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/* kiss.c KISS assembly and byte-stuffing stuff
*
* Copyright 1991, Michael Westerhof, Sun Microsystems, Inc.
* This software may be freely used, distributed, or modified, providing
* this header is not removed.
*
* This is the only module that knows about the internal structure of
* KISS frames.
*/
/*
* dual port changes Feb 95 ve3pnx & ve3djf
*/
#include <stdio.h>
#include <syslog.h>
#include "ax25ipd.h"
#define FEND 0xc0
#define FESC 0xdb
#define TFEND 0xdc
#define TFESC 0xdd
static unsigned char iframe[MAX_FRAME];
static unsigned char *ifptr;
static int ifcount;
static int iescaped;
static unsigned char oframe[MAX_FRAME];
static unsigned char *ofptr;
static int ofcount;
#define PTABLE_SIZE 10
static struct param_table_entry {
unsigned char parameter;
unsigned char value;
} param_tbl[PTABLE_SIZE];
static int param_tbl_top;
/*
* Initialize the KISS variables
*/
void kiss_init(void)
{
ifptr = iframe;
ifcount = 0;
iescaped = 0;
ofptr = oframe;
ofcount = 0;
param_tbl_top = 0;
}
/*
* Assemble a kiss frame from random hunks of incoming data
* Calls the "from_kiss" routine with the kiss frame when a
* frame has been assembled.
*/
void assemble_kiss(unsigned char *buf, int l)
{
int i;
unsigned char c;
for (i = 0; i < l; i++, buf++) {
c = *buf;
if (c == FEND) {
if (ifcount > 0) {
/* Make sure that the control byte is zero */
if (*iframe == '\0' || *iframe == 0x10) {
/* Room for CRC in buffer? */
if (ifcount < (MAX_FRAME - 2)) {
stats.kiss_in++;
from_kiss(iframe +
1, ifcount - 1);
} else {
stats.kiss_toobig++;
LOGL2
("assemble_kiss: dumped - frame too large\n");
}
} else {
stats.kiss_badtype++;
LOGL2
("assemble_kiss: dumped - control byte non-zero\n");
}
}
ifcount = 0;
iescaped = 0;
ifptr = iframe;
continue;
}
if (c == FESC) {
iescaped = 1;
continue;
}
if (iescaped) {
if (c == TFEND)
c = FEND;
if (c == TFESC)
c = FESC;
iescaped = 0;
}
if (ifcount < MAX_FRAME) {
*ifptr = c;
ifptr++;
ifcount++;
}
} /* for every character in the buffer */
}
/* convert a standard AX25 frame into a kiss frame */
void send_kiss(unsigned char type, unsigned char *buf, int l)
{
#define KISSEMIT(x) if (ofcount<MAX_FRAME) {*ofptr=(x);ofptr++;ofcount++;}
int i;
ofptr = oframe;
ofcount = 0;
KISSEMIT(FEND);
if (type == FEND) {
KISSEMIT(FESC);
KISSEMIT(TFEND);
} else if (type == FESC) {
KISSEMIT(FESC);
KISSEMIT(TFESC);
} else {
KISSEMIT(type);
}
for (i = 0; i < l; i++, buf++) {
if (*buf == FEND) {
KISSEMIT(FESC);
KISSEMIT(TFEND);
} else if (*buf == FESC) {
KISSEMIT(FESC);
KISSEMIT(TFESC);
} else {
KISSEMIT(*buf);
}
} /* for each character in the incoming AX25 frame */
KISSEMIT(FEND);
send_tty(oframe, ofcount);
}
/* Add an entry to the parameter table */
void param_add(int p, int v)
{
if (param_tbl_top >= PTABLE_SIZE) {
fprintf(stderr, "param table is full; entry ignored.\n");
}
param_tbl[param_tbl_top].parameter = p & 0xff;
param_tbl[param_tbl_top].value = v & 0xff;
LOGL4("added param: %d\t%d\n",
param_tbl[param_tbl_top].parameter,
param_tbl[param_tbl_top].value);
param_tbl_top++;
}
/* dump the contents of the parameter table */
void dump_params(void)
{
int i;
LOGL1("\n%d parameters\n", param_tbl_top);
for (i = 0; i < param_tbl_top; i++) {
LOGL1(" %d\t%d\n",
param_tbl[i].parameter, param_tbl[i].value);
}
fflush(stdout);
}
/* send the parameters to the TNC */
void send_params(void)
{
int i;
unsigned char p, v;
for (i = 0; i < param_tbl_top; i++) {
p = param_tbl[i].parameter;
v = param_tbl[i].value;
send_kiss(p, &v, 1);
LOGL2("send_params: param %d %d\n", p, v);
}
}
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