/*
 * 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 2012 Joyent, Inc.  All rights reserved.
 * Copyright 2015 Nexenta Systems, Inc. All rights reserved.
 */

/*
 * Console support for zones requires a significant infrastructure.  The
 * core pieces are contained in this file, but other portions of note
 * are in the zlogin(1) command, the zcons(4D) driver, and in the
 * devfsadm(8) misc_link generator.
 *
 * Care is taken to make the console behave in an "intuitive" fashion for
 * administrators.  Essentially, we try as much as possible to mimic the
 * experience of using a system via a tip line and system controller.
 *
 * The zone console architecture looks like this:
 *
 *                                      Global Zone | Non-Global Zone
 *                        .--------------.          |
 *        .-----------.   | zoneadmd -z  |          | .--------. .---------.
 *        | zlogin -C |   |     myzone   |          | | ttymon | | syslogd |
 *        `-----------'   `--------------'          | `--------' `---------'
 *                  |       |       | |             |      |       |
 *  User            |       |       | |             |      V       V
 * - - - - - - - - -|- - - -|- - - -|-|- - - - - - -|- - /dev/zconsole - - -
 *  Kernel          V       V       | |                        |
 *               [AF_UNIX Socket]   | `--------. .-------------'
 *                                  |          | |
 *                                  |          V V
 *                                  |     +-----------+
 *                                  |     |  ldterm,  |
 *                                  |     |   etc.    |
 *                                  |     +-----------+
 *                                  |     +-[Anchor]--+
 *                                  |     |   ptem    |
 *                                  V     +-----------+
 *                           +---manager--+-subsidiary+
 *                           |                        |
 *                           |      zcons driver      |
 *                           |    zonename="myzone"   |
 *                           +------------------------+
 *
 * There are basically two major tasks which the console subsystem in
 * zoneadmd accomplishes:
 *
 * - Setup and teardown of zcons driver instances.  One zcons instance
 *   is maintained per zone; we take advantage of the libdevice APIs
 *   to online new instances of zcons as needed.  Care is taken to
 *   prune and manage these appropriately; see init_console_dev() and
 *   destroy_console_dev().  The end result is the creation of the
 *   zcons(4D) instance and an open file descriptor to the manager side.
 *   zcons instances are associated with zones via their zonename device
 *   property.  This the console instance to persist across reboots,
 *   and while the zone is halted.
 *
 * - Acting as a server for 'zlogin -C' instances.  When zlogin -C is
 *   run, zlogin connects to zoneadmd via unix domain socket.  zoneadmd
 *   functions as a two-way proxy for console I/O, relaying user input
 *   to the manager side of the console, and relaying output from the
 *   zone to the user.
 */

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/termios.h>
#include <sys/zcons.h>
#include <sys/mkdev.h>

#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <stropts.h>
#include <thread.h>
#include <ucred.h>
#include <unistd.h>
#include <zone.h>

#include <libdevinfo.h>
#include <libdevice.h>
#include <libzonecfg.h>

#include <syslog.h>
#include <sys/modctl.h>

#include "zoneadmd.h"

#define ZCONSNEX_DEVTREEPATH    "/pseudo/zconsnex@1"
#define ZCONSNEX_FILEPATH       "/devices/pseudo/zconsnex@1"

#define CONSOLE_SOCKPATH        ZONES_TMPDIR "/%s.console_sock"

static int      serverfd = -1;  /* console server unix domain socket fd */
char boot_args[BOOTARGS_MAX];
char bad_boot_arg[BOOTARGS_MAX];

/*
 * The eventstream is a simple one-directional flow of messages from the
 * door server to the console subsystem, implemented with a pipe.
 * It is used to wake up the console poller when it needs to take action,
 * message the user, die off, etc.
 */
static int eventstream[2];



int
eventstream_init()
{
        if (pipe(eventstream) == -1)
                return (-1);
        return (0);
}

void
eventstream_write(zone_evt_t evt)
{
        (void) write(eventstream[0], &evt, sizeof (evt));
}

static zone_evt_t
eventstream_read(void)
{
        zone_evt_t evt = Z_EVT_NULL;

