/*
 * Copyright 2009 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.
 */

/*
 * 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>

int     vflag;
int     cumode;
FILE    *phfd;

/*
 * 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, 921600, 1000000, 1152000, 1500000,
        2000000, 2500000, 3000000, 3500000, 4000000, -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[15];

        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) snprintf(sbuf, sizeof (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)))) == 0) {
                (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);
        }
}