/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*        All Rights Reserved   */

#include        <stdio.h>
#include        <stdlib.h>
#include        <fcntl.h>
#include        <errno.h>
#include        <sys/types.h>
#include        <termio.h>
#include        <string.h>
#include        <signal.h>
#include        <poll.h>
#include        <unistd.h>
#include        "sys/stropts.h"
#include        <sys/resource.h>
#include        "sac.h"
#include        "ttymon.h"
#include        "tmstruct.h"
#include        "tmextern.h"
#ifdef  SYS_NAME
#include        <sys/utsname.h>
#endif

static void openline(struct pmtab *, struct Gdef *);
static void invoke_service(struct pmtab *);
static char     *do_autobaud(struct pmtab *, struct Gdef *);
static  struct  Gdef    *next_speed(struct Gdef *);
static int check_hup(int);

/*
 * tmchild      - process that handles peeking data, determine baud rate
 *                and invoke service on each individual port.
 *
 */
void
tmchild(struct pmtab *pmtab)
{
        struct Gdef *speedef;
        char    *auto_speed = "";
        struct  sigaction sigact;

#ifdef  DEBUG
        debug("in tmchild");
#endif
        peek_ptr = NULL;
        if (pmtab->p_status != GETTY) {
                child_sigcatch();
                (void) close(PCpipe[0]); /* close parent end of the pipe */
                if (ioctl(PCpipe[1], I_SETSIG, S_HANGUP) == -1) {
                        log("I_SETSIG failed: %s", strerror(errno));
                        exit(1);
                }
                /*
                 * the following check is to make sure no hangup
                 * happens before registering for SIGPOLL
                 */
                if (check_hup(PCpipe[1])) {
#ifdef  DEBUG
                        debug("PCpipe hungup, tmchild exiting");
#endif
                        exit(1);
                }

                if (pmtab->p_ttyflags & (C_FLAG|B_FLAG)) {
                        if (pmtab->p_fd > 0) {
                                (void) close(pmtab->p_fd);
                                pmtab->p_fd = 0;
                        }
                }

                /*
                 * become the session leader so that a controlling tty
                 * will be allocated.
                 */
                (void) setsid();
        }
        speedef = get_speed(pmtab);
        openline(pmtab, speedef);
        if (pmtab->p_ttyflags & (C_FLAG|B_FLAG)) {
                if (pmtab->p_fd >= 0) {
                        if ((pmtab->p_modules != NULL) &&
                            (*(pmtab->p_modules) != '\0')) {
                                if (push_linedisc(pmtab->p_fd,
                                    pmtab->p_modules, pmtab->p_device) == -1) {
                                        (void) close(pmtab->p_fd);
                                        return;
                                }
                        }
                }
        }
        if ((pmtab->p_ttyflags & C_FLAG) &&
            (State != PM_DISABLED) &&
            (!(pmtab->p_flags & X_FLAG))) {
                /*
                 * if "c" flag is set, and the port is not disabled
                 * invoke service immediately
                 */
                if (set_termio(0, speedef->g_fflags, NULL, FALSE,
                    CANON) == -1) {
                        log("set final termio failed");
                        exit(1);
                }
                invoke_service(pmtab);
                exit(1);        /*NOTREACHED*/
        }
        if (speedef->g_autobaud & A_FLAG) {
                auto_speed = do_autobaud(pmtab, speedef);
        }
        if (set_termio(0, speedef->g_fflags, NULL, FALSE, CANON) == -1) {
                log("set final termio failed");
                exit(1);
        }
        if ((pmtab->p_ttyflags & (R_FLAG|A_FLAG)) ||
            (pmtab->p_status == GETTY) || (pmtab->p_timeout > 0)) {
                write_prompt(1, pmtab, TRUE, TRUE);
                if (pmtab->p_timeout) {
                        sigact.sa_flags = 0;
                        sigact.sa_handler = timedout;
                        (void) sigemptyset(&sigact.sa_mask);
                        (void) sigaction(SIGALRM, &sigact, NULL);
                        (void) alarm((unsigned)pmtab->p_timeout);
                }
        } else if ((pmtab->p_ttyflags & (B_FLAG)))
                write_prompt(pmtab->p_fd, pmtab, TRUE, TRUE);


