[linux.git] / net / ax25 / ax25_addr.c

/*
 * This program 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.
 *
 * Copyright (C) Jonathan Naylor G4KLX ([email protected])
 */
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <net/ax25.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <linux/uaccess.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/interrupt.h>

/*
 * The default broadcast address of an interface is QST-0; the default address
 * is LINUX-1.  The null address is defined as a callsign of all spaces with
 * an SSID of zero.
 */

const ax25_address ax25_bcast =
	{{'Q' << 1, 'S' << 1, 'T' << 1, ' ' << 1, ' ' << 1, ' ' << 1, 0 << 1}};
const ax25_address ax25_defaddr =
	{{'L' << 1, 'I' << 1, 'N' << 1, 'U' << 1, 'X' << 1, ' ' << 1, 1 << 1}};
const ax25_address null_ax25_address =
	{{' ' << 1, ' ' << 1, ' ' << 1, ' ' << 1, ' ' << 1, ' ' << 1, 0 << 1}};

EXPORT_SYMBOL_GPL(ax25_bcast);
EXPORT_SYMBOL_GPL(ax25_defaddr);
EXPORT_SYMBOL(null_ax25_address);

/*
 *	ax25 -> ascii conversion
 */
char *ax2asc(char *buf, const ax25_address *a)
{
	char c, *s;
	int n;

	for (n = 0, s = buf; n < 6; n++) {
		c = (a->ax25_call[n] >> 1) & 0x7F;

		if (c != ' ') *s++ = c;
	}

	*s++ = '-';

	if ((n = ((a->ax25_call[6] >> 1) & 0x0F)) > 9) {
		*s++ = '1';
		n -= 10;
	}

	*s++ = n + '0';
	*s++ = '\0';

	if (*buf == '\0' || *buf == '-')
	   return "*";

	return buf;

}

EXPORT_SYMBOL(ax2asc);

/*
 *	ascii -> ax25 conversion
 */
void asc2ax(ax25_address *addr, const char *callsign)
{
	const char *s;
	int n;

	for (s = callsign, n = 0; n < 6; n++) {
		if (*s != '\0' && *s != '-')
			addr->ax25_call[n] = *s++;
		else
			addr->ax25_call[n] = ' ';
		addr->ax25_call[n] <<= 1;
		addr->ax25_call[n] &= 0xFE;
	}

	if (*s++ == '\0') {
		addr->ax25_call[6] = 0x00;
		return;
	}

	addr->ax25_call[6] = *s++ - '0';

	if (*s != '\0') {
		addr->ax25_call[6] *= 10;
		addr->ax25_call[6] += *s++ - '0';
	}

	addr->ax25_call[6] <<= 1;
	addr->ax25_call[6] &= 0x1E;
}

EXPORT_SYMBOL(asc2ax);

/*
 *	Compare two ax.25 addresses
 */
int ax25cmp(const ax25_address *a, const ax25_address *b)
{
	int ct = 0;

	while (ct < 6) {
		if ((a->ax25_call[ct] & 0xFE) != (b->ax25_call[ct] & 0xFE))	/* Clean off repeater bits */
			return 1;
		ct++;
	}

	if ((a->ax25_call[ct] & 0x1E) == (b->ax25_call[ct] & 0x1E))	/* SSID without control bit */
		return 0;

	return 2;			/* Partial match */
}

EXPORT_SYMBOL(ax25cmp);

/*
 *	Compare two AX.25 digipeater paths.
 */
int ax25digicmp(const ax25_digi *digi1, const ax25_digi *digi2)
{
	int i;

	if (digi1->ndigi != digi2->ndigi)
		return 1;

	if (digi1->lastrepeat != digi2->lastrepeat)
		return 1;

	for (i = 0; i < digi1->ndigi; i++)
		if (ax25cmp(&digi1->calls[i], &digi2->calls[i]) != 0)
			return 1;

	return 0;
}

/*
 *	Given an AX.25 address pull of to, from, digi list, command/response and the start of data
 *
 */
const unsigned char *ax25_addr_parse(const unsigned char *buf, int len,
	ax25_address *src, ax25_address *dest, ax25_digi *digi, int *flags,
	int *dama)
{
	int d = 0;

	if (len < 14) return NULL;

	if (flags != NULL) {
		*flags = 0;

		if (buf[6] & AX25_CBIT)
			*flags = AX25_COMMAND;
		if (buf[13] & AX25_CBIT)
			*flags = AX25_RESPONSE;
	}

	if (dama != NULL)
		*dama = ~buf[13] & AX25_DAMA_FLAG;

