[PATCH v1 00/15] Security flavor negotiation fixes

[PATCH v1 00/15] Security flavor negotiation fixes

[Chuck Lever]

Please consider these for 3.10.  With the exception of 15/15, similar
or the same patches have been posted here before.

The NFSv3 MNT changes we discussed at the pub will appear soon.

---

Chuck Lever (15):
      NFS: Use "krb5i" to establish NFSv4 state whenever possible
      NFS: Try AUTH_UNIX when PUTROOTFH gets NFS4ERR_WRONGSEC
      NFS: Use static list of security flavors during root FH lookup recovery
      NFS: Avoid PUTROOTFH when managing leases
      NFS: Clean up nfs4_proc_get_rootfh
      NFS: Handle missing rpc.gssd when looking up root FH
      SUNRPC: Remove EXPORT_SYMBOL_GPL() from GSS mech switch
      SUNRPC: Make gss_mech_get() static
      SUNRPC: Refactor nfsd4_do_encode_secinfo()
      SUNRPC: Consider qop when looking up pseudoflavors
      SUNRPC: Load GSS kernel module by OID
      SUNRPC: Introduce rpcauth_get_pseudoflavor()
      SUNRPC: Define rpcsec_gss_info structure
      NFS: Remove unneeded forward declaration
      SUNRPC: Missing module alias for auth_rpcgss.ko


 fs/nfs/nfs4client.c                   |    2 -
 fs/nfs/nfs4namespace.c                |   43 +++++++-----
 fs/nfs/nfs4proc.c                     |   92 ++++++++++++++++----------
 fs/nfs/nfs4state.c                    |   37 +---------
 fs/nfs/nfs4xdr.c                      |   39 ++++-------
 fs/nfsd/nfs4xdr.c                     |   24 +++----
 include/linux/nfs_xdr.h               |   24 +------
 include/linux/sunrpc/auth.h           |    9 ++
 include/linux/sunrpc/gss_api.h        |   30 ++++++--
 net/sunrpc/Kconfig                    |    1 
 net/sunrpc/auth.c                     |   70 +++++++++++++++++++
 net/sunrpc/auth_gss/auth_gss.c        |    3 +
 net/sunrpc/auth_gss/gss_krb5_mech.c   |    6 +-
 net/sunrpc/auth_gss/gss_mech_switch.c |  119 +++++++++++++++++++++++++--------
 net/sunrpc/auth_gss/svcauth_gss.c     |    4 +
 15 files changed, 319 insertions(+), 184 deletions(-)

-- 
Chuck Lever

[PATCH v1 01/15] SUNRPC: Missing module alias for auth_rpcgss.ko

[Chuck Lever]

Commit f344f6df "SUNRPC: Auto-load RPC authentication kernel
modules", Mon Mar 20 13:44:08 2006, adds a request_module() call
in rpcauth_create() to auto-load RPC security modules when a ULP
tries to create a credential of that flavor.

In rpcauth_create(), the name of the module to load is built like
this:

	request_module("rpc-auth-%u", flavor);

This means that for, say, RPC_AUTH_GSS, request_module() is looking
for a module or alias called "rpc-auth-6".

The GSS module is named "auth_rpcgss", and commit f344f6df does not
add any new module aliases.  There is also no such alias provided in
/etc/modprobe.d on my system (Fedora 16).  Without this alias, the
GSS module is not loaded on demand.

This is used by rpcauth_create().  The pseudoflavor_to_flavor() call
can return RPC_AUTH_GSS, which is passed to request_module().

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---

 net/sunrpc/auth_gss/auth_gss.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 5257d29..282dfb1 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -1733,6 +1733,7 @@ static void __exit exit_rpcsec_gss(void)
 	rcu_barrier(); /* Wait for completion of call_rcu()'s */
 }
 
+MODULE_ALIAS("rpc-auth-6");
 MODULE_LICENSE("GPL");
 module_param_named(expired_cred_retry_delay,
 		   gss_expired_cred_retry_delay,

[PATCH v1 02/15] NFS: Remove unneeded forward declaration

[Chuck Lever]

I've built with NFSv4 enabled and disabled.  This forward
declaration does not seem to be required.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---

 include/linux/nfs_xdr.h |    3 ---
 1 files changed, 0 insertions(+), 3 deletions(-)

diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 4b993d3..94b0406 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -14,9 +14,6 @@
 #define NFS_DEF_FILE_IO_SIZE	(4096U)
 #define NFS_MIN_FILE_IO_SIZE	(1024U)
 
-/* Forward declaration for NFS v3 */
-struct nfs4_secinfo_flavors;
-
 struct nfs4_string {
 	unsigned int len;
 	char *data;

[PATCH v1 03/15] SUNRPC: Define rpcsec_gss_info structure

[Chuck Lever]

The NFSv4 SECINFO procedure returns a list of security flavors.  Any
GSS flavor also has a GSS tuple containing an OID, a quality-of-
protection value, and a service value, which specifies a particular
GSS pseudoflavor.

For simplicity and efficiency, I'd like to return each GSS tuple
from the NFSv4 SECINFO XDR decoder and pass it straight into the RPC
client.

Define a data structure that is visible to both the NFS client and
the RPC client.  Take structure and field names from the relevant
standards to avoid confusion.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---

 fs/nfs/nfs4namespace.c              |   12 ++++++------
 fs/nfs/nfs4xdr.c                    |   21 ++++++++++++---------
 include/linux/nfs_xdr.h             |   21 +++++----------------
 include/linux/sunrpc/gss_api.h      |   14 ++++++++++++--
 net/sunrpc/auth_gss/gss_krb5_mech.c |    2 +-
 5 files changed, 36 insertions(+), 34 deletions(-)

diff --git a/fs/nfs/nfs4namespace.c b/fs/nfs/nfs4namespace.c
index 0dd7660..88231c9 100644
--- a/fs/nfs/nfs4namespace.c
+++ b/fs/nfs/nfs4namespace.c
@@ -138,23 +138,23 @@ rpc_authflavor_t nfs_find_best_sec(struct nfs4_secinfo_flavors *flavors)
 {
 	struct gss_api_mech *mech;
 	struct xdr_netobj oid;
-	int i;
+	unsigned 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];
+		struct nfs4_secinfo4 *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;
+			oid.len  = flavor->flavor_info.oid.len;
+			oid.data = flavor->flavor_info.oid.data;
 			mech = gss_mech_get_by_OID(&oid);
 			if (!mech)
 				continue;
-			pseudoflavor = gss_svc_to_pseudoflavor(mech, flavor->gss.service);
+			pseudoflavor = gss_svc_to_pseudoflavor(mech,
+						flavor->flavor_info.service);
 			gss_mech_put(mech);
 			break;
 		}
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index e3edda5..95b396f 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -5209,27 +5209,30 @@ static int decode_delegreturn(struct xdr_stream *xdr)
 	return decode_op_hdr(xdr, OP_DELEGRETURN);
 }
 
-static int decode_secinfo_gss(struct xdr_stream *xdr, struct nfs4_secinfo_flavor *flavor)
+static int decode_secinfo_gss(struct xdr_stream *xdr,
+			      struct nfs4_secinfo4 *flavor)
 {
+	u32 oid_len;
 	__be32 *p;
 
 	p = xdr_inline_decode(xdr, 4);
 	if (unlikely(!p))
 		goto out_overflow;
-	flavor->gss.sec_oid4.len = be32_to_cpup(p);
-	if (flavor->gss.sec_oid4.len > GSS_OID_MAX_LEN)
+	oid_len = be32_to_cpup(p);
+	if (oid_len > GSS_OID_MAX_LEN)
 		goto out_err;
 
