/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * The contents of this file are subject to the Netscape Public
 * License Version 1.1 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.mozilla.org/NPL/
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * The Original Code is Mozilla Communicator client code, released
 * March 31, 1998.
 *
 * The Initial Developer of the Original Code is Netscape
 * Communications Corporation. Portions created by Netscape are
 * Copyright (C) 1998-1999 Netscape Communications Corporation. All
 * Rights Reserved.
 *
 * Contributor(s):
 */

/*
 * Thread callback functions for libldap that use the NSPR (Netscape
 * Portable Runtime) thread API.
 *
 */

#ifdef _SOLARIS_SDK
#include <thread.h>
#include <synch.h>
#include <prinit.h>
#include <prthread.h>
#include <syslog.h>
#include <string.h>
#include <sys/types.h>
#include <signal.h>
#include <errno.h>
extern int      errno;
#endif  /* _SOLARIS_SDK */

#include "ldappr-int.h"

#ifndef _SOLARIS_SDK
/*
 * Macros:
 */
/*
 * Grow thread private data arrays 10 elements at a time.
 */
#define PRLDAP_TPD_ARRAY_INCREMENT      10

/*
 * Structures and types:
 */
/*
 * Structure used by libldap thread callbacks to maintain error information.
 */
typedef struct prldap_errorinfo {
    int         plei_lderrno;
    char        *plei_matched;
    char        *plei_errmsg;
} PRLDAP_ErrorInfo;

/*
 * Structure used to maintain thread-private data. At the present time,
 * only error info. is thread-private.  One of these structures is allocated
 * for each thread.
 */
typedef struct prldap_tpd_header {
    int                 ptpdh_tpd_count;        /* # of data items allocated */
    void                **ptpdh_dataitems;      /* array of data items */
} PRLDAP_TPDHeader;

/*
 * Structure used by associate a PRLDAP thread-private data index with an
 * LDAP session handle. One of these exists for each active LDAP session
 * handle.
 */
typedef struct prldap_tpd_map {
    LDAP                        *prtm_ld;       /* non-NULL if in use */
    PRUintn                     prtm_index;     /* index into TPD array */
    struct prldap_tpd_map       *prtm_next;
} PRLDAP_TPDMap;

#ifdef _SOLARIS_SDK
extern  mutex_t         inited_mutex;
#endif  /* _SOLARIS_SDK */

/*
 * Static Variables:
 */
/*
 * prldap_map_list points to all of the PRLDAP_TPDMap structures
 * we have ever allocated.  We recycle them as we open and close LDAP
 * sessions.
 */
static PRLDAP_TPDMap *prldap_map_list = NULL;


/*
 * The prldap_map_mutex is used to protect access to the prldap_map_list.
 */
static PRLock   *prldap_map_mutex = NULL;

/*
 * The prldap_tpd_maxindex value is used to track the largest TPD array
 * index we have used.
 */
static PRInt32  prldap_tpd_maxindex = -1;

/*
 * prldap_tpdindex is an NSPR thread private data index we use to
 * maintain our own thread-private data. It is initialized inside
 * prldap_init_tpd().
 */
static PRUintn  prldap_tpdindex = 0;

/*
 * The prldap_callonce_init_tpd structure is used by NSPR to ensure
 * that prldap_init_tpd() is called at most once.
 */
static PRCallOnceType prldap_callonce_init_tpd = { 0, 0, 0 };


/*
 * Private function prototypes:
 */
static void prldap_set_ld_error( int err, char *matched, char *errmsg,
        void *errorarg );
static int prldap_get_ld_error( char **matchedp, char **errmsgp,
        void *errorarg );
#endif
static void *prldap_mutex_alloc( void );
static void prldap_mutex_free( void *mutex );
static int prldap_mutex_lock( void *mutex );
static int prldap_mutex_unlock( void *mutex );
static void *prldap_get_thread_id( void );
#ifndef _SOLARIS_SDK
static PRStatus prldap_init_tpd( void );
static PRLDAP_TPDMap *prldap_allocate_map( LDAP *ld );
static void prldap_return_map( PRLDAP_TPDMap *map );
static PRUintn prldap_new_tpdindex( void );
static int prldap_set_thread_private( PRInt32 tpdindex, void *priv );
static void *prldap_get_thread_private( PRInt32 tpdindex );
static PRLDAP_TPDHeader *prldap_tsd_realloc( PRLDAP_TPDHeader *tsdhdr,
        int maxindex );
static void prldap_tsd_destroy( void *priv );
#endif


