Add SELinux support.

* configure.in: New option: --with(out)-selinux, on by default.
Set HAVE_LIBSELINUX if we find libselinux, and substitute
LIBSELINUX_LIBS in Makefiles.

* src/Makefile.in (LIBSELINUX_LIBS): New.
(LIBES): Add $LIBSELINUX_LIBS.
* src/eval.c, lisp.h (call7): New function.
* src/fileio.c [HAVE_LIBSELINUX]: Include selinux headers.
(Ffile_selinux_context, Fset_file_selinux_context):
New functions.
(Fcopy_file): New parameter preserve-selinux-context.
(Frename_file): Preserve selinux context when renaming by copy-file.

* lisp/files.el (backup-buffer): Handle SELinux context, and return it
if a backup was made by renaming.
(backup-buffer-copy): Set SELinux context to the target file.
(basic-save-buffer): Set SELinux context of the newly written file.
(basic-save-buffer-1): Now it also returns any SELinux context.
(basic-save-buffer-2): Set SELinux context of the newly created file,
and return it.
* lisp/net/tramp.el (tramp-file-name-for-operation):
Add file-selinux-context.

5 files changed, 223 insertions, 8 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index a211e1f66fd..2da967958cd 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,14 @@
+2010-04-21  Karel Klíč  <kklic@redhat.com>
+
+        * Makefile.in (LIBSELINUX_LIBS): New.
+        (LIBES): Add $LIBSELINUX_LIBS.
+        * eval.c, lisp.h (call7): New function.
+        * fileio.c [HAVE_LIBSELINUX]: Include selinux headers.
+        (Ffile_selinux_context, Fset_file_selinux_context):
+        New functions.
+        (Fcopy_file): New parameter preserve-selinux-context.
+        (Frename_file): Preserve selinux context when renaming by copy-file.
+
 2010-04-21  Juanma Barranquero  <lekktu@gmail.com>
             Eli Zaretskii  <eliz@gnu.org>
 
diff --git a/src/Makefile.in b/src/Makefile.in
index 0862aa94725..913ac5a847e 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -243,6 +243,10 @@ shared=no
 DBUS_OBJ = dbusbind.o
 #endif
 
+#ifdef HAVE_LIBSELINUX
+LIBSELINUX_LIBS = @LIBSELINUX_LIBS@
+#endif
+
 /* DO NOT use -R.  There is a special hack described in lastfile.c
    which is used instead.  Some initialized data areas are modified
    at initial startup, then labeled as part of the text area when
@@ -824,7 +828,7 @@ SOME_MACHINE_LISP = ../lisp/mouse.elc \
 
 LIBES = $(LOADLIBES) $(LIBS) $(LIBX) $(LIBSOUND) $(RSVG_LIBS) $(DBUS_LIBS) \
    @LIBGPM@ @LIBRESOLV@ LIBS_SYSTEM LIBS_MACHINE LIBS_TERMCAP \
-   $(GETLOADAVG_LIBS) ${GCONF_LIBS} \
+   $(GETLOADAVG_LIBS) ${GCONF_LIBS} ${LIBSELINUX_LIBS} \
    @FREETYPE_LIBS@ @FONTCONFIG_LIBS@ @LIBOTF_LIBS@ @M17N_FLT_LIBS@ \
    $(GNULIB_VAR) LIB_MATH LIB_STANDARD $(GNULIB_VAR)
 
diff --git a/src/eval.c b/src/eval.c
index cb1d435cb8b..501ffd452cb 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -2952,6 +2952,33 @@ call6 (fn, arg1, arg2, arg3, arg4, arg5, arg6)
 #endif /* not NO_ARG_ARRAY */
 }
 
+/* Call function fn with 7 arguments arg1, arg2, arg3, arg4, arg5, arg6, arg7 */
+/* ARGSUSED */
+Lisp_Object
+call7 (fn, arg1, arg2, arg3, arg4, arg5, arg6, arg7)
+     Lisp_Object fn, arg1, arg2, arg3, arg4, arg5, arg6, arg7;
+{
+  struct gcpro gcpro1;
+#ifdef NO_ARG_ARRAY
+  Lisp_Object args[8];
+  args[0] = fn;
+  args[1] = arg1;
+  args[2] = arg2;
+  args[3] = arg3;
+  args[4] = arg4;
+  args[5] = arg5;
+  args[6] = arg6;
+  args[7] = arg7;
+  GCPRO1 (args[0]);
+  gcpro1.nvars = 8;
+  RETURN_UNGCPRO (Ffuncall (8, args));
+#else /* not NO_ARG_ARRAY */
+  GCPRO1 (fn);
+  gcpro1.nvars = 8;
+  RETURN_UNGCPRO (Ffuncall (8, &fn));
+#endif /* not NO_ARG_ARRAY */
+}
+
 /* The caller should GCPRO all the elements of ARGS.  */
 
