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Linux/net/sunrpc/auth_gss/auth_gss.c

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  1 /*
  2  * linux/net/sunrpc/auth_gss/auth_gss.c
  3  *
  4  * RPCSEC_GSS client authentication.
  5  *
  6  *  Copyright (c) 2000 The Regents of the University of Michigan.
  7  *  All rights reserved.
  8  *
  9  *  Dug Song       <dugsong@monkey.org>
 10  *  Andy Adamson   <andros@umich.edu>
 11  *
 12  *  Redistribution and use in source and binary forms, with or without
 13  *  modification, are permitted provided that the following conditions
 14  *  are met:
 15  *
 16  *  1. Redistributions of source code must retain the above copyright
 17  *     notice, this list of conditions and the following disclaimer.
 18  *  2. Redistributions in binary form must reproduce the above copyright
 19  *     notice, this list of conditions and the following disclaimer in the
 20  *     documentation and/or other materials provided with the distribution.
 21  *  3. Neither the name of the University nor the names of its
 22  *     contributors may be used to endorse or promote products derived
 23  *     from this software without specific prior written permission.
 24  *
 25  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 26  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 27  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 28  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 29  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 30  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 31  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 32  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 33  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 34  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 35  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 36  */
 37 
 38 
 39 #include <linux/module.h>
 40 #include <linux/init.h>
 41 #include <linux/types.h>
 42 #include <linux/slab.h>
 43 #include <linux/sched.h>
 44 #include <linux/pagemap.h>
 45 #include <linux/sunrpc/clnt.h>
 46 #include <linux/sunrpc/auth.h>
 47 #include <linux/sunrpc/auth_gss.h>
 48 #include <linux/sunrpc/svcauth_gss.h>
 49 #include <linux/sunrpc/gss_err.h>
 50 #include <linux/workqueue.h>
 51 #include <linux/sunrpc/rpc_pipe_fs.h>
 52 #include <linux/sunrpc/gss_api.h>
 53 #include <asm/uaccess.h>
 54 #include <linux/hashtable.h>
 55 
 56 #include "../netns.h"
 57 
 58 static const struct rpc_authops authgss_ops;
 59 
 60 static const struct rpc_credops gss_credops;
 61 static const struct rpc_credops gss_nullops;
 62 
 63 #define GSS_RETRY_EXPIRED 5
 64 static unsigned int gss_expired_cred_retry_delay = GSS_RETRY_EXPIRED;
 65 
 66 #define GSS_KEY_EXPIRE_TIMEO 240
 67 static unsigned int gss_key_expire_timeo = GSS_KEY_EXPIRE_TIMEO;
 68 
 69 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 70 # define RPCDBG_FACILITY        RPCDBG_AUTH
 71 #endif
 72 
 73 #define GSS_CRED_SLACK          (RPC_MAX_AUTH_SIZE * 2)
 74 /* length of a krb5 verifier (48), plus data added before arguments when
 75  * using integrity (two 4-byte integers): */
 76 #define GSS_VERF_SLACK          100
 77 
 78 static DEFINE_HASHTABLE(gss_auth_hash_table, 4);
 79 static DEFINE_SPINLOCK(gss_auth_hash_lock);
 80 
 81 struct gss_pipe {
 82         struct rpc_pipe_dir_object pdo;
 83         struct rpc_pipe *pipe;
 84         struct rpc_clnt *clnt;
 85         const char *name;
 86         struct kref kref;
 87 };
 88 
 89 struct gss_auth {
 90         struct kref kref;
 91         struct hlist_node hash;
 92         struct rpc_auth rpc_auth;
 93         struct gss_api_mech *mech;
 94         enum rpc_gss_svc service;
 95         struct rpc_clnt *client;
 96         struct net *net;
 97         /*
 98          * There are two upcall pipes; dentry[1], named "gssd", is used
 99          * for the new text-based upcall; dentry[0] is named after the
100          * mechanism (for example, "krb5") and exists for
101          * backwards-compatibility with older gssd's.
102          */
103         struct gss_pipe *gss_pipe[2];
104         const char *target_name;
105 };
106 
107 /* pipe_version >= 0 if and only if someone has a pipe open. */
108 static DEFINE_SPINLOCK(pipe_version_lock);
109 static struct rpc_wait_queue pipe_version_rpc_waitqueue;
110 static DECLARE_WAIT_QUEUE_HEAD(pipe_version_waitqueue);
111 static void gss_put_auth(struct gss_auth *gss_auth);
112 
113 static void gss_free_ctx(struct gss_cl_ctx *);
114 static const struct rpc_pipe_ops gss_upcall_ops_v0;
115 static const struct rpc_pipe_ops gss_upcall_ops_v1;
116 
117 static inline struct gss_cl_ctx *
118 gss_get_ctx(struct gss_cl_ctx *ctx)
119 {
120         atomic_inc(&ctx->count);
121         return ctx;
122 }
123 
124 static inline void
125 gss_put_ctx(struct gss_cl_ctx *ctx)
126 {
127         if (atomic_dec_and_test(&ctx->count))
128                 gss_free_ctx(ctx);
129 }
130 
131 /* gss_cred_set_ctx:
132  * called by gss_upcall_callback and gss_create_upcall in order
133  * to set the gss context. The actual exchange of an old context
134  * and a new one is protected by the pipe->lock.
135  */
136 static void
137 gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
138 {
139         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
140 
141         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
142                 return;
143         gss_get_ctx(ctx);
144         rcu_assign_pointer(gss_cred->gc_ctx, ctx);
145         set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
146         smp_mb__before_atomic();
147         clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);
148 }
149 
150 static const void *
151 simple_get_bytes(const void *p, const void *end, void *res, size_t len)
152 {
153         const void *q = (const void *)((const char *)p + len);
154         if (unlikely(q > end || q < p))
155                 return ERR_PTR(-EFAULT);
156         memcpy(res, p, len);
157         return q;
158 }
159 
160 static inline const void *
161 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest)
162 {
163         const void *q;
164         unsigned int len;
165 
166         p = simple_get_bytes(p, end, &len, sizeof(len));
167         if (IS_ERR(p))
168                 return p;
169         q = (const void *)((const char *)p + len);
170         if (unlikely(q > end || q < p))
171                 return ERR_PTR(-EFAULT);
172         dest->data = kmemdup(p, len, GFP_NOFS);
173         if (unlikely(dest->data == NULL))
174                 return ERR_PTR(-ENOMEM);
175         dest->len = len;
176         return q;
177 }
178 
179 static struct gss_cl_ctx *
180 gss_cred_get_ctx(struct rpc_cred *cred)
181 {
182         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
183         struct gss_cl_ctx *ctx = NULL;
184 
185         rcu_read_lock();
186         ctx = rcu_dereference(gss_cred->gc_ctx);
187         if (ctx)
188                 gss_get_ctx(ctx);
189         rcu_read_unlock();
190         return ctx;
191 }
192 
193 static struct gss_cl_ctx *
194 gss_alloc_context(void)
195 {
196         struct gss_cl_ctx *ctx;
197 
198         ctx = kzalloc(sizeof(*ctx), GFP_NOFS);
199         if (ctx != NULL) {
200                 ctx->gc_proc = RPC_GSS_PROC_DATA;
201                 ctx->gc_seq = 1;        /* NetApp 6.4R1 doesn't accept seq. no. 0 */
202                 spin_lock_init(&ctx->gc_seq_lock);
203                 atomic_set(&ctx->count,1);
204         }
205         return ctx;
206 }
207 
208 #define GSSD_MIN_TIMEOUT (60 * 60)
209 static const void *
210 gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
211 {
212         const void *q;
213         unsigned int seclen;
214         unsigned int timeout;
215         unsigned long now = jiffies;
216         u32 window_size;
217         int ret;
218 
219         /* First unsigned int gives the remaining lifetime in seconds of the
220          * credential - e.g. the remaining TGT lifetime for Kerberos or
221          * the -t value passed to GSSD.
222          */
223         p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
224         if (IS_ERR(p))
225                 goto err;
226         if (timeout == 0)
227                 timeout = GSSD_MIN_TIMEOUT;
228         ctx->gc_expiry = now + ((unsigned long)timeout * HZ);
229         /* Sequence number window. Determines the maximum number of
230          * simultaneous requests
231          */
232         p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
233         if (IS_ERR(p))
234                 goto err;
235         ctx->gc_win = window_size;
236         /* gssd signals an error by passing ctx->gc_win = 0: */
237         if (ctx->gc_win == 0) {
238                 /*
239                  * in which case, p points to an error code. Anything other
240                  * than -EKEYEXPIRED gets converted to -EACCES.
