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TOMOYO Linux Cross Reference
Linux/net/sunrpc/auth_gss/auth_gss.c

Version: ~ [ linux-5.5-rc1 ] ~ [ linux-5.4.2 ] ~ [ linux-5.3.15 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.88 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.158 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.206 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.206 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.78 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
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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)
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                 atomic_inc(&pos->count);
350                 dprintk("RPC:       %s found msg %p\n", __func__, pos);
351                 return pos;
352         }
353         dprintk("RPC:       %s found nothing\n", __func__);
354         return NULL;
355 }
356 
357 /* Try to add an upcall to the pipefs queue.
358  * If an upcall owned by our uid already exists, then we return a reference
359  * to that upcall instead of adding the new upcall.
360  */
361 static inline struct gss_upcall_msg *
362 gss_add_msg(struct gss_upcall_msg *gss_msg)
363 {
364         struct rpc_pipe *pipe = gss_msg->pipe;
365         struct gss_upcall_msg *old;
366 
367         spin_lock(&pipe->lock);
368         old = __gss_find_upcall(pipe, gss_msg->uid);
369         if (old == NULL) {
370                 atomic_inc(&gss_msg->count);
371                 list_add(&gss_msg->list, &pipe->in_downcall);
372         } else
373                 gss_msg = old;
374         spin_unlock(&pipe->lock);
375         return gss_msg;
376 }
377 
378 static void
379 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
380 {
381         list_del_init(&gss_msg->list);
382         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
383         wake_up_all(&gss_msg->waitqueue);
384         atomic_dec(&gss_msg->count);
385 }
386 
387 static void
388 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
389 {
390         struct rpc_pipe *pipe = gss_msg->pipe;
391 
392         if (list_empty(&gss_msg->list))
393                 return;
394         spin_lock(&pipe->lock);
395         if (!list_empty(&gss_msg->list))
396                 __gss_unhash_msg(gss_msg);
397         spin_unlock(&pipe->lock);
398 }
399 
400 static void
401 gss_handle_downcall_result(struct gss_cred *gss_cred, struct gss_upcall_msg *gss_msg)
402 {
403         switch (gss_msg->msg.errno) {
404         case 0:
405                 if (gss_msg->ctx == NULL)
406                         break;
407                 clear_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
408                 gss_cred_set_ctx(&gss_cred->gc_base, gss_msg->ctx);
409                 break;
410         case -EKEYEXPIRED:
411                 set_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
412         }
413         gss_cred->gc_upcall_timestamp = jiffies;
414         gss_cred->gc_upcall = NULL;
415         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
416 }
417 
418 static void
419 gss_upcall_callback(struct rpc_task *task)
420 {
421         struct gss_cred *gss_cred = container_of(task->tk_rqstp->rq_cred,
422                         struct gss_cred, gc_base);
423         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
424         struct rpc_pipe *pipe = gss_msg->pipe;
425 
426         spin_lock(&pipe->lock);
427         gss_handle_downcall_result(gss_cred, gss_msg);
428         spin_unlock(&pipe->lock);
429         task->tk_status = gss_msg->msg.errno;
430         gss_release_msg(gss_msg);
431 }
432 
433 static void gss_encode_v0_msg(struct gss_upcall_msg *gss_msg)
434 {
435         uid_t uid = from_kuid(&init_user_ns, gss_msg->uid);
436         memcpy(gss_msg->databuf, &uid, sizeof(uid));
437         gss_msg->msg.data = gss_msg->databuf;
438         gss_msg->msg.len = sizeof(uid);
439 
440         BUILD_BUG_ON(sizeof(uid) > sizeof(gss_msg->databuf));
441 }
442 
443 static int gss_encode_v1_msg(struct gss_upcall_msg *gss_msg,
444                                 const char *service_name,
445                                 const char *target_name)
446 {
447         struct gss_api_mech *mech = gss_msg->auth->mech;
448         char *p = gss_msg->databuf;
449         size_t buflen = sizeof(gss_msg->databuf);
450         int len;
451 
452         len = scnprintf(p, buflen, "mech=%s uid=%d ", mech->gm_name,
453                         from_kuid(&init_user_ns, gss_msg->uid));
454         buflen -= len;
455         p += len;
456         gss_msg->msg.len = len;
457         if (target_name) {
458                 len = scnprintf(p, buflen, "target=%s ", target_name);
459                 buflen -= len;
460                 p += len;
461                 gss_msg->msg.len += len;
462         }
463         if (service_name != NULL) {
464                 len = scnprintf(p, buflen, "service=%s ", service_name);
465                 buflen -= len;
466                 p += len;
467                 gss_msg->msg.len += len;
468         }
469         if (mech->gm_upcall_enctypes) {
470                 len = scnprintf(p, buflen, "enctypes=%s ",
471                                 mech->gm_upcall_enctypes);
472                 buflen -= len;
473                 p += len;
474                 gss_msg->msg.len += len;
475         }
476         len = scnprintf(p, buflen, "\n");
477         if (len == 0)
478                 goto out_overflow;
479         gss_msg->msg.len += len;
480 
481         gss_msg->msg.data = gss_msg->databuf;
482         return 0;
483 out_overflow:
484         WARN_ON_ONCE(1);
485         return -ENOMEM;
486 }
487 
488 static struct gss_upcall_msg *
489 gss_alloc_msg(struct gss_auth *gss_auth,
490                 kuid_t uid, const char *service_name)
491 {
492         struct gss_upcall_msg *gss_msg;
493         int vers;
494         int err = -ENOMEM;
495 
496         gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
497         if (gss_msg == NULL)
498                 goto err;
499         vers = get_pipe_version(gss_auth->net);
500         err = vers;
501         if (err < 0)
502                 goto err_free_msg;
503         gss_msg->pipe = gss_auth->gss_pipe[vers]->pipe;
504         INIT_LIST_HEAD(&gss_msg->list);
505         rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
506         init_waitqueue_head(&gss_msg->waitqueue);
507         atomic_set(&gss_msg->count, 1);
508         gss_msg->uid = uid;
509         gss_msg->auth = gss_auth;
510         switch (vers) {
511         case 0:
512                 gss_encode_v0_msg(gss_msg);
513                 break;
514         default:
515                 err = gss_encode_v1_msg(gss_msg, service_name, gss_auth->target_name);
516                 if (err)
517                         goto err_put_pipe_version;
518         };
519         kref_get(&gss_auth->kref);
520         return gss_msg;
521 err_put_pipe_version:
522         put_pipe_version(gss_auth->net);
523 err_free_msg:
524         kfree(gss_msg);
525 err:
526         return ERR_PTR(err);
527 }
528 
529 static struct gss_upcall_msg *
530 gss_setup_upcall(struct gss_auth *gss_auth, struct rpc_cred *cred)
531 {
532         struct gss_cred *gss_cred = container_of(cred,
533                         struct gss_cred, gc_base);
534         struct gss_upcall_msg *gss_new, *gss_msg;
535         kuid_t uid = cred->cr_uid;
536 
537         gss_new = gss_alloc_msg(gss_auth, uid, gss_cred->gc_principal);
538         if (IS_ERR(gss_new))
539                 return gss_new;
540         gss_msg = gss_add_msg(gss_new);
541         if (gss_msg == gss_new) {
542                 int res = rpc_queue_upcall(gss_new->pipe, &gss_new->msg);
543                 if (res) {
544                         gss_unhash_msg(gss_new);
545                         gss_msg = ERR_PTR(res);
546                 }
547         } else
548                 gss_release_msg(gss_new);
549         return gss_msg;
550 }
551 
552 static void warn_gssd(void)
553 {
554         dprintk("AUTH_GSS upcall failed. Please check user daemon is running.\n");
555 }
556 
557 static inline int
558 gss_refresh_upcall(struct rpc_task *task)
559 {
560         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
561         struct gss_auth *gss_auth = container_of(cred->cr_auth,
