[linux-block.git] / net / rose / rose_link.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *
 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
 */
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/jiffies.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/slab.h>
#include <net/ax25.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <net/rose.h>

static void rose_ftimer_expiry(struct timer_list *);
static void rose_t0timer_expiry(struct timer_list *);

static void rose_transmit_restart_confirmation(struct rose_neigh *neigh);
static void rose_transmit_restart_request(struct rose_neigh *neigh);

void rose_start_ftimer(struct rose_neigh *neigh)
{
	del_timer(&neigh->ftimer);

	neigh->ftimer.function = rose_ftimer_expiry;
	neigh->ftimer.expires  =
		jiffies + msecs_to_jiffies(sysctl_rose_link_fail_timeout);

	add_timer(&neigh->ftimer);
}

static void rose_start_t0timer(struct rose_neigh *neigh)
{
	del_timer(&neigh->t0timer);

	neigh->t0timer.function = rose_t0timer_expiry;
	neigh->t0timer.expires  =
		jiffies + msecs_to_jiffies(sysctl_rose_restart_request_timeout);

	add_timer(&neigh->t0timer);
}

void rose_stop_ftimer(struct rose_neigh *neigh)
{
	del_timer(&neigh->ftimer);
}

void rose_stop_t0timer(struct rose_neigh *neigh)
{
	del_timer(&neigh->t0timer);
}

int rose_ftimer_running(struct rose_neigh *neigh)
{
	return timer_pending(&neigh->ftimer);
}

static int rose_t0timer_running(struct rose_neigh *neigh)
{
	return timer_pending(&neigh->t0timer);
}

static void rose_ftimer_expiry(struct timer_list *t)
{
}

static void rose_t0timer_expiry(struct timer_list *t)
{
	struct rose_neigh *neigh = from_timer(neigh, t, t0timer);

	rose_transmit_restart_request(neigh);

	neigh->dce_mode = 0;

	rose_start_t0timer(neigh);
}

/*
 *	Interface to ax25_send_frame. Changes my level 2 callsign depending
 *	on whether we have a global ROSE callsign or use the default port
 *	callsign.
 */
static int rose_send_frame(struct sk_buff *skb, struct rose_neigh *neigh)
{
	ax25_address *rose_call;
	ax25_cb *ax25s;

	if (ax25cmp(&rose_callsign, &null_ax25_address) == 0)
		rose_call = (ax25_address *)neigh->dev->dev_addr;
	else
		rose_call = &rose_callsign;

	ax25s = neigh->ax25;
	neigh->ax25 = ax25_send_frame(skb, 260, rose_call, &neigh->callsign, neigh->digipeat, neigh->dev);
	if (ax25s)
		ax25_cb_put(ax25s);

	return neigh->ax25 != NULL;
}

/*
 *	Interface to ax25_link_up. Changes my level 2 callsign depending
 *	on whether we have a global ROSE callsign or use the default port
 *	callsign.
 */
static int rose_link_up(struct rose_neigh *neigh)
{
	ax25_address *rose_call;
	ax25_cb *ax25s;

	if (ax25cmp(&rose_callsign, &null_ax25_address) == 0)
		rose_call = (ax25_address *)neigh->dev->dev_addr;
	else
		rose_call = &rose_callsign;

	ax25s = neigh->ax25;
	neigh->ax25 = ax25_find_cb(rose_call, &neigh->callsign, neigh->digipeat, neigh->dev);
	if (ax25s)
		ax25_cb_put(ax25s);

	return neigh->ax25 != NULL;
}

/*
 *	This handles all restart and diagnostic frames.
 */
void rose_link_rx_restart(struct sk_buff *skb, struct rose_neigh *neigh, unsigned short frametype)
{
	struct sk_buff *skbn;

	switch (frametype) {
	case ROSE_RESTART_REQUEST:
		rose_stop_t0timer(neigh);
		neigh->restarted = 1;
		neigh->dce_mode  = (skb->data[3] == ROSE_DTE_ORIGINATED);
		rose_transmit_restart_confirmation(neigh);
		break;

	case ROSE_RESTART_CONFIRMATION:
		rose_stop_t0timer(neigh);
		neigh->restarted = 1;
		break;

	case ROSE_DIAGNOSTIC:
		pr_warn("ROSE: received diagnostic #%d - %3ph\n", skb->data[3],
			skb->data + 4);
		break;

	default:
		printk(KERN_WARNING "ROSE: received unknown %02X with LCI 000\n", frametype);
		break;
	}

	if (neigh->restarted) {
		while ((skbn = skb_dequeue(&neigh->queue)) != NULL)
			if (!rose_send_frame(skbn, neigh))
				kfree_skb(skbn);
	}
}

