busybox/libpwdgrp/uidgid_get.c

/*
Copyright (c) 2001-2006, Gerrit Pape
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.
   3. The name of the author may not be used to endorse or promote products
      derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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.
*/

#include "libbb.h"

/* Always sets uid and gid */
int FAST_FUNC get_uidgid(struct bb_uidgid_t *u, const char *ug, int numeric_ok)
{
	struct passwd *pwd;
	struct group *gr;
	char *user, *group;
	unsigned n;

	user = (char*)ug;
	group = strchr(ug, ':');
	if (group) {
		int sz = (++group) - ug;
		user = alloca(sz);
		/* copies sz-1 bytes, stores terminating '\0' */
		safe_strncpy(user, ug, sz);
	}
	if (numeric_ok) {
		n = bb_strtou(user, NULL, 10);
		if (!errno) {
			u->uid = n;
			pwd = getpwuid(n);
			/* If we have e.g. "500" string without user */
			/* with uid 500 in /etc/passwd, we set gid == uid */
			u->gid = pwd ? pwd->pw_gid : n;
			goto skip;
		}
	}
	/* Either it is not numeric, or caller disallows numeric username */
	pwd = getpwnam(user);
	if (!pwd)
		return 0;
	u->uid = pwd->pw_uid;
	u->gid = pwd->pw_gid;

 skip:
	if (group) {
		if (numeric_ok) {
			n = bb_strtou(group, NULL, 10);
			if (!errno) {
				u->gid = n;
				return 1;
			}
		}
		gr = getgrnam(group);
		if (!gr) return 0;
		u->gid = gr->gr_gid;
	}
	return 1;
}
void FAST_FUNC xget_uidgid(struct bb_uidgid_t *u, const char *ug)
{
	if (!get_uidgid(u, ug, 1))
		bb_error_msg_and_die("unknown user/group %s", ug);
}

/* chown-like:
 * "user" sets uid only,
 * ":group" sets gid only
 * "user:" sets uid and gid (to user's primary group id)
 * "user:group" sets uid and gid
 * ('unset' uid or gid retains the value it has on entry)
 */
void FAST_FUNC parse_chown_usergroup_or_die(struct bb_uidgid_t *u, char *user_group)
{
	char *group;

	/* Check if there is a group name */
	group = strchr(user_group, '.'); /* deprecated? */
	if (!group)
		group = strchr(user_group, ':');
	else
		*group = ':'; /* replace '.' with ':' */

	/* Parse "user[:[group]]" */
	if (!group) { /* "user" */
		u->uid = get_ug_id(user_group, xuname2uid);
	} else if (group == user_group) { /* ":group" */
		u->gid = get_ug_id(group + 1, xgroup2gid);
	} else {
		if (!group[1]) /* "user:" */
			*group = '\0';
		xget_uidgid(u, user_group);
	}
}

#if 0
#include <stdio.h>
int main()
{
	unsigned u;
	struct bb_uidgid_t ug;
	u = get_uidgid(&ug, "apache", 0);
	printf("%u = %u:%u\n", u, ug.uid, ug.gid);
	ug.uid = ug.gid = 1111;
	u = get_uidgid(&ug, "apache", 0);
	printf("%u = %u:%u\n", u, ug.uid, ug.gid);
	ug.uid = ug.gid = 1111;
	u = get_uidgid(&ug, "apache:users", 0);
	printf("%u = %u:%u\n", u, ug.uid, ug.gid);
	ug.uid = ug.gid = 1111;
	u = get_uidgid(&ug, "apache:users", 0);
	printf("%u = %u:%u\n", u, ug.uid, ug.gid);
	return 0;
}
#endif
1	/*
2	Copyright (c) 2001-2006, Gerrit Pape
3	All rights reserved.
4
5	Redistribution and use in source and binary forms, with or without
6	modification, 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
16	THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
17	WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
18	MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
19	EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
20	SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21	PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22	OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23	WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24	OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25	ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26	*/
27
28	#include "libbb.h"
29
30	/* Always sets uid and gid */
31	int 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	}
79	void 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	*/
92	void 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>
117	int 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