cmd/nscd/nscd_frontend.c

	nscd_frontend.c revision 80b80bf0416a7eb4be4215b2e192cafd03ca80b7
/*
 * 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"

#include <stdlib.h>
#include <alloca.h>
#include <signal.h>
#include <sys/stat.h>
#include <unistd.h>
#include <pthread.h>
#include <time.h>
#include <errno.h>
#include <door.h>
#include <zone.h>
#include <resolv.h>
#include <sys/socket.h>
#include <net/route.h>
#include <string.h>
#include <net/if.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "nscd_common.h"
#include "nscd_door.h"
#include "nscd_config.h"
#include "nscd_switch.h"
#include "nscd_log.h"
#include "nscd_selfcred.h"
#include "nscd_frontend.h"
#include "nscd_admin.h"

static void rts_mon(void);
static void keep_open_dns_socket(void);

extern nsc_ctx_t *cache_ctx_p[];

/*
 * Current active Configuration data for the frontend component
 */
static nscd_cfg_global_frontend_t   frontend_cfg_g;
static nscd_cfg_frontend_t      *frontend_cfg;

static int  max_servers = 0;
static int  max_servers_set = 0;
static int  per_user_is_on = 1;

static char *main_execname;
static char **main_argv;
extern int  _whoami;
extern long activity;
extern mutex_t  activity_lock;

static sema_t   common_sema;

static thread_key_t lookup_state_key;
static mutex_t      create_lock = DEFAULTMUTEX;
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 avoid hangs if server threads disappear */
    (void) pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
    (void) thr_setspecific(server_key, value);
    (void) door_return(NULL, 0, NULL, 0);

    /* make lint happy */
    return (NULL);
}

/*
 * Server threads are created here.
 */
/*ARGSUSED*/
static void
server_create(door_info_t *dip)
{
    (void) mutex_lock(&create_lock);
    if (++num_servers > max_servers) {
        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);
}

/*
 * get clearance
 */
int
_nscd_get_clearance(sema_t *sema) {
    if (sema_trywait(&common_sema) == 0) {
        (void) thr_setspecific(lookup_state_key, NULL);
        return (0);
    }

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

    return (1);
}


/*
 * release clearance
 */
int
_nscd_release_clearance(sema_t *sema) {
    int which;

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

    (void) sema_post(sema);
    return (1);
}

static void
dozip(void)
{
    /* not much here */
}

void
_nscd_restart_if_cfgfile_changed()
{

    static mutex_t      nsswitch_lock = DEFAULTMUTEX;
    static timestruc_t  last_nsswitch_check = { 0 };
    static timestruc_t  last_nsswitch_modified = { 0 };
    static timestruc_t  last_resolv_modified = { 0 };
    time_t          now = time(NULL);
    char            *me = "_nscd_restart_if_cfgfile_changed";

    if (now - last_nsswitch_check.tv_sec < _NSC_FILE_CHECK_TIME)
        return;

    (void) mutex_lock(&nsswitch_lock);

    if (now - last_nsswitch_check.tv_sec >= _NSC_FILE_CHECK_TIME) {
        struct stat nss_buf;
        struct stat res_buf;

        last_nsswitch_check.tv_sec = now;
        last_nsswitch_check.tv_nsec = 0;

        (void) mutex_unlock(&nsswitch_lock); /* let others continue */

        /*
         *  This code keeps us from statting resolv.conf
         *  if it doesn't exist, yet prevents us from ignoring
         *  it if it happens to disappear later on for a bit.
         */

        if (last_resolv_modified.tv_sec >= 0) {
            if (stat("/etc/resolv.conf", &res_buf) < 0) {
                if (last_resolv_modified.tv_sec == 0) {
                    last_resolv_modified.tv_sec = -1;
                    last_resolv_modified.tv_nsec = 0;
                } else
                    res_buf.st_mtim = last_resolv_modified;
            } else if (last_resolv_modified.tv_sec == 0) {
                last_resolv_modified = res_buf.st_mtim;
            }
        }

        if (stat("/etc/nsswitch.conf", &nss_buf) < 0) {
            return;
        } else if (last_nsswitch_modified.tv_sec == 0) {
            last_nsswitch_modified = nss_buf.st_mtim;
        }

        if (last_nsswitch_modified.tv_sec < nss_buf.st_mtim.tv_sec ||
            (last_nsswitch_modified.tv_sec == nss_buf.st_mtim.tv_sec &&
            last_nsswitch_modified.tv_nsec < nss_buf.st_mtim.tv_nsec) ||
            (last_resolv_modified.tv_sec > 0 &&
            (last_resolv_modified.tv_sec < res_buf.st_mtim.tv_sec ||
            (last_resolv_modified.tv_sec == res_buf.st_mtim.tv_sec &&
            last_resolv_modified.tv_nsec < res_buf.st_mtim.tv_nsec)))) {

            static mutex_t exit_lock = DEFAULTMUTEX;
            char *fmri;

            /*
             * if in self cred mode, kill the forker and
             * child nscds
             */
            if (_nscd_is_self_cred_on(0, NULL)) {
                _nscd_kill_forker();
                _nscd_kill_all_children();
            }

            /*
             * time for restart
             */
            _NSCD_LOG(NSCD_LOG_FRONT_END, NSCD_LOG_LEVEL_INFO)
            (me, "nscd restart due to %s or %s change\n",
                "/etc/nsswitch.conf", "resolv.conf");
            /*
             * try to restart under smf
             */
            if ((fmri = getenv("SMF_FMRI")) == NULL) {
                /* not running under smf - reexec */
                (void) execv(main_execname, main_argv);
                exit(1); /* just in case */
            }

