489 lines
13 KiB
C
489 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/* RxRPC virtual connection handler, common bits.
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*
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* Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/net.h>
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#include <linux/skbuff.h>
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#include "ar-internal.h"
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/*
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* Time till a connection expires after last use (in seconds).
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*/
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unsigned int __read_mostly rxrpc_connection_expiry = 10 * 60;
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unsigned int __read_mostly rxrpc_closed_conn_expiry = 10;
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static void rxrpc_destroy_connection(struct rcu_head *);
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static void rxrpc_connection_timer(struct timer_list *timer)
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{
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struct rxrpc_connection *conn =
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container_of(timer, struct rxrpc_connection, timer);
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rxrpc_queue_conn(conn);
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}
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/*
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* allocate a new connection
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*/
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struct rxrpc_connection *rxrpc_alloc_connection(gfp_t gfp)
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{
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struct rxrpc_connection *conn;
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_enter("");
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conn = kzalloc(sizeof(struct rxrpc_connection), gfp);
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if (conn) {
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INIT_LIST_HEAD(&conn->cache_link);
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timer_setup(&conn->timer, &rxrpc_connection_timer, 0);
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INIT_WORK(&conn->processor, &rxrpc_process_connection);
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INIT_LIST_HEAD(&conn->proc_link);
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INIT_LIST_HEAD(&conn->link);
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skb_queue_head_init(&conn->rx_queue);
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conn->security = &rxrpc_no_security;
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spin_lock_init(&conn->state_lock);
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conn->debug_id = atomic_inc_return(&rxrpc_debug_id);
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conn->size_align = 4;
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conn->idle_timestamp = jiffies;
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}
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_leave(" = %p{%d}", conn, conn ? conn->debug_id : 0);
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return conn;
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}
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/*
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* Look up a connection in the cache by protocol parameters.
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*
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* If successful, a pointer to the connection is returned, but no ref is taken.
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* NULL is returned if there is no match.
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*
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* When searching for a service call, if we find a peer but no connection, we
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* return that through *_peer in case we need to create a new service call.
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*
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* The caller must be holding the RCU read lock.
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*/
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struct rxrpc_connection *rxrpc_find_connection_rcu(struct rxrpc_local *local,
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struct sk_buff *skb,
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struct rxrpc_peer **_peer)
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{
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struct rxrpc_connection *conn;
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struct rxrpc_conn_proto k;
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struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
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struct sockaddr_rxrpc srx;
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struct rxrpc_peer *peer;
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_enter(",%x", sp->hdr.cid & RXRPC_CIDMASK);
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if (rxrpc_extract_addr_from_skb(&srx, skb) < 0)
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goto not_found;
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if (srx.transport.family != local->srx.transport.family &&
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(srx.transport.family == AF_INET &&
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local->srx.transport.family != AF_INET6)) {
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pr_warn_ratelimited("AF_RXRPC: Protocol mismatch %u not %u\n",
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srx.transport.family,
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local->srx.transport.family);
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goto not_found;
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}
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k.epoch = sp->hdr.epoch;
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k.cid = sp->hdr.cid & RXRPC_CIDMASK;
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if (rxrpc_to_server(sp)) {
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/* We need to look up service connections by the full protocol
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* parameter set. We look up the peer first as an intermediate
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* step and then the connection from the peer's tree.
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*/
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peer = rxrpc_lookup_peer_rcu(local, &srx);
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if (!peer)
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goto not_found;
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*_peer = peer;
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conn = rxrpc_find_service_conn_rcu(peer, skb);
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if (!conn || atomic_read(&conn->usage) == 0)
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goto not_found;
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_leave(" = %p", conn);
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return conn;
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} else {
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/* Look up client connections by connection ID alone as their
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* IDs are unique for this machine.
