diff options
| -rw-r--r-- | loginutils/getty.c | 56 |
1 files changed, 33 insertions, 23 deletions
diff --git a/loginutils/getty.c b/loginutils/getty.c index 2d2184a..0355341 100644 --- a/loginutils/getty.c +++ b/loginutils/getty.c @@ -224,6 +224,12 @@ static void open_tty(void) } } +static void set_termios(void) +{ + if (tcsetattr_stdin_TCSANOW(&G.termios) < 0) + bb_perror_msg_and_die("tcsetattr"); +} + /* We manipulate termios this way: * - first, we read existing termios settings * - termios_init modifies some parts and sets it @@ -233,25 +239,31 @@ static void open_tty(void) */ static void termios_init(int speed) { - /* Flush input and output queues, important for modems! - * Users report losing previously queued output chars, and I hesitate - * to use tcdrain here instead of tcflush - I imagine it can block. - * Using small sleep instead. + /* Try to drain output buffer, with 5 sec timeout. + * Added on request from users of ~600 baud serial interface + * with biggish buffer on a 90MHz CPU. + * They were losing hundreds of bytes of buffered output + * on tcflush. */ - usleep(100*1000); /* 0.1 sec */ + signal_no_SA_RESTART_empty_mask(SIGALRM, record_signo); + 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); /* Set speed if it wasn't specified as "0" on command line */ if (speed != B0) cfsetspeed(&G.termios, speed); - /* - * Initial termios settings: 8-bit characters, raw-mode, blocking i/o. + /* Initial termios settings: 8-bit characters, raw-mode, blocking i/o. * Special characters are set after we have read the login name; all * reads will be done in raw mode anyway. Errors will be dealt with * later on. */ - /* 8 bits; hangup (drop DTR) on last close; enable receive */ + /* 8 bits; hang up (drop DTR) on last close; enable receive */ G.termios.c_cflag = CS8 | HUPCL | CREAD; if (option_mask32 & F_LOCAL) { /* ignore Carrier Detect pin: @@ -266,9 +278,8 @@ static void termios_init(int speed) #endif /* Other bits in c_cflag: * CSTOPB 2 stop bits (1 otherwise) - * PARENB Enable parity bit - * PARODD Use odd parity (else even) - * LOBLK Block job control output (??) + * PARENB Enable parity bit (both on input and output) + * PARODD Odd parity (else even) */ G.termios.c_iflag = 0; G.termios.c_lflag = 0; @@ -281,7 +292,7 @@ static void termios_init(int speed) G.termios.c_line = 0; #endif - tcsetattr_stdin_TCSANOW(&G.termios); + set_termios(); debug("term_io 2\n"); } @@ -309,8 +320,8 @@ static void termios_final(void) * ICRNL Map CR to NL * IUCLC Map uppercase to lowercase * IMAXBEL Echo BEL on input line too long - * IUTF8 [Appears to affect tty's idea of char widths, - * observed to improve backspacing through Unicode chars] + * IUTF8 Appears to affect tty's idea of char widths, + * observed to improve backspacing through Unicode chars */ /* line buffered input (NL or EOL or EOF chars end a line); @@ -324,16 +335,16 @@ static void termios_final(void) /* Other bits in c_lflag: * XCASE Map uppercase to \lowercase [tried, doesn't work] * ECHONL Echo NL even if ECHO is not set + * ECHOCTL Echo ctrl chars as ^c (else don't echo) - maybe set this? + * ECHOPRT On erase, echo erased chars + * [qwe<BS><BS><BS> input looks like "qwe\ewq/" on screen] * NOFLSH Don't flush input buffer after interrupt or quit chars * IEXTEN Enable extended functions (??) * [glibc says it enables c_cc[LNEXT] "enter literal char" * and c_cc[VDISCARD] "toggle discard buffered output" chars] - * ECHOCTL Echo ctrl chars as ^c (else don't echo) - maybe set this? - * ECHOPRT On erase, echo erased chars - * [qwe<BS><BS><BS> input looks like "qwe\ewq/" on screen] * FLUSHO Output being flushed (c_cc[VDISCARD] is in effect) * PENDIN Retype pending input at next read or input char - * (c_cc[VREPRINT] is being processes) + * (c_cc[VREPRINT] is being processed) * TOSTOP Send SIGTTOU for background output * (why "stty sane" unsets this bit?) */ @@ -358,8 +369,7 @@ static void termios_final(void) * VSTART, VSTOP - chars used for IXON/IXOFF */ - if (tcsetattr_stdin_TCSANOW(&G.termios) < 0) - bb_perror_msg_and_die("tcsetattr"); + set_termios(); } /* extract baud rate from modem status message */ @@ -383,7 +393,7 @@ static void auto_baud(void) */ G.termios.c_cc[VMIN] = 0; /* don't block reads (min read is 0 chars) */ - tcsetattr_stdin_TCSANOW(&G.termios); + set_termios(); /* * Wait for a while, then read everything the modem has said so far and @@ -407,7 +417,7 @@ static void auto_baud(void) /* Restore terminal settings. Errors will be dealt with later on */ G.termios.c_cc[VMIN] = 1; /* restore to value set by termios_init */ - tcsetattr_stdin_TCSANOW(&G.termios); + set_termios(); } /* get user name, establish parity, speed, erase, kill, eol; @@ -614,7 +624,7 @@ int getty_main(int argc UNUSED_PARAM, char **argv) /* We are here only if G.numspeed > 1 */ baud_index = (baud_index + 1) % G.numspeed; cfsetspeed(&G.termios, G.speeds[baud_index]); - tcsetattr_stdin_TCSANOW(&G.termios); + set_termios(); } } |