SUNRPC: Refactor nfsd4_do_encode_secinfo()
[linux-3.10.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 <asm/uaccess.h>
54
55 static const struct rpc_authops authgss_ops;
56
57 static const struct rpc_credops gss_credops;
58 static const struct rpc_credops gss_nullops;
59
60 #define GSS_RETRY_EXPIRED 5
61 static unsigned int gss_expired_cred_retry_delay = GSS_RETRY_EXPIRED;
62
63 #ifdef RPC_DEBUG
64 # define RPCDBG_FACILITY        RPCDBG_AUTH
65 #endif
66
67 #define GSS_CRED_SLACK          (RPC_MAX_AUTH_SIZE * 2)
68 /* length of a krb5 verifier (48), plus data added before arguments when
69  * using integrity (two 4-byte integers): */
70 #define GSS_VERF_SLACK          100
71
72 struct gss_auth {
73         struct kref kref;
74         struct rpc_auth rpc_auth;
75         struct gss_api_mech *mech;
76         enum rpc_gss_svc service;
77         struct rpc_clnt *client;
78         /*
79          * There are two upcall pipes; dentry[1], named "gssd", is used
80          * for the new text-based upcall; dentry[0] is named after the
81          * mechanism (for example, "krb5") and exists for
82          * backwards-compatibility with older gssd's.
83          */
84         struct rpc_pipe *pipe[2];
85 };
86
87 /* pipe_version >= 0 if and only if someone has a pipe open. */
88 static int pipe_version = -1;
89 static atomic_t pipe_users = ATOMIC_INIT(0);
90 static DEFINE_SPINLOCK(pipe_version_lock);
91 static struct rpc_wait_queue pipe_version_rpc_waitqueue;
92 static DECLARE_WAIT_QUEUE_HEAD(pipe_version_waitqueue);
93
94 static void gss_free_ctx(struct gss_cl_ctx *);
95 static const struct rpc_pipe_ops gss_upcall_ops_v0;
96 static const struct rpc_pipe_ops gss_upcall_ops_v1;
97
98 static inline struct gss_cl_ctx *
99 gss_get_ctx(struct gss_cl_ctx *ctx)
100 {
101         atomic_inc(&ctx->count);
102         return ctx;
103 }
104
105 static inline void
106 gss_put_ctx(struct gss_cl_ctx *ctx)
107 {
108         if (atomic_dec_and_test(&ctx->count))
109                 gss_free_ctx(ctx);
110 }
111
112 /* gss_cred_set_ctx:
113  * called by gss_upcall_callback and gss_create_upcall in order
114  * to set the gss context. The actual exchange of an old context
115  * and a new one is protected by the pipe->lock.
116  */
117 static void
118 gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
119 {
120         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
121
122         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
123                 return;
124         gss_get_ctx(ctx);
125         rcu_assign_pointer(gss_cred->gc_ctx, ctx);
126         set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
127         smp_mb__before_clear_bit();
128         clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);
129 }
130
131 static const void *
132 simple_get_bytes(const void *p, const void *end, void *res, size_t len)
133 {
134         const void *q = (const void *)((const char *)p + len);
135         if (unlikely(q > end || q < p))
136                 return ERR_PTR(-EFAULT);
137         memcpy(res, p, len);
138         return q;
139 }
140
141 static inline const void *
142 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest)
143 {
144         const void *q;
145         unsigned int len;
146
147         p = simple_get_bytes(p, end, &len, sizeof(len));
148         if (IS_ERR(p))
149                 return p;
150         q = (const void *)((const char *)p + len);
151         if (unlikely(q > end || q < p))
152                 return ERR_PTR(-EFAULT);
153         dest->data = kmemdup(p, len, GFP_NOFS);
154         if (unlikely(dest->data == NULL))
155                 return ERR_PTR(-ENOMEM);
156         dest->len = len;
157         return q;
158 }
159
160 static struct gss_cl_ctx *
161 gss_cred_get_ctx(struct rpc_cred *cred)
162 {
163         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
164         struct gss_cl_ctx *ctx = NULL;
165
166         rcu_read_lock();
167         if (gss_cred->gc_ctx)
168                 ctx = gss_get_ctx(gss_cred->gc_ctx);
169         rcu_read_unlock();
170         return ctx;
171 }
172
173 static struct gss_cl_ctx *
174 gss_alloc_context(void)
175 {
176         struct gss_cl_ctx *ctx;
177
178         ctx = kzalloc(sizeof(*ctx), GFP_NOFS);
179         if (ctx != NULL) {
180                 ctx->gc_proc = RPC_GSS_PROC_DATA;
181                 ctx->gc_seq = 1;        /* NetApp 6.4R1 doesn't accept seq. no. 0 */
182                 spin_lock_init(&ctx->gc_seq_lock);
183                 atomic_set(&ctx->count,1);
184         }
185         return ctx;
186 }
187
188 #define GSSD_MIN_TIMEOUT (60 * 60)
189 static const void *
190 gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
191 {
192         const void *q;
193         unsigned int seclen;
194         unsigned int timeout;
195         unsigned long now = jiffies;
196         u32 window_size;
197         int ret;
198
199         /* First unsigned int gives the remaining lifetime in seconds of the
200          * credential - e.g. the remaining TGT lifetime for Kerberos or
201          * the -t value passed to GSSD.
202          */
203         p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
204         if (IS_ERR(p))
205                 goto err;
206         if (timeout == 0)
207                 timeout = GSSD_MIN_TIMEOUT;
208         ctx->gc_expiry = now + ((unsigned long)timeout * HZ);
209         /* Sequence number window. Determines the maximum number of
210          * simultaneous requests
211          */
212         p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
213         if (IS_ERR(p))
214                 goto err;
215         ctx->gc_win = window_size;
216         /* gssd signals an error by passing ctx->gc_win = 0: */
217         if (ctx->gc_win == 0) {
218                 /*
219                  * in which case, p points to an error code. Anything other
220                  * than -EKEYEXPIRED gets converted to -EACCES.