	/* Copy to, from */
	if (dest != NULL)
		memcpy(dest, buf + 0, AX25_ADDR_LEN);
	if (src != NULL)
		memcpy(src,  buf + 7, AX25_ADDR_LEN);

	buf += 2 * AX25_ADDR_LEN;
	len -= 2 * AX25_ADDR_LEN;

	digi->lastrepeat = -1;
	digi->ndigi      = 0;

	while (!(buf[-1] & AX25_EBIT)) {
		if (d >= AX25_MAX_DIGIS)
			return NULL;
		if (len < AX25_ADDR_LEN)
			return NULL;

		memcpy(&digi->calls[d], buf, AX25_ADDR_LEN);
		digi->ndigi = d + 1;

		if (buf[6] & AX25_HBIT) {
			digi->repeated[d] = 1;
			digi->lastrepeat  = d;
		} else {
			digi->repeated[d] = 0;
		}

		buf += AX25_ADDR_LEN;
		len -= AX25_ADDR_LEN;
		d++;
	}

	return buf;
}

/*
 *	Assemble an AX.25 header from the bits
 */
int ax25_addr_build(unsigned char *buf, const ax25_address *src,
	const ax25_address *dest, const ax25_digi *d, int flag, int modulus)
{
	int len = 0;
	int ct  = 0;

	memcpy(buf, dest, AX25_ADDR_LEN);
	buf[6] &= ~(AX25_EBIT | AX25_CBIT);
	buf[6] |= AX25_SSSID_SPARE;

	if (flag == AX25_COMMAND) buf[6] |= AX25_CBIT;

	buf += AX25_ADDR_LEN;
	len += AX25_ADDR_LEN;

	memcpy(buf, src, AX25_ADDR_LEN);
	buf[6] &= ~(AX25_EBIT | AX25_CBIT);
	buf[6] &= ~AX25_SSSID_SPARE;

	if (modulus == AX25_MODULUS)
		buf[6] |= AX25_SSSID_SPARE;
	else
		buf[6] |= AX25_ESSID_SPARE;

	if (flag == AX25_RESPONSE) buf[6] |= AX25_CBIT;

	/*
	 *	Fast path the normal digiless path
	 */
	if (d == NULL || d->ndigi == 0) {
		buf[6] |= AX25_EBIT;
		return 2 * AX25_ADDR_LEN;
	}

	buf += AX25_ADDR_LEN;
	len += AX25_ADDR_LEN;

	while (ct < d->ndigi) {
		memcpy(buf, &d->calls[ct], AX25_ADDR_LEN);

		if (d->repeated[ct])
			buf[6] |= AX25_HBIT;
		else
			buf[6] &= ~AX25_HBIT;

		buf[6] &= ~AX25_EBIT;
		buf[6] |= AX25_SSSID_SPARE;

		buf += AX25_ADDR_LEN;
		len += AX25_ADDR_LEN;
		ct++;
	}

	buf[-1] |= AX25_EBIT;

	return len;
}

int ax25_addr_size(const ax25_digi *dp)
{
	if (dp == NULL)
		return 2 * AX25_ADDR_LEN;

	return AX25_ADDR_LEN * (2 + dp->ndigi);
}

/*
 *	Reverse Digipeat List. May not pass both parameters as same struct
 */
void ax25_digi_invert(const ax25_digi *in, ax25_digi *out)
{
	int ct;

	out->ndigi      = in->ndigi;
	out->lastrepeat = in->ndigi - in->lastrepeat - 2;

