ESP32IGate/lib/LibAPRS_ESP32/AX25.cpp

414 lines
10 KiB
C++

// Based on work by Francesco Sacchi
#include "Arduino.h"
#include <string.h>
#include <stdlib.h>
#include <strings.h>
#include <ctype.h>
#include <stdio.h>
#include "AX25.h"
#include "HDLC.h"
#include "CRC-CCIT.h"
#include "AFSK.h"
size_t ctxbufflen;
uint8_t *ctxbuffer;
#define typeof(x) __typeof__(x)
#define countof(a) sizeof(a) / sizeof(a[0])
#define MIN(a, b) ( \
{ \
typeof(a) _a = (a); \
typeof(b) _b = (b); \
((typeof(_a))((_a < _b) ? _a : _b)); \
})
#define DECODE_CALL(buf, addr) \
for (unsigned i = 0; i < sizeof((addr)) - CALL_OVERSPACE; i++) \
{ \
char c = (*(buf)++ >> 1); \
(addr)[i] = (c == ' ') ? '\x0' : c; \
}
#define AX25_SET_REPEATED(msg, idx, val) \
do \
{ \
if (val) \
{ \
(msg)->rpt_flags |= _BV(idx); \
} \
else \
{ \
(msg)->rpt_flags &= ~_BV(idx); \
} \
} while (0)
extern int LibAPRS_vref;
static void ax25_putchar(AX25Ctx *ctx, uint8_t c);
void ax25_init(AX25Ctx *ctx, ax25_callback_t hook)
{
memset(ctx, 0, sizeof(*ctx));
ctx->hook = hook;
ctx->crc_in = ctx->crc_out = CRC_CCIT_INIT_VAL;
}
static void ax25_decode(AX25Ctx *ctx)
{
AX25Msg msg;
ctxbufflen = ctx->frame_len - 2;
ctxbuffer = ctx->buf;
uint8_t *buf = ctx->buf;
DECODE_CALL(buf, msg.dst.call);
msg.dst.ssid = (*buf++ >> 1) & 0x0F;
msg.dst.call[6] = 0;
DECODE_CALL(buf, msg.src.call);
msg.src.ssid = (*buf >> 1) & 0x0F;
msg.src.call[6] = 0;
for (msg.rpt_count = 0; !(*buf++ & 0x01) && (msg.rpt_count < countof(msg.rpt_list)); msg.rpt_count++)
{
DECODE_CALL(buf, msg.rpt_list[msg.rpt_count].call);
msg.rpt_list[msg.rpt_count].ssid = (*buf >> 1) & 0x0F;
AX25_SET_REPEATED(&msg, msg.rpt_count, (*buf & 0x80));
msg.rpt_list[msg.rpt_count].call[6] = 0;
}
msg.ctrl = *buf++;
if (msg.ctrl != AX25_CTRL_UI)
{
return;
}
msg.pid = *buf++;
if (msg.pid != AX25_PID_NOLAYER3)
{
return;
}
memset(msg.info,0,sizeof(msg.info));
msg.len = ctx->frame_len - 2 - (buf - ctx->buf);
memcpy(msg.info,buf,msg.len);
//msg.info[msg.len]=0;
//msg.info = buf;
if (ctx->hook)
{
cli();
ctx->hook(&msg);
sei();
}
}
void ax25_poll(AX25Ctx *ctx)
{
int c;
while ((c = afsk_getchar()) != EOF)
{
if (!ctx->escape && c == HDLC_FLAG)
{
if (ctx->frame_len >= AX25_MIN_FRAME_LEN)
{
if (ctx->crc_in == AX25_CRC_CORRECT)
{
ax25_decode(ctx);
}
}
ctx->sync = true;
ctx->crc_in = CRC_CCIT_INIT_VAL;
ctx->frame_len = 0;
continue;
}
if (!ctx->escape && c == HDLC_RESET)
{
ctx->sync = false;
continue;
}
if (!ctx->escape && c == AX25_ESC)
{
ctx->escape = true;
continue;
}
if (ctx->sync)
{
if (ctx->frame_len < AX25_MAX_FRAME_LEN)
{
