*/
#define ISSUE "/etc/issue"
-/* Some shorthands for control characters */
-#define CTL(x) ((x) ^ 0100) /* Assumes ASCII dialect */
-#define BS CTL('H') /* back space */
-#define DEL CTL('?') /* delete */
-
-/* Defaults for line-editing etc. characters; you may want to change this */
-#define DEF_INTR CTL('C') /* default interrupt character */
-#define DEF_QUIT CTL('\\') /* default quit char */
-#define DEF_KILL CTL('U') /* default kill char */
-#define DEF_EOF CTL('D') /* default EOF char */
-#define DEF_EOL '\n'
-#define DEF_SWITCH 0 /* default switch char (none) */
+/* Macro to build Ctrl-LETTER. Assumes ASCII dialect */
+#define CTL(x) ((x) ^ 0100)
/*
* When multiple baud rates are specified on the command line,
alarm(5);
tcdrain(STDIN_FILENO);
alarm(0);
- signal(SIGALRM, SIG_DFL); /* do not break -t TIMEOUT! */
/* Flush input and output queues, important for modems! */
tcflush(STDIN_FILENO, TCIOFLUSH);
#ifdef CMSPAR
| CMSPAR /* mark or space parity */
#endif
+#ifdef CBAUD
| CBAUD /* (output) baud rate */
+#endif
#ifdef CBAUDEX
| CBAUDEX /* (output) baud rate */
#endif
/* non-raw output; add CR to each NL */
G.tty_attrs.c_oflag = OPOST | ONLCR;
- G.tty_attrs.c_cc[VMIN] = 1; /* block reads if < 1 char is available */
- G.tty_attrs.c_cc[VTIME] = 0; /* no timeout (reads block forever) */
+ /* reads would block only if < 1 char is available */
+ G.tty_attrs.c_cc[VMIN] = 1;
+ /* no timeout (reads block forever) */
+ G.tty_attrs.c_cc[VTIME] = 0;
#ifdef __linux__
G.tty_attrs.c_line = 0;
#endif
* (why "stty sane" unsets this bit?)
*/
- G.tty_attrs.c_cc[VINTR] = DEF_INTR;
- G.tty_attrs.c_cc[VQUIT] = DEF_QUIT;
- G.tty_attrs.c_cc[VEOF] = DEF_EOF;
- G.tty_attrs.c_cc[VEOL] = DEF_EOL;
+ G.tty_attrs.c_cc[VINTR] = CTL('C');
+ G.tty_attrs.c_cc[VQUIT] = CTL('\\');
+ G.tty_attrs.c_cc[VEOF] = CTL('D');
+ G.tty_attrs.c_cc[VEOL] = '\n';
#ifdef VSWTC
- G.tty_attrs.c_cc[VSWTC] = DEF_SWITCH;
+ G.tty_attrs.c_cc[VSWTC] = 0;
#endif
#ifdef VSWTCH
- G.tty_attrs.c_cc[VSWTCH] = DEF_SWITCH;
+ G.tty_attrs.c_cc[VSWTCH] = 0;
#endif
- G.tty_attrs.c_cc[VKILL] = DEF_KILL;
+ G.tty_attrs.c_cc[VKILL] = CTL('U');
/* Other control chars:
* VEOL2
* VERASE, VWERASE - (word) erase. we may set VERASE in get_logname
*/
set_tty_attrs();
+
+ /* Now the newline character should be properly written */
+ full_write(STDOUT_FILENO, "\n", 1);
}
/* extract baud rate from modem status message */
tcflush(STDIN_FILENO, TCIFLUSH);
/* Prompt for and read a login name */
- G.line_buf[0] = '\0';
- while (!G.line_buf[0]) {
+ do {
/* Write issue file and prompt */
#ifdef ISSUE
if (!(option_mask32 & F_NOISSUE))
#endif
print_login_prompt();
- /* Read name, watch for break, parity, erase, kill, end-of-line */
+ /* Read name, watch for break, erase, kill, end-of-line */
bp = G.line_buf;
- G.eol = '\0';
while (1) {
/* Do not report trivial EINTR/EIO errors */
errno = EINTR; /* make read of 0 bytes be silent too */
if (read(STDIN_FILENO, &c, 1) < 1) {
+ finalize_tty_attrs();
if (errno == EINTR || errno == EIO)
exit(EXIT_SUCCESS);
bb_perror_msg_and_die(bb_msg_read_error);
}
- /* BREAK. If we have speeds to try,
- * return NULL (will switch speeds and return here) */
- if (c == '\0' && G.numspeed > 1)
- return NULL;
-
- /* Do erase, kill and end-of-line processing */
switch (c) {
case '\r':
case '\n':
*bp = '\0';
G.eol = c;
goto got_logname;
- case BS:
- case DEL:
+ case CTL('H'):
+ case 0x7f:
G.tty_attrs.c_cc[VERASE] = c;
if (bp > G.line_buf) {
full_write(STDOUT_FILENO, "\010 \010", 3);
bp--;
}
break;
+ case CTL('C'):
case CTL('D'):
+ finalize_tty_attrs();
exit(EXIT_SUCCESS);
+ case '\0':
+ /* BREAK. If we have speeds to try,
+ * return NULL (will switch speeds and return here) */
+ if (G.numspeed > 1)
+ return NULL;
+ /* fall through and ignore it */
default:
if ((unsigned char)c < ' ') {
/* ignore garbage characters */
}
} /* end of get char loop */
got_logname: ;
- } /* while logname is empty */
+ } while (G.line_buf[0] == '\0'); /* while logname is empty */
return G.line_buf;
}
* a session leader - which is quite possible for getty!
*/
pid = getpid();
- if (getsid(0) != pid)
+ if (getsid(0) != pid) {
+ //for debugging:
+ //bb_perror_msg_and_die("setsid failed:"
+ // " pid %d ppid %d"
+ // " sid %d pgid %d",
+ // pid, getppid(),
+ // getsid(0), getpgid(0));
bb_perror_msg_and_die("setsid");
+ }
/* Looks like we are already a session leader.
* In this case (setsid failed) we may still have ctty,
* and it may be different from tty we need to control!
* If we still have ctty, on Linux ioctl(TIOCSCTTY)
- * (which we are going to call a bit later) always fails.
- * Try to drop ctty now to prevent that.
+ * (which we are going to use a bit later) always fails -
+ * even if we try to take ctty which is already ours!
+ * Try to drop old ctty now to prevent that.
+ * Use O_NONBLOCK: old ctty may be a serial line.
*/
- fd = open("/dev/tty", O_RDWR);
+ fd = open("/dev/tty", O_RDWR | O_NONBLOCK);
if (fd >= 0) {
+ /* TIOCNOTTY sends SIGHUP to the foreground
+ * process group - which may include us!
+ * Make sure to not die on it:
+ */
+ sighandler_t old = signal(SIGHUP, SIG_IGN);
ioctl(fd, TIOCNOTTY);
close(fd);
+ signal(SIGHUP, old);
}
}
finalize_tty_attrs();
- /* Now the newline character should be properly written */
- full_write(STDOUT_FILENO, "\n", 1);
-
/* Let the login program take care of password validation */
/* We use PATH because we trust that root doesn't set "bad" PATH,
* and getty is not suid-root applet */
projects / oweals / busybox.git / blobdiff