/*
 *	This routine is called when a Restart Request is needed
 */
static void rose_transmit_restart_request(struct rose_neigh *neigh)
{
	struct sk_buff *skb;
	unsigned char *dptr;
	int len;

	len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 3;

	if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
		return;

	skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN);

	dptr = skb_put(skb, ROSE_MIN_LEN + 3);

	*dptr++ = AX25_P_ROSE;
	*dptr++ = ROSE_GFI;
	*dptr++ = 0x00;
	*dptr++ = ROSE_RESTART_REQUEST;
	*dptr++ = ROSE_DTE_ORIGINATED;
	*dptr++ = 0;

	if (!rose_send_frame(skb, neigh))
		kfree_skb(skb);
}

/*
 * This routine is called when a Restart Confirmation is needed
 */
static void rose_transmit_restart_confirmation(struct rose_neigh *neigh)
{
	struct sk_buff *skb;
	unsigned char *dptr;
	int len;

	len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 1;

	if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
		return;

	skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN);

	dptr = skb_put(skb, ROSE_MIN_LEN + 1);

	*dptr++ = AX25_P_ROSE;
	*dptr++ = ROSE_GFI;
	*dptr++ = 0x00;
	*dptr++ = ROSE_RESTART_CONFIRMATION;

	if (!rose_send_frame(skb, neigh))
		kfree_skb(skb);
}

/*
 * This routine is called when a Clear Request is needed outside of the context
 * of a connected socket.
 */
void rose_transmit_clear_request(struct rose_neigh *neigh, unsigned int lci, unsigned char cause, unsigned char diagnostic)
{
	struct sk_buff *skb;
	unsigned char *dptr;
	int len;

	len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 3;

	if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
		return;

	skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN);

	dptr = skb_put(skb, ROSE_MIN_LEN + 3);

	*dptr++ = AX25_P_ROSE;
	*dptr++ = ((lci >> 8) & 0x0F) | ROSE_GFI;
	*dptr++ = ((lci >> 0) & 0xFF);
	*dptr++ = ROSE_CLEAR_REQUEST;
	*dptr++ = cause;
	*dptr++ = diagnostic;

	if (!rose_send_frame(skb, neigh))
		kfree_skb(skb);
}

void rose_transmit_link(struct sk_buff *skb, struct rose_neigh *neigh)
{
	unsigned char *dptr;

	if (neigh->loopback) {
		rose_loopback_queue(skb, neigh);
		return;
	}

	if (!rose_link_up(neigh))
		neigh->restarted = 0;

	dptr = skb_push(skb, 1);
	*dptr++ = AX25_P_ROSE;

	if (neigh->restarted) {
		if (!rose_send_frame(skb, neigh))
			kfree_skb(skb);
	} else {
		skb_queue_tail(&neigh->queue, skb);