241                  */
242                 p = simple_get_bytes(p, end, &ret, sizeof(ret));
243                 if (!IS_ERR(p))
244                         p = (ret == -EKEYEXPIRED) ? ERR_PTR(-EKEYEXPIRED) :
245                                                     ERR_PTR(-EACCES);
246                 goto err;
247         }
248         /* copy the opaque wire context */
249         p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
250         if (IS_ERR(p))
251                 goto err;
252         /* import the opaque security context */
253         p  = simple_get_bytes(p, end, &seclen, sizeof(seclen));
254         if (IS_ERR(p))
255                 goto err;
256         q = (const void *)((const char *)p + seclen);
257         if (unlikely(q > end || q < p)) {
258                 p = ERR_PTR(-EFAULT);
259                 goto err;
260         }
261         ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx, NULL, GFP_NOFS);
262         if (ret < 0) {
263                 p = ERR_PTR(ret);
264                 goto err;
265         }
266 
267         /* is there any trailing data? */
268         if (q == end) {
269                 p = q;
270                 goto done;
271         }
272 
273         /* pull in acceptor name (if there is one) */
274         p = simple_get_netobj(q, end, &ctx->gc_acceptor);
275         if (IS_ERR(p))
276                 goto err;
277 done:
278         dprintk("RPC:       %s Success. gc_expiry %lu now %lu timeout %u acceptor %.*s\n",
279                 __func__, ctx->gc_expiry, now, timeout, ctx->gc_acceptor.len,
280                 ctx->gc_acceptor.data);
281         return p;
282 err:
283         dprintk("RPC:       %s returns error %ld\n", __func__, -PTR_ERR(p));
284         return p;
285 }
286 
287 #define UPCALL_BUF_LEN 128
288 
289 struct gss_upcall_msg {
290         atomic_t count;
291         kuid_t  uid;
292         struct rpc_pipe_msg msg;
293         struct list_head list;
294         struct gss_auth *auth;
295         struct rpc_pipe *pipe;
296         struct rpc_wait_queue rpc_waitqueue;
297         wait_queue_head_t waitqueue;
298         struct gss_cl_ctx *ctx;
299         char databuf[UPCALL_BUF_LEN];
300 };
301 
302 static int get_pipe_version(struct net *net)
303 {
304         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
305         int ret;
306 
307         spin_lock(&pipe_version_lock);
308         if (sn->pipe_version >= 0) {
309                 atomic_inc(&sn->pipe_users);
310                 ret = sn->pipe_version;
311         } else
312                 ret = -EAGAIN;
313         spin_unlock(&pipe_version_lock);
314         return ret;
315 }
316 
317 static void put_pipe_version(struct net *net)
318 {
319         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
320 
321         if (atomic_dec_and_lock(&sn->pipe_users, &pipe_version_lock)) {
322                 sn->pipe_version = -1;
323                 spin_unlock(&pipe_version_lock);
324         }
325 }
326 
327 static void
328 gss_release_msg(struct gss_upcall_msg *gss_msg)
329 {
330         struct net *net = gss_msg->auth->net;
331         if (!atomic_dec_and_test(&gss_msg->count))
332                 return;
333         put_pipe_version(net);
334         BUG_ON(!list_empty(&gss_msg->list));
335         if (gss_msg->ctx != NULL)
336                 gss_put_ctx(gss_msg->ctx);
337         rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
338         gss_put_auth(gss_msg->auth);
339         kfree(gss_msg);
340 }
341 
342 static struct gss_upcall_msg *
343 __gss_find_upcall(struct rpc_pipe *pipe, kuid_t uid, const struct gss_auth *auth)
344 {
345         struct gss_upcall_msg *pos;
346         list_for_each_entry(pos, &pipe->in_downcall, list) {
347                 if (!uid_eq(pos->uid, uid))
348                         continue;
349                 if (auth && pos->auth->service != auth->service)
350                         continue;
351                 atomic_inc(&pos->count);
352                 dprintk("RPC:       %s found msg %p\n", __func__, pos);
353                 return pos;
354         }
355         dprintk("RPC:       %s found nothing\n", __func__);
356         return NULL;
357 }
358 
359 /* Try to add an upcall to the pipefs queue.
360  * If an upcall owned by our uid already exists, then we return a reference
361  * to that upcall instead of adding the new upcall.
362  */
363 static inline struct gss_upcall_msg *
364 gss_add_msg(struct gss_upcall_msg *gss_msg)
365 {
366         struct rpc_pipe *pipe = gss_msg->pipe;
367         struct gss_upcall_msg *old;
368 
369         spin_lock(&pipe->lock);
370         old = __gss_find_upcall(pipe, gss_msg->uid, gss_msg->auth);
371         if (old == NULL) {
372                 atomic_inc(&gss_msg->count);
373                 list_add(&gss_msg->list, &pipe->in_downcall);
374         } else
375                 gss_msg = old;
376         spin_unlock(&pipe->lock);
377         return gss_msg;
378 }
379 
380 static void
381 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
382 {
383         list_del_init(&gss_msg->list);
384         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
385         wake_up_all(&gss_msg->waitqueue);
386         atomic_dec(&gss_msg->count);
387 }
388 
389 static void
390 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
391 {
392         struct rpc_pipe *pipe = gss_msg->pipe;
393 
394         if (list_empty(&gss_msg->list))
395                 return;
396         spin_lock(&pipe->lock);
397         if (!list_empty(&gss_msg->list))
398                 __gss_unhash_msg(gss_msg);
399         spin_unlock(&pipe->lock);
400 }
401 
402 static void
403 gss_handle_downcall_result(struct gss_cred *gss_cred, struct gss_upcall_msg *gss_msg)
404 {
405         switch (gss_msg->msg.errno) {
406         case 0:
407                 if (gss_msg->ctx == NULL)
408                         break;
409                 clear_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
410                 gss_cred_set_ctx(&gss_cred->gc_base, gss_msg->ctx);
411                 break;
412         case -EKEYEXPIRED:
413                 set_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
414         }
415         gss_cred->gc_upcall_timestamp = jiffies;
416         gss_cred->gc_upcall = NULL;
417         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
418 }
419 
420 static void
421 gss_upcall_callback(struct rpc_task *task)
422 {
423         struct gss_cred *gss_cred = container_of(task->tk_rqstp->rq_cred,
424                         struct gss_cred, gc_base);
425         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
426         struct rpc_pipe *pipe = gss_msg->pipe;
427 
428         spin_lock(&pipe->lock);
429         gss_handle_downcall_result(gss_cred, gss_msg);
430         spin_unlock(&pipe->lock);
431         task->tk_status = gss_msg->msg.errno;
432         gss_release_msg(gss_msg);
433 }
434 
435 static void gss_encode_v0_msg(struct gss_upcall_msg *gss_msg)
436 {
437         uid_t uid = from_kuid(&init_user_ns, gss_msg->uid);
438         memcpy(gss_msg->databuf, &uid, sizeof(uid));
439         gss_msg->msg.data = gss_msg->databuf;
440         gss_msg->msg.len = sizeof(uid);
441 
442         BUILD_BUG_ON(sizeof(uid) > sizeof(gss_msg->databuf));
443 }
444 
445 static int gss_encode_v1_msg(struct gss_upcall_msg *gss_msg,
446                                 const char *service_name,
447                                 const char *target_name)
448 {
449         struct gss_api_mech *mech = gss_msg->auth->mech;
450         char *p = gss_msg->databuf;
451         size_t buflen = sizeof(gss_msg->databuf);
452         int len;
453 
454         len = scnprintf(p, buflen, "mech=%s uid=%d ", mech->gm_name,
455                         from_kuid(&init_user_ns, gss_msg->uid));
456         buflen -= len;
457         p += len;
458         gss_msg->msg.len = len;
459         if (target_name) {
460                 len = scnprintf(p, buflen, "target=%s ", target_name);
461                 buflen -= len;
462                 p += len;
463                 gss_msg->msg.len += len;
464         }
465         if (service_name != NULL) {
466                 len = scnprintf(p, buflen, "service=%s ", service_name);
467                 buflen -= len;
468                 p += len;
469                 gss_msg->msg.len += len;
470         }
471         if (mech->gm_upcall_enctypes) {
472                 len = scnprintf(p, buflen, "enctypes=%s ",
473                                 mech->gm_upcall_enctypes);
474                 buflen -= len;
475                 p += len;
476                 gss_msg->msg.len += len;
477         }
478         len = scnprintf(p, buflen, "\n");
479         if (len == 0)
480                 goto out_overflow;
481         gss_msg->msg.len += len;
482 
483         gss_msg->msg.data = gss_msg->databuf;
484         return 0;
485 out_overflow:
486         WARN_ON_ONCE(1);
487         return -ENOMEM;
488 }
489 
490 static struct gss_upcall_msg *
491 gss_alloc_msg(struct gss_auth *gss_auth,
492                 kuid_t uid, const char *service_name)
493 {
494         struct gss_upcall_msg *gss_msg;
495         int vers;
496         int err = -ENOMEM;
497 
498         gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
499         if (gss_msg == NULL)
500                 goto err;
501         vers = get_pipe_version(gss_auth->net);
502         err = vers;
503         if (err < 0)
504                 goto err_free_msg;
505         gss_msg->pipe = gss_auth->gss_pipe[vers]->pipe;
506         INIT_LIST_HEAD(&gss_msg->list);
