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-rw-r--r--nscd/nscd_getai.c164
1 files changed, 164 insertions, 0 deletions
diff --git a/nscd/nscd_getai.c b/nscd/nscd_getai.c
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+++ b/nscd/nscd_getai.c
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+/* Copyright (C) 2004 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, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <assert.h>
+#include <errno.h>
+#include <netdb.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <not-cancel.h>
+
+#include "nscd-client.h"
+
+
+/* Define in nscd_gethst_r.c. */
+extern int __nss_not_use_nscd_hosts;
+
+
+libc_locked_map_ptr (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 (gr_map_free)
+{
+
+ if (map_handle.mapped != NO_MAPPING)
+ free (map_handle.mapped);
+}
+
+
+int
+__nscd_getai (const char *key, struct nscd_ai_result **result, int *h_errnop)
+{
+ size_t keylen = strlen (key) + 1;
+ const ai_response_header *ai_resp = NULL;
+ struct nscd_ai_result *resultbuf = NULL;
+ const char *recend = (const char *) ~UINTMAX_C (0);
+ char *respdata = NULL;
+ int retval = -1;
+ int sock = -1;
+ int gc_cycle;
+
+ /* If the mapping is available, try to search there instead of
+ communicating with the nscd. */
+ struct mapped_database *mapped = __nscd_get_map_ref (GETFDHST, "hosts",
+ &map_handle, &gc_cycle);
+ retry:
+ if (mapped != MAP_FAILED)
+ {
+ const struct datahead *found = __nscd_cache_search (GETAI, key, keylen,
+ mapped);
+ if (found != NULL)
+ {
+ ai_resp = &found->data[0].aidata;
+ respdata = (char *) (ai_resp + 1);
+ recend = (const char *) found->data + found->recsize;
+ }
+ }
+
+ /* If we do not have the cache mapped, try to get the data over the
+ socket. */
+ ai_response_header ai_resp_mem;
+ if (ai_resp == NULL)
+ {
+ sock = __nscd_open_socket (key, keylen, GETAI, &ai_resp_mem,
+ sizeof (ai_resp_mem));
+ if (sock == -1)
+ {
+ /* nscd not running or wrong version or hosts caching disabled. */
+ __nss_not_use_nscd_hosts = 1;
+ goto out;;
+ }
+
+ ai_resp = &ai_resp_mem;
+ }
+
+ if (ai_resp->found == 1)
+ {
+ size_t datalen = ai_resp->naddrs + ai_resp->addrslen + ai_resp->canonlen;
+
+ /* This check is really only affects the case where the data
+ comes from the mapped cache. */
+ if ((char *) (ai_resp + 1) + datalen > recend)
+ {
+ assert (sock == -1);
+ goto out;
+ }
+
+ /* Create result. */
+ resultbuf = (struct nscd_ai_result *) malloc (sizeof (*resultbuf)
+ + datalen);
+ if (resultbuf == NULL)
+ {
+ *h_errnop = NETDB_INTERNAL;
+ return -1;
+ }
+
+ /* Set up the data structure, including pointers. */
+ resultbuf->naddrs = ai_resp->naddrs;
+ resultbuf->addrs = (char *) (resultbuf + 1);
+ resultbuf->family = (uint8_t *) (resultbuf->addrs + ai_resp->addrslen);
+ if (ai_resp->canonlen != 0)
+ resultbuf->canon = (char *) (resultbuf->family + resultbuf->naddrs);
+ else
+ resultbuf->canon = NULL;
+
+ if (respdata == NULL)
+ {
+ /* Read the data from the socket. */
+ if ((size_t) TEMP_FAILURE_RETRY (__read (sock, resultbuf + 1,
+ datalen)) == datalen)
+ {
+ retval = 0;
+ *result = resultbuf;
+ }
+ }
+ else
+ {
+ /* Copy the data in the block. */
+ memcpy (resultbuf + 1, respdata, datalen);
+
+ retval = 0;
+ *result = resultbuf;
+ }
+ }
+ else
+ {
+ /* Store the error number. */
+ *h_errnop = ai_resp->error;
+
+ /* The `errno' to some value != ERANGE. */
+ __set_errno (ENOENT);
+ /* Even though we have not found anything, the result is zero. */
+ retval = 0;
+ }
+
+ 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. */
+ goto retry;
+
+ return retval;
+}