-	p = xdr_inline_decode(xdr, flavor->gss.sec_oid4.len);
+	p = xdr_inline_decode(xdr, oid_len);
 	if (unlikely(!p))
 		goto out_overflow;
-	memcpy(flavor->gss.sec_oid4.data, p, flavor->gss.sec_oid4.len);
+	memcpy(flavor->flavor_info.oid.data, p, oid_len);
+	flavor->flavor_info.oid.len = oid_len;
 
 	p = xdr_inline_decode(xdr, 8);
 	if (unlikely(!p))
 		goto out_overflow;
-	flavor->gss.qop4 = be32_to_cpup(p++);
-	flavor->gss.service = be32_to_cpup(p);
+	flavor->flavor_info.qop = be32_to_cpup(p++);
+	flavor->flavor_info.service = be32_to_cpup(p);
 
 	return 0;
 
@@ -5242,10 +5245,10 @@ out_err:
 
 static int decode_secinfo_common(struct xdr_stream *xdr, struct nfs4_secinfo_res *res)
 {
-	struct nfs4_secinfo_flavor *sec_flavor;
+	struct nfs4_secinfo4 *sec_flavor;
+	unsigned int i, num_flavors;
 	int status;
 	__be32 *p;
-	int i, num_flavors;
 
 	p = xdr_inline_decode(xdr, 4);
 	if (unlikely(!p))
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 94b0406..a021eb0 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1047,25 +1047,14 @@ struct nfs4_fs_locations_res {
 	struct nfs4_fs_locations       *fs_locations;
 };
 
-struct nfs4_secinfo_oid {
-	unsigned int len;
-	char data[GSS_OID_MAX_LEN];
-};
-
-struct nfs4_secinfo_gss {
-	struct nfs4_secinfo_oid sec_oid4;
-	unsigned int qop4;
-	unsigned int service;
-};
-
-struct nfs4_secinfo_flavor {
-	unsigned int 		flavor;
-	struct nfs4_secinfo_gss	gss;
+struct nfs4_secinfo4 {
+	u32			flavor;
+	struct rpcsec_gss_info	flavor_info;
 };
 
 struct nfs4_secinfo_flavors {
-	unsigned int num_flavors;
-	struct nfs4_secinfo_flavor flavors[0];
+	unsigned int		num_flavors;
+	struct nfs4_secinfo4	flavors[0];
 };
 
 struct nfs4_secinfo_arg {
diff --git a/include/linux/sunrpc/gss_api.h b/include/linux/sunrpc/gss_api.h
index a19e254..98950e5 100644
--- a/include/linux/sunrpc/gss_api.h
+++ b/include/linux/sunrpc/gss_api.h
@@ -25,10 +25,20 @@ struct gss_ctx {
 
 #define GSS_C_NO_BUFFER		((struct xdr_netobj) 0)
 #define GSS_C_NO_CONTEXT	((struct gss_ctx *) 0)
-#define GSS_C_NULL_OID		((struct xdr_netobj) 0)
 
 /*XXX  arbitrary length - is this set somewhere? */
 #define GSS_OID_MAX_LEN 32
+struct rpcsec_gss_oid {
+	unsigned int	len;
+	u8		data[GSS_OID_MAX_LEN];
+};
+
+/* From RFC 3530 */
+struct rpcsec_gss_info {
+	struct rpcsec_gss_oid	oid;
+	u32			qop;
+	u32			service;
+};
 
 /* gss-api prototypes; note that these are somewhat simplified versions of
  * the prototypes specified in RFC 2744. */
@@ -76,7 +86,7 @@ struct pf_desc {
 struct gss_api_mech {
 	struct list_head	gm_list;
 	struct module		*gm_owner;
-	struct xdr_netobj	gm_oid;
+	struct rpcsec_gss_oid	gm_oid;
 	char			*gm_name;
 	const struct gss_api_ops *gm_ops;
 	/* pseudoflavors supported by this mechanism: */
diff --git a/net/sunrpc/auth_gss/gss_krb5_mech.c b/net/sunrpc/auth_gss/gss_krb5_mech.c
index d3611f1..61d36ce 100644
--- a/net/sunrpc/auth_gss/gss_krb5_mech.c
+++ b/net/sunrpc/auth_gss/gss_krb5_mech.c
@@ -754,7 +754,7 @@ MODULE_ALIAS("rpc-auth-gss-390005");
 static struct gss_api_mech gss_kerberos_mech = {
 	.gm_name	= "krb5",
 	.gm_owner	= THIS_MODULE,
-	.gm_oid		= {9, (void *)"\x2a\x86\x48\x86\xf7\x12\x01\x02\x02"},
+	.gm_oid		= { 9, "\x2a\x86\x48\x86\xf7\x12\x01\x02\x02" },
 	.gm_ops		= &gss_kerberos_ops,
 	.gm_pf_num	= ARRAY_SIZE(gss_kerberos_pfs),
 	.gm_pfs		= gss_kerberos_pfs,

[PATCH v1 04/15] SUNRPC: Introduce rpcauth_get_pseudoflavor()

[Chuck Lever]

A SECINFO reply may contain flavors whose kernel module is not
yet loaded by the client's kernel.  A new RPC client API, called
rpcauth_get_pseudoflavor(), is introduced to do proper checking
for support of a security flavor.

When this API is invoked, the RPC client now tries to load the
module for each flavor first before performing the "is this
supported?" check.  This means if a module is available on the
client, but has not been loaded yet, it will be loaded and
registered automatically when the SECINFO reply is processed.

The new API can take a full GSS tuple (OID, QoP, and service).
Previously only the OID and service were considered.

nfs_find_best_sec() is updated to verify all flavors requested in a
SECINFO reply, including AUTH_NULL and AUTH_UNIX.  Previously these
two flavors were simply assumed to be supported without consulting
the RPC client.

Note that the replaced version of nfs_find_best_sec() can return
RPC_AUTH_MAXFLAVOR if the server returns a recognized OID but an
unsupported "service" value.  nfs_find_best_sec() now returns
RPC_AUTH_UNIX in this case.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---

 fs/nfs/nfs4namespace.c                |   41 +++++++++++++++++++--------------
 include/linux/sunrpc/auth.h           |    5 ++++
 include/linux/sunrpc/gss_api.h        |    5 ++--
 net/sunrpc/auth.c                     |   35 ++++++++++++++++++++++++++++
 net/sunrpc/auth_gss/auth_gss.c        |    1 +
 net/sunrpc/auth_gss/gss_mech_switch.c |   28 +++++++++++++++++++----
 6 files changed, 89 insertions(+), 26 deletions(-)

diff --git a/fs/nfs/nfs4namespace.c b/fs/nfs/nfs4namespace.c
index 88231c9..cdb0b41 100644
--- a/fs/nfs/nfs4namespace.c
+++ b/fs/nfs/nfs4namespace.c
@@ -134,33 +134,38 @@ static size_t nfs_parse_server_name(char *string, size_t len,
 	return ret;
 }
 
