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 <linux/sched/signal.h> 14 15 #include <net/sock.h> 16 #include <net/af_rxrpc.h> 17 #include "internal.h" 18 #include "afs_cm.h" 19 20 struct workqueue_struct *afs_async_calls; 21 22 static void afs_wake_up_call_waiter(struct sock *, struct rxrpc_call *, unsigned long); 23 static long afs_wait_for_call_to_complete(struct afs_call *, struct afs_addr_cursor *); 24 static void afs_wake_up_async_call(struct sock *, struct rxrpc_call *, unsigned long); 25 static void afs_process_async_call(struct work_struct *); 26 static void afs_rx_new_call(struct sock *, struct rxrpc_call *, unsigned long); 27 static void afs_rx_discard_new_call(struct rxrpc_call *, unsigned long); 28 static int afs_deliver_cm_op_id(struct afs_call *); 29 30 /* asynchronous incoming call initial processing */ 31 static const struct afs_call_type afs_RXCMxxxx = { 32 .name = "CB.xxxx", 33 .deliver = afs_deliver_cm_op_id, 34 }; 35 36 /* 37 * open an RxRPC socket and bind it to be a server for callback notifications 38 * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT 39 */ 40 int afs_open_socket(struct afs_net *net) 41 { 42 struct sockaddr_rxrpc srx; 43 struct socket *socket; 44 int ret; 45 46 _enter(""); 47 48 ret = sock_create_kern(&init_net, AF_RXRPC, SOCK_DGRAM, PF_INET6, &socket); 49 if (ret < 0) 50 goto error_1; 51 52 socket->sk->sk_allocation = GFP_NOFS; 53 54 /* bind the callback manager's address to make this a server socket */ 55 memset(&srx, 0, sizeof(srx)); 56 srx.srx_family = AF_RXRPC; 57 srx.srx_service = CM_SERVICE; 58 srx.transport_type = SOCK_DGRAM; 59 srx.transport_len = sizeof(srx.transport.sin6); 60 srx.transport.sin6.sin6_family = AF_INET6; 61 srx.transport.sin6.sin6_port = htons(AFS_CM_PORT); 62 63 ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx)); 64 if (ret == -EADDRINUSE) { 65 srx.transport.sin6.sin6_port = 0; 66 ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx)); 67 } 68 if (ret < 0) 69 goto error_2; 70 71 rxrpc_kernel_new_call_notification(socket, afs_rx_new_call, 72 afs_rx_discard_new_call); 73 74 ret = kernel_listen(socket, INT_MAX); 75 if (ret < 0) 76 goto error_2; 77 78 net->socket = socket; 79 afs_charge_preallocation(&net->charge_preallocation_work); 80 _leave(" = 0"); 81 return 0; 82 83 error_2: 84 sock_release(socket); 85 error_1: 86 _leave(" = %d", ret); 87 return ret; 88 } 89 90 /* 91 * close the RxRPC socket AFS was using 92 */ 93 void afs_close_socket(struct afs_net *net) 94 { 95 _enter(""); 96 97 kernel_listen(net->socket, 0); 98 flush_workqueue(afs_async_calls); 99 100 if (net->spare_incoming_call) { 101 afs_put_call(net->spare_incoming_call); 102 net->spare_incoming_call = NULL; 103 } 104 105 _debug("outstanding %u", atomic_read(&net->nr_outstanding_calls)); 106 wait_on_atomic_t(&net->nr_outstanding_calls, atomic_t_wait, 107 TASK_UNINTERRUPTIBLE); 108 _debug("no outstanding calls"); 109 110 kernel_sock_shutdown(net->socket, SHUT_RDWR); 111 flush_workqueue(afs_async_calls); 112 sock_release(net->socket); 113 114 _debug("dework"); 115 _leave(""); 116 } 117 118 /* 119 * Allocate a call. 120 */ 121 static struct afs_call *afs_alloc_call(struct afs_net *net, 122 const struct afs_call_type *type, 123 gfp_t gfp) 124 { 125 struct afs_call *call; 126 int o; 127 128 call = kzalloc(sizeof(*call), gfp); 129 if (!call) 130 return NULL; 131 132 call->type = type; 133 call->net = net; 134 atomic_set(&call->usage, 