ctx->buf[ctx->frame_len++] = c;
ctx->crc_in = update_crc_ccit(c, ctx->crc_in);
}
else
{
ctx->sync = false;
}
}
ctx->escape = false;
}
}
static void ax25_putchar(AX25Ctx *ctx, uint8_t c)
{
if (c == HDLC_FLAG || c == HDLC_RESET || c == AX25_ESC)
afsk_putchar(AX25_ESC);
ctx->crc_out = update_crc_ccit(c, ctx->crc_out);
afsk_putchar(c);
}
void ax25_sendRaw(AX25Ctx *ctx, void *_buf, size_t len)
{
ctx->crc_out = CRC_CCIT_INIT_VAL;
afsk_putchar(HDLC_FLAG);
const uint8_t *buf = (const uint8_t *)_buf;
while (len--)
ax25_putchar(ctx, *buf++);
uint8_t crcl = (ctx->crc_out & 0xff) ^ 0xff;
uint8_t crch = (ctx->crc_out >> 8) ^ 0xff;
ax25_putchar(ctx, crcl);
ax25_putchar(ctx, crch);
afsk_putchar(HDLC_FLAG);
}
static void ax25_sendCall(AX25Ctx *ctx, const AX25Call *addr, bool last)
{
unsigned len = MIN((sizeof(addr->call) - CALL_OVERSPACE), strlen(addr->call));
for (unsigned i = 0; i < len; i++)
{
uint8_t c = addr->call[i];
c = toupper(c);
ax25_putchar(ctx, c << 1);
}
if (len < (sizeof(addr->call) - CALL_OVERSPACE))
{
for (unsigned i = 0; i < (sizeof(addr->call) - CALL_OVERSPACE) - len; i++)
{
ax25_putchar(ctx, ' ' << 1);
}
}
uint8_t ssid = 0x60 | (addr->ssid << 1) | (last ? 0x01 : 0);
ax25_putchar(ctx, ssid);
}
void ax25_sendVia(AX25Ctx *ctx, const AX25Call *path, size_t path_len, const void *_buf, size_t len)
{
const uint8_t *buf = (const uint8_t *)_buf;
ctx->crc_out = CRC_CCIT_INIT_VAL;
afsk_putchar(HDLC_FLAG);
for (size_t i = 0; i < path_len; i++)
{
ax25_sendCall(ctx, &path[i], (i == path_len - 1));
}
ax25_putchar(ctx, AX25_CTRL_UI);
ax25_putchar(ctx, AX25_PID_NOLAYER3);
while (len--)
{
ax25_putchar(ctx, *buf++);
}
uint8_t crcl = (ctx->crc_out & 0xff) ^ 0xff;
uint8_t crch = (ctx->crc_out >> 8) ^ 0xff;
ax25_putchar(ctx, crcl);
ax25_putchar(ctx, crch);
afsk_putchar(HDLC_FLAG);
}
unsigned int strpos(char *txt, char chk)
{
char *pch;
unsigned int idx = 0;
pch = strchr(txt, chk);
idx = pch - txt;
return idx;
}
void convPath(ax25header *hdr, char *txt, unsigned int size)
{
unsigned int i, p, j;
char num[5];
hdr->ssid = 0;
memset(hdr->addr, 0, 7);
memset(&num[0], 0, sizeof(num));
p = strpos(txt, '-');
if (p > 0 && p < size)
{
for (i = 0; i < p; i++)
{ // Get CallSign/Path
hdr->addr[i] = txt[i];
}
j = 0;
for (i = p + 1; i < size; i++)
{ // get SSID
// if(txt[i]=='*') break;
// if(txt[i]==',') break;
// if(txt[i]==':') break;
if (txt[i] < 0x30)
break;
if (txt[i] > 0x39)
break;
num[j++] = txt[i];
}
if (j > 0)
{
hdr->ssid = atoi(num);
}
hdr->ssid <<= 1;
}
else
{
for (i = 0; i < size; i++)
{ // Get CallSign/Path
if (txt[i] == '*')
