cmd/tip/tip.c

	tip.c revision 8d489c7a815fcac696803219572e95aa01532b0f
/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * Copyright (c) 1983 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * tip - UNIX link to other systems
 *  tip [-v] [-speed] system-name
 * or
 *  cu phone-number [-s speed] [-l line] [-a acu]
 */
#include "tip.h"
#include <sys/wait.h>
#include <locale.h>

/*
 * Baud rate mapping table
 */
int bauds[] = {
    0, 50, 75, 110, 134, 150, 200, 300, 600,
    1200, 1800, 2400, 4800, 9600, 19200, 38400,
    57600, 76800, 115200, 153600, 230400, 307200, 460800, -1
};

extern void tipout(void)    __NORETURN;
extern void timeout(void);
extern esctable_t   etable[];
extern unsigned char    evenpartab[];

void    intprompt(void);
void    deadkid(void);
void    cleanup(void);
void    tipin(void) __NORETURN;
unsigned char   escape(void);
char    *sname(char *);
char    PNbuf[256];     /* This limits the size of a number */
int noparity = 0;

int
main(int argc, char *argv[])
{
    char *system = NOSTR;
    int i;
    char *p;
    char sbuf[12];

    gid = getgid();
    egid = getegid();
    uid = getuid();
    euid = geteuid();
    if (equal(sname(argv[0]), "cu")) {
        cumode = 1;
        cumain(argc, argv);
        goto cucommon;
    }

    if (argc > 4) {
        (void) fprintf(stderr,
            "usage: tip [-v] [-speed] [system-name]\n");
        return (1);
    }
    if (!isatty(0)) {
        (void) fprintf(stderr, "tip: must be interactive\n");
        return (1);
    }

    for (; argc > 1; argv++, argc--) {
        if (argv[1][0] != '-')
            system = argv[1];
        else switch (argv[1][1]) {

        case 'v':
            vflag++;
            break;

        case '0': case '1': case '2': case '3': case '4':
        case '5': case '6': case '7': case '8': case '9':
            BR = atoi(&argv[1][1]);
            break;

        default:
            (void) fprintf(stderr, "tip: %s, unknown option\n",
                argv[1]);
            break;
        }
    }

    (void) setlocale(LC_CTYPE, "");

    if (system == NOSTR)
        goto notnumber;
    for (p = system; *p; p++)
        if (isalpha(*p))
            goto notnumber;
    /*
     * System name is really a phone number...
     * Copy the number then stomp on the original (in case the number
     *  is private, we don't want 'ps' or 'w' to find it).
     */
    if (strlen(system) > sizeof (PNbuf) - 1) {
        (void) fprintf(stderr,
            "tip: phone number too long (max = %d bytes)\n",
            sizeof (PNbuf) - 1);
        return (1);
    }
    (void) strncpy(PNbuf, system, sizeof (PNbuf) - 1);
    for (p = system; *p; p++)
        *p = '\0';
    PN = PNbuf;
    (void) sprintf(sbuf, "tip%d", BR);
    system = sbuf;

notnumber:
    (void) signal(SIGINT, (sig_handler_t)cleanup);
    (void) signal(SIGQUIT, (sig_handler_t)cleanup);
    (void) signal(SIGHUP, (sig_handler_t)cleanup);
    (void) signal(SIGTERM, (sig_handler_t)cleanup);

    if ((i = hunt(system)) == 0) {
        (void) printf("all ports busy\n");
        return (3);
    }
    if (i == -1) {
        (void) printf("link down\n");
        delock(uucplock);
        return (3);
    }
    setbuf(stdout, NULL);
    loginit();

    /*
     * Now that we have the logfile and the ACU open
     *  return to the real uid and gid.  These things will
     *  be closed on exit.  The saved-setuid uid and gid
     *  allows us to get the original setuid permissions back
     *  for removing the uucp lock.
     */
    userperm();

