Merge linux-2.6 with linux-acpi-2.6
[linux-2.6] / net / sunrpc / auth_gss / auth_gss.c
1 /*
2  * linux/net/sunrpc/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  * $Id$
38  */
39
40
41 #include <linux/module.h>
42 #include <linux/init.h>
43 #include <linux/types.h>
44 #include <linux/slab.h>
45 #include <linux/socket.h>
46 #include <linux/in.h>
47 #include <linux/sched.h>
48 #include <linux/sunrpc/clnt.h>
49 #include <linux/sunrpc/auth.h>
50 #include <linux/sunrpc/auth_gss.h>
51 #include <linux/sunrpc/svcauth_gss.h>
52 #include <linux/sunrpc/gss_err.h>
53 #include <linux/workqueue.h>
54 #include <linux/sunrpc/rpc_pipe_fs.h>
55 #include <linux/sunrpc/gss_api.h>
56 #include <asm/uaccess.h>
57
58 static struct rpc_authops authgss_ops;
59
60 static struct rpc_credops gss_credops;
61
62 #ifdef RPC_DEBUG
63 # define RPCDBG_FACILITY        RPCDBG_AUTH
64 #endif
65
66 #define NFS_NGROUPS     16
67
68 #define GSS_CRED_EXPIRE         (60 * HZ)       /* XXX: reasonable? */
69 #define GSS_CRED_SLACK          1024            /* XXX: unused */
70 /* length of a krb5 verifier (48), plus data added before arguments when
71  * using integrity (two 4-byte integers): */
72 #define GSS_VERF_SLACK          56
73
74 /* XXX this define must match the gssd define
75 * as it is passed to gssd to signal the use of
76 * machine creds should be part of the shared rpc interface */
77
78 #define CA_RUN_AS_MACHINE  0x00000200 
79
80 /* dump the buffer in `emacs-hexl' style */
81 #define isprint(c)      ((c > 0x1f) && (c < 0x7f))
82
83 static DEFINE_RWLOCK(gss_ctx_lock);
84
85 struct gss_auth {
86         struct rpc_auth rpc_auth;
87         struct gss_api_mech *mech;
88         enum rpc_gss_svc service;
89         struct list_head upcalls;
90         struct rpc_clnt *client;
91         struct dentry *dentry;
92         char path[48];
93         spinlock_t lock;
94 };
95
96 static void gss_destroy_ctx(struct gss_cl_ctx *);
97 static struct rpc_pipe_ops gss_upcall_ops;
98
99 void
100 print_hexl(u32 *p, u_int length, u_int offset)
101 {
102         u_int i, j, jm;
103         u8 c, *cp;
104         
105         dprintk("RPC: print_hexl: length %d\n",length);
106         dprintk("\n");
107         cp = (u8 *) p;
108         
109         for (i = 0; i < length; i += 0x10) {
110                 dprintk("  %04x: ", (u_int)(i + offset));
111                 jm = length - i;
112                 jm = jm > 16 ? 16 : jm;
113                 
114                 for (j = 0; j < jm; j++) {
115                         if ((j % 2) == 1)
116                                 dprintk("%02x ", (u_int)cp[i+j]);
117                         else
118                                 dprintk("%02x", (u_int)cp[i+j]);
119                 }
120                 for (; j < 16; j++) {
121                         if ((j % 2) == 1)
122                                 dprintk("   ");
123                         else
124                                 dprintk("  ");
125                 }
126                 dprintk(" ");
127                 
128                 for (j = 0; j < jm; j++) {
129                         c = cp[i+j];
130                         c = isprint(c) ? c : '.';
131                         dprintk("%c", c);
132                 }
133                 dprintk("\n");
134         }
135 }
136
137 EXPORT_SYMBOL(print_hexl);
138
139 static inline struct gss_cl_ctx *
140 gss_get_ctx(struct gss_cl_ctx *ctx)
141 {
142         atomic_inc(&ctx->count);
143         return ctx;
144 }
145
146 static inline void
147 gss_put_ctx(struct gss_cl_ctx *ctx)
148 {
149         if (atomic_dec_and_test(&ctx->count))
150                 gss_destroy_ctx(ctx);
151 }
152
153 static void
154 gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
155 {
156         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
157         struct gss_cl_ctx *old;
158         write_lock(&gss_ctx_lock);
159         old = gss_cred->gc_ctx;
160         gss_cred->gc_ctx = ctx;
161         cred->cr_flags |= RPCAUTH_CRED_UPTODATE;
162         write_unlock(&gss_ctx_lock);
163         if (old)
164                 gss_put_ctx(old);
165 }
166
167 static int
168 gss_cred_is_uptodate_ctx(struct rpc_cred *cred)
169 {
170         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
171         int res = 0;
172
173         read_lock(&gss_ctx_lock);
174         if ((cred->cr_flags & RPCAUTH_CRED_UPTODATE) && gss_cred->gc_ctx)
175                 res = 1;
176         read_unlock(&gss_ctx_lock);
177         return res;
178 }
179
180 static const void *
181 simple_get_bytes(const void *p, const void *end, void *res, size_t len)
182 {
183         const void *q = (const void *)((const char *)p + len);
184         if (unlikely(q > end || q < p))
185                 return ERR_PTR(-EFAULT);
186         memcpy(res, p, len);
187         return q;
188 }
189
190 static inline const void *
