Submitted by: phk
Add the V.21 modem emulator code written by phk from the old i4b tarball.
This commit is contained in:
Hellmuth Michaelis
parent
5bfc2e1909
commit
698c326a2e
12
share/examples/isdn/v21/Makefile
Normal file
12
share/examples/isdn/v21/Makefile
Normal file
@ -0,0 +1,12 @@
|
||||
# $FreeBSD$
|
||||
|
||||
PROG= v21modem
|
||||
NOMAN= 1
|
||||
LDADD= -lutil -lm
|
||||
CFLAGS+= -g -Wall
|
||||
|
||||
.if !defined(BSDTYPE)
|
||||
BSDTYPE!=uname
|
||||
.endif
|
||||
|
||||
.include <bsd.prog.mk>
|
||||
50
share/examples/isdn/v21/README
Normal file
50
share/examples/isdn/v21/README
Normal file
@ -0,0 +1,50 @@
|
||||
|
||||
V.21 Modem for ISDN4BSD.
|
||||
|
||||
INTRODUCTION:
|
||||
|
||||
The modem is implemented in software and is rather simple minded.
|
||||
|
||||
It works with my Telebit TB2500 and Zyxel 2864I modems.
|
||||
|
||||
There are plenty of knobs and handles which can be adjusted and I have
|
||||
no real idea what to set them to for best all-round performance.
|
||||
|
||||
The carrier detect timer may be a bit short tempered, and this is
|
||||
probably why the dialing modem needs to be told to talk V.21 up
|
||||
front. If this code were mode tolerant of loss of carrier auto
|
||||
negotiation might work.
|
||||
|
||||
When you get carrier ("CONNECT 300"), you must press a key before the
|
||||
login banner gets printed. See the comments in "input_byte" why this
|
||||
is.
|
||||
|
||||
THE KERNEL PART:
|
||||
|
||||
Implementes a crude "send these tones" facility, but it is enough to
|
||||
take most of the real-time worries out of doing FSK modulation in
|
||||
software. If suitably extended, the code could also be used to
|
||||
send DTMF tones and other similar signals.
|
||||
|
||||
INSTALLATION:
|
||||
|
||||
The program is started from /etc/isdn/isdnd.rc:
|
||||
|
||||
entry
|
||||
name = I4BTEL
|
||||
usrdevicename = tel
|
||||
usrdeviceunit = 0
|
||||
isdncontroller = 0
|
||||
isdnchannel = -1
|
||||
local-phone-incoming = 2934812934
|
||||
remote-phone-incoming = *
|
||||
dialin-reaction = answer
|
||||
answerprog = v21modem
|
||||
b1protocol = raw
|
||||
idletime-incoming = 5
|
||||
|
||||
|
||||
Poul-Henning (phk@freebsd.org)
|
||||
19991212
|
||||
|
||||
$FreeBSD$
|
||||
393
share/examples/isdn/v21/v21modem.c
Normal file
393
share/examples/isdn/v21/v21modem.c
Normal file
@ -0,0 +1,393 @@
|
||||
/*
|
||||
* ----------------------------------------------------------------------------
|
||||
* "THE BEER-WARE LICENSE" (Revision 42):
|
||||
* <phk@FreeBSD.org> wrote this file. As long as you retain this notice you
|
||||
* can do whatever you want with this stuff. If we meet some day, and you think
|
||||
* this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp
|
||||
* ----------------------------------------------------------------------------
|
||||
*
|
||||
* This is a V.21 modem for ISDN4BSD.
