fs/afs/rxrpc.c

   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 <rxrpc/packet.h>
  18 #include "internal.h"
  19 #include "afs_cm.h"
  20
  21 struct socket *afs_socket; /* my RxRPC socket */
  22 static struct workqueue_struct *afs_async_calls;
  23 static struct afs_call *afs_spare_incoming_call;
  24 atomic_t afs_outstanding_calls;
  25
  26 static void afs_wake_up_call_waiter(struct sock *, struct rxrpc_call *, unsigned long);
  27 static int afs_wait_for_call_to_complete(struct afs_call *);
  28 static void afs_wake_up_async_call(struct sock *, struct rxrpc_call *, unsigned long);
  29 static void afs_process_async_call(struct work_struct *);
  30 static void afs_rx_new_call(struct sock *, struct rxrpc_call *, unsigned long);
  31 static void afs_rx_discard_new_call(struct rxrpc_call *, unsigned long);
  32 static int afs_deliver_cm_op_id(struct afs_call *);
  33
  34 /* asynchronous incoming call initial processing */
  35 static const struct afs_call_type afs_RXCMxxxx = {
  36         .name           = "CB.xxxx",
  37         .deliver        = afs_deliver_cm_op_id,
  38         .abort_to_error = afs_abort_to_error,
  39 };
  40
  41 static void afs_charge_preallocation(struct work_struct *);
  42
  43 static DECLARE_WORK(afs_charge_preallocation_work, afs_charge_preallocation);
  44
  45 static int afs_wait_atomic_t(atomic_t *p)
  46 {
  47         schedule();
  48         return 0;
  49 }
  50
  51 /*
  52  * open an RxRPC socket and bind it to be a server for callback notifications
  53  * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT
  54  */
  55 int afs_open_socket(void)
  56 {
  57         struct sockaddr_rxrpc srx;
  58         struct socket *socket;
  59         int ret;
  60
  61         _enter("");
  62
  63         ret = -ENOMEM;
  64         afs_async_calls = alloc_workqueue("kafsd", WQ_MEM_RECLAIM, 0);
  65         if (!afs_async_calls)
  66                 goto error_0;
  67
  68         ret = sock_create_kern(&init_net, AF_RXRPC, SOCK_DGRAM, PF_INET, &socket);
  69         if (ret < 0)
  70                 goto error_1;
  71
  72         socket->sk->sk_allocation = GFP_NOFS;
  73
  74         /* bind the callback manager's address to make this a server socket */
  75         srx.srx_family                  = AF_RXRPC;
  76         srx.srx_service                 = CM_SERVICE;
  77         srx.transport_type              = SOCK_DGRAM;
  78         srx.transport_len               = sizeof(srx.transport.sin);
  79         srx.transport.sin.sin_family    = AF_INET;
  80         srx.transport.sin.sin_port      = htons(AFS_CM_PORT);
  81         memset(&srx.transport.sin.sin_addr, 0,
  82                sizeof(srx.transport.sin.sin_addr));
  83
  84         ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
  85         if (ret < 0)
  86                 goto error_2;
  87
  88         rxrpc_kernel_new_call_notification(socket, afs_rx_new_call,
  89                                            afs_rx_discard_new_call);
  90
  91         ret = kernel_listen(socket, INT_MAX);
  92         if (ret < 0)
  93                 goto error_2;
  94
  95         afs_socket = socket;
  96         afs_charge_preallocation(NULL);
  97         _leave(" = 0");
  98         return 0;
  99
 100 error_2:
 101         sock_release(socket);
 102 error_1:
 103         destroy_workqueue(afs_async_calls);
 104 error_0:
 105         _leave(" = %d", ret);
 106         return ret;
 107 }
 108
 109 /*
 110  * close the RxRPC socket AFS was using
 111  */
 112 void afs_close_socket(void)
 113 {
 114         _enter("");
 115
 116         kernel_listen(afs_socket, 0);
 117         flush_workqueue(afs_async_calls);
 118
 119         if (afs_spare_incoming_call) {
 120                 afs_put_call(afs_spare_incoming_call);
 121                 afs_spare_incoming_call = NULL;
 122         }
 123
 124         _debug("outstanding %u", atomic_read(&afs_outstanding_calls));
 125         wait_on_atomic_t(&afs_outstanding_calls, afs_wait_atomic_t,
 126                          TASK_UNINTERRUPTIBLE);
 127         _debug("no outstanding calls");
 128
 129         kernel_sock_shutdown(afs_socket, SHUT_RDWR);
 130         flush_workqueue(afs_async_calls);
 131         sock_release(afs_socket);
 132
 133         _debug("dework");
 134         destroy_workqueue(afs_async_calls);
 135         _leave("");
 136 }
 137
 138 /*
 139  * Allocate a call.