/*
 * Install NSPR thread functions into ld (if ld is NULL, they are installed
 * as the default functions for new LDAP * handles).
 *
 * Returns 0 if all goes well and -1 if not.
 */
int
prldap_install_thread_functions( LDAP *ld, int shared )
{
    struct ldap_thread_fns              tfns;
    struct ldap_extra_thread_fns        xtfns;

#ifndef _SOLARIS_SDK
    if ( PR_CallOnce( &prldap_callonce_init_tpd, prldap_init_tpd )
                != PR_SUCCESS ) {
        ldap_set_lderrno( ld, LDAP_LOCAL_ERROR, NULL, NULL );
        return( -1 );
    }
#endif  /* _SOLARIS_SDK */

    /* set thread function pointers */
    memset( &tfns, '\0', sizeof(struct ldap_thread_fns) );
    tfns.ltf_get_errno = prldap_get_system_errno;
    tfns.ltf_set_errno = prldap_set_system_errno;
    if ( shared ) {
        tfns.ltf_mutex_alloc = prldap_mutex_alloc;
        tfns.ltf_mutex_free = prldap_mutex_free;
        tfns.ltf_mutex_lock = prldap_mutex_lock;
        tfns.ltf_mutex_unlock = prldap_mutex_unlock;
#ifdef _SOLARIS_SDK
        tfns.ltf_get_lderrno = NULL;
        tfns.ltf_set_lderrno = NULL;
#else
        tfns.ltf_get_lderrno = prldap_get_ld_error;
        tfns.ltf_set_lderrno = prldap_set_ld_error;
        if ( ld != NULL ) {
            /*
             * If this is a real ld (i.e., we are not setting the global
             * defaults) allocate thread private data for error information.
             * If ld is NULL we do not do this here but it is done in
             * prldap_thread_new_handle().
             */
            if (( tfns.ltf_lderrno_arg = (void *)prldap_allocate_map( ld ))
                    == NULL ) {
                return( -1 );
            }
        }
#endif
    }

    if ( ldap_set_option( ld, LDAP_OPT_THREAD_FN_PTRS,
            (void *)&tfns ) != 0 ) {
#ifndef _SOLARIS_SDK
        prldap_return_map( (PRLDAP_TPDMap *)tfns.ltf_lderrno_arg );
#endif
        return( -1 );
    }

    /* set extended thread function pointers */
    memset( &xtfns, '\0', sizeof(struct ldap_extra_thread_fns) );
    xtfns.ltf_threadid_fn = prldap_get_thread_id;
    if ( ldap_set_option( ld, LDAP_OPT_EXTRA_THREAD_FN_PTRS,
            (void *)&xtfns ) != 0 ) {
        return( -1 );
    }

    return( 0 );
}


static void *
prldap_mutex_alloc( void )
{
    return( (void *)PR_NewLock());
}


static void
prldap_mutex_free( void *mutex )
{
    PR_DestroyLock( (PRLock *)mutex );
}


static int
prldap_mutex_lock( void *mutex )
{
    PR_Lock( (PRLock *)mutex );
    return( 0 );
}


static int
prldap_mutex_unlock( void *mutex )
{
    if ( PR_Unlock( (PRLock *)mutex ) == PR_FAILURE ) {
        return( -1 );
    }

    return( 0 );
}


static void *
prldap_get_thread_id( void )
{
#ifdef  _SOLARIS_SDK
        return ((void *)thr_self());
#else
    return( (void *)PR_GetCurrentThread());
#endif
}

#ifndef _SOLARIS_SDK
static int
prldap_get_ld_error( char **matchedp, char **errmsgp, void *errorarg )
{
    PRLDAP_TPDMap       *map;
    PRLDAP_ErrorInfo    *eip;

    if (( map = (PRLDAP_TPDMap *)errorarg ) != NULL && ( eip =
            (PRLDAP_ErrorInfo *)prldap_get_thread_private(
            map->prtm_index )) != NULL ) {
        if ( matchedp != NULL ) {
            *matchedp = eip->plei_matched;
        }
        if ( errmsgp != NULL ) {
            *errmsgp = eip->plei_errmsg;
        }
        return( eip->plei_lderrno );
    } else {
        if ( matchedp != NULL ) {
            *matchedp = NULL;
        }
        if ( errmsgp != NULL ) {
            *errmsgp = NULL;
        }
        return( LDAP_LOCAL_ERROR );     /* punt */
    }
}