|
||||
*
|
||||
* $FreeBSD$
|
||||
*/
|
||||
|
||||
#include <string.h>
|
||||
#include <stdio.h>
|
||||
#include <unistd.h>
|
||||
#include <stdlib.h>
|
||||
#include <fcntl.h>
|
||||
#include <err.h>
|
||||
#include <sys/ioccom.h>
|
||||
#include <errno.h>
|
||||
#include <syslog.h>
|
||||
#include <sys/types.h>
|
||||
#include <sys/ioctl.h>
|
||||
#include <termios.h>
|
||||
#include <libutil.h>
|
||||
|
||||
#include <machine/i4b_tel_ioctl.h>
|
||||
|
||||
static void create_session(void);
|
||||
static void input_byte(int byte, int stopbit);
|
||||
static void sample(int vol, int* tones);
|
||||
static void tonedetect(unsigned char *ptr, int count);
|
||||
static void uart(int bit);
|
||||
|
||||
static int dcd; /* Carrier on ? */
|
||||
static int ptyfd = -1; /* PTY filedescriptor */
|
||||
static int telfd = -1; /* I4BTEL filedescriptor */
|
||||
|
||||
/*
|
||||
* Alaw to Linear [-32767..32767] conversion
|
||||
*/
|
||||
|
||||
static int a2l[256] = { -5504, -5248, -6016, -5760, -4480, -4224,
|
||||
-4992, -4736, -7552, -7296, -8064, -7808, -6528, -6272, -7040,
|
||||
-6784, -2752, -2624, -3008, -2880, -2240, -2112, -2496, -2368,
|
||||
-3776, -3648, -4032, -3904, -3264, -3136, -3520, -3392, -22016,
|
||||
-20992, -24064, -23040, -17920, -16896, -19968, -18944, -30208,
|
||||
-29184, -32256, -31232, -26112, -25088, -28160, -27136, -11008,
|
||||
-10496, -12032, -11520, -8960, -8448, -9984, -9472, -15104, -14592,
|
||||
-16128, -15616, -13056, -12544, -14080, -13568, -344, -328, -376,
|
||||
-360, -280, -264, -312, -296, -472, -456, -504, -488, -408, -392,
|
||||
-440, -424, -88, -72, -120, -104, -24, -8, -56, -40, -216, -200,
|
||||
-248, -232, -152, -136, -184, -168, -1376, -1312, -1504, -1440,
|
||||
-1120, -1056, -1248, -1184, -1888, -1824, -2016, -1952, -1632,
|
||||
-1568, -1760, -1696, -688, -656, -752, -720, -560, -528, -624,
|
||||
-592, -944, -912, -1008, -976, -816, -784, -880, -848, 5504, 5248,
|
||||
6016, 5760, 4480, 4224, 4992, 4736, 7552, 7296, 8064, 7808, 6528,
|
||||
6272, 7040, 6784, 2752, 2624, 3008, 2880, 2240, 2112, 2496, 2368,
|
||||
3776, 3648, 4032, 3904, 3264, 3136, 3520, 3392, 22016, 20992, 24064,
|
||||
23040, 17920, 16896, 19968, 18944, 30208, 29184, 32256, 31232,
|
||||
26112, 25088, 28160, 27136, 11008, 10496, 12032, 11520, 8960, 8448,
|
||||
9984, 9472, 15104, 14592, 16128, 15616, 13056, 12544, 14080, 13568,
|
||||
344, 328, 376, 360, 280, 264, 312, 296, 472, 456, 504, 488, 408,
|
||||
392, 440, 424, 88, 72, 120, 104, 24, 8, 56, 40, 216, 200, 248, 232,
|
||||
152, 136, 184, 168, 1376, 1312, 1504, 1440, 1120, 1056, 1248, 1184,
|
||||
1888, 1824, 2016, 1952, 1632, 1568, 1760, 1696, 688, 656, 752, 720,
|
||||
560, 528, 624, 592, 944, 912, 1008, 976, 816, 784, 880, 848 };