 140  */
 141 static struct afs_call *afs_alloc_call(const struct afs_call_type *type,
 142                                        gfp_t gfp)
 143 {
 144         struct afs_call *call;
 145         int o;
 146
 147         call = kzalloc(sizeof(*call), gfp);
 148         if (!call)
 149                 return NULL;
 150
 151         call->type = type;
 152         atomic_set(&call->usage, 1);
 153         INIT_WORK(&call->async_work, afs_process_async_call);
 154         init_waitqueue_head(&call->waitq);
 155
 156         o = atomic_inc_return(&afs_outstanding_calls);
 157         trace_afs_call(call, afs_call_trace_alloc, 1, o,
 158                        __builtin_return_address(0));
 159         return call;
 160 }
 161
 162 /*
 163  * Dispose of a reference on a call.
 164  */
 165 void afs_put_call(struct afs_call *call)
 166 {
 167         int n = atomic_dec_return(&call->usage);
 168         int o = atomic_read(&afs_outstanding_calls);
 169
 170         trace_afs_call(call, afs_call_trace_put, n + 1, o,
 171                        __builtin_return_address(0));
 172
 173         ASSERTCMP(n, >=, 0);
 174         if (n == 0) {
 175                 ASSERT(!work_pending(&call->async_work));
 176                 ASSERT(call->type->name != NULL);
 177
 178                 if (call->rxcall) {
 179                         rxrpc_kernel_end_call(afs_socket, call->rxcall);
 180                         call->rxcall = NULL;
 181                 }
 182                 if (call->type->destructor)
 183                         call->type->destructor(call);
 184
 185                 kfree(call->request);
 186                 kfree(call);
 187
 188                 o = atomic_dec_return(&afs_outstanding_calls);
 189                 trace_afs_call(call, afs_call_trace_free, 0, o,
 190                                __builtin_return_address(0));
 191                 if (o == 0)
 192                         wake_up_atomic_t(&afs_outstanding_calls);
 193         }
 194 }
 195
 196 /*
 197  * Queue the call for actual work.  Returns 0 unconditionally for convenience.
 198  */
 199 int afs_queue_call_work(struct afs_call *call)
 200 {
 201         int u = atomic_inc_return(&call->usage);
 202
 203         trace_afs_call(call, afs_call_trace_work, u,
 204                        atomic_read(&afs_outstanding_calls),
 205                        __builtin_return_address(0));
 206
 207         INIT_WORK(&call->work, call->type->work);
 208
 209         if (!queue_work(afs_wq, &call->work))
 210                 afs_put_call(call);
 211         return 0;
 212 }
 213
 214 /*
 215  * allocate a call with flat request and reply buffers
 216  */
 217 struct afs_call *afs_alloc_flat_call(const struct afs_call_type *type,
 218                                      size_t request_size, size_t reply_max)
 219 {
 220         struct afs_call *call;
 221
 222         call = afs_alloc_call(type, GFP_NOFS);
 223         if (!call)
 224                 goto nomem_call;
 225
 226         if (request_size) {
 227                 call->request_size = request_size;
 228                 call->request = kmalloc(request_size, GFP_NOFS);
 229                 if (!call->request)
 230                         goto nomem_free;
 231         }
 232
 233         if (reply_max) {
 234                 call->reply_max = reply_max;
 235                 call->buffer = kmalloc(reply_max, GFP_NOFS);
 236                 if (!call->buffer)
 237                         goto nomem_free;
 238         }
 239
 240         init_waitqueue_head(&call->waitq);
 241         return call;
 242
 243 nomem_free:
 244         afs_put_call(call);
 245 nomem_call:
 246         return NULL;
 247 }
 248
 249 /*
 250  * clean up a call with flat buffer
 251  */
 252 void afs_flat_call_destructor(struct afs_call *call)
 253 {
 254         _enter("");
 255
 256         kfree(call->request);
 257         call->request = NULL;
 258         kfree(call->buffer);
 259         call->buffer = NULL;
 260 }
 261
 262 #define AFS_BVEC_MAX 8
 263
 264 /*
 265  * Load the given bvec with the next few pages.
