| /* vi: set sw=4 ts=4: */ |
| /* agetty.c - 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. The entire man-page used to |
| * be here. Now read the real man-page agetty.8 instead. |
| * |
| * option added by Eric Rasmussen <ear@usfirst.org> - 12/28/95 |
| * |
| * 1999-02-22 Arkadiusz Mi¶kiewicz <misiek@misiek.eu.org> |
| * - added Native Language Support |
| |
| * 1999-05-05 Thorsten Kranzkowski <dl8bcu@gmx.net> |
| * - enable hardware flow control before displaying /etc/issue |
| * |
| * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. |
| * |
| */ |
| |
| #include "libbb.h" |
| #include <syslog.h> |
| |
| #if ENABLE_FEATURE_UTMP |
| #include <utmp.h> |
| #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> |
| #include <time.h> |
| #if ENABLE_FEATURE_WTMP |
| extern void updwtmp(const char *filename, const struct utmp *ut); |
| #endif |
| #else /* if !sysV style, wtmp/utmp code is off */ |
| #undef ENABLE_FEATURE_UTMP |
| #undef ENABLE_FEATURE_WTMP |
| #define ENABLE_FEATURE_UTMP 0 |
| #define ENABLE_FEATURE_WTMP 0 |
| #endif /* LOGIN_PROCESS */ |
| |
| /* |
| * Things you may want to modify. |
| * |
| * You may disagree with the default line-editing etc. characters defined |
| * below. Note, however, that DEL cannot be used for interrupt generation |
| * and for line editing at the same time. |
| */ |
| |
| /* I doubt there are systems which still need this */ |
| #undef HANDLE_ALLCAPS |
| #undef ANCIENT_BS_KILL_CHARS |
| |
| #define _PATH_LOGIN "/bin/login" |
| |
| /* If ISSUE is not defined, getty will never display the contents of the |
| * /etc/issue file. You will not want to spit out large "issue" files at the |
| * wrong baud rate. |
| */ |
| #define ISSUE "/etc/issue" /* displayed before the login prompt */ |
| |
| /* 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. */ |
| #define DEF_ERASE DEL /* default erase character */ |
| #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 */ |
| |
| /* |
| * 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 */ |
| |
| /* Storage for command-line options. */ |
| struct options { |
| int flags; /* toggle switches, see below */ |
| unsigned timeout; /* time-out period */ |
| const char *login; /* login program */ |
| 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 */ |
| }; |
| |
| /* Storage for things detected while the login name was read. */ |
| struct chardata { |
| unsigned char erase; /* erase character */ |
| unsigned char kill; /* kill character */ |
| unsigned char eol; /* end-of-line character */ |
| unsigned char parity; /* what parity did we see */ |
| /* (parity & 1): saw odd parity char with 7th bit set */ |
| /* (parity & 2): saw even parity char with 7th bit set */ |
| /* parity == 0: probably 7-bit, space parity? */ |
| /* parity == 1: probably 7-bit, odd parity? */ |
| /* parity == 2: probably 7-bit, even parity? */ |
| /* parity == 3: definitely 8 bit, no parity! */ |
| /* Hmm... with any value of "parity" 8 bit, no parity is possible */ |
| #ifdef HANDLE_ALLCAPS |
| unsigned char capslock; /* upper case without lower case */ |
| #endif |
| }; |
| |
| |
| /* Initial values for the above. */ |
| static const struct chardata init_chardata = { |
| DEF_ERASE, /* default erase character */ |
| DEF_KILL, /* default kill character */ |
| 13, /* default eol char */ |
| 0, /* space parity */ |
| #ifdef HANDLE_ALLCAPS |
| 0, /* no capslock */ |
| #endif |
| }; |
| |
| static const char opt_string[] ALIGN1 = "I:LH:f:hil:mt:wn"; |
| #define F_INITSTRING (1 << 0) /* -I initstring is set */ |
| #define F_LOCAL (1 << 1) /* -L force local */ |
| #define F_FAKEHOST (1 << 2) /* -H fake hostname */ |
| #define F_CUSTISSUE (1 << 3) /* -f give alternative issue file */ |
| #define F_RTSCTS (1 << 4) /* -h enable RTS/CTS flow control */ |
