X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=loginutils%2Fgetty.c;h=62456651b1f5a253d5cc9740f32d085e27c73d7d;hb=abc33ac8b24d2d733aba63ae19e2df6e7da16ec8;hp=8b78856a2fc6251391c41bdd0d52006d4ea27560;hpb=a27a11bb2c033d3e0312dc1d62430a002314686f;p=oweals%2Fbusybox.git diff --git a/loginutils/getty.c b/loginutils/getty.c index 8b78856a2..62456651b 100644 --- a/loginutils/getty.c +++ b/loginutils/getty.c @@ -1,41 +1,50 @@ /* vi: set sw=4 ts=4: */ -/* agetty.c - 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 - * This program is freely distributable. The entire man-page used to - * be here. Now read the real man-page agetty.8 instead. + * This program is freely distributable. * * option added by Eric Rasmussen - 12/28/95 * - * 1999-02-22 Arkadiusz Mi¶kiewicz - * - added Native Language Support - + * 1999-02-22 Arkadiusz Mickiewicz + * - Added Native Language Support + * * 1999-05-05 Thorsten Kranzkowski - * - enable hardware flow control before displaying /etc/issue + * - Enabled hardware flow control before displaying /etc/issue * - * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. + * 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. */ #include "libbb.h" #include +#ifndef IUCLC +# define IUCLC 0 +#endif -#if ENABLE_FEATURE_UTMP -#include +#ifndef LOGIN_PROCESS +# undef ENABLE_FEATURE_UTMP +# undef ENABLE_FEATURE_WTMP +# define ENABLE_FEATURE_UTMP 0 +# define ENABLE_FEATURE_WTMP 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 */ -#define SYSV_STYLE /* select System V style getty */ -#include -#include -#if ENABLE_FEATURE_WTMP -extern void updwtmp(const char *filename, const struct utmp *ut); -static void update_utmp(const char *line); + +/* 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 -#endif /* LOGIN_PROCESS */ + /* * Things you may want to modify. @@ -44,336 +53,339 @@ static void update_utmp(const char *line); * 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 _PATH_LOGIN #define _PATH_LOGIN "/bin/login" -/* If ISSUE is not defined, getty will never display the contents of the +/* Displayed before the login prompt. + * 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 */ +#define ISSUE "/etc/issue" -/* 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 */ +/* 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_ERASE DEL /* default erase character */ +/* 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 */ +#define DEF_SWITCH 0 /* default switch char (none) */ /* - * 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 FIRST_SPEED 0 - -/* Storage for command-line options. */ - #define MAX_SPEED 10 /* max. nr. of baud rates */ -struct options { - int flags; /* toggle switches, see below */ +struct globals { 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 */ + const char *login; /* login program */ + const char *fakehost; + const char *tty; /* name of tty */ + 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 */ + char line_buf[128]; }; -static const char opt_string[] ALIGN1 = "I:LH:f:hil:mt:wn"; -#define F_INITSTRING (1<<0) /* initstring is set */ -#define F_LOCAL (1<<1) /* force local */ -#define F_FAKEHOST (1<<2) /* force fakehost */ -#define F_CUSTISSUE (1<<3) /* give alternative issue file */ -#define F_RTSCTS (1<<4) /* enable RTS/CTS flow control */ -#define F_ISSUE (1<<5) /* display /etc/issue */ -#define F_LOGIN (1<<6) /* non-default login program */ -#define F_PARSE (1<<7) /* process modem status messages */ -#define F_TIMEOUT (1<<8) /* time out */ -#define F_WAITCRLF (1<<9) /* wait for CR or LF */ -#define F_NOPROMPT (1<<10) /* don't ask for login name! */ - -/* 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 */ -#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 -}; - -/* The following is used for understandable diagnostics. */ - -/* Fake hostname for ut_host specified on command line. */ -static char *fakehost = NULL; - -/* ... */ -#ifdef DEBUGGING -#define debug(s) fprintf(dbf,s); fflush(dbf) -#define DEBUGTERM "/dev/ttyp0" -static FILE *dbf; -#else -#define debug(s) /* nothing */ -#endif - +#define G (*ptr_to_globals) +#define INIT_G() do { \ + SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \ +} while (0) + +//usage:#define getty_trivial_usage +//usage: "[OPTIONS] BAUD_RATE[,BAUD_RATE]... TTY [TERMTYPE]" +//usage:#define getty_full_usage "\n\n" +//usage: "Open a tty, prompt for a login name, then invoke /bin/login\n" +//usage: "\n -h Enable hardware RTS/CTS flow control" +//usage: "\n -L Set CLOCAL (ignore Carrier Detect state)" +//usage: "\n -m Get baud rate from modem's CONNECT status message" +//usage: "\n -n Don't prompt for login name" +//usage: "\n -w Wait for CR or LF before sending /etc/issue" +//usage: "\n -i Don't display /etc/issue" +//usage: "\n -f ISSUE_FILE Display ISSUE_FILE instead of /etc/issue" +//usage: "\n -l LOGIN Invoke LOGIN instead of /bin/login" +//usage: "\n -t SEC Terminate after SEC if no login name is read" +//usage: "\n -I INITSTR Send INITSTR before anything else" +//usage: "\n -H HOST Log HOST into the utmp file as the hostname" +//usage: "\n" +//usage: "\nBAUD_RATE of 0 leaves it unchanged" -/* bcode - convert speed string to speed code; return 0 on failure */ +static const char opt_string[] ALIGN1 = "I:LH:f:hil:mt:wn"; +#define F_INITSTRING (1 << 0) /* -I */ +#define F_LOCAL (1 << 1) /* -L */ +#define F_FAKEHOST (1 << 2) /* -H */ +#define F_CUSTISSUE (1 << 3) /* -f */ +#define F_RTSCTS (1 << 4) /* -h */ +#define F_NOISSUE (1 << 5) /* -i */ +#define F_LOGIN (1 << 6) /* -l */ +#define F_PARSE (1 << 7) /* -m */ +#define F_TIMEOUT (1 << 8) /* -t */ +#define F_WAITCRLF (1 << 9) /* -w */ +#define F_NOPROMPT (1 << 10) /* -n */ + + +/* convert speed string to speed code; return <= 0 on failure */ static int bcode(const char *s) { - int r; - unsigned value = bb_strtou(s, NULL, 10); - if (errno) { - return -1; - } - r = tty_value_to_baud(value); - if (r > 0) { - return r; - } - return 0; + 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) +/* parse alternate baud rates */ +static void parse_speeds(char *arg) { char *cp; + /* NB: at least one iteration is always done */ debug("entered parse_speeds\n"); - for (cp = strtok(arg, ","); cp != 0; cp = strtok((char *) 0, ",")) { - if ((op->speeds[op->numspeed++] = bcode(cp)) <= 0) + while ((cp = strsep(&arg, ",")) != NULL) { + G.speeds[G.numspeed] = bcode(cp); + if (G.speeds[G.numspeed] < 0) bb_error_msg_and_die("bad speed: %s", cp); - if (op->numspeed > MAX_SPEED) + /* note: arg "0" turns into speed B0 */ + G.numspeed++; + if (G.numspeed > MAX_SPEED) bb_error_msg_and_die("too many alternate speeds"); } - debug("exiting parsespeeds\n"); + debug("exiting parse_speeds\n"); } - -/* parse_args - parse command-line arguments */ -static void parse_args(int argc, char **argv, struct options *op) +/* parse command-line arguments */ +static void parse_args(char **argv) { char *ts; - - op->flags = getopt32(argc, argv, opt_string, - &(op->initstring), &fakehost, &(op->issue), - &(op->login), &ts); - if (op->flags & F_INITSTRING) { - const char *p = op->initstring; - char *q; - - op->initstring = q = xstrdup(op->initstring); - /* 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; /* revert flag show /etc/issue */ - if (op->flags & F_TIMEOUT) { - op->timeout = xatoul_range(ts, 1, INT_MAX); + int flags; + + opt_complementary = "-2:t+"; /* at least 2 args; -t N */ + flags = getopt32(argv, opt_string, + &G.initstring, &G.fakehost, &G.issue, + &G.login, &G.timeout + ); + if (flags & F_INITSTRING) { + G.initstring = xstrdup(G.initstring); + /* decode \ddd octal codes into chars */ + strcpy_and_process_escape_sequences(G.initstring, G.initstring); } argv += optind; - argc -= optind; - debug("after getopt loop\n"); - if (argc < 2) /* check parameter count */ - bb_show_usage(); + debug("after getopt\n"); - /* we loosen up a bit and accept both "baudrate tty" and "tty baudrate" */ + /* We loosen up a bit and accept both "baudrate tty" and "tty baudrate" */ + G.