221                  */
222                 p = simple_get_bytes(p, end, &ret, sizeof(ret));
223                 if (!IS_ERR(p))
224                         p = (ret == -EKEYEXPIRED) ? ERR_PTR(-EKEYEXPIRED) :
225                                                     ERR_PTR(-EACCES);
226                 goto err;
227         }
228         /* copy the opaque wire context */
229         p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
230         if (IS_ERR(p))
231                 goto err;
232         /* import the opaque security context */
233         p  = simple_get_bytes(p, end, &seclen, sizeof(seclen));
234         if (IS_ERR(p))
235                 goto err;
236         q = (const void *)((const char *)p + seclen);
237         if (unlikely(q > end || q < p)) {
238                 p = ERR_PTR(-EFAULT);
239                 goto err;
240         }
241         ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx, GFP_NOFS);
242         if (ret < 0) {
243                 p = ERR_PTR(ret);
244                 goto err;
245         }
246         dprintk("RPC:       %s Success. gc_expiry %lu now %lu timeout %u\n",
247                 __func__, ctx->gc_expiry, now, timeout);
248         return q;
249 err:
250         dprintk("RPC:       %s returns error %ld\n", __func__, -PTR_ERR(p));
251         return p;
252 }
253
254 #define UPCALL_BUF_LEN 128
255
256 struct gss_upcall_msg {
257         atomic_t count;
258         kuid_t  uid;
259         struct rpc_pipe_msg msg;
260         struct list_head list;
261         struct gss_auth *auth;
262         struct rpc_pipe *pipe;
263         struct rpc_wait_queue rpc_waitqueue;
264         wait_queue_head_t waitqueue;
265         struct gss_cl_ctx *ctx;
266         char databuf[UPCALL_BUF_LEN];
267 };
268
269 static int get_pipe_version(void)
270 {
271         int ret;
272
273         spin_lock(&pipe_version_lock);
274         if (pipe_version >= 0) {
275                 atomic_inc(&pipe_users);
276                 ret = pipe_version;
277         } else
278                 ret = -EAGAIN;
279         spin_unlock(&pipe_version_lock);
280         return ret;
281 }
282
283 static void put_pipe_version(void)
284 {
285         if (atomic_dec_and_lock(&pipe_users, &pipe_version_lock)) {
286                 pipe_version = -1;
287                 spin_unlock(&pipe_version_lock);
288         }
289 }
290
291 static void
292 gss_release_msg(struct gss_upcall_msg *gss_msg)
293 {
294         if (!atomic_dec_and_test(&gss_msg->count))
295                 return;
296         put_pipe_version();
297         BUG_ON(!list_empty(&gss_msg->list));
298         if (gss_msg->ctx != NULL)
299                 gss_put_ctx(gss_msg->ctx);
300         rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
301         kfree(gss_msg);
302 }
303
304 static struct gss_upcall_msg *
305 __gss_find_upcall(struct rpc_pipe *pipe, kuid_t uid)
306 {
307         struct gss_upcall_msg *pos;
308         list_for_each_entry(pos, &pipe->in_downcall, list) {
309                 if (!uid_eq(pos->uid, uid))
310                         continue;
311                 atomic_inc(&pos->count);
312                 dprintk("RPC:       %s found msg %p\n", __func__, pos);
313                 return pos;
314         }
315         dprintk("RPC:       %s found nothing\n", __func__);
316         return NULL;
317 }
318
319 /* Try to add an upcall to the pipefs queue.
320  * If an upcall owned by our uid already exists, then we return a reference
321  * to that upcall instead of adding the new upcall.
322  */
323 static inline struct gss_upcall_msg *
324 gss_add_msg(struct gss_upcall_msg *gss_msg)
325 {
326         struct rpc_pipe *pipe = gss_msg->pipe;
327         struct gss_upcall_msg *old;
328
329         spin_lock(&pipe->lock);
330         old = __gss_find_upcall(pipe, gss_msg->uid);
331         if (old == NULL) {
332                 atomic_inc(&gss_msg->count);
333                 list_add(&gss_msg->list, &pipe->in_downcall);
334         } else
335                 gss_msg = old;
336         spin_unlock(&pipe->lock);
337         return gss_msg;
338 }
339
340 static void
341 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
342 {
343         list_del_init(&gss_msg->list);
344         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
345         wake_up_all(&gss_msg->waitqueue);
346         atomic_dec(&gss_msg->count);
347 }
348
349 static void
350 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
351 {
352         struct rpc_pipe *pipe = gss_msg->pipe;
353
354         if (list_empty(&gss_msg->list))
355                 return;
356         spin_lock(&pipe->lock);
357         if (!list_empty(&gss_msg->list))
358                 __gss_unhash_msg(gss_msg);
359         spin_unlock(&pipe->lock);
360 }
361
362 static void
363 gss_handle_downcall_result(struct gss_cred *gss_cred, struct gss_upcall_msg *gss_msg)
364 {
365         switch (gss_msg->msg.errno) {
366         case 0:
367                 if (gss_msg->ctx == NULL)
368                         break;
369                 clear_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
370                 gss_cred_set_ctx(&gss_cred->gc_base, gss_msg->ctx);
371                 break;
372         case -EKEYEXPIRED:
373                 set_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
374         }
375         gss_cred->gc_upcall_timestamp = jiffies;
376         gss_cred->gc_upcall = NULL;
377         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
378 }
379
380 static void
381 gss_upcall_callback(struct rpc_task *task)
382 {
383         struct gss_cred *gss_cred = container_of(task->tk_rqstp->rq_cred,
384                         struct gss_cred, gc_base);
385         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
386         struct rpc_pipe *pipe = gss_msg->pipe;
387
388         spin_lock(&pipe->lock);
389         gss_handle_downcall_result(gss_cred, gss_msg);
390         spin_unlock(&pipe->lock);
391         task->tk_status = gss_msg->msg.errno;
392         gss_release_msg(gss_msg);
393 }
394
395 static void gss_encode_v0_msg(struct gss_upcall_msg *gss_msg)
396 {
397         uid_t uid = from_kuid(&init_user_ns, gss_msg->uid);
398         memcpy(gss_msg->databuf, &uid, sizeof(uid));
399         gss_msg->msg.data = gss_msg->databuf;
400         gss_msg->msg.len = sizeof(uid);
401         BUG_ON(sizeof(uid) > UPCALL_BUF_LEN);
402 }
403
404 static void gss_encode_v1_msg(struct gss_upcall_msg *gss_msg,
405                                 struct rpc_clnt *clnt,
406                                 const char *service_name)
407 {
408         struct gss_api_mech *mech = gss_msg->auth->mech;
409         char *p = gss_msg->databuf;
410         int len = 0;
411
412         gss_msg->msg.len = sprintf(gss_msg->databuf, "mech=%s uid=%d ",
413                                    mech->gm_name,
414                                    from_kuid(&init_user_ns, gss_msg->uid));
415         p += gss_msg->msg.len;
416         if (clnt->cl_principal) {
417                 len = sprintf(p, "target=%s ", clnt->cl_principal);
418                 p += len;
419                 gss_msg->msg.len += len;
420         }
421         if (service_name != NULL) {
422                 len = sprintf(p, "service=%s ", service_name);
423                 p += len;
424                 gss_msg->msg.len += len;
425         }
426         if (mech->gm_upcall_enctypes) {
427                 len = sprintf(p, "enctypes=%s ", mech->gm_upcall_enctypes);
428                 p += len;
429                 gss_msg->msg.len += len;
430         }
431         len = sprintf(p, "\n");
432         gss_msg->msg.len += len;
433
434         gss_msg->msg.data = gss_msg->databuf;
435         BUG_ON(gss_msg->msg.len > UPCALL_BUF_LEN);
436 }
437
438 static void gss_encode_msg(struct gss_upcall_msg *gss_msg,
439                                 struct rpc_clnt *clnt,
440                                 const char *service_name)
441 {
442         if (pipe_version == 0)
443                 gss_encode_v0_msg(gss_msg);