| #define F_ISSUE (1 << 5) /* -i display /etc/issue */ |
| #define F_LOGIN (1 << 6) /* -l non-default login program */ |
| #define F_PARSE (1 << 7) /* -m process modem status messages */ |
| #define F_TIMEOUT (1 << 8) /* -t time out */ |
| #define F_WAITCRLF (1 << 9) /* -w wait for CR or LF */ |
| #define F_NOPROMPT (1 << 10) /* -n don't ask for login name */ |
| |
| |
| #define line_buf bb_common_bufsiz1 |
| |
| /* The following is used for understandable diagnostics. */ |
| #ifdef DEBUGGING |
| static FILE *dbf; |
| #define DEBUGTERM "/dev/ttyp0" |
| #define debug(...) do { fprintf(dbf, __VA_ARGS__); fflush(dbf); } while (0) |
| #else |
| #define debug(...) ((void)0) |
| #endif |
| |
| |
| /* bcode - convert speed string to speed code; return <= 0 on failure */ |
| static int bcode(const char *s) |
| { |
| int value = bb_strtou(s, NULL, 10); /* yes, int is intended! */ |
| if (value < 0) /* bad terminating char, overflow, etc */ |
| return value; |
| return tty_value_to_baud(value); |
| } |
| |
| /* parse_speeds - parse alternate baud rates */ |
| static void parse_speeds(struct options *op, char *arg) |
| { |
| char *cp; |
| |
| /* NB: at least one iteration is always done */ |
| debug("entered parse_speeds\n"); |
| while ((cp = strsep(&arg, ",")) != NULL) { |
| op->speeds[op->numspeed] = bcode(cp); |
| if (op->speeds[op->numspeed] <= 0) |
| bb_error_msg_and_die("bad speed: %s", cp); |
| op->numspeed++; |
| if (op->numspeed > MAX_SPEED) |
| bb_error_msg_and_die("too many alternate speeds"); |
| } |
| debug("exiting parse_speeds\n"); |
| } |
| |
| /* parse_args - parse command-line arguments */ |
| static void parse_args(char **argv, struct options *op, char **fakehost_p) |
| { |
| char *ts; |
| |
| opt_complementary = "-2:t+"; /* at least 2 args; -t N */ |
| op->flags = getopt32(argv, opt_string, |
| &(op->initstring), fakehost_p, &(op->issue), |
| &(op->login), &op->timeout); |
| argv += optind; |
| if (op->flags & F_INITSTRING) { |
| const char *p = op->initstring; |
| char *q; |
| |
| op->initstring = q = xstrdup(p); |
| /* copy optarg into op->initstring decoding \ddd |
| octal codes into chars */ |
| while (*p) { |
| if (*p == '\\') { |
| p++; |
| *q++ = bb_process_escape_sequence(&p); |
| } else { |
| *q++ = *p++; |
| } |
| } |
| *q = '\0'; |
| } |
| op->flags ^= F_ISSUE; /* invert flag "show /etc/issue" */ |
| debug("after getopt\n"); |
| |
| /* we loosen up a bit and accept both "baudrate tty" and "tty baudrate" */ |
| op->tty = argv[0]; /* tty name */ |
| ts = argv[1]; /* baud rate(s) */ |
| if (isdigit(argv[0][0])) { |
| /* a number first, assume it's a speed (BSD style) */ |
| op->tty = ts; /* tty name is in argv[1] */ |
| ts = argv[0]; /* baud rate(s) */ |
| } |
| parse_speeds(op, ts); |
| |
| // TODO: if applet_name is set to "getty: TTY", bb_error_msg's get simpler! |
| // grep for "%s:" |
| |
| if (argv[2]) |
| xsetenv("TERM", argv[2]); |
| |
| debug("exiting parse_args\n"); |
| } |
| |
| /* open_tty - set up tty as standard { input, output, error } */ |
| static void open_tty(const char *tty) |
| { |
| /* Set up new standard input, unless we are given an already opened port. */ |
| if (NOT_LONE_DASH(tty)) { |
| // struct stat st; |
| // int cur_dir_fd; |
| // int fd; |
| |
| /* Sanity checks... */ |
| // cur_dir_fd = xopen(".", O_DIRECTORY | O_NONBLOCK); |
| // xchdir("/dev"); |
| // xstat(tty, &st); |
| // if ((st.st_mode & S_IFMT) != S_IFCHR) |
| // bb_error_msg_and_die("%s: not a character device", tty); |
| |
| if (tty[0] != '/') |
| tty = xasprintf("/dev/%s", tty); /* will leak it */ |
| |
| /* Open the tty as standard input. */ |
| debug("open(2)\n"); |
| close(0); |
| /*fd =*/ xopen(tty, O_RDWR | O_NONBLOCK); /* uses fd 0 */ |
| |