191 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest)
192 {
193         const void *q;
194         unsigned int len;
195
196         p = simple_get_bytes(p, end, &len, sizeof(len));
197         if (IS_ERR(p))
198                 return p;
199         q = (const void *)((const char *)p + len);
200         if (unlikely(q > end || q < p))
201                 return ERR_PTR(-EFAULT);
202         dest->data = kmalloc(len, GFP_KERNEL);
203         if (unlikely(dest->data == NULL))
204                 return ERR_PTR(-ENOMEM);
205         dest->len = len;
206         memcpy(dest->data, p, len);
207         return q;
208 }
209
210 static struct gss_cl_ctx *
211 gss_cred_get_ctx(struct rpc_cred *cred)
212 {
213         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
214         struct gss_cl_ctx *ctx = NULL;
215
216         read_lock(&gss_ctx_lock);
217         if (gss_cred->gc_ctx)
218                 ctx = gss_get_ctx(gss_cred->gc_ctx);
219         read_unlock(&gss_ctx_lock);
220         return ctx;
221 }
222
223 static struct gss_cl_ctx *
224 gss_alloc_context(void)
225 {
226         struct gss_cl_ctx *ctx;
227
228         ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
229         if (ctx != NULL) {
230                 memset(ctx, 0, sizeof(*ctx));
231                 ctx->gc_proc = RPC_GSS_PROC_DATA;
232                 ctx->gc_seq = 1;        /* NetApp 6.4R1 doesn't accept seq. no. 0 */
233                 spin_lock_init(&ctx->gc_seq_lock);
234                 atomic_set(&ctx->count,1);
235         }
236         return ctx;
237 }
238
239 #define GSSD_MIN_TIMEOUT (60 * 60)
240 static const void *
241 gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
242 {
243         const void *q;
244         unsigned int seclen;
245         unsigned int timeout;
246         u32 window_size;
247         int ret;
248
249         /* First unsigned int gives the lifetime (in seconds) of the cred */
250         p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
251         if (IS_ERR(p))
252                 goto err;
253         if (timeout == 0)
254                 timeout = GSSD_MIN_TIMEOUT;
255         ctx->gc_expiry = jiffies + (unsigned long)timeout * HZ * 3 / 4;
256         /* Sequence number window. Determines the maximum number of simultaneous requests */
257         p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
258         if (IS_ERR(p))
259                 goto err;
260         ctx->gc_win = window_size;
261         /* gssd signals an error by passing ctx->gc_win = 0: */
262         if (ctx->gc_win == 0) {
263                 /* in which case, p points to  an error code which we ignore */
264                 p = ERR_PTR(-EACCES);
265                 goto err;
266         }
267         /* copy the opaque wire context */
268         p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
269         if (IS_ERR(p))
270                 goto err;
271         /* import the opaque security context */
272         p  = simple_get_bytes(p, end, &seclen, sizeof(seclen));
273         if (IS_ERR(p))
274                 goto err;
275         q = (const void *)((const char *)p + seclen);
276         if (unlikely(q > end || q < p)) {
277                 p = ERR_PTR(-EFAULT);
278                 goto err;
279         }
280         ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx);
281         if (ret < 0) {
282                 p = ERR_PTR(ret);
283                 goto err;
284         }
285         return q;
286 err:
287         dprintk("RPC:      gss_fill_context returning %ld\n", -PTR_ERR(p));
288         return p;
289 }
290
291
292 struct gss_upcall_msg {
293         atomic_t count;
294         uid_t   uid;
295         struct rpc_pipe_msg msg;
296         struct list_head list;
297         struct gss_auth *auth;
298         struct rpc_wait_queue rpc_waitqueue;
299         wait_queue_head_t waitqueue;
300         struct gss_cl_ctx *ctx;
301 };
302
303 static void
304 gss_release_msg(struct gss_upcall_msg *gss_msg)
305 {
306         if (!atomic_dec_and_test(&gss_msg->count))
307                 return;
308         BUG_ON(!list_empty(&gss_msg->list));
309         if (gss_msg->ctx != NULL)
310                 gss_put_ctx(gss_msg->ctx);
311         kfree(gss_msg);
312 }
313
314 static struct gss_upcall_msg *
315 __gss_find_upcall(struct gss_auth *gss_auth, uid_t uid)
316 {
317         struct gss_upcall_msg *pos;
318         list_for_each_entry(pos, &gss_auth->upcalls, list) {
319                 if (pos->uid != uid)
320                         continue;
321                 atomic_inc(&pos->count);
322                 dprintk("RPC:      gss_find_upcall found msg %p\n", pos);
323                 return pos;
324         }
325         dprintk("RPC:      gss_find_upcall found nothing\n");
326         return NULL;
327 }
328
329 /* Try to add a upcall to the pipefs queue.