break;
if (txt[i] == ',')
break;
if (txt[i] == ':')
break;
hdr->addr[i] = txt[i];
}
hdr->ssid = 0;
}
p = strpos(txt, '*');
if (p > 0 && p < size)
hdr->ssid |= 0x80;
hdr->ssid |= 0x60;
}
char ax25_encode(ax25frame &frame, char *txt, int size)
{
char *token, *ptr;
int i;
unsigned int p, p2, p3;
char j;
ptr = (char *)&frame;
memset(ptr, 0, sizeof(ax25frame)); // Clear frame
p = strpos(txt, ':');
if (p > 0 && p < size)
{
// printf("p{:}=%d\r\n",p);
// Get String APRS
memset(&frame.data, 0, sizeof(frame.data));
for (i = 0; i < (size - p); i++)
frame.data[i] = txt[p + i + 1];
p2 = strpos(txt, '>');
if (p2 > 0 && p2 < size)
{
// printf("p2{>}=%d\r\n",p2);
convPath(&frame.header[1], &txt[0], p2); // Get callsign src
j = strpos(txt, ',');
if ((j < 1) || (j > p))
j = p;
convPath(&frame.header[0], &txt[p2 + 1], j - p2 - 1); // Get callsign dest
// if(j<p){
p3 = 0;
for (i = j; i < size; i++)
{ // copy path to origin
if (txt[i] == ':')
{
for (; i < size; i++)
txt[p3++] = 0x00;
break;
}
txt[p3++] = txt[i];
}
// printf("Path:%s\r\n",txt);
token = strtok(txt, ",");
j = 0;
while (token != NULL)
{
ptr = token;
convPath(&frame.header[j + 2], ptr, strlen(ptr));
token = strtok(NULL, ",");
j++;
if (j > 7)
break;
}
for (i = 0; i < 10; i++)
frame.header[i].ssid &= 0xFE; // Clear All END Path
// Fix END path
for (i = 2; i < 10; i++)
{
if (frame.header[i].addr[0] == 0x00)
{
frame.header[i - 1].ssid |= 0x01;
break;
}
}
// }
return 1;
}
}
return 0;
}
void ax25sendFrame(AX25Ctx *ctx, ax25frame *pkg)
{
int i, j, c = 0;
uint8_t data = 0;
ctx->crc_out = CRC_CCIT_INIT_VAL;
afsk_putchar(HDLC_FLAG);
for (i = 0; i < 10; i++)
pkg->header[i].ssid &= 0xFE; // Clear All END Path
// Fix END path
for (i = 1; i < 10; i++)
{
if (pkg->header[i].addr[0] == 0x00)
{
pkg->header[i - 1].ssid |= 0x01;
break;
}
}
for (i = 0; i < 10; i++)
{
if (pkg->header[i].addr[0] == 0)
break;
for (j = 0; j < 6; j++)
{
data = (uint8_t)pkg->header[i].addr[j];
if (data == 0)
data = 0x20;
// putchar(data);
data <<= 1;
ax25_putchar(ctx, data);
c++;
}
ax25_putchar(ctx, (uint8_t)pkg->header[i].ssid);
if (pkg->header[i].ssid & 0x01)
break;
}
ax25_putchar(ctx, AX25_CTRL_UI); // Control field - 0x03 is APRS UI-frame
ax25_putchar(ctx, AX25_PID_NOLAYER3); // Protocol ID - 0xF0 is no layer 3
// ax25sendString(&pkg->data[0]);
for (i = 0; i < strlen(pkg->data); i++)
{
ax25_putchar(ctx, (uint8_t)pkg->data[i]);
}
uint8_t crcl = (ctx->crc_out & 0xff) ^ 0xff;
uint8_t crch = (ctx->crc_out >> 8) ^ 0xff;
ax25_putchar(ctx, crcl);
ax25_putchar(ctx, crch);
afsk_putchar(HDLC_FLAG);
return;
}