net/rose/rose_subr.c - linux - Git at Google

 // 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/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 <net/tcp_states.h>
 #include <linux/fcntl.h>
 #include <linux/mm.h>
 #include <linux/interrupt.h>
 #include <net/rose.h>

 static int rose_create_facilities(unsigned char *buffer, struct rose_sock *rose);

 /*
  *	This routine purges all of the queues of frames.
  */
 void rose_clear_queues(struct sock *sk)
 {
 	skb_queue_purge(&sk->sk_write_queue);
 	skb_queue_purge(&rose_sk(sk)->ack_queue);
 }

 /*
  * This routine purges the input queue of those frames that have been
  * acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the
  * SDL diagram.
  */
 void rose_frames_acked(struct sock *sk, unsigned short nr)
 {
 	struct sk_buff *skb;
 	struct rose_sock *rose = rose_sk(sk);

 	/*
 	 * Remove all the ack-ed frames from the ack queue.
 	 */
 	if (rose->va != nr) {
 		while (skb_peek(&rose->ack_queue) != NULL && rose->va != nr) {
 			skb = skb_dequeue(&rose->ack_queue);
 			kfree_skb(skb);
 			rose->va = (rose->va + 1) % ROSE_MODULUS;
 		}
 	}
 }

 void rose_requeue_frames(struct sock *sk)
 {
 	struct sk_buff *skb, *skb_prev = NULL;

 	/*
 	 * Requeue all the un-ack-ed frames on the output queue to be picked
 	 * up by rose_kick. This arrangement handles the possibility of an
 	 * empty output queue.
 	 */
 	while ((skb = skb_dequeue(&rose_sk(sk)->ack_queue)) != NULL) {
 		if (skb_prev == NULL)
 			skb_queue_head(&sk->sk_write_queue, skb);
 		else
 			skb_append(skb_prev, skb, &sk->sk_write_queue);
 		skb_prev = skb;
 	}
 }

 /*
  *	Validate that the value of nr is between va and vs. Return true or
  *	false for testing.
  */
 int rose_validate_nr(struct sock *sk, unsigned short nr)
 {
 	struct rose_sock *rose = rose_sk(sk);
 	unsigned short vc = rose->va;

 	while (vc != rose->vs) {
 		if (nr == vc) return 1;
 		vc = (vc + 1) % ROSE_MODULUS;
 	}

 	return nr == rose->vs;
 }

 /*
  *  This routine is called when the packet layer internally generates a
  *  control frame.
  */
 void rose_write_internal(struct sock *sk, int frametype)
 {
 	struct rose_sock *rose = rose_sk(sk);
 	struct sk_buff *skb;
 	unsigned char  *dptr;
 	unsigned char  lci1, lci2;
 	int maxfaclen = 0;
 	int len, faclen;
 	int reserve;

 	reserve = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + 1;
 	len = ROSE_MIN_LEN;

 	switch (frametype) {
 	case ROSE_CALL_REQUEST:
 		len   += 1 + ROSE_ADDR_LEN + ROSE_ADDR_LEN;
 		maxfaclen = 256;
 		break;
 	case ROSE_CALL_ACCEPTED:
 	case ROSE_CLEAR_REQUEST:
 	case ROSE_RESET_REQUEST:
 		len   += 2;
 		break;
 	}

 	skb = alloc_skb(reserve + len + maxfaclen, GFP_ATOMIC);
 	if (!skb)
 		return;

 	/*
 	 *	Space for AX.25 header and PID.
 	 */
 	skb_reserve(skb, reserve);

 	dptr = skb_put(skb, len);

 	lci1 = (rose->lci >> 8) & 0x0F;
 	lci2 = (rose->lci >> 0) & 0xFF;

 	switch (frametype) {
 	case ROSE_CALL_REQUEST:
 		*dptr++ = ROSE_GFI | lci1;
 		*dptr++ = lci2;
 		*dptr++ = frametype;
 		*dptr++ = ROSE_CALL_REQ_ADDR_LEN_VAL;
 		memcpy(dptr, &rose->dest_addr,  ROSE_ADDR_LEN);
 		dptr   += ROSE_ADDR_LEN;
 		memcpy(dptr, &rose->source_addr, ROSE_ADDR_LEN);
 		dptr   += ROSE_ADDR_LEN;
 		faclen = rose_create_facilities(dptr, rose);
 		skb_put(skb, faclen);
 		dptr   += faclen;
 		break;