+/**
+ * nfs_find_best_sec - Find a security mechanism supported locally
+ * @flavors: List of security tuples returned by SECINFO procedure
+ *
+ * Return the pseudoflavor of the first security mechanism in
+ * "flavors" that is locally supported.  Return RPC_AUTH_UNIX if
+ * no matching flavor is found in the array.  The "flavors" array
+ * is searched in the order returned from the server, per RFC 3530
+ * recommendation.
+ */
 rpc_authflavor_t nfs_find_best_sec(struct nfs4_secinfo_flavors *flavors)
 {
-	struct gss_api_mech *mech;
-	struct xdr_netobj oid;
+	rpc_authflavor_t pseudoflavor;
+	struct nfs4_secinfo4 *secinfo;
 	unsigned int i;
-	rpc_authflavor_t pseudoflavor = RPC_AUTH_UNIX;
 
 	for (i = 0; i < flavors->num_flavors; i++) {
-		struct nfs4_secinfo4 *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->flavor_info.oid.len;
-			oid.data = flavor->flavor_info.oid.data;
-			mech = gss_mech_get_by_OID(&oid);
-			if (!mech)
-				continue;
-			pseudoflavor = gss_svc_to_pseudoflavor(mech,
-						flavor->flavor_info.service);
-			gss_mech_put(mech);
+		secinfo = &flavors->flavors[i];
+
+		switch (secinfo->flavor) {
+		case RPC_AUTH_NULL:
+		case RPC_AUTH_UNIX:
+		case RPC_AUTH_GSS:
+			pseudoflavor = rpcauth_get_pseudoflavor(secinfo->flavor,
+							&secinfo->flavor_info);
+			if (pseudoflavor != RPC_AUTH_MAXFLAVOR)
+				return pseudoflavor;
 			break;
 		}
 	}
 
-	return pseudoflavor;
+	return RPC_AUTH_UNIX;
 }
 
 static rpc_authflavor_t nfs4_negotiate_security(struct inode *inode, struct qstr *name)
diff --git a/include/linux/sunrpc/auth.h b/include/linux/sunrpc/auth.h
index 58fda1c..6851da4 100644
--- a/include/linux/sunrpc/auth.h
+++ b/include/linux/sunrpc/auth.h
@@ -22,6 +22,8 @@
 /* size of the nodename buffer */
 #define UNX_MAXNODENAME	32
 
+struct rpcsec_gss_info;
+
 /* Work around the lack of a VFS credential */
 struct auth_cred {
 	kuid_t	uid;
@@ -103,6 +105,7 @@ struct rpc_authops {
 	int			(*pipes_create)(struct rpc_auth *);
 	void			(*pipes_destroy)(struct rpc_auth *);
 	int			(*list_pseudoflavors)(rpc_authflavor_t *, int);
+	rpc_authflavor_t	(*info2flavor)(struct rpcsec_gss_info *);
 };
 
 struct rpc_credops {
@@ -137,6 +140,8 @@ int			rpcauth_register(const struct rpc_authops *);
 int			rpcauth_unregister(const struct rpc_authops *);
 struct rpc_auth *	rpcauth_create(rpc_authflavor_t, struct rpc_clnt *);
 void			rpcauth_release(struct rpc_auth *);
+rpc_authflavor_t	rpcauth_get_pseudoflavor(rpc_authflavor_t,
+				struct rpcsec_gss_info *);
 int			rpcauth_list_flavors(rpc_authflavor_t *, int);
 struct rpc_cred *	rpcauth_lookup_credcache(struct rpc_auth *, struct auth_cred *, int);
 void			rpcauth_init_cred(struct rpc_cred *, const struct auth_cred *, struct rpc_auth *, const struct rpc_credops *);
diff --git a/include/linux/sunrpc/gss_api.h b/include/linux/sunrpc/gss_api.h
index 98950e5..aba7687 100644
--- a/include/linux/sunrpc/gss_api.h
+++ b/include/linux/sunrpc/gss_api.h
@@ -127,9 +127,8 @@ struct gss_api_ops {
 int gss_mech_register(struct gss_api_mech *);
 void gss_mech_unregister(struct gss_api_mech *);
 
-/* returns a mechanism descriptor given an OID, and increments the mechanism's
- * reference count. */
-struct gss_api_mech * gss_mech_get_by_OID(struct xdr_netobj *);
+/* Given a GSS security tuple, look up a pseudoflavor */
+rpc_authflavor_t gss_mech_info2flavor(struct rpcsec_gss_info *);
 
 /* Returns a reference to a mechanism, given a name like "krb5" etc. */
 struct gss_api_mech *gss_mech_get_by_name(const char *);
diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
index f529404..9b81be8 100644
--- a/net/sunrpc/auth.c
+++ b/net/sunrpc/auth.c
@@ -124,6 +124,41 @@ rpcauth_unregister(const struct rpc_authops *ops)
 EXPORT_SYMBOL_GPL(rpcauth_unregister);
 
 /**
+ * rpcauth_get_pseudoflavor - check if security flavor is supported
+ * @flavor: a security flavor
+ * @info: a GSS mech OID, quality of protection, and service value
+ *
+ * Verifies that an appropriate kernel module is available or already loaded.
+ * Returns an equivalent pseudoflavor, or RPC_AUTH_MAXFLAVOR if "flavor" is
+ * not supported locally.
+ */
+rpc_authflavor_t
+rpcauth_get_pseudoflavor(rpc_authflavor_t flavor, struct rpcsec_gss_info *info)
+{
+	const struct rpc_authops *ops;
+	rpc_authflavor_t pseudoflavor;
+
+	ops = auth_flavors[flavor];
+	if (ops == NULL)
+		request_module("rpc-auth-%u", flavor);
+	spin_lock(&rpc_authflavor_lock);
+	ops = auth_flavors[flavor];
+	if (ops == NULL || !try_module_get(ops->owner)) {
+		spin_unlock(&rpc_authflavor_lock);
+		return RPC_AUTH_MAXFLAVOR;
+	}
+	spin_unlock(&rpc_authflavor_lock);
+
+	pseudoflavor = flavor;
+	if (ops->info2flavor != NULL)
+		pseudoflavor = ops->info2flavor(info);
+
+	module_put(ops->owner);
+	return pseudoflavor;
+}
+EXPORT_SYMBOL_GPL(rpcauth_get_pseudoflavor);
+
+/**
  * rpcauth_list_flavors - discover registered flavors and pseudoflavors
  * @array: array to fill in
  * @size: size of "array"
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 282dfb1..a742007 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -1641,6 +1641,7 @@ static const struct rpc_authops authgss_ops = {
 	.pipes_create	= gss_pipes_dentries_create,
 	.pipes_destroy	= gss_pipes_dentries_destroy,
 	.list_pseudoflavors = gss_mech_list_pseudoflavors,
+	.info2flavor	= gss_mech_info2flavor,
 };
 
 static const struct rpc_credops gss_credops = {
diff --git a/net/sunrpc/auth_gss/gss_mech_switch.c b/net/sunrpc/auth_gss/gss_mech_switch.c
index f0f4eee..4db66f5 100644
--- a/net/sunrpc/auth_gss/gss_mech_switch.c
+++ b/net/sunrpc/auth_gss/gss_mech_switch.c
@@ -171,8 +171,7 @@ struct gss_api_mech * 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)
+static struct gss_api_mech *gss_mech_get_by_OID(struct rpcsec_gss_oid *obj)
 {
 	struct gss_api_mech	*pos, *gm = NULL;
 