562                         struct gss_auth, rpc_auth);
563         struct gss_cred *gss_cred = container_of(cred,
564                         struct gss_cred, gc_base);
565         struct gss_upcall_msg *gss_msg;
566         struct rpc_pipe *pipe;
567         int err = 0;
568 
569         dprintk("RPC: %5u %s for uid %u\n",
570                 task->tk_pid, __func__, from_kuid(&init_user_ns, cred->cr_uid));
571         gss_msg = gss_setup_upcall(gss_auth, cred);
572         if (PTR_ERR(gss_msg) == -EAGAIN) {
573                 /* XXX: warning on the first, under the assumption we
574                  * shouldn't normally hit this case on a refresh. */
575                 warn_gssd();
576                 task->tk_timeout = 15*HZ;
577                 rpc_sleep_on(&pipe_version_rpc_waitqueue, task, NULL);
578                 return -EAGAIN;
579         }
580         if (IS_ERR(gss_msg)) {
581                 err = PTR_ERR(gss_msg);
582                 goto out;
583         }
584         pipe = gss_msg->pipe;
585         spin_lock(&pipe->lock);
586         if (gss_cred->gc_upcall != NULL)
587                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
588         else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
589                 task->tk_timeout = 0;
590                 gss_cred->gc_upcall = gss_msg;
591                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
592                 atomic_inc(&gss_msg->count);
593                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
594         } else {
595                 gss_handle_downcall_result(gss_cred, gss_msg);
596                 err = gss_msg->msg.errno;
597         }
598         spin_unlock(&pipe->lock);
599         gss_release_msg(gss_msg);
600 out:
601         dprintk("RPC: %5u %s for uid %u result %d\n",
602                 task->tk_pid, __func__,
603                 from_kuid(&init_user_ns, cred->cr_uid), err);
604         return err;
605 }
606 
607 static inline int
608 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
609 {
610         struct net *net = gss_auth->net;
611         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
612         struct rpc_pipe *pipe;
613         struct rpc_cred *cred = &gss_cred->gc_base;
614         struct gss_upcall_msg *gss_msg;
615         DEFINE_WAIT(wait);
616         int err;
617 
618         dprintk("RPC:       %s for uid %u\n",
619                 __func__, from_kuid(&init_user_ns, cred->cr_uid));
620 retry:
621         err = 0;
622         /* if gssd is down, just skip upcalling altogether */
623         if (!gssd_running(net)) {
624                 warn_gssd();
625                 return -EACCES;
626         }
627         gss_msg = gss_setup_upcall(gss_auth, cred);
628         if (PTR_ERR(gss_msg) == -EAGAIN) {
629                 err = wait_event_interruptible_timeout(pipe_version_waitqueue,
630                                 sn->pipe_version >= 0, 15 * HZ);
631                 if (sn->pipe_version < 0) {
632                         warn_gssd();
633                         err = -EACCES;
634                 }
635                 if (err < 0)
636                         goto out;
637                 goto retry;
638         }
639         if (IS_ERR(gss_msg)) {
640                 err = PTR_ERR(gss_msg);
641                 goto out;
642         }
643         pipe = gss_msg->pipe;
644         for (;;) {
645                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_KILLABLE);
646                 spin_lock(&pipe->lock);
647                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
648                         break;
649                 }
650                 spin_unlock(&pipe->lock);
651                 if (fatal_signal_pending(current)) {
652                         err = -ERESTARTSYS;
653                         goto out_intr;
654                 }
655                 schedule();
656         }
657         if (gss_msg->ctx)
658                 gss_cred_set_ctx(cred, gss_msg->ctx);
659         else
660                 err = gss_msg->msg.errno;
661         spin_unlock(&pipe->lock);
662 out_intr:
663         finish_wait(&gss_msg->waitqueue, &wait);
664         gss_release_msg(gss_msg);
665 out:
666         dprintk("RPC:       %s for uid %u result %d\n",
667                 __func__, from_kuid(&init_user_ns, cred->cr_uid), err);
668         return err;
669 }
670 
671 #define MSG_BUF_MAXSIZE 1024
672 
673 static ssize_t
674 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
675 {
676         const void *p, *end;
677         void *buf;
678         struct gss_upcall_msg *gss_msg;
679         struct rpc_pipe *pipe = RPC_I(file_inode(filp))->pipe;
680         struct gss_cl_ctx *ctx;
681         uid_t id;
682         kuid_t uid;
683         ssize_t err = -EFBIG;
684 
685         if (mlen > MSG_BUF_MAXSIZE)
686                 goto out;
687         err = -ENOMEM;
688         buf = kmalloc(mlen, GFP_NOFS);
689         if (!buf)
690                 goto out;
691 
692         err = -EFAULT;
693         if (copy_from_user(buf, src, mlen))
694                 goto err;
695 
696         end = (const void *)((char *)buf + mlen);
697         p = simple_get_bytes(buf, end, &id, sizeof(id));
698         if (IS_ERR(p)) {
699                 err = PTR_ERR(p);
700                 goto err;
701         }
702 
703         uid = make_kuid(&init_user_ns, id);
704         if (!uid_valid(uid)) {
705                 err = -EINVAL;
706                 goto err;
707         }
708 
709         err = -ENOMEM;
710         ctx = gss_alloc_context();
711         if (ctx == NULL)
712                 goto err;
713 
714         err = -ENOENT;
715         /* Find a matching upcall */
716         spin_lock(&pipe->lock);
717         gss_msg = __gss_find_upcall(pipe, uid);
718         if (gss_msg == NULL) {
719                 spin_unlock(&pipe->lock);
720                 goto err_put_ctx;
721         }
722         list_del_init(&gss_msg->list);
723         spin_unlock(&pipe->lock);
724 
725         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
726         if (IS_ERR(p)) {
727                 err = PTR_ERR(p);
728                 switch (err) {
729                 case -EACCES:
730                 case -EKEYEXPIRED:
731                         gss_msg->msg.errno = err;
732                         err = mlen;
733                         break;
734                 case -EFAULT:
735                 case -ENOMEM:
736                 case -EINVAL:
737                 case -ENOSYS:
738                         gss_msg->msg.errno = -EAGAIN;
739                         break;
740                 default:
741                         printk(KERN_CRIT "%s: bad return from "
742                                 "gss_fill_context: %zd\n", __func__, err);
743                         BUG();
744                 }
745                 goto err_release_msg;
746         }
747         gss_msg->ctx = gss_get_ctx(ctx);
748         err = mlen;
749 
750 err_release_msg:
751         spin_lock(&pipe->lock);
752         __gss_unhash_msg(gss_msg);
753         spin_unlock(&pipe->lock);
754         gss_release_msg(gss_msg);
755 err_put_ctx:
756         gss_put_ctx(ctx);
757 err:
758         kfree(buf);
759 out:
760         dprintk("RPC:       %s returning %Zd\n", __func__, err);
761         return err;
762 }
763 
764 static int gss_pipe_open(struct inode *inode, int new_version)
765 {
766         struct net *net = inode->i_sb->s_fs_info;
767         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
768         int ret = 0;
769 
770         spin_lock(&pipe_version_lock);
771         if (sn->pipe_version < 0) {
772                 /* First open of any gss pipe determines the version: */
773                 sn->pipe_version = new_version;
774                 rpc_wake_up(&pipe_version_rpc_waitqueue);
775                 wake_up(&pipe_version_waitqueue);
776         } else if (sn->pipe_version != new_version) {
777                 /* Trying to open a pipe of a different version */
778                 ret = -EBUSY;
779                 goto out;
780         }
781         atomic_inc(&sn->pipe_users);
782 out:
783         spin_unlock(&pipe_version_lock);
784         return ret;
785 
786 }
787 
788 static int gss_pipe_open_v0(struct inode *inode)
789 {
790         return gss_pipe_open(inode, 0);
