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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 = rpc_queue_upcall(gss_new->pipe, &gss_new->msg);
545                 if (res) {
546                         gss_unhash_msg(gss_new);
547                         gss_msg = ERR_PTR(res);
548                 }
549         } else
550                 gss_release_msg(gss_new);
551         return gss_msg;
552 }
553 
554 static void warn_gssd(void)
555 {
556         dprintk("AUTH_GSS upcall failed. Please check user daemon is running.\n");
557 }
558 
559 static inline int
560 gss_refresh_upcall(struct rpc_task *task)
561 {
562         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
563         struct gss_auth *gss_auth = container_of(cred->cr_auth,
564                         struct gss_auth, rpc_auth);
565         struct gss_cred *gss_cred = container_of(cred,
566                         struct gss_cred, gc_base);
567         struct gss_upcall_msg *gss_msg;
568         struct rpc_pipe *pipe;
569         int err = 0;
570 
571         dprintk("RPC: %5u %s for uid %u\n",
572                 task->tk_pid, __func__, from_kuid(&init_user_ns, cred->cr_uid));
573         gss_msg = gss_setup_upcall(gss_auth, cred);
574         if (PTR_ERR(gss_msg) == -EAGAIN) {
575                 /* XXX: warning on the first, under the assumption we
576                  * shouldn't normally hit this case on a refresh. */
577                 warn_gssd();
578                 task->tk_timeout = 15*HZ;
579                 rpc_sleep_on(&pipe_version_rpc_waitqueue, task, NULL);
580                 return -EAGAIN;
581         }
582         if (IS_ERR(gss_msg)) {
583                 err = PTR_ERR(gss_msg);
584                 goto out;
585         }
586         pipe = gss_msg->pipe;
587         spin_lock(&pipe->lock);
588         if (gss_cred->gc_upcall != NULL)
589                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
590         else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
591                 task->tk_timeout = 0;
592                 gss_cred->gc_upcall = gss_msg;
593                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
594                 atomic_inc(&gss_msg->count);
595                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
596         } else {
597                 gss_handle_downcall_result(gss_cred, gss_msg);
598                 err = gss_msg->msg.errno;
599         }
600         spin_unlock(&pipe->lock);
601         gss_release_msg(gss_msg);
602 out:
603         dprintk("RPC: %5u %s for uid %u result %d\n",
604                 task->tk_pid, __func__,
605                 from_kuid(&init_user_ns, cred->cr_uid), err);
606         return err;
607 }
608 
609 static inline int
610 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
611 {
612         struct net *net = gss_auth->net;
613         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
614         struct rpc_pipe *pipe;
615         struct rpc_cred *cred = &gss_cred->gc_base;
616         struct gss_upcall_msg *gss_msg;
617         DEFINE_WAIT(wait);
618         int err;
619 
620         dprintk("RPC:       %s for uid %u\n",
621                 __func__, from_kuid(&init_user_ns, cred->cr_uid));
622 retry:
623         err = 0;
624         /* if gssd is down, just skip upcalling altogether */
625         if (!gssd_running(net)) {
626                 warn_gssd();
627                 return -EACCES;
628         }
629         gss_msg = gss_setup_upcall(gss_auth, cred);
630         if (PTR_ERR(gss_msg) == -EAGAIN) {
631                 err = wait_event_interruptible_timeout(pipe_version_waitqueue,
632                                 sn->pipe_version >= 0, 15 * HZ);
633                 if (sn->pipe_version < 0) {
634                         warn_gssd();
635                         err = -EACCES;
636                 }
637                 if (err < 0)
638                         goto out;
639                 goto retry;
640         }
641         if (IS_ERR(gss_msg)) {
642                 err = PTR_ERR(gss_msg);
643                 goto out;
644         }
645         pipe = gss_msg->pipe;
646         for (;;) {
647                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_KILLABLE);
648                 spin_lock(&pipe->lock);
649                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
650                         break;
651                 }
652                 spin_unlock(&pipe->lock);
653                 if (fatal_signal_pending(current)) {
654                         err = -ERESTARTSYS;
655                         goto out_intr;
656                 }
657                 schedule();
658         }
659         if (gss_msg->ctx)
660                 gss_cred_set_ctx(cred, gss_msg->ctx);
661         else
662                 err = gss_msg->msg.errno;
663         spin_unlock(&pipe->lock);
664 out_intr:
665         finish_wait(&gss_msg->waitqueue, &wait);
666         gss_release_msg(gss_msg);
667 out:
668         dprintk("RPC:       %s for uid %u result %d\n",
669                 __func__, from_kuid(&init_user_ns, cred->cr_uid), err);
670         return err;
671 }
672 
673 #define MSG_BUF_MAXSIZE 1024
674 
675 static ssize_t
676 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
677 {
678         const void *p, *end;
679         void *buf;
680         struct gss_upcall_msg *gss_msg;
681         struct rpc_pipe *pipe = RPC_I(file_inode(filp))->pipe;
682         struct gss_cl_ctx *ctx;
683         uid_t id;
684         kuid_t uid;
685         ssize_t err = -EFBIG;
686 
687         if (mlen > MSG_BUF_MAXSIZE)
688                 goto out;
689         err = -ENOMEM;
690         buf = kmalloc(mlen, GFP_NOFS);
691         if (!buf)
692                 goto out;
693 
694         err = -EFAULT;
695         if (copy_from_user(buf, src, mlen))
696                 goto err;
697 
698         end = (const void *)((char *)buf + mlen);
699         p = simple_get_bytes(buf, end, &id, sizeof(id));
700         if (IS_ERR(p)) {
701                 err = PTR_ERR(p);
702                 goto err;
703         }
704 
705         uid = make_kuid(&init_user_ns, id);
706         if (!uid_valid(uid)) {
707                 err = -EINVAL;
708                 goto err;
709         }
710 
711         err = -ENOMEM;
712         ctx = gss_alloc_context();
713         if (ctx == NULL)
714                 goto err;
715 
716         err = -ENOENT;
717         /* Find a matching upcall */
718         spin_lock(&pipe->lock);
719         gss_msg = __gss_find_upcall(pipe, uid, NULL);
720         if (gss_msg == NULL) {
721                 spin_unlock(&pipe->lock);
722                 goto err_put_ctx;
723         }
724         list_del_init(&gss_msg->list);