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) */ - parse_speeds(op, argv[0]); /* baud rate(s) */ - op->tty = argv[1]; /* tty name */ - } else { - op->tty = argv[0]; /* tty name */ - parse_speeds(op, argv[1]); /* baud rate(s) */ + /* A number first, assume it's a speed (BSD style) */ + G.tty = ts; /* tty name is in argv[1] */ + ts = argv[0]; /* baud rate(s) */ } + parse_speeds(ts); + applet_name = xasprintf("getty: %s", G.tty); if (argv[2]) - setenv("TERM", argv[2], 1); + xsetenv("TERM", argv[2]); - debug("exiting parseargs\n"); + debug("exiting parse_args\n"); } -/* open_tty - set up tty as standard { input, output, error } */ -static void open_tty(const char *tty, struct termios *tp, int local) +/* set up tty as standard input, output, error */ +static void open_tty(void) { - int chdir_to_root = 0; - - /* Set up new standard input, unless we are given an already opened port. */ - - if (NOT_LONE_DASH(tty)) { - struct stat st; - int fd; - - /* Sanity checks... */ - - xchdir("/dev"); - chdir_to_root = 1; - xstat(tty, &st); - if ((st.st_mode & S_IFMT) != S_IFCHR) - bb_error_msg_and_die("%s: not a character device", tty); - - /* Open the tty as standard input. */ + /* 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 */ debug("open(2)\n"); - fd = xopen(tty, O_RDWR | O_NONBLOCK); - xdup2(fd, 0); - while (fd > 2) close(fd--); + close(0); + xopen(G.tty, O_RDWR | O_NONBLOCK); /* uses fd 0 */ + + /* 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, 0) & O_RDWR) != O_RDWR) + if ((fcntl(0, F_GETFL) & (O_RDWR|O_RDONLY|O_WRONLY)) != O_RDWR) bb_error_msg_and_die("stdin is not open for read/write"); } +} - /* Replace current standard output/error fd's with new ones */ - debug("duping\n"); - xdup2(0, 1); - xdup2(0, 2); +static void set_termios(void) +{ + if (tcsetattr_stdin_TCSANOW(&G.termios) < 0) + bb_perror_msg_and_die("tcsetattr"); +} - /* - * 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. +/* 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) +{ + /* 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. */ + 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! */ - ioctl_or_perror_and_die(0, TCGETS, tp, "%s: TCGETS", tty); + /* Flush input and output queues, important for modems! */ + tcflush(STDIN_FILENO, TCIOFLUSH); - /* - * It seems to be a terminal. Set proper protections and ownership. Mode - * 0622 is suitable for SYSV <4 because /bin/login does not change - * protections. SunOS 4 login will change the protections to 0620 (write - * access for group tty) after the login has succeeded. - */ + /* Set speed if it wasn't specified as "0" on command line */ + if (speed != B0) + cfsetspeed(&G.termios, speed); -#ifdef DEBIAN -#warning Debian /dev/vcs[a]NN hack is deprecated and will be removed - { - /* tty to root.dialout 660 */ - struct group *gr; - int id; - - gr = getgrnam("dialout"); - id = gr ? gr->gr_gid : 0; - chown(tty, 0, id); - chmod(tty, 0660); - - /* vcs,vcsa to root.sys 600 */ - if (!strncmp(tty, "tty", 3) && isdigit(tty[3])) { - char *vcs, *vcsa; - - vcs = xstrdup(tty); - vcsa = xmalloc(strlen(tty) + 2); - strcpy(vcs, "vcs"); - strcpy(vcs + 3, tty + 3); - strcpy(vcsa, "vcsa"); - strcpy(vcsa + 4, tty + 3); - - gr = getgrnam("sys"); - id = gr ? gr->gr_gid : 0; - chown(vcs, 0, id); - chmod(vcs, 0600); - chown(vcsa, 0, id); - chmod(vcs, 0600); - - free(vcs); - free(vcsa); - } - } -#else - if (NOT_LONE_DASH(tty)) { - chown(tty, 0, 0); /* 0:0 */ - chmod(tty, 0622); /* crw--w--w- */ + /* 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. + */ + /* Clear all bits except: */ + G.termios.c_cflag &= (0 + /* 2 stop bits (1 otherwise) + * Enable parity bit (both on input and output) + * Odd parity (else even) + */ + | CSTOPB | PARENB | PARODD +#ifdef CMSPAR + | CMSPAR /* mark