        /* Loop until user is successful in invoking service. */
        for (;;) {

                /* Peek the user's typed response and respond appropriately. */
                switch (poll_data()) {
                case GOODNAME:
#ifdef  DEBUG
                        debug("got GOODNAME");
#endif
                        if (pmtab->p_timeout) {
                                (void) alarm((unsigned)0);
                                sigact.sa_flags = 0;
                                sigact.sa_handler = SIG_DFL;
                                (void) sigemptyset(&sigact.sa_mask);
                                (void) sigaction(SIGALRM, &sigact, NULL);
                        }
                        if ((State == PM_DISABLED) ||
                            (pmtab->p_flags & X_FLAG)) {
                                write_prompt(1, pmtab, TRUE, FALSE);
                                break;
                        }
                        if (set_termio(0, speedef->g_fflags, auto_speed,
                            FALSE, CANON) == -1) {
                                log("set final termio failed");
                                exit(1);
                        }
                        invoke_service(pmtab);
                        exit(1);        /*NOTREACHED*/

                case BADSPEED:
                        /* wrong speed! try next speed in the list. */
                        speedef = next_speed(speedef);
#ifdef  DEBUG
                        debug("BADSPEED: setup next speed");
#endif
                        if (speedef->g_autobaud & A_FLAG) {
                                if (auto_termio(0) == -1) {
                                        exit(1);
                                }
                                auto_speed = do_autobaud(pmtab, speedef);
                        } else {
                                auto_speed = NULL;
                                /*
                                 * this reset may fail if the speed is not
                                 * supported by the system
                                 * we just cycle through it to the next one
                                 */
                                if (set_termio(0, speedef->g_iflags, NULL,
                                    FALSE, CANON) != 0) {
                                        log("Warning -- speed of <%s> may "
                                            "be not supported by the system",
                                            speedef->g_id);
                                }
                        }
                        write_prompt(1, pmtab, TRUE, TRUE);
                        break;

                case NONAME:
#ifdef  DEBUG
                        debug("got NONAME");
#endif
                        write_prompt(1, pmtab, FALSE, FALSE);
                        break;

                }  /* end switch */

                peek_ptr = NULL;
                if (pmtab->p_timeout) {
                        sigact.sa_flags = 0;
                        sigact.sa_handler = timedout;
                        (void) sigemptyset(&sigact.sa_mask);
                        (void) sigaction(SIGALRM, &sigact, NULL);
                        (void) alarm((unsigned)pmtab->p_timeout);
                }
        } /* end for loop */
}

static void
openline(struct pmtab *pmtab, struct Gdef *speedef)
{
        char     buffer[5];
        int      rtn = 0;
        int      line_count;

#ifdef  DEBUG
        debug("in openline");
#endif
        if (pmtab->p_status != GETTY) {
                (void) close(0);
                /* open should return fd 0, if not, then close it */
                if ((pmtab->p_fd = open(pmtab->p_device, O_RDWR)) != 0) {
                        log("open \"%s\" failed: %s", pmtab->p_device,
                            strerror(errno));
                        exit(1);
                }
        }
        (void) close(1);
        (void) close(2);
        (void) dup(0);
        (void) dup(0);

        if (pmtab->p_ttyflags & R_FLAG) { /* wait_read is needed */
                if (pmtab->p_count) {
                        if (peek_ptr != NULL)
                                if ((peek_ptr->buf[0]&0x7F) == '\n' ||
                                    (peek_ptr->buf[0]&0x7F) == '\r')
                                        pmtab->p_count--;