725         spin_unlock(&pipe->lock);
726 
727         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
728         if (IS_ERR(p)) {
729                 err = PTR_ERR(p);
730                 switch (err) {
731                 case -EACCES:
732                 case -EKEYEXPIRED:
733                         gss_msg->msg.errno = err;
734                         err = mlen;
735                         break;
736                 case -EFAULT:
737                 case -ENOMEM:
738                 case -EINVAL:
739                 case -ENOSYS:
740                         gss_msg->msg.errno = -EAGAIN;
741                         break;
742                 default:
743                         printk(KERN_CRIT "%s: bad return from "
744                                 "gss_fill_context: %zd\n", __func__, err);
745                         gss_msg->msg.errno = -EIO;
746                 }
747                 goto err_release_msg;
748         }
749         gss_msg->ctx = gss_get_ctx(ctx);
750         err = mlen;
751 
752 err_release_msg:
753         spin_lock(&pipe->lock);
754         __gss_unhash_msg(gss_msg);
755         spin_unlock(&pipe->lock);
756         gss_release_msg(gss_msg);
757 err_put_ctx:
758         gss_put_ctx(ctx);
759 err:
760         kfree(buf);
761 out:
762         dprintk("RPC:       %s returning %Zd\n", __func__, err);
763         return err;
764 }
765 
766 static int gss_pipe_open(struct inode *inode, int new_version)
767 {
768         struct net *net = inode->i_sb->s_fs_info;
769         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
770         int ret = 0;
771 
772         spin_lock(&pipe_version_lock);
773         if (sn->pipe_version < 0) {
774                 /* First open of any gss pipe determines the version: */
775                 sn->pipe_version = new_version;
776                 rpc_wake_up(&pipe_version_rpc_waitqueue);
777                 wake_up(&pipe_version_waitqueue);
778         } else if (sn->pipe_version != new_version) {
779                 /* Trying to open a pipe of a different version */
780                 ret = -EBUSY;
781                 goto out;
782         }
783         atomic_inc(&sn->pipe_users);
784 out:
785         spin_unlock(&pipe_version_lock);
786         return ret;
787 
788 }
789 
790 static int gss_pipe_open_v0(struct inode *inode)
791 {
792         return gss_pipe_open(inode, 0);
793 }
794 
795 static int gss_pipe_open_v1(struct inode *inode)
796 {
797         return gss_pipe_open(inode, 1);
798 }
799 
800 static void
801 gss_pipe_release(struct inode *inode)
802 {
803         struct net *net = inode->i_sb->s_fs_info;
804         struct rpc_pipe *pipe = RPC_I(inode)->pipe;
805         struct gss_upcall_msg *gss_msg;
806 
807 restart:
808         spin_lock(&pipe->lock);
809         list_for_each_entry(gss_msg, &pipe->in_downcall, list) {
810 
811                 if (!list_empty(&gss_msg->msg.list))
812                         continue;
813                 gss_msg->msg.errno = -EPIPE;
814                 atomic_inc(&gss_msg->count);
815                 __gss_unhash_msg(gss_msg);
816                 spin_unlock(&pipe->lock);
817                 gss_release_msg(gss_msg);
818                 goto restart;
819         }
820         spin_unlock(&pipe->lock);
821 
822         put_pipe_version(net);
823 }
824 
825 static void
826 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
827 {
828         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
829 
830         if (msg->errno < 0) {
831                 dprintk("RPC:       %s releasing msg %p\n",
832                         __func__, gss_msg);
833                 atomic_inc(&gss_msg->count);
834                 gss_unhash_msg(gss_msg);
835                 if (msg->errno == -ETIMEDOUT)
836                         warn_gssd();
837                 gss_release_msg(gss_msg);
838         }
839 }
840 
841 static void gss_pipe_dentry_destroy(struct dentry *dir,
842                 struct rpc_pipe_dir_object *pdo)
843 {
844         struct gss_pipe *gss_pipe = pdo->pdo_data;
845         struct rpc_pipe *pipe = gss_pipe->pipe;
846 
847         if (pipe->dentry != NULL) {
848                 rpc_unlink(pipe->dentry);
849                 pipe->dentry = NULL;
850         }
851 }
852 
853 static int gss_pipe_dentry_create(struct dentry *dir,
854                 struct rpc_pipe_dir_object *pdo)
855 {
856         struct gss_pipe *p = pdo->pdo_data;
857         struct dentry *dentry;
858 
859         dentry = rpc_mkpipe_dentry(dir, p->name, p->clnt, p->pipe);
860         if (IS_ERR(dentry))
861                 return PTR_ERR(dentry);
862         p->pipe->dentry = dentry;
863         return 0;
864 }
865 
866 static const struct rpc_pipe_dir_object_ops gss_pipe_dir_object_ops = {
867         .create = gss_pipe_dentry_create,
868         .destroy = gss_pipe_dentry_destroy,
869 };
870 
871 static struct gss_pipe *gss_pipe_alloc(struct rpc_clnt *clnt,
872                 const char *name,
873                 const struct rpc_pipe_ops *upcall_ops)
874 {
875         struct gss_pipe *p;
876         int err = -ENOMEM;
877 
878         p = kmalloc(sizeof(*p), GFP_KERNEL);
879         if (p == NULL)
880                 goto err;
881         p->pipe = rpc_mkpipe_data(upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
882         if (IS_ERR(p->pipe)) {
883                 err = PTR_ERR(p->pipe);
884                 goto err_free_gss_pipe;
885         }
886         p->name = name;
887         p->clnt = clnt;
888         kref_init(&p->kref);
889         rpc_init_pipe_dir_object(&p->pdo,
890                         &gss_pipe_dir_object_ops,
891                         p);
892         return p;
893 err_free_gss_pipe:
894         kfree(p);
895 err:
896         return ERR_PTR(err);
897 }
898 
899 struct gss_alloc_pdo {
900         struct rpc_clnt *clnt;
901         const char *name;
902         const struct rpc_pipe_ops *upcall_ops;
903 };
904 
905 static int gss_pipe_match_pdo(struct rpc_pipe_dir_object *pdo, void *data)
906 {
907         struct gss_pipe *gss_pipe;
908         struct gss_alloc_pdo *args = data;
909 
910         if (pdo->pdo_ops != &gss_pipe_dir_object_ops)
911                 return 0;
912         gss_pipe = container_of(pdo, struct gss_pipe, pdo);
913         if (strcmp(gss_pipe->name, args->name) != 0)
914                 return 0;
915         if (!kref_get_unless_zero(&gss_pipe->kref))
916                 return 0;
917         return 1;
918 }
919 
920 static struct rpc_pipe_dir_object *gss_pipe_alloc_pdo(void *data)
921 {
922         struct gss_pipe *gss_pipe;
923         struct gss_alloc_pdo *args = data;
924 
925         gss_pipe = gss_pipe_alloc(args->clnt, args->name, args->upcall_ops);
926         if (!IS_ERR(gss_pipe))
