[Libguestfs] [PATCH] Add 'setcon', 'getcon' commands to set and get the SELinux context

Richard W.M. Jones rjones at redhat.com
Wed Aug 12 16:48:11 UTC 2009


Matt has persuaded me that setcon/getcon aren't necessary.  So for now
I will park this patch, unless someone comes along who would
potentially use it.

Attached is the latest version of the patch.

Rich.

-- 
Richard Jones, Emerging Technologies, Red Hat  http://et.redhat.com/~rjones
virt-df lists disk usage of guests without needing to install any
software inside the virtual machine.  Supports Linux and Windows.
http://et.redhat.com/~rjones/virt-df/
-------------- next part --------------
>From 55845c37c5490e1797ff48fbc74633328e802b2b Mon Sep 17 00:00:00 2001
From: Richard Jones <rjones at trick.home.annexia.org>
Date: Wed, 12 Aug 2009 16:56:09 +0100
Subject: [PATCH 2/2] Add 'setcon', 'getcon' commands to set and get the SELinux context.

---
 appliance/packagelist.in |    1 +
 daemon/Makefile.am       |    1 +
 daemon/configure.ac      |   11 ++++++
 daemon/selinux.c         |   81 ++++++++++++++++++++++++++++++++++++++++++++++
 guestfs.pod              |    8 ++++
 po/POTFILES.in           |    1 +
 src/MAX_PROC_NR          |    2 +-
 src/generator.ml         |   18 ++++++++++
 8 files changed, 122 insertions(+), 1 deletions(-)
 create mode 100644 daemon/selinux.c

diff --git a/appliance/packagelist.in b/appliance/packagelist.in
index be45fc4..abcd429 100644
--- a/appliance/packagelist.in
+++ b/appliance/packagelist.in
@@ -15,6 +15,7 @@
   MAKEDEV
   ntfsprogs
   scrub
+  libselinux
   udev
   util-linux-ng
 #elif DEBIAN == 1
diff --git a/daemon/Makefile.am b/daemon/Makefile.am
index 43cc752..9406944 100644
--- a/daemon/Makefile.am
+++ b/daemon/Makefile.am
@@ -61,6 +61,7 @@ guestfsd_SOURCES = \
 	readdir.c \
 	realpath.c \
 	scrub.c \
+	selinux.c \
 	sfdisk.c \
 	sleep.c \
 	stat.c \
diff --git a/daemon/configure.ac b/daemon/configure.ac
index 43e331b..62c28ee 100644
--- a/daemon/configure.ac
+++ b/daemon/configure.ac
@@ -64,6 +64,17 @@ if test "x$have_augeas" = "xyes"; then
         AC_DEFINE([HAVE_AUGEAS],[1],[Define to 1 if you have Augeas])
 fi
 
+dnl Check for libselinux (optional).
+AC_CHECK_HEADERS([selinux/selinux.h])
+AC_CHECK_LIB([selinux],[setexeccon],[
+        LIBS="-lselinux $LIBS"
+	have_libselinux="$ac_cv_header_selinux_selinux_h"
+        AC_CHECK_FUNCS([setcon getcon])
+        ],[have_libselinux=no])
+if test "x$have_libselinux" = "xyes"; then
+        AC_DEFINE([HAVE_LIBSELINUX],[1],[Define to 1 if you have libselinux])
+fi
+
 dnl Check for XDR library.
 AC_CHECK_LIB([portablexdr],[xdrmem_create],[],[
         AC_SEARCH_LIBS([xdrmem_create],[rpc xdr nsl])
diff --git a/daemon/selinux.c b/daemon/selinux.c
new file mode 100644
index 0000000..6e2b347
--- /dev/null
+++ b/daemon/selinux.c
@@ -0,0 +1,81 @@
+/* libguestfs - the guestfsd daemon
+ * Copyright (C) 2009 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifdef HAVE_SELINUX_SELINUX_H
+#include <selinux/selinux.h>
+#endif
+
+#include "../src/guestfs_protocol.h"
+#include "daemon.h"
+#include "actions.h"
+
+#ifdef HAVE_LIBSELINUX
+
+/* setcon is only valid under the following circumstances:
+ * - single threaded
+ * - enforcing=0
+ */
+int
+do_setcon (char *context)
+{
+#ifdef HAVE_SETCON
+  if (setcon ((char *) context) == -1) {
+    reply_with_perror ("setcon");
+    return -1;
+  }
+
+  return 0;
+#else
+  reply_with_error ("%s is not available", __func__);
+  return -1;
+#endif
+}
+
+char *
+do_getcon (void)
+{
+#ifdef HAVE_GETCON
+  security_context_t context;
+  char *r;
+
+  if (getcon (&context) == -1) {
+    reply_with_perror ("getcon");
+    return NULL;
+  }
+
+  r = strdup (context);
+  freecon (context);
+  if (r == NULL) {
+    reply_with_perror ("strdup");
+    return NULL;
+  }
+
+  return r;                     /* caller frees */
+#else
+  reply_with_error ("%s is not available", __func__);
+  return -1;
+#endif
+}
+
+#endif /* HAVE_LIBSELINUX */
diff --git a/guestfs.pod b/guestfs.pod
index bc16ecb..f657fa1 100644
--- a/guestfs.pod
+++ b/guestfs.pod
@@ -367,6 +367,14 @@ guest itself:
 (Older versions of C<load_policy> require you to specify the
 name of the policy file).
 
+=item 3.
+
+Optionally, set the security context for the API.  The correct
+security context to use can only be known by inspecting the
+guest.  As an example:
+
+ guestfs_setcon (g, "unconfined_u:unconfined_r:unconfined_t:s0");
+
 =back
 
 This will work for running commands and editing existing files.
diff --git a/po/POTFILES.in b/po/POTFILES.in
index 382cd3a..79a2856 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -37,6 +37,7 @@ daemon/proto.c
 daemon/readdir.c
 daemon/realpath.c
 daemon/scrub.c
+daemon/selinux.c
 daemon/sfdisk.c
 daemon/sleep.c
 daemon/stat.c
diff --git a/src/MAX_PROC_NR b/src/MAX_PROC_NR
index dc37bbd..bc3d544 100644
--- a/src/MAX_PROC_NR
+++ b/src/MAX_PROC_NR
@@ -1 +1 @@
-184
+186
diff --git a/src/generator.ml b/src/generator.ml
index b9544ff..3a77202 100755
--- a/src/generator.ml
+++ b/src/generator.ml
@@ -3427,6 +3427,24 @@ This closes the inotify handle which was previously
 opened by inotify_init.  It removes all watches, throws
 away any pending events, and deallocates all resources.");
 
+  ("setcon", (RErr, [String "context"]), 185, [],
+   [],
+   "set SELinux security context",
+   "\
+This sets the SELinux security context of the daemon
+to the string C<context>.
+
+See the documentation about SELINUX in L<guestfs(3)>.");
+
+  ("getcon", (RString "context", []), 186, [],
+   [],
+   "get SELinux security context",
+   "\
+This gets the SELinux security context of the daemon.
+
+See the documentation about SELINUX in L<guestfs(3)>,
+and C<guestfs_setcon>");
+
 ]
 
 let all_functions = non_daemon_functions @ daemon_functions
-- 
1.6.2.5



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