[deliverable/linux.git] / net / x25 / x25_dev.c

/*
 *	X.25 Packet Layer release 002
 *
 *	This is ALPHA test software. This code may break your machine, randomly fail to work with new 
 *	releases, misbehave and/or generally screw up. It might even work. 
 *
 *	This code REQUIRES 2.1.15 or higher
 *
 *	This module:
 *		This module 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.
 *
 *	History
 *	X.25 001	Jonathan Naylor	Started coding.
 *      2000-09-04	Henner Eisen	Prevent freeing a dangling skb.
 */

#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <linux/if_arp.h>
#include <net/x25.h>

static int x25_receive_data(struct sk_buff *skb, struct x25_neigh *nb)
{
	struct sock *sk;
	unsigned short frametype;
	unsigned int lci;

	frametype = skb->data[2];
        lci = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF);

	/*
	 *	LCI of zero is always for us, and its always a link control
	 *	frame.
	 */
	if (lci == 0) {
		x25_link_control(skb, nb, frametype);
		return 0;
	}

	/*
	 *	Find an existing socket.
	 */
	if ((sk = x25_find_socket(lci, nb)) != NULL) {
		int queued = 1;

		skb->h.raw = skb->data;
		bh_lock_sock(sk);
		if (!sock_owned_by_user(sk)) {
			queued = x25_process_rx_frame(sk, skb);
		} else {
			sk_add_backlog(sk, skb);
		}
		bh_unlock_sock(sk);
		return queued;
	}

	/*
	 *	Is is a Call Request ? if so process it.
	 */
	if (frametype == X25_CALL_REQUEST)
		return x25_rx_call_request(skb, nb, lci);

	/*
	 *	Its not a Call Request, nor is it a control frame.
	 *      Let caller throw it away.
	 */
/*
	x25_transmit_clear_request(nb, lci, 0x0D);
*/

	if (frametype != X25_CLEAR_CONFIRMATION)
		printk(KERN_DEBUG "x25_receive_data(): unknown frame type %2x\n",frametype);

	return 0;
}

int x25_lapb_receive_frame(struct sk_buff *skb, struct net_device *dev,
			   struct packet_type *ptype, struct net_device *orig_dev)
{
	struct sk_buff *nskb;
	struct x25_neigh *nb;

	nskb = skb_copy(skb, GFP_ATOMIC);
	if (!nskb)
		goto drop;
	kfree_skb(skb);
	skb = nskb;

	/*
	 * Packet received from unrecognised device, throw it away.
	 */
	nb = x25_get_neigh(dev);
	if (!nb) {
		printk(KERN_DEBUG "X.25: unknown neighbour - %s\n", dev->name);
		goto drop;
	}

	switch (skb->data[0]) {
		case 0x00:
			skb_pull(skb, 1);
			if (x25_receive_data(skb, nb)) {
				x25_neigh_put(nb);
				goto out;
			}
			break;
		case 0x01:
			x25_link_established(nb);
			break;
		case 0x02:
			x25_link_terminated(nb);
			break;
	}
	x25_neigh_put(nb);
drop:
	kfree_skb(skb);
out:
	return 0;
}

void x25_establish_link(struct x25_neigh *nb)
{
	struct sk_buff *skb;
	unsigned char *ptr;

	switch (nb->dev->type) {
		case ARPHRD_X25:
			if ((skb = alloc_skb(1, GFP_ATOMIC)) == NULL) {
				printk(KERN_ERR "x25_dev: out of memory\n");
				return;
			}
			ptr  = skb_put(skb, 1);
			*ptr = 0x01;
			break;

#if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE)
		case ARPHRD_ETHER:
			return;
#endif
		default:
			return;
	}

	skb->protocol = htons(ETH_P_X25);
	skb->dev      = nb->dev;

	dev_queue_xmit(skb);
}

void x25_terminate_link(struct x25_neigh *nb)
{
	struct sk_buff *skb;
	unsigned char *ptr;

#if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE)
	if (nb->dev->type == ARPHRD_ETHER)
		return;
#endif
	if (nb->dev->type != ARPHRD_X25)
		return;

	skb = alloc_skb(1, GFP_ATOMIC);
	if (!skb) {
		printk(KERN_ERR "x25_dev: out of memory\n");
		return;
	}

	ptr  = skb_put(skb, 1);
	*ptr = 0x02;

	skb->protocol = htons(ETH_P_X25);
	skb->dev      = nb->dev;
	dev_queue_xmit(skb);
}

void x25_send_frame(struct sk_buff *skb, struct x25_neigh *nb)
{
	unsigned char *dptr;

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

	switch (nb->dev->type) {
		case ARPHRD_X25:
			dptr  = skb_push(skb, 1);
			*dptr = 0x00;
			break;

#if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE)
		case ARPHRD_ETHER:
			kfree_skb(skb);
			return;
#endif
		default:
			kfree_skb(skb);
			return;
	}

	skb->protocol = htons(ETH_P_X25);
	skb->dev      = nb->dev;