330  * If an upcall owned by our uid already exists, then we return a reference
331  * to that upcall instead of adding the new upcall.
332  */
333 static inline struct gss_upcall_msg *
334 gss_add_msg(struct gss_auth *gss_auth, struct gss_upcall_msg *gss_msg)
335 {
336         struct gss_upcall_msg *old;
337
338         spin_lock(&gss_auth->lock);
339         old = __gss_find_upcall(gss_auth, gss_msg->uid);
340         if (old == NULL) {
341                 atomic_inc(&gss_msg->count);
342                 list_add(&gss_msg->list, &gss_auth->upcalls);
343         } else
344                 gss_msg = old;
345         spin_unlock(&gss_auth->lock);
346         return gss_msg;
347 }
348
349 static void
350 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
351 {
352         if (list_empty(&gss_msg->list))
353                 return;
354         list_del_init(&gss_msg->list);
355         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
356         wake_up_all(&gss_msg->waitqueue);
357         atomic_dec(&gss_msg->count);
358 }
359
360 static void
361 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
362 {
363         struct gss_auth *gss_auth = gss_msg->auth;
364
365         spin_lock(&gss_auth->lock);
366         __gss_unhash_msg(gss_msg);
367         spin_unlock(&gss_auth->lock);
368 }
369
370 static void
371 gss_upcall_callback(struct rpc_task *task)
372 {
373         struct gss_cred *gss_cred = container_of(task->tk_msg.rpc_cred,
374                         struct gss_cred, gc_base);
375         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
376
377         BUG_ON(gss_msg == NULL);
378         if (gss_msg->ctx)
379                 gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_get_ctx(gss_msg->ctx));
380         else
381                 task->tk_status = gss_msg->msg.errno;
382         spin_lock(&gss_msg->auth->lock);
383         gss_cred->gc_upcall = NULL;
384         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
385         spin_unlock(&gss_msg->auth->lock);
386         gss_release_msg(gss_msg);
387 }
388
389 static inline struct gss_upcall_msg *
390 gss_alloc_msg(struct gss_auth *gss_auth, uid_t uid)
391 {
392         struct gss_upcall_msg *gss_msg;
393
394         gss_msg = kmalloc(sizeof(*gss_msg), GFP_KERNEL);
395         if (gss_msg != NULL) {
396                 memset(gss_msg, 0, sizeof(*gss_msg));
397                 INIT_LIST_HEAD(&gss_msg->list);
398                 rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
399                 init_waitqueue_head(&gss_msg->waitqueue);
400                 atomic_set(&gss_msg->count, 1);
401                 gss_msg->msg.data = &gss_msg->uid;
402                 gss_msg->msg.len = sizeof(gss_msg->uid);
403                 gss_msg->uid = uid;
404                 gss_msg->auth = gss_auth;
405         }
406         return gss_msg;
407 }
408
409 static struct gss_upcall_msg *
410 gss_setup_upcall(struct rpc_clnt *clnt, struct gss_auth *gss_auth, struct rpc_cred *cred)
411 {
412         struct gss_upcall_msg *gss_new, *gss_msg;
413
414         gss_new = gss_alloc_msg(gss_auth, cred->cr_uid);
415         if (gss_new == NULL)
416                 return ERR_PTR(-ENOMEM);
417         gss_msg = gss_add_msg(gss_auth, gss_new);
418         if (gss_msg == gss_new) {
419                 int res = rpc_queue_upcall(gss_auth->dentry->d_inode, &gss_new->msg);
420                 if (res) {
421                         gss_unhash_msg(gss_new);
422                         gss_msg = ERR_PTR(res);
423                 }
424         } else
425                 gss_release_msg(gss_new);
426         return gss_msg;
427 }
428
429 static inline int
430 gss_refresh_upcall(struct rpc_task *task)
431 {
432         struct rpc_cred *cred = task->tk_msg.rpc_cred;
433         struct gss_auth *gss_auth = container_of(task->tk_client->cl_auth,
434                         struct gss_auth, rpc_auth);
435         struct gss_cred *gss_cred = container_of(cred,
436                         struct gss_cred, gc_base);
437         struct gss_upcall_msg *gss_msg;
438         int err = 0;
439
440         dprintk("RPC: %4u gss_refresh_upcall for uid %u\n", task->tk_pid, cred->cr_uid);
441         gss_msg = gss_setup_upcall(task->tk_client, gss_auth, cred);
442         if (IS_ERR(gss_msg)) {
443                 err = PTR_ERR(gss_msg);
444                 goto out;
445         }
446         spin_lock(&gss_auth->lock);
447         if (gss_cred->gc_upcall != NULL)
448                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL, NULL);
449         else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
450                 task->tk_timeout = 0;
451                 gss_cred->gc_upcall = gss_msg;
452                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
453                 atomic_inc(&gss_msg->count);
454                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback, NULL);
455         } else
456                 err = gss_msg->msg.errno;
457         spin_unlock(&gss_auth->lock);
