mirror of
https://github.com/sheumann/hush.git
synced 2024-08-21 11:28:57 +00:00
getty: more simplifications; explain how we treat parity now
function old new delta getty_main 1471 1434 -37 Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
parent
6596380f52
commit
faaf8cb3fa
@ -1,15 +1,23 @@
|
||||
/* vi: set sw=4 ts=4: */
|
||||
/* Based on agetty - another getty program for Linux. By W. Z. Venema 1989
|
||||
/*
|
||||
* Based on agetty - another getty program for Linux. By W. Z. Venema 1989
|
||||
* Ported to Linux by Peter Orbaek <poe@daimi.aau.dk>
|
||||
* This program is freely distributable.
|
||||
*
|
||||
* option added by Eric Rasmussen <ear@usfirst.org> - 12/28/95
|
||||
*
|
||||
* 1999-02-22 Arkadiusz Mickiewicz <misiek@misiek.eu.org>
|
||||
* - added Native Language Support
|
||||
* - Added Native Language Support
|
||||
*
|
||||
* 1999-05-05 Thorsten Kranzkowski <dl8bcu@gmx.net>
|
||||
* - enable hardware flow control before displaying /etc/issue
|
||||
* - Enabled hardware flow control before displaying /etc/issue
|
||||
*
|
||||
* 2011-01 Venys Vlasenko
|
||||
* - Removed parity detection code. It can't work reliably:
|
||||
* if all chars received have bit 7 cleared and odd (or even) parity,
|
||||
* it is impossible to determine whether other side is 8-bit,no-parity
|
||||
* or 7-bit,odd(even)-parity. It also interferes with non-ASCII usernames.
|
||||
* - From now on, we assume that parity is correctly set.
|
||||
*
|
||||
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
|
||||
*/
|
||||
@ -23,13 +31,7 @@
|
||||
# define IUCLC 0
|
||||
#endif
|
||||
|
||||
/*
|
||||
* Some heuristics to find out what environment we are in: if it is not
|
||||
* System V, assume it is SunOS 4.
|
||||
*/
|
||||
#ifdef LOGIN_PROCESS /* defined in System V utmp.h */
|
||||
# include <sys/utsname.h>
|
||||
#else /* if !sysV style, wtmp/utmp code is off */
|
||||
#ifndef LOGIN_PROCESS
|
||||
# undef ENABLE_FEATURE_UTMP
|
||||
# undef ENABLE_FEATURE_WTMP
|
||||
# define ENABLE_FEATURE_UTMP 0
|
||||
@ -37,7 +39,7 @@
|
||||
#endif
|
||||
|
||||
|
||||
/* The following is used for understandable diagnostics. */
|
||||
/* The following is used for understandable diagnostics */
|
||||
#ifdef DEBUGGING
|
||||
static FILE *dbf;
|
||||
# define DEBUGTERM "/dev/ttyp0"
|
||||
@ -64,14 +66,14 @@ static FILE *dbf;
|
||||
*/
|
||||
#define ISSUE "/etc/issue"
|
||||
|
||||
/* Some shorthands for control characters. */
|
||||
/* Some shorthands for control characters */
|
||||
#define CTL(x) ((x) ^ 0100) /* Assumes ASCII dialect */
|
||||
#define CR CTL('M') /* carriage return */
|
||||
#define NL CTL('J') /* line feed */
|
||||
#define BS CTL('H') /* back space */
|
||||
#define DEL CTL('?') /* delete */
|
||||
|
||||
/* Defaults for line-editing etc. characters; you may want to change this. */
|
||||
/* Defaults for line-editing etc. characters; you may want to change this */
|
||||
#define DEF_ERASE DEL /* default erase character */
|
||||
#define DEF_INTR CTL('C') /* default interrupt character */
|
||||
#define DEF_QUIT CTL('\\') /* default quit char */
|
||||
@ -81,23 +83,22 @@ static FILE *dbf;
|
||||
#define DEF_SWITCH 0 /* default switch char */
|
||||
|
||||
/*
|
||||
* When multiple baud rates are specified on the command line, the first one
|
||||
* we will try is the first one specified.