507         rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
508         init_waitqueue_head(&gss_msg->waitqueue);
509         atomic_set(&gss_msg->count, 1);
510         gss_msg->uid = uid;
511         gss_msg->auth = gss_auth;
512         switch (vers) {
513         case 0:
514                 gss_encode_v0_msg(gss_msg);
515                 break;
516         default:
517                 err = gss_encode_v1_msg(gss_msg, service_name, gss_auth->target_name);
518                 if (err)
519                         goto err_put_pipe_version;
520         };
521         kref_get(&gss_auth->kref);
522         return gss_msg;
523 err_put_pipe_version:
524         put_pipe_version(gss_auth->net);
525 err_free_msg:
526         kfree(gss_msg);
527 err:
528         return ERR_PTR(err);
529 }
530 
531 static struct gss_upcall_msg *
532 gss_setup_upcall(struct gss_auth *gss_auth, struct rpc_cred *cred)
533 {
534         struct gss_cred *gss_cred = container_of(cred,
535                         struct gss_cred, gc_base);
536         struct gss_upcall_msg *gss_new, *gss_msg;
537         kuid_t uid = cred->cr_uid;
538 
539         gss_new = gss_alloc_msg(gss_auth, uid, gss_cred->gc_principal);
540         if (IS_ERR(gss_new))
541                 return gss_new;
542         gss_msg = gss_add_msg(gss_new);
543         if (gss_msg == gss_new) {
544                 int res;
545                 atomic_inc(&gss_msg->count);
546                 res = rpc_queue_upcall(gss_new->pipe, &gss_new->msg);
547                 if (res) {
548                         gss_unhash_msg(gss_new);
549                         atomic_dec(&gss_msg->count);
550                         gss_release_msg(gss_new);
551                         gss_msg = ERR_PTR(res);
552                 }
553         } else
554                 gss_release_msg(gss_new);
555         return gss_msg;
556 }
557 
558 static void warn_gssd(void)
559 {
560         dprintk("AUTH_GSS upcall failed. Please check user daemon is running.\n");
561 }
562 
563 static inline int
564 gss_refresh_upcall(struct rpc_task *task)
565 {
566         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
567         struct gss_auth *gss_auth = container_of(cred->cr_auth,
568                         struct gss_auth, rpc_auth);
569         struct gss_cred *gss_cred = container_of(cred,
570                         struct gss_cred, gc_base);
571         struct gss_upcall_msg *gss_msg;
572         struct rpc_pipe *pipe;
573         int err = 0;
574 
575         dprintk("RPC: %5u %s for uid %u\n",
576                 task->tk_pid, __func__, from_kuid(&init_user_ns, cred->cr_uid));
577         gss_msg = gss_setup_upcall(gss_auth, cred);
578         if (PTR_ERR(gss_msg) == -EAGAIN) {
579                 /* XXX: warning on the first, under the assumption we
580                  * shouldn't normally hit this case on a refresh. */
581                 warn_gssd();
582                 task->tk_timeout = 15*HZ;
583                 rpc_sleep_on(&pipe_version_rpc_waitqueue, task, NULL);
584                 return -EAGAIN;
585         }
586         if (IS_ERR(gss_msg)) {
587                 err = PTR_ERR(gss_msg);
588                 goto out;
589         }
590         pipe = gss_msg->pipe;
591         spin_lock(&pipe->lock);
592         if (gss_cred->gc_upcall != NULL)
593                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
594         else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
595                 task->tk_timeout = 0;
596                 gss_cred->gc_upcall = gss_msg;
597                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
598                 atomic_inc(&gss_msg->count);
599                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
600         } else {
601                 gss_handle_downcall_result(gss_cred, gss_msg);
602                 err = gss_msg->msg.errno;
603         }
604         spin_unlock(&pipe->lock);
605         gss_release_msg(gss_msg);
606 out:
607         dprintk("RPC: %5u %s for uid %u result %d\n",
608                 task->tk_pid, __func__,
609                 from_kuid(&init_user_ns, cred->cr_uid), err);
610         return err;
611 }
612 
613 static inline int
614 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
615 {
616         struct net *net = gss_auth->net;
617         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
618         struct rpc_pipe *pipe;
619         struct rpc_cred *cred = &gss_cred->gc_base;
620         struct gss_upcall_msg *gss_msg;
621         DEFINE_WAIT(wait);
622         int err;
623 
624         dprintk("RPC:       %s for uid %u\n",
625                 __func__, from_kuid(&init_user_ns, cred->cr_uid));
626 retry:
627         err = 0;
628         /* if gssd is down, just skip upcalling altogether */
629         if (!gssd_running(net)) {
630                 warn_gssd();
631                 return -EACCES;
632         }
633         gss_msg = gss_setup_upcall(gss_auth, cred);
634         if (PTR_ERR(gss_msg) == -EAGAIN) {
635                 err = wait_event_interruptible_timeout(pipe_version_waitqueue,
636                                 sn->pipe_version >= 0, 15 * HZ);
637                 if (sn->pipe_version < 0) {
638                         warn_gssd();
639                         err = -EACCES;
640                 }
641                 if (err < 0)
642                         goto out;
643                 goto retry;
644         }
645         if (IS_ERR(gss_msg)) {
646                 err = PTR_ERR(gss_msg);
647                 goto out;
648         }
649         pipe = gss_msg->pipe;
650         for (;;) {
651                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_KILLABLE);
652                 spin_lock(&pipe->lock);
653                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
654                         break;
655                 }
656                 spin_unlock(&pipe->lock);
657                 if (fatal_signal_pending(current)) {
658                         err = -ERESTARTSYS;
659                         goto out_intr;
660                 }
661                 schedule();
662         }
663         if (gss_msg->ctx)
664                 gss_cred_set_ctx(cred, gss_msg->ctx);
665         else
666                 err = gss_msg->msg.errno;
667         spin_unlock(&pipe->lock);
668 out_intr:
669         finish_wait(&gss_msg->waitqueue, &wait);
670         gss_release_msg(gss_msg);
671 out:
672         dprintk("RPC:       %s for uid %u result %d\n",
673                 __func__, from_kuid(&init_user_ns, cred->cr_uid), err);
674         return err;
675 }
676 
677 #define MSG_BUF_MAXSIZE 1024
678 
679 static ssize_t
680 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
681 {
682         const void *p, *end;
683         void *buf;
684         struct gss_upcall_msg *gss_msg;
685         struct rpc_pipe *pipe = RPC_I(file_inode(filp))->pipe;
686         struct gss_cl_ctx *ctx;
687         uid_t id;
688         kuid_t uid;
689         ssize_t err = -EFBIG;
690 
691         if (mlen > MSG_BUF_MAXSIZE)
692                 goto out;
693         err = -ENOMEM;
694         buf = kmalloc(mlen, GFP_NOFS);
695         if (!buf)
696                 goto out;
697 
698         err = -EFAULT;
699         if (copy_from_user(buf, src, mlen))
700                 goto err;
701 
702         end = (const void *)((char *)buf + mlen);
703         p = simple_get_bytes(buf, end, &id, sizeof(id));
704         if (IS_ERR(p)) {
705                 err = PTR_ERR(p);
706                 goto err;
707         }
708 
709         uid = make_kuid(&init_user_ns, id);
710         if (!uid_valid(uid)) {
711                 err = -EINVAL;
712                 goto err;
713         }
714 
715         err = -ENOMEM;
716         ctx = gss_alloc_context();
717         if (ctx == NULL)
718                 goto err;
719 
720         err = -ENOENT;
721         /* Find a matching upcall */
722         spin_lock(&pipe->lock);
723         gss_msg = __gss_find_upcall(pipe, uid, NULL);
724         if (gss_msg == NULL) {
725                 spin_unlock(&pipe->lock);
726                 goto err_put_ctx;
727         }
728         list_del_init(&gss_msg->list);
729         spin_unlock(&pipe->lock);
730 
731         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
732         if (IS_ERR(p)) {
733                 err = PTR_ERR(p);
734                 switch (err) {
735                 case -EACCES:
736                 case -EKEYEXPIRED:
737                         gss_msg->msg.errno = err;
738                         err = mlen;
739                         break;
740                 case -EFAULT:
741                 case -ENOMEM:
742                 case -EINVAL:
743                 case -ENOSYS:
744                         gss_msg->msg.errno = -EAGAIN;
745                         break;
746                 default:
747                         printk(KERN_CRIT "%s: bad return from "
748                                 "gss_fill_context: %zd\n", __func__, err);
749                         gss_msg->msg.errno = -EIO;
750                 }
751                 goto err_release_msg;
752         }
753         gss_msg->ctx = gss_get_ctx(ctx);
754         err = mlen;
755 
756 err_release_msg:
757         spin_lock(&pipe->lock);
758         __gss_unhash_msg(gss_msg);
759         spin_unlock(&pipe->lock);
760         gss_release_msg(gss_msg);
761 err_put_ctx:
762         gss_put_ctx(ctx);
763 err:
764         kfree(buf);
765 out:
766         dprintk("RPC:       %s returning %Zd\n", __func__, err);
