ClabureDB: Classified Bug-Reports Database

   /*
    * linux/net/sunrpc/auth_gss/auth_gss.c
    *
    * RPCSEC_GSS client authentication.
    *
    *  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>
  #include <linux/pagemap.h>
  #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>
  
  static const struct rpc_authops authgss_ops;
  
  static const struct rpc_credops gss_credops;
  static const struct rpc_credops gss_nullops;
  
  #ifdef RPC_DEBUG
  # define RPCDBG_FACILITY        RPCDBG_AUTH
  #endif
  
  #define GSS_CRED_SLACK                1024
  /* length of a krb5 verifier (48), plus data added before arguments when
   * using integrity (two 4-byte integers): */
  #define GSS_VERF_SLACK                100
  
  struct gss_auth {
          struct kref kref;
          struct rpc_auth rpc_auth;
          struct gss_api_mech *mech;
          enum rpc_gss_svc service;
          struct rpc_clnt *client;
          struct dentry *dentry;
  };
  
  static void gss_free_ctx(struct gss_cl_ctx *);
  static struct rpc_pipe_ops gss_upcall_ops;
  
  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))
                  gss_free_ctx(ctx);
  }
  
  /* 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.
   */
 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);
 
         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
                 return;
         gss_get_ctx(ctx);
         rcu_assign_pointer(gss_cred->gc_ctx, ctx);
         set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
         smp_mb__before_clear_bit();
         clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);
 }
 
 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);
         dest->data = kmemdup(p, len, GFP_NOFS);
         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;
 
         rcu_read_lock();
         if (gss_cred->gc_ctx)
                 ctx = gss_get_ctx(gss_cred->gc_ctx);
         rcu_read_unlock();
         return ctx;
 }
 
 static struct gss_cl_ctx *
 gss_alloc_context(void)
 {
         struct gss_cl_ctx *ctx;
 
         ctx = kzalloc(sizeof(*ctx), GFP_NOFS);
         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:
         dprintk("RPC:       gss_fill_context returning %ld\n", -PTR_ERR(p));
         return p;
 }
 
 
 struct gss_upcall_msg {
         atomic_t count;
         uid_t        uid;
         struct rpc_pipe_msg msg;
         struct list_head list;
         struct gss_auth *auth;
         struct rpc_wait_queue rpc_waitqueue;
         wait_queue_head_t waitqueue;
         struct gss_cl_ctx *ctx;
 };
 
 static void
 gss_release_msg(struct gss_upcall_msg *gss_msg)
 {
         if (!atomic_dec_and_test(&gss_msg->count))
                 return;
         BUG_ON(!list_empty(&gss_msg->list));
         if (gss_msg->ctx != NULL)
                 gss_put_ctx(gss_msg->ctx);
         rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
         kfree(gss_msg);
 }
 
 static struct gss_upcall_msg *
 __gss_find_upcall(struct rpc_inode *rpci, uid_t uid)
 {
         struct gss_upcall_msg *pos;
         list_for_each_entry(pos, &rpci->in_downcall, list) {
                 if (pos->uid != uid)
                         continue;
                 atomic_inc(&pos->count);
                 dprintk("RPC:       gss_find_upcall found msg %p\n", pos);
                 return pos;
         }
         dprintk("RPC:       gss_find_upcall found nothing\n");
         return NULL;
 }
 
 /* Try to add an upcall to the pipefs queue.
  * 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)
 {
         struct inode *inode = gss_auth->dentry->d_inode;
         struct rpc_inode *rpci = RPC_I(inode);
         struct gss_upcall_msg *old;
 
         spin_lock(&inode->i_lock);
         old = __gss_find_upcall(rpci, gss_msg->uid);
         if (old == NULL) {
                 atomic_inc(&gss_msg->count);
                 list_add(&gss_msg->list, &rpci->in_downcall);
         } else
                 gss_msg = old;
         spin_unlock(&inode->i_lock);
         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)
 {
         struct gss_auth *gss_auth = gss_msg->auth;
         struct inode *inode = gss_auth->dentry->d_inode;
 
         if (list_empty(&gss_msg->list))
                 return;
         spin_lock(&inode->i_lock);
         if (!list_empty(&gss_msg->list))
                 __gss_unhash_msg(gss_msg);
         spin_unlock(&inode->i_lock);
 }
 
