af_x25.c

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	 */
	SOCK_DEBUG(sk, "x25_sendmsg: Copying user data\n");

	asmptr = skb->h.raw = skb_put(skb, len);

	memcpy_fromiovec(asmptr, msg->msg_iov, len);

	/*
	 *	If the Q BIT Include socket option is in force, the first
	 *	byte of the user data is the logical value of the Q Bit.
	 */
	if (sk->protinfo.x25->qbitincl) {
		qbit = skb->data[0];
		skb_pull(skb, 1);
	}

	/*
	 *	Push down the X.25 header
	 */
	SOCK_DEBUG(sk, "x25_sendmsg: Building X.25 Header.\n");

	if (msg->msg_flags & MSG_OOB) {
		if (sk->protinfo.x25->neighbour->extended) {
			asmptr    = skb_push(skb, X25_STD_MIN_LEN);
			*asmptr++ = ((sk->protinfo.x25->lci >> 8) & 0x0F) | X25_GFI_EXTSEQ;
			*asmptr++ = (sk->protinfo.x25->lci >> 0) & 0xFF;
			*asmptr++ = X25_INTERRUPT;
		} else {
			asmptr    = skb_push(skb, X25_STD_MIN_LEN);
			*asmptr++ = ((sk->protinfo.x25->lci >> 8) & 0x0F) | X25_GFI_STDSEQ;
			*asmptr++ = (sk->protinfo.x25->lci >> 0) & 0xFF;
			*asmptr++ = X25_INTERRUPT;
		}
	} else {
		if (sk->protinfo.x25->neighbour->extended) {
			/* Build an Extended X.25 header */
			asmptr    = skb_push(skb, X25_EXT_MIN_LEN);
			*asmptr++ = ((sk->protinfo.x25->lci >> 8) & 0x0F) | X25_GFI_EXTSEQ;
			*asmptr++ = (sk->protinfo.x25->lci >> 0) & 0xFF;
			*asmptr++ = X25_DATA;
			*asmptr++ = X25_DATA;
		} else {
			/* Build an Standard X.25 header */
			asmptr    = skb_push(skb, X25_STD_MIN_LEN);
			*asmptr++ = ((sk->protinfo.x25->lci >> 8) & 0x0F) | X25_GFI_STDSEQ;
			*asmptr++ = (sk->protinfo.x25->lci >> 0) & 0xFF;
			*asmptr++ = X25_DATA;
		}

		if (qbit)
			skb->data[0] |= X25_Q_BIT;
	}

	SOCK_DEBUG(sk, "x25_sendmsg: Built header.\n");
	SOCK_DEBUG(sk, "x25_sendmsg: Transmitting buffer\n");

	if (sk->state != TCP_ESTABLISHED) {
		kfree_skb(skb);
		return -ENOTCONN;
	}

	if (msg->msg_flags & MSG_OOB) {
		skb_queue_tail(&sk->protinfo.x25->interrupt_out_queue, skb);
	} else {
	        len = x25_output(sk, skb);
		if(len<0){
			kfree_skb(skb);
		} else {
			if(sk->protinfo.x25->qbitincl) len++;
		}
	}

	/*
	 * lock_sock() is currently only used to serialize this x25_kick()
	 * against input-driven x25_kick() calls. It currently only blocks
	 * incoming packets for this socket and does not protect against
	 * any other socket state changes and is not called from anywhere
	 * else. As x25_kick() cannot block and as long as all socket
	 * operations are BKL-wrapped, we don't need take to care about
	 * purging the backlog queue in x25_release().
	 *
	 * Using lock_sock() to protect all socket operations entirely
	 * (and making the whole x25 stack SMP aware) unfortunately would
	 * require major changes to {send,recv}msg and skb allocation methods.
	 * -> 2.5 ;)
	 */
	lock_sock(sk);
	x25_kick(sk);
	release_sock(sk);

	return len;
}


static int x25_recvmsg(struct socket *sock, struct msghdr *msg, int size, int flags, struct scm_cookie *scm)
{
	struct sock *sk = sock->sk;
	struct sockaddr_x25 *sx25 = (struct sockaddr_x25 *)msg->msg_name;
	int copied, qbit;
	struct sk_buff *skb;
	unsigned char *asmptr;
	int er;

