Commit 7ebb9315 authored by Bryan Schumaker's avatar Bryan Schumaker Committed by Trond Myklebust
Browse files

NFS: use secinfo when crossing mountpoints 



A submount may use different security than the parent
mount does.  We should figure out what sec flavor the
submount uses at mount time.

Signed-off-by: default avatarBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 5a5ea0d4

fs/nfs/inode.c

+5 −3
Original line number Diff line number Diff line
@@ -254,7 +254,9 @@ nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr) 
	struct inode *inode = ERR_PTR(-ENOENT);

	unsigned long hash;



	if ((fattr->valid & NFS_ATTR_FATTR_FILEID) == 0)

	nfs_attr_check_mountpoint(sb, fattr);



	if ((fattr->valid & NFS_ATTR_FATTR_FILEID) == 0 && (fattr->valid & NFS_ATTR_FATTR_MOUNTPOINT) == 0)

		goto out_no_inode;

	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) == 0)

		goto out_no_inode;
@@ -298,8 +300,8 @@ nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr) 
			if (nfs_server_capable(inode, NFS_CAP_READDIRPLUS))

				set_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags);

			/* Deal with crossing mountpoints */

			if ((fattr->valid & NFS_ATTR_FATTR_FSID)

					&& !nfs_fsid_equal(&NFS_SB(sb)->fsid, &fattr->fsid)) {

			if (fattr->valid & NFS_ATTR_FATTR_MOUNTPOINT ||

					fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) {

				if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)

					inode->i_op = &nfs_referral_inode_operations;

				else

fs/nfs/internal.h

+7 −0
Original line number Diff line number Diff line
@@ -39,6 +39,12 @@ static inline int nfs4_has_persistent_session(const struct nfs_client *clp) 
	return 0;

}



static inline void nfs_attr_check_mountpoint(struct super_block *parent, struct nfs_fattr *fattr)

{

	if (!nfs_fsid_equal(&NFS_SB(parent)->fsid, &fattr->fsid))

		fattr->valid |= NFS_ATTR_FATTR_MOUNTPOINT;

}



struct nfs_clone_mount {

	const struct super_block *sb;

	const struct dentry *dentry;
@@ -214,6 +220,7 @@ extern const u32 nfs41_maxwrite_overhead; 
/* nfs4proc.c */

#ifdef CONFIG_NFS_V4

extern struct rpc_procinfo nfs4_procedures[];

void nfs_fixup_secinfo_attributes(struct nfs_fattr *, struct nfs_fh *);

#endif



extern int nfs4_init_ds_session(struct nfs_client *clp);

fs/nfs/namespace.c

+110 −3
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
#include <linux/string.h>

#include <linux/sunrpc/clnt.h>

#include <linux/vfs.h>

#include <linux/sunrpc/gss_api.h>

#include "internal.h"



#define NFSDBG_FACILITY		NFSDBG_VFS
@@ -27,7 +28,8 @@ int nfs_mountpoint_expiry_timeout = 500 * HZ; 


static struct vfsmount *nfs_do_submount(struct dentry *dentry,

					struct nfs_fh *fh,

					struct nfs_fattr *fattr);

					struct nfs_fattr *fattr,

					rpc_authflavor_t authflavor);



/*

 * nfs_path - reconstruct the path given an arbitrary dentry
@@ -116,6 +118,100 @@ char *nfs_path(char **p, struct dentry *dentry, char *buffer, ssize_t buflen) 
	return ERR_PTR(-ENAMETOOLONG);

}



#ifdef CONFIG_NFS_V4

static rpc_authflavor_t nfs_find_best_sec(struct nfs4_secinfo_flavors *flavors, struct inode *inode)

{

	struct gss_api_mech *mech;

	struct xdr_netobj oid;

	int i;

	rpc_authflavor_t pseudoflavor = RPC_AUTH_UNIX;



	for (i = 0; i < flavors->num_flavors; i++) {

		struct nfs4_secinfo_flavor *flavor;

		flavor = &flavors->flavors[i];



		if (flavor->flavor == RPC_AUTH_NULL || flavor->flavor == RPC_AUTH_UNIX) {

			pseudoflavor = flavor->flavor;

			break;

