xref: /freebsd/lib/libc/gen/pw_scan.c (revision 1669d8afc64812c8d2d1d147ae1fd42ff441e1b1)
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  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #if defined(LIBC_SCCS) && !defined(lint)
31 static char sccsid[] = "@(#)pw_scan.c	8.3 (Berkeley) 4/2/94";
32 #endif /* LIBC_SCCS and not lint */
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 /*
37  * This module is used to "verify" password entries by chpass(1) and
38  * pwd_mkdb(8).
39  */
40 
41 #include <sys/param.h>
42 
43 #include <err.h>
44 #include <errno.h>
45 #include <fcntl.h>
46 #include <pwd.h>
47 #include <stdio.h>
48 #include <string.h>
49 #include <stdlib.h>
50 #include <unistd.h>
51 
52 #include "pw_scan.h"
53 
54 /*
55  * Some software assumes that IDs are short.  We should emit warnings
56  * for id's which cannot be stored in a short, but we are more liberal
57  * by default, warning for IDs greater than USHRT_MAX.
58  *
59  * If pw_big_ids_warning is -1 on entry to pw_scan(), it will be set based
60  * on the existence of PW_SCAN_BIG_IDS in the environment.
61  */
62 static int	pw_big_ids_warning = -1;
63 
64 int
65 __pw_scan(char *bp, struct passwd *pw, int flags)
66 {
67 	uid_t id;
68 	int root;
69 	char *ep, *p, *sh;
70 
71 	if (pw_big_ids_warning == -1)
72 		pw_big_ids_warning = getenv("PW_SCAN_BIG_IDS") == NULL ? 1 : 0;
73 
74 	pw->pw_fields = 0;
75 	if (!(pw->pw_name = strsep(&bp, ":")))		/* login */
76 		goto fmt;
77 	root = !strcmp(pw->pw_name, "root");
78 	if (pw->pw_name[0] && (pw->pw_name[0] != '+' || pw->pw_name[1] == '\0'))
79 		pw->pw_fields |= _PWF_NAME;
80 
81 	if (!(pw->pw_passwd = strsep(&bp, ":")))	/* passwd */
82 		goto fmt;
83 	if (pw->pw_passwd[0])
84 		pw->pw_fields |= _PWF_PASSWD;
85 
86 	if (!(p = strsep(&bp, ":")))			/* uid */
87 		goto fmt;
88 	if (p[0])
89 		pw->pw_fields |= _PWF_UID;
90 	else {
91 		if (pw->pw_name[0] != '+' && pw->pw_name[0] != '-') {
92 			if (flags & _PWSCAN_WARN)
93 				warnx("no uid for user %s", pw->pw_name);
94 			return (0);
95 		}
96 	}
97 	id = strtoul(p, &ep, 10);
98 	if (errno == ERANGE) {
99 		if (flags & _PWSCAN_WARN)
100 			warnx("%s > max uid value (%lu)", p, ULONG_MAX);
101 		return (0);
102 	}
103 	if (*ep != '\0') {
104 		if (flags & _PWSCAN_WARN)
105 			warnx("%s uid is incorrect", p);
106 		return (0);
107 	}
108 	if (root && id) {
109 		if (flags & _PWSCAN_WARN)
110 			warnx("root uid should be 0");
111 		return (0);
112 	}
113 	if (flags & _PWSCAN_WARN && pw_big_ids_warning && id > USHRT_MAX) {
114 		warnx("%s > recommended max uid value (%u)", p, USHRT_MAX);
115 		/*return (0);*/ /* THIS SHOULD NOT BE FATAL! */
116 	}
117 	pw->pw_uid = id;
118 
119 	if (!(p = strsep(&bp, ":")))			/* gid */
120 		goto fmt;
121 	if (p[0])
122 		pw->pw_fields |= _PWF_GID;
123 	else {
124 		if (pw->pw_name[0] != '+' && pw->pw_name[0] != '-') {
125 			if (flags & _PWSCAN_WARN)
126 				warnx("no gid for user %s", pw->pw_name);
127 			return (0);
128 		}
129 	}
130 	id = strtoul(p, &ep, 10);
131 	if (errno == ERANGE) {
132 		if (flags & _PWSCAN_WARN)
133 			warnx("%s > max gid value (%lu)", p, ULONG_MAX);
134 		return (0);
135 	}
136 	if (*ep != '\0') {
137 		if (flags & _PWSCAN_WARN)
138 			warnx("%s gid is incorrect", p);
139 		return (0);
140 	}
141 	if (flags & _PWSCAN_WARN && pw_big_ids_warning && id > USHRT_MAX) {
142 		warnx("%s > recommended max gid value (%u)", p, USHRT_MAX);
143 		/* return (0); This should not be fatal! */
144 	}
145 	pw->pw_gid = id;
146 
147 	if (flags & _PWSCAN_MASTER ) {
148 		if (!(pw->pw_class = strsep(&bp, ":")))	/* class */
149 			goto fmt;
150 		if (pw->pw_class[0])
151 			pw->pw_fields |= _PWF_CLASS;
152 
153 		if (!(p = strsep(&bp, ":")))		/* change */
154 			goto fmt;
155 		if (p[0])
156 			pw->pw_fields |= _PWF_CHANGE;
157 		pw->pw_change = atol(p);
158 
159 		if (!(p = strsep(&bp, ":")))		/* expire */
160 			goto fmt;
161 		if (p[0])
162 			pw->pw_fields |= _PWF_EXPIRE;
163 		pw->pw_expire = atol(p);
164 	}
165 	if (!(pw->pw_gecos = strsep(&bp, ":")))		/* gecos */
166 		goto fmt;
167 	if (pw->pw_gecos[0])
168 		pw->pw_fields |= _PWF_GECOS;
169 
170 	if (!(pw->pw_dir = strsep(&bp, ":")))		/* directory */
171 		goto fmt;
172 	if (pw->pw_dir[0])
173 		pw->pw_fields |= _PWF_DIR;
174 
175 	if (!(pw->pw_shell = strsep(&bp, ":")))		/* shell */
176 		goto fmt;
177 
178 	p = pw->pw_shell;
179 	if (root && *p) {				/* empty == /bin/sh */
180 		for (setusershell();;) {
181 			if (!(sh = getusershell())) {
182 				if (flags & _PWSCAN_WARN)
183 					warnx("warning, unknown root shell");
184 				break;
185 			}
186 			if (!strcmp(p, sh))
187 				break;
188 		}
189 		endusershell();
190 	}
191 	if (p[0])
192 		pw->pw_fields |= _PWF_SHELL;
193 
194 	if ((p = strsep(&bp, ":"))) {			/* too many */
195 fmt:
196 		if (flags & _PWSCAN_WARN)
197 			warnx("corrupted entry");
198 		return (0);
199 	}
200 	return (1);
201 }
202