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 au->secret_id = th->secret_id; 302 303 msg_a = au->buf->vec.iov_base; 304 msg_a->struct_v = 1; 305 msg_a->global_id = cpu_to_le64(ac->global_id); 306 msg_a->service_id = cpu_to_le32(th->service); 307 msg_a->ticket_blob.struct_v = 1; 308 msg_a->ticket_blob.secret_id = cpu_to_le64(th->secret_id); 309 msg_a->ticket_blob.blob_len = cpu_to_le32(ticket_blob_len); 310 if (ticket_blob_len) { 311 memcpy(msg_a->ticket_blob.blob, th->ticket_blob->vec.iov_base, 312 th->ticket_blob->vec.iov_len); 313 } 314 dout(" th %p secret_id %lld %lld\n", th, th->secret_id, 315 le64_to_cpu(msg_a->ticket_blob.secret_id)); 316 317 p = msg_a + 1; 318 p += ticket_blob_len; 319 end = au->buf->vec.iov_base + au->buf->vec.iov_len; 320 321 get_random_bytes(&au->nonce, sizeof(au->nonce)); 322 msg_b.struct_v = 1; 323 msg_b.nonce = cpu_to_le64(au->nonce); 324 ret = ceph_x_encrypt(&th->session_key, &msg_b, sizeof(msg_b), 325 p, end - p); 326 if (ret < 0) 327 goto out_buf; 328 p += ret; 329 au->buf->vec.iov_len = p - au->buf->vec.iov_base; 330 dout(" built authorizer nonce %llx len %d\n", au->nonce, 331 (int)au->buf->vec.iov_len); 332 BUG_ON(au->buf->vec.iov_len > maxlen); 333 return 0; 334 335 out_buf: 336 ceph_buffer_put(au->buf); 337 au->buf = NULL; 338 return ret; 339 } 340 341 static int ceph_x_encode_ticket(struct ceph_x_ticket_handler *th, 342 void **p, void *end) 343 { 344 ceph_decode_need(p, end, 1 + sizeof(u64), bad); 345 ceph_encode_8(p, 1); 346 ceph_encode_64(p, th->secret_id); 347 if (th->ticket_blob) { 348 const char *buf = th->ticket_blob->vec.iov_base; 349 u32 len = th->ticket_blob->vec.iov_len; 350 351 ceph_encode_32_safe(p, end, len, bad); 352 ceph_encode_copy_safe(p, end, buf, len, bad); 353 } else { 354 ceph_encode_32_safe(p, end, 0, bad); 355 } 356 357 return 0; 358 bad: 359 return -ERANGE; 360 } 361 362 static void ceph_x_validate_tickets(struct ceph_auth_client *ac, int *pneed) 363 { 364 int want = ac->want_keys; 365 struct ceph_x_info *xi = ac->private; 366 int service; 367 368 *pneed = ac->want_keys & ~(xi->have_keys); 369 370 for (service = 1; service <= want; service <<= 1) { 371 struct ceph_x_ticket_handler *th; 372 373 if (!(ac->want_keys & service)) 374 continue; 375 376 if (*pneed & service) 377 continue; 378 379 th = get_ticket_handler(ac, service); 380 381 if (IS_ERR(th)) { 382 *pneed |= service; 383 continue; 384 } 385 386 if (get_seconds() >= th->renew_after) 387 *pneed |= service; 388 if (get_seconds() >= th->expires) 389 xi->have_keys &= ~service; 390 } 391 } 392 393 394 static int ceph_x_build_request(struct ceph_auth_client *ac, 395 void *buf, void *end) 396 { 397 struct ceph_x_info *xi = ac->private; 398 int need; 399 struct ceph_x_request_header *head = buf; 400 int ret; 401 struct ceph_x_ticket_handler *th = 402 get_ticket_handler(ac, CEPH_ENTITY_TYPE_AUTH); 403 404 if (IS_ERR(th)) 405 return PTR_ERR(th); 406 407 ceph_x_validate_tickets(ac, &need); 408 409 dout("build_request want %x have %x need %x\n", 410 ac->want_keys, xi->have_keys, need); 411 412 if (need & CEPH_ENTITY_TYPE_AUTH) { 413 struct ceph_x_authenticate *auth = (void *)(head + 1); 414 void *p = auth + 1; 415 struct ceph_x_challenge_blob tmp; 416 char tmp_enc[40]; 417 u64 *u; 418 419 if (p > end) 420 return -ERANGE; 421 422 dout(" get_auth_session_key\n"); 423 head->op = cpu_to_le16(CEPHX_GET_AUTH_SESSION_KEY); 424 425 /* encrypt and hash */ 426 get_random_bytes(&auth->client_challenge, sizeof(u64)); 427 tmp.client_challenge = auth->client_challenge; 428 tmp.server_challenge = cpu_to_le64(xi->server_challenge); 429 ret = ceph_x_encrypt(&xi->secret, &tmp, sizeof(tmp), 