444         else /* pipe_version == 1 */
445                 gss_encode_v1_msg(gss_msg, clnt, service_name);
446 }
447
448 static struct gss_upcall_msg *
449 gss_alloc_msg(struct gss_auth *gss_auth, struct rpc_clnt *clnt,
450                 kuid_t uid, const char *service_name)
451 {
452         struct gss_upcall_msg *gss_msg;
453         int vers;
454
455         gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
456         if (gss_msg == NULL)
457                 return ERR_PTR(-ENOMEM);
458         vers = get_pipe_version();
459         if (vers < 0) {
460                 kfree(gss_msg);
461                 return ERR_PTR(vers);
462         }
463         gss_msg->pipe = gss_auth->pipe[vers];
464         INIT_LIST_HEAD(&gss_msg->list);
465         rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
466         init_waitqueue_head(&gss_msg->waitqueue);
467         atomic_set(&gss_msg->count, 1);
468         gss_msg->uid = uid;
469         gss_msg->auth = gss_auth;
470         gss_encode_msg(gss_msg, clnt, service_name);
471         return gss_msg;
472 }
473
474 static struct gss_upcall_msg *
475 gss_setup_upcall(struct rpc_clnt *clnt, struct gss_auth *gss_auth, struct rpc_cred *cred)
476 {
477         struct gss_cred *gss_cred = container_of(cred,
478                         struct gss_cred, gc_base);
479         struct gss_upcall_msg *gss_new, *gss_msg;
480         kuid_t uid = cred->cr_uid;
481
482         gss_new = gss_alloc_msg(gss_auth, clnt, uid, gss_cred->gc_principal);
483         if (IS_ERR(gss_new))
484                 return gss_new;
485         gss_msg = gss_add_msg(gss_new);
486         if (gss_msg == gss_new) {
487                 int res = rpc_queue_upcall(gss_new->pipe, &gss_new->msg);
488                 if (res) {
489                         gss_unhash_msg(gss_new);
490                         gss_msg = ERR_PTR(res);
491                 }
492         } else
493                 gss_release_msg(gss_new);
494         return gss_msg;
495 }
496
497 static void warn_gssd(void)
498 {
499         static unsigned long ratelimit;
500         unsigned long now = jiffies;
501
502         if (time_after(now, ratelimit)) {
503                 printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
504                                 "Please check user daemon is running.\n");
505                 ratelimit = now + 15*HZ;
506         }
507 }
508
509 static inline int
510 gss_refresh_upcall(struct rpc_task *task)
511 {
512         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
513         struct gss_auth *gss_auth = container_of(cred->cr_auth,
514                         struct gss_auth, rpc_auth);
515         struct gss_cred *gss_cred = container_of(cred,
516                         struct gss_cred, gc_base);
517         struct gss_upcall_msg *gss_msg;
518         struct rpc_pipe *pipe;
519         int err = 0;
520
521         dprintk("RPC: %5u %s for uid %u\n",
522                 task->tk_pid, __func__, from_kuid(&init_user_ns, cred->cr_uid));
523         gss_msg = gss_setup_upcall(task->tk_client, gss_auth, cred);
524         if (PTR_ERR(gss_msg) == -EAGAIN) {
525                 /* XXX: warning on the first, under the assumption we
526                  * shouldn't normally hit this case on a refresh. */
527                 warn_gssd();
528                 task->tk_timeout = 15*HZ;
529                 rpc_sleep_on(&pipe_version_rpc_waitqueue, task, NULL);
530                 return -EAGAIN;
531         }
532         if (IS_ERR(gss_msg)) {
533                 err = PTR_ERR(gss_msg);
534                 goto out;
535         }
536         pipe = gss_msg->pipe;
537         spin_lock(&pipe->lock);
538         if (gss_cred->gc_upcall != NULL)
539                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
540         else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
541                 task->tk_timeout = 0;
542                 gss_cred->gc_upcall = gss_msg;
543                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
544                 atomic_inc(&gss_msg->count);
545                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
546         } else {
547                 gss_handle_downcall_result(gss_cred, gss_msg);
548                 err = gss_msg->msg.errno;
549         }
550         spin_unlock(&pipe->lock);
551         gss_release_msg(gss_msg);
552 out:
553         dprintk("RPC: %5u %s for uid %u result %d\n",
554                 task->tk_pid, __func__,
555                 from_kuid(&init_user_ns, cred->cr_uid), err);
556         return err;
557 }
558
559 static inline int
560 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
561 {
562         struct rpc_pipe *pipe;
563         struct rpc_cred *cred = &gss_cred->gc_base;
564         struct gss_upcall_msg *gss_msg;
565         DEFINE_WAIT(wait);
566         int err = 0;
567
568         dprintk("RPC:       %s for uid %u\n",
569                 __func__, from_kuid(&init_user_ns, cred->cr_uid));
570 retry:
571         gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred);
572         if (PTR_ERR(gss_msg) == -EAGAIN) {
573                 err = wait_event_interruptible_timeout(pipe_version_waitqueue,
574                                 pipe_version >= 0, 15*HZ);
575                 if (pipe_version < 0) {
576                         warn_gssd();
577                         err = -EACCES;
578                 }
579                 if (err)
580                         goto out;
581                 goto retry;
582         }
583         if (IS_ERR(gss_msg)) {
584                 err = PTR_ERR(gss_msg);
585                 goto out;
586         }
587         pipe = gss_msg->pipe;
588         for (;;) {
589                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_KILLABLE);
590                 spin_lock(&pipe->lock);
591                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
592                         break;
593                 }
594                 spin_unlock(&pipe->lock);
595                 if (fatal_signal_pending(current)) {
596                         err = -ERESTARTSYS;
597                         goto out_intr;
598                 }
599                 schedule();
600         }
601         if (gss_msg->ctx)
602                 gss_cred_set_ctx(cred, gss_msg->ctx);
603         else
604                 err = gss_msg->msg.errno;
605         spin_unlock(&pipe->lock);
606 out_intr:
607         finish_wait(&gss_msg->waitqueue, &wait);
608         gss_release_msg(gss_msg);
609 out:
610         dprintk("RPC:       %s for uid %u result %d\n",
611                 __func__, from_kuid(&init_user_ns, cred->cr_uid), err);
612         return err;
613 }
614
615 #define MSG_BUF_MAXSIZE 1024
616
617 static ssize_t
618 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
619 {
620         const void *p, *end;
621         void *buf;
622         struct gss_upcall_msg *gss_msg;
623         struct rpc_pipe *pipe = RPC_I(file_inode(filp))->pipe;
624         struct gss_cl_ctx *ctx;
625         uid_t id;
626         kuid_t uid;
627         ssize_t err = -EFBIG;
628
629         if (mlen > MSG_BUF_MAXSIZE)
630                 goto out;
631         err = -ENOMEM;
632         buf = kmalloc(mlen, GFP_NOFS);
633         if (!buf)
634                 goto out;
635
636         err = -EFAULT;
637         if (copy_from_user(buf, src, mlen))
638                 goto err;
639
640         end = (const void *)((char *)buf + mlen);
641         p = simple_get_bytes(buf, end, &id, sizeof(id));
642         if (IS_ERR(p)) {
643                 err = PTR_ERR(p);
644                 goto err;
645         }
646
647         uid = make_kuid(&init_user_ns, id);
648         if (!uid_valid(uid)) {
649                 err = -EINVAL;
650                 goto err;
651         }
652
653         err = -ENOMEM;
654         ctx = gss_alloc_context();
655         if (ctx == NULL)
656                 goto err;
657
658         err = -ENOENT;
659         /* Find a matching upcall */
660         spin_lock(&pipe->lock);
661         gss_msg = __gss_find_upcall(pipe, uid);
