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-rw-r--r--miscutils/microcom.c206
1 files changed, 133 insertions, 73 deletions
diff --git a/miscutils/microcom.c b/miscutils/microcom.c
index 1235f0634..160bff19b 100644
--- a/miscutils/microcom.c
+++ b/miscutils/microcom.c
@@ -9,128 +9,188 @@
*/
#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
+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, TCSANOW, 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, char **argv)
{
struct pollfd pfd[2];
-#define sfd (pfd[1].fd)
- char *device_lock_file = NULL;
- const char *s;
+ int nfd;
+ //int sfd;
+#define sfd (pfd[0].fd)
+ char *device_lock_file;
const char *opt_s = "9600";
- unsigned speed;
- int len;
- int exitcode = 1;
+ speed_t speed;
+ const char *opt_t = "100"; // 0.1 sec timeout
+ unsigned timeout;
struct termios tio0, tiosfd, tio;
+ bool istty;
- getopt32(argv, "s:", &opt_s);
+ // fetch options
+ opt_complementary = "-1"; /* at least one arg should be there */
+ getopt32(argv, "s:t:", &opt_s, &opt_t);
argc -= optind;
argv += optind;
- if (!argv[0])
- bb_show_usage();
+
+ // 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
- 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 = 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) {
- 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
+ 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,
// not text, PID. Making 5+ char file. Brrr...
- s = xasprintf("%4d\n", getpid());
+ char *s = xasprintf("%4d\n", getpid());
write(sfd, s, strlen(s));
if (ENABLE_FEATURE_CLEAN_UP)
- free((char*)s);
+ free(s);
close(sfd);
}
- // open device
- sfd = open(argv[0], O_RDWR);
- if (sfd < 0) {
- bb_perror_msg("can't open device");
- goto unlock_and_exit;
- }
+ // setup signals
+ sig_catch(SIGHUP, signal_handler);
+ sig_catch(SIGINT, signal_handler);
+ sig_catch(SIGTERM, signal_handler);
+ sig_catch(SIGPIPE, signal_handler);
- // 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;
- }
+ // error exit code if we fail to open the device
+ signalled = 1;
- /* 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");
+ // 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);
- // disable SIGINT
- signal(SIGINT, SIG_IGN);
+ /* 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()
+ }
- // drain stdin
- tcflush(STDIN_FILENO, TCIFLUSH);
- printf("connected to '%s' (%d bps), exit with ctrl-X...\r\n", argv[0], speed);
+ // same thing for modem
+ 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;
// main loop: check with poll(), then read/write bytes across
- pfd[0].fd = STDIN_FILENO;
+ /* pfd[0].fd = sfd; - they are the same */
pfd[0].events = POLLIN;
- /*pfd[1].fd = sfd;*/
+ pfd[1].fd = STDIN_FILENO;
pfd[1].events = POLLIN;
- while (1) {
+
+ // TODO: on piped input should we treat NL as CRNL?!
+
+ signalled = 0;
+ // initially we have to poll() both stdin and device
+ nfd = 2;
+ while (!signalled && nfd && safe_poll(pfd, nfd, timeout) > 0) {
int i;
- safe_poll(pfd, 2, -1);
- 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);
+
+ 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;
}
+ // 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);
}
}
}
- done:
+done:
tcsetattr(sfd, TCSANOW, &tiosfd);
- tcsetattr(STDIN_FILENO, TCSANOW, &tio0);
- tcflush(STDIN_FILENO, TCIFLUSH);
+restore0_close_unlock_and_exit:
+ if (istty) {
+// tcflush(STDIN_FILENO, TCIFLUSH);
+ tcsetattr(STDIN_FILENO, TCSANOW, &tio0);
+ }
+
+close_unlock_and_exit:
if (ENABLE_FEATURE_CLEAN_UP)
close(sfd);
- exitcode = 0;
- unlock_and_exit:
+unlock_and_exit:
// delete lock file
if (device_lock_file) {
unlink(device_lock_file);
if (ENABLE_FEATURE_CLEAN_UP)
free(device_lock_file);
}
- return exitcode;
+ return signalled;
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-15 01:21:59 +0000