        (void) read(eventstream[1], &evt, sizeof (evt));
        return (evt);
}

/*
 * count_console_devs() and its helper count_cb() do a walk of the
 * subtree of the device tree where zone console nodes are represented.
 * The goal is to count zone console instances already setup for a zone
 * with the given name.  More than 1 is anomolous, and our caller will
 * have to deal with that if we find that's the case.
 *
 * Note: this algorithm is a linear search of nodes in the zconsnex subtree
 * of the device tree, and could be a scalability problem, but I don't see
 * how to avoid it.
 */

/*
 * cb_data is shared by count_cb and destroy_cb for simplicity.
 */
struct cb_data {
        zlog_t *zlogp;
        int found;
        int killed;
};

static int
count_cb(di_node_t node, void *arg)
{
        struct cb_data *cb = (struct cb_data *)arg;
        char *prop_data;

        if (di_prop_lookup_strings(DDI_DEV_T_ANY, node, "zonename",
            &prop_data) != -1) {
                assert(prop_data != NULL);
                if (strcmp(prop_data, zone_name) == 0) {
                        cb->found++;
                        return (DI_WALK_CONTINUE);
                }
        }
        return (DI_WALK_CONTINUE);
}

static int
count_console_devs(zlog_t *zlogp)
{
        di_node_t root;
        struct cb_data cb;

        bzero(&cb, sizeof (cb));
        cb.zlogp = zlogp;

        if ((root = di_init(ZCONSNEX_DEVTREEPATH, DINFOCPYALL)) ==
            DI_NODE_NIL) {
                zerror(zlogp, B_TRUE, "%s failed", "di_init");
                return (-1);
        }

        (void) di_walk_node(root, DI_WALK_CLDFIRST, (void *)&cb, count_cb);
        di_fini(root);
        return (cb.found);
}

/*
 * destroy_console_devs() and its helper destroy_cb() tears down any console
 * instances associated with this zone.  If things went very wrong, we
 * might have more than one console instance hanging around.  This routine
 * hunts down and tries to remove all of them.  Of course, if the console
 * is open, the instance will not detach, which is a potential issue.
 */
static int
destroy_cb(di_node_t node, void *arg)
{
        struct cb_data *cb = (struct cb_data *)arg;
        char *prop_data;
        char *tmp;
        char devpath[MAXPATHLEN];
        devctl_hdl_t hdl;

        if (di_prop_lookup_strings(DDI_DEV_T_ANY, node, "zonename",
            &prop_data) == -1)
                return (DI_WALK_CONTINUE);

        assert(prop_data != NULL);
        if (strcmp(prop_data, zone_name) != 0) {
                /* this is the console for a different zone */
                return (DI_WALK_CONTINUE);
        }

        cb->found++;
        tmp = di_devfs_path(node);
        (void) snprintf(devpath, sizeof (devpath), "/devices/%s", tmp);
        di_devfs_path_free(tmp);

        if ((hdl = devctl_device_acquire(devpath, 0)) == NULL) {
                zerror(cb->zlogp, B_TRUE, "WARNING: console %s found, "
                    "but it could not be controlled.", devpath);
                return (DI_WALK_CONTINUE);
        }
        if (devctl_device_remove(hdl) == 0) {
                cb->killed++;
        } else {
                zerror(cb->zlogp, B_TRUE, "WARNING: console %s found, "
                    "but it could not be removed.", devpath);
        }
        devctl_release(hdl);
        return (DI_WALK_CONTINUE);
}

static int
destroy_console_devs(zlog_t *zlogp)
{
        char conspath[MAXPATHLEN];
        di_node_t root;
        struct cb_data cb;
        int managerfd;
        int subfd;