	/*
	 * This works for seqpacket too. The receiver has ordered the queue for
	 * us! We do one quick check first though
	 */
	if (sk->state != TCP_ESTABLISHED)
		return -ENOTCONN;

	if (flags & MSG_OOB) {
		if (sk->urginline || skb_peek(&sk->protinfo.x25->interrupt_in_queue) == NULL)
			return -EINVAL;

		skb = skb_dequeue(&sk->protinfo.x25->interrupt_in_queue);

		skb_pull(skb, X25_STD_MIN_LEN);

		/*
		 *	No Q bit information on Interrupt data.
		 */
		if (sk->protinfo.x25->qbitincl) {
			asmptr  = skb_push(skb, 1);
			*asmptr = 0x00;
		}

		msg->msg_flags |= MSG_OOB;
	} else {
		/* Now we can treat all alike */
		if ((skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT, flags & MSG_DONTWAIT, &er)) == NULL)
			return er;

		qbit = (skb->data[0] & X25_Q_BIT) == X25_Q_BIT;

		skb_pull(skb, (sk->protinfo.x25->neighbour->extended) ? X25_EXT_MIN_LEN : X25_STD_MIN_LEN);

		if (sk->protinfo.x25->qbitincl) {
			asmptr  = skb_push(skb, 1);
			*asmptr = qbit;
		}
	}

	skb->h.raw = skb->data;

	copied = skb->len;

	if (copied > size) {
		copied = size;
		msg->msg_flags |= MSG_TRUNC;
	}

	/* Currently, each datagram always contains a complete record */ 
	msg->msg_flags |= MSG_EOR;

	skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);

	if (sx25 != NULL) {
		sx25->sx25_family = AF_X25;
		sx25->sx25_addr   = sk->protinfo.x25->dest_addr;
	}

	msg->msg_namelen = sizeof(struct sockaddr_x25);

	skb_free_datagram(sk, skb);

	return copied;
}


static int x25_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
{
	struct sock *sk = sock->sk;

	switch (cmd) {
		case TIOCOUTQ: {
			int amount;
			amount = sk->sndbuf - atomic_read(&sk->wmem_alloc);
			if (amount < 0)
				amount = 0;
			return put_user(amount, (unsigned int *)arg);
		}

		case TIOCINQ: {
			struct sk_buff *skb;
			int amount = 0;
			/* These two are safe on a single CPU system as only user tasks fiddle here */
			if ((skb = skb_peek(&sk->receive_queue)) != NULL)
				amount = skb->len;
			return put_user(amount, (unsigned int *)arg);
		}

		case SIOCGSTAMP:
			if (sk != NULL) {
				if (sk->stamp.tv_sec == 0)
					return -ENOENT;
				return copy_to_user((void *)arg, &sk->stamp, sizeof(struct timeval)) ? -EFAULT : 0;
			}
			return -EINVAL;

		case SIOCGIFADDR:
		case SIOCSIFADDR:
		case SIOCGIFDSTADDR:
		case SIOCSIFDSTADDR:
		case SIOCGIFBRDADDR:
		case SIOCSIFBRDADDR:
		case SIOCGIFNETMASK:
		case SIOCSIFNETMASK:
		case SIOCGIFMETRIC:
		case SIOCSIFMETRIC:
			return -EINVAL;

		case SIOCADDRT:
		case SIOCDELRT:
			if (!capable(CAP_NET_ADMIN)) return -EPERM;
			return x25_route_ioctl(cmd, (void *)arg);

		case SIOCX25GSUBSCRIP:
			return x25_subscr_ioctl(cmd, (void *)arg);

