Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394...
[linux-2.6] / 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 #ifdef RPC_DEBUG
61 # define RPCDBG_FACILITY        RPCDBG_AUTH
62 #endif
63
64 #define GSS_CRED_SLACK          1024
65 /* length of a krb5 verifier (48), plus data added before arguments when
66  * using integrity (two 4-byte integers): */
67 #define GSS_VERF_SLACK          100
68
69 struct gss_auth {
70         struct kref kref;
71         struct rpc_auth rpc_auth;
72         struct gss_api_mech *mech;
73         enum rpc_gss_svc service;
74         struct rpc_clnt *client;
75         /*
76          * There are two upcall pipes; dentry[1], named "gssd", is used
77          * for the new text-based upcall; dentry[0] is named after the
78          * mechanism (for example, "krb5") and exists for
79          * backwards-compatibility with older gssd's.
80          */
81         struct dentry *dentry[2];
82 };
83
84 /* pipe_version >= 0 if and only if someone has a pipe open. */
85 static int pipe_version = -1;
86 static atomic_t pipe_users = ATOMIC_INIT(0);
87 static DEFINE_SPINLOCK(pipe_version_lock);
88 static struct rpc_wait_queue pipe_version_rpc_waitqueue;
89 static DECLARE_WAIT_QUEUE_HEAD(pipe_version_waitqueue);
90
91 static void gss_free_ctx(struct gss_cl_ctx *);
92 static struct rpc_pipe_ops gss_upcall_ops_v0;
93 static struct rpc_pipe_ops gss_upcall_ops_v1;
94
95 static inline struct gss_cl_ctx *
96 gss_get_ctx(struct gss_cl_ctx *ctx)
97 {
98         atomic_inc(&ctx->count);
99         return ctx;
100 }
101
102 static inline void
103 gss_put_ctx(struct gss_cl_ctx *ctx)
104 {
105         if (atomic_dec_and_test(&ctx->count))
106                 gss_free_ctx(ctx);
107 }
108
109 /* gss_cred_set_ctx:
110  * called by gss_upcall_callback and gss_create_upcall in order
111  * to set the gss context. The actual exchange of an old context
112  * and a new one is protected by the inode->i_lock.
113  */
114 static void
115 gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
116 {
117         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
118
119         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
120                 return;
121         gss_get_ctx(ctx);
122         rcu_assign_pointer(gss_cred->gc_ctx, ctx);
123         set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
124         smp_mb__before_clear_bit();
125         clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);
126 }
127
128 static const void *
129 simple_get_bytes(const void *p, const void *end, void *res, size_t len)
130 {
131         const void *q = (const void *)((const char *)p + len);
132         if (unlikely(q > end || q < p))
133                 return ERR_PTR(-EFAULT);
134         memcpy(res, p, len);
135         return q;
136 }
137
138 static inline const void *
139 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest)
140 {
141         const void *q;
142         unsigned int len;
143
144         p = simple_get_bytes(p, end, &len, sizeof(len));
145         if (IS_ERR(p))
146                 return p;
147         q = (const void *)((const char *)p + len);
148         if (unlikely(q > end || q < p))
149                 return ERR_PTR(-EFAULT);
150         dest->data = kmemdup(p, len, GFP_NOFS);
151         if (unlikely(dest->data == NULL))
152                 return ERR_PTR(-ENOMEM);
153         dest->len = len;
154         return q;
155 }
156
157 static struct gss_cl_ctx *
158 gss_cred_get_ctx(struct rpc_cred *cred)
159 {
160         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
161         struct gss_cl_ctx *ctx = NULL;
162
163         rcu_read_lock();
164         if (gss_cred->gc_ctx)
165                 ctx = gss_get_ctx(gss_cred->gc_ctx);
166         rcu_read_unlock();
167         return ctx;
168 }
169
170 static struct gss_cl_ctx *
171 gss_alloc_context(void)
172 {
173         struct gss_cl_ctx *ctx;
174
175         ctx = kzalloc(sizeof(*ctx), GFP_NOFS);
176         if (ctx != NULL) {
177                 ctx->gc_proc = RPC_GSS_PROC_DATA;
178                 ctx->gc_seq = 1;        /* NetApp 6.4R1 doesn't accept seq. no. 0 */
179                 spin_lock_init(&ctx->gc_seq_lock);
180                 atomic_set(&ctx->count,1);
181         }
182         return ctx;
183 }
184
185 #define GSSD_MIN_TIMEOUT (60 * 60)
186 static const void *
187 gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
188 {
189         const void *q;
190         unsigned int seclen;
191         unsigned int timeout;
192         u32 window_size;
193         int ret;
194
195         /* First unsigned int gives the lifetime (in seconds) of the cred */
196         p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
197         if (IS_ERR(p))
198                 goto err;
199         if (timeout == 0)
200                 timeout = GSSD_MIN_TIMEOUT;
201         ctx->gc_expiry = jiffies + (unsigned long)timeout * HZ * 3 / 4;
202         /* Sequence number window. Determines the maximum number of simultaneous requests */
203         p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
204         if (IS_ERR(p))
205                 goto err;
206         ctx->gc_win = window_size;
207         /* gssd signals an error by passing ctx->gc_win = 0: */
208         if (ctx->gc_win == 0) {
209                 /* in which case, p points to  an error code which we ignore */
210                 p = ERR_PTR(-EACCES);
211                 goto err;
212         }
213         /* copy the opaque wire context */
214         p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
215         if (IS_ERR(p))
216                 goto err;
217         /* import the opaque security context */
218         p  = simple_get_bytes(p, end, &seclen, sizeof(seclen));
219         if (IS_ERR(p))
220                 goto err;
221         q = (const void *)((const char *)p + seclen);
222         if (unlikely(q > end || q < p)) {
223                 p = ERR_PTR(-EFAULT);
224                 goto err;
225         }
226         ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx);
227         if (ret < 0) {
228                 p = ERR_PTR(ret);
229                 goto err;
230         }
231         return q;
232 err:
233         dprintk("RPC:       gss_fill_context returning %ld\n", -PTR_ERR(p));
234         return p;
235 }
236
237 #define UPCALL_BUF_LEN 128
238
239 struct gss_upcall_msg {
240         atomic_t count;
241         uid_t   uid;
242         struct rpc_pipe_msg msg;