        /*
         * Signal the manager side to release its handle on the subsidiary side
         * by issuing a ZC_RELEASESUBSID ioctl.
         */
        (void) snprintf(conspath, sizeof (conspath), "/dev/zcons/%s/%s",
            zone_name, ZCONS_MANAGER_NAME);
        if ((managerfd = open(conspath, O_RDWR | O_NOCTTY)) != -1) {
                (void) snprintf(conspath, sizeof (conspath), "/dev/zcons/%s/%s",
                    zone_name, ZCONS_SUBSIDIARY_NAME);
                if ((subfd = open(conspath, O_RDWR | O_NOCTTY)) != -1) {
                        if (ioctl(managerfd, ZC_RELEASESUBSID,
                            (caddr_t)(intptr_t)subfd) != 0)
                                zerror(zlogp, B_TRUE, "WARNING: error while "
                                    "releasing subsidiary handle of zone "
                                    "console for %s", zone_name);
                        (void) close(subfd);
                } else {
                        zerror(zlogp, B_TRUE, "WARNING: could not open "
                            "subsidiary side of zone console for %s to "
                            "release subsidiary handle", zone_name);
                }
                (void) close(managerfd);
        } else {
                zerror(zlogp, B_TRUE, "WARNING: could not open manager side of "
                    "zone console for %s to release subsidiary handle",
                    zone_name);
        }

        bzero(&cb, sizeof (cb));
        cb.zlogp = zlogp;

        if ((root = di_init(ZCONSNEX_DEVTREEPATH, DINFOCPYALL)) ==
            DI_NODE_NIL) {
                zerror(zlogp, B_TRUE, "%s failed", "di_init");
                return (-1);
        }

        (void) di_walk_node(root, DI_WALK_CLDFIRST, (void *)&cb, destroy_cb);
        if (cb.found > 1) {
                zerror(zlogp, B_FALSE, "WARNING: multiple zone console "
                    "instances detected for zone '%s'; %d of %d "
                    "successfully removed.",
                    zone_name, cb.killed, cb.found);
        }

        di_fini(root);
        return (0);
}

/*
 * init_console_dev() drives the device-tree configuration of the zone
 * console device.  The general strategy is to use the libdevice (devctl)
 * interfaces to instantiate a new zone console node.  We do a lot of
 * sanity checking, and are careful to reuse a console if one exists.
 *
 * Once the device is in the device tree, we kick devfsadm via di_init_devs()
 * to ensure that the appropriate symlinks (to the manager and subsidiary
 * console devices) are placed in /dev in the global zone.
 */
static int
init_console_dev(zlog_t *zlogp)
{
        char conspath[MAXPATHLEN];
        devctl_hdl_t bus_hdl = NULL;
        devctl_hdl_t dev_hdl = NULL;
        devctl_ddef_t ddef_hdl = NULL;
        di_devlink_handle_t dl = NULL;
        int rv = -1;
        int ndevs;
        int managerfd;
        int subfd;
        int i;

        /*
         * Don't re-setup console if it is working and ready already; just
         * skip ahead to making devlinks, which we do for sanity's sake.
         */
        ndevs = count_console_devs(zlogp);
        if (ndevs == 1) {
                goto devlinks;
        } else if (ndevs > 1 || ndevs == -1) {
                /*
                 * For now, this seems like a reasonable but harsh punishment.
                 * If needed, we could try to get clever and delete all but
                 * the console which is pointed at by the current symlink.
                 */
                if (destroy_console_devs(zlogp) == -1) {
                        goto error;
                }
        }

