NFSD: Server implementation of MAC Labeling

Implement labeled NFS on the server: encoding and decoding, and writing
and reading, of file labels.

Enabled with CONFIG_NFSD_V4_SECURITY_LABEL.

Signed-off-by: Matthew N. Dodd <Matthew.Dodd@sparta.com>
Signed-off-by: Miguel Rodel Felipe <Rodel_FM@dsi.a-star.edu.sg>
Signed-off-by: Phua Eu Gene <PHUA_Eu_Gene@dsi.a-star.edu.sg>
Signed-off-by: Khin Mi Mi Aung <Mi_Mi_AUNG@dsi.a-star.edu.sg>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 28 insertions, 0 deletions

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 84ce601d8063..1e757fa45c40 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -28,6 +28,7 @@
 #include <asm/uaccess.h>
 #include <linux/exportfs.h>
 #include <linux/writeback.h>
+#include <linux/security.h>
 
 #ifdef CONFIG_NFSD_V3
 #include "xdr3.h"
@@ -621,6 +622,33 @@ int nfsd4_is_junction(struct dentry *dentry)
                 return 0;
         return 1;
 }
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+__be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp,
+                struct xdr_netobj *label)
+{
+        __be32 error;
+        int host_error;
+        struct dentry *dentry;
+
+        error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, NFSD_MAY_SATTR);
+        if (error)
+                return error;
+
+        dentry = fhp->fh_dentry;
+
+        mutex_lock(&dentry->d_inode->i_mutex);
+        host_error = security_inode_setsecctx(dentry, label->data, label->len);
+        mutex_unlock(&dentry->d_inode->i_mutex);
+        return nfserrno(host_error);
+}
+#else
+__be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp,
+                struct xdr_netobj *label)
+{
+        return nfserr_notsupp;
+}
+#endif
+
 #endif /* defined(CONFIG_NFSD_V4) */
 
 #ifdef CONFIG_NFSD_V3