662         if (gss_msg == NULL) {
663                 spin_unlock(&pipe->lock);
664                 goto err_put_ctx;
665         }
666         list_del_init(&gss_msg->list);
667         spin_unlock(&pipe->lock);
668
669         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
670         if (IS_ERR(p)) {
671                 err = PTR_ERR(p);
672                 switch (err) {
673                 case -EACCES:
674                 case -EKEYEXPIRED:
675                         gss_msg->msg.errno = err;
676                         err = mlen;
677                         break;
678                 case -EFAULT:
679                 case -ENOMEM:
680                 case -EINVAL:
681                 case -ENOSYS:
682                         gss_msg->msg.errno = -EAGAIN;
683                         break;
684                 default:
685                         printk(KERN_CRIT "%s: bad return from "
686                                 "gss_fill_context: %zd\n", __func__, err);
687                         BUG();
688                 }
689                 goto err_release_msg;
690         }
691         gss_msg->ctx = gss_get_ctx(ctx);
692         err = mlen;
693
694 err_release_msg:
695         spin_lock(&pipe->lock);
696         __gss_unhash_msg(gss_msg);
697         spin_unlock(&pipe->lock);
698         gss_release_msg(gss_msg);
699 err_put_ctx:
700         gss_put_ctx(ctx);
701 err:
702         kfree(buf);
703 out:
704         dprintk("RPC:       %s returning %Zd\n", __func__, err);
705         return err;
706 }
707
708 static int gss_pipe_open(struct inode *inode, int new_version)
709 {
710         int ret = 0;
711
712         spin_lock(&pipe_version_lock);
713         if (pipe_version < 0) {
714                 /* First open of any gss pipe determines the version: */
715                 pipe_version = new_version;
716                 rpc_wake_up(&pipe_version_rpc_waitqueue);
717                 wake_up(&pipe_version_waitqueue);
718         } else if (pipe_version != new_version) {
719                 /* Trying to open a pipe of a different version */
720                 ret = -EBUSY;
721                 goto out;
722         }
723         atomic_inc(&pipe_users);
724 out:
725         spin_unlock(&pipe_version_lock);
726         return ret;
727
728 }
729
730 static int gss_pipe_open_v0(struct inode *inode)
731 {
732         return gss_pipe_open(inode, 0);
733 }
734
735 static int gss_pipe_open_v1(struct inode *inode)
736 {
737         return gss_pipe_open(inode, 1);
738 }
739
740 static void
741 gss_pipe_release(struct inode *inode)
742 {
743         struct rpc_pipe *pipe = RPC_I(inode)->pipe;
744         struct gss_upcall_msg *gss_msg;
745
746 restart:
747         spin_lock(&pipe->lock);
748         list_for_each_entry(gss_msg, &pipe->in_downcall, list) {
749
750                 if (!list_empty(&gss_msg->msg.list))
751                         continue;
752                 gss_msg->msg.errno = -EPIPE;
753                 atomic_inc(&gss_msg->count);
754                 __gss_unhash_msg(gss_msg);
755                 spin_unlock(&pipe->lock);
756                 gss_release_msg(gss_msg);
757                 goto restart;
758         }
759         spin_unlock(&pipe->lock);
760
761         put_pipe_version();
762 }
763
764 static void
765 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
766 {
767         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
768
769         if (msg->errno < 0) {
770                 dprintk("RPC:       %s releasing msg %p\n",
771                         __func__, gss_msg);
772                 atomic_inc(&gss_msg->count);
773                 gss_unhash_msg(gss_msg);
774                 if (msg->errno == -ETIMEDOUT)
775                         warn_gssd();
776                 gss_release_msg(gss_msg);
777         }
778 }
779
780 static void gss_pipes_dentries_destroy(struct rpc_auth *auth)
781 {
782         struct gss_auth *gss_auth;
783
784         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
785         if (gss_auth->pipe[0]->dentry)
786                 rpc_unlink(gss_auth->pipe[0]->dentry);
787         if (gss_auth->pipe[1]->dentry)
788                 rpc_unlink(gss_auth->pipe[1]->dentry);
789 }
790
791 static int gss_pipes_dentries_create(struct rpc_auth *auth)
792 {
793         int err;
794         struct gss_auth *gss_auth;
795         struct rpc_clnt *clnt;
796
797         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
798         clnt = gss_auth->client;
799
800         gss_auth->pipe[1]->dentry = rpc_mkpipe_dentry(clnt->cl_dentry,
801                                                       "gssd",
802                                                       clnt, gss_auth->pipe[1]);
803         if (IS_ERR(gss_auth->pipe[1]->dentry))
804                 return PTR_ERR(gss_auth->pipe[1]->dentry);
805         gss_auth->pipe[0]->dentry = rpc_mkpipe_dentry(clnt->cl_dentry,
806                                                       gss_auth->mech->gm_name,
807                                                       clnt, gss_auth->pipe[0]);
808         if (IS_ERR(gss_auth->pipe[0]->dentry)) {
809                 err = PTR_ERR(gss_auth->pipe[0]->dentry);
810                 goto err_unlink_pipe_1;
811         }
812         return 0;
813
814 err_unlink_pipe_1:
815         rpc_unlink(gss_auth->pipe[1]->dentry);
816         return err;
817 }
818
819 static void gss_pipes_dentries_destroy_net(struct rpc_clnt *clnt,
820                                            struct rpc_auth *auth)
821 {
822         struct net *net = rpc_net_ns(clnt);
823         struct super_block *sb;
824
825         sb = rpc_get_sb_net(net);
826         if (sb) {
827                 if (clnt->cl_dentry)
828                         gss_pipes_dentries_destroy(auth);
829                 rpc_put_sb_net(net);
830         }
831 }
832
833 static int gss_pipes_dentries_create_net(struct rpc_clnt *clnt,
834                                          struct rpc_auth *auth)
835 {
836         struct net *net = rpc_net_ns(clnt);
837         struct super_block *sb;
838         int err = 0;
839
840         sb = rpc_get_sb_net(net);
841         if (sb) {
842                 if (clnt->cl_dentry)
843                         err = gss_pipes_dentries_create(auth);
844                 rpc_put_sb_net(net);
845         }
846         return err;
847 }
848
849 /*
850  * NOTE: we have the opportunity to use different
851  * parameters based on the input flavor (which must be a pseudoflavor)
852  */
853 static struct rpc_auth *
854 gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
855 {
856         struct gss_auth *gss_auth;
857         struct rpc_auth * auth;
858         int err = -ENOMEM; /* XXX? */
859
860         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
861
862         if (!try_module_get(THIS_MODULE))
863                 return ERR_PTR(err);
864         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
865                 goto out_dec;
866         gss_auth->client = clnt;
867         err = -EINVAL;
868         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
869         if (!gss_auth->mech) {
870                 printk(KERN_WARNING "%s: Pseudoflavor %d not found!\n",
871                                 __func__, flavor);
872                 goto err_free;
873         }
874         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
875         if (gss_auth->service == 0)
876                 goto err_put_mech;
877         auth = &gss_auth->rpc_auth;
878         auth->au_cslack = GSS_CRED_SLACK >> 2;
879         auth->au_rslack = GSS_VERF_SLACK >> 2;
880         auth->au_ops = &authgss_ops;
881         auth->au_flavor = flavor;
882         atomic_set(&auth->au_count, 1);
883         kref_init(&gss_auth->kref);
884
885         /*
886          * Note: if we created the old pipe first, then someone who
887          * examined the directory at the right moment might conclude
888          * that we supported only the old pipe.  So we instead create
889          * the new pipe first.
