path: root/net/rxrpc/af_rxrpc.c

/* AF_RXRPC implementation
 *
 * 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/module.h>
#include <linux/net.h>
#include <linux/skbuff.h>
#include <linux/poll.h>
#include <linux/proc_fs.h>
#include <linux/key-type.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
#include "ar-internal.h"

MODULE_DESCRIPTION("RxRPC network protocol");
MODULE_AUTHOR("Red Hat, Inc.");
MODULE_LICENSE("GPL");
MODULE_ALIAS_NETPROTO(PF_RXRPC);

unsigned rxrpc_debug; // = RXRPC_DEBUG_KPROTO;
module_param_named(debug, rxrpc_debug, uint, S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(debug, "RxRPC debugging mask");

static int sysctl_rxrpc_max_qlen __read_mostly = 10;

static struct proto rxrpc_proto;
static const struct proto_ops rxrpc_rpc_ops;

/* local epoch for detecting local-end reset */
__be32 rxrpc_epoch;

/* current debugging ID */
atomic_t rxrpc_debug_id;

/* count of skbs currently in use */
atomic_t rxrpc_n_skbs;

struct workqueue_struct *rxrpc_workqueue;

static void rxrpc_sock_destructor(struct sock *);

/*
 * see if an RxRPC socket is currently writable
 */
static inline int rxrpc_writable(struct sock *sk)
{
	return atomic_read(&sk->sk_wmem_alloc) < (size_t) sk->sk_sndbuf;
}

/*
 * wait for write bufferage to become available
 */
static void rxrpc_write_space(struct sock *sk)
{
	_enter("%p", sk);
	read_lock(&sk->sk_callback_lock);
	if (rxrpc_writable(sk)) {
		if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
			wake_up_interruptible(sk->sk_sleep);
		sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
	}
	read_unlock(&sk->sk_callback_lock);
}

/*
 * validate an RxRPC address
 */
static int rxrpc_validate_address(struct rxrpc_sock *rx,
				  struct sockaddr_rxrpc *srx,
				  int len)
{
	if (len < sizeof(struct sockaddr_rxrpc))
		return -EINVAL;

	if (srx->srx_family != AF_RXRPC)
		return -EAFNOSUPPORT;

	if (srx->transport_type != SOCK_DGRAM)
		return -ESOCKTNOSUPPORT;

	len -= offsetof(struct sockaddr_rxrpc, transport);
	if (srx->transport_len < sizeof(sa_family_t) ||
	    srx->transport_len > len)
		return -EINVAL;

	if (srx->transport.family != rx->proto)
		return -EAFNOSUPPORT;

	switch (srx->transport.family) {
	case AF_INET:
		_debug("INET: %x @ %u.%u.%u.%u",
		       ntohs(srx->transport.sin.sin_port),
		       NIPQUAD(srx->transport.sin.sin_addr));
		if (srx->transport_len > 8)
			memset((void *)&srx->transport + 8, 0,
			       srx->transport_len - 8);
		break;

	case AF_INET6:
	default:
		return -EAFNOSUPPORT;
	}

	return 0;
}

/*
 * bind a local address to an RxRPC socket
 */
static int rxrpc_bind(struct socket *sock, struct sockaddr *saddr, int len)
{
	struct sockaddr_rxrpc *srx = (struct sockaddr_rxrpc *) saddr;
	struct sock *sk = sock->sk;
	struct rxrpc_local *local;
	struct rxrpc_sock *rx = rxrpc_sk(sk), *prx;
	__be16 service_id;
	int ret;

	_enter("%p,%p,%d", rx, saddr, len);

	ret = rxrpc_validate_address(rx, srx, len);
	if (ret < 0)
		goto error;

	lock_sock(&rx->sk);

	if (rx->sk.sk_state != RXRPC_UNCONNECTED) {
		ret = -EINVAL;
		goto error_unlock;
	}

	memcpy(&rx->srx, srx, sizeof(rx->srx));

	/* find a local transport endpoint if we don't have one already */
	local = rxrpc_lookup_local(&rx->srx);
	if (IS_ERR(local)) {
		ret = PTR_ERR(local);
		goto error_unlock;
	}

	rx->local = local;
	if (srx->srx_service) {
		service_id = htons(srx->srx_service);
		write_lock_bh(&local->services_lock);
		list_for_each_entry(prx, &local->services, listen_link) {
			if (prx->service_id == service_id)
				goto service_in_use;
		}

		rx->service_id = service_id;
		list_add_tail(&rx->listen_link, &local->services);
		write_unlock_bh(&local->services_lock);

		rx->sk.sk_state = RXRPC_SERVER_BOUND;
	} else {
		rx->sk.sk_state = RXRPC_CLIENT_BOUND;
	}

	release_sock(&rx->sk);
	_leave(" = 0");
	return 0;

service_in_use:
	ret = -EADDRINUSE;
	write_unlock_bh(&local->services_lock);
error_unlock:
	release_sock(&rx->sk);
error:
	_leave(" = %d", ret);
	return ret;