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 <net/sock.h>
  14 #include <net/af_rxrpc.h>
  15 #include <rxrpc/packet.h>
  16 #include "internal.h"
  17 #include "afs_cm.h"
  18
  19 static struct socket *afs_socket; /* my RxRPC socket */
  20 static struct workqueue_struct *afs_async_calls;
  21 static atomic_t afs_outstanding_calls;
  22 static atomic_t afs_outstanding_skbs;
  23
  24 static void afs_wake_up_call_waiter(struct afs_call *);
  25 static int afs_wait_for_call_to_complete(struct afs_call *);
  26 static void afs_wake_up_async_call(struct afs_call *);
  27 static int afs_dont_wait_for_call_to_complete(struct afs_call *);
  28 static void afs_process_async_call(struct afs_call *);
  29 static void afs_rx_interceptor(struct sock *, unsigned long, struct sk_buff *);
  30 static int afs_deliver_cm_op_id(struct afs_call *, struct sk_buff *, bool);
  31
  32 /* synchronous call management */
  33 const struct afs_wait_mode afs_sync_call = {
  34         .rx_wakeup      = afs_wake_up_call_waiter,
  35         .wait           = afs_wait_for_call_to_complete,
  36 };
  37
  38 /* asynchronous call management */
  39 const struct afs_wait_mode afs_async_call = {
  40         .rx_wakeup      = afs_wake_up_async_call,
  41         .wait           = afs_dont_wait_for_call_to_complete,
  42 };
  43
  44 /* asynchronous incoming call management */
  45 static const struct afs_wait_mode afs_async_incoming_call = {
  46         .rx_wakeup      = afs_wake_up_async_call,
  47 };
  48
  49 /* asynchronous incoming call initial processing */
  50 static const struct afs_call_type afs_RXCMxxxx = {
  51         .name           = "CB.xxxx",
  52         .deliver        = afs_deliver_cm_op_id,
  53         .abort_to_error = afs_abort_to_error,
  54 };
  55
  56 static void afs_collect_incoming_call(struct work_struct *);
  57
  58 static struct sk_buff_head afs_incoming_calls;
  59 static DECLARE_WORK(afs_collect_incoming_call_work, afs_collect_incoming_call);
  60
  61 static void afs_async_workfn(struct work_struct *work)
  62 {
  63         struct afs_call *call = container_of(work, struct afs_call, async_work);
  64
  65         call->async_workfn(call);
  66 }
  67
  68 static int afs_wait_atomic_t(atomic_t *p)
  69 {
  70         schedule();
  71         return 0;
  72 }
  73
  74 /*
  75  * open an RxRPC socket and bind it to be a server for callback notifications
  76  * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT
  77  */
  78 int afs_open_socket(void)
  79 {
  80         struct sockaddr_rxrpc srx;
  81         struct socket *socket;
  82         int ret;
  83
  84         _enter("");
  85
  86         skb_queue_head_init(&afs_incoming_calls);
  87
  88         ret = -ENOMEM;
  89         afs_async_calls = create_singlethread_workqueue("kafsd");
  90         if (!afs_async_calls)
  91                 goto error_0;
  92
  93         ret = sock_create_kern(&init_net, AF_RXRPC, SOCK_DGRAM, PF_INET, &socket);
  94         if (ret < 0)
  95                 goto error_1;
  96
  97         socket->sk->sk_allocation = GFP_NOFS;
  98
  99         /* bind the callback manager's address to make this a server socket */
 100         srx.srx_family                  = AF_RXRPC;
 101         srx.srx_service                 = CM_SERVICE;
 102         srx.transport_type              = SOCK_DGRAM;
 103         srx.transport_len               = sizeof(srx.transport.sin);
 104         srx.transport.sin.sin_family    = AF_INET;
 105         srx.transport.sin.sin_port      = htons(AFS_CM_PORT);
 106         memset(&srx.transport.sin.sin_addr, 0,
 107                sizeof(srx.transport.sin.sin_addr));
 108
 109         ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
 110         if (ret < 0)
 111                 goto error_2;
 112
 113         ret = kernel_listen(socket, INT_MAX);
 114         if (ret < 0)
 115                 goto error_2;
 116
 117         rxrpc_kernel_intercept_rx_messages(socket, afs_rx_interceptor);
 118
 119         afs_socket = socket;
 120         _leave(" = 0");
 121         return 0;
 122
 123 error_2:
 124         sock_release(socket);
 125 error_1:
 126         destroy_workqueue(afs_async_calls);
 127 error_0:
 128         _leave(" = %d", ret);
 129         return ret;
 130 }
 131
 132 /*
 133  * close the RxRPC socket AFS was using
 134  */
 135 void afs_close_socket(void)
 136 {
 137         _enter("");
 138
 139         wait_on_atomic_t(&afs_outstanding_calls, afs_wait_atomic_t,
 140                          TASK_UNINTERRUPTIBLE);
 141         _debug("no outstanding calls");
 142
 143         sock_release(afs_socket);
 144
 145         _debug("dework");
 146         destroy_workqueue(afs_async_calls);
 147
 148         ASSERTCMP(atomic_read(&afs_outstanding_skbs), ==, 0);
 149         _leave("");
 150 }
 151
 152 /*
 153  * Note that the data in a socket buffer is now consumed.