	dev_queue_xmit(skb);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* X.25 Packet Layer release 002
	3	*
	4	* This is ALPHA test software. This code may break your machine, randomly fail to work with new
	5	* releases, misbehave and/or generally screw up. It might even work.
	6	*
	7	* This code REQUIRES 2.1.15 or higher
	8	*
	9	* This module:
	10	* This module is free software; you can redistribute it and/or
	11	* modify it under the terms of the GNU General Public License
	12	* as published by the Free Software Foundation; either version
	13	* 2 of the License, or (at your option) any later version.
	14	*
	15	* History
	16	* X.25 001 Jonathan Naylor Started coding.
	17	* 2000-09-04 Henner Eisen Prevent freeing a dangling skb.
	18	*/
	19
1da177e4 LT	20	#include <linux/kernel.h>
	21	#include <linux/netdevice.h>
	22	#include <linux/skbuff.h>
	23	#include <net/sock.h>
	24	#include <linux/if_arp.h>
	25	#include <net/x25.h>
	26
	27	static int x25_receive_data(struct sk_buff skb, struct x25_neigh nb)
	28	{
	29	struct sock *sk;
	30	unsigned short frametype;
	31	unsigned int lci;
	32
	33	frametype = skb->data[2];
	34	lci = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF);
	35
	36	/*
	37	* LCI of zero is always for us, and its always a link control
	38	* frame.
	39	*/
	40	if (lci == 0) {
	41	x25_link_control(skb, nb, frametype);
	42	return 0;
	43	}
	44
	45	/*
	46	* Find an existing socket.
	47	*/
	48	if ((sk = x25_find_socket(lci, nb)) != NULL) {
	49	int queued = 1;
	50
	51	skb->h.raw = skb->data;
	52	bh_lock_sock(sk);
	53	if (!sock_owned_by_user(sk)) {
	54	queued = x25_process_rx_frame(sk, skb);
	55	} else {
	56	sk_add_backlog(sk, skb);
	57	}
	58	bh_unlock_sock(sk);
	59	return queued;
	60	}
	61
	62	/*
	63	* Is is a Call Request ? if so process it.
	64	*/
	65	if (frametype == X25_CALL_REQUEST)
	66	return x25_rx_call_request(skb, nb, lci);
	67
	68	/*
	69	* Its not a Call Request, nor is it a control frame.
	70	* Let caller throw it away.
	71	*/
	72	/*
	73	x25_transmit_clear_request(nb, lci, 0x0D);
	74	*/
	75
	76	if (frametype != X25_CLEAR_CONFIRMATION)
	77	printk(KERN_DEBUG "x25_receive_data(): unknown frame type %2x\n",frametype);
	78
	79	return 0;
	80	}
	81
	82	int x25_lapb_receive_frame(struct sk_buff skb, struct net_device dev,
f2ccd8fa	83	struct packet_type ptype, struct net_device orig_dev)
1da177e4 LT	84	{
	85	struct sk_buff *nskb;
	86	struct x25_neigh *nb;
	87
	88	nskb = skb_copy(skb, GFP_ATOMIC);
	89	if (!nskb)
	90	goto drop;
	91	kfree_skb(skb);
	92	skb = nskb;
	93
	94	/*
	95	* Packet received from unrecognised device, throw it away.
	96	*/
	97	nb = x25_get_neigh(dev);
	98	if (!nb) {
	99	printk(KERN_DEBUG "X.25: unknown neighbour - %s\n", dev->name);
	100	goto drop;
	101	}
	102
	103	switch (skb->data[0]) {
	104	case 0x00:
	105	skb_pull(skb, 1);
	106	if (x25_receive_data(skb, nb)) {
	107	x25_neigh_put(nb);
	108	goto out;
	109	}
	110	break;
	111	case 0x01:
	112	x25_link_established(nb);
	113	break;
	114	case 0x02:
	115	x25_link_terminated(nb);
	116	break;
	117	}
	118	x25_neigh_put(nb);
	119	drop:
	120	kfree_skb(skb);
	121	out:
	122	return 0;
	123	}
	124
	125	void x25_establish_link(struct x25_neigh *nb)
	126	{
	127	struct sk_buff *skb;
	128	unsigned char *ptr;
	129
	130	switch (nb->dev->type) {
	131	case ARPHRD_X25:
	132	if ((skb = alloc_skb(1, GFP_ATOMIC)) == NULL) {
	133	printk(KERN_ERR "x25_dev: out of memory\n");
	134	return;
	135	}
	136	ptr = skb_put(skb, 1);
	137	*ptr = 0x01;
	138	break;
	139
	140	#if defined(CONFIG_LLC) \|\| defined(CONFIG_LLC_MODULE)
	141	case ARPHRD_ETHER:
	142	return;
	143	#endif
	144	default:
	145	return;
	146	}
	147
148	skb->protocol = htons(ETH_P_X25);
149	skb->dev = nb->dev;
150
151	dev_queue_xmit(skb);
152	}
153
154	void x25_terminate_link(struct x25_neigh *nb)
155	{
156	struct sk_buff *skb;
157	unsigned char *ptr;
158
159	#if defined(CONFIG_LLC) \|\| defined(CONFIG_LLC_MODULE)
160	if (nb->dev->type == ARPHRD_ETHER)
161	return;
162	#endif
163	if (nb->dev->type != ARPHRD_X25)
164	return;
165
166	skb = alloc_skb(1, GFP_ATOMIC);
167	if (!skb) {
168	printk(KERN_ERR "x25_dev: out of memory\n");
169	return;
170	}
171
172	ptr = skb_put(skb, 1);
173	*ptr = 0x02;
174
175	skb->protocol = htons(ETH_P_X25);
176	skb->dev = nb->dev;
177	dev_queue_xmit(skb);
178	}
179
180	void x25_send_frame(struct sk_buff skb, struct x25_neigh nb)
181	{
182	unsigned char *dptr;
183
184	skb->nh.raw = skb->data;
185
186	switch (nb->dev->type) {
187	case ARPHRD_X25:
188	dptr = skb_push(skb, 1);
189	*dptr = 0x00;
190	break;
191
192	#if defined(CONFIG_LLC) \|\| defined(CONFIG_LLC_MODULE)
193	case ARPHRD_ETHER:
194	kfree_skb(skb);
195	return;
196	#endif
197	default:
198	kfree_skb(skb);
199	return;
200	}
201
202	skb->protocol = htons(ETH_P_X25);
203	skb->dev = nb->dev;
204
205	dev_queue_xmit(skb);
206	}