cmd/ldapcachemgr/cachemgr.c

	cachemgr.c revision 8142c2b2a11acff39ec7e0576c566a751eb30ba6
/*
 * 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 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * Simple doors ldap cache daemon
 */

#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <door.h>
#include <time.h>
#include <string.h>
#include <strings.h>
#include <libintl.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <stdlib.h>
#include <errno.h>
#include <pthread.h>
#include <thread.h>
#include <stdarg.h>
#include <fcntl.h>
#include <assert.h>
#include <unistd.h>
#include <memory.h>
#include <sys/types.h>
#include <syslog.h>
#include <locale.h> /* LC_ALL */

#include <alloca.h>
#include <ucontext.h>

#include "getxby_door.h"
#include "cachemgr.h"

static void detachfromtty();
admin_t     current_admin;
static int  will_become_server;

static void switcher(void *cookie, char *argp, size_t arg_size,
            door_desc_t *dp, uint_t n_desc);
static void usage(char *s);
static int cachemgr_set_lf(admin_t *ptr, char *logfile);
static int client_getadmin(admin_t *ptr);
static int setadmin(ldap_call_t *ptr);
static  int client_setadmin(admin_t *ptr);
static int client_showstats(admin_t *ptr);
static int is_root(int free_uc, char *dc_str, ucred_t **uc);
static int is_nscd(pid_t pid);

#ifdef SLP
int         use_slp = 0;
static unsigned int refresh = 10800;    /* dynamic discovery interval */
#endif /* SLP */

static ldap_stat_t *
getcacheptr(char *s)
{
    static const char *caches[1] = {"ldap"};

    if (strncmp(caches[0], s, strlen(caches[0])) == 0)
        return (&current_admin.ldap_stat);

    return (NULL);
}

char *
getcacheopt(char *s)
{
    while (*s && *s != ',')
        s++;
    return ((*s == ',') ? (s + 1) : NULL);
}

/*
 *  This is here to prevent the ldap_cachemgr becomes
 *  daemonlized to early to soon during boot time.
 *  This causes problems during boot when automounter
 *  and others try to use libsldap before ldap_cachemgr
 *  finishes walking the server list.
 */
static void
sig_ok_to_exit(int signo)
{
    if (signo == SIGUSR1) {
        logit("sig_ok_to_exit(): parent exiting...\n");
        exit(0);
    } else {
        logit("sig_ok_to_exit(): invalid signal(%d) received.\n",
            signo);
        syslog(LOG_ERR, gettext("ldap_cachemgr: "
            "invalid signal(%d) received."), signo);
        exit(1);
    }
}
#define LDAP_TABLES     1   /* ldap */
#define TABLE_THREADS       10
#define COMMON_THREADS      20
#define CACHE_MISS_THREADS  (COMMON_THREADS + LDAP_TABLES * TABLE_THREADS)
#define CACHE_HIT_THREADS   20
#define MAX_SERVER_THREADS  (CACHE_HIT_THREADS + CACHE_MISS_THREADS)

static sema_t common_sema;
static sema_t ldap_sema;
static thread_key_t lookup_state_key;

static void
initialize_lookup_clearance()
{
    (void) thr_keycreate(&lookup_state_key, NULL);
    (void) sema_init(&common_sema, COMMON_THREADS, USYNC_THREAD, 0);
    (void) sema_init(&ldap_sema, TABLE_THREADS, USYNC_THREAD, 0);
}

int
get_clearance(int callnumber)
{
    sema_t  *table_sema = NULL;
    char    *tab;

    if (sema_trywait(&common_sema) == 0) {
        (void) thr_setspecific(lookup_state_key, NULL);
        return (0);
    }

    switch (callnumber) {
        case GETLDAPCONFIG:
            tab = "ldap";
            table_sema = &ldap_sema;
            break;
        default:
            logit("Internal Error: get_clearance\n");
            break;
    }

    if (sema_trywait(table_sema) == 0) {
        (void) thr_setspecific(lookup_state_key, (void*)1);
        return (0);
    }

    if (current_admin.debug_level >= DBG_CANT_FIND) {
        logit("get_clearance: throttling load for %s table\n", tab);
    }

    return (-1);
}

int
release_clearance(int callnumber)
{
    int which;
    sema_t  *table_sema = NULL;

    (void) thr_getspecific(lookup_state_key, (void**)&which);
    if (which == 0) /* from common pool */ {
        (void) sema_post(&common_sema);
        return (0);
    }

    switch (callnumber) {
        case GETLDAPCONFIG:
            table_sema = &ldap_sema;
            break;
        default:
            logit("Internal Error: release_clearance\n");
            break;
    }
    (void) sema_post(table_sema);

    return (0);
}


static mutex_t      create_lock;
static int      num_servers = 0;
static thread_key_t server_key;


