/*
 * 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.
 */

/*
 * VNTSD main
 *
 * VNTSD takes the following options:
 * -i   <device instance>
 *      VCC device instance to use, e.g. virtual-console-concentrator@0.
 *      Required option.
 * -p   <ip address>
 *      IP address VNTSD listens to.
 * -d
 *      Do not daemonize. This is only available in a DEBUG build.
 * -t   timeout for inactivity 0 = indefinite
 * -A   enable Authorization checking. Mutually exclusive with -p.
 */

#include <stdio.h>
#include <stdio_ext.h>
#include <sys/types.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <time.h>
#include <netinet/in.h>
#include <thread.h>
#include <signal.h>
#include <fcntl.h>
#include <ctype.h>
#include <libintl.h>
#include <locale.h>
#include <syslog.h>
#include <sys/socket.h>
#include <netdb.h>
#include "vntsd.h"
#include "chars.h"

#if !defined(TEXT_DOMAIN)       /* Should be defined by cc -D */
#define TEXT_DOMAIN "SYS_TEST"  /* Use this only if it weren't. */
#endif

/* global variables */

#ifdef DEBUG
int vntsddbg = 0x8;
#endif

#define MINUTE          60

#define VNTSD_INVALID_LISTEN_ADDR           ((in_addr_t)-1)

#define LOCALHOST_IPv4  "127.0.0.1"
#define LOCALHOST_IPv6  "::1"

static vntsd_t *vntsdp;


static void vntsd_exit(void);
/* Signal handler for SIGINT, SIGKILL and SIGHUP */
static void
exit_sig_handler(int sig)
{

        D1(stderr, "t@%d exit_sig_handler%d \n", thr_self(), sig);

        if (thr_self() != vntsdp->tid) {
                /* not main thread, pass to main thread */
                (void) thr_kill(vntsdp->tid, sig);
        } else {
                exit(0);
        }
}

/*
 * Before a thread reads in client's input, it attaches to vntsd timer so that
 * it can be waken up if a client does not access the connection for
 * VNTSD_INPUT_TIMEOUT(10) minutes.
 */

/* attach a thread to timer */
int
vntsd_attach_timer(vntsd_timeout_t *tmop)
{
        int     rv;

        if (vntsdp->timeout == 0) {
                return (VNTSD_SUCCESS);
        }

        (void) mutex_lock(&vntsdp->tmo_lock);
        rv = vntsd_que_append(&vntsdp->tmoq, (void *)tmop);
        (void) mutex_unlock(&vntsdp->tmo_lock);
        return (rv);
}

/* detach a thread from timer */
int
vntsd_detach_timer(vntsd_timeout_t *tmop)
{
        int     rv;

        if (vntsdp->timeout == 0) {
                return (VNTSD_SUCCESS);
        }

        (void) mutex_lock(&vntsdp->tmo_lock);
        rv = vntsd_que_rm(&vntsdp->tmoq, (void *)tmop);
        (void) mutex_unlock(&vntsdp->tmo_lock);

        return (rv);
}

/* check threadd's timeout */
static boolean_t
chk_timeout(vntsd_timeout_t *tmop)
{
        tmop->minutes++;

        if (tmop->minutes == vntsdp->timeout) {
                /* wake up the thread */
                tmop->clientp->status |= VNTSD_CLIENT_TIMEOUT;
                (void) thr_kill(tmop->tid, SIGALRM);
        }

        /* return false to walk the queue */
        return (B_FALSE);
}

/* reset timer */
static int
reset_timeout(void *arg1, void *arg2)
{
        vntsd_timeout_t *tmop = arg1;
        thread_t tid = (uintptr_t)arg2;

        if (tmop->tid == tid) {
                tmop->minutes = 0;
        }
        /* return false to walk the queue */
        return (B_FALSE);
}

void
vntsd_reset_timer(thread_t tid)
{
        if (vntsdp->timeout == 0) {
                return;
        }