            /* prevent multiple restarts */
            (void) mutex_lock(&exit_lock);

            if (smf_restart_instance(fmri) == 0)
                (void) sleep(10); /* wait a bit */
            exit(1); /* give up waiting for resurrection */
        }

    } else
        (void) mutex_unlock(&nsswitch_lock);
}

uid_t
_nscd_get_client_euid()
{
    ucred_t *uc = NULL;
    uid_t   id;
    char    *me = "get_client_euid";

    if (door_ucred(&uc) != 0) {
        _NSCD_LOG(NSCD_LOG_FRONT_END, NSCD_LOG_LEVEL_DEBUG)
        (me, "door_ucred: %s\n", strerror(errno));
        return ((uid_t)-1);
    }

    id = ucred_geteuid(uc);
    ucred_free(uc);
    return (id);
}

/*
 * Check to see if the door client has PRIV_FILE_DAC_READ privilege.
 * Return 0 if yes, -1 otherwise.
 */
int
_nscd_check_client_read_priv()
{
    int         rc = 0;
    ucred_t         *uc = NULL;
    const priv_set_t    *eset;
    char            *me = "_nscd_check_client_read_priv";

    if (door_ucred(&uc) != 0) {
        _NSCD_LOG(NSCD_LOG_FRONT_END, NSCD_LOG_LEVEL_ERROR)
        (me, "door_ucred: %s\n", strerror(errno));
        return (-1);
    }
    eset = ucred_getprivset(uc, PRIV_EFFECTIVE);
    if (!priv_ismember(eset, PRIV_FILE_DAC_READ))
        rc = -1;
    ucred_free(uc);
    return (rc);
}

static void
N2N_check_priv(
    void            *buf,
    char            *dc_str)
{
    nss_pheader_t       *phdr = (nss_pheader_t *)buf;
    ucred_t         *uc = NULL;
    const priv_set_t    *eset;
    zoneid_t        zoneid;
    int         errnum;
    char            *me = "N2N_check_priv";

    if (door_ucred(&uc) != 0) {
        errnum = errno;
        _NSCD_LOG(NSCD_LOG_FRONT_END, NSCD_LOG_LEVEL_DEBUG)
        (me, "door_ucred: %s\n", strerror(errno));

        NSCD_RETURN_STATUS(phdr, NSS_ERROR, errnum);
    }

    eset = ucred_getprivset(uc, PRIV_EFFECTIVE);
    zoneid = ucred_getzoneid(uc);

    if ((zoneid != GLOBAL_ZONEID && zoneid != getzoneid()) ||
        eset != NULL ? !priv_ismember(eset, PRIV_SYS_ADMIN) :
        ucred_geteuid(uc) != 0) {

        _NSCD_LOG(NSCD_LOG_FRONT_END, NSCD_LOG_LEVEL_ALERT)
        (me, "%s call failed(cred): caller pid %d, uid %d, "
            "euid %d, zoneid %d\n", dc_str, ucred_getpid(uc),
            ucred_getruid(uc), ucred_geteuid(uc), zoneid);
        ucred_free(uc);

        NSCD_RETURN_STATUS(phdr, NSS_ERROR, EACCES);
    }

    _NSCD_LOG(NSCD_LOG_FRONT_END, NSCD_LOG_LEVEL_DEBUG)
    (me, "nscd received %s cmd from pid %d, uid %d, "
        "euid %d, zoneid %d\n", dc_str, ucred_getpid(uc),
        ucred_getruid(uc), ucred_geteuid(uc), zoneid);

    ucred_free(uc);

    NSCD_RETURN_STATUS_SUCCESS(phdr);
}

void
_nscd_APP_check_cred(
    void        *buf,
    pid_t       *pidp,
    char        *dc_str,
    int     log_comp,
    int     log_level)
{
    nss_pheader_t   *phdr = (nss_pheader_t *)buf;
    ucred_t     *uc = NULL;
    uid_t       ruid;
    uid_t       euid;
    pid_t       pid;
    int     errnum;
    char        *me = "_nscd_APP_check_cred";

    if (door_ucred(&uc) != 0) {
        errnum = errno;
        _NSCD_LOG(log_comp, NSCD_LOG_LEVEL_ERROR)
        (me, "door_ucred: %s\n", strerror(errno));

        NSCD_RETURN_STATUS(phdr, NSS_ERROR, errnum);
    }

    NSCD_SET_STATUS_SUCCESS(phdr);
    pid = ucred_getpid(uc);
    if (NSS_PACKED_CRED_CHECK(buf, ruid = ucred_getruid(uc),
        euid = ucred_geteuid(uc))) {
        if (pidp != NULL) {
            if (*pidp == (pid_t)-1)
                *pidp = pid;
            else if (*pidp != pid) {
                NSCD_SET_STATUS(phdr, NSS_ERROR, EACCES);
            }
        }
    } else {
        NSCD_SET_STATUS(phdr, NSS_ERROR, EACCES);
    }

    ucred_free(uc);

    if (NSCD_STATUS_IS_NOT_OK(phdr)) {
        _NSCD_LOG(log_comp, log_level)
        (me, "%s call failed: caller pid %d (input pid = %d), ruid %d, "
            "euid %d, header ruid %d, header euid %d\n", dc_str,
            pid, (pidp != NULL) ? *pidp : -1, ruid, euid,
            ((nss_pheader_t *)(buf))->p_ruid,
            ((nss_pheader_t *)(buf))->p_euid);
    }
}

