libceph: fix socket write error handling
[linux-2.6.git] / net / ceph / auth_x.c
1
2 #include <linux/ceph/ceph_debug.h>
3
4 #include <linux/err.h>
5 #include <linux/module.h>
6 #include <linux/random.h>
7 #include <linux/slab.h>
8
9 #include <linux/ceph/decode.h>
10 #include <linux/ceph/auth.h>
11
12 #include "crypto.h"
13 #include "auth_x.h"
14 #include "auth_x_protocol.h"
15
16 #define TEMP_TICKET_BUF_LEN     256
17
18 static void ceph_x_validate_tickets(struct ceph_auth_client *ac, int *pneed);
19
20 static int ceph_x_is_authenticated(struct ceph_auth_client *ac)
21 {
22         struct ceph_x_info *xi = ac->private;
23         int need;
24
25         ceph_x_validate_tickets(ac, &need);
26         dout("ceph_x_is_authenticated want=%d need=%d have=%d\n",
27              ac->want_keys, need, xi->have_keys);
28         return (ac->want_keys & xi->have_keys) == ac->want_keys;
29 }
30
31 static int ceph_x_should_authenticate(struct ceph_auth_client *ac)
32 {
33         struct ceph_x_info *xi = ac->private;
34         int need;
35
36         ceph_x_validate_tickets(ac, &need);
37         dout("ceph_x_should_authenticate want=%d need=%d have=%d\n",
38              ac->want_keys, need, xi->have_keys);
39         return need != 0;
40 }
41
42 static int ceph_x_encrypt_buflen(int ilen)
43 {
44         return sizeof(struct ceph_x_encrypt_header) + ilen + 16 +
45                 sizeof(u32);
46 }
47
48 static int ceph_x_encrypt(struct ceph_crypto_key *secret,
49                           void *ibuf, int ilen, void *obuf, size_t olen)
50 {
51         struct ceph_x_encrypt_header head = {
52                 .struct_v = 1,
53                 .magic = cpu_to_le64(CEPHX_ENC_MAGIC)
54         };
55         size_t len = olen - sizeof(u32);
56         int ret;
57
58         ret = ceph_encrypt2(secret, obuf + sizeof(u32), &len,
59                             &head, sizeof(head), ibuf, ilen);
60         if (ret)
61                 return ret;
62         ceph_encode_32(&obuf, len);
63         return len + sizeof(u32);
64 }
65
66 static int ceph_x_decrypt(struct ceph_crypto_key *secret,
67                           void **p, void *end, void *obuf, size_t olen)
68 {
69         struct ceph_x_encrypt_header head;
70         size_t head_len = sizeof(head);
71         int len, ret;
72
73         len = ceph_decode_32(p);
74         if (*p + len > end)
75                 return -EINVAL;
76
77         dout("ceph_x_decrypt len %d\n", len);
78         ret = ceph_decrypt2(secret, &head, &head_len, obuf, &olen,
79                             *p, len);
80         if (ret)
81                 return ret;
82         if (head.struct_v != 1 || le64_to_cpu(head.magic) != CEPHX_ENC_MAGIC)
83                 return -EPERM;
84         *p += len;
85         return olen;
86 }
87
88 /*
89  * get existing (or insert new) ticket handler
90  */
91 static struct ceph_x_ticket_handler *
92 get_ticket_handler(struct ceph_auth_client *ac, int service)
93 {
94         struct ceph_x_ticket_handler *th;
95         struct ceph_x_info *xi = ac->private;
96         struct rb_node *parent = NULL, **p = &xi->ticket_handlers.rb_node;
97
98         while (*p) {
99                 parent = *p;
100                 th = rb_entry(parent, struct ceph_x_ticket_handler, node);
101                 if (service < th->service)
102                         p = &(*p)->rb_left;
103                 else if (service > th->service)
104                         p = &(*p)->rb_right;
105                 else
106                         return th;
107         }
108
109         /* add it */
110         th = kzalloc(sizeof(*th), GFP_NOFS);
111         if (!th)
112                 return ERR_PTR(-ENOMEM);
113         th->service = service;
114         rb_link_node(&th->node, parent, p);
115         rb_insert_color(&th->node, &xi->ticket_handlers);
116         return th;
117 }
118
119 static void remove_ticket_handler(struct ceph_auth_client *ac,
120                                   struct ceph_x_ticket_handler *th)
121 {
122         struct ceph_x_info *xi = ac->private;
123
124         dout("remove_ticket_handler %p %d\n", th, th->service);
125         rb_erase(&th->node, &xi->ticket_handlers);
