/*
 * 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.
 */

/*
 * Functions for managing thread-local storage for LDAP, and in particular
 * for managing storage of the LDAP error state.
 */

#include <ldap.h>
#include <pthread.h>
#include <errno.h>
#include <note.h>
#include <syslog.h>
#include <string.h>
#include "solaris-int.h"        /* This is a libladp5 private include file */
                                /* which has the defintion for */
                                /* struct ldap_extra_thread_fns */
#include "adutils_impl.h"

struct adutils_lderrno {
        int le_errno;
        char *le_matched;
        char *le_errmsg;
};

static void *adutils_threadid(void);
static void *adutils_mutex_alloc(void);
static void adutils_mutex_free(void *mutexp);
static int adutils_get_errno(void);
static void adutils_set_errno(int err);
static void adutils_set_lderrno(int err, char *matched, char *errmsg,
    void *dummy);
static int adutils_get_lderrno(char **matched, char **errmsg, void *dummy);
static void adutils_lderrno_destructor(void *tsd);

static pthread_key_t adutils_lderrno_key = PTHREAD_ONCE_KEY_NP;

static struct ldap_thread_fns thread_fns = {
        .ltf_mutex_alloc = adutils_mutex_alloc,
        .ltf_mutex_free = adutils_mutex_free,
        .ltf_mutex_lock = (int (*)(void *)) pthread_mutex_lock,
        .ltf_mutex_unlock = (int (*)(void *)) pthread_mutex_unlock,
        .ltf_get_errno = adutils_get_errno,
        .ltf_set_errno = adutils_set_errno,
        .ltf_get_lderrno = adutils_get_lderrno,
        .ltf_set_lderrno = adutils_set_lderrno,
        .ltf_lderrno_arg = NULL
};

struct ldap_extra_thread_fns extra_thread_fns = {
        .ltf_threadid_fn = adutils_threadid
};

/*
 * Set up thread management functions for the specified LDAP session.
 * Returns either LDAP_SUCCESS or -1.
 */
int
adutils_set_thread_functions(LDAP *ld)
{
        int rc;

        if (adutils_lderrno_key == PTHREAD_ONCE_KEY_NP) {
                if ((rc = pthread_key_create_once_np(&adutils_lderrno_key,
                    adutils_lderrno_destructor)) != 0) {
                        logger(LOG_ERR, "adutils_set_thread_functions() "
                            "pthread_key_create_once_np failed (%s)",
                            strerror(rc));
                        rc = -1;
                        return (rc);
                }
        }

        rc = ldap_set_option(ld, LDAP_OPT_THREAD_FN_PTRS,
            &thread_fns);
        if (rc != LDAP_SUCCESS) {
                logger(LOG_ERR,
                    "ldap_set_option LDAP_OPT_THREAD_FN_PTRS failed");
                return (rc);
        }

        rc = ldap_set_option(ld, LDAP_OPT_EXTRA_THREAD_FN_PTRS,
            &extra_thread_fns);
        if (rc != LDAP_SUCCESS) {
                logger(LOG_ERR,
                    "ldap_set_option LDAP_OPT_EXTRA_THREAD_FN_PTRS failed");
                return (rc);
        }
        return (rc);
}

static void *
adutils_threadid(void)
{
        return ((void *)(uintptr_t)pthread_self());
}

/*
 * Allocate a mutex.
 */
static
void *
adutils_mutex_alloc(void)
{
        pthread_mutex_t *mutexp;
        int rc;

        mutexp = malloc(sizeof (pthread_mutex_t));
        if (mutexp == NULL) {
                logger(LOG_ERR,
                    "adutils_mutex_alloc: malloc failed (%s)",
                    strerror(errno));
                return (NULL);
        }

        rc = pthread_mutex_init(mutexp, NULL);
        if (rc != 0) {
                logger(LOG_ERR,
                    "adutils_mutex_alloc: "
                    "pthread_mutex_init failed (%s)",
                    strerror(rc));
                free(mutexp);
                return (NULL);
        }
        return (mutexp);
}

/*
 * Free a mutex.
 */
static
void
adutils_mutex_free(void *mutexp)
{
        (void) pthread_mutex_destroy((pthread_mutex_t *)mutexp);
        free(mutexp);
}

/*
 * Get the thread's local errno.
 */
static
int
adutils_get_errno(void)
{
        return (errno);
}

/*
 * Set the thread's local errno.
 */
static
void
adutils_set_errno(int err)
{
        errno = err;
}

/*
 * Get a pointer to the thread's local LDAP error state structure.
 * Lazily allocate the thread-local storage, so that we don't need
 * initialization when each thread starts.
 */
static
struct adutils_lderrno *
adutils_get_lderrno_struct(void)
{
        struct adutils_lderrno *le;
        int rc;

        le = pthread_getspecific(adutils_lderrno_key);
        if (le == NULL) {
                le = calloc(1, sizeof (*le));
                if (le == NULL) {
                        logger(LOG_ERR,
                            "adutils_get_lderrno_struct:  calloc failed (%s)",
                            strerror(errno));
                        return (NULL);
                }
                rc = pthread_setspecific(adutils_lderrno_key, le);
                if (rc != 0) {
                        logger(LOG_ERR,
                            "adutils_get_lderrno_struct:  "
                            "pthread_setspecific failed (%s)",
                            strerror(rc));
                        free(le);
                        return (NULL);
                }
        }

        return (le);
}

/*
 * Store an error report in the thread's local LDAP error state structure.
 */
static
void
adutils_set_lderrno(int err, char *matched, char *errmsg, void *dummy)
{
        NOTE(ARGUNUSED(dummy))
        struct adutils_lderrno *le;

        le = adutils_get_lderrno_struct();
        if (le != NULL) {
                le->le_errno = err;
                if (le->le_matched != NULL)
                        ldap_memfree(le->le_matched);
                le->le_matched = matched;
                if (le->le_errmsg != NULL)
                        ldap_memfree(le->le_errmsg);
                le->le_errmsg = errmsg;
        }
}

/*
 * Retrieve an error report from the thread's local LDAP error state structure.
 */
static
int
adutils_get_lderrno(char **matched, char **errmsg, void *dummy)
{
        NOTE(ARGUNUSED(dummy))
        struct adutils_lderrno *le;
        static struct adutils_lderrno empty = { LDAP_SUCCESS, NULL, NULL };

        le = adutils_get_lderrno_struct();
        if (le == NULL)
                le = &empty;

        if (matched != NULL)
                *matched = le->le_matched;
        if (errmsg != NULL)
                *errmsg = le->le_errmsg;
        return (le->le_errno);
}

/*
 * Free the thread's local LDAP error state structure.
 */
static
void
adutils_lderrno_destructor(void *tsd)
{
        struct adutils_lderrno *le = tsd;

        if (le == NULL)
                return;

        if (le->le_matched != NULL) {
                ldap_memfree(le->le_matched);
                le->le_matched = NULL;
        }
        if (le->le_errmsg != NULL) {
                ldap_memfree(le->le_errmsg);
                le->le_errmsg = NULL;
        }
        free(le);
}