kernel/gssproxy-backport.patch

From 7e5eee0a24ea886a0b68a8521117c5ef97668443 Mon Sep 17 00:00:00 2001
From: Trond Myklebust <Trond.Myklebust@netapp.com>
Date: Sun, 14 Apr 2013 11:42:00 -0400
Subject: [PATCH 01/16] SUNRPC: Allow rpc_create() to request that TCP slots be
 unlimited

This is mainly for use by NFSv4.1, where the session negotiation
ultimately wants to decide how many RPC slots we can fill.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
---
 include/linux/sunrpc/clnt.h | 1 +
 include/linux/sunrpc/xprt.h | 3 +++
 net/sunrpc/clnt.c           | 2 ++
 net/sunrpc/xprtsock.c       | 6 +++++-
 4 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/include/linux/sunrpc/clnt.h b/include/linux/sunrpc/clnt.h
index 2cf4ffa..e7d492c 100644
--- a/include/linux/sunrpc/clnt.h
+++ b/include/linux/sunrpc/clnt.h
@@ -124,6 +124,7 @@ struct rpc_create_args {
 #define RPC_CLNT_CREATE_NOPING		(1UL << 4)
 #define RPC_CLNT_CREATE_DISCRTRY	(1UL << 5)
 #define RPC_CLNT_CREATE_QUIET		(1UL << 6)
+#define RPC_CLNT_CREATE_INFINITE_SLOTS	(1UL << 7)
 
 struct rpc_clnt *rpc_create(struct rpc_create_args *args);
 struct rpc_clnt	*rpc_bind_new_program(struct rpc_clnt *,
diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index 30834be..12afb29 100644
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -255,6 +255,8 @@ static inline int bc_prealloc(struct rpc_rqst *req)
 }
 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 
+#define XPRT_CREATE_INFINITE_SLOTS	(1U)
+
 struct xprt_create {
 	int			ident;		/* XPRT_TRANSPORT identifier */
 	struct net *		net;
@@ -263,6 +265,7 @@ struct xprt_create {
 	size_t			addrlen;
 	const char		*servername;
 	struct svc_xprt		*bc_xprt;	/* NFSv4.1 backchannel */
+	unsigned int		flags;
 };
 
 struct xprt_class {
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index d5f35f1..54b69fc 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -411,6 +411,8 @@ struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 	};
 	char servername[48];
 
+	if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS)
+		xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS;
 	/*
 	 * If the caller chooses not to specify a hostname, whip
 	 * up a string representation of the passed-in address.
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 3d02130..b08d314 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -2767,9 +2767,13 @@ static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
 	struct rpc_xprt *xprt;
 	struct sock_xprt *transport;
 	struct rpc_xprt *ret;
+	unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
+
+	if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
+		max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
 
 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
-			xprt_max_tcp_slot_table_entries);
+			max_slot_table_size);
 	if (IS_ERR(xprt))
 		return xprt;
 	transport = container_of(xprt, struct sock_xprt, xprt);
-- 
1.8.1.4


From 932c7301413eb94f7b60efaa1a80cb8cf0264459 Mon Sep 17 00:00:00 2001
From: "J. Bruce Fields" <bfields@redhat.com>
Date: Thu, 21 Feb 2013 10:14:22 -0500
Subject: [PATCH 02/16] SUNRPC: attempt AF_LOCAL connect on setup

In the gss-proxy case, setup time is when I know I'll have the right
namespace for the connect.

In other cases, it might be useful to get any connection errors
earlier--though actually in practice it doesn't make any difference for
rpcbind.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
 net/sunrpc/xprtsock.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index b08d314..867ce36 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -2655,6 +2655,9 @@ static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
 		}
 		xprt_set_bound(xprt);
 		xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
+		ret = ERR_PTR(xs_local_setup_socket(transport));
+		if (ret)
+			goto out_err;
 		break;
 	default:
 		ret = ERR_PTR(-EAFNOSUPPORT);
-- 
1.8.1.4


From 915d3592cc8718cc3e83164bb78c532d3a7d1f00 Mon Sep 17 00:00:00 2001
From: "J. Bruce Fields" <bfields@redhat.com>
Date: Thu, 11 Apr 2013 15:06:36 -0400
Subject: [PATCH 03/16] SUNRPC: allow disabling idle timeout

In the gss-proxy case we don't want to have to reconnect at random--we
want to connect only on gss-proxy startup when we can steal gss-proxy's
context to do the connect in the right namespace.

So, provide a flag that allows the rpc_create caller to turn off the
idle timeout.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
 include/linux/sunrpc/clnt.h | 1 +
 include/linux/sunrpc/xprt.h | 1 +
 net/sunrpc/clnt.c           | 2 ++
 net/sunrpc/xprt.c           | 2 ++
 4 files changed, 6 insertions(+)

diff --git a/include/linux/sunrpc/clnt.h b/include/linux/sunrpc/clnt.h
index e7d492c..bfe11be 100644
--- a/include/linux/sunrpc/clnt.h
+++ b/include/linux/sunrpc/clnt.h
@@ -125,6 +125,7 @@ struct rpc_create_args {
 #define RPC_CLNT_CREATE_DISCRTRY	(1UL << 5)
 #define RPC_CLNT_CREATE_QUIET		(1UL << 6)
 #define RPC_CLNT_CREATE_INFINITE_SLOTS	(1UL << 7)
+#define RPC_CLNT_CREATE_NO_IDLE_TIMEOUT	(1UL << 8)
 
 struct rpc_clnt *rpc_create(struct rpc_create_args *args);
 struct rpc_clnt	*rpc_bind_new_program(struct rpc_clnt *,
diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index 12afb29..c8708d8 100644
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -256,6 +256,7 @@ static inline int bc_prealloc(struct rpc_rqst *req)
 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 
 #define XPRT_CREATE_INFINITE_SLOTS	(1U)
+#define XPRT_CREATE_NO_IDLE_TIMEOUT	(1U << 1)
 
 struct xprt_create {
 	int			ident;		/* XPRT_TRANSPORT identifier */
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 54b69fc..6d29b53 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -413,6 +413,8 @@ struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 
 	if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS)
 		xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS;
+	if (args->flags & RPC_CLNT_CREATE_NO_IDLE_TIMEOUT)
+		xprtargs.flags |= XPRT_CREATE_NO_IDLE_TIMEOUT;
 	/*
 	 * If the caller chooses not to specify a hostname, whip
 	 * up a string representation of the passed-in address.
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index b7478d5..33fac38 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -1245,6 +1245,8 @@ found:
 				-PTR_ERR(xprt));
 		goto out;
 	}
+	if (args->flags & XPRT_CREATE_NO_IDLE_TIMEOUT)
+		xprt->idle_timeout = 0;
 	INIT_WORK(&xprt->task_cleanup, xprt_autoclose);
 	if (xprt_has_timer(xprt))
 		setup_timer(&xprt->timer, xprt_init_autodisconnect,
-- 
1.8.1.4


From faa25a9e80ab40a0e923011771aca6a1ddeea30d Mon Sep 17 00:00:00 2001
From: Simo Sorce <simo@redhat.com>
Date: Fri, 25 May 2012 18:09:53 -0400
Subject: [PATCH 04/16] SUNRPC: conditionally return endtime from
 import_sec_context

We expose this parameter for a future caller.
It will be used to extract the endtime from the gss-proxy upcall mechanism,
in order to set the rsc cache expiration time.

Signed-off-by: Simo Sorce <simo@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
 include/linux/sunrpc/gss_api.h        | 2 ++
 net/sunrpc/auth_gss/auth_gss.c        | 2 +-
 net/sunrpc/auth_gss/gss_krb5_mech.c   | 7 +++++--
 net/sunrpc/auth_gss/gss_mech_switch.c | 5 +++--
 net/sunrpc/auth_gss/svcauth_gss.c     | 3 ++-
 5 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/include/linux/sunrpc/gss_api.h b/include/linux/sunrpc/gss_api.h
index a19e254..04d03bb 100644
--- a/include/linux/sunrpc/gss_api.h
+++ b/include/linux/sunrpc/gss_api.h
@@ -37,6 +37,7 @@ int gss_import_sec_context(
 		size_t			bufsize,
 		struct gss_api_mech	*mech,
 		struct gss_ctx		**ctx_id,
+		time_t			*endtime,
 		gfp_t			gfp_mask);
 u32 gss_get_mic(
 		struct gss_ctx		*ctx_id,
@@ -92,6 +93,7 @@ struct gss_api_ops {
 			const void		*input_token,
 			size_t			bufsize,
 			struct gss_ctx		*ctx_id,
+			time_t			*endtime,
 			gfp_t			gfp_mask);
 	u32 (*gss_get_mic)(
 			struct gss_ctx		*ctx_id,
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 5257d29..23563e7 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -238,7 +238,7 @@ gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct
 		p = ERR_PTR(-EFAULT);
 		goto err;
 	}
-	ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx, GFP_NOFS);
+	ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx, NULL, GFP_NOFS);
 	if (ret < 0) {
 		p = ERR_PTR(ret);
 		goto err;
diff --git a/net/sunrpc/auth_gss/gss_krb5_mech.c b/net/sunrpc/auth_gss/gss_krb5_mech.c
index d3611f1..3bc4a23 100644
--- a/net/sunrpc/auth_gss/gss_krb5_mech.c
+++ b/net/sunrpc/auth_gss/gss_krb5_mech.c
@@ -679,6 +679,7 @@ out_err:
 static int
 gss_import_sec_context_kerberos(const void *p, size_t len,
 				struct gss_ctx *ctx_id,
+				time_t *endtime,
 				gfp_t gfp_mask)
 {
 	const void *end = (const void *)((const char *)p + len);
@@ -694,9 +695,11 @@ gss_import_sec_context_kerberos(const void *p, size_t len,
 	else
 		ret = gss_import_v2_context(p, end, ctx, gfp_mask);
 
-	if (ret == 0)
+	if (ret == 0) {
 		ctx_id->internal_ctx_id = ctx;
-	else
+		if (endtime)
+			*endtime = ctx->endtime;
+	} else
 		kfree(ctx);
 
 	dprintk("RPC:       %s: returning %d\n", __func__, ret);
diff --git a/net/sunrpc/auth_gss/gss_mech_switch.c b/net/sunrpc/auth_gss/gss_mech_switch.c
index f0f4eee..43fd5bb 100644
--- a/net/sunrpc/auth_gss/gss_mech_switch.c
+++ b/net/sunrpc/auth_gss/gss_mech_switch.c
@@ -325,14 +325,15 @@ int
 gss_import_sec_context(const void *input_token, size_t bufsize,
 		       struct gss_api_mech	*mech,
 		       struct gss_ctx		**ctx_id,
+		       time_t			*endtime,
 		       gfp_t gfp_mask)
 {
 	if (!(*ctx_id = kzalloc(sizeof(**ctx_id), gfp_mask)))
 		return -ENOMEM;
 	(*ctx_id)->mech_type = gss_mech_get(mech);
 
-	return mech->gm_ops
-		->gss_import_sec_context(input_token, bufsize, *ctx_id, gfp_mask);
+	return mech->gm_ops->gss_import_sec_context(input_token, bufsize,
+						*ctx_id, endtime, gfp_mask);
 }
 
 /* gss_get_mic: compute a mic over message and return mic_token. */
diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
index 5ead605..20eedec 100644
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -497,7 +497,8 @@ static int rsc_parse(struct cache_detail *cd,
 		len = qword_get(&mesg, buf, mlen);
 		if (len < 0)
 			goto out;
-		status = gss_import_sec_context(buf, len, gm, &rsci.mechctx, GFP_KERNEL);
+		status = gss_import_sec_context(buf, len, gm, &rsci.mechctx,
+						NULL, GFP_KERNEL);
 		if (status)
 			goto out;
 
-- 
1.8.1.4


From ffc614331a36038700b7bc13bc2da6b8f120b9d6 Mon Sep 17 00:00:00 2001
From: Simo Sorce <simo@redhat.com>
Date: Fri, 25 May 2012 18:09:55 -0400
Subject: [PATCH 05/16] SUNRPC: Add RPC based upcall mechanism for RPCGSS auth

This patch implements a sunrpc client to use the services of the gssproxy
userspace daemon.

In particular it allows to perform calls in user space using an RPC
call instead of custom hand-coded upcall/downcall messages.

Currently only accept_sec_context is implemented as that is all is needed for
the server case.

File server modules like NFS and CIFS can use full gssapi services this way,
once init_sec_context is also implemented.

For the NFS server case this code allow to lift the limit of max 2k krb5
tickets. This limit is prevents legitimate kerberos deployments from using krb5
authentication with the Linux NFS server as they have normally ticket that are
many kilobytes large.

