/*
* neocon.c - An interface for changing tty devices
*
* Copyright (C) 2007, 2008 by OpenMoko, Inc.
* Copyright 2011, 2013 by Werner Almesberger
* Written by Werner Almesberger <werner@almesberger.net>
* All Rights Reserved
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <stdlib.h>
#include <stdio.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <termios.h>
#include <fcntl.h>
#include <assert.h>
#include <sys/time.h>
#include <sys/select.h>
#define MAX_BUF 2048
static char *const *ttys;
static int num_ttys;
static int curr_tty = -1; /* start with first tty */
static speed_t speed = B115200;
static struct termios console, tty;
static FILE *log = NULL;
static int timestamp = 0;
static char escape = '~';
static struct bps {
speed_t speed;
int bps;
} bps_tab[] = {
{ B300, 300 },
{ B1200, 1200 },
{ B2400, 2400 },
{ B9600, 9600 },
{ B19200, 19200 },
{ B38400, 38400 },
{ B57600, 57600 },
{ B115200, 115200 },
{ 0, 0 }
};
static speed_t bps_to_speed(int bps)
{
const struct bps *p;
for (p = bps_tab; p->bps; p++)
if (p->bps == bps)
return p->speed;
fprintf(stderr, "no such speed: %d bps\n", bps);
exit(1);
}
static void make_raw(int fd, struct termios *old, int cr, int local_edit)
{
struct termios t;
long flags;
if (tcgetattr(fd, &t) < 0) {
perror("tcgetattr");
exit(1);
}
if (old)
*old = t;
if (local_edit)
return;
cfmakeraw(&t);
if (fd) {
t.c_iflag &= ~(IXON | IXOFF);
t.c_cflag |= CLOCAL;
t.c_cflag &= ~CRTSCTS;
if (cfsetispeed(&t, speed) < 0) {
perror("cfsetispeed");
exit(1);
}
if (cfsetospeed(&t, speed) < 0) {
perror("cfsetospeed");
exit(1);
}
}
if (cr)
t.c_oflag |= OPOST | ONLCR;
if (tcsetattr(fd, TCSANOW, &t) < 0) {
perror("tcsetattr");
exit(1);
}
flags = fcntl(fd, F_GETFL);
if (flags < 0) {
perror("fcntl F_GETFL");
exit(1);
}
if (fcntl(fd, F_SETFL, flags & ~O_NONBLOCK) < 0) {
perror("fcntl F_GETFL");
exit(1);
}
}
static int open_next_tty(void)
{
int i, fd = -1;
for (i = 0; i != num_ttys; i++) {
curr_tty = (curr_tty+1) % num_ttys;
fd = open(ttys[curr_tty], O_RDWR | O_NDELAY);
if (fd >= 0)
break;
}
if (fd >= 0)
make_raw(fd, &tty, 0, 0);
return fd;
}
/*
* Return 1 if the user manually forces a device change.
*/
static int scan(const char *s, size_t len)
{
static int state = 0;
const char *p;
int res = 0;
for (p = s; p != s+len; p++)
switch (state) {
case 0:
if (*p == escape)
state++;
else
state = 0;
break;
case 1:
if (*p == '.')