or space parity */ +#endif + | CBAUD /* (output) baud rate */ +#ifdef CBAUDEX + | CBAUDEX /* (output) baud rate */ +#endif +#ifdef CIBAUD + | CIBAUD /* input baud rate */ +#endif + ); + /* Set: 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: + * opens don't block when CD is low, + * losing CD doesn't hang up processes whose ctty is this tty + */ + G.termios.c_cflag |= CLOCAL; } +#ifdef CRTSCTS + if (option_mask32 & F_RTSCTS) + G.termios.c_cflag |= CRTSCTS; /* flow control using RTS/CTS pins */ #endif - if (chdir_to_root) - xchdir("/"); -} + G.termios.c_iflag = 0; + G.termios.c_lflag = 0; + /* non-raw output; add CR to each NL */ + G.termios.c_oflag = OPOST | ONLCR; -/* 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. - */ + G.termios.c_cc[VMIN] = 1; /* block reads if < 1 char is available */ + G.termios.c_cc[VTIME] = 0; /* no timeout (reads block forever) */ #ifdef __linux__ - /* flush input and output queues, important for modems! */ - ioctl(0, TCFLSH, TCIOFLUSH); + G.termios.c_line = 0; #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; + set_termios(); - /* Optionally enable hardware flow control */ + debug("term_io 2\n"); +} -#ifdef CRTSCTS - if (op->flags & F_RTSCTS) - tp->c_cflag |= CRTSCTS; -#endif +static void termios_final(void) +{ + /* software flow control on output (stop sending if XOFF is recvd); + * and on input (send XOFF when buffer is full) + */ + G.termios.c_iflag |= IXON | IXOFF; + if (G.eol == '\r') { + G.termios.c_iflag |= ICRNL; /* map CR on input to NL */ + } + /* Other bits in c_iflag: + * IXANY Any recvd char enables output (any char is also a XON) + * INPCK Enable parity check + * IGNPAR Ignore parity errors (drop bad bytes) + * PARMRK Mark parity errors with 0xff, 0x00 prefix + * (else bad byte is received as 0x00) + * ISTRIP Strip parity bit + * IGNBRK Ignore break condition + * BRKINT Send SIGINT on break - maybe set this? + * INLCR Map NL to CR + * IGNCR Ignore CR + * 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 + */ - ioctl(0, TCSETS, tp); + /* line buffered input (NL or EOL or EOF chars end a line); + * recognize INT/QUIT/SUSP chars; + * echo input chars; + * echo BS-SP-BS on erase character; + * echo kill char specially, not as ^c (ECHOKE controls how exactly); + * erase all input via BS-SP-BS on kill char (else go to next line) + */ + G.termios.c_lflag |= ICANON | ISIG | ECHO | ECHOE | ECHOK | ECHOKE; + /* 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 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] + * 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 processed) + * TOSTOP Send SIGTTOU for background output + * (why "stty sane" unsets this bit?) + */ - /* go to blocking input even in local mode */ - fcntl(0, F_SETFL, fcntl(0, F_GETFL, 0) & ~O_NONBLOCK); + 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 +#ifdef VSWTCH + G.termios.c_cc[VSWTCH] = DEF_SWITCH; +#endif + G.termios.c_cc[VKILL] = DEF_KILL; + /* Other control chars: + * VEOL2 + * VERASE, VWERASE - (word) erase. we may set VERASE in get_logname + * VREPRINT - reprint current input buffer + * VLNEXT, VDISCARD, VSTATUS + * VSUSP, VDSUSP - send (delayed) SIGTSTP + * VSTART, VSTOP - chars used for IXON/IXOFF + */ - debug("term_io 2\n"); + set_termios(); } -/* auto_baud - extract baud rate from modem status message */ -static void auto_baud(char *buf, unsigned size_buf, struct termios *tp) +/* extract baud rate from modem status message */ +static void auto_baud(void) { - int speed; - int vmin; - unsigned iflag; - char *bp; int nread; /* @@ -391,458 +403,255 @@ static void auto_baud(char *buf, unsigned size_buf, struct termios *tp) * 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); + G.termios.c_cc[VMIN] = 0; /* don't block reads (min read is 0 chars) */ + set_termios(); /* * 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 = read(0, buf, size_buf - 1); + nread = safe_read(STDIN_FILENO, G.line_buf, sizeof(G.line_buf) - 1); if (nread > 0) { - buf[nread] = '\0'; - for (bp = buf; bp < buf + nread; bp++) { - if (isascii(*bp) && isdigit(*bp)) { + int speed; + char *bp; + G.line_buf[nread] = '\0'; + for (bp = G.line_buf; bp < G.line_buf + nread; bp++) { + if (isdigit(*bp)) { speed = bcode(bp); - if (speed) { - tp->c_cflag &= ~CBAUD; - tp->c_cflag |= speed; - } + if (speed > 0) + cfsetspeed(&G.termios, 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); + /* Restore terminal settings */ + G.termios.c_cc[VMIN] = 1; /* restore to value set by termios_init */ + set_termios(); } -/* next_speed - select next baud rate */ -static void next_speed(struct termios *tp, struct options *op) +/* get user name, establish parity, speed, erase, kill, eol; + * return NULL on BREAK, logname on success + */ +static char *get_logname(void) { - static int baud_index = FIRST_SPEED; /* current speed index */ - - baud_index = (baud_index + 1) % op->numspeed; - tp->c_cflag &= ~CBAUD; - tp->c_cflag |= op->speeds[baud_index]; - ioctl(0, TCSETS, tp); -} + char *bp; + char c; + /* Flush pending input (esp. after parsing or switching the baud rate) */ + usleep(100*1000); /* 0.1 sec */ + tcflush(STDIN_FILENO, TCIFLUSH); -/* do_prompt - show login prompt, optionally preceded by /etc/issue contents */ -static void do_prompt(struct options *op, struct termios *tp) -{ + /* Prompt for and read a login name */ + G.line_buf[0] = '\0'; + while (!G.line_buf[0]) { + /* Write issue file and prompt */ #ifdef ISSUE - print_login_issue(op->issue, op->tty); -#endif - print_login_prompt(); -} - -#ifdef HANDLE_ALLCAPS -/* caps_lock - string contains upper case without lower case */ -/* returns 1 if true, 0 if false */ -static int caps_lock(const char *s) -{ - while (*s) - if (islower(*s++)) - return 0; - return 1; -} + if (!(option_mask32 & F_NOISSUE)) + print_login_issue(G.issue, G.tty); #endif - -/* get_logname - get user name, establish parity, speed, erase, kill, eol */ -/* return NULL on failure, 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 */ - "\210\240\210", /* no parity */ - }; - - /* Initialize kill, erase, parity etc. (also after switching speeds). */ - - *cp = 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) { + print_login_prompt(); + + /* 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 */ + errno = EINTR; /* make read of 0 bytes be silent too */ + if (read(STDIN_FILENO, &c, 1) < 1) { if (errno == EINTR || errno == EIO) - exit(0); - bb_perror_msg_and_die("%s: read", op->tty); + exit(EXIT_SUCCESS); + bb_perror_msg_and_die(bb_msg_read_error); } - /* Do BREAK handling elsewhere. */ - if (c == '\0' && op->numspeed > 1) + /* BREAK. If we have speeds to try, + * return NULL (will switch speeds and return here) */ + if (c == '\0' && G.numspeed > 1) return NULL; - /* Do parity bit handling. */ - ascval = c & 0177; - if (c != ascval) { /* "parity" bit on ? */ - bits = 1; - mask = 1; - while (mask & 0177) { - if (mask & ascval) - bits++; /* count "1" bits */ - mask <<= 1; - } - /* ... |= 2 - even, 1 - odd */ - cp->parity |= 2 - (bits & 1); - } - - /* Do erase, kill and end-of-line processing. */ - switch (ascval) { - case CR: - case NL: - *bp = '\0'; /* terminate logname */ - cp->eol = ascval; /* set end-of-line char */ - break; + /* 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 '#': - cp->erase = ascval; /* set erase character */ - if (bp > logname) { - write(1, erase[cp->parity], 3); + G.termios.c_cc[VERASE] = c; + if (bp > G.line_buf) { + full_write(STDOUT_FILENO, "\010 \010", 3); bp--; } break; case CTL('U'): - case '@': - cp->kill = ascval; /* set kill character */ - while (bp > logname) { - write(1, erase[cp->parity], 3); + while (bp > G.line_buf) { + full_write(STDOUT_FILENO, "\010 \010", 3); bp--; } break; case CTL('D'): - exit(0); + exit(EXIT_SUCCESS); default: - if (!isascii(ascval) || !isprint(ascval)) { + if ((unsigned char)c < ' ') { /* ignore garbage characters */ - } else if (bp - logname >= size_logname - 1) { - bb_error_msg_and_die("%s: input overrun", op->tty); - } else { - write(1, &c, 1); /* echo the character */ - *bp++ = ascval; /* and store it */ + } else if ((int)(bp - G.line_buf) < sizeof(G.line_buf) - 1) { + /* echo and store the character */ + full_write(STDOUT_FILENO, &c, 1); + *bp++ = c; } break; } - } - } - /* Handle names with upper case and no lower case. */ - -#ifdef HANDLE_ALLCAPS - cp->capslock = caps_lock(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 */ - 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; - 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 */ + } /* end of get char loop */ + got_logname: ; + } /* while logname is empty */ - ioctl_or_perror_and_die(0, TCSETS, tp, "%s: TCSETS", op->tty); + return G.line_buf; } - -#ifdef SYSV_STYLE -#if ENABLE_FEATURE_UTMP -/* update_utmp - update our utmp entry */ -static void update_utmp(const char *line) +int getty_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; +int getty_main(int argc UNUSED_PARAM, char **argv) { - struct utmp ut; - struct utmp *utp; - time_t t; - int mypid = getpid(); + int n; + pid_t pid; + char *logname; - /* - * 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. - */ - if (access(_PATH_UTMP, R_OK|W_OK) == -1) { - close(creat(_PATH_UTMP, 0664)); - } - utmpname(_PATH_UTMP); - setutent(); - while ((utp = getutent()) - && !(utp->ut_type == INIT_PROCESS && utp->ut_pid == mypid)) - /* nothing */; - - if (utp) { - memcpy(&ut, utp, sizeof(ut)); - } else { - /* some inits don't initialize utmp... */ - memset(&ut, 0, sizeof(ut)); - safe_strncpy(ut.ut_id, line + 3, sizeof(ut.ut_id)); - } - /* endutent(); */ - - 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)); - time(&t); - ut.ut_time = t; - ut.ut_type = LOGIN_PROCESS; - ut.ut_pid = mypid; - - pututline(&ut); - endutent(); - -#if ENABLE_FEATURE_WTMP - if (access(bb_path_wtmp_file, R_OK|W_OK) == -1) - close(creat(bb_path_wtmp_file, 0664)); - updwtmp(bb_path_wtmp_file, &ut); -#endif -} - -#endif /* CONFIG_FEATURE_UTMP */ -#endif /* SYSV_STYLE */ - - -int getty_main(int argc, char **argv); -int getty_main(int argc, char **argv) -{ - int nullfd; - char *logname = NULL; /* 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 = { - 0, /* show /etc/issue (SYSV_STYLE) */ - 0, /* no timeout */ - _PATH_LOGIN, /* default login program */ - "tty1", /* default tty line */ - "", /* modem init string */ + INIT_G(); + G.login = _PATH_LOGIN; /* default login program */ #ifdef ISSUE - ISSUE, /* default issue file */ -#else - NULL, + G.issue = ISSUE; /* default issue file */ #endif - 0, /* no baud rates known yet */ - }; + G.eol = '\r'; + + /* Parse command-line arguments */ + parse_args(argv); - /* Already too late because of theoretical - * possibility of getty --help somehow triggered - * inadvertently before we reach this. Oh well. */ 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(); - nullfd = xopen(bb_dev_null, O_RDWR); - /* dup2(nullfd, 0); - no, because of possible "getty - 9600" */ - /* open_tty() will take care of fd# 0 anyway */ - dup2(nullfd, 1); - dup2(nullfd, 2); - while (nullfd > 2) close(nullfd--); - /* We want special flavor of error_msg_and_die */ + /* 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"); - - { - int i; - - for (i = 1; i < argc; i++) { - debug(argv[i]); - debug("\n"); - } + dbf = xfopen_for_write(DEBUGTERM); + for (n = 1; argv[n]; n++) { + debug(argv[n]); + debug("\n"); } #endif - /* Parse command-line arguments. */ - parse_args(argc, argv, &options); - -#ifdef SYSV_STYLE -#if ENABLE_FEATURE_UTMP - /* Update the utmp file. */ - update_utmp(options.tty); -#endif -#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 the tty as standard { input, output, error }. */ - open_tty(options.tty, &termios, options.flags & F_LOCAL); + open_tty(); + ndelay_off(0); + debug("duping\n"); + xdup2(0, 