// 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 ([email protected])
*/
#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_clean_up_connection(struct work_struct *work);
static void rxrpc_set_service_reap_timer(struct rxrpc_net *rxnet,
unsigned long reap_at);
void rxrpc_poke_conn(struct rxrpc_connection *conn, enum rxrpc_conn_trace why)
{
struct rxrpc_local *local = conn->local;
bool busy;
if (WARN_ON_ONCE(!local))
return;
spin_lock_bh(&local->lock);
busy = !list_empty(&conn->attend_link);
if (!busy) {
rxrpc_get_connection(conn, why);
list_add_tail(&conn->attend_link, &local->conn_attend_q);
}
spin_unlock_bh(&local->lock);
rxrpc_wake_up_io_thread(local);
}
static void rxrpc_connection_timer(struct timer_list *timer)
{
struct rxrpc_connection *conn =
container_of(timer, struct rxrpc_connection, timer);
rxrpc_poke_conn(conn, rxrpc_conn_get_poke_timer);
}
/*
* allocate a new connection
*/
struct rxrpc_connection *rxrpc_alloc_connection(struct rxrpc_net *rxnet,
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_WORK(&conn->destructor, rxrpc_clean_up_connection);
INIT_LIST_HEAD(&conn->proc_link);
INIT_LIST_HEAD(&conn->link);
mutex_init(&conn->security_lock);
mutex_init(&conn->tx_data_alloc_lock);
skb_queue_head_init(&conn->rx_queue);
conn->rxnet = rxnet;
conn->security = &rxrpc_no_security;
spin_lock_init(&conn->state_lock);
conn->debug_id = atomic_inc_return(&rxrpc_debug_id);
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_client_connection_rcu(struct rxrpc_local *local,
struct sockaddr_rxrpc *srx,
struct sk_buff *skb)
{
struct rxrpc_connection *conn;
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
struct rxrpc_peer *peer;
_enter(",%x", sp->hdr.cid & RXRPC_CIDMASK);
/* Look up client connections by connection ID alone as their
* IDs are unique for this machine.
*/
conn = idr_find(&local->conn_ids, sp->hdr.cid >> RXRPC_CIDSHIFT);
if (!conn || refcount_read(&conn->ref) == 0) {
_debug("no conn");
goto not_found;
}
if (conn->proto.epoch != sp->hdr.epoch ||
conn->local != local)
goto not_found;
peer = conn->peer;
switch (srx->transport.family) {
case AF_INET:
if (peer->srx.transport.sin.sin_port !=
srx->transport.sin.sin_port)
goto not_found;
break;
#ifdef CONFIG_AF_RXRPC_IPV6
case AF_INET6:
if (peer->srx.transport.sin6.sin6_port !=
srx->transport.sin6.sin6_port)
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 (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_highest_seq;
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;
}
chan->last_call = chan->call_id;
chan->call_id = chan->call_counter;
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;
set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
rxrpc_see_call(call, rxrpc_call_see_disconnected);
call->peer->cong_ssthresh = call->cong_ssthresh;
if (!hlist_unhashed(&call->error_link)) {
spin_lock(&call->peer->lock);
hlist_del_init(&call->error_link);
spin_unlock(&call->peer->lock);
}
if (rxrpc_is_client_call(call)) {
rxrpc_disconnect_client_call(call->bundle, call);
} else {
__rxrpc_disconnect_call(conn, call);
conn->idle_timestamp = jiffies;
if (atomic_dec_and_test(&conn->active))
rxrpc_set_service_reap_timer(conn->rxnet,
jiffies + rxrpc_connection_expiry * HZ);
}
rxrpc_put_call(call, rxrpc_call_put_io_thread);
}
/*
* Queue a connection's work processor, getting a ref to pass to the work
* queue.
*/
void rxrpc_queue_conn(struct rxrpc_connection *conn, enum rxrpc_conn_trace why)
{
if (atomic_read(&conn->active) >= 0 &&
rxrpc_queue_work(&conn->processor))
rxrpc_see_connection(conn, why);
}
/*
* Note the re-emergence of a connection.
*/
void rxrpc_see_connection(struct rxrpc_connection *conn,
enum rxrpc_conn_trace why)
{
if (conn) {
int r = refcount_read(&conn->ref);
trace_rxrpc_conn(conn->debug_id, r, why);
}
}
/*
* Get a ref on a connection.
*/
struct rxrpc_connection *rxrpc_get_connection(struct rxrpc_connection *conn,
enum rxrpc_conn_trace why)
{
int r;
__refcount_inc(&conn->ref, &r);
trace_rxrpc_conn(conn->debug_id, r + 1, why);
return conn;
}
/*
* Try to get a ref on a connection.