|
||||
* When multiple baud rates are specified on the command line,
|
||||
* the first one we will try is the first one specified.
|
||||
*/
|
||||
#define MAX_SPEED 10 /* max. nr. of baud rates */
|
||||
|
||||
struct globals {
|
||||
unsigned timeout; /* time-out period */
|
||||
const char *login; /* login program */
|
||||
const char *fakehost;
|
||||
const char *tty; /* name of tty */
|
||||
const char *initstring; /* modem init string */
|
||||
const char *issue; /* alternative issue file */
|
||||
int numspeed; /* number of baud rates to try */
|
||||
int speeds[MAX_SPEED]; /* baud rates to be tried */
|
||||
unsigned char eol; /* end-of-line char seen (CR or NL) */
|
||||
struct termios termios; /* terminal mode bits */
|
||||
/* Storage for things detected while the login name was read. */
|
||||
unsigned char erase; /* erase character */
|
||||
unsigned char eol; /* end-of-line character */
|
||||
char line_buf[128];
|
||||
};
|
||||
|
||||
@ -168,14 +169,14 @@ static void parse_speeds(char *arg)
|
||||
}
|
||||
|
||||
/* parse command-line arguments */
|
||||
static void parse_args(char **argv, char **fakehost_p)
|
||||
static void parse_args(char **argv)
|
||||
{
|
||||
char *ts;
|
||||
int flags;
|
||||
|
||||
opt_complementary = "-2:t+"; /* at least 2 args; -t N */
|
||||
flags = getopt32(argv, opt_string,
|
||||
&G.initstring, fakehost_p, &G.issue,
|
||||
&G.initstring, &G.fakehost, &G.issue,
|
||||
&G.login, &G.timeout
|
||||
);
|
||||
if (flags & F_INITSTRING) {
|
||||
@ -206,17 +207,17 @@ static void parse_args(char **argv, char **fakehost_p)
|
||||
/* set up tty as standard input, output, error */
|
||||
static void open_tty(void)
|
||||
{
|
||||
/* Set up new standard input, unless we are given an already opened port. */
|
||||
/* Set up new standard input, unless we are given an already opened port */
|
||||
if (NOT_LONE_DASH(G.tty)) {
|
||||
if (G.tty[0] != '/')
|
||||
G.tty = xasprintf("/dev/%s", G.tty); /* will leak it */
|
||||
|
||||
/* Open the tty as standard input. */
|
||||
/* Open the tty as standard input */
|
||||
debug("open(2)\n");
|
||||
close(0);
|
||||
xopen(G.tty, O_RDWR | O_NONBLOCK); /* uses fd 0 */
|
||||
|
||||
/* Set proper protections and ownership. */
|
||||
/* Set proper protections and ownership */
|
||||
fchown(0, 0, 0); /* 0:0 */
|
||||
fchmod(0, 0620); /* crw--w---- */
|
||||
} else {
|
||||
@ -229,7 +230,13 @@ static void open_tty(void)
|
||||
}
|
||||
}
|
||||
|
||||
/* initialize termios settings */
|
||||
/* We manipulate termios this way:
|
||||
* - first, we read existing termios settings
|
||||
* - termios_init modifies some parts and sets it
|
||||
* - auto_baud and/or BREAK processing can set different speed and set termios
|
||||
* - termios_final again modifies some parts and sets termios before
|
||||
* execing login
|
||||
*/
|
||||
static void termios_init(int speed)
|
||||
{
|
||||
/* Flush input and output queues, important for modems!
