Merge tag 'nfs-for-4.19-1' of git://git.linux-nfs.org/projects/anna/linux-nfs
[sfrench/cifs-2.6.git] / net / sunrpc / auth_gss / auth_gss.c
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 <linux/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         refcount_inc(&ctx->count);
121         return ctx;
122 }
123
124 static inline void
125 gss_put_ctx(struct gss_cl_ctx *ctx)
126 {
127         if (refcount_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                 refcount_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 /* XXX: Need some documentation about why UPCALL_BUF_LEN is so small.
288  *      Is user space expecting no more than UPCALL_BUF_LEN bytes?
289  *      Note that there are now _two_ NI_MAXHOST sized data items
290  *      being passed in this string.
291  */
292 #define UPCALL_BUF_LEN  256
293
294 struct gss_upcall_msg {
295         refcount_t count;
296         kuid_t  uid;
297         struct rpc_pipe_msg msg;
298         struct list_head list;
299         struct gss_auth *auth;
300         struct rpc_pipe *pipe;
301         struct rpc_wait_queue rpc_waitqueue;
302         wait_queue_head_t waitqueue;
303         struct gss_cl_ctx *ctx;
304         char databuf[UPCALL_BUF_LEN];
305 };
306
307 static int get_pipe_version(struct net *net)
308 {
309         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
310         int ret;
311
312         spin_lock(&pipe_version_lock);
313         if (sn->pipe_version >= 0) {
314                 atomic_inc(&sn->pipe_users);
315                 ret = sn->pipe_version;
316         } else
317                 ret = -EAGAIN;
318         spin_unlock(&pipe_version_lock);
319         return ret;
320 }
321
322 static void put_pipe_version(struct net *net)
323 {
324         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
325
326         if (atomic_dec_and_lock(&sn->pipe_users, &pipe_version_lock)) {
327                 sn->pipe_version = -1;
328                 spin_unlock(&pipe_version_lock);
329         }
330 }
331
332 static void
333 gss_release_msg(struct gss_upcall_msg *gss_msg)
334 {
335         struct net *net = gss_msg->auth->net;
336         if (!refcount_dec_and_test(&gss_msg->count))
337                 return;
338         put_pipe_version(net);
339         BUG_ON(!list_empty(&gss_msg->list));
340         if (gss_msg->ctx != NULL)
341                 gss_put_ctx(gss_msg->ctx);
342         rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
343         gss_put_auth(gss_msg->auth);
344         kfree(gss_msg);
345 }
346
347 static struct gss_upcall_msg *
348 __gss_find_upcall(struct rpc_pipe *pipe, kuid_t uid, const struct gss_auth *auth)
349 {
350         struct gss_upcall_msg *pos;
351         list_for_each_entry(pos, &pipe->in_downcall, list) {
352                 if (!uid_eq(pos->uid, uid))
353                         continue;
354                 if (auth && pos->auth->service != auth->service)
355                         continue;
356                 refcount_inc(&pos->count);
357                 dprintk("RPC:       %s found msg %p\n", __func__, pos);
358                 return pos;
359         }
360         dprintk("RPC:       %s found nothing\n", __func__);
361         return NULL;
362 }
363
364 /* Try to add an upcall to the pipefs queue.
365  * If an upcall owned by our uid already exists, then we return a reference
366  * to that upcall instead of adding the new upcall.
367  */
368 static inline struct gss_upcall_msg *
369 gss_add_msg(struct gss_upcall_msg *gss_msg)
370 {
371         struct rpc_pipe *pipe = gss_msg->pipe;
372         struct gss_upcall_msg *old;
373
374         spin_lock(&pipe->lock);
375         old = __gss_find_upcall(pipe, gss_msg->uid, gss_msg->auth);
376         if (old == NULL) {
377                 refcount_inc(&gss_msg->count);
378                 list_add(&gss_msg->list, &pipe->in_downcall);
379         } else
380                 gss_msg = old;
381         spin_unlock(&pipe->lock);
382         return gss_msg;
383 }
384
385 static void
386 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
387 {
388         list_del_init(&gss_msg->list);
389         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
390         wake_up_all(&gss_msg->waitqueue);
391         refcount_dec(&gss_msg->count);
392 }
393
394 static void
395 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
396 {
397         struct rpc_pipe *pipe = gss_msg->pipe;
398
399         if (list_empty(&gss_msg->list))
400                 return;
401         spin_lock(&pipe->lock);
402         if (!list_empty(&gss_msg->list))
403                 __gss_unhash_msg(gss_msg);
404         spin_unlock(&pipe->lock);
405 }
406
407 static void
408 gss_handle_downcall_result(struct gss_cred *gss_cred, struct gss_upcall_msg *gss_msg)
409 {
410         switch (gss_msg->msg.errno) {
411         case 0:
412                 if (gss_msg->ctx == NULL)
413                         break;
414                 clear_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
415                 gss_cred_set_ctx(&gss_cred->gc_base, gss_msg->ctx);
416                 break;
417         case -EKEYEXPIRED:
418                 set_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
419         }
420         gss_cred->gc_upcall_timestamp = jiffies;
421         gss_cred->gc_upcall = NULL;
422         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
423 }
424
425 static void
426 gss_upcall_callback(struct rpc_task *task)
427 {
428         struct gss_cred *gss_cred = container_of(task->tk_rqstp->rq_cred,
429                         struct gss_cred, gc_base);
430         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
431         struct rpc_pipe *pipe = gss_msg->pipe;
432
433         spin_lock(&pipe->lock);
434         gss_handle_downcall_result(gss_cred, gss_msg);
435         spin_unlock(&pipe->lock);
436         task->tk_status = gss_msg->msg.errno;
437         gss_release_msg(gss_msg);
438 }
439
440 static void gss_encode_v0_msg(struct gss_upcall_msg *gss_msg)
441 {
442         uid_t uid = from_kuid(&init_user_ns, gss_msg->uid);
443         memcpy(gss_msg->databuf, &uid, sizeof(uid));
444         gss_msg->msg.data = gss_msg->databuf;
445         gss_msg->msg.len = sizeof(uid);
446
447         BUILD_BUG_ON(sizeof(uid) > sizeof(gss_msg->databuf));
448 }
449
450 static int gss_encode_v1_msg(struct gss_upcall_msg *gss_msg,
451                                 const char *service_name,
452                                 const char *target_name)
453 {
454         struct gss_api_mech *mech = gss_msg->auth->mech;
455         char *p = gss_msg->databuf;
456         size_t buflen = sizeof(gss_msg->databuf);
457         int len;
458
459         len = scnprintf(p, buflen, "mech=%s uid=%d ", mech->gm_name,
460                         from_kuid(&init_user_ns, gss_msg->uid));
461         buflen -= len;
462         p += len;
463         gss_msg->msg.len = len;
464
465         /*
466          * target= is a full service principal that names the remote
467          * identity that we are authenticating to.
468          */
469         if (target_name) {
470                 len = scnprintf(p, buflen, "target=%s ", target_name);
471                 buflen -= len;
472                 p += len;
473                 gss_msg->msg.len += len;
474         }
475
476         /*
477          * gssd uses service= and srchost= to select a matching key from
478          * the system's keytab to use as the source principal.
479          *
480          * service= is the service name part of the source principal,
481          * or "*" (meaning choose any).
482          *
483          * srchost= is the hostname part of the source principal. When
484          * not provided, gssd uses the local hostname.