| // /* Restore current directory */ |
| // fchdir(cur_dir_fd); |
| |
| /* Open the tty as standard input, continued */ |
| // xmove_fd(fd, 0); |
| // /* fd is >= cur_dir_fd, and cur_dir_fd gets closed too here: */ |
| // while (fd > 2) |
| // close(fd--); |
| |
| /* Set proper protections and ownership. */ |
| fchown(0, 0, 0); /* 0:0 */ |
| fchmod(0, 0620); /* crw--w---- */ |
| } else { |
| /* |
| * Standard input should already be connected to an open port. Make |
| * sure it is open for read/write. |
| */ |
| if ((fcntl(0, F_GETFL) & O_RDWR) != O_RDWR) |
| bb_error_msg_and_die("stdin is not open for read/write"); |
| } |
| } |
| |
| /* termios_init - initialize termios settings */ |
| static void termios_init(struct termios *tp, int speed, struct options *op) |
| { |
| /* |
| * 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. |
| */ |
| #ifdef __linux__ |
| /* flush input and output queues, important for modems! */ |
| ioctl(0, TCFLSH, TCIOFLUSH); |
| #endif |
| |
| tp->c_cflag = CS8 | HUPCL | CREAD | speed; |
| if (op->flags & F_LOCAL) |
| tp->c_cflag |= CLOCAL; |
| |
| tp->c_iflag = tp->c_lflag = tp->c_line = 0; |
| tp->c_oflag = OPOST | ONLCR; |
| tp->c_cc[VMIN] = 1; |
| tp->c_cc[VTIME] = 0; |
| |
| /* Optionally enable hardware flow control */ |
| #ifdef CRTSCTS |
| if (op->flags & F_RTSCTS) |
| tp->c_cflag |= CRTSCTS; |
| #endif |
| |
| ioctl(0, TCSETS, tp); |
| |
| debug("term_io 2\n"); |
| } |
| |
| /* auto_baud - extract baud rate from modem status message */ |
| static void auto_baud(char *buf, unsigned size_buf, struct termios *tp) |
| { |
| int speed; |
| int vmin; |
| unsigned iflag; |
| char *bp; |
| int nread; |
| |
| /* |
| * This works only if the modem produces its status code AFTER raising |
| * the DCD line, and if the computer is fast enough to set the proper |
| * baud rate before the message has gone by. We expect a message of the |
| * following format: |
| * |
| * <junk><number><junk> |
| * |
| * The number is interpreted as the baud rate of the incoming call. If the |
| * modem does not tell us the baud rate within one second, we will keep |
| * using the current baud rate. It is advisable to enable BREAK |
| * processing (comma-separated list of baud rates) if the processing of |
| * modem status messages is enabled. |
| */ |
| |
| /* |
| * Use 7-bit characters, don't block if input queue is empty. Errors will |
| * be dealt with later on. |
| */ |
| iflag = tp->c_iflag; |
| tp->c_iflag |= ISTRIP; /* enable 8th-bit stripping */ |
| vmin = tp->c_cc[VMIN]; |
| tp->c_cc[VMIN] = 0; /* don't block if queue empty */ |
| ioctl(0, TCSETS, tp); |
| |
| /* |
| * Wait for a while, then read everything the modem has said so far and |
| * try to extract the speed of the dial-in call. |
| */ |
| sleep(1); |
| nread = safe_read(0, buf, size_buf - 1); |
| if (nread > 0) { |
| buf[nread] = '\0'; |
| for (bp = buf; bp < buf + nread; bp++) { |
| if (isdigit(*bp)) { |
| speed = bcode(bp); |
| if (speed > 0) { |
| tp->c_cflag &= ~CBAUD; |
| tp->c_cflag |= speed; |
| } |
| break; |
| } |
| } |
| } |
| |
| /* Restore terminal settings. Errors will be dealt with later on. */ |
| tp->c_iflag = iflag; |
| tp->c_cc[VMIN] = vmin; |
| ioctl(0, TCSETS, tp); |
| } |
| |
| /* do_prompt - show login prompt, optionally preceded by /etc/issue contents */ |
| static void do_prompt(struct options *op, struct termios *tp) |
| { |
| #ifdef ISSUE |
| print_login_issue(op->issue, op->tty); |
| #endif |
| print_login_prompt(); |
| } |
| |
| #ifdef HANDLE_ALLCAPS |
| /* all_is_upcase - string contains upper case without lower case */ |
| /* returns 1 if true, 0 if false */ |
| static int all_is_upcase(const char *s) |
| { |
| while (*s) |
| if (islower(*s++)) |
| return 0; |
| return 1; |
| } |
| #endif |
