2 * Copyright (c) 2002 Tim J. Robbins.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * $FreeBSD: /src/usr.bin/newgrp/newgrp.c,v 1.2 2003/10/30 15:14:34 harti Exp $
27 * $DragonFly: src/usr.bin/newgrp/newgrp.c,v 1.3 2004/12/08 22:26:42 liamfoy Exp $
31 * newgrp -- change to a new group
34 #include <sys/types.h>
41 #include <login_cap.h>
49 static void addgroup(const char *grpname);
50 static void doshell(void);
51 static int inarray(gid_t, const gid_t[], int);
52 static void loginshell(void);
53 static void restoregrps(void);
54 static void usage(void);
56 static struct passwd *pwd;
59 extern char **environ;
61 /* Manipulate effective user ID. */
62 #define PRIV_START do { \
63 if (seteuid(euid) < 0) \
66 #define PRIV_END do { \
67 if (seteuid(getuid()) < 0) \
72 main(int argc, char *argv[])
77 if (seteuid(getuid()) < 0)
80 if ((pwd = getpwuid(getuid())) == NULL)
81 errx(1, "unknown user");
84 while ((ch = getopt(argc, argv, "-l")) != -1) {
86 case '-': /* Obsolescent */
108 if (seteuid(euid) < 0)
110 if (setuid(getuid()) < 0)
126 fprintf(stderr, "usage: newgrp [-l] [group]\n");
136 initres = initgroups(pwd->pw_name, pwd->pw_gid);
137 setres = setgid(pwd->pw_gid);
147 addgroup(const char *grpname)
149 gid_t grps[NGROUPS_MAX];
151 int dbmember, i, ngrps;
154 char *ep, *pass, *cryptpw;
159 /* Try it as a group name, then a group id. */
160 if ((grp = getgrnam(grpname)) == NULL)
161 if ((lgid = strtol(grpname, &ep, 10)) <= 0 || *ep != '\0' ||
162 (grp = getgrgid((gid_t)lgid)) == NULL ) {
163 warnx("%s: bad group name", grpname);
168 * If the user is not a member of the requested group and the group
169 * has a password, prompt and check it.
172 if (pwd->pw_gid == grp->gr_gid)
174 for (p = grp->gr_mem; *p != NULL; p++)
175 if (strcmp(*p, pwd->pw_name) == 0) {
179 if (!dbmember && *grp->gr_passwd != '\0' && getuid() != 0) {
180 pass = getpass("Password:");
183 cryptpw = crypt(pass, grp->gr_passwd);
184 if (cryptpw == NULL || strcmp(grp->gr_passwd, cryptpw) != 0) {
185 fprintf(stderr, "Sorry\n");
190 if ((ngrps = getgroups(NGROUPS_MAX, (gid_t *)grps)) < 0) {
195 /* Remove requested gid from supp. list if it exists. */
196 if (grp->gr_gid != egid && inarray(grp->gr_gid, grps, ngrps)) {
197 for (i = 0; i < ngrps; i++)
198 if (grps[i] == grp->gr_gid)
201 memmove(&grps[i], &grps[i + 1], (ngrps - i) * sizeof(gid_t));
203 if (setgroups(ngrps, (const gid_t *)grps) < 0) {
212 if (setgid(grp->gr_gid)) {
218 grps[0] = grp->gr_gid;
220 /* Add old effective gid to supp. list if it does not exist. */
221 if (egid != grp->gr_gid && !inarray(egid, grps, ngrps)) {
222 if (ngrps == NGROUPS_MAX)
223 warnx("too many groups");
225 grps[ngrps++] = egid;
227 if (setgroups(ngrps, (const gid_t *)grps)) {
239 inarray(gid_t gid, const gid_t grps[], int ngrps)
243 for (i = 0; i < ngrps; i++)
250 * Set the environment to what would be expected if the user logged in
251 * again; this performs the same steps as su(1)'s -l option.
256 char *args[2], **cleanenv, *term, *ticket;
260 shell = pwd->pw_shell;
262 shell = _PATH_BSHELL;
263 if (chdir(pwd->pw_dir) < 0) {
264 warn("%s", pwd->pw_dir);
268 term = getenv("TERM");
269 ticket = getenv("KRBTKFILE");
271 if ((cleanenv = calloc(20, sizeof(char *))) == NULL)
276 lc = login_getpwclass(pwd);
277 setusercontext(lc, pwd, pwd->pw_uid,
278 LOGIN_SETPATH|LOGIN_SETUMASK|LOGIN_SETENV);
280 if (setenv("USER", pwd->pw_name, 1) == -1)
281 err(EXIT_FAILURE, "setenv failed");
283 if (setenv("SHELL", shell, 1) == -1)
284 err(EXIT_FAILURE, "setenv failed");
286 if (setenv("HOME", pwd->pw_dir, 1) == -1)
287 err(EXIT_FAILURE, "setenv failed");
290 if (setenv("TERM", term, 1) == -1)
291 err(EXIT_FAILURE, "setenv failed");
293 if (setenv("KRBTKFILE", ticket, 1) == -1)
294 err(EXIT_FAILURE, "setenv failed");
296 if (asprintf(args, "-%s", basename(shell)) < 0)
309 shell = pwd->pw_shell;
311 shell = _PATH_BSHELL;
312 execl(shell, basename(shell), NULL);