458         gss_release_msg(gss_msg);
459 out:
460         dprintk("RPC: %4u gss_refresh_upcall for uid %u result %d\n", task->tk_pid,
461                         cred->cr_uid, err);
462         return err;
463 }
464
465 static inline int
466 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
467 {
468         struct rpc_cred *cred = &gss_cred->gc_base;
469         struct gss_upcall_msg *gss_msg;
470         DEFINE_WAIT(wait);
471         int err = 0;
472
473         dprintk("RPC: gss_upcall for uid %u\n", cred->cr_uid);
474         gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred);
475         if (IS_ERR(gss_msg)) {
476                 err = PTR_ERR(gss_msg);
477                 goto out;
478         }
479         for (;;) {
480                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_INTERRUPTIBLE);
481                 spin_lock(&gss_auth->lock);
482                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
483                         spin_unlock(&gss_auth->lock);
484                         break;
485                 }
486                 spin_unlock(&gss_auth->lock);
487                 if (signalled()) {
488                         err = -ERESTARTSYS;
489                         goto out_intr;
490                 }
491                 schedule();
492         }
493         if (gss_msg->ctx)
494                 gss_cred_set_ctx(cred, gss_get_ctx(gss_msg->ctx));
495         else
496                 err = gss_msg->msg.errno;
497 out_intr:
498         finish_wait(&gss_msg->waitqueue, &wait);
499         gss_release_msg(gss_msg);
500 out:
501         dprintk("RPC: gss_create_upcall for uid %u result %d\n", cred->cr_uid, err);
502         return err;
503 }
504
505 static ssize_t
506 gss_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
507                 char __user *dst, size_t buflen)
508 {
509         char *data = (char *)msg->data + msg->copied;
510         ssize_t mlen = msg->len;
511         ssize_t left;
512
513         if (mlen > buflen)
514                 mlen = buflen;
515         left = copy_to_user(dst, data, mlen);
516         if (left < 0) {
517                 msg->errno = left;
518                 return left;
519         }
520         mlen -= left;
521         msg->copied += mlen;
522         msg->errno = 0;
523         return mlen;
524 }
525
526 #define MSG_BUF_MAXSIZE 1024
527
528 static ssize_t
529 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
530 {
531         const void *p, *end;
532         void *buf;
533         struct rpc_clnt *clnt;
534         struct gss_auth *gss_auth;
535         struct rpc_cred *cred;
536         struct gss_upcall_msg *gss_msg;
537         struct gss_cl_ctx *ctx;
538         uid_t uid;
539         int err = -EFBIG;
540
541         if (mlen > MSG_BUF_MAXSIZE)
542                 goto out;
543         err = -ENOMEM;
544         buf = kmalloc(mlen, GFP_KERNEL);
545         if (!buf)
546                 goto out;
547
548         clnt = RPC_I(filp->f_dentry->d_inode)->private;
549         err = -EFAULT;
550         if (copy_from_user(buf, src, mlen))
551                 goto err;
552
553         end = (const void *)((char *)buf + mlen);
554         p = simple_get_bytes(buf, end, &uid, sizeof(uid));
555         if (IS_ERR(p)) {
556                 err = PTR_ERR(p);
557                 goto err;
558         }
559
560         err = -ENOMEM;
561         ctx = gss_alloc_context();
562         if (ctx == NULL)
563                 goto err;
564         err = 0;
565         gss_auth = container_of(clnt->cl_auth, struct gss_auth, rpc_auth);
566         p = gss_fill_context(p, end, ctx, gss_auth->mech);
567         if (IS_ERR(p)) {
568                 err = PTR_ERR(p);
569                 if (err != -EACCES)
570                         goto err_put_ctx;
571         }
572         spin_lock(&gss_auth->lock);
573         gss_msg = __gss_find_upcall(gss_auth, uid);
574         if (gss_msg) {
575                 if (err == 0 && gss_msg->ctx == NULL)
576                         gss_msg->ctx = gss_get_ctx(ctx);
577                 gss_msg->msg.errno = err;
578                 __gss_unhash_msg(gss_msg);
579                 spin_unlock(&gss_auth->lock);
580                 gss_release_msg(gss_msg);
581         } else {
582                 struct auth_cred acred = { .uid = uid };
583                 spin_unlock(&gss_auth->lock);
584                 cred = rpcauth_lookup_credcache(clnt->cl_auth, &acred, 0);
585                 if (IS_ERR(cred)) {
586                         err = PTR_ERR(cred);
587                         goto err_put_ctx;
588                 }
589                 gss_cred_set_ctx(cred, gss_get_ctx(ctx));
590         }
591         gss_put_ctx(ctx);
592         kfree(buf);
593         dprintk("RPC:      gss_pipe_downcall returning length %Zu\n", mlen);
594         return mlen;
595 err_put_ctx:
596         gss_put_ctx(ctx);
597 err:
598         kfree(buf);
599 out:
600         dprintk("RPC:      gss_pipe_downcall returning %d\n", err);
601         return err;