static void
prldap_set_ld_error( int err, char *matched, char *errmsg, void *errorarg )
{
    PRLDAP_TPDMap       *map;
    PRLDAP_ErrorInfo    *eip;

    if (( map = (PRLDAP_TPDMap *)errorarg ) != NULL ) {
        if (( eip = (PRLDAP_ErrorInfo *)prldap_get_thread_private(
                map->prtm_index )) == NULL ) {
            /*
             * Error info. has not yet been allocated for this thread.
             * Do so now.  Note that we free this memory only for the
             * thread that calls prldap_thread_dispose_handle(), which
             * should be the one that called ldap_unbind() -- see
             * prldap_return_map().  Not freeing the memory used by
             * other threads is deemed acceptable since it will be
             * recycled and used by other LDAP sessions.  All of the
             * thread-private memory is freed when a thread exits
             * (inside the prldap_tsd_destroy() function).
             */
            eip = (PRLDAP_ErrorInfo *)PR_Calloc( 1,
                    sizeof( PRLDAP_ErrorInfo ));
            if ( eip == NULL ) {
                return; /* punt */
            }
            (void)prldap_set_thread_private( map->prtm_index, eip );
        }

        eip->plei_lderrno = err;
        if ( eip->plei_matched != NULL ) {
            ldap_memfree( eip->plei_matched );
        }
        eip->plei_matched = matched;
        if ( eip->plei_errmsg != NULL ) {
            ldap_memfree( eip->plei_errmsg );
        }
        eip->plei_errmsg = errmsg;
    }
}
#endif


/*
 * Called when a new LDAP * session handle is allocated.
 * Allocate thread-private data for error information, but only if
 * it has not already been allocated and the get_ld_error callback has
 * been installed.  If ld is not NULL when prldap_install_thread_functions()
 * is called, we will have already allocated the thread-private data there.
 */
int
prldap_thread_new_handle( LDAP *ld, void *sessionarg )
{
    struct ldap_thread_fns      tfns;

#ifndef _SOLARIS_SDK
    if ( ldap_get_option( ld, LDAP_OPT_THREAD_FN_PTRS, (void *)&tfns ) != 0 ) {
        return( LDAP_LOCAL_ERROR );
    }

    if ( tfns.ltf_lderrno_arg == NULL && tfns.ltf_get_lderrno != NULL ) {
        if (( tfns.ltf_lderrno_arg = (void *)prldap_allocate_map( ld )) == NULL
                || ldap_set_option( ld, LDAP_OPT_THREAD_FN_PTRS,
                (void *)&tfns ) != 0 ) {
            return( LDAP_LOCAL_ERROR );
        }
    }
#endif

    return( LDAP_SUCCESS );
}


/*
 * Called when an LDAP * session handle is being destroyed.
 * Clean up our thread private data map.
 */
void
prldap_thread_dispose_handle( LDAP *ld, void *sessionarg )
{
#ifndef _SOLARIS_SDK
    struct ldap_thread_fns      tfns;

    if ( ldap_get_option( ld, LDAP_OPT_THREAD_FN_PTRS,
            (void *)&tfns ) == 0 &&
            tfns.ltf_lderrno_arg != NULL ) {
        prldap_return_map( (PRLDAP_TPDMap *)tfns.ltf_lderrno_arg );
    }
#endif
}


#ifndef _SOLARIS_SDK
static PRStatus
prldap_init_tpd( void )
{
    if (( prldap_map_mutex = PR_NewLock()) == NULL || PR_NewThreadPrivateIndex(
                &prldap_tpdindex, prldap_tsd_destroy ) != PR_SUCCESS ) {
        return( PR_FAILURE );
    }

    prldap_map_list = NULL;

    return( PR_SUCCESS );
}


/*
 * Function: prldap_allocate_map()
 * Description: allocate a thread-private data map to use for a new
 *      LDAP session handle.
 * Returns: a pointer to the TPD map or NULL if none available.
 */
static PRLDAP_TPDMap *
prldap_allocate_map( LDAP *ld )
{
    PRLDAP_TPDMap       *map, *prevmap;

    PR_Lock( prldap_map_mutex );