|
||||
|
||||
/*
|
||||
* A High Q Tone detector
|
||||
*/
|
||||
|
||||
#define NTONES 2 /* Number of tones to detect */
|
||||
#define SCALE 4096 /* Scaling factor */
|
||||
#define EXPAVG 14 /* Exponential Average factor */
|
||||
#define POLERAD 3885 /* pole_radius ^ 2 * SCALE */
|
||||
|
||||
/* Table of "-cos(2 * PI * frequency / sample_rate) * SCALE" */
|
||||
static int p[NTONES] = {
|
||||
-2941, /* 980 Hz */
|
||||
-2460 /* 1180 Hz */
|
||||
};
|
||||
|
||||
static void
|
||||
tonedetect(unsigned char *ptr, int count)
|
||||
{
|
||||
int i, j;
|
||||
int y;
|
||||
int c, d, f, n;
|
||||
static int k[NTONES], h[NTONES];
|
||||
static int tones[NTONES];
|
||||
static int amplitude;
|
||||
|
||||
|
||||
for (i = 0; i < count; i++) {
|
||||
y = a2l[*ptr++];
|
||||
if (y > 0)
|
||||
amplitude += (y - amplitude) / EXPAVG;
|
||||
else
|
||||
amplitude += (-y - amplitude) / EXPAVG;
|
||||
|
||||
for(j = 0; j < NTONES; j++) {
|
||||
c = (POLERAD * (y - k[j])) / SCALE;
|
||||
d = y + c;
|
||||
f = (p[j] * (d - h[j])) / SCALE;
|
||||
n = y - k[j] - c;
|
||||
if (n < 0)
|
||||
n = -n;
|
||||
k[j] = h[j] + f;
|
||||
h[j] = f + d;
|
||||
tones[j] += (n - tones[j]) / EXPAVG;
|
||||
}
|
||||
sample(amplitude, tones);
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* Taste each sample, detect (loss off) carrier, and feed uart
|
||||
*/
|
||||
|
||||
#define NCARRIER 1000 /* Samples of carrier for detection */
|
||||
|
||||
static void
|
||||
sample(int vol, int* tones)
|
||||
{
|
||||
static int carrier;
|
||||
|
||||
if ((tones[0] + tones[1]) > vol * 3/2) { /* XXX */
|
||||
if (carrier < NCARRIER)
|
||||
carrier ++;
|
||||
} else {
|
||||
if (carrier > 0)
|
||||
carrier --;
|
||||
}
|
||||
|
||||
if (!dcd && carrier > NCARRIER / 2) {
|
||||
syslog(LOG_ERR, "CARRIER ON");
|
||||
dcd = 1;
|
||||
} else if (dcd && carrier < NCARRIER / 2) {
|
||||
syslog(LOG_ERR, "CARRIER OFF");
|
||||
dcd = 0;
|
||||
}
|
||||
|
||||
if (!dcd)
|
||||
return;
|
||||
|
||||
if (tones[0] > tones[1]) {
|
||||
uart(1);
|
||||
} else {
|
||||
uart(0);
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* A UART in software
|
||||
*/
|
||||
|
||||
#define BITCENTER 13 /* Middle of a bit: 8000/300/2 */
|
||||
static int bitsample[] = { /* table of sampling points */
|
||||
BITCENTER,
|
||||
BITCENTER + 27,
|
||||
BITCENTER + 54,
|
||||
BITCENTER + 80,
|
||||
BITCENTER + 107,
|
||||
BITCENTER + 134,
|
||||
BITCENTER + 160,
|
||||
BITCENTER + 187,
|
||||
BITCENTER + 214,
|
||||
BITCENTER + 240
|
||||
};
|
||||
|
||||
static void
|
||||
uart(int bit)
|
||||
{
|
||||
static int n, v, j;
|
||||
|
||||
if (n == 0 && bit == 1)
|
||||
return; /* Waiting for start bit */
|
||||
if (n == 0) {
|
||||
j = 0; /* Begin start bit */
|
||||