/* log error and return -1 when an invalid packed buffer header is found */
static int
pheader_error(nss_pheader_t *phdr, uint32_t call_number)
{
    char *call_num_str;

    switch (call_number) {
    case NSCD_SEARCH:
        call_num_str = "NSCD_SEARCH";
        break;
    case NSCD_SETENT:
        call_num_str = "NSCD_SETENT";
        break;
    case NSCD_GETENT:
        call_num_str = "NSCD_GETENT";
        break;
    case NSCD_ENDENT:
        call_num_str = "NSCD_ENDENT";
        break;
    case NSCD_PUT:
        call_num_str = "NSCD_PUT";
        break;
    case NSCD_GETHINTS:
        call_num_str = "NSCD_GETHINTS";
        break;
    default:
        call_num_str = "UNKNOWN";
        break;
    }

    _NSCD_LOG(NSCD_LOG_FRONT_END, NSCD_LOG_LEVEL_ALERT)
    ("pheader_error", "call number %s: invalid packed buffer header\n",
        call_num_str);

    NSCD_SET_STATUS(phdr, NSS_ERROR, EINVAL);
    return (-1);
}

/*
 * Validate the header of a getXbyY or setent/getent/endent request.
 * Return 0 if good, -1 otherwise.
 *
 * A valid header looks like the following (size is arg_size, does
 * not include the output area):
 * +----------------------------------+ --
 * | nss_pheader_t (header fixed part)| ^
 * |                                  | |
 * | pbufsiz, dbd,off, key_off,       | len = sizeof(nss_pheader_t)
 * | data_off ....                    | |
 * |                                  | v
 * +----------------------------------+ <----- dbd_off
 * | dbd (database description)       | ^
 * | nss_dbd_t + up to 3 strings      | |
 * | length = sizeof(nss_dbd_t) +     | len = key_off - dbd_off
 * |          length of 3 strings +   | |
 * |          length of padding       | |
 * | (total length in multiple of 4)  | v
 * +----------------------------------+ <----- key_off
 * | lookup key                       | ^
 * | nss_XbyY_key_t, content varies,  | |
 * | based on database and lookup op  | len = data_off - key_off
 * | length = data_off - key_off      | |
 * | including padding, multiple of 4 | v
 * +----------------------------------+ <----- data_off (= arg_size)
 * |                                  | ^
 * | area to hold results             | |
 * |                                  | len = data_len (= pbufsiz -
 * |                                  | |                 data_off)
 * |                                  | v
 * +----------------------------------+ <----- pbufsiz
 */
static int
validate_pheader(
    void        *argp,
    size_t      arg_size,
    uint32_t    call_number)
{
    nss_pheader_t   *phdr = (nss_pheader_t *)(void *)argp;
    nssuint_t   l1, l2;

    /*
     * current version is NSCD_HEADER_REV, length of the fixed part
     * of the header must match the size of nss_pheader_t
     */
    if (phdr->p_version != NSCD_HEADER_REV ||
        phdr->dbd_off != sizeof (nss_pheader_t))
        return (pheader_error(phdr, call_number));

    /*
     * buffer size and offsets must be in multiple of 4
     */
    if ((arg_size & 3) || (phdr->dbd_off & 3) || (phdr->key_off & 3) ||
        (phdr->data_off & 3))
        return (pheader_error(phdr, call_number));

    /*
     * the input arg_size is the length of the request header
     * and should be less than NSCD_PHDR_MAXLEN
     */
    if (phdr->data_off != arg_size || arg_size > NSCD_PHDR_MAXLEN)
        return (pheader_error(phdr, call_number));

    /* get length of the dbd area */
    l1 = phdr->key_off - phdr-> dbd_off;

    /*
     * dbd area may contain padding, so length of dbd should
     * not be less than the length of the actual data
     */
    if (l1 < phdr->dbd_len)
        return (pheader_error(phdr, call_number));

    /* get length of the key area */
    l2 = phdr->data_off - phdr->key_off;

    /*
     * key area may contain padding, so length of key area should
     * not be less than the length of the actual data
     */
    if (l2 < phdr->key_len)
        return (pheader_error(phdr, call_number));

    /*
     * length of fixed part + lengths of dbd and key area = length of
     * the request header
     */
    if (sizeof (nss_pheader_t) + l1 + l2 != phdr->data_off)
        return (pheader_error(phdr, call_number));

    /* header length + data length = buffer length */
    if (phdr->data_off + phdr->data_len != phdr->pbufsiz)
        return (pheader_error(phdr, call_number));

    return (0);
}

/* log error and return -1 when an invalid nscd to nscd buffer is found */
static int
N2Nbuf_error(nss_pheader_t *phdr, uint32_t call_number)
{
    char *call_num_str;

    switch (call_number) {
    case NSCD_PING:
        call_num_str = "NSCD_PING";
        break;

    case NSCD_IMHERE:
        call_num_str = "NSCD_IMHERE";
        break;

    case NSCD_PULSE:
        call_num_str = "NSCD_PULSE";
        break;

    case NSCD_FORK:
        call_num_str = "NSCD_FORK";
        break;

    case NSCD_KILL:
        call_num_str = "NSCD_KILL";
        break;

    case NSCD_REFRESH:
        call_num_str = "NSCD_REFRESH";
        break;

    case NSCD_GETPUADMIN:
        call_num_str = "NSCD_GETPUADMIN";
        break;

    case NSCD_GETADMIN:
        call_num_str = "NSCD_GETADMIN";
        break;

    case NSCD_SETADMIN:
        call_num_str = "NSCD_SETADMIN";
        break;

    case NSCD_KILLSERVER:
        call_num_str = "NSCD_KILLSERVER";
        break;
    default:
        call_num_str = "UNKNOWN";
        break;
    }

    _NSCD_LOG(NSCD_LOG_FRONT_END, NSCD_LOG_LEVEL_ALERT)
    ("N2Nbuf_error", "call number %s: invalid N2N buffer\n", call_num_str);

