/*      $NetBSD: tip.c,v 1.63 2020/04/23 00:35:14 joerg Exp $   */

/*
 * Copyright (c) 1983, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
#include <ctype.h>
#include <libgen.h>

#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1983, 1993\
 The Regents of the University of California.  All rights reserved.");
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)tip.c       8.1 (Berkeley) 6/6/93";
#endif
__RCSID("$NetBSD: tip.c,v 1.63 2020/04/23 00:35:14 joerg Exp $");
#endif /* not lint */

/*
 * tip - UNIX link to other systems
 *  tip [-v] [-speed] system-name
 * or
 *  cu [options] [phone-number|"dir"]
 */
#include "tip.h"
#include "pathnames.h"

struct termios  term;
struct termios  defterm;
struct termios  defchars;

FILE    *fscript;

int     attndes[2];
int     fildes[2];
int     repdes[2];
int     FD;
#ifndef __lint__  /* not used by hayes.c, but used by some other dialers */
int     AC;
#endif /*__lint__*/
int     sfd;
int     pid;
uid_t   uid, euid;
gid_t   gid, egid;
int     stop;
int     quit;
int     stoprompt;
int     timedout;
int     cumode;
int     bits8;
#define STRIP_PAR       (bits8 ? 0377 : 0177)

char    fname[80];
char    copyname[80];
char    ccc;

int     odisc;
int     vflag;

char    *DV;
char    *EL;
char    *CM;
char    *IE;
char    *OE;
char    *CU;
char    *AT;
char    *PN;
char    *DI;
char    *PA;

char    *PH;
char    *RM;
char    *HO;

long    BR;
long    FS;

long    DU;
long    HW;
char    *ES;
char    *EX;
char    *FO;
char    *RC;
char    *RE;
char    *PR;
long    DL;
long    CL;
long    ET;
long    HD;
char    DC;

__dead static void      tipusage(void);

int     escape(void);
__dead static void      intprompt(int);
__dead static void      tipin(void);

char    PNbuf[256];                     /* This limits the size of a number */

static char path_phones[] = _PATH_PHONES;

int
main(int argc, char *argv[])
{
        char *System = NULL;
        int c, i;
        char *p;
        const char *q;
        char sbuf[12];
        int cmdlineBR;
        int fcarg;

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

        if (argc > 4)
                tipusage();

        if (!isatty(0))
                errx(EXIT_FAILURE, "must be interactive");

        cmdlineBR = 0;
        while((c = getopt(argc, argv, "v0123456789")) != -1) {
                switch(c) {

                case 'v':
                        vflag++;
                        break;

                case '0': case '1': case '2': case '3': case '4':
                case '5': case '6': case '7': case '8': case '9':
                        cmdlineBR = cmdlineBR * 10 + (c - '0');
                        BR = cmdlineBR;
                        break;

                default:
                        warnx("%s, unknown option", argv[1]);
                        break;
                }
        }

        argc -= optind;
        argv += optind;

        if (argc != 1)
                tipusage();
        else
                System = argv[0];


        if (System == NULL)
                goto notnumber;
        if (isalpha((unsigned char)*System))
                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) {
                errx(1, "phone number too long (max = %d bytes)",
                        (int)sizeof(PNbuf) - 1);
        }
        (void)strlcpy(PNbuf, System, sizeof(PNbuf));
        for (p = System; *p; p++)
                *p = '\0';
        PN = PNbuf;
        (void)snprintf(sbuf, sizeof sbuf, "tip%d", (int)BR);
        System = sbuf;

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

        if ((i = hunt(System)) == 0) {
                errx(3, "all ports busy");
        }
        if (i == -1) {
                errx(3, "link down");
        }
        setbuf(stdout, NULL);

        /*
         * Kludge, their's no easy way to get the initialization
         *   in the right order, so force it here
         */
        if ((PH = getenv("PHONES")) == NULL)
                PH = path_phones;
        vinit();                                /* init variables */
        setparity("none");                      /* set the parity table */

