path: root/net/rxrpc/ar-call.c

/* RxRPC individual remote procedure call handling
 *
 * 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.
 */

#include <linux/slab.h>
#include <linux/module.h>
#include <linux/circ_buf.h>
#include <linux/hashtable.h>
#include <linux/spinlock_types.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
#include "ar-internal.h"

/*
 * Maximum lifetime of a call (in jiffies).
 */
unsigned rxrpc_max_call_lifetime = 60 * HZ;

/*
 * Time till dead call expires after last use (in jiffies).
 */
unsigned rxrpc_dead_call_expiry = 2 * HZ;

const char *const rxrpc_call_states[] = {
	[RXRPC_CALL_CLIENT_SEND_REQUEST]	= "ClSndReq",
	[RXRPC_CALL_CLIENT_AWAIT_REPLY]		= "ClAwtRpl",
	[RXRPC_CALL_CLIENT_RECV_REPLY]		= "ClRcvRpl",
	[RXRPC_CALL_CLIENT_FINAL_ACK]		= "ClFnlACK",
	[RXRPC_CALL_SERVER_SECURING]		= "SvSecure",
	[RXRPC_CALL_SERVER_ACCEPTING]		= "SvAccept",
	[RXRPC_CALL_SERVER_RECV_REQUEST]	= "SvRcvReq",
	[RXRPC_CALL_SERVER_ACK_REQUEST]		= "SvAckReq",
	[RXRPC_CALL_SERVER_SEND_REPLY]		= "SvSndRpl",
	[RXRPC_CALL_SERVER_AWAIT_ACK]		= "SvAwtACK",
	[RXRPC_CALL_COMPLETE]			= "Complete",
	[RXRPC_CALL_SERVER_BUSY]		= "SvBusy  ",
	[RXRPC_CALL_REMOTELY_ABORTED]		= "RmtAbort",
	[RXRPC_CALL_LOCALLY_ABORTED]		= "LocAbort",
	[RXRPC_CALL_NETWORK_ERROR]		= "NetError",
	[RXRPC_CALL_DEAD]			= "Dead    ",
};

struct kmem_cache *rxrpc_call_jar;
LIST_HEAD(rxrpc_calls);
DEFINE_RWLOCK(rxrpc_call_lock);

static void rxrpc_destroy_call(struct work_struct *work);
static void rxrpc_call_life_expired(unsigned long _call);
static void rxrpc_dead_call_expired(unsigned long _call);
static void rxrpc_ack_time_expired(unsigned long _call);
static void rxrpc_resend_time_expired(unsigned long _call);

static DEFINE_SPINLOCK(rxrpc_call_hash_lock);
static DEFINE_HASHTABLE(rxrpc_call_hash, 10);

/*
 * Hash function for rxrpc_call_hash
 */
static unsigned long rxrpc_call_hashfunc(
	u8		clientflag,
	__be32		cid,
	__be32		call_id,
	__be32		epoch,
	__be16		service_id,
	sa_family_t	proto,
	void		*localptr,
	unsigned int	addr_size,
	const u8	*peer_addr)
{
	const u16 *p;
	unsigned int i;
	unsigned long key;
	u32 hcid = ntohl(cid);

	_enter("");

	key = (unsigned long)localptr;
	/* We just want to add up the __be32 values, so forcing the
	 * cast should be okay.
	 */
	key += (__force u32)epoch;
	key += (__force u16)service_id;
	key += (__force u32)call_id;
	key += (hcid & RXRPC_CIDMASK) >> RXRPC_CIDSHIFT;
	key += hcid & RXRPC_CHANNELMASK;
	key += clientflag;
	key += proto;
	/* Step through the peer address in 16-bit portions for speed */
	for (i = 0, p = (const u16 *)peer_addr; i < addr_size >> 1; i++, p++)
		key += *p;
	_leave(" key = 0x%lx", key);
	return key;
}

/*
 * Add a call to the hashtable
 */
static void rxrpc_call_hash_add(struct rxrpc_call *call)
{
	unsigned long key;
	unsigned int addr_size = 0;

	_enter("");
	switch (call->proto) {
	case AF_INET:
		addr_size = sizeof(call->peer_ip.ipv4_addr);
		break;
	case AF_INET6:
		addr_size = sizeof(call->peer_ip.ipv6_addr);
		break;
	default:
		break;
	}
	key = rxrpc_call_hashfunc(call->in_clientflag, call->cid,
				  call->call_id, call->epoch,
				  call->service_id, call->proto,
				  call->conn->trans->local, addr_size,
				  call->peer_ip.ipv6_addr);
	/* Store the full key in the call */
	call->hash_key = key;
	spin_lock(&rxrpc_call_hash_lock);
	hash_add_rcu(rxrpc_call_hash, &call->hash_node, key);
	spin_unlock(&rxrpc_call_hash_lock);
	_leave("");
}

/*
 * Remove a call from the hashtable
 */
static void rxrpc_call_hash_del(struct rxrpc_call *call)
{
	_enter("");
	spin_lock(&rxrpc_call_hash_lock);
	hash_del_rcu(&call->hash_node);
	spin_unlock(&rxrpc_call_hash_lock);
	_leave(