 	case ROSE_CALL_ACCEPTED:
 		*dptr++ = ROSE_GFI | lci1;
 		*dptr++ = lci2;
 		*dptr++ = frametype;
 		*dptr++ = 0x00;		/* Address length */
 		*dptr++ = 0;		/* Facilities length */
 		break;

 	case ROSE_CLEAR_REQUEST:
 		*dptr++ = ROSE_GFI | lci1;
 		*dptr++ = lci2;
 		*dptr++ = frametype;
 		*dptr++ = rose->cause;
 		*dptr++ = rose->diagnostic;
 		break;

 	case ROSE_RESET_REQUEST:
 		*dptr++ = ROSE_GFI | lci1;
 		*dptr++ = lci2;
 		*dptr++ = frametype;
 		*dptr++ = ROSE_DTE_ORIGINATED;
 		*dptr++ = 0;
 		break;

 	case ROSE_RR:
 	case ROSE_RNR:
 		*dptr++ = ROSE_GFI | lci1;
 		*dptr++ = lci2;
 		*dptr   = frametype;
 		*dptr++ |= (rose->vr << 5) & 0xE0;
 		break;

 	case ROSE_CLEAR_CONFIRMATION:
 	case ROSE_RESET_CONFIRMATION:
 		*dptr++ = ROSE_GFI | lci1;
 		*dptr++ = lci2;
 		*dptr++  = frametype;
 		break;

 	default:
 		printk(KERN_ERR "ROSE: rose_write_internal - invalid frametype %02X\n", frametype);
 		kfree_skb(skb);
 		return;
 	}

 	rose_transmit_link(skb, rose->neighbour);
 }

 int rose_decode(struct sk_buff *skb, int *ns, int *nr, int *q, int *d, int *m)
 {
 	unsigned char *frame;

 	frame = skb->data;

 	*ns = *nr = *q = *d = *m = 0;

 	switch (frame[2]) {
 	case ROSE_CALL_REQUEST:
 	case ROSE_CALL_ACCEPTED:
 	case ROSE_CLEAR_REQUEST:
 	case ROSE_CLEAR_CONFIRMATION:
 	case ROSE_RESET_REQUEST:
 	case ROSE_RESET_CONFIRMATION:
 		return frame[2];
 	default:
 		break;
 	}

 	if ((frame[2] & 0x1F) == ROSE_RR  ||
 	    (frame[2] & 0x1F) == ROSE_RNR) {
 		*nr = (frame[2] >> 5) & 0x07;
 		return frame[2] & 0x1F;
 	}

 	if ((frame[2] & 0x01) == ROSE_DATA) {
 		*q  = (frame[0] & ROSE_Q_BIT) == ROSE_Q_BIT;
 		*d  = (frame[0] & ROSE_D_BIT) == ROSE_D_BIT;
 		*m  = (frame[2] & ROSE_M_BIT) == ROSE_M_BIT;
 		*nr = (frame[2] >> 5) & 0x07;
 		*ns = (frame[2] >> 1) & 0x07;
 		return ROSE_DATA;
 	}

 	return ROSE_ILLEGAL;
 }

 static int rose_parse_national(unsigned char *p, struct rose_facilities_struct *facilities, int len)
 {
 	unsigned char *pt;
 	unsigned char l, lg, n = 0;
 	int fac_national_digis_received = 0;

 	do {
 		switch (*p & 0xC0) {
 		case 0x00:
 			if (len < 2)
 				return -1;
 			p   += 2;
 			n   += 2;
 			len -= 2;
 			break;

 		case 0x40:
 			if (len < 3)
 				return -1;
 			if (*p == FAC_NATIONAL_RAND)
 				facilities->rand = ((p[1] << 8) & 0xFF00) + ((p[2] << 0) & 0x00FF);
 			p   += 3;
 			n   += 3;
 			len -= 3;
 			break;

 		case 0x80:
 			if (len < 4)
 				return -1;
 			p   += 4;
 			n   += 4;
 			len -= 4;
 			break;