485          */
486         if (service_name) {
487                 char *c = strchr(service_name, '@');
488
489                 if (!c)
490                         len = scnprintf(p, buflen, "service=%s ",
491                                         service_name);
492                 else
493                         len = scnprintf(p, buflen,
494                                         "service=%.*s srchost=%s ",
495                                         (int)(c - service_name),
496                                         service_name, c + 1);
497                 buflen -= len;
498                 p += len;
499                 gss_msg->msg.len += len;
500         }
501
502         if (mech->gm_upcall_enctypes) {
503                 len = scnprintf(p, buflen, "enctypes=%s ",
504                                 mech->gm_upcall_enctypes);
505                 buflen -= len;
506                 p += len;
507                 gss_msg->msg.len += len;
508         }
509         len = scnprintf(p, buflen, "\n");
510         if (len == 0)
511                 goto out_overflow;
512         gss_msg->msg.len += len;
513
514         gss_msg->msg.data = gss_msg->databuf;
515         return 0;
516 out_overflow:
517         WARN_ON_ONCE(1);
518         return -ENOMEM;
519 }
520
521 static struct gss_upcall_msg *
522 gss_alloc_msg(struct gss_auth *gss_auth,
523                 kuid_t uid, const char *service_name)
524 {
525         struct gss_upcall_msg *gss_msg;
526         int vers;
527         int err = -ENOMEM;
528
529         gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
530         if (gss_msg == NULL)
531                 goto err;
532         vers = get_pipe_version(gss_auth->net);
533         err = vers;
534         if (err < 0)
535                 goto err_free_msg;
536         gss_msg->pipe = gss_auth->gss_pipe[vers]->pipe;
537         INIT_LIST_HEAD(&gss_msg->list);
538         rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
539         init_waitqueue_head(&gss_msg->waitqueue);
540         refcount_set(&gss_msg->count, 1);
541         gss_msg->uid = uid;
542         gss_msg->auth = gss_auth;
543         switch (vers) {
544         case 0:
545                 gss_encode_v0_msg(gss_msg);
546                 break;
547         default:
548                 err = gss_encode_v1_msg(gss_msg, service_name, gss_auth->target_name);
549                 if (err)
550                         goto err_put_pipe_version;
551         }
552         kref_get(&gss_auth->kref);
553         return gss_msg;
554 err_put_pipe_version:
555         put_pipe_version(gss_auth->net);
556 err_free_msg:
557         kfree(gss_msg);
558 err:
559         return ERR_PTR(err);
560 }
561
562 static struct gss_upcall_msg *
563 gss_setup_upcall(struct gss_auth *gss_auth, struct rpc_cred *cred)
564 {
565         struct gss_cred *gss_cred = container_of(cred,
566                         struct gss_cred, gc_base);
567         struct gss_upcall_msg *gss_new, *gss_msg;
568         kuid_t uid = cred->cr_uid;
569
570         gss_new = gss_alloc_msg(gss_auth, uid, gss_cred->gc_principal);
571         if (IS_ERR(gss_new))
572                 return gss_new;
573         gss_msg = gss_add_msg(gss_new);
574         if (gss_msg == gss_new) {
575                 int res;
576                 refcount_inc(&gss_msg->count);
577                 res = rpc_queue_upcall(gss_new->pipe, &gss_new->msg);
578                 if (res) {
579                         gss_unhash_msg(gss_new);
580                         refcount_dec(&gss_msg->count);
581                         gss_release_msg(gss_new);
582                         gss_msg = ERR_PTR(res);
583                 }
584         } else
585                 gss_release_msg(gss_new);
586         return gss_msg;
587 }
588
589 static void warn_gssd(void)
590 {
591         dprintk("AUTH_GSS upcall failed. Please check user daemon is running.\n");
592 }
593
594 static inline int
595 gss_refresh_upcall(struct rpc_task *task)
596 {
597         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
598         struct gss_auth *gss_auth = container_of(cred->cr_auth,
599                         struct gss_auth, rpc_auth);
600         struct gss_cred *gss_cred = container_of(cred,
601                         struct gss_cred, gc_base);
602         struct gss_upcall_msg *gss_msg;
603         struct rpc_pipe *pipe;
604         int err = 0;
605
606         dprintk("RPC: %5u %s for uid %u\n",
607                 task->tk_pid, __func__, from_kuid(&init_user_ns, cred->cr_uid));
608         gss_msg = gss_setup_upcall(gss_auth, cred);
609         if (PTR_ERR(gss_msg) == -EAGAIN) {
610                 /* XXX: warning on the first, under the assumption we
611                  * shouldn't normally hit this case on a refresh. */
612                 warn_gssd();
613                 task->tk_timeout = 15*HZ;
614                 rpc_sleep_on(&pipe_version_rpc_waitqueue, task, NULL);
615                 return -EAGAIN;
616         }
617         if (IS_ERR(gss_msg)) {
618                 err = PTR_ERR(gss_msg);
619                 goto out;
620         }
621         pipe = gss_msg->pipe;
622         spin_lock(&pipe->lock);
623         if (gss_cred->gc_upcall != NULL)
624                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
625         else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
626                 task->tk_timeout = 0;
627                 gss_cred->gc_upcall = gss_msg;
628                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
629                 refcount_inc(&gss_msg->count);
630                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
631         } else {
632                 gss_handle_downcall_result(gss_cred, gss_msg);
633                 err = gss_msg->msg.errno;
634         }
635         spin_unlock(&pipe->lock);
636         gss_release_msg(gss_msg);
637 out:
638         dprintk("RPC: %5u %s for uid %u result %d\n",
639                 task->tk_pid, __func__,
640                 from_kuid(&init_user_ns, cred->cr_uid), err);
641         return err;
642 }
643
644 static inline int
645 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
646 {
647         struct net *net = gss_auth->net;
648         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
649         struct rpc_pipe *pipe;
650         struct rpc_cred *cred = &gss_cred->gc_base;
651         struct gss_upcall_msg *gss_msg;
652         DEFINE_WAIT(wait);
653         int err;
654
655         dprintk("RPC:       %s for uid %u\n",
656                 __func__, from_kuid(&init_user_ns, cred->cr_uid));
657 retry:
658         err = 0;
659         /* if gssd is down, just skip upcalling altogether */
660         if (!gssd_running(net)) {
661                 warn_gssd();
662                 return -EACCES;
663         }
664         gss_msg = gss_setup_upcall(gss_auth, cred);
665         if (PTR_ERR(gss_msg) == -EAGAIN) {
666                 err = wait_event_interruptible_timeout(pipe_version_waitqueue,
667                                 sn->pipe_version >= 0, 15 * HZ);
668                 if (sn->pipe_version < 0) {
669                         warn_gssd();
670                         err = -EACCES;
671                 }
672                 if (err < 0)
673                         goto out;
674                 goto retry;
675         }
676         if (IS_ERR(gss_msg)) {
677                 err = PTR_ERR(gss_msg);
678                 goto out;
679         }
680         pipe = gss_msg->pipe;
681         for (;;) {
682                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_KILLABLE);
683                 spin_lock(&pipe->lock);
684                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
685                         break;
686                 }
687                 spin_unlock(&pipe->lock);
688                 if (fatal_signal_pending(current)) {
689                         err = -ERESTARTSYS;
690                         goto out_intr;
691                 }