243         struct list_head list;
244         struct gss_auth *auth;
245         struct rpc_inode *inode;
246         struct rpc_wait_queue rpc_waitqueue;
247         wait_queue_head_t waitqueue;
248         struct gss_cl_ctx *ctx;
249         char databuf[UPCALL_BUF_LEN];
250 };
251
252 static int get_pipe_version(void)
253 {
254         int ret;
255
256         spin_lock(&pipe_version_lock);
257         if (pipe_version >= 0) {
258                 atomic_inc(&pipe_users);
259                 ret = pipe_version;
260         } else
261                 ret = -EAGAIN;
262         spin_unlock(&pipe_version_lock);
263         return ret;
264 }
265
266 static void put_pipe_version(void)
267 {
268         if (atomic_dec_and_lock(&pipe_users, &pipe_version_lock)) {
269                 pipe_version = -1;
270                 spin_unlock(&pipe_version_lock);
271         }
272 }
273
274 static void
275 gss_release_msg(struct gss_upcall_msg *gss_msg)
276 {
277         if (!atomic_dec_and_test(&gss_msg->count))
278                 return;
279         put_pipe_version();
280         BUG_ON(!list_empty(&gss_msg->list));
281         if (gss_msg->ctx != NULL)
282                 gss_put_ctx(gss_msg->ctx);
283         rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
284         kfree(gss_msg);
285 }
286
287 static struct gss_upcall_msg *
288 __gss_find_upcall(struct rpc_inode *rpci, uid_t uid)
289 {
290         struct gss_upcall_msg *pos;
291         list_for_each_entry(pos, &rpci->in_downcall, list) {
292                 if (pos->uid != uid)
293                         continue;
294                 atomic_inc(&pos->count);
295                 dprintk("RPC:       gss_find_upcall found msg %p\n", pos);
296                 return pos;
297         }
298         dprintk("RPC:       gss_find_upcall found nothing\n");
299         return NULL;
300 }
301
302 /* Try to add an upcall to the pipefs queue.
303  * If an upcall owned by our uid already exists, then we return a reference
304  * to that upcall instead of adding the new upcall.
305  */
306 static inline struct gss_upcall_msg *
307 gss_add_msg(struct gss_auth *gss_auth, struct gss_upcall_msg *gss_msg)
308 {
309         struct rpc_inode *rpci = gss_msg->inode;
310         struct inode *inode = &rpci->vfs_inode;
311         struct gss_upcall_msg *old;
312
313         spin_lock(&inode->i_lock);
314         old = __gss_find_upcall(rpci, gss_msg->uid);
315         if (old == NULL) {
316                 atomic_inc(&gss_msg->count);
317                 list_add(&gss_msg->list, &rpci->in_downcall);
318         } else
319                 gss_msg = old;
320         spin_unlock(&inode->i_lock);
321         return gss_msg;
322 }
323
324 static void
325 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
326 {
327         list_del_init(&gss_msg->list);
328         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
329         wake_up_all(&gss_msg->waitqueue);
330         atomic_dec(&gss_msg->count);
331 }
332
333 static void
334 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
335 {
336         struct inode *inode = &gss_msg->inode->vfs_inode;
337
338         if (list_empty(&gss_msg->list))
339                 return;
340         spin_lock(&inode->i_lock);
341         if (!list_empty(&gss_msg->list))
342                 __gss_unhash_msg(gss_msg);
343         spin_unlock(&inode->i_lock);
344 }
345
346 static void
347 gss_upcall_callback(struct rpc_task *task)
348 {
349         struct gss_cred *gss_cred = container_of(task->tk_msg.rpc_cred,
350                         struct gss_cred, gc_base);
351         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
352         struct inode *inode = &gss_msg->inode->vfs_inode;
353
354         spin_lock(&inode->i_lock);
355         if (gss_msg->ctx)
356                 gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_msg->ctx);
357         else
358                 task->tk_status = gss_msg->msg.errno;
359         gss_cred->gc_upcall = NULL;
360         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
361         spin_unlock(&inode->i_lock);
362         gss_release_msg(gss_msg);
363 }
364
365 static void gss_encode_v0_msg(struct gss_upcall_msg *gss_msg)
366 {
367         gss_msg->msg.data = &gss_msg->uid;
368         gss_msg->msg.len = sizeof(gss_msg->uid);
369 }
370
371 static void gss_encode_v1_msg(struct gss_upcall_msg *gss_msg,
372                                 struct rpc_clnt *clnt, int machine_cred)
373 {
374         char *p = gss_msg->databuf;
375         int len = 0;
376
377         gss_msg->msg.len = sprintf(gss_msg->databuf, "mech=%s uid=%d ",
378                                    gss_msg->auth->mech->gm_name,
379                                    gss_msg->uid);
380         p += gss_msg->msg.len;
381         if (clnt->cl_principal) {
382                 len = sprintf(p, "target=%s ", clnt->cl_principal);
383                 p += len;
384                 gss_msg->msg.len += len;
385         }
386         if (machine_cred) {
387                 len = sprintf(p, "service=* ");
388                 p += len;
389                 gss_msg->msg.len += len;
390         } else if (!strcmp(clnt->cl_program->name, "nfs4_cb")) {
391                 len = sprintf(p, "service=nfs ");
392                 p += len;
393                 gss_msg->msg.len += len;
394         }
395         len = sprintf(p, "\n");
396         gss_msg->msg.len += len;
397
398         gss_msg->msg.data = gss_msg->databuf;
399         BUG_ON(gss_msg->msg.len > UPCALL_BUF_LEN);
400 }
401
402 static void gss_encode_msg(struct gss_upcall_msg *gss_msg,
403                                 struct rpc_clnt *clnt, int machine_cred)
404 {
405         if (pipe_version == 0)
406                 gss_encode_v0_msg(gss_msg);
407         else /* pipe_version == 1 */
408                 gss_encode_v1_msg(gss_msg, clnt, machine_cred);
409 }
410
411 static inline struct gss_upcall_msg *
412 gss_alloc_msg(struct gss_auth *gss_auth, uid_t uid, struct rpc_clnt *clnt,
413                 int machine_cred)
414 {
415         struct gss_upcall_msg *gss_msg;
416         int vers;
417
418         gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
419         if (gss_msg == NULL)
420                 return ERR_PTR(-ENOMEM);
421         vers = get_pipe_version();
422         if (vers < 0) {
423                 kfree(gss_msg);
424                 return ERR_PTR(vers);
425         }