It will also allow to lift the limitation on the size of the credential set
(uid,gid,gids) passed down from user space for users that have very many groups
associated. Currently the downcall mechanism used by rpc.svcgssd is limited
to around 2k secondary groups of the 65k allowed by kernel structures.

Signed-off-by: Simo Sorce <simo@redhat.com>
[bfields: containerization, concurrent upcalls, misc. fixes and cleanup]
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
 net/sunrpc/auth_gss/Makefile         |   3 +-
 net/sunrpc/auth_gss/gss_rpc_upcall.c | 355 +++++++++++++++
 net/sunrpc/auth_gss/gss_rpc_upcall.h |  47 ++
 net/sunrpc/auth_gss/gss_rpc_xdr.c    | 832 +++++++++++++++++++++++++++++++++++
 net/sunrpc/auth_gss/gss_rpc_xdr.h    | 264 +++++++++++
 net/sunrpc/clnt.c                    |   1 +
 net/sunrpc/netns.h                   |   3 +
 7 files changed, 1504 insertions(+), 1 deletion(-)
 create mode 100644 net/sunrpc/auth_gss/gss_rpc_upcall.c
 create mode 100644 net/sunrpc/auth_gss/gss_rpc_upcall.h
 create mode 100644 net/sunrpc/auth_gss/gss_rpc_xdr.c
 create mode 100644 net/sunrpc/auth_gss/gss_rpc_xdr.h

diff --git a/net/sunrpc/auth_gss/Makefile b/net/sunrpc/auth_gss/Makefile
index 9e4cb59..14e9e53 100644
--- a/net/sunrpc/auth_gss/Makefile
+++ b/net/sunrpc/auth_gss/Makefile
@@ -5,7 +5,8 @@
 obj-$(CONFIG_SUNRPC_GSS) += auth_rpcgss.o
 
 auth_rpcgss-y := auth_gss.o gss_generic_token.o \
-	gss_mech_switch.o svcauth_gss.o
+	gss_mech_switch.o svcauth_gss.o \
+	gss_rpc_upcall.o gss_rpc_xdr.o
 
