* nonlocal-group.c
* group database for nss_nonlocal proxy
*
- * Copyright © 2007 Anders Kaseorg <andersk@mit.edu>
+ * Copyright © 2007–2010 Anders Kaseorg <andersk@mit.edu> and Tim
+ * Abbott <tabbott@mit.edu>
*
- * Permission is hereby granted, free of charge, to any person
- * obtaining a copy of this software and associated documentation
- * files (the "Software"), to deal in the Software without
- * restriction, including without limitation the rights to use, copy,
- * modify, merge, publish, distribute, sublicense, and/or sell copies
- * of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
+ * This file is part of nss_nonlocal.
*
- * The above copyright notice and this permission notice shall be
- * included in all copies or substantial portions of the Software.
+ * nss_nonlocal is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
*
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
- * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
- * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
- * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
- * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
- * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
- * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
+ * nss_nonlocal is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with nss_nonlocal; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301 USA
*/
#define _GNU_SOURCE
#include "nsswitch-internal.h"
#include "nonlocal.h"
+#define MAGIC_NONLOCAL_GROUPNAME "nss-nonlocal-users"
+#define MAGIC_LOCAL_GROUPNAME "nss-local-users"
+
+
+enum nss_status
+_nss_nonlocal_getgrnam_r(const char *name, struct group *grp,
+ char *buffer, size_t buflen, int *errnop);
+
+enum nss_status
+_nss_nonlocal_getgrgid_r(gid_t gid, struct group *grp,
+ char *buffer, size_t buflen, int *errnop);
+
static service_user *
nss_group_nonlocal_database(void)
static service_user *nip = NULL;
if (nip == NULL)
__nss_database_lookup("group_nonlocal", NULL, "", &nip);
-
+
return nip;
}
-static __thread int local_only = 0;
-
enum nss_status
-local_getgrgid_r(gid_t gid, struct group *grp,
- char *buffer, size_t buflen, int *errnop)
+check_nonlocal_gid(const char *user, gid_t gid, int *errnop)
{
- int old_local_only = local_only;
+ static const char *fct_name = "getgrgid_r";
+ static service_user *startp = NULL;
+ static void *fct_start = NULL;
+ enum nss_status status;
+ service_user *nip;
+ union {
+ enum nss_status (*l)(gid_t gid, struct group *grp,
+ char *buffer, size_t buflen, int *errnop);
+ void *ptr;
+ } fct;
+ struct group gbuf;
int old_errno = errno;
- int ret;
- errno = *errnop;
- local_only = 1;
- ret = getgrgid_r(gid, grp, buffer, buflen, &grp);
+ size_t buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
+ char *buf = malloc(buflen);
+ if (buf == NULL) {
+ *errnop = ENOMEM;
+ errno = old_errno;
+ return NSS_STATUS_TRYAGAIN;
+ }
+
+ if (fct_start == NULL &&
+ __nss_group_lookup(&startp, fct_name, &fct_start) != 0) {
+ free(buf);
+ return NSS_STATUS_UNAVAIL;
+ }
+ nip = startp;
+ fct.ptr = fct_start;
+ do {
+ morebuf:
+ if (fct.l == _nss_nonlocal_getgrgid_r)
+ status = NSS_STATUS_NOTFOUND;
+ else
+ status = DL_CALL_FCT(fct.l, (gid, &gbuf, buf, buflen, errnop));
+ if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE) {
+ free(buf);
+ buflen *= 2;
+ buf = malloc(buflen);
+ if (buf == NULL) {
+ *errnop = ENOMEM;
+ errno = old_errno;
+ return NSS_STATUS_TRYAGAIN;
+ }
+ goto morebuf;
+ }
+ } while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
+
+ if (status == NSS_STATUS_SUCCESS) {
+ syslog(LOG_DEBUG, "nss_nonlocal: removing local group %u (%s) from non-local user %s\n", gbuf.gr_gid, gbuf.gr_name, user);
+ status = NSS_STATUS_NOTFOUND;
+ } else if (status != NSS_STATUS_TRYAGAIN) {
