port/gen/nss_common.c

/*
 * 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.
 */

/*
 * Shared code used by the name-service-switch frontends (e.g. getpwnam_r())
 */

#include "lint.h"
#include <mtlib.h>
#include <dlfcn.h>
#include <atomic.h>

#define __NSS_PRIVATE_INTERFACE
#include "nsswitch_priv.h"
#undef  __NSS_PRIVATE_INTERFACE

#include <nss_common.h>
#include <nss_dbdefs.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <thread.h>
#include <synch.h>
#include <pthread.h>
#include <sys/types.h>
#include <sys/mman.h>
#include <errno.h>
#include "libc.h"
#include "tsd.h"

#include <getxby_door.h>

/*
 * configurable values for default buffer sizes
 */

/*
 * PSARC/2005/133 updated the buffering mechanisms to handle
 * up to 2^64 buffering.  But sets a practical limit of 512*1024.
 * The expectation is the practical limit will be dynamic from
 * nscd.  For now, set the group limit to this value.
 */

#define NSS_BUFLEN_PRACTICAL    (512*1024)

static size_t __nss_buflen_group = NSS_BUFLEN_PRACTICAL;
static size_t __nss_buflen_default = NSS_BUFLEN_DOOR;

/*
 * policy component function interposing definitions:
 * nscd if so desired can interpose it's own switch functions over
 * the internal unlocked counterparts.  This will allow nscd to replace
 * the switch policy state engine with one that uses it's internal
 * components.
 * Only nscd can change this through it's use of nss_config.
 * The golden rule is: ptr == NULL checking is used in the switch to
 * see if a function was interposed.  But nscd is responsible for seeing
 * that mutex locking to change the values are observed when the data is
 * changed.  Especially if it happens > once.  The switch does not lock
 * the pointer with mutexs.
 */

typedef struct {
    void    *p;
#if 0
    void        (*nss_delete_fp)(nss_db_root_t *rootp);
    nss_status_t    (*nss_search_fp)(nss_db_root_t *rootp,
                nss_db_initf_t initf, int search_fnum,
                void *search_args);
    void        (*nss_setent_u_fp)(nss_db_root_t *,
                nss_db_initf_t, nss_getent_t *);
    nss_status_t    (*nss_getent_u_fp)(nss_db_root_t *,
                nss_db_initf_t, nss_getent_t *, void *);
    void        (*nss_endent_u_fp)(nss_db_root_t *,
                nss_db_initf_t, nss_getent_t *);
    void        (*end_iter_u_fp)(nss_db_root_t *rootp,
                struct nss_getent_context *contextp);
#endif
} nss_policyf_t;

static mutex_t nss_policyf_lock = DEFAULTMUTEX;
static nss_policyf_t nss_policyf_ptrs =
    { (void *)NULL };

/*
 * nsswitch db_root state machine definitions:
 * The golden rule is:  if you hold a pointer to an nss_db_state struct and
 * you don't hold the lock, you'd better have incremented the refcount
 * while you held the lock;  otherwise, it may vanish or change
 * significantly when you least expect it.
 *
 * The pointer in nss_db_root_t is one such, so the reference count >= 1.
 * Ditto the pointer in struct nss_getent_context.
 */

/*
 * State for one nsswitch database (e.g. "passwd", "hosts")
 */
struct nss_db_state {
    nss_db_root_t       orphan_root;    /* XXX explain */
    unsigned        refcount;   /* One for the pointer in    */
                        /*   nss_db_root_t, plus one */
                        /*   for each active thread. */
    nss_db_params_t     p;
    struct __nsw_switchconfig_v1 *config;
    int         max_src;    /* is == config->num_lookups */
    struct nss_src_state    *src;       /* Pointer to array[max_src] */
};

/*
 * State for one of the sources (e.g. "nis", "compat") for a database
 */
struct nss_src_state {
    struct __nsw_lookup_v1  *lkp;
    int         n_active;
    int         n_dormant;
    int         n_waiting;  /* ... on wanna_be */
    cond_t          wanna_be;
    union {
        nss_backend_t   *single; /* Efficiency hack for common case */
                        /* when limit_dead_backends == 1 */
        nss_backend_t   **multi; /* array[limit_dead_backends] of */
    } dormant;              /* pointers to dormant backends */
    nss_backend_constr_t    be_constr;
    nss_backend_finder_t    *finder;
    void            *finder_priv;
};

static struct nss_db_state  *_nss_db_state_constr(nss_db_initf_t);
void                _nss_db_state_destr(struct nss_db_state *);

/* ==== null definitions if !MTSAFE?  Ditto lock field in nss_db_root_t */

#define NSS_ROOTLOCK(r, sp) (cancel_safe_mutex_lock(&(r)->lock), \
                *(sp) = (r)->s)

#define NSS_UNLOCK(r)       (cancel_safe_mutex_unlock(&(r)->lock))

#define NSS_CHECKROOT(rp, s)    ((s) != (*(rp))->s &&           \
            (cancel_safe_mutex_unlock(&(*(rp))->lock),  \
            cancel_safe_mutex_lock(&(s)->orphan_root.lock), \
            *(rp) = &(s)->orphan_root))

#define NSS_RELOCK(rp, s)   (cancel_safe_mutex_lock(&(*(rp))->lock), \
            NSS_CHECKROOT(rp, s))

#define NSS_STATE_REF_u(s)  (++(s)->refcount)

#define NSS_UNREF_UNLOCK(r, s)  (--(s)->refcount != 0           \
            ? ((void)NSS_UNLOCK(r))             \
            : ((void)NSS_UNLOCK(r), (void)_nss_db_state_destr(s)))

#define NSS_LOCK_CHECK(r, f, sp)    (NSS_ROOTLOCK((r), (sp)),   \
                    *(sp) == 0 &&       \
                    (r->s = *(sp) = _nss_db_state_constr(f)))
/* === In the future, NSS_LOCK_CHECK() may also have to check that   */
/* === the config info hasn't changed (by comparing version numbers) */


/*
 * NSS_OPTIONS/NIS_OPTIONS environment varibles data definitions:
 * This remains for backwards compatibility.  But generally nscd will
 * decide if/how this gets used.
 */
static int checked_env = 0;     /* protected by "rootlock" */

    /* allowing __nss_debug_file to be set could be a security hole. */
FILE *__nss_debug_file = stdout;
int __nss_debug_eng_loop;

/* NIS_OPTIONS infrastructure (from linbsl/nis/cache/cache_api.cc) */
    /* allowing __nis_debug_file to be set could be a security hole. */
FILE *__nis_debug_file = stdout;
int __nis_debug_bind;
int __nis_debug_rpc;
int __nis_debug_calls;
char *__nis_prefsrv;
char *__nis_preftype;
char *__nis_server;   /* if set, use only this server for binding */

#define OPT_INT 1
#define OPT_STRING 2
#ifdef DEBUG
#define OPT_FILE 3
#endif

struct option {
    char *name;
    int type;
    void *address;
};

static struct option nss_options[] = {
#ifdef DEBUG
    /* allowing __nss_debug_file to be set could be a security hole. */
    { "debug_file", OPT_FILE, &__nss_debug_file },
#endif
    { "debug_eng_loop", OPT_INT, &__nss_debug_eng_loop },
    { 0, 0, 0 },
};

static struct option nis_options[] = {
#ifdef DEBUG
    /* allowing __nis_debug_file to be set could be a security hole. */
    { "debug_file", OPT_FILE, &__nis_debug_file },
#endif
    { "debug_bind", OPT_INT, &__nis_debug_bind },
    { "debug_rpc", OPT_INT, &__nis_debug_rpc },
    { "debug_calls", OPT_INT, &__nis_debug_calls },
    { "server", OPT_STRING, &__nis_server },
    { "pref_srvr", OPT_STRING, &__nis_prefsrv },
    { "pref_type", OPT_STRING, &__nis_preftype },
    { 0, 0, 0 },
};

/*
 * switch configuration parameter "database" definitions:
 * The switch maintains a simmple read/write parameter database
 * that nscd and the switch components can use to communicate
 * nscd data to other components for configuration or out of band
 * [IE no in the context of a getXbyY or putXbyY operation] data.
 * The data passed are pointers to a lock  data buffer and a length.
 * Use of this is treated as SunwPrivate between nscd and the switch
 * unless other wise stated.
 */

typedef struct nss_cfgparam {
    char        *name;
    mutex_t     *lock;
    void        *buffer;
    size_t      length;
} nss_cfgparam_t;

typedef struct nss_cfglist {
    char        *name;
    nss_cfgparam_t  *list;
    int     count;
    int     max;
} nss_cfglist_t;

#define NSS_CFG_INCR    16

static nss_cfglist_t *nss_cfg = NULL;
static int nss_cfgcount = 0;
static int nss_cfgmax = 0;
static mutex_t nss_cfglock = DEFAULTMUTEX;

static int nss_cfg_policy_init();

/*
 * A config parameters are in the form component:parameter
 * as in: nss:parameter - switch (internal FE/policy/BE) parameter
 *    nscd:param - nscd application parameter
 *    ldap:param - nss_ldap BE parameter
 *    passwd:param - get/put passwd FE parameter
 */

#define NSS_CONFIG_BRK  ':'