 DEFUN ("funcall", Ffuncall, Sfuncall, 1, MANY, 0,
diff --git a/src/fileio.c b/src/fileio.c
index e9440adabe0..4bfbae91844 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -53,6 +53,11 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <ctype.h>
 #include <errno.h>
 
+#ifdef HAVE_LIBSELINUX
+#include <selinux/selinux.h>
+#include <selinux/context.h>
+#endif
+
 #include "lisp.h"
 #include "intervals.h"
 #include "buffer.h"
@@ -331,6 +336,8 @@ Lisp_Object Qfile_accessible_directory_p;
 Lisp_Object Qfile_modes;
 Lisp_Object Qset_file_modes;
 Lisp_Object Qset_file_times;
+Lisp_Object Qfile_selinux_context;
+Lisp_Object Qset_file_selinux_context;
 Lisp_Object Qfile_newer_than_file_p;
 Lisp_Object Qinsert_file_contents;
 Lisp_Object Qwrite_region;
@@ -1894,7 +1901,7 @@ barf_or_query_if_file_exists (absname, querystring, interactive, statptr, quick)
   return;
 }
 
-DEFUN ("copy-file", Fcopy_file, Scopy_file, 2, 5,
+DEFUN ("copy-file", Fcopy_file, Scopy_file, 2, 6,
        "fCopy file: \nGCopy %s to file: \np\nP",
        doc: /* Copy FILE to NEWNAME.  Both args must be strings.
 If NEWNAME names a directory, copy FILE there.
@@ -1916,10 +1923,13 @@ last-modified time as the old one.  (This works on only some systems.)
 A prefix arg makes KEEP-TIME non-nil.
 
 If PRESERVE-UID-GID is non-nil, we try to transfer the
-uid and gid of FILE to NEWNAME.  */)
-  (file, newname, ok_if_already_exists, keep_time, preserve_uid_gid)
+uid and gid of FILE to NEWNAME.
+
+If PRESERVE-SELINUX-CONTEXT is non-nil and SELinux is enabled 
+on the system, we copy the SELinux context of FILE to NEWNAME.  */)
+     (file, newname, ok_if_already_exists, keep_time, preserve_uid_gid, preserve_selinux_context)
      Lisp_Object file, newname, ok_if_already_exists, keep_time;
-     Lisp_Object preserve_uid_gid;
+     Lisp_Object preserve_uid_gid, preserve_selinux_context;
 {
   int ifd, ofd, n;
   char buf[16 * 1024];
@@ -1929,6 +1939,10 @@ uid and gid of FILE to NEWNAME.  */)
   int count = SPECPDL_INDEX ();
   int input_file_statable_p;
   Lisp_Object encoded_file, encoded_newname;
+#if HAVE_LIBSELINUX
+  security_context_t con;
+  int fail, conlength = 0;
+#endif
 
   encoded_file = encoded_newname = Qnil;
   GCPRO4 (file, newname, encoded_file, encoded_newname);
@@ -1949,8 +1963,9 @@ uid and gid of FILE to NEWNAME.  */)
   if (NILP (handler))
     handler = Ffind_file_name_handler (newname, Qcopy_file);
   if (!NILP (handler))
-    RETURN_UNGCPRO (call6 (handler, Qcopy_file, file, newname,
-                           ok_if_already_exists, keep_time, preserve_uid_gid));
+    RETURN_UNGCPRO (call7 (handler, Qcopy_file, file, newname,
+                           ok_if_already_exists, keep_time, preserve_uid_gid,
+                           preserve_selinux_context));
 
   encoded_file = ENCODE_FILE (file);
   encoded_newname = ENCODE_FILE (newname);
@@ -2004,6 +2019,15 @@ uid and gid of FILE to NEWNAME.  */)
      copyable by us. */
   input_file_statable_p = (fstat (ifd, &st) >= 0);
 
