/*
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/*
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* AX.25 release 037
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* AX.25 release 037
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*
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*
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* This code REQUIRES 2.1.15 or higher/ NET3.038
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* This code REQUIRES 2.1.15 or higher/ NET3.038
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*
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*
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* This module:
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* This module:
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* This module is free software; you can redistribute it and/or
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* This module is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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* 2 of the License, or (at your option) any later version.
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*
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*
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* Most of this code is based on the SDL diagrams published in the 7th
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* Most of this code is based on the SDL diagrams published in the 7th
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* ARRL Computer Networking Conference papers. The diagrams have mistakes
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* ARRL Computer Networking Conference papers. The diagrams have mistakes
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* in them, but are mostly correct. Before you modify the code could you
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* in them, but are mostly correct. Before you modify the code could you
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* read the SDL diagrams as the code is not obvious and probably very
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* read the SDL diagrams as the code is not obvious and probably very
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* easy to break;
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* easy to break;
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*
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*
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* History
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* History
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* AX.25 036 Jonathan(G4KLX) Split from ax25_subr.c.
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* AX.25 036 Jonathan(G4KLX) Split from ax25_subr.c.
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*/
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*/
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#include <linux/errno.h>
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#include <linux/errno.h>
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#include <linux/types.h>
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#include <linux/types.h>
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#include <linux/socket.h>
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#include <linux/socket.h>
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#include <linux/in.h>
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#include <linux/in.h>
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#include <linux/kernel.h>
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#include <linux/kernel.h>
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#include <linux/sched.h>
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#include <linux/sched.h>
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#include <linux/timer.h>
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#include <linux/timer.h>
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#include <linux/string.h>
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#include <linux/string.h>
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#include <linux/sockios.h>
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#include <linux/sockios.h>
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#include <linux/net.h>
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#include <linux/net.h>
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#include <net/ax25.h>
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#include <net/ax25.h>
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#include <linux/inet.h>
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#include <linux/inet.h>
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#include <linux/netdevice.h>
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#include <linux/netdevice.h>
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#include <linux/skbuff.h>
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#include <linux/skbuff.h>
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#include <net/sock.h>
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#include <net/sock.h>
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#include <asm/uaccess.h>
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#include <asm/uaccess.h>
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#include <asm/system.h>
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#include <asm/system.h>
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#include <linux/fcntl.h>
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#include <linux/fcntl.h>
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#include <linux/mm.h>
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#include <linux/mm.h>
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#include <linux/interrupt.h>
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#include <linux/interrupt.h>
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/*
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/*
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* The null address is defined as a callsign of all spaces with an
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* The null address is defined as a callsign of all spaces with an
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* SSID of zero.
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* SSID of zero.
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*/
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*/
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ax25_address null_ax25_address = {{0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x00}};
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ax25_address null_ax25_address = {{0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x00}};
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|
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/*
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/*
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* ax25 -> ascii conversion
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* ax25 -> ascii conversion
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*/
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*/
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char *ax2asc(ax25_address *a)
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char *ax2asc(ax25_address *a)
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{
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{
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static char buf[11];
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static char buf[11];
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char c, *s;
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char c, *s;
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int n;
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int n;
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for (n = 0, s = buf; n < 6; n++) {
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for (n = 0, s = buf; n < 6; n++) {
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c = (a->ax25_call[n] >> 1) & 0x7F;
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c = (a->ax25_call[n] >> 1) & 0x7F;
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if (c != ' ') *s++ = c;
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if (c != ' ') *s++ = c;