        /*
         * Time to make the consoles!
         */
        if ((bus_hdl = devctl_bus_acquire(ZCONSNEX_FILEPATH, 0)) == NULL) {
                zerror(zlogp, B_TRUE, "%s failed", "devctl_bus_acquire");
                goto error;
        }
        if ((ddef_hdl = devctl_ddef_alloc("zcons", 0)) == NULL) {
                zerror(zlogp, B_TRUE, "failed to allocate ddef handle");
                goto error;
        }
        /*
         * Set three properties on this node; the first is the name of the
         * zone; the second is a flag which lets pseudo know that it is
         * OK to automatically allocate an instance # for this device;
         * the third tells the device framework not to auto-detach this
         * node-- we need the node to still be there when we ask devfsadmd
         * to make links, and when we need to open it.
         */
        if (devctl_ddef_string(ddef_hdl, "zonename", zone_name) == -1) {
                zerror(zlogp, B_TRUE, "failed to create zonename property");
                goto error;
        }
        if (devctl_ddef_int(ddef_hdl, "auto-assign-instance", 1) == -1) {
                zerror(zlogp, B_TRUE, "failed to create auto-assign-instance "
                    "property");
                goto error;
        }
        if (devctl_ddef_int(ddef_hdl, "ddi-no-autodetach", 1) == -1) {
                zerror(zlogp, B_TRUE, "failed to create ddi-no-auto-detach "
                    "property");
                goto error;
        }
        if (devctl_bus_dev_create(bus_hdl, ddef_hdl, 0, &dev_hdl) == -1) {
                zerror(zlogp, B_TRUE, "failed to create console node");
                goto error;
        }

devlinks:
        if ((dl = di_devlink_init("zcons", DI_MAKE_LINK)) != NULL) {
                (void) di_devlink_fini(&dl);
        } else {
                zerror(zlogp, B_TRUE, "failed to create devlinks");
                goto error;
        }

        /*
         * Open the manager side of the console and issue the ZC_HOLDSUBSID
         * ioctl, which will cause the manager to retain a reference to the
         * subsidiary.  This prevents ttymon from blowing through the
         * subsidiary's STREAMS anchor.
         */
        (void) snprintf(conspath, sizeof (conspath), "/dev/zcons/%s/%s",
            zone_name, ZCONS_MANAGER_NAME);
        if ((managerfd = open(conspath, O_RDWR | O_NOCTTY)) == -1) {
                zerror(zlogp, B_TRUE, "ERROR: could not open manager side of "
                    "zone console for %s to acquire subsidiary handle",
                    zone_name);
                goto error;
        }
        (void) snprintf(conspath, sizeof (conspath), "/dev/zcons/%s/%s",
            zone_name, ZCONS_SUBSIDIARY_NAME);
        if ((subfd = open(conspath, O_RDWR | O_NOCTTY)) == -1) {
                zerror(zlogp, B_TRUE, "ERROR: could not open subsidiary side "
                    "of zone console for %s to acquire subsidiary handle",
                    zone_name);
                (void) close(managerfd);
                goto error;
        }
        /*
         * This ioctl can occasionally return ENXIO if devfs doesn't have
         * everything plumbed up yet due to heavy zone startup load. Wait for
         * 1 sec. and retry a few times before we fail to boot the zone.
         */
        for (i = 0; i < 5; i++) {
                if (ioctl(managerfd, ZC_HOLDSUBSID, (caddr_t)(intptr_t)subfd)
                    == 0) {
                        rv = 0;
                        break;
                } else if (errno != ENXIO) {
                        break;
                }
                (void) sleep(1);
        }
        if (rv != 0)
                zerror(zlogp, B_TRUE, "ERROR: error while acquiring "
                    "subsidiary handle of zone console for %s", zone_name);

        (void) close(subfd);
        (void) close(managerfd);

error:
        if (ddef_hdl)
                devctl_ddef_free(ddef_hdl);
        if (bus_hdl)
                devctl_release(bus_hdl);
        if (dev_hdl)
                devctl_release(dev_hdl);
        return (rv);
}

static int
init_console_sock(zlog_t *zlogp)
{
        int servfd;
        struct sockaddr_un servaddr;

        bzero(&servaddr, sizeof (servaddr));
        servaddr.sun_family = AF_UNIX;
        (void) snprintf(servaddr.sun_path, sizeof (servaddr.sun_path),
            CONSOLE_SOCKPATH, zone_name);

        if ((servfd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) {
                zerror(zlogp, B_TRUE, "console setup: could not create socket");
                return (-1);
        }
        (void) unlink(servaddr.sun_path);

        if (bind(servfd, (struct sockaddr *)&servaddr,
            sizeof (servaddr)) == -1) {
                zerror(zlogp, B_TRUE,
                    "console setup: could not bind to socket");
                goto out;
        }

        if (listen(servfd, 4) == -1) {
                zerror(zlogp, B_TRUE,
                    "console setup: could not listen on socket");
                goto out;
        }
        return (servfd);

out:
        (void) unlink(servaddr.sun_path);
        (void) close(servfd);
        return (-1);
}

static void
destroy_console_sock(int servfd)
{
        char path[MAXPATHLEN];