 obj-$(CONFIG_RPCSEC_GSS_KRB5) += rpcsec_gss_krb5.o
 
diff --git a/net/sunrpc/auth_gss/gss_rpc_upcall.c b/net/sunrpc/auth_gss/gss_rpc_upcall.c
new file mode 100644
index 0000000..2d33ddf
--- /dev/null
+++ b/net/sunrpc/auth_gss/gss_rpc_upcall.c
@@ -0,0 +1,355 @@
+/*
+ *  linux/net/sunrpc/gss_rpc_upcall.c
+ *
+ *  Copyright (C) 2012 Simo Sorce <simo@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/types.h>
+#include <linux/un.h>
+
+#include <linux/sunrpc/svcauth.h>
+#include "gss_rpc_upcall.h"
+
+#define GSSPROXY_SOCK_PATHNAME	"/var/run/gssproxy.sock"
+
+#define GSSPROXY_PROGRAM	(400112u)
+#define GSSPROXY_VERS_1		(1u)
+
+/*
+ * Encoding/Decoding functions
+ */
+
+enum {
+	GSSX_NULL = 0,	/* Unused */
+        GSSX_INDICATE_MECHS = 1,
+        GSSX_GET_CALL_CONTEXT = 2,
+        GSSX_IMPORT_AND_CANON_NAME = 3,
+        GSSX_EXPORT_CRED = 4,
+        GSSX_IMPORT_CRED = 5,
+        GSSX_ACQUIRE_CRED = 6,
+        GSSX_STORE_CRED = 7,
+        GSSX_INIT_SEC_CONTEXT = 8,
+        GSSX_ACCEPT_SEC_CONTEXT = 9,
+        GSSX_RELEASE_HANDLE = 10,
+        GSSX_GET_MIC = 11,
+        GSSX_VERIFY = 12,
+        GSSX_WRAP = 13,
+        GSSX_UNWRAP = 14,
+        GSSX_WRAP_SIZE_LIMIT = 15,
+};
+
+#define PROC(proc, name)				\
+[GSSX_##proc] = {					\
+	.p_proc   = GSSX_##proc,			\
+	.p_encode = (kxdreproc_t)gssx_enc_##name,	\
+	.p_decode = (kxdrdproc_t)gssx_dec_##name,	\
+	.p_arglen = GSSX_ARG_##name##_sz,		\
+	.p_replen = GSSX_RES_##name##_sz, 		\
+	.p_statidx = GSSX_##proc,			\
+	.p_name   = #proc,				\
+}
+
+struct rpc_procinfo gssp_procedures[] = {
+	PROC(INDICATE_MECHS, indicate_mechs),
+        PROC(GET_CALL_CONTEXT, get_call_context),
+        PROC(IMPORT_AND_CANON_NAME, import_and_canon_name),
+        PROC(EXPORT_CRED, export_cred),
+        PROC(IMPORT_CRED, import_cred),
+        PROC(ACQUIRE_CRED, acquire_cred),
+        PROC(STORE_CRED, store_cred),
+        PROC(INIT_SEC_CONTEXT, init_sec_context),
+        PROC(ACCEPT_SEC_CONTEXT, accept_sec_context),
+        PROC(RELEASE_HANDLE, release_handle),
+        PROC(GET_MIC, get_mic),
+        PROC(VERIFY, verify),
+        PROC(WRAP, wrap),
+        PROC(UNWRAP, unwrap),
+        PROC(WRAP_SIZE_LIMIT, wrap_size_limit),
+};
+
+
+
+/*
+ * Common transport functions
+ */
+
+static const struct rpc_program gssp_program;
+
+static int gssp_rpc_create(struct net *net, struct rpc_clnt **_clnt)
+{
+	static const struct sockaddr_un gssp_localaddr = {
+		.sun_family		= AF_LOCAL,
+		.sun_path		= GSSPROXY_SOCK_PATHNAME,
+	};
+	struct rpc_create_args args = {
+		.net		= net,
+		.protocol	= XPRT_TRANSPORT_LOCAL,
+		.address	= (struct sockaddr *)&gssp_localaddr,
+		.addrsize	= sizeof(gssp_localaddr),
+		.servername	= "localhost",
+		.program	= &gssp_program,
+		.version	= GSSPROXY_VERS_1,
+		.authflavor	= RPC_AUTH_NULL,
+		/*
+		 * Note we want connection to be done in the caller's
+		 * filesystem namespace.  We therefore turn off the idle
+		 * timeout, which would result in reconnections being
+		 * done without the correct namespace:
+		 */
+		.flags		= RPC_CLNT_CREATE_NOPING |
+				  RPC_CLNT_CREATE_NO_IDLE_TIMEOUT
+	};
+	struct rpc_clnt *clnt;
+	int result = 0;
+
+	clnt = rpc_create(&args);
+	if (IS_ERR(clnt)) {
+		dprintk("RPC:       failed to create AF_LOCAL gssproxy "
+				"client (errno %ld).\n", PTR_ERR(clnt));
+		result = -PTR_ERR(clnt);
+		*_clnt = NULL;
+		goto out;
+	}
+
+	dprintk("RPC:       created new gssp local client (gssp_local_clnt: "
+			"%p)\n", clnt);
+	*_clnt = clnt;
+
+out:
+	return result;
+}
+
+void init_gssp_clnt(struct sunrpc_net *sn)
+{
+	mutex_init(&sn->gssp_lock);
+	sn->gssp_clnt = NULL;
+}
+
+int set_gssp_clnt(struct net *net)
+{
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+	struct rpc_clnt *clnt;
+	int ret;
+
+	mutex_lock(&sn->gssp_lock);
+	ret = gssp_rpc_create(net, &clnt);
+	if (!ret) {
+		if (sn->gssp_clnt)
+			rpc_shutdown_client(sn->gssp_clnt);
+		sn->gssp_clnt = clnt;
+	}
+	mutex_unlock(&sn->gssp_lock);
+	return ret;
+}
+
+void clear_gssp_clnt(struct sunrpc_net *sn)
+{
+	mutex_lock(&sn->gssp_lock);
+	if (sn->gssp_clnt) {
+		rpc_shutdown_client(sn->gssp_clnt);
+		sn->gssp_clnt = NULL;
+	}
+	mutex_unlock(&sn->gssp_lock);
+}
+
+static struct rpc_clnt *get_gssp_clnt(struct sunrpc_net *sn)
+{
+	struct rpc_clnt *clnt;
+
+	mutex_lock(&sn->gssp_lock);
+	clnt = sn->gssp_clnt;
+	if (clnt)
+		atomic_inc(&clnt->cl_count);
+	mutex_unlock(&sn->gssp_lock);
+	return clnt;
+}
+
+static int gssp_call(struct net *net, struct rpc_message *msg)
+{
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+	struct rpc_clnt *clnt;
+	int status;
+
+	clnt = get_gssp_clnt(sn);
+	if (!clnt)
+		return -EIO;
+	status = rpc_call_sync(clnt, msg, 0);
+	if (status < 0) {
+		dprintk("gssp: rpc_call returned error %d\n", -status);
+		switch (status) {
+		case -EPROTONOSUPPORT:
+			status = -EINVAL;
+			break;
+		case -ECONNREFUSED:
+		case -ETIMEDOUT:
+		case -ENOTCONN:
+			status = -EAGAIN;
+			break;
+		case -ERESTARTSYS:
+			if (signalled ())
+				status = -EINTR;
+			break;
+		default:
+			break;
+		}
+	}
+	rpc_release_client(clnt);
+	return status;
+}
+
+
+/*
+ * Public functions
+ */
+
+/* numbers somewhat arbitrary but large enough for current needs */
+#define GSSX_MAX_OUT_HANDLE	128
+#define GSSX_MAX_MECH_OID	16
+#define GSSX_MAX_SRC_PRINC	256
+#define GSSX_KMEMBUF (GSSX_max_output_handle_sz + \
+			GSSX_max_oid_sz + \
+			GSSX_max_princ_sz + \
+			sizeof(struct svc_cred))
+
+int gssp_accept_sec_context_upcall(struct net *net,
+				struct gssp_upcall_data *data)
+{
+	struct gssx_ctx ctxh = {
+		.state = data->in_handle
+	};
+	struct gssx_arg_accept_sec_context arg = {
+		.input_token = data->in_token,
+	};
+	struct gssx_ctx rctxh = {
+		/*
+		 * pass in the max length we expect for each of these
+		 * buffers but let the xdr code kmalloc them:
+		 */
+		.exported_context_token.len = GSSX_max_output_handle_sz,
+		.mech.len = GSSX_max_oid_sz,
+		.src_name.display_name.len = GSSX_max_princ_sz
+	};
+	struct gssx_res_accept_sec_context res = {
+		.context_handle = &rctxh,
+		.output_token = &data->out_token
+	};
+	struct rpc_message msg = {
+		.rpc_proc = &gssp_procedures[GSSX_ACCEPT_SEC_CONTEXT],
+		.rpc_argp = &arg,
+		.rpc_resp = &res,
+		.rpc_cred = NULL, /* FIXME ? */
+	};
+	struct xdr_netobj client_name = { 0 , NULL };
+	int ret;
+
+	if (data->in_handle.len != 0)
+		arg.context_handle = &ctxh;
+	res.output_token->len = GSSX_max_output_token_sz;
+
+	/* use nfs/ for targ_name ? */
+
+	ret = gssp_call(net, &msg);
+
+	/* we need to fetch all data even in case of error so
+	 * that we can free special strctures is they have been allocated */
+	data->major_status = res.status.major_status;
+	data->minor_status = res.status.minor_status;
+	if (res.context_handle) {
+		data->out_handle = rctxh.exported_context_token;
+		data->mech_oid = rctxh.mech;
+		client_name = rctxh.src_name.display_name;
+	}
+
+	if (res.options.count == 1) {
+		gssx_buffer *value = &res.options.data[0].value;
+		/* Currently we only decode CREDS_VALUE, if we add
+		 * anything else we'll have to loop and match on the
+		 * option name */
+		if (value->len == 1) {
+			/* steal group info from struct svc_cred */
+			data->creds = *(struct svc_cred *)value->data;
+			data->found_creds = 1;
+		}
+		/* whether we use it or not, free data */
+		kfree(value->data);
+	}
+
+	if (res.options.count != 0) {
+		kfree(res.options.data);
+	}
+
+	/* convert to GSS_NT_HOSTBASED_SERVICE form and set into creds */
+	if (data->found_creds && client_name.data != NULL) {
+		char *c;
+
+		data->creds.cr_principal = kstrndup(client_name.data,
+						client_name.len, GFP_KERNEL);
+		if (data->creds.cr_principal) {
+			/* terminate and remove realm part */
+			c = strchr(data->creds.cr_principal, '@');
+			if (c) {
+				*c = '\0';
+
+				/* change service-hostname delimiter */
+				c = strchr(data->creds.cr_principal, '/');
+				if (c) *c = '@';
+			}
+			if (!c) {
+				/* not a service principal */
+				kfree(data->creds.cr_principal);
+				data->creds.cr_principal = NULL;
+			}
+		}
+	}
+	kfree(client_name.data);
+
+	return ret;
+}
+
+void gssp_free_upcall_data(struct gssp_upcall_data *data)
+{
+	kfree(data->in_handle.data);
+	kfree(data->out_handle.data);
+	kfree(data->out_token.data);
+	kfree(data->mech_oid.data);
+	free_svc_cred(&data->creds);
+}
+
+/*
+ * Initialization stuff
+ */
+
+static const struct rpc_version gssp_version1 = {
+	.number		= GSSPROXY_VERS_1,
+	.nrprocs	= ARRAY_SIZE(gssp_procedures),
+	.procs		= gssp_procedures,
+};
+
+static const struct rpc_version *gssp_version[] = {
+	NULL,
+	&gssp_version1,
+};
+
+static struct rpc_stat gssp_stats;
+
+static const struct rpc_program gssp_program = {
+	.name		= "gssproxy",
+	.number		= GSSPROXY_PROGRAM,
+	.nrvers		= ARRAY_SIZE(gssp_version),
+	.version	= gssp_version,
+	.stats		= &gssp_stats,
+};
diff --git a/net/sunrpc/auth_gss/gss_rpc_upcall.h b/net/sunrpc/auth_gss/gss_rpc_upcall.h
new file mode 100644
index 0000000..4c2caaa
--- /dev/null
+++ b/net/sunrpc/auth_gss/gss_rpc_upcall.h
@@ -0,0 +1,47 @@
+/*
+ *  linux/net/sunrpc/gss_rpc_upcall.h
+ *
+ *  Copyright (C) 2012 Simo Sorce <simo@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef _GSS_RPC_UPCALL_H
+#define _GSS_RPC_UPCALL_H
+
+#include <linux/sunrpc/auth_gss.h>
+#include "gss_rpc_xdr.h"
+#include "../netns.h"
+
+struct gssp_upcall_data {
+	struct xdr_netobj in_handle;
+	struct gssp_in_token in_token;
+	struct xdr_netobj out_handle;
+	struct xdr_netobj out_token;
+	struct xdr_netobj mech_oid;
+	struct svc_cred creds;
+	int found_creds;
+	int major_status;
+	int minor_status;
+};
+
+int gssp_accept_sec_context_upcall(struct net *net,
+				struct gssp_upcall_data *data);
+void gssp_free_upcall_data(struct gssp_upcall_data *data);
+
+void init_gssp_clnt(struct sunrpc_net *);
+int set_gssp_clnt(struct net *);
+void clear_gssp_clnt(struct sunrpc_net *);
+#endif /* _GSS_RPC_UPCALL_H */
diff --git a/net/sunrpc/auth_gss/gss_rpc_xdr.c b/net/sunrpc/auth_gss/gss_rpc_xdr.c
new file mode 100644
index 0000000..d0ccdff
--- /dev/null
+++ b/net/sunrpc/auth_gss/gss_rpc_xdr.c
@@ -0,0 +1,832 @@
+/*
+ * GSS Proxy upcall module
+ *
+ *  Copyright (C) 2012 Simo Sorce <simo@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/sunrpc/svcauth.h>
+#include "gss_rpc_xdr.h"
+
+static bool gssx_check_pointer(struct xdr_stream *xdr)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4);
+	if (unlikely(p == NULL))
+		return -ENOSPC;
+	return *p?true:false;
+}
+
+static int gssx_enc_bool(struct xdr_stream *xdr, int v)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4);
+	if (unlikely(p == NULL))
+		return -ENOSPC;
+	*p = v ? xdr_one : xdr_zero;
+	return 0;
+}
+
+static int gssx_dec_bool(struct xdr_stream *xdr, u32 *v)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(p == NULL))
+		return -ENOSPC;
+	*v = be32_to_cpu(*p);
+	return 0;
+}
+
+static int gssx_enc_buffer(struct xdr_stream *xdr,
+			   gssx_buffer *buf)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, sizeof(u32) + buf->len);
+	if (!p)
+		return -ENOSPC;
+	xdr_encode_opaque(p, buf->data, buf->len);
+	return 0;
+}
+
+static int gssx_enc_in_token(struct xdr_stream *xdr,
+			     struct gssp_in_token *in)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		return -ENOSPC;
+	*p = cpu_to_be32(in->page_len);
+
+	/* all we need to do is to write pages */
+	xdr_write_pages(xdr, in->pages, in->page_base, in->page_len);
+
+	return 0;
+}
+
+
+static int gssx_dec_buffer(struct xdr_stream *xdr,
+			   gssx_buffer *buf)
+{
+	u32 length;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(p == NULL))
+		return -ENOSPC;
+
+	length = be32_to_cpup(p);
+	p = xdr_inline_decode(xdr, length);
+	if (unlikely(p == NULL))
+		return -ENOSPC;
+
+	if (buf->len == 0) {
+		/* we intentionally are not interested in this buffer */
+		return 0;
+	}
+	if (length > buf->len)
+		return -ENOSPC;
+
+	if (!buf->data) {
+		buf->data = kmemdup(p, length, GFP_KERNEL);
+		if (!buf->data)
+			return -ENOMEM;
+	} else {
+		memcpy(buf->data, p, length);
+	}
+	buf->len = length;
+	return 0;
+}
+
+static int gssx_enc_option(struct xdr_stream *xdr,
+			   struct gssx_option *opt)
+{
+	int err;
+
+	err = gssx_enc_buffer(xdr, &opt->option);
+	if (err)
+		return err;
+	err = gssx_enc_buffer(xdr, &opt->value);
+	return err;
+}
+
+static int gssx_dec_option(struct xdr_stream *xdr,
+			   struct gssx_option *opt)
+{
+	int err;
+
+	err = gssx_dec_buffer(xdr, &opt->option);
+	if (err)
+		return err;
+	err = gssx_dec_buffer(xdr, &opt->value);
+	return err;
+}
+
+static int dummy_enc_opt_array(struct xdr_stream *xdr,
+				struct gssx_option_array *oa)
+{
+	__be32 *p;
+
+	if (oa->count != 0)
+		return -EINVAL;
+
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		return -ENOSPC;
+	*p = 0;
+
+	return 0;
+}
+
+static int dummy_dec_opt_array(struct xdr_stream *xdr,
+				struct gssx_option_array *oa)
+{
+	struct gssx_option dummy;
+	u32 count, i;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(p == NULL))
+		return -ENOSPC;
+	count = be32_to_cpup(p++);
+	memset(&dummy, 0, sizeof(dummy));
+	for (i = 0; i < count; i++) {
+		gssx_dec_option(xdr, &dummy);
+	}
+
+	oa->count = 0;
+	oa->data = NULL;
+	return 0;
+}
+
+static int get_s32(void **p, void *max, s32 *res)
+{
+	void *base = *p;
+	void *next = (void *)((char *)base + sizeof(s32));
+	if (unlikely(next > max || next < base))
+		return -EINVAL;
+	memcpy(res, base, sizeof(s32));
+	*p = next;
+	return 0;
+}
+
+static int gssx_dec_linux_creds(struct xdr_stream *xdr,
+				struct svc_cred *creds)
+{
+	u32 length;
+	__be32 *p;
+	void *q, *end;
+	s32 tmp;
+	int N, i, err;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(p == NULL))
+		return -ENOSPC;
+
+	length = be32_to_cpup(p);
+
+	/* FIXME: we do not want to use the scratch buffer for this one
+	 * may need to use functions that allows us to access an io vector
+	 * directly */
+	p = xdr_inline_decode(xdr, length);
+	if (unlikely(p == NULL))
+		return -ENOSPC;
+
+	q = p;
+	end = q + length;
+
+	/* uid */
+	err = get_s32(&q, end, &tmp);
+	if (err)
+		return err;
+	creds->cr_uid = tmp;
+
+	/* gid */
+	err = get_s32(&q, end, &tmp);
+	if (err)
+		return err;
+	creds->cr_gid = tmp;
+
+	/* number of additional gid's */
+	err = get_s32(&q, end, &tmp);
+	if (err)
+		return err;
+	N = tmp;
+	creds->cr_group_info = groups_alloc(N);
+	if (creds->cr_group_info == NULL)
+		return -ENOMEM;
+
+	/* gid's */
+	for (i = 0; i < N; i++) {
+		err = get_s32(&q, end, &tmp);
+		if (err) {
+			groups_free(creds->cr_group_info);
+			return err;
+		}
+		GROUP_AT(creds->cr_group_info, i) = tmp;
+	}
+
+	return 0;
+}
+
+static int gssx_dec_option_array(struct xdr_stream *xdr,
+				 struct gssx_option_array *oa)
+{
+	struct svc_cred *creds;
+	u32 count, i;
+	__be32 *p;
+	int err;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(p == NULL))
+		return -ENOSPC;
+	count = be32_to_cpup(p++);
+	if (count != 0) {
+		/* we recognize only 1 currently: CREDS_VALUE */
+		oa->count = 1;
+
+		oa->data = kmalloc(sizeof(struct gssx_option), GFP_KERNEL);
+		if (!oa->data)
+			return -ENOMEM;
+
+		creds = kmalloc(sizeof(struct svc_cred), GFP_KERNEL);
+		if (!creds) {
+			kfree(oa->data);
+			return -ENOMEM;
+		}
+
+		oa->data[0].option.data = CREDS_VALUE;
+		oa->data[0].option.len = sizeof(CREDS_VALUE);
+		oa->data[0].value.data = (void *)creds;
+		oa->data[0].value.len = 0;
+	}
+	for (i = 0; i < count; i++) {
+		gssx_buffer dummy = { 0, NULL };
+		u32 length;
+
+		/* option buffer */
+		p = xdr_inline_decode(xdr, 4);
+		if (unlikely(p == NULL))
+			return -ENOSPC;
+
+		length = be32_to_cpup(p);
+		p = xdr_inline_decode(xdr, length);
+		if (unlikely(p == NULL))
+			return -ENOSPC;
+
+		if (length == sizeof(CREDS_VALUE) &&
+		    memcmp(p, CREDS_VALUE, sizeof(CREDS_VALUE)) == 0) {
+			/* We have creds here. parse them */
+			err = gssx_dec_linux_creds(xdr, creds);
+			if (err)
+				return err;
+			oa->data[0].value.len = 1; /* presence */
+		} else {
+			/* consume uninteresting buffer */
+			err = gssx_dec_buffer(xdr, &dummy);
+			if (err)
+				return err;
+		}
+	}
+	return 0;
+}
+
+static int gssx_dec_status(struct xdr_stream *xdr,
+			   struct gssx_status *status)
+{
+	__be32 *p;
+	int err;
+
+	/* status->major_status */
+	p = xdr_inline_decode(xdr, 8);
+	if (unlikely(p == NULL))
+		return -ENOSPC;
+	p = xdr_decode_hyper(p, &status->major_status);
+
+	/* status->mech */
+	err = gssx_dec_buffer(xdr, &status->mech);
+	if (err)
+		return err;
+
+	/* status->minor_status */
+	p = xdr_inline_decode(xdr, 8);
+	if (unlikely(p == NULL))
+		return -ENOSPC;
+	p = xdr_decode_hyper(p, &status->minor_status);
+
+	/* status->major_status_string */
+	err = gssx_dec_buffer(xdr, &status->major_status_string);
+	if (err)
+		return err;
+
+	/* status->minor_status_string */
+	err = gssx_dec_buffer(xdr, &status->minor_status_string);
+	if (err)
+		return err;
+
+	/* status->server_ctx */
+	err = gssx_dec_buffer(xdr, &status->server_ctx);
+	if (err)
+		return err;
+
+	/* we assume we have no options for now, so simply consume them */
+	/* status->options */
+	err = dummy_dec_opt_array(xdr, &status->options);
+
+	return err;
+}
+
+static int gssx_enc_call_ctx(struct xdr_stream *xdr,
+			     struct gssx_call_ctx *ctx)
+{
+	struct gssx_option opt;
+	__be32 *p;
+	int err;
+
+	/* ctx->locale */
+	err = gssx_enc_buffer(xdr, &ctx->locale);
+	if (err)
+		return err;
+
+	/* ctx->server_ctx */