927                 return &gss_pipe->pdo;
928         return NULL;
929 }
930 
931 static struct gss_pipe *gss_pipe_get(struct rpc_clnt *clnt,
932                 const char *name,
933                 const struct rpc_pipe_ops *upcall_ops)
934 {
935         struct net *net = rpc_net_ns(clnt);
936         struct rpc_pipe_dir_object *pdo;
937         struct gss_alloc_pdo args = {
938                 .clnt = clnt,
939                 .name = name,
940                 .upcall_ops = upcall_ops,
941         };
942 
943         pdo = rpc_find_or_alloc_pipe_dir_object(net,
944                         &clnt->cl_pipedir_objects,
945                         gss_pipe_match_pdo,
946                         gss_pipe_alloc_pdo,
947                         &args);
948         if (pdo != NULL)
949                 return container_of(pdo, struct gss_pipe, pdo);
950         return ERR_PTR(-ENOMEM);
951 }
952 
953 static void __gss_pipe_free(struct gss_pipe *p)
954 {
955         struct rpc_clnt *clnt = p->clnt;
956         struct net *net = rpc_net_ns(clnt);
957 
958         rpc_remove_pipe_dir_object(net,
959                         &clnt->cl_pipedir_objects,
960                         &p->pdo);
961         rpc_destroy_pipe_data(p->pipe);
962         kfree(p);
963 }
964 
965 static void __gss_pipe_release(struct kref *kref)
966 {
967         struct gss_pipe *p = container_of(kref, struct gss_pipe, kref);
968 
969         __gss_pipe_free(p);
970 }
971 
972 static void gss_pipe_free(struct gss_pipe *p)
973 {
974         if (p != NULL)
975                 kref_put(&p->kref, __gss_pipe_release);
976 }
977 
978 /*
979  * NOTE: we have the opportunity to use different
980  * parameters based on the input flavor (which must be a pseudoflavor)
981  */
982 static struct gss_auth *
983 gss_create_new(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
984 {
985         rpc_authflavor_t flavor = args->pseudoflavor;
986         struct gss_auth *gss_auth;
987         struct gss_pipe *gss_pipe;
988         struct rpc_auth * auth;
989         int err = -ENOMEM; /* XXX? */
990 
991         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
992 
993         if (!try_module_get(THIS_MODULE))
994                 return ERR_PTR(err);
995         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
996                 goto out_dec;
997         INIT_HLIST_NODE(&gss_auth->hash);
998         gss_auth->target_name = NULL;
999         if (args->target_name) {
1000                 gss_auth->target_name = kstrdup(args->target_name, GFP_KERNEL);
1001                 if (gss_auth->target_name == NULL)
1002                         goto err_free;
1003         }
1004         gss_auth->client = clnt;
1005         gss_auth->net = get_net(rpc_net_ns(clnt));
1006         err = -EINVAL;
1007         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
1008         if (!gss_auth->mech) {
1009                 dprintk("RPC:       Pseudoflavor %d not found!\n", flavor);
1010                 goto err_put_net;
1011         }
1012         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
1013         if (gss_auth->service == 0)
1014                 goto err_put_mech;
1015         if (!gssd_running(gss_auth->net))
1016                 goto err_put_mech;
1017         auth = &gss_auth->rpc_auth;
1018         auth->au_cslack = GSS_CRED_SLACK >> 2;
1019         auth->au_rslack = GSS_VERF_SLACK >> 2;
1020         auth->au_ops = &authgss_ops;
1021         auth->au_flavor = flavor;
1022         atomic_set(&auth->au_count, 1);
1023         kref_init(&gss_auth->kref);
1024 
1025         err = rpcauth_init_credcache(auth);
1026         if (err)
1027                 goto err_put_mech;
1028         /*
1029          * Note: if we created the old pipe first, then someone who
1030          * examined the directory at the right moment might conclude
1031          * that we supported only the old pipe.  So we instead create
1032          * the new pipe first.
1033          */
1034         gss_pipe = gss_pipe_get(clnt, "gssd", &gss_upcall_ops_v1);
1035         if (IS_ERR(gss_pipe)) {
1036                 err = PTR_ERR(gss_pipe);
1037                 goto err_destroy_credcache;
1038         }
1039         gss_auth->gss_pipe[1] = gss_pipe;
1040 
1041         gss_pipe = gss_pipe_get(clnt, gss_auth->mech->gm_name,
1042                         &gss_upcall_ops_v0);
1043         if (IS_ERR(gss_pipe)) {
1044                 err = PTR_ERR(gss_pipe);
1045                 goto err_destroy_pipe_1;
1046         }
1047         gss_auth->gss_pipe[0] = gss_pipe;
1048 
1049         return gss_auth;
1050 err_destroy_pipe_1:
1051         gss_pipe_free(gss_auth->gss_pipe[1]);
1052 err_destroy_credcache:
1053         rpcauth_destroy_credcache(auth);
1054 err_put_mech:
1055         gss_mech_put(gss_auth->mech);
1056 err_put_net:
1057         put_net(gss_auth->net);
1058 err_free:
1059         kfree(gss_auth->target_name);
1060         kfree(gss_auth);
1061 out_dec:
1062         module_put(THIS_MODULE);
1063         return ERR_PTR(err);
1064 }
1065 
1066 static void
1067 gss_free(struct gss_auth *gss_auth)
1068 {
1069         gss_pipe_free(gss_auth->gss_pipe[0]);
1070         gss_pipe_free(gss_auth->gss_pipe[1]);
1071         gss_mech_put(gss_auth->mech);
1072         put_net(gss_auth->net);
1073         kfree(gss_auth->target_name);
1074 
1075         kfree(gss_auth);
1076         module_put(THIS_MODULE);
1077 }
1078 
1079 static void
1080 gss_free_callback(struct kref *kref)
1081 {
1082         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
1083 
1084         gss_free(gss_auth);
1085 }
1086 
1087 static void
1088 gss_put_auth(struct gss_auth *gss_auth)
1089 {
1090         kref_put(&gss_auth->kref, gss_free_callback);
1091 }
1092 
1093 static void
1094 gss_destroy(struct rpc_auth *auth)
1095 {
1096         struct gss_auth *gss_auth = container_of(auth,
1097                         struct gss_auth, rpc_auth);
1098 
1099         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
1100                         auth, auth->au_flavor);
1101 
1102         if (hash_hashed(&gss_auth->hash)) {
1103                 spin_lock(&gss_auth_hash_lock);
1104                 hash_del(&gss_auth->hash);
1105                 spin_unlock(&gss_auth_hash_lock);
1106         }
1107 
1108         gss_pipe_free(gss_auth->gss_pipe[0]);
1109         gss_auth->gss_pipe[0] = NULL;
1110         gss_pipe_free(gss_auth->gss_pipe[1]);
1111         gss_auth->gss_pipe[1] = NULL;
1112         rpcauth_destroy_credcache(auth);
1113 
1114         gss_put_auth(gss_auth);
1115 }
1116 
1117 /*
1118  * Auths may be shared between rpc clients that were cloned from a
1119  * common client with the same xprt, if they also share the flavor and
1120  * target_name.