        (void) snprintf(path, sizeof (path), CONSOLE_SOCKPATH, zone_name);
        (void) unlink(path);
        (void) shutdown(servfd, SHUT_RDWR);
        (void) close(servfd);
}

/*
 * Read the "ident" string from the client's descriptor; this routine also
 * tolerates being called with pid=NULL, for times when you want to "eat"
 * the ident string from a client without saving it.
 */
static int
get_client_ident(int clifd, pid_t *pid, char *locale, size_t locale_len,
    int *disconnect)
{
        char buf[BUFSIZ], *bufp;
        size_t buflen = sizeof (buf);
        char c = '\0';
        int i = 0, r;

        /* "eat up the ident string" case, for simplicity */
        if (pid == NULL) {
                assert(locale == NULL && locale_len == 0);
                while (read(clifd, &c, 1) == 1) {
                        if (c == '\n')
                                return (0);
                }
        }

        bzero(buf, sizeof (buf));
        while ((buflen > 1) && (r = read(clifd, &c, 1)) == 1) {
                buflen--;
                if (c == '\n')
                        break;

                buf[i] = c;
                i++;
        }
        if (r == -1)
                return (-1);

        /*
         * We've filled the buffer, but still haven't seen \n.  Keep eating
         * until we find it; we don't expect this to happen, but this is
         * defensive.
         */
        if (c != '\n') {
                while ((r = read(clifd, &c, sizeof (c))) > 0)
                        if (c == '\n')
                                break;
        }

        /*
         * Parse buffer for message of the form:
         * IDENT <pid> <locale> <disconnect flag>
         */
        bufp = buf;
        if (strncmp(bufp, "IDENT ", 6) != 0)
                return (-1);
        bufp += 6;
        errno = 0;
        *pid = strtoll(bufp, &bufp, 10);
        if (errno != 0)
                return (-1);

        while (*bufp != '\0' && isspace(*bufp))
                bufp++;
        buflen = strlen(bufp) - 1;
        *disconnect = atoi(&bufp[buflen]);
        bufp[buflen - 1] = '\0';
        (void) strlcpy(locale, bufp, locale_len);

        return (0);
}

static int
accept_client(int servfd, pid_t *pid, char *locale, size_t locale_len,
    int *disconnect)
{
        int connfd;
        struct sockaddr_un cliaddr;
        socklen_t clilen;

        clilen = sizeof (cliaddr);
        connfd = accept(servfd, (struct sockaddr *)&cliaddr, &clilen);
        if (connfd == -1)
                return (-1);
        if (get_client_ident(connfd, pid, locale, locale_len,
            disconnect) == -1) {
                (void) shutdown(connfd, SHUT_RDWR);
                (void) close(connfd);
                return (-1);
        }
        (void) write(connfd, "OK\n", 3);
        return (connfd);
}

static void
reject_client(int servfd, pid_t clientpid)
{
        int connfd;
        struct sockaddr_un cliaddr;
        socklen_t clilen;
        char nak[MAXPATHLEN];

        clilen = sizeof (cliaddr);
        connfd = accept(servfd, (struct sockaddr *)&cliaddr, &clilen);