791 }
792 
793 static int gss_pipe_open_v1(struct inode *inode)
794 {
795         return gss_pipe_open(inode, 1);
796 }
797 
798 static void
799 gss_pipe_release(struct inode *inode)
800 {
801         struct net *net = inode->i_sb->s_fs_info;
802         struct rpc_pipe *pipe = RPC_I(inode)->pipe;
803         struct gss_upcall_msg *gss_msg;
804 
805 restart:
806         spin_lock(&pipe->lock);
807         list_for_each_entry(gss_msg, &pipe->in_downcall, list) {
808 
809                 if (!list_empty(&gss_msg->msg.list))
810                         continue;
811                 gss_msg->msg.errno = -EPIPE;
812                 atomic_inc(&gss_msg->count);
813                 __gss_unhash_msg(gss_msg);
814                 spin_unlock(&pipe->lock);
815                 gss_release_msg(gss_msg);
816                 goto restart;
817         }
818         spin_unlock(&pipe->lock);
819 
820         put_pipe_version(net);
821 }
822 
823 static void
824 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
825 {
826         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
827 
828         if (msg->errno < 0) {
829                 dprintk("RPC:       %s releasing msg %p\n",
830                         __func__, gss_msg);
831                 atomic_inc(&gss_msg->count);
832                 gss_unhash_msg(gss_msg);
833                 if (msg->errno == -ETIMEDOUT)
834                         warn_gssd();
835                 gss_release_msg(gss_msg);
836         }
837 }
838 
839 static void gss_pipe_dentry_destroy(struct dentry *dir,
840                 struct rpc_pipe_dir_object *pdo)
841 {
842         struct gss_pipe *gss_pipe = pdo->pdo_data;
843         struct rpc_pipe *pipe = gss_pipe->pipe;
844 
845         if (pipe->dentry != NULL) {
846                 rpc_unlink(pipe->dentry);
847                 pipe->dentry = NULL;
848         }
849 }
850 
851 static int gss_pipe_dentry_create(struct dentry *dir,
852                 struct rpc_pipe_dir_object *pdo)
853 {
854         struct gss_pipe *p = pdo->pdo_data;
855         struct dentry *dentry;
856 
857         dentry = rpc_mkpipe_dentry(dir, p->name, p->clnt, p->pipe);
858         if (IS_ERR(dentry))
859                 return PTR_ERR(dentry);
860         p->pipe->dentry = dentry;
861         return 0;
862 }
863 
864 static const struct rpc_pipe_dir_object_ops gss_pipe_dir_object_ops = {
865         .create = gss_pipe_dentry_create,
866         .destroy = gss_pipe_dentry_destroy,
867 };
868 
869 static struct gss_pipe *gss_pipe_alloc(struct rpc_clnt *clnt,
870                 const char *name,
871                 const struct rpc_pipe_ops *upcall_ops)
872 {
873         struct gss_pipe *p;
874         int err = -ENOMEM;
875 
876         p = kmalloc(sizeof(*p), GFP_KERNEL);
877         if (p == NULL)
878                 goto err;
879         p->pipe = rpc_mkpipe_data(upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
880         if (IS_ERR(p->pipe)) {
881                 err = PTR_ERR(p->pipe);
882                 goto err_free_gss_pipe;
883         }
884         p->name = name;
885         p->clnt = clnt;
886         kref_init(&p->kref);
887         rpc_init_pipe_dir_object(&p->pdo,
888                         &gss_pipe_dir_object_ops,
889                         p);
890         return p;
891 err_free_gss_pipe:
892         kfree(p);
893 err:
894         return ERR_PTR(err);
895 }
896 
897 struct gss_alloc_pdo {
898         struct rpc_clnt *clnt;
899         const char *name;
900         const struct rpc_pipe_ops *upcall_ops;
901 };
902 
903 static int gss_pipe_match_pdo(struct rpc_pipe_dir_object *pdo, void *data)
904 {
905         struct gss_pipe *gss_pipe;
906         struct gss_alloc_pdo *args = data;
907 
908         if (pdo->pdo_ops != &gss_pipe_dir_object_ops)
909                 return 0;
910         gss_pipe = container_of(pdo, struct gss_pipe, pdo);
911         if (strcmp(gss_pipe->name, args->name) != 0)
912                 return 0;
913         if (!kref_get_unless_zero(&gss_pipe->kref))
914                 return 0;
915         return 1;
916 }
917 
918 static struct rpc_pipe_dir_object *gss_pipe_alloc_pdo(void *data)
919 {
920         struct gss_pipe *gss_pipe;
921         struct gss_alloc_pdo *args = data;
922 
923         gss_pipe = gss_pipe_alloc(args->clnt, args->name, args->upcall_ops);
924         if (!IS_ERR(gss_pipe))
925                 return &gss_pipe->pdo;
926         return NULL;
927 }
928 
929 static struct gss_pipe *gss_pipe_get(struct rpc_clnt *clnt,
930                 const char *name,
931                 const struct rpc_pipe_ops *upcall_ops)
932 {
933         struct net *net = rpc_net_ns(clnt);
934         struct rpc_pipe_dir_object *pdo;
935         struct gss_alloc_pdo args = {
936                 .clnt = clnt,
937                 .name = name,
938                 .upcall_ops = upcall_ops,
939         };
940 
941         pdo = rpc_find_or_alloc_pipe_dir_object(net,
942                         &clnt->cl_pipedir_objects,
943                         gss_pipe_match_pdo,
944                         gss_pipe_alloc_pdo,
945                         &args);
946         if (pdo != NULL)
947                 return container_of(pdo, struct gss_pipe, pdo);
948         return ERR_PTR(-ENOMEM);
949 }
950 
951 static void __gss_pipe_free(struct gss_pipe *p)
952 {
953         struct rpc_clnt *clnt = p->clnt;
954         struct net *net = rpc_net_ns(clnt);
955 
956         rpc_remove_pipe_dir_object(net,
957                         &clnt->cl_pipedir_objects,
958                         &p->pdo);
959         rpc_destroy_pipe_data(p->pipe);
960         kfree(p);
961 }
962 
963 static void __gss_pipe_release(struct kref *kref)
964 {
965         struct gss_pipe *p = container_of(kref, struct gss_pipe, kref);
966 
967         __gss_pipe_free(p);
968 }
969 
970 static void gss_pipe_free(struct gss_pipe *p)
971 {
972         if (p != NULL)
973                 kref_put(&p->kref, __gss_pipe_release);
974 }
975 
976 /*
977  * NOTE: we have the opportunity to use different
978  * parameters based on the input flavor (which must be a pseudoflavor)
979  */
980 static struct gss_auth *
981 gss_create_new(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
982 {
983         rpc_authflavor_t flavor = args->pseudoflavor;
984         struct gss_auth *gss_auth;
985         struct gss_pipe *gss_pipe;
986         struct rpc_auth * auth;
987         int err = -ENOMEM; /* XXX? */
988 
989         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
990 
991         if (!try_module_get(THIS_MODULE))
992                 return ERR_PTR(err);
993         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
994                 goto out_dec;
995         INIT_HLIST_NODE(&gss_auth->hash);
996         gss_auth->target_name = NULL;
997         if (args->target_name) {
998                 gss_auth->target_name = kstrdup(args->target_name, GFP_KERNEL);
999                 if (gss_auth->target_name == NULL)
1000                         goto err_free;
1001         }
1002         gss_auth->client = clnt;
1003         gss_auth->net = get_net(rpc_net_ns(clnt));
1004         err = -EINVAL;
1005         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
1006         if (!gss_auth->mech) {
1007                 dprintk("RPC:       Pseudoflavor %d not found!\n", flavor);
1008                 goto err_put_net;
1009         }
1010         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
1011         if (gss_auth->service == 0)
1012                 goto err_put_mech;
1013         if (!gssd_running(gss_auth->net))
1014                 goto err_put_mech;
1015         auth = &gss_auth->rpc_auth;
1016         auth->au_cslack = GSS_CRED_SLACK >> 2;
1017         auth->au_rslack = GSS_VERF_SLACK >> 2;
1018         auth->au_ops = &authgss_ops;
1019         auth->au_flavor = flavor;
1020         atomic_set(&auth->au_count, 1);
1021         kref_init(&gss_auth->kref);
1022 
1023         err = rpcauth_init_credcache(auth);
1024         if (err)
1025                 goto err_put_mech;
1026         /*
1027          * Note: if we created the old pipe first, then someone who
1028          * examined the directory at the right moment might conclude
1029          * that we supported only the old pipe.  So we instead create
1030          * the new pipe first.
