1 /* Maintain an RxRPC server socket to do AFS communications through 2 * 3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. 4 * Written by David Howells (dhowells@redhat.com) 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 */ 11 12 #include <linux/slab.h> 13 #include <net/sock.h> 14 #include <net/af_rxrpc.h> 15 #include <rxrpc/packet.h> 16 #include "internal.h" 17 #include "afs_cm.h" 18 19 static struct socket *afs_socket; /* my RxRPC socket */ 20 static struct workqueue_struct *afs_async_calls; 21 static atomic_t afs_outstanding_calls; 22 static atomic_t afs_outstanding_skbs; 23 24 static void afs_wake_up_call_waiter(struct afs_call *); 25 static int afs_wait_for_call_to_complete(struct afs_call *); 26 static void afs_wake_up_async_call(struct afs_call *); 27 static int afs_dont_wait_for_call_to_complete(struct afs_call *); 28 static void afs_process_async_call(struct afs_call *); 29 static void afs_rx_interceptor(struct sock *, unsigned long, struct sk_buff *); 30 static int afs_deliver_cm_op_id(struct afs_call *, struct sk_buff *, bool); 31 32 /* synchronous call management */ 33 const struct afs_wait_mode afs_sync_call = { 34 .rx_wakeup = afs_wake_up_call_waiter, 35 .wait = afs_wait_for_call_to_complete, 36 }; 37 38 /* asynchronous call management */ 39 const struct afs_wait_mode afs_async_call = { 40 .rx_wakeup = afs_wake_up_async_call, 41 .wait = afs_dont_wait_for_call_to_complete, 42 }; 43 44 /* asynchronous incoming call management */ 45 static const struct afs_wait_mode afs_async_incoming_call = { 46 .rx_wakeup = afs_wake_up_async_call, 47 }; 48 49 /* asynchronous incoming call initial processing */ 50 static const struct afs_call_type afs_RXCMxxxx = { 51 .name = "CB.xxxx", 52 .deliver = afs_deliver_cm_op_id, 53 .abort_to_error = afs_abort_to_error, 54 }; 55 56 static void afs_collect_incoming_call(struct work_struct *); 57 58 static struct sk_buff_head afs_incoming_calls; 59 static DECLARE_WORK(afs_collect_incoming_call_work, afs_collect_incoming_call); 60 61 static void afs_async_workfn(struct work_struct *work) 62 { 63 struct afs_call *call = container_of(work, struct afs_call, async_work); 64 65 call->async_workfn(call); 66 } 67 68 static int afs_wait_atomic_t(atomic_t *p) 69 { 70 schedule(); 71 return 0; 72 } 73 74 /* 75 * open an RxRPC socket and bind it to be a server for callback notifications 76 * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT 77 */ 78 int afs_open_socket(void) 79 { 80 struct sockaddr_rxrpc srx; 81 struct socket *socket; 82 int ret; 83 84 _enter(""); 85 86 skb_queue_head_init(&afs_incoming_calls); 87 88 ret = -ENOMEM; 89 afs_async_calls = create_singlethread_workqueue("kafsd"); 90 if (!afs_async_calls) 91 goto error_0; 92 93 ret = sock_create_kern(&init_net, AF_RXRPC, SOCK_DGRAM, PF_INET, &socket); 94 if (ret < 0) 95 goto error_1; 96 97 socket->sk->sk_allocation = GFP_NOFS; 98 99 /* bind the callback manager's address to make this a server socket */ 100 srx.srx_family = AF_RXRPC; 101 srx.srx_service = CM_SERVICE; 102 srx.transport_type = SOCK_DGRAM; 103 srx.transport_len = sizeof(srx.transport.sin); 104 srx.transport.sin.sin_family = AF_INET; 105 srx.transport.sin.sin_port = htons(AFS_CM_PORT); 106 memset(&srx.transport.sin.sin_addr, 0, 107 sizeof(srx.transport.sin.sin_addr)); 