+ status = NSS_STATUS_SUCCESS;
+ }
+
+ free(buf);
+ return status;
+}
+
+enum nss_status
+check_nonlocal_group(const char *user, struct group *grp, int *errnop)
+{
+ enum nss_status status = NSS_STATUS_SUCCESS;
+ int old_errno = errno;
+ char *end;
+ unsigned long gid;
- local_only = old_local_only;
- *errnop = errno;
+ errno = 0;
+ gid = strtoul(grp->gr_name, &end, 10);
+ if (errno == 0 && *end == '\0' && (gid_t)gid == gid)
+ status = check_nonlocal_gid(user, gid, errnop);
errno = old_errno;
+ if (status != NSS_STATUS_SUCCESS)
+ return status;
- if (grp != NULL)
- return NSS_STATUS_SUCCESS;
- else if (ret == 0)
- return NSS_STATUS_NOTFOUND;
- else
- return NSS_STATUS_TRYAGAIN;
+ return check_nonlocal_gid(user, grp->gr_gid, errnop);
}
enum nss_status
-check_nonlocal_gid(const char *user, gid_t gid, int *errnop)
+get_local_group(const char *name, struct group *grp, char **buffer, int *errnop)
{
- struct group local_grp;
- int local_errno = errno;
- enum nss_status local_status, status = NSS_STATUS_SUCCESS;
- int local_buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
- char *local_buffer = malloc(local_buflen);
- if (local_buffer == NULL) {
+ static const char *fct_name = "getgrnam_r";
+ static service_user *startp = NULL;
+ static void *fct_start = NULL;
+ enum nss_status status;
+ service_user *nip;
+ union {
+ enum nss_status (*l)(const char *name, struct group *grp,
+ char *buffer, size_t buflen, int *errnop);
+ void *ptr;
+ } fct;
+ size_t buflen;
+ int old_errno = errno;
+
+ buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
+ *buffer = malloc(buflen);
+ if (*buffer == NULL) {
*errnop = ENOMEM;
- errno = local_errno;
+ errno = old_errno;
return NSS_STATUS_TRYAGAIN;
}
- local_errno = 0;
- local_status = local_getgrgid_r(gid, &local_grp, local_buffer,
- local_buflen, &local_errno);
- if (local_status == NSS_STATUS_SUCCESS) {
- syslog(LOG_WARNING, "nss_nonlocal: removing local group %u (%s) from non-local user %s\n", local_grp.gr_gid, local_grp.gr_name, user);
- status = NSS_STATUS_NOTFOUND;
- } else if (local_status != NSS_STATUS_NOTFOUND &&
- local_status != NSS_STATUS_UNAVAIL) {
- *errnop = local_errno;
- status = local_status;
+
+ if (fct_start == NULL &&
+ __nss_group_lookup(&startp, fct_name, &fct_start) != 0) {
+ free(*buffer);
+ *buffer = NULL;
+ return NSS_STATUS_UNAVAIL;
+ }
+ nip = startp;
+ fct.ptr = fct_start;
+ do {
+ morebuf:
+ if (fct.l == _nss_nonlocal_getgrnam_r)
+ status = NSS_STATUS_NOTFOUND;
+ else
+ status = DL_CALL_FCT(fct.l, (name, grp, *buffer, buflen, errnop));
+ if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE) {
+ free(*buffer);
+ buflen *= 2;
+ *buffer = malloc(buflen);
+ if (*buffer == NULL) {
+ *errnop = ENOMEM;
+ errno = old_errno;
+ return NSS_STATUS_TRYAGAIN;
+ }
+ goto morebuf;
+ }
+ } while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
+
+ if (status != NSS_STATUS_SUCCESS) {
+ free(*buffer);
+ *buffer = NULL;
}
- free(local_buffer);
+
return status;
}
-
static service_user *grent_nip = NULL;
static void *grent_fct_start;
static union {
int *errnop)
{
enum nss_status status;
+
+ char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
+ if (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0')
+ return NSS_STATUS_UNAVAIL;
+
if (grent_nip == NULL) {
status = _nss_nonlocal_setgrent(0);
if (status != NSS_STATUS_SUCCESS)
do
status = DL_CALL_FCT(grent_fct.l, (grp, buffer, buflen, errnop));
while (status == NSS_STATUS_SUCCESS &&
- check_nonlocal_gid("(unknown)", grp->gr_gid, &nonlocal_errno) != NSS_STATUS_SUCCESS);
+ check_nonlocal_group("(unknown)", grp, &nonlocal_errno) != NSS_STATUS_SUCCESS);
}
if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
return status;
void *ptr;
} fct;
