auth_gss.c 40.0 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		1024
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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) {
		/* in which case, p points to  an error code which we ignore */
		p = ERR_PTR(-EACCES);
		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;
	}
	ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx);
	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 *
gss_add_msg(struct gss_auth *gss_auth, struct gss_upcall_msg *gss_msg)
{
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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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	char *p = gss_msg->databuf;
	int len = 0;

	gss_msg->msg.len = sprintf(gss_msg->databuf, "mech=%s uid=%d ",
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				   gss_msg->auth->mech->gm_name,
				   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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	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_auth, gss_new);
	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 (IS_ERR(gss_msg) == -EAGAIN) {
		/* 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);
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		rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
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	} else
		err = gss_msg->msg.errno;
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	spin_unlock(&inode->i_lock);
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	gss_release_msg(gss_msg);
out:
519 520
	dprintk("RPC: %5u gss_refresh_upcall for uid %u result %d\n",
			task->tk_pid, cred->cr_uid, err);
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	return err;
}

static inline int
gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
{
527
	struct inode *inode;
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528 529 530 531 532
	struct rpc_cred *cred = &gss_cred->gc_base;
	struct gss_upcall_msg *gss_msg;
	DEFINE_WAIT(wait);
	int err = 0;

533
	dprintk("RPC:       gss_upcall for uid %u\n", cred->cr_uid);
534
retry:
L
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535
	gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred);
536 537 538 539 540 541 542 543 544
	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;
	}
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545 546 547 548
	if (IS_ERR(gss_msg)) {
		err = PTR_ERR(gss_msg);
		goto out;
	}
549
	inode = &gss_msg->inode->vfs_inode;
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	for (;;) {
		prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_INTERRUPTIBLE);
552
		spin_lock(&inode->i_lock);
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553 554 555
		if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
			break;
		}
556
		spin_unlock(&inode->i_lock);
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		if (signalled()) {
			err = -ERESTARTSYS;
			goto out_intr;
		}
		schedule();
	}
	if (gss_msg->ctx)
564
		gss_cred_set_ctx(cred, gss_msg->ctx);
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	else
		err = gss_msg->msg.errno;
567
	spin_unlock(&inode->i_lock);
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out_intr:
	finish_wait(&gss_msg->waitqueue, &wait);
	gss_release_msg(gss_msg);
out:
572 573
	dprintk("RPC:       gss_create_upcall for uid %u result %d\n",
			cred->cr_uid, err);
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	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;
582 583
	size_t mlen = min(msg->len, buflen);
	unsigned long left;
L
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584 585

	left = copy_to_user(dst, data, mlen);
586 587 588
	if (left == mlen) {
		msg->errno = -EFAULT;
		return -EFAULT;
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589
	}
590

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	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;
605
	struct inode *inode = filp->f_path.dentry->d_inode;
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	struct gss_cl_ctx *ctx;
	uid_t uid;
608
	ssize_t err = -EFBIG;
L
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	if (mlen > MSG_BUF_MAXSIZE)
		goto out;
	err = -ENOMEM;
613
	buf = kmalloc(mlen, GFP_NOFS);
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	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;
632 633 634 635

	err = -ENOENT;
	/* Find a matching upcall */
	spin_lock(&inode->i_lock);
636
	gss_msg = __gss_find_upcall(RPC_I(inode), uid);
637 638 639 640 641 642 643
	if (gss_msg == NULL) {
		spin_unlock(&inode->i_lock);
		goto err_put_ctx;
	}
	list_del_init(&gss_msg->list);
	spin_unlock(&inode->i_lock);

644
	p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
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	if (IS_ERR(p)) {
		err = PTR_ERR(p);
647
		gss_msg->msg.errno = (err == -EAGAIN) ? -EAGAIN : -EACCES;
648
		goto err_release_msg;
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649
	}
650 651 652 653
	gss_msg->ctx = gss_get_ctx(ctx);
	err = mlen;

err_release_msg:
654
	spin_lock(&inode->i_lock);
655 656 657
	__gss_unhash_msg(gss_msg);
	spin_unlock(&inode->i_lock);
	gss_release_msg(gss_msg);
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658 659 660 661 662
err_put_ctx:
	gss_put_ctx(ctx);
err:
	kfree(buf);
out:
663
	dprintk("RPC:       gss_pipe_downcall returning %Zd\n", err);
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	return err;
}

