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784 lines
24 KiB
C
784 lines
24 KiB
C
/* vi: set sw=4 ts=4: */
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/* agetty.c - another getty program for Linux. By W. Z. Venema 1989
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* Ported to Linux by Peter Orbaek <poe@daimi.aau.dk>
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* This program is freely distributable. The entire man-page used to
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* be here. Now read the real man-page agetty.8 instead.
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*
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* option added by Eric Rasmussen <ear@usfirst.org> - 12/28/95
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*
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* 1999-02-22 Arkadiusz Mickiewicz <misiek@misiek.eu.org>
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* - added Native Language Support
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*
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* 1999-05-05 Thorsten Kranzkowski <dl8bcu@gmx.net>
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* - enable hardware flow control before displaying /etc/issue
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*
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* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
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*/
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#include "libbb.h"
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#include <syslog.h>
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#if ENABLE_FEATURE_UTMP
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#include <utmp.h> /* updwtmp() */
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#endif
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/*
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* Some heuristics to find out what environment we are in: if it is not
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* System V, assume it is SunOS 4.
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*/
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#ifdef LOGIN_PROCESS /* defined in System V utmp.h */
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#include <sys/utsname.h>
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#else /* if !sysV style, wtmp/utmp code is off */
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#undef ENABLE_FEATURE_UTMP
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#undef ENABLE_FEATURE_WTMP
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#define ENABLE_FEATURE_UTMP 0
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#define ENABLE_FEATURE_WTMP 0
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#endif /* LOGIN_PROCESS */
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/*
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* Things you may want to modify.
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*
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* You may disagree with the default line-editing etc. characters defined
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* below. Note, however, that DEL cannot be used for interrupt generation
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* and for line editing at the same time.
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*/
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/* I doubt there are systems which still need this */
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#undef HANDLE_ALLCAPS
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#undef ANCIENT_BS_KILL_CHARS
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#define _PATH_LOGIN "/bin/login"
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/* If ISSUE is not defined, getty will never display the contents of the
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* /etc/issue file. You will not want to spit out large "issue" files at the
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* wrong baud rate.
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*/
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#define ISSUE "/etc/issue" /* displayed before the login prompt */
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/* Some shorthands for control characters. */
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#define CTL(x) ((x) ^ 0100) /* Assumes ASCII dialect */
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#define CR CTL('M') /* carriage return */
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#define NL CTL('J') /* line feed */
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#define BS CTL('H') /* back space */
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#define DEL CTL('?') /* delete */
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/* Defaults for line-editing etc. characters; you may want to change this. */
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#define DEF_ERASE DEL /* default erase character */
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#define DEF_INTR CTL('C') /* default interrupt character */
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#define DEF_QUIT CTL('\\') /* default quit char */
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#define DEF_KILL CTL('U') /* default kill char */
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#define DEF_EOF CTL('D') /* default EOF char */
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#define DEF_EOL '\n'
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#define DEF_SWITCH 0 /* default switch char */
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/*
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* When multiple baud rates are specified on the command line, the first one
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* we will try is the first one specified.