1); + xdup2(0, 2); -#ifdef __linux__ - { - int iv; + /* + * 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. + */ + if (tcgetattr(STDIN_FILENO, &G.termios) < 0) + bb_perror_msg_and_die("tcgetattr"); - iv = getpid(); - ioctl(0, TIOCSPGRP, &iv); - } + pid = getpid(); +#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(STDIN_FILENO, TIOCSCTTY, (void*)1); + /* Make ourself a foreground process group within our session */ + tcsetpgrp(STDIN_FILENO, pid); #endif - /* Initialize the termios settings (raw mode, eight-bit, blocking i/o). */ + + /* Update the utmp file. This tty is ours now! */ + update_utmp(pid, LOGIN_PROCESS, G.tty, "LOGIN", G.fakehost); + + /* Initialize the termios settings (raw mode, eight-bit, blocking i/o) */ debug("calling termios_init\n"); - termios_init(&termios, options.speeds[FIRST_SPEED], &options); + termios_init(G.speeds[0]); - /* write the modem init string and DON'T flush the buffers */ - if (options.flags & F_INITSTRING) { + /* Write the modem init string and DON'T flush the buffers */ + if (option_mask32 & F_INITSTRING) { debug("writing init string\n"); - write(1, options.initstring, strlen(options.initstring)); - } - - if (!(options.flags & F_LOCAL)) { - /* go to blocking write mode unless -L is specified */ - fcntl(1, F_SETFL, fcntl(1, F_GETFL, 0) & ~O_NONBLOCK); + full_write1_str(G.initstring); } - /* Optionally detect the baud rate from the modem status message. */ + /* Optionally detect the baud rate from the modem status message */ debug("before autobaud\n"); - if (options.flags & F_PARSE) - auto_baud(bb_common_bufsiz1, sizeof(bb_common_bufsiz1), &termios); + if (option_mask32 & F_PARSE) + auto_baud(); - /* Set the optional timer. */ - if (options.timeout) - alarm(options.timeout); + /* Set the optional timer */ + alarm(G.timeout); /* if 0, alarm is not set */ +//BUG: death by signal won't restore termios - /* optionally wait for CR or LF before writing /etc/issue */ - if (options.flags & F_WAITCRLF) { + /* Optionally wait for CR or LF before writing /etc/issue */ + if (option_mask32 & F_WAITCRLF) { char ch; - debug("waiting for cr-lf\n"); - while (read(0, &ch, 1) == 1) { - ch &= 0x7f; /* strip "parity bit" */ -#ifdef DEBUGGING - fprintf(dbf, "read %c\n", ch); -#endif + while (safe_read(STDIN_FILENO, &ch, 1) == 1) { + debug("read %x\n", (unsigned char)ch); if (ch == '\n' || ch == '\r') break; } } - chardata = init_chardata; - if (!(options.flags & F_NOPROMPT)) { - /* Read the login name. */ - debug("reading login name\n"); - logname = get_logname(bb_common_bufsiz1, sizeof(bb_common_bufsiz1), - &options, &chardata, &termios); - while (logname == NULL) - next_speed(&termios, &options); + logname = NULL; + if (!(option_mask32 & F_NOPROMPT)) { + /* NB: termios_init already set line speed + * to G.speeds[0] */ + int baud_index = 0; + + while (1) { + /* Read the login name */ + debug("reading login name\n"); + logname = get_logname(); + if (logname) + break; + /* We are here only if G.numspeed > 1 */ + baud_index = (baud_index + 1) % G.numspeed; + cfsetspeed(&G.termios, G.speeds[baud_index]); + set_termios(); + } } - /* Disable timer. */ - - if (options.timeout) - alarm(0); - - /* Finalize the termios settings. */ - - termios_final(&options, &termios, &chardata); - - /* Now the newline character should be properly written. */ + /* Disable timer */ + alarm(0); - write(1, "\n", 1); + /* Finalize the termios settings */ + termios_final(); - /* Let the login program take care of password validation. */ + /* Now the newline character should be properly written */ + full_write(STDOUT_FILENO, "\n", 1); - execl(options.login, options.login, "--", logname, (char *) 0); - bb_error_msg_and_die("%s: can't exec %s", options.tty, options.login); + /* 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(G.login, G.login, "--", logname, NULL); + bb_error_msg_and_die("can't execute '%s'", G.login); }