\
\"J. Bruce Fields\ 已提交
667
static int gss_pipe_open(struct inode *inode, int new_version)
668
{
\
\"J. Bruce Fields\ 已提交
669 670
	int ret = 0;

671 672
	spin_lock(&pipe_version_lock);
	if (pipe_version < 0) {
\
\"J. Bruce Fields\ 已提交
673 674
		/* First open of any gss pipe determines the version: */
		pipe_version = new_version;
675 676
		rpc_wake_up(&pipe_version_rpc_waitqueue);
		wake_up(&pipe_version_waitqueue);
\
\"J. Bruce Fields\ 已提交
677 678 679 680
	} else if (pipe_version != new_version) {
		/* Trying to open a pipe of a different version */
		ret = -EBUSY;
		goto out;
681
	}
682
	atomic_inc(&pipe_users);
\
\"J. Bruce Fields\ 已提交
683
out:
684
	spin_unlock(&pipe_version_lock);
\
\"J. Bruce Fields\ 已提交
685 686 687 688 689 690 691 692 693 694 695 696
	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);
697 698
}

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static void
gss_pipe_release(struct inode *inode)
{
	struct rpc_inode *rpci = RPC_I(inode);
703
	struct gss_upcall_msg *gss_msg;
L
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704

705
	spin_lock(&inode->i_lock);
706
	while (!list_empty(&rpci->in_downcall)) {
L
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707

708
		gss_msg = list_entry(rpci->in_downcall.next,
L
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709 710 711 712
				struct gss_upcall_msg, list);
		gss_msg->msg.errno = -EPIPE;
		atomic_inc(&gss_msg->count);
		__gss_unhash_msg(gss_msg);
713
		spin_unlock(&inode->i_lock);
L
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714
		gss_release_msg(gss_msg);
715
		spin_lock(&inode->i_lock);
L
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716
	}
717
	spin_unlock(&inode->i_lock);
718

719
	put_pipe_version();
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720 721 722 723 724 725 726 727
}

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) {
728
		dprintk("RPC:       gss_pipe_destroy_msg releasing msg %p\n",
L
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729 730 731
				gss_msg);
		atomic_inc(&gss_msg->count);
		gss_unhash_msg(gss_msg);
732 733
		if (msg->errno == -ETIMEDOUT)
			warn_gssd();
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734 735 736 737
		gss_release_msg(gss_msg);
	}
}

738 739
/*
 * NOTE: we have the opportunity to use different
L
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740 741 742 743 744 745 746
 * 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;
747
	int err = -ENOMEM; /* XXX? */
L
Linus Torvalds 已提交
748

749
	dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
L
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750 751

	if (!try_module_get(THIS_MODULE))
752
		return ERR_PTR(err);
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753 754 755
	if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
		goto out_dec;
	gss_auth->client = clnt;
756
	err = -EINVAL;
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	gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
	if (!gss_auth->mech) {
759
		printk(KERN_WARNING "%s: Pseudoflavor %d not found!\n",
760
				__func__, flavor);
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		goto err_free;
	}
	gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
764 765
	if (gss_auth->service == 0)
		goto err_put_mech;
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	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);
772
	kref_init(&gss_auth->kref);
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\
\"J. Bruce Fields\ 已提交
774 775 776 777 778 779 780 781 782 783 784 785
	/*
	 * 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.
	 */
	gss_auth->dentry[1] = rpc_mkpipe(clnt->cl_dentry,
					 "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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786
		goto err_put_mech;
787
	}
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788

\
\"J. Bruce Fields\ 已提交
789 790 791 792 793 794 795 796
	gss_auth->dentry[0] = rpc_mkpipe(clnt->cl_dentry,
					 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;
	}
797
	err = rpcauth_init_credcache(auth);
798
	if (err)
\
\"J. Bruce Fields\ 已提交
799
		goto err_unlink_pipe_0;
800

