af_ax25.c

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				return -EINVAL;

			dtmp.ndigi      = usax->sax25_ndigis;

			while (ct < usax->sax25_ndigis) {
				dtmp.repeated[ct] = 0;
				dtmp.calls[ct]    = fsa->fsa_digipeater[ct];
				ct++;
			}

			dtmp.lastrepeat = 0;
		}

		sax = *usax;
		if (sk->type == SOCK_SEQPACKET && ax25cmp(&sk->protinfo.ax25->dest_addr, &sax.sax25_call) != 0)
			return -EISCONN;
		if (usax->sax25_ndigis == 0)
			dp = NULL;
		else
			dp = &dtmp;
	} else {
		/*
		 *	FIXME: 1003.1g - if the socket is like this because
		 *	it has become closed (not started closed) and is VC
		 *	we ought to SIGPIPE, EPIPE
		 */
		if (sk->state != TCP_ESTABLISHED)
			return -ENOTCONN;
		sax.sax25_family = AF_AX25;
		sax.sax25_call   = sk->protinfo.ax25->dest_addr;
		dp = sk->protinfo.ax25->digipeat;
	}

	SOCK_DEBUG(sk, "AX.25: sendto: Addresses built.\n");

	/* Build a packet */
	SOCK_DEBUG(sk, "AX.25: sendto: building packet.\n");

	/* Assume the worst case */
	size = len + 3 + ax25_addr_size(dp) + AX25_BPQ_HEADER_LEN;

	if ((skb = sock_alloc_send_skb(sk, size, msg->msg_flags & MSG_DONTWAIT, &err)) == NULL)
		return err;

	skb_reserve(skb, size - len);

	SOCK_DEBUG(sk, "AX.25: Appending user data\n");

	/* User data follows immediately after the AX.25 data */
	memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
	skb->nh.raw = skb->data;

	/* Add the PID if one is not supplied by the user in the skb */
	if (!sk->protinfo.ax25->pidincl) {
		asmptr  = skb_push(skb, 1);
		*asmptr = sk->protocol;
	}

	SOCK_DEBUG(sk, "AX.25: Transmitting buffer\n");

	if (sk->type == SOCK_SEQPACKET) {
		/* Connected mode sockets go via the LAPB machine */
		if (sk->state != TCP_ESTABLISHED) {
			kfree_skb(skb);
			return -ENOTCONN;
		}

		ax25_output(sk->protinfo.ax25, sk->protinfo.ax25->paclen, skb);	/* Shove it onto the queue and kick */

		return len;
	} else {
		asmptr = skb_push(skb, 1 + ax25_addr_size(dp));

		SOCK_DEBUG(sk, "Building AX.25 Header (dp=%p).\n", dp);

		if (dp != NULL)
			SOCK_DEBUG(sk, "Num digipeaters=%d\n", dp->ndigi);

		/* Build an AX.25 header */
		asmptr += (lv = ax25_addr_build(asmptr, &sk->protinfo.ax25->source_addr, &sax.sax25_call, dp, AX25_COMMAND, AX25_MODULUS));

		SOCK_DEBUG(sk, "Built header (%d bytes)\n",lv);

		skb->h.raw = asmptr;

		SOCK_DEBUG(sk, "base=%p pos=%p\n", skb->data, asmptr);

		*asmptr = AX25_UI;

		/* Datagram frames go straight out of the door as UI */
		skb->dev      = sk->protinfo.ax25->ax25_dev->dev;

		ax25_queue_xmit(skb);

		return len;
	}
}

static int ax25_recvmsg(struct socket *sock, struct msghdr *msg, int size, int flags, struct scm_cookie *scm)
{
	struct sock *sk = sock->sk;
	int copied;
	struct sk_buff *skb;
	int er;

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

	/* Now we can treat all alike */
	if ((skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT, flags & MSG_DONTWAIT, &er)) == NULL)
		return er;

	if (!sk->protinfo.ax25->pidincl)
		skb_pull(skb, 1);		/* Remove PID */

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

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

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

	if (msg->msg_namelen != 0) {
		struct sockaddr_ax25 *sax = (struct sockaddr_ax25 *)msg->msg_name;
		ax25_digi digi;
		ax25_address dest;

		ax25_addr_parse(skb->mac.raw+1, skb->data-skb->mac.raw-1, NULL, &dest, &digi, NULL, NULL);

		sax->sax25_family = AF_AX25;
		/* We set this correctly, even though we may not let the
		   application know the digi calls further down (because it
		   did NOT ask to know them).  This could get political... **/
		sax->sax25_ndigis = digi.ndigi;
		sax->sax25_call   = dest;

		if (sax->sax25_ndigis != 0) {
			int ct;
			struct full_sockaddr_ax25 *fsa = (struct full_sockaddr_ax25 *)sax;

			for (ct = 0; ct < digi.ndigi; ct++)
				fsa->fsa_digipeater[ct] = digi.calls[ct];
		}
		msg->msg_namelen = sizeof(struct full_sockaddr_ax25);
	}

	skb_free_datagram(sk, skb);

	return copied;
}

static int ax25_shutdown(struct socket *sk, int how)
{
	/* FIXME - generate DM and RNR states */
	return -EOPNOTSUPP;
}

static int ax25_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
{
	struct sock *sk = sock->sk;