/*
 * Bind a TSD value to a server thread. This enables the destructor to
 * be called if/when this thread exits.  This would be a programming error,
 * but better safe than sorry.
 */

/*ARGSUSED*/
static void *
server_tsd_bind(void *arg)
{
    static void *value = 0;

    /*
     * disable cancellation to prevent hangs when server
     * threads disappear
     */

    (void) thr_setspecific(server_key, value);
    (void) door_return(NULL, 0, NULL, 0);

    return (value);
}

/*
 * Server threads are created here.
 */

/*ARGSUSED*/
static void
server_create(door_info_t *dip)
{
    (void) mutex_lock(&create_lock);
    if (++num_servers > MAX_SERVER_THREADS) {
        num_servers--;
        (void) mutex_unlock(&create_lock);
        return;
    }
    (void) mutex_unlock(&create_lock);
    (void) thr_create(NULL, 0, server_tsd_bind, NULL,
        THR_BOUND|THR_DETACHED, NULL);
}

/*
 * Server thread are destroyed here
 */

/*ARGSUSED*/
static void
server_destroy(void *arg)
{
    (void) mutex_lock(&create_lock);
    num_servers--;
    (void) mutex_unlock(&create_lock);
}

int
main(int argc, char ** argv)
{
    int         did;
    int         opt;
    int         errflg = 0;
    int         showstats = 0;
    int         doset = 0;
    int         dofg = 0;
    struct stat     buf;
    sigset_t        myset;
    struct sigaction    sighupaction;
    static void     client_killserver();
    int         debug_level = 0;

    /* setup for localization */
    (void) setlocale(LC_ALL, "");
    (void) textdomain(TEXT_DOMAIN);

    openlog("ldap_cachemgr", LOG_PID, LOG_DAEMON);

    if (chdir(NSLDAPDIRECTORY) < 0) {
        (void) fprintf(stderr, gettext("chdir(\"%s\") failed: %s\n"),
            NSLDAPDIRECTORY, strerror(errno));
        exit(1);
    }

    /*
     * Correctly set file mode creation mask, so to make the new files
     * created for door calls being readable by all.
     */
    (void) umask(0);

    /*
     *  Special case non-root user here -   he/she/they/it can just print
     *                  stats
     */

    if (geteuid()) {
        if (argc != 2 || strcmp(argv[1], "-g")) {
            (void) fprintf(stderr,
                gettext("Must be root to use any option "
                "other than -g.\n\n"));
            usage(argv[0]);
        }

        if ((__ns_ldap_cache_ping() != SUCCESS) ||
            (client_getadmin(&current_admin) != 0)) {
            (void) fprintf(stderr,
                gettext("%s doesn't appear to be running.\n"),
                argv[0]);
            exit(1);
        }
        (void) client_showstats(&current_admin);
        exit(0);
    }


    /*
     *  Determine if there is already a daemon running
     */

    will_become_server = (__ns_ldap_cache_ping() != SUCCESS);

    /*
     *  load normal config file
     */

    if (will_become_server) {
        static const ldap_stat_t defaults = {
            0,      /* stat */
            DEFAULTTTL};    /* ttl */

        current_admin.ldap_stat = defaults;
        (void) strcpy(current_admin.logfile, LOGFILE);
    } else {
        if (client_getadmin(&current_admin)) {
            (void) fprintf(stderr, gettext("Cannot contact %s "
                "properly(?)\n"), argv[0]);
            exit(1);
        }
    }

#ifndef SLP
    while ((opt = getopt(argc, argv, "fKgl:r:d:")) != EOF) {
#else
    while ((opt = getopt(argc, argv, "fKgs:l:r:d:")) != EOF) {
#endif /* SLP */
        ldap_stat_t *cache;

        switch (opt) {
        case 'K':
            client_killserver();
            exit(0);
            break;
        case 'g':
            showstats++;
            break;
        case 'f':
            dofg++;
            break;
        case 'r':
            doset++;
            cache = getcacheptr("ldap");
            if (!optarg) {
                errflg++;
                break;
            }
            cache->ldap_ttl = atoi(optarg);
            break;
        case 'l':
            doset++;
            (void) strlcpy(current_admin.logfile,
                optarg, sizeof (current_admin.logfile));
            break;
        case 'd':
            doset++;
            debug_level = atoi(optarg);
            break;
#ifdef SLP
        case 's':   /* undocumented: use dynamic (SLP) config */
            use_slp = 1;
            break;
#endif /* SLP */
        default:
            errflg++;
            break;
        }
    }

    if (errflg)
        usage(argv[0]);

