af_econet.c

linux 内核源代码

out_unlock:
	mutex_unlock(&econet_mutex);
	return 0;
}

static struct proto econet_proto = {
	.name	  = "ECONET",
	.owner	  = THIS_MODULE,
	.obj_size = sizeof(struct econet_sock),
};

/*
 *	Create an Econet socket
 */

static int econet_create(struct net *net, struct socket *sock, int protocol)
{
	struct sock *sk;
	struct econet_sock *eo;
	int err;

	if (net != &init_net)
		return -EAFNOSUPPORT;

	/* Econet only provides datagram services. */
	if (sock->type != SOCK_DGRAM)
		return -ESOCKTNOSUPPORT;

	sock->state = SS_UNCONNECTED;

	err = -ENOBUFS;
	sk = sk_alloc(net, PF_ECONET, GFP_KERNEL, &econet_proto);
	if (sk == NULL)
		goto out;

	sk->sk_reuse = 1;
	sock->ops = &econet_ops;
	sock_init_data(sock, sk);

	eo = ec_sk(sk);
	sock_reset_flag(sk, SOCK_ZAPPED);
	sk->sk_family = PF_ECONET;
	eo->num = protocol;

	econet_insert_socket(&econet_sklist, sk);
	return(0);
out:
	return err;
}

/*
 *	Handle Econet specific ioctls
 */

static int ec_dev_ioctl(struct socket *sock, unsigned int cmd, void __user *arg)
{
	struct ifreq ifr;
	struct ec_device *edev;
	struct net_device *dev;
	struct sockaddr_ec *sec;
	int err;

	/*
	 *	Fetch the caller's info block into kernel space
	 */

	if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
		return -EFAULT;

	if ((dev = dev_get_by_name(&init_net, ifr.ifr_name)) == NULL)
		return -ENODEV;

	sec = (struct sockaddr_ec *)&ifr.ifr_addr;

	mutex_lock(&econet_mutex);

	err = 0;
	switch (cmd) {
	case SIOCSIFADDR:
		edev = dev->ec_ptr;
		if (edev == NULL) {
			/* Magic up a new one. */
			edev = kzalloc(sizeof(struct ec_device), GFP_KERNEL);
			if (edev == NULL) {
				err = -ENOMEM;
				break;
			}
			dev->ec_ptr = edev;
		} else
			net2dev_map[edev->net] = NULL;
		edev->station = sec->addr.station;
		edev->net = sec->addr.net;
		net2dev_map[sec->addr.net] = dev;
		if (!net2dev_map[0])
			net2dev_map[0] = dev;
		break;

	case SIOCGIFADDR:
		edev = dev->ec_ptr;
		if (edev == NULL) {
			err = -ENODEV;
			break;
		}
		memset(sec, 0, sizeof(struct sockaddr_ec));
		sec->addr.station = edev->station;
		sec->addr.net = edev->net;
		sec->sec_family = AF_ECONET;
		dev_put(dev);
		if (copy_to_user(arg, &ifr, sizeof(struct ifreq)))
			err = -EFAULT;
		break;

	default:
		err = -EINVAL;
		break;
	}

	mutex_unlock(&econet_mutex);

	dev_put(dev);

	return err;
}

/*
 *	Handle generic ioctls
 */

static int econet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
{
	struct sock *sk = sock->sk;
	void __user *argp = (void __user *)arg;

	switch(cmd) {
		case SIOCGSTAMP:
			return sock_get_timestamp(sk, argp);

		case SIOCGSTAMPNS:
			return sock_get_timestampns(sk, argp);

		case SIOCSIFADDR:
		case SIOCGIFADDR:
			return ec_dev_ioctl(sock, cmd, argp);
			break;

		default:
			return -ENOIOCTLCMD;
	}
	/*NOTREACHED*/
	return 0;
}

static struct net_proto_family econet_family_ops = {
	.family =	PF_ECONET,
	.create =	econet_create,
	.owner	=	THIS_MODULE,
};

static const struct proto_ops econet_ops = {
	.family =	PF_ECONET,
	.owner =	THIS_MODULE,
	.release =	econet_release,
	.bind =		econet_bind,
	.connect =	sock_no_connect,
	.socketpair =	sock_no_socketpair,
	.accept =	sock_no_accept,
	.getname =	econet_getname,
	.poll =		datagram_poll,
	.ioctl =	econet_ioctl,
	.listen =	sock_no_listen,
	.shutdown =	sock_no_shutdown,
	.setsockopt =	sock_no_setsockopt,
	.getsockopt =	sock_no_getsockopt,
	.sendmsg =	econet_sendmsg,
	.recvmsg =	econet_recvmsg,
	.mmap =		sock_no_mmap,
	.sendpage =	sock_no_sendpage,
};