1031          */
1032         gss_pipe = gss_pipe_get(clnt, "gssd", &gss_upcall_ops_v1);
1033         if (IS_ERR(gss_pipe)) {
1034                 err = PTR_ERR(gss_pipe);
1035                 goto err_destroy_credcache;
1036         }
1037         gss_auth->gss_pipe[1] = gss_pipe;
1038 
1039         gss_pipe = gss_pipe_get(clnt, gss_auth->mech->gm_name,
1040                         &gss_upcall_ops_v0);
1041         if (IS_ERR(gss_pipe)) {
1042                 err = PTR_ERR(gss_pipe);
1043                 goto err_destroy_pipe_1;
1044         }
1045         gss_auth->gss_pipe[0] = gss_pipe;
1046 
1047         return gss_auth;
1048 err_destroy_pipe_1:
1049         gss_pipe_free(gss_auth->gss_pipe[1]);
1050 err_destroy_credcache:
1051         rpcauth_destroy_credcache(auth);
1052 err_put_mech:
1053         gss_mech_put(gss_auth->mech);
1054 err_put_net:
1055         put_net(gss_auth->net);
1056 err_free:
1057         kfree(gss_auth->target_name);
1058         kfree(gss_auth);
1059 out_dec:
1060         module_put(THIS_MODULE);
1061         return ERR_PTR(err);
1062 }
1063 
1064 static void
1065 gss_free(struct gss_auth *gss_auth)
1066 {
1067         gss_pipe_free(gss_auth->gss_pipe[0]);
1068         gss_pipe_free(gss_auth->gss_pipe[1]);
1069         gss_mech_put(gss_auth->mech);
1070         put_net(gss_auth->net);
1071         kfree(gss_auth->target_name);
1072 
1073         kfree(gss_auth);
1074         module_put(THIS_MODULE);
1075 }
1076 
1077 static void
1078 gss_free_callback(struct kref *kref)
1079 {
1080         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
1081 
1082         gss_free(gss_auth);
1083 }
1084 
1085 static void
1086 gss_put_auth(struct gss_auth *gss_auth)
1087 {
1088         kref_put(&gss_auth->kref, gss_free_callback);
1089 }
1090 
1091 static void
1092 gss_destroy(struct rpc_auth *auth)
1093 {
1094         struct gss_auth *gss_auth = container_of(auth,
1095                         struct gss_auth, rpc_auth);
1096 
1097         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
1098                         auth, auth->au_flavor);
1099 
1100         if (hash_hashed(&gss_auth->hash)) {
1101                 spin_lock(&gss_auth_hash_lock);
1102                 hash_del(&gss_auth->hash);
1103                 spin_unlock(&gss_auth_hash_lock);
1104         }
1105 
1106         gss_pipe_free(gss_auth->gss_pipe[0]);
1107         gss_auth->gss_pipe[0] = NULL;
1108         gss_pipe_free(gss_auth->gss_pipe[1]);
1109         gss_auth->gss_pipe[1] = NULL;
1110         rpcauth_destroy_credcache(auth);
1111 
1112         gss_put_auth(gss_auth);
1113 }
1114 
1115 /*
1116  * Auths may be shared between rpc clients that were cloned from a
1117  * common client with the same xprt, if they also share the flavor and
1118  * target_name.
1119  *
1120  * The auth is looked up from the oldest parent sharing the same
1121  * cl_xprt, and the auth itself references only that common parent
1122  * (which is guaranteed to last as long as any of its descendants).
1123  */
1124 static struct gss_auth *
1125 gss_auth_find_or_add_hashed(struct rpc_auth_create_args *args,
1126                 struct rpc_clnt *clnt,
1127                 struct gss_auth *new)
1128 {
1129         struct gss_auth *gss_auth;
1130         unsigned long hashval = (unsigned long)clnt;
1131 
1132         spin_lock(&gss_auth_hash_lock);
1133         hash_for_each_possible(gss_auth_hash_table,
1134                         gss_auth,
1135                         hash,
1136                         hashval) {
1137                 if (gss_auth->client != clnt)
1138                         continue;
1139                 if (gss_auth->rpc_auth.au_flavor != args->pseudoflavor)
1140                         continue;
1141                 if (gss_auth->target_name != args->target_name) {
1142                         if (gss_auth->target_name == NULL)
1143                                 continue;
1144                         if (args->target_name == NULL)
1145                                 continue;
1146                         if (strcmp(gss_auth->target_name, args->target_name))
1147                                 continue;
1148                 }
1149                 if (!atomic_inc_not_zero(&gss_auth->rpc_auth.au_count))
1150                         continue;
1151                 goto out;
1152         }
1153         if (new)
1154                 hash_add(gss_auth_hash_table, &new->hash, hashval);
1155         gss_auth = new;
1156 out:
1157         spin_unlock(&gss_auth_hash_lock);
1158         return gss_auth;
1159 }
1160 
1161 static struct gss_auth *
1162 gss_create_hashed(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1163 {
1164         struct gss_auth *gss_auth;
1165         struct gss_auth *new;
1166 
1167         gss_auth = gss_auth_find_or_add_hashed(args, clnt, NULL);
1168         if (gss_auth != NULL)
1169                 goto out;
1170         new = gss_create_new(args, clnt);
1171         if (IS_ERR(new))
1172                 return new;
1173         gss_auth = gss_auth_find_or_add_hashed(args, clnt, new);
1174         if (gss_auth != new)
1175                 gss_destroy(&new->rpc_auth);
1176 out:
1177         return gss_auth;
1178 }
1179 
1180 static struct rpc_auth *
1181 gss_create(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1182 {
1183         struct gss_auth *gss_auth;
1184         struct rpc_xprt *xprt = rcu_access_pointer(clnt->cl_xprt);
1185 
1186         while (clnt != clnt->cl_parent) {
1187                 struct rpc_clnt *parent = clnt->cl_parent;
1188                 /* Find the original parent for this transport */
1189                 if (rcu_access_pointer(parent->cl_xprt) != xprt)
1190                         break;
1191                 clnt = parent;
1192         }
1193 
1194         gss_auth = gss_create_hashed(args, clnt);
1195         if (IS_ERR(gss_auth))
1196                 return ERR_CAST(gss_auth);
1197         return &gss_auth->rpc_auth;
1198 }
1199 
1200 /*
1201  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
1202  * to the server with the GSS control procedure field set to
1203  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
1204  * all RPCSEC_GSS state associated with that context.