692                 schedule();
693         }
694         if (gss_msg->ctx)
695                 gss_cred_set_ctx(cred, gss_msg->ctx);
696         else
697                 err = gss_msg->msg.errno;
698         spin_unlock(&pipe->lock);
699 out_intr:
700         finish_wait(&gss_msg->waitqueue, &wait);
701         gss_release_msg(gss_msg);
702 out:
703         dprintk("RPC:       %s for uid %u result %d\n",
704                 __func__, from_kuid(&init_user_ns, cred->cr_uid), err);
705         return err;
706 }
707
708 #define MSG_BUF_MAXSIZE 1024
709
710 static ssize_t
711 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
712 {
713         const void *p, *end;
714         void *buf;
715         struct gss_upcall_msg *gss_msg;
716         struct rpc_pipe *pipe = RPC_I(file_inode(filp))->pipe;
717         struct gss_cl_ctx *ctx;
718         uid_t id;
719         kuid_t uid;
720         ssize_t err = -EFBIG;
721
722         if (mlen > MSG_BUF_MAXSIZE)
723                 goto out;
724         err = -ENOMEM;
725         buf = kmalloc(mlen, GFP_NOFS);
726         if (!buf)
727                 goto out;
728
729         err = -EFAULT;
730         if (copy_from_user(buf, src, mlen))
731                 goto err;
732
733         end = (const void *)((char *)buf + mlen);
734         p = simple_get_bytes(buf, end, &id, sizeof(id));
735         if (IS_ERR(p)) {
736                 err = PTR_ERR(p);
737                 goto err;
738         }
739
740         uid = make_kuid(&init_user_ns, id);
741         if (!uid_valid(uid)) {
742                 err = -EINVAL;
743                 goto err;
744         }
745
746         err = -ENOMEM;
747         ctx = gss_alloc_context();
748         if (ctx == NULL)
749                 goto err;
750
751         err = -ENOENT;
752         /* Find a matching upcall */
753         spin_lock(&pipe->lock);
754         gss_msg = __gss_find_upcall(pipe, uid, NULL);
755         if (gss_msg == NULL) {
756                 spin_unlock(&pipe->lock);
757                 goto err_put_ctx;
758         }
759         list_del_init(&gss_msg->list);
760         spin_unlock(&pipe->lock);
761
762         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
763         if (IS_ERR(p)) {
764                 err = PTR_ERR(p);
765                 switch (err) {
766                 case -EACCES:
767                 case -EKEYEXPIRED:
768                         gss_msg->msg.errno = err;
769                         err = mlen;
770                         break;
771                 case -EFAULT:
772                 case -ENOMEM:
773                 case -EINVAL:
774                 case -ENOSYS:
775                         gss_msg->msg.errno = -EAGAIN;
776                         break;
777                 default:
778                         printk(KERN_CRIT "%s: bad return from "
779                                 "gss_fill_context: %zd\n", __func__, err);
780                         gss_msg->msg.errno = -EIO;
781                 }
782                 goto err_release_msg;
783         }
784         gss_msg->ctx = gss_get_ctx(ctx);
785         err = mlen;
786
787 err_release_msg:
788         spin_lock(&pipe->lock);
789         __gss_unhash_msg(gss_msg);
790         spin_unlock(&pipe->lock);
791         gss_release_msg(gss_msg);
792 err_put_ctx:
793         gss_put_ctx(ctx);
794 err:
795         kfree(buf);
796 out:
797         dprintk("RPC:       %s returning %zd\n", __func__, err);
798         return err;
799 }
800
801 static int gss_pipe_open(struct inode *inode, int new_version)
802 {
803         struct net *net = inode->i_sb->s_fs_info;
804         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
805         int ret = 0;
806
807         spin_lock(&pipe_version_lock);
808         if (sn->pipe_version < 0) {
809                 /* First open of any gss pipe determines the version: */
810                 sn->pipe_version = new_version;
811                 rpc_wake_up(&pipe_version_rpc_waitqueue);
812                 wake_up(&pipe_version_waitqueue);
813         } else if (sn->pipe_version != new_version) {
814                 /* Trying to open a pipe of a different version */
815                 ret = -EBUSY;
816                 goto out;
817         }
818         atomic_inc(&sn->pipe_users);
819 out:
820         spin_unlock(&pipe_version_lock);
821         return ret;
822
823 }
824
825 static int gss_pipe_open_v0(struct inode *inode)
826 {
827         return gss_pipe_open(inode, 0);
828 }
829
830 static int gss_pipe_open_v1(struct inode *inode)
831 {
832         return gss_pipe_open(inode, 1);
833 }
834
835 static void
836 gss_pipe_release(struct inode *inode)
837 {
838         struct net *net = inode->i_sb->s_fs_info;
839         struct rpc_pipe *pipe = RPC_I(inode)->pipe;
840         struct gss_upcall_msg *gss_msg;
841
842 restart:
843         spin_lock(&pipe->lock);
844         list_for_each_entry(gss_msg, &pipe->in_downcall, list) {
845
846                 if (!list_empty(&gss_msg->msg.list))
847                         continue;
848                 gss_msg->msg.errno = -EPIPE;
849                 refcount_inc(&gss_msg->count);
850                 __gss_unhash_msg(gss_msg);
851                 spin_unlock(&pipe->lock);
852                 gss_release_msg(gss_msg);
853                 goto restart;
854         }
855         spin_unlock(&pipe->lock);
856
857         put_pipe_version(net);
858 }
859
860 static void
861 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
862 {
863         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
864
865         if (msg->errno < 0) {
866                 dprintk("RPC:       %s releasing msg %p\n",
867                         __func__, gss_msg);
868                 refcount_inc(&gss_msg->count);
869                 gss_unhash_msg(gss_msg);
870                 if (msg->errno == -ETIMEDOUT)
871                         warn_gssd();
872                 gss_release_msg(gss_msg);
873         }
874         gss_release_msg(gss_msg);
875 }
876
877 static void gss_pipe_dentry_destroy(struct dentry *dir,
878                 struct rpc_pipe_dir_object *pdo)
879 {
880         struct gss_pipe *gss_pipe = pdo->pdo_data;
881         struct rpc_pipe *pipe = gss_pipe->pipe;
882
883         if (pipe->dentry != NULL) {
884                 rpc_unlink(pipe->dentry);
885                 pipe->dentry = NULL;
886         }
887 }
888
889 static int gss_pipe_dentry_create(struct dentry *dir,
890                 struct rpc_pipe_dir_object *pdo)
891 {
892         struct gss_pipe *p = pdo->pdo_data;
893         struct dentry *dentry;
894
895         dentry = rpc_mkpipe_dentry(dir, p->name, p->clnt, p->pipe);
896         if (IS_ERR(dentry))
897                 return PTR_ERR(dentry);
898         p->pipe->dentry = dentry;
899         return 0;
900 }
901
902 static const struct rpc_pipe_dir_object_ops gss_pipe_dir_object_ops = {
903         .create = gss_pipe_dentry_create,
904         .destroy = gss_pipe_dentry_destroy,
905 };
906
907 static struct gss_pipe *gss_pipe_alloc(struct rpc_clnt *clnt,
908                 const char *name,
909                 const struct rpc_pipe_ops *upcall_ops)
910 {
911         struct gss_pipe *p;
912         int err = -ENOMEM;
913
914         p = kmalloc(sizeof(*p), GFP_KERNEL);
915         if (p == NULL)
916                 goto err;
917         p->pipe = rpc_mkpipe_data(upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
918         if (IS_ERR(p->pipe)) {
919                 err = PTR_ERR(p->pipe);
920                 goto err_free_gss_pipe;
921         }
922         p->name = name;
923         p->clnt = clnt;
924         kref_init(&p->kref);
925         rpc_init_pipe_dir_object(&p->pdo,
926                         &gss_pipe_dir_object_ops,
927                         p);
928         return p;
929 err_free_gss_pipe:
930         kfree(p);
931 err:
932         return ERR_PTR(err);
933 }
934
935 struct gss_alloc_pdo {
936         struct rpc_clnt *clnt;
937         const char *name;
938         const struct rpc_pipe_ops *upcall_ops;