890          */
891         gss_auth->pipe[1] = rpc_mkpipe_data(&gss_upcall_ops_v1,
892                                             RPC_PIPE_WAIT_FOR_OPEN);
893         if (IS_ERR(gss_auth->pipe[1])) {
894                 err = PTR_ERR(gss_auth->pipe[1]);
895                 goto err_put_mech;
896         }
897
898         gss_auth->pipe[0] = rpc_mkpipe_data(&gss_upcall_ops_v0,
899                                             RPC_PIPE_WAIT_FOR_OPEN);
900         if (IS_ERR(gss_auth->pipe[0])) {
901                 err = PTR_ERR(gss_auth->pipe[0]);
902                 goto err_destroy_pipe_1;
903         }
904         err = gss_pipes_dentries_create_net(clnt, auth);
905         if (err)
906                 goto err_destroy_pipe_0;
907         err = rpcauth_init_credcache(auth);
908         if (err)
909                 goto err_unlink_pipes;
910
911         return auth;
912 err_unlink_pipes:
913         gss_pipes_dentries_destroy_net(clnt, auth);
914 err_destroy_pipe_0:
915         rpc_destroy_pipe_data(gss_auth->pipe[0]);
916 err_destroy_pipe_1:
917         rpc_destroy_pipe_data(gss_auth->pipe[1]);
918 err_put_mech:
919         gss_mech_put(gss_auth->mech);
920 err_free:
921         kfree(gss_auth);
922 out_dec:
923         module_put(THIS_MODULE);
924         return ERR_PTR(err);
925 }
926
927 static void
928 gss_free(struct gss_auth *gss_auth)
929 {
930         gss_pipes_dentries_destroy_net(gss_auth->client, &gss_auth->rpc_auth);
931         rpc_destroy_pipe_data(gss_auth->pipe[0]);
932         rpc_destroy_pipe_data(gss_auth->pipe[1]);
933         gss_mech_put(gss_auth->mech);
934
935         kfree(gss_auth);
936         module_put(THIS_MODULE);
937 }
938
939 static void
940 gss_free_callback(struct kref *kref)
941 {
942         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
943
944         gss_free(gss_auth);
945 }
946
947 static void
948 gss_destroy(struct rpc_auth *auth)
949 {
950         struct gss_auth *gss_auth;
951
952         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
953                         auth, auth->au_flavor);
954
955         rpcauth_destroy_credcache(auth);
956
957         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
958         kref_put(&gss_auth->kref, gss_free_callback);
959 }
960
961 /*
962  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
963  * to the server with the GSS control procedure field set to
964  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
965  * all RPCSEC_GSS state associated with that context.
966  */
967 static int
968 gss_destroying_context(struct rpc_cred *cred)
969 {
970         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
971         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
972         struct rpc_task *task;
973
974         if (gss_cred->gc_ctx == NULL ||
975             test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
976                 return 0;
977
978         gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY;
979         cred->cr_ops = &gss_nullops;
980
981         /* Take a reference to ensure the cred will be destroyed either
982          * by the RPC call or by the put_rpccred() below */
983         get_rpccred(cred);
984
985         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
986         if (!IS_ERR(task))
987                 rpc_put_task(task);
988
989         put_rpccred(cred);
990         return 1;
991 }
992
993 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
994  * to create a new cred or context, so they check that things have been
995  * allocated before freeing them. */
996 static void
997 gss_do_free_ctx(struct gss_cl_ctx *ctx)
998 {
999         dprintk("RPC:       %s\n", __func__);
1000
1001         gss_delete_sec_context(&ctx->gc_gss_ctx);
1002         kfree(ctx->gc_wire_ctx.data);
1003         kfree(ctx);
1004 }
1005
1006 static void
1007 gss_free_ctx_callback(struct rcu_head *head)
1008 {
1009         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
1010         gss_do_free_ctx(ctx);
1011 }
1012
1013 static void
1014 gss_free_ctx(struct gss_cl_ctx *ctx)
1015 {
1016         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
1017 }
1018
1019 static void
1020 gss_free_cred(struct gss_cred *gss_cred)
1021 {
1022         dprintk("RPC:       %s cred=%p\n", __func__, gss_cred);
1023         kfree(gss_cred);
1024 }
1025
1026 static void
1027 gss_free_cred_callback(struct rcu_head *head)
1028 {
1029         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
1030         gss_free_cred(gss_cred);
1031 }
1032
1033 static void
1034 gss_destroy_nullcred(struct rpc_cred *cred)
1035 {
1036         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1037         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1038         struct gss_cl_ctx *ctx = gss_cred->gc_ctx;
1039
1040         RCU_INIT_POINTER(gss_cred->gc_ctx, NULL);
1041         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
1042         if (ctx)
1043                 gss_put_ctx(ctx);
1044         kref_put(&gss_auth->kref, gss_free_callback);
1045 }
1046
1047 static void
1048 gss_destroy_cred(struct rpc_cred *cred)
1049 {
1050
1051         if (gss_destroying_context(cred))
1052                 return;
1053         gss_destroy_nullcred(cred);
1054 }
1055
1056 /*
1057  * Lookup RPCSEC_GSS cred for the current process
1058  */
1059 static struct rpc_cred *
1060 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1061 {
1062         return rpcauth_lookup_credcache(auth, acred, flags);
1063 }
1064
1065 static struct rpc_cred *
1066 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1067 {
1068         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1069         struct gss_cred *cred = NULL;
1070         int err = -ENOMEM;
1071
1072         dprintk("RPC:       %s for uid %d, flavor %d\n",
1073                 __func__, from_kuid(&init_user_ns, acred->uid),
1074                 auth->au_flavor);
1075
1076         if (!(cred = kzalloc(sizeof(*cred), GFP_NOFS)))
1077                 goto out_err;
1078
1079         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
1080         /*
1081          * Note: in order to force a call to call_refresh(), we deliberately
1082          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
1083          */
1084         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
1085         cred->gc_service = gss_auth->service;
1086         cred->gc_principal = NULL;
1087         if (acred->machine_cred)
1088                 cred->gc_principal = acred->principal;
1089         kref_get(&gss_auth->kref);
1090         return &cred->gc_base;
1091
1092 out_err:
1093         dprintk("RPC:       %s failed with error %d\n", __func__, err);
1094         return ERR_PTR(err);
1095 }
1096
1097 static int
1098 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
1099 {
1100         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1101         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
1102         int err;
1103
1104         do {
1105                 err = gss_create_upcall(gss_auth, gss_cred);
1106         } while (err == -EAGAIN);
1107         return err;
1108 }
1109
1110 static int
1111 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
1112 {
1113         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1114
1115         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
1116                 goto out;
1117         /* Don't match with creds that have expired. */
1118         if (time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
1119                 return 0;
1120         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
1121                 return 0;
1122 out:
1123         if (acred->principal != NULL) {
1124                 if (gss_cred->gc_principal == NULL)
1125                         return 0;
1126                 return strcmp(acred->principal, gss_cred->gc_principal) == 0;
1127         }
1128         if (gss_cred->gc_principal != NULL)
1129                 return 0;
1130         return uid_eq(rc->cr_uid, acred->uid);
1131 }
1132
1133 /*
1134 * Marshal credentials.
