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; write_unlock_bh(&rx->recvmsg_lock); if (put) rxrpc_put_call(call, rxrpc_call_put); 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)); rxrpc_put_call(call, rxrpc_call_put_userid); } list_del(&call->sock_link); write_unlock(&rx->call_lock); _debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn); if (conn) rxrpc_disconnect_call(call); for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) { rxrpc_free_skb(call->rxtx_buffer[i], (call->tx_phase ? rxrpc_skb_tx_cleaned : rxrpc_skb_rx_cleaned)); call->rxtx_buffer[i] = NULL; } _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_abort_call("SKR", call, 0, RX_CALL_DEAD, ECONNRESET); rxrpc_put_call(call, rxrpc_call_put); } while (!list_empty(&rx->sock_calls)) { call = list_entry(rx->sock_calls.next, struct rxrpc_call, sock_link); rxrpc_get_call(call, rxrpc_call_got); rxrpc_abort_call("SKT", call, 0, RX_CALL_DEAD, ECONNRESET); rxrpc_send_abort_packet(call); rxrpc_release_call(rx, call); rxrpc_put_call(call, rxrpc_call_put); } _leave(""); } /* * release a call */ void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace op) { const void *here = __builtin_return_address(0); int n; ASSERT(call != NULL); n = atomic_dec_return(&call->usage); trace_rxrpc_call(call, op, n, here, NULL); ASSERTCMP(n, >=, 0); if (n == 0) { _debug("call %d dead", call->debug_id); ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE); write_lock(&rxrpc_call_lock); list_del_init(&call->link); write_unlock(&rxrpc_call_lock); rxrpc_cleanup_call(call); } } /* * Final call destruction under RCU. */ static void rxrpc_rcu_destroy_call(struct rcu_head *rcu) { struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu); rxrpc_put_peer(call->peer); kfree(call->rxtx_buffer); kfree(call->rxtx_annotations); kmem_cache_free(rxrpc_call_jar, call); } /* * clean up a call */ void rxrpc_cleanup_call(struct rxrpc_call *call) { int i; _net("DESTROY CALL %d", call->debug_id); memset(&call->sock_node, 0xcd, sizeof(call->sock_node)); del_timer_sync(&call->timer); ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE); ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags)); ASSERTCMP(call->conn, ==, NULL); /* Clean up the Rx/Tx buffer */ for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) rxrpc_free_skb(call->rxtx_buffer[i], (call->tx_phase ? rxrpc_skb_tx_cleaned : rxrpc_skb_rx_cleaned)); rxrpc_free_skb(call->tx_pending, rxrpc_skb_tx_cleaned); call_rcu(&call->rcu, rxrpc_rcu_destroy_call); } /* * Make sure that all calls are gone. */ void __exit rxrpc_destroy_all_calls(void) { struct rxrpc_call *call; _enter(""); if (list_empty(&rxrpc_calls)) return; write_lock(&rxrpc_call_lock); while (!list_empty(&rxrpc_calls)) { call = list_entry(rxrpc_calls.next, struct rxrpc_call, link); _debug("Zapping call %p", call); rxrpc_see_call(call); list_del_init(&call->link); pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n", call, atomic_read(&call->usage), rxrpc_call_states[call->state], call->flags, call->events); write_unlock(&rxrpc_call_lock); cond_resched(); write_lock(&rxrpc_call_lock); } write_unlock(&rxrpc_call_lock); }