L
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801
	return auth;
\
\"J. Bruce Fields\ 已提交
802 803 804 805
err_unlink_pipe_0:
	rpc_unlink(gss_auth->dentry[0]);
err_unlink_pipe_1:
	rpc_unlink(gss_auth->dentry[1]);
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err_put_mech:
	gss_mech_put(gss_auth->mech);
err_free:
	kfree(gss_auth);
out_dec:
	module_put(THIS_MODULE);
812
	return ERR_PTR(err);
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813 814
}

815 816 817
static void
gss_free(struct gss_auth *gss_auth)
{
\
\"J. Bruce Fields\ 已提交
818 819
	rpc_unlink(gss_auth->dentry[1]);
	rpc_unlink(gss_auth->dentry[0]);
820 821 822 823 824 825 826 827 828 829 830 831 832 833
	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);
}

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834 835 836 837 838
static void
gss_destroy(struct rpc_auth *auth)
{
	struct gss_auth *gss_auth;

839 840
	dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
			auth, auth->au_flavor);
L
Linus Torvalds 已提交
841

842 843
	rpcauth_destroy_credcache(auth);

L
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844
	gss_auth = container_of(auth, struct gss_auth, rpc_auth);
845
	kref_put(&gss_auth->kref, gss_free_callback);
L
Linus Torvalds 已提交
846 847
}

848 849 850 851 852 853 854 855 856 857 858 859 860 861
/*
 * 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 ||
862
	    test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
863 864 865 866 867 868 869 870 871
		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);

872
	task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
873 874 875 876 877 878 879 880
	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
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881 882 883
 * to create a new cred or context, so they check that things have been
 * allocated before freeing them. */
static void
884
gss_do_free_ctx(struct gss_cl_ctx *ctx)
L
Linus Torvalds 已提交
885
{
886
	dprintk("RPC:       gss_free_ctx\n");
L
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887 888 889 890 891

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

892 893 894 895 896 897 898 899 900 901
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)
{
902 903 904 905
	struct gss_ctx *gc_gss_ctx;

	gc_gss_ctx = rcu_dereference(ctx->gc_gss_ctx);
	rcu_assign_pointer(ctx->gc_gss_ctx, NULL);
906
	call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
907 908
	if (gc_gss_ctx)
		gss_delete_sec_context(&gc_gss_ctx);
909 910
}

L
Linus Torvalds 已提交
911
static void
912
gss_free_cred(struct gss_cred *gss_cred)
L
Linus Torvalds 已提交
913
{
914 915 916
	dprintk("RPC:       gss_free_cred %p\n", gss_cred);
	kfree(gss_cred);
}
L
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917

918 919 920 921 922 923
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
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924

925
static void
926
gss_destroy_nullcred(struct rpc_cred *cred)
927
{
928
	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
929
	struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
930 931 932
	struct gss_cl_ctx *ctx = gss_cred->gc_ctx;

	rcu_assign_pointer(gss_cred->gc_ctx, NULL);
933
	call_rcu(&cred->cr_rcu, gss_free_cred_callback);
934 935
	if (ctx)
		gss_put_ctx(ctx);
936
	kref_put(&gss_auth->kref, gss_free_callback);
L
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937 938
}

939 940 941 942 943 944 945 946 947
static void
gss_destroy_cred(struct rpc_cred *cred)
{

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

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948 949 950 951
/*
 * Lookup RPCSEC_GSS cred for the current process
 */
static struct rpc_cred *
952
gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
L
Linus Torvalds 已提交
953
{
954
	return rpcauth_lookup_credcache(auth, acred, flags);
L
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955 956 957
}

static struct rpc_cred *
958
gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
L
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959 960 961 962 963
{
	struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
	struct gss_cred	*cred = NULL;
	int err = -ENOMEM;

964
	dprintk("RPC:       gss_create_cred for uid %d, flavor %d\n",
L
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965 966
		acred->uid, auth->au_flavor);

967
	if (!(cred = kzalloc(sizeof(*cred), GFP_NOFS)))
L
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968 969
		goto out_err;