        /*
         * Hardwired connections require the
         *  line speed set before they make any transmissions
         *  (this is particularly true of things like a DF03-AC)
         */
        if (HW) {
                if (ttysetup((speed_t)number(value(BAUDRATE))) != 0) {
                        errx(3, "bad baud rate %d",
                            (int)number(value(BAUDRATE)));
                }
        }
        if ((q = tip_connect()) != NULL) {
                errx(1, "\07%s\n[EOT]", q);
        }
        if (!HW) {
                if (ttysetup((speed_t)number(value(BAUDRATE))) != 0) {
                        errx(3, "bad baud rate %d",
                            (int)number(value(BAUDRATE)));
                }
        }


cucommon:
        /*
         * From here down the code is shared with
         * the "cu" version of tip.
         */

        /*
         * Direct connections with no carrier require using O_NONBLOCK on
         * open, but we don't want to keep O_NONBLOCK after open because it
         * will cause busy waits.
         */
        if (DC &&
            ((fcarg = fcntl(FD, F_GETFL, 0)) < 0 ||
             fcntl(FD, F_SETFL, fcarg & ~O_NONBLOCK) < 0)) {
                err(1, "can't clear O_NONBLOCK");
        }

        (void)tcgetattr(0, &defterm);
        term = defterm;
        term.c_lflag &= ~(ICANON|IEXTEN|ECHO);
        term.c_iflag &= ~(INPCK|ICRNL);
        term.c_oflag &= ~OPOST;
        term.c_cc[VMIN] = 1;
        term.c_cc[VTIME] = 0;
        defchars = term;
        term.c_cc[VINTR] = term.c_cc[VQUIT] = term.c_cc[VSUSP] =
                term.c_cc[VDSUSP] = term.c_cc[VDISCARD] =
                term.c_cc[VLNEXT] = _POSIX_VDISABLE;
        raw();

        (void)pipe(attndes);
        (void)pipe(fildes);
        (void)pipe(repdes);
        (void)signal(SIGALRM, alrmtimeout);

        /*
         * 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.
         */
        (void)printf("%s", cumode ? "Connected\r\n" : "\07connected\r\n");
        switch (pid = fork()) {
        default:
                tipin();
                break;
        case 0:
                tipout();
                break;
        case -1:
                err(1, "can't fork");
        }
        /*NOTREACHED*/
        exit(0);        /* XXX: pacify gcc */
}

void
tipusage(void)
{
        (void)fprintf(stderr, "usage: %s [-v] [-speed] system-name\n",
            getprogname());
        (void)fprintf(stderr, "       %s [-v] [-speed] phone-number\n",
            getprogname());
        exit(1);
}

void
/*ARGSUSED*/
cleanup(int dummy __unused)
{

        if (odisc)
                (void)ioctl(0, TIOCSETD, &odisc);
        _exit(0);
}

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

        (void)tcsetattr(0, TCSADRAIN, &term);
}


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

        (void)tcsetattr(0, TCSADRAIN, &defterm);
}

static  jmp_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(const char *s, char *volatile p, size_t l)
{
        int c;
        char *b = p;
        sig_t oint, oquit;

        stoprompt = 0;
        oint = signal(SIGINT, intprompt);
        oquit = signal(SIGQUIT, SIG_IGN);
        unraw();
        (void)printf("%s", s);
        if (setjmp(promptbuf) == 0)
                while ((c = getchar()) != EOF && (*p = c) != '\n' &&
                    b + l > p)
                        p++;
        *p = '\0';

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

/*
 * Interrupt service routine during prompting
 */
static void
/*ARGSUSED*/
intprompt(int dummy __unused)
{