+#if HAVE_LIBSELINUX
+  if (!NILP (preserve_selinux_context) && is_selinux_enabled ())
+    {
+      conlength = fgetfilecon (ifd, &con);
+      if (conlength == -1)
+        report_file_error ("Doing fgetfilecon", Fcons (file, Qnil));
+    }
+#endif
+
   if (out_st.st_mode != 0
       && st.st_dev == out_st.st_dev && st.st_ino == out_st.st_ino)
     {
@@ -2061,6 +2085,18 @@ uid and gid of FILE to NEWNAME.  */)
     }
 #endif  /* not MSDOS */
 
+#if HAVE_LIBSELINUX
+  if (conlength > 0)
+    {
+      /* Set the modified context back to the file. */
+      fail = fsetfilecon (ofd, con);
+      if (fail)
+        report_file_error ("Doing fsetfilecon", Fcons (newname, Qnil));
+
+      freecon (con);
+    }
+#endif
+
   /* Closing the output clobbers the file times on some systems.  */
   if (emacs_close (ofd) < 0)
     report_file_error ("I/O error", Fcons (newname, Qnil));
@@ -2287,7 +2323,7 @@ This is what happens in interactive use with M-x.  */)
                have copy-file prompt again.  */
             Fcopy_file (file, newname,
                         NILP (ok_if_already_exists) ? Qnil : Qt,
-                        Qt, Qt);
+                        Qt, Qt, Qt);
 
           count = SPECPDL_INDEX ();
           specbind (Qdelete_by_moving_to_trash, Qnil);
@@ -2844,6 +2880,136 @@ See `file-symlink-p' to distinguish symlinks.  */)
 #endif
 }
 
