1/* vi: set sw=4 ts=4: */
2/*
3 * password utility routines.
4 *
5 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
6 *
7 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
8 */
9
10#include "libbb.h"
11
12#define assert(x) ((void)0)
13
14/* internal function for bb_getpwuid and bb_getgrgid */
15/* Hacked by Tito Ragusa (c) 2004 <farmatito@tiscali.it> to make it more
16 * flexible:
17 *
18 * bufsize > 0:      If idname is not NULL it is copied to buffer,
19 *                   and buffer is returned. Else id as string is written
20 *                   to buffer, and NULL is returned.
21 *
22 * bufsize == 0:     idname is returned.
23 *
24 * bufsize < 0:      If idname is not NULL it is returned.
25 *                   Else an error message is printed and the program exits.
26 */
27static char* bb_getug(char *buffer, int bufsize, char *idname, long id, char prefix)
28{
29	if (bufsize > 0) {
30		assert(buffer != NULL);
31		if (idname) {
32			return safe_strncpy(buffer, idname, bufsize);
33		}
34		snprintf(buffer, bufsize, "%ld", id);
35	} else if (bufsize < 0 && !idname) {
36		bb_error_msg_and_die("unknown %cid %ld", prefix, id);
37	}
38	return idname;
39}
40
41/* bb_getpwuid, bb_getgrgid:
42 * bb_getXXXid(buf, bufsz, id) - copy user/group name or id
43 *               as a string to buf, return user/group name or NULL
44 * bb_getXXXid(NULL, 0, id) - return user/group name or NULL
45 * bb_getXXXid(NULL, -1, id) - return user/group name or exit
46 */
47/* gets a username given a uid */
48char* bb_getpwuid(char *name, int bufsize, long uid)
49{
50	struct passwd *myuser = getpwuid(uid);
51
52	return bb_getug(name, bufsize,
53			(myuser ? myuser->pw_name : (char*)myuser),
54			uid, 'u');
55}
56/* gets a groupname given a gid */
57char* bb_getgrgid(char *group, int bufsize, long gid)
58{
59	struct group *mygroup = getgrgid(gid);
60
61	return bb_getug(group, bufsize,
62			(mygroup ? mygroup->gr_name : (char*)mygroup),
63			gid, 'g');
64}
65
66/* returns a gid given a group name */
67long xgroup2gid(const char *name)
68{
69	struct group *mygroup;
70
71	mygroup = getgrnam(name);
72	if (mygroup == NULL)
73		bb_error_msg_and_die("unknown group name: %s", name);
74
75	return mygroup->gr_gid;
76}
77
78/* returns a uid given a username */
79long xuname2uid(const char *name)
80{
81	struct passwd *myuser;
82
83	myuser = getpwnam(name);
84	if (myuser == NULL)
85		bb_error_msg_and_die("unknown user name: %s", name);
86
87	return myuser->pw_uid;
88}
89
90unsigned long get_ug_id(const char *s,
91		long (*xname2id)(const char *))
92{
93	unsigned long r;
94
95	r = bb_strtoul(s, NULL, 10);
96	if (errno)
97		return xname2id(s);
98	return r;
99}
100