auth_gss.c 40.8 KB
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/*
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 * linux/net/sunrpc/auth_gss/auth_gss.c
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 *
 * RPCSEC_GSS client authentication.
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 *
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 *  Copyright (c) 2000 The Regents of the University of Michigan.
 *  All rights reserved.
 *
 *  Dug Song       <dugsong@monkey.org>
 *  Andy Adamson   <andros@umich.edu>
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *
 *  1. Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *  3. Neither the name of the University nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */


#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/sched.h>
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#include <linux/pagemap.h>
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#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/auth.h>
#include <linux/sunrpc/auth_gss.h>
#include <linux/sunrpc/svcauth_gss.h>
#include <linux/sunrpc/gss_err.h>
#include <linux/workqueue.h>
#include <linux/sunrpc/rpc_pipe_fs.h>
#include <linux/sunrpc/gss_api.h>
#include <asm/uaccess.h>

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static const struct rpc_authops authgss_ops;
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static const struct rpc_credops gss_credops;
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static const struct rpc_credops gss_nullops;
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#ifdef RPC_DEBUG
# define RPCDBG_FACILITY	RPCDBG_AUTH
#endif

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#define GSS_CRED_SLACK		(RPC_MAX_AUTH_SIZE * 2)
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/* length of a krb5 verifier (48), plus data added before arguments when
 * using integrity (two 4-byte integers): */
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#define GSS_VERF_SLACK		100
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struct gss_auth {
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	struct kref kref;
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	struct rpc_auth rpc_auth;
	struct gss_api_mech *mech;
	enum rpc_gss_svc service;
	struct rpc_clnt *client;
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	/*
	 * There are two upcall pipes; dentry[1], named "gssd", is used
	 * for the new text-based upcall; dentry[0] is named after the
	 * mechanism (for example, "krb5") and exists for
	 * backwards-compatibility with older gssd's.
	 */
	struct dentry *dentry[2];
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};

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/* pipe_version >= 0 if and only if someone has a pipe open. */
static int pipe_version = -1;
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static atomic_t pipe_users = ATOMIC_INIT(0);
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static DEFINE_SPINLOCK(pipe_version_lock);
static struct rpc_wait_queue pipe_version_rpc_waitqueue;
static DECLARE_WAIT_QUEUE_HEAD(pipe_version_waitqueue);
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static void gss_free_ctx(struct gss_cl_ctx *);
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static const struct rpc_pipe_ops gss_upcall_ops_v0;
static const struct rpc_pipe_ops gss_upcall_ops_v1;
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static inline struct gss_cl_ctx *
gss_get_ctx(struct gss_cl_ctx *ctx)
{
	atomic_inc(&ctx->count);
	return ctx;
}

static inline void
gss_put_ctx(struct gss_cl_ctx *ctx)
{
	if (atomic_dec_and_test(&ctx->count))
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		gss_free_ctx(ctx);
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}

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/* gss_cred_set_ctx:
 * called by gss_upcall_callback and gss_create_upcall in order
 * to set the gss context. The actual exchange of an old context
 * and a new one is protected by the inode->i_lock.
 */
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static void
gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
{
	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
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	if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
		return;
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	gss_get_ctx(ctx);
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	rcu_assign_pointer(gss_cred->gc_ctx, ctx);
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	set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
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	smp_mb__before_clear_bit();
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	clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);
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}

static const void *
simple_get_bytes(const void *p, const void *end, void *res, size_t len)
{
	const void *q = (const void *)((const char *)p + len);
	if (unlikely(q > end || q < p))
		return ERR_PTR(-EFAULT);
	memcpy(res, p, len);
	return q;
}

static inline const void *
simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest)
{
	const void *q;
	unsigned int len;

	p = simple_get_bytes(p, end, &len, sizeof(len));
	if (IS_ERR(p))
		return p;
	q = (const void *)((const char *)p + len);
	if (unlikely(q > end || q < p))
		return ERR_PTR(-EFAULT);
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	dest->data = kmemdup(p, len, GFP_NOFS);
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	if (unlikely(dest->data == NULL))
		return ERR_PTR(-ENOMEM);
	dest->len = len;
	return q;
}

static struct gss_cl_ctx *
gss_cred_get_ctx(struct rpc_cred *cred)
{
	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
	struct gss_cl_ctx *ctx = NULL;

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	rcu_read_lock();
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	if (gss_cred->gc_ctx)
		ctx = gss_get_ctx(gss_cred->gc_ctx);
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	rcu_read_unlock();
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	return ctx;
}

static struct gss_cl_ctx *
gss_alloc_context(void)
{
	struct gss_cl_ctx *ctx;

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	ctx = kzalloc(sizeof(*ctx), GFP_NOFS);
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	if (ctx != NULL) {
		ctx->gc_proc = RPC_GSS_PROC_DATA;
		ctx->gc_seq = 1;	/* NetApp 6.4R1 doesn't accept seq. no. 0 */
		spin_lock_init(&ctx->gc_seq_lock);
		atomic_set(&ctx->count,1);
	}
	return ctx;
}

#define GSSD_MIN_TIMEOUT (60 * 60)
static const void *
gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
{
	const void *q;
	unsigned int seclen;
	unsigned int timeout;
	u32 window_size;
	int ret;

	/* First unsigned int gives the lifetime (in seconds) of the cred */
	p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
	if (IS_ERR(p))
		goto err;
	if (timeout == 0)
		timeout = GSSD_MIN_TIMEOUT;
	ctx->gc_expiry = jiffies + (unsigned long)timeout * HZ * 3 / 4;
	/* Sequence number window. Determines the maximum number of simultaneous requests */
	p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
	if (IS_ERR(p))
		goto err;
	ctx->gc_win = window_size;
	/* gssd signals an error by passing ctx->gc_win = 0: */
	if (ctx->gc_win == 0) {
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		/*
		 * in which case, p points to an error code. Anything other
		 * than -EKEYEXPIRED gets converted to -EACCES.
		 */
		p = simple_get_bytes(p, end, &ret, sizeof(ret));
		if (!IS_ERR(p))
			p = (ret == -EKEYEXPIRED) ? ERR_PTR(-EKEYEXPIRED) :
						    ERR_PTR(-EACCES);
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		goto err;
	}
	/* copy the opaque wire context */
	p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
	if (IS_ERR(p))
		goto err;
	/* import the opaque security context */
	p  = simple_get_bytes(p, end, &seclen, sizeof(seclen));
	if (IS_ERR(p))
		goto err;
	q = (const void *)((const char *)p + seclen);
	if (unlikely(q > end || q < p)) {
		p = ERR_PTR(-EFAULT);
		goto err;
	}
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	ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx, GFP_NOFS);
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	if (ret < 0) {
		p = ERR_PTR(ret);
		goto err;
	}
	return q;
err:
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	dprintk("RPC:       gss_fill_context returning %ld\n", -PTR_ERR(p));
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	return p;
}