1135 * Maybe we should keep a cached credential for performance reasons.
1136 */
1137 static __be32 *
1138 gss_marshal(struct rpc_task *task, __be32 *p)
1139 {
1140         struct rpc_rqst *req = task->tk_rqstp;
1141         struct rpc_cred *cred = req->rq_cred;
1142         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1143                                                  gc_base);
1144         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
1145         __be32          *cred_len;
1146         u32             maj_stat = 0;
1147         struct xdr_netobj mic;
1148         struct kvec     iov;
1149         struct xdr_buf  verf_buf;
1150
1151         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1152
1153         *p++ = htonl(RPC_AUTH_GSS);
1154         cred_len = p++;
1155
1156         spin_lock(&ctx->gc_seq_lock);
1157         req->rq_seqno = ctx->gc_seq++;
1158         spin_unlock(&ctx->gc_seq_lock);
1159
1160         *p++ = htonl((u32) RPC_GSS_VERSION);
1161         *p++ = htonl((u32) ctx->gc_proc);
1162         *p++ = htonl((u32) req->rq_seqno);
1163         *p++ = htonl((u32) gss_cred->gc_service);
1164         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
1165         *cred_len = htonl((p - (cred_len + 1)) << 2);
1166
1167         /* We compute the checksum for the verifier over the xdr-encoded bytes
1168          * starting with the xid and ending at the end of the credential: */
1169         iov.iov_base = xprt_skip_transport_header(req->rq_xprt,
1170                                         req->rq_snd_buf.head[0].iov_base);
1171         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
1172         xdr_buf_from_iov(&iov, &verf_buf);
1173
1174         /* set verifier flavor*/
1175         *p++ = htonl(RPC_AUTH_GSS);
1176
1177         mic.data = (u8 *)(p + 1);
1178         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1179         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
1180                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1181         } else if (maj_stat != 0) {
1182                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
1183                 goto out_put_ctx;
1184         }
1185         p = xdr_encode_opaque(p, NULL, mic.len);
1186         gss_put_ctx(ctx);
1187         return p;
1188 out_put_ctx:
1189         gss_put_ctx(ctx);
1190         return NULL;
1191 }
1192
1193 static int gss_renew_cred(struct rpc_task *task)
1194 {
1195         struct rpc_cred *oldcred = task->tk_rqstp->rq_cred;
1196         struct gss_cred *gss_cred = container_of(oldcred,
1197                                                  struct gss_cred,
1198                                                  gc_base);
1199         struct rpc_auth *auth = oldcred->cr_auth;
1200         struct auth_cred acred = {
1201                 .uid = oldcred->cr_uid,
1202                 .principal = gss_cred->gc_principal,
1203                 .machine_cred = (gss_cred->gc_principal != NULL ? 1 : 0),
1204         };
1205         struct rpc_cred *new;
1206
1207         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
1208         if (IS_ERR(new))
1209                 return PTR_ERR(new);
1210         task->tk_rqstp->rq_cred = new;
1211         put_rpccred(oldcred);
1212         return 0;
1213 }
1214
1215 static int gss_cred_is_negative_entry(struct rpc_cred *cred)
1216 {
1217         if (test_bit(RPCAUTH_CRED_NEGATIVE, &cred->cr_flags)) {
1218                 unsigned long now = jiffies;
1219                 unsigned long begin, expire;
1220                 struct gss_cred *gss_cred; 
1221
1222                 gss_cred = container_of(cred, struct gss_cred, gc_base);
1223                 begin = gss_cred->gc_upcall_timestamp;
1224                 expire = begin + gss_expired_cred_retry_delay * HZ;
1225
1226                 if (time_in_range_open(now, begin, expire))
1227                         return 1;
1228         }
1229         return 0;
1230 }
1231
1232 /*
1233 * Refresh credentials. XXX - finish
1234 */
1235 static int
1236 gss_refresh(struct rpc_task *task)
1237 {
1238         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1239         int ret = 0;
1240
1241         if (gss_cred_is_negative_entry(cred))
1242                 return -EKEYEXPIRED;
1243
1244         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
1245                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
1246                 ret = gss_renew_cred(task);
1247                 if (ret < 0)
1248                         goto out;
1249                 cred = task->tk_rqstp->rq_cred;
1250         }
1251
1252         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
1253                 ret = gss_refresh_upcall(task);
1254 out:
1255         return ret;
1256 }
1257
1258 /* Dummy refresh routine: used only when destroying the context */
1259 static int
1260 gss_refresh_null(struct rpc_task *task)
1261 {
1262         return -EACCES;
1263 }
1264
1265 static __be32 *
1266 gss_validate(struct rpc_task *task, __be32 *p)
1267 {
1268         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1269         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1270         __be32          seq;
1271         struct kvec     iov;
1272         struct xdr_buf  verf_buf;
1273         struct xdr_netobj mic;
1274         u32             flav,len;
1275         u32             maj_stat;
1276
1277         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1278
1279         flav = ntohl(*p++);
1280         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
1281                 goto out_bad;
1282         if (flav != RPC_AUTH_GSS)
1283                 goto out_bad;
1284         seq = htonl(task->tk_rqstp->rq_seqno);
1285         iov.iov_base = &seq;
1286         iov.iov_len = sizeof(seq);
1287         xdr_buf_from_iov(&iov, &verf_buf);
1288         mic.data = (u8 *)p;
1289         mic.len = len;
1290
1291         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1292         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1293                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1294         if (maj_stat) {
1295                 dprintk("RPC: %5u %s: gss_verify_mic returned error 0x%08x\n",
1296                         task->tk_pid, __func__, maj_stat);
1297                 goto out_bad;
1298         }
1299         /* We leave it to unwrap to calculate au_rslack. For now we just
1300          * calculate the length of the verifier: */
1301         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1302         gss_put_ctx(ctx);
1303         dprintk("RPC: %5u %s: gss_verify_mic succeeded.\n",
1304                         task->tk_pid, __func__);
1305         return p + XDR_QUADLEN(len);
1306 out_bad:
1307         gss_put_ctx(ctx);
1308         dprintk("RPC: %5u %s failed.\n", task->tk_pid, __func__);
1309         return NULL;
1310 }
1311
1312 static void gss_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
1313                                 __be32 *p, void *obj)
1314 {
1315         struct xdr_stream xdr;
1316