602 }
603
604 static void
605 gss_pipe_release(struct inode *inode)
606 {
607         struct rpc_inode *rpci = RPC_I(inode);
608         struct rpc_clnt *clnt;
609         struct rpc_auth *auth;
610         struct gss_auth *gss_auth;
611
612         clnt = rpci->private;
613         auth = clnt->cl_auth;
614         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
615         spin_lock(&gss_auth->lock);
616         while (!list_empty(&gss_auth->upcalls)) {
617                 struct gss_upcall_msg *gss_msg;
618
619                 gss_msg = list_entry(gss_auth->upcalls.next,
620                                 struct gss_upcall_msg, list);
621                 gss_msg->msg.errno = -EPIPE;
622                 atomic_inc(&gss_msg->count);
623                 __gss_unhash_msg(gss_msg);
624                 spin_unlock(&gss_auth->lock);
625                 gss_release_msg(gss_msg);
626                 spin_lock(&gss_auth->lock);
627         }
628         spin_unlock(&gss_auth->lock);
629 }
630
631 static void
632 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
633 {
634         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
635         static unsigned long ratelimit;
636
637         if (msg->errno < 0) {
638                 dprintk("RPC:      gss_pipe_destroy_msg releasing msg %p\n",
639                                 gss_msg);
640                 atomic_inc(&gss_msg->count);
641                 gss_unhash_msg(gss_msg);
642                 if (msg->errno == -ETIMEDOUT || msg->errno == -EPIPE) {
643                         unsigned long now = jiffies;
644                         if (time_after(now, ratelimit)) {
645                                 printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
646                                                     "Please check user daemon is running!\n");
647                                 ratelimit = now + 15*HZ;
648                         }
649                 }
650                 gss_release_msg(gss_msg);
651         }
652 }
653
654 /* 
655  * NOTE: we have the opportunity to use different 
656  * parameters based on the input flavor (which must be a pseudoflavor)
657  */
658 static struct rpc_auth *
659 gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
660 {
661         struct gss_auth *gss_auth;
662         struct rpc_auth * auth;
663         int err = -ENOMEM; /* XXX? */
664
665         dprintk("RPC:      creating GSS authenticator for client %p\n",clnt);
666
667         if (!try_module_get(THIS_MODULE))
668                 return ERR_PTR(err);
669         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
670                 goto out_dec;
671         gss_auth->client = clnt;
672         err = -EINVAL;
673         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
674         if (!gss_auth->mech) {
675                 printk(KERN_WARNING "%s: Pseudoflavor %d not found!",
676                                 __FUNCTION__, flavor);
677                 goto err_free;
678         }
679         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
680         if (gss_auth->service == 0)
681                 goto err_put_mech;
682         INIT_LIST_HEAD(&gss_auth->upcalls);
683         spin_lock_init(&gss_auth->lock);
684         auth = &gss_auth->rpc_auth;
685         auth->au_cslack = GSS_CRED_SLACK >> 2;
686         auth->au_rslack = GSS_VERF_SLACK >> 2;
687         auth->au_ops = &authgss_ops;
688         auth->au_flavor = flavor;
689         atomic_set(&auth->au_count, 1);
690
691         err = rpcauth_init_credcache(auth, GSS_CRED_EXPIRE);
692         if (err)
693                 goto err_put_mech;
694
695         snprintf(gss_auth->path, sizeof(gss_auth->path), "%s/%s",
696                         clnt->cl_pathname,
697                         gss_auth->mech->gm_name);
698         gss_auth->dentry = rpc_mkpipe(gss_auth->path, clnt, &gss_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
699         if (IS_ERR(gss_auth->dentry)) {
700                 err = PTR_ERR(gss_auth->dentry);
701                 goto err_put_mech;
702         }
703
704         return auth;
705 err_put_mech:
706         gss_mech_put(gss_auth->mech);
707 err_free:
708         kfree(gss_auth);
709 out_dec:
710         module_put(THIS_MODULE);
711         return ERR_PTR(err);
712 }
713
714 static void
715 gss_destroy(struct rpc_auth *auth)
716 {
717         struct gss_auth *gss_auth;
718
719         dprintk("RPC:      destroying GSS authenticator %p flavor %d\n",
720                 auth, auth->au_flavor);
721
722         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
723         rpc_unlink(gss_auth->path);
724         gss_mech_put(gss_auth->mech);
725
726         rpcauth_free_credcache(auth);
727         kfree(gss_auth);
728         module_put(THIS_MODULE);
729 }
730
731 /* gss_destroy_cred (and gss_destroy_ctx) are used to clean up after failure
732  * to create a new cred or context, so they check that things have been
733  * allocated before freeing them. */
734 static void