|
||||
@ -240,7 +247,7 @@ static void termios_init(int speed)
|
||||
usleep(100*1000); /* 0.1 sec */
|
||||
tcflush(STDIN_FILENO, TCIOFLUSH);
|
||||
|
||||
/* Set speed if it wasn't specified as "0" on command line. */
|
||||
/* Set speed if it wasn't specified as "0" on command line */
|
||||
if (speed != B0)
|
||||
cfsetspeed(&G.termios, speed);
|
||||
|
||||
@ -271,13 +278,44 @@ static void termios_init(int speed)
|
||||
debug("term_io 2\n");
|
||||
}
|
||||
|
||||
static void termios_final(void)
|
||||
{
|
||||
/* General terminal-independent stuff */
|
||||
G.termios.c_iflag |= IXON | IXOFF; /* 2-way flow control */
|
||||
G.termios.c_lflag |= ICANON | ISIG | ECHO | ECHOE | ECHOK | ECHOKE;
|
||||
/* no longer in lflag: | ECHOCTL | ECHOPRT */
|
||||
G.termios.c_oflag |= OPOST;
|
||||
/* G.termios.c_cflag = 0; */
|
||||
G.termios.c_cc[VINTR] = DEF_INTR;
|
||||
G.termios.c_cc[VQUIT] = DEF_QUIT;
|
||||
G.termios.c_cc[VEOF] = DEF_EOF;
|
||||
G.termios.c_cc[VEOL] = DEF_EOL;
|
||||
#ifdef VSWTC
|
||||
G.termios.c_cc[VSWTC] = DEF_SWITCH;
|
||||
#endif
|
||||
|
||||
/* Account for special characters seen in input */
|
||||
if (G.eol == CR) {
|
||||
G.termios.c_iflag |= ICRNL; /* map CR in input to NL */
|
||||
/* already done by termios_init */
|
||||
/* G.termios.c_oflag |= ONLCR; map NL in output to CR-NL */
|
||||
}
|
||||
G.termios.c_cc[VKILL] = DEF_KILL;
|
||||
|
||||
#ifdef CRTSCTS
|
||||
/* Optionally enable hardware flow control */
|
||||
if (option_mask32 & F_RTSCTS)
|
||||
G.termios.c_cflag |= CRTSCTS;
|
||||
#endif
|
||||
|
||||
/* Finally, make the new settings effective */
|
||||
if (tcsetattr_stdin_TCSANOW(&G.termios) < 0)
|
||||
bb_perror_msg_and_die("tcsetattr");
|
||||
}
|
||||
|
||||
/* extract baud rate from modem status message */
|
||||
static void auto_baud(void)
|
||||
{
|
||||
int speed;
|
||||
int vmin;
|
||||
unsigned iflag;
|
||||
char *bp;
|
||||
int nread;
|
||||
|
||||
/*
|
||||
@ -296,12 +334,9 @@ static void auto_baud(void)
|
||||
*/
|
||||
|
||||
/*
|
||||
* Use 7-bit characters, don't block if input queue is empty. Errors will
|
||||
* be dealt with later on.
|
||||
* Don't block if input queue is empty.
|
||||
* Errors will be dealt with later on.