108 109 ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx)); 110 if (ret < 0) 111 goto error_2; 112 113 ret = kernel_listen(socket, INT_MAX); 114 if (ret < 0) 115 goto error_2; 116 117 rxrpc_kernel_intercept_rx_messages(socket, afs_rx_interceptor); 118 119 afs_socket = socket; 120 _leave(" = 0"); 121 return 0; 122 123 error_2: 124 sock_release(socket); 125 error_1: 126 destroy_workqueue(afs_async_calls); 127 error_0: 128 _leave(" = %d", ret); 129 return ret; 130 } 131 132 /* 133 * close the RxRPC socket AFS was using 134 */ 135 void afs_close_socket(void) 136 { 137 _enter(""); 138 139 wait_on_atomic_t(&afs_outstanding_calls, afs_wait_atomic_t, 140 TASK_UNINTERRUPTIBLE); 141 _debug("no outstanding calls"); 142 143 sock_release(afs_socket); 144 145 _debug("dework"); 146 destroy_workqueue(afs_async_calls); 147 148 ASSERTCMP(atomic_read(&afs_outstanding_skbs), ==, 0); 149 _leave(""); 150 } 151 152 /* 153 * note that the data in a socket buffer is now delivered and that the buffer 154 * should be freed 155 */ 156 static void afs_data_delivered(struct sk_buff *skb) 157 { 158 if (!skb) { 159 _debug("DLVR NULL [%d]", atomic_read(&afs_outstanding_skbs)); 160 dump_stack(); 161 } else { 162 _debug("DLVR %p{%u} [%d]", 163 skb, skb->mark, atomic_read(&afs_outstanding_skbs)); 164 if (atomic_dec_return(&afs_outstanding_skbs) == -1) 165 BUG(); 166 rxrpc_kernel_data_delivered(skb); 167 } 168 } 169 170 /* 171 * free a socket buffer 172 */ 173 static void afs_free_skb(struct sk_buff *skb) 174 { 175 if (!skb) { 176 _debug("FREE NULL [%d]", atomic_read(&afs_outstanding_skbs)); 177 dump_stack(); 178 } else { 179 _debug("FREE %p{%u} [%d]", 180 skb, skb->mark, atomic_read(&afs_outstanding_skbs)); 181 if (atomic_dec_return(&afs_outstanding_skbs) == -1) 182 BUG(); 183 rxrpc_kernel_free_skb(skb); 184 } 185 } 186 187 /* 188 * free a call 189 */ 190 static void afs_free_call(struct afs_call *call) 191 { 192 _debug("DONE %p{%s} [%d]", 193 call, call->type->name, atomic_read(&afs_outstanding_calls)); 194 195 ASSERTCMP(call->rxcall, ==, NULL); 196 ASSERT(!work_pending(&call->async_work)); 197 ASSERT(skb_queue_empty(&call->rx_queue)); 198 ASSERT(call->type->name != NULL); 199 200 kfree(call->request); 201 kfree(call); 202 203 if (atomic_dec_and_test(&afs_outstanding_calls)) 204 wake_up_atomic_t(&afs_outstanding_calls); 205 } 206 207 /* 208 * End a call but do not free it 209 */ 210 static void afs_end_call_nofree(struct afs_call *call) 211 { 212 if (call->rxcall) { 213 rxrpc_kernel_end_call(call->rxcall); 214 call->rxcall = NULL; 215 } 216 if (call->type->destructor) 217 call->type->destructor(call); 218 } 219 220 /* 221 * End a call and free it 222 */ 223 static void afs_end_call(struct afs_call *call) 224 { 225 afs_end_call_nofree(call); 226 afs_free_call(call); 227 } 228 229 /* 230 * allocate a call with flat request and reply buffers 231 */ 232 struct afs_call *afs_alloc_flat_call(const struct afs_call_type *type, 233 size_t request_size, size_t reply_size) 234 { 235 struct afs_call *call; 236 237 call = kzalloc(sizeof(*call), GFP_NOFS); 238 if (!call) 239 goto nomem_call; 240 241 _debug("CALL %p{%s} [%d]", 242 call, type->name, atomic_read(&afs_outstanding_calls)); 243 atomic_inc(&afs_outstanding_calls); 244 245 call->type = type; 246 call->request_size = request_size; 247 call->reply_max = reply_size; 248 249 if (request_size) { 250 call->request = kmalloc(request_size, GFP_NOFS); 251 if (!call->request) 252 goto nomem_free; 253 } 254 255 if (reply_size) { 256 call->buffer = kmalloc(reply_size, GFP_NOFS); 257 if (!call->buffer) 258 goto nomem_free; 259 } 260 261 init_waitqueue_head(&call->waitq); 262 skb_queue_head_init(&call->rx_queue); 263 return call; 264 265 nomem_free: 266 afs_free_call(call); 267 nomem_call: 268 return NULL; 269 } 270 271 /* 272 * clean up a call with flat buffer 273 */ 274 void afs_flat_call_destructor(struct afs_call *call) 275 { 276 _enter(""); 277 278 kfree(call->request); 279 call->request = NULL; 280 kfree(call->buffer); 281 call->buffer = NULL; 282 } 283 284 /* 285 * attach the data from a bunch of pages on an inode to a call 286 */ 287 static int afs_send_pages(struct afs_call *call, struct msghdr *msg, 288 struct kvec *iov) 289 { 290 struct page *pages[8]; 291 unsigned count, n, loop, offset, to; 292 pgoff_t first = call->first, last = call->last; 293 int ret; 294 295 _enter(""); 296 297 offset = call->first_offset; 298 call->first_offset = 0; 299 300 do { 301 _debug("attach %lx-%lx", first, last); 302 303 count = last - first + 1; 304 if (count > ARRAY_SIZE(pages)) 305 count = ARRAY_SIZE(pages); 306 n = find_get_pages_contig(call->mapping, first, count, pages); 307 ASSERTCMP(n, ==, count); 308 309 loop = 0; 310 do { 311 msg->msg_flags = 0; 312 to = PAGE_SIZE; 313 if (first + loop >= last) 314 to = call->last_to; 315 else 316 msg->msg_flags = MSG_MORE; 317 iov->iov_base = kmap(pages[loop]) + offset; 318 iov->iov_len = to - offset; 319 offset = 0; 320 321 _debug("- range %u-%u%s", 322 offset, to, msg->msg_flags ? " [more]" : ""); 323 iov_iter_kvec(&msg->msg_iter, WRITE | ITER_KVEC, 324 iov, 1, to - offset); 325 326 /* have to change the state *before* sending the last 327 * packet as RxRPC might give us the reply before it 328 * returns from sending the request */ 329 if (first + loop >= last) 330 call->state = AFS_CALL_AWAIT_REPLY; 331 ret = rxrpc_kernel_send_data(call->rxcall, msg, 332 to - offset); 333 kunmap(pages[loop]); 334 if (ret < 0) 335 break; 336 } while (++loop < count); 337 first += count; 338 339 for (loop = 0; loop < count; loop++) 340 put_page(pages[loop]); 341 if (ret < 0) 342 break; 343 } while (first <= last); 344 345 _leave(" = %d", ret); 346 return ret; 347 } 348 349 /* 350 * initiate a call 351 */ 352 int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp, 353 const struct afs_wait_mode *wait_mode) 354 { 355 struct sockaddr_rxrpc srx; 356 struct rxrpc_call *rxcall; 357 struct msghdr msg; 358 struct kvec iov[1]; 359 int ret; 360 struct sk_buff *skb; 361 362 _enter("%x,{%d},", addr->s_addr, ntohs(call->port)); 363 364 ASSERT(call->type != NULL); 365 ASSERT(call->type->name != NULL); 366 367 _debug("____MAKE %p{%s,%x} [%d]____", 368 call, call->type->name, key_serial(call->key), 369 atomic_read(&afs_outstanding_calls)); 370 371 call->wait_mode = wait_mode; 372 call->async_workfn = afs_process_async_call; 373 INIT_WORK(&call->async_work, afs_async_workfn); 374 375 memset(&srx, 0, sizeof(srx)); 376 srx.srx_family = AF_RXRPC; 377 srx.srx_service = call->service_id; 378 srx.transport_type = SOCK_DGRAM; 379 srx.transport_len = sizeof(srx.transport.sin); 380 srx.transport.sin.sin_family = AF_INET; 381 srx.transport.sin.sin_port = call->port; 382 memcpy(&srx.transport.sin.sin_addr, addr, 4); 383 384 /* create a call */ 385 rxcall = rxrpc_kernel_begin_call(afs_socket, &srx, call->key, 386 (unsigned long) call, gfp); 387 call->key = NULL; 388 if (IS_ERR(rxcall)) { 389 ret = PTR_ERR(rxcall); 390 goto error_kill_call; 391 } 392 393 call->rxcall = rxcall; 394 395 /* send the request */ 396 iov[0].iov_base = call->request; 397 iov[0].iov_len = call->request_size; 398 399 msg.msg_name = NULL; 400 msg.msg_namelen = 0; 401 iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1, 402 call->request_size); 403 msg.msg_control = NULL; 404 msg.msg_controllen = 0; 405 msg.msg_flags = (call->send_pages ? MSG_MORE : 0); 406 407 /* have to change the state *before* sending the last packet as RxRPC 408 * might give us the reply before it returns from sending the 409 * request */ 410 if (!call->send_pages) 411 call->state = AFS_CALL_AWAIT_REPLY; 412 ret = rxrpc_kernel_send_data(rxcall, &msg, call->request_size); 413 if (ret < 0) 414 goto error_do_abort; 415 416 if (call->send_pages) { 417 ret = afs_send_pages(call, &msg, iov); 418 if (ret < 0) 419 goto error_do_abort; 420 } 421 422 /* at this point, an async call may no longer exist as it may have 423 * already completed */ 424 return wait_mode->wait(call); 425 426 error_do_abort: 427 rxrpc_kernel_abort_call(rxcall, RX_USER_ABORT); 428 while ((skb = skb_dequeue(&call->rx_queue))) 429 afs_free_skb(skb); 430 error_kill_call: 431 afs_end_call(call); 432 _leave(" = %d", ret); 433 return ret; 434 } 435 436 /* 437 * Handles intercepted messages that were arriving in the socket's Rx queue. 438 * 439 * Called from the AF_RXRPC call processor in waitqueue process context. For 440 * each call, it is guaranteed this will be called in order of packet to be 441 * delivered. 442 */ 443 static void afs_rx_interceptor(struct sock *sk, unsigned long user_call_ID, 444 struct sk_buff *skb) 445 { 446 struct afs_call *call = (struct afs_call *) user_call_ID; 447 448 _enter("%p,,%u", call, skb->mark); 449 450 _debug("ICPT %p{%u} [%d]", 451 skb, skb->mark, atomic_read(&afs_outstanding_skbs)); 452 453 ASSERTCMP(sk, ==, afs_socket->sk); 454 atomic_inc(&afs_outstanding_skbs); 455 456 if (!call) { 457 /* its an incoming call for our callback service */ 458 skb_queue_tail(&afs_incoming_calls, skb); 459 queue_work(afs_wq, &afs_collect_incoming_call_work); 460 } else { 461 /* route the messages directly to the appropriate call */ 462 skb_queue_tail(&call->rx_queue, skb); 463 call->wait_mode->rx_wakeup(call); 464 } 465 466 _leave(""); 467 } 468 469 /* 470 * deliver messages to a call 471 */ 472 static void afs_deliver_to_call(struct afs_call *call) 473 { 474 struct sk_buff *skb; 475 bool last; 476 u32 abort_code; 477 int ret; 478 479 _enter(""); 480 481 while ((call->state == AFS_CALL_AWAIT_REPLY || 482 call->state == AFS_CALL_AWAIT_OP_ID || 483 call->state == AFS_CALL_AWAIT_REQUEST || 484 call->state == AFS_CALL_AWAIT_ACK) && 485 (skb = skb_dequeue(&call->rx_queue))) { 486 switch (skb->mark) { 487 case RXRPC_SKB_MARK_DATA: 488 _debug("Rcv DATA"); 489 last = rxrpc_kernel_is_data_last(skb); 490 