939 };
940
941 static int gss_pipe_match_pdo(struct rpc_pipe_dir_object *pdo, void *data)
942 {
943         struct gss_pipe *gss_pipe;
944         struct gss_alloc_pdo *args = data;
945
946         if (pdo->pdo_ops != &gss_pipe_dir_object_ops)
947                 return 0;
948         gss_pipe = container_of(pdo, struct gss_pipe, pdo);
949         if (strcmp(gss_pipe->name, args->name) != 0)
950                 return 0;
951         if (!kref_get_unless_zero(&gss_pipe->kref))
952                 return 0;
953         return 1;
954 }
955
956 static struct rpc_pipe_dir_object *gss_pipe_alloc_pdo(void *data)
957 {
958         struct gss_pipe *gss_pipe;
959         struct gss_alloc_pdo *args = data;
960
961         gss_pipe = gss_pipe_alloc(args->clnt, args->name, args->upcall_ops);
962         if (!IS_ERR(gss_pipe))
963                 return &gss_pipe->pdo;
964         return NULL;
965 }
966
967 static struct gss_pipe *gss_pipe_get(struct rpc_clnt *clnt,
968                 const char *name,
969                 const struct rpc_pipe_ops *upcall_ops)
970 {
971         struct net *net = rpc_net_ns(clnt);
972         struct rpc_pipe_dir_object *pdo;
973         struct gss_alloc_pdo args = {
974                 .clnt = clnt,
975                 .name = name,
976                 .upcall_ops = upcall_ops,
977         };
978
979         pdo = rpc_find_or_alloc_pipe_dir_object(net,
980                         &clnt->cl_pipedir_objects,
981                         gss_pipe_match_pdo,
982                         gss_pipe_alloc_pdo,
983                         &args);
984         if (pdo != NULL)
985                 return container_of(pdo, struct gss_pipe, pdo);
986         return ERR_PTR(-ENOMEM);
987 }
988
989 static void __gss_pipe_free(struct gss_pipe *p)
990 {
991         struct rpc_clnt *clnt = p->clnt;
992         struct net *net = rpc_net_ns(clnt);
993
994         rpc_remove_pipe_dir_object(net,
995                         &clnt->cl_pipedir_objects,
996                         &p->pdo);
997         rpc_destroy_pipe_data(p->pipe);
998         kfree(p);
999 }
1000
1001 static void __gss_pipe_release(struct kref *kref)
1002 {
1003         struct gss_pipe *p = container_of(kref, struct gss_pipe, kref);
1004
1005         __gss_pipe_free(p);
1006 }
1007
1008 static void gss_pipe_free(struct gss_pipe *p)
1009 {
1010         if (p != NULL)
1011                 kref_put(&p->kref, __gss_pipe_release);
1012 }
1013
1014 /*
1015  * NOTE: we have the opportunity to use different
1016  * parameters based on the input flavor (which must be a pseudoflavor)
1017  */
1018 static struct gss_auth *
1019 gss_create_new(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1020 {
1021         rpc_authflavor_t flavor = args->pseudoflavor;
1022         struct gss_auth *gss_auth;
1023         struct gss_pipe *gss_pipe;
1024         struct rpc_auth * auth;
1025         int err = -ENOMEM; /* XXX? */
1026
1027         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
1028
1029         if (!try_module_get(THIS_MODULE))
1030                 return ERR_PTR(err);
1031         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
1032                 goto out_dec;
1033         INIT_HLIST_NODE(&gss_auth->hash);
1034         gss_auth->target_name = NULL;
1035         if (args->target_name) {
1036                 gss_auth->target_name = kstrdup(args->target_name, GFP_KERNEL);
1037                 if (gss_auth->target_name == NULL)
1038                         goto err_free;
1039         }
1040         gss_auth->client = clnt;
1041         gss_auth->net = get_net(rpc_net_ns(clnt));
1042         err = -EINVAL;
1043         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
1044         if (!gss_auth->mech) {
1045                 dprintk("RPC:       Pseudoflavor %d not found!\n", flavor);
1046                 goto err_put_net;
1047         }
1048         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
1049         if (gss_auth->service == 0)
1050                 goto err_put_mech;
1051         if (!gssd_running(gss_auth->net))
1052                 goto err_put_mech;
1053         auth = &gss_auth->rpc_auth;
1054         auth->au_cslack = GSS_CRED_SLACK >> 2;
1055         auth->au_rslack = GSS_VERF_SLACK >> 2;
1056         auth->au_flags = 0;
1057         auth->au_ops = &authgss_ops;
1058         auth->au_flavor = flavor;
1059         if (gss_pseudoflavor_to_datatouch(gss_auth->mech, flavor))
1060                 auth->au_flags |= RPCAUTH_AUTH_DATATOUCH;
1061         atomic_set(&auth->au_count, 1);
1062         kref_init(&gss_auth->kref);
1063
1064         err = rpcauth_init_credcache(auth);
1065         if (err)
1066                 goto err_put_mech;
1067         /*
1068          * Note: if we created the old pipe first, then someone who
1069          * examined the directory at the right moment might conclude
1070          * that we supported only the old pipe.  So we instead create
1071          * the new pipe first.
1072          */
1073         gss_pipe = gss_pipe_get(clnt, "gssd", &gss_upcall_ops_v1);
1074         if (IS_ERR(gss_pipe)) {
1075                 err = PTR_ERR(gss_pipe);
1076                 goto err_destroy_credcache;
1077         }
1078         gss_auth->gss_pipe[1] = gss_pipe;
1079
1080         gss_pipe = gss_pipe_get(clnt, gss_auth->mech->gm_name,
1081                         &gss_upcall_ops_v0);
1082         if (IS_ERR(gss_pipe)) {
1083                 err = PTR_ERR(gss_pipe);
1084                 goto err_destroy_pipe_1;
1085         }
1086         gss_auth->gss_pipe[0] = gss_pipe;
1087
1088         return gss_auth;
1089 err_destroy_pipe_1:
1090         gss_pipe_free(gss_auth->gss_pipe[1]);
1091 err_destroy_credcache:
1092         rpcauth_destroy_credcache(auth);
1093 err_put_mech:
1094         gss_mech_put(gss_auth->mech);
1095 err_put_net:
1096         put_net(gss_auth->net);
1097 err_free:
1098         kfree(gss_auth->target_name);
1099         kfree(gss_auth);
1100 out_dec:
1101         module_put(THIS_MODULE);
1102         return ERR_PTR(err);
1103 }
1104
1105 static void
1106 gss_free(struct gss_auth *gss_auth)
1107 {
1108         gss_pipe_free(gss_auth->gss_pipe[0]);
1109         gss_pipe_free(gss_auth->gss_pipe[1]);
1110         gss_mech_put(gss_auth->mech);
1111         put_net(gss_auth->net);
1112         kfree(gss_auth->target_name);
1113
1114         kfree(gss_auth);
1115         module_put(THIS_MODULE);
1116 }
1117
1118 static void
1119 gss_free_callback(struct kref *kref)
1120 {
1121         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
1122
1123         gss_free(gss_auth);
1124 }
1125
1126 static void
1127 gss_put_auth(struct gss_auth *gss_auth)
1128 {
1129         kref_put(&gss_auth->kref, gss_free_callback);
1130 }
1131
1132 static void
1133 gss_destroy(struct rpc_auth *auth)
1134 {
1135         struct gss_auth *gss_auth = container_of(auth,
1136                         struct gss_auth, rpc_auth);
1137
1138         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
1139                         auth, auth->au_flavor);
1140
1141         if (hash_hashed(&gss_auth->hash)) {
1142                 spin_lock(&gss_auth_hash_lock);
1143                 hash_del(&gss_auth->hash);
1144                 spin_unlock(&gss_auth_hash_lock);
1145         }
1146
1147         gss_pipe_free(gss_auth->gss_pipe[0]);
1148         gss_auth->gss_pipe[0] = NULL;
1149         gss_pipe_free(gss_auth->gss_pipe[1]);
1150         gss_auth->gss_pipe[1] = NULL;
1151         rpcauth_destroy_credcache(auth);
1152
1153         gss_put_auth(gss_auth);
1154 }
1155
1156 /*
1157  * Auths may be shared between rpc clients that were cloned from a
1158  * common client with the same xprt, if they also share the flavor and
1159  * target_name.
1160  *
1161  * The auth is looked up from the oldest parent sharing the same
1162  * cl_xprt, and the auth itself references only that common parent
1163  * (which is guaranteed to last as long as any of its descendants).
