[net-next-2.6.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 <linux/slab.h>
#include <net/sock.h>
#include <linux/if_arp.h>
#include <net/x25.h>
#include <net/x25device.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 {
			queued = !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 X25_IFACE_DATA:
		skb_pull(skb, 1);
		if (x25_receive_data(skb, nb)) {
			x25_neigh_put(nb);
			goto out;
		}
		break;

	case X25_IFACE_CONNECT:
		x25_link_established(nb);
		break;

	case X25_IFACE_DISCONNECT:
		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 = X25_IFACE_CONNECT;
			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 = X25_IFACE_DISCONNECT;

	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 = X25_IFACE_DATA;
			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>
5a0e3ad6	23	#include <linux/slab.h>
1da177e4 LT	24	#include <net/sock.h>
	25	#include <linux/if_arp.h>
	26	#include <net/x25.h>
5ebfbc06	27	#include <net/x25device.h>
1da177e4 LT	28
	29	static int x25_receive_data(struct sk_buff skb, struct x25_neigh nb)
	30	{
	31	struct sock *sk;
	32	unsigned short frametype;
	33	unsigned int lci;
	34
	35	frametype = skb->data[2];
f8e1d201	36	lci = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF);
1da177e4 LT	37
	38	/*
	39	* LCI of zero is always for us, and its always a link control
	40	* frame.
	41	*/
	42	if (lci == 0) {
	43	x25_link_control(skb, nb, frametype);
	44	return 0;
	45	}
	46
	47	/*
	48	* Find an existing socket.
	49	*/
	50	if ((sk = x25_find_socket(lci, nb)) != NULL) {
	51	int queued = 1;
	52
badff6d0	53	skb_reset_transport_header(skb);
1da177e4 LT	54	bh_lock_sock(sk);
	55	if (!sock_owned_by_user(sk)) {
	56	queued = x25_process_rx_frame(sk, skb);
	57	} else {
a3a858ff	58	queued = !sk_add_backlog(sk, skb);
1da177e4 LT	59	}
1da177e4 LT	60	bh_unlock_sock(sk);
9d0f7d29	61	sock_put(sk);
1da177e4 LT	62	return queued;
	63	}
	64
	65	/*
	66	* Is is a Call Request ? if so process it.
	67	*/
	68	if (frametype == X25_CALL_REQUEST)
	69	return x25_rx_call_request(skb, nb, lci);
	70
	71	/*
95a9dc43 AH	72	* Its not a Call Request, nor is it a control frame.
95a9dc43 AH	73	* Can we forward it?
1da177e4	74	*/
95a9dc43 AH	75
	76	if (x25_forward_data(lci, nb, skb)) {
	77	if (frametype == X25_CLEAR_CONFIRMATION) {
	78	x25_clear_forward_by_lci(lci);
	79	}
	80	kfree_skb(skb);
	81	return 1;
	82	}
	83
1da177e4 LT	84	/*
	85	x25_transmit_clear_request(nb, lci, 0x0D);
	86	*/
	87
	88	if (frametype != X25_CLEAR_CONFIRMATION)
	89	printk(KERN_DEBUG "x25_receive_data(): unknown frame type %2x\n",frametype);
	90
	91	return 0;
	92	}
	93
	94	int x25_lapb_receive_frame(struct sk_buff skb, struct net_device dev,
f2ccd8fa	95	struct packet_type ptype, struct net_device orig_dev)
1da177e4 LT	96	{
	97	struct sk_buff *nskb;