426         gss_msg->inode = RPC_I(gss_auth->dentry[vers]->d_inode);
427         INIT_LIST_HEAD(&gss_msg->list);
428         rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
429         init_waitqueue_head(&gss_msg->waitqueue);
430         atomic_set(&gss_msg->count, 1);
431         gss_msg->uid = uid;
432         gss_msg->auth = gss_auth;
433         gss_encode_msg(gss_msg, clnt, machine_cred);
434         return gss_msg;
435 }
436
437 static struct gss_upcall_msg *
438 gss_setup_upcall(struct rpc_clnt *clnt, struct gss_auth *gss_auth, struct rpc_cred *cred)
439 {
440         struct gss_cred *gss_cred = container_of(cred,
441                         struct gss_cred, gc_base);
442         struct gss_upcall_msg *gss_new, *gss_msg;
443         uid_t uid = cred->cr_uid;
444
445         gss_new = gss_alloc_msg(gss_auth, uid, clnt, gss_cred->gc_machine_cred);
446         if (IS_ERR(gss_new))
447                 return gss_new;
448         gss_msg = gss_add_msg(gss_auth, gss_new);
449         if (gss_msg == gss_new) {
450                 struct inode *inode = &gss_new->inode->vfs_inode;
451                 int res = rpc_queue_upcall(inode, &gss_new->msg);
452                 if (res) {
453                         gss_unhash_msg(gss_new);
454                         gss_msg = ERR_PTR(res);
455                 }
456         } else
457                 gss_release_msg(gss_new);
458         return gss_msg;
459 }
460
461 static void warn_gssd(void)
462 {
463         static unsigned long ratelimit;
464         unsigned long now = jiffies;
465
466         if (time_after(now, ratelimit)) {
467                 printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
468                                 "Please check user daemon is running.\n");
469                 ratelimit = now + 15*HZ;
470         }
471 }
472
473 static inline int
474 gss_refresh_upcall(struct rpc_task *task)
475 {
476         struct rpc_cred *cred = task->tk_msg.rpc_cred;
477         struct gss_auth *gss_auth = container_of(cred->cr_auth,
478                         struct gss_auth, rpc_auth);
479         struct gss_cred *gss_cred = container_of(cred,
480                         struct gss_cred, gc_base);
481         struct gss_upcall_msg *gss_msg;
482         struct inode *inode;
483         int err = 0;
484
485         dprintk("RPC: %5u gss_refresh_upcall for uid %u\n", task->tk_pid,
486                                                                 cred->cr_uid);
487         gss_msg = gss_setup_upcall(task->tk_client, gss_auth, cred);
488         if (IS_ERR(gss_msg) == -EAGAIN) {
489                 /* XXX: warning on the first, under the assumption we
490                  * shouldn't normally hit this case on a refresh. */
491                 warn_gssd();
492                 task->tk_timeout = 15*HZ;
493                 rpc_sleep_on(&pipe_version_rpc_waitqueue, task, NULL);
494                 return 0;
495         }
496         if (IS_ERR(gss_msg)) {
497                 err = PTR_ERR(gss_msg);
498                 goto out;
499         }
500         inode = &gss_msg->inode->vfs_inode;
501         spin_lock(&inode->i_lock);
502         if (gss_cred->gc_upcall != NULL)
503                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
504         else if (gss_msg->ctx != NULL) {
505                 gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_msg->ctx);
506                 gss_cred->gc_upcall = NULL;
507                 rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
508         } else if (gss_msg->msg.errno >= 0) {
509                 task->tk_timeout = 0;
510                 gss_cred->gc_upcall = gss_msg;
511                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
512                 atomic_inc(&gss_msg->count);
513                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
514         } else
515                 err = gss_msg->msg.errno;
516         spin_unlock(&inode->i_lock);
517         gss_release_msg(gss_msg);
518 out:
519         dprintk("RPC: %5u gss_refresh_upcall for uid %u result %d\n",
520                         task->tk_pid, cred->cr_uid, err);
521         return err;
522 }
523
524 static inline int
525 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
526 {
527         struct inode *inode;
528         struct rpc_cred *cred = &gss_cred->gc_base;
529         struct gss_upcall_msg *gss_msg;
530         DEFINE_WAIT(wait);
531         int err = 0;
532
533         dprintk("RPC:       gss_upcall for uid %u\n", cred->cr_uid);
534 retry:
535         gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred);
536         if (PTR_ERR(gss_msg) == -EAGAIN) {
537                 err = wait_event_interruptible_timeout(pipe_version_waitqueue,
538                                 pipe_version >= 0, 15*HZ);
539                 if (err)
540                         goto out;
541                 if (pipe_version < 0)
542                         warn_gssd();
543                 goto retry;
544         }
545         if (IS_ERR(gss_msg)) {
546                 err = PTR_ERR(gss_msg);
547                 goto out;
548         }
549         inode = &gss_msg->inode->vfs_inode;
550         for (;;) {
551                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_INTERRUPTIBLE);
552                 spin_lock(&inode->i_lock);
553                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
554                         break;
555                 }
556                 spin_unlock(&inode->i_lock);
557                 if (signalled()) {
558                         err = -ERESTARTSYS;
559                         goto out_intr;
560                 }
561                 schedule();
562         }
563         if (gss_msg->ctx)
564                 gss_cred_set_ctx(cred, gss_msg->ctx);
565         else
566                 err = gss_msg->msg.errno;
567         spin_unlock(&inode->i_lock);
568 out_intr:
569         finish_wait(&gss_msg->waitqueue, &wait);
570         gss_release_msg(gss_msg);
571 out:
572         dprintk("RPC:       gss_create_upcall for uid %u result %d\n",
573                         cred->cr_uid, err);
574         return err;
575 }
576
577 static ssize_t
578 gss_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
579                 char __user *dst, size_t buflen)
580 {
581         char *data = (char *)msg->data + msg->copied;
582         size_t mlen = min(msg->len, buflen);
583         unsigned long left;
584
