LSM/SELinux: show LSM mount options in /proc/mounts

[mirror_ubuntu-bionic-kernel.git] / security / selinux / hooks.c

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 85f74f665765e33006cd0996fab42be5a457acdb..33dee83fdd2f43ce5b59580b5e9b3e80d3bb5d9d 100644 (file)
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -9,7 +9,8 @@
  *           James Morris <jmorris@redhat.com>
  *
  *  Copyright (C) 2001,2002 Networks Associates Technology, Inc.
- *  Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
+ *  Copyright (C) 2003-2008 Red Hat, Inc., James Morris <jmorris@redhat.com>
+ *                                        Eric Paris <eparis@redhat.com>
  *  Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
  *                         <dgoeddel@trustedcs.com>
  *  Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
@@ -970,6 +971,57 @@ out_err:
        return rc;
 }
 
+void selinux_write_opts(struct seq_file *m, struct security_mnt_opts *opts)
+{
+       int i;
+       char *prefix;
+
+       for (i = 0; i < opts->num_mnt_opts; i++) {
+               char *has_comma = strchr(opts->mnt_opts[i], ',');
+
+               switch (opts->mnt_opts_flags[i]) {
+               case CONTEXT_MNT:
+                       prefix = CONTEXT_STR;
+                       break;
+               case FSCONTEXT_MNT:
+                       prefix = FSCONTEXT_STR;
+                       break;
+               case ROOTCONTEXT_MNT:
+                       prefix = ROOTCONTEXT_STR;
+                       break;
+               case DEFCONTEXT_MNT:
+                       prefix = DEFCONTEXT_STR;
+                       break;
+               default:
+                       BUG();
+               };
+               /* we need a comma before each option */
+               seq_putc(m, ',');
+               seq_puts(m, prefix);
+               if (has_comma)
+                       seq_putc(m, '\"');
+               seq_puts(m, opts->mnt_opts[i]);
+               if (has_comma)
+                       seq_putc(m, '\"');
+       }
+}
+
+static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
+{
+       struct security_mnt_opts opts;
+       int rc;
+
+       rc = selinux_get_mnt_opts(sb, &opts);
+       if (rc)
+               return rc;
+
+       selinux_write_opts(m, &opts);
+
+       security_free_mnt_opts(&opts);
+
+       return rc;
+}
+
 static inline u16 inode_mode_to_security_class(umode_t mode)
 {
        switch (mode & S_IFMT) {
@@ -5365,6 +5417,7 @@ static struct security_operations selinux_ops = {
        .sb_free_security =             selinux_sb_free_security,
        .sb_copy_data =                 selinux_sb_copy_data,
        .sb_kern_mount =                selinux_sb_kern_mount,
+       .sb_show_options =              selinux_sb_show_options,
        .sb_statfs =                    selinux_sb_statfs,
        .sb_mount =                     selinux_mount,
        .sb_umount =                    selinux_umount,