#if defined(CONFIG_ECONET_AUNUDP) || defined(CONFIG_ECONET_NATIVE)
/*
 *	Find the listening socket, if any, for the given data.
 */

static struct sock *ec_listening_socket(unsigned char port, unsigned char
				 station, unsigned char net)
{
	struct sock *sk;
	struct hlist_node *node;

	sk_for_each(sk, node, &econet_sklist) {
		struct econet_sock *opt = ec_sk(sk);
		if ((opt->port == port || opt->port == 0) &&
		    (opt->station == station || opt->station == 0) &&
		    (opt->net == net || opt->net == 0))
			goto found;
	}
	sk = NULL;
found:
	return sk;
}

/*
 *	Queue a received packet for a socket.
 */

static int ec_queue_packet(struct sock *sk, struct sk_buff *skb,
			   unsigned char stn, unsigned char net,
			   unsigned char cb, unsigned char port)
{
	struct ec_cb *eb = (struct ec_cb *)&skb->cb;
	struct sockaddr_ec *sec = (struct sockaddr_ec *)&eb->sec;

	memset(sec, 0, sizeof(struct sockaddr_ec));
	sec->sec_family = AF_ECONET;
	sec->type = ECTYPE_PACKET_RECEIVED;
	sec->port = port;
	sec->cb = cb;
	sec->addr.net = net;
	sec->addr.station = stn;

	return sock_queue_rcv_skb(sk, skb);
}
#endif

#ifdef CONFIG_ECONET_AUNUDP
/*
 *	Send an AUN protocol response.
 */

static void aun_send_response(__u32 addr, unsigned long seq, int code, int cb)
{
	struct sockaddr_in sin = {
		.sin_family = AF_INET,
		.sin_port = htons(AUN_PORT),
		.sin_addr = {.s_addr = addr}
	};
	struct aunhdr ah = {.code = code, .cb = cb, .handle = seq};
	struct kvec iov = {.iov_base = (void *)&ah, .iov_len = sizeof(ah)};
	struct msghdr udpmsg;

	udpmsg.msg_name = (void *)&sin;
	udpmsg.msg_namelen = sizeof(sin);
	udpmsg.msg_control = NULL;
	udpmsg.msg_controllen = 0;
	udpmsg.msg_flags=0;

	kernel_sendmsg(udpsock, &udpmsg, &iov, 1, sizeof(ah));
}


/*
 *	Handle incoming AUN packets.  Work out if anybody wants them,
 *	and send positive or negative acknowledgements as appropriate.
 */

static void aun_incoming(struct sk_buff *skb, struct aunhdr *ah, size_t len)
{
	struct iphdr *ip = ip_hdr(skb);
	unsigned char stn = ntohl(ip->saddr) & 0xff;
	struct sock *sk;
	struct sk_buff *newskb;
	struct ec_device *edev = skb->dev->ec_ptr;

	if (! edev)
		goto bad;

	if ((sk = ec_listening_socket(ah->port, stn, edev->net)) == NULL)
		goto bad;		/* Nobody wants it */

	newskb = alloc_skb((len - sizeof(struct aunhdr) + 15) & ~15,
			   GFP_ATOMIC);
	if (newskb == NULL)
	{
		printk(KERN_DEBUG "AUN: memory squeeze, dropping packet.\n");
		/* Send nack and hope sender tries again */
		goto bad;
	}

	memcpy(skb_put(newskb, len - sizeof(struct aunhdr)), (void *)(ah+1),
	       len - sizeof(struct aunhdr));

	if (ec_queue_packet(sk, newskb, stn, edev->net, ah->cb, ah->port))
	{
		/* Socket is bankrupt. */
		kfree_skb(newskb);
		goto bad;
	}

	aun_send_response(ip->saddr, ah->handle, 3, 0);
	return;