    /*
     * will not show statistics if no daemon running
     */
    if (will_become_server && showstats) {
        (void) fprintf(stderr,
            gettext("%s doesn't appear to be running.\n"),
            argv[0]);
        exit(1);
    }

    if (!will_become_server) {
        if (showstats) {
            (void) client_showstats(&current_admin);
        }
        if (doset) {
            current_admin.debug_level = debug_level;
            if (client_setadmin(&current_admin) < 0) {
                (void) fprintf(stderr,
                    gettext("Error during admin call\n"));
                exit(1);
            }
        }
        if (!showstats && !doset) {
            (void) fprintf(stderr,
            gettext("%s already running....use '%s "
                "-K' to stop\n"), argv[0], argv[0]);
        }
        exit(0);
    }

    /*
     *   daemon from here on
     */

    if (debug_level) {
        /*
         * we're debugging...
         */
        if (strlen(current_admin.logfile) == 0)
            /*
             * no specified log file
             */
            (void) strcpy(current_admin.logfile, LOGFILE);
        else
            (void) cachemgr_set_lf(&current_admin,
                current_admin.logfile);
        /*
         * validate the range of debug level number
         * and set the number to current_admin.debug_level
         */
        if (cachemgr_set_dl(&current_admin, debug_level) < 0) {
                /*
                 * print error messages to the screen
                 * cachemgr_set_dl prints msgs to cachemgr.log
                 * only
                 */
                (void) fprintf(stderr,
                gettext("Incorrect Debug Level: %d\n"
                "It should be between %d and %d\n"),
                    debug_level, DBG_OFF, MAXDEBUG);
            exit(-1);
        }
    } else {
        if (strlen(current_admin.logfile) == 0)
            (void) strcpy(current_admin.logfile, "/dev/null");
            (void) cachemgr_set_lf(&current_admin,
                current_admin.logfile);
    }

    if (dofg == 0)
        detachfromtty(argv[0]);

    /*
     * perform some initialization
     */

    initialize_lookup_clearance();

    if (getldap_init() != 0)
        exit(-1);

    /*
     * Establish our own server thread pool
     */

    (void) door_server_create(server_create);
    if (thr_keycreate(&server_key, server_destroy) != 0) {
        logit("thr_keycreate() call failed\n");
        syslog(LOG_ERR,
            gettext("ldap_cachemgr: thr_keycreate() call failed"));
        perror("thr_keycreate");
        exit(-1);
    }

    /*
     * Create a door
     */

    if ((did = door_create(switcher, LDAP_CACHE_DOOR_COOKIE,
        DOOR_UNREF | DOOR_REFUSE_DESC | DOOR_NO_CANCEL)) < 0) {
        logit("door_create() call failed\n");
        syslog(LOG_ERR, gettext(
            "ldap_cachemgr: door_create() call failed"));
        perror("door_create");
        exit(-1);
    }

    /*
     * bind to file system
     */

    if (stat(LDAP_CACHE_DOOR, &buf) < 0) {
        int newfd;

        if ((newfd = creat(LDAP_CACHE_DOOR, 0444)) < 0) {
            logit("Cannot create %s:%s\n",
                LDAP_CACHE_DOOR,
                strerror(errno));
            exit(1);
        }
        (void) close(newfd);
    }

    if (fattach(did, LDAP_CACHE_DOOR) < 0) {
        if ((errno != EBUSY) ||
            (fdetach(LDAP_CACHE_DOOR) <  0) ||
            (fattach(did, LDAP_CACHE_DOOR) < 0)) {
            logit("fattach() call failed\n");
            syslog(LOG_ERR, gettext(
                "ldap_cachemgr: fattach() call failed"));
            perror("fattach");
            exit(2);
        }
    }

    /* catch SIGHUP revalid signals */
    sighupaction.sa_handler = getldap_revalidate;
    sighupaction.sa_flags = 0;
    (void) sigemptyset(&sighupaction.sa_mask);
    (void) sigemptyset(&myset);
    (void) sigaddset(&myset, SIGHUP);

    if (sigaction(SIGHUP, &sighupaction, NULL) < 0) {
        logit("sigaction() call failed\n");
        syslog(LOG_ERR,
            gettext("ldap_cachemgr: sigaction() call failed"));
        perror("sigaction");
        exit(1);
    }

    if (thr_sigsetmask(SIG_BLOCK, &myset, NULL) < 0) {
        logit("thr_sigsetmask() call failed\n");
        syslog(LOG_ERR,
            gettext("ldap_cachemgr: thr_sigsetmask() call failed"));
        perror("thr_sigsetmask");
        exit(1);
    }

    /*
     *  kick off revalidate threads only if ttl != 0
     */

    if (thr_create(NULL, NULL, (void *(*)(void*))getldap_refresh,
        0, 0, NULL) != 0) {
        logit("thr_create() call failed\n");
        syslog(LOG_ERR,
            gettext("ldap_cachemgr: thr_create() call failed"));
        perror("thr_create");
        exit(1);
    }