767         return err;
768 }
769 
770 static int gss_pipe_open(struct inode *inode, int new_version)
771 {
772         struct net *net = inode->i_sb->s_fs_info;
773         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
774         int ret = 0;
775 
776         spin_lock(&pipe_version_lock);
777         if (sn->pipe_version < 0) {
778                 /* First open of any gss pipe determines the version: */
779                 sn->pipe_version = new_version;
780                 rpc_wake_up(&pipe_version_rpc_waitqueue);
781                 wake_up(&pipe_version_waitqueue);
782         } else if (sn->pipe_version != new_version) {
783                 /* Trying to open a pipe of a different version */
784                 ret = -EBUSY;
785                 goto out;
786         }
787         atomic_inc(&sn->pipe_users);
788 out:
789         spin_unlock(&pipe_version_lock);
790         return ret;
791 
792 }
793 
794 static int gss_pipe_open_v0(struct inode *inode)
795 {
796         return gss_pipe_open(inode, 0);
797 }
798 
799 static int gss_pipe_open_v1(struct inode *inode)
800 {
801         return gss_pipe_open(inode, 1);
802 }
803 
804 static void
805 gss_pipe_release(struct inode *inode)
806 {
807         struct net *net = inode->i_sb->s_fs_info;
808         struct rpc_pipe *pipe = RPC_I(inode)->pipe;
809         struct gss_upcall_msg *gss_msg;
810 
811 restart:
812         spin_lock(&pipe->lock);
813         list_for_each_entry(gss_msg, &pipe->in_downcall, list) {
814 
815                 if (!list_empty(&gss_msg->msg.list))
816                         continue;
817                 gss_msg->msg.errno = -EPIPE;
818                 atomic_inc(&gss_msg->count);
819                 __gss_unhash_msg(gss_msg);
820                 spin_unlock(&pipe->lock);
821                 gss_release_msg(gss_msg);
822                 goto restart;
823         }
824         spin_unlock(&pipe->lock);
825 
826         put_pipe_version(net);
827 }
828 
829 static void
830 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
831 {
832         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
833 
834         if (msg->errno < 0) {
835                 dprintk("RPC:       %s releasing msg %p\n",
836                         __func__, gss_msg);
837                 atomic_inc(&gss_msg->count);
838                 gss_unhash_msg(gss_msg);
839                 if (msg->errno == -ETIMEDOUT)
840                         warn_gssd();
841                 gss_release_msg(gss_msg);
842         }
843         gss_release_msg(gss_msg);
844 }
845 
846 static void gss_pipe_dentry_destroy(struct dentry *dir,
847                 struct rpc_pipe_dir_object *pdo)
848 {
849         struct gss_pipe *gss_pipe = pdo->pdo_data;
850         struct rpc_pipe *pipe = gss_pipe->pipe;
851 
852         if (pipe->dentry != NULL) {
853                 rpc_unlink(pipe->dentry);
854                 pipe->dentry = NULL;
855         }
856 }
857 
858 static int gss_pipe_dentry_create(struct dentry *dir,
859                 struct rpc_pipe_dir_object *pdo)
860 {
861         struct gss_pipe *p = pdo->pdo_data;
862         struct dentry *dentry;
863 
864         dentry = rpc_mkpipe_dentry(dir, p->name, p->clnt, p->pipe);
865         if (IS_ERR(dentry))
866                 return PTR_ERR(dentry);
867         p->pipe->dentry = dentry;
868         return 0;
869 }
870 
871 static const struct rpc_pipe_dir_object_ops gss_pipe_dir_object_ops = {
872         .create = gss_pipe_dentry_create,
873         .destroy = gss_pipe_dentry_destroy,
874 };
875 
876 static struct gss_pipe *gss_pipe_alloc(struct rpc_clnt *clnt,
877                 const char *name,
878                 const struct rpc_pipe_ops *upcall_ops)
879 {
880         struct gss_pipe *p;
881         int err = -ENOMEM;
882 
883         p = kmalloc(sizeof(*p), GFP_KERNEL);
884         if (p == NULL)
885                 goto err;
886         p->pipe = rpc_mkpipe_data(upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
887         if (IS_ERR(p->pipe)) {
888                 err = PTR_ERR(p->pipe);
889                 goto err_free_gss_pipe;
890         }
891         p->name = name;
892         p->clnt = clnt;
893         kref_init(&p->kref);
894         rpc_init_pipe_dir_object(&p->pdo,
895                         &gss_pipe_dir_object_ops,
896                         p);
897         return p;
898 err_free_gss_pipe:
899         kfree(p);
900 err:
901         return ERR_PTR(err);
902 }
903 
904 struct gss_alloc_pdo {
905         struct rpc_clnt *clnt;
906         const char *name;
907         const struct rpc_pipe_ops *upcall_ops;
908 };
909 
910 static int gss_pipe_match_pdo(struct rpc_pipe_dir_object *pdo, void *data)
911 {
912         struct gss_pipe *gss_pipe;
913         struct gss_alloc_pdo *args = data;
914 
915         if (pdo->pdo_ops != &gss_pipe_dir_object_ops)
916                 return 0;
917         gss_pipe = container_of(pdo, struct gss_pipe, pdo);
918         if (strcmp(gss_pipe->name, args->name) != 0)
919                 return 0;
920         if (!kref_get_unless_zero(&gss_pipe->kref))
921                 return 0;
922         return 1;
923 }
924 
925 static struct rpc_pipe_dir_object *gss_pipe_alloc_pdo(void *data)
926 {
927         struct gss_pipe *gss_pipe;
928         struct gss_alloc_pdo *args = data;
929 
930         gss_pipe = gss_pipe_alloc(args->clnt, args->name, args->upcall_ops);
931         if (!IS_ERR(gss_pipe))
932                 return &gss_pipe->pdo;
933         return NULL;
934 }
935 
936 static struct gss_pipe *gss_pipe_get(struct rpc_clnt *clnt,
937                 const char *name,
938                 const struct rpc_pipe_ops *upcall_ops)
939 {
940         struct net *net = rpc_net_ns(clnt);
941         struct rpc_pipe_dir_object *pdo;
942         struct gss_alloc_pdo args = {
943                 .clnt = clnt,
944                 .name = name,
945                 .upcall_ops = upcall_ops,
946         };
947 
948         pdo = rpc_find_or_alloc_pipe_dir_object(net,
949                         &clnt->cl_pipedir_objects,
950                         gss_pipe_match_pdo,
951                         gss_pipe_alloc_pdo,
952                         &args);
953         if (pdo != NULL)
954                 return container_of(pdo, struct gss_pipe, pdo);
955         return ERR_PTR(-ENOMEM);
956 }
957 
958 static void __gss_pipe_free(struct gss_pipe *p)
959 {
960         struct rpc_clnt *clnt = p->clnt;
961         struct net *net = rpc_net_ns(clnt);
962 
963         rpc_remove_pipe_dir_object(net,
964                         &clnt->cl_pipedir_objects,
965                         &p->pdo);
966         rpc_destroy_pipe_data(p->pipe);
967         kfree(p);
968 }
969 
970 static void __gss_pipe_release(struct kref *kref)
971 {
972         struct gss_pipe *p = container_of(kref, struct gss_pipe, kref);
973 
974         __gss_pipe_free(p);
975 }
976 
977 static void gss_pipe_free(struct gss_pipe *p)
978 {
979         if (p != NULL)
980                 kref_put(&p->kref, __gss_pipe_release);
981 }
982 
983 /*
984  * NOTE: we have the opportunity to use different
985  * parameters based on the input flavor (which must be a pseudoflavor)
986  */
987 static struct gss_auth *
988 gss_create_new(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
989 {
990         rpc_authflavor_t flavor = args->pseudoflavor;
991         struct gss_auth *gss_auth;
992         struct gss_pipe *gss_pipe;
993         struct rpc_auth * auth;
994         int err = -ENOMEM; /* XXX? */
995 
996         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
997 
998         if (!try_module_get(THIS_MODULE))
999                 return ERR_PTR(err);
1000         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
1001                 goto out_dec;
1002         INIT_HLIST_NODE(&gss_auth->hash);
1003         gss_auth->target_name = NULL;
1004         if (args->target_name) {
1005                 gss_auth->target_name = kstrdup(args->target_name, GFP_KERNEL);
1006                 if (gss_auth->target_name == NULL)
1007                         goto err_free;
1008         }
1009         gss_auth->client = clnt;
1010         gss_auth->net = get_net(rpc_net_ns(clnt));
1011         err = -EINVAL;
1012         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
1013         if (!gss_auth->mech) {
1014                 dprintk("RPC:       Pseudoflavor %d not found!\n", flavor);
1015                 goto err_put_net;
1016         }
1017         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
1018         if (gss_auth->service == 0)
1019                 goto err_put_mech;
1020         if (!gssd_running(gss_auth->net))
1021                 goto err_put_mech;
1022         auth = &gss_auth->rpc_auth;
1023         auth->au_cslack = GSS_CRED_SLACK >> 2;
1024         auth->au_rslack = GSS_VERF_SLACK >> 2;
1025         auth->au_flags = 0;
1026         auth->au_ops = &authgss_ops;
1027         auth->au_flavor = flavor;
1028         if (gss_pseudoflavor_to_datatouch(gss_auth->mech, flavor))
1029                 auth->au_flags |= RPCAUTH_AUTH_DATATOUCH;
1030         atomic_set(&auth->au_count, 1);
1031         kref_init(&gss_auth->kref);
1032 
1033         err = rpcauth_init_credcache(auth);
1034         if (err)
1035                 goto err_put_mech;
1036         /*
1037          * Note: if we created the old pipe first, then someone who
1038          * examined the directory at the right moment might conclude
1039          * that we supported only the old pipe.  So we instead create
1040          * the new pipe first.