1121  *
1122  * The auth is looked up from the oldest parent sharing the same
1123  * cl_xprt, and the auth itself references only that common parent
1124  * (which is guaranteed to last as long as any of its descendants).
1125  */
1126 static struct gss_auth *
1127 gss_auth_find_or_add_hashed(struct rpc_auth_create_args *args,
1128                 struct rpc_clnt *clnt,
1129                 struct gss_auth *new)
1130 {
1131         struct gss_auth *gss_auth;
1132         unsigned long hashval = (unsigned long)clnt;
1133 
1134         spin_lock(&gss_auth_hash_lock);
1135         hash_for_each_possible(gss_auth_hash_table,
1136                         gss_auth,
1137                         hash,
1138                         hashval) {
1139                 if (gss_auth->client != clnt)
1140                         continue;
1141                 if (gss_auth->rpc_auth.au_flavor != args->pseudoflavor)
1142                         continue;
1143                 if (gss_auth->target_name != args->target_name) {
1144                         if (gss_auth->target_name == NULL)
1145                                 continue;
1146                         if (args->target_name == NULL)
1147                                 continue;
1148                         if (strcmp(gss_auth->target_name, args->target_name))
1149                                 continue;
1150                 }
1151                 if (!atomic_inc_not_zero(&gss_auth->rpc_auth.au_count))
1152                         continue;
1153                 goto out;
1154         }
1155         if (new)
1156                 hash_add(gss_auth_hash_table, &new->hash, hashval);
1157         gss_auth = new;
1158 out:
1159         spin_unlock(&gss_auth_hash_lock);
1160         return gss_auth;
1161 }
1162 
1163 static struct gss_auth *
1164 gss_create_hashed(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1165 {
1166         struct gss_auth *gss_auth;
1167         struct gss_auth *new;
1168 
1169         gss_auth = gss_auth_find_or_add_hashed(args, clnt, NULL);
1170         if (gss_auth != NULL)
1171                 goto out;
1172         new = gss_create_new(args, clnt);
1173         if (IS_ERR(new))
1174                 return new;
1175         gss_auth = gss_auth_find_or_add_hashed(args, clnt, new);
1176         if (gss_auth != new)
1177                 gss_destroy(&new->rpc_auth);
1178 out:
1179         return gss_auth;
1180 }
1181 
1182 static struct rpc_auth *
1183 gss_create(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1184 {
1185         struct gss_auth *gss_auth;
1186         struct rpc_xprt_switch *xps = rcu_access_pointer(clnt->cl_xpi.xpi_xpswitch);
1187 
1188         while (clnt != clnt->cl_parent) {
1189                 struct rpc_clnt *parent = clnt->cl_parent;
1190                 /* Find the original parent for this transport */
1191                 if (rcu_access_pointer(parent->cl_xpi.xpi_xpswitch) != xps)
1192                         break;
1193                 clnt = parent;
1194         }
1195 
1196         gss_auth = gss_create_hashed(args, clnt);
1197         if (IS_ERR(gss_auth))
1198                 return ERR_CAST(gss_auth);
1199         return &gss_auth->rpc_auth;
1200 }
1201 
1202 /*
1203  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
1204  * to the server with the GSS control procedure field set to
1205  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
1206  * all RPCSEC_GSS state associated with that context.
1207  */
1208 static int
1209 gss_destroying_context(struct rpc_cred *cred)
1210 {
1211         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1212         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1213         struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
1214         struct rpc_task *task;
1215 
1216         if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
1217                 return 0;
1218 
1219         ctx->gc_proc = RPC_GSS_PROC_DESTROY;
1220         cred->cr_ops = &gss_nullops;
1221 
1222         /* Take a reference to ensure the cred will be destroyed either
1223          * by the RPC call or by the put_rpccred() below */
1224         get_rpccred(cred);
1225 
1226         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
1227         if (!IS_ERR(task))
1228                 rpc_put_task(task);
1229 
1230         put_rpccred(cred);
1231         return 1;
1232 }
1233 
1234 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
1235  * to create a new cred or context, so they check that things have been
1236  * allocated before freeing them. */
1237 static void
1238 gss_do_free_ctx(struct gss_cl_ctx *ctx)
1239 {
1240         dprintk("RPC:       %s\n", __func__);
1241 
1242         gss_delete_sec_context(&ctx->gc_gss_ctx);
1243         kfree(ctx->gc_wire_ctx.data);
1244         kfree(ctx->gc_acceptor.data);
1245         kfree(ctx);
1246 }
1247 
1248 static void
1249 gss_free_ctx_callback(struct rcu_head *head)
1250 {
1251         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
1252         gss_do_free_ctx(ctx);
1253 }
1254 
1255 static void
1256 gss_free_ctx(struct gss_cl_ctx *ctx)
1257 {
1258         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
1259 }
1260 
1261 static void
1262 gss_free_cred(struct gss_cred *gss_cred)
1263 {
1264         dprintk("RPC:       %s cred=%p\n", __func__, gss_cred);
1265         kfree(gss_cred);
1266 }
1267 
1268 static void
1269 gss_free_cred_callback(struct rcu_head *head)
1270 {
1271         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
1272         gss_free_cred(gss_cred);
1273 }
1274 
1275 static void
1276 gss_destroy_nullcred(struct rpc_cred *cred)
1277 {
1278         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1279         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1280         struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
1281 
1282         RCU_INIT_POINTER(gss_cred->gc_ctx, NULL);
1283         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
1284         if (ctx)
1285                 gss_put_ctx(ctx);
1286         gss_put_auth(gss_auth);
1287 }
1288 
1289 static void
1290 gss_destroy_cred(struct rpc_cred *cred)
1291 {
1292 
1293         if (gss_destroying_context(cred))
1294                 return;