 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;
         struct inode *inode = gss_msg->auth->dentry->d_inode;
 
         spin_lock(&inode->i_lock);
         if (gss_msg->ctx)
                 gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_msg->ctx);
         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);
         spin_unlock(&inode->i_lock);
         gss_release_msg(gss_msg);
 }
 
 static inline struct gss_upcall_msg *
 gss_alloc_msg(struct gss_auth *gss_auth, uid_t uid)
 {
         struct gss_upcall_msg *gss_msg;
 
         gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
         if (gss_msg != NULL) {
                 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->msg.data = &gss_msg->uid;
                 gss_msg->msg.len = sizeof(gss_msg->uid);
                 gss_msg->uid = uid;
                 gss_msg->auth = gss_auth;
         }
         return gss_msg;
 }
 
 static struct gss_upcall_msg *
 gss_setup_upcall(struct rpc_clnt *clnt, struct gss_auth *gss_auth, struct rpc_cred *cred)
 {
         struct gss_cred *gss_cred = container_of(cred,
                         struct gss_cred, gc_base);
         struct gss_upcall_msg *gss_new, *gss_msg;
         uid_t uid = cred->cr_uid;
 
         /* Special case: rpc.gssd assumes that uid == 0 implies machine creds */
         if (gss_cred->gc_machine_cred != 0)
                 uid = 0;
 
         gss_new = gss_alloc_msg(gss_auth, uid);
         if (gss_new == NULL)
                 return ERR_PTR(-ENOMEM);
         gss_msg = gss_add_msg(gss_auth, gss_new);
         if (gss_msg == gss_new) {
                 int res = rpc_queue_upcall(gss_auth->dentry->d_inode, &gss_new->msg);
                 if (res) {
                         gss_unhash_msg(gss_new);
                         gss_msg = ERR_PTR(res);
                 }
         } else
                 gss_release_msg(gss_new);
         return gss_msg;
 }
 
 static inline int
 gss_refresh_upcall(struct rpc_task *task)
 {
         struct rpc_cred *cred = task->tk_msg.rpc_cred;
         struct gss_auth *gss_auth = container_of(cred->cr_auth,
                         struct gss_auth, rpc_auth);
         struct gss_cred *gss_cred = container_of(cred,
                         struct gss_cred, gc_base);
         struct gss_upcall_msg *gss_msg;
         struct inode *inode = gss_auth->dentry->d_inode;
         int err = 0;
 
         dprintk("RPC: %5u gss_refresh_upcall for uid %u\n", task->tk_pid,
                                                                 cred->cr_uid);
         gss_msg = gss_setup_upcall(task->tk_client, gss_auth, cred);
         if (IS_ERR(gss_msg)) {
                 err = PTR_ERR(gss_msg);
                 goto out;
         }
         spin_lock(&inode->i_lock);
         if (gss_cred->gc_upcall != NULL)
                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
         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) {
                 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);
                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
         } else
                 err = gss_msg->msg.errno;
         spin_unlock(&inode->i_lock);
         gss_release_msg(gss_msg);
 out:
         dprintk("RPC: %5u gss_refresh_upcall for uid %u result %d\n",
                         task->tk_pid, cred->cr_uid, err);
         return err;
 }
 
 static inline int
 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 {
         struct inode *inode = gss_auth->dentry->d_inode;
         struct rpc_cred *cred = &gss_cred->gc_base;
         struct gss_upcall_msg *gss_msg;
         DEFINE_WAIT(wait);
         int err = 0;
 
         dprintk("RPC:       gss_upcall for uid %u\n", cred->cr_uid);
         gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred);
         if (IS_ERR(gss_msg)) {
                 err = PTR_ERR(gss_msg);
                 goto out;
         }
         for (;;) {
                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_INTERRUPTIBLE);
                 spin_lock(&inode->i_lock);
                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
                         break;
                 }
                 spin_unlock(&inode->i_lock);
                 if (signalled()) {
                         err = -ERESTARTSYS;
                         goto out_intr;
                 }
                 schedule();
         }
         if (gss_msg->ctx)
                 gss_cred_set_ctx(cred, gss_msg->ctx);
         else
                 err = gss_msg->msg.errno;
         spin_unlock(&inode->i_lock);
 out_intr:
         finish_wait(&gss_msg->waitqueue, &wait);
         gss_release_msg(gss_msg);
 out:
         dprintk("RPC:       gss_create_upcall for uid %u result %d\n",
                         cred->cr_uid, err);
         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;
         size_t mlen = min(msg->len, buflen);
         unsigned long left;
 
         left = copy_to_user(dst, data, mlen);
         if (left == mlen) {
                 msg->errno = -EFAULT;
                 return -EFAULT;
         }
 