585         left = copy_to_user(dst, data, mlen);
586         if (left == mlen) {
587                 msg->errno = -EFAULT;
588                 return -EFAULT;
589         }
590
591         mlen -= left;
592         msg->copied += mlen;
593         msg->errno = 0;
594         return mlen;
595 }
596
597 #define MSG_BUF_MAXSIZE 1024
598
599 static ssize_t
600 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
601 {
602         const void *p, *end;
603         void *buf;
604         struct gss_upcall_msg *gss_msg;
605         struct inode *inode = filp->f_path.dentry->d_inode;
606         struct gss_cl_ctx *ctx;
607         uid_t uid;
608         ssize_t err = -EFBIG;
609
610         if (mlen > MSG_BUF_MAXSIZE)
611                 goto out;
612         err = -ENOMEM;
613         buf = kmalloc(mlen, GFP_NOFS);
614         if (!buf)
615                 goto out;
616
617         err = -EFAULT;
618         if (copy_from_user(buf, src, mlen))
619                 goto err;
620
621         end = (const void *)((char *)buf + mlen);
622         p = simple_get_bytes(buf, end, &uid, sizeof(uid));
623         if (IS_ERR(p)) {
624                 err = PTR_ERR(p);
625                 goto err;
626         }
627
628         err = -ENOMEM;
629         ctx = gss_alloc_context();
630         if (ctx == NULL)
631                 goto err;
632
633         err = -ENOENT;
634         /* Find a matching upcall */
635         spin_lock(&inode->i_lock);
636         gss_msg = __gss_find_upcall(RPC_I(inode), uid);
637         if (gss_msg == NULL) {
638                 spin_unlock(&inode->i_lock);
639                 goto err_put_ctx;
640         }
641         list_del_init(&gss_msg->list);
642         spin_unlock(&inode->i_lock);
643
644         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
645         if (IS_ERR(p)) {
646                 err = PTR_ERR(p);
647                 gss_msg->msg.errno = (err == -EAGAIN) ? -EAGAIN : -EACCES;
648                 goto err_release_msg;
649         }
650         gss_msg->ctx = gss_get_ctx(ctx);
651         err = mlen;
652
653 err_release_msg:
654         spin_lock(&inode->i_lock);
655         __gss_unhash_msg(gss_msg);
656         spin_unlock(&inode->i_lock);
657         gss_release_msg(gss_msg);
658 err_put_ctx:
659         gss_put_ctx(ctx);
660 err:
661         kfree(buf);
662 out:
663         dprintk("RPC:       gss_pipe_downcall returning %Zd\n", err);
664         return err;
665 }
666
667 static int gss_pipe_open(struct inode *inode, int new_version)
668 {
669         int ret = 0;
670
671         spin_lock(&pipe_version_lock);
672         if (pipe_version < 0) {
673                 /* First open of any gss pipe determines the version: */
674                 pipe_version = new_version;
675                 rpc_wake_up(&pipe_version_rpc_waitqueue);
676                 wake_up(&pipe_version_waitqueue);
677         } else if (pipe_version != new_version) {
678                 /* Trying to open a pipe of a different version */
679                 ret = -EBUSY;
680                 goto out;
681         }
682         atomic_inc(&pipe_users);
683 out:
684         spin_unlock(&pipe_version_lock);
685         return ret;
686
687 }
688
689 static int gss_pipe_open_v0(struct inode *inode)
690 {
691         return gss_pipe_open(inode, 0);
692 }
693
694 static int gss_pipe_open_v1(struct inode *inode)
695 {
696         return gss_pipe_open(inode, 1);
697 }
698
699 static void
700 gss_pipe_release(struct inode *inode)
701 {
702         struct rpc_inode *rpci = RPC_I(inode);
703         struct gss_upcall_msg *gss_msg;
704
705         spin_lock(&inode->i_lock);
706         while (!list_empty(&rpci->in_downcall)) {
707
708                 gss_msg = list_entry(rpci->in_downcall.next,
709                                 struct gss_upcall_msg, list);
710                 gss_msg->msg.errno = -EPIPE;
711                 atomic_inc(&gss_msg->count);
712                 __gss_unhash_msg(gss_msg);
713                 spin_unlock(&inode->i_lock);
714                 gss_release_msg(gss_msg);
715                 spin_lock(&inode->i_lock);
716         }
717         spin_unlock(&inode->i_lock);
718
719         put_pipe_version();
720 }
721
722 static void
723 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
724 {
725         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
726
727         if (msg->errno < 0) {
728                 dprintk("RPC:       gss_pipe_destroy_msg releasing msg %p\n",
729                                 gss_msg);
730                 atomic_inc(&gss_msg->count);
731                 gss_unhash_msg(gss_msg);
732                 if (msg->errno == -ETIMEDOUT)
733                         warn_gssd();
734                 gss_release_msg(gss_msg);
735         }
736 }
737
738 /*
739  * NOTE: we have the opportunity to use different
740  * parameters based on the input flavor (which must be a pseudoflavor)
741  */
742 static struct rpc_auth *
743 gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
744 {
745         struct gss_auth *gss_auth;
746         struct rpc_auth * auth;
747         int err = -ENOMEM; /* XXX? */
748
749         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
750
751         if (!try_module_get(THIS_MODULE))
752                 return ERR_PTR(err);
753         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
754                 goto out_dec;
755         gss_auth->client = clnt;
756         err = -EINVAL;
757         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
758         if (!gss_auth->mech) {
759                 printk(KERN_WARNING "%s: Pseudoflavor %d not found!\n",
760                                 __func__, flavor);
761                 goto err_free;
762         }
763         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
764         if (gss_auth->service == 0)
765                 goto err_put_mech;
766         auth = &gss_auth->rpc_auth;
767         auth->au_cslack = GSS_CRED_SLACK >> 2;
768         auth->au_rslack = GSS_VERF_SLACK >> 2;
769         auth->au_ops = &authgss_ops;
770         auth->au_flavor = flavor;
771         atomic_set(&auth->au_count, 1);
772         kref_init(&gss_auth->kref);
773
774         /*
775          * Note: if we created the old pipe first, then someone who
776          * examined the directory at the right moment might conclude
777          * that we supported only the old pipe.  So we instead create
778          * the new pipe first.