bad:
	aun_send_response(ip->saddr, ah->handle, 4, 0);
}

/*
 *	Handle incoming AUN transmit acknowledgements.  If the sequence
 *      number matches something in our backlog then kill it and tell
 *	the user.  If the remote took too long to reply then we may have
 *	dropped the packet already.
 */

static void aun_tx_ack(unsigned long seq, int result)
{
	struct sk_buff *skb;
	unsigned long flags;
	struct ec_cb *eb;

	spin_lock_irqsave(&aun_queue_lock, flags);
	skb = skb_peek(&aun_queue);
	while (skb && skb != (struct sk_buff *)&aun_queue)
	{
		struct sk_buff *newskb = skb->next;
		eb = (struct ec_cb *)&skb->cb;
		if (eb->seq == seq)
			goto foundit;

		skb = newskb;
	}
	spin_unlock_irqrestore(&aun_queue_lock, flags);
	printk(KERN_DEBUG "AUN: unknown sequence %ld\n", seq);
	return;

foundit:
	tx_result(skb->sk, eb->cookie, result);
	skb_unlink(skb, &aun_queue);
	spin_unlock_irqrestore(&aun_queue_lock, flags);
	kfree_skb(skb);
}

/*
 *	Deal with received AUN frames - sort out what type of thing it is
 *	and hand it to the right function.
 */

static void aun_data_available(struct sock *sk, int slen)
{
	int err;
	struct sk_buff *skb;
	unsigned char *data;
	struct aunhdr *ah;
	struct iphdr *ip;
	size_t len;

	while ((skb = skb_recv_datagram(sk, 0, 1, &err)) == NULL) {
		if (err == -EAGAIN) {
			printk(KERN_ERR "AUN: no data available?!");
			return;
		}
		printk(KERN_DEBUG "AUN: recvfrom() error %d\n", -err);
	}

	data = skb_transport_header(skb) + sizeof(struct udphdr);
	ah = (struct aunhdr *)data;
	len = skb->len - sizeof(struct udphdr);
	ip = ip_hdr(skb);

	switch (ah->code)
	{
	case 2:
		aun_incoming(skb, ah, len);
		break;
	case 3:
		aun_tx_ack(ah->handle, ECTYPE_TRANSMIT_OK);
		break;
	case 4:
		aun_tx_ack(ah->handle, ECTYPE_TRANSMIT_NOT_LISTENING);
		break;
#if 0
		/* This isn't quite right yet. */
	case 5:
		aun_send_response(ip->saddr, ah->handle, 6, ah->cb);
		break;
#endif
	default:
		printk(KERN_DEBUG "unknown AUN packet (type %d)\n", data[0]);
	}

	skb_free_datagram(sk, skb);
}

/*
 *	Called by the timer to manage the AUN transmit queue.  If a packet
 *	was sent to a dead or nonexistent host then we will never get an
 *	acknowledgement back.  After a few seconds we need to spot this and
 *	drop the packet.
 */

static void ab_cleanup(unsigned long h)
{
	struct sk_buff *skb;
	unsigned long flags;

	spin_lock_irqsave(&aun_queue_lock, flags);
	skb = skb_peek(&aun_queue);
	while (skb && skb != (struct sk_buff *)&aun_queue)
	{
		struct sk_buff *newskb = skb->next;
		struct ec_cb *eb = (struct ec_cb *)&skb->cb;
		if ((jiffies - eb->start) > eb->timeout)
		{
			tx_result(skb->sk, eb->cookie,
				  ECTYPE_TRANSMIT_NOT_PRESENT);
			skb_unlink(skb, &aun_queue);
			kfree_skb(skb);
		}
		skb = newskb;
	}
	spin_unlock_irqrestore(&aun_queue_lock, flags);

	mod_timer(&ab_cleanup_timer, jiffies + (HZ*2));
}

static int __init aun_udp_initialise(void)
{
	int error;
	struct sockaddr_in sin;

	skb_queue_head_init(&aun_queue);
	spin_lock_init(&aun_queue_lock);
	init_timer(&ab_cleanup_timer);
	ab_cleanup_timer.expires = jiffies + (HZ*2);
	ab_cleanup_timer.function = ab_cleanup;
	add_timer(&ab_cleanup_timer);

	memset(&sin, 0, sizeof(sin));
	sin.sin_port = htons(AUN_PORT);