/*
 * The policy components initial parameter list
 */
static nss_config_t nss_policy_params[] = {
    { "nss:policyfunc", NSS_CONFIG_ADD, &nss_policyf_lock,
        (void *)&nss_policyf_ptrs, (size_t)sizeof (nss_policyf_t) },
    { NULL, NSS_CONFIG_ADD, (mutex_t *)NULL, (void *)NULL, (size_t)0 },
};

/*
 * NSS parameter configuration routines
 */

/* compare config name (component:parameter) to a component name */
static int
nss_cfgcn_cmp(const char *cfgname, const char *compname)
{
    char *c;
    size_t len, len2;

    /* this code assumes valid pointers */
    if ((c = strchr(cfgname, NSS_CONFIG_BRK)) == NULL)
        return (-1);
    len = (size_t)(c - cfgname);
    len2 = strlen(compname);
    if (len2 != len)
        return (-1);
    return (strncmp(cfgname, compname, len));
}

/* init configuration arena */
static int
nss_cfg_init()
{
    nss_cfglist_t *cfg;
    int i;

    /* First time caller? */
    if (nss_cfg != NULL) {
        membar_consumer();
        return (0);
    }

    /* Initialize internal tables */
    lmutex_lock(&nss_cfglock);
    if (nss_cfg != NULL) {
        lmutex_unlock(&nss_cfglock);
        membar_consumer();
        return (0);
    }
    cfg = libc_malloc(NSS_CFG_INCR * sizeof (nss_cfglist_t));
    if (cfg == NULL) {
        errno = ENOMEM;
        lmutex_unlock(&nss_cfglock);
        return (-1);
    }
    for (i = 0; i < NSS_CFG_INCR; i++) {
        cfg[i].list = libc_malloc(
            NSS_CFG_INCR * sizeof (nss_cfgparam_t));
        if (cfg[i].list == NULL) {
            while (--i >= 0)
                libc_free(cfg[i].list);
            libc_free(cfg);
            errno = ENOMEM;
            lmutex_unlock(&nss_cfglock);
            return (-1);
        }
        cfg[i].max = NSS_CFG_INCR;
    }
    nss_cfgmax = NSS_CFG_INCR;
    membar_producer();
    nss_cfg = cfg;
    lmutex_unlock(&nss_cfglock);

    /* Initialize Policy Engine values */
    if (nss_cfg_policy_init() < 0) {
        return (-1);
    }
    return (0);
}

/* find the name'd component list - create it if non-existent */
static nss_cfglist_t *
nss_cfgcomp_get(char *name, int add)
{
    nss_cfglist_t   *next;
    char    *c;
    int i, len;
    size_t  nsize;

    /* Make sure system is init'd */
    if (nss_cfg_init() < 0)
        return ((nss_cfglist_t *)NULL);

    /* and check component:name validity */
    if (name == NULL || (c = strchr(name, NSS_CONFIG_BRK)) == NULL)
        return ((nss_cfglist_t *)NULL);

    lmutex_lock(&nss_cfglock);
    next = nss_cfg;
    for (i = 0; i < nss_cfgcount; i++) {
        if (next->name && nss_cfgcn_cmp(name, next->name) == 0) {
            lmutex_unlock(&nss_cfglock);
            return (next);
        }
        next++;
    }
    if (!add) {
        lmutex_unlock(&nss_cfglock);
        return (NULL);
    }

    /* not found, create a fresh one */
    if (nss_cfgcount >= nss_cfgmax) {
        /* realloc first */
        nsize = (nss_cfgmax + NSS_CFG_INCR) * sizeof (nss_cfgparam_t);
        next = (nss_cfglist_t *)libc_realloc(nss_cfg, nsize);
        if (next == NULL) {
            errno = ENOMEM;
            lmutex_unlock(&nss_cfglock);
            return ((nss_cfglist_t *)NULL);
        }
        (void) memset((void *)(next + nss_cfgcount), '\0',
            NSS_CFG_INCR * sizeof (nss_cfglist_t));
        nss_cfgmax += NSS_CFG_INCR;
        nss_cfg = next;
    }
    next = nss_cfg + nss_cfgcount;
    len = (size_t)(c - name) + 1;
    if ((next->name = libc_malloc(len)) == NULL) {
        errno = ENOMEM;
        lmutex_unlock(&nss_cfglock);
        return ((nss_cfglist_t *)NULL);
    }
    nss_cfgcount++;
    (void) strlcpy(next->name, name, len);
    lmutex_unlock(&nss_cfglock);
    return (next);
}

/* find the name'd parameter - create it if non-existent */
static nss_cfgparam_t *
nss_cfgparam_get(char *name, int add)
{
    nss_cfglist_t   *comp;
    nss_cfgparam_t  *next;
    int count, i;
    size_t  nsize;

    if ((comp = nss_cfgcomp_get(name, add)) == NULL)
        return ((nss_cfgparam_t *)NULL);
    lmutex_lock(&nss_cfglock);
    count = comp->count;
    next = comp->list;
    for (i = 0; i < count; i++) {
        if (next->name && strcmp(name, next->name) == 0) {
            lmutex_unlock(&nss_cfglock);
            return (next);
        }
        next++;
    }
    if (!add) {
        lmutex_unlock(&nss_cfglock);
        return (NULL);
    }

    /* not found, create a fresh one */
    if (count >= comp->max) {
        /* realloc first */
        nsize = (comp->max + NSS_CFG_INCR) * sizeof (nss_cfgparam_t);
        next = (nss_cfgparam_t *)libc_realloc(comp->list, nsize);
        if (next == NULL) {
            errno = ENOMEM;
            lmutex_unlock(&nss_cfglock);
            return ((nss_cfgparam_t *)NULL);
        }
        comp->max += NSS_CFG_INCR;
        comp->list = next;
    }
    next = comp->list + comp->count;
    if ((next->name = libc_strdup(name)) == NULL) {
        errno = ENOMEM;
        lmutex_unlock(&nss_cfglock);
        return ((nss_cfgparam_t *)NULL);
    }
    comp->count++;
    lmutex_unlock(&nss_cfglock);
    return (next);
}

/* find the name'd parameter - delete it if it exists */
static void
nss_cfg_del(nss_config_t *cfgp)
{
    char        *name;
    nss_cfglist_t   *comp;
    nss_cfgparam_t  *next, *cur;
    int count, i, j;

    /* exit if component name does not already exist */
    if ((name = cfgp->name) == NULL ||
        (comp = nss_cfgcomp_get(name, 0)) == NULL)
        return;

    /* find it */
    lmutex_lock(&nss_cfglock);
    count = comp->count;
    next = comp->list;
    for (i = 0; i < count; i++) {
        if (next->name && strcmp(name, next->name) == 0) {
            break;  /* found it... */
        }
        next++;
    }
    if (i >= count) {
        /* not found, already deleted */
        lmutex_unlock(&nss_cfglock);
        return;
    }

    /* copy down the remaining parameters, and clean up */
    /* don't try to clean up component tables */
    cur = next;
    next++;
    for (j = i+1; j < count; j++) {
        *cur = *next;
        cur++;
        next++;
    }
    /* erase the last one */
    if (cur->name) {
        libc_free(cur->name);
        cur->name = (char *)NULL;
    }
    cur->lock = (mutex_t *)NULL;
    cur->buffer = (void *)NULL;
    cur->length = 0;
    comp->count--;
    lmutex_unlock(&nss_cfglock);
}

static int
nss_cfg_get(nss_config_t *next)
{
    nss_cfgparam_t  *param;

    errno = 0;
    if ((param = nss_cfgparam_get(next->name, 0)) == NULL)
        return (-1);
    next->lock = param->lock;
    next->buffer = param->buffer;
    next->length = param->length;
    return (0);
}

static int
nss_cfg_put(nss_config_t *next, int add)
{
    nss_cfgparam_t  *param;

    errno = 0;
    if ((param = nss_cfgparam_get(next->name, add)) == NULL)
        return (-1);
    param->lock = next->lock;
    param->buffer = next->buffer;
    param->length = next->length;
    return (0);
}

/*
 * Policy engine configurator - set and get interface
 * argument is a NULL terminated list of set/get requests
 * with input/result buffers and lengths.  nss_cname is the
 * specifier of a set or get operation and the property being
 * managed.  The intent is limited functions and expandability.
 */

nss_status_t
nss_config(nss_config_t **plist, int cnt)
{
    nss_config_t    *next;
    int     i;

    /* interface is only available to nscd */
    if (_nsc_proc_is_cache() <= 0) {
        return (NSS_UNAVAIL);
    }
    if (plist == NULL || cnt <= 0)
        return (NSS_SUCCESS);
    for (i = 0; i < cnt; i++) {
        next = plist[i];
        if (next == NULL)
            break;
        if (next->name == NULL) {
            errno = EFAULT;
            return (NSS_ERROR);
        }
        switch (next->cop) {
        case NSS_CONFIG_GET:
            /* get current lock/buffer/length fields */
            if (nss_cfg_get(next) < 0) {
                return (NSS_ERROR);
            }
            break;
        case NSS_CONFIG_PUT:
            /* set new lock/buffer/length fields */
            if (nss_cfg_put(next, 0) < 0) {
                return (NSS_ERROR);
            }
            break;
        case NSS_CONFIG_ADD:
            /* add parameter & set new lock/buffer/length fields */
            if (nss_cfg_put(next, 1) < 0) {
                return (NSS_ERROR);
            }
            break;
        case NSS_CONFIG_DELETE:
            /* delete parameter - should always work... */
            nss_cfg_del(next);
            break;
        case NSS_CONFIG_LIST:
            break;
        default:
            continue;
        }
    }
    return (NSS_SUCCESS);
}