exit(0);
if (*p == 'n')
res = 1;
state = 0;
break;
}
return res;
}
static int write_log(const char *buf, ssize_t len)
{
size_t wrote;
wrote = fwrite(buf, 1, len, log);
if (wrote == len)
return 1;
fprintf(stderr, "write failed. closing log file.\n");
fclose(log);
log = NULL;
return 0;
}
static int add_timestamp(void)
{
struct timeval tv;
char buf[40]; /* be generous */
int len;
if (gettimeofday(&tv, NULL) < 0) {
perror("gettimeofday");
exit(1);
}
len = sprintf(buf, "%lu.%06lu ",
(unsigned long) tv.tv_sec, (unsigned long) tv.tv_usec);
return write_log(buf, len);
}
static void do_log(const char *buf, ssize_t len)
{
static int nl = 1; /* we're at the beginning of a new line */
char tmp[MAX_BUF];
const char *from;
char *to;
assert(len <= MAX_BUF);
from = buf;
to = tmp;
while (from != buf+len) {
if (*from == '\r') {
from++;
continue;
}
if (nl && timestamp)
if (!add_timestamp())
return;
nl = 0;
if (*from == '\n') {
*to++ = *from++;
if (!write_log(tmp, to-tmp))
return;
to = tmp;
nl = 1;
continue;
}
*to++ = *from < ' ' || *from > '~' ? '#' : *from;
from++;
}
write_log(tmp, to-tmp);
}
static int copy(int in, int out, int from_user, int single)
{
char buffer[MAX_BUF];
ssize_t got, wrote, pos;
got = read(in, buffer, single ? 1 : sizeof(buffer));
if (got <= 0)
return 0;
if (from_user) {
if (scan(buffer, got))
return 0;
} else {
if (log)
do_log(buffer, got);
}
for (pos = 0; pos != got; pos += wrote) {
wrote = write(out, buffer+pos, got-pos);
if (wrote < 0)
return 0;
}
return 1;
}
static void write_string(const char *s)
{
int len = strlen(s);
while (len) {
ssize_t wrote;
wrote = write(1, s, len);
if (wrote < 0) {
perror("write");
exit(1);
}
s += wrote;
len -= wrote;
}
}
static void cleanup(void)
{
if (tcsetattr(0, TCSANOW, &console) < 0)
perror("tcsetattr");
write(1, "\n", 1);
}
static void usage(const char *name)
{
fprintf(stderr,
"usage: %s [-b bps] [-c] [-e escape] [-l logfile [-a] [-T]] [-L]\n"
" %*s [-t delay_ms] tty ...\n\n"
" -a append to the log file if it already exists\n"
" -b bps set the TTY to the specified bit rate\n"
" -c add carriage return before newline (on console)\n"
" -e escape set the escape character (default: ~)\n"
" -l logfile log all output to the specified file\n"
" -L enable local line editing\n"
" -t delay_ms wait the specified amount of time between input characters\n"
" -T add timestamps to the log file\n"
, name, (int) strlen(name), "");
exit(1);
}
int main(int argc, char *const *argv)
{
char *end;
int c, bps, cr = 0;
int local_edit = 0;
int fd = -1;
int append = 0;
const char *logfile = NULL;
int throttle_us = 0;
int throttle = 0;
while ((c = getopt(argc, argv, "ab:ce:l:Lt:T")) != EOF)
switch (c) {
case 'a':
append = 1;
break;
case 'b':
bps = strtoul(optarg, &end, 0);
if (*end)
usage(*argv);
speed = bps_to_speed(bps);
break;
case 'c':
cr = 1;
break;
case 'e':
if (strlen(optarg) != 1)
usage(*argv);
escape = *optarg;
break;
case 'l':
logfile = optarg;
break;
case 'L':
local_edit = 1;
break;
case 't':
throttle_us = strtoul(optarg, &end, 0)*1000;
if (*end)
usage(*argv);
break;
case 'T':
timestamp = 1;
break;
default:
usage(*argv);
}
num_ttys = argc-optind;
ttys = argv+optind;
if (logfile) {
log = fopen(logfile, append ? "a" : "w");
if (!log) {
perror(logfile);
exit(1);
}
setlinebuf(log);
}
make_raw(0, &console, cr, local_edit);
atexit(cleanup);
while (1) {
struct timeval tv;
fd_set set;
int res;
if (fd < 0) {
fd = open_next_tty();
if (fd > 0) {
char buf[1024]; /* enough :-) */
sprintf(buf, "\r\r[Open %s]\r\n",
ttys[curr_tty]);
write_string(buf);
}
}
FD_ZERO(&set);
if (!throttle)
FD_SET(0, &set);
if (fd >= 0)
FD_SET(fd, &set);
tv.tv_sec = 0;
tv.tv_usec = throttle ? throttle_us : 100000;
res = select(fd < 0 ? 1 : fd+1, &set, NULL, NULL, &tv);
if (res < 0) {
perror("select");
return 1;
}
if (!res)
throttle = 0;
if (FD_ISSET(0, &set)) {
if (throttle_us)
throttle = 1;
if (!copy(0, fd, 1, throttle_us != 0))
goto failed;
}
if (fd >= 0 && FD_ISSET(fd, &set))
if (!copy(fd, 1, 0, 0))
goto failed;
continue;
failed:
write_string("\r\n[Closed]\r\n");
(void) close(fd);
fd = -1;
}
return 0;
}