970
	rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
L
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971 972 973 974
	/*
	 * Note: in order to force a call to call_refresh(), we deliberately
	 * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
	 */
975
	cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
L
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976
	cred->gc_service = gss_auth->service;
977
	cred->gc_machine_cred = acred->machine_cred;
978
	kref_get(&gss_auth->kref);
L
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979 980 981
	return &cred->gc_base;

out_err:
982
	dprintk("RPC:       gss_create_cred failed with error %d\n", err);
L
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983 984 985
	return ERR_PTR(err);
}

986 987 988 989 990 991 992 993 994 995 996 997 998
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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999
static int
1000
gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
L
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1001 1002 1003
{
	struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);

1004
	if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
1005
		goto out;
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1006
	/* Don't match with creds that have expired. */
1007 1008 1009
	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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1010
		return 0;
1011
out:
1012 1013
	if (acred->machine_cred != gss_cred->gc_machine_cred)
		return 0;
L
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1014 1015 1016 1017 1018 1019 1020
	return (rc->cr_uid == acred->uid);
}

/*
* Marshal credentials.
* Maybe we should keep a cached credential for performance reasons.
*/
1021 1022
static __be32 *
gss_marshal(struct rpc_task *task, __be32 *p)
L
Linus Torvalds 已提交
1023 1024 1025 1026 1027
{
	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);
1028
	__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;

1035
	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: */
1053 1054
	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);
1062
	maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
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1063
	if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
1064
		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;
}

1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097
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)
{
1104 1105 1106 1107 1108 1109 1110 1111 1112 1113
	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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1115 1116 1117 1118
	if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
		ret = gss_refresh_upcall(task);
out:
	return ret;
L
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}

1121 1122 1123 1124 1125 1126 1127
/* Dummy refresh routine: used only when destroying the context */
static int
gss_refresh_null(struct rpc_task *task)
{
	return -EACCES;
}

1128 1129
static __be32 *
gss_validate(struct rpc_task *task, __be32 *p)
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{
	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1133
	__be32		seq;
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	struct kvec	iov;
	struct xdr_buf	verf_buf;
	struct xdr_netobj mic;
	u32		flav,len;
	u32		maj_stat;

1140
	dprintk("RPC: %5u gss_validate\n", task->tk_pid);
L
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1141 1142 1143

	flav = ntohl(*p++);
	if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
1144
		goto out_bad;
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1145 1146 1147 1148 1149 1150 1151 1152 1153
	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;

1154
	maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
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1155
	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1156
		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1157
	if (maj_stat) {
1158
		dprintk("RPC: %5u gss_validate: gss_verify_mic returned "
1159
				"error 0x%08x\n", task->tk_pid, maj_stat);
L
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1160
		goto out_bad;
1161
	}
1162 1163
	/* We leave it to unwrap to calculate au_rslack. For now we just
	 * calculate the length of the verifier: */
1164
	cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
L
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	gss_put_ctx(ctx);
1166
	dprintk("RPC: %5u gss_validate: gss_verify_mic succeeded.\n",
L
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1167 1168 1169 1170
			task->tk_pid);
	return p + XDR_QUADLEN(len);
out_bad:
	gss_put_ctx(ctx);
1171
	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,
1177
		kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
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{
	struct xdr_buf	*snd_buf = &rqstp->rq_snd_buf;
	struct xdr_buf	integ_buf;
1181
	__be32          *integ_len = NULL;
L
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	struct xdr_netobj mic;
1183 1184
	u32		offset;
	__be32		*q;
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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);

1193
	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: */
1203
	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);

1210
	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)
1213
		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;
}

1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269
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:
	for (i--; i >= 0; i--) {
		__free_page(rqstp->rq_enc_pages[i]);
	}
out:
	return -EAGAIN;
}

static inline int
gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1270
		kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
1271 1272 1273 1274 1275
{
	struct xdr_buf	*snd_buf = &rqstp->rq_snd_buf;
	u32		offset;
	u32             maj_stat;
	int		status;
1276
	__be32		*opaque_len;
1277 1278 1279 1280 1281 1282 1283 1284 1285 1286
	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);