@@ -188,11 +187,8 @@ gss_mech_get_by_OID(struct xdr_netobj *obj)
 	}
 	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)
 {
@@ -282,6 +278,28 @@ gss_svc_to_pseudoflavor(struct gss_api_mech *gm, u32 service)
 }
 EXPORT_SYMBOL_GPL(gss_svc_to_pseudoflavor);
 
+/**
+ * gss_mech_info2flavor - look up a pseudoflavor given a GSS tuple
+ * @info: a GSS mech OID, quality of protection, and service value
+ *
+ * Returns a matching pseudoflavor, or RPC_AUTH_MAXFLAVOR if the tuple is
+ * not supported.
+ */
+rpc_authflavor_t gss_mech_info2flavor(struct rpcsec_gss_info *info)
+{
+	rpc_authflavor_t pseudoflavor;
+	struct gss_api_mech *gm;
+
+	gm = gss_mech_get_by_OID(&info->oid);
+	if (gm == NULL)
+		return RPC_AUTH_MAXFLAVOR;
+
+	pseudoflavor = gss_svc_to_pseudoflavor(gm, info->service);
+
+	gss_mech_put(gm);
+	return pseudoflavor;
+}
+
 u32
 gss_pseudoflavor_to_service(struct gss_api_mech *gm, u32 pseudoflavor)
 {

[PATCH v1 05/15] SUNRPC: Load GSS kernel module by OID

[Chuck Lever]

The current GSS mech switch can find and load GSS pseudoflavor
modules by name ("krb5") or pseudoflavor number ("390003"), but
cannot find GSS modules by GSS tuple:

  [ "1.2.840.113554.1.2.2", GSS_C_QOP_DEFAULT, RPC_GSS_SVC_NONE ]

This is important when dealing with a SECINFO request.  A SECINFO
reply contains a list of flavors the server supports for the
requested export, but GSS flavors also have a GSS tuple that maps
to a pseudoflavor (like 390003 for krb5).

If the GSS module that supports the OID in the tuple is not loaded,
our client is not able to load that module dynamically to support
that pseudoflavor.

Add a way for the GSS mech switch to load GSS pseudoflavor support
by OID before searching for the pseudoflavor that matches the OID
and service.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: David Howells <dhowells@redhat.com>
---

 net/sunrpc/Kconfig                    |    1 +
 net/sunrpc/auth_gss/gss_krb5_mech.c   |    1 +
 net/sunrpc/auth_gss/gss_mech_switch.c |    7 +++++++
 3 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/net/sunrpc/Kconfig b/net/sunrpc/Kconfig
index 516fe2c..804f4f6 100644
--- a/net/sunrpc/Kconfig
+++ b/net/sunrpc/Kconfig
@@ -3,6 +3,7 @@ config SUNRPC
 
 config SUNRPC_GSS
 	tristate
+	select OID_REGISTRY
 
 config SUNRPC_BACKCHANNEL
 	bool
diff --git a/net/sunrpc/auth_gss/gss_krb5_mech.c b/net/sunrpc/auth_gss/gss_krb5_mech.c
index 61d36ce..b822ec5 100644
--- a/net/sunrpc/auth_gss/gss_krb5_mech.c
+++ b/net/sunrpc/auth_gss/gss_krb5_mech.c
@@ -750,6 +750,7 @@ MODULE_ALIAS("rpc-auth-gss-krb5p");
 MODULE_ALIAS("rpc-auth-gss-390003");
 MODULE_ALIAS("rpc-auth-gss-390004");
 MODULE_ALIAS("rpc-auth-gss-390005");
+MODULE_ALIAS("rpc-auth-gss-1.2.840.113554.1.2.2");
 
 static struct gss_api_mech gss_kerberos_mech = {
 	.gm_name	= "krb5",
diff --git a/net/sunrpc/auth_gss/gss_mech_switch.c b/net/sunrpc/auth_gss/gss_mech_switch.c
index 4db66f5..92a7240 100644
--- a/net/sunrpc/auth_gss/gss_mech_switch.c
+++ b/net/sunrpc/auth_gss/gss_mech_switch.c
@@ -36,6 +36,7 @@
 #include <linux/types.h>
 #include <linux/slab.h>
 #include <linux/module.h>
+#include <linux/oid_registry.h>
 #include <linux/sunrpc/msg_prot.h>
 #include <linux/sunrpc/gss_asn1.h>
 #include <linux/sunrpc/auth_gss.h>
@@ -174,6 +175,12 @@ EXPORT_SYMBOL_GPL(gss_mech_get_by_name);
 static struct gss_api_mech *gss_mech_get_by_OID(struct rpcsec_gss_oid *obj)
 {
 	struct gss_api_mech	*pos, *gm = NULL;
+	char buf[32];
+
+	if (sprint_oid(obj->data, obj->len, buf, sizeof(buf)) < 0)
+		return NULL;
+	dprintk("RPC:       %s(%s)\n", __func__, buf);
+	request_module("rpc-auth-gss-%s", buf);
 
 	spin_lock(&registered_mechs_lock);
 	list_for_each_entry(pos, &registered_mechs, gm_list) {

[PATCH v1 06/15] SUNRPC: Consider qop when looking up pseudoflavors

[Chuck Lever]

The NFSv4 SECINFO operation returns a list of security flavors that
the server supports for a particular share.  An NFSv4 client is
supposed to pick a pseudoflavor it supports that corresponds to one
of the flavors returned by the server.

GSS flavors in this list have a GSS tuple that identify a specific
GSS pseudoflavor.

Currently our client ignores the GSS tuple's "qop" value.  A
matching pseudoflavor is chosen based only on the OID and service
value.

So far this omission has not had much effect on Linux.  The NFSv4
protocol currently supports only one qop value: GSS_C_QOP_DEFAULT,
also known as zero.

However, if an NFSv4 server happens to return something other than
zero in the qop field, our client won't notice.  This could cause
the client to behave in incorrect ways that could have security
implications.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---

 include/linux/sunrpc/gss_api.h        |    5 ++++-
 net/sunrpc/auth_gss/gss_krb5_mech.c   |    3 +++
 net/sunrpc/auth_gss/gss_mech_switch.c |   20 ++++++++++++++------
 net/sunrpc/auth_gss/svcauth_gss.c     |    4 +++-
 4 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/include/linux/sunrpc/gss_api.h b/include/linux/sunrpc/gss_api.h
index aba7687..96e5a81 100644
--- a/include/linux/sunrpc/gss_api.h
+++ b/include/linux/sunrpc/gss_api.h
@@ -25,6 +25,7 @@ struct gss_ctx {
 
 #define GSS_C_NO_BUFFER		((struct xdr_netobj) 0)
 #define GSS_C_NO_CONTEXT	((struct gss_ctx *) 0)
+#define GSS_C_QOP_DEFAULT	(0)
 
 /*XXX  arbitrary length - is this set somewhere? */
 #define GSS_OID_MAX_LEN 32
@@ -68,12 +69,14 @@ u32 gss_unwrap(
 u32 gss_delete_sec_context(
 		struct gss_ctx		**ctx_id);
 