1295         gss_destroy_nullcred(cred);
1296 }
1297 
1298 /*
1299  * Lookup RPCSEC_GSS cred for the current process
1300  */
1301 static struct rpc_cred *
1302 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1303 {
1304         return rpcauth_lookup_credcache(auth, acred, flags, GFP_NOFS);
1305 }
1306 
1307 static struct rpc_cred *
1308 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags, gfp_t gfp)
1309 {
1310         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1311         struct gss_cred *cred = NULL;
1312         int err = -ENOMEM;
1313 
1314         dprintk("RPC:       %s for uid %d, flavor %d\n",
1315                 __func__, from_kuid(&init_user_ns, acred->uid),
1316                 auth->au_flavor);
1317 
1318         if (!(cred = kzalloc(sizeof(*cred), gfp)))
1319                 goto out_err;
1320 
1321         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
1322         /*
1323          * Note: in order to force a call to call_refresh(), we deliberately
1324          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
1325          */
1326         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
1327         cred->gc_service = gss_auth->service;
1328         cred->gc_principal = NULL;
1329         if (acred->machine_cred)
1330                 cred->gc_principal = acred->principal;
1331         kref_get(&gss_auth->kref);
1332         return &cred->gc_base;
1333 
1334 out_err:
1335         dprintk("RPC:       %s failed with error %d\n", __func__, err);
1336         return ERR_PTR(err);
1337 }
1338 
1339 static int
1340 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
1341 {
1342         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1343         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
1344         int err;
1345 
1346         do {
1347                 err = gss_create_upcall(gss_auth, gss_cred);
1348         } while (err == -EAGAIN);
1349         return err;
1350 }
1351 
1352 static char *
1353 gss_stringify_acceptor(struct rpc_cred *cred)
1354 {
1355         char *string = NULL;
1356         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1357         struct gss_cl_ctx *ctx;
1358         unsigned int len;
1359         struct xdr_netobj *acceptor;
1360 
1361         rcu_read_lock();
1362         ctx = rcu_dereference(gss_cred->gc_ctx);
1363         if (!ctx)
1364                 goto out;
1365 
1366         len = ctx->gc_acceptor.len;
1367         rcu_read_unlock();
1368 
1369         /* no point if there's no string */
1370         if (!len)
1371                 return NULL;
1372 realloc:
1373         string = kmalloc(len + 1, GFP_KERNEL);
1374         if (!string)
1375                 return NULL;
1376 
1377         rcu_read_lock();
1378         ctx = rcu_dereference(gss_cred->gc_ctx);
1379 
1380         /* did the ctx disappear or was it replaced by one with no acceptor? */
1381         if (!ctx || !ctx->gc_acceptor.len) {
1382                 kfree(string);
1383                 string = NULL;
1384                 goto out;
1385         }
1386 
1387         acceptor = &ctx->gc_acceptor;
1388 
1389         /*
1390          * Did we find a new acceptor that's longer than the original? Allocate
1391          * a longer buffer and try again.
1392          */
1393         if (len < acceptor->len) {
1394                 len = acceptor->len;
1395                 rcu_read_unlock();
1396                 kfree(string);
1397                 goto realloc;
1398         }
1399 
1400         memcpy(string, acceptor->data, acceptor->len);
1401         string[acceptor->len] = '\0';
1402 out:
1403         rcu_read_unlock();
1404         return string;
1405 }
1406 
1407 /*
1408  * Returns -EACCES if GSS context is NULL or will expire within the
1409  * timeout (miliseconds)
1410  */
1411 static int
1412 gss_key_timeout(struct rpc_cred *rc)
1413 {
1414         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1415         struct gss_cl_ctx *ctx;
1416         unsigned long timeout = jiffies + (gss_key_expire_timeo * HZ);
1417         int ret = 0;
1418 
1419         rcu_read_lock();
1420         ctx = rcu_dereference(gss_cred->gc_ctx);
1421         if (!ctx || time_after(timeout, ctx->gc_expiry))
1422                 ret = -EACCES;
1423         rcu_read_unlock();
1424 
1425         return ret;
1426 }
1427 
1428 static int
1429 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
1430 {
1431         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1432         struct gss_cl_ctx *ctx;
1433         int ret;
1434 
1435         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
1436                 goto out;
1437         /* Don't match with creds that have expired. */
1438         rcu_read_lock();
1439         ctx = rcu_dereference(gss_cred->gc_ctx);
1440         if (!ctx || time_after(jiffies, ctx->gc_expiry)) {
1441                 rcu_read_unlock();
1442                 return 0;
1443         }
1444         rcu_read_unlock();
1445         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
1446                 return 0;
1447 out:
1448         if (acred->principal != NULL) {
1449                 if (gss_cred->gc_principal == NULL)
1450                         return 0;
1451                 ret = strcmp(acred->principal, gss_cred->gc_principal) == 0;
1452                 goto check_expire;
1453         }
1454         if (gss_cred->gc_principal != NULL)
1455                 return 0;
1456         ret = uid_eq(rc->cr_uid, acred->uid);
1457 
1458 check_expire:
1459         if (ret == 0)
1460                 return ret;
1461 
1462         /* Notify acred users of GSS context expiration timeout */
1463         if (test_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags) &&
1464             (gss_key_timeout(rc) != 0)) {
1465                 /* test will now be done from generic cred */
1466                 test_and_clear_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags);
1467                 /* tell NFS layer that key will expire soon */
1468                 set_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags);
1469         }
1470         return ret;
1471 }
1472 
1473 /*
1474 * Marshal credentials.
1475 * Maybe we should keep a cached credential for performance reasons.