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*/
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#define MAX_SPEED 10 /* max. nr. of baud rates */
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/* Storage for command-line options. */
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struct options {
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int flags; /* toggle switches, see below */
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unsigned timeout; /* time-out period */
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const char *login; /* login program */
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const char *tty; /* name of tty */
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const char *initstring; /* modem init string */
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const char *issue; /* alternative issue file */
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int numspeed; /* number of baud rates to try */
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int speeds[MAX_SPEED]; /* baud rates to be tried */
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};
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/* Storage for things detected while the login name was read. */
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struct chardata {
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unsigned char erase; /* erase character */
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unsigned char kill; /* kill character */
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unsigned char eol; /* end-of-line character */
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unsigned char parity; /* what parity did we see */
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/* (parity & 1): saw odd parity char with 7th bit set */
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/* (parity & 2): saw even parity char with 7th bit set */
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/* parity == 0: probably 7-bit, space parity? */
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/* parity == 1: probably 7-bit, odd parity? */
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/* parity == 2: probably 7-bit, even parity? */
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/* parity == 3: definitely 8 bit, no parity! */
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/* Hmm... with any value of "parity" 8 bit, no parity is possible */
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#ifdef HANDLE_ALLCAPS
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unsigned char capslock; /* upper case without lower case */
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#endif
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};
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/* Initial values for the above. */
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static const struct chardata init_chardata = {
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DEF_ERASE, /* default erase character */
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DEF_KILL, /* default kill character */
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13, /* default eol char */
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0, /* space parity */
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#ifdef HANDLE_ALLCAPS
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0, /* no capslock */
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#endif
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};
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static const char opt_string[] ALIGN1 = "I:LH:f:hil:mt:wn";
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#define F_INITSTRING (1 << 0) /* -I initstring is set */
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#define F_LOCAL (1 << 1) /* -L force local */
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#define F_FAKEHOST (1 << 2) /* -H fake hostname */
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#define F_CUSTISSUE (1 << 3) /* -f give alternative issue file */
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#define F_RTSCTS (1 << 4) /* -h enable RTS/CTS flow control */
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#define F_ISSUE (1 << 5) /* -i display /etc/issue */
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#define F_LOGIN (1 << 6) /* -l non-default login program */
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#define F_PARSE (1 << 7) /* -m process modem status messages */
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#define F_TIMEOUT (1 << 8) /* -t time out */
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#define F_WAITCRLF (1 << 9) /* -w wait for CR or LF */
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#define F_NOPROMPT (1 << 10) /* -n don't ask for login name */
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#define line_buf bb_common_bufsiz1
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/* The following is used for understandable diagnostics. */
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#ifdef DEBUGGING
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static FILE *dbf;
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#define DEBUGTERM "/dev/ttyp0"
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#define debug(...) do { fprintf(dbf, __VA_ARGS__); fflush(dbf); } while (0)
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#else
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#define debug(...) ((void)0)
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#endif
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/* bcode - convert speed string to speed code; return <= 0 on failure */
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static int bcode(const char *s)
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{
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int value = bb_strtou(s, NULL, 10); /* yes, int is intended! */
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if (value < 0) /* bad terminating char, overflow, etc */
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return value;
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return tty_value_to_baud(value);
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}
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/* parse_speeds - parse alternate baud rates */
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static void parse_speeds(struct options *op, char *arg)
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{
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char *cp;
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/* NB: at least one iteration is always done */
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debug("entered parse_speeds\n");
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while ((cp = strsep(&arg, ",")) != NULL) {
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op->speeds[op->numspeed] = bcode(cp);
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if (op->speeds[op->numspeed] < 0)
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bb_error_msg_and_die("bad speed: %s", cp);
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else if (op->speeds[op->numspeed] == 0) {
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struct termios tio;
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if (tcgetattr(1, &tio) != 0)
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bb_error_msg_and_die("auto baudrate detection failed");
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op->speeds[op->numspeed] = cfgetospeed(&tio);
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}
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op->numspeed++;
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if (op->numspeed > MAX_SPEED)
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bb_error_msg_and_die("too many alternate speeds");
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}
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debug("exiting parse_speeds\n");
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}
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/* parse_args - parse command-line arguments */
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static void parse_args(char **argv, struct options *op, char **fakehost_p)
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{
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char *ts;
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opt_complementary = "-2:t+"; /* at least 2 args; -t N */
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op->flags = getopt32(argv, opt_string,
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&(op->initstring), fakehost_p, &(op->issue),
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&(op->login), &op->timeout);
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argv += optind;
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if (op->flags & F_INITSTRING) {
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const char *p = op->initstring;
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char *q;
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op->initstring = q = xstrdup(p);
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/* copy optarg into op->initstring decoding \ddd
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octal codes into chars */
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while (*p) {
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if (*p == '\\') {
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p++;
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*q++ = bb_process_escape_sequence(&p);
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} else {
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*q++ = *p++;
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}
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}
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*q = '\0';
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}
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op->flags ^= F_ISSUE; /* invert flag "show /etc/issue" */
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debug("after getopt\n");
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/* we loosen up a bit and accept both "baudrate tty" and "tty baudrate" */
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op->tty = argv[0]; /* tty name */
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ts = argv[1]; /* baud rate(s) */
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if (isdigit(argv[0][0])) {
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/* a number first, assume it's a speed (BSD style) */
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op->tty = ts; /* tty name is in argv[1] */
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ts = argv[0]; /* baud rate(s) */
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}
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parse_speeds(op, ts);
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// TODO: if applet_name is set to "getty: TTY", bb_error_msg's get simpler!