+	err = gssx_enc_buffer(xdr, &ctx->server_ctx);
+	if (err)
+		return err;
+
+	/* we always want to ask for lucid contexts */
+	/* ctx->options */
+	p = xdr_reserve_space(xdr, 4);
+	*p = cpu_to_be32(2);
+
+	/* we want a lucid_v1 context */
+	opt.option.data = LUCID_OPTION;
+	opt.option.len = sizeof(LUCID_OPTION);
+	opt.value.data = LUCID_VALUE;
+	opt.value.len = sizeof(LUCID_VALUE);
+	err = gssx_enc_option(xdr, &opt);
+
+	/* ..and user creds */
+	opt.option.data = CREDS_OPTION;
+	opt.option.len = sizeof(CREDS_OPTION);
+	opt.value.data = CREDS_VALUE;
+	opt.value.len = sizeof(CREDS_VALUE);
+	err = gssx_enc_option(xdr, &opt);
+
+	return err;
+}
+
+static int gssx_dec_name_attr(struct xdr_stream *xdr,
+			     struct gssx_name_attr *attr)
+{
+	int err;
+
+	/* attr->attr */
+	err = gssx_dec_buffer(xdr, &attr->attr);
+	if (err)
+		return err;
+
+	/* attr->value */
+	err = gssx_dec_buffer(xdr, &attr->value);
+	if (err)
+		return err;
+
+	/* attr->extensions */
+	err = dummy_dec_opt_array(xdr, &attr->extensions);
+
+	return err;
+}
+
+static int dummy_enc_nameattr_array(struct xdr_stream *xdr,
+				    struct gssx_name_attr_array *naa)
+{
+	__be32 *p;
+
+	if (naa->count != 0)
+		return -EINVAL;
+
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		return -ENOSPC;
+	*p = 0;
+
+	return 0;
+}
+
+static int dummy_dec_nameattr_array(struct xdr_stream *xdr,
+				    struct gssx_name_attr_array *naa)
+{
+	struct gssx_name_attr dummy;
+	u32 count, i;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(p == NULL))
+		return -ENOSPC;
+	count = be32_to_cpup(p++);
+	for (i = 0; i < count; i++) {
+		gssx_dec_name_attr(xdr, &dummy);
+	}
+
+	naa->count = 0;
+	naa->data = NULL;
+	return 0;
+}
+
+static struct xdr_netobj zero_netobj = {};
+
+static struct gssx_name_attr_array zero_name_attr_array = {};
+
+static struct gssx_option_array zero_option_array = {};
+
+static int gssx_enc_name(struct xdr_stream *xdr,
+			 struct gssx_name *name)
+{
+	int err;
+
+	/* name->display_name */
+	err = gssx_enc_buffer(xdr, &name->display_name);
+	if (err)
+		return err;
+
+	/* name->name_type */
+	err = gssx_enc_buffer(xdr, &zero_netobj);
+	if (err)
+		return err;
+
+	/* name->exported_name */
+	err = gssx_enc_buffer(xdr, &zero_netobj);
+	if (err)
+		return err;
+
+	/* name->exported_composite_name */
+	err = gssx_enc_buffer(xdr, &zero_netobj);
+	if (err)
+		return err;
+
+	/* leave name_attributes empty for now, will add once we have any
+	 * to pass up at all */
+	/* name->name_attributes */
+	err = dummy_enc_nameattr_array(xdr, &zero_name_attr_array);
+	if (err)
+		return err;
+
+	/* leave options empty for now, will add once we have any options
+	 * to pass up at all */
+	/* name->extensions */
+	err = dummy_enc_opt_array(xdr, &zero_option_array);
+
+	return err;
+}
+
+static int gssx_dec_name(struct xdr_stream *xdr,
+			 struct gssx_name *name)
+{
+	struct xdr_netobj dummy_netobj;
+	struct gssx_name_attr_array dummy_name_attr_array;
+	struct gssx_option_array dummy_option_array;
+	int err;
+
+	/* name->display_name */
+	err = gssx_dec_buffer(xdr, &name->display_name);
+	if (err)
+		return err;
+
+	/* name->name_type */
+	err = gssx_dec_buffer(xdr, &dummy_netobj);
+	if (err)
+		return err;
+
+	/* name->exported_name */
+	err = gssx_dec_buffer(xdr, &dummy_netobj);
+	if (err)
+		return err;
+
+	/* name->exported_composite_name */
+	err = gssx_dec_buffer(xdr, &dummy_netobj);
+	if (err)
+		return err;
+
+	/* we assume we have no attributes for now, so simply consume them */
+	/* name->name_attributes */
+	err = dummy_dec_nameattr_array(xdr, &dummy_name_attr_array);
+	if (err)
+		return err;
+
+	/* we assume we have no options for now, so simply consume them */
+	/* name->extensions */
+	err = dummy_dec_opt_array(xdr, &dummy_option_array);
+
+	return err;
+}
+
+static int dummy_enc_credel_array(struct xdr_stream *xdr,
+				  struct gssx_cred_element_array *cea)
+{
+	__be32 *p;
+
+	if (cea->count != 0)
+		return -EINVAL;
+
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		return -ENOSPC;
+	*p = 0;
+
+	return 0;
+}
+
+static int gssx_enc_cred(struct xdr_stream *xdr,
+			 struct gssx_cred *cred)
+{
+	int err;
+
+	/* cred->desired_name */
+	err = gssx_enc_name(xdr, &cred->desired_name);
+	if (err)
+		return err;
+
+	/* cred->elements */
+	err = dummy_enc_credel_array(xdr, &cred->elements);
+
+	/* cred->cred_handle_reference */
+	err = gssx_enc_buffer(xdr, &cred->cred_handle_reference);
+	if (err)
+		return err;
+
+	/* cred->needs_release */
+	err = gssx_enc_bool(xdr, cred->needs_release);
+
+	return err;
+}
+
+static int gssx_enc_ctx(struct xdr_stream *xdr,
+			struct gssx_ctx *ctx)
+{
+	__be32 *p;
+	int err;
+
+	/* ctx->exported_context_token */
+	err = gssx_enc_buffer(xdr, &ctx->exported_context_token);
+	if (err)
+		return err;
+
+	/* ctx->state */
+	err = gssx_enc_buffer(xdr, &ctx->state);
+	if (err)
+		return err;
+
+	/* ctx->need_release */
+	err = gssx_enc_bool(xdr, ctx->need_release);
+	if (err)
+		return err;
+
+	/* ctx->mech */
+	err = gssx_enc_buffer(xdr, &ctx->mech);
+	if (err)
+		return err;
+
+	/* ctx->src_name */
+	err = gssx_enc_name(xdr, &ctx->src_name);
+	if (err)
+		return err;
+
+	/* ctx->targ_name */
+	err = gssx_enc_name(xdr, &ctx->targ_name);
+	if (err)
+		return err;
+
+	/* ctx->lifetime */
+	p = xdr_reserve_space(xdr, 8+8);
+	if (!p)
+		return -ENOSPC;
+	p = xdr_encode_hyper(p, ctx->lifetime);
+
+	/* ctx->ctx_flags */
+	p = xdr_encode_hyper(p, ctx->ctx_flags);
+
+	/* ctx->locally_initiated */
+	err = gssx_enc_bool(xdr, ctx->locally_initiated);
+	if (err)
+		return err;
+
+	/* ctx->open */
+	err = gssx_enc_bool(xdr, ctx->open);
+	if (err)
+		return err;
+
+	/* leave options empty for now, will add once we have any options
+	 * to pass up at all */
+	/* ctx->options */
+	err = dummy_enc_opt_array(xdr, &ctx->options);
+
+	return err;
+}
+
+static int gssx_dec_ctx(struct xdr_stream *xdr,
+			struct gssx_ctx *ctx)
+{
+	__be32 *p;
+	int err;
+
+	/* ctx->exported_context_token */
+	err = gssx_dec_buffer(xdr, &ctx->exported_context_token);
+	if (err)
+		return err;
+
+	/* ctx->state */
+	err = gssx_dec_buffer(xdr, &ctx->state);
+	if (err)
+		return err;
+
+	/* ctx->need_release */
+	err = gssx_dec_bool(xdr, &ctx->need_release);
+	if (err)
+		return err;
+
+	/* ctx->mech */
+	err = gssx_dec_buffer(xdr, &ctx->mech);
+	if (err)
+		return err;
+
+	/* ctx->src_name */
+	err = gssx_dec_name(xdr, &ctx->src_name);
+	if (err)
+		return err;
+
+	/* ctx->targ_name */
+	err = gssx_dec_name(xdr, &ctx->targ_name);
+	if (err)
+		return err;
+
+	/* ctx->lifetime */
+	p = xdr_inline_decode(xdr, 8+8);
+	if (unlikely(p == NULL))
+		return -ENOSPC;
+	p = xdr_decode_hyper(p, &ctx->lifetime);
+
+	/* ctx->ctx_flags */
+	p = xdr_decode_hyper(p, &ctx->ctx_flags);
+
+	/* ctx->locally_initiated */
+	err = gssx_dec_bool(xdr, &ctx->locally_initiated);
+	if (err)
+		return err;
+
+	/* ctx->open */
+	err = gssx_dec_bool(xdr, &ctx->open);
+	if (err)
+		return err;
+
+	/* we assume we have no options for now, so simply consume them */
+	/* ctx->options */
+	err = dummy_dec_opt_array(xdr, &ctx->options);
+
+	return err;
+}
+
+static int gssx_enc_cb(struct xdr_stream *xdr, struct gssx_cb *cb)
+{
+	__be32 *p;
+	int err;
+
+	/* cb->initiator_addrtype */
+	p = xdr_reserve_space(xdr, 8);
+	if (!p)
+		return -ENOSPC;
+	p = xdr_encode_hyper(p, cb->initiator_addrtype);
+
+	/* cb->initiator_address */
+	err = gssx_enc_buffer(xdr, &cb->initiator_address);
+	if (err)
+		return err;
+
+	/* cb->acceptor_addrtype */
+	p = xdr_reserve_space(xdr, 8);
+	if (!p)
+		return -ENOSPC;
+	p = xdr_encode_hyper(p, cb->acceptor_addrtype);
+
+	/* cb->acceptor_address */
+	err = gssx_enc_buffer(xdr, &cb->acceptor_address);
+	if (err)
+		return err;
+
+	/* cb->application_data */
+	err = gssx_enc_buffer(xdr, &cb->application_data);
+
+	return err;
+}
+
+void gssx_enc_accept_sec_context(struct rpc_rqst *req,
+				 struct xdr_stream *xdr,
+				 struct gssx_arg_accept_sec_context *arg)
+{
+	int err;
+
+	err = gssx_enc_call_ctx(xdr, &arg->call_ctx);
+	if (err)
+		goto done;
+
+	/* arg->context_handle */
+	if (arg->context_handle) {
+		err = gssx_enc_ctx(xdr, arg->context_handle);
+		if (err)
+			goto done;
+	} else {
+		err = gssx_enc_bool(xdr, 0);
+	}
+
+	/* arg->cred_handle */
+	if (arg->cred_handle) {
+		err = gssx_enc_cred(xdr, arg->cred_handle);
+		if (err)
+			goto done;
+	} else {
+		err = gssx_enc_bool(xdr, 0);
+	}
+
+	/* arg->input_token */
+	err = gssx_enc_in_token(xdr, &arg->input_token);
+	if (err)
+		goto done;
+
+	/* arg->input_cb */
+	if (arg->input_cb) {
+		err = gssx_enc_cb(xdr, arg->input_cb);
+		if (err)
+			goto done;
+	} else {
+		err = gssx_enc_bool(xdr, 0);
+	}
+
+	err = gssx_enc_bool(xdr, arg->ret_deleg_cred);
+	if (err)
+		goto done;
+
+	/* leave options empty for now, will add once we have any options
+	 * to pass up at all */
+	/* arg->options */
+	err = dummy_enc_opt_array(xdr, &arg->options);
+
+done:
+	if (err)
+		dprintk("RPC:       gssx_enc_accept_sec_context: %d\n", err);
+}
+
+int gssx_dec_accept_sec_context(struct rpc_rqst *rqstp,
+				struct xdr_stream *xdr,
+				struct gssx_res_accept_sec_context *res)
+{
+	int err;
+
+	/* res->status */
+	err = gssx_dec_status(xdr, &res->status);
+	if (err)
+		return err;
+
+	/* res->context_handle */
+	if (gssx_check_pointer(xdr)) {
+		err = gssx_dec_ctx(xdr, res->context_handle);
+		if (err)
+			return err;
+	} else {
+		res->context_handle = NULL;
+	}
+
+	/* res->output_token */
+	if (gssx_check_pointer(xdr)) {
+		err = gssx_dec_buffer(xdr, res->output_token);
+		if (err)
+			return err;
+	} else {
+		res->output_token = NULL;
+	}
+
+	/* res->delegated_cred_handle */
+	if (gssx_check_pointer(xdr)) {
+		/* we do not support upcall servers sending this data. */
+		return -EINVAL;
+	}
+
+	/* res->options */
+	err = gssx_dec_option_array(xdr, &res->options);
+
+	return err;
+}
diff --git a/net/sunrpc/auth_gss/gss_rpc_xdr.h b/net/sunrpc/auth_gss/gss_rpc_xdr.h
new file mode 100644
index 0000000..1c98b27
--- /dev/null
+++ b/net/sunrpc/auth_gss/gss_rpc_xdr.h
@@ -0,0 +1,264 @@
+/*
+ * GSS Proxy upcall module
+ *
+ *  Copyright (C) 2012 Simo Sorce <simo@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef _LINUX_GSS_RPC_XDR_H
+#define _LINUX_GSS_RPC_XDR_H
+
+#include <linux/sunrpc/xdr.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/xprtsock.h>
+
+#ifdef RPC_DEBUG
+# define RPCDBG_FACILITY	RPCDBG_AUTH
+#endif
+
+#define LUCID_OPTION "exported_context_type"
+#define LUCID_VALUE  "linux_lucid_v1"
+#define CREDS_OPTION "exported_creds_type"
+#define CREDS_VALUE  "linux_creds_v1"
+
+typedef struct xdr_netobj gssx_buffer;
+typedef struct xdr_netobj utf8string;
+typedef struct xdr_netobj gssx_OID;
+
+enum gssx_cred_usage {
+	GSSX_C_INITIATE = 1,
+	GSSX_C_ACCEPT = 2,
+	GSSX_C_BOTH = 3,
+};
+
+struct gssx_option {
+	gssx_buffer option;
+	gssx_buffer value;
+};
+
+struct gssx_option_array {
+	u32 count;
+	struct gssx_option *data;
+};
+
+struct gssx_status {
+	u64 major_status;
+	gssx_OID mech;
+	u64 minor_status;
+	utf8string major_status_string;
+	utf8string minor_status_string;
+	gssx_buffer server_ctx;
+	struct gssx_option_array options;
+};
+
+struct gssx_call_ctx {
+	utf8string locale;
+	gssx_buffer server_ctx;
+	struct gssx_option_array options;
+};
+
+struct gssx_name_attr {
+	gssx_buffer attr;
+	gssx_buffer value;
+	struct gssx_option_array extensions;
+};
+
+struct gssx_name_attr_array {
+	u32 count;
+	struct gssx_name_attr *data;
+};
+
+struct gssx_name {
+	gssx_buffer display_name;
+};
+typedef struct gssx_name gssx_name;
+
+struct gssx_cred_element {
+	gssx_name MN;
+	gssx_OID mech;
+	u32 cred_usage;
+	u64 initiator_time_rec;
+	u64 acceptor_time_rec;
+	struct gssx_option_array options;
+};
+
+struct gssx_cred_element_array {
+	u32 count;
+	struct gssx_cred_element *data;
+};
+
+struct gssx_cred {
+	gssx_name desired_name;
+	struct gssx_cred_element_array elements;
+	gssx_buffer cred_handle_reference;
+	u32 needs_release;
+};
+
+struct gssx_ctx {
+	gssx_buffer exported_context_token;
+	gssx_buffer state;
+	u32 need_release;
+	gssx_OID mech;
+	gssx_name src_name;
+	gssx_name targ_name;
+	u64 lifetime;
+	u64 ctx_flags;
+	u32 locally_initiated;
+	u32 open;
+	struct gssx_option_array options;
+};
+
+struct gssx_cb {
+	u64 initiator_addrtype;
+	gssx_buffer initiator_address;
+	u64 acceptor_addrtype;
+	gssx_buffer acceptor_address;
+	gssx_buffer application_data;
+};
+
+
+/* This structure is not defined in the protocol.
+ * It is used in the kernel to carry around a big buffer
+ * as a set of pages */
+struct gssp_in_token {
+	struct page **pages;	/* Array of contiguous pages */
+	unsigned int page_base;	/* Start of page data */
+	unsigned int page_len;	/* Length of page data */
+};
+
+struct gssx_arg_accept_sec_context {
+	struct gssx_call_ctx call_ctx;
+	struct gssx_ctx *context_handle;
+	struct gssx_cred *cred_handle;
+	struct gssp_in_token input_token;
+	struct gssx_cb *input_cb;
+	u32 ret_deleg_cred;
+	struct gssx_option_array options;
+};
+
+struct gssx_res_accept_sec_context {
+	struct gssx_status status;
+	struct gssx_ctx *context_handle;
+	gssx_buffer *output_token;
+	/* struct gssx_cred *delegated_cred_handle; not used in kernel */
+	struct gssx_option_array options;
+};
+
+
+
+#define gssx_enc_indicate_mechs NULL
+#define gssx_dec_indicate_mechs NULL
+#define gssx_enc_get_call_context NULL
+#define gssx_dec_get_call_context NULL
+#define gssx_enc_import_and_canon_name NULL
+#define gssx_dec_import_and_canon_name NULL
+#define gssx_enc_export_cred NULL
+#define gssx_dec_export_cred NULL
+#define gssx_enc_import_cred NULL
+#define gssx_dec_import_cred NULL
+#define gssx_enc_acquire_cred NULL
+#define gssx_dec_acquire_cred NULL
+#define gssx_enc_store_cred NULL
+#define gssx_dec_store_cred NULL
+#define gssx_enc_init_sec_context NULL
+#define gssx_dec_init_sec_context NULL
+void gssx_enc_accept_sec_context(struct rpc_rqst *req,
+				 struct xdr_stream *xdr,
+				 struct gssx_arg_accept_sec_context *args);
+int gssx_dec_accept_sec_context(struct rpc_rqst *rqstp,
+				struct xdr_stream *xdr,
+				struct gssx_res_accept_sec_context *res);
+#define gssx_enc_release_handle NULL
+#define gssx_dec_release_handle NULL
+#define gssx_enc_get_mic NULL
+#define gssx_dec_get_mic NULL
+#define gssx_enc_verify NULL
+#define gssx_dec_verify NULL
+#define gssx_enc_wrap NULL
+#define gssx_dec_wrap NULL
+#define gssx_enc_unwrap NULL
+#define gssx_dec_unwrap NULL
+#define gssx_enc_wrap_size_limit NULL
+#define gssx_dec_wrap_size_limit NULL
+
+/* non implemented calls are set to 0 size */
+#define GSSX_ARG_indicate_mechs_sz 0
+#define GSSX_RES_indicate_mechs_sz 0
+#define GSSX_ARG_get_call_context_sz 0
+#define GSSX_RES_get_call_context_sz 0
+#define GSSX_ARG_import_and_canon_name_sz 0
+#define GSSX_RES_import_and_canon_name_sz 0
+#define GSSX_ARG_export_cred_sz 0
+#define GSSX_RES_export_cred_sz 0
+#define GSSX_ARG_import_cred_sz 0
+#define GSSX_RES_import_cred_sz 0
+#define GSSX_ARG_acquire_cred_sz 0
+#define GSSX_RES_acquire_cred_sz 0
+#define GSSX_ARG_store_cred_sz 0
+#define GSSX_RES_store_cred_sz 0
+#define GSSX_ARG_init_sec_context_sz 0
+#define GSSX_RES_init_sec_context_sz 0
+
+#define GSSX_default_in_call_ctx_sz (4 + 4 + 4 + \
+			8 + sizeof(LUCID_OPTION) + sizeof(LUCID_VALUE) + \
+			8 + sizeof(CREDS_OPTION) + sizeof(CREDS_VALUE))
+#define GSSX_default_in_ctx_hndl_sz (4 + 4+8 + 4 + 4 + 6*4 + 6*4 + 8 + 8 + \
+					4 + 4 + 4)
+#define GSSX_default_in_cred_sz 4 /* we send in no cred_handle */
+#define GSSX_default_in_token_sz 4 /* does *not* include token data */
+#define GSSX_default_in_cb_sz 4 /* we do not use channel bindings */
+#define GSSX_ARG_accept_sec_context_sz (GSSX_default_in_call_ctx_sz + \
+					GSSX_default_in_ctx_hndl_sz + \
+					GSSX_default_in_cred_sz + \
+					GSSX_default_in_token_sz + \
+					GSSX_default_in_cb_sz + \
+					4 /* no deleg creds boolean */ + \
+					4) /* empty options */
+
+/* somewhat arbitrary numbers but large enough (we ignore some of the data
+ * sent down, but it is part of the protocol so we need enough space to take
+ * it in) */
+#define GSSX_default_status_sz 8 + 24 + 8 + 256 + 256 + 16 + 4
+#define GSSX_max_output_handle_sz 128
+#define GSSX_max_oid_sz 16
+#define GSSX_max_princ_sz 256
+#define GSSX_default_ctx_sz (GSSX_max_output_handle_sz + \
+			     16 + 4 + GSSX_max_oid_sz + \
+			     2 * GSSX_max_princ_sz + \
+			     8 + 8 + 4 + 4 + 4)
+#define GSSX_max_output_token_sz 1024
+#define GSSX_max_creds_sz (4 + 4 + 4 + NGROUPS_MAX * 4)
+#define GSSX_RES_accept_sec_context_sz (GSSX_default_status_sz + \
+					GSSX_default_ctx_sz + \
+					GSSX_max_output_token_sz + \
+					4 + GSSX_max_creds_sz)
+
+#define GSSX_ARG_release_handle_sz 0
+#define GSSX_RES_release_handle_sz 0
+#define GSSX_ARG_get_mic_sz 0
+#define GSSX_RES_get_mic_sz 0
+#define GSSX_ARG_verify_sz 0
+#define GSSX_RES_verify_sz 0
+#define GSSX_ARG_wrap_sz 0
+#define GSSX_RES_wrap_sz 0
+#define GSSX_ARG_unwrap_sz 0
+#define GSSX_RES_unwrap_sz 0
+#define GSSX_ARG_wrap_size_limit_sz 0
+#define GSSX_RES_wrap_size_limit_sz 0
+
+
+
+#endif /* _LINUX_GSS_RPC_XDR_H */
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 6d29b53..eb4cb72 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -683,6 +683,7 @@ rpc_release_client(struct rpc_clnt *clnt)
 	if (atomic_dec_and_test(&clnt->cl_count))
 		rpc_free_auth(clnt);
 }
+EXPORT_SYMBOL_GPL(rpc_release_client);
 