    NSCD_SET_N2N_STATUS(phdr, NSS_NSCD_PRIV, 0,
        NSCD_DOOR_BUFFER_CHECK_FAILED);

    return (-1);
}

/*
 * Validate the buffer of an nscd to nscd request.
 * Return 0 if good, -1 otherwise.
 *
 * A valid buffer looks like the following (size is arg_size):
 * +----------------------------------+ --
 * | nss_pheader_t (header fixed part)| ^
 * |                                  | |
 * | pbufsiz, dbd,off, key_off,       | len = sizeof(nss_pheader_t)
 * | data_off ....                    | |
 * |                                  | v
 * +----------------------------------+ <---dbd_off = key_off = data_off
 * |                                  | ^
 * | input data/output data           | |
 * | OR no data                       | len = data_len (= pbufsiz -
 * |                                  | |                 data_off)
 * |                                  | | len could be zero
 * |                                  | v
 * +----------------------------------+ <--- pbufsiz
 */
static int
validate_N2Nbuf(
    void        *argp,
    size_t      arg_size,
    uint32_t    call_number)
{
    nss_pheader_t   *phdr = (nss_pheader_t *)(void *)argp;

    /*
     * current version is NSCD_HEADER_REV, length of the fixed part
     * of the header must match the size of nss_pheader_t
     */
    if (phdr->p_version != NSCD_HEADER_REV ||
        phdr->dbd_off != sizeof (nss_pheader_t))
        return (N2Nbuf_error(phdr, call_number));

    /*
     * There are no dbd and key data, so the dbd, key, data
     * offsets should be equal
     */
    if (phdr->dbd_off != phdr->key_off ||
        phdr->dbd_off != phdr->data_off)
        return (N2Nbuf_error(phdr, call_number));

    /*
     * the input arg_size is the buffer length and should
     * be less or equal than NSCD_N2NBUF_MAXLEN
     */
    if (phdr->pbufsiz != arg_size || arg_size > NSCD_N2NBUF_MAXLEN)
        return (N2Nbuf_error(phdr, call_number));

    /* header length + data length = buffer length */
    if (phdr->data_off + phdr->data_len != phdr->pbufsiz)
        return (N2Nbuf_error(phdr, call_number));

    return (0);
}

static void
lookup(char *argp, size_t arg_size)
{
    nsc_lookup_args_t   largs;
    char            space[NSCD_LOOKUP_BUFSIZE];
    nss_pheader_t       *phdr = (nss_pheader_t *)(void *)argp;

    NSCD_ALLOC_LOOKUP_BUFFER(argp, arg_size, phdr, space,
        sizeof (space));

    /*
     * make sure the first couple bytes of the data area is null,
     * so that bad strings in the packed header stop here
     */
    (void) memset((char *)phdr + phdr->data_off, 0, 16);

    (void) memset(&largs, 0, sizeof (largs));
    largs.buffer = argp;
    largs.bufsize = arg_size;
    nsc_lookup(&largs, 0);

    /*
     * only the PUN needs to keep track of the
     * activity count to determine when to
     * terminate itself
     */
    if (_whoami == NSCD_CHILD) {
        (void) mutex_lock(&activity_lock);
        ++activity;
        (void) mutex_unlock(&activity_lock);
    }

    NSCD_SET_RETURN_ARG(phdr, arg_size);
    (void) door_return(argp, arg_size, NULL, 0);
}

static void
getent(char *argp, size_t arg_size)
{
    char            space[NSCD_LOOKUP_BUFSIZE];
    nss_pheader_t       *phdr = (nss_pheader_t *)(void *)argp;

    NSCD_ALLOC_LOOKUP_BUFFER(argp, arg_size, phdr, space, sizeof (space));

    nss_pgetent(argp, arg_size);

    NSCD_SET_RETURN_ARG(phdr, arg_size);
    (void) door_return(argp, arg_size, NULL, 0);
}

static int
is_db_per_user(void *buf, char *dblist)
{
    nss_pheader_t   *phdr = (nss_pheader_t *)buf;
    nss_dbd_t   *pdbd;
    char        *dbname, *dbn;
    int     len;

    /* copy db name into a temp buffer */
    pdbd = (nss_dbd_t *)((void *)((char *)buf + phdr->dbd_off));
    dbname = (char *)pdbd + pdbd->o_name;
    len = strlen(dbname);
    dbn = alloca(len + 2);
    (void) memcpy(dbn, dbname, len);

    /* check if <dbname> + ',' can be found in the dblist string */
    dbn[len] = ',';
    dbn[len + 1] = '\0';
    if (strstr(dblist, dbn) != NULL)
        return (1);

    /*
     * check if <dbname> can be found in the last part
     * of the dblist string
     */
    dbn[len] = '\0';
    if (strstr(dblist, dbn) != NULL)
        return (1);

    return (0);
}

/*
 * Check to see if all conditions are met for processing per-user
 * requests. Returns 1 if yes, -1 if backend is not configured,
 * 0 otherwise.
 */
static int
need_per_user_door(void *buf, int whoami, uid_t uid, char **dblist)
{
    nss_pheader_t   *phdr = (nss_pheader_t *)buf;

    NSCD_SET_STATUS_SUCCESS(phdr);

    /* if already a per-user nscd, no need to get per-user door */
    if (whoami == NSCD_CHILD)
        return (0);

    /* forker shouldn't be asked */
    if (whoami == NSCD_FORKER) {
        NSCD_SET_STATUS(phdr, NSS_ERROR, ENOTSUP);
        return (0);
    }

    /* if door client is root, no need for a per-user door */
    if (uid == 0)
        return (0);

    /*
     * if per-user lookup is not configured, no per-user
     * door available
     */
    if (_nscd_is_self_cred_on(0, dblist) == 0)
        return (-1);