        /*
         * After hear its ident string, tell client to get lost.
         */
        if (get_client_ident(connfd, NULL, NULL, 0, NULL) == 0) {
                (void) snprintf(nak, sizeof (nak), "%lu\n",
                    clientpid);
                (void) write(connfd, nak, strlen(nak));
        }
        (void) shutdown(connfd, SHUT_RDWR);
        (void) close(connfd);
}

static void
event_message(int clifd, char *clilocale, zone_evt_t evt, int dflag)
{
        char *str, *lstr = NULL;
        char lmsg[BUFSIZ];
        char outbuf[BUFSIZ];

        if (clifd == -1)
                return;

        switch (evt) {
        case Z_EVT_ZONE_BOOTING:
                if (*boot_args == '\0') {
                        str = "NOTICE: Zone booting up";
                        break;
                }
                /*LINTED*/
                (void) snprintf(lmsg, sizeof (lmsg), localize_msg(clilocale,
                    "NOTICE: Zone booting up with arguments: %s"), boot_args);
                lstr = lmsg;
                break;
        case Z_EVT_ZONE_READIED:
                str = "NOTICE: Zone readied";
                break;
        case Z_EVT_ZONE_HALTED:
                if (dflag)
                        str = "NOTICE: Zone halted.  Disconnecting...";
                else
                        str = "NOTICE: Zone halted";
                break;
        case Z_EVT_ZONE_REBOOTING:
                if (*boot_args == '\0') {
                        str = "NOTICE: Zone rebooting";
                        break;
                }
                /*LINTED*/
                (void) snprintf(lmsg, sizeof (lmsg), localize_msg(clilocale,
                    "NOTICE: Zone rebooting with arguments: %s"), boot_args);
                lstr = lmsg;
                break;
        case Z_EVT_ZONE_UNINSTALLING:
                str = "NOTICE: Zone is being uninstalled.  Disconnecting...";
                break;
        case Z_EVT_ZONE_BOOTFAILED:
                if (dflag)
                        str = "NOTICE: Zone boot failed.  Disconnecting...";
                else
                        str = "NOTICE: Zone boot failed";
                break;
        case Z_EVT_ZONE_BADARGS:
                /*LINTED*/
                (void) snprintf(lmsg, sizeof (lmsg),
                    localize_msg(clilocale,
                    "WARNING: Ignoring invalid boot arguments: %s"),
                    bad_boot_arg);
                lstr = lmsg;
                break;
        default:
                return;
        }

        if (lstr == NULL)
                lstr = localize_msg(clilocale, str);
        (void) snprintf(outbuf, sizeof (outbuf), "\r\n[%s]\r\n", lstr);
        (void) write(clifd, outbuf, strlen(outbuf));
}

/*
 * Check to see if the client at the other end of the socket is still
 * alive; we know it is not if it throws EPIPE at us when we try to write
 * an otherwise harmless 0-length message to it.
 */
static int
test_client(int clifd)
{
        if ((write(clifd, "", 0) == -1) && errno == EPIPE)
                return (-1);
        return (0);
}

/*
 * This routine drives the console I/O loop.  It polls for input from the
 * manager side of the console (output to the console), and from the client
 * (input from the console user).  Additionally, it polls on the server fd,
 * and disconnects any clients that might try to hook up with the zone while
 * the console is in use.
 *
 * When the client first calls us up, it is expected to send a line giving
 * its "identity"; this consists of the string 'IDENT <pid> <locale>'.
 * This is so that we can report that the console is busy along with
 * some diagnostics about who has it busy; the locale is used so that
 * asynchronous messages about zone state (like the NOTICE: zone halted
 * messages) can be output in the user's locale.
 */
static void
do_console_io(zlog_t *zlogp, int consfd, int servfd)
{
        struct pollfd pollfds[4];
        char ibuf[BUFSIZ];
        int cc, ret;
        int clifd = -1;
        int pollerr = 0;
        char clilocale[MAXPATHLEN];
        pid_t clipid = 0;
        int disconnect = 0;

        /* console side, watch for read events */
        pollfds[0].fd = consfd;
        pollfds[0].events = POLLIN | POLLRDNORM | POLLRDBAND |
            POLLPRI | POLLERR | POLLHUP | POLLNVAL;