 266  */
 267 static void afs_load_bvec(struct afs_call *call, struct msghdr *msg,
 268                           struct bio_vec *bv, pgoff_t first, pgoff_t last,
 269                           unsigned offset)
 270 {
 271         struct page *pages[AFS_BVEC_MAX];
 272         unsigned int nr, n, i, to, bytes = 0;
 273
 274         nr = min_t(pgoff_t, last - first + 1, AFS_BVEC_MAX);
 275         n = find_get_pages_contig(call->mapping, first, nr, pages);
 276         ASSERTCMP(n, ==, nr);
 277
 278         msg->msg_flags |= MSG_MORE;
 279         for (i = 0; i < nr; i++) {
 280                 to = PAGE_SIZE;
 281                 if (first + i >= last) {
 282                         to = call->last_to;
 283                         msg->msg_flags &= ~MSG_MORE;
 284                 }
 285                 bv[i].bv_page = pages[i];
 286                 bv[i].bv_len = to - offset;
 287                 bv[i].bv_offset = offset;
 288                 bytes += to - offset;
 289                 offset = 0;
 290         }
 291
 292         iov_iter_bvec(&msg->msg_iter, WRITE | ITER_BVEC, bv, nr, bytes);
 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                 offset = 0;
 311                 bytes = msg->msg_iter.count;
 312                 nr = msg->msg_iter.nr_segs;
 313
 314                 /* Have to change the state *before* sending the last
 315                  * packet as RxRPC might give us the reply before it
 316                  * returns from sending the request.
 317                  */
 318                 if (first + nr - 1 >= last)
 319                         call->state = AFS_CALL_AWAIT_REPLY;
 320                 ret = rxrpc_kernel_send_data(afs_socket, call->rxcall,
 321                                              msg, bytes);
 322                 for (loop = 0; loop < nr; loop++)
 323                         put_page(bv[loop].bv_page);
 324                 if (ret < 0)
 325                         break;
 326
 327                 first += nr;
 328         } while (first <= last);
 329
 330         return ret;
 331 }
 332
 333 /*
 334  * initiate a call
 335  */
 336 int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp,
 337                   bool async)
 338 {
 339         struct sockaddr_rxrpc srx;
 340         struct rxrpc_call *rxcall;
 341         struct msghdr msg;
 342         struct kvec iov[1];
 343         size_t offset;
 344         s64 tx_total_len;
 345         u32 abort_code;
 346         int ret;
 347
 348         _enter("%x,{%d},", addr->s_addr, ntohs(call->port));
 349
 350         ASSERT(call->type != NULL);
 351         ASSERT(call->type->name != NULL);
 352
 353         _debug("____MAKE %p{%s,%x} [%d]____",
 354                call, call->type->name, key_serial(call->key),
 355                atomic_read(&afs_outstanding_calls));
 356
 357         call->async = async;
 358
 359         memset(&srx, 0, sizeof(srx));
 360         srx.srx_family = AF_RXRPC;
 361         srx.srx_service = call->service_id;
 362         srx.transport_type = SOCK_DGRAM;
 363         srx.transport_len = sizeof(srx.transport.sin);
 364         srx.transport.sin.sin_family = AF_INET;
 365         srx.transport.sin.sin_port = call->port;
 366         memcpy(&srx.transport.sin.sin_addr, addr, 4);
 367
 368         /* Work out the length we're going to transmit.  This is awkward for
 369          * calls such as FS.StoreData where there's an extra injection of data
 370          * after the initial fixed part.