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*/
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conn = idr_find(&rxrpc_client_conn_ids,
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sp->hdr.cid >> RXRPC_CIDSHIFT);
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if (!conn || atomic_read(&conn->usage) == 0) {
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_debug("no conn");
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goto not_found;
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}
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if (conn->proto.epoch != k.epoch ||
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conn->params.local != local)
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goto not_found;
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peer = conn->params.peer;
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switch (srx.transport.family) {
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case AF_INET:
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if (peer->srx.transport.sin.sin_port !=
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srx.transport.sin.sin_port ||
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peer->srx.transport.sin.sin_addr.s_addr !=
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srx.transport.sin.sin_addr.s_addr)
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goto not_found;
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break;
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#ifdef CONFIG_AF_RXRPC_IPV6
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case AF_INET6:
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if (peer->srx.transport.sin6.sin6_port !=
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srx.transport.sin6.sin6_port ||
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memcmp(&peer->srx.transport.sin6.sin6_addr,
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&srx.transport.sin6.sin6_addr,
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sizeof(struct in6_addr)) != 0)
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goto not_found;
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break;
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#endif
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default:
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BUG();
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}
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_leave(" = %p", conn);
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return conn;
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}
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not_found:
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_leave(" = NULL");
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return NULL;
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}
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/*
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* Disconnect a call and clear any channel it occupies when that call
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* terminates. The caller must hold the channel_lock and must release the
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* call's ref on the connection.
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*/
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void __rxrpc_disconnect_call(struct rxrpc_connection *conn,
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struct rxrpc_call *call)
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{
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struct rxrpc_channel *chan =
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&conn->channels[call->cid & RXRPC_CHANNELMASK];
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_enter("%d,%x", conn->debug_id, call->cid);
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if (rcu_access_pointer(chan->call) == call) {
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/* Save the result of the call so that we can repeat it if necessary
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* through the channel, whilst disposing of the actual call record.
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*/
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trace_rxrpc_disconnect_call(call);
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switch (call->completion) {
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case RXRPC_CALL_SUCCEEDED:
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chan->last_seq = call->rx_hard_ack;
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chan->last_type = RXRPC_PACKET_TYPE_ACK;
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break;
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case RXRPC_CALL_LOCALLY_ABORTED:
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chan->last_abort = call->abort_code;
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chan->last_type = RXRPC_PACKET_TYPE_ABORT;
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break;
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default:
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chan->last_abort = RX_USER_ABORT;
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chan->last_type = RXRPC_PACKET_TYPE_ABORT;
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break;
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}
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/* Sync with rxrpc_conn_retransmit(). */
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smp_wmb();
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chan->last_call = chan->call_id;
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chan->call_id = chan->call_counter;
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rcu_assign_pointer(chan->call, NULL);
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}
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_leave("");
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}
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/*
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* Disconnect a call and clear any channel it occupies when that call
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* terminates.
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*/
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void rxrpc_disconnect_call(struct rxrpc_call *call)
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{
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struct rxrpc_connection *conn = call->conn;
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call->peer->cong_cwnd = call->cong_cwnd;
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if (!hlist_unhashed(&call->error_link)) {
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spin_lock_bh(&call->peer->lock);
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hlist_del_rcu(&call->error_link);
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spin_unlock_bh(&call->peer->lock);
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}
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if (rxrpc_is_client_call(call))
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return rxrpc_disconnect_client_call(conn->bundle, call);
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spin_lock(&conn->bundle->channel_lock);
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__rxrpc_disconnect_call(conn, call);
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spin_unlock(&conn->bundle->channel_lock);
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set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
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conn->idle_timestamp = jiffies;
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}
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/*
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* Kill off a connection.
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*/
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void rxrpc_kill_connection(struct rxrpc_connection *conn)
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{
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struct rxrpc_net *rxnet = conn->params.local->rxnet;
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ASSERT(!rcu_access_pointer(conn->channels[0].call) &&
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!rcu_access_pointer(conn->channels[1].call) &&
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!rcu_access_pointer(conn->channels[2].call) &&
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!rcu_access_pointer(conn->channels[3].call));
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ASSERT(list_empty(&conn->cache_link));
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write_lock(&rxnet->conn_lock);
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list_del_init(&conn->proc_link);
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write_unlock(&rxnet->conn_lock);
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/* Drain the Rx queue. Note that even though we've unpublished, an
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* incoming packet could still be being added to our Rx queue, so we
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* will need to drain it again in the RCU cleanup handler.