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}
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}
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*s++ = '-';
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*s++ = '-';
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if ((n = ((a->ax25_call[6] >> 1) & 0x0F)) > 9) {
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if ((n = ((a->ax25_call[6] >> 1) & 0x0F)) > 9) {
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*s++ = '1';
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*s++ = '1';
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n -= 10;
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n -= 10;
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}
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}
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*s++ = n + '0';
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*s++ = n + '0';
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*s++ = '\0';
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*s++ = '\0';
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if (*buf == '\0' || *buf == '-')
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if (*buf == '\0' || *buf == '-')
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return "*";
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return "*";
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return buf;
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return buf;
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}
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}
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/*
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/*
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* ascii -> ax25 conversion
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* ascii -> ax25 conversion
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*/
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*/
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ax25_address *asc2ax(char *callsign)
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ax25_address *asc2ax(char *callsign)
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{
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{
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static ax25_address addr;
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static ax25_address addr;
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char *s;
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char *s;
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int n;
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int n;
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for (s = callsign, n = 0; n < 6; n++) {
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for (s = callsign, n = 0; n < 6; n++) {
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if (*s != '\0' && *s != '-')
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if (*s != '\0' && *s != '-')
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addr.ax25_call[n] = *s++;
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addr.ax25_call[n] = *s++;
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else
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else
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addr.ax25_call[n] = ' ';
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addr.ax25_call[n] = ' ';
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addr.ax25_call[n] <<= 1;
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addr.ax25_call[n] <<= 1;
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addr.ax25_call[n] &= 0xFE;
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addr.ax25_call[n] &= 0xFE;
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}
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}
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if (*s++ == '\0') {
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if (*s++ == '\0') {
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addr.ax25_call[6] = 0x00;
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addr.ax25_call[6] = 0x00;
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return &addr;
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return &addr;
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}
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}
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addr.ax25_call[6] = *s++ - '0';
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addr.ax25_call[6] = *s++ - '0';
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if (*s != '\0') {
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if (*s != '\0') {
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addr.ax25_call[6] *= 10;
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addr.ax25_call[6] *= 10;
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addr.ax25_call[6] += *s++ - '0';
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addr.ax25_call[6] += *s++ - '0';
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}
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}
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addr.ax25_call[6] <<= 1;
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addr.ax25_call[6] <<= 1;
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addr.ax25_call[6] &= 0x1E;
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addr.ax25_call[6] &= 0x1E;
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return &addr;
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return &addr;
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}
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}
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/*
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/*
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* Compare two ax.25 addresses
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* Compare two ax.25 addresses
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*/
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*/
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int ax25cmp(ax25_address *a, ax25_address *b)
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int ax25cmp(ax25_address *a, ax25_address *b)
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{
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{
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int ct = 0;
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int ct = 0;
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while (ct < 6) {
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while (ct < 6) {
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if ((a->ax25_call[ct] & 0xFE) != (b->ax25_call[ct] & 0xFE)) /* Clean off repeater bits */
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if ((a->ax25_call[ct] & 0xFE) != (b->ax25_call[ct] & 0xFE)) /* Clean off repeater bits */
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return 1;
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return 1;
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ct++;
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ct++;
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}
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}
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if ((a->ax25_call[ct] & 0x1E) == (b->ax25_call[ct] & 0x1E)) /* SSID without control bit */
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if ((a->ax25_call[ct] & 0x1E) == (b->ax25_call[ct] & 0x1E)) /* SSID without control bit */
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return 0;
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return 0;
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return 2; /* Partial match */
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return 2; /* Partial match */
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}
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}
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/*
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/*
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* Compare two AX.25 digipeater paths.
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* Compare two AX.25 digipeater paths.
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*/
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*/
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int ax25digicmp(ax25_digi *digi1, ax25_digi *digi2)