126         ceph_crypto_key_destroy(&th->session_key);
127         if (th->ticket_blob)
128                 ceph_buffer_put(th->ticket_blob);
129         kfree(th);
130 }
131
132 static int ceph_x_proc_ticket_reply(struct ceph_auth_client *ac,
133                                     struct ceph_crypto_key *secret,
134                                     void *buf, void *end)
135 {
136         struct ceph_x_info *xi = ac->private;
137         int num;
138         void *p = buf;
139         int ret;
140         char *dbuf;
141         char *ticket_buf;
142         u8 reply_struct_v;
143
144         dbuf = kmalloc(TEMP_TICKET_BUF_LEN, GFP_NOFS);
145         if (!dbuf)
146                 return -ENOMEM;
147
148         ret = -ENOMEM;
149         ticket_buf = kmalloc(TEMP_TICKET_BUF_LEN, GFP_NOFS);
150         if (!ticket_buf)
151                 goto out_dbuf;
152
153         ceph_decode_need(&p, end, 1 + sizeof(u32), bad);
154         reply_struct_v = ceph_decode_8(&p);
155         if (reply_struct_v != 1)
156                 goto bad;
157         num = ceph_decode_32(&p);
158         dout("%d tickets\n", num);
159         while (num--) {
160                 int type;
161                 u8 tkt_struct_v, blob_struct_v;
162                 struct ceph_x_ticket_handler *th;
163                 void *dp, *dend;
164                 int dlen;
165                 char is_enc;
166                 struct timespec validity;
167                 struct ceph_crypto_key old_key;
168                 void *tp, *tpend;
169                 struct ceph_timespec new_validity;
170                 struct ceph_crypto_key new_session_key;
171                 struct ceph_buffer *new_ticket_blob;
172                 unsigned long new_expires, new_renew_after;
173                 u64 new_secret_id;
174
175                 ceph_decode_need(&p, end, sizeof(u32) + 1, bad);
176
177                 type = ceph_decode_32(&p);
178                 dout(" ticket type %d %s\n", type, ceph_entity_type_name(type));
179
180                 tkt_struct_v = ceph_decode_8(&p);
181                 if (tkt_struct_v != 1)
182                         goto bad;
183
184                 th = get_ticket_handler(ac, type);
185                 if (IS_ERR(th)) {
186                         ret = PTR_ERR(th);
187                         goto out;
188                 }
189
190                 /* blob for me */
191                 dlen = ceph_x_decrypt(secret, &p, end, dbuf,
192                                       TEMP_TICKET_BUF_LEN);
193                 if (dlen <= 0) {
194                         ret = dlen;
195                         goto out;
196                 }
197                 dout(" decrypted %d bytes\n", dlen);
198                 dend = dbuf + dlen;
199                 dp = dbuf;
200
201                 tkt_struct_v = ceph_decode_8(&dp);
202                 if (tkt_struct_v != 1)
203                         goto bad;
204
205                 memcpy(&old_key, &th->session_key, sizeof(old_key));
206                 ret = ceph_crypto_key_decode(&new_session_key, &dp, dend);
207                 if (ret)
208                         goto out;
209
210                 ceph_decode_copy(&dp, &new_validity, sizeof(new_validity));
211                 ceph_decode_timespec(&validity, &new_validity);
212                 new_expires = get_seconds() + validity.tv_sec;
213                 new_renew_after = new_expires - (validity.tv_sec / 4);
214                 dout(" expires=%lu renew_after=%lu\n", new_expires,
215                      new_renew_after);
216
217                 /* ticket blob for service */
218                 ceph_decode_8_safe(&p, end, is_enc, bad);
219                 tp = ticket_buf;
220                 if (is_enc) {
221                         /* encrypted */
222                         dout(" encrypted ticket\n");
223                         dlen = ceph_x_decrypt(&old_key, &p, end, ticket_buf,
224                                               TEMP_TICKET_BUF_LEN);
225                         if (dlen < 0) {
226                                 ret = dlen;
227                                 goto out;