 /**
  * rpc_bind_new_program - bind a new RPC program to an existing client
diff --git a/net/sunrpc/netns.h b/net/sunrpc/netns.h
index ce7bd44..e9f8895 100644
--- a/net/sunrpc/netns.h
+++ b/net/sunrpc/netns.h
@@ -23,6 +23,9 @@ struct sunrpc_net {
 	struct rpc_clnt *rpcb_local_clnt4;
 	spinlock_t rpcb_clnt_lock;
 	unsigned int rpcb_users;
+
+	struct mutex gssp_lock;
+	struct rpc_clnt *gssp_clnt;
 };
 
 extern int sunrpc_net_id;
-- 
1.8.1.4


From f682043df7bb81715124c82e9cea8bc68ded9667 Mon Sep 17 00:00:00 2001
From: Simo Sorce <simo@redhat.com>
Date: Fri, 25 May 2012 18:09:56 -0400
Subject: [PATCH 06/16] SUNRPC: Use gssproxy upcall for server RPCGSS
 authentication.

The main advantge of this new upcall mechanism is that it can handle
big tickets as seen in Kerberos implementations where tickets carry
authorization data like the MS-PAC buffer with AD or the Posix Authorization
Data being discussed in IETF on the krbwg working group.

The Gssproxy program is used to perform the accept_sec_context call on the
kernel's behalf. The code is changed to also pass the input buffer straight
to upcall mechanism to avoid allocating and copying many pages as tokens can
be as big (potentially more in future) as 64KiB.

