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