v = 0;
|
||||
n++;
|
||||
} else if (j == 0 && bit && n > bitsample[j]) {
|
||||
n = 0; /* Gone by middle of start bit */
|
||||
} else if (n > bitsample[j]) {
|
||||
j++; /* Sample point */
|
||||
if (j == 10) {
|
||||
n = 0;
|
||||
input_byte(v, bit);
|
||||
} else {
|
||||
v = v / 2 + 128 * bit;
|
||||
n++;
|
||||
}
|
||||
} else {
|
||||
n++;
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* Send a byte using kenrnel tone generation support
|
||||
*/
|
||||
|
||||
static void
|
||||
output_byte(int val)
|
||||
{
|
||||
struct i4b_tel_tones tt;
|
||||
int i;
|
||||
|
||||
i = 0;
|
||||
tt.frequency[i] = 1850; tt.duration[i++] = 27;
|
||||
|
||||
tt.frequency[i] = val & 1 ? 1650 : 1850; tt.duration[i++] = 27;
|
||||
tt.frequency[i] = val & 2 ? 1650 : 1850; tt.duration[i++] = 26;
|
||||
tt.frequency[i] = val & 4 ? 1650 : 1850; tt.duration[i++] = 27;
|
||||
tt.frequency[i] = val & 8 ? 1650 : 1850; tt.duration[i++] = 27;
|
||||
tt.frequency[i] = val & 16 ? 1650 : 1850; tt.duration[i++] = 26;
|
||||
tt.frequency[i] = val & 32 ? 1650 : 1850; tt.duration[i++] = 27;
|
||||
tt.frequency[i] = val & 64 ? 1650 : 1850; tt.duration[i++] = 27;
|
||||
tt.frequency[i] = val & 128 ? 1650 : 1850; tt.duration[i++] = 26;
|
||||
|
||||
tt.frequency[i] = 1650; tt.duration[i++] = 27;
|
||||
tt.frequency[i] = 1650; tt.duration[i++] = 0;
|
||||
|
||||
i = ioctl(telfd, I4B_TEL_TONES, &tt);
|
||||
if (i != 0 && errno != EAGAIN) {
|
||||
syslog(LOG_ERR, "%d: *** %d/%d ***", __LINE__, i, errno);
|
||||
exit(0);
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* Create Session
|
||||
*/
|
||||
|
||||
static void
|
||||
create_session(void)
|
||||
{
|
||||
int i;
|
||||
char buf[100];
|
||||
|
||||
i = forkpty(&ptyfd, buf, 0, 0);
|
||||
if (i == 0) {
|
||||
execl("/usr/libexec/getty", "getty", "std.300", "-", NULL);
|
||||
syslog(LOG_ERR, "exec getty %d", errno);
|
||||
exit(2);
|
||||
} else if (i < 0) {
|
||||
syslog(LOG_ERR, "forkpty failed %d", errno);
|
||||
exit(2);
|
||||
}
|
||||
syslog(LOG_ERR, "pty %s", buf);
|
||||
}
|
||||
|
||||
static void
|
||||
input_byte(int byte, int stopbit)
|
||||
{
|
||||
u_char c;
|
||||
int i;
|
||||
static int first;
|
||||
static u_char buf[80];
|
||||
|
||||
if (!stopbit)
|
||||
return;
|
||||
c = byte;
|
||||
/*
|
||||
* I have no idea why, but my TB2500 modem sends a sequence of
|
||||
* 28 bytes after carrier is established at the link level, but
|
||||
* before it is acceptted at the logical level.
|
||||
*
|
||||
* [16100214010201060100000000ff0201020301080402400010034510]
|
||||
*
|
||||
* Unfortunately this contains a ^D which kills getty.
|
||||
* The following code swallows this sequence, assuming that it
|
||||
* is always the same length and always start with 0x16.