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// grep for "%s:"
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if (argv[2])
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xsetenv("TERM", argv[2]);
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debug("exiting parse_args\n");
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}
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/* open_tty - set up tty as standard { input, output, error } */
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static void open_tty(const char *tty)
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{
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/* Set up new standard input, unless we are given an already opened port. */
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if (NOT_LONE_DASH(tty)) {
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// struct stat st;
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// int cur_dir_fd;
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// int fd;
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/* Sanity checks... */
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// cur_dir_fd = xopen(".", O_DIRECTORY | O_NONBLOCK);
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// xchdir("/dev");
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// xstat(tty, &st);
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// if ((st.st_mode & S_IFMT) != S_IFCHR)
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// bb_error_msg_and_die("%s: not a character device", tty);
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if (tty[0] != '/')
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tty = xasprintf("/dev/%s", tty); /* will leak it */
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/* Open the tty as standard input. */
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debug("open(2)\n");
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close(0);
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/*fd =*/ xopen(tty, O_RDWR | O_NONBLOCK); /* uses fd 0 */
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// /* Restore current directory */
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// fchdir(cur_dir_fd);
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/* Open the tty as standard input, continued */
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// xmove_fd(fd, 0);
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// /* fd is >= cur_dir_fd, and cur_dir_fd gets closed too here: */
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// while (fd > 2)
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// close(fd--);
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/* Set proper protections and ownership. */
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fchown(0, 0, 0); /* 0:0 */
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fchmod(0, 0620); /* crw--w---- */
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} else {
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/*
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* Standard input should already be connected to an open port. Make
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* sure it is open for read/write.
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*/
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if ((fcntl(0, F_GETFL) & O_RDWR) != O_RDWR)
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bb_error_msg_and_die("stdin is not open for read/write");
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}
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}
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/* termios_init - initialize termios settings */
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static void termios_init(struct termios *tp, int speed, struct options *op)
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{
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/*
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* Initial termios settings: 8-bit characters, raw-mode, blocking i/o.
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* Special characters are set after we have read the login name; all
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* reads will be done in raw mode anyway. Errors will be dealt with
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* later on.
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*/
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#ifdef __linux__
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/* flush input and output queues, important for modems! */
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ioctl(0, TCFLSH, TCIOFLUSH); /* tcflush(0, TCIOFLUSH)? - same */
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#endif
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tp->c_cflag = CS8 | HUPCL | CREAD | speed;
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if (op->flags & F_LOCAL)
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tp->c_cflag |= CLOCAL;
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tp->c_iflag = tp->c_lflag = tp->c_line = 0;
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tp->c_oflag = OPOST | ONLCR;
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tp->c_cc[VMIN] = 1;
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tp->c_cc[VTIME] = 0;
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/* Optionally enable hardware flow control */
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#ifdef CRTSCTS
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if (op->flags & F_RTSCTS)
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tp->c_cflag |= CRTSCTS;
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#endif
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tcsetattr_stdin_TCSANOW(tp);
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debug("term_io 2\n");
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}
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/* auto_baud - extract baud rate from modem status message */
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static void auto_baud(char *buf, unsigned size_buf, struct termios *tp)
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{
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int speed;
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int vmin;
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unsigned iflag;
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char *bp;
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int nread;
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/*
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* This works only if the modem produces its status code AFTER raising
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* the DCD line, and if the computer is fast enough to set the proper
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* baud rate before the message has gone by. We expect a message of the
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* following format:
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*
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* <junk><number><junk>
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*
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* The number is interpreted as the baud rate of the incoming call. If the
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* modem does not tell us the baud rate within one second, we will keep
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* using the current baud rate. It is advisable to enable BREAK
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* processing (comma-separated list of baud rates) if the processing of
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* modem status messages is enabled.
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*/
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/*
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* Use 7-bit characters, don't block if input queue is empty. Errors will
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* be dealt with later on.
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*/
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iflag = tp->c_iflag;
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tp->c_iflag |= ISTRIP; /* enable 8th-bit stripping */
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vmin = tp->c_cc[VMIN];
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tp->c_cc[VMIN] = 0; /* don't block if queue empty */
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tcsetattr_stdin_TCSANOW(tp);
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/*
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* Wait for a while, then read everything the modem has said so far and
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* try to extract the speed of the dial-in call.