         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;
         struct inode *inode = filp->f_path.dentry->d_inode;
         struct gss_cl_ctx *ctx;
         uid_t uid;
         ssize_t err = -EFBIG;
 
         if (mlen > MSG_BUF_MAXSIZE)
                 goto out;
         err = -ENOMEM;
         buf = kmalloc(mlen, GFP_NOFS);
         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;
 
         err = -ENOENT;
         /* Find a matching upcall */
         spin_lock(&inode->i_lock);
         gss_msg = __gss_find_upcall(RPC_I(inode), uid);
         if (gss_msg == NULL) {
                 spin_unlock(&inode->i_lock);
                 goto err_put_ctx;
         }
         list_del_init(&gss_msg->list);
         spin_unlock(&inode->i_lock);
 
         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
         if (IS_ERR(p)) {
                 err = PTR_ERR(p);
                 gss_msg->msg.errno = (err == -EAGAIN) ? -EAGAIN : -EACCES;
                 goto err_release_msg;
         }
         gss_msg->ctx = gss_get_ctx(ctx);
         err = mlen;
 
 err_release_msg:
         spin_lock(&inode->i_lock);
         __gss_unhash_msg(gss_msg);
         spin_unlock(&inode->i_lock);
         gss_release_msg(gss_msg);
 err_put_ctx:
         gss_put_ctx(ctx);
 err:
         kfree(buf);
 out:
         dprintk("RPC:       gss_pipe_downcall returning %Zd\n", err);
         return err;
 }
 
 static void
 gss_pipe_release(struct inode *inode)
 {
         struct rpc_inode *rpci = RPC_I(inode);
         struct gss_upcall_msg *gss_msg;
 
         spin_lock(&inode->i_lock);
         while (!list_empty(&rpci->in_downcall)) {
 
                 gss_msg = list_entry(rpci->in_downcall.next,
                                 struct gss_upcall_msg, list);
                 gss_msg->msg.errno = -EPIPE;
                 atomic_inc(&gss_msg->count);
                 __gss_unhash_msg(gss_msg);
                 spin_unlock(&inode->i_lock);
                 gss_release_msg(gss_msg);
                 spin_lock(&inode->i_lock);
         }
         spin_unlock(&inode->i_lock);
 }
 
 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);
         static unsigned long ratelimit;
 
         if (msg->errno < 0) {
                 dprintk("RPC:       gss_pipe_destroy_msg releasing msg %p\n",
                                 gss_msg);
                 atomic_inc(&gss_msg->count);
                 gss_unhash_msg(gss_msg);
                 if (msg->errno == -ETIMEDOUT) {
                         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;
                         }
                 }
                 gss_release_msg(gss_msg);
         }
 }
 
 /*
  * NOTE: we have the opportunity to use different
  * 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;
         int err = -ENOMEM; /* XXX? */
 
         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
 
         if (!try_module_get(THIS_MODULE))
                 return ERR_PTR(err);
         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
                 goto out_dec;
         gss_auth->client = clnt;
         err = -EINVAL;
         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
         if (!gss_auth->mech) {
                 printk(KERN_WARNING "%s: Pseudoflavor %d not found!\n",
                                 __func__, flavor);
                 goto err_free;
         }
         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
         if (gss_auth->service == 0)
                 goto err_put_mech;
         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);
         kref_init(&gss_auth->kref);
 
         gss_auth->dentry = rpc_mkpipe(clnt->cl_dentry, gss_auth->mech->gm_name,
                         clnt, &gss_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
         if (IS_ERR(gss_auth->dentry)) {
                 err = PTR_ERR(gss_auth->dentry);
                 goto err_put_mech;
         }
 
         err = rpcauth_init_credcache(auth);
         if (err)
                 goto err_unlink_pipe;
 
         return auth;
 err_unlink_pipe:
         rpc_unlink(gss_auth->dentry);
 err_put_mech:
         gss_mech_put(gss_auth->mech);
 err_free:
         kfree(gss_auth);
 out_dec:
         module_put(THIS_MODULE);
         return ERR_PTR(err);
 }
 
 static void
 gss_free(struct gss_auth *gss_auth)
 {
         rpc_unlink(gss_auth->dentry);
         gss_auth->dentry = NULL;
         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);
 }
 
 static void
 gss_destroy(struct rpc_auth *auth)
 {
         struct gss_auth *gss_auth;
 
         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
                         auth, auth->au_flavor);
 
         rpcauth_destroy_credcache(auth);
 
         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
         kref_put(&gss_auth->kref, gss_free_callback);
 }
 