| |
| /* get_logname - get user name, establish parity, speed, erase, kill, eol; |
| * return NULL on BREAK, logname on success */ |
| static char *get_logname(char *logname, unsigned size_logname, |
| struct options *op, struct chardata *cp, struct termios *tp) |
| { |
| char *bp; |
| char c; /* input character, full eight bits */ |
| char ascval; /* low 7 bits of input character */ |
| int bits; /* # of "1" bits per character */ |
| int mask; /* mask with 1 bit up */ |
| static const char erase[][3] = {/* backspace-space-backspace */ |
| "\010\040\010", /* space parity */ |
| "\010\040\010", /* odd parity */ |
| "\210\240\210", /* even parity */ |
| "\010\040\010", /* 8 bit no parity */ |
| }; |
| |
| /* NB: *cp is pre-initialized with init_chardata */ |
| |
| /* Flush pending input (esp. after parsing or switching the baud rate). */ |
| sleep(1); |
| ioctl(0, TCFLSH, TCIFLUSH); |
| |
| /* Prompt for and read a login name. */ |
| logname[0] = '\0'; |
| while (!logname[0]) { |
| /* Write issue file and prompt, with "parity" bit == 0. */ |
| do_prompt(op, tp); |
| |
| /* Read name, watch for break, parity, erase, kill, end-of-line. */ |
| bp = logname; |
| cp->eol = '\0'; |
| while (cp->eol == '\0') { |
| |
| /* Do not report trivial EINTR/EIO errors. */ |
| if (read(0, &c, 1) < 1) { |
| if (errno == EINTR || errno == EIO) |
| exit(0); |
| bb_perror_msg_and_die("%s: read", op->tty); |
| } |
| |
| /* BREAK. If we have speeds to try, |
| * return NULL (will switch speeds and return here) */ |
| if (c == '\0' && op->numspeed > 1) |
| return NULL; |
| |
| /* Do parity bit handling. */ |
| if (!(op->flags & F_LOCAL) && (c & 0x80)) { /* "parity" bit on? */ |
| bits = 1; |
| mask = 1; |
| while (mask & 0x7f) { |
| if (mask & c) |
| bits++; /* count "1" bits */ |
| mask <<= 1; |
| } |
| /* ... |= 2 - even, 1 - odd */ |
| cp->parity |= 2 - (bits & 1); |
| } |
| |
| /* Do erase, kill and end-of-line processing. */ |
| ascval = c & 0x7f; |
| switch (ascval) { |
| case CR: |
| case NL: |
| *bp = '\0'; /* terminate logname */ |
| cp->eol = ascval; /* set end-of-line char */ |
| break; |
| case BS: |
| case DEL: |
| #ifdef ANCIENT_BS_KILL_CHARS |
| case '#': |
| #endif |
| cp->erase = ascval; /* set erase character */ |
| if (bp > logname) { |
| full_write(1, erase[cp->parity], 3); |
| bp--; |
| } |
| break; |
| case CTL('U'): |
| #ifdef ANCIENT_BS_KILL_CHARS |
| case '@': |
| #endif |
| cp->kill = ascval; /* set kill character */ |
| while (bp > logname) { |
| full_write(1, erase[cp->parity], 3); |
| bp--; |
| } |
| break; |
| case CTL('D'): |
| exit(0); |
| default: |
| if (!isascii(ascval) || !isprint(ascval)) { |
| /* ignore garbage characters */ |
| } else if (bp - logname >= size_logname - 1) { |
| bb_error_msg_and_die("%s: input overrun", op->tty); |
| } else { |
| full_write(1, &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 */ |
| 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_time = 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, 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(DEBUGTERM, "w"); |
| for (n = 1; n < argc; 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. |
| */ |
| 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"); |
| full_write(1, 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(0, &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, &termios); |
| 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]; |
| ioctl(0, TCSETS, &termios); |
| } |
| } |
| |
| /* Disable timer. */ |
| alarm(0); |
| |
| /* Finalize the termios settings. */ |
| termios_final(&options, &termios, &chardata); |
| |
| /* Now the newline character should be properly written. */ |
| full_write(1, "\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); |
| } |