* bare bones 'talk to modem' program - similar to 'cu -l $device'
* inspired by mgetty's microcom
*
- * Copyright (C) 2007 by Vladimir Dronnikov <dronnikov@gmail.ru>
+ * Copyright (C) 2008 by Vladimir Dronnikov <dronnikov@gmail.com>
*
- * Licensed under GPLv2, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2, see file LICENSE in this source tree.
*/
-#include "libbb.h"
-/* All known arches use small ints for signals */
-static volatile smallint signalled;
+//usage:#define microcom_trivial_usage
+//usage: "[-d DELAY] [-t TIMEOUT] [-s SPEED] [-X] TTY"
+//usage:#define microcom_full_usage "\n\n"
+//usage: "Copy bytes for stdin to TTY and from TTY to stdout\n"
+//usage: "\n -d Wait up to DELAY ms for TTY output before sending every"
+//usage: "\n next byte to it"
+//usage: "\n -t Exit if both stdin and TTY are silent for TIMEOUT ms"
+//usage: "\n -s Set serial line to SPEED"
+//usage: "\n -X Disable special meaning of NUL and Ctrl-X from stdin"
-static void signal_handler(int signo)
-{
- signalled = signo;
-}
+#include "libbb.h"
// set raw tty mode
static void xget1(int fd, struct termios *t, struct termios *oldt)
-{
+{
tcgetattr(fd, oldt);
*t = *oldt;
cfmakeraw(t);
}
int microcom_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int microcom_main(int argc, char **argv)
+int microcom_main(int argc UNUSED_PARAM, char **argv)
{
int sfd;
int nfd;
enum {
OPT_X = 1 << 0, // do not respect Ctrl-X, Ctrl-@
OPT_s = 1 << 1, // baudrate
- OPT_d = 1 << 2, // wait for device response, msecs
+ OPT_d = 1 << 2, // wait for device response, ms
OPT_t = 1 << 3, // timeout, ms
};
speed_t speed = 9600;
int delay = -1;
int timeout = -1;
-
- // fetch options
- char *opt_s;
- char *opt_d;
- char *opt_t;
unsigned opts;
- opt_complementary = "=1"; // exactly one arg should be there
- opts = getopt32(argv, "Xs:d:t:", &opt_s, &opt_d, &opt_t);
-
- // apply options
- if (opts & OPT_s)
- speed = xatoi_u(opt_s);
- if (opts & OPT_d)
- delay = xatoi_u(opt_d);
- if (opts & OPT_t)
- timeout = xatoi_u(opt_t);
+ // fetch options
+ opt_complementary = "=1:s+:d+:t+"; // exactly one arg, numeric options
+ opts = getopt32(argv, "Xs:d:t:", &speed, &delay, &timeout);
// argc -= optind;
argv += optind;
device_lock_file = xasprintf("/var/lock/LCK..%s", device_lock_file);
sfd = open(device_lock_file, O_CREAT | O_WRONLY | O_TRUNC | O_EXCL, 0644);
if (sfd < 0) {
+ // device already locked -> bail out
if (errno == EEXIST)
- bb_perror_msg_and_die("can't create %s", device_lock_file);
+ bb_perror_msg_and_die("can't create '%s'", device_lock_file);
+ // can't create lock -> don't care
if (ENABLE_FEATURE_CLEAN_UP)
free(device_lock_file);
device_lock_file = NULL;
- }
- if (sfd > 0) {
- // %4d to make mgetty happy. It treats 4-bytes lock files as binary,
+ } else {
+ // %4d to make concurrent mgetty (if any) happy.
+ // Mgetty treats 4-bytes lock files as binary,
// not text, PID. Making 5+ char file. Brrr...