735 gss_destroy_ctx(struct gss_cl_ctx *ctx)
736 {
737         dprintk("RPC:      gss_destroy_ctx\n");
738
739         if (ctx->gc_gss_ctx)
740                 gss_delete_sec_context(&ctx->gc_gss_ctx);
741
742         kfree(ctx->gc_wire_ctx.data);
743         kfree(ctx);
744 }
745
746 static void
747 gss_destroy_cred(struct rpc_cred *rc)
748 {
749         struct gss_cred *cred = container_of(rc, struct gss_cred, gc_base);
750
751         dprintk("RPC:      gss_destroy_cred \n");
752
753         if (cred->gc_ctx)
754                 gss_put_ctx(cred->gc_ctx);
755         kfree(cred);
756 }
757
758 /*
759  * Lookup RPCSEC_GSS cred for the current process
760  */
761 static struct rpc_cred *
762 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int taskflags)
763 {
764         return rpcauth_lookup_credcache(auth, acred, taskflags);
765 }
766
767 static struct rpc_cred *
768 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int taskflags)
769 {
770         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
771         struct gss_cred *cred = NULL;
772         int err = -ENOMEM;
773
774         dprintk("RPC:      gss_create_cred for uid %d, flavor %d\n",
775                 acred->uid, auth->au_flavor);
776
777         if (!(cred = kmalloc(sizeof(*cred), GFP_KERNEL)))
778                 goto out_err;
779
780         memset(cred, 0, sizeof(*cred));
781         atomic_set(&cred->gc_count, 1);
782         cred->gc_uid = acred->uid;
783         /*
784          * Note: in order to force a call to call_refresh(), we deliberately
785          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
786          */
787         cred->gc_flags = 0;
788         cred->gc_base.cr_ops = &gss_credops;
789         cred->gc_service = gss_auth->service;
790         err = gss_create_upcall(gss_auth, cred);
791         if (err < 0)
792                 goto out_err;
793
794         return &cred->gc_base;
795
796 out_err:
797         dprintk("RPC:      gss_create_cred failed with error %d\n", err);
798         if (cred) gss_destroy_cred(&cred->gc_base);
799         return ERR_PTR(err);
800 }
801
802 static int
803 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int taskflags)
804 {
805         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
806
807         /* Don't match with creds that have expired. */
808         if (gss_cred->gc_ctx && time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
809                 return 0;
810         return (rc->cr_uid == acred->uid);
811 }
812
813 /*
814 * Marshal credentials.
815 * Maybe we should keep a cached credential for performance reasons.
816 */
817 static u32 *
818 gss_marshal(struct rpc_task *task, u32 *p)
819 {
820         struct rpc_cred *cred = task->tk_msg.rpc_cred;
821         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
822                                                  gc_base);
823         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
824         u32             *cred_len;
825         struct rpc_rqst *req = task->tk_rqstp;
826         u32             maj_stat = 0;
827         struct xdr_netobj mic;
828         struct kvec     iov;
829         struct xdr_buf  verf_buf;
830
831         dprintk("RPC: %4u gss_marshal\n", task->tk_pid);
832
833         *p++ = htonl(RPC_AUTH_GSS);
834         cred_len = p++;
835
836         spin_lock(&ctx->gc_seq_lock);
837         req->rq_seqno = ctx->gc_seq++;
838         spin_unlock(&ctx->gc_seq_lock);
839
840         *p++ = htonl((u32) RPC_GSS_VERSION);
841         *p++ = htonl((u32) ctx->gc_proc);
842         *p++ = htonl((u32) req->rq_seqno);
843         *p++ = htonl((u32) gss_cred->gc_service);
844         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
845         *cred_len = htonl((p - (cred_len + 1)) << 2);
846
847         /* We compute the checksum for the verifier over the xdr-encoded bytes
848          * starting with the xid and ending at the end of the credential: */
849         iov.iov_base = req->rq_snd_buf.head[0].iov_base;
850         if (task->tk_client->cl_xprt->stream)
851                 /* See clnt.c:call_header() */
852                 iov.iov_base += 4;
853         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
854         xdr_buf_from_iov(&iov, &verf_buf);
855
856         /* set verifier flavor*/
857         *p++ = htonl(RPC_AUTH_GSS);
858
859         mic.data = (u8 *)(p + 1);
860         maj_stat = gss_get_mic(ctx->gc_gss_ctx,
861                                GSS_C_QOP_DEFAULT, 
862                                &verf_buf, &mic);
863         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
864                 cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
865         } else if (maj_stat != 0) {
866                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
867                 goto out_put_ctx;
868         }
869         p = xdr_encode_opaque(p, NULL, mic.len);
870         gss_put_ctx(ctx);
871         return p;
872 out_put_ctx:
873         gss_put_ctx(ctx);
874         return NULL;
875 }