1); 135 INIT_WORK(&call->async_work, afs_process_async_call); 136 init_waitqueue_head(&call->waitq); 137 spin_lock_init(&call->state_lock); 138 139 o = atomic_inc_return(&net->nr_outstanding_calls); 140 trace_afs_call(call, afs_call_trace_alloc, 1, o, 141 __builtin_return_address(0)); 142 return call; 143 } 144 145 /* 146 * Dispose of a reference on a call. 147 */ 148 void afs_put_call(struct afs_call *call) 149 { 150 struct afs_net *net = call->net; 151 int n = atomic_dec_return(&call->usage); 152 int o = atomic_read(&net->nr_outstanding_calls); 153 154 trace_afs_call(call, afs_call_trace_put, n + 1, o, 155 __builtin_return_address(0)); 156 157 ASSERTCMP(n, >=, 0); 158 if (n == 0) { 159 ASSERT(!work_pending(&call->async_work)); 160 ASSERT(call->type->name != NULL); 161 162 if (call->rxcall) { 163 rxrpc_kernel_end_call(net->socket, call->rxcall); 164 call->rxcall = NULL; 165 } 166 if (call->type->destructor) 167 call->type->destructor(call); 168 169 afs_put_server(call->net, call->cm_server); 170 afs_put_cb_interest(call->net, call->cbi); 171 kfree(call->request); 172 kfree(call); 173 174 o = atomic_dec_return(&net->nr_outstanding_calls); 175 trace_afs_call(call, afs_call_trace_free, 0, o, 176 __builtin_return_address(0)); 177 if (o == 0) 178 wake_up_atomic_t(&net->nr_outstanding_calls); 179 } 180 } 181 182 /* 183 * Queue the call for actual work. Returns 0 unconditionally for convenience. 184 */ 185 int afs_queue_call_work(struct afs_call *call) 186 { 187 int u = atomic_inc_return(&call->usage); 188 189 trace_afs_call(call, afs_call_trace_work, u, 190 atomic_read(&call->net->nr_outstanding_calls), 191 __builtin_return_address(0)); 192 193 INIT_WORK(&call->work, call->type->work); 194 195 if (!queue_work(afs_wq, &call->work)) 196 afs_put_call(call); 197 return 0; 198 } 199 200 /* 201 * allocate a call with flat request and reply buffers 202 */ 203 struct afs_call *afs_alloc_flat_call(struct afs_net *net, 204 const struct afs_call_type *type, 205 size_t request_size, size_t reply_max) 206 { 207 struct afs_call *call; 208 209 call = afs_alloc_call(net, type, GFP_NOFS); 210 if (!call) 211 goto nomem_call; 212 213 if (request_size) { 214 call->request_size = request_size; 215 call->request = kmalloc(request_size, GFP_NOFS); 216 if (!call->request) 217 goto nomem_free; 218 } 219 220 if (reply_max) { 221 call->reply_max = reply_max; 222 call->buffer = kmalloc(reply_max, GFP_NOFS); 223 if (!call->buffer) 224 goto nomem_free; 225 } 226 227 call->operation_ID = type->op; 228 init_waitqueue_head(&call->waitq); 229 return call; 230 231 nomem_free: 232 afs_put_call(call); 233 nomem_call: 234 return NULL; 235 } 236 237 /* 238 * clean up a call with flat buffer 239 */ 240 void afs_flat_call_destructor(struct afs_call *call) 241 { 242 _enter(""); 243 244 kfree(call->request); 245 call->request = NULL; 246 kfree(call->buffer); 247 call->buffer = NULL; 248 } 249 250 #define AFS_BVEC_MAX 8 251 252 /* 253 * Load the given bvec with the next few pages. 