- char *s = xasprintf("%4d\n", getpid());
- write(sfd, s, strlen(s));
- if (ENABLE_FEATURE_CLEAN_UP)
- free(s);
+ fdprintf(sfd, "%4d\n", getpid());
close(sfd);
}
// setup signals
- sig_catch(SIGHUP, signal_handler);
- sig_catch(SIGINT, signal_handler);
- sig_catch(SIGTERM, signal_handler);
- sig_catch(SIGPIPE, signal_handler);
+ bb_signals(0
+ + (1 << SIGHUP)
+ + (1 << SIGINT)
+ + (1 << SIGTERM)
+ + (1 << SIGPIPE)
+ , record_signo);
// error exit code if we fail to open the device
- signalled = 1;
+ bb_got_signal = 1;
// open device
sfd = open_or_warn(argv[0], O_RDWR | O_NOCTTY | O_NONBLOCK);
if (sfd < 0)
goto done;
- fcntl(sfd, F_SETFL, O_RDWR | O_NOCTTY);
+ fcntl(sfd, F_SETFL, O_RDWR);
+
+ // put device to "raw mode"
+ xget1(sfd, &tio, &tiosfd);
+ // set device speed
+ cfsetspeed(&tio, tty_value_to_baud(speed));
+ if (xset1(sfd, &tio, argv[0]))
+ goto done;
// put stdin to "raw mode" (if stdin is a TTY),
// handle one character at a time
goto done;
}
- // same thing for modem
- xget1(sfd, &tio, &tiosfd);
- // order device to hang up at exit
- tio.c_cflag |= (CREAD|HUPCL);
-// if (!istty)
-// tio.c_iflag |= (IGNCR);
- // set device speed
- cfsetspeed(&tio, tty_value_to_baud(speed));
- if (xset1(sfd, &tio, argv[0]))
- goto restore0_and_done;
-
// main loop: check with poll(), then read/write bytes across
pfd[0].fd = sfd;
pfd[0].events = POLLIN;
pfd[1].fd = STDIN_FILENO;
pfd[1].events = POLLIN;
- signalled = 0;
+ bb_got_signal = 0;
nfd = 2;
- while (!signalled && safe_poll(pfd, nfd, timeout) > 0) {
- if (pfd[1].revents) {
+ // Not safe_poll: we want to exit on signal
+ while (!bb_got_signal && poll(pfd, nfd, timeout) > 0) {
+ if (nfd > 1 && pfd[1].revents) {
char c;
// read from stdin -> write to device
if (safe_read(STDIN_FILENO, &c, 1) < 1) {
// don't poll stdin anymore if we got EOF/error
- pfd[1].revents = 0;
nfd--;
- goto check_stdin;
+ goto skip_write;
}
// do we need special processing?
if (!(opts & OPT_X)) {
// ^@ sends Break
if (VINTR == c) {
tcsendbreak(sfd, 0);
- goto check_stdin;
+ goto skip_write;
}
// ^X exits
if (24 == c)
write(sfd, &c, 1);
if (delay >= 0)
safe_poll(pfd, 1, delay);
+skip_write: ;
}
-check_stdin:
if (pfd[0].revents) {
+#define iobuf bb_common_bufsiz1
ssize_t len;
// read from device -> write to stdout
- len = safe_read(sfd, bb_common_bufsiz1, sizeof(bb_common_bufsiz1));
+ len = safe_read(sfd, iobuf, sizeof(iobuf));
if (len > 0)
- full_write(STDOUT_FILENO, bb_common_bufsiz1, len);
- // else { EOF/error - what to do? }
+ full_write(STDOUT_FILENO, iobuf, len);
+ else {
+ // EOF/error -> bail out
+ bb_got_signal = SIGHUP;
+ break;
+ }
}
}
+ // restore device mode
tcsetattr(sfd, TCSAFLUSH, &tiosfd);
-restore0_and_done:
if (isatty(STDIN_FILENO))
tcsetattr(STDIN_FILENO, TCSAFLUSH, &tio0);
if (device_lock_file)
unlink(device_lock_file);
- return signalled;
+ return bb_got_signal;
}
projects / oweals / busybox.git / blobdiff