 371          */
 372         tx_total_len = call->request_size;
 373         if (call->send_pages) {
 374                 tx_total_len += call->last_to - call->first_offset;
 375                 tx_total_len += (call->last - call->first) * PAGE_SIZE;
 376         }
 377
 378         /* create a call */
 379         rxcall = rxrpc_kernel_begin_call(afs_socket, &srx, call->key,
 380                                          (unsigned long)call,
 381                                          tx_total_len, gfp,
 382                                          (async ?
 383                                           afs_wake_up_async_call :
 384                                           afs_wake_up_call_waiter));
 385         call->key = NULL;
 386         if (IS_ERR(rxcall)) {
 387                 ret = PTR_ERR(rxcall);
 388                 goto error_kill_call;
 389         }
 390
 391         call->rxcall = rxcall;
 392
 393         /* send the request */
 394         iov[0].iov_base = call->request;
 395         iov[0].iov_len  = call->request_size;
 396
 397         msg.msg_name            = NULL;
 398         msg.msg_namelen         = 0;
 399         iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1,
 400                       call->request_size);
 401         msg.msg_control         = NULL;
 402         msg.msg_controllen      = 0;
 403         msg.msg_flags           = (call->send_pages ? MSG_MORE : 0);
 404
 405         /* We have to change the state *before* sending the last packet as
 406          * rxrpc might give us the reply before it returns from sending the
 407          * request.  Further, if the send fails, we may already have been given
 408          * a notification and may have collected it.
 409          */
 410         if (!call->send_pages)
 411                 call->state = AFS_CALL_AWAIT_REPLY;
 412         ret = rxrpc_kernel_send_data(afs_socket, rxcall,
 413                                      &msg, call->request_size);
 414         if (ret < 0)
 415                 goto error_do_abort;
 416
 417         if (call->send_pages) {
 418                 ret = afs_send_pages(call, &msg);
 419                 if (ret < 0)
 420                         goto error_do_abort;
 421         }
 422
 423         /* at this point, an async call may no longer exist as it may have
 424          * already completed */
 425         if (call->async)
 426                 return -EINPROGRESS;
 427
 428         return afs_wait_for_call_to_complete(call);
 429
 430 error_do_abort:
 431         call->state = AFS_CALL_COMPLETE;
 432         if (ret != -ECONNABORTED) {
 433                 rxrpc_kernel_abort_call(afs_socket, rxcall, RX_USER_ABORT,
 434                                         ret, "KSD");
 435         } else {
 436                 abort_code = 0;
 437                 offset = 0;
 438                 rxrpc_kernel_recv_data(afs_socket, rxcall, NULL, 0, &offset,
 439                                        false, &abort_code);
 440                 ret = call->type->abort_to_error(abort_code);
 441         }
 442 error_kill_call:
 443         afs_put_call(call);
 444         _leave(" = %d", ret);
 445         return ret;
 446 }
 447
 448 /*
 449  * deliver messages to a call
 450  */
 451 static void afs_deliver_to_call(struct afs_call *call)
 452 {
 453         u32 abort_code;
 454         int ret;
 455
 456         _enter("%s", call->type->name);
 457
 458         while (call->state == AFS_CALL_AWAIT_REPLY ||
 459                call->state == AFS_CALL_AWAIT_OP_ID ||
 460                call->state == AFS_CALL_AWAIT_REQUEST ||
 461                call->state == AFS_CALL_AWAIT_ACK
 462                ) {
 463                 if (call->state == AFS_CALL_AWAIT_ACK) {
 464                         size_t offset = 0;
 465                         ret = rxrpc_kernel_recv_data(afs_socket, call->rxcall,
 466                                                      NULL, 0, &offset, false,
 467                                                      &call->abort_code);
 468                         trace_afs_recv_data(call, 0, offset, false, ret);
 469
 470                         if (ret == -EINPROGRESS || ret == -EAGAIN)
 471                                 return;
 472                         if (ret == 1 || ret < 0) {
 473                                 call->state = AFS_CALL_COMPLETE;
 474                                 goto done;
 475                         }
 476                         return;
 477                 }
 478
 479                 ret = call->type->deliver(call);
 480                 switch (ret) {
 481                 case 0:
 482                         if (call->state == AFS_CALL_AWAIT_REPLY)