1041          */
1042         gss_pipe = gss_pipe_get(clnt, "gssd", &gss_upcall_ops_v1);
1043         if (IS_ERR(gss_pipe)) {
1044                 err = PTR_ERR(gss_pipe);
1045                 goto err_destroy_credcache;
1046         }
1047         gss_auth->gss_pipe[1] = gss_pipe;
1048 
1049         gss_pipe = gss_pipe_get(clnt, gss_auth->mech->gm_name,
1050                         &gss_upcall_ops_v0);
1051         if (IS_ERR(gss_pipe)) {
1052                 err = PTR_ERR(gss_pipe);
1053                 goto err_destroy_pipe_1;
1054         }
1055         gss_auth->gss_pipe[0] = gss_pipe;
1056 
1057         return gss_auth;
1058 err_destroy_pipe_1:
1059         gss_pipe_free(gss_auth->gss_pipe[1]);
1060 err_destroy_credcache:
1061         rpcauth_destroy_credcache(auth);
1062 err_put_mech:
1063         gss_mech_put(gss_auth->mech);
1064 err_put_net:
1065         put_net(gss_auth->net);
1066 err_free:
1067         kfree(gss_auth->target_name);
1068         kfree(gss_auth);
1069 out_dec:
1070         module_put(THIS_MODULE);
1071         return ERR_PTR(err);
1072 }
1073 
1074 static void
1075 gss_free(struct gss_auth *gss_auth)
1076 {
1077         gss_pipe_free(gss_auth->gss_pipe[0]);
1078         gss_pipe_free(gss_auth->gss_pipe[1]);
1079         gss_mech_put(gss_auth->mech);
1080         put_net(gss_auth->net);
1081         kfree(gss_auth->target_name);
1082 
1083         kfree(gss_auth);
1084         module_put(THIS_MODULE);
1085 }
1086 
1087 static void
1088 gss_free_callback(struct kref *kref)
1089 {
1090         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
1091 
1092         gss_free(gss_auth);
1093 }
1094 
1095 static void
1096 gss_put_auth(struct gss_auth *gss_auth)
1097 {
1098         kref_put(&gss_auth->kref, gss_free_callback);
1099 }
1100 
1101 static void
1102 gss_destroy(struct rpc_auth *auth)
1103 {
1104         struct gss_auth *gss_auth = container_of(auth,
1105                         struct gss_auth, rpc_auth);
1106 
1107         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
1108                         auth, auth->au_flavor);
1109 
1110         if (hash_hashed(&gss_auth->hash)) {
1111                 spin_lock(&gss_auth_hash_lock);
1112                 hash_del(&gss_auth->hash);
1113                 spin_unlock(&gss_auth_hash_lock);
1114         }
1115 
1116         gss_pipe_free(gss_auth->gss_pipe[0]);
1117         gss_auth->gss_pipe[0] = NULL;
1118         gss_pipe_free(gss_auth->gss_pipe[1]);
1119         gss_auth->gss_pipe[1] = NULL;
1120         rpcauth_destroy_credcache(auth);
1121 
1122         gss_put_auth(gss_auth);
1123 }
1124 
1125 /*
1126  * Auths may be shared between rpc clients that were cloned from a
1127  * common client with the same xprt, if they also share the flavor and
1128  * target_name.
1129  *
1130  * The auth is looked up from the oldest parent sharing the same
1131  * cl_xprt, and the auth itself references only that common parent
1132  * (which is guaranteed to last as long as any of its descendants).
1133  */
1134 static struct gss_auth *
1135 gss_auth_find_or_add_hashed(struct rpc_auth_create_args *args,
1136                 struct rpc_clnt *clnt,
1137                 struct gss_auth *new)
1138 {
1139         struct gss_auth *gss_auth;
1140         unsigned long hashval = (unsigned long)clnt;
1141 
1142         spin_lock(&gss_auth_hash_lock);
1143         hash_for_each_possible(gss_auth_hash_table,
1144                         gss_auth,
1145                         hash,
1146                         hashval) {
1147                 if (gss_auth->client != clnt)
1148                         continue;
1149                 if (gss_auth->rpc_auth.au_flavor != args->pseudoflavor)
1150                         continue;
1151                 if (gss_auth->target_name != args->target_name) {
1152                         if (gss_auth->target_name == NULL)
1153                                 continue;
1154                         if (args->target_name == NULL)
1155                                 continue;
1156                         if (strcmp(gss_auth->target_name, args->target_name))
1157                                 continue;
1158                 }
1159                 if (!atomic_inc_not_zero(&gss_auth->rpc_auth.au_count))
1160                         continue;
1161                 goto out;
1162         }
1163         if (new)
1164                 hash_add(gss_auth_hash_table, &new->hash, hashval);
1165         gss_auth = new;
1166 out:
1167         spin_unlock(&gss_auth_hash_lock);
1168         return gss_auth;
1169 }
1170 
1171 static struct gss_auth *
1172 gss_create_hashed(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1173 {
1174         struct gss_auth *gss_auth;
1175         struct gss_auth *new;
1176 
1177         gss_auth = gss_auth_find_or_add_hashed(args, clnt, NULL);
1178         if (gss_auth != NULL)
1179                 goto out;
1180         new = gss_create_new(args, clnt);
1181         if (IS_ERR(new))
1182                 return new;
1183         gss_auth = gss_auth_find_or_add_hashed(args, clnt, new);
1184         if (gss_auth != new)
1185                 gss_destroy(&new->rpc_auth);
1186 out:
1187         return gss_auth;
1188 }
1189 
1190 static struct rpc_auth *
1191 gss_create(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1192 {
1193         struct gss_auth *gss_auth;
1194         struct rpc_xprt_switch *xps = rcu_access_pointer(clnt->cl_xpi.xpi_xpswitch);
1195 
1196         while (clnt != clnt->cl_parent) {
1197                 struct rpc_clnt *parent = clnt->cl_parent;
1198                 /* Find the original parent for this transport */
1199                 if (rcu_access_pointer(parent->cl_xpi.xpi_xpswitch) != xps)
1200                         break;
1201                 clnt = parent;
1202         }
1203 
1204         gss_auth = gss_create_hashed(args, clnt);
1205         if (IS_ERR(gss_auth))
1206                 return ERR_CAST(gss_auth);
1207         return &gss_auth->rpc_auth;
1208 }
1209 
1210 /*
1211  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
1212  * to the server with the GSS control procedure field set to
1213  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
1214  * all RPCSEC_GSS state associated with that context.