    /*
     * if per-user lookup is not configured for the db,
     * don't bother
     */
    if (is_db_per_user(phdr, *dblist) == 0)
        return (0);

    return (1);
}

static void
if_selfcred_return_per_user_door(char *argp, size_t arg_size,
    door_desc_t *dp, int whoami)
{
    nss_pheader_t   *phdr = (nss_pheader_t *)((void *)argp);
    char        *dblist;
    int     door = -1;
    int     rc = 0;
    door_desc_t desc;
    char        *space;
    int     len;

    /*
     * check to see if self-cred is configured and
     * need to return an alternate PUN door
     */
    if (per_user_is_on == 1) {
        rc = need_per_user_door(argp, whoami,
            _nscd_get_client_euid(), &dblist);
        if (rc == -1)
            per_user_is_on = 0;
    }
    if (rc <= 0) {
        /*
         * self-cred not configured, and no error detected,
         * return to continue the door call processing
         */
        if (NSCD_STATUS_IS_OK(phdr))
            return;
        else
            /*
             * configured but error detected,
             * stop the door call processing
             */
            (void) door_return(argp, phdr->data_off, NULL, 0);
    }

    /* get the alternate PUN door */
    _nscd_proc_alt_get(argp, &door);
    if (NSCD_GET_STATUS(phdr) != NSS_ALTRETRY) {
        (void) door_return(argp, phdr->data_off, NULL, 0);
    }

    /* return the alternate door descriptor */
    len = strlen(dblist) + 1;
    space = alloca(arg_size + len);
    phdr->data_len = len;
    (void) memcpy(space, phdr, arg_size);
    (void) strncpy((char *)space + arg_size, dblist, len);
    dp = &desc;
    dp->d_attributes = DOOR_DESCRIPTOR;
    dp->d_data.d_desc.d_descriptor = door;
    arg_size += len;
    (void) door_return(space, arg_size, dp, 1);
}

/*ARGSUSED*/
static void
switcher(void *cookie, char *argp, size_t arg_size,
    door_desc_t *dp, uint_t n_desc)
{
    int         iam;
    pid_t           ent_pid = -1;
    nss_pheader_t       *phdr = (nss_pheader_t *)((void *)argp);
    void            *uptr;
    int         len;
    size_t          buflen;
    int         callnum;
    char            *me = "switcher";

    _NSCD_LOG(NSCD_LOG_FRONT_END, NSCD_LOG_LEVEL_DEBUG)
    (me, "switcher ...\n");

    if (argp == DOOR_UNREF_DATA) {
        (void) printf("Door Slam... exiting\n");
        exit(0);
    }

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

    /*
     *  need to restart if main nscd and config file(s) changed
     */
    if (_whoami == NSCD_MAIN)
        _nscd_restart_if_cfgfile_changed();

    if ((phdr->nsc_callnumber & NSCDV2CATMASK) == NSCD_CALLCAT_APP) {

        /* make sure the packed buffer header is good */
        if (validate_pheader(argp, arg_size,
            phdr->nsc_callnumber) == -1)
            (void) door_return(argp, arg_size, NULL, 0);

        switch (phdr->nsc_callnumber) {

        case NSCD_SEARCH:

        /* if a fallback to main nscd, skip per-user setup */
        if (phdr->p_status != NSS_ALTRETRY)
            if_selfcred_return_per_user_door(argp, arg_size,
                dp, _whoami);
        lookup(argp, arg_size);

        break;

        case NSCD_SETENT:

        _nscd_APP_check_cred(argp, &ent_pid, "NSCD_SETENT",
            NSCD_LOG_FRONT_END, NSCD_LOG_LEVEL_ALERT);
        if (NSCD_STATUS_IS_OK(phdr)) {
            if_selfcred_return_per_user_door(argp, arg_size,
                dp, _whoami);
            nss_psetent(argp, arg_size, ent_pid);
        }
        break;

        case NSCD_GETENT:

        getent(argp, arg_size);
        break;

        case NSCD_ENDENT:

        nss_pendent(argp, arg_size);
        break;

        case NSCD_PUT:

        _NSCD_LOG(NSCD_LOG_FRONT_END, NSCD_LOG_LEVEL_ERROR)
        (me, "door call NSCD_PUT not supported yet\n");

        NSCD_SET_STATUS(phdr, NSS_ERROR, ENOTSUP);
        break;

        case NSCD_GETHINTS:

        _NSCD_LOG(NSCD_LOG_FRONT_END, NSCD_LOG_LEVEL_ERROR)
        (me, "door call NSCD_GETHINTS not supported yet\n");

        NSCD_SET_STATUS(phdr, NSS_ERROR, ENOTSUP);
        break;

        default:

        _NSCD_LOG(NSCD_LOG_FRONT_END, NSCD_LOG_LEVEL_ERROR)
        (me, "Unknown name service door call op %x\n",
            phdr->nsc_callnumber);

        NSCD_SET_STATUS(phdr, NSS_ERROR, EINVAL);
        break;
        }

        (void) door_return(argp, arg_size, NULL, 0);
    }

    iam = NSCD_MAIN;
    callnum = phdr->nsc_callnumber & ~NSCD_WHOAMI;
    if (callnum == NSCD_IMHERE ||
        callnum == NSCD_PULSE || callnum == NSCD_FORK)
        iam = phdr->nsc_callnumber & NSCD_WHOAMI;
    else
        callnum = phdr->nsc_callnumber;