 		case 0xC0:
 			if (len < 2)
 				return -1;
 			l = p[1];
 			if (len < 2 + l)
 				return -1;
 			if (*p == FAC_NATIONAL_DEST_DIGI) {
 				if (!fac_national_digis_received) {
 					if (l < AX25_ADDR_LEN)
 						return -1;
 					memcpy(&facilities->source_digis[0], p + 2, AX25_ADDR_LEN);
 					facilities->source_ndigis = 1;
 				}
 			}
 			else if (*p == FAC_NATIONAL_SRC_DIGI) {
 				if (!fac_national_digis_received) {
 					if (l < AX25_ADDR_LEN)
 						return -1;
 					memcpy(&facilities->dest_digis[0], p + 2, AX25_ADDR_LEN);
 					facilities->dest_ndigis = 1;
 				}
 			}
 			else if (*p == FAC_NATIONAL_FAIL_CALL) {
 				if (l < AX25_ADDR_LEN)
 					return -1;
 				memcpy(&facilities->fail_call, p + 2, AX25_ADDR_LEN);
 			}
 			else if (*p == FAC_NATIONAL_FAIL_ADD) {
 				if (l < 1 + ROSE_ADDR_LEN)
 					return -1;
 				memcpy(&facilities->fail_addr, p + 3, ROSE_ADDR_LEN);
 			}
 			else if (*p == FAC_NATIONAL_DIGIS) {
 				if (l % AX25_ADDR_LEN)
 					return -1;
 				fac_national_digis_received = 1;
 				facilities->source_ndigis = 0;
 				facilities->dest_ndigis   = 0;
 				for (pt = p + 2, lg = 0 ; lg < l ; pt += AX25_ADDR_LEN, lg += AX25_ADDR_LEN) {
 					if (pt[6] & AX25_HBIT) {
 						if (facilities->dest_ndigis >= ROSE_MAX_DIGIS)
 							return -1;
 						memcpy(&facilities->dest_digis[facilities->dest_ndigis++], pt, AX25_ADDR_LEN);
 					} else {
 						if (facilities->source_ndigis >= ROSE_MAX_DIGIS)
 							return -1;
 						memcpy(&facilities->source_digis[facilities->source_ndigis++], pt, AX25_ADDR_LEN);
 					}
 				}
 			}
 			p   += l + 2;
 			n   += l + 2;
 			len -= l + 2;
 			break;
 		}
 	} while (*p != 0x00 && len > 0);

 	return n;
 }

 static int rose_parse_ccitt(unsigned char *p, struct rose_facilities_struct *facilities, int len)
 {
 	unsigned char l, n = 0;
 	char callsign[11];

 	do {
 		switch (*p & 0xC0) {
 		case 0x00:
 			if (len < 2)
 				return -1;
 			p   += 2;
 			n   += 2;
 			len -= 2;
 			break;

 		case 0x40:
 			if (len < 3)
 				return -1;
 			p   += 3;
 			n   += 3;
 			len -= 3;
 			break;

 		case 0x80:
 			if (len < 4)
 				return -1;
 			p   += 4;
 			n   += 4;
 			len -= 4;
 			break;

 		case 0xC0:
 			if (len < 2)
 				return -1;
 			l = p[1];

 			/* Prevent overflows*/
 			if (l < 10 || l > 20)
 				return -1;

 			if (*p == FAC_CCITT_DEST_NSAP) {
 				memcpy(&facilities->source_addr, p + 7, ROSE_ADDR_LEN);
 				memcpy(callsign, p + 12,   l - 10);
 				callsign[l - 10] = '\0';
 				asc2ax(&facilities->source_call, callsign);
 			}
 			if (*p == FAC_CCITT_SRC_NSAP) {
 				memcpy(&facilities->dest_addr, p + 7, ROSE_ADDR_LEN);
 				memcpy(callsign, p + 12, l - 10);
 				callsign[l - 10] = '\0';
 				asc2ax(&facilities->dest_call, callsign);
 			}
 			p   += l + 2;
 			n   += l + 2;
 			len -= l + 2;
 			break;
 		}
 	} while (*p != 0x00 && len > 0);

 	return n;
 }

 int rose_parse_facilities(unsigned char *p, unsigned packet_len,
 	struct rose_facilities_struct *facilities)
 {
 	int facilities_len, len;

 	facilities_len = *p++;

 	if (facilities_len == 0 || (unsigned int)facilities_len > packet_len)
 		return 0;

 	while (facilities_len >= 3 && *p == 0x00) {
 		facilities_len--;
 		p++;

 		switch (*p) {
 		case FAC_NATIONAL:		/* National */
 			len = rose_parse_national(p + 1, facilities, facilities_len - 1);
 			break;

 		case FAC_CCITT:		/* CCITT */
 			len = rose_parse_ccitt(p + 1, facilities, facilities_len - 1);
 			break;

 		default:
 			printk(KERN_DEBUG "ROSE: rose_parse_facilities - unknown facilities family %02X\n", *p);
 			len = 1;
 			break;
 		}

 		if (len < 0)
 			return 0;
 		if (WARN_ON(len >= facilities_len))
 			return 0;
 		facilities_len -= len + 1;
 		p += len + 1;
 	}

 	return facilities_len == 0;
 }

 static int rose_create_facilities(unsigned char *buffer, struct rose_sock *rose)
 {
 	unsigned char *p = buffer + 1;
 	char *callsign;
 	char buf[11];
 	int len, nb;