|
||||
*/
|
||||
iflag = G.termios.c_iflag;
|
||||
G.termios.c_iflag |= ISTRIP; /* enable 8th-bit stripping */
|
||||
vmin = G.termios.c_cc[VMIN];
|
||||
G.termios.c_cc[VMIN] = 0; /* don't block if queue empty */
|
||||
tcsetattr_stdin_TCSANOW(&G.termios);
|
||||
|
||||
@ -312,6 +347,8 @@ static void auto_baud(void)
|
||||
sleep(1);
|
||||
nread = safe_read(STDIN_FILENO, G.line_buf, sizeof(G.line_buf) - 1);
|
||||
if (nread > 0) {
|
||||
int speed;
|
||||
char *bp;
|
||||
G.line_buf[nread] = '\0';
|
||||
for (bp = G.line_buf; bp < G.line_buf + nread; bp++) {
|
||||
if (isdigit(*bp)) {
|
||||
@ -323,38 +360,38 @@ static void auto_baud(void)
|
||||
}
|
||||
}
|
||||
|
||||
/* Restore terminal settings. Errors will be dealt with later on. */
|
||||
G.termios.c_iflag = iflag;
|
||||
G.termios.c_cc[VMIN] = vmin;
|
||||
/* 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);
|
||||
}
|
||||
|
||||
/* get user name, establish parity, speed, erase, kill, eol;
|
||||
* return NULL on BREAK, logname on success */
|
||||
* return NULL on BREAK, logname on success
|
||||
*/
|
||||
static char *get_logname(void)
|
||||
{
|
||||
char *bp;
|
||||
char c;
|
||||
|
||||
/* Flush pending input (esp. after parsing or switching the baud rate). */
|
||||
/* Flush pending input (esp. after parsing or switching the baud rate) */
|
||||
usleep(100*1000); /* 0.1 sec */
|
||||
tcflush(STDIN_FILENO, TCIOFLUSH);
|
||||
|
||||
/* Prompt for and read a login name. */
|
||||
/* Prompt for and read a login name */
|
||||
G.line_buf[0] = '\0';
|
||||
while (!G.line_buf[0]) {
|
||||
/* Write issue file and prompt. */
|
||||
/* Write issue file and prompt */
|
||||
#ifdef ISSUE
|
||||
if (!(option_mask32 & F_NOISSUE))
|
||||
print_login_issue(G.issue, G.tty);
|
||||
#endif
|
||||
print_login_prompt();
|
||||
|
||||
/* Read name, watch for break, parity, erase, kill, end-of-line. */
|
||||
/* Read name, watch for break, parity, erase, kill, end-of-line */
|
||||
bp = G.line_buf;
|
||||
G.eol = '\0';
|
||||
while (1) {
|
||||
/* Do not report trivial EINTR/EIO errors. */
|
||||
/* Do not report trivial EINTR/EIO errors */
|
||||
errno = EINTR; /* make read of 0 bytes be silent too */
|
||||
if (read(STDIN_FILENO, &c, 1) < 1) {
|
||||
if (errno == EINTR || errno == EIO)
|
||||
@ -367,7 +404,7 @@ static char *get_logname(void)
|
||||
if (c == '\0' && G.numspeed > 1)
|
||||
return NULL;
|
||||
|
||||
/* Do erase, kill and end-of-line processing. */
|
||||
/* Do erase, kill and end-of-line processing */
|
||||
switch (c) {
|
||||
case CR:
|
||||
case NL:
|
||||
@ -376,7 +413,7 @@ static char *get_logname(void)
|
||||
goto got_logname;
|
||||
case BS:
|
||||
case DEL:
|
||||
G.erase = c;
|
||||
G.termios.c_cc[VERASE] = c;
|
||||
if (bp > G.line_buf) {
|
||||
full_write(STDOUT_FILENO, "\010 \010", 3);
|
||||
bp--;
|
||||
@ -407,61 +444,22 @@ static char *get_logname(void)
|
||||
return G.line_buf;
|
||||
}
|
||||
|
||||
/* set the final tty mode bits */
|
||||
static void termios_final(void)
|
||||
{
|
||||
/* General terminal-independent stuff. */
|
||||
G.termios.c_iflag |= IXON | IXOFF; /* 2-way flow control */
|
||||
G.termios.c_lflag |= ICANON | ISIG | ECHO | ECHOE | ECHOK | ECHOKE;
|
||||
/* no longer in lflag: | ECHOCTL | ECHOPRT */
|
||||
G.termios.c_oflag |= OPOST;
|
||||
/* G.termios.c_cflag = 0; */
|
||||
G.termios.c_cc[VINTR] = DEF_INTR; /* default interrupt */
|
||||
G.termios.c_cc[VQUIT] = DEF_QUIT; /* default quit */
