[mirror_ubuntu-eoan-kernel.git] / drivers / net / wan / hdlc_x25.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Generic HDLC support routines for Linux
 * X.25 support
 *
 * Copyright (C) 1999 - 2006 Krzysztof Halasa <khc@pm.waw.pl>
 */

#include <linux/errno.h>
#include <linux/gfp.h>
#include <linux/hdlc.h>
#include <linux/if_arp.h>
#include <linux/inetdevice.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/lapb.h>
#include <linux/module.h>
#include <linux/pkt_sched.h>
#include <linux/poll.h>
#include <linux/rtnetlink.h>
#include <linux/skbuff.h>
#include <net/x25device.h>

static int x25_ioctl(struct net_device *dev, struct ifreq *ifr);

/* These functions are callbacks called by LAPB layer */

static void x25_connect_disconnect(struct net_device *dev, int reason, int code)
{
	struct sk_buff *skb;
	unsigned char *ptr;

	if ((skb = dev_alloc_skb(1)) == NULL) {
		netdev_err(dev, "out of memory\n");
		return;
	}

	ptr = skb_put(skb, 1);
	*ptr = code;

	skb->protocol = x25_type_trans(skb, dev);
	netif_rx(skb);
}


static void x25_connected(struct net_device *dev, int reason)
{
	x25_connect_disconnect(dev, reason, X25_IFACE_CONNECT);
}


static void x25_disconnected(struct net_device *dev, int reason)
{
	x25_connect_disconnect(dev, reason, X25_IFACE_DISCONNECT);
}


static int x25_data_indication(struct net_device *dev, struct sk_buff *skb)
{
	unsigned char *ptr;

	skb_push(skb, 1);

	if (skb_cow(skb, 1))
		return NET_RX_DROP;

	ptr  = skb->data;
	*ptr = X25_IFACE_DATA;

	skb->protocol = x25_type_trans(skb, dev);
	return netif_rx(skb);
}


static void x25_data_transmit(struct net_device *dev, struct sk_buff *skb)
{
	hdlc_device *hdlc = dev_to_hdlc(dev);
	hdlc->xmit(skb, dev); /* Ignore return value :-( */
}


static netdev_tx_t x25_xmit(struct sk_buff *skb, struct net_device *dev)
{
	int result;


	/* X.25 to LAPB */
	switch (skb->data[0]) {
	case X25_IFACE_DATA:	/* Data to be transmitted */
		skb_pull(skb, 1);
		if ((result = lapb_data_request(dev, skb)) != LAPB_OK)
			dev_kfree_skb(skb);
		return NETDEV_TX_OK;

	case X25_IFACE_CONNECT:
		if ((result = lapb_connect_request(dev))!= LAPB_OK) {
			if (result == LAPB_CONNECTED)
				/* Send connect confirm. msg to level 3 */
				x25_connected(dev, 0);
			else
				netdev_err(dev, "LAPB connect request failed, error code = %i\n",
					   result);
		}
		break;

	case X25_IFACE_DISCONNECT:
		if ((result = lapb_disconnect_request(dev)) != LAPB_OK) {
			if (result == LAPB_NOTCONNECTED)
				/* Send disconnect confirm. msg to level 3 */
				x25_disconnected(dev, 0);
			else
				netdev_err(dev, "LAPB disconnect request failed, error code = %i\n",
					   result);
		}
		break;

	default:		/* to be defined */
		break;
	}

	dev_kfree_skb(skb);
	return NETDEV_TX_OK;
}


static int x25_open(struct net_device *dev)
{
	int result;
	static const struct lapb_register_struct cb = {
		.connect_confirmation = x25_connected,
		.connect_indication = x25_connected,
		.disconnect_confirmation = x25_disconnected,
		.disconnect_indication = x25_disconnected,
		.data_indication = x25_data_indication,
		.data_transmit = x25_data_transmit,
	};

	result = lapb_register(dev, &cb);
	if (result != LAPB_OK)
		return result;
	return 0;
}


static void x25_close(struct net_device *dev)
{
	lapb_unregister(dev);
}


static int x25_rx(struct sk_buff *skb)
{
	struct net_device *dev = skb->dev;

	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
		dev->stats.rx_dropped++;
		return NET_RX_DROP;
	}

	if (lapb_data_received(dev, skb) == LAPB_OK)
		return NET_RX_SUCCESS;

	dev->stats.rx_errors++;
	dev_kfree_skb_any(skb);
	return NET_RX_DROP;
}


static struct hdlc_proto proto = {
	.open		= x25_open,
	.close		= x25_close,
	.ioctl		= x25_ioctl,
	.netif_rx	= x25_rx,
	.xmit		= x25_xmit,
	.module		= THIS_MODULE,
};


static int x25_ioctl(struct net_device *dev, struct ifreq *ifr)
{
	hdlc_device *hdlc = dev_to_hdlc(dev);
	int result;

