* 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 "busybox.h"
-int microcom_main(int argc, char **argv);
-int microcom_main(int argc, char **argv)
+//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"
+
+#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);
+// t->c_lflag &= ~(ISIG|ICANON|ECHO|IEXTEN);
+// t->c_iflag &= ~(BRKINT|IXON|ICRNL);
+// t->c_oflag &= ~(ONLCR);
+// t->c_cc[VMIN] = 1;
+// t->c_cc[VTIME] = 0;
+}
+
+static int xset1(int fd, struct termios *tio, const char *device)
+{
+ int ret = tcsetattr(fd, TCSAFLUSH, tio);
+
+ if (ret) {
+ bb_perror_msg("can't tcsetattr for %s", device);
+ }
+ return ret;
+}
+
+int microcom_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int microcom_main(int argc UNUSED_PARAM, char **argv)
{
+ int sfd;
+ int nfd;
struct pollfd pfd[2];
-#define sfd (pfd[1].fd)
- char *device_lock_file = NULL;
- const char *s;
- const char *opt_s = "9600";
- unsigned speed;
- int len;
- int exitcode = 1;
struct termios tio0, tiosfd, tio;
+ 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;
- getopt32(argv, "s:", &opt_s);
- argc -= optind;
+ // 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;
- if (!argv[0])
- bb_show_usage();
- speed = xatou(opt_s);
// try to create lock file in /var/lock
- s = bb_basename(argv[0]);
- if (!s[0]) {
- errno = ENODEV;
- bb_perror_msg_and_die("can't lock device");
- }
- device_lock_file = xasprintf("/var/lock/LCK..%s", s);
+ 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 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 (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
} 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...
- s = xasprintf("%4d\n", getpid());
- write(sfd, s, strlen(s));
- if (ENABLE_FEATURE_CLEAN_UP)
- free((char*)s);
+ fdprintf(sfd, "%4d\n", getpid());
close(sfd);
}
- // open device
- sfd = open(argv[0], O_RDWR | O_NDELAY);
- if (sfd < 0) {
- bb_perror_msg("can't open device");
- goto unlock_and_exit;
- }
- fcntl(sfd, F_SETFL, O_RDWR); // why?
-
- // put stdin to "raw mode", handle one character at a time
- tcgetattr(STDIN_FILENO, &tio0);
- tio = tio0;
- tio.c_lflag &= ~(ICANON|ECHO);
- tio.c_iflag &= ~(IXON|ICRNL);
- tio.c_oflag &= ~(ONLCR);
- tio.c_cc[VMIN] = 1;
- tio.c_cc[VTIME] = 0;
- if (tcsetattr(STDIN_FILENO, TCSANOW, &tio)) {
- bb_perror_msg("can't tcsetattr for %s", "stdin");
- goto unlock_and_exit;
- }
+ // setup signals
+ bb_signals(0
+ + (1 << SIGHUP)
+ + (1 << SIGINT)
+ + (1 << SIGTERM)
+ + (1 << SIGPIPE)
+ , record_signo);
- /* same thing for modem (plus: set baud rate) - TODO: make CLI option */
- tcgetattr(sfd, &tiosfd);
- tio = tiosfd;
- tio.c_lflag &= ~(ICANON|ECHO);
- tio.c_iflag &= ~(IXON|ICRNL);
- tio.c_oflag &= ~(ONLCR);
- tio.c_cc[VMIN] = 1;
- tio.c_cc[VTIME] = 0;
- cfsetispeed(&tio, tty_value_to_baud(speed));
- cfsetospeed(&tio, tty_value_to_baud(speed));
- if (tcsetattr(sfd, TCSANOW, &tio)) {
- bb_perror_msg("can't tcsetattr for %s", "device");
- goto unlock_and_exit;
- }
+ // error exit code if we fail to open the device
+ 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);
- // disable SIGINT
- signal(SIGINT, SIG_IGN);
+ // 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;
- // drain stdin
- tcflush(STDIN_FILENO, TCIFLUSH);
- printf("connected to '%s' (%d bps), exit with ctrl-X...\r\n", argv[0], speed);
+ // 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 = STDIN_FILENO;
+ pfd[0].fd = sfd;
pfd[0].events = POLLIN;
- /*pfd[1].fd = sfd;*/
+ pfd[1].fd = STDIN_FILENO;
pfd[1].events = POLLIN;
- while (1) {
- int i;
- while (-1 == poll(pfd, 2, -1) && EINTR == errno)
- continue;
- for (i = 0; i < 2; ++i) {
- if (pfd[i].revents & POLLIN) {
- len = read(pfd[i].fd, bb_common_bufsiz1, COMMON_BUFSIZE);
- if (len > 0) {
- if (!i && 24 == bb_common_bufsiz1[0])
- goto done; // ^X exits
- write(pfd[1-i].fd, bb_common_bufsiz1, len);
+
+ bb_got_signal = 0;
+ nfd = 2;
+ // 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;
}
+ // ^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);
- tcsetattr(STDIN_FILENO, TCSANOW, &tio0);
- tcflush(STDIN_FILENO, TCIFLUSH);
- if (ENABLE_FEATURE_CLEAN_UP)
- close(sfd);
- exitcode = 0;
+ // restore device mode
+ tcsetattr(sfd, TCSAFLUSH, &tiosfd);
+
+ 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 exitcode;
+
+ return bb_got_signal;
}
projects / platform / upstream / busybox.git / blobdiff