usr.bin/newgrp/newgrp.c

   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 }