		} else if (flavor->flavor == RPC_AUTH_GSS) {

			oid.len  = flavor->gss.sec_oid4.len;

			oid.data = flavor->gss.sec_oid4.data;

			mech = gss_mech_get_by_OID(&oid);

			if (!mech)

				continue;

			pseudoflavor = gss_svc_to_pseudoflavor(mech, flavor->gss.service);

			gss_mech_put(mech);

			break;

		}

	}



	return pseudoflavor;

}



static rpc_authflavor_t nfs_negotiate_security(const struct dentry *parent, const struct dentry *dentry)

{

	int status = 0;

	struct page *page;

	struct nfs4_secinfo_flavors *flavors;

	int (*secinfo)(struct inode *, const struct qstr *, struct nfs4_secinfo_flavors *);

	rpc_authflavor_t flavor = RPC_AUTH_UNIX;



	secinfo = NFS_PROTO(parent->d_inode)->secinfo;

	if (secinfo != NULL) {

		page = alloc_page(GFP_KERNEL);

		if (!page) {

			status = -ENOMEM;

			goto out;

		}

		flavors = page_address(page);

		status = secinfo(parent->d_inode, &dentry->d_name, flavors);

		flavor = nfs_find_best_sec(flavors, dentry->d_inode);

		put_page(page);

	}



	return flavor;



out:

	status = -ENOMEM;

	return status;

}



static rpc_authflavor_t nfs_lookup_with_sec(struct nfs_server *server, struct dentry *parent,

				     struct dentry *dentry, struct path *path,

				     struct nfs_fh *fh, struct nfs_fattr *fattr)

{

	rpc_authflavor_t flavor;

	struct rpc_clnt *clone;

	struct rpc_auth *auth;

	int err;



	flavor = nfs_negotiate_security(parent, path->dentry);

	if (flavor < 0)

		goto out;

	clone  = rpc_clone_client(server->client);

	auth   = rpcauth_create(flavor, clone);

	if (!auth) {

		flavor = -EIO;

		goto out;

	}

	err = server->nfs_client->rpc_ops->lookup(clone, parent->d_inode,

						  &path->dentry->d_name,

						  fh, fattr);

	if (err < 0)

		flavor = err;

out:

	return flavor;

}

#else /* CONFIG_NFS_V4 */

static inline rpc_authflavor_t nfs_lookup_with_sec(struct nfs_server *server,

				     struct dentry *parent, struct dentry *dentry,

				     struct path *path, struct nfs_fh *fh,

				     struct nfs_fattr *fattr)

{

	return -EPERM;

}

#endif /* CONFIG_NFS_V4 */



/*

 * nfs_d_automount - Handle crossing a mountpoint on the server

 * @path - The mountpoint
@@ -136,6 +232,7 @@ struct vfsmount *nfs_d_automount(struct path *path) 
	struct nfs_fh *fh = NULL;

	struct nfs_fattr *fattr = NULL;

	int err;

	rpc_authflavor_t flavor = 1;



	dprintk("--> nfs_d_automount()\n");
@@ -156,6 +253,13 @@ struct vfsmount *nfs_d_automount(struct path *path) 
	err = server->nfs_client->rpc_ops->lookup(server->client, parent->d_inode,

						  &path->dentry->d_name,

						  fh, fattr);

	if (err == -EPERM) {

		flavor = nfs_lookup_with_sec(server, parent, path->dentry, path, fh, fattr);

		if (flavor < 0)

			err = flavor;

		else

			err = 0;

	}

	dput(parent);

	if (err != 0) {

		mnt = ERR_PTR(err);
@@ -165,7 +269,7 @@ struct vfsmount *nfs_d_automount(struct path *path) 
	if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)

		mnt = nfs_do_refmount(path->dentry);

	else

		mnt = nfs_do_submount(path->dentry, fh, fattr);

		mnt = nfs_do_submount(path->dentry, fh, fattr, flavor);

	if (IS_ERR(mnt))

		goto out;
@@ -232,17 +336,20 @@ static struct vfsmount *nfs_do_clone_mount(struct nfs_server *server, 
 * @dentry - parent directory

 * @fh - filehandle for new root dentry

 * @fattr - attributes for new root inode

 * @authflavor - security flavor to use when performing the mount

 *

 */

static struct vfsmount *nfs_do_submount(struct dentry *dentry,

					struct nfs_fh *fh,

					struct nfs_fattr *fattr)

					struct nfs_fattr *fattr,

					rpc_authflavor_t authflavor)

