[linux-block.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_reset_transport_header(skb);
		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);
		sock_put(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.
	 *	Can we forward it?
	 */

	if (x25_forward_data(lci, nb, skb)) {
		if (frametype == X25_CLEAR_CONFIRMATION) {
			x25_clear_forward_by_lci(lci);
		}
		kfree_skb(skb);
		return 1;
	}

/*
	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;

	if (!net_eq(dev_net(dev), &init_net))
		goto drop;

	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_reset_network_header(skb);

	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	*
f8e1d201 YH	4	* This is ALPHA test software. This code may break your machine, randomly fail to work with new
f8e1d201 YH	5	* releases, misbehave and/or generally screw up. It might even work.
1da177e4 LT	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];
f8e1d201	34	lci = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF);
1da177e4 LT	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
badff6d0	51	skb_reset_transport_header(skb);
1da177e4 LT	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);
9d0f7d29	59	sock_put(sk);
1da177e4 LT	60	return queued;
	61	}
	62
	63	/*
	64	* Is is a Call Request ? if so process it.
	65	*/
	66	if (frametype == X25_CALL_REQUEST)
	67	return x25_rx_call_request(skb, nb, lci);
	68
	69	/*
95a9dc43 AH	70	* Its not a Call Request, nor is it a control frame.
95a9dc43 AH	71	* Can we forward it?
1da177e4	72	*/
95a9dc43 AH	73
	74	if (x25_forward_data(lci, nb, skb)) {
	75	if (frametype == X25_CLEAR_CONFIRMATION) {
	76	x25_clear_forward_by_lci(lci);
	77	}
	78	kfree_skb(skb);
	79	return 1;
	80	}
	81
1da177e4 LT	82	/*
	83	x25_transmit_clear_request(nb, lci, 0x0D);
	84	*/
	85
	86	if (frametype != X25_CLEAR_CONFIRMATION)
	87	printk(KERN_DEBUG "x25_receive_data(): unknown frame type %2x\n",frametype);
	88
	89	return 0;
	90	}
	91
	92	int x25_lapb_receive_frame(struct sk_buff skb, struct net_device dev,
f2ccd8fa	93	struct packet_type ptype, struct net_device orig_dev)
1da177e4 LT	94	{
	95	struct sk_buff *nskb;
	96	struct x25_neigh *nb;
	97
721499e8	98	if (!net_eq(dev_net(dev), &init_net))
e730c155 EB	99	goto drop;
e730c155 EB	100
1da177e4 LT	101	nskb = skb_copy(skb, GFP_ATOMIC);
	102	if (!nskb)
	103	goto drop;
	104	kfree_skb(skb);
	105	skb = nskb;
	106
	107	/*
	108	* Packet received from unrecognised device, throw it away.
	109	*/
	110	nb = x25_get_neigh(dev);
	111	if (!nb) {
	112	printk(KERN_DEBUG "X.25: unknown neighbour - %s\n", dev->name);
	113	goto drop;
	114	}
	115
	116	switch (skb->data[0]) {
	117	case 0x00:
	118	skb_pull(skb, 1);
	119	if (x25_receive_data(skb, nb)) {
	120	x25_neigh_put(nb);
	121	goto out;
	122	}
	123	break;
	124	case 0x01:
	125	x25_link_established(nb);
	126	break;
	127	case 0x02:
	128	x25_link_terminated(nb);
	129	break;
	130	}
	131	x25_neigh_put(nb);
	132	drop:
	133	kfree_skb(skb);
	134	out:
	135	return 0;
	136	}
	137
	138	void x25_establish_link(struct x25_neigh *nb)
	139	{
	140	struct sk_buff *skb;
	141	unsigned char *ptr;
	142
	143	switch (nb->dev->type) {
	144	case ARPHRD_X25:
	145	if ((skb = alloc_skb(1, GFP_ATOMIC)) == NULL) {
	146	printk(KERN_ERR "x25_dev: out of memory\n");
	147	return;
	148	}
	149	ptr = skb_put(skb, 1);
	150	*ptr = 0x01;
	151	break;
	152
	153	#if defined(CONFIG_LLC) \|\| defined(CONFIG_LLC_MODULE)
	154	case ARPHRD_ETHER:
	155	return;
	156	#endif
	157	default:
	158	return;
	159	}
	160
	161	skb->protocol = htons(ETH_P_X25);
	162	skb->dev = nb->dev;
	163
	164	dev_queue_xmit(skb);
165	}
166
167	void x25_terminate_link(struct x25_neigh *nb)
168	{
169	struct sk_buff *skb;
170	unsigned char *ptr;
171
172	#if defined(CONFIG_LLC) \|\| defined(CONFIG_LLC_MODULE)
173	if (nb->dev->type == ARPHRD_ETHER)
174	return;
175	#endif
176	if (nb->dev->type != ARPHRD_X25)
177	return;
178
179	skb = alloc_skb(1, GFP_ATOMIC);
180	if (!skb) {
181	printk(KERN_ERR "x25_dev: out of memory\n");
182	return;
183	}
184
185	ptr = skb_put(skb, 1);
186	*ptr = 0x02;
187
188	skb->protocol = htons(ETH_P_X25);
189	skb->dev = nb->dev;
190	dev_queue_xmit(skb);
191	}
192
193	void x25_send_frame(struct sk_buff skb, struct x25_neigh nb)
194	{
195	unsigned char *dptr;
196
c1d2bbe1	197	skb_reset_network_header(skb);
1da177e4 LT	198
	199	switch (nb->dev->type) {
	200	case ARPHRD_X25:
	201	dptr = skb_push(skb, 1);
	202	*dptr = 0x00;
	203	break;
	204
	205	#if defined(CONFIG_LLC) \|\| defined(CONFIG_LLC_MODULE)
	206	case ARPHRD_ETHER:
	207	kfree_skb(skb);
	208	return;
	209	#endif
	210	default:
	211	kfree_skb(skb);
	212	return;
	213	}
	214
	215	skb->protocol = htons(ETH_P_X25);
	216	skb->dev = nb->dev;
	217
	218	dev_queue_xmit(skb);
	219	}