779          */
780         gss_auth->dentry[1] = rpc_mkpipe(clnt->cl_dentry,
781                                          "gssd",
782                                          clnt, &gss_upcall_ops_v1,
783                                          RPC_PIPE_WAIT_FOR_OPEN);
784         if (IS_ERR(gss_auth->dentry[1])) {
785                 err = PTR_ERR(gss_auth->dentry[1]);
786                 goto err_put_mech;
787         }
788
789         gss_auth->dentry[0] = rpc_mkpipe(clnt->cl_dentry,
790                                          gss_auth->mech->gm_name,
791                                          clnt, &gss_upcall_ops_v0,
792                                          RPC_PIPE_WAIT_FOR_OPEN);
793         if (IS_ERR(gss_auth->dentry[0])) {
794                 err = PTR_ERR(gss_auth->dentry[0]);
795                 goto err_unlink_pipe_1;
796         }
797         err = rpcauth_init_credcache(auth);
798         if (err)
799                 goto err_unlink_pipe_0;
800
801         return auth;
802 err_unlink_pipe_0:
803         rpc_unlink(gss_auth->dentry[0]);
804 err_unlink_pipe_1:
805         rpc_unlink(gss_auth->dentry[1]);
806 err_put_mech:
807         gss_mech_put(gss_auth->mech);
808 err_free:
809         kfree(gss_auth);
810 out_dec:
811         module_put(THIS_MODULE);
812         return ERR_PTR(err);
813 }
814
815 static void
816 gss_free(struct gss_auth *gss_auth)
817 {
818         rpc_unlink(gss_auth->dentry[1]);
819         rpc_unlink(gss_auth->dentry[0]);
820         gss_mech_put(gss_auth->mech);
821
822         kfree(gss_auth);
823         module_put(THIS_MODULE);
824 }
825
826 static void
827 gss_free_callback(struct kref *kref)
828 {
829         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
830
831         gss_free(gss_auth);
832 }
833
834 static void
835 gss_destroy(struct rpc_auth *auth)
836 {
837         struct gss_auth *gss_auth;
838
839         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
840                         auth, auth->au_flavor);
841
842         rpcauth_destroy_credcache(auth);
843
844         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
845         kref_put(&gss_auth->kref, gss_free_callback);
846 }
847
848 /*
849  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
850  * to the server with the GSS control procedure field set to
851  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
852  * all RPCSEC_GSS state associated with that context.
853  */
854 static int
855 gss_destroying_context(struct rpc_cred *cred)
856 {
857         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
858         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
859         struct rpc_task *task;
860
861         if (gss_cred->gc_ctx == NULL ||
862             test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
863                 return 0;
864
865         gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY;
866         cred->cr_ops = &gss_nullops;
867
868         /* Take a reference to ensure the cred will be destroyed either
869          * by the RPC call or by the put_rpccred() below */
870         get_rpccred(cred);
871
872         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
873         if (!IS_ERR(task))
874                 rpc_put_task(task);
875
876         put_rpccred(cred);
877         return 1;
878 }
879
880 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
881  * to create a new cred or context, so they check that things have been
882  * allocated before freeing them. */
883 static void
884 gss_do_free_ctx(struct gss_cl_ctx *ctx)
885 {
886         dprintk("RPC:       gss_free_ctx\n");
887
888         kfree(ctx->gc_wire_ctx.data);
889         kfree(ctx);
890 }
891
892 static void
893 gss_free_ctx_callback(struct rcu_head *head)
894 {
895         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
896         gss_do_free_ctx(ctx);
897 }
898
899 static void
900 gss_free_ctx(struct gss_cl_ctx *ctx)
901 {
902         struct gss_ctx *gc_gss_ctx;
903
904         gc_gss_ctx = rcu_dereference(ctx->gc_gss_ctx);
905         rcu_assign_pointer(ctx->gc_gss_ctx, NULL);
906         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
907         if (gc_gss_ctx)
908                 gss_delete_sec_context(&gc_gss_ctx);
909 }
910
911 static void
912 gss_free_cred(struct gss_cred *gss_cred)
913 {
914         dprintk("RPC:       gss_free_cred %p\n", gss_cred);
915         kfree(gss_cred);
916 }
917
918 static void
919 gss_free_cred_callback(struct rcu_head *head)
920 {
921         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
922         gss_free_cred(gss_cred);
923 }
924
925 static void
926 gss_destroy_nullcred(struct rpc_cred *cred)
927 {
928         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
929         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
930         struct gss_cl_ctx *ctx = gss_cred->gc_ctx;
931
932         rcu_assign_pointer(gss_cred->gc_ctx, NULL);
933         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
934         if (ctx)
935                 gss_put_ctx(ctx);
936         kref_put(&gss_auth->kref, gss_free_callback);
937 }
938
939 static void
940 gss_destroy_cred(struct rpc_cred *cred)
941 {
942
943         if (gss_destroying_context(cred))
944                 return;
945         gss_destroy_nullcred(cred);
946 }
947
948 /*
949  * Lookup RPCSEC_GSS cred for the current process
950  */
951 static struct rpc_cred *
952 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
953 {
954         return rpcauth_lookup_credcache(auth, acred, flags);
955 }
956
957 static struct rpc_cred *
958 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
959 {
960         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
961         struct gss_cred *cred = NULL;
962         int err = -ENOMEM;
963
964         dprintk("RPC:       gss_create_cred for uid %d, flavor %d\n",
965                 acred->uid, auth->au_flavor);
966
967         if (!(cred = kzalloc(sizeof(*cred), GFP_NOFS)))
968                 goto out_err;
969
970         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
971         /*
972          * Note: in order to force a call to call_refresh(), we deliberately
973          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
974          */
975         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
976         cred->gc_service = gss_auth->service;
977         cred->gc_machine_cred = acred->machine_cred;
978         kref_get(&gss_auth->kref);
979         return &cred->gc_base;
980
981 out_err:
982         dprintk("RPC:       gss_create_cred failed with error %d\n", err);
983         return ERR_PTR(err);
984 }
985
986 static int
987 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
988 {
989         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
990         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
991         int err;
992
993         do {
994                 err = gss_create_upcall(gss_auth, gss_cred);
995         } while (err == -EAGAIN);
996         return err;
997 }
998
999 static int
1000 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
1001 {
1002         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1003
1004         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
1005                 goto out;
1006         /* Don't match with creds that have expired. */
1007         if (time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
1008                 return 0;
1009         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
1010                 return 0;
1011 out:
1012         if (acred->machine_cred != gss_cred->gc_machine_cred)
1013                 return 0;
1014         return (rc->cr_uid == acred->uid);
1015 }
1016
1017 /*
1018 * Marshal credentials.