876
877 /*
878 * Refresh credentials. XXX - finish
879 */
880 static int
881 gss_refresh(struct rpc_task *task)
882 {
883
884         if (!gss_cred_is_uptodate_ctx(task->tk_msg.rpc_cred))
885                 return gss_refresh_upcall(task);
886         return 0;
887 }
888
889 static u32 *
890 gss_validate(struct rpc_task *task, u32 *p)
891 {
892         struct rpc_cred *cred = task->tk_msg.rpc_cred;
893         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
894                                                 gc_base);
895         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
896         u32             seq, qop_state;
897         struct kvec     iov;
898         struct xdr_buf  verf_buf;
899         struct xdr_netobj mic;
900         u32             flav,len;
901         u32             maj_stat;
902
903         dprintk("RPC: %4u gss_validate\n", task->tk_pid);
904
905         flav = ntohl(*p++);
906         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
907                 goto out_bad;
908         if (flav != RPC_AUTH_GSS)
909                 goto out_bad;
910         seq = htonl(task->tk_rqstp->rq_seqno);
911         iov.iov_base = &seq;
912         iov.iov_len = sizeof(seq);
913         xdr_buf_from_iov(&iov, &verf_buf);
914         mic.data = (u8 *)p;
915         mic.len = len;
916
917         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic, &qop_state);
918         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
919                 cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
920         if (maj_stat)
921                 goto out_bad;
922        switch (gss_cred->gc_service) {
923        case RPC_GSS_SVC_NONE:
924                /* verifier data, flavor, length: */
925                task->tk_auth->au_rslack = XDR_QUADLEN(len) + 2;
926                break;
927        case RPC_GSS_SVC_INTEGRITY:
928                /* verifier data, flavor, length, length, sequence number: */
929                task->tk_auth->au_rslack = XDR_QUADLEN(len) + 4;
930                break;
931        case RPC_GSS_SVC_PRIVACY:
932                goto out_bad;
933        }
934         gss_put_ctx(ctx);
935         dprintk("RPC: %4u GSS gss_validate: gss_verify_mic succeeded.\n",
936                         task->tk_pid);
937         return p + XDR_QUADLEN(len);
938 out_bad:
939         gss_put_ctx(ctx);
940         dprintk("RPC: %4u gss_validate failed.\n", task->tk_pid);
941         return NULL;
942 }
943
944 static inline int
945 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
946                 kxdrproc_t encode, struct rpc_rqst *rqstp, u32 *p, void *obj)
947 {
948         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
949         struct xdr_buf  integ_buf;
950         u32             *integ_len = NULL;
951         struct xdr_netobj mic;
952         u32             offset, *q;
953         struct kvec     *iov;
954         u32             maj_stat = 0;
955         int             status = -EIO;
956
957         integ_len = p++;
958         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
959         *p++ = htonl(rqstp->rq_seqno);
960
961         status = encode(rqstp, p, obj);
962         if (status)
963                 return status;
964
965         if (xdr_buf_subsegment(snd_buf, &integ_buf,
966                                 offset, snd_buf->len - offset))
967                 return status;
968         *integ_len = htonl(integ_buf.len);
969
970         /* guess whether we're in the head or the tail: */
971         if (snd_buf->page_len || snd_buf->tail[0].iov_len) 
972                 iov = snd_buf->tail;
973         else
974                 iov = snd_buf->head;
975         p = iov->iov_base + iov->iov_len;
976         mic.data = (u8 *)(p + 1);
977
978         maj_stat = gss_get_mic(ctx->gc_gss_ctx,
979                         GSS_C_QOP_DEFAULT, &integ_buf, &mic);
980         status = -EIO; /* XXX? */
981         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
982                 cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
983         else if (maj_stat)
984                 return status;
985         q = xdr_encode_opaque(p, NULL, mic.len);
986
987         offset = (u8 *)q - (u8 *)p;
988         iov->iov_len += offset;
989         snd_buf->len += offset;
990         return 0;
991 }
992
993 static int
994 gss_wrap_req(struct rpc_task *task,
995              kxdrproc_t encode, void *rqstp, u32 *p, void *obj)
996 {
997         struct rpc_cred *cred = task->tk_msg.rpc_cred;
998         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
999                         gc_base);
1000         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1001         int             status = -EIO;
1002
1003         dprintk("RPC: %4u gss_wrap_req\n", task->tk_pid);
1004         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1005                 /* The spec seems a little ambiguous here, but I think that not
1006                  * wrapping context destruction requests makes the most sense.