|
||||
G.termios.c_cc[VEOF] = DEF_EOF; /* default EOF character */
|
||||
G.termios.c_cc[VEOL] = DEF_EOL;
|
||||
#ifdef VSWTC
|
||||
G.termios.c_cc[VSWTC] = DEF_SWITCH; /* default switch character */
|
||||
#endif
|
||||
|
||||
/* Account for special characters seen in input. */
|
||||
if (G.eol == CR) {
|
||||
G.termios.c_iflag |= ICRNL; /* map CR in input to NL */
|
||||
G.termios.c_oflag |= ONLCR; /* map NL in output to CR-NL */
|
||||
}
|
||||
G.termios.c_cc[VERASE] = G.erase; /* set erase character */
|
||||
G.termios.c_cc[VKILL] = DEF_KILL; /* set kill character */
|
||||
|
||||
#ifdef CRTSCTS
|
||||
/* Optionally enable hardware flow control */
|
||||
if (option_mask32 & F_RTSCTS)
|
||||
G.termios.c_cflag |= CRTSCTS;
|
||||
#endif
|
||||
|
||||
/* Finally, make the new settings effective */
|
||||
if (tcsetattr_stdin_TCSANOW(&G.termios) < 0)
|
||||
bb_perror_msg_and_die("tcsetattr");
|
||||
}
|
||||
|
||||
int getty_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
||||
int getty_main(int argc UNUSED_PARAM, char **argv)
|
||||
{
|
||||
int n;
|
||||
pid_t pid;
|
||||
char *fakehost = NULL; /* Fake hostname for ut_host */
|
||||
char *logname;
|
||||
|
||||
INIT_G();
|
||||
G.login = _PATH_LOGIN; /* default login program */
|
||||
G.initstring = ""; /* modem init string */
|
||||
#ifdef ISSUE
|
||||
G.issue = ISSUE; /* default issue file */
|
||||
#endif
|
||||
G.erase = DEF_ERASE;
|
||||
G.eol = CR;
|
||||
|
||||
/* Parse command-line arguments. */
|
||||
parse_args(argv, &fakehost);
|
||||
/* Parse command-line arguments */
|
||||
parse_args(argv);
|
||||
|
||||
logmode = LOGMODE_NONE;
|
||||
|
||||
@ -524,9 +522,9 @@ int getty_main(int argc UNUSED_PARAM, char **argv)
|
||||
#endif
|
||||
|
||||
/* Update the utmp file. This tty is ours now! */
|
||||
update_utmp(pid, LOGIN_PROCESS, G.tty, "LOGIN", fakehost);
|
||||
update_utmp(pid, LOGIN_PROCESS, G.tty, "LOGIN", G.fakehost);
|
||||
|
||||
/* Initialize the termios settings (raw mode, eight-bit, blocking i/o). */
|
||||
/* Initialize the termios settings (raw mode, eight-bit, blocking i/o) */
|
||||
debug("calling termios_init\n");
|
||||
termios_init(G.speeds[0]);
|
||||
|
||||
@ -563,30 +561,30 @@ int getty_main(int argc UNUSED_PARAM, char **argv)
|
||||
int baud_index = 0;
|
||||
|
||||
while (1) {
|
||||
/* Read the login name. */
|
||||
/* Read the login name */
|
||||
debug("reading login name\n");
|
||||
logname = get_logname();
|
||||
if (logname)
|
||||
break;
|
||||
/* We are here only if G.numspeed > 1. */
|
||||
/* 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);
|
||||
}
|
||||
}
|
||||
|
||||
/* Disable timer. */
|
||||
/* Disable timer */
|
||||
alarm(0);
|
||||
|
||||
/* Finalize the termios settings. */
|
||||
/* Finalize the termios settings */
|
||||
termios_final();
|
||||
|
||||
/* Now the newline character should be properly written. */
|
||||
/* Now the newline character should be properly written */
|
||||
full_write(STDOUT_FILENO, "\n", 1);
|
||||
|
||||
/* Let the login program take care of password validation. */
|
||||
/* 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. */
|
||||
* and getty is not suid-root applet */
|
||||
/* With -n, logname == NULL, and login will ask for username instead */
|
||||
BB_EXECLP(G.login, G.login, "--", logname, NULL);
|
||||
bb_error_msg_and_die("can't execute '%s'", G.login);
|
||||
|
Loading…
Reference in New Issue
Block a user