        (void) mutex_lock(&vntsdp->tmo_lock);
        (void) vntsd_que_find(vntsdp->tmoq, reset_timeout,
            (void *)(uintptr_t)tid);
        (void) mutex_unlock(&vntsdp->tmo_lock);
}

/*
 * When alarm goes off, wake up timeout threads. Alarm is set off every
 * minutes.
 */
static void
vntsd_alarm_sig_handler(int sig)
{
        static thread_t main_thread = 0;

        D1(stderr, "t@%d alarm signal %d\n", thr_self(), sig);
        if (vntsdp->timeout == 0) {
                DERR(stderr, "t@%d alarm signal should not recv %d\n",
                    thr_self(), sig);
                return;
        }


        if (main_thread == 0) {
                /* initialize thread id  */
                main_thread = thr_self();
        } else if (main_thread != thr_self()) {
                /* get signal because thread is timeout */
                return;
        }

        /* in main thread */
        (void) mutex_lock(&vntsdp->tmo_lock);

        /* wake up timeout threads */
        (void) vntsd_que_walk(vntsdp->tmoq, (el_func_t)chk_timeout);
        (void) mutex_unlock(&vntsdp->tmo_lock);

        /* reset alarm */
        (void) alarm(MINUTE);
}

/* got a  SIGUSER1 siginal */
static void
vntsd_sig_handler(int sig)
{
        char err_msg[VNTSD_LINE_LEN];

        (void) snprintf(err_msg, sizeof (err_msg), "sig_handler() sig=%d",
            sig);

        if (sig != SIGUSR1) {
                vntsd_log(VNTSD_STATUS_SIG, err_msg);
        }
}

/* vntsd exits */
static void
vntsd_exit(void)
{
        D1(stderr, "t@%d vntsd_exit\n", thr_self());

        (void) mutex_lock(&vntsdp->lock);

        if (vntsdp->timeout > 0) {
                /* cancel the timer */
                (void) alarm(0);
        }
        /* delete all  groups */
        vntsd_free_que(&vntsdp->grouppq, (clean_func_t)vntsd_clean_group);

        /* close control port */
        (void) close(vntsdp->ctrl_fd);

        assert(vntsdp->tmoq == NULL);
        (void) mutex_unlock(&vntsdp->lock);

        /* clean up vntsdp */
        (void) mutex_destroy(&vntsdp->tmo_lock);
        (void) mutex_destroy(&vntsdp->lock);
        free(vntsdp);
        closelog();
}

/*
 * vntsd_help()
 * print out valid command line options
 */
static void
vntsd_help(void)
{
        (void) fprintf(stderr, gettext("Usage: vntsd -i <VCC device instance> "
            "[-p <listen address>] [-t <timeout in minutes>] [-A]\n"));
}

/*
 * get_listen_ip_addr()
 * check for a valid control domain ip address in format of xxx.xxx.xxx.xxx.
 * if ip address is valid and is assigned to this host, return ip address
 * or else return VNTSD_INVALID_LISTEN_ADDR.
 */
static in_addr_t
get_listen_ip_addr(char *listen_addr)
{
        char host_name[MAXPATHLEN];
        in_addr_t addr;
        struct addrinfo hints;
        struct addrinfo *res, *infop;
        int err;
        struct sockaddr_in *sa;

        if (gethostname(host_name, MAXPATHLEN) != 0) {
                syslog(LOG_ERR, "Can not get host name!");
                return (VNTSD_INVALID_LISTEN_ADDR);
        }

        if ((int)(addr = inet_addr(listen_addr)) == -1)
                /* bad IP address format */
                return (VNTSD_INVALID_LISTEN_ADDR);

        bzero(&hints, sizeof (hints));
        hints.ai_family = PF_INET;
        hints.ai_socktype = SOCK_STREAM;

        err = getaddrinfo(host_name, NULL, &hints, &res);
        if (err != 0) {
                syslog(LOG_ERR, "getaddrinfo failed: %s", gai_strerror(err));
                return (VNTSD_INVALID_LISTEN_ADDR);
        }

        infop = res;
        while (infop != NULL) {
                /* LINTED E_BAD_PTR_CAST_ALIGN */
                sa = (struct sockaddr_in *)infop->ai_addr;
                if (sa->sin_addr.s_addr == addr) {
                        /* ip address found */
                        freeaddrinfo(res);
                        return (addr);
                }
                infop = infop->ai_next;
        }