1317         xdr_init_encode(&xdr, &rqstp->rq_snd_buf, p);
1318         encode(rqstp, &xdr, obj);
1319 }
1320
1321 static inline int
1322 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1323                    kxdreproc_t encode, struct rpc_rqst *rqstp,
1324                    __be32 *p, void *obj)
1325 {
1326         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1327         struct xdr_buf  integ_buf;
1328         __be32          *integ_len = NULL;
1329         struct xdr_netobj mic;
1330         u32             offset;
1331         __be32          *q;
1332         struct kvec     *iov;
1333         u32             maj_stat = 0;
1334         int             status = -EIO;
1335
1336         integ_len = p++;
1337         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1338         *p++ = htonl(rqstp->rq_seqno);
1339
1340         gss_wrap_req_encode(encode, rqstp, p, obj);
1341
1342         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1343                                 offset, snd_buf->len - offset))
1344                 return status;
1345         *integ_len = htonl(integ_buf.len);
1346
1347         /* guess whether we're in the head or the tail: */
1348         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1349                 iov = snd_buf->tail;
1350         else
1351                 iov = snd_buf->head;
1352         p = iov->iov_base + iov->iov_len;
1353         mic.data = (u8 *)(p + 1);
1354
1355         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1356         status = -EIO; /* XXX? */
1357         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1358                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1359         else if (maj_stat)
1360                 return status;
1361         q = xdr_encode_opaque(p, NULL, mic.len);
1362
1363         offset = (u8 *)q - (u8 *)p;
1364         iov->iov_len += offset;
1365         snd_buf->len += offset;
1366         return 0;
1367 }
1368
1369 static void
1370 priv_release_snd_buf(struct rpc_rqst *rqstp)
1371 {
1372         int i;
1373
1374         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1375                 __free_page(rqstp->rq_enc_pages[i]);
1376         kfree(rqstp->rq_enc_pages);
1377 }
1378
1379 static int
1380 alloc_enc_pages(struct rpc_rqst *rqstp)
1381 {
1382         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1383         int first, last, i;
1384
1385         if (snd_buf->page_len == 0) {
1386                 rqstp->rq_enc_pages_num = 0;
1387                 return 0;
1388         }
1389
1390         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1391         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT;
1392         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1393         rqstp->rq_enc_pages
1394                 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
1395                                 GFP_NOFS);
1396         if (!rqstp->rq_enc_pages)
1397                 goto out;
1398         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1399                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1400                 if (rqstp->rq_enc_pages[i] == NULL)
1401                         goto out_free;
1402         }
1403         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1404         return 0;
1405 out_free:
1406         rqstp->rq_enc_pages_num = i;
1407         priv_release_snd_buf(rqstp);
1408 out:
1409         return -EAGAIN;
1410 }
1411
1412 static inline int
1413 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1414                   kxdreproc_t encode, struct rpc_rqst *rqstp,
1415                   __be32 *p, void *obj)
1416 {
1417         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1418         u32             offset;
1419         u32             maj_stat;
1420         int             status;
1421         __be32          *opaque_len;
1422         struct page     **inpages;
1423         int             first;
1424         int             pad;
1425         struct kvec     *iov;
1426         char            *tmp;
1427
1428         opaque_len = p++;
1429         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1430         *p++ = htonl(rqstp->rq_seqno);
1431
1432         gss_wrap_req_encode(encode, rqstp, p, obj);
1433
1434         status = alloc_enc_pages(rqstp);
1435         if (status)
1436                 return status;
1437         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1438         inpages = snd_buf->pages + first;
1439         snd_buf->pages = rqstp->rq_enc_pages;
1440         snd_buf->page_base -= first << PAGE_CACHE_SHIFT;
1441         /*
1442          * Give the tail its own page, in case we need extra space in the
1443          * head when wrapping:
1444          *
1445          * call_allocate() allocates twice the slack space required
1446          * by the authentication flavor to rq_callsize.
1447          * For GSS, slack is GSS_CRED_SLACK.
1448          */
1449         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1450                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1451                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1452                 snd_buf->tail[0].iov_base = tmp;
1453         }
1454         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1455         /* slack space should prevent this ever happening: */
1456         BUG_ON(snd_buf->len > snd_buf->buflen);
1457         status = -EIO;
1458         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1459          * done anyway, so it's safe to put the request on the wire: */
1460         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1461                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1462         else if (maj_stat)
1463                 return status;
1464
1465         *opaque_len = htonl(snd_buf->len - offset);
1466         /* guess whether we're in the head or the tail: */
1467         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1468                 iov = snd_buf->tail;
1469         else
1470                 iov = snd_buf->head;
1471         p = iov->iov_base + iov->iov_len;
1472         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1473         memset(p, 0, pad);
1474         iov->iov_len += pad;
1475         snd_buf->len += pad;
1476
1477         return 0;
1478 }
1479
1480 static int
1481 gss_wrap_req(struct rpc_task *task,
1482              kxdreproc_t encode, void *rqstp, __be32 *p, void *obj)
1483 {
1484         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1485         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1486                         gc_base);
1487         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1488         int             status = -EIO;
1489
1490         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1491         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1492                 /* The spec seems a little ambiguous here, but I think that not
1493                  * wrapping context destruction requests makes the most sense.