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*/
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rxrpc_purge_queue(&conn->rx_queue);
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/* Leave final destruction to RCU. The connection processor work item
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* must carry a ref on the connection to prevent us getting here whilst
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* it is queued or running.
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*/
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call_rcu(&conn->rcu, rxrpc_destroy_connection);
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}
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/*
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* Queue a connection's work processor, getting a ref to pass to the work
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* queue.
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*/
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bool rxrpc_queue_conn(struct rxrpc_connection *conn)
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{
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const void *here = __builtin_return_address(0);
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int n = atomic_fetch_add_unless(&conn->usage, 1, 0);
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if (n == 0)
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return false;
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if (rxrpc_queue_work(&conn->processor))
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trace_rxrpc_conn(conn->debug_id, rxrpc_conn_queued, n + 1, here);
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else
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rxrpc_put_connection(conn);
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return true;
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}
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/*
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* Note the re-emergence of a connection.
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*/
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void rxrpc_see_connection(struct rxrpc_connection *conn)
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{
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const void *here = __builtin_return_address(0);
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if (conn) {
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int n = atomic_read(&conn->usage);
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trace_rxrpc_conn(conn->debug_id, rxrpc_conn_seen, n, here);
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}
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}
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/*
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* Get a ref on a connection.
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*/
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struct rxrpc_connection *rxrpc_get_connection(struct rxrpc_connection *conn)
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{
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const void *here = __builtin_return_address(0);
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int n = atomic_inc_return(&conn->usage);
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trace_rxrpc_conn(conn->debug_id, rxrpc_conn_got, n, here);
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return conn;
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}
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/*
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* Try to get a ref on a connection.
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*/
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struct rxrpc_connection *
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rxrpc_get_connection_maybe(struct rxrpc_connection *conn)
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{
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const void *here = __builtin_return_address(0);
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if (conn) {
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int n = atomic_fetch_add_unless(&conn->usage, 1, 0);
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if (n > 0)
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trace_rxrpc_conn(conn->debug_id, rxrpc_conn_got, n + 1, here);
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else
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conn = NULL;
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}
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return conn;
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}
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/*
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* Set the service connection reap timer.
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*/
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static void rxrpc_set_service_reap_timer(struct rxrpc_net *rxnet,
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unsigned long reap_at)
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{
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if (rxnet->live)
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timer_reduce(&rxnet->service_conn_reap_timer, reap_at);
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}
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/*
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* Release a service connection
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*/
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void rxrpc_put_service_conn(struct rxrpc_connection *conn)
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{
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const void *here = __builtin_return_address(0);
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unsigned int debug_id = conn->debug_id;
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int n;
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n = atomic_dec_return(&conn->usage);
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trace_rxrpc_conn(debug_id, rxrpc_conn_put_service, n, here);
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ASSERTCMP(n, >=, 0);
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if (n == 1)
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rxrpc_set_service_reap_timer(conn->params.local->rxnet,
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jiffies + rxrpc_connection_expiry);
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}
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/*
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* destroy a virtual connection
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*/
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static void rxrpc_destroy_connection(struct rcu_head *rcu)
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{
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struct rxrpc_connection *conn =
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container_of(rcu, struct rxrpc_connection, rcu);
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_enter("{%d,u=%d}", conn->debug_id, atomic_read(&conn->usage));
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ASSERTCMP(atomic_read(&conn->usage), ==, 0);
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_net("DESTROY CONN %d", conn->debug_id);
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del_timer_sync(&conn->timer);
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rxrpc_purge_queue(&conn->rx_queue);
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conn->security->clear(conn);
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key_put(conn->params.key);
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key_put(conn->server_key);
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rxrpc_put_bundle(conn->bundle);
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rxrpc_put_peer(conn->params.peer);