    /*
     *  kick off the thread which refreshes the server info
     */

    if (thr_create(NULL, NULL, (void *(*)(void*))getldap_serverInfo_refresh,
        0, 0, NULL) != 0) {
        logit("thr_create() call failed\n");
        syslog(LOG_ERR,
            gettext("ldap_cachemgr: thr_create() call failed"));
        perror("thr_create");
        exit(1);
    }

#ifdef SLP
    if (use_slp) {
        /* kick off SLP discovery thread */
        if (thr_create(NULL, NULL, (void *(*)(void *))discover,
            (void *)&refresh, 0, NULL) != 0) {
            logit("thr_create() call failed\n");
            syslog(LOG_ERR, gettext("ldap_cachemgr: thr_create() "
                "call failed"));
            perror("thr_create");
            exit(1);
        }
    }
#endif /* SLP */

    if (thr_sigsetmask(SIG_UNBLOCK, &myset, NULL) < 0) {
        logit("thr_sigsetmask() call failed\n");
        syslog(LOG_ERR,
            gettext("ldap_cachemgr: the_sigsetmask() call failed"));
        perror("thr_sigsetmask");
        exit(1);
    }

    /*CONSTCOND*/
    while (1) {
        (void) pause();
    }
    /* NOTREACHED */
    /*LINTED E_FUNC_HAS_NO_RETURN_STMT*/
}


/*
 * Before calling the alloca() function we have to be sure that we won't get
 * beyond the stack. Since we don't know the precise layout of the stack,
 * the address of an automatic of the function gives us a rough idea, plus/minus
 * a bit. We also need a bit more of stackspace after the call to be able
 * to call further functions. Even something as simple as making a system call
 * from within this function can take ~100 Bytes of stackspace.
 */
#define SAFETY_BUFFER 32 * 1024 /* 32KB */

static
size_t
get_data_size(LineBuf *config_info, int *err_code)
{
    size_t      configSize = sizeof (ldap_return_t);
    dataunion   *buf = NULL; /* For the 'sizeof' purpose */

    if (config_info->str != NULL &&
        config_info->len >= sizeof (buf->data.ldap_ret.ldap_u.config)) {
        configSize = sizeof (buf->space) +
            config_info->len -
            sizeof (buf->data.ldap_ret.ldap_u.config);

        if (!stack_inbounds((char *)&buf -
            (configSize + SAFETY_BUFFER))) {
            /*
             * We do not have enough space on the stack
             * to accomodate the whole DUAProfile
             */
            logit("The DUAProfile is too big. There is not enough "
                "space to process it. Ignoring it.\n");
            syslog(LOG_ERR, gettext("ldap_cachemgr: The DUAProfile "
                "is too big. There is not enough space "
                "to process it. Ignoring it."));

            *err_code = SERVERERROR;

            free(config_info->str);
            config_info->str = NULL;
            config_info->len = 0;
            configSize = sizeof (ldap_return_t);
        }
    }

    return (configSize);
}

/*ARGSUSED*/
static void
switcher(void *cookie, char *argp, size_t arg_size,
    door_desc_t *dp, uint_t n_desc)
{
#define GETSIZE 1000
#define ALLOCATE 1001

    ldap_call_t *ptr = (ldap_call_t *)argp;
    ucred_t     *uc = NULL;

    LineBuf     configInfo;
    dataunion   *buf = NULL;
    /*
     * By default the size of  a buffer to be passed down to a client
     * is equal to the size of the ldap_return_t structure. We need
     * a bigger buffer in a few cases.
     */
    size_t      configSize = sizeof (ldap_return_t);
    int     ldapErrno = 0, state, callnumber;
    struct {
        void    *begin;
        size_t  size;
        uint8_t destroy;
    } dataSource;

    if (argp == DOOR_UNREF_DATA) {
        logit("Door Slam... invalid door param\n");
        syslog(LOG_ERR, gettext("ldap_cachemgr: Door Slam... "
            "invalid door param"));
        (void) printf(gettext("Door Slam... invalid door param\n"));
        exit(0);
    }

    if (ptr == NULL) { /* empty door call */
        (void) door_return(NULL, 0, 0, 0); /* return the favor */
    }

    bzero(&dataSource, sizeof (dataSource));

