xref: /netbsd/usr.bin/newgrp/newgrp.c (revision 6550d01e)
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  *
17  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
18  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
19  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
20  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
21  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27  * POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 
32 #ifndef lint
33 __RCSID("$NetBSD: newgrp.c,v 1.6 2008/04/28 20:24:14 martin Exp $");
34 #endif /* not lint */
35 
36 #include <sys/param.h>
37 #include <sys/types.h>
38 
39 #include <err.h>
40 #include <grp.h>
41 #include <libgen.h>
42 #include <paths.h>
43 #include <pwd.h>
44 #include <stdio.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <unistd.h>
48 
49 #ifdef LOGIN_CAP
50 #include <login_cap.h>
51 #endif
52 
53 #include "grutil.h"
54 
55 static void
56 usage(void)
57 {
58 	(void)fprintf(stderr, "usage: %s [-l] [group]\n", getprogname());
59 	exit(EXIT_FAILURE);
60 }
61 
62 int
63 main(int argc, char *argv[])
64 {
65 	extern char **environ;
66 	struct passwd *pwd;
67 	int c, lflag;
68 	char *shell, sbuf[MAXPATHLEN + 2];
69 	uid_t uid;
70 #ifdef LOGIN_CAP
71 	login_cap_t *lc;
72 	u_int flags = LOGIN_SETUSER;
73 #endif
74 
75 	uid = getuid();
76 	pwd = getpwuid(uid);
77 	if (pwd == NULL)
78 		errx(EXIT_FAILURE, "who are you?");
79 
80 #ifdef LOGIN_CAP
81 	if ((lc = login_getclass(pwd->pw_class)) == NULL)
82 		errx(EXIT_FAILURE, "%s: unknown login class", pwd->pw_class);
83 #endif
84 
85 	(void)setprogname(argv[0]);
86 	lflag = 0;
87 	while ((c = getopt(argc, argv, "-l")) != -1) {
88 		switch (c) {
89 		case '-':
90 		case 'l':
91 			if (lflag)
92 				usage();
93 			lflag = 1;
94 			break;
95 		default:
96 			usage();
97 			break;
98 		}
99 	}
100 
101 	argc -= optind;
102 	argv += optind;
103 
104 	if (argc > 0) {
105 #if 0
106 		pwd->pw_gid = newgrp(*argv, pwd);
107 		addgrp(pwd->pw_gid);
108 		if (setgid(pwd->pw_gid) < 0)
109 			err(1, "setgid");
110 #endif
111 #ifdef LOGIN_CAP
112 		addgroup(lc, *argv, pwd, getuid(), "Password:");
113 #else
114 		addgroup(*argv, pwd, getuid(), "Password:");
115 #endif
116 	} else {
117 #ifdef LOGIN_CAP
118 		flags |= LOGIN_SETGROUP;
119 #else
120 		if (initgroups(pwd->pw_name, pwd->pw_gid) == -1)
121 			err(EXIT_FAILURE, "initgroups");
122 		if (setgid(pwd->pw_gid) == -1)
123 			err(EXIT_FAILURE, "setgid");
124 #endif
125 	}
126 
127 #ifdef LOGIN_CAP
128 	if (setusercontext(lc, pwd, uid, flags) == -1)
129 		err(EXIT_FAILURE, "setusercontext");
130 	if (!lflag)
131 		login_close(lc);
132 #else
133 	if (setuid(pwd->pw_uid) == -1)
134 		err(EXIT_FAILURE, "setuid");
135 #endif
136 
137 	if (*pwd->pw_shell == '\0') {
138 #ifdef TRUST_ENV_SHELL
139 		shell = getenv("SHELL");
140 		if (shell != NULL)
141 			pwd->pw_shell = shell;
142 		else
143 #endif
144 			pwd->pw_shell = __UNCONST(_PATH_BSHELL);
145 	}
146 
147 	shell = pwd->pw_shell;
148 
149 	if (lflag) {
150 		char *term;
151 #ifdef KERBEROS
152 		char *krbtkfile;
153 #endif
154 
155 		if (chdir(pwd->pw_dir) == -1)
156 			warn("%s", pwd->pw_dir);
157 
158 		term = getenv("TERM");
159 #ifdef KERBEROS
160 		krbtkfile = getenv("KRBTKFILE");
161 #endif
162 
163 		/* create an empty environment */
164 		if ((environ = malloc(sizeof(char *))) == NULL)
165 			err(EXIT_FAILURE, NULL);
166 		environ[0] = NULL;
167 #ifdef LOGIN_CAP
168 		if (setusercontext(lc, pwd, uid, LOGIN_SETENV | LOGIN_SETPATH) == -1)
169 			err(EXIT_FAILURE, "setusercontext");
170 		login_close(lc);
171 #else
172 		(void)setenv("PATH", _PATH_DEFPATH, 1);
173 #endif
174 		if (term != NULL)
175 			(void)setenv("TERM", term, 1);
176 #ifdef KERBEROS
177 		if (krbtkfile != NULL)
178 			(void)setenv("KRBTKFILE", krbtkfile, 1);
179 #endif
180 
181 		(void)setenv("LOGNAME", pwd->pw_name, 1);
182 		(void)setenv("USER", pwd->pw_name, 1);
183 		(void)setenv("HOME", pwd->pw_dir, 1);
184 		(void)setenv("SHELL", pwd->pw_shell, 1);
185 
186 		sbuf[0] = '-';
187 		(void)strlcpy(sbuf + 1, basename(pwd->pw_shell),
188 			      sizeof(sbuf) - 1);
189 		shell = sbuf;
190 	}
191 
192 	(void)execl(pwd->pw_shell, shell, NULL);
193 	err(EXIT_FAILURE, "%s", pwd->pw_shell);
194 	/* NOTREACHED */
195 }
196