| /* Copyright (C) 2004-2014 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Contributed by Ulrich Drepper <drepper@redhat.com>, 2004. |
| |
| The GNU C Library 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 GNU C Library 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 the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <assert.h> |
| #include <errno.h> |
| #include <grp.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <unistd.h> |
| #include <not-cancel.h> |
| |
| #include "nscd-client.h" |
| #include "nscd_proto.h" |
| |
| |
| /* We use the same mapping as in nscd_getgr. */ |
| libc_locked_map_ptr (extern, __gr_map_handle) attribute_hidden; |
| |
| |
| int |
| __nscd_getgrouplist (const char *user, gid_t group, long int *size, |
| gid_t **groupsp, long int limit) |
| { |
| size_t userlen = strlen (user) + 1; |
| int gc_cycle; |
| int nretries = 0; |
| |
| /* If the mapping is available, try to search there instead of |
| communicating with the nscd. */ |
| struct mapped_database *mapped; |
| mapped = __nscd_get_map_ref (GETFDGR, "group", &__gr_map_handle, &gc_cycle); |
| |
| retry:; |
| char *respdata = NULL; |
| int retval = -1; |
| int sock = -1; |
| initgr_response_header initgr_resp; |
| |
| if (mapped != NO_MAPPING) |
| { |
| struct datahead *found = __nscd_cache_search (INITGROUPS, user, |
| userlen, mapped, |
| sizeof initgr_resp); |
| if (found != NULL) |
| { |
| respdata = (char *) (&found->data[0].initgrdata + 1); |
| initgr_resp = found->data[0].initgrdata; |
| char *recend = (char *) found->data + found->recsize; |
| |
| /* Now check if we can trust initgr_resp fields. If GC is |
| in progress, it can contain anything. */ |
| if (mapped->head->gc_cycle != gc_cycle) |
| { |
| retval = -2; |
| goto out; |
| } |
| |
| if (respdata + initgr_resp.ngrps * sizeof (int32_t) > recend) |
| goto out; |
| } |
| } |
| |
| /* If we do not have the cache mapped, try to get the data over the |
| socket. */ |
| if (respdata == NULL) |
| { |
| sock = __nscd_open_socket (user, userlen, INITGROUPS, &initgr_resp, |
| sizeof (initgr_resp)); |
| if (sock == -1) |
| { |
| /* nscd not running or wrong version. */ |
| __nss_not_use_nscd_group = 1; |
| goto out; |
| } |
| } |
| |
| if (initgr_resp.found == 1) |
| { |
| /* The following code assumes that gid_t and int32_t are the |
| same size. This is the case for al existing implementation. |
| If this should change some code needs to be added which |
| doesn't use memcpy but instead copies each array element one |
| by one. */ |
| assert (sizeof (int32_t) == sizeof (gid_t)); |
| assert (initgr_resp.ngrps >= 0); |
| |
| /* Make sure we have enough room. We always count GROUP in even |
| though we might not end up adding it. */ |
| if (*size < initgr_resp.ngrps + 1) |
| { |
| gid_t *newp = realloc (*groupsp, |
| (initgr_resp.ngrps + 1) * sizeof (gid_t)); |
| if (newp == NULL) |
| /* We cannot increase the buffer size. */ |
| goto out_close; |
| |
| *groupsp = newp; |
| *size = initgr_resp.ngrps + 1; |
| } |
| |
| if (respdata == NULL) |
| { |
| /* Read the data from the socket. */ |
| if ((size_t) __readall (sock, *groupsp, initgr_resp.ngrps |
| * sizeof (gid_t)) |
| == initgr_resp.ngrps * sizeof (gid_t)) |
| retval = initgr_resp.ngrps; |
| } |
| else |
| { |
| /* Just copy the data. */ |
| retval = initgr_resp.ngrps; |
| memcpy (*groupsp, respdata, retval * sizeof (gid_t)); |
| } |
| } |
| else |
| { |
| if (__builtin_expect (initgr_resp.found == -1, 0)) |
| { |
| /* The daemon does not cache this database. */ |
| __nss_not_use_nscd_group = 1; |
| goto out_close; |
| } |
| |
| /* No group found yet. */ |
| retval = 0; |
| |
| assert (*size >= 1); |
| } |
| |
| /* Check whether GROUP is part of the mix. If not, add it. */ |
| if (retval >= 0) |
| { |
| int cnt; |
| for (cnt = 0; cnt < retval; ++cnt) |
| if ((*groupsp)[cnt] == group) |
| break; |
| |
| if (cnt == retval) |
| (*groupsp)[retval++] = group; |
| } |
| |
| out_close: |
| if (sock != -1) |
| close_not_cancel_no_status (sock); |
| out: |
| if (__nscd_drop_map_ref (mapped, &gc_cycle) != 0) |
| { |
| /* When we come here this means there has been a GC cycle while we |
| were looking for the data. This means the data might have been |
| inconsistent. Retry if possible. */ |
| if ((gc_cycle & 1) != 0 || ++nretries == 5 || retval == -1) |
| { |
| /* nscd is just running gc now. Disable using the mapping. */ |
| if (atomic_decrement_val (&mapped->counter) == 0) |
| __nscd_unmap (mapped); |
| mapped = NO_MAPPING; |
| } |
| |
| if (retval != -1) |
| goto retry; |
| } |
| |
| return retval; |
| } |