diff options
Diffstat (limited to 'net/rxrpc/conn_object.c')
-rw-r--r-- | net/rxrpc/conn_object.c | 489 |
1 files changed, 489 insertions, 0 deletions
diff --git a/net/rxrpc/conn_object.c b/net/rxrpc/conn_object.c new file mode 100644 index 000000000..d829b9755 --- /dev/null +++ b/net/rxrpc/conn_object.c @@ -0,0 +1,489 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* RxRPC virtual connection handler, common bits. + * + * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/net.h> +#include <linux/skbuff.h> +#include "ar-internal.h" + +/* + * Time till a connection expires after last use (in seconds). + */ +unsigned int __read_mostly rxrpc_connection_expiry = 10 * 60; +unsigned int __read_mostly rxrpc_closed_conn_expiry = 10; + +static void rxrpc_destroy_connection(struct rcu_head *); + +static void rxrpc_connection_timer(struct timer_list *timer) +{ + struct rxrpc_connection *conn = + container_of(timer, struct rxrpc_connection, timer); + + rxrpc_queue_conn(conn); +} + +/* + * allocate a new connection + */ +struct rxrpc_connection *rxrpc_alloc_connection(gfp_t gfp) +{ + struct rxrpc_connection *conn; + + _enter(""); + + conn = kzalloc(sizeof(struct rxrpc_connection), gfp); + if (conn) { + INIT_LIST_HEAD(&conn->cache_link); + timer_setup(&conn->timer, &rxrpc_connection_timer, 0); + INIT_WORK(&conn->processor, &rxrpc_process_connection); + INIT_LIST_HEAD(&conn->proc_link); + INIT_LIST_HEAD(&conn->link); + skb_queue_head_init(&conn->rx_queue); + conn->security = &rxrpc_no_security; + spin_lock_init(&conn->state_lock); + conn->debug_id = atomic_inc_return(&rxrpc_debug_id); + conn->size_align = 4; + conn->idle_timestamp = jiffies; + } + + _leave(" = %p{%d}", conn, conn ? conn->debug_id : 0); + return conn; +} + +/* + * Look up a connection in the cache by protocol parameters. + * + * If successful, a pointer to the connection is returned, but no ref is taken. + * NULL is returned if there is no match. + * + * When searching for a service call, if we find a peer but no connection, we + * return that through *_peer in case we need to create a new service call. + * + * The caller must be holding the RCU read lock. + */ +struct rxrpc_connection *rxrpc_find_connection_rcu(struct rxrpc_local *local, + struct sk_buff *skb, + struct rxrpc_peer **_peer) +{ + struct rxrpc_connection *conn; + struct rxrpc_conn_proto k; + struct rxrpc_skb_priv *sp = rxrpc_skb(skb); + struct sockaddr_rxrpc srx; + struct rxrpc_peer *peer; + + _enter(",%x", sp->hdr.cid & RXRPC_CIDMASK); + + if (rxrpc_extract_addr_from_skb(&srx, skb) < 0) + goto not_found; + + if (srx.transport.family != local->srx.transport.family && + (srx.transport.family == AF_INET && + local->srx.transport.family != AF_INET6)) { + pr_warn_ratelimited("AF_RXRPC: Protocol mismatch %u not %u\n", + srx.transport.family, + local->srx.transport.family); + goto not_found; + } + + k.epoch = sp->hdr.epoch; + k.cid = sp->hdr.cid & RXRPC_CIDMASK; + + if (rxrpc_to_server(sp)) { + /* We need to look up service connections by the full protocol + * parameter set. We look up the peer first as an intermediate + * step and then the connection from the peer's tree. + */ + peer = rxrpc_lookup_peer_rcu(local, &srx); + if (!peer) + goto not_found; + *_peer = peer; + conn = rxrpc_find_service_conn_rcu(peer, skb); + if (!conn || refcount_read(&conn->ref) == 0) + goto not_found; + _leave(" = %p", conn); + return conn; + } else { + /* Look up client connections by connection ID alone as their + * IDs are unique for this machine. + */ + conn = idr_find(&rxrpc_client_conn_ids, + sp->hdr.cid >> RXRPC_CIDSHIFT); + if (!conn || refcount_read(&conn->ref) == 0) { + _debug("no conn"); + goto not_found; + } + + if (conn->proto.epoch != k.epoch || + conn->params.local != local) + goto not_found; + + peer = conn->params.peer; + switch (srx.transport.family) { + case AF_INET: + if (peer->srx.transport.sin.sin_port != + srx.transport.sin.sin_port || + peer->srx.transport.sin.sin_addr.s_addr != + srx.transport.sin.sin_addr.s_addr) + goto not_found; + break; +#ifdef CONFIG_AF_RXRPC_IPV6 + case AF_INET6: + if (peer->srx.transport.sin6.sin6_port != + srx.transport.sin6.sin6_port || + memcmp(&peer->srx.transport.sin6.sin6_addr, + &srx.transport.sin6.sin6_addr, + sizeof(struct in6_addr)) != 0) + goto not_found; + break; +#endif + default: + BUG(); + } + + _leave(" = %p", conn); + return conn; + } + +not_found: + _leave(" = NULL"); + return NULL; +} + +/* + * Disconnect a call and clear any channel it occupies when that call + * terminates. The caller must hold the channel_lock and must release the + * call's ref on the connection. + */ +void __rxrpc_disconnect_call(struct rxrpc_connection *conn, + struct rxrpc_call *call) +{ + struct rxrpc_channel *chan = + &conn->channels[call->cid & RXRPC_CHANNELMASK]; + + _enter("%d,%x", conn->debug_id, call->cid); + + if (rcu_access_pointer(chan->call) == call) { + /* Save the result of the call so that we can repeat it if necessary + * through the channel, whilst disposing of the actual call record. + */ + trace_rxrpc_disconnect_call(call); + switch (call->completion) { + case RXRPC_CALL_SUCCEEDED: + chan->last_seq = call->rx_hard_ack; + chan->last_type = RXRPC_PACKET_TYPE_ACK; + break; + case RXRPC_CALL_LOCALLY_ABORTED: + chan->last_abort = call->abort_code; + chan->last_type = RXRPC_PACKET_TYPE_ABORT; + break; + default: + chan->last_abort = RX_CALL_DEAD; + chan->last_type = RXRPC_PACKET_TYPE_ABORT; + break; + } + + /* Sync with rxrpc_conn_retransmit(). */ + smp_wmb(); + chan->last_call = chan->call_id; + chan->call_id = chan->call_counter; + + rcu_assign_pointer(chan->call, NULL); + } + + _leave(""); +} + +/* + * Disconnect a call and clear any channel it occupies when that call + * terminates. + */ +void rxrpc_disconnect_call(struct rxrpc_call *call) +{ + struct rxrpc_connection *conn = call->conn; + + call->peer->cong_cwnd = call->cong_cwnd; + + if (!hlist_unhashed(&call->error_link)) { + spin_lock_bh(&call->peer->lock); + hlist_del_rcu(&call->error_link); + spin_unlock_bh(&call->peer->lock); + } + + if (rxrpc_is_client_call(call)) + return rxrpc_disconnect_client_call(conn->bundle, call); + + spin_lock(&conn->bundle->channel_lock); + __rxrpc_disconnect_call(conn, call); + spin_unlock(&conn->bundle->channel_lock); + + set_bit(RXRPC_CALL_DISCONNECTED, &call->flags); + conn->idle_timestamp = jiffies; +} + +/* + * Kill off a connection. + */ +void rxrpc_kill_connection(struct rxrpc_connection *conn) +{ + struct rxrpc_net *rxnet = conn->params.local->rxnet; + + ASSERT(!rcu_access_pointer(conn->channels[0].call) && + !rcu_access_pointer(conn->channels[1].call) && + !rcu_access_pointer(conn->channels[2].call) && + !rcu_access_pointer(conn->channels[3].call)); + ASSERT(list_empty(&conn->cache_link)); + + write_lock(&rxnet->conn_lock); + list_del_init(&conn->proc_link); + write_unlock(&rxnet->conn_lock); + + /* Drain the Rx queue. Note that even though we've unpublished, an + * incoming packet could still be being added to our Rx queue, so we + * will need to drain it again in the RCU cleanup handler. + */ + rxrpc_purge_queue(&conn->rx_queue); + + /* Leave final destruction to RCU. The connection processor work item + * must carry a ref on the connection to prevent us getting here whilst + * it is queued or running. + */ + call_rcu(&conn->rcu, rxrpc_destroy_connection); +} + +/* + * Queue a connection's work processor, getting a ref to pass to the work + * queue. + */ +bool rxrpc_queue_conn(struct rxrpc_connection *conn) +{ + const void *here = __builtin_return_address(0); + int r; + + if (!__refcount_inc_not_zero(&conn->ref, &r)) + return false; + if (rxrpc_queue_work(&conn->processor)) + trace_rxrpc_conn(conn->debug_id, rxrpc_conn_queued, r + 1, here); + else + rxrpc_put_connection(conn); + return true; +} + +/* + * Note the re-emergence of a connection. + */ +void rxrpc_see_connection(struct rxrpc_connection *conn) +{ + const void *here = __builtin_return_address(0); + if (conn) { + int n = refcount_read(&conn->ref); + + trace_rxrpc_conn(conn->debug_id, rxrpc_conn_seen, n, here); + } +} + +/* + * Get a ref on a connection. + */ +struct rxrpc_connection *rxrpc_get_connection(struct rxrpc_connection *conn) +{ + const void *here = __builtin_return_address(0); + int r; + + __refcount_inc(&conn->ref, &r); + trace_rxrpc_conn(conn->debug_id, rxrpc_conn_got, r, here); + return conn; +} + +/* + * Try to get a ref on a connection. + */ +struct rxrpc_connection * +rxrpc_get_connection_maybe(struct rxrpc_connection *conn) +{ + const void *here = __builtin_return_address(0); + int r; + + if (conn) { + if (__refcount_inc_not_zero(&conn->ref, &r)) + trace_rxrpc_conn(conn->debug_id, rxrpc_conn_got, r + 1, here); + else + conn = NULL; + } + return conn; +} + +/* + * Set the service connection reap timer. + */ +static void rxrpc_set_service_reap_timer(struct rxrpc_net *rxnet, + unsigned long reap_at) +{ + if (rxnet->live) + timer_reduce(&rxnet->service_conn_reap_timer, reap_at); +} + +/* + * Release a service connection + */ +void rxrpc_put_service_conn(struct rxrpc_connection *conn) +{ + const void *here = __builtin_return_address(0); + unsigned int debug_id = conn->debug_id; + int r; + + __refcount_dec(&conn->ref, &r); + trace_rxrpc_conn(debug_id, rxrpc_conn_put_service, r - 1, here); + if (r - 1 == 1) + rxrpc_set_service_reap_timer(conn->params.local->rxnet, + jiffies + rxrpc_connection_expiry); +} + +/* + * destroy a virtual connection + */ +static void rxrpc_destroy_connection(struct rcu_head *rcu) +{ + struct rxrpc_connection *conn = + container_of(rcu, struct rxrpc_connection, rcu); + + _enter("{%d,u=%d}", conn->debug_id, refcount_read(&conn->ref)); + + ASSERTCMP(refcount_read(&conn->ref), ==, 0); + + _net("DESTROY CONN %d", conn->debug_id); + + del_timer_sync(&conn->timer); + rxrpc_purge_queue(&conn->rx_queue); + + conn->security->clear(conn); + key_put(conn->params.key); + key_put(conn->server_key); + rxrpc_put_bundle(conn->bundle); + rxrpc_put_peer(conn->params.peer); + + if (atomic_dec_and_test(&conn->params.local->rxnet->nr_conns)) + wake_up_var(&conn->params.local->rxnet->nr_conns); + rxrpc_put_local(conn->params.local); + + kfree(conn); + _leave(""); +} + +/* + * reap dead service connections + */ +void rxrpc_service_connection_reaper(struct work_struct *work) +{ + struct rxrpc_connection *conn, *_p; + struct rxrpc_net *rxnet = + container_of(work, struct rxrpc_net, service_conn_reaper); + unsigned long expire_at, earliest, idle_timestamp, now; + + LIST_HEAD(graveyard); + + _enter(""); + + now = jiffies; + earliest = now + MAX_JIFFY_OFFSET; + + write_lock(&rxnet->conn_lock); + list_for_each_entry_safe(conn, _p, &rxnet->service_conns, link) { + ASSERTCMP(refcount_read(&conn->ref), >, 0); + if (likely(refcount_read(&conn->ref) > 1)) + continue; + if (conn->state == RXRPC_CONN_SERVICE_PREALLOC) + continue; + + if (rxnet->live && !conn->params.local->dead) { + idle_timestamp = READ_ONCE(conn->idle_timestamp); + expire_at = idle_timestamp + rxrpc_connection_expiry * HZ; + if (conn->params.local->service_closed) + expire_at = idle_timestamp + rxrpc_closed_conn_expiry * HZ; + + _debug("reap CONN %d { u=%d,t=%ld }", + conn->debug_id, refcount_read(&conn->ref), + (long)expire_at - (long)now); + + if (time_before(now, expire_at)) { + if (time_before(expire_at, earliest)) + earliest = expire_at; + continue; + } + } + + /* The usage count sits at 1 whilst the object is unused on the + * list; we reduce that to 0 to make the object unavailable. + */ + if (!refcount_dec_if_one(&conn->ref)) + continue; + trace_rxrpc_conn(conn->debug_id, rxrpc_conn_reap_service, 0, NULL); + + if (rxrpc_conn_is_client(conn)) + BUG(); + else + rxrpc_unpublish_service_conn(conn); + + list_move_tail(&conn->link, &graveyard); + } + write_unlock(&rxnet->conn_lock); + + if (earliest != now + MAX_JIFFY_OFFSET) { + _debug("reschedule reaper %ld", (long)earliest - (long)now); + ASSERT(time_after(earliest, now)); + rxrpc_set_service_reap_timer(rxnet, earliest); + } + + while (!list_empty(&graveyard)) { + conn = list_entry(graveyard.next, struct rxrpc_connection, + link); + list_del_init(&conn->link); + + ASSERTCMP(refcount_read(&conn->ref), ==, 0); + rxrpc_kill_connection(conn); + } + + _leave(""); +} + +/* + * preemptively destroy all the service connection records rather than + * waiting for them to time out + */ +void rxrpc_destroy_all_connections(struct rxrpc_net *rxnet) +{ + struct rxrpc_connection *conn, *_p; + bool leak = false; + + _enter(""); + + atomic_dec(&rxnet->nr_conns); + rxrpc_destroy_all_client_connections(rxnet); + + del_timer_sync(&rxnet->service_conn_reap_timer); + rxrpc_queue_work(&rxnet->service_conn_reaper); + flush_workqueue(rxrpc_workqueue); + + write_lock(&rxnet->conn_lock); + list_for_each_entry_safe(conn, _p, &rxnet->service_conns, link) { + pr_err("AF_RXRPC: Leaked conn %p {%d}\n", + conn, refcount_read(&conn->ref)); + leak = true; + } + write_unlock(&rxnet->conn_lock); + BUG_ON(leak); + + ASSERT(list_empty(&rxnet->conn_proc_list)); + + /* We need to wait for the connections to be destroyed by RCU as they + * pin things that we still need to get rid of. + */ + wait_var_event(&rxnet->nr_conns, !atomic_read(&rxnet->nr_conns)); + _leave(""); +} |