1/*
2Copyright (c) 2001-2006, Gerrit Pape
3All rights reserved.
4
5Redistribution and use in source and binary forms, with or without
6modification, are permitted provided that the following conditions are met:
7
8   1. Redistributions of source code must retain the above copyright notice,
9      this list of conditions and the following disclaimer.
10   2. Redistributions in binary form must reproduce the above copyright
11      notice, this list of conditions and the following disclaimer in the
12      documentation and/or other materials provided with the distribution.
13   3. The name of the author may not be used to endorse or promote products
14      derived from this software without specific prior written permission.
15
16THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
17WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
18MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
19EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
20SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26*/
27
28#include "libbb.h"
29
30/* Always sets uid and gid */
31int FAST_FUNC get_uidgid(struct bb_uidgid_t *u, const char *ug, int numeric_ok)
32{
33	struct passwd *pwd;
34	struct group *gr;
35	char *user, *group;
36	unsigned n;
37
38	user = (char*)ug;
39	group = strchr(ug, ':');
40	if (group) {
41		int sz = (++group) - ug;
42		user = alloca(sz);
43		/* copies sz-1 bytes, stores terminating '\0' */
44		safe_strncpy(user, ug, sz);
45	}
46	if (numeric_ok) {
47		n = bb_strtou(user, NULL, 10);
48		if (!errno) {
49			u->uid = n;
50			pwd = getpwuid(n);
51			/* If we have e.g. "500" string without user */
52			/* with uid 500 in /etc/passwd, we set gid == uid */
53			u->gid = pwd ? pwd->pw_gid : n;
54			goto skip;
55		}
56	}
57	/* Either it is not numeric, or caller disallows numeric username */
58	pwd = getpwnam(user);
59	if (!pwd)
60		return 0;
61	u->uid = pwd->pw_uid;
62	u->gid = pwd->pw_gid;
63
64 skip:
65	if (group) {
66		if (numeric_ok) {
67			n = bb_strtou(group, NULL, 10);
68			if (!errno) {
69				u->gid = n;
70				return 1;
71			}
72		}
73		gr = getgrnam(group);
74		if (!gr) return 0;
75		u->gid = gr->gr_gid;
76	}
77	return 1;
78}
79void FAST_FUNC xget_uidgid(struct bb_uidgid_t *u, const char *ug)
80{
81	if (!get_uidgid(u, ug, 1))
82		bb_error_msg_and_die("unknown user/group %s", ug);
83}
84
85/* chown-like:
86 * "user" sets uid only,
87 * ":group" sets gid only
88 * "user:" sets uid and gid (to user's primary group id)
89 * "user:group" sets uid and gid
90 * ('unset' uid or gid retains the value it has on entry)
91 */
92void FAST_FUNC parse_chown_usergroup_or_die(struct bb_uidgid_t *u, char *user_group)
93{
94	char *group;
95
96	/* Check if there is a group name */
97	group = strchr(user_group, '.'); /* deprecated? */
98	if (!group)
99		group = strchr(user_group, ':');
100	else
101		*group = ':'; /* replace '.' with ':' */
102
103	/* Parse "user[:[group]]" */
104	if (!group) { /* "user" */
105		u->uid = get_ug_id(user_group, xuname2uid);
106	} else if (group == user_group) { /* ":group" */
107		u->gid = get_ug_id(group + 1, xgroup2gid);
108	} else {
109		if (!group[1]) /* "user:" */
110			*group = '\0';
111		xget_uidgid(u, user_group);
112	}
113}
114
115#if 0
116#include <stdio.h>
117int main()
118{
119	unsigned u;
120	struct bb_uidgid_t ug;
121	u = get_uidgid(&ug, "apache", 0);
122	printf("%u = %u:%u\n", u, ug.uid, ug.gid);
123	ug.uid = ug.gid = 1111;
124	u = get_uidgid(&ug, "apache", 0);
125	printf("%u = %u:%u\n", u, ug.uid, ug.gid);
126	ug.uid = ug.gid = 1111;
127	u = get_uidgid(&ug, "apache:users", 0);
128	printf("%u = %u:%u\n", u, ug.uid, ug.gid);
129	ug.uid = ug.gid = 1111;
130	u = get_uidgid(&ug, "apache:users", 0);
131	printf("%u = %u:%u\n", u, ug.uid, ug.gid);
132	return 0;
133}
134#endif
135