		if (!rose_t0timer_running(neigh)) {
			rose_transmit_restart_request(neigh);
			neigh->dce_mode = 0;
			rose_start_t0timer(neigh);
		}
	}
}
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
1da177e4	2	/*
1da177e4 LT	3	*
	4	* Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
	5	*/
	6	#include <linux/errno.h>
	7	#include <linux/types.h>
	8	#include <linux/socket.h>
	9	#include <linux/in.h>
	10	#include <linux/kernel.h>
	11	#include <linux/jiffies.h>
	12	#include <linux/timer.h>
	13	#include <linux/string.h>
	14	#include <linux/sockios.h>
	15	#include <linux/net.h>
5a0e3ad6	16	#include <linux/slab.h>
1da177e4 LT	17	#include <net/ax25.h>
	18	#include <linux/inet.h>
	19	#include <linux/netdevice.h>
	20	#include <linux/skbuff.h>
	21	#include <net/sock.h>
1da177e4 LT	22	#include <linux/fcntl.h>
	23	#include <linux/mm.h>
	24	#include <linux/interrupt.h>
1da177e4 LT	25	#include <net/rose.h>
1da177e4 LT	26
4966babd KC	27	static void rose_ftimer_expiry(struct timer_list *);
4966babd KC	28	static void rose_t0timer_expiry(struct timer_list *);
1da177e4 LT	29
	30	static void rose_transmit_restart_confirmation(struct rose_neigh *neigh);
	31	static void rose_transmit_restart_request(struct rose_neigh *neigh);
	32
	33	void rose_start_ftimer(struct rose_neigh *neigh)
	34	{
	35	del_timer(&neigh->ftimer);
	36
841b86f3	37	neigh->ftimer.function = rose_ftimer_expiry;
82e84249 RB	38	neigh->ftimer.expires =
82e84249 RB	39	jiffies + msecs_to_jiffies(sysctl_rose_link_fail_timeout);
1da177e4 LT	40
	41	add_timer(&neigh->ftimer);
	42	}
	43
	44	static void rose_start_t0timer(struct rose_neigh *neigh)
	45	{
	46	del_timer(&neigh->t0timer);
	47
841b86f3	48	neigh->t0timer.function = rose_t0timer_expiry;
82e84249 RB	49	neigh->t0timer.expires =
82e84249 RB	50	jiffies + msecs_to_jiffies(sysctl_rose_restart_request_timeout);
1da177e4 LT	51
	52	add_timer(&neigh->t0timer);
	53	}
	54
	55	void rose_stop_ftimer(struct rose_neigh *neigh)
	56	{
	57	del_timer(&neigh->ftimer);
	58	}
	59
	60	void rose_stop_t0timer(struct rose_neigh *neigh)
	61	{
	62	del_timer(&neigh->t0timer);
	63	}
	64
	65	int rose_ftimer_running(struct rose_neigh *neigh)
	66	{
	67	return timer_pending(&neigh->ftimer);
	68	}
	69
	70	static int rose_t0timer_running(struct rose_neigh *neigh)
	71	{
	72	return timer_pending(&neigh->t0timer);
	73	}
	74
4966babd	75	static void rose_ftimer_expiry(struct timer_list *t)
1da177e4 LT	76	{
	77	}
	78
4966babd	79	static void rose_t0timer_expiry(struct timer_list *t)
1da177e4	80	{
4966babd	81	struct rose_neigh *neigh = from_timer(neigh, t, t0timer);
1da177e4 LT	82
	83	rose_transmit_restart_request(neigh);
	84
	85	neigh->dce_mode = 0;
	86
	87	rose_start_t0timer(neigh);
	88	}
	89
	90	/*
	91	* Interface to ax25_send_frame. Changes my level 2 callsign depending
	92	* on whether we have a global ROSE callsign or use the default port
	93	* callsign.
	94	*/
	95	static int rose_send_frame(struct sk_buff skb, struct rose_neigh neigh)
	96	{
	97	ax25_address *rose_call;
d00c362f	98	ax25_cb *ax25s;
1da177e4 LT	99
	100	if (ax25cmp(&rose_callsign, &null_ax25_address) == 0)
	101	rose_call = (ax25_address *)neigh->dev->dev_addr;
	102	else
	103	rose_call = &rose_callsign;
	104
d00c362f	105	ax25s = neigh->ax25;
1da177e4	106	neigh->ax25 = ax25_send_frame(skb, 260, rose_call, &neigh->callsign, neigh->digipeat, neigh->dev);
d00c362f JP	107	if (ax25s)
d00c362f JP	108	ax25_cb_put(ax25s);
1da177e4	109
a02cec21	110	return neigh->ax25 != NULL;
1da177e4 LT	111	}
	112
	113	/*
	114	* Interface to ax25_link_up. Changes my level 2 callsign depending
	115	* on whether we have a global ROSE callsign or use the default port
	116	* callsign.
	117	*/
	118	static int rose_link_up(struct rose_neigh *neigh)
	119	{
	120	ax25_address *rose_call;
d00c362f	121	ax25_cb *ax25s;
1da177e4 LT	122
	123	if (ax25cmp(&rose_callsign, &null_ax25_address) == 0)
	124	rose_call = (ax25_address *)neigh->dev->dev_addr;
	125	else
	126	rose_call = &rose_callsign;
	127
d00c362f	128	ax25s = neigh->ax25;
1da177e4	129	neigh->ax25 = ax25_find_cb(rose_call, &neigh->callsign, neigh->digipeat, neigh->dev);
