Update.

2004-09-16  Ulrich Drepper  <drepper@redhat.com>

	* configure.in: Add test for required SELinux features.
	* config.make.in: Add have-selinux entry.
	* config.h.in: Add HAVE_SELINUX entry.
	* nscd/Makefile (nscd-modules): Add selinux.
	(CFLAGS-selinux.c): Add -fpie.
	Define selinux-LIBS and use in link line.
	* nscd/connections.c (handle_request): Check access SELinux permissions
	before processing request.
	* nscd/nscd.c (main): Initialize selinux_enabled and stop avc thread.
	* nscd/nscd_stat.c: Transmit and print AVC statistics.
	* nscd/selinux.c: New file.
	* nscd/selinux.h: New file.

2004-09-16  Jakub Jelinek  <jakub@redhat.com>

	* nscd/nscd_helper.c (__nscd_unmap, get_mapping): Use __munmap
	instead of munmap.

	* nscd/Makefile (CFLAGS-aicache.c): Set to -fpie.

2004-09-16  Thorsten Kukuk  <kukuk@suse.de>

	* sysdeps/posix/getaddrinfo.c (gaih_inet): Check
	__nss_not_use_nscd_hosts variable if nscd should be used or not.

2004-09-16  Ulrich Drepper  <drepper@redhat.com>

	* nscd/nscd_proto.h: Define NSS_NSCD_RETRY.
	Add __nscd_getai prototype.
	* nss/getXXbyYY_r.c: Remode definition of NSS_NSCD_RETRY.
	* nscd/nscd-client.h: Remove __nscd_getai prototype.
	* nscd/nscd_getai.c: Include nscd_proto.h.

	* elf/ldd.bash.in: Add support for SELinux environments.
	Patch by Stephen Smalley <sds@epoch.ncsc.mil>.