/*
 * This routine is called immediately after nss_cfg_init but prior to
 * any commands from nscd being processed.  The intent here is to
 * initialize the nss:* parameters allowed by the policy component
 * so that nscd can then proceed and modify them if so desired.
 *
 * We know we can only get here if we are nscd so we can skip the
 * preliminaries.
 */

static int
nss_cfg_policy_init()
{
    nss_config_t    *next = &nss_policy_params[0];

    for (; next && next->name != NULL; next++) {
        if (nss_cfg_put(next, 1) < 0)
            return (-1);
    }
    return (0);
}

/*
 * NSS_OPTION & NIS_OPTION environment variable functions
 */

static
void
set_option(struct option *opt, char *name, char *val)
{
    int n;
    char *p;
#ifdef DEBUG
    FILE *fp;
#endif

    for (; opt->name; opt++) {
        if (strcmp(name, opt->name) == 0) {
            switch (opt->type) {
            case OPT_STRING:
                p = libc_strdup(val);
                *((char **)opt->address) = p;
                break;

            case OPT_INT:
                if (strcmp(val, "") == 0)
                    n = 1;
                else
                    n = atoi(val);
                *((int *)opt->address) = n;
                break;
#ifdef DEBUG
            case OPT_FILE:
                fp = fopen(val, "wF");
                *((FILE **)opt->address) = fp;
                break;
#endif
            }
            break;
        }
    }
}

static
void
__parse_environment(struct option *opt, char *p)
{
    char *base;
    char optname[100];
    char optval[100];

    while (*p) {
        while (isspace(*p))
            p++;
        if (*p == '\0')
            break;

        base = p;
        while (*p && *p != '=' && !isspace(*p))
            p++;
        /*
         * play it safe and keep it simple, bail if an opt name
         * is too long.
         */
        if ((p-base) >= sizeof (optname))
            return;

        (void) strncpy(optname, base, p-base);
        optname[p-base] = '\0';

        if (*p == '=') {
            p++;
            base = p;
            while (*p && !isspace(*p))
                p++;
            /*
             * play it safe and keep it simple, bail if an opt
             * value is too long.
             */
            if ((p-base) >= sizeof (optval))
                return;

            (void) strncpy(optval, base, p-base);
            optval[p-base] = '\0';
        } else {
            optval[0] = '\0';
        }

        set_option(opt, optname, optval);
    }
}

static
void
nss_get_environment()
{
    char *p;

/* NSS_OPTIONS is undocumented and should be used without nscd running. */
    p = getenv("NSS_OPTIONS");
    if (p == NULL)
        return;
    __parse_environment(nss_options, p);
}

/*
 * sole external routine called from libnsl/nis/cache/cache_api.cc in the
 * routines _nis_CacheInit/__nis_CacheLocalInit/__nis_CacheMgrInit_discard
 * Only after checking "checked_env" (which must be done with mutex
 * "cur_cache_lock" held) and is done once, (then "checked_env" is set)
 */
void
__nis_get_environment()
{
    char *p;

    p = getenv("NIS_OPTIONS");
    if (p == NULL)
        return;
    __parse_environment(nis_options, p);
}


/*
 * Switch policy component backend state machine functions
 */

static nss_backend_t *
nss_get_backend_u(nss_db_root_t **rootpp, struct nss_db_state *s, int n_src)
{
    struct nss_src_state    *src = &s->src[n_src];
    nss_backend_t       *be;
    int cancel_state;

    for (;;) {
        if (src->n_dormant > 0) {
            src->n_dormant--;
            src->n_active++;
            if (s->p.max_dormant_per_src == 1) {
                be = src->dormant.single;
            } else {
                be = src->dormant.multi[src->n_dormant];
            }
            break;
        }

        if (src->be_constr == 0) {
            nss_backend_finder_t    *bf;

            for (bf = s->p.finders;  bf != 0;  bf = bf->next) {
                nss_backend_constr_t c;

                c = (*bf->lookup) (bf->lookup_priv, s->p.name,
                    src->lkp->service_name, &src->finder_priv);
                if (c != 0) {
                    src->be_constr = c;
                    src->finder = bf;
                    break;
                }
            }
            if (src->be_constr == 0) {
                /* Couldn't find the backend anywhere */
                be = 0;
                break;
            }
        }

        if (src->n_active < s->p.max_active_per_src) {
            be = (*src->be_constr)(s->p.name,
                src->lkp->service_name, 0 /* === unimplemented */);
            if (be != 0) {
                src->n_active++;
                break;
            } else if (src->n_active == 0) {
                /* Something's wrong;  we should be */
                /*   able to create at least one    */
                /*   instance of the backend        */
                break;
            }
            /*
             * Else it's odd that we can't create another backend
             *   instance, but don't sweat it;  instead, queue for
             *   an existing backend instance.
             */
        }

        src->n_waiting++;
        (void) pthread_setcancelstate(PTHREAD_CANCEL_DISABLE,
            &cancel_state);
        (void) cond_wait(&src->wanna_be, &(*rootpp)->lock);
        (void) pthread_setcancelstate(cancel_state, NULL);
        NSS_CHECKROOT(rootpp, s);
        src->n_waiting--;

        /*
         * Loop and see whether things got better for us, or whether
         *   someone else got scheduled first and we have to try
         *   this again.
         *
         * === ?? Should count iterations, assume bug if many ??
         */
    }
    return (be);
}

static void
nss_put_backend_u(struct nss_db_state *s, int n_src, nss_backend_t *be)
{
    struct nss_src_state    *src = &s->src[n_src];

    if (be == 0) {
        return;
    }

    src->n_active--;

    if (src->n_dormant < s->p.max_dormant_per_src) {
        if (s->p.max_dormant_per_src == 1) {
            src->dormant.single = be;
            src->n_dormant++;
        } else if (src->dormant.multi != 0 ||
            (src->dormant.multi =
            libc_malloc(s->p.max_dormant_per_src *
            sizeof (nss_backend_t *))) != NULL) {
            src->dormant.multi[src->n_dormant] = be;
            src->n_dormant++;
        } else {
            /* Can't store it, so toss it */
            (void) NSS_INVOKE_DBOP(be, NSS_DBOP_DESTRUCTOR, 0);
        }
    } else {
        /* We've stored as many as we want, so toss it */
        (void) NSS_INVOKE_DBOP(be, NSS_DBOP_DESTRUCTOR, 0);
    }
    if (src->n_waiting > 0) {
        (void) cond_signal(&src->wanna_be);
    }
}

static struct nss_db_state *
_nss_db_state_constr(nss_db_initf_t initf)
{
    struct nss_db_state *s;
    struct __nsw_switchconfig_v1 *config = 0;
    struct __nsw_lookup_v1  *lkp;
    enum __nsw_parse_err    err;
    const char      *config_name;
    int         n_src;

    if ((s = libc_malloc(sizeof (*s))) == 0) {
        return (0);
    }
    (void) mutex_init(&s->orphan_root.lock, USYNC_THREAD, 0);

    s->p.max_active_per_src = 10;
    s->p.max_dormant_per_src = 1;
    s->p.finders = nss_default_finders;
    (*initf)(&s->p);
    if (s->p.name == 0) {
        _nss_db_state_destr(s);
        return (0);
    }

    if (!checked_env) {
/* NSS_OPTIONS is undocumented and should be used without nscd running. */
        nss_get_environment();
        checked_env = 1;
    }

    config_name = s->p.config_name ? s->p.config_name : s->p.name;
    if (! (s->p.flags & NSS_USE_DEFAULT_CONFIG)) {
        config = __nsw_getconfig_v1(config_name, &err);
        /* === ? test err ? */
    }
    if (config == 0) {
        /* getconfig failed, or frontend demanded default config */

        char    *str;   /* _nsw_getoneconfig() clobbers its argument */

        if ((str = libc_strdup(s->p.default_config)) != 0) {
            config = _nsw_getoneconfig_v1(config_name, str, &err);
            libc_free(str);
        }
        if (config == 0) {
            _nss_db_state_destr(s);
            return (0);
        }
    }
    s->config = config;
    if ((s->max_src = config->num_lookups) <= 0 ||
        (s->src = libc_malloc(s->max_src * sizeof (*s->src))) == 0) {
        _nss_db_state_destr(s);
        return (0);
    }
    for (n_src = 0, lkp = config->lookups;
        n_src < s->max_src; n_src++, lkp = lkp->next) {
        s->src[n_src].lkp = lkp;
        (void) cond_init(&s->src[n_src].wanna_be, USYNC_THREAD, 0);
    }
    s->refcount = 1;
    return (s);
}

void
_nss_src_state_destr(struct nss_src_state *src, int max_dormant)
{
    if (max_dormant == 1) {
        if (src->n_dormant != 0) {
            (void) NSS_INVOKE_DBOP(src->dormant.single,
                NSS_DBOP_DESTRUCTOR, 0);
        };
    } else if (src->dormant.multi != 0) {
        int n;

        for (n = 0;  n < src->n_dormant;  n++) {
            (void) NSS_INVOKE_DBOP(src->dormant.multi[n],
                NSS_DBOP_DESTRUCTOR, 0);
        }
        libc_free(src->dormant.multi);
    }

    /* cond_destroy(&src->wanna_be); */

    if (src->finder != 0) {
        (*src->finder->delete)(src->finder_priv, src->be_constr);
    }
}