ret = call->type->deliver(call, skb, last); 491 switch (ret) { 492 case 0: 493 if (last && 494 call->state == AFS_CALL_AWAIT_REPLY) 495 call->state = AFS_CALL_COMPLETE; 496 break; 497 case -ENOTCONN: 498 abort_code = RX_CALL_DEAD; 499 goto do_abort; 500 case -ENOTSUPP: 501 abort_code = RX_INVALID_OPERATION; 502 goto do_abort; 503 default: 504 abort_code = RXGEN_CC_UNMARSHAL; 505 if (call->state != AFS_CALL_AWAIT_REPLY) 506 abort_code = RXGEN_SS_UNMARSHAL; 507 do_abort: 508 rxrpc_kernel_abort_call(call->rxcall, 509 abort_code); 510 call->error = ret; 511 call->state = AFS_CALL_ERROR; 512 break; 513 } 514 afs_data_delivered(skb); 515 skb = NULL; 516 continue; 517 case RXRPC_SKB_MARK_FINAL_ACK: 518 _debug("Rcv ACK"); 519 call->state = AFS_CALL_COMPLETE; 520 break; 521 case RXRPC_SKB_MARK_BUSY: 522 _debug("Rcv BUSY"); 523 call->error = -EBUSY; 524 call->state = AFS_CALL_BUSY; 525 break; 526 case RXRPC_SKB_MARK_REMOTE_ABORT: 527 abort_code = rxrpc_kernel_get_abort_code(skb); 528 call->error = call->type->abort_to_error(abort_code); 529 call->state = AFS_CALL_ABORTED; 530 _debug("Rcv ABORT %u -> %d", abort_code, call->error); 531 break; 532 case RXRPC_SKB_MARK_LOCAL_ABORT: 533 abort_code = rxrpc_kernel_get_abort_code(skb); 534 call->error = call->type->abort_to_error(abort_code); 535 call->state = AFS_CALL_ABORTED; 536 _debug("Loc ABORT %u -> %d", abort_code, call->error); 537 break; 538 case RXRPC_SKB_MARK_NET_ERROR: 539 call->error = -rxrpc_kernel_get_error_number(skb); 540 call->state = AFS_CALL_ERROR; 541 _debug("Rcv NET ERROR %d", call->error); 542 break; 543 case RXRPC_SKB_MARK_LOCAL_ERROR: 544 call->error = -rxrpc_kernel_get_error_number(skb); 545 call->state = AFS_CALL_ERROR; 546 _debug("Rcv LOCAL ERROR %d", call->error); 547 break; 548 default: 549 BUG(); 550 break; 551 } 552 553 afs_free_skb(skb); 554 } 555 556 /* make sure the queue is empty if the call is done with (we might have 557 * aborted the call early because of an unmarshalling error) */ 558 if (call->state >= AFS_CALL_COMPLETE) { 559 while ((skb = skb_dequeue(&call->rx_queue))) 560 afs_free_skb(skb); 561 if (call->incoming) 562 afs_end_call(call); 563 } 564 565 _leave(""); 566 } 567 568 /* 569 * wait synchronously for a call to complete 570 */ 571 static int afs_wait_for_call_to_complete(struct afs_call *call) 572 { 573 struct sk_buff *skb; 574 int ret; 575 576 DECLARE_WAITQUEUE(myself, current); 577 578 _enter(""); 579 580 add_wait_queue(&call->waitq, &myself); 581 for (;;) { 582 set_current_state(TASK_INTERRUPTIBLE); 583 584 /* deliver any messages that are in the queue */ 585 if (!skb_queue_empty(&call->rx_queue)) { 586 __set_current_state(TASK_RUNNING); 587 afs_deliver_to_call(call); 588 continue; 589 } 590 591 ret = call->error; 592 if (call->state >= AFS_CALL_COMPLETE) 593 break; 594 ret = -EINTR; 595 if (signal_pending(current)) 596 break; 597 schedule(); 598 } 599 600 remove_wait_queue(&call->waitq, &myself); 601 __set_current_state(TASK_RUNNING); 602 603 /* kill the call */ 604 if (call->state < AFS_CALL_COMPLETE) { 605 _debug("call incomplete"); 606 rxrpc_kernel_abort_call(call->rxcall, RX_CALL_DEAD); 607 while ((skb = skb_dequeue(&call->rx_queue))) 608 afs_free_skb(skb); 609 } 610 611 _debug("call complete"); 612 afs_end_call(call); 613 _leave(" = %d", ret); 614 return ret; 615 } 616 617 /* 618 * wake up a waiting call 619 */ 620 static void afs_wake_up_call_waiter(struct afs_call *call) 621 { 622 wake_up(&call->waitq); 623 } 624 625 /* 626 * wake up an asynchronous call 627 */ 628 static void afs_wake_up_async_call(struct afs_call *call) 629 { 630 _enter(""); 631 queue_work(afs_async_calls, &call->async_work); 632 } 633 634 /* 635 * put a call into asynchronous mode 636 * - mustn't touch the call descriptor as the call my have completed by the 637 * time we get here 638 */ 639 static int afs_dont_wait_for_call_to_complete(struct afs_call *call) 640 { 641 _enter(""); 642 return -EINPROGRESS; 643 } 644 645 /* 646 * delete an asynchronous call 647 */ 648 static void afs_delete_async_call(struct afs_call *call) 649 { 650 _enter(""); 651 652 afs_free_call(call); 653 654 _leave(""); 655 } 656 657 /* 658 * perform processing on an asynchronous call 659 * - on a multiple-thread workqueue this work item may try to run on several 660 * CPUs at the same time 661 */ 662 static void afs_process_async_call(struct afs_call *call) 663 { 664 _enter(""); 665 666 if (!skb_queue_empty(&call->rx_queue)) 667 afs_deliver_to_call(call); 668 669 if (call->state >= AFS_CALL_COMPLETE && call->wait_mode) { 670 if (call->wait_mode->async_complete) 671 call->wait_mode->async_complete(call->reply, 672 call->error); 673 call->reply = NULL; 674 675 /* kill the call */ 676 afs_end_call_nofree(call); 677 678 /* we can't just delete the call because the work item may be 679 * queued */ 680 call->async_workfn = afs_delete_async_call; 681 queue_work(afs_async_calls, &call->async_work); 682 } 683 684 _leave(""); 685 } 686 687 /* 688 * empty a socket buffer into a flat reply buffer 689 */ 690 void afs_transfer_reply(struct afs_call *call, struct sk_buff *skb) 691 { 692 size_t len = skb->len; 693 694 if (skb_copy_bits(skb, 0, call->buffer + call->reply_size, len) < 0) 695 BUG(); 696 call->reply_size += len; 697 } 698 699 /* 700 * accept the backlog of incoming calls 701 */ 702 static void afs_collect_incoming_call(struct work_struct *work) 703 { 704 struct rxrpc_call *rxcall; 705 struct afs_call *call = NULL; 706 struct sk_buff *skb; 707 708 while ((skb = skb_dequeue(&afs_incoming_calls))) { 709 _debug("new call"); 710 711 /* don't need the notification */ 712 afs_free_skb(skb); 713 714 if (!call) { 715 call = kzalloc(sizeof(struct afs_call), GFP_KERNEL); 716 if (!call) { 717 rxrpc_kernel_reject_call(afs_socket); 718 return; 719 } 720 721 call->async_workfn = afs_process_async_call; 722 INIT_WORK(&call->async_work, afs_async_workfn); 723 call->wait_mode = &afs_async_incoming_call; 724 call->type = &afs_RXCMxxxx; 725 init_waitqueue_head(&call->waitq); 726 skb_queue_head_init(&call->rx_queue); 727 call->state = AFS_CALL_AWAIT_OP_ID; 728 729 _debug("CALL %p{%s} [%d]", 730 call, call->type->name, 731 atomic_read(&afs_outstanding_calls)); 732 atomic_inc(&afs_outstanding_calls); 733 } 734 735 rxcall = rxrpc_kernel_accept_call(afs_socket, 736 (unsigned long) call); 737 if (!IS_ERR(rxcall)) { 738 call->rxcall = rxcall; 739 call = NULL; 740 } 741 } 742 743 if (call) 744 afs_free_call(call); 745 } 746 747 /* 748 * grab the operation ID from an incoming cache manager call 749 */ 750 static int