    /*
     * Kludge, there's no easy way to get the initialization
     *   in the right order, so force it here.
     * Do the open here, before we change back to real uid.
     * We will check whether the open succeeded later, when
     * (and if) we actually go to use the file.
     */
    if ((PH = getenv("PHONES")) == NOSTR) {
        myperm();
        PH = "/etc/phones";
    }
    phfd = fopen(PH, "r");

    userperm();

    vinit();                /* init variables */
    setparity("none");          /* set the parity table */
    if ((i = speed(number(value(BAUDRATE)))) == NULL) {
        (void) printf("tip: bad baud rate %d\n",
            number(value(BAUDRATE)));
        myperm();
        delock(uucplock);
        return (3);
    }


    /*
     * Hardwired connections require the
     *  line speed set before they make any transmissions
     *  (this is particularly true of things like a DF03-AC)
     */
    if (HW)
        ttysetup(i);
    if (p = connect()) {
        (void) printf("\07%s\n[EOT]\n", p);
        myperm();
        delock(uucplock);
        return (1);
    }

    /*
     * Always setup the tty again here in case hardware flow
     *  control was selected, which can only be set after the
     *  connection is made, or in case this is not a hardwired
     *  modem (rare these days) that likewise can only be setup
     *  after the connection is made.
     */
    ttysetup(i);
cucommon:
    /*
     * From here down the code is shared with
     * the "cu" version of tip.
     */

    (void) ioctl(0, TCGETS, (char *)&defarg);
    arg = defarg;
    /* turn off input processing */
    arg.c_lflag &= ~(ICANON|ISIG|ECHO|IEXTEN);
    arg.c_cc[VMIN] = 1;
    arg.c_cc[VTIME] = 0;
    arg.c_iflag &= ~(INPCK|IXON|IXOFF|ICRNL);
    arg.c_oflag = 0;        /* turn off all output processing */
    /* handle tandem mode in case was set in remote file */
    if (boolean(value(TAND)))
        tandem("on");
    else
        tandem("off");
    raw();

    (void) pipe(fildes); (void) pipe(repdes);
    (void) signal(SIGALRM, (sig_handler_t)timeout);

    /*
     * Everything's set up now:
     *  connection established (hardwired or dialup)
     *  line conditioned (baud rate, mode, etc.)
     *  internal data structures (variables)
     * so, fork one process for local side and one for remote.
     */
    if (CM != NOSTR) {
        (void) sleep(2);    /* let line settle */
        parwrite(FD, (unsigned char *)CM, strlen(CM));
    }
    (void) printf(cumode ? "Connected\r\n" : "\07connected\r\n");
    (void) signal(SIGCHLD, (sig_handler_t)deadkid);
    if (pid = fork())
        tipin();
    else
        tipout();
    /*NOTREACHED*/
}

void
deadkid(void)
{

    if (pid >= 0 && waitpid(pid, NULL, WNOHANG) == pid)
        tip_abort("Connection Closed");
}

void
cleanup(void)
{

    if (uid != getuid()) {
        myperm();
    }
    delock(uucplock);
    exit(0);
}

/*
 * put the controlling keyboard into raw mode
 */
void
raw(void)
{

    (void) ioctl(0, TCSETSF, (char *)&arg);
}


/*
 * return keyboard to normal mode
 */
void
unraw(void)
{

    (void) ioctl(0, TCSETSF, (char *)&defarg);
}

/*
 * switch to using invoking user's permissions
 */
void
userperm(void)
{

    (void) setegid(gid);
    (void) seteuid(uid);
}

/*
 * switch to using my special (setuid) permissions
 */
void
myperm(void)
{

    (void) setegid(egid);
    (void) seteuid(euid);
}

static  sigjmp_buf promptbuf;