/*
 * _nss_db_state_destr() -- used by NSS_UNREF_UNLOCK() to free the entire
 *  nss_db_state structure.
 * Assumes that s has been ref-counted down to zero (in particular,
 *  rootp->s has already been dealt with).
 *
 * Nobody else holds a pointer to *s (if they did, refcount != 0),
 *   so we can clean up state *after* we drop the lock (also, by the
 *   time we finish freeing the state structures, the lock may have
 *   ceased to exist -- if we were using the orphan_root).
 */

void
_nss_db_state_destr(struct nss_db_state *s)
{

    if (s == NULL)
        return;

    /* === mutex_destroy(&s->orphan_root.lock); */
    if (s->p.cleanup != 0) {
        (*s->p.cleanup)(&s->p);
    }
    if (s->config != 0) {
        (void) __nsw_freeconfig_v1(s->config);
    }
    if (s->src != 0) {
        int n_src;

        for (n_src = 0;  n_src < s->max_src;  n_src++) {
            _nss_src_state_destr(&s->src[n_src],
                s->p.max_dormant_per_src);
        }
        libc_free(s->src);
    }
    libc_free(s);
}


/*
 * _nss_status_vec() returns a bit vector of all status codes returned during
 * the most recent call to nss_search().
 * _nss_status_vec_p() returns a pointer to this bit vector, or NULL on
 * failure.
 * These functions are private.  Don't use them externally without discussing
 * it with the switch maintainers.
 */
static uint_t *
_nss_status_vec_p()
{
    return (tsdalloc(_T_NSS_STATUS_VEC, sizeof (uint_t), NULL));
}

unsigned int
_nss_status_vec(void)
{
    unsigned int *status_vec_p = _nss_status_vec_p();

    return ((status_vec_p != NULL) ? *status_vec_p : (1 << NSS_UNAVAIL));
}

static void
output_loop_diag_a(int n,
    char *dbase,
    struct __nsw_lookup_v1 *lkp)
{
    (void) fprintf(__nss_debug_file,
        "NSS_retry(%d): '%s': trying '%s' ... ",
        n, dbase, lkp->service_name);
    (void) fflush(__nss_debug_file);

}

static void
output_loop_diag_b(nss_status_t res,
    struct __nsw_lookup_v1 *lkp)
{
    (void) fprintf(__nss_debug_file, "result=");
    switch (res) {
    case NSS_SUCCESS:
        (void) fprintf(__nss_debug_file, "SUCCESS");
        break;
    case NSS_NOTFOUND:
        (void) fprintf(__nss_debug_file, "NOTFOUND");
        break;
    case NSS_UNAVAIL:
        (void) fprintf(__nss_debug_file, "UNAVAIL");
        break;
    case NSS_TRYAGAIN:
        (void) fprintf(__nss_debug_file, "TRYAGAIN");
        break;
    case NSS_NISSERVDNS_TRYAGAIN:
        (void) fprintf(__nss_debug_file, "NISSERVDNS_TRYAGAIN");
        break;
    default:
        (void) fprintf(__nss_debug_file, "undefined");
    }
    (void) fprintf(__nss_debug_file, ", action=");
    switch (lkp->actions[res]) {
    case __NSW_CONTINUE:
        (void) fprintf(__nss_debug_file, "CONTINUE");
        break;
    case  __NSW_RETURN:
        (void) fprintf(__nss_debug_file, "RETURN");
        break;
    case __NSW_TRYAGAIN_FOREVER:
        (void) fprintf(__nss_debug_file, "TRYAGAIN_FOREVER");
        break;
    case __NSW_TRYAGAIN_NTIMES:
        (void) fprintf(__nss_debug_file, "TRYAGAIN_NTIMES (N=%d)",
            lkp->max_retries);
        break;
    case __NSW_TRYAGAIN_PAUSED:
        (void) fprintf(__nss_debug_file, "TRYAGAIN_PAUSED");
        break;
    default:
        (void) fprintf(__nss_debug_file, "undefined");
    }
    (void) fprintf(__nss_debug_file, "\n");
}

#define NSS_BACKOFF(n, b, t) \
            ((n) > ((b) + 3) ? t : (1 << ((n) - ((b) + 1))))

static int
retry_test(nss_status_t res, int n, struct __nsw_lookup_v1 *lkp)
{
    if (res != NSS_TRYAGAIN && res !=  NSS_NISSERVDNS_TRYAGAIN) {
        if (res == NSS_SUCCESS) {
            __NSW_UNPAUSE_ACTION(lkp->actions[__NSW_TRYAGAIN]);
            __NSW_UNPAUSE_ACTION(
                lkp->actions[__NSW_NISSERVDNS_TRYAGAIN]);
        }
        return (0);
    }

    if ((res == NSS_TRYAGAIN &&
        lkp->actions[__NSW_TRYAGAIN] == __NSW_TRYAGAIN_FOREVER) ||
        (res == NSS_NISSERVDNS_TRYAGAIN &&
        lkp->actions[__NSW_NISSERVDNS_TRYAGAIN] == __NSW_TRYAGAIN_FOREVER))
        return (1);

    if (res == NSS_TRYAGAIN &&
        lkp->actions[__NSW_TRYAGAIN] == __NSW_TRYAGAIN_NTIMES)
        if (n <= lkp->max_retries)
            return (1);
        else {
            lkp->actions[__NSW_TRYAGAIN] = __NSW_TRYAGAIN_PAUSED;
            return (0);
        }

    if (res == NSS_NISSERVDNS_TRYAGAIN &&
        lkp->actions[__NSW_NISSERVDNS_TRYAGAIN] == __NSW_TRYAGAIN_NTIMES)
        if (n <= lkp->max_retries)
            return (1);
        else {
            lkp->actions[__NSW_NISSERVDNS_TRYAGAIN] =
                __NSW_TRYAGAIN_PAUSED;
            return (0);
        }

    return (0);
}

/*
 * Switch policy component functional interfaces
 */

void
nss_delete(nss_db_root_t *rootp)
{
    struct nss_db_state *s;

    /* no name service cache daemon divert here */
    /* local nss_delete decrements state reference counts */
    /* and may free up opened switch resources. */

    NSS_ROOTLOCK(rootp, &s);
    if (s == 0) {
        NSS_UNLOCK(rootp);
    } else {
        rootp->s = 0;
        NSS_UNREF_UNLOCK(rootp, s);
    }
}

nss_status_t
nss_search(nss_db_root_t *rootp, nss_db_initf_t initf, int search_fnum,
    void *search_args)
{
    nss_status_t        res = NSS_UNAVAIL;
    struct nss_db_state *s;
    int         n_src;
    unsigned int        *status_vec_p;

    /* name service cache daemon divert */
    res = _nsc_search(rootp, initf, search_fnum, search_args);
    if (res != NSS_TRYLOCAL)
        return (res);

    /* fall through - process locally */
    errno = 0;          /* just in case ... */
    res = NSS_UNAVAIL;
    status_vec_p = _nss_status_vec_p();

    if (status_vec_p == NULL) {
        return (NSS_UNAVAIL);
    }
    *status_vec_p = 0;

    NSS_LOCK_CHECK(rootp, initf, &s);
    if (s == 0) {
        NSS_UNLOCK(rootp);
        return (res);
    }
    NSS_STATE_REF_u(s);

    for (n_src = 0;  n_src < s->max_src;  n_src++) {
        nss_backend_t       *be;
        nss_backend_op_t    funcp;

        res = NSS_UNAVAIL;
        if ((be = nss_get_backend_u(&rootp, s, n_src)) != 0) {
            if ((funcp = NSS_LOOKUP_DBOP(be, search_fnum)) != 0) {
                int n_loop = 0;
                int no_backoff = 19;
                int max_backoff = 5;    /* seconds */

                do {
                    /*
                     * Backend operation may take a while;
                     * drop the lock so we don't serialize
                     * more than necessary.
                     */
                    NSS_UNLOCK(rootp);

                    /* After several tries, backoff... */
                    if (n_loop > no_backoff) {
                        if (__nss_debug_eng_loop > 1)
                            (void) fprintf(
                                __nss_debug_file,
                                "NSS: loop: "
                                "sleeping %d ...\n",
                                NSS_BACKOFF(n_loop,
                                no_backoff,
                                max_backoff));

                        (void) sleep(NSS_BACKOFF(n_loop,
                            no_backoff, max_backoff));
                    }

                    if (__nss_debug_eng_loop)
                        output_loop_diag_a(n_loop,
                            s->config->dbase,
                            s->src[n_src].lkp);


                    res = (*funcp)(be, search_args);
                    NSS_RELOCK(&rootp, s);
                    n_loop++;
                    if (__nss_debug_eng_loop)
                        output_loop_diag_b(res,
                            s->src[n_src].lkp);
                } while (retry_test(res, n_loop,
                    s->src[n_src].lkp));
            }
            nss_put_backend_u(s, n_src, be);
        }
        *status_vec_p |= (1 << res);
        if (__NSW_ACTION_V1(s->src[n_src].lkp, res) == __NSW_RETURN) {
            if (__nss_debug_eng_loop)
                (void) fprintf(__nss_debug_file,
                    "NSS: '%s': return.\n",
                    s->config->dbase);
            break;
        } else
            if (__nss_debug_eng_loop)
                (void) fprintf(__nss_debug_file,
                    "NSS: '%s': continue ...\n",
                    s->config->dbase);
    }
    NSS_UNREF_UNLOCK(rootp, s);
    return (res);
}