1019 * Maybe we should keep a cached credential for performance reasons.
1020 */
1021 static __be32 *
1022 gss_marshal(struct rpc_task *task, __be32 *p)
1023 {
1024         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1025         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1026                                                  gc_base);
1027         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
1028         __be32          *cred_len;
1029         struct rpc_rqst *req = task->tk_rqstp;
1030         u32             maj_stat = 0;
1031         struct xdr_netobj mic;
1032         struct kvec     iov;
1033         struct xdr_buf  verf_buf;
1034
1035         dprintk("RPC: %5u gss_marshal\n", task->tk_pid);
1036
1037         *p++ = htonl(RPC_AUTH_GSS);
1038         cred_len = p++;
1039
1040         spin_lock(&ctx->gc_seq_lock);
1041         req->rq_seqno = ctx->gc_seq++;
1042         spin_unlock(&ctx->gc_seq_lock);
1043
1044         *p++ = htonl((u32) RPC_GSS_VERSION);
1045         *p++ = htonl((u32) ctx->gc_proc);
1046         *p++ = htonl((u32) req->rq_seqno);
1047         *p++ = htonl((u32) gss_cred->gc_service);
1048         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
1049         *cred_len = htonl((p - (cred_len + 1)) << 2);
1050
1051         /* We compute the checksum for the verifier over the xdr-encoded bytes
1052          * starting with the xid and ending at the end of the credential: */
1053         iov.iov_base = xprt_skip_transport_header(task->tk_xprt,
1054                                         req->rq_snd_buf.head[0].iov_base);
1055         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
1056         xdr_buf_from_iov(&iov, &verf_buf);
1057
1058         /* set verifier flavor*/
1059         *p++ = htonl(RPC_AUTH_GSS);
1060
1061         mic.data = (u8 *)(p + 1);
1062         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1063         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
1064                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1065         } else if (maj_stat != 0) {
1066                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
1067                 goto out_put_ctx;
1068         }
1069         p = xdr_encode_opaque(p, NULL, mic.len);
1070         gss_put_ctx(ctx);
1071         return p;
1072 out_put_ctx:
1073         gss_put_ctx(ctx);
1074         return NULL;
1075 }
1076
1077 static int gss_renew_cred(struct rpc_task *task)
1078 {
1079         struct rpc_cred *oldcred = task->tk_msg.rpc_cred;
1080         struct gss_cred *gss_cred = container_of(oldcred,
1081                                                  struct gss_cred,
1082                                                  gc_base);
1083         struct rpc_auth *auth = oldcred->cr_auth;
1084         struct auth_cred acred = {
1085                 .uid = oldcred->cr_uid,
1086                 .machine_cred = gss_cred->gc_machine_cred,
1087         };
1088         struct rpc_cred *new;
1089
1090         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
1091         if (IS_ERR(new))
1092                 return PTR_ERR(new);
1093         task->tk_msg.rpc_cred = new;
1094         put_rpccred(oldcred);
1095         return 0;
1096 }
1097
1098 /*
1099 * Refresh credentials. XXX - finish
1100 */
1101 static int
1102 gss_refresh(struct rpc_task *task)
1103 {
1104         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1105         int ret = 0;
1106
1107         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
1108                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
1109                 ret = gss_renew_cred(task);
1110                 if (ret < 0)
1111                         goto out;
1112                 cred = task->tk_msg.rpc_cred;
1113         }
1114
1115         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
1116                 ret = gss_refresh_upcall(task);
1117 out:
1118         return ret;
1119 }
1120
1121 /* Dummy refresh routine: used only when destroying the context */
1122 static int
1123 gss_refresh_null(struct rpc_task *task)
1124 {
1125         return -EACCES;
1126 }
1127
1128 static __be32 *
1129 gss_validate(struct rpc_task *task, __be32 *p)
1130 {
1131         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1132         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1133         __be32          seq;
1134         struct kvec     iov;
1135         struct xdr_buf  verf_buf;
1136         struct xdr_netobj mic;
1137         u32             flav,len;
1138         u32             maj_stat;
1139
1140         dprintk("RPC: %5u gss_validate\n", task->tk_pid);
1141
1142         flav = ntohl(*p++);
1143         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
1144                 goto out_bad;
1145         if (flav != RPC_AUTH_GSS)
1146                 goto out_bad;
1147         seq = htonl(task->tk_rqstp->rq_seqno);
1148         iov.iov_base = &seq;
1149         iov.iov_len = sizeof(seq);
1150         xdr_buf_from_iov(&iov, &verf_buf);
1151         mic.data = (u8 *)p;
1152         mic.len = len;
1153
1154         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1155         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1156                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1157         if (maj_stat) {
1158                 dprintk("RPC: %5u gss_validate: gss_verify_mic returned "
1159                                 "error 0x%08x\n", task->tk_pid, maj_stat);
1160                 goto out_bad;
1161         }
1162         /* We leave it to unwrap to calculate au_rslack. For now we just
1163          * calculate the length of the verifier: */
1164         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1165         gss_put_ctx(ctx);
1166         dprintk("RPC: %5u gss_validate: gss_verify_mic succeeded.\n",
1167                         task->tk_pid);
1168         return p + XDR_QUADLEN(len);
1169 out_bad:
1170         gss_put_ctx(ctx);
1171         dprintk("RPC: %5u gss_validate failed.\n", task->tk_pid);
1172         return NULL;
1173 }
1174
1175 static inline int
1176 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1177                 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
1178 {
1179         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1180         struct xdr_buf  integ_buf;
1181         __be32          *integ_len = NULL;
1182         struct xdr_netobj mic;