        /* ip address not found */
        freeaddrinfo(res);
        return (VNTSD_INVALID_LISTEN_ADDR);
}

#ifdef DEBUG
#define DEBUG_OPTIONS   "d"
#else
#define DEBUG_OPTIONS   ""
#endif

int
main(int argc, char ** argv)
{
        char        *path;
        struct      pollfd poll_drv[1];
        struct      sigaction act;
        struct      rlimit rlim;
        char        *listen_addr = NULL;
        pid_t       pid;
        int         i;
        int         option;
        int         sz;
        int         fd;
        int         n;

        /* internationalization */
        (void) setlocale(LC_MESSAGES, "");
        (void) textdomain(TEXT_DOMAIN);
        vntsd_init_esctable_msgs();

        /* initialization */
        bzero(&act, sizeof (act));

        /*
         * ensure that we can obtain sufficient file descriptors for all
         * the accept() calls when a machine contains many domains.
         */
        (void) getrlimit(RLIMIT_NOFILE, &rlim);
        if (rlim.rlim_cur < rlim.rlim_max)
                rlim.rlim_cur = rlim.rlim_max;
        if (setrlimit(RLIMIT_NOFILE, &rlim) < 0)
                vntsd_log(VNTSD_STATUS_CONTINUE, "Unable to increase file "
                    "descriptor limit.");
        (void) enable_extended_FILE_stdio(-1, -1);

        vntsdp = calloc(1, sizeof (vntsd_t));
        if (vntsdp == NULL) {
                vntsd_log(VNTSD_ERR_NO_MEM, "main:vntsdp");
                exit(1);
        }

        vntsdp->ctrl_fd = -1;
        vntsdp->devinst = NULL;

        (void) mutex_init(&vntsdp->lock, USYNC_THREAD|LOCK_ERRORCHECK, NULL);
        (void) mutex_init(&vntsdp->tmo_lock, USYNC_THREAD|LOCK_ERRORCHECK,
            NULL);

        /* get CLI options */
        while ((option = getopt(argc, argv, "i:t:p:A"DEBUG_OPTIONS)) != EOF) {
                switch (option) {
#ifdef DEBUG
                case 'd':
                        vntsdp->options |= VNTSD_OPT_DAEMON_OFF;
                        break;
#endif
                case 'i':
                        vntsdp->devinst = optarg;
                        break;
                case 'p':
                        listen_addr = optarg;
                        break;

                case 't':
                        n = sscanf(optarg, "%d", &(vntsdp->timeout));
                        if (n  != 1) {
                                vntsdp->timeout = -1;
                        }
                        break;

                case 'A':
                        /*
                         * This option enables authorization checking of the
                         * user for the console(s) being accessed. As the
                         * authorization checking can be done only for a local
                         * client process, it requires that vntsd listen only
                         * on the loopback address. It means while this option
                         * is enabled, vntsd cannot listen on either INADDR_ANY
                         * or a specific ip address and thus the telnet client
                         * must also run on the local machine in order to
                         * connect to vntsd. The '-p' option if specified while
                         * this option is enabled, will be ignored and the auth
                         * checking takes precedence forcing vntsd to listen on
                         * the loopback interface.
                         */
                        vntsdp->options |= VNTSD_OPT_AUTH_CHECK;
                        break;

                default:
                        vntsd_help();
                        exit(1);
                }
        }

        if ((vntsdp->devinst == NULL) || (vntsdp->timeout == -1)) {
                vntsd_help();
                exit(1);
        }