/*
 * Start of nss_{setent|getent|endent}
 */

/*
 * State (here called "context") for one setent/getent.../endent sequence.
 *   In principle there could be multiple contexts active for a single
 *   database;  in practice, since Posix and UI have helpfully said that
 *   getent() state is global rather than, say, per-thread or user-supplied,
 *   we have at most one of these per nss_db_state.
 *   XXX ? Is this statement still true?
 *
 * NSS2 - a client's context is maintained as a cookie delivered by and
 * passed to nscd.  The cookie is a 64 bit (nssuint_t) unique opaque value
 * created by nscd.
 * cookie states:
 *  NSCD_NEW_COOKIE     - cookie value uninitialized
 *  NSCD_LOCAL_COOKIE   - setent is a local setent
 *  all other       - NSCD unique opaque id for this setent
 * A client's context is also associated with a seq_num.  This is a nscd
 * opaque 64 bit (nssuint_t) value passed with a cookie, and used to by nscd
 * to validate the sequencing of the context.  The client treats this as
 * a pass through value.
 *
 * XXX ??  Use Cookie as cross-check info so that we can detect an
 * nss_context that missed an nss_delete() or similar.
 */

struct nss_getent_context {
    int         n_src;  /* >= max_src ==> end of sequence */
    nss_backend_t       *be;
    struct nss_db_state *s;
    nssuint_t       cookie;
    nssuint_t       seq_num;
    nssuint_t       cookie_setent;
    nss_db_params_t     param;
};

static void     nss_setent_u(nss_db_root_t *,
                    nss_db_initf_t,
                    nss_getent_t *);
static nss_status_t nss_getent_u(nss_db_root_t *,
                    nss_db_initf_t,
                    nss_getent_t *,
                    void *);
static void     nss_endent_u(nss_db_root_t *,
                    nss_db_initf_t,
                    nss_getent_t *);

void
nss_setent(nss_db_root_t *rootp, nss_db_initf_t initf, nss_getent_t *contextpp)
{
    if (contextpp == 0) {
        return;
    }
    cancel_safe_mutex_lock(&contextpp->lock);
    nss_setent_u(rootp, initf, contextpp);
    cancel_safe_mutex_unlock(&contextpp->lock);
}

nss_status_t
nss_getent(nss_db_root_t *rootp, nss_db_initf_t initf, nss_getent_t *contextpp,
    void *args)
{
    nss_status_t        status;

    if (contextpp == 0) {
        return (NSS_UNAVAIL);
    }
    cancel_safe_mutex_lock(&contextpp->lock);
    status = nss_getent_u(rootp, initf, contextpp, args);
    cancel_safe_mutex_unlock(&contextpp->lock);
    return (status);
}

void
nss_endent(nss_db_root_t *rootp, nss_db_initf_t initf, nss_getent_t *contextpp)
{
    if (contextpp == 0) {
        return;
    }
    cancel_safe_mutex_lock(&contextpp->lock);
    nss_endent_u(rootp, initf, contextpp);
    cancel_safe_mutex_unlock(&contextpp->lock);
}

/*
 * Each of the _u versions of the nss interfaces assume that the context
 * lock is held.  No need to divert to nscd.  Private to local sequencing.
 */

static void
end_iter_u(nss_db_root_t *rootp, struct nss_getent_context *contextp)
{
    struct nss_db_state *s;
    nss_backend_t       *be;
    int         n_src;

    s = contextp->s;
    n_src = contextp->n_src;
    be = contextp->be;

    if (s != 0) {
        if (n_src < s->max_src && be != 0) {
            (void) NSS_INVOKE_DBOP(be, NSS_DBOP_ENDENT, 0);
            NSS_RELOCK(&rootp, s);
            nss_put_backend_u(s, n_src, be);
            contextp->be = 0;  /* Should be unnecessary, but hey */
            NSS_UNREF_UNLOCK(rootp, s);
        }
        contextp->s = 0;
    }
}

static void
nss_setent_u(nss_db_root_t *rootp, nss_db_initf_t initf,
    nss_getent_t *contextpp)
{
    nss_status_t        status;
    struct nss_db_state *s;
    struct nss_getent_context *contextp;
    nss_backend_t       *be;
    int         n_src;

    /* setup process wide context while locked */
    if ((contextp = contextpp->ctx) == 0) {
        if ((contextp = libc_malloc(sizeof (*contextp))) == 0) {
            return;
        }
        contextpp->ctx = contextp;
        contextp->cookie = NSCD_NEW_COOKIE; /* cookie init */
        contextp->seq_num = 0;          /* seq_num init */
        s = 0;
    } else {
        s = contextp->s;
        if (contextp->cookie != NSCD_LOCAL_COOKIE)
            contextp->cookie = NSCD_NEW_COOKIE;
    }

    /* name service cache daemon divert */
    if (contextp->cookie == NSCD_NEW_COOKIE) {
        status = _nsc_setent_u(rootp, initf, contextpp);
        if (status != NSS_TRYLOCAL)
            return;
    }

    /* fall through - process locally */
    if (s == 0) {
        NSS_LOCK_CHECK(rootp, initf, &s);
        if (s == 0) {
            /* Couldn't set up state, so quit */
            NSS_UNLOCK(rootp);
            /* ==== is there any danger of not having done an */
            /* end_iter() here, and hence of losing backends? */
            contextpp->ctx = 0;
            libc_free(contextp);
            return;
        }
        NSS_STATE_REF_u(s);
        contextp->s = s;
    } else {
        s   = contextp->s;
        n_src   = contextp->n_src;
        be  = contextp->be;
        if (n_src == 0 && be != 0) {
            /*
             * Optimization:  don't do endent, don't change
             *   backends, just do the setent.  Look Ma, no locks
             *   (nor any context that needs updating).
             */
            (void) NSS_INVOKE_DBOP(be, NSS_DBOP_SETENT, 0);
            return;
        }
        if (n_src < s->max_src && be != 0) {
            (void) NSS_INVOKE_DBOP(be, NSS_DBOP_ENDENT, 0);
            NSS_RELOCK(&rootp, s);
            nss_put_backend_u(s, n_src, be);
            contextp->be = 0;   /* Play it safe */
        } else {
            NSS_RELOCK(&rootp, s);
        }
    }
    for (n_src = 0, be = 0; n_src < s->max_src &&
        (be = nss_get_backend_u(&rootp, s, n_src)) == 0; n_src++) {
        ;
    }
    NSS_UNLOCK(rootp);

    contextp->n_src = n_src;
    contextp->be    = be;

    if (be == 0) {
        /* Things are broken enough that we can't do setent/getent */
        nss_endent_u(rootp, initf, contextpp);
        return;
    }
    (void) NSS_INVOKE_DBOP(be, NSS_DBOP_SETENT, 0);
}

static nss_status_t
nss_getent_u(nss_db_root_t *rootp, nss_db_initf_t initf,
    nss_getent_t *contextpp, void *args)
{
    nss_status_t        status;
    struct nss_db_state *s;
    struct nss_getent_context *contextp;
    int         n_src;
    nss_backend_t       *be;

    if ((contextp = contextpp->ctx) == 0) {
        nss_setent_u(rootp, initf, contextpp);
        if ((contextp = contextpp->ctx) == 0) {
            /* Give up */
            return (NSS_UNAVAIL);
        }
    }
    /* name service cache daemon divert */
    status = _nsc_getent_u(rootp, initf, contextpp, args);
    if (status != NSS_TRYLOCAL)
        return (status);

    /* fall through - process locally */
    s   = contextp->s;
    n_src   = contextp->n_src;
    be  = contextp->be;

    if (s == 0) {
        /*
         * We've done an end_iter() and haven't done nss_setent()
         * or nss_endent() since;  we should stick in this state
         * until the caller invokes one of those two routines.
         */
        return (NSS_SUCCESS);
    }

    while (n_src < s->max_src) {
        nss_status_t res;

        if (be == 0) {
            /* If it's null it's a bug, but let's play safe */
            res = NSS_UNAVAIL;
        } else {
            res = NSS_INVOKE_DBOP(be, NSS_DBOP_GETENT, args);
        }

        if (__NSW_ACTION_V1(s->src[n_src].lkp, res) == __NSW_RETURN) {
            if (res != __NSW_SUCCESS) {
                end_iter_u(rootp, contextp);
            }
            return (res);
        }
        (void) NSS_INVOKE_DBOP(be, NSS_DBOP_ENDENT, 0);
        NSS_RELOCK(&rootp, s);
        nss_put_backend_u(s, n_src, be);
        do {
            n_src++;
        } while (n_src < s->max_src &&
            (be = nss_get_backend_u(&rootp, s, n_src)) == 0);
        contextp->be = be;
        if (be == 0) {
            /*
             * This is the case where we failed to get the backend
             * for the last source. We exhausted all sources.
             *
             * We need to do cleanup ourselves because end_iter_u()
             * does not do it for be == 0.
             */
            NSS_UNREF_UNLOCK(rootp, s);
            contextp->s = 0;
            break;
        } else {
            NSS_UNLOCK(rootp);
            contextp->n_src = n_src;
            (void) NSS_INVOKE_DBOP(be, NSS_DBOP_SETENT, 0);
        }
    }
    /* Got to the end of the sources without finding another entry */
    end_iter_u(rootp, contextp);
    return (NSS_SUCCESS);
    /* success is either a successful entry or end of the sources */
}