1215  */
1216 static int
1217 gss_destroying_context(struct rpc_cred *cred)
1218 {
1219         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1220         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1221         struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
1222         struct rpc_task *task;
1223 
1224         if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
1225                 return 0;
1226 
1227         ctx->gc_proc = RPC_GSS_PROC_DESTROY;
1228         cred->cr_ops = &gss_nullops;
1229 
1230         /* Take a reference to ensure the cred will be destroyed either
1231          * by the RPC call or by the put_rpccred() below */
1232         get_rpccred(cred);
1233 
1234         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
1235         if (!IS_ERR(task))
1236                 rpc_put_task(task);
1237 
1238         put_rpccred(cred);
1239         return 1;
1240 }
1241 
1242 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
1243  * to create a new cred or context, so they check that things have been
1244  * allocated before freeing them. */
1245 static void
1246 gss_do_free_ctx(struct gss_cl_ctx *ctx)
1247 {
1248         dprintk("RPC:       %s\n", __func__);
1249 
1250         gss_delete_sec_context(&ctx->gc_gss_ctx);
1251         kfree(ctx->gc_wire_ctx.data);
1252         kfree(ctx->gc_acceptor.data);
1253         kfree(ctx);
1254 }
1255 
1256 static void
1257 gss_free_ctx_callback(struct rcu_head *head)
1258 {
1259         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
1260         gss_do_free_ctx(ctx);
1261 }
1262 
1263 static void
1264 gss_free_ctx(struct gss_cl_ctx *ctx)
1265 {
1266         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
1267 }
1268 
1269 static void
1270 gss_free_cred(struct gss_cred *gss_cred)
1271 {
1272         dprintk("RPC:       %s cred=%p\n", __func__, gss_cred);
1273         kfree(gss_cred);
1274 }
1275 
1276 static void
1277 gss_free_cred_callback(struct rcu_head *head)
1278 {
1279         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
1280         gss_free_cred(gss_cred);
1281 }
1282 
1283 static void
1284 gss_destroy_nullcred(struct rpc_cred *cred)
1285 {
1286         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1287         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1288         struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
1289 
1290         RCU_INIT_POINTER(gss_cred->gc_ctx, NULL);
1291         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
1292         if (ctx)
1293                 gss_put_ctx(ctx);
1294         gss_put_auth(gss_auth);
1295 }
1296 
1297 static void
1298 gss_destroy_cred(struct rpc_cred *cred)
1299 {
1300 
1301         if (gss_destroying_context(cred))
1302                 return;
1303         gss_destroy_nullcred(cred);
1304 }
1305 
1306 /*
1307  * Lookup RPCSEC_GSS cred for the current process
1308  */
1309 static struct rpc_cred *
1310 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1311 {
1312         return rpcauth_lookup_credcache(auth, acred, flags, GFP_NOFS);
1313 }
1314 
1315 static struct rpc_cred *
1316 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags, gfp_t gfp)
1317 {
1318         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1319         struct gss_cred *cred = NULL;
1320         int err = -ENOMEM;
1321 
1322         dprintk("RPC:       %s for uid %d, flavor %d\n",
1323                 __func__, from_kuid(&init_user_ns, acred->uid),
1324                 auth->au_flavor);
1325 
1326         if (!(cred = kzalloc(sizeof(*cred), gfp)))
1327                 goto out_err;
1328 
1329         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
1330         /*
1331          * Note: in order to force a call to call_refresh(), we deliberately
1332          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
1333          */
1334         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
1335         cred->gc_service = gss_auth->service;
1336         cred->gc_principal = NULL;
1337         if (acred->machine_cred)
1338                 cred->gc_principal = acred->principal;
1339         kref_get(&gss_auth->kref);
1340         return &cred->gc_base;
1341 
1342 out_err:
1343         dprintk("RPC:       %s failed with error %d\n", __func__, err);
1344         return ERR_PTR(err);
1345 }
1346 
1347 static int
1348 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
1349 {
1350         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1351         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
1352         int err;
1353 
1354         do {
1355                 err = gss_create_upcall(gss_auth, gss_cred);
1356         } while (err == -EAGAIN);
1357         return err;
1358 }
1359 
1360 static char *
1361 gss_stringify_acceptor(struct rpc_cred *cred)
1362 {
1363         char *string = NULL;
1364         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1365         struct gss_cl_ctx *ctx;
1366         unsigned int len;
1367         struct xdr_netobj *acceptor;
1368 
1369         rcu_read_lock();
1370         ctx = rcu_dereference(gss_cred->gc_ctx);
1371         if (!ctx)
1372                 goto out;
1373 
1374         len = ctx->gc_acceptor.len;
1375         rcu_read_unlock();
1376 
1377         /* no point if there's no string */
1378         if (!len)
1379                 return NULL;
1380 realloc:
1381         string = kmalloc(len + 1, GFP_KERNEL);
1382         if (!string)
1383                 return NULL;
1384 
1385         rcu_read_lock();
1386         ctx = rcu_dereference(gss_cred->gc_ctx);
1387 
1388         /* did the ctx disappear or was it replaced by one with no acceptor? */
1389         if (!ctx || !ctx->gc_acceptor.len) {
1390                 kfree(string);
1391                 string = NULL;
1392                 goto out;
1393         }
1394 
1395         acceptor = &ctx->gc_acceptor;
1396 
1397         /*
1398          * Did we find a new acceptor that's longer than the original? Allocate
1399          * a longer buffer and try again.
1400          */
1401         if (len < acceptor->len) {
1402                 len = acceptor->len;
1403                 rcu_read_unlock();
1404                 kfree(string);
1405                 goto realloc;
1406         }
1407 
1408         memcpy(string, acceptor->data, acceptor->len);
1409         string[acceptor->len] = '\0';
1410 out:
1411         rcu_read_unlock();
1412         return string;
1413 }
1414 
1415 /*
1416  * Returns -EACCES if GSS context is NULL or will expire within the
1417  * timeout (miliseconds)
1418  */
1419 static int
1420 gss_key_timeout(struct rpc_cred *rc)
1421 {
1422         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1423         struct gss_cl_ctx *ctx;
1424         unsigned long timeout = jiffies + (gss_key_expire_timeo * HZ);
1425         int ret = 0;
1426 
1427         rcu_read_lock();
1428         ctx = rcu_dereference(gss_cred->gc_ctx);
1429         if (!ctx || time_after(timeout, ctx->gc_expiry))
1430                 ret = -EACCES;
1431         rcu_read_unlock();
1432 
1433         return ret;
1434 }
1435 
1436 static int
1437 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
1438 {
1439         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1440         struct gss_cl_ctx *ctx;
1441         int ret;
1442 
1443         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
1444                 goto out;
1445         /* Don't match with creds that have expired. */
1446         rcu_read_lock();
1447         ctx = rcu_dereference(gss_cred->gc_ctx);
1448         if (!ctx || time_after(jiffies, ctx->gc_expiry)) {
1449                 rcu_read_unlock();
1450                 return 0;
1451         }
1452         rcu_read_unlock();
1453         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
1454                 return 0;
1455 out:
1456         if (acred->principal != NULL) {
1457                 if (gss_cred->gc_principal == NULL)
1458                         return 0;
1459                 ret = strcmp(acred->principal, gss_cred->gc_principal) == 0;
1460                 goto check_expire;
1461         }
1462         if (gss_cred->gc_principal != NULL)
1463                 return 0;
1464         ret = uid_eq(rc->cr_uid, acred->uid);
1465 
1466 check_expire:
1467         if (ret == 0)
1468                 return ret;
1469 
1470         /* Notify acred users of GSS context expiration timeout */
1471         if (test_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags) &&
1472             (gss_key_timeout(rc) != 0)) {
1473                 /* test will now be done from generic cred */
1474                 test_and_clear_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags);
1475                 /* tell NFS layer that key will expire soon */
1476                 set_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags);
1477         }
1478         return ret;
1479 }
1480 
1481 /*
1482 * Marshal credentials.
1483 * Maybe we should keep a cached credential for performance reasons.
1484 */
1485 static __be32 *
1486 gss_marshal(struct rpc_task *task, __be32 *p)
1487 {
1488         struct rpc_rqst *req = task->tk_rqstp;
1489         struct rpc_cred *cred = req->rq_cred;
1490         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1491                                                  gc_base);
1492         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
1493         __be32          *cred_len;
1494         u32             maj_stat = 0;
1495         struct xdr_netobj mic;
1496         struct kvec     iov;
1497         struct xdr_buf  verf_buf;
1498 
1499         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1500 
1501         *p++ = htonl(RPC_AUTH_GSS);
1502         cred_len = p++;
1503 
1504         spin_lock(&ctx->gc_seq_lock);
1505         req->rq_seqno = ctx->gc_seq++;
1506         spin_unlock(&ctx->gc_seq_lock);
1507 
1508         *p++ = htonl((u32) RPC_GSS_VERSION);
1509         *p++ = htonl((u32) ctx->gc_proc);
1510         *p++ = htonl((u32) req->rq_seqno);
1511         *p++ = htonl((u32) gss_cred->gc_service);
1512         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
1513         *cred_len = htonl((p - (cred_len + 1)) << 2);
1514 
1515         /* We compute the checksum for the verifier over the xdr-encoded bytes
1516          * starting with the xid and ending at the end of the credential: */
1517         iov.iov_base = xprt_skip_transport_header(req->rq_xprt,
1518                                         req->rq_snd_buf.head[0].iov_base);
1519         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
1520         xdr_buf_from_iov(&iov, &verf_buf);
1521 
1522         /* set verifier flavor*/
1523         *p++ = htonl(RPC_AUTH_GSS);
1524 
1525         mic.data = (u8 *)(p + 1);
1526         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1527         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
1528                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1529         } else if (maj_stat != 0) {
1530                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
1531                 goto out_put_ctx;
1532         }
1533         p = xdr_encode_opaque(p, NULL, mic.len);
1534         gss_put_ctx(ctx);
1535         return p;
1536 out_put_ctx:
1537         gss_put_ctx(ctx);
1538         return NULL;
1539 }
1540 
1541 static int gss_renew_cred(struct rpc_task *task)
1542 {
1543         struct rpc_cred *oldcred = task->tk_rqstp->rq_cred;
1544         struct gss_cred *gss_cred = container_of(oldcred,
1545                                                  struct gss_cred,
