xref: /netbsd-src/usr.bin/newgrp/newgrp.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*-
2  * Copyright (c) 2007 The NetBSD Foundation, Inc.
3  * All rights reserved.
4  *
5  * This code is derived from software contributed to The NetBSD Foundation
6  * by Brian Ginsbach.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *        This product includes software developed by the NetBSD
19  *        Foundation, Inc. and its contributors.
20  * 4. Neither the name of The NetBSD Foundation nor the names of its
21  *    contributors may be used to endorse or promote products derived
22  *    from this software without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
25  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
26  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
27  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
28  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
32  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34  * POSSIBILITY OF SUCH DAMAGE.
35  */
36 
37 #include <sys/cdefs.h>
38 
39 #ifndef lint
40 __RCSID("$NetBSD: newgrp.c,v 1.4 2007/10/17 21:07:49 christos Exp $");
41 #endif /* not lint */
42 
43 #include <sys/param.h>
44 #include <sys/types.h>
45 
46 #include <err.h>
47 #include <grp.h>
48 #include <libgen.h>
49 #include <paths.h>
50 #include <pwd.h>
51 #include <stdio.h>
52 #include <stdlib.h>
53 #include <string.h>
54 #include <unistd.h>
55 
56 #ifdef LOGIN_CAP
57 #include <login_cap.h>
58 #endif
59 
60 #include "grutil.h"
61 
62 static void
63 usage(void)
64 {
65 	(void)fprintf(stderr, "usage: %s [-l] [group]\n", getprogname());
66 	exit(EXIT_FAILURE);
67 }
68 
69 int
70 main(int argc, char *argv[])
71 {
72 	extern char **environ;
73 	struct passwd *pwd;
74 	int c, lflag;
75 	char *shell, sbuf[MAXPATHLEN + 2];
76 	uid_t uid;
77 #ifdef LOGIN_CAP
78 	login_cap_t *lc;
79 	u_int flags = LOGIN_SETUSER;
80 #endif
81 
82 	uid = getuid();
83 	pwd = getpwuid(uid);
84 	if (pwd == NULL)
85 		errx(EXIT_FAILURE, "who are you?");
86 
87 #ifdef LOGIN_CAP
88 	if ((lc = login_getclass(pwd->pw_class)) == NULL)
89 		errx(EXIT_FAILURE, "%s: unknown login class", pwd->pw_class);
90 #endif
91 
92 	lflag = 0;
93 	while ((c = getopt(argc, argv, "-l")) != -1) {
94 		switch (c) {
95 		case '-':
96 		case 'l':
97 			if (lflag)
98 				usage();
99 			lflag = 1;
100 			break;
101 		default:
102 			usage();
103 			break;
104 		}
105 	}
106 
107 	argc -= optind;
108 	argv += optind;
109 
110 	if (argc > 0) {
111 #if 0
112 		pwd->pw_gid = newgrp(*argv, pwd);
113 		addgrp(pwd->pw_gid);
114 		if (setgid(pwd->pw_gid) < 0)
115 			err(1, "setgid");
116 #endif
117 #ifdef LOGIN_CAP
118 		addgroup(lc, *argv, pwd, getuid(), "Password:");
119 #else
120 		addgroup(*argv, pwd, getuid(), "Password:");
121 #endif
122 	} else {
123 #ifdef LOGIN_CAP
124 		flags |= LOGIN_SETGROUP;
125 #else
126 		if (initgroups(pwd->pw_name, pwd->pw_gid) == -1)
127 			err(EXIT_FAILURE, "initgroups");
128 		if (setgid(pwd->pw_gid) == -1)
129 			err(EXIT_FAILURE, "setgid");
130 #endif
131 	}
132 
133 #ifdef LOGIN_CAP
134 	if (setusercontext(lc, pwd, uid, flags) == -1)
135 		err(EXIT_FAILURE, "setusercontext");
136 	if (!lflag)
137 		login_close(lc);
138 #else
139 	if (setuid(pwd->pw_uid) == -1)
140 		err(EXIT_FAILURE, "setuid");
141 #endif
142 
143 	if (*pwd->pw_shell == '\0') {
144 #ifdef TRUST_ENV_SHELL
145 		shell = getenv("SHELL");
146 		if (shell != NULL)
147 			pwd->pw_shell = shell;
148 		else
149 #endif
150 			pwd->pw_shell = __UNCONST(_PATH_BSHELL);
151 	}
152 
153 	shell = pwd->pw_shell;
154 
155 	if (lflag) {
156 		char *term;
157 #ifdef KERBEROS
158 		char *krbtkfile;
159 #endif
160 
161 		if (chdir(pwd->pw_dir) == -1)
162 			warn("%s", pwd->pw_dir);
163 
164 		term = getenv("TERM");
165 #ifdef KERBEROS
166 		krbtkfile = getenv("KRBTKFILE");
167 #endif
168 
169 		/* create an empty environment */
170 		if ((environ = malloc(sizeof(char *))) == NULL)
171 			err(EXIT_FAILURE, NULL);
172 		environ[0] = NULL;
173 #ifdef LOGIN_CAP
174 		if (setusercontext(lc, pwd, uid, LOGIN_SETENV | LOGIN_SETPATH) == -1)
175 			err(EXIT_FAILURE, "setusercontext");
176 		login_close(lc);
177 #else
178 		(void)setenv("PATH", _PATH_DEFPATH, 1);
179 #endif
180 		if (term != NULL)
181 			(void)setenv("TERM", term, 1);
182 #ifdef KERBEROS
183 		if (krbtkfile != NULL)
184 			(void)setenv("KRBTKFILE", krbtkfile, 1);
185 #endif
186 
187 		(void)setenv("LOGNAME", pwd->pw_name, 1);
188 		(void)setenv("USER", pwd->pw_name, 1);
189 		(void)setenv("HOME", pwd->pw_dir, 1);
190 		(void)setenv("SHELL", pwd->pw_shell, 1);
191 
192 		sbuf[0] = '-';
193 		(void)strlcpy(sbuf + 1, basename(pwd->pw_shell),
194 			      sizeof(sbuf) - 1);
195 		shell = sbuf;
196 	}
197 
198 	(void)execl(pwd->pw_shell, shell, NULL);
199 	err(EXIT_FAILURE, "%s", pwd->pw_shell);
200 	/* NOTREACHED */
201 }
202