/*ARGSUSED*/
static void
nss_endent_u(nss_db_root_t *rootp, nss_db_initf_t initf,
    nss_getent_t *contextpp)
{
    nss_status_t        status;
    struct nss_getent_context *contextp;

    if ((contextp = contextpp->ctx) == 0) {
        /* nss_endent() on an unused context is a no-op */
        return;
    }

    /* notify name service cache daemon */
    status = _nsc_endent_u(rootp, initf, contextpp);
    if (status != NSS_TRYLOCAL) {
        /* clean up */
        libc_free(contextp);
        contextpp->ctx = 0;
        return;
    }

    /* fall through - process locally */

    /*
     * Existing code (BSD, SunOS) works in such a way that getXXXent()
     *   following an endXXXent() behaves as though the user had invoked
     *   setXXXent(), i.e. it iterates properly from the beginning.
     * We'd better not break this, so our choices are
     *  (1) leave the context structure around, and do nss_setent or
     *      something equivalent,
     *   or (2) free the context completely, and rely on the code in
     *      nss_getent() that makes getXXXent() do the right thing
     *      even without a preceding setXXXent().
     * The code below does (2), which frees up resources nicely but will
     * cost more if the user then does more getXXXent() operations.
     * Moral:  for efficiency, don't call endXXXent() prematurely.
     */
    end_iter_u(rootp, contextp);
    libc_free(contextp);
    contextpp->ctx = 0;
}

/*
 * pack dbd data into header
 * Argment pointers assumed valid.
 * poff offset position pointer
 *   IN = starting offset for dbd header
 *   OUT = starting offset for next section
 */

static nss_status_t
nss_pack_dbd(void *buffer, size_t bufsize, nss_db_params_t *p, size_t *poff)
{
    nss_pheader_t       *pbuf = (nss_pheader_t *)buffer;
    nss_dbd_t       *pdbd;
    size_t          off = *poff;
    size_t          len, blen;
    size_t          n, nc, dc;
    char            *bptr;

    pbuf->dbd_off = (nssuint_t)off;
    bptr = (char *)buffer + off;
    blen = bufsize - off;
    len = sizeof (nss_dbd_t);

    n = nc = dc = 0;
    if (p->name == NULL) {
        errno = ERANGE;         /* actually EINVAL */
        return (NSS_ERROR);
    }

    /* if default config not specified, the flag should be reset */
    if (p->default_config == NULL) {
        p->default_config = "<NULL>";
        p->flags = p->flags & ~NSS_USE_DEFAULT_CONFIG;
    }

    n = strlen(p->name) + 1;
    dc = strlen(p->default_config) + 1;
    if (n < 2 || dc < 2) {          /* What no DB? */
        errno = ERANGE;         /* actually EINVAL */
        return (NSS_ERROR);
    }
    if (p->config_name != NULL) {
        nc = strlen(p->config_name) + 1;
    }
    if ((len + n + nc + dc) >= blen) {
        errno = ERANGE;         /* actually EINVAL */
        return (NSS_ERROR);
    }

    pdbd = (nss_dbd_t *)((void *)bptr);
    bptr += len;
    pdbd->flags = p->flags;
    pdbd->o_name = len;
    (void) strlcpy(bptr, p->name, n);
    len += n;
    bptr += n;
    if (nc == 0) {
        pdbd->o_config_name = 0;
    } else {
        pdbd->o_config_name = len;
        (void) strlcpy(bptr, p->config_name, nc);
        bptr += nc;
        len += nc;
    }
    pdbd->o_default_config = len;
    (void) strlcpy(bptr, p->default_config, dc);
    len += dc;
    pbuf->dbd_len = (nssuint_t)len;
    off += ROUND_UP(len, sizeof (nssuint_t));
    *poff = off;
    return (NSS_SUCCESS);
}

/*
 * Switch packed and _nsc (switch->nscd) interfaces
 * Return: NSS_SUCCESS (OK to proceed), NSS_ERROR, NSS_NOTFOUND
 */

/*ARGSUSED*/
nss_status_t
nss_pack(void *buffer, size_t bufsize, nss_db_root_t *rootp,
    nss_db_initf_t initf, int search_fnum, void *search_args)
{
    nss_pheader_t       *pbuf = (nss_pheader_t *)buffer;
    nss_XbyY_args_t     *in = (nss_XbyY_args_t *)search_args;
    nss_db_params_t     tparam = { 0 };
    nss_status_t        ret = NSS_ERROR;
    const char      *dbn;
    size_t          blen, len, off = 0;
    char            *bptr;
    struct nss_groupsbymem  *gbm;

    if (pbuf == NULL || in == NULL || initf == (nss_db_initf_t)NULL) {
        errno = ERANGE;         /* actually EINVAL */
        return (ret);
    }
    tparam.cleanup = NULL;
    (*initf)(&tparam);
    if ((dbn = tparam.name) == 0) {
        if (tparam.cleanup != 0)
            (tparam.cleanup)(&tparam);
        errno = ERANGE;         /* actually EINVAL */
        return (ret);
    }

    /* init buffer header */
    pbuf->pbufsiz = (nssuint_t)bufsize;
    pbuf->p_ruid = (uint32_t)getuid();
    pbuf->p_euid = (uint32_t)geteuid();
    pbuf->p_version = NSCD_HEADER_REV;
    pbuf->p_status = 0;
    pbuf->p_errno = 0;
    pbuf->p_herrno = 0;

    /* possible audituser init */
    if (strcmp(dbn, NSS_DBNAM_AUTHATTR) == 0 && in->h_errno != 0)
        pbuf->p_herrno = (uint32_t)in->h_errno;

    pbuf->libpriv = 0;

    off = sizeof (nss_pheader_t);

    /* setup getXbyY operation - database and sub function */
    pbuf->nss_dbop = (uint32_t)search_fnum;
    ret = nss_pack_dbd(buffer, bufsize, &tparam, &off);
    if (ret != NSS_SUCCESS) {
        errno = ERANGE;         /* actually EINVAL */
        return (ret);
    }
    ret = NSS_ERROR;
    /* setup request key */
    pbuf->key_off = (nssuint_t)off;
    bptr = (char *)buffer + off;
    blen = bufsize - off;
    /* use key2str if provided, else call default getXbyY packer */
    if (strcmp(dbn, NSS_DBNAM_NETGROUP) == 0) {
        /* This has to run locally due to backend knowledge */
        if (search_fnum == NSS_DBOP_NETGROUP_SET) {
            errno = 0;
            return (NSS_TRYLOCAL);
        }
        /* use default packer for known getXbyY ops */
        ret = nss_default_key2str(bptr, blen, in, dbn,
            search_fnum, &len);
    } else if (in->key2str == NULL ||
        (search_fnum == NSS_DBOP_GROUP_BYMEMBER &&
        strcmp(dbn, NSS_DBNAM_GROUP) == 0)) {
        /* use default packer for known getXbyY ops */
        ret = nss_default_key2str(bptr, blen, in, dbn,
            search_fnum, &len);
    } else {
        ret = (*in->key2str)(bptr, blen, &in->key, &len);
    }
    if (tparam.cleanup != 0)
        (tparam.cleanup)(&tparam);
    if (ret != NSS_SUCCESS) {
        errno = ERANGE;         /* actually ENOMEM */
        return (ret);
    }
    pbuf->key_len = (nssuint_t)len;
    off += ROUND_UP(len, sizeof (nssuint_t));

    pbuf->data_off = (nssuint_t)off;
    pbuf->data_len = (nssuint_t)(bufsize - off);
    /*
     * Prime data return with first result if
     * the first result is passed in
     * [_getgroupsbymember oddness]
     */
    gbm = (struct nss_groupsbymem *)search_args;
    if (search_fnum == NSS_DBOP_GROUP_BYMEMBER &&
        strcmp(dbn, NSS_DBNAM_GROUP) == 0 && gbm->numgids == 1) {
        gid_t   *gidp;
        gidp = (gid_t *)((void *)((char *)buffer + off));
        *gidp = gbm->gid_array[0];
    }

    errno = 0;              /* just in case ... */
    return (NSS_SUCCESS);
}

/*
 * Switch packed and _nsc (switch->nscd) {set/get/end}ent interfaces
 * Return: NSS_SUCCESS (OK to proceed), NSS_ERROR, NSS_NOTFOUND
 */

/*ARGSUSED*/
nss_status_t
nss_pack_ent(void *buffer, size_t bufsize, nss_db_root_t *rootp,
    nss_db_initf_t initf, nss_getent_t *contextpp)
{
    nss_pheader_t       *pbuf = (nss_pheader_t *)buffer;
    struct nss_getent_context *contextp = contextpp->ctx;
    nss_status_t        ret = NSS_ERROR;
    size_t          blen, len = 0, off = 0;
    char            *bptr;
    nssuint_t       *nptr;

    if (pbuf == NULL || initf == (nss_db_initf_t)NULL) {
        errno = ERANGE;         /* actually EINVAL */
        return (ret);
    }

    /* init buffer header */
    pbuf->pbufsiz = (nssuint_t)bufsize;
    pbuf->p_ruid = (uint32_t)getuid();
    pbuf->p_euid = (uint32_t)geteuid();
    pbuf->p_version = NSCD_HEADER_REV;
    pbuf->p_status = 0;
    pbuf->p_errno = 0;
    pbuf->p_herrno = 0;
    pbuf->libpriv = 0;

    off = sizeof (nss_pheader_t);