1 files changed, 266 insertions, 0 deletions

diff --git a/nscd/selinux.c b/nscd/selinux.c
new file mode 100644
index 0000000000..0f975f71f6
--- /dev/null
+++ b/nscd/selinux.c
@@ -0,0 +1,266 @@
+/* SELinux access controls for nscd.
+   Copyright (C) 2004 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Matthew Rickard <mjricka@epoch.ncsc.mil>, 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 <error.h>
+#include <errno.h>
+#include <libintl.h>
+#include <pthread.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <syslog.h>
+#include <selinux/av_permissions.h>
+#include <selinux/avc.h>
+#include <selinux/flask.h>
+#include <selinux/selinux.h>
+
+#include "dbg_log.h"
+#include "selinux.h"
+
+
+#ifdef HAVE_SELINUX
+/* Global variable to tell if the kernel has SELinux support.  */
+int selinux_enabled;
+
+/* Define mappings of access vector permissions to request types.  */
+static const int perms[LASTREQ] =
+{
+  [GETPWBYNAME] = NSCD__GETPWD,
+  [GETPWBYUID] = NSCD__GETPWD,
+  [GETGRBYNAME] = NSCD__GETGRP,
+  [GETGRBYGID] = NSCD__GETGRP,
+  [GETHOSTBYNAME] = NSCD__GETHOST,
+  [GETHOSTBYNAMEv6] = NSCD__GETHOST,
+  [GETHOSTBYADDR] = NSCD__GETHOST,
+  [GETHOSTBYADDRv6] = NSCD__GETHOST,
+  [GETSTAT] = NSCD__GETSTAT,
+  [SHUTDOWN] = NSCD__ADMIN,
+  [INVALIDATE] = NSCD__ADMIN,
+  [GETFDPW] = NSCD__SHMEMPWD,
+  [GETFDGR] = NSCD__SHMEMGRP,
+  [GETFDHST] = NSCD__SHMEMHOST,
+  [GETAI] = NSCD__GETHOST
+};
+
+/* Store an entry ref to speed AVC decisions.  */
+static struct avc_entry_ref aeref;
+
+/* Thread to listen for SELinux status changes via netlink.  */
+static pthread_t avc_notify_thread;
+
+/* Prototypes for AVC callback functions.  */
+static void *avc_create_thread (void (*run) (void));
+static void avc_stop_thread (void *thread);
+static void *avc_alloc_lock (void);
+static void avc_get_lock (void *lock);
+static void avc_release_lock (void *lock);
+static void avc_free_lock (void *lock);
+
+/* AVC callback structures for use in avc_init.  */
+static const struct avc_log_callback log_cb =
+{
+  .func_log = dbg_log,
+  .func_audit = NULL
+};
+static const struct avc_thread_callback thread_cb =
+{
+  .func_create_thread = avc_create_thread,
+  .func_stop_thread = avc_stop_thread
+};
+static const struct avc_lock_callback lock_cb =
+{
+  .func_alloc_lock = avc_alloc_lock,
+  .func_get_lock = avc_get_lock,
+  .func_release_lock = avc_release_lock,
+  .func_free_lock = avc_free_lock
+};
+
+
+/* Determine if we are running on an SELinux kernel. Set selinux_enabled
+   to the result.  */
+void
+nscd_selinux_enabled (int *selinux_enabled)
+{
+  *selinux_enabled = is_selinux_enabled ();
+  if (*selinux_enabled < 0)
+    {
+      dbg_log (_("Failed to determine if kernel supports SELinux"));
+      exit (EXIT_FAILURE);
+    }
+}
+
+
+/* Create thread for AVC netlink notification.  */
+static void *
+avc_create_thread (void (*run) (void))
+{
+  int rc;
+
+  rc =
+    pthread_create (&avc_notify_thread, NULL, (void *(*) (void *)) run, NULL);
+  if (rc != 0)
+    error (EXIT_FAILURE, rc, _("Failed to start AVC thread"));
+
+  return &avc_notify_thread;
+}
+
+
+/* Stop AVC netlink thread.  */
+static void
+avc_stop_thread (void *thread)
+{
+  pthread_cancel (*(pthread_t *) thread);
+}
+
+
+/* Allocate a new AVC lock.  */
+static void *
+avc_alloc_lock (void)
+{
+  pthread_mutex_t *avc_mutex;
+
+  avc_mutex = malloc (sizeof (pthread_mutex_t));
+  if (avc_mutex == NULL)
+    error (EXIT_FAILURE, errno, _("Failed to create AVC lock"));
+  pthread_mutex_init (avc_mutex, NULL);
+
+  return avc_mutex;
+}
+
+
+/* Acquire an AVC lock.  */
+static void
+avc_get_lock (void *lock)
+{
+  pthread_mutex_lock (lock);
+}
+
+
+/* Release an AVC lock.  */
+static void
+avc_release_lock (void *lock)
+{
+  pthread_mutex_unlock (lock);
+}
+
+
+/* Free an AVC lock.  */
+static void
+avc_free_lock (void *lock)
+{
+  pthread_mutex_destroy (lock);
+  free (lock);
+}
+
+
+/* Initialize the user space access vector cache (AVC) for NSCD along with
+   log/thread/lock callbacks.  */
+void
+nscd_avc_init (void)
+{
+  avc_entry_ref_init (&aeref);
+
+  if (avc_init ("avc", NULL, &log_cb, &thread_cb, &lock_cb) < 0)
+    error (EXIT_FAILURE, errno, _("Failed to start AVC"));
+  else
+    dbg_log (_("Access Vector Cache (AVC) started"));
+}
+
+
+/* Check the permission from the caller (via getpeercon) to nscd.
+   Returns 0 if access is allowed, 1 if denied, and -1 on error.  */
+int
+nscd_request_avc_has_perm (int fd, request_type req)
+{
+  /* Initialize to NULL so we know what to free in case of failure.  */
+  security_context_t scon = NULL;
+  security_context_t tcon = NULL;
+  security_id_t ssid = NULL;
+  security_id_t tsid = NULL;
+  int rc = -1;
+
+  if (getpeercon (fd, &scon) < 0)
+    {
+      dbg_log (_("Error getting context of socket peer"));
+      goto out;
+    }
+  if (getcon (&tcon) < 0)
+    {
+      dbg_log (_("Error getting context of nscd"));
+      goto out;
+    }
+  if (avc_context_to_sid (scon, &ssid) < 0 ||
+      avc_context_to_sid (tcon, &tsid) < 0)
+    {
+      dbg_log (_("Error getting sid from context"));
+      goto out;
+    }
+
+  rc = avc_has_perm (ssid, tsid, SECCLASS_NSCD, perms[req], &aeref, NULL) < 0;
+
+out:
+  if (scon)
+    freecon (scon);
+  if (tcon)
+    freecon (tcon);
+  if (ssid)
+    sidput (ssid);
+  if (tsid)
+    sidput (tsid);
+
+  return rc;
+}
+
+
+/* Wrapper to get AVC statistics.  */
+void
+nscd_avc_cache_stats (struct avc_cache_stats *cstats)
+{
+  avc_cache_stats (cstats);
+}
+
+
+/* Print the AVC statistics to stdout.  */
+void
+nscd_avc_print_stats (struct avc_cache_stats *cstats)
+{
+  printf (_("\nSELinux AVC Statistics:\n\n"
+	    "%15u  entry lookups\n"
+	    "%15u  entry hits\n"
+	    "%15u  entry misses\n"
+	    "%15u  entry discards\n"
+	    "%15u  CAV lookups\n"
+	    "%15u  CAV hits\n"
+	    "%15u  CAV probes\n"
+	    "%15u  CAV misses\n"),
+	  cstats->entry_lookups, cstats->entry_hits, cstats->entry_misses,
+	  cstats->entry_discards, cstats->cav_lookups, cstats->cav_hits,
+	  cstats->cav_probes, cstats->cav_misses);
+}
+
+
+/* Clean up the AVC before exiting.  */
+void
+nscd_avc_destroy (void)
+{
+  avc_destroy ();
+}
+
+#endif /* HAVE_SELINUX */