+DEFUN ("file-selinux-context", Ffile_selinux_context,
+       Sfile_selinux_context, 1, 1, 0,
+       doc: /* Return SELinux context of file named FILENAME,
+as a list ("user", "role", "type", "range"). Return (nil, nil, nil, nil)
+if file does not exist, is not accessible, or SELinux is disabled */)
+     (filename)
+     Lisp_Object filename;
+{
+  Lisp_Object absname;
+  Lisp_Object values[4];
+  Lisp_Object handler;
+#if HAVE_LIBSELINUX
+  security_context_t con;
+  int conlength;
+  context_t context;
+#endif
+
+  absname = expand_and_dir_to_file (filename, current_buffer->directory);
+
+  /* If the file name has special constructs in it,
+     call the corresponding file handler.  */
+  handler = Ffind_file_name_handler (absname, Qfile_selinux_context);
+  if (!NILP (handler))
+    return call2 (handler, Qfile_selinux_context, absname);
+
+  absname = ENCODE_FILE (absname);
+
+  values[0] = Qnil;
+  values[1] = Qnil;
+  values[2] = Qnil;
+  values[3] = Qnil;
+#if HAVE_LIBSELINUX
+  if (is_selinux_enabled ())
+    {
+      conlength = lgetfilecon (SDATA (absname), &con);
+      if (conlength > 0)
+        {
+          context = context_new (con);
+          values[0] = build_string (context_user_get (context));
+          values[1] = build_string (context_role_get (context));
+          values[2] = build_string (context_type_get (context));
+          values[3] = build_string (context_range_get (context));
+          context_free (context);
+        }
+      if (con)
+        freecon (con);
+    }
+#endif
+
+  return Flist (sizeof(values) / sizeof(values[0]), values);
+}
+
+DEFUN ("set-file-selinux-context", Fset_file_selinux_context,
+       Sset_file_selinux_context, 2, 2, 0,
+       doc: /* Set SELinux context of file named FILENAME to CONTEXT
+as a list ("user", "role", "type", "range"). Has no effect if SELinux
+is disabled. */)
+     (filename, context)
+     Lisp_Object filename, context;
+{
+  Lisp_Object absname, encoded_absname;
+  Lisp_Object handler;
+  Lisp_Object user = CAR_SAFE (context);
+  Lisp_Object role = CAR_SAFE (CDR_SAFE (context));
+  Lisp_Object type = CAR_SAFE (CDR_SAFE (CDR_SAFE (context)));
+  Lisp_Object range = CAR_SAFE (CDR_SAFE (CDR_SAFE (CDR_SAFE (context))));
+#if HAVE_LIBSELINUX
+  security_context_t con;
+  int fail, conlength;
+  context_t parsed_con;
+#endif
+
+  absname = Fexpand_file_name (filename, current_buffer->directory);
+
+  /* If the file name has special constructs in it,
+     call the corresponding file handler.  */
+  handler = Ffind_file_name_handler (absname, Qset_file_selinux_context);
+  if (!NILP (handler))
+    return call3 (handler, Qset_file_selinux_context, absname, context);
+
+  encoded_absname = ENCODE_FILE (absname);
+
+#if HAVE_LIBSELINUX
+  if (is_selinux_enabled ())
+    {
+      /* Get current file context. */
+      conlength = lgetfilecon (SDATA (encoded_absname), &con);
+      if (conlength > 0)
+        {
+          parsed_con = context_new (con);
+          /* Change the parts defined in the parameter.*/
+          if (STRINGP (user))
+            {
+              if (context_user_set (parsed_con, SDATA (user)))
+                error ("Doing context_user_set");
+            }
+          if (STRINGP (role))
+            {
+              if (context_role_set (parsed_con, SDATA (role)))
+                error ("Doing context_role_set");
+            }
+          if (STRINGP (type))
+            {
+              if (context_type_set (parsed_con, SDATA (type)))
+                error ("Doing context_type_set");
+            }
+          if (STRINGP (range))
+            {
+              if (context_range_set (parsed_con, SDATA (range)))
+                error ("Doing context_range_set");
+            }
+
+          /* Set the modified context back to the file. */
+          fail = lsetfilecon (SDATA (encoded_absname), context_str (parsed_con));
+          if (fail)
+            report_file_error ("Doing lsetfilecon", Fcons (absname, Qnil));
+
+          context_free (parsed_con);
+        }
+      else
+        report_file_error("Doing lgetfilecon", Fcons (absname, Qnil));
+
+      if (con)
+        freecon (con);
+    }
+#endif
+
+  return Qnil;
+}
+
 DEFUN ("file-modes", Ffile_modes, Sfile_modes, 1, 1, 0,
        doc: /* Return mode bits of file named FILENAME, as an integer.
 Return nil, if file does not exist or is not accessible.  */)
@@ -5505,6 +5671,8 @@ syms_of_fileio ()
   Qfile_modes = intern_c_string ("file-modes");
   Qset_file_modes = intern_c_string ("set-file-modes");
   Qset_file_times = intern_c_string ("set-file-times");
+  Qfile_selinux_context = intern_c_string("file-selinux-context");
+  Qset_file_selinux_context = intern_c_string("set-file-selinux-context");
   Qfile_newer_than_file_p = intern_c_string ("file-newer-than-file-p");
   Qinsert_file_contents = intern_c_string ("insert-file-contents");
   Qwrite_region = intern_c_string ("write-region");
@@ -5540,6 +5708,8 @@ syms_of_fileio ()
   staticpro (&Qfile_modes);
   staticpro (&Qset_file_modes);
   staticpro (&Qset_file_times);
+  staticpro (&Qfile_selinux_context);
+  staticpro (&Qset_file_selinux_context);
   staticpro (&Qfile_newer_than_file_p);
   staticpro (&Qinsert_file_contents);
   staticpro (&Qwrite_region);
@@ -5773,6 +5943,8 @@ When non-nil, the function `move-file-to-trash' will be used by
   defsubr (&Sfile_modes);
   defsubr (&Sset_file_modes);
   defsubr (&Sset_file_times);
+  defsubr (&Sfile_selinux_context);
+  defsubr (&Sset_file_selinux_context);
   defsubr (&Sset_default_file_modes);
   defsubr (&Sdefault_file_modes);
   defsubr (&Sfile_newer_than_file_p);
diff --git a/src/lisp.h b/src/lisp.h
index d7e88e7c8b8..357fc6fada3 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -2897,6 +2897,7 @@ extern Lisp_Object call3 P_ ((Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object
 extern Lisp_Object call4 P_ ((Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object));
 extern Lisp_Object call5 P_ ((Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object));
 extern Lisp_Object call6 P_ ((Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object));
+extern Lisp_Object call7 P_ ((Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object));
 EXFUN (Fdo_auto_save, 2);
 extern Lisp_Object apply_lambda P_ ((Lisp_Object, Lisp_Object, int));
 extern Lisp_Object internal_catch P_ ((Lisp_Object, Lisp_Object (*) (Lisp_Object), Lisp_Object));