                        /*
                         * - wait for "p_count" lines
                         * - datakit switch does not
                         *   know you are a host or a terminal
                         * - so it send you several lines of msg
                         * - we need to swallow that msg
                         * - we assume the baud rate is correct
                         * - if it is not, '\n' will not look like '\n'
                         * and we will wait forever here
                         */
                        if (set_termio(0, speedef->g_fflags, NULL, TRUE,
                            CANON) == -1) {
                                log("set final termio failed");
                                exit(1);
                        }
                        for (line_count = 0; line_count < pmtab->p_count; ) {
                                if (read(0, buffer, 1) < 0 ||
                                    *buffer == '\0' ||
                                    *buffer == '\004') {
                                        (void) close(0);
                                        exit(0);
                                }
                                if (*buffer == '\n')
                                        line_count++;
                        }
                } else { /* wait for 1 char */
                        if (peek_ptr == NULL) {
                                if (set_termio(0, NULL, NULL, TRUE,
                                    RAW) == -1) {
                                        log("set termio RAW failed");
                                        exit(1);
                                }
                                rtn = read(0, buffer, 1);
                        } else
                                *buffer = (peek_ptr->buf[0]&0x7F);

                        /*
                         * NOTE: Cu on a direct line when ~. is encountered will
                         * send EOTs to the other side.  EOT=\004
                         */
                        if (rtn < 0 || *buffer == '\004') {
                                (void) close(0);
                                exit(0);
                        }
                }
                peek_ptr = NULL;
                if (!(pmtab->p_ttyflags & A_FLAG)) { /* autobaud not enabled */
                        if (set_termio(0, speedef->g_fflags, NULL, TRUE,
                            CANON) == -1) {
                                log("set final termio failed");
                                exit(1);
                        }
                }
        }
        if (pmtab->p_ttyflags & B_FLAG) { /* port is bi-directional */
                /* set advisory lock on the line */
                if (tm_lock(0) != 0) {
                        /*
                         * device is locked
                         * child exits and let the parent wait for
                         * the lock to go away
                         */
                        exit(0);
                }
                /* change ownership back to root */
                (void) fchown(0, ROOTUID, Tty_gid);
                (void) fchmod(0, 0620);
        }
}

/*
 *      write_prompt    - write the msg to fd
 *                      - if flush is set, flush input queue
 *                      - if clear is set, write a new line
 */
void
write_prompt(int fd, struct pmtab *pmtab, int flush, int clear)
{

#ifdef DEBUG
        debug("in write_prompt");
#endif
        if (flush)
                flush_input(fd);
        if (clear) {
                (void) write(fd, "\r\n", 2);
        }
#ifdef SYS_NAME
        sys_name(fd);
#endif
        /* Print prompt/disable message. */
        if ((State == PM_DISABLED) || (pmtab->p_flags & X_FLAG))
                (void) write(fd, pmtab->p_dmsg,
                    (unsigned)strlen(pmtab->p_dmsg));
        else
                (void) write(fd, pmtab->p_prompt,
                    (unsigned)strlen(pmtab->p_prompt));
}

/*
 *      timedout        - input period timed out
 */
void
timedout(int signal __unused)
{
        exit(1);
}

#ifdef SYS_NAME
/*
 * void sys_name() - generate a msg with system id
 *                 - print out /etc/issue file if it exists
 */
void
sys_name(int fd)
{
        char    *ptr, buffer[BUFSIZ];
        FILE    *fp;

#if 0   /* 1111333 - don't print node name, we already do this elsewhere */
        struct  utsname utsname;

        if (uname(&utsname) != FAILURE) {
                (void) sprintf(buffer, "%.9s\r\n", utsname.nodename);
                (void) write(fd, buffer, strlen(buffer));
        }
#endif

        if ((fp = fopen(ISSUEFILE, "r")) != NULL) {
                while ((ptr = fgets(buffer, sizeof (buffer), fp)) != NULL) {
                        (void) write(fd, ptr, strlen(ptr));
                }
                (void) fclose(fp);
        }
}
#endif


/*
 *      do_autobaud     - do autobaud
 *                      - if it succeed, set the new speed and return
 *                      - if it failed, it will get the nextlabel
 *                      - if next entry is also autobaud,
 *                        it will loop back to do autobaud again
 *                      - otherwise, it will set new termio and return
 */
static  char    *
do_autobaud(struct pmtab *pmtab, struct Gdef *speedef)
{
        int     done = FALSE;
        char    *auto_speed;