 483                                 call->state = AFS_CALL_COMPLETE;
 484                         goto done;
 485                 case -EINPROGRESS:
 486                 case -EAGAIN:
 487                         goto out;
 488                 case -ECONNABORTED:
 489                         goto call_complete;
 490                 case -ENOTCONN:
 491                         abort_code = RX_CALL_DEAD;
 492                         rxrpc_kernel_abort_call(afs_socket, call->rxcall,
 493                                                 abort_code, ret, "KNC");
 494                         goto save_error;
 495                 case -ENOTSUPP:
 496                         abort_code = RXGEN_OPCODE;
 497                         rxrpc_kernel_abort_call(afs_socket, call->rxcall,
 498                                                 abort_code, ret, "KIV");
 499                         goto save_error;
 500                 case -ENODATA:
 501                 case -EBADMSG:
 502                 case -EMSGSIZE:
 503                 default:
 504                         abort_code = RXGEN_CC_UNMARSHAL;
 505                         if (call->state != AFS_CALL_AWAIT_REPLY)
 506                                 abort_code = RXGEN_SS_UNMARSHAL;
 507                         rxrpc_kernel_abort_call(afs_socket, call->rxcall,
 508                                                 abort_code, -EBADMSG, "KUM");
 509                         goto save_error;
 510                 }
 511         }
 512
 513 done:
 514         if (call->state == AFS_CALL_COMPLETE && call->incoming)
 515                 afs_put_call(call);
 516 out:
 517         _leave("");
 518         return;
 519
 520 save_error:
 521         call->error = ret;
 522 call_complete:
 523         call->state = AFS_CALL_COMPLETE;
 524         goto done;
 525 }
 526
 527 /*
 528  * wait synchronously for a call to complete
 529  */
 530 static int afs_wait_for_call_to_complete(struct afs_call *call)
 531 {
 532         int ret;
 533
 534         DECLARE_WAITQUEUE(myself, current);
 535
 536         _enter("");
 537
 538         add_wait_queue(&call->waitq, &myself);
 539         for (;;) {
 540                 set_current_state(TASK_INTERRUPTIBLE);
 541
 542                 /* deliver any messages that are in the queue */
 543                 if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
 544                         call->need_attention = false;
 545                         __set_current_state(TASK_RUNNING);
 546                         afs_deliver_to_call(call);
 547                         continue;
 548                 }
 549
 550                 if (call->state == AFS_CALL_COMPLETE ||
 551                     signal_pending(current))
 552                         break;
 553                 schedule();
 554         }
 555
 556         remove_wait_queue(&call->waitq, &myself);
 557         __set_current_state(TASK_RUNNING);
 558
 559         /* Kill off the call if it's still live. */
 560         if (call->state < AFS_CALL_COMPLETE) {
 561                 _debug("call interrupted");
 562                 rxrpc_kernel_abort_call(afs_socket, call->rxcall,
 563                                         RX_USER_ABORT, -EINTR, "KWI");
 564         }
 565
 566         ret = call->error;
 567         _debug("call complete");
 568         afs_put_call(call);
 569         _leave(" = %d", ret);
 570         return ret;
 571 }
 572
 573 /*
 574  * wake up a waiting call
 575  */
 576 static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall,
 577                                     unsigned long call_user_ID)
 578 {
 579         struct afs_call *call = (struct afs_call *)call_user_ID;
 580
 581         call->need_attention = true;
 582         wake_up(&call->waitq);
 583 }
 584
 585 /*
 586  * wake up an asynchronous call
 587  */
 588 static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
 589                                    unsigned long call_user_ID)
 590 {
 591         struct afs_call *call = (struct afs_call *)call_user_ID;
 592         int u;
 593
 594         trace_afs_notify_call(rxcall, call);
 595         call->need_attention = true;
 596
 597         u = __atomic_add_unless(&call->usage, 1, 0);
 598         if (u != 0) {
 599                 trace_afs_call(call, afs_call_trace_wake, u,
 600                                atomic_read(&afs_outstanding_calls),
 601                                __builtin_return_address(0));
 602
 603                 if (!queue_work(afs_async_calls, &call->async_work))
 604                         afs_put_call(call);
 605         }
 606 }
 607
 608 /*
 609  * Delete an asynchronous call.  The work item carries a ref to the call struct
 610  * that we need to release.
