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NFS: use secinfo when crossing mountpoints

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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: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Bryan Schumaker 2011-03-24 17:12:30 +00:00 committed by Trond Myklebust
parent 5a5ea0d485
commit 7ebb931598
7 changed files with 165 additions and 11 deletions
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8
fs/nfs/inode.c
View File

@ -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

7
fs/nfs/internal.h
View File

@ -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);

113
fs/nfs/namespace.c
View File

@ -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 @@ Elong:
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);

14
fs/nfs/nfs4proc.c
View File

@ -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;
}

11
fs/nfs/nfs4xdr.c
View File

@ -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 }
};

1
include/linux/nfs_xdr.h
View File

@ -82,6 +82,7 @@ struct nfs_fattr {
#define NFS_ATTR_FATTR_CHANGE (1U << 17)
#define NFS_ATTR_FATTR_PRECHANGE (1U << 18)
#define NFS_ATTR_FATTR_V4_REFERRAL (1U << 19) /* NFSv4 referral */
#define NFS_ATTR_FATTR_MOUNTPOINT (1U << 20) /* Treat as mountpoint */
#define NFS_ATTR_FATTR (NFS_ATTR_FATTR_TYPE \
| NFS_ATTR_FATTR_MODE \

22
net/sunrpc/auth_gss/gss_mech_switch.c
View File

@ -160,6 +160,28 @@ gss_mech_get_by_name(const char *name)
EXPORT_SYMBOL_GPL(gss_mech_get_by_name);
struct gss_api_mech *
gss_mech_get_by_OID(struct xdr_netobj *obj)
{
struct gss_api_mech *pos, *gm = NULL;
spin_lock(&registered_mechs_lock);
list_for_each_entry(pos, &registered_mechs, gm_list) {
if (obj->len == pos->gm_oid.len) {
if (0 == memcmp(obj->data, pos->gm_oid.data, obj->len)) {
if (try_module_get(pos->gm_owner))
gm = pos;
break;
}
}
}
spin_unlock(&registered_mechs_lock);
return gm;
}
EXPORT_SYMBOL_GPL(gss_mech_get_by_OID);
static inline int
mech_supports_pseudoflavor(struct gss_api_mech *gm, u32 pseudoflavor)
{