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

/*
 * getchar() wrapper that checks for EOF on the local end.
 */
static int
xgetchar(void)
{
        int c = getchar();
        if (__predict_false(c == EOF)) {
                cleanup(SIGHUP);
                /* NOTREACHED */
        }

        return c & STRIP_PAR;
}


/*
 * ****TIPIN   TIPIN****
 */
static void
tipin(void)
{
        char gch, 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 = xgetchar();
                if ((gch == character(value(ESCAPE))) && bol) {
                        if (!(gch = escape()))
                                continue;
                } else if (!cumode &&
                    gch && gch == character(value(RAISECHAR))) {
                        setboolean(value(RAISE), !boolean(value(RAISE)));
                        continue;
                } else if (gch == '\r' || gch == '\n') {
                        bol = 1;
                        xpwrite(FD, &gch, 1);
                        if (boolean(value(HALFDUPLEX)))
                                (void)printf("%s\n", gch == '\r' ? "\r" : "");
                        continue;
                } else if (!cumode && gch && gch == character(value(FORCE)))
                        gch = xgetchar();
                bol = any(gch, value(EOL));
                if (boolean(value(RAISE)) && islower((unsigned char)gch))
                        gch = toupper((unsigned char)gch);
                xpwrite(FD, &gch, 1);
                if (boolean(value(HALFDUPLEX)))
                        (void)printf("%c", gch);
        }
}

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

        gch = xgetchar();
        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)
                xpwrite(FD, &c, 1);
        return (gch);
}

int
any(char c, const char *p)
{

        while (p && *p)
                if (*p++ == c)
                        return (1);
        return (0);
}

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

        while ((c = *s++) != 0 && buf + sizeof buf - p > 2) {
                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(char 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
 */
int
ttysetup(speed_t spd)
{
        struct termios  cntrl;

        (void)tcgetattr(FD, &cntrl);
        (void)cfsetospeed(&cntrl, spd);
        (void)cfsetispeed(&cntrl, spd);
        cntrl.c_cflag &= ~(CSIZE|PARENB);
        cntrl.c_cflag |= CS8;
        if (DC)
                cntrl.c_cflag |= CLOCAL;
        if (boolean(value(HARDWAREFLOW)))
                cntrl.c_cflag |= CRTSCTS;
        cntrl.c_iflag &= ~(ISTRIP|ICRNL);
        cntrl.c_oflag &= ~OPOST;
        cntrl.c_lflag &= ~(ICANON|ISIG|IEXTEN|ECHO);
        cntrl.c_cc[VMIN] = 1;
        cntrl.c_cc[VTIME] = 0;
        if (boolean(value(TAND)))
                cntrl.c_iflag |= IXOFF|IXON;
        else
                cntrl.c_iflag &= ~(IXOFF|IXON);
        return tcsetattr(FD, TCSAFLUSH, &cntrl);
}

static char partab[0200];

/*
 * 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
xpwrite(int fd, char *buf, size_t n)
{
        size_t i;
        char *bp;

        bp = buf;
        if (bits8 == 0)
                for (i = 0; i < n; i++) {
                        *bp = partab[(*bp) & 0177];
                        bp++;
                }
        if (write(fd, buf, n) < 0) {
                if (errno == EIO)
                        tipabort("Lost carrier.");
                /* this is questionable */
                warn("write");
        }
}

/*
 * Build a parity table with appropriate high-order bit.
 */
void
setparity(const char *defparity)
{
        int i, flip, clr, set;
        const char *parity;
        static char *curpar;

        if (value(PARITY) == NULL || ((char *)value(PARITY))[0] == '\0') {
                if (curpar != NULL)
                        free(curpar);
                value(PARITY) = curpar = strdup(defparity);
        }
        parity = value(PARITY);
        if (strcmp(parity, "none") == 0) {
                bits8 = 1;
                return;
        }
        bits8 = 0;
        flip = 0;
        clr = 0377;
        set = 0;
        if (strcmp(parity, "odd") == 0)
                flip = 0200;                    /* reverse bit 7 */
        else if (strcmp(parity, "zero") == 0)
                clr = 0177;                     /* turn off bit 7 */
        else if (strcmp(parity, "one") == 0)
                set = 0200;                     /* turn on bit 7 */
        else if (strcmp(parity, "even") != 0) {
                (void)fprintf(stderr, "%s: unknown parity value\r\n", parity);
                (void)fflush(stderr);
        }
        for (i = 0; i < 0200; i++)
                partab[i] = ((evenpartab[i] ^ flip) | set) & clr;
}