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#define UPCALL_BUF_LEN 128
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struct gss_upcall_msg {
	atomic_t count;
	uid_t	uid;
	struct rpc_pipe_msg msg;
	struct list_head list;
	struct gss_auth *auth;
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	struct rpc_inode *inode;
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	struct rpc_wait_queue rpc_waitqueue;
	wait_queue_head_t waitqueue;
	struct gss_cl_ctx *ctx;
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	char databuf[UPCALL_BUF_LEN];
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};

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static int get_pipe_version(void)
{
	int ret;

	spin_lock(&pipe_version_lock);
	if (pipe_version >= 0) {
		atomic_inc(&pipe_users);
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		ret = pipe_version;
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	} else
		ret = -EAGAIN;
	spin_unlock(&pipe_version_lock);
	return ret;
}

static void put_pipe_version(void)
{
	if (atomic_dec_and_lock(&pipe_users, &pipe_version_lock)) {
		pipe_version = -1;
		spin_unlock(&pipe_version_lock);
	}
}

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static void
gss_release_msg(struct gss_upcall_msg *gss_msg)
{
	if (!atomic_dec_and_test(&gss_msg->count))
		return;
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	put_pipe_version();
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	BUG_ON(!list_empty(&gss_msg->list));
	if (gss_msg->ctx != NULL)
		gss_put_ctx(gss_msg->ctx);
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	rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
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	kfree(gss_msg);
}

static struct gss_upcall_msg *
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__gss_find_upcall(struct rpc_inode *rpci, uid_t uid)
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{
	struct gss_upcall_msg *pos;
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	list_for_each_entry(pos, &rpci->in_downcall, list) {
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		if (pos->uid != uid)
			continue;
		atomic_inc(&pos->count);
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		dprintk("RPC:       gss_find_upcall found msg %p\n", pos);
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		return pos;
	}
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	dprintk("RPC:       gss_find_upcall found nothing\n");
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	return NULL;
}

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/* Try to add an upcall to the pipefs queue.
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 * If an upcall owned by our uid already exists, then we return a reference
 * to that upcall instead of adding the new upcall.
 */
static inline struct gss_upcall_msg *
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gss_add_msg(struct gss_upcall_msg *gss_msg)
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{
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	struct rpc_inode *rpci = gss_msg->inode;
	struct inode *inode = &rpci->vfs_inode;
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	struct gss_upcall_msg *old;

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	spin_lock(&inode->i_lock);
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	old = __gss_find_upcall(rpci, gss_msg->uid);
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	if (old == NULL) {
		atomic_inc(&gss_msg->count);
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		list_add(&gss_msg->list, &rpci->in_downcall);
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	} else
		gss_msg = old;
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	spin_unlock(&inode->i_lock);
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	return gss_msg;
}

static void
__gss_unhash_msg(struct gss_upcall_msg *gss_msg)
{
	list_del_init(&gss_msg->list);
	rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
	wake_up_all(&gss_msg->waitqueue);
	atomic_dec(&gss_msg->count);
}

static void
gss_unhash_msg(struct gss_upcall_msg *gss_msg)
{
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	struct inode *inode = &gss_msg->inode->vfs_inode;
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	if (list_empty(&gss_msg->list))
		return;
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	spin_lock(&inode->i_lock);
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	if (!list_empty(&gss_msg->list))
		__gss_unhash_msg(gss_msg);
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	spin_unlock(&inode->i_lock);
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}

static void
gss_upcall_callback(struct rpc_task *task)
{
	struct gss_cred *gss_cred = container_of(task->tk_msg.rpc_cred,
			struct gss_cred, gc_base);
	struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
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	struct inode *inode = &gss_msg->inode->vfs_inode;
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	spin_lock(&inode->i_lock);
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	if (gss_msg->ctx)
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		gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_msg->ctx);
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	else
		task->tk_status = gss_msg->msg.errno;
	gss_cred->gc_upcall = NULL;
	rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
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	spin_unlock(&inode->i_lock);
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	gss_release_msg(gss_msg);
}

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static void gss_encode_v0_msg(struct gss_upcall_msg *gss_msg)
{
	gss_msg->msg.data = &gss_msg->uid;
	gss_msg->msg.len = sizeof(gss_msg->uid);
}

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static void gss_encode_v1_msg(struct gss_upcall_msg *gss_msg,
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				struct rpc_clnt *clnt, int machine_cred)
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{
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	struct gss_api_mech *mech = gss_msg->auth->mech;
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	char *p = gss_msg->databuf;
	int len = 0;

	gss_msg->msg.len = sprintf(gss_msg->databuf, "mech=%s uid=%d ",
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				   mech->gm_name,
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				   gss_msg->uid);
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	p += gss_msg->msg.len;
	if (clnt->cl_principal) {
		len = sprintf(p, "target=%s ", clnt->cl_principal);
		p += len;
		gss_msg->msg.len += len;
	}
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	if (machine_cred) {
		len = sprintf(p, "service=* ");
		p += len;
		gss_msg->msg.len += len;
	} else if (!strcmp(clnt->cl_program->name, "nfs4_cb")) {
		len = sprintf(p, "service=nfs ");
		p += len;
		gss_msg->msg.len += len;
	}
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	if (mech->gm_upcall_enctypes) {
		len = sprintf(p, mech->gm_upcall_enctypes);
		p += len;
		gss_msg->msg.len += len;
	}
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	len = sprintf(p, "\n");
	gss_msg->msg.len += len;

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	gss_msg->msg.data = gss_msg->databuf;
	BUG_ON(gss_msg->msg.len > UPCALL_BUF_LEN);
}

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static void gss_encode_msg(struct gss_upcall_msg *gss_msg,
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				struct rpc_clnt *clnt, int machine_cred)
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{
	if (pipe_version == 0)
		gss_encode_v0_msg(gss_msg);
	else /* pipe_version == 1 */
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		gss_encode_v1_msg(gss_msg, clnt, machine_cred);
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}

