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