1183         u32             offset;
1184         __be32          *q;
1185         struct kvec     *iov;
1186         u32             maj_stat = 0;
1187         int             status = -EIO;
1188
1189         integ_len = p++;
1190         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1191         *p++ = htonl(rqstp->rq_seqno);
1192
1193         status = encode(rqstp, p, obj);
1194         if (status)
1195                 return status;
1196
1197         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1198                                 offset, snd_buf->len - offset))
1199                 return status;
1200         *integ_len = htonl(integ_buf.len);
1201
1202         /* guess whether we're in the head or the tail: */
1203         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1204                 iov = snd_buf->tail;
1205         else
1206                 iov = snd_buf->head;
1207         p = iov->iov_base + iov->iov_len;
1208         mic.data = (u8 *)(p + 1);
1209
1210         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1211         status = -EIO; /* XXX? */
1212         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1213                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1214         else if (maj_stat)
1215                 return status;
1216         q = xdr_encode_opaque(p, NULL, mic.len);
1217
1218         offset = (u8 *)q - (u8 *)p;
1219         iov->iov_len += offset;
1220         snd_buf->len += offset;
1221         return 0;
1222 }
1223
1224 static void
1225 priv_release_snd_buf(struct rpc_rqst *rqstp)
1226 {
1227         int i;
1228
1229         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1230                 __free_page(rqstp->rq_enc_pages[i]);
1231         kfree(rqstp->rq_enc_pages);
1232 }
1233
1234 static int
1235 alloc_enc_pages(struct rpc_rqst *rqstp)
1236 {
1237         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1238         int first, last, i;
1239
1240         if (snd_buf->page_len == 0) {
1241                 rqstp->rq_enc_pages_num = 0;
1242                 return 0;
1243         }
1244
1245         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1246         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT;
1247         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1248         rqstp->rq_enc_pages
1249                 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
1250                                 GFP_NOFS);
1251         if (!rqstp->rq_enc_pages)
1252                 goto out;
1253         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1254                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1255                 if (rqstp->rq_enc_pages[i] == NULL)
1256                         goto out_free;
1257         }
1258         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1259         return 0;
1260 out_free:
1261         for (i--; i >= 0; i--) {
1262                 __free_page(rqstp->rq_enc_pages[i]);
1263         }
1264 out:
1265         return -EAGAIN;
1266 }
1267
1268 static inline int
1269 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1270                 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
1271 {
1272         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1273         u32             offset;
1274         u32             maj_stat;
1275         int             status;
1276         __be32          *opaque_len;
1277         struct page     **inpages;
1278         int             first;
1279         int             pad;
1280         struct kvec     *iov;
1281         char            *tmp;
1282
1283         opaque_len = p++;
1284         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1285         *p++ = htonl(rqstp->rq_seqno);
1286
1287         status = encode(rqstp, p, obj);
1288         if (status)
1289                 return status;
1290
1291         status = alloc_enc_pages(rqstp);
1292         if (status)
1293                 return status;
1294         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1295         inpages = snd_buf->pages + first;
1296         snd_buf->pages = rqstp->rq_enc_pages;
1297         snd_buf->page_base -= first << PAGE_CACHE_SHIFT;
1298         /* Give the tail its own page, in case we need extra space in the
1299          * head when wrapping: */
1300         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1301                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1302                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1303                 snd_buf->tail[0].iov_base = tmp;
1304         }
1305         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1306         /* RPC_SLACK_SPACE should prevent this ever happening: */
1307         BUG_ON(snd_buf->len > snd_buf->buflen);
1308         status = -EIO;
1309         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1310          * done anyway, so it's safe to put the request on the wire: */
1311         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1312                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1313         else if (maj_stat)
1314                 return status;
1315
1316         *opaque_len = htonl(snd_buf->len - offset);
1317         /* guess whether we're in the head or the tail: */
1318         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1319                 iov = snd_buf->tail;
1320         else
1321                 iov = snd_buf->head;
1322         p = iov->iov_base + iov->iov_len;
1323         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1324         memset(p, 0, pad);
1325         iov->iov_len += pad;
1326         snd_buf->len += pad;
1327
1328         return 0;
1329 }
1330
1331 static int
1332 gss_wrap_req(struct rpc_task *task,
1333              kxdrproc_t encode, void *rqstp, __be32 *p, void *obj)
1334 {
1335         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1336         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1337                         gc_base);
1338         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1339         int             status = -EIO;
1340
1341         dprintk("RPC: %5u gss_wrap_req\n", task->tk_pid);
1342         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1343                 /* The spec seems a little ambiguous here, but I think that not
1344                  * wrapping context destruction requests makes the most sense.
