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- /* RxRPC virtual connection handler
- *
- * 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/module.h>
- #include <linux/slab.h>
- #include <linux/net.h>
- #include <linux/skbuff.h>
- #include <net/sock.h>
- #include <net/af_rxrpc.h>
- #include "ar-internal.h"
- /*
- * Time till a connection expires after last use (in seconds).
- */
- unsigned int rxrpc_connection_expiry = 10 * 60;
- static void rxrpc_connection_reaper(struct work_struct *work);
- LIST_HEAD(rxrpc_connections);
- DEFINE_RWLOCK(rxrpc_connection_lock);
- static DECLARE_DELAYED_WORK(rxrpc_connection_reap, rxrpc_connection_reaper);
- /*
- * 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) {
- spin_lock_init(&conn->channel_lock);
- init_waitqueue_head(&conn->channel_wq);
- INIT_WORK(&conn->processor, &rxrpc_process_connection);
- INIT_LIST_HEAD(&conn->link);
- skb_queue_head_init(&conn->rx_queue);
- conn->security = &rxrpc_no_security;
- spin_lock_init(&conn->state_lock);
- /* We maintain an extra ref on the connection whilst it is
- * on the rxrpc_connections list.
- */
- atomic_set(&conn->usage, 2);
- conn->debug_id = atomic_inc_return(&rxrpc_debug_id);
- atomic_set(&conn->avail_chans, RXRPC_MAXCALLS);
- conn->size_align = 4;
- conn->header_size = sizeof(struct rxrpc_wire_header);
- }
- _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.
- *
- * 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_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;
- k.epoch = sp->hdr.epoch;
- k.cid = sp->hdr.cid & RXRPC_CIDMASK;
- /* We may have to handle mixing IPv4 and IPv6 */
- if (srx.transport.family != local->srx.transport.family) {
- 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 (sp->hdr.flags & RXRPC_CLIENT_INITIATED) {
- /* 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;
- conn = rxrpc_find_service_conn_rcu(peer, skb);
- if (!conn || atomic_read(&conn->usage) == 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 || atomic_read(&conn->usage) == 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;
- 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_call *call)
- {
- struct rxrpc_connection *conn = call->conn;
- struct rxrpc_channel *chan = &conn->channels[call->channel];
- _enter("%d,%d", conn->debug_id, call->channel);
- 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.
- */
- chan->last_result = call->local_abort;
- smp_wmb();
- chan->last_call = chan->call_id;
- chan->call_id = chan->call_counter;
- rcu_assign_pointer(chan->call, NULL);
- atomic_inc(&conn->avail_chans);
- wake_up(&conn->channel_wq);
- }
- _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;
- spin_lock(&conn->channel_lock);
- __rxrpc_disconnect_call(call);
- spin_unlock(&conn->channel_lock);
- call->conn = NULL;
- rxrpc_put_connection(conn);
- }
- /*
- * release a virtual connection
- */
- void rxrpc_put_connection(struct rxrpc_connection *conn)
- {
- if (!conn)
- return;
- _enter("%p{u=%d,d=%d}",
- conn, atomic_read(&conn->usage), conn->debug_id);
- ASSERTCMP(atomic_read(&conn->usage), >, 1);
- conn->put_time = ktime_get_seconds();
- if (atomic_dec_return(&conn->usage) == 1) {
- _debug("zombie");
- rxrpc_queue_delayed_work(&rxrpc_connection_reap, 0);
- }
- _leave("");
- }
- /*
- * 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, atomic_read(&conn->usage));
- ASSERTCMP(atomic_read(&conn->usage), ==, 0);
- _net("DESTROY CONN %d", conn->debug_id);
- rxrpc_purge_queue(&conn->rx_queue);
- conn->security->clear(conn);
- key_put(conn->params.key);
- key_put(conn->server_key);
- rxrpc_put_peer(conn->params.peer);
- rxrpc_put_local(conn->params.local);
- kfree(conn);
- _leave("");
- }
- /*
- * reap dead connections
- */
- static void rxrpc_connection_reaper(struct work_struct *work)
- {
- struct rxrpc_connection *conn, *_p;
- unsigned long reap_older_than, earliest, put_time, now;
- LIST_HEAD(graveyard);
- _enter("");
- now = ktime_get_seconds();
- reap_older_than = now - rxrpc_connection_expiry;
- earliest = ULONG_MAX;
- write_lock(&rxrpc_connection_lock);
- list_for_each_entry_safe(conn, _p, &rxrpc_connections, link) {
- ASSERTCMP(atomic_read(&conn->usage), >, 0);
- if (likely(atomic_read(&conn->usage) > 1))
- continue;
- put_time = READ_ONCE(conn->put_time);
- if (time_after(put_time, reap_older_than)) {
- if (time_before(put_time, earliest))
- earliest = put_time;
- 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 (atomic_cmpxchg(&conn->usage, 1, 0) != 1)
- continue;
- if (rxrpc_conn_is_client(conn))
- rxrpc_unpublish_client_conn(conn);
- else
- rxrpc_unpublish_service_conn(conn);
- list_move_tail(&conn->link, &graveyard);
- }
- write_unlock(&rxrpc_connection_lock);
- if (earliest != ULONG_MAX) {
- _debug("reschedule reaper %ld", (long) earliest - now);
- ASSERTCMP(earliest, >, now);
- rxrpc_queue_delayed_work(&rxrpc_connection_reap,
- (earliest - now) * HZ);
- }
- while (!list_empty(&graveyard)) {
- conn = list_entry(graveyard.next, struct rxrpc_connection,
- link);
- list_del_init(&conn->link);
- ASSERTCMP(atomic_read(&conn->usage), ==, 0);
- skb_queue_purge(&conn->rx_queue);
- call_rcu(&conn->rcu, rxrpc_destroy_connection);
- }
- _leave("");
- }
- /*
- * preemptively destroy all the connection records rather than waiting for them
- * to time out
- */
- void __exit rxrpc_destroy_all_connections(void)
- {
- struct rxrpc_connection *conn, *_p;
- bool leak = false;
- _enter("");
- rxrpc_connection_expiry = 0;
- cancel_delayed_work(&rxrpc_connection_reap);
- rxrpc_queue_delayed_work(&rxrpc_connection_reap, 0);
- flush_workqueue(rxrpc_workqueue);
- write_lock(&rxrpc_connection_lock);
- list_for_each_entry_safe(conn, _p, &rxrpc_connections, link) {
- pr_err("AF_RXRPC: Leaked conn %p {%d}\n",
- conn, atomic_read(&conn->usage));
- leak = true;
- }
- write_unlock(&rxrpc_connection_lock);
- BUG_ON(leak);
- /* Make sure the local and peer records pinned by any dying connections
- * are released.
- */
- rcu_barrier();
- rxrpc_destroy_client_conn_ids();
- _leave("");
- }
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