|
||||
*
|
||||
*/
|
||||
if (first == 0 && c == 0x16) {
|
||||
sprintf(buf, "%02x", c);
|
||||
first = 27;
|
||||
return;
|
||||
} else if (first == 0) {
|
||||
first = -1;
|
||||
dcd = 2;
|
||||
return;
|
||||
}
|
||||
if (first > 0) {
|
||||
sprintf(buf + strlen(buf), "%02x", c);
|
||||
first--;
|
||||
if (!first) {
|
||||
syslog(LOG_NOTICE, "Got magic [%s]", buf);
|
||||
*buf = 0;
|
||||
}
|
||||
return;
|
||||
}
|
||||
if (ptyfd != -1 && dcd) {
|
||||
i = write(ptyfd, &c, 1);
|
||||
if (i != 1 && errno != EAGAIN) {
|
||||
syslog(LOG_ERR, "%d: *** %d/%d ***", __LINE__, i, errno);
|
||||
exit(0);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
int
|
||||
main(int argc, char **argv)
|
||||
{
|
||||
char *device = "/dev/tel0";
|
||||
u_char ibuf[2048];
|
||||
int ii, io;
|
||||
int i, maxfd;
|
||||
struct i4b_tel_tones tt;
|
||||
fd_set rfd, wfd, efd;
|
||||
|
||||
openlog("v21modem", LOG_PID, LOG_DAEMON);
|
||||
/* Find our device name */
|
||||
for (i = 0; i < argc; i++)
|
||||
if (!strcmp(argv[i], "-D"))
|
||||
device = argv[i + 1];
|
||||
telfd = open(device, O_RDWR, 0);
|
||||
if (telfd < 0) {
|
||||
syslog(LOG_ERR, "open %s: %m", device);
|
||||
exit (0);
|
||||
}
|
||||
syslog(LOG_NOTICE, "Running on %s", device);
|
||||
|
||||
/* Output V.25 tone and carrier */
|
||||
i = 0;
|
||||
tt.frequency[i] = 0; tt.duration[i++] = 1000;
|
||||
tt.frequency[i] = 2100; tt.duration[i++] = 2*8000;
|
||||
tt.frequency[i] = 0; tt.duration[i++] = 400;
|
||||
tt.frequency[i] = 1650; tt.duration[i++] = 1;
|
||||
tt.frequency[i] = 1650; tt.duration[i++] = 0;
|
||||
tt.frequency[i] = 0; tt.duration[i++] = 0;
|
||||
i = ioctl(telfd, I4B_TEL_TONES, &tt);
|
||||
if (i < 0) {
|
||||
syslog(LOG_ERR, "hangup");
|
||||
exit(0);
|
||||
}
|
||||
|
||||
create_session();
|
||||
|
||||
/* Wait for carrier */
|
||||
do {
|
||||
ii = read(telfd, ibuf, sizeof ibuf);
|
||||
tonedetect(ibuf, ii);
|
||||
} while (ii > 0 && dcd != 2);
|
||||
if (ii < 0) {
|
||||
syslog(LOG_ERR, "hangup");
|
||||
exit(0);
|
||||
}
|
||||
|
||||
maxfd = ptyfd;
|
||||
if (telfd > maxfd)
|
||||
maxfd = telfd;
|
||||
maxfd += 1;
|
||||
do {
|
||||
FD_ZERO(&rfd);
|
||||
FD_SET(telfd, &rfd);
|
||||
FD_SET(ptyfd, &rfd);
|
||||
FD_ZERO(&wfd);
|
||||
FD_ZERO(&efd);
|
||||
FD_SET(telfd, &efd);
|
||||
FD_SET(ptyfd, &efd);
|
||||
i = select(maxfd, &rfd, &wfd, &efd, NULL);
|
||||
if (FD_ISSET(telfd, &rfd)) {
|
||||
ii = read(telfd, ibuf, sizeof ibuf);
|
||||
if (ii > 0)
|
||||
tonedetect(ibuf, ii);
|
||||
else
|
||||
syslog(LOG_ERR, "hangup");
|
||||
}
|
||||
if (FD_ISSET(ptyfd, &rfd)) {
|
||||
io = read(ptyfd, ibuf, 1);
|
||||
if (io == 1)
|
||||
output_byte(*ibuf);
|
||||
else if (io == 0) {
|
||||
syslog(LOG_ERR, "Session EOF");
|
||||
exit(0);
|
||||
}
|
||||
|
||||
}
|
||||
if (FD_ISSET(telfd, &efd)) {
|
||||
syslog(LOG_ERR, "Exception TELFD");
|
||||
exit (0);
|
||||
}
|
||||
if (FD_ISSET(ptyfd, &efd)) {
|
||||
syslog(LOG_ERR, "Exception PTYFD");
|
||||
exit (0);
|
||||
}
|
||||
} while (dcd);
|
||||
syslog(LOG_ERR, "Carrier Lost");
|
||||
exit(0);
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user