1476 */
1477 static __be32 *
1478 gss_marshal(struct rpc_task *task, __be32 *p)
1479 {
1480         struct rpc_rqst *req = task->tk_rqstp;
1481         struct rpc_cred *cred = req->rq_cred;
1482         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1483                                                  gc_base);
1484         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
1485         __be32          *cred_len;
1486         u32             maj_stat = 0;
1487         struct xdr_netobj mic;
1488         struct kvec     iov;
1489         struct xdr_buf  verf_buf;
1490 
1491         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1492 
1493         *p++ = htonl(RPC_AUTH_GSS);
1494         cred_len = p++;
1495 
1496         spin_lock(&ctx->gc_seq_lock);
1497         req->rq_seqno = ctx->gc_seq++;
1498         spin_unlock(&ctx->gc_seq_lock);
1499 
1500         *p++ = htonl((u32) RPC_GSS_VERSION);
1501         *p++ = htonl((u32) ctx->gc_proc);
1502         *p++ = htonl((u32) req->rq_seqno);
1503         *p++ = htonl((u32) gss_cred->gc_service);
1504         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
1505         *cred_len = htonl((p - (cred_len + 1)) << 2);
1506 
1507         /* We compute the checksum for the verifier over the xdr-encoded bytes
1508          * starting with the xid and ending at the end of the credential: */
1509         iov.iov_base = xprt_skip_transport_header(req->rq_xprt,
1510                                         req->rq_snd_buf.head[0].iov_base);
1511         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
1512         xdr_buf_from_iov(&iov, &verf_buf);
1513 
1514         /* set verifier flavor*/
1515         *p++ = htonl(RPC_AUTH_GSS);
1516 
1517         mic.data = (u8 *)(p + 1);
1518         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1519         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
1520                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1521         } else if (maj_stat != 0) {
1522                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
1523                 goto out_put_ctx;
1524         }
1525         p = xdr_encode_opaque(p, NULL, mic.len);
1526         gss_put_ctx(ctx);
1527         return p;
1528 out_put_ctx:
1529         gss_put_ctx(ctx);
1530         return NULL;
1531 }
1532 
1533 static int gss_renew_cred(struct rpc_task *task)
1534 {
1535         struct rpc_cred *oldcred = task->tk_rqstp->rq_cred;
1536         struct gss_cred *gss_cred = container_of(oldcred,
1537                                                  struct gss_cred,
1538                                                  gc_base);
1539         struct rpc_auth *auth = oldcred->cr_auth;
1540         struct auth_cred acred = {
1541                 .uid = oldcred->cr_uid,
1542                 .principal = gss_cred->gc_principal,
1543                 .machine_cred = (gss_cred->gc_principal != NULL ? 1 : 0),
1544         };
1545         struct rpc_cred *new;
1546 
1547         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
1548         if (IS_ERR(new))
1549                 return PTR_ERR(new);
1550         task->tk_rqstp->rq_cred = new;
1551         put_rpccred(oldcred);
1552         return 0;
1553 }
1554 
1555 static int gss_cred_is_negative_entry(struct rpc_cred *cred)
1556 {
1557         if (test_bit(RPCAUTH_CRED_NEGATIVE, &cred->cr_flags)) {
1558                 unsigned long now = jiffies;
1559                 unsigned long begin, expire;
1560                 struct gss_cred *gss_cred; 
1561 
1562                 gss_cred = container_of(cred, struct gss_cred, gc_base);
1563                 begin = gss_cred->gc_upcall_timestamp;
1564                 expire = begin + gss_expired_cred_retry_delay * HZ;
1565 
1566                 if (time_in_range_open(now, begin, expire))
1567                         return 1;
1568         }
1569         return 0;
1570 }
1571 
1572 /*
1573 * Refresh credentials. XXX - finish
1574 */
1575 static int
1576 gss_refresh(struct rpc_task *task)
1577 {
1578         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1579         int ret = 0;
1580 
1581         if (gss_cred_is_negative_entry(cred))
1582                 return -EKEYEXPIRED;
1583 
1584         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
1585                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
1586                 ret = gss_renew_cred(task);
1587                 if (ret < 0)
1588                         goto out;
1589                 cred = task->tk_rqstp->rq_cred;
1590         }
1591 
1592         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
1593                 ret = gss_refresh_upcall(task);
1594 out:
1595         return ret;
1596 }
1597 
1598 /* Dummy refresh routine: used only when destroying the context */
1599 static int
1600 gss_refresh_null(struct rpc_task *task)
1601 {
1602         return 0;
1603 }
1604 
1605 static __be32 *
1606 gss_validate(struct rpc_task *task, __be32 *p)
1607 {
1608         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1609         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1610         __be32          seq;
1611         struct kvec     iov;
1612         struct xdr_buf  verf_buf;
1613         struct xdr_netobj mic;
1614         u32             flav,len;
1615         u32             maj_stat;
1616         __be32          *ret = ERR_PTR(-EIO);
1617 
1618         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1619 
1620         flav = ntohl(*p++);
1621         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
1622                 goto out_bad;
1623         if (flav != RPC_AUTH_GSS)
1624                 goto out_bad;
1625         seq = htonl(task->tk_rqstp->rq_seqno);
1626         iov.iov_base = &seq;
1627         iov.iov_len = sizeof(seq);
1628         xdr_buf_from_iov(&iov, &verf_buf);
1629         mic.data = (u8 *)p;
1630         mic.len = len;
1631 
1632         ret = ERR_PTR(-EACCES);
1633         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1634         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1635                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1636         if (maj_stat) {
1637                 dprintk("RPC: %5u %s: gss_verify_mic returned error 0x%08x\n",
1638                         task->tk_pid, __func__, maj_stat);
1639                 goto out_bad;
1640         }
1641         /* We leave it to unwrap to calculate au_rslack. For now we just
1642          * calculate the length of the verifier: */
1643         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1644         gss_put_ctx(ctx);
1645         dprintk("RPC: %5u %s: gss_verify_mic succeeded.\n",
1646                         task->tk_pid, __func__);
1647         return p + XDR_QUADLEN(len);
1648 out_bad:
1649         gss_put_ctx(ctx);
1650         dprintk("RPC: %5u %s failed ret %ld.\n", task->tk_pid, __func__,
1651                 PTR_ERR(ret));
1652         return ret;
1653 }
1654 
1655 static void gss_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
1656                                 __be32 *p, void *obj)
1657 {
1658         struct xdr_stream xdr;
1659 
1660         xdr_init_encode(&xdr, &rqstp->rq_snd_buf, p);
1661         encode(rqstp, &xdr, obj);
1662 }
1663 
1664 static inline int
1665 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1666                    kxdreproc_t encode, struct rpc_rqst *rqstp,
1667                    __be32 *p, void *obj)
1668 {
1669         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1670         struct xdr_buf  integ_buf;
1671         __be32          *integ_len = NULL;
1672         struct xdr_netobj mic;
1673         u32             offset;
1674         __be32          *q;
1675         struct kvec     *iov;
1676         u32             maj_stat = 0;
1677         int             status = -EIO;
1678 
1679         integ_len = p++;
1680         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1681         *p++ = htonl(rqstp->rq_seqno);
1682 
1683         gss_wrap_req_encode(encode, rqstp, p, obj);
1684 
1685         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1686                                 offset, snd_buf->len - offset))