1345                  */
1346                 status = encode(rqstp, p, obj);
1347                 goto out;
1348         }
1349         switch (gss_cred->gc_service) {
1350                 case RPC_GSS_SVC_NONE:
1351                         status = encode(rqstp, p, obj);
1352                         break;
1353                 case RPC_GSS_SVC_INTEGRITY:
1354                         status = gss_wrap_req_integ(cred, ctx, encode,
1355                                                                 rqstp, p, obj);
1356                         break;
1357                 case RPC_GSS_SVC_PRIVACY:
1358                         status = gss_wrap_req_priv(cred, ctx, encode,
1359                                         rqstp, p, obj);
1360                         break;
1361         }
1362 out:
1363         gss_put_ctx(ctx);
1364         dprintk("RPC: %5u gss_wrap_req returning %d\n", task->tk_pid, status);
1365         return status;
1366 }
1367
1368 static inline int
1369 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1370                 struct rpc_rqst *rqstp, __be32 **p)
1371 {
1372         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1373         struct xdr_buf integ_buf;
1374         struct xdr_netobj mic;
1375         u32 data_offset, mic_offset;
1376         u32 integ_len;
1377         u32 maj_stat;
1378         int status = -EIO;
1379
1380         integ_len = ntohl(*(*p)++);
1381         if (integ_len & 3)
1382                 return status;
1383         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1384         mic_offset = integ_len + data_offset;
1385         if (mic_offset > rcv_buf->len)
1386                 return status;
1387         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1388                 return status;
1389
1390         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1391                                 mic_offset - data_offset))
1392                 return status;
1393
1394         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1395                 return status;
1396
1397         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1398         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1399                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1400         if (maj_stat != GSS_S_COMPLETE)
1401                 return status;
1402         return 0;
1403 }
1404
1405 static inline int
1406 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1407                 struct rpc_rqst *rqstp, __be32 **p)
1408 {
1409         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1410         u32 offset;
1411         u32 opaque_len;
1412         u32 maj_stat;
1413         int status = -EIO;
1414
1415         opaque_len = ntohl(*(*p)++);
1416         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1417         if (offset + opaque_len > rcv_buf->len)
1418                 return status;
1419         /* remove padding: */
1420         rcv_buf->len = offset + opaque_len;
1421
1422         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1423         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1424                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1425         if (maj_stat != GSS_S_COMPLETE)
1426                 return status;
1427         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1428                 return status;
1429
1430         return 0;
1431 }
1432
1433
1434 static int
1435 gss_unwrap_resp(struct rpc_task *task,
1436                 kxdrproc_t decode, void *rqstp, __be32 *p, void *obj)
1437 {
1438         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1439         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1440                         gc_base);
1441         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1442         __be32          *savedp = p;
1443         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1444         int             savedlen = head->iov_len;
1445         int             status = -EIO;
1446
1447         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1448                 goto out_decode;
1449         switch (gss_cred->gc_service) {
1450                 case RPC_GSS_SVC_NONE:
1451                         break;
1452                 case RPC_GSS_SVC_INTEGRITY:
1453                         status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1454                         if (status)
1455                                 goto out;
1456                         break;
1457                 case RPC_GSS_SVC_PRIVACY:
1458                         status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1459                         if (status)
1460                                 goto out;
1461                         break;
1462         }
1463         /* take into account extra slack for integrity and privacy cases: */
1464         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1465                                                 + (savedlen - head->iov_len);
1466 out_decode:
1467         status = decode(rqstp, p, obj);
1468 out:
1469         gss_put_ctx(ctx);
1470         dprintk("RPC: %5u gss_unwrap_resp returning %d\n", task->tk_pid,
1471                         status);
1472         return status;
1473 }
1474
1475 static const struct rpc_authops authgss_ops = {
1476         .owner          = THIS_MODULE,
1477         .au_flavor      = RPC_AUTH_GSS,
1478         .au_name        = "RPCSEC_GSS",
1479         .create         = gss_create,
1480         .destroy        = gss_destroy,
1481         .lookup_cred    = gss_lookup_cred,
1482         .crcreate       = gss_create_cred
1483 };
1484
1485 static const struct rpc_credops gss_credops = {
1486         .cr_name        = "AUTH_GSS",
1487         .crdestroy      = gss_destroy_cred,
1488         .cr_init        = gss_cred_init,
1489         .crbind         = rpcauth_generic_bind_cred,
1490         .crmatch        = gss_match,
1491         .crmarshal      = gss_marshal,
1492         .crrefresh      = gss_refresh,
1493         .crvalidate     = gss_validate,
1494         .crwrap_req     = gss_wrap_req,
1495         .crunwrap_resp  = gss_unwrap_resp,
1496 };
1497
1498 static const struct rpc_credops gss_nullops = {
1499         .cr_name        = "AUTH_GSS",
1500         .crdestroy      = gss_destroy_nullcred,
1501         .crbind         = rpcauth_generic_bind_cred,
1502         .crmatch        = gss_match,
1503         .crmarshal      = gss_marshal,
1504         .crrefresh      = gss_refresh_null,
1505         .crvalidate     = gss_validate,
1506         .crwrap_req     = gss_wrap_req,
1507         .crunwrap_resp  = gss_unwrap_resp,
1508 };
1509
1510 static struct rpc_pipe_ops gss_upcall_ops_v0 = {
1511         .upcall         = gss_pipe_upcall,
1512         .downcall       = gss_pipe_downcall,
1513         .destroy_msg    = gss_pipe_destroy_msg,
1514         .open_pipe      = gss_pipe_open_v0,
1515         .release_pipe   = gss_pipe_release,
1516 };
1517
1518 static struct rpc_pipe_ops gss_upcall_ops_v1 = {
1519         .upcall         = gss_pipe_upcall,
1520         .downcall       = gss_pipe_downcall,
1521         .destroy_msg    = gss_pipe_destroy_msg,
1522         .open_pipe      = gss_pipe_open_v1,
1523         .release_pipe   = gss_pipe_release,
1524 };
1525
1526 /*
1527  * Initialize RPCSEC_GSS module
1528  */
1529 static int __init init_rpcsec_gss(void)
1530 {
1531         int err = 0;
1532
1533         err = rpcauth_register(&authgss_ops);
1534         if (err)
1535                 goto out;
1536         err = gss_svc_init();
1537         if (err)
1538                 goto out_unregister;
1539         rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
1540         return 0;
1541 out_unregister:
1542         rpcauth_unregister(&authgss_ops);
1543 out:
1544         return err;
1545 }
1546
1547 static void __exit exit_rpcsec_gss(void)
1548 {
1549         gss_svc_shutdown();
1550         rpcauth_unregister(&authgss_ops);
1551         rcu_barrier(); /* Wait for completion of call_rcu()'s */
1552 }
1553
1554 MODULE_LICENSE("GPL");
1555 module_init(init_rpcsec_gss)
1556 module_exit(exit_rpcsec_gss)