    /* nscd -> nscd v2 calls */

    /* make sure the buffer is good */
    if (validate_N2Nbuf(argp, arg_size, callnum) == -1)
        (void) door_return(argp, arg_size, NULL, 0);

    switch (callnum) {

    case NSCD_PING:
        NSCD_SET_STATUS_SUCCESS(phdr);
        break;

    case NSCD_IMHERE:
        _nscd_proc_iamhere(argp, dp, n_desc, iam);
        break;

    case NSCD_PULSE:
        N2N_check_priv(argp, "NSCD_PULSE");
        if (NSCD_STATUS_IS_OK(phdr))
            _nscd_proc_pulse(argp, iam);
        break;

    case NSCD_FORK:
        N2N_check_priv(argp, "NSCD_FORK");
        if (NSCD_STATUS_IS_OK(phdr))
            _nscd_proc_fork(argp, iam);
        break;

    case NSCD_KILL:
        N2N_check_priv(argp, "NSCD_KILL");
        if (NSCD_STATUS_IS_OK(phdr))
            exit(0);
        break;

    case NSCD_REFRESH:
        N2N_check_priv(argp, "NSCD_REFRESH");
        if (NSCD_STATUS_IS_OK(phdr)) {
            if (_nscd_refresh() != NSCD_SUCCESS)
                exit(1);
            NSCD_SET_STATUS_SUCCESS(phdr);
        }
        break;

    case NSCD_GETPUADMIN:

        if (_nscd_is_self_cred_on(0, NULL)) {
            _nscd_peruser_getadmin(argp, sizeof (nscd_admin_t));
        } else {
            NSCD_SET_N2N_STATUS(phdr, NSS_NSCD_PRIV, 0,
                NSCD_SELF_CRED_NOT_CONFIGURED);
        }
        break;

    case NSCD_GETADMIN:

        len = _nscd_door_getadmin((void *)argp);
        if (len == 0)
            break;

        /* size of door buffer not big enough, allocate one */
        NSCD_ALLOC_DOORBUF(NSCD_GETADMIN, len, uptr, buflen);

        /* copy packed header */
        *(nss_pheader_t *)uptr = *(nss_pheader_t *)((void *)argp);

        /* set new buffer size */
        ((nss_pheader_t *)uptr)->pbufsiz = buflen;

        /* try one more time */
        (void) _nscd_door_getadmin((void *)uptr);
        (void) door_return(uptr, buflen, NULL, 0);
        break;

    case NSCD_SETADMIN:
        N2N_check_priv(argp, "NSCD_SETADMIN");
        if (NSCD_STATUS_IS_OK(phdr))
            _nscd_door_setadmin(argp);
        break;

    case NSCD_KILLSERVER:
        N2N_check_priv(argp, "NSCD_KILLSERVER");
        if (NSCD_STATUS_IS_OK(phdr)) {
            /* also kill the forker nscd if one is running */
            _nscd_kill_forker();
            exit(0);
        }
        break;

    default:
        _NSCD_LOG(NSCD_LOG_FRONT_END, NSCD_LOG_LEVEL_ERROR)
        (me, "Unknown name service door call op %d\n",
            phdr->nsc_callnumber);

        NSCD_SET_STATUS(phdr, NSS_ERROR, EINVAL);

        (void) door_return(argp, arg_size, NULL, 0);
        break;

    }
    (void) door_return(argp, arg_size, NULL, 0);
}

int
_nscd_setup_server(char *execname, char **argv)
{

    int     fd;
    int     errnum;
    int     bind_failed = 0;
    mode_t      old_mask;
    struct stat buf;
    sigset_t    myset;
    struct sigaction action;
    char        *me = "_nscd_setup_server";

    main_execname = execname;
    main_argv = argv;

    keep_open_dns_socket();

    /*
     * the max number of server threads should be fixed now, so
     * set flag to indicate that no in-flight change is allowed
     */
    max_servers_set = 1;

    (void) thr_keycreate(&lookup_state_key, NULL);
    (void) sema_init(&common_sema, frontend_cfg_g.common_worker_threads,
        USYNC_THREAD, 0);

    /* Establish server thread pool */
    (void) door_server_create(server_create);
    if (thr_keycreate(&server_key, server_destroy) != 0) {
        errnum = errno;
        _NSCD_LOG(NSCD_LOG_FRONT_END, NSCD_LOG_LEVEL_ERROR)
        (me, "thr_keycreate (server thread): %s\n",
            strerror(errnum));
        return (-1);
    }

    /* Create a door */
    if ((fd = door_create(switcher, NAME_SERVICE_DOOR_COOKIE,
        DOOR_UNREF | DOOR_NO_CANCEL)) < 0) {
        errnum = errno;
        _NSCD_LOG(NSCD_LOG_FRONT_END, NSCD_LOG_LEVEL_ERROR)
        (me, "door_create: %s\n", strerror(errnum));
        return (-1);
    }

    /* if not main nscd, no more setup to do */
    if (_whoami != NSCD_MAIN)
        return (fd);

    /* bind to file system */
    if (is_system_labeled() && (getzoneid() == GLOBAL_ZONEID)) {
        if (stat(TSOL_NAME_SERVICE_DOOR, &buf) < 0) {
            int newfd;

            /* make sure the door will be readable by all */
            old_mask = umask(0);
            if ((newfd = creat(TSOL_NAME_SERVICE_DOOR, 0444)) < 0) {
                errnum = errno;
                _NSCD_LOG(NSCD_LOG_FRONT_END,
                    NSCD_LOG_LEVEL_ERROR)
                (me, "Cannot create %s: %s\n",
                    TSOL_NAME_SERVICE_DOOR,
                    strerror(errnum));
                bind_failed = 1;
            }
            /* rstore the old file mode creation mask */
            (void) umask(old_mask);
            (void) close(newfd);
        }
        if (symlink(TSOL_NAME_SERVICE_DOOR, NAME_SERVICE_DOOR) != 0) {
            if (errno != EEXIST) {
                errnum = errno;
                _NSCD_LOG(NSCD_LOG_FRONT_END,
                    NSCD_LOG_LEVEL_ERROR)
                (me, "Cannot symlink %s: %s\n",
                    NAME_SERVICE_DOOR, strerror(errnum));
                bind_failed = 1;
            }
        }
    } else if (stat(NAME_SERVICE_DOOR, &buf) < 0) {
        int newfd;