1205  */
1206 static int
1207 gss_destroying_context(struct rpc_cred *cred)
1208 {
1209         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1210         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1211         struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
1212         struct rpc_task *task;
1213 
1214         if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
1215                 return 0;
1216 
1217         ctx->gc_proc = RPC_GSS_PROC_DESTROY;
1218         cred->cr_ops = &gss_nullops;
1219 
1220         /* Take a reference to ensure the cred will be destroyed either
1221          * by the RPC call or by the put_rpccred() below */
1222         get_rpccred(cred);
1223 
1224         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
1225         if (!IS_ERR(task))
1226                 rpc_put_task(task);
1227 
1228         put_rpccred(cred);
1229         return 1;
1230 }
1231 
1232 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
1233  * to create a new cred or context, so they check that things have been
1234  * allocated before freeing them. */
1235 static void
1236 gss_do_free_ctx(struct gss_cl_ctx *ctx)
1237 {
1238         dprintk("RPC:       %s\n", __func__);
1239 
1240         gss_delete_sec_context(&ctx->gc_gss_ctx);
1241         kfree(ctx->gc_wire_ctx.data);
1242         kfree(ctx->gc_acceptor.data);
1243         kfree(ctx);
1244 }
1245 
1246 static void
1247 gss_free_ctx_callback(struct rcu_head *head)
1248 {
1249         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
1250         gss_do_free_ctx(ctx);
1251 }
1252 
1253 static void
1254 gss_free_ctx(struct gss_cl_ctx *ctx)
1255 {
1256         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
1257 }
1258 
1259 static void
1260 gss_free_cred(struct gss_cred *gss_cred)
1261 {
1262         dprintk("RPC:       %s cred=%p\n", __func__, gss_cred);
1263         kfree(gss_cred);
1264 }
1265 
1266 static void
1267 gss_free_cred_callback(struct rcu_head *head)
1268 {
1269         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
1270         gss_free_cred(gss_cred);
1271 }
1272 
1273 static void
1274 gss_destroy_nullcred(struct rpc_cred *cred)
1275 {
1276         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1277         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1278         struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
1279 
1280         RCU_INIT_POINTER(gss_cred->gc_ctx, NULL);
1281         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
1282         if (ctx)
1283                 gss_put_ctx(ctx);
1284         gss_put_auth(gss_auth);
1285 }
1286 
1287 static void
1288 gss_destroy_cred(struct rpc_cred *cred)
1289 {
1290 
1291         if (gss_destroying_context(cred))
1292                 return;
1293         gss_destroy_nullcred(cred);
1294 }
1295 
1296 /*
1297  * Lookup RPCSEC_GSS cred for the current process
1298  */
1299 static struct rpc_cred *
1300 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1301 {
1302         return rpcauth_lookup_credcache(auth, acred, flags);
1303 }
1304 
1305 static struct rpc_cred *
1306 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1307 {
1308         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1309         struct gss_cred *cred = NULL;
1310         int err = -ENOMEM;
1311 
1312         dprintk("RPC:       %s for uid %d, flavor %d\n",
1313                 __func__, from_kuid(&init_user_ns, acred->uid),
1314                 auth->au_flavor);
1315 
1316         if (!(cred = kzalloc(sizeof(*cred), GFP_NOFS)))
1317                 goto out_err;
1318 
1319         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
1320         /*
1321          * Note: in order to force a call to call_refresh(), we deliberately
1322          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
1323          */
1324         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
1325         cred->gc_service = gss_auth->service;
1326         cred->gc_principal = NULL;
1327         if (acred->machine_cred)
1328                 cred->gc_principal = acred->principal;
1329         kref_get(&gss_auth->kref);
1330         return &cred->gc_base;
1331 
1332 out_err:
1333         dprintk("RPC:       %s failed with error %d\n", __func__, err);
1334         return ERR_PTR(err);
1335 }
1336 
1337 static int
1338 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
1339 {
1340         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1341         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
1342         int err;
1343 
1344         do {
1345                 err = gss_create_upcall(gss_auth, gss_cred);
1346         } while (err == -EAGAIN);
1347         return err;
1348 }
1349 
1350 static char *
1351 gss_stringify_acceptor(struct rpc_cred *cred)
1352 {
1353         char *string = NULL;
1354         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1355         struct gss_cl_ctx *ctx;
1356         unsigned int len;
1357         struct xdr_netobj *acceptor;
1358 
1359         rcu_read_lock();
1360         ctx = rcu_dereference(gss_cred->gc_ctx);
1361         if (!ctx)
1362                 goto out;
1363 
1364         len = ctx->gc_acceptor.len;
1365         rcu_read_unlock();
1366 
1367         /* no point if there's no string */
1368         if (!len)
1369                 return NULL;
1370 realloc:
1371         string = kmalloc(len + 1, GFP_KERNEL);
1372         if (!string)
1373                 return NULL;
1374 
1375         rcu_read_lock();
1376         ctx = rcu_dereference(gss_cred->gc_ctx);
1377 
1378         /* did the ctx disappear or was it replaced by one with no acceptor? */
1379         if (!ctx || !ctx->gc_acceptor.len) {
1380                 kfree(string);
1381                 string = NULL;
1382                 goto out;
1383         }
1384 
1385         acceptor = &ctx->gc_acceptor;
1386 
1387         /*
1388          * Did we find a new acceptor that's longer than the original? Allocate
1389          * a longer buffer and try again.
