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 */
get_uidgid(struct bb_uidgid_t * u,const char * ug)31 int FAST_FUNC get_uidgid(struct bb_uidgid_t *u, const char *ug)
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 	n = bb_strtou(user, NULL, 10);
47 	if (!errno) {
48 		u->uid = n;
49 		pwd = getpwuid(n);
50 		/* If we have e.g. "500" string without user */
51 		/* with uid 500 in /etc/passwd, we set gid == uid */
52 		u->gid = pwd ? pwd->pw_gid : n;
53 		goto skip;
54 	}
55 	/* it is not numeric */
56 	pwd = getpwnam(user);
57 	if (!pwd)
58 		return 0;
59 	u->uid = pwd->pw_uid;
60 	u->gid = pwd->pw_gid;
61 
62  skip:
63 	if (group) {
64 		n = bb_strtou(group, NULL, 10);
65 		if (!errno) {
66 			u->gid = n;
67 			return 1;
68 		}
69 		gr = getgrnam(group);
70 		if (!gr)
71 			return 0;
72 		u->gid = gr->gr_gid;
73 	}
74 	return 1;
75 }
xget_uidgid(struct bb_uidgid_t * u,const char * ug)76 void FAST_FUNC xget_uidgid(struct bb_uidgid_t *u, const char *ug)
77 {
78 	if (!get_uidgid(u, ug))
79 		bb_error_msg_and_die("unknown user/group %s", ug);
80 }
81 
82 /* chown-like:
83  * "user" sets uid only,
84  * ":group" sets gid only
85  * "user:" sets uid and gid (to user's primary group id)
86  * "user:group" sets uid and gid
87  * ('unset' uid or gid retains the value it has on entry)
88  */
parse_chown_usergroup_or_die(struct bb_uidgid_t * u,char * user_group)89 void FAST_FUNC parse_chown_usergroup_or_die(struct bb_uidgid_t *u, char *user_group)
90 {
91 	char *group;
92 
93 	u->uid = u->gid = (gid_t)-1L;
94 
95 	/* Check if there is a group name */
96 	group = strchr(user_group, '.'); /* deprecated? */
97 	if (!group)
98 		group = strchr(user_group, ':');
99 	else
100 		*group = ':'; /* replace '.' with ':' */
101 
102 	/* Parse "user[:[group]]" */
103 	if (!group) { /* "user" */
104 		u->uid = get_ug_id(user_group, xuname2uid);
105 	} else if (group == user_group) { /* ":group" */
106 		u->gid = get_ug_id(group + 1, xgroup2gid);
107 	} else {
108 		if (!group[1]) /* "user:" */
109 			*group = '\0';
110 		xget_uidgid(u, user_group);
111 	}
112 }
113 
114 #if 0
115 #include <stdio.h>
116 int main()
117 {
118 	unsigned u;
119 	struct bb_uidgid_t ug;
120 	u = get_uidgid(&ug, "apache");
121 	printf("%u = %u:%u\n", u, ug.uid, ug.gid);
122 	ug.uid = ug.gid = 1111;
123 	u = get_uidgid(&ug, "apache");
124 	printf("%u = %u:%u\n", u, ug.uid, ug.gid);
125 	ug.uid = ug.gid = 1111;
126 	u = get_uidgid(&ug, "apache:users");
127 	printf("%u = %u:%u\n", u, ug.uid, ug.gid);
128 	ug.uid = ug.gid = 1111;
129 	u = get_uidgid(&ug, "apache:users");
130 	printf("%u = %u:%u\n", u, ug.uid, ug.gid);
131 	return 0;
132 }
133 #endif
134