Home | History | Annotate | Line # | Download | only in posix1e 
      1 /*-
      2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
      3  *
      4  * Copyright (c) 1999-2001, 2008 Robert N. M. Watson
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26  * SUCH DAMAGE.
     27  */
     28 /*
     29  * Support functionality for the POSIX.1e ACL interface
     30  * These calls are intended only to be called within the library.
     31  */
     32 
     33 #include <sys/cdefs.h>
     34 #if 0
     35 __FBSDID("$FreeBSD: head/lib/libc/posix1e/acl_id_to_name.c 326193 2017-11-25 17:12:48Z pfg $");
     36 #else
     37 __RCSID("$NetBSD: acl_id_to_name.c,v 1.1 2020/05/16 18:31:47 christos Exp $");
     38 #endif
     39 
     40 #include "namespace.h"
     41 #include <sys/types.h>
     42 #include <sys/acl.h>
     43 #include <errno.h>
     44 #include <grp.h>
     45 #include <pwd.h>
     46 #include <stdio.h>
     47 #include <stdlib.h>
     48 #include <string.h>
     49 #include <assert.h>
     50 
     51 #include "acl_support.h"
     52 
     53 /*
     54  * Given a uid/gid, return a username/groupname for the text form of an ACL.
     55  * Note that we truncate user and group names, rather than error out, as
     56  * this is consistent with other tools manipulating user and group names.
     57  * XXX NOT THREAD SAFE, RELIES ON GETPWUID, GETGRGID
     58  * XXX USES *PW* AND *GR* WHICH ARE STATEFUL AND THEREFORE THIS ROUTINE
     59  * MAY HAVE SIDE-EFFECTS
     60  */
     61 int
     62 _posix1e_acl_id_to_name(acl_tag_t tag, uid_t id, ssize_t buf_len, char *buf,
     63     int flags)
     64 {
     65 	struct group	*g;
     66 	struct passwd	*p;
     67 	int	i;
     68 
     69 	switch(tag) {
     70 	case ACL_USER:
     71 		if (flags & ACL_TEXT_NUMERIC_IDS)
     72 			p = NULL;
     73 		else
     74 			p = getpwuid(id);
     75 		if (!p)
     76 			i = snprintf(buf, buf_len, "%d", id);
     77 		else
     78 			i = snprintf(buf, buf_len, "%s", p->pw_name);
     79 
     80 		if (i < 0) {
     81 			errno = ENOMEM;
     82 			return (-1);
     83 		}
     84 		return (0);
     85 
     86 	case ACL_GROUP:
     87 		if (flags & ACL_TEXT_NUMERIC_IDS)
     88 			g = NULL;
     89 		else
     90 			g = getgrgid(id);
     91 		if (g == NULL)
     92 			i = snprintf(buf, buf_len, "%d", id);
     93 		else
     94 			i = snprintf(buf, buf_len, "%s", g->gr_name);
     95 
     96 		if (i < 0) {
     97 			errno = ENOMEM;
     98 			return (-1);
     99 		}
    100 		return (0);
    101 
    102 	default:
    103 		return (EINVAL);
    104 	}
    105 }
    106