    /*
     * We presume that sizeof (ldap_return_t) bytes are always available
     * on the stack
     */
    callnumber = ptr->ldap_callnumber;

    switch (callnumber) {
        case NULLCALL:
            /*
             * Just a 'ping'. Use the default size
             * of the buffer and set the
             * 'OK' error code.
             */
            state = ALLOCATE;
            break;
        case GETLDAPCONFIG:
            /*
             * Get the current LDAP configuration.
             * Since this is dynamic data and its size can exceed
             * the size of ldap_return_t, the next step will
             * calculate who much space exactly is required.
             */
            getldap_lookup(&configInfo, ptr);

            state = GETSIZE;
            break;
        case GETLDAPSERVER:
            /*
             * Get the root DSE for a next server in the list.
             * Since this is dynamic data and its size can exceed
             * the size of ldap_return_t, the next step will
             * calculate who much space exactly is required.
             */
            getldap_getserver(&configInfo, ptr);

            state = GETSIZE;
            break;
        case GETCACHESTAT:
            /*
             * Get the cache stattistics.
             * Since this is dynamic data and its size can exceed
             * the size of ldap_return_t, the next step will
             * calculate how much space exactly is required.
             */
            getldap_get_cacheStat(&configInfo);

            state = GETSIZE;
            break;
        case GETADMIN:
            /*
             * Get current configuration and statistics.
             * The size of the statistics structure is less then
             * sizeof (ldap_return_t). So specify the source
             * where to take the info and proceed with the memory
             * allocation.
             */
            state = ALLOCATE;

            if (ldapErrno == 0) {
                dataSource.begin = &current_admin;
                dataSource.size = sizeof (current_admin);
                dataSource.destroy = 0;
            }
            break;
        case KILLSERVER:
            /*
             * Process the request and proceed with the default
             * buffer allocation.
             */
            if (is_root(1, "KILLSERVER", &uc))
                exit(0);

            ldapErrno = -1;
            state = ALLOCATE;
            break;
        case SETADMIN:
            /*
             * Process the request and proceed with the default
             * buffer allocation.
             */
            if (is_root(1, "SETADMIN", &uc))
                ldapErrno = setadmin(ptr);
            else
                ldapErrno = -1;

            state = ALLOCATE;
            break;
        case GETCACHE:
            /*
             * Get the cache stattistics.
             * Since this is dynamic data and its size can exceed
             * the size of ldap_return_t, the next step will
             * calculate how much space exactly is required.
             */
            getldap_get_cacheData(&configInfo, ptr);

            state = GETSIZE;
            break;
        case SETCACHE:
            /*
             * Process the request and proceed with the default
             * buffer allocation.
             */
            if (is_root(0, "SETCACHE", &uc) &&
                is_nscd(ucred_getpid(uc))) {
                ldapErrno = getldap_set_cacheData(ptr);
                current_admin.ldap_stat.ldap_numbercalls++;
            } else
                ldapErrno = -1;

            if (uc != NULL)
                ucred_free(uc);
            state = ALLOCATE;
            break;
        default:
            /*
             * This means an unknown request type. Proceed with
             * the default buffer allocation.
             */
            logit("Unknown ldap service door call op %d\n",
                ptr->ldap_callnumber);
            ldapErrno = -99;

            state = ALLOCATE;
            break;
    }

    switch (state) {
        case GETSIZE:
            /*
             * This stage calculates how much data will be
             * passed down to the client, checks if there is
             * enough space on the stack to accommodate the data,
             * increases the value of the configSize variable
             * if necessary and specifies the data source.
             * In case of any error occurred ldapErrno will be set
             * appropriately.
             */
            if (configInfo.str == NULL) {
                ldapErrno = -1;
            }

            configSize = get_data_size(&configInfo, &ldapErrno);

            if (ldapErrno == 0) {
                dataSource.begin = configInfo.str;
                dataSource.size = configInfo.len;
                dataSource.destroy = 1;
            }

            current_admin.ldap_stat.ldap_numbercalls++;
            /* FALLTHRU */
        case ALLOCATE:
            /*
             * Allocate a buffer of the calculated (or default) size
             * and proceed with populating it with data.
             */
            buf = (dataunion *) alloca(configSize);

            /*
             * Set a return code and, if a data source is specified,
             * copy data from the source to the buffer.
             */
            buf->data.ldap_ret.ldap_errno = ldapErrno;
            buf->data.ldap_ret.ldap_return_code = ldapErrno;
            buf->data.ldap_ret.ldap_bufferbytesused = configSize;

            if (dataSource.begin != NULL) {
                (void) memcpy(buf->data.ldap_ret.ldap_u.config,
                    dataSource.begin,
                    dataSource.size);
                if (dataSource.destroy) {
                    free(dataSource.begin);
                }
            }

    }
    (void) door_return((char *)&buf->data,
        buf->data.ldap_ret.ldap_bufferbytesused,
        NULL,
        0);
#undef  GETSIZE
#undef  ALLOCATE
}

static void
usage(char *s)
{
    (void) fprintf(stderr,
        gettext("Usage: %s [-d debug_level] [-l logfilename]\n"), s);
    (void) fprintf(stderr, gettext("    [-K] "
        "[-r revalidate_interval] "));
#ifndef SLP
    (void) fprintf(stderr, gettext("    [-g]\n"));
#else
    (void) fprintf(stderr, gettext("    [-g] [-s]\n"));
#endif /* SLP */
    exit(1);
}


static int  logfd = -1;

static int
cachemgr_set_lf(admin_t *ptr, char *logfile)
{
    int newlogfd;