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int ax25digicmp(ax25_digi *digi1, ax25_digi *digi2)
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{
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{
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int i;
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int i;
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if (digi1->ndigi != digi2->ndigi)
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if (digi1->ndigi != digi2->ndigi)
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return 1;
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return 1;
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if (digi1->lastrepeat != digi2->lastrepeat)
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if (digi1->lastrepeat != digi2->lastrepeat)
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return 1;
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return 1;
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for (i = 0; i < digi1->ndigi; i++)
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for (i = 0; i < digi1->ndigi; i++)
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if (ax25cmp(&digi1->calls[i], &digi2->calls[i]) != 0)
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if (ax25cmp(&digi1->calls[i], &digi2->calls[i]) != 0)
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return 1;
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return 1;
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return 0;
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return 0;
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}
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}
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/*
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/*
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* Given an AX.25 address pull of to, from, digi list, command/response and the start of data
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* Given an AX.25 address pull of to, from, digi list, command/response and the start of data
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*
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*
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*/
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*/
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unsigned char *ax25_addr_parse(unsigned char *buf, int len, ax25_address *src, ax25_address *dest, ax25_digi *digi, int *flags, int *dama)
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unsigned char *ax25_addr_parse(unsigned char *buf, int len, ax25_address *src, ax25_address *dest, ax25_digi *digi, int *flags, int *dama)
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{
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{
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int d = 0;
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int d = 0;
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if (len < 14) return NULL;
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if (len < 14) return NULL;
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if (flags != NULL) {
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if (flags != NULL) {
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*flags = 0;
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*flags = 0;
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if (buf[6] & AX25_CBIT)
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if (buf[6] & AX25_CBIT)
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*flags = AX25_COMMAND;
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*flags = AX25_COMMAND;
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if (buf[13] & AX25_CBIT)
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if (buf[13] & AX25_CBIT)
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*flags = AX25_RESPONSE;
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*flags = AX25_RESPONSE;
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}
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}
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if (dama != NULL)
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if (dama != NULL)
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*dama = ~buf[13] & AX25_DAMA_FLAG;
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*dama = ~buf[13] & AX25_DAMA_FLAG;
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/* Copy to, from */
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/* Copy to, from */
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if (dest != NULL)
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if (dest != NULL)
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memcpy(dest, buf + 0, AX25_ADDR_LEN);
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memcpy(dest, buf + 0, AX25_ADDR_LEN);
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if (src != NULL)
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if (src != NULL)
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memcpy(src, buf + 7, AX25_ADDR_LEN);
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memcpy(src, buf + 7, AX25_ADDR_LEN);
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buf += 2 * AX25_ADDR_LEN;
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buf += 2 * AX25_ADDR_LEN;
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len -= 2 * AX25_ADDR_LEN;
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len -= 2 * AX25_ADDR_LEN;
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digi->lastrepeat = -1;
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digi->lastrepeat = -1;
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digi->ndigi = 0;
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digi->ndigi = 0;
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while (!(buf[-1] & AX25_EBIT)) {
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while (!(buf[-1] & AX25_EBIT)) {
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if (d >= AX25_MAX_DIGIS) return NULL; /* Max of 6 digis */
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if (d >= AX25_MAX_DIGIS) return NULL; /* Max of 6 digis */
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if (len < 7) return NULL; /* Short packet */
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if (len < 7) return NULL; /* Short packet */
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memcpy(&digi->calls[d], buf, AX25_ADDR_LEN);
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memcpy(&digi->calls[d], buf, AX25_ADDR_LEN);
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digi->ndigi = d + 1;
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digi->ndigi = d + 1;
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if (buf[6] & AX25_HBIT) {
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if (buf[6] & AX25_HBIT) {
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digi->repeated[d] = 1;
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digi->repeated[d] = 1;
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digi->lastrepeat = d;
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digi->lastrepeat = d;
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} else {
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} else {
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digi->repeated[d] = 0;
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digi->repeated[d] = 0;
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}
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}
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buf += AX25_ADDR_LEN;
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buf += AX25_ADDR_LEN;
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len -= AX25_ADDR_LEN;
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len -= AX25_ADDR_LEN;
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d++;
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d++;
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}
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}
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return buf;
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return buf;
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}
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}
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/*
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/*
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* Assemble an AX.25 header from the bits