	/* Invert the digipeaters */
	for (ct = 0; ct < in->ndigi; ct++) {
		out->calls[ct] = in->calls[in->ndigi - ct - 1];

		if (ct <= out->lastrepeat) {
			out->calls[ct].ax25_call[6] |= AX25_HBIT;
			out->repeated[ct]            = 1;
		} else {
			out->calls[ct].ax25_call[6] &= ~AX25_HBIT;
			out->repeated[ct]            = 0;
		}
	}
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* This program is free software; you can redistribute it and/or modify
	3	* it under the terms of the GNU General Public License as published by
	4	* the Free Software Foundation; either version 2 of the License, or
	5	* (at your option) any later version.
	6	*
	7	* Copyright (C) Jonathan Naylor G4KLX ([email protected])
	8	*/
	9	#include <linux/errno.h>
	10	#include <linux/types.h>
	11	#include <linux/socket.h>
	12	#include <linux/in.h>
	13	#include <linux/kernel.h>
70868eac	14	#include <linux/module.h>
1da177e4 LT	15	#include <linux/timer.h>
	16	#include <linux/string.h>
	17	#include <linux/sockios.h>
	18	#include <linux/net.h>
	19	#include <net/ax25.h>
	20	#include <linux/inet.h>
	21	#include <linux/netdevice.h>
	22	#include <linux/skbuff.h>
	23	#include <net/sock.h>
7c0f6ba6	24	#include <linux/uaccess.h>
1da177e4 LT	25	#include <linux/fcntl.h>
	26	#include <linux/mm.h>
	27	#include <linux/interrupt.h>
	28
	29	/*
15b1c0e8 RB	30	* The default broadcast address of an interface is QST-0; the default address
	31	* is LINUX-1. The null address is defined as a callsign of all spaces with
	32	* an SSID of zero.
1da177e4	33	*/
1da177e4	34
15b1c0e8 RB	35	const ax25_address ax25_bcast =
	36	{{'Q' << 1, 'S' << 1, 'T' << 1, ' ' << 1, ' ' << 1, ' ' << 1, 0 << 1}};
	37	const ax25_address ax25_defaddr =
	38	{{'L' << 1, 'I' << 1, 'N' << 1, 'U' << 1, 'X' << 1, ' ' << 1, 1 << 1}};
	39	const ax25_address null_ax25_address =
	40	{{' ' << 1, ' ' << 1, ' ' << 1, ' ' << 1, ' ' << 1, ' ' << 1, 0 << 1}};
	41
	42	EXPORT_SYMBOL_GPL(ax25_bcast);
	43	EXPORT_SYMBOL_GPL(ax25_defaddr);
70868eac RB	44	EXPORT_SYMBOL(null_ax25_address);
70868eac RB	45
1da177e4 LT	46	/*
	47	* ax25 -> ascii conversion
	48	*/
e8cc49bb	49	char ax2asc(char buf, const ax25_address *a)
1da177e4	50	{
1da177e4 LT	51	char c, *s;
	52	int n;
	53
	54	for (n = 0, s = buf; n < 6; n++) {
	55	c = (a->ax25_call[n] >> 1) & 0x7F;
	56
	57	if (c != ' ') *s++ = c;
	58	}
	59
	60	*s++ = '-';
	61
	62	if ((n = ((a->ax25_call[6] >> 1) & 0x0F)) > 9) {
	63	*s++ = '1';
	64	n -= 10;
	65	}
	66
	67	*s++ = n + '0';
	68	*s++ = '\0';
	69
	70	if (buf == '\0' \|\| buf == '-')
	71	return "*";
	72
	73	return buf;
	74
	75	}
	76
70868eac RB	77	EXPORT_SYMBOL(ax2asc);
70868eac RB	78
1da177e4 LT	79	/*
	80	* ascii -> ax25 conversion
	81	*/
e8cc49bb	82	void asc2ax(ax25_address addr, const char callsign)
1da177e4	83	{