*/
struct rxrpc_connection *
rxrpc_get_connection_maybe(struct rxrpc_connection *conn,
enum rxrpc_conn_trace why)
{
int r;
if (conn) {
if (__refcount_inc_not_zero(&conn->ref, &r))
trace_rxrpc_conn(conn->debug_id, r + 1, why);
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);
}
/*
* destroy a virtual connection
*/
static void rxrpc_rcu_free_connection(struct rcu_head *rcu)
{
struct rxrpc_connection *conn =
container_of(rcu, struct rxrpc_connection, rcu);
struct rxrpc_net *rxnet = conn->rxnet;
_enter("{%d,u=%d}", conn->debug_id, refcount_read(&conn->ref));
trace_rxrpc_conn(conn->debug_id, refcount_read(&conn->ref),
rxrpc_conn_free);
kfree(conn);
if (atomic_dec_and_test(&rxnet->nr_conns))
wake_up_var(&rxnet->nr_conns);
}
/*
* Clean up a dead connection.
*/
static void rxrpc_clean_up_connection(struct work_struct *work)
{
struct rxrpc_connection *conn =
container_of(work, struct rxrpc_connection, destructor);
struct rxrpc_net *rxnet = conn->rxnet;
ASSERT(!conn->channels[0].call &&
!conn->channels[1].call &&
!conn->channels[2].call &&
!conn->channels[3].call);
ASSERT(list_empty(&conn->cache_link));
del_timer_sync(&conn->timer);
cancel_work_sync(&conn->processor); /* Processing may restart the timer */
del_timer_sync(&conn->timer);
write_lock(&rxnet->conn_lock);
list_del_init(&conn->proc_link);
write_unlock(&rxnet->conn_lock);
rxrpc_purge_queue(&conn->rx_queue);
rxrpc_kill_client_conn(conn);
conn->security->clear(conn);
key_put(conn->key);
rxrpc_put_bundle(conn->bundle, rxrpc_bundle_put_conn);
rxrpc_put_peer(conn->peer, rxrpc_peer_put_conn);
rxrpc_put_local(conn->local, rxrpc_local_put_kill_conn);
/* 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);
if (conn->tx_data_alloc.va)
__page_frag_cache_drain(virt_to_page(conn->tx_data_alloc.va),
conn->tx_data_alloc.pagecnt_bias);
call_rcu(&conn->rcu, rxrpc_rcu_free_connection);
}
/*
* Drop a ref on a connection.
*/
void rxrpc_put_connection(struct rxrpc_connection *conn,
enum rxrpc_conn_trace why)
{
unsigned int debug_id;
bool dead;
int r;
if (!conn)
return;
debug_id = conn->debug_id;
dead = __refcount_dec_and_test(&conn->ref, &r);
trace_rxrpc_conn(debug_id, r - 1, why);
if (dead) {
del_timer(&conn->timer);
cancel_work(&conn->processor);
if (in_softirq() || work_busy(&conn->processor) ||
timer_pending(&conn->timer))
/* Can't use the rxrpc workqueue as we need to cancel/flush
* something that may be running/waiting there.
*/
schedule_work(&conn->destructor);
else
rxrpc_clean_up_connection(&conn->destructor);
}
}
/*
* 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;
int active;
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(atomic_read(&conn->active), >=, 0);
if (likely(atomic_read(&conn->active) > 0))
continue;
if (conn->state == RXRPC_CONN_SERVICE_PREALLOC)
continue;
if (rxnet->live && !conn->local->dead) {
idle_timestamp = READ_ONCE(conn->idle_timestamp);
expire_at = idle_timestamp + rxrpc_connection_expiry * HZ;
if (conn->local->service_closed)
expire_at = idle_timestamp + rxrpc_closed_conn_expiry * HZ;
_debug("reap CONN %d { a=%d,t=%ld }",
conn->debug_id, atomic_read(&conn->active),
(long)expire_at - (long)now);
if (time_before(now, expire_at)) {
if (time_before(expire_at, earliest))
earliest = expire_at;
continue;
}
}
/* The activity count sits at 0 whilst the conn is unused on
* the list; we reduce that to -1 to make the conn unavailable.
*/
active = 0;
if (!atomic_try_cmpxchg(&conn->active, &active, -1))
continue;
rxrpc_see_connection(conn, rxrpc_conn_see_reap_service);
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(atomic_read(&conn->active), ==, -1);
rxrpc_put_connection(conn, rxrpc_conn_put_service_reaped);
}
_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);
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("");
}
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