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static inline struct gss_upcall_msg *
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gss_alloc_msg(struct gss_auth *gss_auth, uid_t uid, struct rpc_clnt *clnt,
		int machine_cred)
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{
	struct gss_upcall_msg *gss_msg;
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	int vers;
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	gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
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	if (gss_msg == NULL)
		return ERR_PTR(-ENOMEM);
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	vers = get_pipe_version();
	if (vers < 0) {
		kfree(gss_msg);
		return ERR_PTR(vers);
	}
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	gss_msg->inode = RPC_I(gss_auth->dentry[vers]->d_inode);
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	INIT_LIST_HEAD(&gss_msg->list);
	rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
	init_waitqueue_head(&gss_msg->waitqueue);
	atomic_set(&gss_msg->count, 1);
	gss_msg->uid = uid;
	gss_msg->auth = gss_auth;
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	gss_encode_msg(gss_msg, clnt, machine_cred);
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	return gss_msg;
}

static struct gss_upcall_msg *
gss_setup_upcall(struct rpc_clnt *clnt, struct gss_auth *gss_auth, struct rpc_cred *cred)
{
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	struct gss_cred *gss_cred = container_of(cred,
			struct gss_cred, gc_base);
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	struct gss_upcall_msg *gss_new, *gss_msg;
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	uid_t uid = cred->cr_uid;
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	gss_new = gss_alloc_msg(gss_auth, uid, clnt, gss_cred->gc_machine_cred);
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	if (IS_ERR(gss_new))
		return gss_new;
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	gss_msg = gss_add_msg(gss_new);
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	if (gss_msg == gss_new) {
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		struct inode *inode = &gss_new->inode->vfs_inode;
		int res = rpc_queue_upcall(inode, &gss_new->msg);
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		if (res) {
			gss_unhash_msg(gss_new);
			gss_msg = ERR_PTR(res);
		}
	} else
		gss_release_msg(gss_new);
	return gss_msg;
}

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static void warn_gssd(void)
{
	static unsigned long ratelimit;
	unsigned long now = jiffies;

	if (time_after(now, ratelimit)) {
		printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
				"Please check user daemon is running.\n");
		ratelimit = now + 15*HZ;
	}
}

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static inline int
gss_refresh_upcall(struct rpc_task *task)
{
	struct rpc_cred *cred = task->tk_msg.rpc_cred;
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	struct gss_auth *gss_auth = container_of(cred->cr_auth,
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			struct gss_auth, rpc_auth);
	struct gss_cred *gss_cred = container_of(cred,
			struct gss_cred, gc_base);
	struct gss_upcall_msg *gss_msg;
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	struct inode *inode;
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	int err = 0;

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	dprintk("RPC: %5u gss_refresh_upcall for uid %u\n", task->tk_pid,
								cred->cr_uid);
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	gss_msg = gss_setup_upcall(task->tk_client, gss_auth, cred);
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	if (PTR_ERR(gss_msg) == -EAGAIN) {
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		/* XXX: warning on the first, under the assumption we
		 * shouldn't normally hit this case on a refresh. */
		warn_gssd();
		task->tk_timeout = 15*HZ;
		rpc_sleep_on(&pipe_version_rpc_waitqueue, task, NULL);
		return 0;
	}
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	if (IS_ERR(gss_msg)) {
		err = PTR_ERR(gss_msg);
		goto out;
	}
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	inode = &gss_msg->inode->vfs_inode;
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	spin_lock(&inode->i_lock);
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	if (gss_cred->gc_upcall != NULL)
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		rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
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	else if (gss_msg->ctx != NULL) {
		gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_msg->ctx);
		gss_cred->gc_upcall = NULL;
		rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
	} else if (gss_msg->msg.errno >= 0) {
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		task->tk_timeout = 0;
		gss_cred->gc_upcall = gss_msg;
		/* gss_upcall_callback will release the reference to gss_upcall_msg */
		atomic_inc(&gss_msg->count);
525
		rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
L
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526 527
	} else
		err = gss_msg->msg.errno;
528
	spin_unlock(&inode->i_lock);
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529 530
	gss_release_msg(gss_msg);
out:
531 532
	dprintk("RPC: %5u gss_refresh_upcall for uid %u result %d\n",
			task->tk_pid, cred->cr_uid, err);
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533 534 535 536 537 538
	return err;
}

static inline int
gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
{
539
	struct inode *inode;
L
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540 541 542 543 544
	struct rpc_cred *cred = &gss_cred->gc_base;
	struct gss_upcall_msg *gss_msg;
	DEFINE_WAIT(wait);
	int err = 0;

545
	dprintk("RPC:       gss_upcall for uid %u\n", cred->cr_uid);
546
retry:
L
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547
	gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred);
548 549 550 551 552 553 554 555 556
	if (PTR_ERR(gss_msg) == -EAGAIN) {
		err = wait_event_interruptible_timeout(pipe_version_waitqueue,
				pipe_version >= 0, 15*HZ);
		if (err)
			goto out;
		if (pipe_version < 0)
			warn_gssd();
		goto retry;
	}
L
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557 558 559 560
	if (IS_ERR(gss_msg)) {
		err = PTR_ERR(gss_msg);
		goto out;
	}
561
	inode = &gss_msg->inode->vfs_inode;
L
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562 563
	for (;;) {
		prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_INTERRUPTIBLE);
564
		spin_lock(&inode->i_lock);
L
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565 566 567
		if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
			break;
		}
568
		spin_unlock(&inode->i_lock);
L
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569 570 571 572 573 574 575
		if (signalled()) {
			err = -ERESTARTSYS;
			goto out_intr;
		}
		schedule();
	}
	if (gss_msg->ctx)
576
		gss_cred_set_ctx(cred, gss_msg->ctx);
L
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577 578
	else
		err = gss_msg->msg.errno;
579
	spin_unlock(&inode->i_lock);
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580 581 582 583
out_intr:
	finish_wait(&gss_msg->waitqueue, &wait);
	gss_release_msg(gss_msg);
out:
584 585
	dprintk("RPC:       gss_create_upcall for uid %u result %d\n",
			cred->cr_uid, err);
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586 587 588 589 590 591 592 593
	return err;
}

static ssize_t
gss_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
		char __user *dst, size_t buflen)
{
	char *data = (char *)msg->data + msg->copied;
594 595
	size_t mlen = min(msg->len, buflen);
	unsigned long left;
L
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596 597

	left = copy_to_user(dst, data, mlen);
598 599 600
	if (left == mlen) {
		msg->errno = -EFAULT;
		return -EFAULT;
L
Linus Torvalds 已提交
601
	}
602