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if (atomic_dec_and_test(&conn->params.local->rxnet->nr_conns))
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wake_up_var(&conn->params.local->rxnet->nr_conns);
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rxrpc_put_local(conn->params.local);
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kfree(conn);
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_leave("");
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}
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/*
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* reap dead service connections
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*/
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void rxrpc_service_connection_reaper(struct work_struct *work)
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{
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struct rxrpc_connection *conn, *_p;
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struct rxrpc_net *rxnet =
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container_of(work, struct rxrpc_net, service_conn_reaper);
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unsigned long expire_at, earliest, idle_timestamp, now;
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LIST_HEAD(graveyard);
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_enter("");
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now = jiffies;
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earliest = now + MAX_JIFFY_OFFSET;
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write_lock(&rxnet->conn_lock);
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list_for_each_entry_safe(conn, _p, &rxnet->service_conns, link) {
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ASSERTCMP(atomic_read(&conn->usage), >, 0);
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if (likely(atomic_read(&conn->usage) > 1))
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continue;
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if (conn->state == RXRPC_CONN_SERVICE_PREALLOC)
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continue;
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if (rxnet->live && !conn->params.local->dead) {
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idle_timestamp = READ_ONCE(conn->idle_timestamp);
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expire_at = idle_timestamp + rxrpc_connection_expiry * HZ;
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if (conn->params.local->service_closed)
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expire_at = idle_timestamp + rxrpc_closed_conn_expiry * HZ;
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_debug("reap CONN %d { u=%d,t=%ld }",
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conn->debug_id, atomic_read(&conn->usage),
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(long)expire_at - (long)now);
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if (time_before(now, expire_at)) {
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if (time_before(expire_at, earliest))
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earliest = expire_at;
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continue;
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}
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}
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/* The usage count sits at 1 whilst the object is unused on the
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* list; we reduce that to 0 to make the object unavailable.
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*/
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if (atomic_cmpxchg(&conn->usage, 1, 0) != 1)
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continue;
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trace_rxrpc_conn(conn->debug_id, rxrpc_conn_reap_service, 0, NULL);
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if (rxrpc_conn_is_client(conn))
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BUG();
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else
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rxrpc_unpublish_service_conn(conn);
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list_move_tail(&conn->link, &graveyard);
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}
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write_unlock(&rxnet->conn_lock);
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if (earliest != now + MAX_JIFFY_OFFSET) {
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_debug("reschedule reaper %ld", (long)earliest - (long)now);
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ASSERT(time_after(earliest, now));
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rxrpc_set_service_reap_timer(rxnet, earliest);
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}
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while (!list_empty(&graveyard)) {
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conn = list_entry(graveyard.next, struct rxrpc_connection,
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link);
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list_del_init(&conn->link);
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ASSERTCMP(atomic_read(&conn->usage), ==, 0);
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rxrpc_kill_connection(conn);
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}
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_leave("");
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}
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/*
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* preemptively destroy all the service connection records rather than
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* waiting for them to time out
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*/
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void rxrpc_destroy_all_connections(struct rxrpc_net *rxnet)
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{
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struct rxrpc_connection *conn, *_p;
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bool leak = false;
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_enter("");
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atomic_dec(&rxnet->nr_conns);
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rxrpc_destroy_all_client_connections(rxnet);
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del_timer_sync(&rxnet->service_conn_reap_timer);
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rxrpc_queue_work(&rxnet->service_conn_reaper);
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flush_workqueue(rxrpc_workqueue);
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write_lock(&rxnet->conn_lock);
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list_for_each_entry_safe(conn, _p, &rxnet->service_conns, link) {
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pr_err("AF_RXRPC: Leaked conn %p {%d}\n",
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conn, atomic_read(&conn->usage));
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leak = true;
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}
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write_unlock(&rxnet->conn_lock);
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BUG_ON(leak);
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ASSERT(list_empty(&rxnet->conn_proc_list));
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/* We need to wait for the connections to be destroyed by RCU as they
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* pin things that we still need to get rid of.
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*/
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wait_var_event(&rxnet->nr_conns, !atomic_read(&rxnet->nr_conns));
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_leave("");
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}
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