-u32 gss_svc_to_pseudoflavor(struct gss_api_mech *, u32 service);
+rpc_authflavor_t gss_svc_to_pseudoflavor(struct gss_api_mech *, u32 qop,
+					u32 service);
 u32 gss_pseudoflavor_to_service(struct gss_api_mech *, u32 pseudoflavor);
 char *gss_service_to_auth_domain_name(struct gss_api_mech *, u32 service);
 
 struct pf_desc {
 	u32	pseudoflavor;
+	u32	qop;
 	u32	service;
 	char	*name;
 	char	*auth_domain_name;
diff --git a/net/sunrpc/auth_gss/gss_krb5_mech.c b/net/sunrpc/auth_gss/gss_krb5_mech.c
index b822ec5..33255ff 100644
--- a/net/sunrpc/auth_gss/gss_krb5_mech.c
+++ b/net/sunrpc/auth_gss/gss_krb5_mech.c
@@ -729,16 +729,19 @@ static const struct gss_api_ops gss_kerberos_ops = {
 static struct pf_desc gss_kerberos_pfs[] = {
 	[0] = {
 		.pseudoflavor = RPC_AUTH_GSS_KRB5,
+		.qop = GSS_C_QOP_DEFAULT,
 		.service = RPC_GSS_SVC_NONE,
 		.name = "krb5",
 	},
 	[1] = {
 		.pseudoflavor = RPC_AUTH_GSS_KRB5I,
+		.qop = GSS_C_QOP_DEFAULT,
 		.service = RPC_GSS_SVC_INTEGRITY,
 		.name = "krb5i",
 	},
 	[2] = {
 		.pseudoflavor = RPC_AUTH_GSS_KRB5P,
+		.qop = GSS_C_QOP_DEFAULT,
 		.service = RPC_GSS_SVC_PRIVACY,
 		.name = "krb5p",
 	},
diff --git a/net/sunrpc/auth_gss/gss_mech_switch.c b/net/sunrpc/auth_gss/gss_mech_switch.c
index 92a7240..81fb6f3 100644
--- a/net/sunrpc/auth_gss/gss_mech_switch.c
+++ b/net/sunrpc/auth_gss/gss_mech_switch.c
@@ -271,19 +271,27 @@ int gss_mech_list_pseudoflavors(rpc_authflavor_t *array_ptr, int size)
 	return i;
 }
 
-u32
-gss_svc_to_pseudoflavor(struct gss_api_mech *gm, u32 service)
+/**
+ * gss_svc_to_pseudoflavor - map a GSS service number to a pseudoflavor
+ * @gm: GSS mechanism handle
+ * @qop: GSS quality-of-protection value
+ * @service: GSS service value
+ *
+ * Returns a matching security flavor, or RPC_AUTH_MAXFLAVOR if none is found.
+ */
+rpc_authflavor_t gss_svc_to_pseudoflavor(struct gss_api_mech *gm, u32 qop,
+					 u32 service)
 {
 	int i;
 
 	for (i = 0; i < gm->gm_pf_num; i++) {
-		if (gm->gm_pfs[i].service == service) {
+		if (gm->gm_pfs[i].qop == qop &&
+		    gm->gm_pfs[i].service == service) {
 			return gm->gm_pfs[i].pseudoflavor;
 		}
 	}
-	return RPC_AUTH_MAXFLAVOR; /* illegal value */
+	return RPC_AUTH_MAXFLAVOR;
 }
-EXPORT_SYMBOL_GPL(gss_svc_to_pseudoflavor);
 
 /**
  * gss_mech_info2flavor - look up a pseudoflavor given a GSS tuple
@@ -301,7 +309,7 @@ rpc_authflavor_t gss_mech_info2flavor(struct rpcsec_gss_info *info)
 	if (gm == NULL)
 		return RPC_AUTH_MAXFLAVOR;
 
-	pseudoflavor = gss_svc_to_pseudoflavor(gm, info->service);
+	pseudoflavor = gss_svc_to_pseudoflavor(gm, info->qop, info->service);
 
 	gss_mech_put(gm);
 	return pseudoflavor;
diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
index f7d34e7..74f6d30 100644
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -1216,7 +1216,9 @@ svcauth_gss_accept(struct svc_rqst *rqstp, __be32 *authp)
 		svcdata->rsci = rsci;
 		cache_get(&rsci->h);
 		rqstp->rq_cred.cr_flavor = gss_svc_to_pseudoflavor(
-					rsci->mechctx->mech_type, gc->gc_svc);
+					rsci->mechctx->mech_type,
+					GSS_C_QOP_DEFAULT,
+					gc->gc_svc);
 		ret = SVC_OK;
 		goto out;
 	}

[PATCH v1 08/15] SUNRPC: Make gss_mech_get() static

[Chuck Lever]

gss_mech_get() is no longer used outside of gss_mech_switch.c.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---

 include/linux/sunrpc/gss_api.h        |    3 ---
 net/sunrpc/auth_gss/gss_mech_switch.c |    5 +----
 2 files changed, 1 insertions(+), 7 deletions(-)

diff --git a/include/linux/sunrpc/gss_api.h b/include/linux/sunrpc/gss_api.h
index fca2338..f32b7a4 100644
--- a/include/linux/sunrpc/gss_api.h
+++ b/include/linux/sunrpc/gss_api.h
@@ -145,9 +145,6 @@ struct gss_api_mech *gss_mech_get_by_pseudoflavor(u32);
 /* Fill in an array with a list of supported pseudoflavors */
 int gss_mech_list_pseudoflavors(rpc_authflavor_t *, int);
 
-/* Just increments the mechanism's reference count and returns its input: */
-struct gss_api_mech * gss_mech_get(struct gss_api_mech *);
-
 /* For every successful gss_mech_get or gss_mech_get_by_* call there must be a
  * corresponding call to gss_mech_put. */
 void gss_mech_put(struct gss_api_mech *);
diff --git a/net/sunrpc/auth_gss/gss_mech_switch.c b/net/sunrpc/auth_gss/gss_mech_switch.c
index deaa7ae..8941652 100644
--- a/net/sunrpc/auth_gss/gss_mech_switch.c
+++ b/net/sunrpc/auth_gss/gss_mech_switch.c
@@ -132,15 +132,12 @@ gss_mech_unregister(struct gss_api_mech *gm)
 
 EXPORT_SYMBOL_GPL(gss_mech_unregister);
 
-struct gss_api_mech *
-gss_mech_get(struct gss_api_mech *gm)
+static struct gss_api_mech *gss_mech_get(struct gss_api_mech *gm)
 {
 	__module_get(gm->gm_owner);
 	return gm;
 }
 
-EXPORT_SYMBOL_GPL(gss_mech_get);
-
 static struct gss_api_mech *
 _gss_mech_get_by_name(const char *name)
 {

[PATCH v1 09/15] SUNRPC: Remove EXPORT_SYMBOL_GPL() from GSS mech switch

[Chuck Lever]

Clean up: Reduce the symbol table footprint for auth_rpcgss.ko by
removing exported symbols for functions that are no longer used
outside of auth_rpcgss.ko.