        if (listen_addr == NULL || strcmp(listen_addr, "localhost") == 0 ||
            strcmp(listen_addr, LOCALHOST_IPv4) == 0 ||
            strcmp(listen_addr, LOCALHOST_IPv6) == 0) {
                /* by default listen on loopback interface */
                vntsdp->ip_addr.s_addr = htonl(INADDR_LOOPBACK);
        } else if ((vntsdp->options & VNTSD_OPT_AUTH_CHECK) != 0) {
                vntsd_log(VNTSD_STATUS_AUTH_ENABLED,
                    "Listen address ignored as authorization checking "
                    "is enabled");
                vntsdp->ip_addr.s_addr = htonl(INADDR_LOOPBACK);
        } else if (strcmp(listen_addr, "any") == 0) {
                vntsdp->ip_addr.s_addr = htonl(INADDR_ANY);
        } else {
                vntsdp->ip_addr.s_addr = get_listen_ip_addr(listen_addr);
                if (vntsdp->ip_addr.s_addr == VNTSD_INVALID_LISTEN_ADDR) {
                        syslog(LOG_ERR,
                            "Invalid listen address '%s'\n",
                            listen_addr);
                        exit(2);
                }
        }

        D3(stderr, "options = %llx, instance = %s, listen = %s\n",
            vntsdp->options, vntsdp->devinst,
            listen_addr ? listen_addr : "<null>");

        /* open VCC driver control port */
        sz = strlen(VCC_DEVICE_CTL_PATH) + strlen(vntsdp->devinst) + 1;
        path = calloc(sz, 1);
        if (path == NULL) {
                vntsd_log(VNTSD_ERR_NO_MEM, "main(): alloc dev path");
                exit(1);
        }
        (void) snprintf(path, sz-1, VCC_DEVICE_CTL_PATH, vntsdp->devinst,
            sizeof (vntsdp->devinst));
        vntsdp->ctrl_fd = open(path, O_RDWR);

        if (vntsdp->ctrl_fd == -1) {
                /* print error if device is not present */
                syslog(LOG_ERR,
                    "Error opening VCC device control port: %s",
                    path);
                /* tell SMF no retry */
                exit(2);
        }

        free(path);

        if ((vntsdp->options & VNTSD_OPT_DAEMON_OFF) == 0) {
                /* daemonize it */
                pid = fork();
                if (pid < 0) {
                        perror("fork");
                        exit(1);
                }
                if (pid > 0) {
                        /* parent */
                        exit(0);
                }

                /*
                 * child process (daemon)
                 *
                 * Close all file descriptors other than 2 and the ctrl fd.
                 */
                (void) close(0);
                (void) close(1);
                for (i = 3; i < vntsdp->ctrl_fd; i++) {
                        (void) close(i);
                }
                closefrom(vntsdp->ctrl_fd + 1);

                /* obtain a new process group */
                (void) setsid();
                fd =  open("/dev/null", O_RDWR);
                if (fd < 0) {
                        syslog(LOG_ERR, "Can not open /dev/null");
                        exit(1);
                }
                /* handle standard I/O */
                if (dup2(fd, 0) < 0) {
                        syslog(LOG_ERR, "Failed dup2()");
                        exit(1);
                }

                if (dup2(fd, 1) < 0) {
                        syslog(LOG_ERR, "Failed dup2()");
                        exit(1);
                }

                /* ignore terminal signals */
                (void) signal(SIGTSTP, SIG_IGN);
                (void) signal(SIGTTOU, SIG_IGN);
                (void) signal(SIGTTIN, SIG_IGN);
        }


        /* set up signal handlers */

        /* exit signals */
        act.sa_handler = exit_sig_handler;

        (void) sigemptyset(&act.sa_mask);
        (void) sigaction(SIGINT, &act, NULL);
        (void) sigaction(SIGTERM, &act, NULL);
        (void) sigaction(SIGHUP, &act, NULL);

        /* vntsd internal signals */
        act.sa_handler = vntsd_sig_handler;
        (void) sigemptyset(&act.sa_mask);
        (void) sigaction(SIGUSR1, &act, NULL);


        act.sa_handler = vntsd_alarm_sig_handler;
        (void) sigemptyset(&act.sa_mask);
        (void) sigaction(SIGALRM, &act, NULL);