1687                 return status;
1688         *integ_len = htonl(integ_buf.len);
1689 
1690         /* guess whether we're in the head or the tail: */
1691         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1692                 iov = snd_buf->tail;
1693         else
1694                 iov = snd_buf->head;
1695         p = iov->iov_base + iov->iov_len;
1696         mic.data = (u8 *)(p + 1);
1697 
1698         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1699         status = -EIO; /* XXX? */
1700         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1701                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1702         else if (maj_stat)
1703                 return status;
1704         q = xdr_encode_opaque(p, NULL, mic.len);
1705 
1706         offset = (u8 *)q - (u8 *)p;
1707         iov->iov_len += offset;
1708         snd_buf->len += offset;
1709         return 0;
1710 }
1711 
1712 static void
1713 priv_release_snd_buf(struct rpc_rqst *rqstp)
1714 {
1715         int i;
1716 
1717         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1718                 __free_page(rqstp->rq_enc_pages[i]);
1719         kfree(rqstp->rq_enc_pages);
1720 }
1721 
1722 static int
1723 alloc_enc_pages(struct rpc_rqst *rqstp)
1724 {
1725         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1726         int first, last, i;
1727 
1728         if (snd_buf->page_len == 0) {
1729                 rqstp->rq_enc_pages_num = 0;
1730                 return 0;
1731         }
1732 
1733         first = snd_buf->page_base >> PAGE_SHIFT;
1734         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_SHIFT;
1735         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1736         rqstp->rq_enc_pages
1737                 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
1738                                 GFP_NOFS);
1739         if (!rqstp->rq_enc_pages)
1740                 goto out;
1741         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1742                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1743                 if (rqstp->rq_enc_pages[i] == NULL)
1744                         goto out_free;
1745         }
1746         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1747         return 0;
1748 out_free:
1749         rqstp->rq_enc_pages_num = i;
1750         priv_release_snd_buf(rqstp);
1751 out:
1752         return -EAGAIN;
1753 }
1754 
1755 static inline int
1756 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1757                   kxdreproc_t encode, struct rpc_rqst *rqstp,
1758                   __be32 *p, void *obj)
1759 {
1760         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1761         u32             offset;
1762         u32             maj_stat;
1763         int             status;
1764         __be32          *opaque_len;
1765         struct page     **inpages;
1766         int             first;
1767         int             pad;
1768         struct kvec     *iov;
1769         char            *tmp;
1770 
1771         opaque_len = p++;
1772         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1773         *p++ = htonl(rqstp->rq_seqno);
1774 
1775         gss_wrap_req_encode(encode, rqstp, p, obj);
1776 
1777         status = alloc_enc_pages(rqstp);
1778         if (status)
1779                 return status;
1780         first = snd_buf->page_base >> PAGE_SHIFT;
1781         inpages = snd_buf->pages + first;
1782         snd_buf->pages = rqstp->rq_enc_pages;
1783         snd_buf->page_base -= first << PAGE_SHIFT;
1784         /*
1785          * Give the tail its own page, in case we need extra space in the
1786          * head when wrapping:
1787          *
1788          * call_allocate() allocates twice the slack space required
1789          * by the authentication flavor to rq_callsize.
1790          * For GSS, slack is GSS_CRED_SLACK.
1791          */
1792         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1793                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1794                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1795                 snd_buf->tail[0].iov_base = tmp;
1796         }
1797         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1798         /* slack space should prevent this ever happening: */
1799         BUG_ON(snd_buf->len > snd_buf->buflen);
1800         status = -EIO;
1801         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1802          * done anyway, so it's safe to put the request on the wire: */
1803         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1804                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1805         else if (maj_stat)
1806                 return status;
1807 
1808         *opaque_len = htonl(snd_buf->len - offset);
1809         /* guess whether we're in the head or the tail: */
1810         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1811                 iov = snd_buf->tail;
1812         else
1813                 iov = snd_buf->head;
1814         p = iov->iov_base + iov->iov_len;
1815         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1816         memset(p, 0, pad);
1817         iov->iov_len += pad;
1818         snd_buf->len += pad;
1819 
1820         return 0;
1821 }
1822 
1823 static int
1824 gss_wrap_req(struct rpc_task *task,
1825              kxdreproc_t encode, void *rqstp, __be32 *p, void *obj)
1826 {
1827         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1828         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1829                         gc_base);
1830         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1831         int             status = -EIO;
1832 
1833         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1834         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1835                 /* The spec seems a little ambiguous here, but I think that not
1836                  * wrapping context destruction requests makes the most sense.
1837                  */
1838                 gss_wrap_req_encode(encode, rqstp, p, obj);
1839                 status = 0;
1840                 goto out;
1841         }
1842         switch (gss_cred->gc_service) {
1843         case RPC_GSS_SVC_NONE:
1844                 gss_wrap_req_encode(encode, rqstp, p, obj);
1845                 status = 0;
1846                 break;
1847         case RPC_GSS_SVC_INTEGRITY:
1848                 status = gss_wrap_req_integ(cred, ctx, encode, rqstp, p, obj);
1849                 break;
1850         case RPC_GSS_SVC_PRIVACY:
1851                 status = gss_wrap_req_priv(cred, ctx, encode, rqstp, p, obj);
1852                 break;
1853         }
1854 out:
1855         gss_put_ctx(ctx);
1856         dprintk("RPC: %5u %s returning %d\n", task->tk_pid, __func__, status);
1857         return status;
1858 }
1859 
1860 static inline int
1861 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1862                 struct rpc_rqst *rqstp, __be32 **p)
1863 {
1864         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1865         struct xdr_buf integ_buf;
1866         struct xdr_netobj mic;
1867         u32 data_offset, mic_offset;
1868         u32 integ_len;
1869         u32 maj_stat;
1870         int status = -EIO;
1871 
1872         integ_len = ntohl(*(*p)++);
1873         if (integ_len & 3)
1874                 return status;
1875         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1876         mic_offset = integ_len + data_offset;
1877         if (mic_offset > rcv_buf->len)
1878                 return status;
1879         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1880                 return status;
1881 
1882         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1883                                 mic_offset - data_offset))
1884                 return status;
1885 
1886         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1887                 return status;
1888 