The remaining two EXPORTs in gss_mech_switch.c get documenting
comments.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---

 net/sunrpc/auth_gss/gss_mech_switch.c |   26 +++++++++++++-------------
 1 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/net/sunrpc/auth_gss/gss_mech_switch.c b/net/sunrpc/auth_gss/gss_mech_switch.c
index 8941652..79881d6 100644
--- a/net/sunrpc/auth_gss/gss_mech_switch.c
+++ b/net/sunrpc/auth_gss/gss_mech_switch.c
@@ -103,8 +103,13 @@ out:
 	return status;
 }
 
-int
-gss_mech_register(struct gss_api_mech *gm)
+/**
+ * gss_mech_register - register a GSS mechanism
+ * @gm: GSS mechanism handle
+ *
+ * Returns zero if successful, or a negative errno.
+ */
+int gss_mech_register(struct gss_api_mech *gm)
 {
 	int status;
 
@@ -117,11 +122,14 @@ gss_mech_register(struct gss_api_mech *gm)
 	dprintk("RPC:       registered gss mechanism %s\n", gm->gm_name);
 	return 0;
 }
-
 EXPORT_SYMBOL_GPL(gss_mech_register);
 
-void
-gss_mech_unregister(struct gss_api_mech *gm)
+/**
+ * gss_mech_unregister - release a GSS mechanism
+ * @gm: GSS mechanism handle
+ *
+ */
+void gss_mech_unregister(struct gss_api_mech *gm)
 {
 	spin_lock(&registered_mechs_lock);
 	list_del(&gm->gm_list);
@@ -129,7 +137,6 @@ gss_mech_unregister(struct gss_api_mech *gm)
 	dprintk("RPC:       unregistered gss mechanism %s\n", gm->gm_name);
 	gss_mech_free(gm);
 }
-
 EXPORT_SYMBOL_GPL(gss_mech_unregister);
 
 static struct gss_api_mech *gss_mech_get(struct gss_api_mech *gm)
@@ -167,7 +174,6 @@ struct gss_api_mech * gss_mech_get_by_name(const char *name)
 	}
 	return gm;
 }
-EXPORT_SYMBOL_GPL(gss_mech_get_by_name);
 
 static struct gss_api_mech *gss_mech_get_by_OID(struct rpcsec_gss_oid *obj)
 {
@@ -355,8 +361,6 @@ gss_pseudoflavor_to_service(struct gss_api_mech *gm, u32 pseudoflavor)
 	return 0;
 }
 
-EXPORT_SYMBOL_GPL(gss_pseudoflavor_to_service);
-
 char *
 gss_service_to_auth_domain_name(struct gss_api_mech *gm, u32 service)
 {
@@ -369,8 +373,6 @@ gss_service_to_auth_domain_name(struct gss_api_mech *gm, u32 service)
 	return NULL;
 }
 
-EXPORT_SYMBOL_GPL(gss_service_to_auth_domain_name);
-
 void
 gss_mech_put(struct gss_api_mech * gm)
 {
@@ -378,8 +380,6 @@ gss_mech_put(struct gss_api_mech * gm)
 		module_put(gm->gm_owner);
 }
 
-EXPORT_SYMBOL_GPL(gss_mech_put);
-
 /* The mech could probably be determined from the token instead, but it's just
  * as easy for now to pass it in. */
 int

[PATCH v1 10/15] NFS: Handle missing rpc.gssd when looking up root FH

[Chuck Lever]

When rpc.gssd is not running, any NFS operation that needs to use a
GSS security flavor of course does not work.

If looking up a server's root file handle results in an
NFS4ERR_WRONGSEC, nfs4_find_root_sec() is called to try a bunch of
security flavors until one works or all reasonable flavors have
been tried.  When rpc.gssd isn't running, this loop seems to fail
immediately after rpcauth_create() craps out on the first GSS
flavor.

When the rpcauth_create() call in nfs4_lookup_root_sec() fails
because rpc.gssd is not available, nfs4_lookup_root_sec()
unconditionally returns -EIO.  This prevents nfs4_find_root_sec()
from retrying any other flavors; it drops out of its loop and fails
immediately.

Having nfs4_lookup_root_sec() return -EACCES instead allows
nfs4_find_root_sec() to try all flavors in its list.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Bryan Schumaker <bjschuma@netapp.com>
---

 fs/nfs/nfs4proc.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index b2671cb..c05e78b 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2443,7 +2443,7 @@ static int nfs4_lookup_root_sec(struct nfs_server *server, struct nfs_fh *fhandl
 
 	auth = rpcauth_create(flavor, server->client);
 	if (IS_ERR(auth)) {
-		ret = -EIO;
+		ret = -EACCES;
 		goto out;
 	}
 	ret = nfs4_lookup_root(server, fhandle, info);

[PATCH v1 11/15] NFS: Clean up nfs4_proc_get_rootfh

[Chuck Lever]

The long lines with no vertical white space make this function
difficult for humans to read.  Add a proper documenting comment
while we're here.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Bryan Schumaker <bjschuma@netapp.com>
---

 fs/nfs/nfs4proc.c |   32 ++++++++++++++++++++++----------
 1 files changed, 22 insertions(+), 10 deletions(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index c05e78b..addcdaf 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2484,24 +2484,36 @@ static int nfs4_find_root_sec(struct nfs_server *server, struct nfs_fh *fhandle,
 	return status;
 }
 
-/*
- * get the file handle for the "/" directory on the server
+static int nfs4_do_find_root_sec(struct nfs_server *server,
+		struct nfs_fh *fhandle, struct nfs_fsinfo *info)
+{
+	int mv = server->nfs_client->cl_minorversion;
+	return nfs_v4_minor_ops[mv]->find_root_sec(server, fhandle, info);
+}
+
+/**
+ * nfs4_proc_get_rootfh - get file handle for server's pseudoroot
+ * @server: initialized nfs_server handle
+ * @fhandle: we fill in the pseudo-fs root file handle
+ * @info: we fill in an FSINFO struct
+ *
+ * Returns zero on success, or a negative errno.
  */
 int nfs4_proc_get_rootfh(struct nfs_server *server, struct nfs_fh *fhandle,
 			 struct nfs_fsinfo *info)
 {
-	int minor_version = server->nfs_client->cl_minorversion;
-	int status = nfs4_lookup_root(server, fhandle, info);
-	if ((status == -NFS4ERR_WRONGSEC) && !(server->flags & NFS_MOUNT_SECFLAVOUR))
-		/*
-		 * A status of -NFS4ERR_WRONGSEC will be mapped to -EPERM
-		 * by nfs4_map_errors() as this function exits.
-		 */
-		status = nfs_v4_minor_ops[minor_version]->find_root_sec(server, fhandle, info);
+	int status;
+
+	status = nfs4_lookup_root(server, fhandle, info);
+	if ((status == -NFS4ERR_WRONGSEC) &&
+	    !(server->flags & NFS_MOUNT_SECFLAVOUR))
+		status = nfs4_do_find_root_sec(server, fhandle, info);
+
 	if (status == 0)
 		status = nfs4_server_capabilities(server, fhandle);
 	if (status == 0)
 		status = nfs4_do_fsinfo(server, fhandle, info);
+
 	return nfs4_map_errors(status);
 }
 

[PATCH v1 12/15] NFS: Avoid PUTROOTFH when managing leases

[Chuck Lever]

Currently, the compound operation the Linux NFS client sends to the
server to confirm a client ID looks like this:

	{ SETCLIENTID_CONFIRM; PUTROOTFH; GETATTR(lease_time) }

Once the lease is confirmed, it makes sense to know how long before
the client will have to renew it.  And, performing these operations
in the same compound saves a round trip.

Unfortunately, this arrangement assumes that the security flavor
used for establishing a client ID can also be used to access the
server's pseudo-fs.

If the server requires a different security flavor to access its
pseudo-fs than it allowed for the client's SETCLIENTID operation,
the PUTROOTFH in this compound fails with NFS4ERR_WRONGSEC.  Even
though the SETCLIENTID_CONFIRM succeeded, our client's trunking
detection logic interprets the failure of the compound as a failure
by the server to confirm the client ID.