    /*
     *  we don't really want to try and open the log file
     *  /dev/null since that will fail w/ our security fixes
     */

    if (logfile == NULL || *logfile == 0) {
        /*EMPTY*/;
    } else if (strcmp(logfile, "/dev/null") == 0) {
        (void) strcpy(current_admin.logfile, "/dev/null");
        (void) close(logfd);
        logfd = -1;
    } else {
        if ((newlogfd =
            open(logfile, O_EXCL|O_WRONLY|O_CREAT, 0644)) < 0) {
            /*
             * File already exists... now we need to get cute
             * since opening a file in a world-writeable directory
             * safely is hard = it could be a hard link or a
             * symbolic link to a system file.
             *
             */
            struct stat before;

            if (lstat(logfile, &before) < 0) {
                logit("Cannot open new logfile \"%s\": %sn",
                    logfile, strerror(errno));
                return (-1);
            }
            if (S_ISREG(before.st_mode) &&  /* no symbolic links */
                (before.st_nlink == 1) &&   /* no hard links */
                (before.st_uid == 0)) { /* owned by root */
                if ((newlogfd =
                    open(logfile,
                    O_APPEND|O_WRONLY, 0644)) < 0) {
                    logit("Cannot open new logfile "
                        "\"%s\": %s\n",
                        logfile, strerror(errno));
                    return (-1);
                }
            } else {
                logit("Cannot use specified logfile "
                    "\"%s\": file is/has links or isn't "
                    "owned by root\n", logfile);
                return (-1);
            }
        }
        (void) strlcpy(ptr->logfile, logfile, sizeof (ptr->logfile));
        (void) close(logfd);
        logfd = newlogfd;
        logit("Starting ldap_cachemgr, logfile %s\n", logfile);
    }
    return (0);
}

/*PRINTFLIKE1*/
void
logit(char *format, ...)
{
    static mutex_t  loglock;
    struct timeval  tv;
    char        buffer[BUFSIZ];
    va_list     ap;

    va_start(ap, format);

    if (logfd >= 0) {
        int safechars;

        (void) gettimeofday(&tv, NULL);
        (void) ctime_r(&tv.tv_sec, buffer, BUFSIZ);
        (void) snprintf(buffer+19, BUFSIZE, ".%.4ld ",
            tv.tv_usec/100);
        safechars = sizeof (buffer) - 30;
        if (vsnprintf(buffer+25, safechars, format, ap) > safechars)
            (void) strcat(buffer, "...\n");
        (void) mutex_lock(&loglock);
        (void) write(logfd, buffer, strlen(buffer));
        (void) mutex_unlock(&loglock);
    }
    va_end(ap);
}


static int
client_getadmin(admin_t *ptr)
{
    dataunion       u;
    ldap_data_t *dptr;
    int     ndata;
    int     adata;

    u.data.ldap_call.ldap_callnumber = GETADMIN;
    ndata = sizeof (u);
    adata = sizeof (u.data);
    dptr = &u.data;

    if (__ns_ldap_trydoorcall(&dptr, &ndata, &adata) != SUCCESS) {
        return (-1);
    }
    (void) memcpy(ptr, dptr->ldap_ret.ldap_u.buff, sizeof (*ptr));

    return (0);
}


static int
setadmin(ldap_call_t *ptr)
{
    admin_t *new;

    new = (admin_t *)ptr->ldap_u.domainname;

    /*
     *  global admin stuff
     */

    if ((cachemgr_set_lf(&current_admin, new->logfile) < 0) ||
        cachemgr_set_dl(&current_admin, new->debug_level) < 0) {
        return (-1);
    }

    if (cachemgr_set_ttl(&current_admin.ldap_stat,
        "ldap",
        new->ldap_stat.ldap_ttl) < 0) {
        return (-1);
    }

    return (0);
}


static void
client_killserver()
{
    dataunion       u;
    ldap_data_t     *dptr;
    int         ndata;
    int         adata;

    u.data.ldap_call.ldap_callnumber = KILLSERVER;
    ndata = sizeof (u);
    adata = sizeof (ldap_call_t);
    dptr = &u.data;

    __ns_ldap_trydoorcall(&dptr, &ndata, &adata);
}


static int
client_setadmin(admin_t *ptr)
{
    dataunion       u;
    ldap_data_t     *dptr;
    int         ndata;
    int         adata;

    u.data.ldap_call.ldap_callnumber = SETADMIN;
    (void) memcpy(u.data.ldap_call.ldap_u.domainname, ptr, sizeof (*ptr));
    ndata = sizeof (u);
    adata = sizeof (*ptr);
    dptr = &u.data;

    if (__ns_ldap_trydoorcall(&dptr, &ndata, &adata) != SUCCESS) {
        return (-1);
    }

    return (0);
}

static int
client_showstats(admin_t *ptr)
{
    dataunion   u;
    ldap_data_t *dptr;
    int     ndata;
    int     adata;
    char        *rbuf, *sptr, *rest;

