path: root/net/econet/af_econet.c

/*
 *	An implementation of the Acorn Econet and AUN protocols.
 *	Philip Blundell <philb@gnu.org>
 *
 *	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/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/in.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/if_ether.h>
#include <linux/netdevice.h>
#include <linux/inetdevice.h>
#include <linux/route.h>
#include <linux/inet.h>
#include <linux/etherdevice.h>
#include <linux/if_arp.h>
#include <linux/wireless.h>
#include <linux/skbuff.h>
#include <linux/udp.h>
#include <net/sock.h>
#include <net/inet_common.h>
#include <linux/stat.h>
#include <linux/init.h>
#include <linux/if_ec.h>
#include <net/udp.h>
#include <net/ip.h>
#include <linux/spinlock.h>
#include <linux/rcupdate.h>
#include <linux/bitops.h>
#include <linux/mutex.h>

#include <asm/uaccess.h>
#include <asm/system.h>

static const struct proto_ops econet_ops;
static struct hlist_head econet_sklist;
static DEFINE_RWLOCK(econet_lock);
static DEFINE_MUTEX(econet_mutex);

/* Since there are only 256 possible network numbers (or fewer, depends
   how you count) it makes sense to use a simple lookup table. */
static struct net_device *net2dev_map[256];

#define EC_PORT_IP	0xd2

#ifdef CONFIG_ECONET_AUNUDP
static DEFINE_SPINLOCK(aun_queue_lock);
static struct socket *udpsock;
#define AUN_PORT	0x8000


struct aunhdr
{
	unsigned char code;		/* AUN magic protocol byte */
	unsigned char port;
	unsigned char cb;
	unsigned char pad;
	unsigned long handle;
};

static unsigned long aun_seq;

/* Queue of packets waiting to be transmitted. */
static struct sk_buff_head aun_queue;
static struct timer_list ab_cleanup_timer;

#endif		/* CONFIG_ECONET_AUNUDP */

/* Per-packet information */
struct ec_cb
{
	struct sockaddr_ec sec;
	unsigned long cookie;		/* Supplied by user. */
#ifdef CONFIG_ECONET_AUNUDP
	int done;
	unsigned long seq;		/* Sequencing */
	unsigned long timeout;		/* Timeout */
	unsigned long start;		/* jiffies */
#endif
#ifdef CONFIG_ECONET_NATIVE
	void (*sent)(struct sk_buff *, int result);
#endif
};

static void econet_remove_socket(struct hlist_head *list, struct sock *sk)
{
	write_lock_bh(&econet_lock);
	sk_del_node_init(sk);
	write_unlock_bh(&econet_lock);
}

static void econet_insert_socket(struct hlist_head *list, struct sock *sk)
{
	write_lock_bh(&econet_lock);
	sk_add_node(sk, list);
	write_unlock_bh(&econet_lock);
}

/*
 *	Pull a packet from our receive queue and hand it to the user.
 *	If necessary we block.
 */

static int econet_recvmsg(struct kiocb *iocb, struct socket *sock,
			  struct msghdr *msg, size_t len, int flags)
{
	struct sock *sk = sock->sk;
	struct sk_buff *skb;
	size_t copied;
	int err;

	msg->msg_namelen = sizeof(struct sockaddr_ec);

	mutex_lock(&econet_mutex);

	/*
	 *	Call the generic datagram receiver. This handles all sorts
	 *	of horrible races and re-entrancy so we can forget about it
	 *	in the protocol layers.
	 *
	 *	Now it will return ENETDOWN, if device have just gone down,
	 *	but then it will block.
	 */

	skb=skb_recv_datagram(sk,flags,flags&MSG_DONTWAIT,&err);

	/*
	 *	An error occurred so return it. Because skb_recv_datagram()
	 *	handles the blocking we don't see and worry about blocking
	 *	retries.
	 */

	if(skb==NULL)
		goto out;

	/*
	 *	You lose any data beyond the buffer you gave. If it worries a
	 *	user program they can ask the device for its MTU anyway.
	 */

	copied =