    /* setup getXXXent operation - database and sub function */
    pbuf->nss_dbop = (uint32_t)0;   /* iterators have no dbop */
    ret = nss_pack_dbd(buffer, bufsize, &contextp->param, &off);
    if (ret != NSS_SUCCESS) {
        errno = ERANGE;         /* actually EINVAL */
        return (ret);
    }
    ret = NSS_ERROR;
    off += ROUND_UP(len, sizeof (nssuint_t));

    pbuf->key_off = (nssuint_t)off;
    bptr = (char *)buffer + off;
    blen = bufsize - off;
    len = (size_t)(sizeof (nssuint_t) * 2);
    if (len >= blen) {
        errno = ERANGE;         /* actually EINVAL */
        return (ret);
    }
    nptr = (nssuint_t *)((void *)bptr);
    *nptr++ = contextp->cookie;
    *nptr = contextp->seq_num;
    pbuf->key_len = (nssuint_t)len;

    off += len;
    pbuf->data_off = (nssuint_t)off;
    pbuf->data_len = (nssuint_t)(bufsize - off);
    return (NSS_SUCCESS);
}

/*
 * Unpack packed arguments buffer
 * Return: status, errnos and results from requested operation.
 *
 * NOTES: When getgroupsbymember is being processed in the NSCD backend,
 * or via the backwards compatibility interfaces then the standard
 * str2group API is used in conjunction with process_cstr.  When,
 * processing a returned buffer, in NSS2 the return results are the
 * already digested groups array.  Therefore, unpack the digested results
 * back to the return buffer.
 *
 * Note: the digested results are nssuint_t quantities.  _getgroupsbymember
 * digests int quantities.  Therefore convert.  Assume input is in nssuint_t
 * quantities.  Store in an int array... Assume gid's are <= 32 bits...
 */

/*ARGSUSED*/
nss_status_t
nss_unpack(void *buffer, size_t bufsize, nss_db_root_t *rootp,
    nss_db_initf_t initf, int search_fnum, void *search_args)
{
    nss_pheader_t       *pbuf = (nss_pheader_t *)buffer;
    nss_XbyY_args_t     *in = (nss_XbyY_args_t *)search_args;
    nss_dbd_t       *pdbd;
    char            *dbn;
    nss_status_t        status;
    char            *buf;
    int         len;
    int         ret;
    int         i;
    int         fmt_type;
    gid_t           *gidp;
    gid_t           *gptr;
    struct nss_groupsbymem  *arg;


    if (pbuf == NULL || in == NULL)
        return (-1);
    status = pbuf->p_status;
    /* Identify odd cases */
    pdbd = (nss_dbd_t *)((void *)((char *)buffer + pbuf->dbd_off));
    dbn = (char *)pdbd + pdbd->o_name;
    fmt_type = 0; /* nss_XbyY_args_t */
    if (search_fnum == NSS_DBOP_GROUP_BYMEMBER &&
        strcmp(dbn, NSS_DBNAM_GROUP) == 0)
        fmt_type = 1; /* struct nss_groupsbymem */
    else if (search_fnum == NSS_DBOP_NETGROUP_IN &&
        strcmp(dbn, NSS_DBNAM_NETGROUP) == 0)
        fmt_type = 2; /* struct nss_innetgr_args */

    /* if error - door's switch error */
    /* extended data could contain additional information? */
    if (status != NSS_SUCCESS) {
        if (fmt_type == 0) {
            in->h_errno = (int)pbuf->p_herrno;
            if (pbuf->p_errno == ERANGE)
                in->erange = 1;
        }
        return (status);
    }

    if (pbuf->data_off == 0 || pbuf->data_len == 0)
        return (NSS_NOTFOUND);

    buf = (char *)buffer + pbuf->data_off;
    len = pbuf->data_len;

    /* sidestep odd cases */
    if (fmt_type == 1) {
        arg = (struct nss_groupsbymem *)in;
        /* copy returned gid array from returned nscd buffer */
        i = len / sizeof (gid_t);
        /* not enough buffer */
        if (i > arg->maxgids) {
            i = arg->maxgids;
        }
        arg->numgids = i;
        gidp = arg->gid_array;
        gptr = (gid_t *)((void *)buf);
        (void) memcpy(gidp, gptr, len);
        return (NSS_SUCCESS);
    }
    if (fmt_type == 2) {
        struct nss_innetgr_args *arg = (struct nss_innetgr_args *)in;

        if (pbuf->p_status == NSS_SUCCESS) {
            arg->status = NSS_NETGR_FOUND;
            return (NSS_SUCCESS);
        } else {
            arg->status = NSS_NETGR_NO;
            return (NSS_NOTFOUND);
        }
    }

    /* process the normal cases */
    /* marshall data directly into users buffer */
    ret = (*in->str2ent)(buf, len, in->buf.result, in->buf.buffer,
        in->buf.buflen);
    if (ret == NSS_STR_PARSE_ERANGE) {
        in->returnval = 0;
        in->returnlen = 0;
        in->erange    = 1;
        ret = NSS_NOTFOUND;
    } else if (ret == NSS_STR_PARSE_SUCCESS) {
        in->returnval = in->buf.result;
        in->returnlen =  len;
        ret = NSS_SUCCESS;
    }
    in->h_errno = (int)pbuf->p_herrno;
    return ((nss_status_t)ret);
}

/*
 * Unpack a returned packed {set,get,end}ent arguments buffer
 * Return: status, errnos, cookie info and results from requested operation.
 */

/*ARGSUSED*/
nss_status_t
nss_unpack_ent(void *buffer, size_t bufsize, nss_db_root_t *rootp,
    nss_db_initf_t initf, nss_getent_t *contextpp, void *args)
{
    nss_pheader_t       *pbuf = (nss_pheader_t *)buffer;
    nss_XbyY_args_t     *in = (nss_XbyY_args_t *)args;
    struct nss_getent_context *contextp = contextpp->ctx;
    nssuint_t       *nptr;
    nssuint_t       cookie;
    nss_status_t        status;
    char            *buf;
    int         len;
    int         ret;

    if (pbuf == NULL)
        return (-1);
    status = pbuf->p_status;
    /* if error - door's switch error */
    /* extended data could contain additional information? */
    if (status != NSS_SUCCESS)
        return (status);

    /* unpack assigned cookie from SET/GET/END request */
    if (pbuf->key_off == 0 ||
        pbuf->key_len != (sizeof (nssuint_t) * 2))
        return (NSS_NOTFOUND);

    nptr = (nssuint_t *)((void *)((char *)buffer + pbuf->key_off));
    cookie = contextp->cookie;
    if (cookie != NSCD_NEW_COOKIE && cookie != contextp->cookie_setent &&
        cookie != *nptr) {
        /*
         * Should either be new, or the cookie returned by the last
         * setent (i.e., this is the first getent after the setent)
         * or a match, else error
         */
        return (NSS_NOTFOUND);
    }
    /* save away for the next ent request */
    contextp->cookie = *nptr++;
    contextp->seq_num = *nptr;

    /* All done if no marshalling is expected {set,end}ent */
    if (args == NULL)
        return (NSS_SUCCESS);

    /* unmarshall the data */
    if (pbuf->data_off == 0 || pbuf->data_len == 0)
        return (NSS_NOTFOUND);
    buf = (char *)buffer + pbuf->data_off;

    len = pbuf->data_len;

    /* marshall data directly into users buffer */
    ret = (*in->str2ent)(buf, len, in->buf.result, in->buf.buffer,
        in->buf.buflen);
    if (ret == NSS_STR_PARSE_ERANGE) {
        in->returnval = 0;
        in->returnlen = 0;
        in->erange    = 1;
    } else if (ret == NSS_STR_PARSE_SUCCESS) {
        in->returnval = in->buf.result;
        in->returnlen =  len;
    }
    in->h_errno = (int)pbuf->p_herrno;
    return ((nss_status_t)ret);
}

/*
 * Start of _nsc_{search|setent_u|getent_u|endent_u} NSCD interposition funcs
 */

nss_status_t
_nsc_search(nss_db_root_t *rootp, nss_db_initf_t initf, int search_fnum,
    void *search_args)
{
    nss_pheader_t       *pbuf;
    void            *doorptr = NULL;
    size_t          bufsize = 0;
    size_t          datasize = 0;
    nss_status_t        status;

    if (_nsc_proc_is_cache() > 0) {
        /* internal nscd call - don't use the door */
        return (NSS_TRYLOCAL);
    }

    /* standard client calls nscd code */
    if (search_args == NULL)
        return (NSS_NOTFOUND);

    /* get the door buffer  & configured size */
    bufsize = ((nss_XbyY_args_t *)search_args)->buf.buflen;
    if (_nsc_getdoorbuf(&doorptr, &bufsize) != 0)
        return (NSS_TRYLOCAL);
    if (doorptr == NULL || bufsize == 0)
        return (NSS_TRYLOCAL);

    pbuf = (nss_pheader_t *)doorptr;
    /* pack argument and request into door buffer */
    pbuf->nsc_callnumber = NSCD_SEARCH;
    /* copy relevant door request info into door buffer */
    status = nss_pack((void *)pbuf, bufsize, rootp,
        initf, search_fnum, search_args);

    /* Packing error return error results */
    if (status != NSS_SUCCESS)
        return (status);