254 */ 255 static void afs_load_bvec(struct afs_call *call, struct msghdr *msg, 256 struct bio_vec *bv, pgoff_t first, pgoff_t last, 257 unsigned offset) 258 { 259 struct page *pages[AFS_BVEC_MAX]; 260 unsigned int nr, n, i, to, bytes = 0; 261 262 nr = min_t(pgoff_t, last - first + 1, AFS_BVEC_MAX); 263 n = find_get_pages_contig(call->mapping, first, nr, pages); 264 ASSERTCMP(n, ==, nr); 265 266 msg->msg_flags |= MSG_MORE; 267 for (i = 0; i < nr; i++) { 268 to = PAGE_SIZE; 269 if (first + i >= last) { 270 to = call->last_to; 271 msg->msg_flags &= ~MSG_MORE; 272 } 273 bv[i].bv_page = pages[i]; 274 bv[i].bv_len = to - offset; 275 bv[i].bv_offset = offset; 276 bytes += to - offset; 277 offset = 0; 278 } 279 280 iov_iter_bvec(&msg->msg_iter, WRITE | ITER_BVEC, bv, nr, bytes); 281 } 282 283 /* 284 * Advance the AFS call state when the RxRPC call ends the transmit phase. 285 */ 286 static void afs_notify_end_request_tx(struct sock *sock, 287 struct rxrpc_call *rxcall, 288 unsigned long call_user_ID) 289 { 290 struct afs_call *call = (struct afs_call *)call_user_ID; 291 292 afs_set_call_state(call, AFS_CALL_CL_REQUESTING, AFS_CALL_CL_AWAIT_REPLY); 293 } 294 295 /* 296 * attach the data from a bunch of pages on an inode to a call 297 */ 298 static int afs_send_pages(struct afs_call *call, struct msghdr *msg) 299 { 300 struct bio_vec bv[AFS_BVEC_MAX]; 301 unsigned int bytes, nr, loop, offset; 302 pgoff_t first = call->first, last = call->last; 303 int ret; 304 305 offset = call->first_offset; 306 call->first_offset = 0; 307 308 do { 309 afs_load_bvec(call, msg, bv, first, last, offset); 310 trace_afs_send_pages(call, msg, first, last, offset); 311 312 offset = 0; 313 bytes = msg->msg_iter.count; 314 nr = msg->msg_iter.nr_segs; 315 316 ret = rxrpc_kernel_send_data(call->net->socket, call->rxcall, msg, 317 bytes, afs_notify_end_request_tx); 318 for (loop = 0; loop < nr; loop++) 319 put_page(bv[loop].bv_page); 320 if (ret < 0) 321 break; 322 323 first += nr; 324 } while (first <= last); 325 326 trace_afs_sent_pages(call, call->first, last, first, ret); 327 return ret; 328 } 329 330 /* 331 * initiate a call 332 */ 333 long afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call, 334 gfp_t gfp, bool async) 335 { 336 struct sockaddr_rxrpc *srx = ac->addr; 337 struct rxrpc_call *rxcall; 338 struct msghdr msg; 339 struct kvec iov[1]; 340 size_t offset; 341 s64 tx_total_len; 342 int ret; 343 344 _enter(",{%pISp},", &srx->transport); 345 346 ASSERT(call->type != NULL); 347 ASSERT(call->type->name != NULL); 348 349 _debug("____MAKE %p{%s,%x} [%d]____", 350 call, call->type->name, key_serial(call->key), 351 atomic_read(&call->net->nr_outstanding_calls)); 352 353 call->async = async; 354 355 /* Work out the length we're going to transmit. This is awkward for 356 * calls such as FS.StoreData where there's an extra injection of data 357 * after the initial fixed part. 358 */ 359 tx_total_len = call->request_size; 360 if (call->send_pages) { 361 if (call->last == call->first) { 362 tx_total_len += call->last_to - call->first_offset; 363 } else { 364 /* It looks mathematically like you should be able to 365 * combine the following lines with the ones above, but 366 * unsigned arithmetic is fun when it wraps... 367 */ 368 tx_total_len += PAGE_SIZE - call->first_offset; 369 tx_total_len += call->last_to; 370 tx_total_len += (call->last - call->first - 1) * PAGE_SIZE; 371 } 372 } 373 374 /* create a call */ 375 rxcall = rxrpc_kernel_begin_call(call->net->socket, srx, call->key, 376 (unsigned long)call, 377 tx_total_len, gfp, 378 (async ? 