    /*
     * first look for a map that is already allocated but free to be re-used
     */
    prevmap = NULL;
    for ( map = prldap_map_list; map != NULL; map = map->prtm_next ) {
        if ( map->prtm_ld == NULL ) {
            break;
        }
        prevmap = map;
    }

    /*
     * if none we found (map == NULL), try to allocate a new one and add it
     * to the end of our global list.
     */
    if ( map == NULL ) {
        PRUintn tpdindex;

        tpdindex = prldap_new_tpdindex();
        map = (PRLDAP_TPDMap *)PR_Malloc( sizeof( PRLDAP_TPDMap ));
        if ( map != NULL ) {
            map->prtm_index = tpdindex;
            map->prtm_next = NULL;
            if ( prevmap == NULL ) {
                prldap_map_list = map;
            } else {
                prevmap->prtm_next = map;
            }
        }
    }

    if ( map != NULL ) {
        map->prtm_ld = ld;      /* now marked as "in use" */
                                /* since we are reusing...reset */
                                /* to initial state */
        (void)prldap_set_thread_private( map->prtm_index, NULL );
    }

    PR_Unlock( prldap_map_mutex );

    return( map );
}


/*
 * Function: prldap_return_map()
 * Description: return a thread-private data map to the pool of ones
 *      available for re-use.
 */
static void
prldap_return_map( PRLDAP_TPDMap *map )
{
    PRLDAP_ErrorInfo    *eip;

    PR_Lock( prldap_map_mutex );

    /*
     * Dispose of thread-private LDAP error information.  Note that this
     * only disposes of the memory consumed on THIS thread, but that is
     * okay.  See the comment in prldap_set_ld_error() for the reason why.
     */
    if (( eip = (PRLDAP_ErrorInfo *)prldap_get_thread_private(
                map->prtm_index )) != NULL &&
                prldap_set_thread_private( map->prtm_index, NULL ) == 0 ) {
        if ( eip->plei_matched != NULL ) {
            ldap_memfree( eip->plei_matched );
        }
        if ( eip->plei_errmsg != NULL ) {
            ldap_memfree( eip->plei_errmsg );
        }

        PR_Free( eip );
    }

    /* mark map as available for re-use */
    map->prtm_ld = NULL;

    PR_Unlock( prldap_map_mutex );
}


/*
 * Function: prldap_new_tpdindex()
 * Description: allocate a thread-private data index.
 * Returns: the new index.
 */
static PRUintn
prldap_new_tpdindex( void )
{
    PRUintn     tpdindex;

    tpdindex = (PRUintn)PR_AtomicIncrement( &prldap_tpd_maxindex );
    return( tpdindex );
}


/*
 * Function: prldap_set_thread_private()
 * Description: store a piece of thread-private data.
 * Returns: 0 if successful and -1 if not.
 */
static int
prldap_set_thread_private( PRInt32 tpdindex, void *priv )
{
    PRLDAP_TPDHeader    *tsdhdr;

    if ( tpdindex > prldap_tpd_maxindex ) {
        return( -1 );   /* bad index */
    }

    tsdhdr = (PRLDAP_TPDHeader *)PR_GetThreadPrivate( prldap_tpdindex );
    if ( tsdhdr == NULL || tpdindex >= tsdhdr->ptpdh_tpd_count ) {
        tsdhdr = prldap_tsd_realloc( tsdhdr, tpdindex );
        if ( tsdhdr == NULL ) {
            return( -1 );       /* realloc failed */
        }
    }

    tsdhdr->ptpdh_dataitems[ tpdindex ] = priv;
    return( 0 );
}


/*
 * Function: prldap_get_thread_private()
 * Description: retrieve a piece of thread-private data.  If not set,
 *      NULL is returned.
 * Returns: 0 if successful and -1 if not.
 */
static void *
prldap_get_thread_private( PRInt32 tpdindex )
{
    PRLDAP_TPDHeader    *tsdhdr;

    tsdhdr = (PRLDAP_TPDHeader *)PR_GetThreadPrivate( prldap_tpdindex );
    if ( tsdhdr == NULL ) {
        return( NULL ); /* no thread private data */
    }

    if ( tpdindex >= tsdhdr->ptpdh_tpd_count
                || tsdhdr->ptpdh_dataitems == NULL ) {
        return( NULL ); /* fewer data items than requested index */
    }