L
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603 604 605 606 607 608 609 610 611 612 613 614 615 616
	mlen -= left;
	msg->copied += mlen;
	msg->errno = 0;
	return mlen;
}

#define MSG_BUF_MAXSIZE 1024

static ssize_t
gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
{
	const void *p, *end;
	void *buf;
	struct gss_upcall_msg *gss_msg;
617
	struct inode *inode = filp->f_path.dentry->d_inode;
L
Linus Torvalds 已提交
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	struct gss_cl_ctx *ctx;
	uid_t uid;
620
	ssize_t err = -EFBIG;
L
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621 622 623 624

	if (mlen > MSG_BUF_MAXSIZE)
		goto out;
	err = -ENOMEM;
625
	buf = kmalloc(mlen, GFP_NOFS);
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626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643
	if (!buf)
		goto out;

	err = -EFAULT;
	if (copy_from_user(buf, src, mlen))
		goto err;

	end = (const void *)((char *)buf + mlen);
	p = simple_get_bytes(buf, end, &uid, sizeof(uid));
	if (IS_ERR(p)) {
		err = PTR_ERR(p);
		goto err;
	}

	err = -ENOMEM;
	ctx = gss_alloc_context();
	if (ctx == NULL)
		goto err;
644 645 646 647

	err = -ENOENT;
	/* Find a matching upcall */
	spin_lock(&inode->i_lock);
648
	gss_msg = __gss_find_upcall(RPC_I(inode), uid);
649 650 651 652 653 654 655
	if (gss_msg == NULL) {
		spin_unlock(&inode->i_lock);
		goto err_put_ctx;
	}
	list_del_init(&gss_msg->list);
	spin_unlock(&inode->i_lock);

656
	p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
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657 658
	if (IS_ERR(p)) {
		err = PTR_ERR(p);
659 660
		switch (err) {
		case -EACCES:
661
		case -EKEYEXPIRED:
662 663 664 665 666 667 668 669 670 671 672
			gss_msg->msg.errno = err;
			err = mlen;
			break;
		case -EFAULT:
		case -ENOMEM:
		case -EINVAL:
		case -ENOSYS:
			gss_msg->msg.errno = -EAGAIN;
			break;
		default:
			printk(KERN_CRIT "%s: bad return from "
R
Randy Dunlap 已提交
673
				"gss_fill_context: %zd\n", __func__, err);
674 675
			BUG();
		}
676
		goto err_release_msg;
L
Linus Torvalds 已提交
677
	}
678 679 680 681
	gss_msg->ctx = gss_get_ctx(ctx);
	err = mlen;

err_release_msg:
682
	spin_lock(&inode->i_lock);
683 684 685
	__gss_unhash_msg(gss_msg);
	spin_unlock(&inode->i_lock);
	gss_release_msg(gss_msg);
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686 687 688 689 690
err_put_ctx:
	gss_put_ctx(ctx);
err:
	kfree(buf);
out:
691
	dprintk("RPC:       gss_pipe_downcall returning %Zd\n", err);
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692 693 694
	return err;
}

\
\"J. Bruce Fields\ 已提交
695
static int gss_pipe_open(struct inode *inode, int new_version)
696
{
\
\"J. Bruce Fields\ 已提交
697 698
	int ret = 0;

699 700
	spin_lock(&pipe_version_lock);
	if (pipe_version < 0) {
\
\"J. Bruce Fields\ 已提交
701 702
		/* First open of any gss pipe determines the version: */
		pipe_version = new_version;
703 704
		rpc_wake_up(&pipe_version_rpc_waitqueue);
		wake_up(&pipe_version_waitqueue);
\
\"J. Bruce Fields\ 已提交
705 706 707 708
	} else if (pipe_version != new_version) {
		/* Trying to open a pipe of a different version */
		ret = -EBUSY;
		goto out;
709
	}
710
	atomic_inc(&pipe_users);
\
\"J. Bruce Fields\ 已提交
711
out:
712
	spin_unlock(&pipe_version_lock);
\
\"J. Bruce Fields\ 已提交
713 714 715 716 717 718 719 720 721 722 723 724
	return ret;

}

static int gss_pipe_open_v0(struct inode *inode)
{
	return gss_pipe_open(inode, 0);
}

static int gss_pipe_open_v1(struct inode *inode)
{
	return gss_pipe_open(inode, 1);
725 726
}

L
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727 728 729 730
static void
gss_pipe_release(struct inode *inode)
{
	struct rpc_inode *rpci = RPC_I(inode);
731
	struct gss_upcall_msg *gss_msg;
L
Linus Torvalds 已提交
732

733
	spin_lock(&inode->i_lock);
734
	while (!list_empty(&rpci->in_downcall)) {
L
Linus Torvalds 已提交
735

736
		gss_msg = list_entry(rpci->in_downcall.next,
L
Linus Torvalds 已提交
737 738 739 740
				struct gss_upcall_msg, list);
		gss_msg->msg.errno = -EPIPE;
		atomic_inc(&gss_msg->count);
		__gss_unhash_msg(gss_msg);
741
		spin_unlock(&inode->i_lock);
L
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742
		gss_release_msg(gss_msg);
743
		spin_lock(&inode->i_lock);
L
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744
	}
745
	spin_unlock(&inode->i_lock);
746

747
	put_pipe_version();
L
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748 749 750 751 752 753 754 755
}

static void
gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
{
	struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);

	if (msg->errno < 0) {
756
		dprintk("RPC:       gss_pipe_destroy_msg releasing msg %p\n",
L
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757 758 759
				gss_msg);
		atomic_inc(&gss_msg->count);
		gss_unhash_msg(gss_msg);
760 761
		if (msg->errno == -ETIMEDOUT)
			warn_gssd();
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		gss_release_msg(gss_msg);
	}
}

766 767
/*
 * NOTE: we have the opportunity to use different
L
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 * parameters based on the input flavor (which must be a pseudoflavor)
 */
static struct rpc_auth *
gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
{
	struct gss_auth *gss_auth;
	struct rpc_auth * auth;
775
	int err = -ENOMEM; /* XXX? */
L
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776