{

	struct nfs_clone_mount mountdata = {

		.sb = dentry->d_sb,

		.dentry = dentry,

		.fh = fh,

		.fattr = fattr,

		.authflavor = authflavor,

	};

	struct vfsmount *mnt = ERR_PTR(-ENOMEM);

	char *page = (char *) __get_free_page(GFP_USER);

fs/nfs/nfs4proc.c

+14 −0
Original line number Diff line number Diff line
@@ -87,6 +87,8 @@ static int nfs4_map_errors(int err) 
	switch (err) {

	case -NFS4ERR_RESOURCE:

		return -EREMOTEIO;

	case -NFS4ERR_WRONGSEC:

		return -EPERM;

	case -NFS4ERR_BADOWNER:

	case -NFS4ERR_BADNAME:

		return -EINVAL;
@@ -2383,6 +2385,16 @@ static int _nfs4_proc_lookup(struct rpc_clnt *clnt, struct inode *dir, 
	return status;

}



void nfs_fixup_secinfo_attributes(struct nfs_fattr *fattr, struct nfs_fh *fh)

{

	memset(fh, 0, sizeof(struct nfs_fh));

	fattr->fsid.major = 1;

	fattr->valid |= NFS_ATTR_FATTR_TYPE | NFS_ATTR_FATTR_MODE |

		NFS_ATTR_FATTR_NLINK | NFS_ATTR_FATTR_FSID | NFS_ATTR_FATTR_MOUNTPOINT;

	fattr->mode = S_IFDIR | S_IRUGO | S_IXUGO;

	fattr->nlink = 2;

}



static int nfs4_proc_lookup(struct rpc_clnt *clnt, struct inode *dir, struct qstr *name,

			    struct nfs_fh *fhandle, struct nfs_fattr *fattr)

{
@@ -2392,6 +2404,8 @@ static int nfs4_proc_lookup(struct rpc_clnt *clnt, struct inode *dir, struct qst 
		err = nfs4_handle_exception(NFS_SERVER(dir),

				_nfs4_proc_lookup(clnt, dir, name, fhandle, fattr),

				&exception);

		if (err == -EPERM)

			nfs_fixup_secinfo_attributes(fattr, fhandle);

	} while (exception.retry);

	return err;

}

fs/nfs/nfs4xdr.c

+6 −5
Original line number Diff line number Diff line
@@ -113,7 +113,7 @@ static int nfs4_stat_to_errno(int); 
#define encode_restorefh_maxsz  (op_encode_hdr_maxsz)

#define decode_restorefh_maxsz  (op_decode_hdr_maxsz)

#define encode_fsinfo_maxsz	(encode_getattr_maxsz)

#define decode_fsinfo_maxsz	(op_decode_hdr_maxsz + 11)

#define decode_fsinfo_maxsz	(op_decode_hdr_maxsz + 15)

#define encode_renew_maxsz	(op_encode_hdr_maxsz + 3)

#define decode_renew_maxsz	(op_decode_hdr_maxsz)

#define encode_setclientid_maxsz \
@@ -2966,6 +2966,7 @@ static int decode_attr_error(struct xdr_stream *xdr, uint32_t *bitmap) 
		if (unlikely(!p))

			goto out_overflow;

		bitmap[0] &= ~FATTR4_WORD0_RDATTR_ERROR;

		return -be32_to_cpup(p);

	}

	return 0;

out_overflow:
@@ -3953,6 +3954,10 @@ static int decode_getfattr_attrs(struct xdr_stream *xdr, uint32_t *bitmap, 
	fattr->valid |= status;



	status = decode_attr_error(xdr, bitmap);

	if (status == -NFS4ERR_WRONGSEC) {

		nfs_fixup_secinfo_attributes(fattr, fh);

		status = 0;

	}

	if (status < 0)

		goto xdr_error;
@@ -6314,10 +6319,6 @@ static struct { 
	{ NFS4ERR_SYMLINK,	-ELOOP		},

	{ NFS4ERR_OP_ILLEGAL,	-EOPNOTSUPP	},

	{ NFS4ERR_DEADLOCK,	-EDEADLK	},

	{ NFS4ERR_WRONGSEC,	-EPERM		}, /* FIXME: this needs

						    * to be handled by a

						    * middle-layer.

						    */

	{ -1,			-EIO		}

};