228                         }
229                         dlen = ceph_decode_32(&tp);
230                 } else {
231                         /* unencrypted */
232                         ceph_decode_32_safe(&p, end, dlen, bad);
233                         ceph_decode_need(&p, end, dlen, bad);
234                         ceph_decode_copy(&p, ticket_buf, dlen);
235                 }
236                 tpend = tp + dlen;
237                 dout(" ticket blob is %d bytes\n", dlen);
238                 ceph_decode_need(&tp, tpend, 1 + sizeof(u64), bad);
239                 blob_struct_v = ceph_decode_8(&tp);
240                 new_secret_id = ceph_decode_64(&tp);
241                 ret = ceph_decode_buffer(&new_ticket_blob, &tp, tpend);
242                 if (ret)
243                         goto out;
244
245                 /* all is well, update our ticket */
246                 ceph_crypto_key_destroy(&th->session_key);
247                 if (th->ticket_blob)
248                         ceph_buffer_put(th->ticket_blob);
249                 th->session_key = new_session_key;
250                 th->ticket_blob = new_ticket_blob;
251                 th->validity = new_validity;
252                 th->secret_id = new_secret_id;
253                 th->expires = new_expires;
254                 th->renew_after = new_renew_after;
255                 dout(" got ticket service %d (%s) secret_id %lld len %d\n",
256                      type, ceph_entity_type_name(type), th->secret_id,
257                      (int)th->ticket_blob->vec.iov_len);
258                 xi->have_keys |= th->service;
259         }
260
261         ret = 0;
262 out:
263         kfree(ticket_buf);
264 out_dbuf:
265         kfree(dbuf);
266         return ret;
267
268 bad:
269         ret = -EINVAL;
270         goto out;
271 }
272
273 static int ceph_x_build_authorizer(struct ceph_auth_client *ac,
274                                    struct ceph_x_ticket_handler *th,
275                                    struct ceph_x_authorizer *au)
276 {
277         int maxlen;
278         struct ceph_x_authorize_a *msg_a;
279         struct ceph_x_authorize_b msg_b;
280         void *p, *end;
281         int ret;
282         int ticket_blob_len =
283                 (th->ticket_blob ? th->ticket_blob->vec.iov_len : 0);
284
285         dout("build_authorizer for %s %p\n",
286              ceph_entity_type_name(th->service), au);
287
288         maxlen = sizeof(*msg_a) + sizeof(msg_b) +
289                 ceph_x_encrypt_buflen(ticket_blob_len);
290         dout("  need len %d\n", maxlen);
291         if (au->buf && au->buf->alloc_len < maxlen) {
292                 ceph_buffer_put(au->buf);
293                 au->buf = NULL;
294         }
295         if (!au->buf) {
296                 au->buf = ceph_buffer_new(maxlen, GFP_NOFS);
297                 if (!au->buf)
298                         return -ENOMEM;
299         }
300         au->service = th->service;
301
302         msg_a = au->buf->vec.iov_base;
303         msg_a->struct_v = 1;
304         msg_a->global_id = cpu_to_le64(ac->global_id);
305         msg_a->service_id = cpu_to_le32(th->service);
306         msg_a->ticket_blob.struct_v = 1;
307         msg_a->ticket_blob.secret_id = cpu_to_le64(th->secret_id);
308         msg_a->ticket_blob.blob_len = cpu_to_le32(ticket_blob_len);
309         if (ticket_blob_len) {
310                 memcpy(msg_a->ticket_blob.blob, th->ticket_blob->vec.iov_base,
311                        th->ticket_blob->vec.iov_len);
312         }
313         dout(" th %p secret_id %lld %lld\n", th, th->secret_id,
314              le64_to_cpu(msg_a->ticket_blob.secret_id));
315
316         p = msg_a + 1;
317         p += ticket_blob_len;
318         end = au->buf->vec.iov_base + au->buf->vec.iov_len;
319
320         get_random_bytes(&au->nonce, sizeof(au->nonce));
321         msg_b.struct_v = 1;
322         msg_b.nonce = cpu_to_le64(au->nonce);
323         ret = ceph_x_encrypt(&th->session_key, &msg_b, sizeof(msg_b),
324                              p, end - p);
325         if (ret < 0)
326                 goto out_buf;
327         p += ret;