 	/* National Facilities */
 	if (rose->rand != 0 || rose->source_ndigis == 1 || rose->dest_ndigis == 1) {
 		*p++ = 0x00;
 		*p++ = FAC_NATIONAL;

 		if (rose->rand != 0) {
 			*p++ = FAC_NATIONAL_RAND;
 			*p++ = (rose->rand >> 8) & 0xFF;
 			*p++ = (rose->rand >> 0) & 0xFF;
 		}

 		/* Sent before older facilities */
 		if ((rose->source_ndigis > 0) || (rose->dest_ndigis > 0)) {
 			int maxdigi = 0;
 			*p++ = FAC_NATIONAL_DIGIS;
 			*p++ = AX25_ADDR_LEN * (rose->source_ndigis + rose->dest_ndigis);
 			for (nb = 0 ; nb < rose->source_ndigis ; nb++) {
 				if (++maxdigi >= ROSE_MAX_DIGIS)
 					break;
 				memcpy(p, &rose->source_digis[nb], AX25_ADDR_LEN);
 				p[6] |= AX25_HBIT;
 				p += AX25_ADDR_LEN;
 			}
 			for (nb = 0 ; nb < rose->dest_ndigis ; nb++) {
 				if (++maxdigi >= ROSE_MAX_DIGIS)
 					break;
 				memcpy(p, &rose->dest_digis[nb], AX25_ADDR_LEN);
 				p[6] &= ~AX25_HBIT;
 				p += AX25_ADDR_LEN;
 			}
 		}

 		/* For compatibility */
 		if (rose->source_ndigis > 0) {
 			*p++ = FAC_NATIONAL_SRC_DIGI;
 			*p++ = AX25_ADDR_LEN;
 			memcpy(p, &rose->source_digis[0], AX25_ADDR_LEN);
 			p   += AX25_ADDR_LEN;
 		}

 		/* For compatibility */
 		if (rose->dest_ndigis > 0) {
 			*p++ = FAC_NATIONAL_DEST_DIGI;
 			*p++ = AX25_ADDR_LEN;
 			memcpy(p, &rose->dest_digis[0], AX25_ADDR_LEN);
 			p   += AX25_ADDR_LEN;
 		}
 	}

 	*p++ = 0x00;
 	*p++ = FAC_CCITT;

 	*p++ = FAC_CCITT_DEST_NSAP;

 	callsign = ax2asc(buf, &rose->dest_call);

 	*p++ = strlen(callsign) + 10;
 	*p++ = (strlen(callsign) + 9) * 2;		/* ??? */

 	*p++ = 0x47; *p++ = 0x00; *p++ = 0x11;
 	*p++ = ROSE_ADDR_LEN * 2;
 	memcpy(p, &rose->dest_addr, ROSE_ADDR_LEN);
 	p   += ROSE_ADDR_LEN;

 	memcpy(p, callsign, strlen(callsign));
 	p   += strlen(callsign);

 	*p++ = FAC_CCITT_SRC_NSAP;

 	callsign = ax2asc(buf, &rose->source_call);

 	*p++ = strlen(callsign) + 10;
 	*p++ = (strlen(callsign) + 9) * 2;		/* ??? */

 	*p++ = 0x47; *p++ = 0x00; *p++ = 0x11;
 	*p++ = ROSE_ADDR_LEN * 2;
 	memcpy(p, &rose->source_addr, ROSE_ADDR_LEN);
 	p   += ROSE_ADDR_LEN;

 	memcpy(p, callsign, strlen(callsign));
 	p   += strlen(callsign);

 	len       = p - buffer;
 	buffer[0] = len - 1;

 	return len;
 }

 void rose_disconnect(struct sock *sk, int reason, int cause, int diagnostic)
 {
 	struct rose_sock *rose = rose_sk(sk);

 	rose_stop_timer(sk);
 	rose_stop_idletimer(sk);