 /*
  * 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 ||
             test_and_clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
                 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);
 
         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
         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
  * to create a new cred or context, so they check that things have been
  * allocated before freeing them. */
 static void
 gss_do_free_ctx(struct gss_cl_ctx *ctx)
 {
         dprintk("RPC:       gss_free_ctx\n");
 
         kfree(ctx->gc_wire_ctx.data);
         kfree(ctx);
 }
 
 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)
 {
         struct gss_ctx *gc_gss_ctx;
 
         gc_gss_ctx = rcu_dereference(ctx->gc_gss_ctx);
         rcu_assign_pointer(ctx->gc_gss_ctx, NULL);
         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
         if (gc_gss_ctx)
                 gss_delete_sec_context(&gc_gss_ctx);
 }
 
 static void
 gss_free_cred(struct gss_cred *gss_cred)
 {
         dprintk("RPC:       gss_free_cred %p\n", gss_cred);
         kfree(gss_cred);
 }
 
 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);
 }
 
 static void
 gss_destroy_cred(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 gss_cl_ctx *ctx = gss_cred->gc_ctx;
 
         if (gss_destroying_context(cred))
                 return;
         rcu_assign_pointer(gss_cred->gc_ctx, NULL);
         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
         if (ctx)
                 gss_put_ctx(ctx);
         kref_put(&gss_auth->kref, gss_free_callback);
 }
 
 /*
  * Lookup RPCSEC_GSS cred for the current process
  */
 static struct rpc_cred *
 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 {
         return rpcauth_lookup_credcache(auth, acred, flags);
 }
 
 static struct rpc_cred *
 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 {
         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
         struct gss_cred        *cred = NULL;
         int err = -ENOMEM;
 
         dprintk("RPC:       gss_create_cred for uid %d, flavor %d\n",
                 acred->uid, auth->au_flavor);
 
         if (!(cred = kzalloc(sizeof(*cred), GFP_NOFS)))
                 goto out_err;
 
         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
         /*
          * Note: in order to force a call to call_refresh(), we deliberately
          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
          */
         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
         cred->gc_service = gss_auth->service;
         cred->gc_machine_cred = acred->machine_cred;
         kref_get(&gss_auth->kref);
         return &cred->gc_base;
 
 out_err:
         dprintk("RPC:       gss_create_cred failed with error %d\n", err);
         return ERR_PTR(err);
 }
 
 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;
 }
 
 static int
 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
 {
         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
 
         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
                 goto out;
         /* Don't match with creds that have expired. */
         if (time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
                 return 0;
         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
                 return 0;
 out:
         if (acred->machine_cred != gss_cred->gc_machine_cred)
                 return 0;
         return (rc->cr_uid == acred->uid);
 }
 
 /*
 * Marshal credentials.
 * Maybe we should keep a cached credential for performance reasons.
 */
 static __be32 *
 gss_marshal(struct rpc_task *task, __be32 *p)
 {
         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);
         __be32                *cred_len;
         struct rpc_rqst *req = task->tk_rqstp;
         u32             maj_stat = 0;
         struct xdr_netobj mic;
         struct kvec        iov;
         struct xdr_buf        verf_buf;
 
         dprintk("RPC: %5u gss_marshal\n", task->tk_pid);
 
         *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: */
         iov.iov_base = xprt_skip_transport_header(task->tk_xprt,
                                         req->rq_snd_buf.head[0].iov_base);
         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);
         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
         } 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;
 }
 
 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;
 }
 
 /*
 * Refresh credentials. XXX - finish
 */
 static int
 gss_refresh(struct rpc_task *task)
 {
         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;
         }
 
         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
                 ret = gss_refresh_upcall(task);
 out:
         return ret;
 }
 
 /* Dummy refresh routine: used only when destroying the context */
 static int
 gss_refresh_null(struct rpc_task *task)
 {
         return -EACCES;
 }
 
 static __be32 *
 gss_validate(struct rpc_task *task, __be32 *p)
 {
         struct rpc_cred *cred = task->tk_msg.rpc_cred;
         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
         __be32                seq;
         struct kvec        iov;
         struct xdr_buf        verf_buf;
         struct xdr_netobj mic;
         u32                flav,len;
         u32                maj_stat;
 
         dprintk("RPC: %5u gss_validate\n", task->tk_pid);
 
         flav = ntohl(*p++);
         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
                 goto out_bad;
         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;
 