1390          */
1391         if (len < acceptor->len) {
1392                 len = acceptor->len;
1393                 rcu_read_unlock();
1394                 kfree(string);
1395                 goto realloc;
1396         }
1397 
1398         memcpy(string, acceptor->data, acceptor->len);
1399         string[acceptor->len] = '\0';
1400 out:
1401         rcu_read_unlock();
1402         return string;
1403 }
1404 
1405 /*
1406  * Returns -EACCES if GSS context is NULL or will expire within the
1407  * timeout (miliseconds)
1408  */
1409 static int
1410 gss_key_timeout(struct rpc_cred *rc)
1411 {
1412         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1413         struct gss_cl_ctx *ctx;
1414         unsigned long now = jiffies;
1415         unsigned long expire;
1416 
1417         rcu_read_lock();
1418         ctx = rcu_dereference(gss_cred->gc_ctx);
1419         if (ctx)
1420                 expire = ctx->gc_expiry - (gss_key_expire_timeo * HZ);
1421         rcu_read_unlock();
1422         if (!ctx || time_after(now, expire))
1423                 return -EACCES;
1424         return 0;
1425 }
1426 
1427 static int
1428 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
1429 {
1430         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1431         struct gss_cl_ctx *ctx;
1432         int ret;
1433 
1434         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
1435                 goto out;
1436         /* Don't match with creds that have expired. */
1437         rcu_read_lock();
1438         ctx = rcu_dereference(gss_cred->gc_ctx);
1439         if (!ctx || time_after(jiffies, ctx->gc_expiry)) {
1440                 rcu_read_unlock();
1441                 return 0;
1442         }
1443         rcu_read_unlock();
1444         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
1445                 return 0;
1446 out:
1447         if (acred->principal != NULL) {
1448                 if (gss_cred->gc_principal == NULL)
1449                         return 0;
1450                 ret = strcmp(acred->principal, gss_cred->gc_principal) == 0;
1451                 goto check_expire;
1452         }
1453         if (gss_cred->gc_principal != NULL)
1454                 return 0;
1455         ret = uid_eq(rc->cr_uid, acred->uid);
1456 
1457 check_expire:
1458         if (ret == 0)
1459                 return ret;
1460 
1461         /* Notify acred users of GSS context expiration timeout */
1462         if (test_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags) &&
1463             (gss_key_timeout(rc) != 0)) {
1464                 /* test will now be done from generic cred */
1465                 test_and_clear_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags);
1466                 /* tell NFS layer that key will expire soon */
1467                 set_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags);
1468         }
1469         return ret;
1470 }
1471 
1472 /*
1473 * Marshal credentials.
1474 * Maybe we should keep a cached credential for performance reasons.
1475 */
1476 static __be32 *
1477 gss_marshal(struct rpc_task *task, __be32 *p)
1478 {
1479         struct rpc_rqst *req = task->tk_rqstp;
1480         struct rpc_cred *cred = req->rq_cred;
1481         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1482                                                  gc_base);
1483         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
1484         __be32          *cred_len;
1485         u32             maj_stat = 0;
1486         struct xdr_netobj mic;
1487         struct kvec     iov;
1488         struct xdr_buf  verf_buf;
1489 
1490         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1491 
1492         *p++ = htonl(RPC_AUTH_GSS);
1493         cred_len = p++;
1494 
1495         spin_lock(&ctx->gc_seq_lock);
1496         req->rq_seqno = ctx->gc_seq++;
1497         spin_unlock(&ctx->gc_seq_lock);
1498 
1499         *p++ = htonl((u32) RPC_GSS_VERSION);
1500         *p++ = htonl((u32) ctx->gc_proc);
1501         *p++ = htonl((u32) req->rq_seqno);
1502         *p++ = htonl((u32) gss_cred->gc_service);
1503         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
1504         *cred_len = htonl((p - (cred_len + 1)) << 2);
1505 
1506         /* We compute the checksum for the verifier over the xdr-encoded bytes
1507          * starting with the xid and ending at the end of the credential: */
1508         iov.iov_base = xprt_skip_transport_header(req->rq_xprt,
1509                                         req->rq_snd_buf.head[0].iov_base);
1510         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
1511         xdr_buf_from_iov(&iov, &verf_buf);
1512 
1513         /* set verifier flavor*/
1514         *p++ = htonl(RPC_AUTH_GSS);
1515 
1516         mic.data = (u8 *)(p + 1);
1517         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1518         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
1519                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1520         } else if (maj_stat != 0) {
1521                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
1522                 goto out_put_ctx;
1523         }
1524         p = xdr_encode_opaque(p, NULL, mic.len);
1525         gss_put_ctx(ctx);
1526         return p;
1527 out_put_ctx:
1528         gss_put_ctx(ctx);
1529         return NULL;
1530 }
1531 
1532 static int gss_renew_cred(struct rpc_task *task)
1533 {
1534         struct rpc_cred *oldcred = task->tk_rqstp->rq_cred;
1535         struct gss_cred *gss_cred = container_of(oldcred,
1536                                                  struct gss_cred,
1537                                                  gc_base);
1538         struct rpc_auth *auth = oldcred->cr_auth;
1539         struct auth_cred acred = {
1540                 .uid = oldcred->cr_uid,
1541                 .principal = gss_cred->gc_principal,
1542                 .machine_cred = (gss_cred->gc_principal != NULL ? 1 : 0),
1543         };
1544         struct rpc_cred *new;
1545 
1546         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
1547         if (IS_ERR(new))
1548                 return PTR_ERR(new);
1549         task->tk_rqstp->rq_cred = new;
1550         put_rpccred(oldcred);
1551         return 0;
1552 }
1553 
1554 static int gss_cred_is_negative_entry(struct rpc_cred *cred)
1555 {
1556         if (test_bit(RPCAUTH_CRED_NEGATIVE, &cred->cr_flags)) {
1557                 unsigned long now = jiffies;
1558                 unsigned long begin, expire;
1559                 struct gss_cred *gss_cred; 
1560 
1561                 gss_cred = container_of(cred, struct gss_cred, gc_base);
1562                 begin = gss_cred->gc_upcall_timestamp;
1563                 expire = begin + gss_expired_cred_retry_delay * HZ;
1564 
1565                 if (time_in_range_open(now, begin, expire))
1566                         return 1;
1567         }
1568         return 0;
1569 }
1570 
1571 /*
1572 * Refresh credentials. XXX - finish
1573 */
1574 static int
1575 gss_refresh(struct rpc_task *task)
1576 {
1577         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1578         int ret = 0;
1579 
1580         if (gss_cred_is_negative_entry(cred))
1581                 return -EKEYEXPIRED;
1582 
1583         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
1584                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
1585                 ret = gss_renew_cred(task);
1586                 if (ret < 0)
1587                         goto out;
1588                 cred = task->tk_rqstp->rq_cred;
1589         }
1590 
1591         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
1592                 ret = gss_refresh_upcall(task);
1593 out:
1594         return ret;
1595 }
1596 
1597 /* Dummy refresh routine: used only when destroying the context */
1598 static int
1599 gss_refresh_null(struct rpc_task *task)
1600 {
1601         return 0;
1602 }
1603 
1604 static __be32 *
1605 gss_validate(struct rpc_task *task, __be32 *p)
1606 {
1607         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1608         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1609         __be32          seq;
1610         struct kvec     iov;
1611         struct xdr_buf  verf_buf;
1612         struct xdr_netobj mic;
1613         u32             flav,len;
1614         u32             maj_stat;
1615         __be32          *ret = ERR_PTR(-EIO);
1616 
1617         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1618 
1619         flav = ntohl(*p++);
1620         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
1621                 goto out_bad;