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*/
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sleep(1);
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nread = safe_read(STDIN_FILENO, buf, size_buf - 1);
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if (nread > 0) {
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buf[nread] = '\0';
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for (bp = buf; bp < buf + nread; bp++) {
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if (isdigit(*bp)) {
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speed = bcode(bp);
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if (speed > 0) {
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tp->c_cflag &= ~CBAUD;
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tp->c_cflag |= speed;
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}
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break;
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}
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}
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}
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/* Restore terminal settings. Errors will be dealt with later on. */
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tp->c_iflag = iflag;
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tp->c_cc[VMIN] = vmin;
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tcsetattr_stdin_TCSANOW(tp);
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}
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/* do_prompt - show login prompt, optionally preceded by /etc/issue contents */
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static void do_prompt(struct options *op)
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{
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#ifdef ISSUE
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print_login_issue(op->issue, op->tty);
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#endif
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print_login_prompt();
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}
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#ifdef HANDLE_ALLCAPS
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/* all_is_upcase - string contains upper case without lower case */
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/* returns 1 if true, 0 if false */
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static int all_is_upcase(const char *s)
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{
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while (*s)
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if (islower(*s++))
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return 0;
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return 1;
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}
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#endif
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/* get_logname - get user name, establish parity, speed, erase, kill, eol;
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* return NULL on BREAK, logname on success */
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static char *get_logname(char *logname, unsigned size_logname,
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struct options *op, struct chardata *cp)
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{
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char *bp;
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char c; /* input character, full eight bits */
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char ascval; /* low 7 bits of input character */
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int bits; /* # of "1" bits per character */
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int mask; /* mask with 1 bit up */
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static const char erase[][3] = {/* backspace-space-backspace */
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"\010\040\010", /* space parity */
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"\010\040\010", /* odd parity */
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"\210\240\210", /* even parity */
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"\010\040\010", /* 8 bit no parity */
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};
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/* NB: *cp is pre-initialized with init_chardata */
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/* Flush pending input (esp. after parsing or switching the baud rate). */
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sleep(1);
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ioctl(0, TCFLSH, TCIFLUSH); /* tcflush(0, TCIOFLUSH)? - same */
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/* Prompt for and read a login name. */
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logname[0] = '\0';
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while (!logname[0]) {
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/* Write issue file and prompt, with "parity" bit == 0. */
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do_prompt(op);
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/* Read name, watch for break, parity, erase, kill, end-of-line. */
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bp = logname;
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cp->eol = '\0';
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while (cp->eol == '\0') {
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/* Do not report trivial EINTR/EIO errors. */
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if (read(STDIN_FILENO, &c, 1) < 1) {
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if (errno == EINTR || errno == EIO)
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exit(EXIT_SUCCESS);
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bb_perror_msg_and_die("%s: read", op->tty);
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}
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/* BREAK. If we have speeds to try,
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* return NULL (will switch speeds and return here) */
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if (c == '\0' && op->numspeed > 1)
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return NULL;
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/* Do parity bit handling. */
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if (!(op->flags & F_LOCAL) && (c & 0x80)) { /* "parity" bit on? */
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bits = 1;
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mask = 1;
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while (mask & 0x7f) {