/*
 * Print string ``s'', then read a string
 *  in from the terminal.  Handles signals & allows use of
 *  normal erase and kill characters.
 */
int
prompt(char *s, char *p, size_t len)
{
    char *b = p;
    int c;
    sig_handler_t   ointr, oquit;

    stoprompt = 0;
    ointr = signal(SIGINT, (sig_handler_t)intprompt);
    oquit = signal(SIGQUIT, SIG_IGN);
    unraw();
    (void) printf("%s", s);
    if (sigsetjmp(promptbuf, 1) == 0)
        while (p < b + len - 1 &&
            ((c = getchar()) != EOF) && (c != '\n'))
            *p++ = c;
    *p = '\0';

    raw();
    (void) signal(SIGINT, ointr);
    (void) signal(SIGQUIT, oquit);
    return (stoprompt || p == b);
}

/*
 * Interrupt service routine during prompting
 */
void
intprompt(void)
{

    (void) signal(SIGINT, SIG_IGN);
    (void) signal(SIGQUIT, SIG_IGN);
    stoprompt = 1;
    (void) printf("\r\n");
    siglongjmp(promptbuf, 1);
}

/*
 * ****TIPIN   TIPIN****
 */
void
tipin(void)
{
    unsigned char gch, c;
    int bol = 1;

    /*
     * Kinda klugey here...
     *   check for scripting being turned on from the .tiprc file,
     *   but be careful about just using setscript(), as we may
     *   send a SIGEMT before tipout has a chance to set up catching
     *   it; so wait a second, then setscript()
     */
    if (boolean(value(SCRIPT))) {
        (void) sleep(1);
        setscript();
    }

    for (;;) {
        gch = getchar()&0377;
        if ((gch == character(value(ESCAPE))) && bol) {
            if (!(gch = escape()))
                continue;
        } else if (!cumode && gch == character(value(RAISECHAR))) {
            boolean(value(RAISE)) = !boolean(value(RAISE));
            continue;
        } else if (gch == '\r') {
            bol = 1;
            parwrite(FD, &gch, 1);
            if (boolean(value(HALFDUPLEX)))
                (void) printf("\r\n");
            continue;
        } else if (!cumode && gch == character(value(FORCE)))
            gch = getchar()&0377;
        bol = any(gch, value(EOL));
        if (boolean(value(RAISE)) && islower(gch))
            gch = toupper(gch);
        c = gch;
        parwrite(FD, &gch, 1);
        if (boolean(value(HALFDUPLEX)))
            (void) putchar(c);
    }
}

/*
 * Escape handler --
 *  called on recognition of ``escapec'' at the beginning of a line
 */
unsigned char
escape(void)
{
    unsigned char gch;
    esctable_t *p;
    char c = character(value(ESCAPE));

    gch = (getchar()&0377);
    for (p = etable; p->e_char; p++)
        if (p->e_char == gch) {
            if ((p->e_flags&PRIV) && uid)
                continue;
            (void) printf("%s", ctrl(c));
            (*p->e_func)(gch);
            return (0);
        }
    /* ESCAPE ESCAPE forces ESCAPE */
    if (c != gch)
        parwrite(FD, (unsigned char *)&c, 1);
    return (gch);
}

int
speed(int n)
{
    int *p;

    for (p = bauds; *p != -1;  p++)
        if (*p == n)
            return (p - bauds);
    return (0);
}

int
any(char c, char *p)
{
    while (p && *p)
        if (*p++ == c)
            return (1);
    return (0);
}

char *
interp(char *s)
{
    static char buf[256];
    char *p = buf, c, *q;

    while (c = *s++) {
        for (q = "\nn\rr\tt\ff\033E\bb"; *q; q++)
            if (*q++ == c) {
                *p++ = '\\'; *p++ = *q;
                goto next;
            }
        if (c < 040) {
            *p++ = '^'; *p++ = c + 'A'-1;
        } else if (c == 0177) {
            *p++ = '^'; *p++ = '?';
        } else
            *p++ = c;
    next:
        ;
    }
    *p = '\0';
    return (buf);
}

char *
ctrl(char c)
{
    static char s[3];

    if (c < 040 || c == 0177) {
        s[0] = '^';
        s[1] = c == 0177 ? '?' : c+'A'-1;
        s[2] = '\0';
    } else {
        s[0] = c;
        s[1] = '\0';
    }
    return (s);
}

