From e3d30a03225dd1d26012ecd39b09e4ccf91befb5 Mon Sep 17 00:00:00 2001
From: Havoc Pennington <hp@redhat.com>
Date: Wed, 13 Jun 2007 16:30:43 +0000
Subject: 2007-06-13  Havoc Pennington  <hp@redhat.com>

	* configure.ac, bus/selinux.c, dbus/dbus-sysdeps-unix-util.c: add
	libaudit support, no clue what this means really but now we have
	it. Patches from Fedora package.

	* bus/bus.c (bus_context_new): move selinux initialization after
	changing to daemon user, patch from Fedora package

	* dbus/dbus-transport.c (auth_via_unix_user_function): fix a typo
---
 dbus/dbus-sysdeps-util-unix.c | 104 ++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 100 insertions(+), 4 deletions(-)

(limited to 'dbus/dbus-sysdeps-util-unix.c')

diff --git a/dbus/dbus-sysdeps-util-unix.c b/dbus/dbus-sysdeps-util-unix.c
index 339b8f96..e81c752e 100644
--- a/dbus/dbus-sysdeps-util-unix.c
+++ b/dbus/dbus-sysdeps-util-unix.c
@@ -43,6 +43,11 @@
 #include <sys/socket.h>
 #include <dirent.h>
 #include <sys/un.h>
+#ifdef HAVE_LIBAUDIT
+#include <sys/prctl.h>
+#include <sys/capability.h>
+#include <libaudit.h>
+#endif /* HAVE_LIBAUDIT */
 
 #ifdef HAVE_SYS_SYSLIMITS_H
 #include <sys/syslimits.h>
@@ -273,7 +278,11 @@ _dbus_change_to_daemon_user  (const char    *user,
   dbus_uid_t uid;
   dbus_gid_t gid;
   DBusString u;
-
+#ifdef HAVE_LIBAUDIT
+  dbus_bool_t we_were_root;
+  cap_t new_caps;
+#endif
+  
   _dbus_string_init_const (&u, user);
   
   if (!_dbus_get_user_id_and_primary_group (&u, &uid, &gid))
@@ -284,6 +293,58 @@ _dbus_change_to_daemon_user  (const char    *user,
       return FALSE;
     }
   
+#ifdef HAVE_LIBAUDIT
+  we_were_root = _dbus_getuid () == 0;
+  new_caps = NULL;
+  /* have a tmp set of caps that we use to transition to the usr/grp dbus should
+   * run as ... doesn't really help. But keeps people happy.
+   */
+    
+  if (!we_were_root)
+    {
+      cap_value_t new_cap_list[] = { CAP_AUDIT_WRITE };
+      cap_value_t tmp_cap_list[] = { CAP_AUDIT_WRITE, CAP_SETUID, CAP_SETGID };
+      cap_t tmp_caps = cap_init();
+        
+      if (!tmp_caps || !(new_caps = cap_init ()))
+        {
+          dbus_set_error (error, DBUS_ERROR_FAILED,
+                          "Failed to initialize drop of capabilities: %s\n",
+                          _dbus_strerror (errno));
+
+          if (tmp_caps)
+            cap_free (tmp_caps);
+
+          return FALSE;
+        }
+
+      /* assume these work... */
+      cap_set_flag (new_caps, CAP_PERMITTED, 1, new_cap_list, CAP_SET);
+      cap_set_flag (new_caps, CAP_EFFECTIVE, 1, new_cap_list, CAP_SET);
+      cap_set_flag (tmp_caps, CAP_PERMITTED, 3, tmp_cap_list, CAP_SET);
+      cap_set_flag (tmp_caps, CAP_EFFECTIVE, 3, tmp_cap_list, CAP_SET);
+      
+      if (prctl (PR_SET_KEEPCAPS, 1, 0, 0, 0) == -1)
+        {
+          dbus_set_error (error, _dbus_error_from_errno (errno),
+                          "Failed to set keep-capabilities: %s\n",
+                          _dbus_strerror (errno));
+          cap_free (tmp_caps);
+          goto fail;
+        }
+        
+      if (cap_set_proc (tmp_caps) == -1)
+        {
+          dbus_set_error (error, DBUS_ERROR_FAILED,
+                          "Failed to drop capabilities: %s\n",
+                          _dbus_strerror (errno));
+          cap_free (tmp_caps);
+          goto fail;
+        }
+      cap_free (tmp_caps);
+    }
+#endif /* HAVE_LIBAUDIT */
+  
   /* setgroups() only works if we are a privileged process,
    * so we don't return error on failure; the only possible
    * failure is that we don't have perms to do it.
@@ -303,7 +364,7 @@ _dbus_change_to_daemon_user  (const char    *user,
       dbus_set_error (error, _dbus_error_from_errno (errno),
                       "Failed to set GID to %lu: %s", gid,
                       _dbus_strerror (errno));
-      return FALSE;
+      goto fail;
     }
   
   if (setuid (uid) < 0)
@@ -311,10 +372,45 @@ _dbus_change_to_daemon_user  (const char    *user,
       dbus_set_error (error, _dbus_error_from_errno (errno),
                       "Failed to set UID to %lu: %s", uid,
                       _dbus_strerror (errno));
-      return FALSE;
+      goto fail;
     }
   
-  return TRUE;
+#ifdef HAVE_LIBAUDIT
+  if (!we_were_root)
+    {
+      if (cap_set_proc (new_caps))
+        {
+          dbus_set_error (error, DBUS_ERROR_FAILED,
+                          "Failed to drop capabilities: %s\n",
+                          _dbus_strerror (errno));
+          goto fail;
+        }
+      cap_free (new_caps);
+
+      /* should always work, if it did above */      
+      if (prctl (PR_SET_KEEPCAPS, 0, 0, 0, 0) == -1)
+        {
+          dbus_set_error (error, _dbus_error_from_errno (errno),
+                          "Failed to unset keep-capabilities: %s\n",
+                          _dbus_strerror (errno));
+          return FALSE;
+        }
+    }
+#endif
+
+ return TRUE;
+
+ fail:
+#ifdef HAVE_LIBAUDIT
+ if (!we_were_root)
+   {
+     /* should always work, if it did above */
+     prctl (PR_SET_KEEPCAPS, 0, 0, 0, 0);
+     cap_free (new_caps);
+   }
+#endif
+
+ return FALSE;
 }
 
 /** Installs a UNIX signal handler
-- 
cgit