d00c362f JP	130	if (ax25s)
d00c362f JP	131	ax25_cb_put(ax25s);
1da177e4	132
a02cec21	133	return neigh->ax25 != NULL;
1da177e4 LT	134	}
	135
	136	/*
	137	* This handles all restart and diagnostic frames.
	138	*/
	139	void rose_link_rx_restart(struct sk_buff skb, struct rose_neigh neigh, unsigned short frametype)
	140	{
	141	struct sk_buff *skbn;
	142
	143	switch (frametype) {
	144	case ROSE_RESTART_REQUEST:
	145	rose_stop_t0timer(neigh);
	146	neigh->restarted = 1;
	147	neigh->dce_mode = (skb->data[3] == ROSE_DTE_ORIGINATED);
	148	rose_transmit_restart_confirmation(neigh);
	149	break;
	150
	151	case ROSE_RESTART_CONFIRMATION:
	152	rose_stop_t0timer(neigh);
	153	neigh->restarted = 1;
	154	break;
	155
	156	case ROSE_DIAGNOSTIC:
13aa3463 AS	157	pr_warn("ROSE: received diagnostic #%d - %3ph\n", skb->data[3],
13aa3463 AS	158	skb->data + 4);
1da177e4 LT	159	break;
	160
	161	default:
	162	printk(KERN_WARNING "ROSE: received unknown %02X with LCI 000\n", frametype);
	163	break;
	164	}
	165
	166	if (neigh->restarted) {
	167	while ((skbn = skb_dequeue(&neigh->queue)) != NULL)
	168	if (!rose_send_frame(skbn, neigh))
	169	kfree_skb(skbn);
	170	}
	171	}
	172
	173	/*
	174	* This routine is called when a Restart Request is needed
	175	*/
	176	static void rose_transmit_restart_request(struct rose_neigh *neigh)
	177	{
	178	struct sk_buff *skb;
	179	unsigned char *dptr;
	180	int len;
	181
	182	len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 3;
	183
	184	if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
	185	return;
	186
	187	skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN);
	188
	189	dptr = skb_put(skb, ROSE_MIN_LEN + 3);
	190
	191	*dptr++ = AX25_P_ROSE;
	192	*dptr++ = ROSE_GFI;
	193	*dptr++ = 0x00;
	194	*dptr++ = ROSE_RESTART_REQUEST;
	195	*dptr++ = ROSE_DTE_ORIGINATED;
	196	*dptr++ = 0;
	197
	198	if (!rose_send_frame(skb, neigh))
	199	kfree_skb(skb);
	200	}
	201
	202	/*
	203	* This routine is called when a Restart Confirmation is needed
	204	*/
	205	static void rose_transmit_restart_confirmation(struct rose_neigh *neigh)
	206	{
	207	struct sk_buff *skb;
	208	unsigned char *dptr;
	209	int len;
	210
	211	len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 1;
	212
	213	if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
	214	return;
	215
	216	skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN);
	217
	218	dptr = skb_put(skb, ROSE_MIN_LEN + 1);
	219
	220	*dptr++ = AX25_P_ROSE;
	221	*dptr++ = ROSE_GFI;
	222	*dptr++ = 0x00;
223	*dptr++ = ROSE_RESTART_CONFIRMATION;
224
225	if (!rose_send_frame(skb, neigh))
226	kfree_skb(skb);
227	}
228
229	/*
230	* This routine is called when a Clear Request is needed outside of the context
231	* of a connected socket.
232	*/
233	void rose_transmit_clear_request(struct rose_neigh *neigh, unsigned int lci, unsigned char cause, unsigned char diagnostic)
234	{
235	struct sk_buff *skb;
236	unsigned char *dptr;
237	int len;
238
239	len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 3;
240
241	if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
242	return;
243
244	skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN);
245
246	dptr = skb_put(skb, ROSE_MIN_LEN + 3);
247
248	*dptr++ = AX25_P_ROSE;
249	*dptr++ = ((lci >> 8) & 0x0F) \| ROSE_GFI;
250	*dptr++ = ((lci >> 0) & 0xFF);
251	*dptr++ = ROSE_CLEAR_REQUEST;
252	*dptr++ = cause;
253	*dptr++ = diagnostic;
254
255	if (!rose_send_frame(skb, neigh))
256	kfree_skb(skb);
257	}
258
259	void rose_transmit_link(struct sk_buff skb, struct rose_neigh neigh)
260	{
261	unsigned char *dptr;
262
1da177e4 LT	263	if (neigh->loopback) {
	264	rose_loopback_queue(skb, neigh);
	265	return;
	266	}
	267
	268	if (!rose_link_up(neigh))
	269	neigh->restarted = 0;
	270
	271	dptr = skb_push(skb, 1);
	272	*dptr++ = AX25_P_ROSE;
	273
	274	if (neigh->restarted) {
	275	if (!rose_send_frame(skb, neigh))
	276	kfree_skb(skb);
	277	} else {
	278	skb_queue_tail(&neigh->queue, skb);
	279
	280	if (!rose_t0timer_running(neigh)) {
	281	rose_transmit_restart_request(neigh);
	282	neigh->dce_mode = 0;
	283	rose_start_t0timer(neigh);
	284	}
	285	}
	286	}