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if (mask & c)
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bits++; /* count "1" bits */
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mask <<= 1;
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}
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/* ... |= 2 - even, 1 - odd */
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cp->parity |= 2 - (bits & 1);
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}
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/* Do erase, kill and end-of-line processing. */
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ascval = c & 0x7f;
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switch (ascval) {
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case CR:
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case NL:
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*bp = '\0'; /* terminate logname */
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cp->eol = ascval; /* set end-of-line char */
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break;
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case BS:
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case DEL:
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#ifdef ANCIENT_BS_KILL_CHARS
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case '#':
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#endif
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cp->erase = ascval; /* set erase character */
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if (bp > logname) {
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full_write(STDOUT_FILENO, erase[cp->parity], 3);
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bp--;
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}
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break;
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case CTL('U'):
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#ifdef ANCIENT_BS_KILL_CHARS
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case '@':
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#endif
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cp->kill = ascval; /* set kill character */
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while (bp > logname) {
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full_write(STDOUT_FILENO, erase[cp->parity], 3);
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bp--;
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}
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break;
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case CTL('D'):
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exit(EXIT_SUCCESS);
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default:
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if (!isprint(ascval)) {
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/* ignore garbage characters */
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} else if ((int)(bp - logname) >= size_logname - 1) {
|
|
bb_error_msg_and_die("%s: input overrun", op->tty);
|
|
} else {
|
|
full_write(STDOUT_FILENO, &c, 1); /* echo the character */
|
|
*bp++ = ascval; /* and store it */
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
/* Handle names with upper case and no lower case. */
|
|
|
|
#ifdef HANDLE_ALLCAPS
|
|
cp->capslock = all_is_upcase(logname);
|
|
if (cp->capslock) {
|
|
for (bp = logname; *bp; bp++)
|
|
if (isupper(*bp))
|
|
*bp = tolower(*bp); /* map name to lower case */
|
|
}
|
|
#endif
|
|
return logname;
|
|
}
|
|
|
|
/* termios_final - set the final tty mode bits */
|
|
static void termios_final(struct options *op, struct termios *tp, struct chardata *cp)
|
|
{
|
|
/* General terminal-independent stuff. */
|
|
tp->c_iflag |= IXON | IXOFF; /* 2-way flow control */
|
|
tp->c_lflag |= ICANON | ISIG | ECHO | ECHOE | ECHOK | ECHOKE;
|
|
/* no longer| ECHOCTL | ECHOPRT */
|
|
tp->c_oflag |= OPOST;
|
|
/* tp->c_cflag = 0; */
|
|
tp->c_cc[VINTR] = DEF_INTR; /* default interrupt */
|
|
tp->c_cc[VQUIT] = DEF_QUIT; /* default quit */
|
|
tp->c_cc[VEOF] = DEF_EOF; /* default EOF character */
|
|
tp->c_cc[VEOL] = DEF_EOL;
|
|
tp->c_cc[VSWTC] = DEF_SWITCH; /* default switch character */
|
|
|
|
/* Account for special characters seen in input. */
|
|
if (cp->eol == CR) {
|
|
tp->c_iflag |= ICRNL; /* map CR in input to NL */
|
|
tp->c_oflag |= ONLCR; /* map NL in output to CR-NL */
|
|
}
|
|
tp->c_cc[VERASE] = cp->erase; /* set erase character */
|
|
tp->c_cc[VKILL] = cp->kill; /* set kill character */
|
|
|
|
/* Account for the presence or absence of parity bits in input. */
|
|
switch (cp->parity) {
|
|
case 0: /* space (always 0) parity */
|
|
// I bet most people go here - they use only 7-bit chars in usernames....
|
|
break;
|
|
case 1: /* odd parity */
|
|
tp->c_cflag |= PARODD;
|
|
/* FALLTHROUGH */
|
|
case 2: /* even parity */
|
|
tp->c_cflag |= PARENB;
|
|
tp->c_iflag |= INPCK | ISTRIP;
|
|
/* FALLTHROUGH */
|
|
case (1 | 2): /* no parity bit */
|
|
tp->c_cflag &= ~CSIZE;
|
|
tp->c_cflag |= CS7;
|
|
// FIXME: wtf? case 3: we saw both even and odd 8-bit bytes -
|
|
// it's probably some umlauts etc, but definitely NOT 7-bit!!!
|
|
// Entire parity detection madness here just begs for deletion...
|
|
break;
|
|
}
|
|
|
|
/* Account for upper case without lower case. */
|
|
#ifdef HANDLE_ALLCAPS
|
|
if (cp->capslock) {
|
|
tp->c_iflag |= IUCLC;
|
|
tp->c_lflag |= XCASE;
|
|
tp->c_oflag |= OLCUC;
|
|
}
|
|
#endif
|
|
/* Optionally enable hardware flow control */
|
|
#ifdef CRTSCTS
|
|
if (op->flags & F_RTSCTS)
|
|
tp->c_cflag |= CRTSCTS;
|
|
#endif
|
|
|
|
/* Finally, make the new settings effective */
|
|
/* It's tcsetattr_stdin_TCSANOW() + error check */
|
|
ioctl_or_perror_and_die(0, TCSETS, tp, "%s: TCSETS", op->tty);
|
|
}
|
|
|
|
#if ENABLE_FEATURE_UTMP
|
|
static void touch(const char *filename)
|
|
{
|
|
if (access(filename, R_OK | W_OK) == -1)
|
|
close(open(filename, O_WRONLY | O_CREAT, 0664));
|
|
}
|
|
|
|
/* update_utmp - update our utmp entry */
|
|
static void update_utmp(const char *line, char *fakehost)
|
|
{
|
|
struct utmp ut;
|
|
struct utmp *utp;
|
|
int mypid = getpid();
|
|
|
|
/* In case we won't find an entry below... */
|
|
memset(&ut, 0, sizeof(ut));
|
|
safe_strncpy(ut.ut_id, line + 3, sizeof(ut.ut_id));
|
|
|
|
/*
|
|
* The utmp file holds miscellaneous information about things started by
|
|
* /sbin/init and other system-related events. Our purpose is to update
|
|
* the utmp entry for the current process, in particular the process type
|
|
* and the tty line we are listening to. Return successfully only if the
|
|
* utmp file can be opened for update, and if we are able to find our
|
|
* entry in the utmp file.