1622         if (flav != RPC_AUTH_GSS)
1623                 goto out_bad;
1624         seq = htonl(task->tk_rqstp->rq_seqno);
1625         iov.iov_base = &seq;
1626         iov.iov_len = sizeof(seq);
1627         xdr_buf_from_iov(&iov, &verf_buf);
1628         mic.data = (u8 *)p;
1629         mic.len = len;
1630 
1631         ret = ERR_PTR(-EACCES);
1632         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1633         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1634                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1635         if (maj_stat) {
1636                 dprintk("RPC: %5u %s: gss_verify_mic returned error 0x%08x\n",
1637                         task->tk_pid, __func__, maj_stat);
1638                 goto out_bad;
1639         }
1640         /* We leave it to unwrap to calculate au_rslack. For now we just
1641          * calculate the length of the verifier: */
1642         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1643         gss_put_ctx(ctx);
1644         dprintk("RPC: %5u %s: gss_verify_mic succeeded.\n",
1645                         task->tk_pid, __func__);
1646         return p + XDR_QUADLEN(len);
1647 out_bad:
1648         gss_put_ctx(ctx);
1649         dprintk("RPC: %5u %s failed ret %ld.\n", task->tk_pid, __func__,
1650                 PTR_ERR(ret));
1651         return ret;
1652 }
1653 
1654 static void gss_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
1655                                 __be32 *p, void *obj)
1656 {
1657         struct xdr_stream xdr;
1658 
1659         xdr_init_encode(&xdr, &rqstp->rq_snd_buf, p);
1660         encode(rqstp, &xdr, obj);
1661 }
1662 
1663 static inline int
1664 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1665                    kxdreproc_t encode, struct rpc_rqst *rqstp,
1666                    __be32 *p, void *obj)
1667 {
1668         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1669         struct xdr_buf  integ_buf;
1670         __be32          *integ_len = NULL;
1671         struct xdr_netobj mic;
1672         u32             offset;
1673         __be32          *q;
1674         struct kvec     *iov;
1675         u32             maj_stat = 0;
1676         int             status = -EIO;
1677 
1678         integ_len = p++;
1679         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1680         *p++ = htonl(rqstp->rq_seqno);
1681 
1682         gss_wrap_req_encode(encode, rqstp, p, obj);
1683 
1684         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1685                                 offset, snd_buf->len - offset))
1686                 return status;
1687         *integ_len = htonl(integ_buf.len);
1688 
1689         /* guess whether we're in the head or the tail: */
1690         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1691                 iov = snd_buf->tail;
1692         else
1693                 iov = snd_buf->head;
1694         p = iov->iov_base + iov->iov_len;
1695         mic.data = (u8 *)(p + 1);
1696 
1697         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1698         status = -EIO; /* XXX? */
1699         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1700                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1701         else if (maj_stat)
1702                 return status;
1703         q = xdr_encode_opaque(p, NULL, mic.len);
1704 
1705         offset = (u8 *)q - (u8 *)p;
1706         iov->iov_len += offset;
1707         snd_buf->len += offset;
1708         return 0;
1709 }
1710 
1711 static void
1712 priv_release_snd_buf(struct rpc_rqst *rqstp)
1713 {
1714         int i;
1715 
1716         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1717                 __free_page(rqstp->rq_enc_pages[i]);
1718         kfree(rqstp->rq_enc_pages);
1719 }
1720 
1721 static int
1722 alloc_enc_pages(struct rpc_rqst *rqstp)
1723 {
1724         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1725         int first, last, i;
1726 
1727         if (snd_buf->page_len == 0) {
1728                 rqstp->rq_enc_pages_num = 0;
1729                 return 0;
1730         }
1731 
1732         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1733         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT;
1734         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1735         rqstp->rq_enc_pages
1736                 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
1737                                 GFP_NOFS);
1738         if (!rqstp->rq_enc_pages)
1739                 goto out;
1740         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1741                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1742                 if (rqstp->rq_enc_pages[i] == NULL)
1743                         goto out_free;
1744         }
1745         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1746         return 0;
1747 out_free:
1748         rqstp->rq_enc_pages_num = i;
1749         priv_release_snd_buf(rqstp);
1750 out:
1751         return -EAGAIN;
1752 }
1753 
1754 static inline int
1755 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1756                   kxdreproc_t encode, struct rpc_rqst *rqstp,
1757                   __be32 *p, void *obj)
1758 {
1759         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1760         u32             offset;
1761         u32             maj_stat;
1762         int             status;
1763         __be32          *opaque_len;
1764         struct page     **inpages;
1765         int             first;
1766         int             pad;
1767         struct kvec     *iov;
1768         char            *tmp;
1769 
1770         opaque_len = p++;
1771         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1772         *p++ = htonl(rqstp->rq_seqno);
1773 
1774         gss_wrap_req_encode(encode, rqstp, p, obj);
1775 
1776         status = alloc_enc_pages(rqstp);
1777         if (status)
1778                 return status;
1779         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1780         inpages = snd_buf->pages + first;
1781         snd_buf->pages = rqstp->rq_enc_pages;
1782         snd_buf->page_base -= first << PAGE_CACHE_SHIFT;
1783         /*
1784          * Give the tail its own page, in case we need extra space in the
1785          * head when wrapping:
1786          *
1787          * call_allocate() allocates twice the slack space required
1788          * by the authentication flavor to rq_callsize.
1789          * For GSS, slack is GSS_CRED_SLACK.
1790          */
1791         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1792                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1793                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1794                 snd_buf->tail[0].iov_base = tmp;
1795         }
1796         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1797         /* slack space should prevent this ever happening: */
1798         BUG_ON(snd_buf->len > snd_buf->buflen);
1799         status = -EIO;
1800         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1801          * done anyway, so it's safe to put the request on the wire: */
1802         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1803                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1804         else if (maj_stat)
1805                 return status;
1806 
1807         *opaque_len = htonl(snd_buf->len - offset);
1808         /* guess whether we're in the head or the tail: */
1809         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1810                 iov = snd_buf->tail;
1811         else
1812                 iov = snd_buf->head;
1813         p = iov->iov_base + iov->iov_len;
1814         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1815         memset(p, 0, pad);
1816         iov->iov_len += pad;
1817         snd_buf->len += pad;
1818 
1819         return 0;
1820 }
1821 
1822 static int
1823 gss_wrap_req(struct rpc_task *task,
1824              kxdreproc_t encode, void *rqstp, __be32 *p, void *obj)
1825 {
1826         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1827         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1828                         gc_base);
1829         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1830         int             status = -EIO;
1831 
1832         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1833         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1834                 /* The spec seems a little ambiguous here, but I think that not
1835                  * wrapping context destruction requests makes the most sense.