 611  */
 612 static void afs_delete_async_call(struct work_struct *work)
 613 {
 614         struct afs_call *call = container_of(work, struct afs_call, async_work);
 615
 616         _enter("");
 617
 618         afs_put_call(call);
 619
 620         _leave("");
 621 }
 622
 623 /*
 624  * Perform I/O processing on an asynchronous call.  The work item carries a ref
 625  * to the call struct that we either need to release or to pass on.
 626  */
 627 static void afs_process_async_call(struct work_struct *work)
 628 {
 629         struct afs_call *call = container_of(work, struct afs_call, async_work);
 630
 631         _enter("");
 632
 633         if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
 634                 call->need_attention = false;
 635                 afs_deliver_to_call(call);
 636         }
 637
 638         if (call->state == AFS_CALL_COMPLETE) {
 639                 call->reply = NULL;
 640
 641                 /* We have two refs to release - one from the alloc and one
 642                  * queued with the work item - and we can't just deallocate the
 643                  * call because the work item may be queued again.
 644                  */
 645                 call->async_work.func = afs_delete_async_call;
 646                 if (!queue_work(afs_async_calls, &call->async_work))
 647                         afs_put_call(call);
 648         }
 649
 650         afs_put_call(call);
 651         _leave("");
 652 }
 653
 654 static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)
 655 {
 656         struct afs_call *call = (struct afs_call *)user_call_ID;
 657
 658         call->rxcall = rxcall;
 659 }
 660
 661 /*
 662  * Charge the incoming call preallocation.
 663  */
 664 static void afs_charge_preallocation(struct work_struct *work)
 665 {
 666         struct afs_call *call = afs_spare_incoming_call;
 667
 668         for (;;) {
 669                 if (!call) {
 670                         call = afs_alloc_call(&afs_RXCMxxxx, GFP_KERNEL);
 671                         if (!call)
 672                                 break;
 673
 674                         call->async = true;
 675                         call->state = AFS_CALL_AWAIT_OP_ID;
 676                         init_waitqueue_head(&call->waitq);
 677                 }
 678
 679                 if (rxrpc_kernel_charge_accept(afs_socket,
 680                                                afs_wake_up_async_call,
 681                                                afs_rx_attach,
 682                                                (unsigned long)call,
 683                                                GFP_KERNEL) < 0)
 684                         break;
 685                 call = NULL;
 686         }
 687         afs_spare_incoming_call = call;
 688 }
 689
 690 /*
 691  * Discard a preallocated call when a socket is shut down.
 692  */
 693 static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
 694                                     unsigned long user_call_ID)
 695 {
 696         struct afs_call *call = (struct afs_call *)user_call_ID;
 697
 698         call->rxcall = NULL;
 699         afs_put_call(call);
 700 }
 701
 702 /*
 703  * Notification of an incoming call.
 704  */
 705 static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
 706                             unsigned long user_call_ID)
 707 {
 708         queue_work(afs_wq, &afs_charge_preallocation_work);
 709 }
 710
 711 /*
 712  * Grab the operation ID from an incoming cache manager call.  The socket
 713  * buffer is discarded on error or if we don't yet have sufficient data.