328         au->buf->vec.iov_len = p - au->buf->vec.iov_base;
329         dout(" built authorizer nonce %llx len %d\n", au->nonce,
330              (int)au->buf->vec.iov_len);
331         BUG_ON(au->buf->vec.iov_len > maxlen);
332         return 0;
333
334 out_buf:
335         ceph_buffer_put(au->buf);
336         au->buf = NULL;
337         return ret;
338 }
339
340 static int ceph_x_encode_ticket(struct ceph_x_ticket_handler *th,
341                                 void **p, void *end)
342 {
343         ceph_decode_need(p, end, 1 + sizeof(u64), bad);
344         ceph_encode_8(p, 1);
345         ceph_encode_64(p, th->secret_id);
346         if (th->ticket_blob) {
347                 const char *buf = th->ticket_blob->vec.iov_base;
348                 u32 len = th->ticket_blob->vec.iov_len;
349
350                 ceph_encode_32_safe(p, end, len, bad);
351                 ceph_encode_copy_safe(p, end, buf, len, bad);
352         } else {
353                 ceph_encode_32_safe(p, end, 0, bad);
354         }
355
356         return 0;
357 bad:
358         return -ERANGE;
359 }
360
361 static void ceph_x_validate_tickets(struct ceph_auth_client *ac, int *pneed)
362 {
363         int want = ac->want_keys;
364         struct ceph_x_info *xi = ac->private;
365         int service;
366
367         *pneed = ac->want_keys & ~(xi->have_keys);
368
369         for (service = 1; service <= want; service <<= 1) {
370                 struct ceph_x_ticket_handler *th;
371
372                 if (!(ac->want_keys & service))
373                         continue;
374
375                 if (*pneed & service)
376                         continue;
377
378                 th = get_ticket_handler(ac, service);
379
380                 if (IS_ERR(th)) {
381                         *pneed |= service;
382                         continue;
383                 }
384
385                 if (get_seconds() >= th->renew_after)
386                         *pneed |= service;
387                 if (get_seconds() >= th->expires)
388                         xi->have_keys &= ~service;
389         }
390 }
391
392
393 static int ceph_x_build_request(struct ceph_auth_client *ac,
394                                 void *buf, void *end)
395 {
396         struct ceph_x_info *xi = ac->private;
397         int need;
398         struct ceph_x_request_header *head = buf;
399         int ret;
400         struct ceph_x_ticket_handler *th =
401                 get_ticket_handler(ac, CEPH_ENTITY_TYPE_AUTH);
402
403         if (IS_ERR(th))
404                 return PTR_ERR(th);
405
406         ceph_x_validate_tickets(ac, &need);
407
408         dout("build_request want %x have %x need %x\n",
409              ac->want_keys, xi->have_keys, need);
410
411         if (need & CEPH_ENTITY_TYPE_AUTH) {
412                 struct ceph_x_authenticate *auth = (void *)(head + 1);
413                 void *p = auth + 1;
414                 struct ceph_x_challenge_blob tmp;
415                 char tmp_enc[40];
416                 u64 *u;
417
418                 if (p > end)
419                         return -ERANGE;
420
421                 dout(" get_auth_session_key\n");
422                 head->op = cpu_to_le16(CEPHX_GET_AUTH_SESSION_KEY);
423
424                 /* encrypt and hash */
425                 get_random_bytes(&auth->client_challenge, sizeof(u64));
426                 tmp.client_challenge = auth->client_challenge;
427                 tmp.server_challenge = cpu_to_le64(xi->server_challenge);
428                 ret = ceph_x_encrypt(&xi->secret, &tmp, sizeof(tmp),
429                                      tmp_enc, sizeof(tmp_enc));
430                 if (ret < 0)
431                         return ret;
432
433                 auth->struct_v = 1;
434                 auth->key = 0;
435                 for (u = (u64 *)tmp_enc; u + 1 <= (u64 *)(tmp_enc + ret); u++)
436                         auth->key ^= *(__le64 *)u;
437                 dout(" server_challenge %llx client_challenge %llx key %llx\n",
438                      xi->server_challenge, le64_to_cpu(auth->client_challenge),
439                      le64_to_cpu(auth->key));