    return( tsdhdr->ptpdh_dataitems[ tpdindex ] );
}


/*
 * Function: prldap_tsd_realloc()
 * Description: enlarge the thread-private data array.
 * Returns: the new PRLDAP_TPDHeader value (non-NULL if successful).
 * Note: tsdhdr can be NULL (allocates a new PRLDAP_TPDHeader).
 */
static PRLDAP_TPDHeader *
prldap_tsd_realloc( PRLDAP_TPDHeader *tsdhdr, int maxindex )
{
    void        *newdataitems = NULL;
    int         count;

    if ( tsdhdr == NULL ) {
        /* allocate a new thread private data header */
        if (( tsdhdr = PR_Calloc( 1, sizeof( PRLDAP_TPDHeader ))) == NULL ) {
            return( NULL );
        }
        (void)PR_SetThreadPrivate( prldap_tpdindex, tsdhdr );
    }

    /*
     * Make the size of the new array the next highest multiple of
     * the array increment value that is greater than maxindex.
     */
    count = PRLDAP_TPD_ARRAY_INCREMENT *
                ( 1 + ( maxindex / PRLDAP_TPD_ARRAY_INCREMENT ));

    /* increase the size of the data item array if necessary */
    if ( count > tsdhdr->ptpdh_tpd_count  ) {
        newdataitems = (PRLDAP_ErrorInfo *)PR_Calloc( count, sizeof( void * ));
        if ( newdataitems == NULL ) {
            return( NULL );
        }
        if ( tsdhdr->ptpdh_dataitems != NULL ) {        /* preserve old data */
            memcpy( newdataitems, tsdhdr->ptpdh_dataitems,
                        tsdhdr->ptpdh_tpd_count * sizeof( void * ));
            PR_Free( tsdhdr->ptpdh_dataitems );
        }

        tsdhdr->ptpdh_tpd_count = count;
        tsdhdr->ptpdh_dataitems = newdataitems;
    }

    return( tsdhdr );
}


/*
 * Function: prldap_tsd_destroy()
 * Description: Free a thread-private data array. Installed as an NSPR TPD
 *      destructor function
 * Returns: nothing.
 * Note: this function assumes that each TPD item installed at the PRLDAP
 *      level can be freed with a call to PR_Free().
 */
static void
prldap_tsd_destroy( void *priv )
{
    PRLDAP_TPDHeader    *tsdhdr;
    int                 i;

    tsdhdr = (PRLDAP_TPDHeader *)priv;
    if ( tsdhdr != NULL ) {
        if ( tsdhdr->ptpdh_dataitems != NULL ) {
            for ( i = 0; i < tsdhdr->ptpdh_tpd_count; ++i ) {
                if ( tsdhdr->ptpdh_dataitems[ i ] != NULL ) {
                    PR_Free( tsdhdr->ptpdh_dataitems[ i ] );
                    tsdhdr->ptpdh_dataitems[ i ] = NULL;
                }
            }
            PR_Free( tsdhdr->ptpdh_dataitems );
            tsdhdr->ptpdh_dataitems = NULL;
        }
        PR_Free( tsdhdr );
    }
}
#endif

#ifdef  _SOLARIS_SDK
#pragma init(prldap_nspr_init)
static mutex_t  nspr_init_lock = DEFAULTMUTEX;
static int      nspr_initialized = 0;

/*
 * Initialize NSPR once
 *
 */
void
prldap_nspr_init(void) {
        struct sigaction        action;

        /*
         * For performance reason, test it here first
         */
        if (nspr_initialized != 0)
                return;

        (void) mutex_lock(&nspr_init_lock);
        /* Make sure PR_Init() is executed only once */
        if (nspr_initialized == 0) {
                /*
                 * PR_Init changes the signal handler of SIGPIPE to SIG_IGN.
                 * Save the original and restore it after PR_Init.
                 */
                (void) sigaction(SIGPIPE, NULL, &action);

                if (PR_Initialized() == PR_FALSE) {
                        /*
                         * PR_Init() changes the current thread's
                         * priority.  Save and restore the priority.
                         */
                        int priority;
                        (void) thr_getprio(thr_self(), &priority);
                        PR_Init(PR_USER_THREAD, PR_PRIORITY_NORMAL, 0);
                        (void) thr_setprio(thr_self(), priority);
                }
                nspr_initialized = 1;
                /*
                 * Restore signal handling attributes of SIGPIPE
                 */
                (void) sigaction(SIGPIPE, &action, NULL);
        }
        (void) mutex_unlock(&nspr_init_lock);
}
#endif