        /* make sure the door will be readable by all */
        old_mask = umask(0);
        if ((newfd = creat(NAME_SERVICE_DOOR, 0444)) < 0) {
            errnum = errno;
            _NSCD_LOG(NSCD_LOG_FRONT_END, NSCD_LOG_LEVEL_ERROR)
            (me, "Cannot create %s: %s\n", NAME_SERVICE_DOOR,
                strerror(errnum));
            bind_failed = 1;
        }
        /* rstore the old file mode creation mask */
        (void) umask(old_mask);
        (void) close(newfd);
    }

    if (bind_failed == 1) {
        (void) door_revoke(fd);
        return (-1);
    }

    if (fattach(fd, NAME_SERVICE_DOOR) < 0) {
        if ((errno != EBUSY) ||
            (fdetach(NAME_SERVICE_DOOR) <  0) ||
            (fattach(fd, NAME_SERVICE_DOOR) < 0)) {
            errnum = errno;
            _NSCD_LOG(NSCD_LOG_FRONT_END, NSCD_LOG_LEVEL_ERROR)
            (me, "fattach: %s\n", strerror(errnum));
            (void) door_revoke(fd);
            return (-1);
        }
    }

    /*
     * kick off routing socket monitor thread
     */
    if (thr_create(NULL, NULL,
        (void *(*)(void *))rts_mon, 0, 0, NULL) != 0) {
        errnum = errno;
        _NSCD_LOG(NSCD_LOG_FRONT_END, NSCD_LOG_LEVEL_ERROR)
        (me, "thr_create (routing socket monitor): %s\n",
            strerror(errnum));

        (void) door_revoke(fd);
        return (-1);
    }

    /*
     * set up signal handler for SIGHUP
     */
    action.sa_handler = dozip;
    action.sa_flags = 0;
    (void) sigemptyset(&action.sa_mask);
    (void) sigemptyset(&myset);
    (void) sigaddset(&myset, SIGHUP);

    if (sigaction(SIGHUP, &action, NULL) < 0) {
        errnum = errno;
        _NSCD_LOG(NSCD_LOG_FRONT_END, NSCD_LOG_LEVEL_ERROR)
        (me, "sigaction (SIGHUP): %s\n", strerror(errnum));

        (void) door_revoke(fd);
        return (-1);
    }

    return (fd);
}

int
_nscd_setup_child_server(int did)
{

    int     errnum;
    int     fd;
    nscd_rc_t   rc;
    char        *me = "_nscd_setup_child_server";

    /* Re-establish our own server thread pool */
    (void) door_server_create(server_create);
    if (thr_keycreate(&server_key, server_destroy) != 0) {
        errnum = errno;
        _NSCD_LOG(NSCD_LOG_FRONT_END, NSCD_LOG_LEVEL_DEBUG)
        (me, "thr_keycreate failed: %s", strerror(errnum));
        return (-1);
    }

    /*
     * Create a new door.
     * Keep DOOR_REFUSE_DESC (self-cred nscds don't fork)
     */
    (void) close(did);
    if ((fd = door_create(switcher, NAME_SERVICE_DOOR_COOKIE,
        DOOR_REFUSE_DESC|DOOR_UNREF|DOOR_NO_CANCEL)) < 0) {
        errnum = errno;
        _NSCD_LOG(NSCD_LOG_FRONT_END, NSCD_LOG_LEVEL_DEBUG)
        (me, "door_create failed: %s", strerror(errnum));
        return (-1);
    }

    /*
     * kick off routing socket monitor thread
     */
    if (thr_create(NULL, NULL,
        (void *(*)(void *))rts_mon, 0, 0, NULL) != 0) {
        errnum = errno;
        _NSCD_LOG(NSCD_LOG_FRONT_END, NSCD_LOG_LEVEL_ERROR)
        (me, "thr_create (routing socket monitor): %s\n",
            strerror(errnum));
        (void) door_revoke(fd);
        return (-1);
    }

    /*
     * start monitoring the states of the name service clients
     */
    rc = _nscd_init_smf_monitor();
    if (rc != NSCD_SUCCESS) {
        _NSCD_LOG(NSCD_LOG_FRONT_END, NSCD_LOG_LEVEL_ERROR)
    (me, "unable to start the SMF monitor (rc = %d)\n", rc);

        (void) door_revoke(fd);
        return (-1);
    }

    return (fd);
}

nscd_rc_t
_nscd_alloc_frontend_cfg()
{
    frontend_cfg  = calloc(NSCD_NUM_DB, sizeof (nscd_cfg_frontend_t));
    if (frontend_cfg == NULL)
        return (NSCD_NO_MEMORY);

    return (NSCD_SUCCESS);
}


/* ARGSUSED */
nscd_rc_t
_nscd_cfg_frontend_notify(
    void                *data,
    struct nscd_cfg_param_desc  *pdesc,
    nscd_cfg_id_t           *nswdb,
    nscd_cfg_flag_t         dflag,
    nscd_cfg_error_t        **errorp,
    void                *cookie)
{
    void                *dp;

    /*
     * At init time, the whole group of config params are received.
     * At update time, group or individual parameter value could
     * be received.
     */

    if (_nscd_cfg_flag_is_set(dflag, NSCD_CFG_DFLAG_INIT) ||
        _nscd_cfg_flag_is_set(dflag, NSCD_CFG_DFLAG_GROUP)) {
        /*
         * group data is received, copy in the
         * entire strcture
         */
        if (_nscd_cfg_flag_is_set(pdesc->pflag, NSCD_CFG_PFLAG_GLOBAL))
            frontend_cfg_g = *(nscd_cfg_global_frontend_t *)data;
        else
            frontend_cfg[nswdb->index] =
                *(nscd_cfg_frontend_t *)data;