440
441                 /* now encode the old ticket if exists */
442                 ret = ceph_x_encode_ticket(th, &p, end);
443                 if (ret < 0)
444                         return ret;
445
446                 return p - buf;
447         }
448
449         if (need) {
450                 void *p = head + 1;
451                 struct ceph_x_service_ticket_request *req;
452
453                 if (p > end)
454                         return -ERANGE;
455                 head->op = cpu_to_le16(CEPHX_GET_PRINCIPAL_SESSION_KEY);
456
457                 ret = ceph_x_build_authorizer(ac, th, &xi->auth_authorizer);
458                 if (ret)
459                         return ret;
460                 ceph_encode_copy(&p, xi->auth_authorizer.buf->vec.iov_base,
461                                  xi->auth_authorizer.buf->vec.iov_len);
462
463                 req = p;
464                 req->keys = cpu_to_le32(need);
465                 p += sizeof(*req);
466                 return p - buf;
467         }
468
469         return 0;
470 }
471
472 static int ceph_x_handle_reply(struct ceph_auth_client *ac, int result,
473                                void *buf, void *end)
474 {
475         struct ceph_x_info *xi = ac->private;
476         struct ceph_x_reply_header *head = buf;
477         struct ceph_x_ticket_handler *th;
478         int len = end - buf;
479         int op;
480         int ret;
481
482         if (result)
483                 return result;  /* XXX hmm? */
484
485         if (xi->starting) {
486                 /* it's a hello */
487                 struct ceph_x_server_challenge *sc = buf;
488
489                 if (len != sizeof(*sc))
490                         return -EINVAL;
491                 xi->server_challenge = le64_to_cpu(sc->server_challenge);
492                 dout("handle_reply got server challenge %llx\n",
493                      xi->server_challenge);
494                 xi->starting = false;
495                 xi->have_keys &= ~CEPH_ENTITY_TYPE_AUTH;
496                 return -EAGAIN;
497         }
498
499         op = le16_to_cpu(head->op);
500         result = le32_to_cpu(head->result);
501         dout("handle_reply op %d result %d\n", op, result);
502         switch (op) {
503         case CEPHX_GET_AUTH_SESSION_KEY:
504                 /* verify auth key */
505                 ret = ceph_x_proc_ticket_reply(ac, &xi->secret,
506                                                buf + sizeof(*head), end);
507                 break;
508
509         case CEPHX_GET_PRINCIPAL_SESSION_KEY:
510                 th = get_ticket_handler(ac, CEPH_ENTITY_TYPE_AUTH);
511                 if (IS_ERR(th))
512                         return PTR_ERR(th);
513                 ret = ceph_x_proc_ticket_reply(ac, &th->session_key,
514                                                buf + sizeof(*head), end);
515                 break;
516
517         default:
518                 return -EINVAL;
519         }
520         if (ret)
521                 return ret;
522         if (ac->want_keys == xi->have_keys)
523                 return 0;
524         return -EAGAIN;
525 }
526
527 static int ceph_x_create_authorizer(
528         struct ceph_auth_client *ac, int peer_type,
529         struct ceph_authorizer **a,
530         void **buf, size_t *len,
531         void **reply_buf, size_t *reply_len)
532 {
533         struct ceph_x_authorizer *au;
534         struct ceph_x_ticket_handler *th;
535         int ret;
536
537         th = get_ticket_handler(ac, peer_type);
538         if (IS_ERR(th))
539                 return PTR_ERR(th);
540
541         au = kzalloc(sizeof(*au), GFP_NOFS);
542         if (!au)
543                 return -ENOMEM;
544
545         ret = ceph_x_build_authorizer(ac, th, au);
546         if (ret) {
547                 kfree(au);
548                 return ret;
549         }
550
551         *a = (struct ceph_authorizer *)au;
552         *buf = au->buf->vec.iov_base;
553         *len = au->buf->vec.iov_len;
554         *reply_buf = au->reply_buf;
555         *reply_len = sizeof(au->reply_buf);
556         return 0;
557 }
558