 	rose_clear_queues(sk);

 	rose->lci   = 0;
 	rose->state = ROSE_STATE_0;

 	if (cause != -1)
 		rose->cause = cause;

 	if (diagnostic != -1)
 		rose->diagnostic = diagnostic;

 	sk->sk_state     = TCP_CLOSE;
 	sk->sk_err       = reason;
 	sk->sk_shutdown |= SEND_SHUTDOWN;

 	if (!sock_flag(sk, SOCK_DEAD)) {
 		sk->sk_state_change(sk);
 		sock_set_flag(sk, SOCK_DEAD);
 	}
 }
	// 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/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 <net/tcp_states.h>
	#include <linux/fcntl.h>
	#include <linux/mm.h>
	#include <linux/interrupt.h>
	#include <net/rose.h>

	static int rose_create_facilities(unsigned char buffer, struct rose_sock rose);

	/*
	* This routine purges all of the queues of frames.
	*/
	void rose_clear_queues(struct sock *sk)
	{
	skb_queue_purge(&sk->sk_write_queue);
	skb_queue_purge(&rose_sk(sk)->ack_queue);
	}

	/*
	* This routine purges the input queue of those frames that have been
	* acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the
	* SDL diagram.
	*/
	void rose_frames_acked(struct sock *sk, unsigned short nr)
	{
	struct sk_buff *skb;
	struct rose_sock *rose = rose_sk(sk);

	/*
	* Remove all the ack-ed frames from the ack queue.
	*/
	if (rose->va != nr) {
	while (skb_peek(&rose->ack_queue) != NULL && rose->va != nr) {
	skb = skb_dequeue(&rose->ack_queue);
	kfree_skb(skb);
	rose->va = (rose->va + 1) % ROSE_MODULUS;
	}
	}
	}

	void rose_requeue_frames(struct sock *sk)
	{
	struct sk_buff skb, skb_prev = NULL;

	/*
	* Requeue all the un-ack-ed frames on the output queue to be picked
	* up by rose_kick. This arrangement handles the possibility of an
	* empty output queue.
	*/
	while ((skb = skb_dequeue(&rose_sk(sk)->ack_queue)) != NULL) {
	if (skb_prev == NULL)
	skb_queue_head(&sk->sk_write_queue, skb);
	else
	skb_append(skb_prev, skb, &sk->sk_write_queue);
	skb_prev = skb;
	}
	}

	/*
	* Validate that the value of nr is between va and vs. Return true or
	* false for testing.
	*/
	int rose_validate_nr(struct sock *sk, unsigned short nr)
	{
	struct rose_sock *rose = rose_sk(sk);
	unsigned short vc = rose->va;

	while (vc != rose->vs) {
	if (nr == vc) return 1;
	vc = (vc + 1) % ROSE_MODULUS;
	}

	return nr == rose->vs;
	}

	/*
	* This routine is called when the packet layer internally generates a
	* control frame.
	*/
	void rose_write_internal(struct sock *sk, int frametype)
	{
	struct rose_sock *rose = rose_sk(sk);
	struct sk_buff *skb;
	unsigned char *dptr;
	unsigned char lci1, lci2;
	int maxfaclen = 0;
	int len, faclen;
	int reserve;

	reserve = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + 1;
	len = ROSE_MIN_LEN;

	switch (frametype) {
	case ROSE_CALL_REQUEST:
	len += 1 + ROSE_ADDR_LEN + ROSE_ADDR_LEN;
	maxfaclen = 256;
	break;
	case ROSE_CALL_ACCEPTED:
	case ROSE_CLEAR_REQUEST:
	case ROSE_RESET_REQUEST:
	len += 2;
	break;
	}

	skb = alloc_skb(reserve + len + maxfaclen, GFP_ATOMIC);
	if (!skb)
	return;

