xref: /freebsd/lib/libc/gen/pw_scan.c (revision c17d43407fe04133a94055b0dbc7ea8965654a9f)
1 /*-
2  * Copyright (c) 1990, 1993, 1994
3  *	The Regents of the University of California.  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
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, 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. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #if defined(LIBC_SCCS) && !defined(lint)
35 static char sccsid[] = "@(#)pw_scan.c	8.3 (Berkeley) 4/2/94";
36 #endif /* LIBC_SCCS and not lint */
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 /*
41  * This module is used to "verify" password entries by chpass(1) and
42  * pwd_mkdb(8).
43  */
44 
45 #include <sys/param.h>
46 
47 #include <err.h>
48 #include <errno.h>
49 #include <fcntl.h>
50 #include <pwd.h>
51 #include <stdio.h>
52 #include <string.h>
53 #include <stdlib.h>
54 #include <unistd.h>
55 
56 #include "pw_scan.h"
57 
58 /*
59  * Some software assumes that IDs are short.  We should emit warnings
60  * for id's which cannot be stored in a short, but we are more liberal
61  * by default, warning for IDs greater than USHRT_MAX.
62  *
63  * If pw_big_ids_warning is -1 on entry to pw_scan(), it will be set based
64  * on the existence of PW_SCAN_BIG_IDS in the environment.
65  */
66 static int	pw_big_ids_warning = -1;
67 
68 int
69 __pw_scan(char *bp, struct passwd *pw, int flags)
70 {
71 	uid_t id;
72 	int root;
73 	char *p, *sh;
74 
75 	if (pw_big_ids_warning == -1)
76 		pw_big_ids_warning = getenv("PW_SCAN_BIG_IDS") == NULL ? 1 : 0;
77 
78 	pw->pw_fields = 0;
79 	if (!(pw->pw_name = strsep(&bp, ":")))		/* login */
80 		goto fmt;
81 	root = !strcmp(pw->pw_name, "root");
82 	if (pw->pw_name[0] && (pw->pw_name[0] != '+' || pw->pw_name[1] == '\0'))
83 		pw->pw_fields |= _PWF_NAME;
84 
85 	if (!(pw->pw_passwd = strsep(&bp, ":")))	/* passwd */
86 		goto fmt;
87 	if (pw->pw_passwd[0])
88 		pw->pw_fields |= _PWF_PASSWD;
89 
90 	if (!(p = strsep(&bp, ":")))			/* uid */
91 		goto fmt;
92 	if (p[0])
93 		pw->pw_fields |= _PWF_UID;
94 	else {
95 		if (pw->pw_name[0] != '+' && pw->pw_name[0] != '-') {
96 			if (flags & _PWSCAN_WARN)
97 				warnx("no uid for user %s", pw->pw_name);
98 			return (0);
99 		}
100 	}
101 	id = strtoul(p, (char **)NULL, 10);
102 	if (errno == ERANGE) {
103 		if (flags & _PWSCAN_WARN)
104 			warnx("%s > max uid value (%lu)", p, ULONG_MAX);
105 		return (0);
106 	}
107 	if (root && id) {
108 		if (flags & _PWSCAN_WARN)
109 			warnx("root uid should be 0");
110 		return (0);
111 	}
112 	if (flags & _PWSCAN_WARN && pw_big_ids_warning && id > USHRT_MAX) {
113 		warnx("%s > recommended max uid value (%u)", p, USHRT_MAX);
114 		/*return (0);*/ /* THIS SHOULD NOT BE FATAL! */
115 	}
116 	pw->pw_uid = id;
117 
118 	if (!(p = strsep(&bp, ":")))			/* gid */
119 		goto fmt;
120 	if (p[0])
121 		pw->pw_fields |= _PWF_GID;
122 	id = strtoul(p, (char **)NULL, 10);
123 	if (errno == ERANGE) {
124 		if (flags & _PWSCAN_WARN)
125 			warnx("%s > max gid value (%lu)", p, ULONG_MAX);
126 		return (0);
127 	}
128 	if (flags & _PWSCAN_WARN && pw_big_ids_warning && id > USHRT_MAX) {
129 		warnx("%s > recommended max gid value (%u)", p, USHRT_MAX);
130 		/* return (0); This should not be fatal! */
131 	}
132 	pw->pw_gid = id;
133 
134 	if (flags & _PWSCAN_MASTER ) {
135 		if (!(pw->pw_class = strsep(&bp, ":")))	/* class */
136 			goto fmt;
137 		if (pw->pw_class[0])
138 			pw->pw_fields |= _PWF_CLASS;
139 
140 		if (!(p = strsep(&bp, ":")))		/* change */
141 			goto fmt;
142 		if (p[0])
143 			pw->pw_fields |= _PWF_CHANGE;
144 		pw->pw_change = atol(p);
145 
146 		if (!(p = strsep(&bp, ":")))		/* expire */
147 			goto fmt;
148 		if (p[0])
149 			pw->pw_fields |= _PWF_EXPIRE;
150 		pw->pw_expire = atol(p);
151 	}
152 	if (!(pw->pw_gecos = strsep(&bp, ":")))		/* gecos */
153 		goto fmt;
154 	if (pw->pw_gecos[0])
155 		pw->pw_fields |= _PWF_GECOS;
156 
157 	if (!(pw->pw_dir = strsep(&bp, ":")))		/* directory */
158 		goto fmt;
159 	if (pw->pw_dir[0])
160 		pw->pw_fields |= _PWF_DIR;
161 
162 	if (!(pw->pw_shell = strsep(&bp, ":")))		/* shell */
163 		goto fmt;
164 
165 	p = pw->pw_shell;
166 	if (root && *p)					/* empty == /bin/sh */
167 		for (setusershell();;) {
168 			if (!(sh = getusershell())) {
169 				if (flags & _PWSCAN_WARN)
170 					warnx("warning, unknown root shell");
171 				break;
172 			}
173 			if (!strcmp(p, sh))
174 				break;
175 		}
176 	if (p[0])
177 		pw->pw_fields |= _PWF_SHELL;
178 
179 	if ((p = strsep(&bp, ":"))) {			/* too many */
180 fmt:
181 		if (flags & _PWSCAN_WARN)
182 			warnx("corrupted entry");
183 		return (0);
184 	}
185 	return (1);
186 }
187