559 static int ceph_x_verify_authorizer_reply(struct ceph_auth_client *ac,
560                                           struct ceph_authorizer *a, size_t len)
561 {
562         struct ceph_x_authorizer *au = (void *)a;
563         struct ceph_x_ticket_handler *th;
564         int ret = 0;
565         struct ceph_x_authorize_reply reply;
566         void *p = au->reply_buf;
567         void *end = p + sizeof(au->reply_buf);
568
569         th = get_ticket_handler(ac, au->service);
570         if (IS_ERR(th))
571                 return PTR_ERR(th);
572         ret = ceph_x_decrypt(&th->session_key, &p, end, &reply, sizeof(reply));
573         if (ret < 0)
574                 return ret;
575         if (ret != sizeof(reply))
576                 return -EPERM;
577
578         if (au->nonce + 1 != le64_to_cpu(reply.nonce_plus_one))
579                 ret = -EPERM;
580         else
581                 ret = 0;
582         dout("verify_authorizer_reply nonce %llx got %llx ret %d\n",
583              au->nonce, le64_to_cpu(reply.nonce_plus_one), ret);
584         return ret;
585 }
586
587 static void ceph_x_destroy_authorizer(struct ceph_auth_client *ac,
588                                       struct ceph_authorizer *a)
589 {
590         struct ceph_x_authorizer *au = (void *)a;
591
592         ceph_buffer_put(au->buf);
593         kfree(au);
594 }
595
596
597 static void ceph_x_reset(struct ceph_auth_client *ac)
598 {
599         struct ceph_x_info *xi = ac->private;
600
601         dout("reset\n");
602         xi->starting = true;
603         xi->server_challenge = 0;
604 }
605
606 static void ceph_x_destroy(struct ceph_auth_client *ac)
607 {
608         struct ceph_x_info *xi = ac->private;
609         struct rb_node *p;
610
611         dout("ceph_x_destroy %p\n", ac);
612         ceph_crypto_key_destroy(&xi->secret);
613
614         while ((p = rb_first(&xi->ticket_handlers)) != NULL) {
615                 struct ceph_x_ticket_handler *th =
616                         rb_entry(p, struct ceph_x_ticket_handler, node);
617                 remove_ticket_handler(ac, th);
618         }
619
620         if (xi->auth_authorizer.buf)
621                 ceph_buffer_put(xi->auth_authorizer.buf);
622
623         kfree(ac->private);
624         ac->private = NULL;
625 }
626
627 static void ceph_x_invalidate_authorizer(struct ceph_auth_client *ac,
628                                    int peer_type)
629 {
630         struct ceph_x_ticket_handler *th;
631
632         th = get_ticket_handler(ac, peer_type);
633         if (!IS_ERR(th))
634                 remove_ticket_handler(ac, th);
635 }
636
637
638 static const struct ceph_auth_client_ops ceph_x_ops = {
639         .name = "x",
640         .is_authenticated = ceph_x_is_authenticated,
641         .should_authenticate = ceph_x_should_authenticate,
642         .build_request = ceph_x_build_request,
643         .handle_reply = ceph_x_handle_reply,
644         .create_authorizer = ceph_x_create_authorizer,
645         .verify_authorizer_reply = ceph_x_verify_authorizer_reply,
646         .destroy_authorizer = ceph_x_destroy_authorizer,
647         .invalidate_authorizer = ceph_x_invalidate_authorizer,
648         .reset =  ceph_x_reset,
649         .destroy = ceph_x_destroy,
650 };
651
652
653 int ceph_x_init(struct ceph_auth_client *ac)
654 {
655         struct ceph_x_info *xi;
656         int ret;
657
658         dout("ceph_x_init %p\n", ac);
659         ret = -ENOMEM;
660         xi = kzalloc(sizeof(*xi), GFP_NOFS);
661         if (!xi)
662                 goto out;
663
664         ret = -EINVAL;
665         if (!ac->secret) {
666                 pr_err("no secret set (for auth_x protocol)\n");
667                 goto out_nomem;
668         }
669
670         ret = ceph_crypto_key_unarmor(&xi->secret, ac->secret);
671         if (ret)
672                 goto out_nomem;
673
674         xi->starting = true;
675         xi->ticket_handlers = RB_ROOT;
676
677         ac->protocol = CEPH_AUTH_CEPHX;
678         ac->private = xi;
679         ac->ops = &ceph_x_ops;
680         return 0;
681
682 out_nomem:
683         kfree(xi);
684 out:
685         return ret;
686 }
687
688