	/*
	* Space for AX.25 header and PID.
	*/
	skb_reserve(skb, reserve);

	dptr = skb_put(skb, len);

	lci1 = (rose->lci >> 8) & 0x0F;
	lci2 = (rose->lci >> 0) & 0xFF;

	switch (frametype) {
	case ROSE_CALL_REQUEST:
	*dptr++ = ROSE_GFI \| lci1;
	*dptr++ = lci2;
	*dptr++ = frametype;
	*dptr++ = ROSE_CALL_REQ_ADDR_LEN_VAL;
	memcpy(dptr, &rose->dest_addr, ROSE_ADDR_LEN);
	dptr += ROSE_ADDR_LEN;
	memcpy(dptr, &rose->source_addr, ROSE_ADDR_LEN);
	dptr += ROSE_ADDR_LEN;
	faclen = rose_create_facilities(dptr, rose);
	skb_put(skb, faclen);
	dptr += faclen;
	break;

	case ROSE_CALL_ACCEPTED:
	*dptr++ = ROSE_GFI \| lci1;
	*dptr++ = lci2;
	*dptr++ = frametype;
	dptr++ = 0x00; / Address length */
	dptr++ = 0; / Facilities length */
	break;

	case ROSE_CLEAR_REQUEST:
	*dptr++ = ROSE_GFI \| lci1;
	*dptr++ = lci2;
	*dptr++ = frametype;
	*dptr++ = rose->cause;
	*dptr++ = rose->diagnostic;
	break;

	case ROSE_RESET_REQUEST:
	*dptr++ = ROSE_GFI \| lci1;
	*dptr++ = lci2;
	*dptr++ = frametype;
	*dptr++ = ROSE_DTE_ORIGINATED;
	*dptr++ = 0;
	break;

	case ROSE_RR:
	case ROSE_RNR:
	*dptr++ = ROSE_GFI \| lci1;
	*dptr++ = lci2;
	*dptr = frametype;
	*dptr++ \|= (rose->vr << 5) & 0xE0;
	break;

	case ROSE_CLEAR_CONFIRMATION:
	case ROSE_RESET_CONFIRMATION:
	*dptr++ = ROSE_GFI \| lci1;
	*dptr++ = lci2;
	*dptr++ = frametype;
	break;

	default:
	printk(KERN_ERR "ROSE: rose_write_internal - invalid frametype %02X\n", frametype);
	kfree_skb(skb);
	return;
	}

	rose_transmit_link(skb, rose->neighbour);
	}

	int rose_decode(struct sk_buff skb, int ns, int nr, int q, int d, int m)
	{
	unsigned char *frame;

	frame = skb->data;

	ns = nr = q = d = *m = 0;

	switch (frame[2]) {
	case ROSE_CALL_REQUEST:
	case ROSE_CALL_ACCEPTED:
	case ROSE_CLEAR_REQUEST:
	case ROSE_CLEAR_CONFIRMATION:
	case ROSE_RESET_REQUEST:
	case ROSE_RESET_CONFIRMATION:
	return frame[2];
	default:
	break;
	}

	if ((frame[2] & 0x1F) == ROSE_RR \|\|
	(frame[2] & 0x1F) == ROSE_RNR) {
	*nr = (frame[2] >> 5) & 0x07;
	return frame[2] & 0x1F;
	}

	if ((frame[2] & 0x01) == ROSE_DATA) {
	*q = (frame[0] & ROSE_Q_BIT) == ROSE_Q_BIT;
	*d = (frame[0] & ROSE_D_BIT) == ROSE_D_BIT;
	*m = (frame[2] & ROSE_M_BIT) == ROSE_M_BIT;
	*nr = (frame[2] >> 5) & 0x07;
	*ns = (frame[2] >> 1) & 0x07;
	return ROSE_DATA;
	}

	return ROSE_ILLEGAL;
	}

	static int rose_parse_national(unsigned char p, struct rose_facilities_struct facilities, int len)
	{
	unsigned char *pt;
	unsigned char l, lg, n = 0;
	int fac_national_digis_received = 0;

	do {
	switch (*p & 0xC0) {
	case 0x00:
	if (len < 2)
	return -1;
	p += 2;
	n += 2;
	len -= 2;
	break;

	case 0x40:
	if (len < 3)
	return -1;
	if (*p == FAC_NATIONAL_RAND)
	facilities->rand = ((p[1] << 8) & 0xFF00) + ((p[2] << 0) & 0x00FF);
	p += 3;
	n += 3;
	len -= 3;
	break;

	case 0x80:
	if (len < 4)
	return -1;
	p += 4;
	n += 4;
	len -= 4;
	break;