1546                                                  gc_base);
1547         struct rpc_auth *auth = oldcred->cr_auth;
1548         struct auth_cred acred = {
1549                 .uid = oldcred->cr_uid,
1550                 .principal = gss_cred->gc_principal,
1551                 .machine_cred = (gss_cred->gc_principal != NULL ? 1 : 0),
1552         };
1553         struct rpc_cred *new;
1554 
1555         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
1556         if (IS_ERR(new))
1557                 return PTR_ERR(new);
1558         task->tk_rqstp->rq_cred = new;
1559         put_rpccred(oldcred);
1560         return 0;
1561 }
1562 
1563 static int gss_cred_is_negative_entry(struct rpc_cred *cred)
1564 {
1565         if (test_bit(RPCAUTH_CRED_NEGATIVE, &cred->cr_flags)) {
1566                 unsigned long now = jiffies;
1567                 unsigned long begin, expire;
1568                 struct gss_cred *gss_cred; 
1569 
1570                 gss_cred = container_of(cred, struct gss_cred, gc_base);
1571                 begin = gss_cred->gc_upcall_timestamp;
1572                 expire = begin + gss_expired_cred_retry_delay * HZ;
1573 
1574                 if (time_in_range_open(now, begin, expire))
1575                         return 1;
1576         }
1577         return 0;
1578 }
1579 
1580 /*
1581 * Refresh credentials. XXX - finish
1582 */
1583 static int
1584 gss_refresh(struct rpc_task *task)
1585 {
1586         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1587         int ret = 0;
1588 
1589         if (gss_cred_is_negative_entry(cred))
1590                 return -EKEYEXPIRED;
1591 
1592         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
1593                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
1594                 ret = gss_renew_cred(task);
1595                 if (ret < 0)
1596                         goto out;
1597                 cred = task->tk_rqstp->rq_cred;
1598         }
1599 
1600         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
1601                 ret = gss_refresh_upcall(task);
1602 out:
1603         return ret;
1604 }
1605 
1606 /* Dummy refresh routine: used only when destroying the context */
1607 static int
1608 gss_refresh_null(struct rpc_task *task)
1609 {
1610         return 0;
1611 }
1612 
1613 static __be32 *
1614 gss_validate(struct rpc_task *task, __be32 *p)
1615 {
1616         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1617         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1618         __be32          seq;
1619         struct kvec     iov;
1620         struct xdr_buf  verf_buf;
1621         struct xdr_netobj mic;
1622         u32             flav,len;
1623         u32             maj_stat;
1624         __be32          *ret = ERR_PTR(-EIO);
1625 
1626         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1627 
1628         flav = ntohl(*p++);
1629         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
1630                 goto out_bad;
1631         if (flav != RPC_AUTH_GSS)
1632                 goto out_bad;
1633         seq = htonl(task->tk_rqstp->rq_seqno);
1634         iov.iov_base = &seq;
1635         iov.iov_len = sizeof(seq);
1636         xdr_buf_from_iov(&iov, &verf_buf);
1637         mic.data = (u8 *)p;
1638         mic.len = len;
1639 
1640         ret = ERR_PTR(-EACCES);
1641         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1642         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1643                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1644         if (maj_stat) {
1645                 dprintk("RPC: %5u %s: gss_verify_mic returned error 0x%08x\n",
1646                         task->tk_pid, __func__, maj_stat);
1647                 goto out_bad;
1648         }
1649         /* We leave it to unwrap to calculate au_rslack. For now we just
1650          * calculate the length of the verifier: */
1651         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1652         gss_put_ctx(ctx);
1653         dprintk("RPC: %5u %s: gss_verify_mic succeeded.\n",
1654                         task->tk_pid, __func__);
1655         return p + XDR_QUADLEN(len);
1656 out_bad:
1657         gss_put_ctx(ctx);
1658         dprintk("RPC: %5u %s failed ret %ld.\n", task->tk_pid, __func__,
1659                 PTR_ERR(ret));
1660         return ret;
1661 }
1662 
1663 static void gss_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
1664                                 __be32 *p, void *obj)
1665 {
1666         struct xdr_stream xdr;
1667 
1668         xdr_init_encode(&xdr, &rqstp->rq_snd_buf, p);
1669         encode(rqstp, &xdr, obj);
1670 }
1671 
1672 static inline int
1673 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1674                    kxdreproc_t encode, struct rpc_rqst *rqstp,
1675                    __be32 *p, void *obj)
1676 {
1677         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1678         struct xdr_buf  integ_buf;
1679         __be32          *integ_len = NULL;
1680         struct xdr_netobj mic;
1681         u32             offset;
1682         __be32          *q;
1683         struct kvec     *iov;
1684         u32             maj_stat = 0;
1685         int             status = -EIO;
1686 
1687         integ_len = p++;
1688         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1689         *p++ = htonl(rqstp->rq_seqno);
1690 
1691         gss_wrap_req_encode(encode, rqstp, p, obj);
1692 
1693         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1694                                 offset, snd_buf->len - offset))
1695                 return status;
1696         *integ_len = htonl(integ_buf.len);
1697 
1698         /* guess whether we're in the head or the tail: */
1699         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1700                 iov = snd_buf->tail;
1701         else
1702                 iov = snd_buf->head;
1703         p = iov->iov_base + iov->iov_len;
1704         mic.data = (u8 *)(p + 1);
1705 
1706         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1707         status = -EIO; /* XXX? */
1708         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1709                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1710         else if (maj_stat)
1711                 return status;
1712         q = xdr_encode_opaque(p, NULL, mic.len);
1713 
1714         offset = (u8 *)q - (u8 *)p;
1715         iov->iov_len += offset;
1716         snd_buf->len += offset;
1717         return 0;
1718 }
1719 
1720 static void
1721 priv_release_snd_buf(struct rpc_rqst *rqstp)
1722 {
1723         int i;
1724 
1725         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1726                 __free_page(rqstp->rq_enc_pages[i]);
1727         kfree(rqstp->rq_enc_pages);
1728 }
1729 
1730 static int
1731 alloc_enc_pages(struct rpc_rqst *rqstp)
1732 {
1733         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1734         int first, last, i;
1735 
1736         if (snd_buf->page_len == 0) {
1737                 rqstp->rq_enc_pages_num = 0;
1738                 return 0;
1739         }
1740 
1741         first = snd_buf->page_base >> PAGE_SHIFT;
1742         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_SHIFT;
1743         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1744         rqstp->rq_enc_pages
1745                 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
1746                                 GFP_NOFS);
1747         if (!rqstp->rq_enc_pages)
1748                 goto out;
1749         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1750                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1751                 if (rqstp->rq_enc_pages[i] == NULL)
1752                         goto out_free;
1753         }
1754         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1755         return 0;
1756 out_free:
1757         rqstp->rq_enc_pages_num = i;
1758         priv_release_snd_buf(rqstp);
1759 out:
1760         return -EAGAIN;
1761 }
1762 
1763 static inline int
1764 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1765                   kxdreproc_t encode, struct rpc_rqst *rqstp,
1766                   __be32 *p, void *obj)
1767 {
1768         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1769         u32             offset;
1770         u32             maj_stat;
1771         int             status;
1772         __be32          *opaque_len;
1773         struct page     **inpages;
1774         int             first;
1775         int             pad;
1776         struct kvec     *iov;
1777         char            *tmp;
1778 
1779         opaque_len = p++;
1780         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1781         *p++ = htonl(rqstp->rq_seqno);
1782 
1783         gss_wrap_req_encode(encode, rqstp, p, obj);
1784 
1785         status = alloc_enc_pages(rqstp);
1786         if (status)
1787                 return status;
1788         first = snd_buf->page_base >> PAGE_SHIFT;
1789         inpages = snd_buf->pages + first;
1790         snd_buf->pages = rqstp->rq_enc_pages;
1791         snd_buf->page_base -= first << PAGE_SHIFT;
1792         /*
1793          * Give the tail its own page, in case we need extra space in the
1794          * head when wrapping:
1795          *
1796          * call_allocate() allocates twice the slack space required
1797          * by the authentication flavor to rq_callsize.
1798          * For GSS, slack is GSS_CRED_SLACK.
1799          */
1800         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1801                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1802                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1803                 snd_buf->tail[0].iov_base = tmp;
1804         }
1805         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1806         /* slack space should prevent this ever happening: */
1807         BUG_ON(snd_buf->len > snd_buf->buflen);
1808         status = -EIO;
1809         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1810          * done anyway, so it's safe to put the request on the wire: */
1811         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1812                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1813         else if (maj_stat)
1814                 return status;
1815 
1816         *opaque_len = htonl(snd_buf->len - offset);
1817         /* guess whether we're in the head or the tail: */
1818         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1819                 iov = snd_buf->tail;
1820         else
1821                 iov = snd_buf->head;
1822         p = iov->iov_base + iov->iov_len;
1823         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1824         memset(p, 0, pad);
1825         iov->iov_len += pad;
1826         snd_buf->len += pad;
1827 
1828         return 0;
1829 }
1830 
1831 static int
1832 gss_wrap_req(struct rpc_task *task,
1833              kxdreproc_t encode, void *rqstp, __be32 *p, void *obj)
1834 {
1835         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1836         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1837                         gc_base);
1838         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1839         int             status = -EIO;
1840 
1841         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1842         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1843                 /* The spec seems a little ambiguous here, but I think that not
1844                  * wrapping context destruction requests makes the most sense.
