about summary refs log tree commit diff
path: root/REORG.TODO/nscd/nscd_initgroups.c
diff options
context:
space:
mode:
authorZack Weinberg <zackw@panix.com>2017-06-08 15:39:03 -0400
committerZack Weinberg <zackw@panix.com>2017-06-08 15:39:03 -0400
commit5046dbb4a7eba5eccfd258f92f4735c9ffc8d069 (patch)
tree4470480d904b65cf14ca524f96f79eca818c3eaf /REORG.TODO/nscd/nscd_initgroups.c
parent199fc19d3aaaf57944ef036e15904febe877fc93 (diff)
downloadglibc-zack/build-layout-experiment.tar.gz
glibc-zack/build-layout-experiment.tar.xz
glibc-zack/build-layout-experiment.zip
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).
Diffstat (limited to 'REORG.TODO/nscd/nscd_initgroups.c')
-rw-r--r--REORG.TODO/nscd/nscd_initgroups.c180
1 files changed, 180 insertions, 0 deletions
diff --git a/REORG.TODO/nscd/nscd_initgroups.c b/REORG.TODO/nscd/nscd_initgroups.c
new file mode 100644
index 0000000000..00c650896a
--- /dev/null
+++ b/REORG.TODO/nscd/nscd_initgroups.c
@@ -0,0 +1,180 @@
+/* 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 <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 (__glibc_unlikely (initgr_resp.found == -1))
+	{
+	  /* 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;
+}