|
|
*/
|
|
touch(_PATH_UTMP);
|
|
|
|
utmpname(_PATH_UTMP);
|
|
setutent();
|
|
while ((utp = getutent()) != NULL) {
|
|
if (utp->ut_type == INIT_PROCESS && utp->ut_pid == mypid) {
|
|
memcpy(&ut, utp, sizeof(ut));
|
|
break;
|
|
}
|
|
}
|
|
|
|
strcpy(ut.ut_user, "LOGIN");
|
|
safe_strncpy(ut.ut_line, line, sizeof(ut.ut_line));
|
|
if (fakehost)
|
|
safe_strncpy(ut.ut_host, fakehost, sizeof(ut.ut_host));
|
|
ut.ut_tv.tv_sec = time(NULL);
|
|
ut.ut_type = LOGIN_PROCESS;
|
|
ut.ut_pid = mypid;
|
|
|
|
pututline(&ut);
|
|
endutent();
|
|
|
|
#if ENABLE_FEATURE_WTMP
|
|
touch(bb_path_wtmp_file);
|
|
updwtmp(bb_path_wtmp_file, &ut);
|
|
#endif
|
|
}
|
|
#endif /* CONFIG_FEATURE_UTMP */
|
|
|
|
int getty_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
|
int getty_main(int argc UNUSED_PARAM, char **argv)
|
|
{
|
|
int n;
|
|
char *fakehost = NULL; /* Fake hostname for ut_host */
|
|
char *logname; /* login name, given to /bin/login */
|
|
/* Merging these into "struct local" may _seem_ to reduce
|
|
* parameter passing, but today's gcc will inline
|
|
* statics which are called once anyway, so don't do that */
|
|
struct chardata chardata; /* set by get_logname() */
|
|
struct termios termios; /* terminal mode bits */
|
|
struct options options;
|
|
|
|
chardata = init_chardata;
|
|
|
|
memset(&options, 0, sizeof(options));
|
|
options.login = _PATH_LOGIN; /* default login program */
|
|
options.tty = "tty1"; /* default tty line */
|
|
options.initstring = ""; /* modem init string */
|
|
#ifdef ISSUE
|
|
options.issue = ISSUE; /* default issue file */
|
|
#endif
|
|
|
|
/* Parse command-line arguments. */
|
|
parse_args(argv, &options, &fakehost);
|
|
|
|
logmode = LOGMODE_NONE;
|
|
|
|
/* Create new session, lose controlling tty, if any */
|
|
/* docs/ctty.htm says:
|
|
* "This is allowed only when the current process
|
|
* is not a process group leader" - is this a problem? */
|
|
setsid();
|
|
/* close stdio, and stray descriptors, just in case */
|
|
n = xopen(bb_dev_null, O_RDWR);
|
|
/* dup2(n, 0); - no, we need to handle "getty - 9600" too */
|
|
xdup2(n, 1);
|
|
xdup2(n, 2);
|
|
while (n > 2)
|
|
close(n--);
|
|
|
|
/* Logging. We want special flavor of error_msg_and_die */
|
|
die_sleep = 10;
|
|
msg_eol = "\r\n";
|
|
/* most likely will internally use fd #3 in CLOEXEC mode: */
|
|
openlog(applet_name, LOG_PID, LOG_AUTH);
|
|
logmode = LOGMODE_BOTH;
|
|
|
|
#ifdef DEBUGGING
|
|
dbf = xfopen_for_write(DEBUGTERM);
|
|
for (n = 1; argv[n]; n++) {
|
|
debug(argv[n]);
|
|
debug("\n");
|
|
}
|
|
#endif
|
|
|
|
/* Open the tty as standard input, if it is not "-" */
|
|
/* If it's not "-" and not taken yet, it will become our ctty */
|
|
debug("calling open_tty\n");
|
|
open_tty(options.tty);
|
|
ndelay_off(0);
|
|
debug("duping\n");
|
|
xdup2(0, 1);
|
|
xdup2(0, 2);
|
|
|
|
/*
|
|
* The following ioctl will fail if stdin is not a tty, but also when
|
|
* there is noise on the modem control lines. In the latter case, the
|
|
* common course of action is (1) fix your cables (2) give the modem more
|
|
* time to properly reset after hanging up. SunOS users can achieve (2)
|
|
* by patching the SunOS kernel variable "zsadtrlow" to a larger value;
|
|
* 5 seconds seems to be a good value.