1287
	status = encode(rqstp, p, obj);
1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304
	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;
	/* Give the tail its own page, in case we need extra space in the
	 * head when wrapping: */
	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;
	}
1305
	maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1306 1307
	/* RPC_SLACK_SPACE should prevent this ever happening: */
	BUG_ON(snd_buf->len > snd_buf->buflen);
1308
	status = -EIO;
1309 1310 1311
	/* 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)
1312
		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330
	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,
1333
	     kxdrproc_t encode, void *rqstp, __be32 *p, void *obj)
L
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1334 1335 1336 1337 1338 1339 1340
{
	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;

1341
	dprintk("RPC: %5u gss_wrap_req\n", task->tk_pid);
L
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1342 1343 1344 1345
	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.
		 */
1346
		status = encode(rqstp, p, obj);
L
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1347 1348 1349 1350
		goto out;
	}
	switch (gss_cred->gc_service) {
		case RPC_GSS_SVC_NONE:
1351
			status = encode(rqstp, p, obj);
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1352 1353 1354 1355 1356
			break;
		case RPC_GSS_SVC_INTEGRITY:
			status = gss_wrap_req_integ(cred, ctx, encode,
								rqstp, p, obj);
			break;
1357
		case RPC_GSS_SVC_PRIVACY:
1358 1359
			status = gss_wrap_req_priv(cred, ctx, encode,
					rqstp, p, obj);
L
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1360 1361 1362 1363
			break;
	}
out:
	gss_put_ctx(ctx);
1364
	dprintk("RPC: %5u gss_wrap_req returning %d\n", task->tk_pid, status);
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	return status;
}

static inline int
gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1370
		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;

1397
	maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
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1398
	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1399
		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
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1400 1401 1402 1403 1404
	if (maj_stat != GSS_S_COMPLETE)
		return status;
	return 0;
}

1405 1406
static inline int
gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1407
		struct rpc_rqst *rqstp, __be32 **p)
1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421
{
	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;

1422
	maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1423
	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1424
		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1425 1426 1427 1428 1429 1430 1431 1432 1433
	if (maj_stat != GSS_S_COMPLETE)
		return status;
	if (ntohl(*(*p)++) != rqstp->rq_seqno)
		return status;

	return 0;
}


L
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1434 1435
static int
gss_unwrap_resp(struct rpc_task *task,
1436
		kxdrproc_t decode, void *rqstp, __be32 *p, void *obj)
L
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1437 1438 1439 1440 1441
{
	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);
1442
	__be32		*savedp = p;
1443 1444
	struct kvec	*head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
	int		savedlen = head->iov_len;
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1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456
	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;
1457
		case RPC_GSS_SVC_PRIVACY:
1458 1459 1460
			status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
			if (status)
				goto out;
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1461 1462
			break;
	}
1463
	/* take into account extra slack for integrity and privacy cases: */
1464
	cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1465
						+ (savedlen - head->iov_len);
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out_decode:
1467
	status = decode(rqstp, p, obj);
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out:
	gss_put_ctx(ctx);
1470
	dprintk("RPC: %5u gss_unwrap_resp returning %d\n", task->tk_pid,
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1471 1472 1473
			status);
	return status;
}
1474

1475
static const struct rpc_authops authgss_ops = {
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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
};

1485
static const struct rpc_credops gss_credops = {
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1486 1487
	.cr_name	= "AUTH_GSS",
	.crdestroy	= gss_destroy_cred,
1488
	.cr_init	= gss_cred_init,
1489
	.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,
};

1498 1499
static const struct rpc_credops gss_nullops = {
	.cr_name	= "AUTH_GSS",
1500
	.crdestroy	= gss_destroy_nullcred,
1501
	.crbind		= rpcauth_generic_bind_cred,
1502 1503 1504 1505 1506 1507 1508 1509
	.crmatch	= gss_match,
	.crmarshal	= gss_marshal,
	.crrefresh	= gss_refresh_null,
	.crvalidate	= gss_validate,
	.crwrap_req	= gss_wrap_req,
	.crunwrap_resp	= gss_unwrap_resp,
};

1510
static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
\
\"J. Bruce Fields\ 已提交
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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,
};

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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;
1539
	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)