	case 0xC0:
	if (len < 2)
	return -1;
	l = p[1];
	if (len < 2 + l)
	return -1;
	if (*p == FAC_NATIONAL_DEST_DIGI) {
	if (!fac_national_digis_received) {
	if (l < AX25_ADDR_LEN)
	return -1;
	memcpy(&facilities->source_digis[0], p + 2, AX25_ADDR_LEN);
	facilities->source_ndigis = 1;
	}
	}
	else if (*p == FAC_NATIONAL_SRC_DIGI) {
	if (!fac_national_digis_received) {
	if (l < AX25_ADDR_LEN)
	return -1;
	memcpy(&facilities->dest_digis[0], p + 2, AX25_ADDR_LEN);
	facilities->dest_ndigis = 1;
	}
	}
	else if (*p == FAC_NATIONAL_FAIL_CALL) {
	if (l < AX25_ADDR_LEN)
	return -1;
	memcpy(&facilities->fail_call, p + 2, AX25_ADDR_LEN);
	}
	else if (*p == FAC_NATIONAL_FAIL_ADD) {
	if (l < 1 + ROSE_ADDR_LEN)
	return -1;
	memcpy(&facilities->fail_addr, p + 3, ROSE_ADDR_LEN);
	}
	else if (*p == FAC_NATIONAL_DIGIS) {
	if (l % AX25_ADDR_LEN)
	return -1;
	fac_national_digis_received = 1;
	facilities->source_ndigis = 0;
	facilities->dest_ndigis = 0;
	for (pt = p + 2, lg = 0 ; lg < l ; pt += AX25_ADDR_LEN, lg += AX25_ADDR_LEN) {
	if (pt[6] & AX25_HBIT) {
	if (facilities->dest_ndigis >= ROSE_MAX_DIGIS)
	return -1;
	memcpy(&facilities->dest_digis[facilities->dest_ndigis++], pt, AX25_ADDR_LEN);
	} else {
	if (facilities->source_ndigis >= ROSE_MAX_DIGIS)
	return -1;
	memcpy(&facilities->source_digis[facilities->source_ndigis++], pt, AX25_ADDR_LEN);
	}
	}
	}
	p += l + 2;
	n += l + 2;
	len -= l + 2;
	break;
	}
	} while (*p != 0x00 && len > 0);

	return n;
	}

	static int rose_parse_ccitt(unsigned char p, struct rose_facilities_struct facilities, int len)
	{
	unsigned char l, n = 0;
	char callsign[11];

	do {
	switch (*p & 0xC0) {
	case 0x00:
	if (len < 2)
	return -1;
	p += 2;
	n += 2;
	len -= 2;
	break;

	case 0x40:
	if (len < 3)
	return -1;
	p += 3;
	n += 3;
	len -= 3;
	break;

	case 0x80:
	if (len < 4)
	return -1;
	p += 4;
	n += 4;
	len -= 4;
	break;

	case 0xC0:
	if (len < 2)
	return -1;
	l = p[1];

	/* Prevent overflows*/
	if (l < 10 \|\| l > 20)
	return -1;

	if (*p == FAC_CCITT_DEST_NSAP) {
	memcpy(&facilities->source_addr, p + 7, ROSE_ADDR_LEN);
	memcpy(callsign, p + 12, l - 10);
	callsign[l - 10] = '\0';
	asc2ax(&facilities->source_call, callsign);
	}
	if (*p == FAC_CCITT_SRC_NSAP) {
	memcpy(&facilities->dest_addr, p + 7, ROSE_ADDR_LEN);
	memcpy(callsign, p + 12, l - 10);
	callsign[l - 10] = '\0';
	asc2ax(&facilities->dest_call, callsign);
	}
	p += l + 2;
	n += l + 2;
	len -= l + 2;
	break;
	}
	} while (*p != 0x00 && len > 0);

	return n;
	}

	int rose_parse_facilities(unsigned char *p, unsigned packet_len,
	struct rose_facilities_struct *facilities)
	{
	int facilities_len, len;

	facilities_len = *p++;

	if (facilities_len == 0 \|\| (unsigned int)facilities_len > packet_len)
	return 0;

	while (facilities_len >= 3 && *p == 0x00) {
	facilities_len--;
	p++;

	switch (*p) {
	case FAC_NATIONAL: /* National */
	len = rose_parse_national(p + 1, facilities, facilities_len - 1);
	break;

	case FAC_CCITT: /* CCITT */
	len = rose_parse_ccitt(p + 1, facilities, facilities_len - 1);
	break;

	default:
	printk(KERN_DEBUG "ROSE: rose_parse_facilities - unknown facilities family %02X\n", *p);
	len = 1;
	break;
	}

	if (len < 0)
	return 0;
	if (WARN_ON(len >= facilities_len))
	return 0;
	facilities_len -= len + 1;
	p += len + 1;
	}

	return facilities_len == 0;
	}

	static int rose_create_facilities(unsigned char buffer, struct rose_sock rose)
	{
	unsigned char *p = buffer + 1;
	char *callsign;
	char buf[11];
	int len, nb;