|
|
*/
|
|
/* tcgetattr() + error check */
|
|
ioctl_or_perror_and_die(0, TCGETS, &termios, "%s: TCGETS", options.tty);
|
|
|
|
#ifdef __linux__
|
|
// FIXME: do we need this? Otherwise "-" case seems to be broken...
|
|
// /* Forcibly make fd 0 our controlling tty, even if another session
|
|
// * has it as a ctty. (Another session loses ctty). */
|
|
// ioctl(0, TIOCSCTTY, (void*)1);
|
|
/* Make ourself a foreground process group within our session */
|
|
tcsetpgrp(0, getpid());
|
|
#endif
|
|
|
|
#if ENABLE_FEATURE_UTMP
|
|
/* Update the utmp file. This tty is ours now! */
|
|
update_utmp(options.tty, fakehost);
|
|
#endif
|
|
|
|
/* Initialize the termios settings (raw mode, eight-bit, blocking i/o). */
|
|
debug("calling termios_init\n");
|
|
termios_init(&termios, options.speeds[0], &options);
|
|
|
|
/* Write the modem init string and DON'T flush the buffers */
|
|
if (options.flags & F_INITSTRING) {
|
|
debug("writing init string\n");
|
|
/* todo: use xwrite_str? */
|
|
full_write(STDOUT_FILENO, options.initstring, strlen(options.initstring));
|
|
}
|
|
|
|
/* Optionally detect the baud rate from the modem status message */
|
|
debug("before autobaud\n");
|
|
if (options.flags & F_PARSE)
|
|
auto_baud(line_buf, sizeof(line_buf), &termios);
|
|
|
|
/* Set the optional timer */
|
|
alarm(options.timeout); /* if 0, alarm is not set */
|
|
|
|
/* Optionally wait for CR or LF before writing /etc/issue */
|
|
if (options.flags & F_WAITCRLF) {
|
|
char ch;
|
|
|
|
debug("waiting for cr-lf\n");
|
|
while (safe_read(STDIN_FILENO, &ch, 1) == 1) {
|
|
debug("read %x\n", (unsigned char)ch);
|
|
ch &= 0x7f; /* strip "parity bit" */
|
|
if (ch == '\n' || ch == '\r')
|
|
break;
|
|
}
|
|
}
|
|
|
|
logname = NULL;
|
|
if (!(options.flags & F_NOPROMPT)) {
|
|
/* NB:termios_init already set line speed
|
|
* to options.speeds[0] */
|
|
int baud_index = 0;
|
|
|
|
while (1) {
|
|
/* Read the login name. */
|
|
debug("reading login name\n");
|
|
logname = get_logname(line_buf, sizeof(line_buf),
|
|
&options, &chardata);
|
|
if (logname)
|
|
break;
|
|
/* we are here only if options.numspeed > 1 */
|
|
baud_index = (baud_index + 1) % options.numspeed;
|
|
termios.c_cflag &= ~CBAUD;
|
|
termios.c_cflag |= options.speeds[baud_index];
|
|
tcsetattr_stdin_TCSANOW(&termios);
|
|
}
|
|
}
|
|
|
|
/* Disable timer. */
|
|
alarm(0);
|
|
|
|
/* Finalize the termios settings. */
|
|
termios_final(&options, &termios, &chardata);
|
|
|
|
/* 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. */
|
|
/* With -n, logname == NULL, and login will ask for username instead */
|
|
BB_EXECLP(options.login, options.login, "--", logname, NULL);
|
|
bb_error_msg_and_die("%s: can't exec %s", options.tty, options.login);
|
|
}
|