379 afs_wake_up_async_call : 380 afs_wake_up_call_waiter), 381 call->upgrade); 382 if (IS_ERR(rxcall)) { 383 ret = PTR_ERR(rxcall); 384 goto error_kill_call; 385 } 386 387 call->rxcall = rxcall; 388 389 /* send the request */ 390 iov[0].iov_base = call->request; 391 iov[0].iov_len = call->request_size; 392 393 msg.msg_name = NULL; 394 msg.msg_namelen = 0; 395 iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1, 396 call->request_size); 397 msg.msg_control = NULL; 398 msg.msg_controllen = 0; 399 msg.msg_flags = MSG_WAITALL | (call->send_pages ? MSG_MORE : 0); 400 401 ret = rxrpc_kernel_send_data(call->net->socket, rxcall, 402 &msg, call->request_size, 403 afs_notify_end_request_tx); 404 if (ret < 0) 405 goto error_do_abort; 406 407 if (call->send_pages) { 408 ret = afs_send_pages(call, &msg); 409 if (ret < 0) 410 goto error_do_abort; 411 } 412 413 /* at this point, an async call may no longer exist as it may have 414 * already completed */ 415 if (call->async) 416 return -EINPROGRESS; 417 418 return afs_wait_for_call_to_complete(call, ac); 419 420 error_do_abort: 421 call->state = AFS_CALL_COMPLETE; 422 if (ret != -ECONNABORTED) { 423 rxrpc_kernel_abort_call(call->net->socket, rxcall, 424 RX_USER_ABORT, ret, "KSD"); 425 } else { 426 offset = 0; 427 rxrpc_kernel_recv_data(call->net->socket, rxcall, NULL, 428 0, &offset, false, &call->abort_code, 429 &call->service_id); 430 ac->abort_code = call->abort_code; 431 ac->responded = true; 432 } 433 call->error = ret; 434 trace_afs_call_done(call); 435 error_kill_call: 436 afs_put_call(call); 437 ac->error = ret; 438 _leave(" = %d", ret); 439 return ret; 440 } 441 442 /* 443 * deliver messages to a call 444 */ 445 static void afs_deliver_to_call(struct afs_call *call) 446 { 447 enum afs_call_state state; 448 u32 abort_code, remote_abort = 0; 449 int ret; 450 451 _enter("%s", call->type->name); 452 453 while (state = READ_ONCE(call->state), 454 state == AFS_CALL_CL_AWAIT_REPLY || 455 state == AFS_CALL_SV_AWAIT_OP_ID || 456 state == AFS_CALL_SV_AWAIT_REQUEST || 457 state == AFS_CALL_SV_AWAIT_ACK 458 ) { 459 if (state == AFS_CALL_SV_AWAIT_ACK) { 460 size_t offset = 0; 461 ret = rxrpc_kernel_recv_data(call->net->socket, 462 call->rxcall, 463 NULL, 0, &offset, false, 464 &remote_abort, 465 &call->service_id); 466 trace_afs_recv_data(call, 0, offset, false, ret); 467 468 if (ret == -EINPROGRESS || ret == -EAGAIN) 469 return; 470 if (ret < 0 || ret == 1) { 471 if (ret == 1) 472 ret = 0; 473 goto call_complete; 474 } 475 return; 476 } 477 478 ret = call->type->deliver(call); 479 state = READ_ONCE(call->state); 480 switch (ret) { 481 case 0: 482 if (state == AFS_CALL_CL_PROC_REPLY) 483 goto call_complete; 484 ASSERTCMP(state, >, AFS_CALL_CL_PROC_REPLY); 485 goto done; 486 case -EINPROGRESS: 487 case -EAGAIN: 488 goto out; 489 case -EIO: 490 case -ECONNABORTED: 491 ASSERTCMP(state, ==, AFS_CALL_COMPLETE); 492 goto done; 493 case -ENOTCONN: 494 abort_code = RX_CALL_DEAD; 495 rxrpc_kernel_abort_call(call->net->socket, call->rxcall, 496 abort_code, ret, "KNC"); 497 goto local_abort; 498 case -ENOTSUPP: 499 abort_code = RXGEN_OPCODE; 500 rxrpc_kernel_abort_call(call->net->socket, call->rxcall, 501 abort_code, ret, "KIV"); 502 goto local_abort; 503 case -ENODATA: 504 case -EBADMSG: 505 case -EMSGSIZE: 506 default: 507 abort_code = RXGEN_CC_UNMARSHAL; 508 if (state != AFS_CALL_CL_AWAIT_REPLY) 509 abort_code = RXGEN_SS_UNMARSHAL; 510 rxrpc_kernel_abort_call(call->net->socket, call->rxcall, 511 abort_code, -EBADMSG, "KUM"); 512 goto local_abort; 513 } 514 } 515 516 done: 517 if (state == AFS_CALL_COMPLETE && call->incoming) 518 afs_put_call(call); 519 out: 520 _leave(""); 521 return; 522 523 local_abort: 524 