1836                  */
1837                 gss_wrap_req_encode(encode, rqstp, p, obj);
1838                 status = 0;
1839                 goto out;
1840         }
1841         switch (gss_cred->gc_service) {
1842         case RPC_GSS_SVC_NONE:
1843                 gss_wrap_req_encode(encode, rqstp, p, obj);
1844                 status = 0;
1845                 break;
1846         case RPC_GSS_SVC_INTEGRITY:
1847                 status = gss_wrap_req_integ(cred, ctx, encode, rqstp, p, obj);
1848                 break;
1849         case RPC_GSS_SVC_PRIVACY:
1850                 status = gss_wrap_req_priv(cred, ctx, encode, rqstp, p, obj);
1851                 break;
1852         }
1853 out:
1854         gss_put_ctx(ctx);
1855         dprintk("RPC: %5u %s returning %d\n", task->tk_pid, __func__, status);
1856         return status;
1857 }
1858 
1859 static inline int
1860 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1861                 struct rpc_rqst *rqstp, __be32 **p)
1862 {
1863         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1864         struct xdr_buf integ_buf;
1865         struct xdr_netobj mic;
1866         u32 data_offset, mic_offset;
1867         u32 integ_len;
1868         u32 maj_stat;
1869         int status = -EIO;
1870 
1871         integ_len = ntohl(*(*p)++);
1872         if (integ_len & 3)
1873                 return status;
1874         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1875         mic_offset = integ_len + data_offset;
1876         if (mic_offset > rcv_buf->len)
1877                 return status;
1878         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1879                 return status;
1880 
1881         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1882                                 mic_offset - data_offset))
1883                 return status;
1884 
1885         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1886                 return status;
1887 
1888         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1889         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1890                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1891         if (maj_stat != GSS_S_COMPLETE)
1892                 return status;
1893         return 0;
1894 }
1895 
1896 static inline int
1897 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1898                 struct rpc_rqst *rqstp, __be32 **p)
1899 {
1900         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1901         u32 offset;
1902         u32 opaque_len;
1903         u32 maj_stat;
1904         int status = -EIO;
1905 
1906         opaque_len = ntohl(*(*p)++);
1907         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1908         if (offset + opaque_len > rcv_buf->len)
1909                 return status;
1910         /* remove padding: */
1911         rcv_buf->len = offset + opaque_len;
1912 
1913         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1914         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1915                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1916         if (maj_stat != GSS_S_COMPLETE)
1917                 return status;
1918         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1919                 return status;
1920 
1921         return 0;
1922 }
1923 
1924 static int
1925 gss_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
1926                       __be32 *p, void *obj)
1927 {
1928         struct xdr_stream xdr;
1929 
1930         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
1931         return decode(rqstp, &xdr, obj);
1932 }
1933 
1934 static int
1935 gss_unwrap_resp(struct rpc_task *task,
1936                 kxdrdproc_t decode, void *rqstp, __be32 *p, void *obj)
1937 {
1938         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1939         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1940                         gc_base);
1941         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1942         __be32          *savedp = p;
1943         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1944         int             savedlen = head->iov_len;
1945         int             status = -EIO;
1946 
1947         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1948                 goto out_decode;
1949         switch (gss_cred->gc_service) {
1950         case RPC_GSS_SVC_NONE:
1951                 break;
1952         case RPC_GSS_SVC_INTEGRITY:
1953                 status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1954                 if (status)
1955                         goto out;
1956                 break;
1957         case RPC_GSS_SVC_PRIVACY:
1958                 status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1959                 if (status)
1960                         goto out;
1961                 break;
1962         }
1963         /* take into account extra slack for integrity and privacy cases: */
1964         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1965                                                 + (savedlen - head->iov_len);
1966 out_decode:
1967         status = gss_unwrap_req_decode(decode, rqstp, p, obj);
1968 out:
1969         gss_put_ctx(ctx);
1970         dprintk("RPC: %5u %s returning %d\n",
1971                 task->tk_pid, __func__, status);
1972         return status;
1973 }
1974 
1975 static const struct rpc_authops authgss_ops = {
1976         .owner          = THIS_MODULE,
1977         .au_flavor      = RPC_AUTH_GSS,
1978         .au_name        = "RPCSEC_GSS",
1979         .create         = gss_create,
1980         .destroy        = gss_destroy,
1981         .lookup_cred    = gss_lookup_cred,
1982         .crcreate       = gss_create_cred,
1983         .list_pseudoflavors = gss_mech_list_pseudoflavors,
1984         .info2flavor    = gss_mech_info2flavor,
1985         .flavor2info    = gss_mech_flavor2info,
1986 };
1987 
1988 static const struct rpc_credops gss_credops = {
1989         .cr_name                = "AUTH_GSS",
1990         .crdestroy              = gss_destroy_cred,
1991         .cr_init                = gss_cred_init,
1992         .crbind                 = rpcauth_generic_bind_cred,
1993         .crmatch                = gss_match,
1994         .crmarshal              = gss_marshal,
1995         .crrefresh              = gss_refresh,
1996         .crvalidate             = gss_validate,
1997         .crwrap_req             = gss_wrap_req,
1998         .crunwrap_resp          = gss_unwrap_resp,
1999         .crkey_timeout          = gss_key_timeout,
2000         .crstringify_acceptor   = gss_stringify_acceptor,
2001 };
2002 
2003 static const struct rpc_credops gss_nullops = {
2004         .cr_name                = "AUTH_GSS",
2005         .crdestroy              = gss_destroy_nullcred,
2006         .crbind                 = rpcauth_generic_bind_cred,
2007         .crmatch                = gss_match,
2008         .crmarshal              = gss_marshal,
2009         .crrefresh              = gss_refresh_null,
2010         .crvalidate             = gss_validate,
2011         .crwrap_req             = gss_wrap_req,
2012         .crunwrap_resp          = gss_unwrap_resp,
2013         .crstringify_acceptor   = gss_stringify_acceptor,
2014 };
2015 
2016 static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
2017         .upcall         = rpc_pipe_generic_upcall,
2018         .downcall       = gss_pipe_downcall,
2019         .destroy_msg    = gss_pipe_destroy_msg,
2020         .open_pipe      = gss_pipe_open_v0,
2021         .release_pipe   = gss_pipe_release,
2022 };
2023 
2024 static const struct rpc_pipe_ops gss_upcall_ops_v1 = {
2025         .upcall         = rpc_pipe_generic_upcall,
2026         .downcall       = gss_pipe_downcall,
2027         .destroy_msg    = gss_pipe_destroy_msg,
2028         .open_pipe      = gss_pipe_open_v1,
2029         .release_pipe   = gss_pipe_release,
2030 };
2031 
2032 static __net_init int rpcsec_gss_init_net(struct net *net)
2033 {
2034         return gss_svc_init_net(net);
2035 }
2036 
2037 static __net_exit void rpcsec_gss_exit_net(struct net *net)
2038 {
2039         gss_svc_shutdown_net(net);
2040 }
2041 
2042 static struct pernet_operations rpcsec_gss_net_ops = {
2043         .init = rpcsec_gss_init_net,
2044         .exit = rpcsec_gss_exit_net,
2045 };
2046 
2047 /*
2048  * Initialize RPCSEC_GSS module
2049  */
2050 static int __init init_rpcsec_gss(void)
2051 {
2052         int err = 0;
2053 
2054         err = rpcauth_register(&authgss_ops);
2055         if (err)
2056                 goto out;
2057         err = gss_svc_init();
2058         if (err)
2059                 goto out_unregister;
2060         err = register_pernet_subsys(&rpcsec_gss_net_ops);
2061         if (err)
2062                 goto out_svc_exit;
2063         rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
2064         return 0;
2065 out_svc_exit:
2066         gss_svc_shutdown();
2067 out_unregister:
2068         rpcauth_unregister(&authgss_ops);
2069 out:
2070         return err;
2071 }
2072 
2073 static void __exit exit_rpcsec_gss(void)
2074 {
2075         unregister_pernet_subsys(&rpcsec_gss_net_ops);
2076         gss_svc_shutdown();
2077         rpcauth_unregister(&authgss_ops);
2078         rcu_barrier(); /* Wait for completion of call_rcu()'s */
2079 }
2080 
2081 MODULE_ALIAS("rpc-auth-6");
2082 MODULE_LICENSE("GPL");
2083 module_param_named(expired_cred_retry_delay,
2084                    gss_expired_cred_retry_delay,
2085                    uint, 0644);
2086 MODULE_PARM_DESC(expired_cred_retry_delay, "Timeout (in seconds) until "
2087                 "the RPC engine retries an expired credential");
2088 
2089 module_param_named(key_expire_timeo,
2090                    gss_key_expire_timeo,
2091                    uint, 0644);
2092 MODULE_PARM_DESC(key_expire_timeo, "Time (in seconds) at the end of a "
2093                 "credential keys lifetime where the NFS layer cleans up "
2094                 "prior to key expiration");
2095 
2096 module_init(init_rpcsec_gss)
2097 module_exit(exit_rpcsec_gss)
2098 

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