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|
/* RxRPC virtual connection handler, common bits.
*
* Copyright (C) 2007, 2016 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 "ar-internal.h"
/*
* Time till a connection expires after last use (in seconds).
*/
unsigned int rxrpc_connection_expiry = 10 * 60;
static void rxrpc_destroy_connection(struct rcu_head *);
/*
* 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);
spin_lock_init(&conn->channel_lock);
INIT_LIST_HEAD(&conn->waiting_calls);
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.
*
* 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(local, &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;
#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);
if (call->abort_code) {
chan->last_abort = call->abort_code;
chan->last_type = RXRPC_PACKET_TYPE_ABORT;
} else {
chan->last_seq = call->rx_hard_ack;
chan->last_type = RXRPC_PACKET_TYPE_ACK;
}
/* 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;
spin_lock_bh(&conn->params.peer->lock);
hlist_del_init(&call->error_link);
spin_unlock_bh(&conn->params.peer->lock);
if (rxrpc_is_client_call(call))
return rxrpc_disconnect_client_call(call);
spin_lock(&conn->channel_lock);
__rxrpc_disconnect_call(conn, call);
spin_unlock(&conn->channel_lock);
call->conn = NULL;
conn->idle_timestamp = jiffies;
rxrpc_put_connection(conn);
}
/*
* 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 n = __atomic_add_unless(&conn->usage, 1, 0);
if (n == 0)
return false;
if (rxrpc_queue_work(&conn->processor))
trace_rxrpc_conn(conn, rxrpc_conn_queued, n + 1, here);
else
rxrpc_put_connection(conn);
return true;
}
/*
* Note the re-emergence of a connection.
*/
void rxrpc_see_connection(struct rxrpc_connection *
|