1164  */
1165 static struct gss_auth *
1166 gss_auth_find_or_add_hashed(const struct rpc_auth_create_args *args,
1167                 struct rpc_clnt *clnt,
1168                 struct gss_auth *new)
1169 {
1170         struct gss_auth *gss_auth;
1171         unsigned long hashval = (unsigned long)clnt;
1172
1173         spin_lock(&gss_auth_hash_lock);
1174         hash_for_each_possible(gss_auth_hash_table,
1175                         gss_auth,
1176                         hash,
1177                         hashval) {
1178                 if (gss_auth->client != clnt)
1179                         continue;
1180                 if (gss_auth->rpc_auth.au_flavor != args->pseudoflavor)
1181                         continue;
1182                 if (gss_auth->target_name != args->target_name) {
1183                         if (gss_auth->target_name == NULL)
1184                                 continue;
1185                         if (args->target_name == NULL)
1186                                 continue;
1187                         if (strcmp(gss_auth->target_name, args->target_name))
1188                                 continue;
1189                 }
1190                 if (!atomic_inc_not_zero(&gss_auth->rpc_auth.au_count))
1191                         continue;
1192                 goto out;
1193         }
1194         if (new)
1195                 hash_add(gss_auth_hash_table, &new->hash, hashval);
1196         gss_auth = new;
1197 out:
1198         spin_unlock(&gss_auth_hash_lock);
1199         return gss_auth;
1200 }
1201
1202 static struct gss_auth *
1203 gss_create_hashed(const struct rpc_auth_create_args *args,
1204                   struct rpc_clnt *clnt)
1205 {
1206         struct gss_auth *gss_auth;
1207         struct gss_auth *new;
1208
1209         gss_auth = gss_auth_find_or_add_hashed(args, clnt, NULL);
1210         if (gss_auth != NULL)
1211                 goto out;
1212         new = gss_create_new(args, clnt);
1213         if (IS_ERR(new))
1214                 return new;
1215         gss_auth = gss_auth_find_or_add_hashed(args, clnt, new);
1216         if (gss_auth != new)
1217                 gss_destroy(&new->rpc_auth);
1218 out:
1219         return gss_auth;
1220 }
1221
1222 static struct rpc_auth *
1223 gss_create(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1224 {
1225         struct gss_auth *gss_auth;
1226         struct rpc_xprt_switch *xps = rcu_access_pointer(clnt->cl_xpi.xpi_xpswitch);
1227
1228         while (clnt != clnt->cl_parent) {
1229                 struct rpc_clnt *parent = clnt->cl_parent;
1230                 /* Find the original parent for this transport */
1231                 if (rcu_access_pointer(parent->cl_xpi.xpi_xpswitch) != xps)
1232                         break;
1233                 clnt = parent;
1234         }
1235
1236         gss_auth = gss_create_hashed(args, clnt);
1237         if (IS_ERR(gss_auth))
1238                 return ERR_CAST(gss_auth);
1239         return &gss_auth->rpc_auth;
1240 }
1241
1242 /*
1243  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
1244  * to the server with the GSS control procedure field set to
1245  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
1246  * all RPCSEC_GSS state associated with that context.
1247  */
1248 static int
1249 gss_destroying_context(struct rpc_cred *cred)
1250 {
1251         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1252         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1253         struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
1254         struct rpc_task *task;
1255
1256         if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
1257                 return 0;
1258
1259         ctx->gc_proc = RPC_GSS_PROC_DESTROY;
1260         cred->cr_ops = &gss_nullops;
1261
1262         /* Take a reference to ensure the cred will be destroyed either
1263          * by the RPC call or by the put_rpccred() below */
1264         get_rpccred(cred);
1265
1266         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
1267         if (!IS_ERR(task))
1268                 rpc_put_task(task);
1269
1270         put_rpccred(cred);
1271         return 1;
1272 }
1273
1274 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
1275  * to create a new cred or context, so they check that things have been
1276  * allocated before freeing them. */
1277 static void
1278 gss_do_free_ctx(struct gss_cl_ctx *ctx)
1279 {
1280         dprintk("RPC:       %s\n", __func__);
1281
1282         gss_delete_sec_context(&ctx->gc_gss_ctx);
1283         kfree(ctx->gc_wire_ctx.data);
1284         kfree(ctx->gc_acceptor.data);
1285         kfree(ctx);
1286 }
1287
1288 static void
1289 gss_free_ctx_callback(struct rcu_head *head)
1290 {
1291         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
1292         gss_do_free_ctx(ctx);
1293 }
1294
1295 static void
1296 gss_free_ctx(struct gss_cl_ctx *ctx)
1297 {
1298         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
1299 }
1300
1301 static void
1302 gss_free_cred(struct gss_cred *gss_cred)
1303 {
1304         dprintk("RPC:       %s cred=%p\n", __func__, gss_cred);
1305         kfree(gss_cred);
1306 }
1307
1308 static void
1309 gss_free_cred_callback(struct rcu_head *head)
1310 {
1311         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
1312         gss_free_cred(gss_cred);
1313 }
1314
1315 static void
1316 gss_destroy_nullcred(struct rpc_cred *cred)
1317 {
1318         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1319         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1320         struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
1321
1322         RCU_INIT_POINTER(gss_cred->gc_ctx, NULL);
1323         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
1324         if (ctx)
1325                 gss_put_ctx(ctx);
1326         gss_put_auth(gss_auth);
1327 }
1328
1329 static void
1330 gss_destroy_cred(struct rpc_cred *cred)
1331 {
1332
1333         if (gss_destroying_context(cred))
1334                 return;
1335         gss_destroy_nullcred(cred);
1336 }
1337
1338 static int
1339 gss_hash_cred(struct auth_cred *acred, unsigned int hashbits)
1340 {
1341         return hash_64(from_kuid(&init_user_ns, acred->uid), hashbits);
1342 }
1343
1344 /*
1345  * Lookup RPCSEC_GSS cred for the current process
1346  */
1347 static struct rpc_cred *
1348 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1349 {
1350         return rpcauth_lookup_credcache(auth, acred, flags, GFP_NOFS);
1351 }
1352
1353 static struct rpc_cred *
1354 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags, gfp_t gfp)
1355 {
1356         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1357         struct gss_cred *cred = NULL;
1358         int err = -ENOMEM;
1359
1360         dprintk("RPC:       %s for uid %d, flavor %d\n",
1361                 __func__, from_kuid(&init_user_ns, acred->uid),
1362                 auth->au_flavor);
1363
1364         if (!(cred = kzalloc(sizeof(*cred), gfp)))
1365                 goto out_err;
1366
1367         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
1368         /*
1369          * Note: in order to force a call to call_refresh(), we deliberately
1370          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
1371          */
1372         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
1373         cred->gc_service = gss_auth->service;
1374         cred->gc_principal = NULL;
1375         if (acred->machine_cred)
1376                 cred->gc_principal = acred->principal;
1377         kref_get(&gss_auth->kref);
1378         return &cred->gc_base;
1379
1380 out_err:
1381         dprintk("RPC:       %s failed with error %d\n", __func__, err);
1382         return ERR_PTR(err);
1383 }
1384
1385 static int
1386 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
1387 {
1388         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1389         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
1390         int err;
1391
1392         do {
1393                 err = gss_create_upcall(gss_auth, gss_cred);
1394         } while (err == -EAGAIN);
1395         return err;
1396 }
1397
1398 static char *
1399 gss_stringify_acceptor(struct rpc_cred *cred)
1400 {
1401         char *string = NULL;
1402         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1403         struct gss_cl_ctx *ctx;
1404         unsigned int len;
1405         struct xdr_netobj *acceptor;
1406
1407         rcu_read_lock();
1408         ctx = rcu_dereference(gss_cred->gc_ctx);
1409         if (!ctx)
1410                 goto out;
1411
1412         len = ctx->gc_acceptor.len;
1413         rcu_read_unlock();
1414
1415         /* no point if there's no string */
1416         if (!len)
1417                 return NULL;
1418 realloc:
1419         string = kmalloc(len + 1, GFP_KERNEL);
1420         if (!string)
1421                 return NULL;
1422
1423         rcu_read_lock();
1424         ctx = rcu_dereference(gss_cred->gc_ctx);
1425
1426         /* did the ctx disappear or was it replaced by one with no acceptor? */
1427         if (!ctx || !ctx->gc_acceptor.len) {
1428                 kfree(string);
1429                 string = NULL;
1430                 goto out;
1431         }
1432
1433         acceptor = &ctx->gc_acceptor;
1434
1435         /*
1436          * Did we find a new acceptor that's longer than the original? Allocate
1437          * a longer buffer and try again.