abort_code = 0; 525 call_complete: 526 afs_set_call_complete(call, ret, remote_abort); 527 state = AFS_CALL_COMPLETE; 528 goto done; 529 } 530 531 /* 532 * wait synchronously for a call to complete 533 */ 534 static long afs_wait_for_call_to_complete(struct afs_call *call, 535 struct afs_addr_cursor *ac) 536 { 537 signed long rtt2, timeout; 538 long ret; 539 u64 rtt; 540 u32 life, last_life; 541 542 DECLARE_WAITQUEUE(myself, current); 543 544 _enter(""); 545 546 rtt = rxrpc_kernel_get_rtt(call->net->socket, call->rxcall); 547 rtt2 = nsecs_to_jiffies64(rtt) * 2; 548 if (rtt2 < 2) 549 rtt2 = 2; 550 551 timeout = rtt2; 552 last_life = rxrpc_kernel_check_life(call->net->socket, call->rxcall); 553 554 add_wait_queue(&call->waitq, &myself); 555 for (;;) { 556 set_current_state(TASK_UNINTERRUPTIBLE); 557 558 /* deliver any messages that are in the queue */ 559 if (!afs_check_call_state(call, AFS_CALL_COMPLETE) && 560 call->need_attention) { 561 call->need_attention = false; 562 __set_current_state(TASK_RUNNING); 563 afs_deliver_to_call(call); 564 continue; 565 } 566 567 if (afs_check_call_state(call, AFS_CALL_COMPLETE)) 568 break; 569 570 life = rxrpc_kernel_check_life(call->net->socket, call->rxcall); 571 if (timeout == 0 && 572 life == last_life && signal_pending(current)) 573 break; 574 575 if (life != last_life) { 576 timeout = rtt2; 577 last_life = life; 578 } 579 580 timeout = schedule_timeout(timeout); 581 } 582 583 remove_wait_queue(&call->waitq, &myself); 584 __set_current_state(TASK_RUNNING); 585 586 /* Kill off the call if it's still live. */ 587 if (!afs_check_call_state(call, AFS_CALL_COMPLETE)) { 588 _debug("call interrupted"); 589 if (rxrpc_kernel_abort_call(call->net->socket, call->rxcall, 590 RX_USER_ABORT, -EINTR, "KWI")) 591 afs_set_call_complete(call, -EINTR, 0); 592 } 593 594 spin_lock_bh(&call->state_lock); 595 ac->abort_code = call->abort_code; 596 ac->error = call->error; 597 spin_unlock_bh(&call->state_lock); 598 599 ret = ac->error; 600 switch (ret) { 601 case 0: 602 if (call->ret_reply0) { 603 ret = (long)call->reply[0]; 604 call->reply[0] = NULL; 605 } 606 /* Fall through */ 607 case -ECONNABORTED: 608 ac->responded = true; 609 break; 610 } 611 612 _debug("call complete"); 613 afs_put_call(call); 614 _leave(" = %p", (void *)ret); 615 return ret; 616 } 617 618 /* 619 * wake up a waiting call 620 */ 621 static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall, 622 unsigned long call_user_ID) 623 { 624 struct afs_call *call = (struct afs_call *)call_user_ID; 625 626 call->need_attention = true; 627 wake_up(&call->waitq); 628 } 629 630 /* 631 * wake up an asynchronous call 632 */ 633 static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall, 634 unsigned long call_user_ID) 635 { 636 struct afs_call *call = (struct afs_call *)call_user_ID; 637 int u; 638 639 trace_afs_notify_call(rxcall, call); 640 call->need_attention = true; 641 642 u = __atomic_add_unless(&call->usage, 1, 0); 643 if (u != 0) { 644 trace_afs_call(call, afs_call_trace_wake, u, 645 atomic_read(&call->net->nr_outstanding_calls), 646 __builtin_return_address(0)); 647 648 if (!queue_work(afs_async_calls, &call->async_work)) 649 afs_put_call(call); 650 } 651 } 652 653 /* 654 * Delete an asynchronous call. The work item carries a ref to the call struct 655 * that we need to release. 