1845                  */
1846                 gss_wrap_req_encode(encode, rqstp, p, obj);
1847                 status = 0;
1848                 goto out;
1849         }
1850         switch (gss_cred->gc_service) {
1851         case RPC_GSS_SVC_NONE:
1852                 gss_wrap_req_encode(encode, rqstp, p, obj);
1853                 status = 0;
1854                 break;
1855         case RPC_GSS_SVC_INTEGRITY:
1856                 status = gss_wrap_req_integ(cred, ctx, encode, rqstp, p, obj);
1857                 break;
1858         case RPC_GSS_SVC_PRIVACY:
1859                 status = gss_wrap_req_priv(cred, ctx, encode, rqstp, p, obj);
1860                 break;
1861         }
1862 out:
1863         gss_put_ctx(ctx);
1864         dprintk("RPC: %5u %s returning %d\n", task->tk_pid, __func__, status);
1865         return status;
1866 }
1867 
1868 static inline int
1869 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1870                 struct rpc_rqst *rqstp, __be32 **p)
1871 {
1872         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1873         struct xdr_buf integ_buf;
1874         struct xdr_netobj mic;
1875         u32 data_offset, mic_offset;
1876         u32 integ_len;
1877         u32 maj_stat;
1878         int status = -EIO;
1879 
1880         integ_len = ntohl(*(*p)++);
1881         if (integ_len & 3)
1882                 return status;
1883         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1884         mic_offset = integ_len + data_offset;
1885         if (mic_offset > rcv_buf->len)
1886                 return status;
1887         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1888                 return status;
1889 
1890         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1891                                 mic_offset - data_offset))
1892                 return status;
1893 
1894         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1895                 return status;
1896 
1897         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1898         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1899                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1900         if (maj_stat != GSS_S_COMPLETE)
1901                 return status;
1902         return 0;
1903 }
1904 
1905 static inline int
1906 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1907                 struct rpc_rqst *rqstp, __be32 **p)
1908 {
1909         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1910         u32 offset;
1911         u32 opaque_len;
1912         u32 maj_stat;
1913         int status = -EIO;
1914 
1915         opaque_len = ntohl(*(*p)++);
1916         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1917         if (offset + opaque_len > rcv_buf->len)
1918                 return status;
1919         /* remove padding: */
1920         rcv_buf->len = offset + opaque_len;
1921 
1922         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1923         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1924                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1925         if (maj_stat != GSS_S_COMPLETE)
1926                 return status;
1927         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1928                 return status;
1929 
1930         return 0;
1931 }
1932 
1933 static int
1934 gss_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
1935                       __be32 *p, void *obj)
1936 {
1937         struct xdr_stream xdr;
1938 
1939         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
1940         return decode(rqstp, &xdr, obj);
1941 }
1942 
1943 static int
1944 gss_unwrap_resp(struct rpc_task *task,
1945                 kxdrdproc_t decode, void *rqstp, __be32 *p, void *obj)
1946 {
1947         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1948         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1949                         gc_base);
1950         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1951         __be32          *savedp = p;
1952         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1953         int             savedlen = head->iov_len;
1954         int             status = -EIO;
1955 
1956         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1957                 goto out_decode;
1958         switch (gss_cred->gc_service) {
1959         case RPC_GSS_SVC_NONE:
1960                 break;
1961         case RPC_GSS_SVC_INTEGRITY:
1962                 status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1963                 if (status)
1964                         goto out;
1965                 break;
1966         case RPC_GSS_SVC_PRIVACY:
1967                 status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1968                 if (status)
1969                         goto out;
1970                 break;
1971         }
1972         /* take into account extra slack for integrity and privacy cases: */
1973         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1974                                                 + (savedlen - head->iov_len);
1975 out_decode:
1976         status = gss_unwrap_req_decode(decode, rqstp, p, obj);
1977 out:
1978         gss_put_ctx(ctx);
1979         dprintk("RPC: %5u %s returning %d\n",
1980                 task->tk_pid, __func__, status);
1981         return status;
1982 }
1983 
1984 static const struct rpc_authops authgss_ops = {
1985         .owner          = THIS_MODULE,
1986         .au_flavor      = RPC_AUTH_GSS,
1987         .au_name        = "RPCSEC_GSS",
1988         .create         = gss_create,
1989         .destroy        = gss_destroy,
1990         .lookup_cred    = gss_lookup_cred,
1991         .crcreate       = gss_create_cred,
1992         .list_pseudoflavors = gss_mech_list_pseudoflavors,
1993         .info2flavor    = gss_mech_info2flavor,
1994         .flavor2info    = gss_mech_flavor2info,
1995 };
1996 
1997 static const struct rpc_credops gss_credops = {
1998         .cr_name                = "AUTH_GSS",
1999         .crdestroy              = gss_destroy_cred,
2000         .cr_init                = gss_cred_init,
2001         .crbind                 = rpcauth_generic_bind_cred,
2002         .crmatch                = gss_match,
2003         .crmarshal              = gss_marshal,
2004         .crrefresh              = gss_refresh,
2005         .crvalidate             = gss_validate,
2006         .crwrap_req             = gss_wrap_req,
2007         .crunwrap_resp          = gss_unwrap_resp,
2008         .crkey_timeout          = gss_key_timeout,
2009         .crstringify_acceptor   = gss_stringify_acceptor,
2010 };
2011 
2012 static const struct rpc_credops gss_nullops = {
2013         .cr_name                = "AUTH_GSS",
2014         .crdestroy              = gss_destroy_nullcred,
2015         .crbind                 = rpcauth_generic_bind_cred,
2016         .crmatch                = gss_match,
2017         .crmarshal              = gss_marshal,
2018         .crrefresh              = gss_refresh_null,
2019         .crvalidate             = gss_validate,
2020         .crwrap_req             = gss_wrap_req,
2021         .crunwrap_resp          = gss_unwrap_resp,
2022         .crstringify_acceptor   = gss_stringify_acceptor,
2023 };
2024 
2025 static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
2026         .upcall         = rpc_pipe_generic_upcall,
2027         .downcall       = gss_pipe_downcall,
2028         .destroy_msg    = gss_pipe_destroy_msg,
2029         .open_pipe      = gss_pipe_open_v0,
2030         .release_pipe   = gss_pipe_release,
2031 };
2032 
2033 static const struct rpc_pipe_ops gss_upcall_ops_v1 = {
2034         .upcall         = rpc_pipe_generic_upcall,
2035         .downcall       = gss_pipe_downcall,
2036         .destroy_msg    = gss_pipe_destroy_msg,
2037         .open_pipe      = gss_pipe_open_v1,
2038         .release_pipe   = gss_pipe_release,
2039 };
2040 
2041 static __net_init int rpcsec_gss_init_net(struct net *net)
2042 {
2043         return gss_svc_init_net(net);
2044 }
2045 
2046 static __net_exit void rpcsec_gss_exit_net(struct net *net)
2047 {
2048         gss_svc_shutdown_net(net);
2049 }
2050 
2051 static struct pernet_operations rpcsec_gss_net_ops = {
2052         .init = rpcsec_gss_init_net,
2053         .exit = rpcsec_gss_exit_net,
2054 };
2055 
2056 /*
2057  * Initialize RPCSEC_GSS module
2058  */
2059 static int __init init_rpcsec_gss(void)
2060 {
2061         int err = 0;
2062 
2063         err = rpcauth_register(&authgss_ops);
2064         if (err)
2065                 goto out;
2066         err = gss_svc_init();
2067         if (err)
2068                 goto out_unregister;
2069         err = register_pernet_subsys(&rpcsec_gss_net_ops);
2070         if (err)
2071                 goto out_svc_exit;
2072         rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
2073         return 0;
2074 out_svc_exit:
2075         gss_svc_shutdown();
2076 out_unregister:
2077         rpcauth_unregister(&authgss_ops);
2078 out:
2079         return err;
2080 }
2081 
2082 static void __exit exit_rpcsec_gss(void)
2083 {
2084         unregister_pernet_subsys(&rpcsec_gss_net_ops);
2085         gss_svc_shutdown();
2086         rpcauth_unregister(&authgss_ops);
2087         rcu_barrier(); /* Wait for completion of call_rcu()'s */
2088 }
2089 
2090 MODULE_ALIAS("rpc-auth-6");
2091 MODULE_LICENSE("GPL");
2092 module_param_named(expired_cred_retry_delay,
2093                    gss_expired_cred_retry_delay,
2094                    uint, 0644);
2095 MODULE_PARM_DESC(expired_cred_retry_delay, "Timeout (in seconds) until "
2096                 "the RPC engine retries an expired credential");
2097 
2098 module_param_named(key_expire_timeo,
2099                    gss_key_expire_timeo,
2100                    uint, 0644);
2101 MODULE_PARM_DESC(key_expire_timeo, "Time (in seconds) at the end of a "
2102                 "credential keys lifetime where the NFS layer cleans up "
2103                 "prior to key expiration");
2104 
2105 module_init(init_rpcsec_gss)
2106 module_exit(exit_rpcsec_gss)
2107 

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