glibc/nscd/nscd_netgroup.c

290 lines
7.2 KiB
C

/* Copyright (C) 2011 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@gmail.com>, 2011.
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 <alloca.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <not-cancel.h>
#include "nscd-client.h"
#include "nscd_proto.h"
int __nss_not_use_nscd_netgroup;
libc_locked_map_ptr (static, map_handle);
/* Note that we only free the structure if necessary. The memory
mapping is not removed since it is not visible to the malloc
handling. */
libc_freeres_fn (pw_map_free)
{
if (map_handle.mapped != NO_MAPPING)
{
void *p = map_handle.mapped;
map_handle.mapped = NO_MAPPING;
free (p);
}
}
int
__nscd_setnetgrent (const char *group, struct __netgrent *datap)
{
int gc_cycle;
int nretries = 0;
size_t group_len = strlen (group);
/* If the mapping is available, try to search there instead of
communicating with the nscd. */
struct mapped_database *mapped;
mapped = __nscd_get_map_ref (GETFDNETGR, "netgroup", &map_handle, &gc_cycle);
retry:;
char *respdata = NULL;
int retval = -1;
netgroup_response_header netgroup_resp;
if (mapped != NO_MAPPING)
{
struct datahead *found = __nscd_cache_search (GETNETGRENT, group,
group_len, mapped,
sizeof netgroup_resp);
if (found != NULL)
{
respdata = (char *) (&found->data[0].netgroupdata + 1);
netgroup_resp = found->data[0].netgroupdata;
/* Now check if we can trust pw_resp fields. If GC is
in progress, it can contain anything. */
if (mapped->head->gc_cycle != gc_cycle)
{
retval = -2;
goto out;
}
}
}
int sock = -1;
if (respdata == NULL)
{
sock = __nscd_open_socket (group, group_len, GETNETGRENT,
&netgroup_resp, sizeof (netgroup_resp));
if (sock == -1)
{
/* nscd not running or wrong version. */
__nss_not_use_nscd_netgroup = 1;
goto out;
}
}
if (netgroup_resp.found == 1)
{
size_t datalen = netgroup_resp.result_len;
/* If we do not have to read the data here it comes from the
mapped data and does not have to be freed. */
if (respdata == NULL)
{
/* The data will come via the socket. */
respdata = malloc (datalen);
if (respdata == NULL)
goto out_close;
if ((size_t) __readall (sock, respdata, datalen) != datalen)
{
free (respdata);
goto out_close;
}
}
datap->data = respdata;
datap->data_size = datalen;
datap->cursor = respdata;
datap->first = 1;
datap->nip = (service_user *) -1l;
datap->known_groups = NULL;
datap->needed_groups = NULL;
retval = 1;
}
else
{
if (__builtin_expect (netgroup_resp.found == -1, 0))
{
/* The daemon does not cache this database. */
__nss_not_use_nscd_netgroup = 1;
goto out_close;
}
/* Set errno to 0 to indicate no error, just no found record. */
__set_errno (0);
/* Even though we have not found anything, the result is zero. */
retval = 0;
}
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;
}
int
__nscd_innetgr (const char *netgroup, const char *host, const char *user,
const char *domain)
{
size_t key_len = (strlen (netgroup) + strlen (host ?: "")
+ strlen (user ?: "") + strlen (domain ?: "") + 7);
char *key;
bool use_alloca = __libc_use_alloca (key_len);
if (use_alloca)
key = alloca (key_len);
else
{
key = malloc (key_len);
if (key == NULL)
return -1;
}
char *wp = stpcpy (key, netgroup) + 1;
if (host != NULL)
{
*wp++ = '\1';
wp = stpcpy (wp, host) + 1;
}
else
*wp++ = '\0';
if (user != NULL)
{
*wp++ = '\1';
wp = stpcpy (wp, user) + 1;
}
else
*wp++ = '\0';
if (domain != NULL)
{
*wp++ = '\1';
wp = stpcpy (wp, domain) + 1;
}
else
*wp++ = '\0';
key_len = wp - key;
/* If the mapping is available, try to search there instead of
communicating with the nscd. */
int gc_cycle;
int nretries = 0;
struct mapped_database *mapped;
mapped = __nscd_get_map_ref (GETFDNETGR, "netgroup", &map_handle, &gc_cycle);
retry:;
int retval = -1;
innetgroup_response_header innetgroup_resp;
int sock = -1;
if (mapped != NO_MAPPING)
{
struct datahead *found = __nscd_cache_search (INNETGR, key,
key_len, mapped,
sizeof innetgroup_resp);
if (found != NULL)
{
innetgroup_resp = found->data[0].innetgroupdata;
/* Now check if we can trust pw_resp fields. If GC is
in progress, it can contain anything. */
if (mapped->head->gc_cycle != gc_cycle)
{
retval = -2;
goto out;
}
goto found_entry;
}
}
sock = __nscd_open_socket (key, key_len, INNETGR,
&innetgroup_resp, sizeof (innetgroup_resp));
if (sock == -1)
{
/* nscd not running or wrong version. */
__nss_not_use_nscd_netgroup = 1;
goto out;
}
found_entry:
if (innetgroup_resp.found == 1)
retval = innetgroup_resp.result;
else
{
if (__builtin_expect (innetgroup_resp.found == -1, 0))
{
/* The daemon does not cache this database. */
__nss_not_use_nscd_netgroup = 1;
goto out_close;
}
/* Set errno to 0 to indicate no error, just no found record. */
__set_errno (0);
/* Even though we have not found anything, the result is zero. */
retval = 0;
}
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;
}
if (! use_alloca)
free (key);
return retval;
}