    /*
     * print admin data
     */
    (void) printf(gettext("\ncachemgr configuration:\n"));
    (void) printf(gettext("server debug level %10d\n"), ptr->debug_level);
    (void) printf(gettext("server log file\t\"%s\"\n"), ptr->logfile);
    (void) printf(gettext("number of calls to ldapcachemgr %10d\n"),
        ptr->ldap_stat.ldap_numbercalls);

    /*
     * get cache data statistics
     */
    u.data.ldap_call.ldap_callnumber = GETCACHESTAT;
    ndata = sizeof (u);
    adata = sizeof (ldap_call_t);
    dptr = &u.data;

    if (__ns_ldap_trydoorcall(&dptr, &ndata, &adata) != SUCCESS) {
        (void) printf(
            gettext("\nCache data statistics not available!\n"));
        return (0);
    }

    /*
     * print cache data statistics line by line
     */
    (void) printf(gettext("\ncachemgr cache data statistics:\n"));
    rbuf = dptr->ldap_ret.ldap_u.buff;
    sptr = strtok_r(rbuf, DOORLINESEP, &rest);
    for (;;) {
        (void) printf("%s\n", sptr);
        sptr = strtok_r(NULL, DOORLINESEP, &rest);
        if (sptr == NULL)
            break;
    }
    return (0);
}


/*
 * detach from tty
 */
static void
detachfromtty(char *pgm)
{
    int     status;
    pid_t   pid, wret;

    (void) close(0);
    (void) close(1);
    /*
     * Block the SIGUSR1 signal
     * just in case that the child
     * process may run faster than
     * the parent process and
     * send this signal before
     * the signal handler is ready
     * in the parent process.
     * This error will cause the parent
     * to exit with the User Signal 1
     * exit code (144).
     */
    (void) sighold(SIGUSR1);
    pid = fork1();
    switch (pid) {
        case (pid_t)-1:
            logit("detachfromtty(): fork1() call failed\n");
            (void) fprintf(stderr,
                gettext("%s: fork1() call failed.\n"),
                pgm);
            syslog(LOG_ERR,
                gettext("ldap_cachemgr: fork1() call failed."));
            exit(1);
            break;
        case 0:
            /*
             * child process does not
             * need to worry about
             * the SIGUSR1 signal
             */
            (void) sigrelse(SIGUSR1);
            (void) close(2);
            break;
        default:
            /*
             * Wait forever until the child process
             * has exited, or has signalled that at
             * least one server in the server list
             * is up.
             */
            if (signal(SIGUSR1, sig_ok_to_exit) == SIG_ERR) {
                logit("detachfromtty(): "
                    "can't set up signal handler to "
                    " catch SIGUSR1.\n");
                (void) fprintf(stderr,
                    gettext("%s: signal() call failed.\n"),
                    pgm);
                syslog(LOG_ERR, gettext("ldap_cachemgr: "
                    "can't set up signal handler to "
                    " catch SIGUSR1."));
                exit(1);
            }

            /*
             * now unblock the SIGUSR1 signal
             * to handle the pending or
             * soon to arrive SIGUSR1 signal
             */
            (void) sigrelse(SIGUSR1);
            wret = waitpid(pid, &status, 0);

            if (wret == -1) {
                logit("detachfromtty(): "
                    "waitpid() call failed\n");
                (void) fprintf(stderr,
                    gettext("%s: waitpid() call failed.\n"),
                    pgm);
                syslog(LOG_ERR,
                    gettext("ldap_cachemgr: waitpid() "
                    "call failed."));
                exit(1);
            }
            if (wret != pid) {
                logit("detachfromtty(): "
                    "waitpid() returned %ld when "
                    "child pid was %ld\n",
                    wret, pid);
                (void) fprintf(stderr,
                    gettext(
                    "%s: waitpid() returned %ld when "
                    "child pid was %ld.\n"),
                    pgm, wret, pid);
                syslog(LOG_ERR,
                    gettext("ldap_cachemgr: waitpid() "
                    "returned different "
                    "child pid."));
                exit(1);
            }