Signed-off-by: Simo Sorce <simo@redhat.com>
[bfields: containerization, negotiation api]
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
 Documentation/filesystems/nfs/00-INDEX           |   2 +
 Documentation/filesystems/nfs/rpc-server-gss.txt |  91 ++++++
 net/sunrpc/auth_gss/gss_rpc_upcall.c             |   2 +
 net/sunrpc/auth_gss/svcauth_gss.c                | 347 ++++++++++++++++++++++-
 net/sunrpc/netns.h                               |   3 +
 5 files changed, 436 insertions(+), 9 deletions(-)
 create mode 100644 Documentation/filesystems/nfs/rpc-server-gss.txt

diff --git a/Documentation/filesystems/nfs/00-INDEX b/Documentation/filesystems/nfs/00-INDEX
index 1716874..66eb6c8 100644
--- a/Documentation/filesystems/nfs/00-INDEX
+++ b/Documentation/filesystems/nfs/00-INDEX
@@ -20,3 +20,5 @@ rpc-cache.txt
 	- introduction to the caching mechanisms in the sunrpc layer.
 idmapper.txt
 	- information for configuring request-keys to be used by idmapper
+knfsd-rpcgss.txt
+	- Information on GSS authentication support in the NFS Server
diff --git a/Documentation/filesystems/nfs/rpc-server-gss.txt b/Documentation/filesystems/nfs/rpc-server-gss.txt
new file mode 100644
index 0000000..716f4be
--- /dev/null
+++ b/Documentation/filesystems/nfs/rpc-server-gss.txt
@@ -0,0 +1,91 @@
+
+rpcsec_gss support for kernel RPC servers
+=========================================
+
+This document gives references to the standards and protocols used to
+implement RPCGSS authentication in kernel RPC servers such as the NFS
+server and the NFS client's NFSv4.0 callback server.  (But note that
+NFSv4.1 and higher don't require the client to act as a server for the
+purposes of authentication.)
+
+RPCGSS is specified in a few IETF documents:
+ - RFC2203 v1: http://tools.ietf.org/rfc/rfc2203.txt
+ - RFC5403 v2: http://tools.ietf.org/rfc/rfc5403.txt
+and there is a 3rd version  being proposed:
+ - http://tools.ietf.org/id/draft-williams-rpcsecgssv3.txt
+   (At draft n. 02 at the time of writing)
+
+Background
+----------
+
+The RPCGSS Authentication method describes a way to perform GSSAPI
+Authentication for NFS.  Although GSSAPI is itself completely mechanism
+agnostic, in many cases only the KRB5 mechanism is supported by NFS
+implementations.
+
+The Linux kernel, at the moment, supports only the KRB5 mechanism, and
+depends on GSSAPI extensions that are KRB5 specific.
+
+GSSAPI is a complex library, and implementing it completely in kernel is
+unwarranted. However GSSAPI operations are fundementally separable in 2
+parts:
+- initial context establishment
+- integrity/privacy protection (signing and encrypting of individual
+  packets)
+
+The former is more complex and policy-independent, but less
+performance-sensitive.  The latter is simpler and needs to be very fast.
+
+Therefore, we perform per-packet integrity and privacy protection in the
+kernel, but leave the initial context establishment to userspace.  We
+need upcalls to request userspace to perform context establishment.
+
+NFS Server Legacy Upcall Mechanism
+----------------------------------
+
+The classic upcall mechanism uses a custom text based upcall mechanism
+to talk to a custom daemon called rpc.svcgssd that is provide by the
+nfs-utils package.
+
+This upcall mechanism has 2 limitations:
+
+A) It can handle tokens that are no bigger than 2KiB
+
+In some Kerberos deployment GSSAPI tokens can be quite big, up and
+beyond 64KiB in size due to various authorization extensions attacked to
+the Kerberos tickets, that needs to be sent through the GSS layer in
+order to perform context establishment.
+
+B) It does not properly handle creds where the user is member of more
+than a few housand groups (the current hard limit in the kernel is 65K
+groups) due to limitation on the size of the buffer that can be send
+back to the kernel (4KiB).
+
+NFS Server New RPC Upcall Mechanism
+-----------------------------------
+
+The newer upcall mechanism uses RPC over a unix socket to a daemon
+called gss-proxy, implemented by a userspace program called Gssproxy.
+
+The gss_proxy RPC protocol is currently documented here:
+
+	https://fedorahosted.org/gss-proxy/wiki/ProtocolDocumentation
+
+This upcall mechanism uses the kernel rpc client and connects to the gssproxy
+userspace program over a regular unix socket. The gssproxy protocol does not
+suffer from the size limitations of the legacy protocol.
+
+Negotiating Upcall Mechanisms
+-----------------------------
+
+To provide backward compatibility, the kernel defaults to using the
+legacy mechanism.  To switch to the new mechanism, gss-proxy must bind
+to /var/run/gssproxy.sock and then write "1" to
+/proc/net/rpc/use-gss-proxy.  If gss-proxy dies, it must repeat both
+steps.
+
+Once the upcall mechanism is chosen, it cannot be changed.  To prevent
+locking into the legacy mechanisms, the above steps must be performed
+before starting nfsd.  Whoever starts nfsd can guarantee this by reading
+from /proc/net/rpc/use-gss-proxy and checking that it contains a
+"1"--the read will block until gss-proxy has done its write to the file.
diff --git a/net/sunrpc/auth_gss/gss_rpc_upcall.c b/net/sunrpc/auth_gss/gss_rpc_upcall.c
index 2d33ddf..3f874d7 100644
--- a/net/sunrpc/auth_gss/gss_rpc_upcall.c
+++ b/net/sunrpc/auth_gss/gss_rpc_upcall.c
@@ -137,6 +137,7 @@ void init_gssp_clnt(struct sunrpc_net *sn)
 {
 	mutex_init(&sn->gssp_lock);
 	sn->gssp_clnt = NULL;
+	init_waitqueue_head(&sn->gssp_wq);
 }
 
 int set_gssp_clnt(struct net *net)
@@ -153,6 +154,7 @@ int set_gssp_clnt(struct net *net)
 		sn->gssp_clnt = clnt;
 	}
 	mutex_unlock(&sn->gssp_lock);
+	wake_up(&sn->gssp_wq);
 	return ret;
 }
 
diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
index 20eedec..58f5bc3 100644
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -48,8 +48,8 @@
 #include <linux/sunrpc/svcauth.h>
 #include <linux/sunrpc/svcauth_gss.h>
 #include <linux/sunrpc/cache.h>
+#include "gss_rpc_upcall.h"
 
-#include "../netns.h"
 
 #ifdef RPC_DEBUG
 # define RPCDBG_FACILITY	RPCDBG_AUTH
@@ -988,13 +988,10 @@ gss_write_init_verf(struct cache_detail *cd, struct svc_rqst *rqstp,
 }
 
 static inline int
-gss_read_verf(struct rpc_gss_wire_cred *gc,
-	      struct kvec *argv, __be32 *authp,
-	      struct xdr_netobj *in_handle,
-	      struct xdr_netobj *in_token)
+gss_read_common_verf(struct rpc_gss_wire_cred *gc,
+		     struct kvec *argv, __be32 *authp,
+		     struct xdr_netobj *in_handle)
 {
-	struct xdr_netobj tmpobj;
-
 	/* Read the verifier; should be NULL: */
 	*authp = rpc_autherr_badverf;
 	if (argv->iov_len < 2 * 4)
@@ -1010,6 +1007,23 @@ gss_read_verf(struct rpc_gss_wire_cred *gc,
 	if (dup_netobj(in_handle, &gc->gc_ctx))
 		return SVC_CLOSE;
 	*authp = rpc_autherr_badverf;
+
+	return 0;
+}
+
+static inline int
+gss_read_verf(struct rpc_gss_wire_cred *gc,
+	      struct kvec *argv, __be32 *authp,
+	      struct xdr_netobj *in_handle,
+	      struct xdr_netobj *in_token)
+{
+	struct xdr_netobj tmpobj;
+	int res;
+
+	res = gss_read_common_verf(gc, argv, authp, in_handle);
+	if (res)
+		return res;
+
 	if (svc_safe_getnetobj(argv, &tmpobj)) {
 		kfree(in_handle->data);
 		return SVC_DENIED;
@@ -1022,6 +1036,40 @@ gss_read_verf(struct rpc_gss_wire_cred *gc,
 	return 0;
 }
 
+/* Ok this is really heavily depending on a set of semantics in
+ * how rqstp is set up by svc_recv and pages laid down by the
+ * server when reading a request. We are basically guaranteed that
+ * the token lays all down linearly across a set of pages, starting
+ * at iov_base in rq_arg.head[0] which happens to be the first of a
+ * set of pages stored in rq_pages[].
+ * rq_arg.head[0].iov_base will provide us the page_base to pass
+ * to the upcall.
+ */
+static inline int
+gss_read_proxy_verf(struct svc_rqst *rqstp,
+		    struct rpc_gss_wire_cred *gc, __be32 *authp,
+		    struct xdr_netobj *in_handle,
+		    struct gssp_in_token *in_token)
+{
+	struct kvec *argv = &rqstp->rq_arg.head[0];
+	u32 inlen;
+	int res;
+
+	res = gss_read_common_verf(gc, argv, authp, in_handle);
+	if (res)
+		return res;
+
+	inlen = svc_getnl(argv);
+	if (inlen > (argv->iov_len + rqstp->rq_arg.page_len))
+		return SVC_DENIED;
+
+	in_token->pages = rqstp->rq_pages;
+	in_token->page_base = (ulong)argv->iov_base & ~PAGE_MASK;
+	in_token->page_len = inlen;
+
+	return 0;
+}
+
 static inline int
 gss_write_resv(struct kvec *resv, size_t size_limit,
 	       struct xdr_netobj *out_handle, struct xdr_netobj *out_token,
@@ -1049,7 +1097,7 @@ gss_write_resv(struct kvec *resv, size_t size_limit,
  * the upcall results are available, write the verifier and result.
  * Otherwise, drop the request pending an answer to the upcall.
  */
-static int svcauth_gss_handle_init(struct svc_rqst *rqstp,
+static int svcauth_gss_legacy_init(struct svc_rqst *rqstp,
 			struct rpc_gss_wire_cred *gc, __be32 *authp)
 {
 	struct kvec *argv = &rqstp->rq_arg.head[0];
@@ -1089,6 +1137,278 @@ out:
 	return ret;
 }
 
