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/* nbdkit
* Copyright Red Hat
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* * Neither the name of Red Hat nor the names of its contributors may be
* used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#ifdef HAVE_PWD_H
#include <pwd.h>
#endif
#ifdef HAVE_GRP_H
#include <grp.h>
#endif
#include "internal.h"
#if defined (HAVE_PWD_H) && defined (HAVE_GRP_H)
static uid_t parseuser (const char *);
static gid_t parsegroup (const char *);
/* Handle the -u and -g options. If user and group are non-NULL
* then this parses them to work out the UID/GID and changes
* user and group.
*/
void
change_user (void)
{
if (group) {
gid_t gid = parsegroup (group);
if (setgid (gid) == -1) {
perror ("setgid");
exit (EXIT_FAILURE);
}
/* Kill supplemental groups from parent process. */
if (setgroups (1, &gid) == -1) {
perror ("setgroups");
exit (EXIT_FAILURE);
}
debug ("changed group to %s", group);
}
if (user) {
uid_t uid = parseuser (user);
if (setuid (uid) == -1) {
perror ("setuid");
exit (EXIT_FAILURE);
}
debug ("changed user to %s", user);
}
}
static uid_t
parseuser (const char *id)
{
struct passwd *pwd;
int saved_errno;
errno = 0;
pwd = getpwnam (id);
if (NULL == pwd) {
int val;
saved_errno = errno;
if (nbdkit_parse_int ("parseuser", id, &val) == 0)
return val;
fprintf (stderr, "%s: -u option: %s is not a valid user name or uid",
program_name, id);
if (saved_errno != 0)
fprintf (stderr, " (getpwnam error: %s)", strerror (saved_errno));
fprintf (stderr, "\n");
exit (EXIT_FAILURE);
}
return pwd->pw_uid;
}
static gid_t
parsegroup (const char *id)
{
struct group *grp;
int saved_errno;
errno = 0;
grp = getgrnam (id);
if (NULL == grp) {
int val;
saved_errno = errno;
if (nbdkit_parse_int ("parsegroup", id, &val) == 0)
return val;
fprintf (stderr, "%s: -g option: %s is not a valid group name or gid",
program_name, id);
if (saved_errno != 0)
fprintf (stderr, " (getgrnam error: %s)", strerror (saved_errno));
fprintf (stderr, "\n");
exit (EXIT_FAILURE);
}
return grp->gr_gid;
}
#else /* a platform like Windows which lacks pwd/grp functions */
void
change_user (void)
{
if (!user && !group)
return;
NOT_IMPLEMENTED_ON_WINDOWS ("--user/--group");
}
#endif
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