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

		case TIOCINQ: {
			struct sk_buff *skb;
			long amount = 0L;
			/* 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, (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 SIOCAX25ADDUID:	/* Add a uid to the uid/call map table */
		case SIOCAX25DELUID:	/* Delete a uid from the uid/call map table */
		case SIOCAX25GETUID: {
			struct sockaddr_ax25 sax25;
			if (copy_from_user(&sax25, (void *)arg, sizeof(sax25)))
				return -EFAULT;
			return ax25_uid_ioctl(cmd, &sax25);
		}

		case SIOCAX25NOUID: {	/* Set the default policy (default/bar) */
			long amount;
			if (!capable(CAP_NET_ADMIN))
				return -EPERM;
			if (get_user(amount, (long *)arg))
				return -EFAULT;
			if (amount > AX25_NOUID_BLOCK)
				return -EINVAL;
			ax25_uid_policy = amount;
			return 0;
		}

		case SIOCADDRT:
		case SIOCDELRT:
		case SIOCAX25OPTRT:
			if (!capable(CAP_NET_ADMIN))
				return -EPERM;
			return ax25_rt_ioctl(cmd, (void *)arg);

		case SIOCAX25CTLCON:
			if (!capable(CAP_NET_ADMIN))
				return -EPERM;
			return ax25_ctl_ioctl(cmd, (void *)arg);

		case SIOCAX25GETINFO: 
		case SIOCAX25GETINFOOLD: {
			struct ax25_info_struct ax25_info;

			ax25_info.t1        = sk->protinfo.ax25->t1   / HZ;
			ax25_info.t2        = sk->protinfo.ax25->t2   / HZ;
			ax25_info.t3        = sk->protinfo.ax25->t3   / HZ;
			ax25_info.idle      = sk->protinfo.ax25->idle / (60 * HZ);
			ax25_info.n2        = sk->protinfo.ax25->n2;
			ax25_info.t1timer   = ax25_display_timer(&sk->protinfo.ax25->t1timer)   / HZ;
			ax25_info.t2timer   = ax25_display_timer(&sk->protinfo.ax25->t2timer)   / HZ;
			ax25_info.t3timer   = ax25_display_timer(&sk->protinfo.ax25->t3timer)   / HZ;
			ax25_info.idletimer = ax25_display_timer(&sk->protinfo.ax25->idletimer) / (60 * HZ);
			ax25_info.n2count   = sk->protinfo.ax25->n2count;
			ax25_info.state     = sk->protinfo.ax25->state;
			ax25_info.rcv_q     = atomic_read(&sk->rmem_alloc);
			ax25_info.snd_q     = atomic_read(&sk->wmem_alloc);
			ax25_info.vs        = sk->protinfo.ax25->vs;
			ax25_info.vr        = sk->protinfo.ax25->vr;
			ax25_info.va        = sk->protinfo.ax25->va;
			ax25_info.vs_max    = sk->protinfo.ax25->vs; /* reserved */
			ax25_info.paclen    = sk->protinfo.ax25->paclen;
			ax25_info.window    = sk->protinfo.ax25->window;

			/* old structure? */
			if (cmd == SIOCAX25GETINFOOLD) {
				static int warned = 0;
				if (!warned) {
					printk(KERN_INFO "%s uses old SIOCAX25GETINFO\n",
						current->comm);
					warned=1;
				}

				if (copy_to_user((void *)arg, &ax25_info, sizeof(struct ax25_info_struct_depreciated)))
					return -EFAULT;
			} else {
				if (copy_to_user((void *)arg, &ax25_info, sizeof(struct ax25_info_struct)))
					return -EINVAL;
			} 
			return 0;
		}

		case SIOCAX25ADDFWD:
		case SIOCAX25DELFWD: {
			struct ax25_fwd_struct ax25_fwd;
			if (!capable(CAP_NET_ADMIN))
				return -EPERM;
			if (copy_from_user(&ax25_fwd, (void *)arg, sizeof(ax25_fwd)))
				return -EFAULT;
			return ax25_fwd_ioctl(cmd, &ax25_fwd);
		}

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

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

	/*NOTREACHED*/
	return 0;
}

static int ax25_get_info(char *buffer, char **start, off_t offset, int length)
{
	ax25_cb *ax25;
	int k;
	int len = 0;
	off_t pos = 0;
	off_t begin = 0;

	cli();

