* 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;
-
-static void signal_handler(int signo)
-{
- signalled = signo;
-}
-
-// set canonical tty mode
+// set raw tty mode
static void xget1(int fd, struct termios *t, struct termios *oldt)
-{
+{
tcgetattr(fd, oldt);
*t = *oldt;
cfmakeraw(t);
static int xset1(int fd, struct termios *tio, const char *device)
{
- int ret = tcsetattr(fd, TCSANOW, tio);
+ int ret = tcsetattr(fd, TCSAFLUSH, tio);
if (ret) {
bb_perror_msg("can't tcsetattr for %s", device);
}
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)
{
- struct pollfd pfd[2];
- int nfd;
int sfd;
-/* #define sfd (pfd[0].fd) - gcc 4.2.1 is still not smart enough */
- char *device_lock_file;
- const char *opt_s = "9600";
- speed_t speed;
- const char *opt_t = "100"; // 0.1 sec timeout
- unsigned timeout;
+ int nfd;
+ struct pollfd pfd[2];
struct termios tio0, tiosfd, tio;
- bool istty;
+ char *device_lock_file;
+ enum {
+ OPT_X = 1 << 0, // do not respect Ctrl-X, Ctrl-@
+ OPT_s = 1 << 1, // baudrate
+ 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;
+ unsigned opts;
// fetch options
- opt_complementary = "-1"; /* at least one arg should be there */
- getopt32(argv, "s:t:", &opt_s, &opt_t);
- argc -= optind;
+ opt_complementary = "=1:s+:d+:t+"; // exactly one arg, numeric options
+ opts = getopt32(argv, "Xs:d:t:", &speed, &delay, &timeout);
+// argc -= optind;
argv += optind;
- // check sanity
- speed = xatou(opt_s);
- timeout = xatou(opt_t);
- device_lock_file = (char *)bb_basename(argv[0]);
-
// try to create lock file in /var/lock
+ device_lock_file = (char *)bb_basename(argv[0]);
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 lock device");
- // We don't abort on other errors: /var/lock can be
- // non-writable or non-existent
+ 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;
} else {
- // %4d to make mgetty happy. It treats 4-bytes lock files as binary,
+ // %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 unlock_and_exit;
- fcntl(sfd, F_SETFL, O_RDWR | O_NOCTTY);
-
- /* put stdin to "raw mode" (if stdin is a TTY),
- handle one character at a time */
- istty = isatty(STDIN_FILENO);
- if (istty) {
- xget1(STDIN_FILENO, &tio, &tio0);
- if (xset1(STDIN_FILENO, &tio, "stdin"))
- goto close_unlock_and_exit;
-// tcflush(STDIN_FILENO, TCIFLUSH);
- timeout = -1; // tty input? -> set infinite timeout for poll()
- }
+ goto done;
+ fcntl(sfd, F_SETFL, O_RDWR);
- // same thing for modem
+ // put device to "raw mode"
xget1(sfd, &tio, &tiosfd);
- // order device to hang up at exit
- tio.c_cflag |= (CREAD|HUPCL);
// set device speed
cfsetspeed(&tio, tty_value_to_baud(speed));
if (xset1(sfd, &tio, argv[0]))
- goto restore0_close_unlock_and_exit;
+ goto done;
+
+ // put stdin to "raw mode" (if stdin is a TTY),
+ // handle one character at a time
+ if (isatty(STDIN_FILENO)) {
+ xget1(STDIN_FILENO, &tio, &tio0);
+ if (xset1(STDIN_FILENO, &tio, "stdin"))
+ goto done;
+ }
// main loop: check with poll(), then read/write bytes across
pfd[0].fd = sfd;
pfd[1].fd = STDIN_FILENO;
pfd[1].events = POLLIN;
- // TODO: on piped input should we treat NL as CRNL?!
-
- signalled = 0;
- // initially we have to poll() both stdin and device
+ bb_got_signal = 0;
nfd = 2;
- while (!signalled && nfd && safe_poll(pfd, nfd, timeout) > 0) {
- int i;
-
- for (i = 0; i < nfd; ++i) {
- if (pfd[i].revents & (POLLIN | POLLHUP)) {
-// int fd;
- char c;
- // read a byte
- if (safe_read(pfd[i].fd, &c, 1) < 1) {
- // this can occur at the end of piped input
- // from now we only poll() for device
- nfd--;
- continue;
- }
-// fd = STDOUT_FILENO;
- // stdin requires additional processing
- // (TODO: must be controlled by command line switch)
- if (i) {
- // ^@ sends Break
- if (0 == c) {
- tcsendbreak(sfd, 0);
- continue;
- }
- // ^X exits
- if (24 == c)
- goto done;
-// fd = sfd;
+ // 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
+ nfd--;
+ goto skip_write;
+ }
+ // do we need special processing?
+ if (!(opts & OPT_X)) {
+ // ^@ sends Break
+ if (VINTR == c) {
+ tcsendbreak(sfd, 0);
+ goto skip_write;
}
- // write the byte
- write(i ? sfd : STDOUT_FILENO, &c, 1);
-// write(fd, &c, 1);
- // give device a chance to get data
- // wait 0.01 msec
- // (TODO: seems to be arbitrary to me)
- if (i)
- usleep(10);
+ // ^X exits
+ if (24 == c)
+ break;
+ }
+ write(sfd, &c, 1);
+ if (delay >= 0)
+ safe_poll(pfd, 1, delay);
+skip_write: ;
+ }
+ if (pfd[0].revents) {
+#define iobuf bb_common_bufsiz1
+ ssize_t len;
+ // read from device -> write to stdout
+ len = safe_read(sfd, iobuf, sizeof(iobuf));
+ if (len > 0)
+ full_write(STDOUT_FILENO, iobuf, len);
+ else {
+ // EOF/error -> bail out
+ bb_got_signal = SIGHUP;
+ break;
}
}
}
-done:
- tcsetattr(sfd, TCSANOW, &tiosfd);
-restore0_close_unlock_and_exit:
- if (istty) {
-// tcflush(STDIN_FILENO, TCIFLUSH);
- tcsetattr(STDIN_FILENO, TCSANOW, &tio0);
- }
+ // restore device mode
+ tcsetattr(sfd, TCSAFLUSH, &tiosfd);
-close_unlock_and_exit:
- if (ENABLE_FEATURE_CLEAN_UP)
- close(sfd);
+ if (isatty(STDIN_FILENO))
+ tcsetattr(STDIN_FILENO, TCSAFLUSH, &tio0);
-unlock_and_exit:
- // delete lock file
- if (device_lock_file) {
+done:
+ if (device_lock_file)
unlink(device_lock_file);
- if (ENABLE_FEATURE_CLEAN_UP)
- free(device_lock_file);
- }
- return signalled;
+
+ return bb_got_signal;
}
projects / oweals / busybox.git / blobdiff