        /* client side, watch for read events */
        pollfds[1].fd = clifd;
        pollfds[1].events = pollfds[0].events;

        /* the server socket; watch for events (new connections) */
        pollfds[2].fd = servfd;
        pollfds[2].events = pollfds[0].events;

        /* the eventstram; watch for events (e.g.: zone halted) */
        pollfds[3].fd = eventstream[1];
        pollfds[3].events = pollfds[0].events;

        for (;;) {
                pollfds[0].revents = pollfds[1].revents = 0;
                pollfds[2].revents = pollfds[3].revents = 0;

                ret = poll(pollfds,
                    sizeof (pollfds) / sizeof (struct pollfd), -1);
                if (ret == -1 && errno != EINTR) {
                        zerror(zlogp, B_TRUE, "poll failed");
                        /* we are hosed, close connection */
                        break;
                }

                /* event from console side */
                if (pollfds[0].revents) {
                        if (pollfds[0].revents &
                            (POLLIN | POLLRDNORM | POLLRDBAND | POLLPRI)) {
                                errno = 0;
                                cc = read(consfd, ibuf, BUFSIZ);
                                if (cc <= 0 && (errno != EINTR) &&
                                    (errno != EAGAIN))
                                        break;
                                /*
                                 * Lose I/O if no one is listening
                                 */
                                if (clifd != -1 && cc > 0)
                                        (void) write(clifd, ibuf, cc);
                        } else {
                                pollerr = pollfds[0].revents;
                                zerror(zlogp, B_FALSE,
                                    "closing connection with (console) "
                                    "pollerr %d\n", pollerr);
                                break;
                        }
                }

                /* event from client side */
                if (pollfds[1].revents) {
                        if (pollfds[1].revents &
                            (POLLIN | POLLRDNORM | POLLRDBAND | POLLPRI)) {
                                errno = 0;
                                cc = read(clifd, ibuf, BUFSIZ);
                                if (cc <= 0 && (errno != EINTR) &&
                                    (errno != EAGAIN))
                                        break;
                                (void) write(consfd, ibuf, cc);
                        } else {
                                pollerr = pollfds[1].revents;
                                zerror(zlogp, B_FALSE,
                                    "closing connection with (client) "
                                    "pollerr %d\n", pollerr);
                                break;
                        }
                }

                /* event from server socket */
                if (pollfds[2].revents &&
                    (pollfds[2].revents & (POLLIN | POLLRDNORM))) {
                        if (clifd != -1) {
                                /*
                                 * Test the client to see if it is really
                                 * still alive.  If it has died but we
                                 * haven't yet detected that, we might
                                 * deny a legitimate connect attempt.  If it
                                 * is dead, we break out; once we tear down
                                 * the old connection, the new connection
                                 * will happen.
                                 */
                                if (test_client(clifd) == -1) {
                                        break;
                                }
                                /* we're already handling a client */
                                reject_client(servfd, clipid);


                        } else if ((clifd = accept_client(servfd, &clipid,
                            clilocale, sizeof (clilocale),
                            &disconnect)) != -1) {
                                pollfds[1].fd = clifd;

                        } else {
                                break;
                        }
                }

                /*
                 * Watch for events on the eventstream.  This is how we get
                 * notified of the zone halting, etc.  It provides us a
                 * "wakeup" from poll when important things happen, which
                 * is good.
                 */
                if (pollfds[3].revents) {
                        int evt = eventstream_read();
                        /*
                         * After we drain out the event, if we aren't servicing
                         * a console client, we hop back out to our caller,
                         * which will check to see if it is time to shutdown
                         * the daemon, or if we should take another console
                         * service lap.
                         */
                        if (clifd == -1) {
                                break;
                        }
                        event_message(clifd, clilocale, evt, disconnect);
                        /*
                         * Special handling for the message that the zone is
                         * uninstalling; we boot the client, then break out
                         * of this function.  When we return to the
                         * serve_console loop, we will see that the zone is
                         * in a state < READY, and so zoneadmd will shutdown.
                         */
                        if (evt == Z_EVT_ZONE_UNINSTALLING) {
                                break;
                        }
                        /*
                         * Diconnect if -C and -d options were specified and
                         * zone was halted or failed to boot.
                         */
                        if ((evt == Z_EVT_ZONE_HALTED ||
                            evt == Z_EVT_ZONE_BOOTFAILED) && disconnect) {
                                break;
                        }
                }