        /* setup exit */
        (void) atexit(vntsd_exit);



        /* initialization */
        openlog("vntsd", LOG_CONS, LOG_DAEMON);


        /* set alarm */
        if (vntsdp->timeout > 0) {
                (void) alarm(MINUTE);
        }

        vntsdp->tid = thr_self();

        /* get exiting consoles from vcc */
        vntsd_get_config(vntsdp);

        for (; ; ) {
                /* poll vcc for configuration change */
                bzero(poll_drv, sizeof (poll_drv));

                poll_drv[0].fd = vntsdp->ctrl_fd;
                poll_drv[0].events = POLLIN;

                if (poll(poll_drv, 1, -1) == -1) {
                        if (errno == EINTR) {
                                /* wake up because a consle was deleted */
                                vntsd_delete_cons(vntsdp);
                                continue;
                        }
                        vntsd_log(VNTSD_ERR_VCC_POLL,
                            "vcc control poll err! aborting..");
                        exit(1);
                }

                D1(stderr, "t@%d driver event %x\n", thr_self(),
                    poll_drv[0].revents);

                vntsd_daemon_wakeup(vntsdp);
                /*
                 * Main thread may miss a console-delete signal when it is
                 * not polling vcc. check if any console is deleted.
                 */
                vntsd_delete_cons(vntsdp);

        }

        /*NOTREACHED*/
        return (0);
}

/* export ip_addr */
struct in_addr
vntsd_ip_addr(void)
{
        return (vntsdp->ip_addr);
}

/*
 * ioctl to vcc control port
 * Supported ioctls interface are:
 *              ioctl code          parameters     return data
 *              VCC_NUM_CONSOLE     none           uint_t  no consoles
 *              VCC_CONS_TBL        none           array of vcc_cons_t
 *              VCC_INQUIRY         none           vcc_response_t response
 *              VCC_CONS_INFO       uint_t portno   vcc_cons_t
 *              VCC_CONS_STATUS     uint_t portno
 *              VCC_FORCE_CLOSE     uint_t portno
 */
int
vntsd_vcc_ioctl(int ioctl_code, uint_t portno, void *buf)
{
        D1(stderr, "t@%d vcc_ioctl@%d code=%x\n", thr_self(), portno,
            ioctl_code);

        if ((ioctl_code == (VCC_CONS_INFO)) ||
            (ioctl_code == (VCC_FORCE_CLOSE))) {
                /* construct vcc in buf */
                *((uint_t *)buf) = portno;
        }

        if (ioctl(vntsdp->ctrl_fd, ioctl_code, (caddr_t)buf)) {
                /*  ioctl request error */
                return (VNTSD_STATUS_VCC_IO_ERR);
        }

        return (VNTSD_SUCCESS);
}

/*
 * check if a vcc i/o error is caused by removal of a console. If so
 * wake up main thread to cleanup the console.
 */
int
vntsd_vcc_err(vntsd_cons_t *consp)
{
        vntsd_group_t *groupp;

        assert(consp);
        groupp = consp->group;
        assert(groupp);

        if (consp->status & VNTSD_CONS_DELETED) {
                /* console was deleted  */
                return (VNTSD_STATUS_VCC_IO_ERR);
        }

        if (vntsd_vcc_cons_alive(consp)) {
                /* console is ok */
                return (VNTSD_STATUS_CONTINUE);
        }

        /* console needs to be deleted */
        (void) mutex_lock(&consp->lock);
        consp->status |= VNTSD_CONS_DELETED;

        /*
         * main thread will close all clients after receiving console
         * delete signal.
         */
        (void) mutex_unlock(&consp->lock);

        /* mark the group */
        (void) mutex_lock(&groupp->lock);
        groupp->status |= VNTSD_GROUP_CLEAN_CONS;
        (void) mutex_unlock(&groupp->lock);

        /* signal main thread to deleted console */
        (void) thr_kill(vntsdp->tid, SIGUSR1);

        return (VNTSD_STATUS_VCC_IO_ERR);
}