777
	dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
L
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778 779

	if (!try_module_get(THIS_MODULE))
780
		return ERR_PTR(err);
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781 782 783
	if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
		goto out_dec;
	gss_auth->client = clnt;
784
	err = -EINVAL;
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785 786
	gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
	if (!gss_auth->mech) {
787
		printk(KERN_WARNING "%s: Pseudoflavor %d not found!\n",
788
				__func__, flavor);
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789 790 791
		goto err_free;
	}
	gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
792 793
	if (gss_auth->service == 0)
		goto err_put_mech;
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794 795 796 797 798 799
	auth = &gss_auth->rpc_auth;
	auth->au_cslack = GSS_CRED_SLACK >> 2;
	auth->au_rslack = GSS_VERF_SLACK >> 2;
	auth->au_ops = &authgss_ops;
	auth->au_flavor = flavor;
	atomic_set(&auth->au_count, 1);
800
	kref_init(&gss_auth->kref);
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Linus Torvalds 已提交
801

\
\"J. Bruce Fields\ 已提交
802 803 804 805 806 807
	/*
	 * Note: if we created the old pipe first, then someone who
	 * examined the directory at the right moment might conclude
	 * that we supported only the old pipe.  So we instead create
	 * the new pipe first.
	 */
808
	gss_auth->dentry[1] = rpc_mkpipe(clnt->cl_path.dentry,
\
\"J. Bruce Fields\ 已提交
809 810 811 812 813
					 "gssd",
					 clnt, &gss_upcall_ops_v1,
					 RPC_PIPE_WAIT_FOR_OPEN);
	if (IS_ERR(gss_auth->dentry[1])) {
		err = PTR_ERR(gss_auth->dentry[1]);
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814
		goto err_put_mech;
815
	}
L
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816

817
	gss_auth->dentry[0] = rpc_mkpipe(clnt->cl_path.dentry,
\
\"J. Bruce Fields\ 已提交
818 819 820 821 822 823 824
					 gss_auth->mech->gm_name,
					 clnt, &gss_upcall_ops_v0,
					 RPC_PIPE_WAIT_FOR_OPEN);
	if (IS_ERR(gss_auth->dentry[0])) {
		err = PTR_ERR(gss_auth->dentry[0]);
		goto err_unlink_pipe_1;
	}
825
	err = rpcauth_init_credcache(auth);
826
	if (err)
\
\"J. Bruce Fields\ 已提交
827
		goto err_unlink_pipe_0;
828

L
Linus Torvalds 已提交
829
	return auth;
\
\"J. Bruce Fields\ 已提交
830 831 832 833
err_unlink_pipe_0:
	rpc_unlink(gss_auth->dentry[0]);
err_unlink_pipe_1:
	rpc_unlink(gss_auth->dentry[1]);
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Linus Torvalds 已提交
834 835 836 837 838 839
err_put_mech:
	gss_mech_put(gss_auth->mech);
err_free:
	kfree(gss_auth);
out_dec:
	module_put(THIS_MODULE);
840
	return ERR_PTR(err);
L
Linus Torvalds 已提交
841 842
}

843 844 845
static void
gss_free(struct gss_auth *gss_auth)
{
\
\"J. Bruce Fields\ 已提交
846 847
	rpc_unlink(gss_auth->dentry[1]);
	rpc_unlink(gss_auth->dentry[0]);
848 849 850 851 852 853 854 855 856 857 858 859 860 861
	gss_mech_put(gss_auth->mech);

	kfree(gss_auth);
	module_put(THIS_MODULE);
}

static void
gss_free_callback(struct kref *kref)
{
	struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);

	gss_free(gss_auth);
}

L
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862 863 864 865 866
static void
gss_destroy(struct rpc_auth *auth)
{
	struct gss_auth *gss_auth;

867 868
	dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
			auth, auth->au_flavor);
L
Linus Torvalds 已提交
869

870 871
	rpcauth_destroy_credcache(auth);

L
Linus Torvalds 已提交
872
	gss_auth = container_of(auth, struct gss_auth, rpc_auth);
873
	kref_put(&gss_auth->kref, gss_free_callback);
L
Linus Torvalds 已提交
874 875
}

876 877 878 879 880 881 882 883 884 885 886 887 888 889
/*
 * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
 * to the server with the GSS control procedure field set to
 * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
 * all RPCSEC_GSS state associated with that context.
 */
static int
gss_destroying_context(struct rpc_cred *cred)
{
	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
	struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
	struct rpc_task *task;

	if (gss_cred->gc_ctx == NULL ||
890
	    test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
891 892 893 894 895 896 897 898 899
		return 0;

	gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY;
	cred->cr_ops = &gss_nullops;

	/* Take a reference to ensure the cred will be destroyed either
	 * by the RPC call or by the put_rpccred() below */
	get_rpccred(cred);

900
	task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
901 902 903 904 905 906 907 908
	if (!IS_ERR(task))
		rpc_put_task(task);

	put_rpccred(cred);
	return 1;
}

/* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
L
Linus Torvalds 已提交
909 910 911
 * to create a new cred or context, so they check that things have been
 * allocated before freeing them. */
static void
912
gss_do_free_ctx(struct gss_cl_ctx *ctx)
L
Linus Torvalds 已提交
913
{
914
	dprintk("RPC:       gss_free_ctx\n");
L
Linus Torvalds 已提交
915 916 917 918 919

	kfree(ctx->gc_wire_ctx.data);
	kfree(ctx);
}

920 921 922 923 924 925 926 927 928 929
static void
gss_free_ctx_callback(struct rcu_head *head)
{
	struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
	gss_do_free_ctx(ctx);
}

static void
gss_free_ctx(struct gss_cl_ctx *ctx)
{
930 931 932 933
	struct gss_ctx *gc_gss_ctx;

	gc_gss_ctx = rcu_dereference(ctx->gc_gss_ctx);
	rcu_assign_pointer(ctx->gc_gss_ctx, NULL);
934
	call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
935 936
	if (gc_gss_ctx)
		gss_delete_sec_context(&gc_gss_ctx);
937 938
}

L
Linus Torvalds 已提交
939
static void
940
gss_free_cred(struct gss_cred *gss_cred)
L
Linus Torvalds 已提交
941
{
942 943 944
	dprintk("RPC:       gss_free_cred %p\n", gss_cred);
	kfree(gss_cred);
}
L
Linus Torvalds 已提交
945

946 947 948 949 950 951
static void
gss_free_cred_callback(struct rcu_head *head)
{
	struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
	gss_free_cred(gss_cred);
}
L
Linus Torvalds 已提交
952

953
static void
954
gss_destroy_nullcred(struct rpc_cred *cred)
955
{
956
	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
957
	struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
958 959 960
	struct gss_cl_ctx *ctx = gss_cred->gc_ctx;

	rcu_assign_pointer(gss_cred->gc_ctx, NULL);
961
	call_rcu(&cred->cr_rcu, gss_free_cred_callback);
962 963
	if (ctx)
		gss_put_ctx(ctx);
964
	kref_put(&gss_auth->kref, gss_free_callback);
L
Linus Torvalds 已提交
965 966
}