1889         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1890         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1891                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1892         if (maj_stat != GSS_S_COMPLETE)
1893                 return status;
1894         return 0;
1895 }
1896 
1897 static inline int
1898 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1899                 struct rpc_rqst *rqstp, __be32 **p)
1900 {
1901         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1902         u32 offset;
1903         u32 opaque_len;
1904         u32 maj_stat;
1905         int status = -EIO;
1906 
1907         opaque_len = ntohl(*(*p)++);
1908         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1909         if (offset + opaque_len > rcv_buf->len)
1910                 return status;
1911         /* remove padding: */
1912         rcv_buf->len = offset + opaque_len;
1913 
1914         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1915         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1916                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1917         if (maj_stat != GSS_S_COMPLETE)
1918                 return status;
1919         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1920                 return status;
1921 
1922         return 0;
1923 }
1924 
1925 static int
1926 gss_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
1927                       __be32 *p, void *obj)
1928 {
1929         struct xdr_stream xdr;
1930 
1931         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
1932         return decode(rqstp, &xdr, obj);
1933 }
1934 
1935 static int
1936 gss_unwrap_resp(struct rpc_task *task,
1937                 kxdrdproc_t decode, void *rqstp, __be32 *p, void *obj)
1938 {
1939         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1940         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1941                         gc_base);
1942         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1943         __be32          *savedp = p;
1944         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1945         int             savedlen = head->iov_len;
1946         int             status = -EIO;
1947 
1948         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1949                 goto out_decode;
1950         switch (gss_cred->gc_service) {
1951         case RPC_GSS_SVC_NONE:
1952                 break;
1953         case RPC_GSS_SVC_INTEGRITY:
1954                 status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1955                 if (status)
1956                         goto out;
1957                 break;
1958         case RPC_GSS_SVC_PRIVACY:
1959                 status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1960                 if (status)
1961                         goto out;
1962                 break;
1963         }
1964         /* take into account extra slack for integrity and privacy cases: */
1965         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1966                                                 + (savedlen - head->iov_len);
1967 out_decode:
1968         status = gss_unwrap_req_decode(decode, rqstp, p, obj);
1969 out:
1970         gss_put_ctx(ctx);
1971         dprintk("RPC: %5u %s returning %d\n",
1972                 task->tk_pid, __func__, status);
1973         return status;
1974 }
1975 
1976 static const struct rpc_authops authgss_ops = {
1977         .owner          = THIS_MODULE,
1978         .au_flavor      = RPC_AUTH_GSS,
1979         .au_name        = "RPCSEC_GSS",
1980         .create         = gss_create,
1981         .destroy        = gss_destroy,
1982         .lookup_cred    = gss_lookup_cred,
1983         .crcreate       = gss_create_cred,
1984         .list_pseudoflavors = gss_mech_list_pseudoflavors,
1985         .info2flavor    = gss_mech_info2flavor,
1986         .flavor2info    = gss_mech_flavor2info,
1987 };
1988 
1989 static const struct rpc_credops gss_credops = {
1990         .cr_name                = "AUTH_GSS",
1991         .crdestroy              = gss_destroy_cred,
1992         .cr_init                = gss_cred_init,
1993         .crbind                 = rpcauth_generic_bind_cred,
1994         .crmatch                = gss_match,
1995         .crmarshal              = gss_marshal,
1996         .crrefresh              = gss_refresh,
1997         .crvalidate             = gss_validate,
1998         .crwrap_req             = gss_wrap_req,
1999         .crunwrap_resp          = gss_unwrap_resp,
2000         .crkey_timeout          = gss_key_timeout,
2001         .crstringify_acceptor   = gss_stringify_acceptor,
2002 };
2003 
2004 static const struct rpc_credops gss_nullops = {
2005         .cr_name                = "AUTH_GSS",
2006         .crdestroy              = gss_destroy_nullcred,
2007         .crbind                 = rpcauth_generic_bind_cred,
2008         .crmatch                = gss_match,
2009         .crmarshal              = gss_marshal,
2010         .crrefresh              = gss_refresh_null,
2011         .crvalidate             = gss_validate,
2012         .crwrap_req             = gss_wrap_req,
2013         .crunwrap_resp          = gss_unwrap_resp,
2014         .crstringify_acceptor   = gss_stringify_acceptor,
2015 };
2016 
2017 static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
2018         .upcall         = rpc_pipe_generic_upcall,
2019         .downcall       = gss_pipe_downcall,
2020         .destroy_msg    = gss_pipe_destroy_msg,
2021         .open_pipe      = gss_pipe_open_v0,
2022         .release_pipe   = gss_pipe_release,
2023 };
2024 
2025 static const struct rpc_pipe_ops gss_upcall_ops_v1 = {
2026         .upcall         = rpc_pipe_generic_upcall,
2027         .downcall       = gss_pipe_downcall,
2028         .destroy_msg    = gss_pipe_destroy_msg,
2029         .open_pipe      = gss_pipe_open_v1,
2030         .release_pipe   = gss_pipe_release,
2031 };
2032 
2033 static __net_init int rpcsec_gss_init_net(struct net *net)
2034 {
2035         return gss_svc_init_net(net);
2036 }
2037 
2038 static __net_exit void rpcsec_gss_exit_net(struct net *net)
2039 {
2040         gss_svc_shutdown_net(net);
2041 }
2042 
2043 static struct pernet_operations rpcsec_gss_net_ops = {
2044         .init = rpcsec_gss_init_net,
2045         .exit = rpcsec_gss_exit_net,
2046 };
2047 
2048 /*
2049  * Initialize RPCSEC_GSS module
2050  */
2051 static int __init init_rpcsec_gss(void)
2052 {
2053         int err = 0;
2054 
2055         err = rpcauth_register(&authgss_ops);
2056         if (err)
2057                 goto out;
2058         err = gss_svc_init();
2059         if (err)
2060                 goto out_unregister;
2061         err = register_pernet_subsys(&rpcsec_gss_net_ops);
2062         if (err)
2063                 goto out_svc_exit;
2064         rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
2065         return 0;
2066 out_svc_exit:
2067         gss_svc_shutdown();
2068 out_unregister:
2069         rpcauth_unregister(&authgss_ops);
2070 out:
2071         return err;
2072 }
2073 
2074 static void __exit exit_rpcsec_gss(void)
2075 {
2076         unregister_pernet_subsys(&rpcsec_gss_net_ops);
2077         gss_svc_shutdown();
2078         rpcauth_unregister(&authgss_ops);
2079         rcu_barrier(); /* Wait for completion of call_rcu()'s */
2080 }
2081 
2082 MODULE_ALIAS("rpc-auth-6");
2083 MODULE_LICENSE("GPL");
2084 module_param_named(expired_cred_retry_delay,
2085                    gss_expired_cred_retry_delay,
2086                    uint, 0644);
2087 MODULE_PARM_DESC(expired_cred_retry_delay, "Timeout (in seconds) until "
2088                 "the RPC engine retries an expired credential");
2089 
2090 module_param_named(key_expire_timeo,
2091                    gss_key_expire_timeo,
2092                    uint, 0644);
2093 MODULE_PARM_DESC(key_expire_timeo, "Time (in seconds) at the end of a "
2094                 "credential keys lifetime where the NFS layer cleans up "
2095                 "prior to key expiration");
2096 
2097 module_init(init_rpcsec_gss)
2098 module_exit(exit_rpcsec_gss)
2099 

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