656 */ 657 static void afs_delete_async_call(struct work_struct *work) 658 { 659 struct afs_call *call = container_of(work, struct afs_call, async_work); 660 661 _enter(""); 662 663 afs_put_call(call); 664 665 _leave(""); 666 } 667 668 /* 669 * Perform I/O processing on an asynchronous call. The work item carries a ref 670 * to the call struct that we either need to release or to pass on. 671 */ 672 static void afs_process_async_call(struct work_struct *work) 673 { 674 struct afs_call *call = container_of(work, struct afs_call, async_work); 675 676 _enter(""); 677 678 if (call->state < AFS_CALL_COMPLETE && call->need_attention) { 679 call->need_attention = false; 680 afs_deliver_to_call(call); 681 } 682 683 if (call->state == AFS_CALL_COMPLETE) { 684 call->reply[0] = NULL; 685 686 /* We have two refs to release - one from the alloc and one 687 * queued with the work item - and we can't just deallocate the 688 * call because the work item may be queued again. 689 */ 690 call->async_work.func = afs_delete_async_call; 691 if (!queue_work(afs_async_calls, &call->async_work)) 692 afs_put_call(call); 693 } 694 695 afs_put_call(call); 696 _leave(""); 697 } 698 699 static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID) 700 { 701 struct afs_call *call = (struct afs_call *)user_call_ID; 702 703 call->rxcall = rxcall; 704 } 705 706 /* 707 * Charge the incoming call preallocation. 708 */ 709 void afs_charge_preallocation(struct work_struct *work) 710 { 711 struct afs_net *net = 712 container_of(work, struct afs_net, charge_preallocation_work); 713 struct afs_call *call = net->spare_incoming_call; 714 715 for (;;) { 716 if (!call) { 717 call = afs_alloc_call(net, &afs_RXCMxxxx, GFP_KERNEL); 718 if (!call) 719 break; 720 721 call->async = true; 722 call->state = AFS_CALL_SV_AWAIT_OP_ID; 723 init_waitqueue_head(&call->waitq); 724 } 725 726 if (rxrpc_kernel_charge_accept(net->socket, 727 afs_wake_up_async_call, 728 afs_rx_attach, 729 (unsigned long)call, 730 GFP_KERNEL) < 0) 731 break; 732 call = NULL; 733 } 734 net->spare_incoming_call = call; 735 } 736 737 /* 738 * Discard a preallocated call when a socket is shut down. 739 */ 740 static void afs_rx_discard_new_call(struct rxrpc_call *rxcall, 741 unsigned long user_call_ID) 742 { 743 struct afs_call *call = (struct afs_call *)user_call_ID; 744 745 call->rxcall = NULL; 746 afs_put_call(call); 747 } 748 749 /* 750 * Notification of an incoming call. 751 */ 752 static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall, 753 unsigned long user_call_ID) 754 { 755 struct afs_net *net = afs_sock2net(sk); 756 757 queue_work(afs_wq, &net->charge_preallocation_work); 758 } 759 760 /* 761 * Grab the operation ID from an incoming cache manager call. The socket 762 * buffer is discarded on error or if we don't yet have sufficient data. 763 */ 764 static int afs_deliver_cm_op_id(struct afs_call *call) 765 { 766 int ret; 767 768 _enter("{%zu}", call->offset); 769 770 ASSERTCMP(call->offset, <, 4); 771 772 /* the operation ID forms the first four bytes of the request data */ 773 ret = afs_extract_data(call, &call->tmp, 4, true); 774 if (ret < 0) 775 return ret; 776 777 call->operation_ID = ntohl(call->tmp); 778 afs_set_call_state(call, AFS_CALL_SV_AWAIT_OP_ID, AFS_CALL_SV_AWAIT_REQUEST); 779 call->offset = 0; 780 781 /* ask the cache manager to route the call (it'll change the call type 782 * if successful) */ 783 if (!afs_cm_incoming_call(call)) 784 return -ENOTSUPP; 785 786 trace_afs_cb_call(call); 787 788 /* pass responsibility for the remainer of this message off to the 789 * cache manager op */ 790 return call->type->deliver(call); 791 } 792 793 /* 794 * Advance the AFS call state when an RxRPC service call ends the transmit 795 * phase. 