As part of server trunking detection, the client then begins another
SETCLIENTID pass with the same nfs4_client_id.  This fails with
NFS4ERR_CLID_INUSE because the first SETCLIENTID/SETCLIENTID_CONFIRM
already succeeded in confirming that client ID -- it was the
PUTROOTFH operation that caused the SETCLIENTID_CONFIRM compound to
fail.

To address this issue, separate the "establish client ID" step from
the "accessing the server's pseudo-fs root" step.  The first access
of the server's pseudo-fs may require retrying the PUTROOTFH
operation with different security flavors.  This access is done in
nfs4_proc_get_rootfh().

That leaves the matter of how to retrieve the server's lease time.
nfs4_proc_fsinfo() already retrieves the lease time value, though
none of its callers do anything with the retrieved value (nor do
they mark the lease as "renewed").

Note that NFSv4.1 state recovery invokes nfs4_proc_get_lease_time()
using the lease management security flavor.  This may cause some
heartburn if that security flavor isn't the same as the security
flavor the server requires for accessing the pseudo-fs.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Bryan Schumaker <bjschuma@netapp.com>
---

 fs/nfs/nfs4proc.c |   25 ++++++++++++-------------
 fs/nfs/nfs4xdr.c  |   18 +++---------------
 2 files changed, 15 insertions(+), 28 deletions(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index addcdaf..b83fddf 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -3392,12 +3392,21 @@ static int _nfs4_do_fsinfo(struct nfs_server *server, struct nfs_fh *fhandle,
 static int nfs4_do_fsinfo(struct nfs_server *server, struct nfs_fh *fhandle, struct nfs_fsinfo *fsinfo)
 {
 	struct nfs4_exception exception = { };
+	unsigned long now = jiffies;
 	int err;
 
 	do {
-		err = nfs4_handle_exception(server,
-				_nfs4_do_fsinfo(server, fhandle, fsinfo),
-				&exception);
+		err = _nfs4_do_fsinfo(server, fhandle, fsinfo);
+		if (err == 0) {
+			struct nfs_client *clp = server->nfs_client;
+
+			spin_lock(&clp->cl_lock);
+			clp->cl_lease_time = fsinfo->lease_time * HZ;
+			clp->cl_last_renewal = now;
+			spin_unlock(&clp->cl_lock);
+			break;
+		}
+		err = nfs4_handle_exception(server, err, &exception);
 	} while (exception.retry);
 	return err;
 }
@@ -4155,27 +4164,17 @@ int nfs4_proc_setclientid_confirm(struct nfs_client *clp,
 		struct nfs4_setclientid_res *arg,
 		struct rpc_cred *cred)
 {
-	struct nfs_fsinfo fsinfo;
 	struct rpc_message msg = {
 		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_SETCLIENTID_CONFIRM],
 		.rpc_argp = arg,
-		.rpc_resp = &fsinfo,
 		.rpc_cred = cred,
 	};
-	unsigned long now;
 	int status;
 
 	dprintk("NFS call  setclientid_confirm auth=%s, (client ID %llx)\n",
 		clp->cl_rpcclient->cl_auth->au_ops->au_name,
 		clp->cl_clientid);
-	now = jiffies;
 	status = rpc_call_sync(clp->cl_rpcclient, &msg, RPC_TASK_TIMEOUT);
-	if (status == 0) {
-		spin_lock(&clp->cl_lock);
-		clp->cl_lease_time = fsinfo.lease_time * HZ;
-		clp->cl_last_renewal = now;
-		spin_unlock(&clp->cl_lock);
-	}
 	dprintk("NFS reply setclientid_confirm: %d\n", status);
 	return status;
 }
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 95b396f..d632dc7 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -530,14 +530,10 @@ static int nfs4_stat_to_errno(int);
 				decode_setclientid_maxsz)
 #define NFS4_enc_setclientid_confirm_sz \
 				(compound_encode_hdr_maxsz + \
-				encode_setclientid_confirm_maxsz + \
-				encode_putrootfh_maxsz + \
-				encode_fsinfo_maxsz)
+				encode_setclientid_confirm_maxsz)
 #define NFS4_dec_setclientid_confirm_sz \
 				(compound_decode_hdr_maxsz + \
-				decode_setclientid_confirm_maxsz + \
-				decode_putrootfh_maxsz + \
-				decode_fsinfo_maxsz)
+				decode_setclientid_confirm_maxsz)
 #define NFS4_enc_lock_sz        (compound_encode_hdr_maxsz + \
 				encode_sequence_maxsz + \
 				encode_putfh_maxsz + \
@@ -2609,12 +2605,9 @@ static void nfs4_xdr_enc_setclientid_confirm(struct rpc_rqst *req,
 	struct compound_hdr hdr = {
 		.nops	= 0,
 	};
-	const u32 lease_bitmap[3] = { FATTR4_WORD0_LEASE_TIME };
 
 	encode_compound_hdr(xdr, req, &hdr);
 	encode_setclientid_confirm(xdr, arg, &hdr);
-	encode_putrootfh(xdr, &hdr);
-	encode_fsinfo(xdr, lease_bitmap, &hdr);
 	encode_nops(&hdr);
 }
 
@@ -6651,8 +6644,7 @@ static int nfs4_xdr_dec_setclientid(struct rpc_rqst *req,
  * Decode SETCLIENTID_CONFIRM response
  */
 static int nfs4_xdr_dec_setclientid_confirm(struct rpc_rqst *req,
-					    struct xdr_stream *xdr,
-					    struct nfs_fsinfo *fsinfo)
+					    struct xdr_stream *xdr)
 {
 	struct compound_hdr hdr;
 	int status;
@@ -6660,10 +6652,6 @@ static int nfs4_xdr_dec_setclientid_confirm(struct rpc_rqst *req,
 	status = decode_compound_hdr(xdr, &hdr);
 	if (!status)
 		status = decode_setclientid_confirm(xdr);
-	if (!status)
-		status = decode_putrootfh(xdr);
-	if (!status)
-		status = decode_fsinfo(xdr, fsinfo);
 	return status;
 }
 

[PATCH v1 13/15] NFS: Use static list of security flavors during root FH lookup recovery

[Chuck Lever]

If the Linux NFS client receives an NFS4ERR_WRONGSEC error while
trying to look up an NFS server's root file handle, it retries the
lookup operation with various security flavors to see what flavor
the NFS server will accept for pseudo-fs access.

The list of flavors the client uses during retry consists only of
flavors that are currently registered in the kernel RPC client.
This list may not include any GSS pseudoflavors if auth_rpcgss.ko
has not yet been loaded.

Let's instead use a static list of security flavors that the NFS
standard requires the server to implement (RFC 3530bis, section
3.2.1).  The RPC client should now be able to load support for
these dynamically; if not, they are skipped.