1007                  */
1008                 status = encode(rqstp, p, obj);
1009                 goto out;
1010         }
1011         switch (gss_cred->gc_service) {
1012                 case RPC_GSS_SVC_NONE:
1013                         status = encode(rqstp, p, obj);
1014                         break;
1015                 case RPC_GSS_SVC_INTEGRITY:
1016                         status = gss_wrap_req_integ(cred, ctx, encode,
1017                                                                 rqstp, p, obj);
1018                         break;
1019                 case RPC_GSS_SVC_PRIVACY:
1020                         break;
1021         }
1022 out:
1023         gss_put_ctx(ctx);
1024         dprintk("RPC: %4u gss_wrap_req returning %d\n", task->tk_pid, status);
1025         return status;
1026 }
1027
1028 static inline int
1029 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1030                 struct rpc_rqst *rqstp, u32 **p)
1031 {
1032         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1033         struct xdr_buf integ_buf;
1034         struct xdr_netobj mic;
1035         u32 data_offset, mic_offset;
1036         u32 integ_len;
1037         u32 maj_stat;
1038         int status = -EIO;
1039
1040         integ_len = ntohl(*(*p)++);
1041         if (integ_len & 3)
1042                 return status;
1043         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1044         mic_offset = integ_len + data_offset;
1045         if (mic_offset > rcv_buf->len)
1046                 return status;
1047         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1048                 return status;
1049
1050         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1051                                 mic_offset - data_offset))
1052                 return status;
1053
1054         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1055                 return status;
1056
1057         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf,
1058                         &mic, NULL);
1059         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1060                 cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
1061         if (maj_stat != GSS_S_COMPLETE)
1062                 return status;
1063         return 0;
1064 }
1065
1066 static int
1067 gss_unwrap_resp(struct rpc_task *task,
1068                 kxdrproc_t decode, void *rqstp, u32 *p, void *obj)
1069 {
1070         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1071         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1072                         gc_base);
1073         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1074         int             status = -EIO;
1075
1076         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1077                 goto out_decode;
1078         switch (gss_cred->gc_service) {
1079                 case RPC_GSS_SVC_NONE:
1080                         break;
1081                 case RPC_GSS_SVC_INTEGRITY:
1082                         status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1083                         if (status)
1084                                 goto out;
1085                         break;
1086                 case RPC_GSS_SVC_PRIVACY:
1087                         break;
1088         }
1089 out_decode:
1090         status = decode(rqstp, p, obj);
1091 out:
1092         gss_put_ctx(ctx);
1093         dprintk("RPC: %4u gss_unwrap_resp returning %d\n", task->tk_pid,
1094                         status);
1095         return status;
1096 }
1097   
1098 static struct rpc_authops authgss_ops = {
1099         .owner          = THIS_MODULE,
1100         .au_flavor      = RPC_AUTH_GSS,
1101 #ifdef RPC_DEBUG
1102         .au_name        = "RPCSEC_GSS",
1103 #endif
1104         .create         = gss_create,
1105         .destroy        = gss_destroy,
1106         .lookup_cred    = gss_lookup_cred,
1107         .crcreate       = gss_create_cred
1108 };
1109
1110 static struct rpc_credops gss_credops = {
1111         .cr_name        = "AUTH_GSS",
1112         .crdestroy      = gss_destroy_cred,
1113         .crmatch        = gss_match,
1114         .crmarshal      = gss_marshal,
1115         .crrefresh      = gss_refresh,
1116         .crvalidate     = gss_validate,
1117         .crwrap_req     = gss_wrap_req,
1118         .crunwrap_resp  = gss_unwrap_resp,
1119 };
1120
1121 static struct rpc_pipe_ops gss_upcall_ops = {
1122         .upcall         = gss_pipe_upcall,
1123         .downcall       = gss_pipe_downcall,
1124         .destroy_msg    = gss_pipe_destroy_msg,
1125         .release_pipe   = gss_pipe_release,
1126 };
1127
1128 /*
1129  * Initialize RPCSEC_GSS module
1130  */
1131 static int __init init_rpcsec_gss(void)
1132 {
1133         int err = 0;
1134
1135         err = rpcauth_register(&authgss_ops);
1136         if (err)
1137                 goto out;
1138         err = gss_svc_init();
1139         if (err)
1140                 goto out_unregister;
1141         return 0;
1142 out_unregister:
1143         rpcauth_unregister(&authgss_ops);
1144 out:
1145         return err;
1146 }
1147
1148 static void __exit exit_rpcsec_gss(void)
1149 {
1150         gss_svc_shutdown();
1151         rpcauth_unregister(&authgss_ops);
1152 }
1153
1154 MODULE_LICENSE("GPL");
1155 module_init(init_rpcsec_gss)
1156 module_exit(exit_rpcsec_gss)