    } else {
        /*
         * individual paramater is received: copy in the
         * parameter value.
         */
        if (_nscd_cfg_flag_is_set(pdesc->pflag, NSCD_CFG_PFLAG_GLOBAL))
            dp = (char *)&frontend_cfg_g + pdesc->p_offset;
        else
            dp = (char *)&frontend_cfg[nswdb->index] +
                pdesc->p_offset;
        (void) memcpy(dp, data, pdesc->p_size);
    }

    return (NSCD_SUCCESS);
}

/* ARGSUSED */
nscd_rc_t
_nscd_cfg_frontend_verify(
    void                *data,
    struct  nscd_cfg_param_desc *pdesc,
    nscd_cfg_id_t           *nswdb,
    nscd_cfg_flag_t         dflag,
    nscd_cfg_error_t        **errorp,
    void                **cookie)
{

    char                *me = "_nscd_cfg_frontend_verify";

    /*
     * if max. number of server threads is set and in effect,
     * don't allow changing of the frontend configuration
     */
    if (max_servers_set) {
        _NSCD_LOG(NSCD_LOG_FRONT_END, NSCD_LOG_LEVEL_INFO)
    (me, "changing of the frontend configuration not allowed now");

        return (NSCD_CFG_CHANGE_NOT_ALLOWED);
    }

    return (NSCD_SUCCESS);
}

/* ARGSUSED */
nscd_rc_t
_nscd_cfg_frontend_get_stat(
    void                **stat,
    struct nscd_cfg_stat_desc   *sdesc,
    nscd_cfg_id_t           *nswdb,
    nscd_cfg_flag_t         *dflag,
    void                (**free_stat)(void *stat),
    nscd_cfg_error_t        **errorp)
{
    return (NSCD_SUCCESS);
}

void
_nscd_init_cache_sema(sema_t *sema, char *cache_name)
{
    int i, j;
    char    *dbn;

    if (max_servers == 0)
        max_servers = frontend_cfg_g.common_worker_threads +
            frontend_cfg_g.cache_hit_threads;

    for (i = 0; i < NSCD_NUM_DB; i++) {

        dbn = NSCD_NSW_DB_NAME(i);
        if (strcasecmp(dbn, cache_name) == 0) {
            j = frontend_cfg[i].worker_thread_per_nsw_db;
            (void) sema_init(sema, j, USYNC_THREAD, 0);
            max_servers += j;
            break;
        }
    }
}

/*
 * Monitor the routing socket.  Address lists stored in the ipnodes
 * cache are sorted based on destination address selection rules,
 * so when things change that could affect that sorting (interfaces
 * go up or down, flags change, etc.), we clear that cache so the
 * list will be re-ordered the next time the hostname is resolved.
 */
static void
rts_mon(void)
{
    int rt_sock, rdlen, idx;
    union {
        struct {
            struct rt_msghdr rtm;
            struct sockaddr_storage addrs[RTA_NUMBITS];
        } r;
        struct if_msghdr ifm;
        struct ifa_msghdr ifam;
    } mbuf;
    struct ifa_msghdr *ifam = &mbuf.ifam;
    char    *me = "rts_mon";

    rt_sock = socket(PF_ROUTE, SOCK_RAW, 0);
    if (rt_sock < 0) {
        _NSCD_LOG(NSCD_LOG_FRONT_END, NSCD_LOG_LEVEL_ERROR)
        (me, "Failed to open routing socket: %s\n", strerror(errno));
        thr_exit(0);
    }

    for (;;) {
        rdlen = read(rt_sock, &mbuf, sizeof (mbuf));
        if (rdlen <= 0) {
            if (rdlen == 0 || (errno != EINTR && errno != EAGAIN)) {
                _NSCD_LOG(NSCD_LOG_FRONT_END,
                    NSCD_LOG_LEVEL_ERROR)
                (me, "routing socket read: %s\n",
                    strerror(errno));
                thr_exit(0);
            }
            continue;
        }
        if (ifam->ifam_version != RTM_VERSION) {
                _NSCD_LOG(NSCD_LOG_FRONT_END,
                    NSCD_LOG_LEVEL_ERROR)
                (me, "rx unknown version (%d) on "
                    "routing socket.\n",
                    ifam->ifam_version);
            continue;
        }
        switch (ifam->ifam_type) {
        case RTM_NEWADDR:
        case RTM_DELADDR:
            /* if no ipnodes cache, then nothing to do */
            idx = get_cache_idx("ipnodes");
            if (cache_ctx_p[idx] == NULL ||
                cache_ctx_p[idx]->reaper_on != nscd_true)
                break;
            nsc_invalidate(cache_ctx_p[idx], NULL, NULL);
            break;
        case RTM_ADD:
        case RTM_DELETE:
        case RTM_CHANGE:
        case RTM_GET:
        case RTM_LOSING:
        case RTM_REDIRECT:
        case RTM_MISS:
        case RTM_LOCK:
        case RTM_OLDADD:
        case RTM_OLDDEL:
        case RTM_RESOLVE:
        case RTM_IFINFO:
            break;
        default:
            _NSCD_LOG(NSCD_LOG_FRONT_END, NSCD_LOG_LEVEL_ERROR)
            (me, "rx unknown msg type (%d) on routing socket.\n",
                ifam->ifam_type);
            break;
        }
    }
}

static void
keep_open_dns_socket(void)
{
    _res.options |= RES_STAYOPEN; /* just keep this udp socket open */
}