Recovery behavior here is prescribed by RFC 3530bis, section
15.33.5:

> For LOOKUPP, PUTROOTFH and PUTPUBFH, the client will be unable to
> use the SECINFO operation since SECINFO requires a current
> filehandle and none exist for these two [sic] operations.  Therefore,
> the client must iterate through the security triples available at
> the client and reattempt the PUTROOTFH or PUTPUBFH operation.  In
> the unfortunate event none of the MANDATORY security triples are
> supported by the client and server, the client SHOULD try using
> others that support integrity.  Failing that, the client can try
> using AUTH_NONE, but because such forms lack integrity checks,
> this puts the client at risk.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Bryan Schumaker <bjschuma@netapp.com>
---

 fs/nfs/nfs4proc.c |   32 ++++++++++++++++++++------------
 1 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index b83fddf..ddbebfe 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2451,27 +2451,35 @@ out:
 	return ret;
 }
 
+/*
+ * Retry pseudoroot lookup with various security flavors.  We do this when:
+ *
+ *   NFSv4.0: the PUTROOTFH operation returns NFS4ERR_WRONGSEC
+ *   NFSv4.1: the server does not support the SECINFO_NO_NAME operation
+ *
+ * Returns zero on success, or a negative NFS4ERR value, or a
+ * negative errno value.
+ */
 static int nfs4_find_root_sec(struct nfs_server *server, struct nfs_fh *fhandle,
 			      struct nfs_fsinfo *info)
 {
-	int i, len, status = 0;
-	rpc_authflavor_t flav_array[NFS_MAX_SECFLAVORS];
-
-	len = rpcauth_list_flavors(flav_array, ARRAY_SIZE(flav_array));
-	if (len < 0)
-		return len;
-
-	for (i = 0; i < len; i++) {
-		/* AUTH_UNIX is the default flavor if none was specified,
-		 * thus has already been tried. */
-		if (flav_array[i] == RPC_AUTH_UNIX)
-			continue;
+	/* Per 3530bis 15.33.5 */
+	static const rpc_authflavor_t flav_array[] = {
+		RPC_AUTH_GSS_KRB5P,
+		RPC_AUTH_GSS_KRB5I,
+		RPC_AUTH_GSS_KRB5,
+		RPC_AUTH_NULL,
+	};
+	int status = -EPERM;
+	size_t i;
 
+	for (i = 0; i < ARRAY_SIZE(flav_array); i++) {
 		status = nfs4_lookup_root_sec(server, fhandle, info, flav_array[i]);
 		if (status == -NFS4ERR_WRONGSEC || status == -EACCES)
 			continue;
 		break;
 	}
+
 	/*
 	 * -EACCESS could mean that the user doesn't have correct permissions
 	 * to access the mount.  It could also mean that we tried to mount

[PATCH v1 14/15] NFS: Try AUTH_UNIX when PUTROOTFH gets NFS4ERR_WRONGSEC

[Chuck Lever]

Most NFSv4 servers implement AUTH_UNIX, and administrators will
prefer this over AUTH_NULL.  It is harmless for our client to try
this flavor in addition to the flavors mandated by RFC 3530/5661.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---

 fs/nfs/nfs4proc.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index ddbebfe..12f7318 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2468,6 +2468,7 @@ static int nfs4_find_root_sec(struct nfs_server *server, struct nfs_fh *fhandle,
 		RPC_AUTH_GSS_KRB5P,
 		RPC_AUTH_GSS_KRB5I,
 		RPC_AUTH_GSS_KRB5,
+		RPC_AUTH_UNIX,			/* courtesy */
 		RPC_AUTH_NULL,
 	};
 	int status = -EPERM;

[PATCH v1 15/15] NFS: Use "krb5i" to establish NFSv4 state whenever possible

[Chuck Lever]

Currently our client uses AUTH_UNIX for state management on Kerberos
NFS mounts in some cases.  For example, if the first mount of a
server specifies "sec=sys," the SETCLIENTID operation is performed
with AUTH_UNIX.  Subsequent mounts using stronger security flavors
can not change the flavor used for lease establishment.  This might
be less security than an administrator was expecting.

Dave Noveck's migration issues draft recommends the use of an
integrity-protecting security flavor for the SETCLIENTID operation.
Let's ignore the mount's sec= setting and use krb5i as the default
security flavor for SETCLIENTID.

If our client can't establish a GSS context (eg. because it doesn't
have a keytab or the server doesn't support Kerberos) we fall back
to using AUTH_NULL.  For an operation that requires a
machine credential (which never represents a particular user)
AUTH_NULL is as secure as AUTH_UNIX.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---

 fs/nfs/nfs4client.c |    2 +-
 fs/nfs/nfs4state.c  |   37 +++++--------------------------------
 2 files changed, 6 insertions(+), 33 deletions(-)

diff --git a/fs/nfs/nfs4client.c b/fs/nfs/nfs4client.c
index ac4fc9a..0194cab 100644
--- a/fs/nfs/nfs4client.c
+++ b/fs/nfs/nfs4client.c
@@ -199,7 +199,7 @@ struct nfs_client *nfs4_init_client(struct nfs_client *clp,
 	clp->rpc_ops = &nfs_v4_clientops;
 
 	__set_bit(NFS_CS_DISCRTRY, &clp->cl_flags);
-	error = nfs_create_rpc_client(clp, timeparms, authflavour);
+	error = nfs_create_rpc_client(clp, timeparms, RPC_AUTH_GSS_KRB5I);
 	if (error < 0)
 		goto error;
 
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 6ace365..3e30e85 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -1823,26 +1823,13 @@ int nfs4_discover_server_trunking(struct nfs_client *clp,
 {
 	const struct nfs4_state_recovery_ops *ops =
 				clp->cl_mvops->reboot_recovery_ops;
-	rpc_authflavor_t *flavors, flav, save;
 	struct rpc_clnt *clnt;
 	struct rpc_cred *cred;
-	int i, len, status;
+	int i, status;
 
 	dprintk("NFS: %s: testing '%s'\n", __func__, clp->cl_hostname);
 
-	len = NFS_MAX_SECFLAVORS;
-	flavors = kcalloc(len, sizeof(*flavors), GFP_KERNEL);
-	if (flavors == NULL) {
-		status = -ENOMEM;
-		goto out;
-	}
-	len = rpcauth_list_flavors(flavors, len);
-	if (len < 0) {
-		status = len;
-		goto out_free;
-	}
 	clnt = clp->cl_rpcclient;
-	save = clnt->cl_auth->au_flavor;
 	i = 0;
 
 	mutex_lock(&nfs_clid_init_mutex);
@@ -1857,12 +1844,6 @@ again:
 	switch (status) {
 	case 0:
 		break;
-
-	case -EACCES:
-		if (clp->cl_machine_cred == NULL)
-			break;
-		/* Handle case where the user hasn't set up machine creds */
-		nfs4_clear_machine_cred(clp);
 	case -NFS4ERR_DELAY:
 	case -ETIMEDOUT:
 	case -EAGAIN:
@@ -1871,17 +1852,12 @@ again:
 		dprintk("NFS: %s after status %d, retrying\n",
 			__func__, status);
 		goto again;
-
+	case -EACCES:
+		if (i++)
+			break;
 	case -NFS4ERR_CLID_INUSE:
 	case -NFS4ERR_WRONGSEC:
-		status = -EPERM;
-		if (i >= len)
-			break;
-
-		flav = flavors[i++];
-		if (flav == save)
-			flav = flavors[i++];
-		clnt = rpc_clone_client_set_auth(clnt, flav);
+		clnt = rpc_clone_client_set_auth(clnt, RPC_AUTH_NULL);
 		if (IS_ERR(clnt)) {
 			status = PTR_ERR(clnt);
 			break;
@@ -1901,9 +1877,6 @@ again:
 
 out_unlock:
 	mutex_unlock(&nfs_clid_init_mutex);
-out_free:
-	kfree(flavors);
-out:
 	dprintk("NFS: %s: status = %d\n", __func__, status);
 	return status;
 }