1438          */
1439         if (len < acceptor->len) {
1440                 len = acceptor->len;
1441                 rcu_read_unlock();
1442                 kfree(string);
1443                 goto realloc;
1444         }
1445
1446         memcpy(string, acceptor->data, acceptor->len);
1447         string[acceptor->len] = '\0';
1448 out:
1449         rcu_read_unlock();
1450         return string;
1451 }
1452
1453 /*
1454  * Returns -EACCES if GSS context is NULL or will expire within the
1455  * timeout (miliseconds)
1456  */
1457 static int
1458 gss_key_timeout(struct rpc_cred *rc)
1459 {
1460         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1461         struct gss_cl_ctx *ctx;
1462         unsigned long timeout = jiffies + (gss_key_expire_timeo * HZ);
1463         int ret = 0;
1464
1465         rcu_read_lock();
1466         ctx = rcu_dereference(gss_cred->gc_ctx);
1467         if (!ctx || time_after(timeout, ctx->gc_expiry))
1468                 ret = -EACCES;
1469         rcu_read_unlock();
1470
1471         return ret;
1472 }
1473
1474 static int
1475 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
1476 {
1477         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1478         struct gss_cl_ctx *ctx;
1479         int ret;
1480
1481         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
1482                 goto out;
1483         /* Don't match with creds that have expired. */
1484         rcu_read_lock();
1485         ctx = rcu_dereference(gss_cred->gc_ctx);
1486         if (!ctx || time_after(jiffies, ctx->gc_expiry)) {
1487                 rcu_read_unlock();
1488                 return 0;
1489         }
1490         rcu_read_unlock();
1491         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
1492                 return 0;
1493 out:
1494         if (acred->principal != NULL) {
1495                 if (gss_cred->gc_principal == NULL)
1496                         return 0;
1497                 ret = strcmp(acred->principal, gss_cred->gc_principal) == 0;
1498                 goto check_expire;
1499         }
1500         if (gss_cred->gc_principal != NULL)
1501                 return 0;
1502         ret = uid_eq(rc->cr_uid, acred->uid);
1503
1504 check_expire:
1505         if (ret == 0)
1506                 return ret;
1507
1508         /* Notify acred users of GSS context expiration timeout */
1509         if (test_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags) &&
1510             (gss_key_timeout(rc) != 0)) {
1511                 /* test will now be done from generic cred */
1512                 test_and_clear_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags);
1513                 /* tell NFS layer that key will expire soon */
1514                 set_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags);
1515         }
1516         return ret;
1517 }
1518
1519 /*
1520 * Marshal credentials.
1521 * Maybe we should keep a cached credential for performance reasons.
1522 */
1523 static __be32 *
1524 gss_marshal(struct rpc_task *task, __be32 *p)
1525 {
1526         struct rpc_rqst *req = task->tk_rqstp;
1527         struct rpc_cred *cred = req->rq_cred;
1528         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1529                                                  gc_base);
1530         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
1531         __be32          *cred_len;
1532         u32             maj_stat = 0;
1533         struct xdr_netobj mic;
1534         struct kvec     iov;
1535         struct xdr_buf  verf_buf;
1536
1537         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1538
1539         *p++ = htonl(RPC_AUTH_GSS);
1540         cred_len = p++;
1541
1542         spin_lock(&ctx->gc_seq_lock);
1543         req->rq_seqno = ctx->gc_seq++;
1544         spin_unlock(&ctx->gc_seq_lock);
1545
1546         *p++ = htonl((u32) RPC_GSS_VERSION);
1547         *p++ = htonl((u32) ctx->gc_proc);
1548         *p++ = htonl((u32) req->rq_seqno);
1549         *p++ = htonl((u32) gss_cred->gc_service);
1550         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
1551         *cred_len = htonl((p - (cred_len + 1)) << 2);
1552
1553         /* We compute the checksum for the verifier over the xdr-encoded bytes
1554          * starting with the xid and ending at the end of the credential: */
1555         iov.iov_base = xprt_skip_transport_header(req->rq_xprt,
1556                                         req->rq_snd_buf.head[0].iov_base);
1557         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
1558         xdr_buf_from_iov(&iov, &verf_buf);
1559
1560         /* set verifier flavor*/
1561         *p++ = htonl(RPC_AUTH_GSS);
1562
1563         mic.data = (u8 *)(p + 1);
1564         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1565         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
1566                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1567         } else if (maj_stat != 0) {
1568                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
1569                 goto out_put_ctx;
1570         }
1571         p = xdr_encode_opaque(p, NULL, mic.len);
1572         gss_put_ctx(ctx);
1573         return p;
1574 out_put_ctx:
1575         gss_put_ctx(ctx);
1576         return NULL;
1577 }
1578
1579 static int gss_renew_cred(struct rpc_task *task)
1580 {
1581         struct rpc_cred *oldcred = task->tk_rqstp->rq_cred;
1582         struct gss_cred *gss_cred = container_of(oldcred,
1583                                                  struct gss_cred,
1584                                                  gc_base);
1585         struct rpc_auth *auth = oldcred->cr_auth;
1586         struct auth_cred acred = {
1587                 .uid = oldcred->cr_uid,
1588                 .principal = gss_cred->gc_principal,
1589                 .machine_cred = (gss_cred->gc_principal != NULL ? 1 : 0),
1590         };
1591         struct rpc_cred *new;
1592
1593         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
1594         if (IS_ERR(new))
1595                 return PTR_ERR(new);
1596         task->tk_rqstp->rq_cred = new;
1597         put_rpccred(oldcred);
1598         return 0;
1599 }
1600
1601 static int gss_cred_is_negative_entry(struct rpc_cred *cred)
1602 {
1603         if (test_bit(RPCAUTH_CRED_NEGATIVE, &cred->cr_flags)) {
1604                 unsigned long now = jiffies;
1605                 unsigned long begin, expire;
1606                 struct gss_cred *gss_cred;
1607
1608                 gss_cred = container_of(cred, struct gss_cred, gc_base);
1609                 begin = gss_cred->gc_upcall_timestamp;
1610                 expire = begin + gss_expired_cred_retry_delay * HZ;
1611
1612                 if (time_in_range_open(now, begin, expire))
1613                         return 1;
1614         }
1615         return 0;
1616 }
1617
1618 /*
1619 * Refresh credentials. XXX - finish
1620 */
1621 static int
1622 gss_refresh(struct rpc_task *task)
1623 {
1624         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1625         int ret = 0;
1626
1627         if (gss_cred_is_negative_entry(cred))
1628                 return -EKEYEXPIRED;
1629
1630         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
1631                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
1632                 ret = gss_renew_cred(task);
1633                 if (ret < 0)
1634                         goto out;
1635                 cred = task->tk_rqstp->rq_cred;
1636         }
1637
1638         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
1639                 ret = gss_refresh_upcall(task);
1640 out:
1641         return ret;
1642 }
1643
1644 /* Dummy refresh routine: used only when destroying the context */
1645 static int
1646 gss_refresh_null(struct rpc_task *task)
1647 {
1648         return 0;
1649 }
1650
1651 static __be32 *
1652 gss_validate(struct rpc_task *task, __be32 *p)
1653 {
1654         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1655         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1656         __be32          *seq = NULL;
1657         struct kvec     iov;
1658         struct xdr_buf  verf_buf;
1659         struct xdr_netobj mic;
1660         u32             flav,len;
1661         u32             maj_stat;
1662         __be32          *ret = ERR_PTR(-EIO);
1663
1664         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1665
1666         flav = ntohl(*p++);
1667         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
1668                 goto out_bad;
1669         if (flav != RPC_AUTH_GSS)
1670                 goto out_bad;
1671         seq = kmalloc(4, GFP_NOFS);