	/*
	 * New format:
	 * magic dev src_addr dest_addr,digi1,digi2,.. st vs vr va t1 t1 t2 t2 t3 t3 idle idle n2 n2 rtt window paclen Snd-Q Rcv-Q inode 
	 */
	
	for (ax25 = ax25_list; ax25 != NULL; ax25 = ax25->next) {
		len += sprintf(buffer+len, "%8.8lx %s %s%s ", 
				(long) ax25, 
				ax25->ax25_dev == NULL? "???" : ax25->ax25_dev->dev->name,
				ax2asc(&ax25->source_addr),
				ax25->iamdigi? "*":"");

		len += sprintf(buffer+len, "%s", ax2asc(&ax25->dest_addr));
				
		for (k=0; (ax25->digipeat != NULL) && (k < ax25->digipeat->ndigi); k++) {
			len += sprintf(buffer+len, ",%s%s",
					ax2asc(&ax25->digipeat->calls[k]),
					ax25->digipeat->repeated[k]? "*":"");
		}
		
		len += sprintf(buffer+len, " %d %d %d %d %lu %lu %lu %lu %lu %lu %lu %lu %d %d %lu %d %d",
			ax25->state,
			ax25->vs, ax25->vr, ax25->va,
			ax25_display_timer(&ax25->t1timer) / HZ, ax25->t1 / HZ,
			ax25_display_timer(&ax25->t2timer) / HZ, ax25->t2 / HZ,
			ax25_display_timer(&ax25->t3timer) / HZ, ax25->t3 / HZ,
			ax25_display_timer(&ax25->idletimer) / (60 * HZ),
			ax25->idle / (60 * HZ),
			ax25->n2count, ax25->n2,
			ax25->rtt / HZ,
			ax25->window,
			ax25->paclen);

		if (ax25->sk != NULL) {
			len += sprintf(buffer + len, " %d %d %ld\n",
				atomic_read(&ax25->sk->wmem_alloc),
				atomic_read(&ax25->sk->rmem_alloc),
				ax25->sk->socket != NULL ? ax25->sk->socket->inode->i_ino : 0L);
		} else {
			len += sprintf(buffer + len, " * * *\n");
		}

		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);
}

static struct net_proto_family ax25_family_ops = {
	family:		PF_AX25,
	create:		ax25_create,
};

static struct proto_ops SOCKOPS_WRAPPED(ax25_proto_ops) = {
	family:		PF_AX25,

	release:	ax25_release,
	bind:		ax25_bind,
	connect:	ax25_connect,
	socketpair:	sock_no_socketpair,
	accept:		ax25_accept,
	getname:	ax25_getname,
	poll:		datagram_poll,
	ioctl:		ax25_ioctl,
	listen:		ax25_listen,
	shutdown:	ax25_shutdown,
	setsockopt:	ax25_setsockopt,
	getsockopt:	ax25_getsockopt,
	sendmsg:	ax25_sendmsg,
	recvmsg:	ax25_recvmsg,
	mmap:		sock_no_mmap,
	sendpage:	sock_no_sendpage,
};

#include <linux/smp_lock.h>
SOCKOPS_WRAP(ax25_proto, PF_AX25);

/*
 *	Called by socket.c on kernel start up
 */
static struct packet_type ax25_packet_type = {
	type:		__constant_htons(ETH_P_AX25),
	func:		ax25_kiss_rcv,
};

static struct notifier_block ax25_dev_notifier = {
	notifier_call:	ax25_device_event,
};

EXPORT_SYMBOL(ax25_encapsulate);
EXPORT_SYMBOL(ax25_rebuild_header);
EXPORT_SYMBOL(ax25_findbyuid);
EXPORT_SYMBOL(ax25_find_cb);
EXPORT_SYMBOL(ax25_linkfail_register);
EXPORT_SYMBOL(ax25_linkfail_release);
EXPORT_SYMBOL(ax25_listen_register);
EXPORT_SYMBOL(ax25_listen_release);
EXPORT_SYMBOL(ax25_protocol_register);
EXPORT_SYMBOL(ax25_protocol_release);
EXPORT_SYMBOL(ax25_send_frame);
EXPORT_SYMBOL(ax25_uid_policy);
EXPORT_SYMBOL(ax25cmp);
EXPORT_SYMBOL(ax2asc);
EXPORT_SYMBOL(asc2ax);
EXPORT_SYMBOL(null_ax25_address);
EXPORT_SYMBOL(ax25_display_timer);

static char banner[] __initdata = KERN_INFO "NET4: G4KLX/GW4PTS AX.25 for Linux. Version 0.37 for Linux NET4.0\n";

static int __init ax25_init(void)
{
	sock_register(&ax25_family_ops);
	dev_add_pack(&ax25_packet_type);
	register_netdevice_notifier(&ax25_dev_notifier);
	ax25_register_sysctl();

	proc_net_create("ax25_route", 0, ax25_rt_get_info);
	proc_net_create("ax25", 0, ax25_get_info);
	proc_net_create("ax25_calls", 0, ax25_uid_get_info);

	printk(banner);
	return 0;
}
module_init(ax25_init);


MODULE_AUTHOR("Jonathan Naylor G4KLX <[e-mail]>");
MODULE_DESCRIPTION("The amateur radio AX.25 link layer protocol");

static void __exit ax25_exit(void)
{
	proc_net_remove("ax25_route");
	proc_net_remove("ax25");
	proc_net_remove("ax25_calls");
	ax25_rt_free();
	ax25_uid_free();
	ax25_dev_free();

	ax25_unregister_sysctl();
	unregister_netdevice_notifier(&ax25_dev_notifier);

	dev_remove_pack(&ax25_packet_type);

	sock_unregister(PF_AX25);
}
module_exit(ax25_exit);