1494                  */
1495                 gss_wrap_req_encode(encode, rqstp, p, obj);
1496                 status = 0;
1497                 goto out;
1498         }
1499         switch (gss_cred->gc_service) {
1500         case RPC_GSS_SVC_NONE:
1501                 gss_wrap_req_encode(encode, rqstp, p, obj);
1502                 status = 0;
1503                 break;
1504         case RPC_GSS_SVC_INTEGRITY:
1505                 status = gss_wrap_req_integ(cred, ctx, encode, rqstp, p, obj);
1506                 break;
1507         case RPC_GSS_SVC_PRIVACY:
1508                 status = gss_wrap_req_priv(cred, ctx, encode, rqstp, p, obj);
1509                 break;
1510         }
1511 out:
1512         gss_put_ctx(ctx);
1513         dprintk("RPC: %5u %s returning %d\n", task->tk_pid, __func__, status);
1514         return status;
1515 }
1516
1517 static inline int
1518 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1519                 struct rpc_rqst *rqstp, __be32 **p)
1520 {
1521         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1522         struct xdr_buf integ_buf;
1523         struct xdr_netobj mic;
1524         u32 data_offset, mic_offset;
1525         u32 integ_len;
1526         u32 maj_stat;
1527         int status = -EIO;
1528
1529         integ_len = ntohl(*(*p)++);
1530         if (integ_len & 3)
1531                 return status;
1532         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1533         mic_offset = integ_len + data_offset;
1534         if (mic_offset > rcv_buf->len)
1535                 return status;
1536         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1537                 return status;
1538
1539         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1540                                 mic_offset - data_offset))
1541                 return status;
1542
1543         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1544                 return status;
1545
1546         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1547         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1548                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1549         if (maj_stat != GSS_S_COMPLETE)
1550                 return status;
1551         return 0;
1552 }
1553
1554 static inline int
1555 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1556                 struct rpc_rqst *rqstp, __be32 **p)
1557 {
1558         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1559         u32 offset;
1560         u32 opaque_len;
1561         u32 maj_stat;
1562         int status = -EIO;
1563
1564         opaque_len = ntohl(*(*p)++);
1565         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1566         if (offset + opaque_len > rcv_buf->len)
1567                 return status;
1568         /* remove padding: */
1569         rcv_buf->len = offset + opaque_len;
1570
1571         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1572         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1573                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1574         if (maj_stat != GSS_S_COMPLETE)
1575                 return status;
1576         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1577                 return status;
1578
1579         return 0;
1580 }
1581
1582 static int
1583 gss_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
1584                       __be32 *p, void *obj)
1585 {
1586         struct xdr_stream xdr;
1587
1588         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
1589         return decode(rqstp, &xdr, obj);
1590 }
1591
1592 static int
1593 gss_unwrap_resp(struct rpc_task *task,
1594                 kxdrdproc_t decode, void *rqstp, __be32 *p, void *obj)
1595 {
1596         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1597         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1598                         gc_base);
1599         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1600         __be32          *savedp = p;
1601         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1602         int             savedlen = head->iov_len;
1603         int             status = -EIO;
1604
1605         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1606                 goto out_decode;
1607         switch (gss_cred->gc_service) {
1608         case RPC_GSS_SVC_NONE:
1609                 break;
1610         case RPC_GSS_SVC_INTEGRITY:
1611                 status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1612                 if (status)
1613                         goto out;
1614                 break;
1615         case RPC_GSS_SVC_PRIVACY:
1616                 status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1617                 if (status)
1618                         goto out;
1619                 break;
1620         }
1621         /* take into account extra slack for integrity and privacy cases: */
1622         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1623                                                 + (savedlen - head->iov_len);
1624 out_decode:
1625         status = gss_unwrap_req_decode(decode, rqstp, p, obj);
1626 out:
1627         gss_put_ctx(ctx);
1628         dprintk("RPC: %5u %s returning %d\n",
1629                 task->tk_pid, __func__, status);
1630         return status;
1631 }
1632
1633 static const struct rpc_authops authgss_ops = {
1634         .owner          = THIS_MODULE,
1635         .au_flavor      = RPC_AUTH_GSS,
1636         .au_name        = "RPCSEC_GSS",
1637         .create         = gss_create,
1638         .destroy        = gss_destroy,
1639         .lookup_cred    = gss_lookup_cred,
1640         .crcreate       = gss_create_cred,
1641         .pipes_create   = gss_pipes_dentries_create,
1642         .pipes_destroy  = gss_pipes_dentries_destroy,
1643         .list_pseudoflavors = gss_mech_list_pseudoflavors,
1644         .info2flavor    = gss_mech_info2flavor,
1645         .flavor2info    = gss_mech_flavor2info,
1646 };
1647
1648 static const struct rpc_credops gss_credops = {
1649         .cr_name        = "AUTH_GSS",
1650         .crdestroy      = gss_destroy_cred,
1651         .cr_init        = gss_cred_init,
1652         .crbind         = rpcauth_generic_bind_cred,
1653         .crmatch        = gss_match,
1654         .crmarshal      = gss_marshal,
1655         .crrefresh      = gss_refresh,
1656         .crvalidate     = gss_validate,
1657         .crwrap_req     = gss_wrap_req,
1658         .crunwrap_resp  = gss_unwrap_resp,
1659 };
1660
1661 static const struct rpc_credops gss_nullops = {
1662         .cr_name        = "AUTH_GSS",
1663         .crdestroy      = gss_destroy_nullcred,
1664         .crbind         = rpcauth_generic_bind_cred,
1665         .crmatch        = gss_match,
1666         .crmarshal      = gss_marshal,
1667         .crrefresh      = gss_refresh_null,
1668         .crvalidate     = gss_validate,
1669         .crwrap_req     = gss_wrap_req,
1670         .crunwrap_resp  = gss_unwrap_resp,
1671 };
1672
1673 static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
1674         .upcall         = rpc_pipe_generic_upcall,
1675         .downcall       = gss_pipe_downcall,
1676         .destroy_msg    = gss_pipe_destroy_msg,
1677         .open_pipe      = gss_pipe_open_v0,
1678         .release_pipe   = gss_pipe_release,
1679 };
1680
1681 static const struct rpc_pipe_ops gss_upcall_ops_v1 = {
1682         .upcall         = rpc_pipe_generic_upcall,
1683         .downcall       = gss_pipe_downcall,
1684         .destroy_msg    = gss_pipe_destroy_msg,
1685         .open_pipe      = gss_pipe_open_v1,
1686         .release_pipe   = gss_pipe_release,
1687 };
1688
1689 static __net_init int rpcsec_gss_init_net(struct net *net)
1690 {
1691         return gss_svc_init_net(net);
1692 }
1693
1694 static __net_exit void rpcsec_gss_exit_net(struct net *net)
1695 {
1696         gss_svc_shutdown_net(net);
1697 }
1698
1699 static struct pernet_operations rpcsec_gss_net_ops = {
1700         .init = rpcsec_gss_init_net,
1701         .exit = rpcsec_gss_exit_net,
1702 };
1703
1704 /*
1705  * Initialize RPCSEC_GSS module
1706  */
1707 static int __init init_rpcsec_gss(void)
1708 {
1709         int err = 0;
1710
1711         err = rpcauth_register(&authgss_ops);
1712         if (err)
1713                 goto out;
1714         err = gss_svc_init();
1715         if (err)
1716                 goto out_unregister;
1717         err = register_pernet_subsys(&rpcsec_gss_net_ops);
1718         if (err)
1719                 goto out_svc_exit;
1720         rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
1721         return 0;
1722 out_svc_exit:
1723         gss_svc_shutdown();
1724 out_unregister:
1725         rpcauth_unregister(&authgss_ops);
1726 out:
1727         return err;
1728 }
1729
1730 static void __exit exit_rpcsec_gss(void)
1731 {
1732         unregister_pernet_subsys(&rpcsec_gss_net_ops);
1733         gss_svc_shutdown();
1734         rpcauth_unregister(&authgss_ops);
1735         rcu_barrier(); /* Wait for completion of call_rcu()'s */
1736 }
1737
1738 MODULE_ALIAS("rpc-auth-6");
1739 MODULE_LICENSE("GPL");
1740 module_param_named(expired_cred_retry_delay,
1741                    gss_expired_cred_retry_delay,
1742                    uint, 0644);
1743 MODULE_PARM_DESC(expired_cred_retry_delay, "Timeout (in seconds) until "
1744                 "the RPC engine retries an expired credential");
1745
1746 module_init(init_rpcsec_gss)
1747 module_exit(exit_rpcsec_gss)