1672         if (!seq)
1673                 goto out_bad;
1674         *seq = htonl(task->tk_rqstp->rq_seqno);
1675         iov.iov_base = seq;
1676         iov.iov_len = 4;
1677         xdr_buf_from_iov(&iov, &verf_buf);
1678         mic.data = (u8 *)p;
1679         mic.len = len;
1680
1681         ret = ERR_PTR(-EACCES);
1682         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1683         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1684                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1685         if (maj_stat) {
1686                 dprintk("RPC: %5u %s: gss_verify_mic returned error 0x%08x\n",
1687                         task->tk_pid, __func__, maj_stat);
1688                 goto out_bad;
1689         }
1690         /* We leave it to unwrap to calculate au_rslack. For now we just
1691          * calculate the length of the verifier: */
1692         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1693         gss_put_ctx(ctx);
1694         dprintk("RPC: %5u %s: gss_verify_mic succeeded.\n",
1695                         task->tk_pid, __func__);
1696         kfree(seq);
1697         return p + XDR_QUADLEN(len);
1698 out_bad:
1699         gss_put_ctx(ctx);
1700         dprintk("RPC: %5u %s failed ret %ld.\n", task->tk_pid, __func__,
1701                 PTR_ERR(ret));
1702         kfree(seq);
1703         return ret;
1704 }
1705
1706 static void gss_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
1707                                 __be32 *p, void *obj)
1708 {
1709         struct xdr_stream xdr;
1710
1711         xdr_init_encode(&xdr, &rqstp->rq_snd_buf, p);
1712         encode(rqstp, &xdr, obj);
1713 }
1714
1715 static inline int
1716 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1717                    kxdreproc_t encode, struct rpc_rqst *rqstp,
1718                    __be32 *p, void *obj)
1719 {
1720         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1721         struct xdr_buf  integ_buf;
1722         __be32          *integ_len = NULL;
1723         struct xdr_netobj mic;
1724         u32             offset;
1725         __be32          *q;
1726         struct kvec     *iov;
1727         u32             maj_stat = 0;
1728         int             status = -EIO;
1729
1730         integ_len = p++;
1731         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1732         *p++ = htonl(rqstp->rq_seqno);
1733
1734         gss_wrap_req_encode(encode, rqstp, p, obj);
1735
1736         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1737                                 offset, snd_buf->len - offset))
1738                 return status;
1739         *integ_len = htonl(integ_buf.len);
1740
1741         /* guess whether we're in the head or the tail: */
1742         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1743                 iov = snd_buf->tail;
1744         else
1745                 iov = snd_buf->head;
1746         p = iov->iov_base + iov->iov_len;
1747         mic.data = (u8 *)(p + 1);
1748
1749         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1750         status = -EIO; /* XXX? */
1751         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1752                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1753         else if (maj_stat)
1754                 return status;
1755         q = xdr_encode_opaque(p, NULL, mic.len);
1756
1757         offset = (u8 *)q - (u8 *)p;
1758         iov->iov_len += offset;
1759         snd_buf->len += offset;
1760         return 0;
1761 }
1762
1763 static void
1764 priv_release_snd_buf(struct rpc_rqst *rqstp)
1765 {
1766         int i;
1767
1768         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1769                 __free_page(rqstp->rq_enc_pages[i]);
1770         kfree(rqstp->rq_enc_pages);
1771 }
1772
1773 static int
1774 alloc_enc_pages(struct rpc_rqst *rqstp)
1775 {
1776         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1777         int first, last, i;
1778
1779         if (snd_buf->page_len == 0) {
1780                 rqstp->rq_enc_pages_num = 0;
1781                 return 0;
1782         }
1783
1784         first = snd_buf->page_base >> PAGE_SHIFT;
1785         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_SHIFT;
1786         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1787         rqstp->rq_enc_pages
1788                 = kmalloc_array(rqstp->rq_enc_pages_num,
1789                                 sizeof(struct page *),
1790                                 GFP_NOFS);
1791         if (!rqstp->rq_enc_pages)
1792                 goto out;
1793         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1794                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1795                 if (rqstp->rq_enc_pages[i] == NULL)
1796                         goto out_free;
1797         }
1798         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1799         return 0;
1800 out_free:
1801         rqstp->rq_enc_pages_num = i;
1802         priv_release_snd_buf(rqstp);
1803 out:
1804         return -EAGAIN;
1805 }
1806
1807 static inline int
1808 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1809                   kxdreproc_t encode, struct rpc_rqst *rqstp,
1810                   __be32 *p, void *obj)
1811 {
1812         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1813         u32             offset;
1814         u32             maj_stat;
1815         int             status;
1816         __be32          *opaque_len;
1817         struct page     **inpages;
1818         int             first;
1819         int             pad;
1820         struct kvec     *iov;
1821         char            *tmp;
1822
1823         opaque_len = p++;
1824         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1825         *p++ = htonl(rqstp->rq_seqno);
1826
1827         gss_wrap_req_encode(encode, rqstp, p, obj);
1828
1829         status = alloc_enc_pages(rqstp);
1830         if (status)
1831                 return status;
1832         first = snd_buf->page_base >> PAGE_SHIFT;
1833         inpages = snd_buf->pages + first;
1834         snd_buf->pages = rqstp->rq_enc_pages;
1835         snd_buf->page_base -= first << PAGE_SHIFT;
1836         /*
1837          * Give the tail its own page, in case we need extra space in the
1838          * head when wrapping:
1839          *
1840          * call_allocate() allocates twice the slack space required
1841          * by the authentication flavor to rq_callsize.
1842          * For GSS, slack is GSS_CRED_SLACK.
1843          */
1844         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1845                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1846                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1847                 snd_buf->tail[0].iov_base = tmp;
1848         }
1849         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1850         /* slack space should prevent this ever happening: */
1851         BUG_ON(snd_buf->len > snd_buf->buflen);
1852         status = -EIO;
1853         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1854          * done anyway, so it's safe to put the request on the wire: */
1855         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1856                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1857         else if (maj_stat)
1858                 return status;
1859
1860         *opaque_len = htonl(snd_buf->len - offset);
1861         /* guess whether we're in the head or the tail: */
1862         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1863                 iov = snd_buf->tail;
1864         else
1865                 iov = snd_buf->head;
1866         p = iov->iov_base + iov->iov_len;
1867         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1868         memset(p, 0, pad);
1869         iov->iov_len += pad;
1870         snd_buf->len += pad;
1871
1872         return 0;
1873 }
1874
1875 static int
1876 gss_wrap_req(struct rpc_task *task,
1877              kxdreproc_t encode, void *rqstp, __be32 *p, void *obj)
1878 {
1879         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1880         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1881                         gc_base);
1882         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1883         int             status = -EIO;
1884
1885         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1886         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1887                 /* The spec seems a little ambiguous here, but I think that not
1888                  * wrapping context destruction requests makes the most sense.