    /* transfer packed switch request to nscd via door */
    /* data_off can be used because it is header+dbd_len+key_len */
    datasize = pbuf->data_off;
    status = _nsc_trydoorcall_ext(&doorptr, &bufsize, &datasize);

    /* If unsuccessful fallback to standard nss logic */
    if (status != NSS_SUCCESS) {
        /*
         * check if doors reallocated the memory underneath us
         * if they did munmap it or suffer a memory leak
         */
        if (doorptr != (void *)pbuf) {
            _nsc_resizedoorbuf(bufsize);
            (void) munmap((void *)doorptr, bufsize);
        }
        return (NSS_TRYLOCAL);
    }

    /* unpack and marshall data/errors to user structure */
    /* set any error conditions */
    status = nss_unpack((void *)doorptr, bufsize, rootp, initf,
        search_fnum, search_args);
    /*
     * check if doors reallocated the memory underneath us
     * if they did munmap it or suffer a memory leak
     */
    if (doorptr != (void *)pbuf) {
        _nsc_resizedoorbuf(bufsize);
        (void) munmap((void *)doorptr, bufsize);
    }
    return (status);
}

/*
 * contact nscd for a cookie or to reset an existing cookie
 * if nscd fails (NSS_TRYLOCAL) then set cookie to -1 and
 * continue diverting to local
 */
nss_status_t
_nsc_setent_u(nss_db_root_t *rootp, nss_db_initf_t initf,
    nss_getent_t *contextpp)
{
    nss_status_t        status = NSS_TRYLOCAL;
    struct nss_getent_context *contextp = contextpp->ctx;
    nss_pheader_t       *pbuf;
    void            *doorptr = NULL;
    size_t          bufsize = 0;
    size_t          datasize = 0;

    /* return if already in local mode */
    if (contextp->cookie == NSCD_LOCAL_COOKIE)
        return (NSS_TRYLOCAL);

    if (_nsc_proc_is_cache() > 0) {
        /* internal nscd call - don't try to use the door */
        contextp->cookie = NSCD_LOCAL_COOKIE;
        return (NSS_TRYLOCAL);
    }

    /* get the door buffer & configured size */
    if (_nsc_getdoorbuf(&doorptr, &bufsize) != 0) {
        contextp->cookie = NSCD_LOCAL_COOKIE;
        return (NSS_TRYLOCAL);
    }
    if (doorptr == NULL || bufsize == 0) {
        contextp->cookie = NSCD_LOCAL_COOKIE;
        return (NSS_TRYLOCAL);
    }

    pbuf = (nss_pheader_t *)doorptr;
    pbuf->nsc_callnumber = NSCD_SETENT;

    contextp->param.cleanup = NULL;
    (*initf)(&contextp->param);
    if (contextp->param.name == 0) {
        if (contextp->param.cleanup != 0)
            (contextp->param.cleanup)(&contextp->param);
        errno = ERANGE;         /* actually EINVAL */
        return (NSS_ERROR);
    }

    /* pack relevant setent request info into door buffer */
    status = nss_pack_ent((void *)pbuf, bufsize, rootp, initf, contextpp);
    if (status != NSS_SUCCESS)
        return (status);

    /* transfer packed switch request to nscd via door */
    /* data_off can be used because it is header+dbd_len+key_len */
    datasize = pbuf->data_off;
    status = _nsc_trydoorcall_ext(&doorptr, &bufsize, &datasize);

    /* If fallback to standard nss logic (door failure) if possible */
    if (status != NSS_SUCCESS) {
        if (contextp->cookie == NSCD_NEW_COOKIE) {
            contextp->cookie = NSCD_LOCAL_COOKIE;
            return (NSS_TRYLOCAL);
        }
        return (NSS_UNAVAIL);
    }
    /* unpack returned cookie stash it away */
    status = nss_unpack_ent((void *)doorptr, bufsize, rootp,
        initf, contextpp, NULL);
    /* save the setent cookie for later use */
    contextp->cookie_setent = contextp->cookie;
    /*
     * check if doors reallocated the memory underneath us
     * if they did munmap it or suffer a memory leak
     */
    if (doorptr != (void *)pbuf) {
        _nsc_resizedoorbuf(bufsize);
        (void) munmap((void *)doorptr, bufsize);
    }
    return (status);
}

nss_status_t
_nsc_getent_u(nss_db_root_t *rootp, nss_db_initf_t initf,
    nss_getent_t *contextpp, void *args)
{
    nss_status_t        status = NSS_TRYLOCAL;
    struct nss_getent_context *contextp = contextpp->ctx;
    nss_pheader_t       *pbuf;
    void            *doorptr = NULL;
    size_t          bufsize = 0;
    size_t          datasize = 0;

    /* return if already in local mode */
    if (contextp->cookie == NSCD_LOCAL_COOKIE)
        return (NSS_TRYLOCAL);

    /* _nsc_setent_u already checked for nscd local case ... proceed */
    if (args == NULL)
        return (NSS_NOTFOUND);

    /* get the door buffer  & configured size */
    bufsize = ((nss_XbyY_args_t *)args)->buf.buflen;
    if (_nsc_getdoorbuf(&doorptr, &bufsize) != 0)
        return (NSS_UNAVAIL);
    if (doorptr == NULL || bufsize == 0)
        return (NSS_UNAVAIL);

    pbuf = (nss_pheader_t *)doorptr;
    pbuf->nsc_callnumber = NSCD_GETENT;

    /* pack relevant setent request info into door buffer */
    status = nss_pack_ent((void *)pbuf, bufsize, rootp, initf, contextpp);
    if (status != NSS_SUCCESS)
        return (status);

    /* transfer packed switch request to nscd via door */
    /* data_off can be used because it is header+dbd_len+key_len */
    datasize = pbuf->data_off;
    status = _nsc_trydoorcall_ext(&doorptr, &bufsize, &datasize);

    /* If fallback to standard nss logic (door failure) if possible */
    if (status != NSS_SUCCESS) {
        if (status == NSS_TRYLOCAL ||
            contextp->cookie == NSCD_NEW_COOKIE) {
            contextp->cookie = NSCD_LOCAL_COOKIE;

            /* init the local cookie */
            nss_setent_u(rootp, initf, contextpp);
            if (contextpp->ctx == 0)
                return (NSS_UNAVAIL);
            return (NSS_TRYLOCAL);
        }
        return (NSS_UNAVAIL);
    }
    /* check error, unpack and process results */
    status = nss_unpack_ent((void *)doorptr, bufsize, rootp,
        initf, contextpp, args);
    /*
     * check if doors reallocated the memory underneath us
     * if they did munmap it or suffer a memory leak
     */
    if (doorptr != (void *)pbuf) {
        _nsc_resizedoorbuf(bufsize);
        (void) munmap((void *)doorptr, bufsize);
    }
    return (status);
}

nss_status_t
_nsc_endent_u(nss_db_root_t *rootp, nss_db_initf_t initf,
    nss_getent_t *contextpp)
{
    nss_status_t        status = NSS_TRYLOCAL;
    struct nss_getent_context *contextp = contextpp->ctx;
    nss_pheader_t       *pbuf;
    void            *doorptr = NULL;
    size_t          bufsize = 0;
    size_t          datasize = 0;

    /* return if already in local mode */
    if (contextp->cookie == NSCD_LOCAL_COOKIE)
        return (NSS_TRYLOCAL);

    /* _nsc_setent_u already checked for nscd local case ... proceed */

    /* get the door buffer  & configured size */
    if (_nsc_getdoorbuf(&doorptr, &bufsize) != 0)
        return (NSS_UNAVAIL);
    if (doorptr == NULL || bufsize == 0)
        return (NSS_UNAVAIL);

    /* pack up a NSCD_ENDGET request passing in the cookie */
    pbuf = (nss_pheader_t *)doorptr;
    pbuf->nsc_callnumber = NSCD_ENDENT;

    /* pack relevant setent request info into door buffer */
    status = nss_pack_ent((void *)pbuf, bufsize, rootp, initf, contextpp);
    if (status != NSS_SUCCESS)
        return (status);

    /* transfer packed switch request to nscd via door */
    /* data_off can be used because it is header+dbd_len+key_len */
    datasize = pbuf->data_off;
    (void) _nsc_trydoorcall_ext(&doorptr, &bufsize, &datasize);

    /* error codes & unpacking ret values don't matter.  We're done */

    /*
     * check if doors reallocated the memory underneath us
     * if they did munmap it or suffer a memory leak
     */
    if (doorptr != (void *)pbuf) {
        _nsc_resizedoorbuf(bufsize);
        (void) munmap((void *)doorptr, bufsize);
    }

    /* clean up initf setup */
    if (contextp->param.cleanup != 0)
        (contextp->param.cleanup)(&contextp->param);
    contextp->param.cleanup = NULL;

    /* clear cookie */
    contextp->cookie = NSCD_NEW_COOKIE;
    return (NSS_SUCCESS);
}

/*
 * Internal private API to return default suggested buffer sizes
 * for nsswitch API requests.
 */

size_t
_nss_get_bufsizes(int arg)
{
    switch (arg) {
    case _SC_GETGR_R_SIZE_MAX:
        return (__nss_buflen_group);
    }
    return (__nss_buflen_default);
}

void *
_nss_XbyY_fini(nss_XbyY_args_t *args)
{
    if ((args->returnval == NULL) && (args->erange != 0))
        errno = ERANGE;
    return (args->returnval);
}