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

#include <thread.h>
#include <pthread.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <libelf.h>
#include <libintl.h>
#include "msg.h"
#include "decl.h"

#define ELFERRSHIFT     16
#define SYSERRMASK      0xffff

/*
 * _elf_err has two values encoded in it, both the _elf_err # and
 * the system errno value (if relevant).  These values are encoded
 * in the upper & lower 16 bits of the 4 byte integer.
 */
static int              _elf_err = 0;

static thread_key_t     errkey = THR_ONCE_KEY;
static thread_key_t     bufkey = THR_ONCE_KEY;

const char *
_libelf_msg(Msg mid)
{
        return (dgettext(MSG_ORIG(MSG_SUNW_OST_SGS), MSG_ORIG(mid)));
}

void
_elf_seterr(Msg lib_err, int sys_err)
{
        /*LINTED*/
        intptr_t encerr = ((int)lib_err << ELFERRSHIFT) |
            (sys_err & SYSERRMASK);

        if (thr_main()) {
                _elf_err = (int)encerr;
                return;
        }
        (void) thr_keycreate_once(&errkey, 0);
        (void) thr_setspecific(errkey, (void *)encerr);
}

int
_elf_geterr() {
        if (thr_main())
                return (_elf_err);
        return ((uintptr_t)pthread_getspecific(errkey));
}

const char *
elf_errmsg(int err)
{
        char                    *errno_str;
        char                    *elferr_str;
        char                    *buffer = 0;
        int                     syserr;
        int                     elferr;
        static char             intbuf[MAXELFERR];

        if (err == 0) {
                if ((err = _elf_geterr()) == 0)
                        return (0);
        } else if (err == -1) {
                if ((err = _elf_geterr()) == 0)
                        /*LINTED*/ /* MSG_INTL(EINF_NULLERROR) */
                        err = (int)EINF_NULLERROR << ELFERRSHIFT;
        }

        if (thr_main())
                buffer = intbuf;
        else {
                /*
                 * If this is a threaded APP then we store the
                 * errmsg buffer in Thread Specific Storage.
                 *
                 * Each thread has its own private buffer.
                 */
                if (thr_keycreate_once(&bufkey, free) != 0)
                        return (MSG_INTL(EBUG_THRDKEY));
                buffer = pthread_getspecific(bufkey);

                if (!buffer) {
                        if ((buffer = malloc(MAXELFERR)) == 0)
                                return (MSG_INTL(EMEM_ERRMSG));
                        if (thr_setspecific(bufkey, buffer) != 0) {
                                free(buffer);
                                return (MSG_INTL(EBUG_THRDSET));
                        }
                }
        }

        elferr = (int)((uint_t)err >> ELFERRSHIFT);
        syserr = err & SYSERRMASK;
        /*LINTED*/
        elferr_str = (char *)MSG_INTL(elferr);
        if (syserr && (errno_str = strerror(syserr)))
                (void) snprintf(buffer, MAXELFERR,
                    MSG_ORIG(MSG_FMT_ERR), elferr_str, errno_str);
        else {
                (void) strncpy(buffer, elferr_str, MAXELFERR - 1);
                buffer[MAXELFERR - 1] = '\0';
        }

        return (buffer);
}

int
elf_errno()
{
        int     rc = _elf_geterr();

        _elf_seterr(0, 0);
        return (rc);
}