430 tmp_enc, sizeof(tmp_enc)); 431 if (ret < 0) 432 return ret; 433 434 auth->struct_v = 1; 435 auth->key = 0; 436 for (u = (u64 *)tmp_enc; u + 1 <= (u64 *)(tmp_enc + ret); u++) 437 auth->key ^= *(__le64 *)u; 438 dout(" server_challenge %llx client_challenge %llx key %llx\n", 439 xi->server_challenge, le64_to_cpu(auth->client_challenge), 440 le64_to_cpu(auth->key)); 441 442 /* now encode the old ticket if exists */ 443 ret = ceph_x_encode_ticket(th, &p, end); 444 if (ret < 0) 445 return ret; 446 447 return p - buf; 448 } 449 450 if (need) { 451 void *p = head + 1; 452 struct ceph_x_service_ticket_request *req; 453 454 if (p > end) 455 return -ERANGE; 456 head->op = cpu_to_le16(CEPHX_GET_PRINCIPAL_SESSION_KEY); 457 458 ret = ceph_x_build_authorizer(ac, th, &xi->auth_authorizer); 459 if (ret) 460 return ret; 461 ceph_encode_copy(&p, xi->auth_authorizer.buf->vec.iov_base, 462 xi->auth_authorizer.buf->vec.iov_len); 463 464 req = p; 465 req->keys = cpu_to_le32(need); 466 p += sizeof(*req); 467 return p - buf; 468 } 469 470 return 0; 471 } 472 473 static int ceph_x_handle_reply(struct ceph_auth_client *ac, int result, 474 void *buf, void *end) 475 { 476 struct ceph_x_info *xi = ac->private; 477 struct ceph_x_reply_header *head = buf; 478 struct ceph_x_ticket_handler *th; 479 int len = end - buf; 480 int op; 481 int ret; 482 483 if (result) 484 return result; /* XXX hmm? */ 485 486 if (xi->starting) { 487 /* it's a hello */ 488 struct ceph_x_server_challenge *sc = buf; 489 490 if (len != sizeof(*sc)) 491 return -EINVAL; 492 xi->server_challenge = le64_to_cpu(sc->server_challenge); 493 dout("handle_reply got server challenge %llx\n", 494 xi->server_challenge); 495 xi->starting = false; 496 xi->have_keys &= ~CEPH_ENTITY_TYPE_AUTH; 497 return -EAGAIN; 498 } 499 500 op = le16_to_cpu(head->op); 501 result = le32_to_cpu(head->result); 502 dout("handle_reply op %d result %d\n", op, result); 503 switch (op) { 504 case CEPHX_GET_AUTH_SESSION_KEY: 505 /* verify auth key */ 506 ret = ceph_x_proc_ticket_reply(ac, &xi->secret, 507 buf + sizeof(*head), end); 508 break; 509 510 case CEPHX_GET_PRINCIPAL_SESSION_KEY: 511 th = get_ticket_handler(ac, CEPH_ENTITY_TYPE_AUTH); 512 if (IS_ERR(th)) 513 return PTR_ERR(th); 514 ret = ceph_x_proc_ticket_reply(ac, &th->session_key, 515 buf + sizeof(*head), end); 516 break; 517 518 default: 519 return -EINVAL; 520 } 521 if (ret) 522 return ret; 523 if (ac->want_keys == xi->have_keys) 524 return 0; 525 return -EAGAIN; 526 } 527 528 static int ceph_x_create_authorizer( 529 struct ceph_auth_client *ac, int peer_type, 530 struct ceph_auth_handshake *auth) 531 { 532 struct ceph_x_authorizer *au; 533 struct ceph_x_ticket_handler *th; 534 int ret; 535 536 th = get_ticket_handler(ac, peer_type); 537 if (IS_ERR(th)) 538 return PTR_ERR(th); 539 540 au = kzalloc(sizeof(*au), GFP_NOFS); 541 if (!au) 542 return -ENOMEM; 543 544 ret = ceph_x_build_authorizer(ac, th, au); 545 if (ret) { 546 kfree(au); 547 return ret; 548 } 549 550 auth->authorizer = (struct ceph_authorizer *) au; 551 auth->authorizer_buf = au->buf->vec.iov_base; 552 auth->authorizer_buf_len = au->buf->vec.iov_len; 553 auth->authorizer_reply_buf = au->reply_buf; 554 auth->authorizer_reply_buf_len = sizeof (au->reply_buf); 555 556 return 0; 557 } 558 559 static int ceph_x_update_authorizer( 560 struct ceph_auth_client *ac, int peer_type, 561 struct ceph_auth_handshake *auth) 562 { 563 struct ceph_x_authorizer *au; 564 struct ceph_x_ticket_handler *th; 565 566 th = get_ticket_handler(ac, peer_type); 567 if (IS_ERR(th)) 568 return PTR_ERR(th); 569 570 au = (struct ceph_x_authorizer *)auth->authorizer; 571 if (au->secret_id < th->secret_id) { 572 dout("ceph_x_update_authorizer service %u secret %llu < %llu\n", 573 au->service, au->secret_id, th->secret_id); 574 return ceph_x_build_authorizer(ac, th, au); 575 } 576 return 0; 577 } 578 579 static int ceph_x_verify_authorizer_reply(struct ceph_auth_client *ac, 580 struct ceph_authorizer *a, size_t len) 581 { 582 struct ceph_x_authorizer *au = (void *)a; 583 struct ceph_x_ticket_handler *th; 584 int ret = 0; 585 struct ceph_x_authorize_reply reply; 586 void *p = au->reply_buf; 587 void *end = p + sizeof(au->reply_buf); 588 589 th = get_ticket_handler(ac, au->service); 590 if (IS_ERR(th)) 591 return PTR_ERR(th); 592 ret = ceph_x_decrypt(&th->session_key, &p, end, &reply, sizeof(reply)); 593 if (ret < 0) 594 return ret; 595 if (ret != sizeof(reply)) 596 return -EPERM; 597 598 if (au->nonce + 1 != le64_to_cpu(reply.nonce_plus_one)) 599 ret = -EPERM; 600 else 601 ret = 0; 602 dout("verify_authorizer_reply nonce %llx got %llx ret %d\n", 603 au->nonce, le64_to_cpu(reply.nonce_plus_one), ret); 604 return ret; 605 } 606 607 static void ceph_x_destroy_authorizer(struct ceph_auth_client *ac, 608 struct ceph_authorizer *a) 609 { 610 struct ceph_x_authorizer *au = (void *)a; 611 612 ceph_buffer_put(au->buf); 613 kfree(au); 614 } 615 616 617 static void ceph_x_reset(struct ceph_auth_client *ac) 618 { 619 struct ceph_x_info *xi = ac->private; 620 621 dout("reset\n"); 622 xi->starting = true; 623 xi->server_challenge = 0; 624 } 625 626 static void ceph_x_destroy(struct ceph_auth_client *ac) 627 { 628 struct ceph_x_info *xi = ac->private; 629 struct rb_node *p; 630 631 dout("ceph_x_destroy %p\n", ac); 632 ceph_crypto_key_destroy(&xi->secret); 633 634 while ((p = rb_first(&xi->ticket_handlers)) != NULL) { 635 struct ceph_x_ticket_handler *th = 636 rb_entry(p, struct ceph_x_ticket_handler, node); 637 remove_ticket_handler(ac, th); 638 } 639 640 if (xi->auth_authorizer.buf) 641 ceph_buffer_put(xi->auth_authorizer.buf); 642 643 kfree(ac->private); 644 ac->private = NULL; 645 } 646 647 static void ceph_x_invalidate_authorizer(struct ceph_auth_client *ac, 648 int peer_type) 649 { 650 struct ceph_x_ticket_handler *th; 651 652 th = get_ticket_handler(ac, peer_type); 653 if (!IS_ERR(th)) 654 memset(&th->validity, 0, sizeof(th->validity)); 655 } 656 657 658 static const struct ceph_auth_client_ops ceph_x_ops = { 659 .name = "x", 660 .is_authenticated = ceph_x_is_authenticated, 661 .should_authenticate = ceph_x_should_authenticate, 662 .build_request = ceph_x_build_request, 663 .handle_reply = ceph_x_handle_reply, 664 .create_authorizer = ceph_x_create_authorizer, 665 .update_authorizer = ceph_x_update_authorizer, 666 .verify_authorizer_reply = ceph_x_verify_authorizer_reply, 667 .destroy_authorizer = ceph_x_destroy_authorizer, 668 .invalidate_authorizer = ceph_x_invalidate_authorizer, 669 .reset = ceph_x_reset, 670 .destroy = ceph_x_destroy, 671 }; 672 673 674 int ceph_x_init(struct ceph_auth_client *ac) 675 { 676 struct ceph_x_info *xi; 677 int ret; 678 679 dout("ceph_x_init %p\n", ac); 680 ret = -ENOMEM; 681 xi = kzalloc(sizeof(*xi), GFP_NOFS); 682 if (!xi) 683 goto out; 684 685 ret = -EINVAL; 686 if (!ac->key) { 687 pr_err("no secret set (for auth_x protocol)\n"); 688 goto out_nomem; 689 } 690 691 ret = ceph_crypto_key_clone(&xi->secret, ac->key); 692 if (ret < 0) { 693 pr_err("cannot clone key: %d\n", ret); 694 goto out_nomem; 695 } 696 697 xi->starting = true; 698 xi->ticket_handlers = RB_ROOT; 699 700 ac->protocol = CEPH_AUTH_CEPHX; 701 ac->private = xi; 702 ac->ops = &ceph_x_ops; 703 return 0; 704 705 out_nomem: 706 kfree(xi); 707 out: 708 return ret; 709 } 710 711 712