967 968 969 970 971 972 973 974 975
static void
gss_destroy_cred(struct rpc_cred *cred)
{

	if (gss_destroying_context(cred))
		return;
	gss_destroy_nullcred(cred);
}

L
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976 977 978 979
/*
 * Lookup RPCSEC_GSS cred for the current process
 */
static struct rpc_cred *
980
gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
L
Linus Torvalds 已提交
981
{
982
	return rpcauth_lookup_credcache(auth, acred, flags);
L
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983 984 985
}

static struct rpc_cred *
986
gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
L
Linus Torvalds 已提交
987 988 989 990 991
{
	struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
	struct gss_cred	*cred = NULL;
	int err = -ENOMEM;

992
	dprintk("RPC:       gss_create_cred for uid %d, flavor %d\n",
L
Linus Torvalds 已提交
993 994
		acred->uid, auth->au_flavor);

995
	if (!(cred = kzalloc(sizeof(*cred), GFP_NOFS)))
L
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996 997
		goto out_err;

998
	rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
L
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999 1000 1001 1002
	/*
	 * Note: in order to force a call to call_refresh(), we deliberately
	 * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
	 */
1003
	cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
L
Linus Torvalds 已提交
1004
	cred->gc_service = gss_auth->service;
1005
	cred->gc_machine_cred = acred->machine_cred;
1006
	kref_get(&gss_auth->kref);
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1007 1008 1009
	return &cred->gc_base;

out_err:
1010
	dprintk("RPC:       gss_create_cred failed with error %d\n", err);
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1011 1012 1013
	return ERR_PTR(err);
}

1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026
static int
gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
{
	struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
	struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
	int err;

	do {
		err = gss_create_upcall(gss_auth, gss_cred);
	} while (err == -EAGAIN);
	return err;
}

L
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1027
static int
1028
gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
L
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{
	struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);

1032
	if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
1033
		goto out;
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	/* Don't match with creds that have expired. */
1035 1036 1037
	if (time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
		return 0;
	if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
L
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		return 0;
1039
out:
1040 1041
	if (acred->machine_cred != gss_cred->gc_machine_cred)
		return 0;
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	return (rc->cr_uid == acred->uid);
}

/*
* Marshal credentials.
* Maybe we should keep a cached credential for performance reasons.
*/
1049 1050
static __be32 *
gss_marshal(struct rpc_task *task, __be32 *p)
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{
	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	struct gss_cred	*gss_cred = container_of(cred, struct gss_cred,
						 gc_base);
	struct gss_cl_ctx	*ctx = gss_cred_get_ctx(cred);
1056
	__be32		*cred_len;
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	struct rpc_rqst *req = task->tk_rqstp;
	u32             maj_stat = 0;
	struct xdr_netobj mic;
	struct kvec	iov;
	struct xdr_buf	verf_buf;

1063
	dprintk("RPC: %5u gss_marshal\n", task->tk_pid);
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	*p++ = htonl(RPC_AUTH_GSS);
	cred_len = p++;

	spin_lock(&ctx->gc_seq_lock);
	req->rq_seqno = ctx->gc_seq++;
	spin_unlock(&ctx->gc_seq_lock);

	*p++ = htonl((u32) RPC_GSS_VERSION);
	*p++ = htonl((u32) ctx->gc_proc);
	*p++ = htonl((u32) req->rq_seqno);
	*p++ = htonl((u32) gss_cred->gc_service);
	p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
	*cred_len = htonl((p - (cred_len + 1)) << 2);

	/* We compute the checksum for the verifier over the xdr-encoded bytes
	 * starting with the xid and ending at the end of the credential: */
1081 1082
	iov.iov_base = xprt_skip_transport_header(task->tk_xprt,
					req->rq_snd_buf.head[0].iov_base);
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	iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
	xdr_buf_from_iov(&iov, &verf_buf);

	/* set verifier flavor*/
	*p++ = htonl(RPC_AUTH_GSS);

	mic.data = (u8 *)(p + 1);
1090
	maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
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	if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
1092
		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
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	} else if (maj_stat != 0) {
		printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
		goto out_put_ctx;
	}
	p = xdr_encode_opaque(p, NULL, mic.len);
	gss_put_ctx(ctx);
	return p;
out_put_ctx:
	gss_put_ctx(ctx);
	return NULL;
}

1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125
static int gss_renew_cred(struct rpc_task *task)
{
	struct rpc_cred *oldcred = task->tk_msg.rpc_cred;
	struct gss_cred *gss_cred = container_of(oldcred,
						 struct gss_cred,
						 gc_base);
	struct rpc_auth *auth = oldcred->cr_auth;
	struct auth_cred acred = {
		.uid = oldcred->cr_uid,
		.machine_cred = gss_cred->gc_machine_cred,
	};
	struct rpc_cred *new;

	new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
	if (IS_ERR(new))
		return PTR_ERR(new);
	task->tk_msg.rpc_cred = new;
	put_rpccred(oldcred);
	return 0;
}

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/*
* Refresh credentials. XXX - finish
*/
static int
gss_refresh(struct rpc_task *task)
{
1132 1133 1134 1135 1136 1137 1138 1139 1140 1141
	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	int ret = 0;

	if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
			!test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
		ret = gss_renew_cred(task);
		if (ret < 0)
			goto out;
		cred = task->tk_msg.rpc_cred;
	}
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1143 1144 1145 1146
	if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
		ret = gss_refresh_upcall(task);
out:
	return ret;
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}

1149 1150 1151 1152 1153 1154 1155
/* Dummy refresh routine: used only when destroying the context */
static int
gss_refresh_null(struct rpc_task *task)
{
	return -EACCES;
}

1156 1157
static __be32 *
gss_validate(struct rpc_task *task, __be32 *p)
L
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{
	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1161
	__be32		seq;
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	struct kvec	iov;
	struct xdr_buf	verf_buf;
	struct xdr_netobj mic;
	u32		flav,len;
	u32		maj_stat;

1168
	dprintk("RPC: %5u gss_validate\n", task->tk_pid);
L
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1169 1170 1171

	flav = ntohl(*p++);
	if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
1172
		goto out_bad;
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	if (flav != RPC_AUTH_GSS)
		goto out_bad;
	seq = htonl(task->tk_rqstp->rq_seqno);
	iov.iov_base = &seq;
	iov.iov_len = sizeof(seq);
	xdr_buf_from_iov(&iov, &verf_buf);
	mic.data = (u8 *)p;
	mic.len = len;

