linux/net/ax25/ax25_addr.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

304 lines
5.8 KiB
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/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;
}
}
}