	98	struct x25_neigh *nb;
	99
721499e8	100	if (!net_eq(dev_net(dev), &init_net))
e730c155 EB	101	goto drop;
e730c155 EB	102
1da177e4 LT	103	nskb = skb_copy(skb, GFP_ATOMIC);
	104	if (!nskb)
	105	goto drop;
	106	kfree_skb(skb);
	107	skb = nskb;
	108
	109	/*
	110	* Packet received from unrecognised device, throw it away.
	111	*/
	112	nb = x25_get_neigh(dev);
	113	if (!nb) {
	114	printk(KERN_DEBUG "X.25: unknown neighbour - %s\n", dev->name);
	115	goto drop;
	116	}
	117
	118	switch (skb->data[0]) {
5ebfbc06 AH	119
	120	case X25_IFACE_DATA:
	121	skb_pull(skb, 1);
	122	if (x25_receive_data(skb, nb)) {
	123	x25_neigh_put(nb);
	124	goto out;
	125	}
	126	break;
	127
	128	case X25_IFACE_CONNECT:
	129	x25_link_established(nb);
	130	break;
	131
	132	case X25_IFACE_DISCONNECT:
	133	x25_link_terminated(nb);
	134	break;
1da177e4 LT	135	}
	136	x25_neigh_put(nb);
	137	drop:
	138	kfree_skb(skb);
	139	out:
	140	return 0;
	141	}
	142
	143	void x25_establish_link(struct x25_neigh *nb)
	144	{
	145	struct sk_buff *skb;
	146	unsigned char *ptr;
	147
	148	switch (nb->dev->type) {
	149	case ARPHRD_X25:
	150	if ((skb = alloc_skb(1, GFP_ATOMIC)) == NULL) {
	151	printk(KERN_ERR "x25_dev: out of memory\n");
	152	return;
	153	}
	154	ptr = skb_put(skb, 1);
5ebfbc06	155	*ptr = X25_IFACE_CONNECT;
1da177e4 LT	156	break;
	157
	158	#if defined(CONFIG_LLC) \|\| defined(CONFIG_LLC_MODULE)
	159	case ARPHRD_ETHER:
	160	return;
	161	#endif
	162	default:
	163	return;
	164	}
	165
	166	skb->protocol = htons(ETH_P_X25);
	167	skb->dev = nb->dev;
	168
	169	dev_queue_xmit(skb);
	170	}
	171
	172	void x25_terminate_link(struct x25_neigh *nb)
	173	{
	174	struct sk_buff *skb;
	175	unsigned char *ptr;
	176
	177	#if defined(CONFIG_LLC) \|\| defined(CONFIG_LLC_MODULE)
	178	if (nb->dev->type == ARPHRD_ETHER)
	179	return;
	180	#endif
	181	if (nb->dev->type != ARPHRD_X25)
	182	return;
	183
	184	skb = alloc_skb(1, GFP_ATOMIC);
	185	if (!skb) {
	186	printk(KERN_ERR "x25_dev: out of memory\n");
	187	return;
	188	}
	189
	190	ptr = skb_put(skb, 1);
5ebfbc06	191	*ptr = X25_IFACE_DISCONNECT;
1da177e4 LT	192
	193	skb->protocol = htons(ETH_P_X25);
	194	skb->dev = nb->dev;
	195	dev_queue_xmit(skb);
	196	}
	197
	198	void x25_send_frame(struct sk_buff skb, struct x25_neigh nb)
	199	{
	200	unsigned char *dptr;
	201
c1d2bbe1	202	skb_reset_network_header(skb);
1da177e4 LT	203
	204	switch (nb->dev->type) {
	205	case ARPHRD_X25:
	206	dptr = skb_push(skb, 1);
5ebfbc06	207	*dptr = X25_IFACE_DATA;
1da177e4 LT	208	break;
	209
	210	#if defined(CONFIG_LLC) \|\| defined(CONFIG_LLC_MODULE)
	211	case ARPHRD_ETHER:
	212	kfree_skb(skb);
	213	return;
	214	#endif
	215	default:
	216	kfree_skb(skb);
	217	return;
	218	}
	219
	220	skb->protocol = htons(ETH_P_X25);
	221	skb->dev = nb->dev;
	222
	223	dev_queue_xmit(skb);
	224	}