+static int gss_proxy_save_rsc(struct cache_detail *cd,
+				struct gssp_upcall_data *ud,
+				uint64_t *handle)
+{
+	struct rsc rsci, *rscp = NULL;
+	static atomic64_t ctxhctr;
+	long long ctxh;
+	struct gss_api_mech *gm = NULL;
+	time_t expiry;
+	int status = -EINVAL;
+
+	memset(&rsci, 0, sizeof(rsci));
+	/* context handle */
+	status = -ENOMEM;
+	/* the handle needs to be just a unique id,
+	 * use a static counter */
+	ctxh = atomic64_inc_return(&ctxhctr);
+
+	/* make a copy for the caller */
+	*handle = ctxh;
+
+	/* make a copy for the rsc cache */
+	if (dup_to_netobj(&rsci.handle, (char *)handle, sizeof(uint64_t)))
+		goto out;
+	rscp = rsc_lookup(cd, &rsci);
+	if (!rscp)
+		goto out;
+
+	/* creds */
+	if (!ud->found_creds) {
+		/* userspace seem buggy, we should always get at least a
+		 * mapping to nobody */
+		dprintk("RPC:       No creds found, marking Negative!\n");
+		set_bit(CACHE_NEGATIVE, &rsci.h.flags);
+	} else {
+
+		/* steal creds */
+		rsci.cred = ud->creds;
+		memset(&ud->creds, 0, sizeof(struct svc_cred));
+
+		status = -EOPNOTSUPP;
+		/* get mech handle from OID */
+		gm = gss_mech_get_by_OID(&ud->mech_oid);
+		if (!gm)
+			goto out;
+
+		status = -EINVAL;
+		/* mech-specific data: */
+		status = gss_import_sec_context(ud->out_handle.data,
+						ud->out_handle.len,
+						gm, &rsci.mechctx,
+						&expiry, GFP_KERNEL);
+		if (status)
+			goto out;
+	}
+
+	rsci.h.expiry_time = expiry;
+	rscp = rsc_update(cd, &rsci, rscp);
+	status = 0;
+out:
+	gss_mech_put(gm);
+	rsc_free(&rsci);
+	if (rscp)
+		cache_put(&rscp->h, cd);
+	else
+		status = -ENOMEM;
+	return status;
+}
+
+static int svcauth_gss_proxy_init(struct svc_rqst *rqstp,
+			struct rpc_gss_wire_cred *gc, __be32 *authp)
+{
+	struct kvec *resv = &rqstp->rq_res.head[0];
+	struct xdr_netobj cli_handle;
+	struct gssp_upcall_data ud;
+	uint64_t handle;
+	int status;
+	int ret;
+	struct net *net = rqstp->rq_xprt->xpt_net;
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+
+	memset(&ud, 0, sizeof(ud));
+	ret = gss_read_proxy_verf(rqstp, gc, authp,
+				  &ud.in_handle, &ud.in_token);
+	if (ret)
+		return ret;
+
+	ret = SVC_CLOSE;
+
+	/* Perform synchronous upcall to gss-proxy */
+	status = gssp_accept_sec_context_upcall(net, &ud);
+	if (status)
+		goto out;
+
+	dprintk("RPC:       svcauth_gss: gss major status = %d\n",
+			ud.major_status);
+
+	switch (ud.major_status) {
+	case GSS_S_CONTINUE_NEEDED:
+		cli_handle = ud.out_handle;
+		break;
+	case GSS_S_COMPLETE:
+		status = gss_proxy_save_rsc(sn->rsc_cache, &ud, &handle);
+		if (status)
+			goto out;
+		cli_handle.data = (u8 *)&handle;
+		cli_handle.len = sizeof(handle);
+		break;
+	default:
+		ret = SVC_CLOSE;
+		goto out;
+	}
+
+	/* Got an answer to the upcall; use it: */
+	if (gss_write_init_verf(sn->rsc_cache, rqstp,
+				&cli_handle, &ud.major_status))
+		goto out;
+	if (gss_write_resv(resv, PAGE_SIZE,
+			   &cli_handle, &ud.out_token,
+			   ud.major_status, ud.minor_status))
+		goto out;
+
+	ret = SVC_COMPLETE;
+out:
+	gssp_free_upcall_data(&ud);
+	return ret;
+}
+
+DEFINE_SPINLOCK(use_gssp_lock);
+
+static bool use_gss_proxy(struct net *net)
+{
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+
+	if (sn->use_gss_proxy != -1)
+		return sn->use_gss_proxy;
+	spin_lock(&use_gssp_lock);
+	/*
+	 * If you wanted gss-proxy, you should have said so before
+	 * starting to accept requests:
+	 */
+	sn->use_gss_proxy = 0;
+	spin_unlock(&use_gssp_lock);
+	return 0;
+}
+
+static bool set_gss_proxy(struct net *net, int type)
+{
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+	int ret = 0;
+
+	WARN_ON_ONCE(type != 0 && type != 1);
+	spin_lock(&use_gssp_lock);
+	if (sn->use_gss_proxy == -1 || sn->use_gss_proxy == type)
+		sn->use_gss_proxy = type;
+	else
+		ret = -EBUSY;
+	spin_unlock(&use_gssp_lock);
+	wake_up(&sn->gssp_wq);
+	return ret;
+}
+
+static inline bool gssp_ready(struct sunrpc_net *sn)
+{
+	switch (sn->use_gss_proxy) {
+		case -1:
+			return false;
+		case 0:
+			return true;
+		case 1:
+			return sn->gssp_clnt;
+	}
+	WARN_ON_ONCE(1);
+	return false;
+}
+
+static int wait_for_gss_proxy(struct net *net)
+{
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+
+	return wait_event_interruptible(sn->gssp_wq, gssp_ready(sn));
+}
+
+#ifdef CONFIG_PROC_FS
+
+static ssize_t write_gssp(struct file *file, const char __user *buf,
+			 size_t count, loff_t *ppos)
+{
+	struct net *net = PDE(file->f_path.dentry->d_inode)->data;
+	char tbuf[20];
+	unsigned long i;
+	int res;
+
+	if (*ppos || count > sizeof(tbuf)-1)
+		return -EINVAL;
+	if (copy_from_user(tbuf, buf, count))
+		return -EFAULT;
+
+	tbuf[count] = 0;
+	res = kstrtoul(tbuf, 0, &i);
+	if (res)
+		return res;
+	if (i != 1)
+		return -EINVAL;
+	res = set_gss_proxy(net, 1);
+	if (res)
+		return res;
+	res = set_gssp_clnt(net);
+	if (res)
+		return res;
+	return count;
+}
+
+static ssize_t read_gssp(struct file *file, char __user *buf,
+			 size_t count, loff_t *ppos)
+{
+	struct net *net = PDE(file->f_path.dentry->d_inode)->data;
+	unsigned long p = *ppos;
+	char tbuf[10];
+	size_t len;
+	int ret;
+
+	ret = wait_for_gss_proxy(net);
+	if (ret)
+		return ret;
+
+	snprintf(tbuf, sizeof(tbuf), "%d\n", use_gss_proxy(net));
+	len = strlen(tbuf);
+	if (p >= len)
+		return 0;
+	len -= p;
+	if (len > count)
+		len = count;
+	if (copy_to_user(buf, (void *)(tbuf+p), len))
+		return -EFAULT;
+	*ppos += len;
+	return len;
+}
+
+static const struct file_operations use_gss_proxy_ops = {
+	.open = nonseekable_open,
+	.write = write_gssp,
+	.read = read_gssp,
+};
+
+static int create_use_gss_proxy_proc_entry(struct net *net)
+{
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+	struct proc_dir_entry **p = &sn->use_gssp_proc;
+
+	sn->use_gss_proxy = -1;
+	*p = proc_create_data("use-gss-proxy", S_IFREG|S_IRUSR|S_IWUSR,
+			      sn->proc_net_rpc,
+			      &use_gss_proxy_ops, net);
+	if (!*p)
+		return -ENOMEM;
+	init_gssp_clnt(sn);
+	return 0;
+}
+
+static void destroy_use_gss_proxy_proc_entry(struct net *net)
+{
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+
+	if (sn->use_gssp_proc) {
+		remove_proc_entry("use-gss-proxy", sn->proc_net_rpc); 
+		clear_gssp_clnt(sn);
+	}
+}
+
+#endif /* CONFIG_PROC_FS */
+
 /*
  * Accept an rpcsec packet.
  * If context establishment, punt to user space
@@ -1155,7 +1475,10 @@ svcauth_gss_accept(struct svc_rqst *rqstp, __be32 *authp)
 	switch (gc->gc_proc) {
 	case RPC_GSS_PROC_INIT:
 	case RPC_GSS_PROC_CONTINUE_INIT:
-		return svcauth_gss_handle_init(rqstp, gc, authp);
+		if (use_gss_proxy(SVC_NET(rqstp)))
+			return svcauth_gss_proxy_init(rqstp, gc, authp);
+		else
+			return svcauth_gss_legacy_init(rqstp, gc, authp);
 	case RPC_GSS_PROC_DATA:
 	case RPC_GSS_PROC_DESTROY:
 		/* Look up the context, and check the verifier: */
@@ -1530,7 +1853,12 @@ gss_svc_init_net(struct net *net)
 	rv = rsi_cache_create_net(net);
 	if (rv)
 		goto out1;
+	rv = create_use_gss_proxy_proc_entry(net);
+	if (rv)
+		goto out2;
 	return 0;
+out2:
+	destroy_use_gss_proxy_proc_entry(net);
 out1:
 	rsc_cache_destroy_net(net);
 	return rv;
@@ -1539,6 +1867,7 @@ out1:
 void
 gss_svc_shutdown_net(struct net *net)
 {
+	destroy_use_gss_proxy_proc_entry(net);
 	rsi_cache_destroy_net(net);
 	rsc_cache_destroy_net(net);
 }
diff --git a/net/sunrpc/netns.h b/net/sunrpc/netns.h
index e9f8895..7111a4c 100644
--- a/net/sunrpc/netns.h
+++ b/net/sunrpc/netns.h
@@ -25,7 +25,10 @@ struct sunrpc_net {
 	unsigned int rpcb_users;
 
 	struct mutex gssp_lock;
+	wait_queue_head_t gssp_wq;
 	struct rpc_clnt *gssp_clnt;
+	int use_gss_proxy;
+	struct proc_dir_entry *use_gssp_proc;
 };
 
 extern int sunrpc_net_id;
-- 
1.8.1.4


From 06404241b88b51c50427b833268d7cad7dec30f5 Mon Sep 17 00:00:00 2001
From: "J. Bruce Fields" <bfields@redhat.com>
Date: Mon, 29 Apr 2013 17:03:31 -0400
Subject: [PATCH 07/16] SUNRPC: define
 {create,destroy}_use_gss_proxy_proc_entry in !PROC case

Though I wonder whether we should really just depend on CONFIG_PROC_FS
at some point.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
---
 net/sunrpc/auth_gss/svcauth_gss.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
index 58f5bc3..71446b6 100644
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -1283,6 +1283,8 @@ static bool use_gss_proxy(struct net *net)
 	return 0;
 }
 
+#ifdef CONFIG_PROC_FS
+
 static bool set_gss_proxy(struct net *net, int type)
 {
 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
@@ -1320,7 +1322,6 @@ static int wait_for_gss_proxy(struct net *net)
 	return wait_event_interruptible(sn->gssp_wq, gssp_ready(sn));
 }
 
-#ifdef CONFIG_PROC_FS
 
 static ssize_t write_gssp(struct file *file, const char __user *buf,
 			 size_t count, loff_t *ppos)
@@ -1406,6 +1407,14 @@ static void destroy_use_gss_proxy_proc_entry(struct net *net)
 		clear_gssp_clnt(sn);
 	}
 }
+#else /* CONFIG_PROC_FS */
+
+static int create_use_gss_proxy_proc_entry(struct net *net)
+{
+	return 0;
+}
+
+static void destroy_use_gss_proxy_proc_entry(struct net *net) {}
 
 #endif /* CONFIG_PROC_FS */
 
-- 
1.8.1.4


From 3cc961ce9784f0b4a9cb21217dd4a8403efc220d Mon Sep 17 00:00:00 2001
From: Fengguang Wu <fengguang.wu@intel.com>
Date: Mon, 29 Apr 2013 17:19:48 -0400
Subject: [PATCH 08/16] SUNRPC: gssp_procedures[] can be static

Cc: Simo Sorce <simo@redhat.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
---
 net/sunrpc/auth_gss/gss_rpc_upcall.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/sunrpc/auth_gss/gss_rpc_upcall.c b/net/sunrpc/auth_gss/gss_rpc_upcall.c
index 3f874d7..98818d6 100644
--- a/net/sunrpc/auth_gss/gss_rpc_upcall.c
+++ b/net/sunrpc/auth_gss/gss_rpc_upcall.c
@@ -63,7 +63,7 @@ enum {
 	.p_name   = #proc,				\
 }
 
-struct rpc_procinfo gssp_procedures[] = {
+static struct rpc_procinfo gssp_procedures[] = {
 	PROC(INDICATE_MECHS, indicate_mechs),
         PROC(GET_CALL_CONTEXT, get_call_context),
         PROC(IMPORT_AND_CANON_NAME, import_and_canon_name),
-- 
1.8.1.4


From d6afcafd515bbf16e39817170cd212a7debd8959 Mon Sep 17 00:00:00 2001
From: "J. Bruce Fields" <bfields@redhat.com>
Date: Mon, 29 Apr 2013 18:21:29 -0400
Subject: [PATCH 09/16] svcrpc: fix gss-proxy to respect user namespaces

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
 net/sunrpc/auth_gss/gss_rpc_xdr.c | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/net/sunrpc/auth_gss/gss_rpc_xdr.c b/net/sunrpc/auth_gss/gss_rpc_xdr.c
index d0ccdff..5c4c61d 100644
--- a/net/sunrpc/auth_gss/gss_rpc_xdr.c
+++ b/net/sunrpc/auth_gss/gss_rpc_xdr.c
@@ -216,13 +216,13 @@ static int gssx_dec_linux_creds(struct xdr_stream *xdr,
 	err = get_s32(&q, end, &tmp);
 	if (err)
 		return err;
-	creds->cr_uid = tmp;
+	creds->cr_uid = make_kuid(&init_user_ns, tmp);
 
 	/* gid */
 	err = get_s32(&q, end, &tmp);
 	if (err)
 		return err;
-	creds->cr_gid = tmp;
+	creds->cr_gid = make_kgid(&init_user_ns, tmp);
 
 	/* number of additional gid's */
 	err = get_s32(&q, end, &tmp);
@@ -235,15 +235,21 @@ static int gssx_dec_linux_creds(struct xdr_stream *xdr,
 
