Prepare for radical source tree reorganization. zack/build-layout-experiment

All top-level files and directories are moved into a temporary storage
directory, REORG.TODO, except for files that will certainly still
exist in their current form at top level when we're done (COPYING,
COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which
are moved to the new directory OldChangeLogs, instead), and the
generated file INSTALL (which is just deleted; in the new order, there
will be no generated files checked into version control).

1 files changed, 216 insertions, 0 deletions

diff --git a/REORG.TODO/nscd/nscd_getai.c b/REORG.TODO/nscd/nscd_getai.c
new file mode 100644
index 0000000000..daaf6d68b2
--- /dev/null
+++ b/REORG.TODO/nscd/nscd_getai.c
@@ -0,0 +1,216 @@
+/* Copyright (C) 2004-2017 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 <netdb.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <not-cancel.h>
+
+#include "nscd-client.h"
+#include "nscd_proto.h"
+
+
+/* Define in nscd_gethst_r.c.  */
+extern int __nss_not_use_nscd_hosts;
+
+
+/* We use the mapping from nscd_gethst.  */
+libc_locked_map_ptr (extern, __hst_map_handle) attribute_hidden;
+
+/* Defined in nscd_gethst_r.c.  */
+extern int __nss_have_localdomain attribute_hidden;
+
+
+int
+__nscd_getai (const char *key, struct nscd_ai_result **result, int *h_errnop)
+{
+  if (__glibc_unlikely (__nss_have_localdomain >= 0))
+    {
+      if (__nss_have_localdomain == 0)
+	__nss_have_localdomain = getenv ("LOCALDOMAIN") != NULL ? 1 : -1;
+      if (__nss_have_localdomain > 0)
+	{
+	  __nss_not_use_nscd_hosts = 1;
+	  return -1;
+	}
+    }
+
+  size_t keylen = strlen (key) + 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 (GETFDHST, "hosts", &__hst_map_handle,
+			       &gc_cycle);
+
+ retry:;
+  struct nscd_ai_result *resultbuf = NULL;
+  const char *recend = (const char *) ~UINTMAX_C (0);
+  char *respdata = NULL;
+  int retval = -1;
+  int sock = -1;
+  ai_response_header ai_resp;
+
+  if (mapped != NO_MAPPING)
+    {
+      struct datahead *found = __nscd_cache_search (GETAI, key, keylen,
+						    mapped, sizeof ai_resp);
+      if (found != NULL)
+	{
+	  respdata = (char *) (&found->data[0].aidata + 1);
+	  ai_resp = found->data[0].aidata;
+	  recend = (const char *) found->data + found->recsize;
+	  /* Now check if we can trust ai_resp fields.  If GC is
+	     in progress, it can contain anything.  */
+	  if (mapped->head->gc_cycle != gc_cycle)
+	    {
+	      retval = -2;
+	      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 (key, keylen, GETAI, &ai_resp,
+				 sizeof (ai_resp));
+      if (sock == -1)
+	{
+	  /* nscd not running or wrong version.  */
+	  __nss_not_use_nscd_hosts = 1;
+	  goto out;
+	}
+    }
+
+  if (ai_resp.found == 1)
+    {
+      size_t datalen = ai_resp.naddrs + ai_resp.addrslen + ai_resp.canonlen;
+
+      /* This check really only affects the case where the data
+	 comes from the mapped cache.  */
+      if (respdata + 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;
+	  goto out_close;
+	}
+
+      /* 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) __readall (sock, resultbuf + 1, datalen) == datalen)
+	    {
+	      retval = 0;
+	      *result = resultbuf;
+	    }
+	  else
+	    {
+	      free (resultbuf);
+	      *h_errnop = NETDB_INTERNAL;
+	    }
+	}
+      else
+	{
+	  /* Copy the data in the block.  */
+	  memcpy (resultbuf + 1, respdata, datalen);
+
+	  /* Try to detect corrupt databases.  */
+	  if (resultbuf->canon != NULL
+	      && resultbuf->canon[ai_resp.canonlen - 1] != '\0')
+	    /* We cannot use the database.  */
+	    {
+	      if (mapped->head->gc_cycle != gc_cycle)
+		retval = -2;
+	      else
+		free (resultbuf);
+	      goto out_close;
+	    }
+
+	  retval = 0;
+	  *result = resultbuf;
+	}
+    }
+  else
+    {
+      if (__glibc_unlikely (ai_resp.found == -1))
+	{
+	  /* The daemon does not cache this database.  */
+	  __nss_not_use_nscd_hosts = 1;
+	  goto out_close;
+	}
+
+      /* Store the error number.  */
+      *h_errnop = ai_resp.error;
+
+      /* 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)
+	{
+	  *result = NULL;
+	  free (resultbuf);
+	  goto retry;
+	}
+    }
+
+  return retval;
+}