f654c854	84	const char *s;
1da177e4 LT	85	int n;
	86
	87	for (s = callsign, n = 0; n < 6; n++) {
	88	if (s != '\0' && s != '-')
baed16a7	89	addr->ax25_call[n] = *s++;
1da177e4	90	else
baed16a7 RB	91	addr->ax25_call[n] = ' ';
	92	addr->ax25_call[n] <<= 1;
	93	addr->ax25_call[n] &= 0xFE;
1da177e4 LT	94	}
	95
	96	if (*s++ == '\0') {
baed16a7 RB	97	addr->ax25_call[6] = 0x00;
baed16a7 RB	98	return;
1da177e4 LT	99	}
1da177e4 LT	100
baed16a7	101	addr->ax25_call[6] = *s++ - '0';
1da177e4 LT	102
1da177e4 LT	103	if (*s != '\0') {
baed16a7 RB	104	addr->ax25_call[6] *= 10;
baed16a7 RB	105	addr->ax25_call[6] += *s++ - '0';
1da177e4 LT	106	}
1da177e4 LT	107
baed16a7 RB	108	addr->ax25_call[6] <<= 1;
baed16a7 RB	109	addr->ax25_call[6] &= 0x1E;
1da177e4 LT	110	}
1da177e4 LT	111
70868eac RB	112	EXPORT_SYMBOL(asc2ax);
70868eac RB	113
1da177e4 LT	114	/*
	115	* Compare two ax.25 addresses
	116	*/
e8cc49bb	117	int ax25cmp(const ax25_address a, const ax25_address b)
1da177e4 LT	118	{
	119	int ct = 0;
	120
	121	while (ct < 6) {
	122	if ((a->ax25_call[ct] & 0xFE) != (b->ax25_call[ct] & 0xFE)) /* Clean off repeater bits */
	123	return 1;
	124	ct++;
	125	}
	126
528930b9 YH	127	if ((a->ax25_call[ct] & 0x1E) == (b->ax25_call[ct] & 0x1E)) /* SSID without control bit */
528930b9 YH	128	return 0;
1da177e4	129
528930b9	130	return 2; /* Partial match */
1da177e4 LT	131	}
1da177e4 LT	132
70868eac RB	133	EXPORT_SYMBOL(ax25cmp);
70868eac RB	134
1da177e4 LT	135	/*
	136	* Compare two AX.25 digipeater paths.
	137	*/
e8cc49bb	138	int ax25digicmp(const ax25_digi digi1, const ax25_digi digi2)
1da177e4 LT	139	{
	140	int i;
	141
	142	if (digi1->ndigi != digi2->ndigi)
	143	return 1;
	144
	145	if (digi1->lastrepeat != digi2->lastrepeat)
	146	return 1;
	147
	148	for (i = 0; i < digi1->ndigi; i++)
	149	if (ax25cmp(&digi1->calls[i], &digi2->calls[i]) != 0)
	150	return 1;
	151
	152	return 0;
	153	}
	154
	155	/*
	156	* Given an AX.25 address pull of to, from, digi list, command/response and the start of data
	157	*
	158	*/
e8cc49bb RB	159	const unsigned char ax25_addr_parse(const unsigned char buf, int len,
	160	ax25_address src, ax25_address dest, ax25_digi digi, int flags,
	161	int *dama)
1da177e4 LT	162	{
	163	int d = 0;
	164
	165	if (len < 14) return NULL;
	166
	167	if (flags != NULL) {
	168	*flags = 0;
	169
	170	if (buf[6] & AX25_CBIT)
	171	*flags = AX25_COMMAND;
	172	if (buf[13] & AX25_CBIT)
	173	*flags = AX25_RESPONSE;
	174	}
	175
	176	if (dama != NULL)
	177	*dama = ~buf[13] & AX25_DAMA_FLAG;
	178
	179	/* Copy to, from */
	180	if (dest != NULL)
	181	memcpy(dest, buf + 0, AX25_ADDR_LEN);
	182	if (src != NULL)
	183	memcpy(src, buf + 7, AX25_ADDR_LEN);
	184
	185	buf += 2 * AX25_ADDR_LEN;
	186	len -= 2 * AX25_ADDR_LEN;
	187
	188	digi->lastrepeat = -1;