        }

        if (clifd != -1) {
                (void) shutdown(clifd, SHUT_RDWR);
                (void) close(clifd);
        }
}

int
init_console(zlog_t *zlogp)
{
        if (init_console_dev(zlogp) == -1) {
                zerror(zlogp, B_FALSE,
                    "console setup: device initialization failed");
                return (-1);
        }

        if ((serverfd = init_console_sock(zlogp)) == -1) {
                zerror(zlogp, B_FALSE,
                    "console setup: socket initialization failed");
                return (-1);
        }
        return (0);
}

/*
 * serve_console() is the master loop for driving console I/O.  It is also the
 * routine which is ultimately responsible for "pulling the plug" on zoneadmd
 * when it realizes that the daemon should shut down.
 *
 * The rules for shutdown are: there must be no console client, and the zone
 * state must be < ready.  However, we need to give things a chance to actually
 * get going when the daemon starts up-- otherwise the daemon would immediately
 * exit on startup if the zone was in the installed state, so we first drop
 * into the do_console_io() loop in order to give *something* a chance to
 * happen.
 */
void
serve_console(zlog_t *zlogp)
{
        int managerfd;
        zone_state_t zstate;
        char conspath[MAXPATHLEN];

        (void) snprintf(conspath, sizeof (conspath),
            "/dev/zcons/%s/%s", zone_name, ZCONS_MANAGER_NAME);

        for (;;) {
                managerfd = open(conspath, O_RDWR|O_NONBLOCK|O_NOCTTY);
                if (managerfd == -1) {
                        zerror(zlogp, B_TRUE, "failed to open console manager");
                        (void) mutex_lock(&lock);
                        goto death;
                }

                /*
                 * Setting RPROTDIS on the stream means that the control
                 * portion of messages received (which we don't care about)
                 * will be discarded by the stream head.  If we allowed such
                 * messages, we wouldn't be able to use read(2), as it fails
                 * (EBADMSG) when a message with a control element is received.
                 */
                if (ioctl(managerfd, I_SRDOPT, RNORM|RPROTDIS) == -1) {
                        zerror(zlogp, B_TRUE, "failed to set options on "
                            "console manager");
                        (void) mutex_lock(&lock);
                        goto death;
                }

                do_console_io(zlogp, managerfd, serverfd);

                /*
                 * We would prefer not to do this, but hostile zone processes
                 * can cause the stream to become tainted, and reads will
                 * fail.  So, in case something has gone seriously ill,
                 * we dismantle the stream and reopen the console when we
                 * take another lap.
                 */
                (void) close(managerfd);

                (void) mutex_lock(&lock);
                /*
                 * We need to set death_throes (see below) atomically with
                 * respect to noticing that (a) we have no console client and
                 * (b) the zone is not installed.  Otherwise we could get a
                 * request to boot during this time.  Once we set death_throes,
                 * any incoming door stuff will be turned away.
                 */
                if (zone_get_state(zone_name, &zstate) == Z_OK) {
                        if (zstate < ZONE_STATE_READY)
                                goto death;
                } else {
                        zerror(zlogp, B_FALSE,
                            "unable to determine state of zone");
                        goto death;
                }
                /*
                 * Even if zone_get_state() fails, stay conservative, and
                 * take another lap.
                 */
                (void) mutex_unlock(&lock);
        }

death:
        assert(MUTEX_HELD(&lock));
        in_death_throes = B_TRUE;
        (void) mutex_unlock(&lock);

        destroy_console_sock(serverfd);
        (void) destroy_console_devs(zlogp);
}