         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
         if (maj_stat) {
                 dprintk("RPC: %5u gss_validate: gss_verify_mic returned "
                                 "error 0x%08x\n", task->tk_pid, maj_stat);
                 goto out_bad;
         }
         /* We leave it to unwrap to calculate au_rslack. For now we just
          * calculate the length of the verifier: */
         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
         gss_put_ctx(ctx);
         dprintk("RPC: %5u gss_validate: gss_verify_mic succeeded.\n",
                         task->tk_pid);
         return p + XDR_QUADLEN(len);
 out_bad:
         gss_put_ctx(ctx);
         dprintk("RPC: %5u gss_validate failed.\n", task->tk_pid);
         return NULL;
}

static inline int
gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
                kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
{
        struct xdr_buf        *snd_buf = &rqstp->rq_snd_buf;
        struct xdr_buf        integ_buf;
        __be32          *integ_len = NULL;
        struct xdr_netobj mic;
        u32                offset;
        __be32                *q;
        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);

        status = rpc_call_xdrproc(encode, rqstp, p, obj);
        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: */
        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;
        mic.data = (u8 *)(p + 1);

        maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
        status = -EIO; /* XXX? */
        if (maj_stat == GSS_S_CONTEXT_EXPIRED)
                clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
        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;
}

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,
                kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
{
        struct xdr_buf        *snd_buf = &rqstp->rq_snd_buf;
        u32                offset;
        u32             maj_stat;
        int                status;
        __be32                *opaque_len;
        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);

        status = rpc_call_xdrproc(encode, rqstp, p, obj);
        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;
        }
        maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
        /* RPC_SLACK_SPACE should prevent this ever happening: */
        BUG_ON(snd_buf->len > snd_buf->buflen);
        status = -EIO;
        /* 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)
                clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
        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;
}

static int
gss_wrap_req(struct rpc_task *task,
             kxdrproc_t encode, void *rqstp, __be32 *p, void *obj)
{
        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;

        dprintk("RPC: %5u gss_wrap_req\n", task->tk_pid);
        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.
                 */
                status = rpc_call_xdrproc(encode, rqstp, p, obj);
                goto out;
        }
        switch (gss_cred->gc_service) {
                case RPC_GSS_SVC_NONE:
                        status = rpc_call_xdrproc(encode, rqstp, p, obj);
                        break;
                case RPC_GSS_SVC_INTEGRITY:
                        status = gss_wrap_req_integ(cred, ctx, encode,
                                                                rqstp, p, obj);
                        break;
                case RPC_GSS_SVC_PRIVACY:
                        status = gss_wrap_req_priv(cred, ctx, encode,
                                        rqstp, p, obj);
                        break;
        }
out:
        gss_put_ctx(ctx);
        dprintk("RPC: %5u gss_wrap_req returning %d\n", task->tk_pid, status);
        return status;
}

static inline int
gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
                struct rpc_rqst *rqstp, __be32 **p)
{
        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;

        maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
        if (maj_stat == GSS_S_CONTEXT_EXPIRED)
                clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
        if (maj_stat != GSS_S_COMPLETE)
                return status;
        return 0;
}

static inline int
gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
                struct rpc_rqst *rqstp, __be32 **p)
{
        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;

        maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
        if (maj_stat == GSS_S_CONTEXT_EXPIRED)
                clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
        if (maj_stat != GSS_S_COMPLETE)
                return status;
        if (ntohl(*(*p)++) != rqstp->rq_seqno)
                return status;

        return 0;
}


static int
gss_unwrap_resp(struct rpc_task *task,
                kxdrproc_t decode, void *rqstp, __be32 *p, void *obj)
{
        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);
        __be32                *savedp = p;
        struct kvec        *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
        int                savedlen = head->iov_len;
        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;
                case RPC_GSS_SVC_PRIVACY:
                        status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
                        if (status)
                                goto out;
                        break;
        }
        /* take into account extra slack for integrity and privacy cases: */
        cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
                                                + (savedlen - head->iov_len);
out_decode:
        status = rpc_call_xdrproc(decode, rqstp, p, obj);
out:
        gss_put_ctx(ctx);
        dprintk("RPC: %5u gss_unwrap_resp returning %d\n", task->tk_pid,
                        status);
        return status;
}

static const struct rpc_authops authgss_ops = {
        .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
};

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

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

static struct rpc_pipe_ops gss_upcall_ops = {
        .upcall                = gss_pipe_upcall,
        .downcall        = gss_pipe_downcall,
        .destroy_msg        = gss_pipe_destroy_msg,
        .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;
        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);
}

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