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