/*-
 * Copyright (c) 1999 Robert N. M. Watson
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $FreeBSD: src/lib/libposix1e/acl_to_text.c,v 1.2 2000/01/26 04:19:38 rwatson Exp $
 */
/*
 * acl_to_text - return a text string with a text representation of the acl
 * in it.
 */

#include <sys/param.h>
#include <sys/acl.h>
#include <sys/errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "acl_support.h"

/*
 * acl_to_text - generate a text form of an acl
 * spec says nothing about output ordering, so leave in acl order
 *
 * This function will not produce nice results if it is called with
 * a non-POSIX.1e semantics ACL.
 */
char *
acl_to_text(acl_t acl, ssize_t *len_p)
{
        char    *buf, *tmpbuf;
        char    name_buf[MAXLOGNAME];
        char    perm_buf[ACL_STRING_PERM_MAXSIZE+1],
                effective_perm_buf[ACL_STRING_PERM_MAXSIZE+1];
        int     i, error, len;
        uid_t   ae_id;
        acl_tag_t       ae_tag;
        acl_perm_t      ae_perm, effective_perm, mask_perm;

        buf = strdup("");

        mask_perm = ACL_PERM_BITS;      /* effective is regular if no mask */
        for (i = 0; i < acl->acl_cnt; i++)
                if (acl->acl_entry[i].ae_tag == ACL_MASK) 
                        mask_perm = acl->acl_entry[i].ae_perm;

        for (i = 0; i < acl->acl_cnt; i++) {
                ae_tag = acl->acl_entry[i].ae_tag;
                ae_id = acl->acl_entry[i].ae_id;
                ae_perm = acl->acl_entry[i].ae_perm;

                switch(ae_tag) {
                case ACL_USER_OBJ:
                        error = acl_perm_to_string(ae_perm,
                            ACL_STRING_PERM_MAXSIZE+1, perm_buf);
                        if (error)
                                goto error_label;
                        len = asprintf(&tmpbuf, "%suser::%s\n", buf,
                            perm_buf);
                        if (len == -1) {
                                errno = ENOMEM;
                                goto error_label;
                        }
                        free(buf);
                        buf = tmpbuf;
                        break;

                case ACL_USER:
                        error = acl_perm_to_string(ae_perm,
                            ACL_STRING_PERM_MAXSIZE+1, perm_buf);
                        if (error)
                                goto error_label;

                        error = acl_id_to_name(ae_tag, ae_id, MAXLOGNAME,
                            name_buf);
                        if (error)
                                goto error_label;

                        effective_perm = ae_perm & mask_perm;
                        if (effective_perm != ae_perm) {
                                error = acl_perm_to_string(effective_perm,
                                    ACL_STRING_PERM_MAXSIZE+1,
                                    effective_perm_buf);
                                if (error)
                                        goto error_label;
                                len = asprintf(&tmpbuf, "%suser:%s:%s\t\t# "
                                    "effective: %s\n",
                                    buf, name_buf, perm_buf,
                                    effective_perm_buf);
                        } else {
                                len = asprintf(&tmpbuf, "%suser:%s:%s\n", buf,
                                    name_buf, perm_buf);
                        }
                        if (len == -1) {
                                errno = ENOMEM;
                                goto error_label;
                        }
                        free(buf);
                        buf = tmpbuf;
                        break;

                case ACL_GROUP_OBJ:
                        error = acl_perm_to_string(ae_perm,
                            ACL_STRING_PERM_MAXSIZE+1, perm_buf);
                        if (error)
                                goto error_label;

                        effective_perm = ae_perm & mask_perm;
                        if (effective_perm != ae_perm) {
                                error = acl_perm_to_string(effective_perm,
                                    ACL_STRING_PERM_MAXSIZE+1,
                                    effective_perm_buf);
                                if (error)
                                        goto error_label;
                                len = asprintf(&tmpbuf, "%sgroup::%s\t\t# "
                                    "effective: %s\n",
                                    buf, perm_buf, effective_perm_buf);
                        } else {
                                len = asprintf(&tmpbuf, "%sgroup::%s\n", buf,
                                    perm_buf);
                        }
                        if (len == -1) {
                                errno = ENOMEM;
                                goto error_label;
                        }
                        free(buf);
                        buf = tmpbuf;
                        break;

                case ACL_GROUP:
                        error = acl_perm_to_string(ae_perm,
                            ACL_STRING_PERM_MAXSIZE+1, perm_buf);
                        if (error)
                                goto error_label;

                        error = acl_id_to_name(ae_tag, ae_id, MAXLOGNAME,
                            name_buf);
                        if (error)
                                goto error_label;

                        effective_perm = ae_perm & mask_perm;
                        if (effective_perm != ae_perm) {
                                error = acl_perm_to_string(effective_perm,
                                    ACL_STRING_PERM_MAXSIZE+1,
                                    effective_perm_buf);
                                if (error)
                                        goto error_label;
                                len = asprintf(&tmpbuf, "%sgroup::%s\t\t# "
                                    "effective: %s\n",
                                    buf, perm_buf, effective_perm_buf);
                        } else {
                                len = asprintf(&tmpbuf, "%sgroup:%s:%s\n", buf,
                                    name_buf, perm_buf);
                        }
                        if (len == -1) {
                                errno = ENOMEM;
                                goto error_label;
                        }
                        free(buf);
                        buf = tmpbuf;
                        break;

                case ACL_MASK:
                        error = acl_perm_to_string(ae_perm,
                            ACL_STRING_PERM_MAXSIZE+1, perm_buf);
                        if (error)
                                goto error_label;

                        len = asprintf(&tmpbuf, "%smask::%s\n", buf,
                            perm_buf);
                        if (len == -1) {
                                errno = ENOMEM;
                                goto error_label;
                        }
                        free(buf);
                        buf = tmpbuf;
                        break;

                case ACL_OTHER:
                        error = acl_perm_to_string(ae_perm,
                            ACL_STRING_PERM_MAXSIZE+1, perm_buf);
                        if (error)
                                goto error_label;

                        len = asprintf(&tmpbuf, "%sother::%s\n", buf,
                            perm_buf);
                        if (len == -1) {
                                errno = ENOMEM;
                                goto error_label;
                        }
                        free(buf);
                        buf = tmpbuf;
                        break;

                default:
                        free(buf);
                        errno = EINVAL;
                        return (0);
                }
        }

        if (len_p) {
                *len_p = strlen(buf);
        }
        return (buf);

error_label:
        /* jump to here sets errno already, we just clean up */
        if (buf) free(buf);
        return (0);
}