	switch (ifr->ifr_settings.type) {
	case IF_GET_PROTO:
		if (dev_to_hdlc(dev)->proto != &proto)
			return -EINVAL;
		ifr->ifr_settings.type = IF_PROTO_X25;
		return 0; /* return protocol only, no settable parameters */

	case IF_PROTO_X25:
		if (!capable(CAP_NET_ADMIN))
			return -EPERM;

		if (dev->flags & IFF_UP)
			return -EBUSY;

		result=hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
		if (result)
			return result;

		if ((result = attach_hdlc_protocol(dev, &proto, 0)))
			return result;
		dev->type = ARPHRD_X25;
		call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev);
		netif_dormant_off(dev);
		return 0;
	}

	return -EINVAL;
}


static int __init mod_init(void)
{
	register_hdlc_protocol(&proto);
	return 0;
}


static void __exit mod_exit(void)
{
	unregister_hdlc_protocol(&proto);
}


module_init(mod_init);
module_exit(mod_exit);

MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
MODULE_DESCRIPTION("X.25 protocol support for generic HDLC");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
25763b3c	1	// SPDX-License-Identifier: GPL-2.0-only
1da177e4 LT	2	/*
	3	* Generic HDLC support routines for Linux
	4	* X.25 support
	5	*
eb2a2fd9	6	* Copyright (C) 1999 - 2006 Krzysztof Halasa <khc@pm.waw.pl>
1da177e4 LT	7	*/
1da177e4 LT	8
1da177e4	9	#include <linux/errno.h>
5a0e3ad6	10	#include <linux/gfp.h>
4dfce407	11	#include <linux/hdlc.h>
1da177e4	12	#include <linux/if_arp.h>
1da177e4	13	#include <linux/inetdevice.h>
4dfce407 KH	14	#include <linux/init.h>
4dfce407 KH	15	#include <linux/kernel.h>
1da177e4	16	#include <linux/lapb.h>
4dfce407 KH	17	#include <linux/module.h>
	18	#include <linux/pkt_sched.h>
	19	#include <linux/poll.h>
1da177e4	20	#include <linux/rtnetlink.h>
4dfce407	21	#include <linux/skbuff.h>
1da177e4 LT	22	#include <net/x25device.h>
1da177e4 LT	23
eb2a2fd9 KH	24	static int x25_ioctl(struct net_device dev, struct ifreq ifr);
eb2a2fd9 KH	25
1da177e4 LT	26	/* These functions are callbacks called by LAPB layer */
	27
	28	static void x25_connect_disconnect(struct net_device *dev, int reason, int code)
	29	{
	30	struct sk_buff *skb;
	31	unsigned char *ptr;
	32
	33	if ((skb = dev_alloc_skb(1)) == NULL) {
12a3bfef	34	netdev_err(dev, "out of memory\n");
1da177e4 LT	35	return;
	36	}
	37
	38	ptr = skb_put(skb, 1);
	39	*ptr = code;
	40
	41	skb->protocol = x25_type_trans(skb, dev);
	42	netif_rx(skb);
	43	}
	44
	45
	46
	47	static void x25_connected(struct net_device *dev, int reason)
	48	{
90b3e030	49	x25_connect_disconnect(dev, reason, X25_IFACE_CONNECT);
1da177e4 LT	50	}
	51
	52
	53
	54	static void x25_disconnected(struct net_device *dev, int reason)
	55	{
90b3e030	56	x25_connect_disconnect(dev, reason, X25_IFACE_DISCONNECT);
1da177e4 LT	57	}
	58
	59
	60
	61	static int x25_data_indication(struct net_device dev, struct sk_buff skb)
	62	{
	63	unsigned char *ptr;
	64
	65	skb_push(skb, 1);
	66
	67	if (skb_cow(skb, 1))
	68	return NET_RX_DROP;
	69
	70	ptr = skb->data;
90b3e030	71	*ptr = X25_IFACE_DATA;
1da177e4 LT	72
	73	skb->protocol = x25_type_trans(skb, dev);
	74	return netif_rx(skb);
	75	}
	76
	77
	78
	79	static void x25_data_transmit(struct net_device dev, struct sk_buff skb)
	80	{
	81	hdlc_device *hdlc = dev_to_hdlc(dev);
	82	hdlc->xmit(skb, dev); /* Ignore return value :-( */
	83	}
	84
	85
	86
d71a6749	87	static netdev_tx_t x25_xmit(struct sk_buff skb, struct net_device dev)
1da177e4 LT	88	{
	89	int result;
	90
	91
	92	/* X.25 to LAPB */
	93	switch (skb->data[0]) {
90b3e030	94	case X25_IFACE_DATA: /* Data to be transmitted */
1da177e4 LT	95	skb_pull(skb, 1);
	96	if ((result = lapb_data_request(dev, skb)) != LAPB_OK)
	97	dev_kfree_skb(skb);
d71a6749	98	return NETDEV_TX_OK;
1da177e4	99
90b3e030	100	case X25_IFACE_CONNECT:
1da177e4 LT	101	if ((result = lapb_connect_request(dev))!= LAPB_OK) {
