[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 <asm/uaccess.h>
#include <asm/system.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;	/* Max of 6 digis */
		if (len < 7) return NULL;	/* Short packet */

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