1182
	maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
L
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1183
	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1184
		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1185
	if (maj_stat) {
1186
		dprintk("RPC: %5u gss_validate: gss_verify_mic returned "
1187
				"error 0x%08x\n", task->tk_pid, maj_stat);
L
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1188
		goto out_bad;
1189
	}
1190 1191
	/* We leave it to unwrap to calculate au_rslack. For now we just
	 * calculate the length of the verifier: */
1192
	cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
L
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	gss_put_ctx(ctx);
1194
	dprintk("RPC: %5u gss_validate: gss_verify_mic succeeded.\n",
L
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1195 1196 1197 1198
			task->tk_pid);
	return p + XDR_QUADLEN(len);
out_bad:
	gss_put_ctx(ctx);
1199
	dprintk("RPC: %5u gss_validate failed.\n", task->tk_pid);
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	return NULL;
}

static inline int
gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1205
		kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
L
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{
	struct xdr_buf	*snd_buf = &rqstp->rq_snd_buf;
	struct xdr_buf	integ_buf;
1209
	__be32          *integ_len = NULL;
L
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	struct xdr_netobj mic;
1211 1212
	u32		offset;
	__be32		*q;
L
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	struct kvec	*iov;
	u32             maj_stat = 0;
	int		status = -EIO;

	integ_len = p++;
	offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
	*p++ = htonl(rqstp->rq_seqno);

1221
	status = encode(rqstp, p, obj);
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	if (status)
		return status;

	if (xdr_buf_subsegment(snd_buf, &integ_buf,
				offset, snd_buf->len - offset))
		return status;
	*integ_len = htonl(integ_buf.len);

	/* guess whether we're in the head or the tail: */
1231
	if (snd_buf->page_len || snd_buf->tail[0].iov_len)
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		iov = snd_buf->tail;
	else
		iov = snd_buf->head;
	p = iov->iov_base + iov->iov_len;
	mic.data = (u8 *)(p + 1);

1238
	maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
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	status = -EIO; /* XXX? */
	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1241
		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
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	else if (maj_stat)
		return status;
	q = xdr_encode_opaque(p, NULL, mic.len);

	offset = (u8 *)q - (u8 *)p;
	iov->iov_len += offset;
	snd_buf->len += offset;
	return 0;
}

1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288
static void
priv_release_snd_buf(struct rpc_rqst *rqstp)
{
	int i;

	for (i=0; i < rqstp->rq_enc_pages_num; i++)
		__free_page(rqstp->rq_enc_pages[i]);
	kfree(rqstp->rq_enc_pages);
}

static int
alloc_enc_pages(struct rpc_rqst *rqstp)
{
	struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
	int first, last, i;

	if (snd_buf->page_len == 0) {
		rqstp->rq_enc_pages_num = 0;
		return 0;
	}

	first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
	last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT;
	rqstp->rq_enc_pages_num = last - first + 1 + 1;
	rqstp->rq_enc_pages
		= kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
				GFP_NOFS);
	if (!rqstp->rq_enc_pages)
		goto out;
	for (i=0; i < rqstp->rq_enc_pages_num; i++) {
		rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
		if (rqstp->rq_enc_pages[i] == NULL)
			goto out_free;
	}
	rqstp->rq_release_snd_buf = priv_release_snd_buf;
	return 0;
out_free:
1289 1290
	rqstp->rq_enc_pages_num = i;
	priv_release_snd_buf(rqstp);
1291 1292 1293 1294 1295 1296
out:
	return -EAGAIN;
}

static inline int
gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1297
		kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
1298 1299 1300 1301 1302
{
	struct xdr_buf	*snd_buf = &rqstp->rq_snd_buf;
	u32		offset;
	u32             maj_stat;
	int		status;
1303
	__be32		*opaque_len;
1304 1305 1306 1307 1308 1309 1310 1311 1312 1313
	struct page	**inpages;
	int		first;
	int		pad;
	struct kvec	*iov;
	char		*tmp;

	opaque_len = p++;
	offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
	*p++ = htonl(rqstp->rq_seqno);

1314
	status = encode(rqstp, p, obj);
1315 1316 1317 1318 1319 1320 1321 1322 1323 1324
	if (status)
		return status;

	status = alloc_enc_pages(rqstp);
	if (status)
		return status;
	first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
	inpages = snd_buf->pages + first;
	snd_buf->pages = rqstp->rq_enc_pages;
	snd_buf->page_base -= first << PAGE_CACHE_SHIFT;
1325 1326 1327 1328 1329 1330 1331 1332
	/*
	 * Give the tail its own page, in case we need extra space in the
	 * head when wrapping:
	 *
	 * call_allocate() allocates twice the slack space required
	 * by the authentication flavor to rq_callsize.
	 * For GSS, slack is GSS_CRED_SLACK.
	 */
1333 1334 1335 1336 1337
	if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
		tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
		memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
		snd_buf->tail[0].iov_base = tmp;
	}
1338
	maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1339
	/* slack space should prevent this ever happening: */
1340
	BUG_ON(snd_buf->len > snd_buf->buflen);
1341
	status = -EIO;
1342 1343 1344
	/* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
	 * done anyway, so it's safe to put the request on the wire: */
	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1345
		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363
	else if (maj_stat)
		return status;

	*opaque_len = htonl(snd_buf->len - offset);
	/* guess whether we're in the head or the tail: */
	if (snd_buf->page_len || snd_buf->tail[0].iov_len)
		iov = snd_buf->tail;
	else
		iov = snd_buf->head;
	p = iov->iov_base + iov->iov_len;
	pad = 3 - ((snd_buf->len - offset - 1) & 3);
	memset(p, 0, pad);
	iov->iov_len += pad;
	snd_buf->len += pad;

	return 0;
}

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static int
gss_wrap_req(struct rpc_task *task,
1366
	     kxdrproc_t encode, void *rqstp, __be32 *p, void *obj)
L
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1367 1368 1369 1370 1371 1372 1373
{
	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	struct gss_cred	*gss_cred = container_of(cred, struct gss_cred,
			gc_base);
	struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
	int             status = -EIO;