796 */ 797 static void afs_notify_end_reply_tx(struct sock *sock, 798 struct rxrpc_call *rxcall, 799 unsigned long call_user_ID) 800 { 801 struct afs_call *call = (struct afs_call *)call_user_ID; 802 803 afs_set_call_state(call, AFS_CALL_SV_REPLYING, AFS_CALL_SV_AWAIT_ACK); 804 } 805 806 /* 807 * send an empty reply 808 */ 809 void afs_send_empty_reply(struct afs_call *call) 810 { 811 struct afs_net *net = call->net; 812 struct msghdr msg; 813 814 _enter(""); 815 816 rxrpc_kernel_set_tx_length(net->socket, call->rxcall, 0); 817 818 msg.msg_name = NULL; 819 msg.msg_namelen = 0; 820 iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, NULL, 0, 0); 821 msg.msg_control = NULL; 822 msg.msg_controllen = 0; 823 msg.msg_flags = 0; 824 825 switch (rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, 0, 826 afs_notify_end_reply_tx)) { 827 case 0: 828 _leave(" [replied]"); 829 return; 830 831 case -ENOMEM: 832 _debug("oom"); 833 rxrpc_kernel_abort_call(net->socket, call->rxcall, 834 RX_USER_ABORT, -ENOMEM, "KOO"); 835 default: 836 _leave(" [error]"); 837 return; 838 } 839 } 840 841 /* 842 * send a simple reply 843 */ 844 void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len) 845 { 846 struct afs_net *net = call->net; 847 struct msghdr msg; 848 struct kvec iov[1]; 849 int n; 850 851 _enter(""); 852 853 rxrpc_kernel_set_tx_length(net->socket, call->rxcall, len); 854 855 iov[0].iov_base = (void *) buf; 856 iov[0].iov_len = len; 857 msg.msg_name = NULL; 858 msg.msg_namelen = 0; 859 iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1, len); 860 msg.msg_control = NULL; 861 msg.msg_controllen = 0; 862 msg.msg_flags = 0; 863 864 n = rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, len, 865 afs_notify_end_reply_tx); 866 if (n >= 0) { 867 /* Success */ 868 _leave(" [replied]"); 869 return; 870 } 871 872 if (n == -ENOMEM) { 873 _debug("oom"); 874 rxrpc_kernel_abort_call(net->socket, call->rxcall, 875 RX_USER_ABORT, -ENOMEM, "KOO"); 876 } 877 _leave(" [error]"); 878 } 879 880 /* 881 * Extract a piece of data from the received data socket buffers. 882 */ 883 int afs_extract_data(struct afs_call *call, void *buf, size_t count, 884 bool want_more) 885 { 886 struct afs_net *net = call->net; 887 enum afs_call_state state; 888 u32 remote_abort; 889 int ret; 890 891 _enter("{%s,%zu},,%zu,%d", 892 call->type->name, call->offset, count, want_more); 893 894 ASSERTCMP(call->offset, <=, count); 895 896 ret = rxrpc_kernel_recv_data(net->socket, call->rxcall, 897 buf, count, &call->offset, 898 want_more, &remote_abort, 899 &call->service_id); 900 trace_afs_recv_data(call, count, call->offset, want_more, ret); 901 if (ret == 0 || ret == -EAGAIN) 902 return ret; 903 904 state = READ_ONCE(call->state); 905 if (ret == 1) { 906 switch (state) { 907 case AFS_CALL_CL_AWAIT_REPLY: 908 afs_set_call_state(call, state, AFS_CALL_CL_PROC_REPLY); 909 break; 910 case AFS_CALL_SV_AWAIT_REQUEST: 911 afs_set_call_state(call, state, AFS_CALL_SV_REPLYING); 912 break; 913 case AFS_CALL_COMPLETE: 914 kdebug("prem complete %d", call->error); 915 return -EIO; 916 default: 917 break; 918 } 919 return 0; 920 } 921 922 afs_set_call_complete(call, ret, remote_abort); 923 return ret; 924 } 925