afs_deliver_cm_op_id(struct afs_call *call, struct sk_buff *skb, 751 bool last) 752 { 753 size_t len = skb->len; 754 void *oibuf = (void *) &call->operation_ID; 755 756 _enter("{%u},{%zu},%d", call->offset, len, last); 757 758 ASSERTCMP(call->offset, <, 4); 759 760 /* the operation ID forms the first four bytes of the request data */ 761 len = min_t(size_t, len, 4 - call->offset); 762 if (skb_copy_bits(skb, 0, oibuf + call->offset, len) < 0) 763 BUG(); 764 if (!pskb_pull(skb, len)) 765 BUG(); 766 call->offset += len; 767 768 if (call->offset < 4) { 769 if (last) { 770 _leave(" = -EBADMSG [op ID short]"); 771 return -EBADMSG; 772 } 773 _leave(" = 0 [incomplete]"); 774 return 0; 775 } 776 777 call->state = AFS_CALL_AWAIT_REQUEST; 778 779 /* ask the cache manager to route the call (it'll change the call type 780 * if successful) */ 781 if (!afs_cm_incoming_call(call)) 782 return -ENOTSUPP; 783 784 /* pass responsibility for the remainer of this message off to the 785 * cache manager op */ 786 return call->type->deliver(call, skb, last); 787 } 788 789 /* 790 * send an empty reply 791 */ 792 void afs_send_empty_reply(struct afs_call *call) 793 { 794 struct msghdr msg; 795 796 _enter(""); 797 798 msg.msg_name = NULL; 799 msg.msg_namelen = 0; 800 iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, NULL, 0, 0); 801 msg.msg_control = NULL; 802 msg.msg_controllen = 0; 803 msg.msg_flags = 0; 804 805 call->state = AFS_CALL_AWAIT_ACK; 806 switch (rxrpc_kernel_send_data(call->rxcall, &msg, 0)) { 807 case 0: 808 _leave(" [replied]"); 809 return; 810 811 case -ENOMEM: 812 _debug("oom"); 813 rxrpc_kernel_abort_call(call->rxcall, RX_USER_ABORT); 814 default: 815 afs_end_call(call); 816 _leave(" [error]"); 817 return; 818 } 819 } 820 821 /* 822 * send a simple reply 823 */ 824 void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len) 825 { 826 struct msghdr msg; 827 struct kvec iov[1]; 828 int n; 829 830 _enter(""); 831 832 iov[0].iov_base = (void *) buf; 833 iov[0].iov_len = len; 834 msg.msg_name = NULL; 835 msg.msg_namelen = 0; 836 iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1, len); 837 msg.msg_control = NULL; 838 msg.msg_controllen = 0; 839 msg.msg_flags = 0; 840 841 call->state = AFS_CALL_AWAIT_ACK; 842 n = rxrpc_kernel_send_data(call->rxcall, &msg, len); 843 if (n >= 0) { 844 /* Success */ 845 _leave(" [replied]"); 846 return; 847 } 848 849 if (n == -ENOMEM) { 850 _debug("oom"); 851 rxrpc_kernel_abort_call(call->rxcall, RX_USER_ABORT); 852 } 853 afs_end_call(call); 854 _leave(" [error]"); 855 } 856 857 /* 858 * extract a piece of data from the received data socket buffers 859 */ 860 int afs_extract_data(struct afs_call *call, struct sk_buff *skb, 861 bool last, void *buf, size_t count) 862 { 863 size_t len = skb->len; 864 865 _enter("{%u},{%zu},%d,,%zu", call->offset, len, last, count); 866 867 ASSERTCMP(call->offset, <, count); 868 869 len = min_t(size_t, len, count - call->offset); 870 if (skb_copy_bits(skb, 0, buf + call->offset, len) < 0 || 871 !pskb_pull(skb, len)) 872 BUG(); 873 call->offset += len; 874 875 if (call->offset < count) { 876 if (last) { 877 _leave(" = -EBADMSG [%d < %zu]", call->offset, count); 878 return -EBADMSG; 879 } 880 _leave(" = -EAGAIN"); 881 return -EAGAIN; 882 } 883 return 0; 884 } 885