		case SIOCX25SSUBSCRIP:
			if (!capable(CAP_NET_ADMIN)) return -EPERM;
			return x25_subscr_ioctl(cmd, (void *)arg);

		case SIOCX25GFACILITIES: {
			struct x25_facilities facilities;
			facilities = sk->protinfo.x25->facilities;
			return copy_to_user((void *)arg, &facilities, sizeof(facilities)) ? -EFAULT : 0;
		}

		case SIOCX25SFACILITIES: {
			struct x25_facilities facilities;
			if (copy_from_user(&facilities, (void *)arg, sizeof(facilities)))
				return -EFAULT;
			if (sk->state != TCP_LISTEN && sk->state != TCP_CLOSE)
				return -EINVAL;
			if (facilities.pacsize_in < X25_PS16 || facilities.pacsize_in > X25_PS4096)
				return -EINVAL;
			if (facilities.pacsize_out < X25_PS16 || facilities.pacsize_out > X25_PS4096)
				return -EINVAL;
			if (facilities.winsize_in < 1 || facilities.winsize_in > 127)
				return -EINVAL;
			if (facilities.throughput < 0x03 || facilities.throughput > 0xDD)
				return -EINVAL;
			if (facilities.reverse != 0 && facilities.reverse != 1)
				return -EINVAL;
			sk->protinfo.x25->facilities = facilities;
			return 0;
		}

		case SIOCX25GCALLUSERDATA: {
			struct x25_calluserdata calluserdata;
			calluserdata = sk->protinfo.x25->calluserdata;
			return copy_to_user((void *)arg, &calluserdata, sizeof(calluserdata)) ? -EFAULT : 0;
		}

		case SIOCX25SCALLUSERDATA: {
			struct x25_calluserdata calluserdata;
			if (copy_from_user(&calluserdata, (void *)arg, sizeof(calluserdata)))
				return -EFAULT;
			if (calluserdata.cudlength > X25_MAX_CUD_LEN)
				return -EINVAL;
			sk->protinfo.x25->calluserdata = calluserdata;
			return 0;
		}

		case SIOCX25GCAUSEDIAG: {
			struct x25_causediag causediag;
			causediag = sk->protinfo.x25->causediag;
			return copy_to_user((void *)arg, &causediag, sizeof(causediag)) ? -EFAULT : 0;
		}

 		default:
			return dev_ioctl(cmd, (void *)arg);
	}

	/*NOTREACHED*/
	return 0;
}

static int x25_get_info(char *buffer, char **start, off_t offset, int length)
{
	struct sock *s;
	struct net_device *dev;
	const char *devname;
	int len = 0;
	off_t pos = 0;
	off_t begin = 0;

	cli();

	len += sprintf(buffer, "dest_addr  src_addr   dev   lci st vs vr va   t  t2 t21 t22 t23 Snd-Q Rcv-Q inode\n");

	for (s = x25_list; s != NULL; s = s->next) {
		if (s->protinfo.x25->neighbour == NULL || (dev = s->protinfo.x25->neighbour->dev) == NULL)
			devname = "???";
		else
			devname = s->protinfo.x25->neighbour->dev->name;

		len += sprintf(buffer + len, "%-10s %-10s %-5s %3.3X  %d  %d  %d  %d %3lu %3lu %3lu %3lu %3lu %5d %5d %ld\n",
			(s->protinfo.x25->dest_addr.x25_addr[0] == '\0')   ? "*" : s->protinfo.x25->dest_addr.x25_addr,
			(s->protinfo.x25->source_addr.x25_addr[0] == '\0') ? "*" : s->protinfo.x25->source_addr.x25_addr,
			devname, 
			s->protinfo.x25->lci & 0x0FFF,
			s->protinfo.x25->state,
			s->protinfo.x25->vs,
			s->protinfo.x25->vr,
			s->protinfo.x25->va,
			x25_display_timer(s) / HZ,
			s->protinfo.x25->t2  / HZ,
			s->protinfo.x25->t21 / HZ,
			s->protinfo.x25->t22 / HZ,
			s->protinfo.x25->t23 / HZ,
			atomic_read(&s->wmem_alloc),
			atomic_read(&s->rmem_alloc),
			s->socket != NULL ? s->socket->inode->i_ino : 0L);

		pos = begin + len;

		if (pos < offset) {
			len   = 0;
			begin = pos;
		}

		if (pos > offset + length)
			break;
	}

	sti();