	/* We can count ourselves lucky Acorn machines are too dim to
	   speak IPv6. :-) */
	if ((error = sock_create_kern(PF_INET, SOCK_DGRAM, 0, &udpsock)) < 0)
	{
		printk("AUN: socket error %d\n", -error);
		return error;
	}

	udpsock->sk->sk_reuse = 1;
	udpsock->sk->sk_allocation = GFP_ATOMIC; /* we're going to call it
						    from interrupts */

	error = udpsock->ops->bind(udpsock, (struct sockaddr *)&sin,
				sizeof(sin));
	if (error < 0)
	{
		printk("AUN: bind error %d\n", -error);
		goto release;
	}

	udpsock->sk->sk_data_ready = aun_data_available;

	return 0;

release:
	sock_release(udpsock);
	udpsock = NULL;
	return error;
}
#endif

#ifdef CONFIG_ECONET_NATIVE

/*
 *	Receive an Econet frame from a device.
 */

static int econet_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
{
	struct ec_framehdr *hdr;
	struct sock *sk;
	struct ec_device *edev = dev->ec_ptr;

	if (dev->nd_net != &init_net)
		goto drop;

	if (skb->pkt_type == PACKET_OTHERHOST)
		goto drop;

	if (!edev)
		goto drop;

	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
		return NET_RX_DROP;

	if (!pskb_may_pull(skb, sizeof(struct ec_framehdr)))
		goto drop;

	hdr = (struct ec_framehdr *) skb->data;

	/* First check for encapsulated IP */
	if (hdr->port == EC_PORT_IP) {
		skb->protocol = htons(ETH_P_IP);
		skb_pull(skb, sizeof(struct ec_framehdr));
		netif_rx(skb);
		return 0;
	}

	sk = ec_listening_socket(hdr->port, hdr->src_stn, hdr->src_net);
	if (!sk)
		goto drop;

	if (ec_queue_packet(sk, skb, edev->net, hdr->src_stn, hdr->cb,
			    hdr->port))
		goto drop;

	return 0;

drop:
	kfree_skb(skb);
	return NET_RX_DROP;
}

static struct packet_type econet_packet_type = {
	.type =		__constant_htons(ETH_P_ECONET),
	.func =		econet_rcv,
};

static void econet_hw_initialise(void)
{
	dev_add_pack(&econet_packet_type);
}

#endif

static int econet_notifier(struct notifier_block *this, unsigned long msg, void *data)
{
	struct net_device *dev = (struct net_device *)data;
	struct ec_device *edev;

	if (dev->nd_net != &init_net)
		return NOTIFY_DONE;

	switch (msg) {
	case NETDEV_UNREGISTER:
		/* A device has gone down - kill any data we hold for it. */
		edev = dev->ec_ptr;
		if (edev)
		{
			if (net2dev_map[0] == dev)
				net2dev_map[0] = NULL;
			net2dev_map[edev->net] = NULL;
			kfree(edev);
			dev->ec_ptr = NULL;
		}
		break;
	}

	return NOTIFY_DONE;
}

static struct notifier_block econet_netdev_notifier = {
	.notifier_call =econet_notifier,
};

static void __exit econet_proto_exit(void)
{
#ifdef CONFIG_ECONET_AUNUDP
	del_timer(&ab_cleanup_timer);
	if (udpsock)
		sock_release(udpsock);
#endif
	unregister_netdevice_notifier(&econet_netdev_notifier);
#ifdef CONFIG_ECONET_NATIVE
	dev_remove_pack(&econet_packet_type);
#endif
	sock_unregister(econet_family_ops.family);
	proto_unregister(&econet_proto);
}

static int __init econet_proto_init(void)
{
	int err = proto_register(&econet_proto, 0);

	if (err != 0)
		goto out;
	sock_register(&econet_family_ops);
#ifdef CONFIG_ECONET_AUNUDP
	spin_lock_init(&aun_queue_lock);
	aun_udp_initialise();
#endif
#ifdef CONFIG_ECONET_NATIVE
	econet_hw_initialise();
#endif
	register_netdevice_notifier(&econet_netdev_notifier);
out:
	return err;
}

module_init(econet_proto_init);
module_exit(econet_proto_exit);

MODULE_LICENSE("GPL");
MODULE_ALIAS_NETPROTO(PF_ECONET);