+ char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
+ if (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0')
+ return NSS_STATUS_UNAVAIL;
+
nip = nss_group_nonlocal_database();
if (nip == NULL)
return NSS_STATUS_UNAVAIL;
if (status != NSS_STATUS_SUCCESS)
return status;
- return check_nonlocal_gid(name, grp->gr_gid, errnop);
+ if (strcmp(name, grp->gr_name) != 0) {
+ syslog(LOG_ERR, "nss_nonlocal: discarding group %s from lookup for group %s\n", grp->gr_name, name);
+ return NSS_STATUS_NOTFOUND;
+ }
+
+ return check_nonlocal_group(name, grp, errnop);
}
enum nss_status
void *ptr;
} fct;
- if (local_only == 1)
+ char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
+ if (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0')
return NSS_STATUS_UNAVAIL;
nip = nss_group_nonlocal_database();
if (status != NSS_STATUS_SUCCESS)
return status;
- return check_nonlocal_gid(grp->gr_name, grp->gr_gid, errnop);
+ if (gid != grp->gr_gid) {
+ syslog(LOG_ERR, "nss_nonlocal: discarding gid %d from lookup for gid %d\n", grp->gr_gid, gid);
+ return NSS_STATUS_NOTFOUND;
+ }
+
+ return check_nonlocal_group(grp->gr_name, grp, errnop);
}
enum nss_status
int *errnop);
void *ptr;
} fct;
- int in = *start, out = *start, i;
+
+ struct group local_users_group, nonlocal_users_group;
+ gid_t local_users_gid, gid;
+ int is_local = 0;
+ char *buffer;
+ int old_errno;
+ int in, out, i;
+
+ /* Check that the user is a nonlocal user before adding any groups. */
+ status = check_nonlocal_user(user, errnop);
+ if (status == NSS_STATUS_TRYAGAIN)
+ return status;
+ else if (status != NSS_STATUS_SUCCESS)
+ is_local = 1;
+
+ old_errno = errno;
+
+ status = get_local_group(MAGIC_LOCAL_GROUPNAME,
+ &local_users_group, &buffer, errnop);
+ if (status == NSS_STATUS_SUCCESS) {
+ local_users_gid = local_users_group.gr_gid;
+ free(buffer);
+ } else if (status == NSS_STATUS_TRYAGAIN) {
+ return status;
+ } else {
+ syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!",
+ MAGIC_LOCAL_GROUPNAME);
+ local_users_gid = -1;
+ }
+
+ if (is_local) {
+ gid = local_users_gid;
+ } else {
+ status = get_local_group(MAGIC_NONLOCAL_GROUPNAME,
+ &nonlocal_users_group, &buffer, errnop);
+ if (status == NSS_STATUS_SUCCESS) {
+ gid = nonlocal_users_group.gr_gid;
+ free(buffer);
+ } else if (status == NSS_STATUS_TRYAGAIN) {
+ return status;
+ } else {
+ syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!",
+ MAGIC_NONLOCAL_GROUPNAME);
+ gid = -1;
+ }
+ }
+
+ if (gid != -1) {
+ int i;
+ for (i = 0; i < *start; ++i)
+ if ((*groupsp)[i] == gid)
+ break;
+ if (i >= *start) {
+ if (*start + 1 > *size) {
+ gid_t *newgroups;
+ long int newsize = 2 * *size;
+ if (limit > 0) {
+ if (*size >= limit)
+ return NSS_STATUS_SUCCESS;
+ if (newsize > limit)
+ newsize = limit;
+ }
+ newgroups = realloc(*groupsp, newsize * sizeof((*groupsp)[0]));
+ if (newgroups == NULL) {
+ *errnop = ENOMEM;
+ errno = old_errno;
+ return NSS_STATUS_TRYAGAIN;
+ }
+ *groupsp = newgroups;
+ *size = newsize;
+ }
+ (*groupsp)[(*start)++] = gid;
+ }
+ }
+
+ if (is_local)
+ return NSS_STATUS_SUCCESS;
+
+ in = out = *start;
nip = nss_group_nonlocal_database();
if (nip == NULL)
if (i < out)
continue;
+ /* Don't let users get into MAGIC_LOCAL_GROUPNAME from nonlocal reasons. */
+ if (local_users_gid == (*groupsp)[in]) {
+ syslog(LOG_WARNING, "nss_nonlocal: Nonlocal user %s removed from special local users group %s",
+ user, MAGIC_LOCAL_GROUPNAME);
+ continue;
+ }
+
status = check_nonlocal_gid(user, (*groupsp)[in], &nonlocal_errno);
if (status == NSS_STATUS_SUCCESS) {
(*groupsp)[out++] = (*groupsp)[in];
- } else if (status != NSS_STATUS_NOTFOUND) {
+ } else if (status == NSS_STATUS_TRYAGAIN) {
*start = out;
*errnop = nonlocal_errno;
return status;
andersk / nss_nonlocal.git / blobdiff