[PATCH 07/11] NFS/SELinux: Add security_label text mount option to nfs and add handling code to the security server.

David P. Quigley
2008-02-27T23:09:11Z

The new method for pulling argument for NFS from mount is through a text
parsing system. This patch adds two new entries to the argument parsing code
"securlty_label" and "nosecurity_label". Even though we use text across the
user/kernel boundary internally we still pack a binary structure for mount info
to be passed around. We add a flag for use in the nfs{4,}_mount_data struct to
indicate that are using security labels. Finally we add the SELinux support to
mark the labeling method as native.

Signed-off-by: David P. Quigley <dpquigl@tycho.nsa.gov>
---
fs/nfs/super.c | 10 +++++++++-
fs/nfsd/export.c | 3 +++
include/linux/nfs4_mount.h | 3 ++-
include/linux/nfs_mount.h | 3 ++-
security/selinux/hooks.c | 13 ++++++++++++-
5 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 1fb3818..f3e327e 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -75,6 +75,7 @@ enum {
Opt_acl, Opt_noacl,
Opt_rdirplus, Opt_nordirplus,
Opt_sharecache, Opt_nosharecache,
+ Opt_seclabel, Opt_noseclabel,

/* Mount options that take integer arguments */
Opt_port,
@@ -124,6 +125,8 @@ static match_table_t nfs_mount_option_tokens = {
{ Opt_nordirplus, "nordirplus" },
{ Opt_sharecache, "sharecache" },
{ Opt_nosharecache, "nosharecache" },
+ { Opt_seclabel, "security_label" },
+ { Opt_noseclabel, "nosecurity_label" },

{ Opt_port, "port=%u" },
{ Opt_rsize, "rsize=%u" },
@@ -779,7 +782,12 @@ static int nfs_parse_mount_options(char *raw,
case Opt_nosharecache:
mnt->flags |= NFS_MOUNT_UNSHARED;
break;
-
+ case Opt_seclabel:
+ mnt->flags |= NFS_MOUNT_SECURITY_LABEL;
+ break;
+ case Opt_noseclabel:
+ mnt->flags &= ~NFS_MOUNT_SECURITY_LABEL;
+ break;
case Opt_port:
if (match_int(args, &option))
return 0;
diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
index 8a6f7c9..d32ae56 100644
--- a/fs/nfsd/export.c
+++ b/fs/nfsd/export.c
@@ -1435,6 +1435,9 @@ static struct flags {
{ NFSEXP_ALLSQUASH, {"all_squash", ""}},
{ NFSEXP_ASYNC, {"async", "sync"}},
{ NFSEXP_GATHERED_WRITES, {"wdelay", "no_wdelay"}},
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+ { NFSEXP_SECURITY_LABEL, {"security_label", ""}},
+#endif
{ NFSEXP_NOHIDE, {"nohide", ""}},
{ NFSEXP_CROSSMOUNT, {"crossmnt", ""}},
{ NFSEXP_NOSUBTREECHECK, {"no_subtree_check", ""}},
diff --git a/include/linux/nfs4_mount.h b/include/linux/nfs4_mount.h
index a0dcf66..d7abc3b 100644
--- a/include/linux/nfs4_mount.h
+++ b/include/linux/nfs4_mount.h
@@ -66,6 +66,7 @@ struct nfs4_mount_data {
#define NFS4_MOUNT_NOAC 0x0020 /* 1 */
#define NFS4_MOUNT_STRICTLOCK 0x1000 /* 1 */
#define NFS4_MOUNT_UNSHARED 0x8000 /* 1 */
-#define NFS4_MOUNT_FLAGMASK 0x9033
+#define NFS4_MOUNT_SECURITY_LABEL 0x10000 /* Text Only */
+#define NFS4_MOUNT_FLAGMASK 0x19033

#endif
diff --git a/include/linux/nfs_mount.h b/include/linux/nfs_mount.h
index df7c6b7..1ca5260 100644
--- a/include/linux/nfs_mount.h
+++ b/include/linux/nfs_mount.h
@@ -63,6 +63,7 @@ struct nfs_mount_data {
#define NFS_MOUNT_SECFLAVOUR 0x2000 /* 5 */
#define NFS_MOUNT_NORDIRPLUS 0x4000 /* 5 */
#define NFS_MOUNT_UNSHARED 0x8000 /* 5 */
-#define NFS_MOUNT_FLAGMASK 0xFFFF
+#define NFS_MOUNT_SECURITY_LABEL 0x10000 /* reserved for NFSv4 */
+#define NFS_MOUNT_FLAGMASK 0x1FFFF

#endif
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index ebe4e18..e3ed7c3 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -68,6 +68,7 @@
#include <net/af_unix.h> /* for Unix socket types */
#include <linux/parser.h>
#include <linux/nfs_mount.h>
+#include <linux/nfs4_mount.h>
#include <net/ipv6.h>
#include <linux/hugetlb.h>
#include <linux/personality.h>
@@ -807,6 +808,7 @@ static int superblock_doinit(struct super_block *sb, void *data)
/* selinux only know about a fixed number of mount options */
char *mnt_opts[NUM_SEL_MNT_OPTS];
int mnt_opts_flags[NUM_SEL_MNT_OPTS], num_mnt_opts = 0;
+ struct superblock_security_struct *sbsec = sb->s_security;

if (!data)
goto out;
@@ -829,6 +831,15 @@ static int superblock_doinit(struct super_block *sb, void *data)
}
}
goto build_flags;
+ } else if (!strcmp(name, "nfs4")) {
+ struct nfs4_mount_data *d = data;
+
+ if (d->version != NFS4_MOUNT_VERSION)
+ goto out;
+
+ if (d->flags & NFS4_MOUNT_SECURITY_LABEL)
+ sbsec->behavior = SECURITY_FS_USE_NATIVE;
+ goto build_flags;
} else
goto out;
}
@@ -898,7 +909,7 @@ static int superblock_doinit(struct super_block *sb, void *data)

default:
rc = -EINVAL;
- printk(KERN_WARNING "SELinux: unknown mount option\n");
+ printk(KERN_WARNING "SELinux: unknown mount option \"%s\"\n", p);
goto out_err;

}
--
1.5.3.8