#ifdef  DEBUG
        debug("in do_autobaud");
#endif
        while (!done) {
                if ((auto_speed = autobaud(0, pmtab->p_timeout)) == NULL) {
                        speedef = next_speed(speedef);
                        if (speedef->g_autobaud & A_FLAG) {
                                continue;
                        } else {
                                if (set_termio(0, speedef->g_iflags, NULL,
                                    TRUE, CANON) != 0) {
                                        exit(1);
                                }
                                done = TRUE;
                        }
                } else {
                        if (set_termio(0, speedef->g_fflags, auto_speed,
                            TRUE, CANON) != 0) {
                                exit(1);
                        }
                        done = TRUE;
                }
        }
#ifdef  DEBUG
        debug("autobaud done");
#endif
        return (auto_speed);
}

/*
 *      next_speed(speedef)
 *      - find the next entry according to nextlabel. If "nextlabel"
 *        is not valid, go back to the old ttylabel.
 */

static  struct  Gdef *
next_speed(struct Gdef *speedef)
{
        struct  Gdef *sp;

        if (strcmp(speedef->g_nextid, speedef->g_id) == 0)
                return (speedef);
        if ((sp = find_def(speedef->g_nextid)) == NULL) {
                log("%s's next speed-label (%s) is bad.", speedef->g_id,
                    speedef->g_nextid);

                /* go back to the original entry. */
                if ((sp = find_def(speedef->g_id)) == NULL) {
                        /* if failed, complain and quit. */
                        log("unable to find (%s) again", speedef->g_id);
                        exit(1);
                }
        }
        return (sp);
}

/*
 * inform_parent()      - inform ttymon that tmchild is going to exec service
 */
static  void
inform_parent(int fd)
{
        pid_t   pid;

        pid = getpid();
        (void) write(fd, &pid, sizeof (pid));
}

static  char     pbuf[BUFSIZ];  /* static buf for TTYPROMPT     */
static  char     hbuf[BUFSIZ];  /* static buf for HOME          */
static  char     tbuf[BUFSIZ];  /* static buf for TERM          */

/*
 * void invoke_service  - invoke the service
 */

static  void
invoke_service(struct pmtab *pmtab)
{
        char     *argvp[MAXARGS];               /* service cmd args */
        int      cnt = 0;                       /* arg counter */
        int      i;
        struct   sigaction      sigact;

#ifdef  DEBUG
        debug("in invoke_service");
#endif

        if (tcgetsid(0) != getsid(getpid())) {
                cons_printf("Warning -- ttymon cannot allocate controlling "
                    "tty on \"%s\",\n", pmtab->p_device);
                cons_printf("\tThere may be another session active on this "
                    "port.\n");

                if (strcmp("/dev/console", pmtab->p_device) != 0) {
                        /*
                         * if not on console, write to stderr to warn the user
                         * also.
                         */
                        (void) fprintf(stderr, "Warning -- ttymon cannot "
                            "allocate controlling tty on \"%s\",\n",
                            pmtab->p_device);
                        (void) fprintf(stderr, "\tthere may be another session "
                            "active on this port.\n");
                }
        }

        if (pmtab->p_status != GETTY) {
                inform_parent(PCpipe[1]);
                sigact.sa_flags = 0;
                sigact.sa_handler = SIG_DFL;
                (void) sigemptyset(&sigact.sa_mask);
                (void) sigaction(SIGPOLL, &sigact, NULL);
        }

        if (pmtab->p_flags & U_FLAG) {
                if (account(pmtab->p_device) != 0) {
                        log("invoke_service: account failed");
                        exit(1);
                }
        }