	/* National Facilities */
	if (rose->rand != 0 \|\| rose->source_ndigis == 1 \|\| rose->dest_ndigis == 1) {
	*p++ = 0x00;
	*p++ = FAC_NATIONAL;

	if (rose->rand != 0) {
	*p++ = FAC_NATIONAL_RAND;
	*p++ = (rose->rand >> 8) & 0xFF;
	*p++ = (rose->rand >> 0) & 0xFF;
	}

	/* Sent before older facilities */
	if ((rose->source_ndigis > 0) \|\| (rose->dest_ndigis > 0)) {
	int maxdigi = 0;
	*p++ = FAC_NATIONAL_DIGIS;
	p++ = AX25_ADDR_LEN (rose->source_ndigis + rose->dest_ndigis);
	for (nb = 0 ; nb < rose->source_ndigis ; nb++) {
	if (++maxdigi >= ROSE_MAX_DIGIS)
	break;
	memcpy(p, &rose->source_digis[nb], AX25_ADDR_LEN);
	p[6] \|= AX25_HBIT;
	p += AX25_ADDR_LEN;
	}
	for (nb = 0 ; nb < rose->dest_ndigis ; nb++) {
	if (++maxdigi >= ROSE_MAX_DIGIS)
	break;
	memcpy(p, &rose->dest_digis[nb], AX25_ADDR_LEN);
	p[6] &= ~AX25_HBIT;
	p += AX25_ADDR_LEN;
	}
	}

	/* For compatibility */
	if (rose->source_ndigis > 0) {
	*p++ = FAC_NATIONAL_SRC_DIGI;
	*p++ = AX25_ADDR_LEN;
	memcpy(p, &rose->source_digis[0], AX25_ADDR_LEN);
	p += AX25_ADDR_LEN;
	}

	/* For compatibility */
	if (rose->dest_ndigis > 0) {
	*p++ = FAC_NATIONAL_DEST_DIGI;
	*p++ = AX25_ADDR_LEN;
	memcpy(p, &rose->dest_digis[0], AX25_ADDR_LEN);
	p += AX25_ADDR_LEN;
	}
	}

	*p++ = 0x00;
	*p++ = FAC_CCITT;

	*p++ = FAC_CCITT_DEST_NSAP;

	callsign = ax2asc(buf, &rose->dest_call);

	*p++ = strlen(callsign) + 10;
	p++ = (strlen(callsign) + 9) 2; /* ??? */

	p++ = 0x47; p++ = 0x00; *p++ = 0x11;
	p++ = ROSE_ADDR_LEN 2;
	memcpy(p, &rose->dest_addr, ROSE_ADDR_LEN);
	p += ROSE_ADDR_LEN;

	memcpy(p, callsign, strlen(callsign));
	p += strlen(callsign);

	*p++ = FAC_CCITT_SRC_NSAP;

	callsign = ax2asc(buf, &rose->source_call);

	*p++ = strlen(callsign) + 10;
	p++ = (strlen(callsign) + 9) 2; /* ??? */

	p++ = 0x47; p++ = 0x00; *p++ = 0x11;
	p++ = ROSE_ADDR_LEN 2;
	memcpy(p, &rose->source_addr, ROSE_ADDR_LEN);
	p += ROSE_ADDR_LEN;

	memcpy(p, callsign, strlen(callsign));
	p += strlen(callsign);

	len = p - buffer;
	buffer[0] = len - 1;

	return len;
	}

	void rose_disconnect(struct sock *sk, int reason, int cause, int diagnostic)
	{
	struct rose_sock *rose = rose_sk(sk);

	rose_stop_timer(sk);
	rose_stop_idletimer(sk);

	rose_clear_queues(sk);

	rose->lci = 0;
	rose->state = ROSE_STATE_0;

	if (cause != -1)
	rose->cause = cause;

	if (diagnostic != -1)
	rose->diagnostic = diagnostic;

	sk->sk_state = TCP_CLOSE;
	sk->sk_err = reason;
	sk->sk_shutdown \|= SEND_SHUTDOWN;

	if (!sock_flag(sk, SOCK_DEAD)) {
	sk->sk_state_change(sk);
	sock_set_flag(sk, SOCK_DEAD);
	}
	}