1374
	dprintk("RPC: %5u gss_wrap_req\n", task->tk_pid);
L
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1375 1376 1377 1378
	if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
		/* The spec seems a little ambiguous here, but I think that not
		 * wrapping context destruction requests makes the most sense.
		 */
1379
		status = encode(rqstp, p, obj);
L
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1380 1381 1382 1383
		goto out;
	}
	switch (gss_cred->gc_service) {
		case RPC_GSS_SVC_NONE:
1384
			status = encode(rqstp, p, obj);
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			break;
		case RPC_GSS_SVC_INTEGRITY:
			status = gss_wrap_req_integ(cred, ctx, encode,
								rqstp, p, obj);
			break;
1390
		case RPC_GSS_SVC_PRIVACY:
1391 1392
			status = gss_wrap_req_priv(cred, ctx, encode,
					rqstp, p, obj);
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			break;
	}
out:
	gss_put_ctx(ctx);
1397
	dprintk("RPC: %5u gss_wrap_req returning %d\n", task->tk_pid, status);
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1398 1399 1400 1401 1402
	return status;
}

static inline int
gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1403
		struct rpc_rqst *rqstp, __be32 **p)
L
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{
	struct xdr_buf	*rcv_buf = &rqstp->rq_rcv_buf;
	struct xdr_buf integ_buf;
	struct xdr_netobj mic;
	u32 data_offset, mic_offset;
	u32 integ_len;
	u32 maj_stat;
	int status = -EIO;

	integ_len = ntohl(*(*p)++);
	if (integ_len & 3)
		return status;
	data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
	mic_offset = integ_len + data_offset;
	if (mic_offset > rcv_buf->len)
		return status;
	if (ntohl(*(*p)++) != rqstp->rq_seqno)
		return status;

	if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
				mic_offset - data_offset))
		return status;

	if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
		return status;

1430
	maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
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1431
	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1432
		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
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1433 1434 1435 1436 1437
	if (maj_stat != GSS_S_COMPLETE)
		return status;
	return 0;
}

1438 1439
static inline int
gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1440
		struct rpc_rqst *rqstp, __be32 **p)
1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454
{
	struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
	u32 offset;
	u32 opaque_len;
	u32 maj_stat;
	int status = -EIO;

	opaque_len = ntohl(*(*p)++);
	offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
	if (offset + opaque_len > rcv_buf->len)
		return status;
	/* remove padding: */
	rcv_buf->len = offset + opaque_len;

1455
	maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1456
	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1457
		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1458 1459 1460 1461 1462 1463 1464 1465 1466
	if (maj_stat != GSS_S_COMPLETE)
		return status;
	if (ntohl(*(*p)++) != rqstp->rq_seqno)
		return status;

	return 0;
}


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static int
gss_unwrap_resp(struct rpc_task *task,
1469
		kxdrproc_t decode, void *rqstp, __be32 *p, void *obj)
L
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1470 1471 1472 1473 1474
{
	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
			gc_base);
	struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1475
	__be32		*savedp = p;
1476 1477
	struct kvec	*head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
	int		savedlen = head->iov_len;
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1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489
	int             status = -EIO;

	if (ctx->gc_proc != RPC_GSS_PROC_DATA)
		goto out_decode;
	switch (gss_cred->gc_service) {
		case RPC_GSS_SVC_NONE:
			break;
		case RPC_GSS_SVC_INTEGRITY:
			status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
			if (status)
				goto out;
			break;
1490
		case RPC_GSS_SVC_PRIVACY:
1491 1492 1493
			status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
			if (status)
				goto out;
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1494 1495
			break;
	}
1496
	/* take into account extra slack for integrity and privacy cases: */
1497
	cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1498
						+ (savedlen - head->iov_len);
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1499
out_decode:
1500
	status = decode(rqstp, p, obj);
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out:
	gss_put_ctx(ctx);
1503
	dprintk("RPC: %5u gss_unwrap_resp returning %d\n", task->tk_pid,
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1504 1505 1506
			status);
	return status;
}
1507

1508
static const struct rpc_authops authgss_ops = {
L
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	.owner		= THIS_MODULE,
	.au_flavor	= RPC_AUTH_GSS,
	.au_name	= "RPCSEC_GSS",
	.create		= gss_create,
	.destroy	= gss_destroy,
	.lookup_cred	= gss_lookup_cred,
	.crcreate	= gss_create_cred
};

1518
static const struct rpc_credops gss_credops = {
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	.cr_name	= "AUTH_GSS",
	.crdestroy	= gss_destroy_cred,
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	.cr_init	= gss_cred_init,
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	.crbind		= rpcauth_generic_bind_cred,
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	.crmatch	= gss_match,
	.crmarshal	= gss_marshal,
	.crrefresh	= gss_refresh,
	.crvalidate	= gss_validate,
	.crwrap_req	= gss_wrap_req,
	.crunwrap_resp	= gss_unwrap_resp,
};

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static const struct rpc_credops gss_nullops = {
	.cr_name	= "AUTH_GSS",
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	.crdestroy	= gss_destroy_nullcred,
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	.crbind		= rpcauth_generic_bind_cred,
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	.crmatch	= gss_match,
	.crmarshal	= gss_marshal,
	.crrefresh	= gss_refresh_null,
	.crvalidate	= gss_validate,
	.crwrap_req	= gss_wrap_req,
	.crunwrap_resp	= gss_unwrap_resp,
};

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static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
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	.upcall		= gss_pipe_upcall,
	.downcall	= gss_pipe_downcall,
	.destroy_msg	= gss_pipe_destroy_msg,
	.open_pipe	= gss_pipe_open_v0,
	.release_pipe	= gss_pipe_release,
};

1551
static const struct rpc_pipe_ops gss_upcall_ops_v1 = {
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	.upcall		= gss_pipe_upcall,
	.downcall	= gss_pipe_downcall,
	.destroy_msg	= gss_pipe_destroy_msg,
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	.open_pipe	= gss_pipe_open_v1,
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	.release_pipe	= gss_pipe_release,
};

/*
 * Initialize RPCSEC_GSS module
 */
static int __init init_rpcsec_gss(void)
{
	int err = 0;

	err = rpcauth_register(&authgss_ops);
	if (err)
		goto out;
	err = gss_svc_init();
	if (err)
		goto out_unregister;
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	rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
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	return 0;
out_unregister:
	rpcauth_unregister(&authgss_ops);
out:
	return err;
}

static void __exit exit_rpcsec_gss(void)
{
	gss_svc_shutdown();
	rpcauth_unregister(&authgss_ops);
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	rcu_barrier(); /* Wait for completion of call_rcu()'s */
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}

MODULE_LICENSE("GPL");
module_init(init_rpcsec_gss)
module_exit(exit_rpcsec_gss)