        /* parse command line */
        mkargv(pmtab->p_server, &argvp[0], &cnt, MAXARGS-1);

        if (!(pmtab->p_ttyflags & C_FLAG)) {
                (void) sprintf(pbuf, "TTYPROMPT=%s", pmtab->p_prompt);
                if (putenv(pbuf)) {
                        log("cannot expand service <%s> environment", argvp[0]);
                        exit(1);
                }
        }
        if (pmtab->p_status != GETTY) {
                (void) sprintf(hbuf, "HOME=%s", pmtab->p_dir);
                if (putenv(hbuf)) {
                        log("cannot expand service <%s> environment", argvp[0]);
                        exit(1);
                }
#ifdef  DEBUG
                debug("about to run config script");
#endif
                if ((i = doconfig(0, pmtab->p_tag, 0)) != 0) {
                        if (i < 0) {
                                log("doconfig failed, system error");
                        } else {
                                log("doconfig failed on line %d of script %s",
                                    i, pmtab->p_tag);
                        }
                        exit(1);
                }
        }

        if (setgid(pmtab->p_gid)) {
                log("cannot set group id to %ld: %s", pmtab->p_gid,
                    strerror(errno));
                exit(1);
        }

        if (setuid(pmtab->p_uid)) {
                log("cannot set user id to %ld: %s", pmtab->p_uid,
                    strerror(errno));
                exit(1);
        }

        if (chdir(pmtab->p_dir)) {
                log("cannot chdir to %s: %s", pmtab->p_dir, strerror(errno));
                exit(1);
        }

        if (pmtab->p_uid != ROOTUID) {
                /* change ownership and mode of device */
                (void) fchown(0, pmtab->p_uid, Tty_gid);
                (void) fchmod(0, 0620);
        }


        if (pmtab->p_status != GETTY) {
                sigact.sa_flags = 0;
                sigact.sa_handler = SIG_DFL;
                (void) sigemptyset(&sigact.sa_mask);
                (void) sigaction(SIGINT, &sigact, NULL);
                if (setrlimit(RLIMIT_NOFILE, &Rlimit) == -1) {
                        log("setrlimit failed: %s", strerror(errno));
                        exit(1);
                }
                /* invoke the service */
                log("Starting service (%s) on %s", argvp[0], pmtab->p_device);
        }

        if (pmtab->p_termtype != (char *)NULL) {
                (void) sprintf(tbuf, "TERM=%s", pmtab->p_termtype);
                if (putenv(tbuf)) {
                        log("cannot expand service <%s> environment", argvp[0]);
                        exit(1);
                }
        }
        /* restore signal handlers and mask */
        (void) sigaction(SIGINT, &Sigint, NULL);
        (void) sigaction(SIGALRM, &Sigalrm, NULL);
        (void) sigaction(SIGPOLL, &Sigpoll, NULL);
        (void) sigaction(SIGQUIT, &Sigquit, NULL);
        (void) sigaction(SIGCLD, &Sigcld, NULL);
        (void) sigaction(SIGTERM, &Sigterm, NULL);
#ifdef  DEBUG
        (void) sigaction(SIGUSR1, &Sigusr1, NULL);
        (void) sigaction(SIGUSR2, &Sigusr2, NULL);
#endif
        (void) sigprocmask(SIG_SETMASK, &Origmask, NULL);
        (void) execve(argvp[0], argvp, environ);

        /* exec returns only on failure! */
        log("tmchild: exec service failed: %s", strerror(errno));
        exit(1);
}

/*
 *      check_hup(fd)   - do a poll on fd to check if it is in hangup state
 *                      - return 1 if hangup, otherwise return 0
 */

static  int
check_hup(int fd)
{
        int     ret;
        struct  pollfd  pfd[1];

        pfd[0].fd = fd;
        pfd[0].events = POLLHUP;
        for (;;) {
                ret = poll(pfd, 1, 0);
                if (ret < 0) {
                        if (errno == EINTR)
                                continue;
                        log("check_hup: poll failed: %s", strerror(errno));
                        exit(1);
                } else if (ret > 0) {
                        if (pfd[0].revents & POLLHUP) {
                                return (1);
                        }
                }
                return (0);
        }
}

/*
 * sigpoll()    - SIGPOLL handle for tmchild
 *              - when SIGPOLL is received by tmchild,
 *                the pipe between ttymon and tmchild is broken.
 *                Something must happen to ttymon.
 */
void
sigpoll(int s __unused)
{
#ifdef  DEBUG
        debug("tmchild got SIGPOLL, exiting");
#endif
        exit(1);
}