/*
 * Help command
 */
void
help(int c)
{
    esctable_t *p;

    (void) printf("%c\r\n", c);
    for (p = etable; p->e_char; p++) {
        if ((p->e_flags&PRIV) && uid)
            continue;
        (void) printf("%2s", ctrl(character(value(ESCAPE))));
        (void) printf("%-2s %c   %s\r\n", ctrl(p->e_char),
            p->e_flags&EXP ? '*': ' ', p->e_help);
    }
}

/*
 * Set up the "remote" tty's state
 */
void
ttysetup(int speed)
{
    struct termios buf;
    char *loc;

    (void) ioctl(FD, TCGETS, (char *)&buf);
    buf.c_cflag &= (CREAD|HUPCL|CLOCAL|CRTSCTS|CRTSXOFF);
    buf.c_cflag |= CS8;
    (void) cfsetospeed(&buf, speed);
    if (boolean(value(HARDWAREFLOW))) {
        int i = TIOCM_CAR;

        /*
         * Only set hardware flow control if carrier is up,
         * because some devices require both CD and RTS to
         * be up before sending.
         */
        (void) ioctl(FD, TIOCMGET, &i);
        if (i & TIOCM_CAR)
            buf.c_cflag |= (CRTSCTS|CRTSXOFF);
    }

    /*
     * Careful to only penalize the 8-bit users here on the
     * incoming tty port.  The default 7-bit users will
     * still get the parity bit from the other side's login
     * process (which happens to be the default for sun tip
     * configurations).
     */
    loc = setlocale(LC_CTYPE, NULL);
    if (noparity && loc != 0 && strcmp(loc, "C") != 0)
        buf.c_iflag = 0;
    else
        buf.c_iflag = ISTRIP;
    buf.c_oflag = 0;
    buf.c_lflag = 0;
    buf.c_cc[VMIN] = 1;
    buf.c_cc[VTIME] = 0;
    (void) ioctl(FD, TCSETSF, (char *)&buf);
}

/*
 * Return "simple" name from a file name,
 * strip leading directories.
 */
char *
sname(char *s)
{
    char *p = s;

    while (*s)
        if (*s++ == '/')
            p = s;
    return (p);
}

static char partab[0400];

/*
 * Do a write to the remote machine with the correct parity.
 * We are doing 8 bit wide output, so we just generate a character
 * with the right parity and output it.
 */
void
parwrite(int fd, unsigned char *buf, int n)
{
    int i;
    unsigned char *bp;

    bp = buf;
    for (i = 0; i < n; i++) {
        *bp = partab[(*bp)&0377];
        bp++;
    }
    if (write(fd, buf, n) < 0) {
        if (errno == EIO || errno == ENXIO)
            tip_abort("Lost carrier.");
        /* this is questionable */
        perror("write");
    }
}

/*
 * Build a parity table with appropriate high-order bit.
 */
void
setparity(char *defparity)
{
    int i;
    char *parity;

    if (value(PARITY) == NOSTR)
        value(PARITY) = defparity;
    parity = value(PARITY);
    for (i = 0; i < 0400; i++)
        partab[i] = evenpartab[i];
    if (equal(parity, "even")) {
        /* EMPTY */
    } else if (equal(parity, "odd")) {
        for (i = 0; i < 0400; i++)
            partab[i] ^= 0200;  /* reverse bit 7 */
    } else if (equal(parity, "none")) {
        /* Do nothing so we can pass thru 8-bit chars */
        noparity = 1;
        for (i = 0; i < 0400; i++)
            partab[i] = i;
    } else if (equal(parity, "zero")) {
        for (i = 0; i < 0400; i++)
            partab[i] &= ~0200; /* turn off bit 7 */
    } else if (equal(parity, "one")) {
        for (i = 0; i < 0400; i++)
            partab[i] |= 0200;  /* turn on bit 7 */
    } else {
        (void) fprintf(stderr, "%s: unknown parity value\n", PA);
        (void) fflush(stderr);
    }
}