	102	if (result == LAPB_CONNECTED)
	103	/* Send connect confirm. msg to level 3 */
	104	x25_connected(dev, 0);
	105	else
12a3bfef JP	106	netdev_err(dev, "LAPB connect request failed, error code = %i\n",
12a3bfef JP	107	result);
1da177e4 LT	108	}
	109	break;
	110
90b3e030	111	case X25_IFACE_DISCONNECT:
1da177e4 LT	112	if ((result = lapb_disconnect_request(dev)) != LAPB_OK) {
	113	if (result == LAPB_NOTCONNECTED)
	114	/* Send disconnect confirm. msg to level 3 */
	115	x25_disconnected(dev, 0);
	116	else
12a3bfef JP	117	netdev_err(dev, "LAPB disconnect request failed, error code = %i\n",
12a3bfef JP	118	result);
1da177e4 LT	119	}
	120	break;
	121
	122	default: /* to be defined */
	123	break;
	124	}
	125
	126	dev_kfree_skb(skb);
d71a6749	127	return NETDEV_TX_OK;
1da177e4 LT	128	}
	129
	130
	131
	132	static int x25_open(struct net_device *dev)
	133	{
1da177e4	134	int result;
d97a077a	135	static const struct lapb_register_struct cb = {
	136	.connect_confirmation = x25_connected,
	137	.connect_indication = x25_connected,
	138	.disconnect_confirmation = x25_disconnected,
	139	.disconnect_indication = x25_disconnected,
	140	.data_indication = x25_data_indication,
	141	.data_transmit = x25_data_transmit,
	142	};
1da177e4 LT	143
	144	result = lapb_register(dev, &cb);
	145	if (result != LAPB_OK)
	146	return result;
	147	return 0;
	148	}
	149
	150
	151
	152	static void x25_close(struct net_device *dev)
	153	{
	154	lapb_unregister(dev);
	155	}
	156
	157
	158
	159	static int x25_rx(struct sk_buff *skb)
	160	{
54069511 KH	161	struct net_device *dev = skb->dev;
54069511 KH	162
1da177e4	163	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
54069511	164	dev->stats.rx_dropped++;
1da177e4 LT	165	return NET_RX_DROP;
	166	}
	167
54069511	168	if (lapb_data_received(dev, skb) == LAPB_OK)
1da177e4 LT	169	return NET_RX_SUCCESS;
1da177e4 LT	170
54069511	171	dev->stats.rx_errors++;
1da177e4 LT	172	dev_kfree_skb_any(skb);
	173	return NET_RX_DROP;
	174	}
	175
	176
eb2a2fd9 KH	177	static struct hdlc_proto proto = {
	178	.open = x25_open,
	179	.close = x25_close,
	180	.ioctl = x25_ioctl,
40d25142	181	.netif_rx = x25_rx,
991990a1	182	.xmit = x25_xmit,
eb2a2fd9 KH	183	.module = THIS_MODULE,
	184	};
	185
1da177e4	186
eb2a2fd9	187	static int x25_ioctl(struct net_device dev, struct ifreq ifr)
1da177e4 LT	188	{
	189	hdlc_device *hdlc = dev_to_hdlc(dev);
	190	int result;
	191
	192	switch (ifr->ifr_settings.type) {
	193	case IF_GET_PROTO:
eb2a2fd9 KH	194	if (dev_to_hdlc(dev)->proto != &proto)
eb2a2fd9 KH	195	return -EINVAL;
1da177e4 LT	196	ifr->ifr_settings.type = IF_PROTO_X25;
	197	return 0; /* return protocol only, no settable parameters */
	198
	199	case IF_PROTO_X25:
640462cb	200	if (!capable(CAP_NET_ADMIN))
1da177e4 LT	201	return -EPERM;
1da177e4 LT	202
640462cb	203	if (dev->flags & IFF_UP)
1da177e4 LT	204	return -EBUSY;
	205
	206	result=hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
	207	if (result)
	208	return result;
	209
40d25142	210	if ((result = attach_hdlc_protocol(dev, &proto, 0)))
eb2a2fd9	211	return result;
1da177e4	212	dev->type = ARPHRD_X25;
2f8364a2	213	call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev);
4bc83b4d	214	netif_dormant_off(dev);
1da177e4 LT	215	return 0;
	216	}
	217
	218	return -EINVAL;
	219	}
eb2a2fd9 KH	220
	221
	222	static int __init mod_init(void)
	223	{
	224	register_hdlc_protocol(&proto);
	225	return 0;
	226	}
	227
	228
	229
	230	static void __exit mod_exit(void)
	231	{
	232	unregister_hdlc_protocol(&proto);
	233	}
	234
	235
	236	module_init(mod_init);
	237	module_exit(mod_exit);
	238
	239	MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
	240	MODULE_DESCRIPTION("X.25 protocol support for generic HDLC");
	241	MODULE_LICENSE("GPL v2");