 	/* gid's */
 	for (i = 0; i < N; i++) {
+		kgid_t kgid;
 		err = get_s32(&q, end, &tmp);
-		if (err) {
-			groups_free(creds->cr_group_info);
-			return err;
-		}
-		GROUP_AT(creds->cr_group_info, i) = tmp;
+		if (err)
+			goto out_free_groups;
+		err = -EINVAL;
+		kgid = make_kgid(&init_user_ns, tmp);
+		if (!gid_valid(kgid))
+			goto out_free_groups;
+		GROUP_AT(creds->cr_group_info, i) = kgid;
 	}
 
 	return 0;
+out_free_groups:
+	groups_free(creds->cr_group_info);
+	return err;
 }
 
 static int gssx_dec_option_array(struct xdr_stream *xdr,
-- 
1.8.1.4


From e4f7a037aa575bdbe6d1e42e58283cb4d663b000 Mon Sep 17 00:00:00 2001
From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: Mon, 6 May 2013 09:21:03 +0200
Subject: [PATCH 10/16] SUNRPC: Refactor gssx_dec_option_array() to kill
 uninitialized warning
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

net/sunrpc/auth_gss/gss_rpc_xdr.c: In function ‘gssx_dec_option_array’:
net/sunrpc/auth_gss/gss_rpc_xdr.c:258: warning: ‘creds’ may be used uninitialized in this function

Return early if count is zero, to make it clearer to the compiler (and the
casual reviewer) that no more processing is done.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
 net/sunrpc/auth_gss/gss_rpc_xdr.c | 32 +++++++++++++++++---------------
 1 file changed, 17 insertions(+), 15 deletions(-)

diff --git a/net/sunrpc/auth_gss/gss_rpc_xdr.c b/net/sunrpc/auth_gss/gss_rpc_xdr.c
index 5c4c61d..a1e1b1a 100644
--- a/net/sunrpc/auth_gss/gss_rpc_xdr.c
+++ b/net/sunrpc/auth_gss/gss_rpc_xdr.c
@@ -264,25 +264,27 @@ static int gssx_dec_option_array(struct xdr_stream *xdr,
 	if (unlikely(p == NULL))
 		return -ENOSPC;
 	count = be32_to_cpup(p++);
-	if (count != 0) {
-		/* we recognize only 1 currently: CREDS_VALUE */
-		oa->count = 1;
+	if (!count)
+		return 0;
 
-		oa->data = kmalloc(sizeof(struct gssx_option), GFP_KERNEL);
-		if (!oa->data)
-			return -ENOMEM;
+	/* we recognize only 1 currently: CREDS_VALUE */
+	oa->count = 1;
 
-		creds = kmalloc(sizeof(struct svc_cred), GFP_KERNEL);
-		if (!creds) {
-			kfree(oa->data);
-			return -ENOMEM;
-		}
+	oa->data = kmalloc(sizeof(struct gssx_option), GFP_KERNEL);
+	if (!oa->data)
+		return -ENOMEM;
 
-		oa->data[0].option.data = CREDS_VALUE;
-		oa->data[0].option.len = sizeof(CREDS_VALUE);
-		oa->data[0].value.data = (void *)creds;
-		oa->data[0].value.len = 0;
+	creds = kmalloc(sizeof(struct svc_cred), GFP_KERNEL);
+	if (!creds) {
+		kfree(oa->data);
+		return -ENOMEM;
 	}
+
+	oa->data[0].option.data = CREDS_VALUE;
+	oa->data[0].option.len = sizeof(CREDS_VALUE);
+	oa->data[0].value.data = (void *)creds;
+	oa->data[0].value.len = 0;
+
 	for (i = 0; i < count; i++) {
 		gssx_buffer dummy = { 0, NULL };
 		u32 length;
-- 
1.8.1.4


From f174f54afb853cd818e2121a0b5dc66012a4a3eb Mon Sep 17 00:00:00 2001
From: "J. Bruce Fields" <bfields@redhat.com>
Date: Tue, 7 May 2013 17:45:20 -0400
Subject: [PATCH 11/16] SUNRPC: fix decoding of optional gss-proxy xdr fields

The current code works, but sort of by accident: it obviously didn't
intend the error return to be interpreted as "true".

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
 net/sunrpc/auth_gss/gss_rpc_xdr.c | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/net/sunrpc/auth_gss/gss_rpc_xdr.c b/net/sunrpc/auth_gss/gss_rpc_xdr.c
index a1e1b1a..357f613 100644
--- a/net/sunrpc/auth_gss/gss_rpc_xdr.c
+++ b/net/sunrpc/auth_gss/gss_rpc_xdr.c
@@ -21,16 +21,6 @@
 #include <linux/sunrpc/svcauth.h>
 #include "gss_rpc_xdr.h"
 
-static bool gssx_check_pointer(struct xdr_stream *xdr)
-{
-	__be32 *p;
-
-	p = xdr_reserve_space(xdr, 4);
-	if (unlikely(p == NULL))
-		return -ENOSPC;
-	return *p?true:false;
-}
-
 static int gssx_enc_bool(struct xdr_stream *xdr, int v)
 {
 	__be32 *p;
@@ -802,6 +792,7 @@ int gssx_dec_accept_sec_context(struct rpc_rqst *rqstp,
 				struct xdr_stream *xdr,
 				struct gssx_res_accept_sec_context *res)
 {
+	u32 value_follows;
 	int err;
 
 	/* res->status */
@@ -810,7 +801,10 @@ int gssx_dec_accept_sec_context(struct rpc_rqst *rqstp,
 		return err;
 
 	/* res->context_handle */
-	if (gssx_check_pointer(xdr)) {
+	err = gssx_dec_bool(xdr, &value_follows);
+	if (err)
+		return err;
+	if (value_follows) {
 		err = gssx_dec_ctx(xdr, res->context_handle);
 		if (err)
 			return err;
@@ -819,7 +813,10 @@ int gssx_dec_accept_sec_context(struct rpc_rqst *rqstp,
 	}
 
 	/* res->output_token */
-	if (gssx_check_pointer(xdr)) {
+	err = gssx_dec_bool(xdr, &value_follows);
+	if (err)
+		return err;
+	if (value_follows) {
 		err = gssx_dec_buffer(xdr, res->output_token);
 		if (err)
 			return err;
@@ -828,7 +825,10 @@ int gssx_dec_accept_sec_context(struct rpc_rqst *rqstp,
 	}
 
 	/* res->delegated_cred_handle */
-	if (gssx_check_pointer(xdr)) {
+	err = gssx_dec_bool(xdr, &value_follows);
+	if (err)
+		return err;
+	if (value_follows) {
 		/* we do not support upcall servers sending this data. */
 		return -EINVAL;
 	}
-- 
1.8.1.4


From 653ba539c4d845b004c7d29416c9083cb74f8270 Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Sat, 11 May 2013 19:13:49 +0300
Subject: [PATCH 12/16] svcauth_gss: fix error code in use_gss_proxy()

This should return zero on success and -EBUSY on error so the type
needs to be int instead of bool.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
 net/sunrpc/auth_gss/svcauth_gss.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
index 71446b6..141902e 100644
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -1285,7 +1285,7 @@ static bool use_gss_proxy(struct net *net)
 
 #ifdef CONFIG_PROC_FS
 
-static bool set_gss_proxy(struct net *net, int type)
+static int set_gss_proxy(struct net *net, int type)
 {
 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 	int ret = 0;
-- 
1.8.1.4


From 66a26c8c42ebbdfb7dbf297b3d7f404f0dc86ed8 Mon Sep 17 00:00:00 2001
From: "J. Bruce Fields" <bfields@redhat.com>
Date: Fri, 24 May 2013 09:47:49 -0400
Subject: [PATCH 13/16] svcrpc: implement O_NONBLOCK behavior for use-gss-proxy

Somebody noticed LTP was complaining about O_NONBLOCK opens of
/proc/net/rpc/use-gss-proxy succeeding and then a following read
hanging.

I'm not convinced LTP really has any business opening random proc files
and expecting them to behave a certain way.  Maybe this isn't really a
bug.

But in any case the O_NONBLOCK behavior could be useful for someone that
wants to test whether gss-proxy is up without waiting.

Reported-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
 net/sunrpc/auth_gss/svcauth_gss.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
index 141902e..a7d4dfa 100644
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -1315,10 +1315,12 @@ static inline bool gssp_ready(struct sunrpc_net *sn)
 	return false;
 }
 
-static int wait_for_gss_proxy(struct net *net)
+static int wait_for_gss_proxy(struct net *net, struct file *file)
 {
 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 
+	if (file->f_flags & O_NONBLOCK && !gssp_ready(sn))
+		return -EAGAIN;
 	return wait_event_interruptible(sn->gssp_wq, gssp_ready(sn));
 }
 
@@ -1360,7 +1362,7 @@ static ssize_t read_gssp(struct file *file, char __user *buf,
 	size_t len;
 	int ret;
 
-	ret = wait_for_gss_proxy(net);
+	ret = wait_for_gss_proxy(net, file);
 	if (ret)
 		return ret;
 
-- 
1.8.1.4


From 30e8ac5e689fb6de9d27eeeca080fa46ed59c856 Mon Sep 17 00:00:00 2001
From: "J. Bruce Fields" <bfields@redhat.com>
Date: Mon, 10 Jun 2013 16:06:44 -0400
Subject: [PATCH 14/16] svcrpc: fix gss_rpc_upcall create error

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
 net/sunrpc/auth_gss/gss_rpc_upcall.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/sunrpc/auth_gss/gss_rpc_upcall.c b/net/sunrpc/auth_gss/gss_rpc_upcall.c
index 98818d6..aed11b7 100644
--- a/net/sunrpc/auth_gss/gss_rpc_upcall.c
+++ b/net/sunrpc/auth_gss/gss_rpc_upcall.c
@@ -120,7 +120,7 @@ static int gssp_rpc_create(struct net *net, struct rpc_clnt **_clnt)
 	if (IS_ERR(clnt)) {
 		dprintk("RPC:       failed to create AF_LOCAL gssproxy "
 				"client (errno %ld).\n", PTR_ERR(clnt));
-		result = -PTR_ERR(clnt);
+		result = PTR_ERR(clnt);
 		*_clnt = NULL;
 		goto out;
 	}
-- 
1.8.1.4


From aca1b52cdbef080ed3963810d2f41baeb746b8b2 Mon Sep 17 00:00:00 2001
From: "J. Bruce Fields" <bfields@redhat.com>
Date: Fri, 7 Jun 2013 10:11:19 -0400
Subject: [PATCH 15/16] svcrpc: fix gss-proxy xdr decoding oops

Uninitialized stack data was being used as the destination for memcpy's.

Longer term we'll just delete some of this code; all we're doing is
skipping over xdr that we don't care about.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
 net/sunrpc/auth_gss/gss_rpc_xdr.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/net/sunrpc/auth_gss/gss_rpc_xdr.c b/net/sunrpc/auth_gss/gss_rpc_xdr.c
index 357f613..3c85d1c 100644
--- a/net/sunrpc/auth_gss/gss_rpc_xdr.c
+++ b/net/sunrpc/auth_gss/gss_rpc_xdr.c
@@ -430,7 +430,7 @@ static int dummy_enc_nameattr_array(struct xdr_stream *xdr,
 static int dummy_dec_nameattr_array(struct xdr_stream *xdr,
 				    struct gssx_name_attr_array *naa)
 {
-	struct gssx_name_attr dummy;
+	struct gssx_name_attr dummy = { .attr = {.len = 0} };
 	u32 count, i;
 	__be32 *p;
 
@@ -493,12 +493,13 @@ static int gssx_enc_name(struct xdr_stream *xdr,
 	return err;
 }
 
+
 static int gssx_dec_name(struct xdr_stream *xdr,
 			 struct gssx_name *name)
 {
-	struct xdr_netobj dummy_netobj;
-	struct gssx_name_attr_array dummy_name_attr_array;
-	struct gssx_option_array dummy_option_array;
+	struct xdr_netobj dummy_netobj = { .len = 0 };
+	struct gssx_name_attr_array dummy_name_attr_array = { .count = 0 };
+	struct gssx_option_array dummy_option_array = { .count = 0 };
 	int err;
 
 	/* name->display_name */
-- 
1.8.1.4


From 127f9cd74d532b5189b767e803eaaf6d0c5015bf Mon Sep 17 00:00:00 2001
From: Chuck Lever <chuck.lever@oracle.com>
Date: Sat, 16 Mar 2013 15:54:52 -0400
Subject: [PATCH 16/16] SUNRPC: Load GSS kernel module by OID

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>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.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(+)

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 3bc4a23..69be03f 100644
--- a/net/sunrpc/auth_gss/gss_krb5_mech.c
+++ b/net/sunrpc/auth_gss/gss_krb5_mech.c
@@ -753,6 +753,7 @@ 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 43fd5bb..f921647 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>
@@ -175,6 +176,12 @@ struct gss_api_mech *
 gss_mech_get_by_OID(struct xdr_netobj *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) {
-- 
1.8.1.4