            /* evaluate return status */
            if (WIFEXITED(status)) {
                if (WEXITSTATUS(status) == 0) {
                    exit(0);
                }
                logit("detachfromtty(): "
                    "child failed (rc = %d).\n",
                    WEXITSTATUS(status));
                (void) fprintf(stderr,
                    gettext("%s: failed. Please see "
                    "syslog for details.\n"),
                    pgm);
                syslog(LOG_ERR,
                    gettext("ldap_cachemgr: failed "
                    "(rc = %d)."),
                    WEXITSTATUS(status));
            } else if (WIFSIGNALED(status)) {
                logit("detachfromtty(): "
                    "child terminated by signal %d.\n",
                    WTERMSIG(status));
                (void) fprintf(stderr,
                gettext("%s: terminated by signal %d.\n"),
                    pgm, WTERMSIG(status));
                syslog(LOG_ERR,
                    gettext("ldap_cachemgr: terminated by "
                    "signal %d.\n"),
                    WTERMSIG(status));
            } else if (WCOREDUMP(status)) {
                logit("detachfromtty(): child core dumped.\n"),
                    (void) fprintf(stderr,
                    gettext("%s: core dumped.\n"),
                    pgm);
                syslog(LOG_ERR,
                    gettext("ldap_cachemgr: "
                    "core dumped.\n"));
            }

            exit(1);
    }
    (void) setsid();
    if (open("/dev/null", O_RDWR, 0) != -1) {
        (void) dup(0);
        (void) dup(0);
    }
}

/*
 * Check if the door client's euid is 0
 *
 * We could check for some privilege or re-design the interfaces that
 * lead to is_root() being called so that we rely on SMF and RBAC, but
 * we need this check only for dealing with undocumented-but-possibly-
 * used interfaces.  Anything beyond checking for euid == 0 here would
 * be overkill considering that those are undocumented interfaces.
 *
 * If free_uc is 0, the caller is responsible for freeing *ucp.
 *
 * return - 0 euid != 0
 *          1 euid == 0
 */
static int
is_root(int free_uc, char *dc_str, ucred_t **ucp)
{
    int rc;

    if (door_ucred(ucp) != 0) {
        rc = errno;
        logit("door_ucred() call failed %s\n", strerror(rc));
        syslog(LOG_ERR, gettext("ldap_cachemgr: door_ucred() call %s "
            "failed %s"), strerror(rc));
        return (0);
    }


    if (ucred_geteuid(*ucp) != 0) {

        if (current_admin.debug_level >= DBG_CANT_FIND)
            logit("%s call failed(cred): caller pid %ld, uid %u, "
                "euid %u\n", dc_str, ucred_getpid(*ucp),
                ucred_getruid(*ucp), ucred_geteuid(*ucp));

        rc = 0;
    } else {

        if (current_admin.debug_level >= DBG_ALL)
            logit("ldap_cachemgr received %s call from pid %ld, "
                "uid %u, euid %u\n", dc_str, ucred_getpid(*ucp),
                ucred_getruid(*ucp), ucred_geteuid(*ucp));
        rc = 1;
    }

    if (free_uc)
        ucred_free(*ucp);

    return (rc);
}

/*
 * Check if pid is nscd
 *
 * Input: pid - process id of the door client that calls ldap_cachemgr
 *
 * Return: 0 - No
 *         1 - Yes
 */

static int
is_nscd(pid_t pid)

{
    static mutex_t  _door_lock = DEFAULTMUTEX;
    static  int doorfd = -1;
    int     match;
    door_info_t     my_door;

    /*
     * the first time in we try and open and validate the door.
     * the validations are that the door must have been
     * created with the door cookie and
     * that the file attached to the door is owned by root
     * and readonly by user, group and other.  If any of these
     * validations fail we refuse to use the door.
     */

    (void) mutex_lock(&_door_lock);

try_again:

    if (doorfd == -1) {

        if ((doorfd = open(NAME_SERVICE_DOOR, O_RDONLY, 0))
            == -1) {
            (void) mutex_unlock(&_door_lock);
            return (0);
        }

        if (door_info(doorfd, &my_door) == -1 ||
            (my_door.di_attributes & DOOR_REVOKED) ||
            my_door.di_data != (uintptr_t)NAME_SERVICE_DOOR_COOKIE) {
            /*
             * we should close doorfd because we just opened it
             */
            (void) close(doorfd);
            doorfd = -1;
            (void) mutex_unlock(&_door_lock);
            return (0);
        }
    } else {
        /*
         * doorfd is cached. Double check just in case
         * the door server is restarted or is down.
         */
        if (door_info(doorfd, &my_door) == -1 ||
            my_door.di_data != (uintptr_t)NAME_SERVICE_DOOR_COOKIE) {
            /*
             * don't close it -
             * someone else has clobbered fd
             */
            doorfd = -1;
            goto try_again;
        }

        if (my_door.di_attributes & DOOR_REVOKED) {
            (void) close(doorfd);
            doorfd = -1;    /* try and restart connection */
            goto try_again;
        }
    }

    /*
     * door descriptor exists and is valid
     */
    if (pid == my_door.di_target)
        match = 1;
    else
        match = 0;

    (void) mutex_unlock(&_door_lock);

    return (match);

}