 714  */
 715 static int afs_deliver_cm_op_id(struct afs_call *call)
 716 {
 717         int ret;
 718
 719         _enter("{%zu}", call->offset);
 720
 721         ASSERTCMP(call->offset, <, 4);
 722
 723         /* the operation ID forms the first four bytes of the request data */
 724         ret = afs_extract_data(call, &call->tmp, 4, true);
 725         if (ret < 0)
 726                 return ret;
 727
 728         call->operation_ID = ntohl(call->tmp);
 729         call->state = AFS_CALL_AWAIT_REQUEST;
 730         call->offset = 0;
 731
 732         /* ask the cache manager to route the call (it'll change the call type
 733          * if successful) */
 734         if (!afs_cm_incoming_call(call))
 735                 return -ENOTSUPP;
 736
 737         trace_afs_cb_call(call);
 738
 739         /* pass responsibility for the remainer of this message off to the
 740          * cache manager op */
 741         return call->type->deliver(call);
 742 }
 743
 744 /*
 745  * send an empty reply
 746  */
 747 void afs_send_empty_reply(struct afs_call *call)
 748 {
 749         struct msghdr msg;
 750
 751         _enter("");
 752
 753         rxrpc_kernel_set_tx_length(afs_socket, call->rxcall, 0);
 754
 755         msg.msg_name            = NULL;
 756         msg.msg_namelen         = 0;
 757         iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, NULL, 0, 0);
 758         msg.msg_control         = NULL;
 759         msg.msg_controllen      = 0;
 760         msg.msg_flags           = 0;
 761
 762         call->state = AFS_CALL_AWAIT_ACK;
 763         switch (rxrpc_kernel_send_data(afs_socket, call->rxcall, &msg, 0)) {
 764         case 0:
 765                 _leave(" [replied]");
 766                 return;
 767
 768         case -ENOMEM:
 769                 _debug("oom");
 770                 rxrpc_kernel_abort_call(afs_socket, call->rxcall,
 771                                         RX_USER_ABORT, -ENOMEM, "KOO");
 772         default:
 773                 _leave(" [error]");
 774                 return;
 775         }
 776 }
 777
 778 /*
 779  * send a simple reply
 780  */
 781 void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
 782 {
 783         struct msghdr msg;
 784         struct kvec iov[1];
 785         int n;
 786
 787         _enter("");
 788
 789         rxrpc_kernel_set_tx_length(afs_socket, call->rxcall, len);
 790
 791         iov[0].iov_base         = (void *) buf;
 792         iov[0].iov_len          = len;
 793         msg.msg_name            = NULL;
 794         msg.msg_namelen         = 0;
 795         iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1, len);
 796         msg.msg_control         = NULL;
 797         msg.msg_controllen      = 0;
 798         msg.msg_flags           = 0;
 799
 800         call->state = AFS_CALL_AWAIT_ACK;
 801         n = rxrpc_kernel_send_data(afs_socket, call->rxcall, &msg, len);
 802         if (n >= 0) {
 803                 /* Success */
 804                 _leave(" [replied]");
 805                 return;
 806         }
 807
 808         if (n == -ENOMEM) {
 809                 _debug("oom");
 810                 rxrpc_kernel_abort_call(afs_socket, call->rxcall,
 811                                         RX_USER_ABORT, -ENOMEM, "KOO");
 812         }
 813         _leave(" [error]");
 814 }
 815
 816 /*
 817  * Extract a piece of data from the received data socket buffers.
 818  */
 819 int afs_extract_data(struct afs_call *call, void *buf, size_t count,
 820                      bool want_more)
 821 {
 822         int ret;
 823
 824         _enter("{%s,%zu},,%zu,%d",
 825                call->type->name, call->offset, count, want_more);
 826
 827         ASSERTCMP(call->offset, <=, count);
 828
 829         ret = rxrpc_kernel_recv_data(afs_socket, call->rxcall,
 830                                      buf, count, &call->offset,
 831                                      want_more, &call->abort_code);
 832         trace_afs_recv_data(call, count, call->offset, want_more, ret);
 833         if (ret == 0 || ret == -EAGAIN)
 834                 return ret;
 835
 836         if (ret == 1) {
 837                 switch (call->state) {
 838                 case AFS_CALL_AWAIT_REPLY:
 839                         call->state = AFS_CALL_COMPLETE;
 840                         break;
 841                 case AFS_CALL_AWAIT_REQUEST:
 842                         call->state = AFS_CALL_REPLYING;
 843                         break;
 844                 default:
 845                         break;
 846                 }
 847                 return 0;
 848         }
 849
 850         if (ret == -ECONNABORTED)
 851                 call->error = call->type->abort_to_error(call->abort_code);
 852         else
 853                 call->error = ret;
 854         call->state = AFS_CALL_COMPLETE;
 855         return ret;
 856 }