	189	digi->ndigi = 0;
	190
	191	while (!(buf[-1] & AX25_EBIT)) {
5c9df5fe DC	192	if (d >= AX25_MAX_DIGIS)
	193	return NULL;
	194	if (len < AX25_ADDR_LEN)
	195	return NULL;
1da177e4 LT	196
	197	memcpy(&digi->calls[d], buf, AX25_ADDR_LEN);
	198	digi->ndigi = d + 1;
	199
	200	if (buf[6] & AX25_HBIT) {
	201	digi->repeated[d] = 1;
	202	digi->lastrepeat = d;
	203	} else {
	204	digi->repeated[d] = 0;
	205	}
	206
	207	buf += AX25_ADDR_LEN;
	208	len -= AX25_ADDR_LEN;
	209	d++;
	210	}
	211
	212	return buf;
	213	}
	214
	215	/*
	216	* Assemble an AX.25 header from the bits
	217	*/
e8cc49bb RB	218	int ax25_addr_build(unsigned char buf, const ax25_address src,
e8cc49bb RB	219	const ax25_address dest, const ax25_digi d, int flag, int modulus)
1da177e4 LT	220	{
	221	int len = 0;
	222	int ct = 0;
	223
	224	memcpy(buf, dest, AX25_ADDR_LEN);
	225	buf[6] &= ~(AX25_EBIT \| AX25_CBIT);
	226	buf[6] \|= AX25_SSSID_SPARE;
	227
	228	if (flag == AX25_COMMAND) buf[6] \|= AX25_CBIT;
	229
	230	buf += AX25_ADDR_LEN;
	231	len += AX25_ADDR_LEN;
	232
	233	memcpy(buf, src, AX25_ADDR_LEN);
	234	buf[6] &= ~(AX25_EBIT \| AX25_CBIT);
	235	buf[6] &= ~AX25_SSSID_SPARE;
	236
	237	if (modulus == AX25_MODULUS)
	238	buf[6] \|= AX25_SSSID_SPARE;
	239	else
	240	buf[6] \|= AX25_ESSID_SPARE;
	241
	242	if (flag == AX25_RESPONSE) buf[6] \|= AX25_CBIT;
	243
	244	/*
	245	* Fast path the normal digiless path
	246	*/
	247	if (d == NULL \|\| d->ndigi == 0) {
	248	buf[6] \|= AX25_EBIT;
	249	return 2 * AX25_ADDR_LEN;
	250	}
	251
	252	buf += AX25_ADDR_LEN;
	253	len += AX25_ADDR_LEN;
	254
	255	while (ct < d->ndigi) {
	256	memcpy(buf, &d->calls[ct], AX25_ADDR_LEN);
	257
	258	if (d->repeated[ct])
	259	buf[6] \|= AX25_HBIT;
	260	else
	261	buf[6] &= ~AX25_HBIT;
	262
	263	buf[6] &= ~AX25_EBIT;
	264	buf[6] \|= AX25_SSSID_SPARE;
	265
	266	buf += AX25_ADDR_LEN;
	267	len += AX25_ADDR_LEN;
	268	ct++;
	269	}
	270
	271	buf[-1] \|= AX25_EBIT;
	272
	273	return len;
	274	}
	275
e8cc49bb	276	int ax25_addr_size(const ax25_digi *dp)
1da177e4 LT	277	{
	278	if (dp == NULL)
	279	return 2 * AX25_ADDR_LEN;
	280
	281	return AX25_ADDR_LEN * (2 + dp->ndigi);
	282	}
	283
	284	/*
	285	* Reverse Digipeat List. May not pass both parameters as same struct
	286	*/
e8cc49bb	287	void ax25_digi_invert(const ax25_digi in, ax25_digi out)
1da177e4 LT	288	{
	289	int ct;
	290
	291	out->ndigi = in->ndigi;
	292	out->lastrepeat = in->ndigi - in->lastrepeat - 2;
	293
	294	/* Invert the digipeaters */
	295	for (ct = 0; ct < in->ndigi; ct++) {
	296	out->calls[ct] = in->calls[in->ndigi - ct - 1];
	297
	298	if (ct <= out->lastrepeat) {
	299	out->calls[ct].ax25_call[6] \|= AX25_HBIT;
	300	out->repeated[ct] = 1;
	301	} else {
	302	out->calls[ct].ax25_call[6] &= ~AX25_HBIT;
	303	out->repeated[ct] = 0;
	304	}
	305	}
	306	}
	307