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* Assemble an AX.25 header from the bits
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*/
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*/
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int ax25_addr_build(unsigned char *buf, ax25_address *src, ax25_address *dest, ax25_digi *d, int flag, int modulus)
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int ax25_addr_build(unsigned char *buf, ax25_address *src, ax25_address *dest, ax25_digi *d, int flag, int modulus)
|
{
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{
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int len = 0;
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int len = 0;
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int ct = 0;
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int ct = 0;
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memcpy(buf, dest, AX25_ADDR_LEN);
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memcpy(buf, dest, AX25_ADDR_LEN);
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buf[6] &= ~(AX25_EBIT | AX25_CBIT);
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buf[6] &= ~(AX25_EBIT | AX25_CBIT);
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buf[6] |= AX25_SSSID_SPARE;
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buf[6] |= AX25_SSSID_SPARE;
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if (flag == AX25_COMMAND) buf[6] |= AX25_CBIT;
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if (flag == AX25_COMMAND) buf[6] |= AX25_CBIT;
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buf += AX25_ADDR_LEN;
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buf += AX25_ADDR_LEN;
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len += AX25_ADDR_LEN;
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len += AX25_ADDR_LEN;
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memcpy(buf, src, AX25_ADDR_LEN);
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memcpy(buf, src, AX25_ADDR_LEN);
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buf[6] &= ~(AX25_EBIT | AX25_CBIT);
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buf[6] &= ~(AX25_EBIT | AX25_CBIT);
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buf[6] &= ~AX25_SSSID_SPARE;
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buf[6] &= ~AX25_SSSID_SPARE;
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|
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if (modulus == AX25_MODULUS)
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if (modulus == AX25_MODULUS)
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buf[6] |= AX25_SSSID_SPARE;
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buf[6] |= AX25_SSSID_SPARE;
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else
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else
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buf[6] |= AX25_ESSID_SPARE;
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buf[6] |= AX25_ESSID_SPARE;
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|
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if (flag == AX25_RESPONSE) buf[6] |= AX25_CBIT;
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if (flag == AX25_RESPONSE) buf[6] |= AX25_CBIT;
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|
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/*
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/*
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* Fast path the normal digiless path
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* Fast path the normal digiless path
|
*/
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*/
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if (d == NULL || d->ndigi == 0) {
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if (d == NULL || d->ndigi == 0) {
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buf[6] |= AX25_EBIT;
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buf[6] |= AX25_EBIT;
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return 2 * AX25_ADDR_LEN;
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return 2 * AX25_ADDR_LEN;
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}
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}
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buf += AX25_ADDR_LEN;
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buf += AX25_ADDR_LEN;
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len += AX25_ADDR_LEN;
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len += AX25_ADDR_LEN;
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|
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while (ct < d->ndigi) {
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while (ct < d->ndigi) {
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memcpy(buf, &d->calls[ct], AX25_ADDR_LEN);
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memcpy(buf, &d->calls[ct], AX25_ADDR_LEN);
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|
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if (d->repeated[ct])
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if (d->repeated[ct])
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buf[6] |= AX25_HBIT;
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buf[6] |= AX25_HBIT;
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else
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else
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buf[6] &= ~AX25_HBIT;
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buf[6] &= ~AX25_HBIT;
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|
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buf[6] &= ~AX25_EBIT;
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buf[6] &= ~AX25_EBIT;
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buf[6] |= AX25_SSSID_SPARE;
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buf[6] |= AX25_SSSID_SPARE;
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|
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buf += AX25_ADDR_LEN;
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buf += AX25_ADDR_LEN;
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len += AX25_ADDR_LEN;
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len += AX25_ADDR_LEN;
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ct++;
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ct++;
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}
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}
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|
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buf[-1] |= AX25_EBIT;
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buf[-1] |= AX25_EBIT;
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|
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return len;
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return len;
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}
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}
|
|
|
int ax25_addr_size(ax25_digi *dp)
|
int ax25_addr_size(ax25_digi *dp)
|
{
|
{
|
if (dp == NULL)
|
if (dp == NULL)
|
return 2 * AX25_ADDR_LEN;
|
return 2 * AX25_ADDR_LEN;
|
|
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return AX25_ADDR_LEN * (2 + dp->ndigi);
|
return AX25_ADDR_LEN * (2 + dp->ndigi);
|
}
|
}
|
|
|
/*
|
/*
|
* Reverse Digipeat List. May not pass both parameters as same struct
|
* Reverse Digipeat List. May not pass both parameters as same struct
|
*/
|
*/
|
void ax25_digi_invert(ax25_digi *in, ax25_digi *out)
|
void ax25_digi_invert(ax25_digi *in, ax25_digi *out)
|
{
|
{
|
int ct;
|
int ct;
|
|
|
out->ndigi = in->ndigi;
|
out->ndigi = in->ndigi;
|
out->lastrepeat = in->ndigi - in->lastrepeat - 2;
|
out->lastrepeat = in->ndigi - in->lastrepeat - 2;
|
|
|
/* Invert the digipeaters */
|
/* Invert the digipeaters */
|
for (ct = 0; ct < in->ndigi; ct++) {
|
for (ct = 0; ct < in->ndigi; ct++) {
|
out->calls[ct] = in->calls[in->ndigi - ct - 1];
|
out->calls[ct] = in->calls[in->ndigi - ct - 1];
|
|
|
if (ct <= out->lastrepeat) {
|
if (ct <= out->lastrepeat) {
|
out->calls[ct].ax25_call[6] |= AX25_HBIT;
|
out->calls[ct].ax25_call[6] |= AX25_HBIT;
|
out->repeated[ct] = 1;
|
out->repeated[ct] = 1;
|
} else {
|
} else {
|
out->calls[ct].ax25_call[6] &= ~AX25_HBIT;
|
out->calls[ct].ax25_call[6] &= ~AX25_HBIT;
|
out->repeated[ct] = 0;
|
out->repeated[ct] = 0;
|
}
|
}
|
}
|
}
|
}
|
}
|
|
|
|
|
