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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;
+}