	*start = buffer + (offset - begin);
	len   -= (offset - begin);

	if (len > length) len = length;

	return(len);
} 

struct net_proto_family x25_family_ops = {
	AF_X25,
	x25_create
};

static struct proto_ops SOCKOPS_WRAPPED(x25_proto_ops) = {
	family:		AF_X25,

	release:	x25_release,
	bind:		x25_bind,
	connect:	x25_connect,
	socketpair:	sock_no_socketpair,
	accept:		x25_accept,
	getname:	x25_getname,
	poll:		datagram_poll,
	ioctl:		x25_ioctl,
	listen:		x25_listen,
	shutdown:	sock_no_shutdown,
	setsockopt:	x25_setsockopt,
	getsockopt:	x25_getsockopt,
	sendmsg:	x25_sendmsg,
	recvmsg:	x25_recvmsg,
	mmap:		sock_no_mmap,
};

#include <linux/smp_lock.h>
SOCKOPS_WRAP(x25_proto, AF_X25);


static struct packet_type x25_packet_type =
{
	0,		/* MUTTER ntohs(ETH_P_X25),*/
	0,		/* copy */
	x25_lapb_receive_frame,
	NULL,
	NULL,
};

struct notifier_block x25_dev_notifier = {
	x25_device_event,
	0
};

void x25_kill_by_neigh(struct x25_neigh *neigh)
{
	struct sock *s;

	for( s=x25_list; s != NULL; s=s->next){
		if( s->protinfo.x25->neighbour == neigh )
			x25_disconnect(s, ENETUNREACH, 0, 0);
	} 
}

static int __init x25_init(void)
{
#ifdef MODULE
	struct net_device *dev;
#endif /* MODULE */
	sock_register(&x25_family_ops);

	x25_packet_type.type = htons(ETH_P_X25);
	dev_add_pack(&x25_packet_type);

	register_netdevice_notifier(&x25_dev_notifier);

	printk(KERN_INFO "X.25 for Linux. Version 0.2 for Linux 2.1.15\n");

#ifdef CONFIG_SYSCTL
	x25_register_sysctl();
#endif

	proc_net_create("x25", 0, x25_get_info);
	proc_net_create("x25_routes", 0, x25_routes_get_info);

#ifdef MODULE
	/*
	 *	Register any pre existing devices.
	 */
	read_lock(&dev_base_lock);
	for (dev = dev_base; dev != NULL; dev = dev->next) {
		if ((dev->flags & IFF_UP) && (dev->type == ARPHRD_X25
#if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE)
					   || dev->type == ARPHRD_ETHER
#endif
			))
			x25_link_device_up(dev);
	}
	read_unlock(&dev_base_lock);
#endif /* MODULE */
	return 0;
}
module_init(x25_init);



EXPORT_NO_SYMBOLS;

MODULE_AUTHOR("Jonathan Naylor <[e-mail]>");
MODULE_DESCRIPTION("The X.25 Packet Layer network layer protocol");

static void __exit x25_exit(void)
{

	proc_net_remove("x25");
	proc_net_remove("x25_routes");

	x25_link_free();
	x25_route_free();

#ifdef CONFIG_SYSCTL
	x25_unregister_sysctl();
#endif

	unregister_netdevice_notifier(&x25_dev_notifier);

	dev_remove_pack(&x25_packet_type);

	sock_unregister(AF_X25);
}
module_exit(x25_exit);