1889                  */
1890                 gss_wrap_req_encode(encode, rqstp, p, obj);
1891                 status = 0;
1892                 goto out;
1893         }
1894         switch (gss_cred->gc_service) {
1895         case RPC_GSS_SVC_NONE:
1896                 gss_wrap_req_encode(encode, rqstp, p, obj);
1897                 status = 0;
1898                 break;
1899         case RPC_GSS_SVC_INTEGRITY:
1900                 status = gss_wrap_req_integ(cred, ctx, encode, rqstp, p, obj);
1901                 break;
1902         case RPC_GSS_SVC_PRIVACY:
1903                 status = gss_wrap_req_priv(cred, ctx, encode, rqstp, p, obj);
1904                 break;
1905         }
1906 out:
1907         gss_put_ctx(ctx);
1908         dprintk("RPC: %5u %s returning %d\n", task->tk_pid, __func__, status);
1909         return status;
1910 }
1911
1912 static inline int
1913 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1914                 struct rpc_rqst *rqstp, __be32 **p)
1915 {
1916         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1917         struct xdr_buf integ_buf;
1918         struct xdr_netobj mic;
1919         u32 data_offset, mic_offset;
1920         u32 integ_len;
1921         u32 maj_stat;
1922         int status = -EIO;
1923
1924         integ_len = ntohl(*(*p)++);
1925         if (integ_len & 3)
1926                 return status;
1927         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1928         mic_offset = integ_len + data_offset;
1929         if (mic_offset > rcv_buf->len)
1930                 return status;
1931         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1932                 return status;
1933
1934         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1935                                 mic_offset - data_offset))
1936                 return status;
1937
1938         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1939                 return status;
1940
1941         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1942         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1943                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1944         if (maj_stat != GSS_S_COMPLETE)
1945                 return status;
1946         return 0;
1947 }
1948
1949 static inline int
1950 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1951                 struct rpc_rqst *rqstp, __be32 **p)
1952 {
1953         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1954         u32 offset;
1955         u32 opaque_len;
1956         u32 maj_stat;
1957         int status = -EIO;
1958
1959         opaque_len = ntohl(*(*p)++);
1960         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1961         if (offset + opaque_len > rcv_buf->len)
1962                 return status;
1963         /* remove padding: */
1964         rcv_buf->len = offset + opaque_len;
1965
1966         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1967         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1968                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1969         if (maj_stat != GSS_S_COMPLETE)
1970                 return status;
1971         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1972                 return status;
1973
1974         return 0;
1975 }
1976
1977 static int
1978 gss_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
1979                       __be32 *p, void *obj)
1980 {
1981         struct xdr_stream xdr;
1982
1983         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
1984         return decode(rqstp, &xdr, obj);
1985 }
1986
1987 static int
1988 gss_unwrap_resp(struct rpc_task *task,
1989                 kxdrdproc_t decode, void *rqstp, __be32 *p, void *obj)
1990 {
1991         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1992         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1993                         gc_base);
1994         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1995         __be32          *savedp = p;
1996         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1997         int             savedlen = head->iov_len;
1998         int             status = -EIO;
1999
2000         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
2001                 goto out_decode;
2002         switch (gss_cred->gc_service) {
2003         case RPC_GSS_SVC_NONE:
2004                 break;
2005         case RPC_GSS_SVC_INTEGRITY:
2006                 status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
2007                 if (status)
2008                         goto out;
2009                 break;
2010         case RPC_GSS_SVC_PRIVACY:
2011                 status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
2012                 if (status)
2013                         goto out;
2014                 break;
2015         }
2016         /* take into account extra slack for integrity and privacy cases: */
2017         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
2018                                                 + (savedlen - head->iov_len);
2019 out_decode:
2020         status = gss_unwrap_req_decode(decode, rqstp, p, obj);
2021 out:
2022         gss_put_ctx(ctx);
2023         dprintk("RPC: %5u %s returning %d\n",
2024                 task->tk_pid, __func__, status);
2025         return status;
2026 }
2027
2028 static const struct rpc_authops authgss_ops = {
2029         .owner          = THIS_MODULE,
2030         .au_flavor      = RPC_AUTH_GSS,
2031         .au_name        = "RPCSEC_GSS",
2032         .create         = gss_create,
2033         .destroy        = gss_destroy,
2034         .hash_cred      = gss_hash_cred,
2035         .lookup_cred    = gss_lookup_cred,
2036         .crcreate       = gss_create_cred,
2037         .list_pseudoflavors = gss_mech_list_pseudoflavors,
2038         .info2flavor    = gss_mech_info2flavor,
2039         .flavor2info    = gss_mech_flavor2info,
2040 };
2041
2042 static const struct rpc_credops gss_credops = {
2043         .cr_name                = "AUTH_GSS",
2044         .crdestroy              = gss_destroy_cred,
2045         .cr_init                = gss_cred_init,
2046         .crbind                 = rpcauth_generic_bind_cred,
2047         .crmatch                = gss_match,
2048         .crmarshal              = gss_marshal,
2049         .crrefresh              = gss_refresh,
2050         .crvalidate             = gss_validate,
2051         .crwrap_req             = gss_wrap_req,
2052         .crunwrap_resp          = gss_unwrap_resp,
2053         .crkey_timeout          = gss_key_timeout,
2054         .crstringify_acceptor   = gss_stringify_acceptor,
2055 };
2056
2057 static const struct rpc_credops gss_nullops = {
2058         .cr_name                = "AUTH_GSS",
2059         .crdestroy              = gss_destroy_nullcred,
2060         .crbind                 = rpcauth_generic_bind_cred,
2061         .crmatch                = gss_match,
2062         .crmarshal              = gss_marshal,
2063         .crrefresh              = gss_refresh_null,
2064         .crvalidate             = gss_validate,
2065         .crwrap_req             = gss_wrap_req,
2066         .crunwrap_resp          = gss_unwrap_resp,
2067         .crstringify_acceptor   = gss_stringify_acceptor,
2068 };
2069
2070 static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
2071         .upcall         = rpc_pipe_generic_upcall,
2072         .downcall       = gss_pipe_downcall,
2073         .destroy_msg    = gss_pipe_destroy_msg,
2074         .open_pipe      = gss_pipe_open_v0,
2075         .release_pipe   = gss_pipe_release,
2076 };
2077
2078 static const struct rpc_pipe_ops gss_upcall_ops_v1 = {
2079         .upcall         = rpc_pipe_generic_upcall,
2080         .downcall       = gss_pipe_downcall,
2081         .destroy_msg    = gss_pipe_destroy_msg,
2082         .open_pipe      = gss_pipe_open_v1,
2083         .release_pipe   = gss_pipe_release,
2084 };
2085
2086 static __net_init int rpcsec_gss_init_net(struct net *net)
2087 {
2088         return gss_svc_init_net(net);
2089 }
2090
2091 static __net_exit void rpcsec_gss_exit_net(struct net *net)
2092 {
2093         gss_svc_shutdown_net(net);
2094 }
2095
2096 static struct pernet_operations rpcsec_gss_net_ops = {
2097         .init = rpcsec_gss_init_net,
2098         .exit = rpcsec_gss_exit_net,
2099 };
2100
2101 /*
2102  * Initialize RPCSEC_GSS module
2103  */
2104 static int __init init_rpcsec_gss(void)
2105 {
2106         int err = 0;
2107
2108         err = rpcauth_register(&authgss_ops);
2109         if (err)
2110                 goto out;
2111         err = gss_svc_init();
2112         if (err)
2113                 goto out_unregister;
2114         err = register_pernet_subsys(&rpcsec_gss_net_ops);
2115         if (err)
2116                 goto out_svc_exit;
2117         rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
2118         return 0;
2119 out_svc_exit:
2120         gss_svc_shutdown();
2121 out_unregister:
2122         rpcauth_unregister(&authgss_ops);
2123 out:
2124         return err;
2125 }
2126
2127 static void __exit exit_rpcsec_gss(void)
2128 {
2129         unregister_pernet_subsys(&rpcsec_gss_net_ops);
2130         gss_svc_shutdown();
2131         rpcauth_unregister(&authgss_ops);
2132         rcu_barrier(); /* Wait for completion of call_rcu()'s */
2133 }
2134
2135 MODULE_ALIAS("rpc-auth-6");
2136 MODULE_LICENSE("GPL");
2137 module_param_named(expired_cred_retry_delay,
2138                    gss_expired_cred_retry_delay,
2139                    uint, 0644);
2140 MODULE_PARM_DESC(expired_cred_retry_delay, "Timeout (in seconds) until "
2141                 "the RPC engine retries an expired credential");
2142
2143 module_param_named(key_expire_timeo,
2144                    gss_key_expire_timeo,
2145                    uint, 0644);
2146 MODULE_PARM_DESC(key_expire_timeo, "Time (in seconds) at the end of a "
2147                 "credential keys lifetime where the NFS layer cleans up "
2148                 "prior to key expiration");
2149
2150 module_init(init_rpcsec_gss)
2151 module_exit(exit_rpcsec_gss)