 154  */
 155 void afs_data_consumed(struct afs_call *call, struct sk_buff *skb)
 156 {
 157         if (!skb) {
 158                 _debug("DLVR NULL [%d]", atomic_read(&afs_outstanding_skbs));
 159                 dump_stack();
 160         } else {
 161                 _debug("DLVR %p{%u} [%d]",
 162                        skb, skb->mark, atomic_read(&afs_outstanding_skbs));
 163                 rxrpc_kernel_data_consumed(call->rxcall, skb);
 164         }
 165 }
 166
 167 /*
 168  * free a socket buffer
 169  */
 170 static void afs_free_skb(struct sk_buff *skb)
 171 {
 172         if (!skb) {
 173                 _debug("FREE NULL [%d]", atomic_read(&afs_outstanding_skbs));
 174                 dump_stack();
 175         } else {
 176                 _debug("FREE %p{%u} [%d]",
 177                        skb, skb->mark, atomic_read(&afs_outstanding_skbs));
 178                 if (atomic_dec_return(&afs_outstanding_skbs) == -1)
 179                         BUG();
 180                 rxrpc_kernel_free_skb(skb);
 181         }
 182 }
 183
 184 /*
 185  * free a call
 186  */
 187 static void afs_free_call(struct afs_call *call)
 188 {
 189         _debug("DONE %p{%s} [%d]",
 190                call, call->type->name, atomic_read(&afs_outstanding_calls));
 191
 192         ASSERTCMP(call->rxcall, ==, NULL);
 193         ASSERT(!work_pending(&call->async_work));
 194         ASSERT(skb_queue_empty(&call->rx_queue));
 195         ASSERT(call->type->name != NULL);
 196
 197         kfree(call->request);
 198         kfree(call);
 199
 200         if (atomic_dec_and_test(&afs_outstanding_calls))
 201                 wake_up_atomic_t(&afs_outstanding_calls);
 202 }
 203
 204 /*
 205  * End a call but do not free it
 206  */
 207 static void afs_end_call_nofree(struct afs_call *call)
 208 {
 209         if (call->rxcall) {
 210                 rxrpc_kernel_end_call(call->rxcall);
 211                 call->rxcall = NULL;
 212         }
 213         if (call->type->destructor)
 214                 call->type->destructor(call);
 215 }
 216
 217 /*
 218  * End a call and free it
 219  */
 220 static void afs_end_call(struct afs_call *call)
 221 {
 222         afs_end_call_nofree(call);
 223         afs_free_call(call);
 224 }
 225
 226 /*
 227  * allocate a call with flat request and reply buffers
 228  */
 229 struct afs_call *afs_alloc_flat_call(const struct afs_call_type *type,
 230                                      size_t request_size, size_t reply_size)
 231 {
 232         struct afs_call *call;
 233
 234         call = kzalloc(sizeof(*call), GFP_NOFS);
 235         if (!call)
 236                 goto nomem_call;
 237
 238         _debug("CALL %p{%s} [%d]",
 239                call, type->name, atomic_read(&afs_outstanding_calls));
 240         atomic_inc(&afs_outstanding_calls);
 241
 242         call->type = type;
 243         call->request_size = request_size;
 244         call->reply_max = reply_size;
 245
 246         if (request_size) {
 247                 call->request = kmalloc(request_size, GFP_NOFS);
 248                 if (!call->request)
 249                         goto nomem_free;
 250         }
 251
 252         if (reply_size) {
 253                 call->buffer = kmalloc(reply_size, GFP_NOFS);
 254                 if (!call->buffer)
 255                         goto nomem_free;
 256         }
 257
 258         init_waitqueue_head(&call->waitq);
 259         skb_queue_head_init(&call->rx_queue);
 260         return call;
 261
 262 nomem_free:
 263         afs_free_call(call);
 264 nomem_call:
 265         return NULL;
 266 }
 267
 268 /*
 269  * clean up a call with flat buffer
 270  */
 271 void afs_flat_call_destructor(struct afs_call *call)
 272 {
 273         _enter("");
 274
 275         kfree(call->request);
 276         call->request = NULL;
 277         kfree(call->buffer);
 278         call->buffer = NULL;
 279 }
 280
 281 /*
 282  * attach the data from a bunch of pages on an inode to a call
 283  */
 284 static int afs_send_pages(struct afs_call *call, struct msghdr *msg,
 285                           struct kvec *iov)
 286 {
 287         struct page *pages[8];
 288         unsigned count, n, loop, offset, to;
 289         pgoff_t first = call->first, last = call->last;
 290         int ret;
 291
 292         _enter("");
 293
 294         offset = call->first_offset;
 295         call->first_offset = 0;
 296
 297         do {
 298                 _debug("attach %lx-%lx", first, last);
 299
 300                 count = last - first + 1;
 301                 if (count > ARRAY_SIZE(pages))
 302                         count = ARRAY_SIZE(pages);
 303                 n = find_get_pages_contig(call->mapping, first, count, pages);
 304                 ASSERTCMP(n, ==, count);
 305
 306                 loop = 0;
 307                 do {
 308                         msg->msg_flags = 0;
 309                         to = PAGE_SIZE;
 310                         if (first + loop >= last)
 311                                 to = call->last_to;
 312                         else
 313                                 msg->msg_flags = MSG_MORE;
 314                         iov->iov_base = kmap(pages[loop]) + offset;
 315                         iov->iov_len = to - offset;
 316                         offset = 0;
 317
 318                         _debug("- range %u-%u%s",
 319                                offset, to, msg->msg_flags ? " [more]" : "");
 320                         iov_iter_kvec(&msg->msg_iter, WRITE | ITER_KVEC,
 321                                       iov, 1, to - offset);
 322
 323                         /* have to change the state *before* sending the last
 324                          * packet as RxRPC might give us the reply before it
 325                          * returns from sending the request */
 326                         if (first + loop >= last)
 327                                 call->state = AFS_CALL_AWAIT_REPLY;
 328                         ret = rxrpc_kernel_send_data(call->rxcall, msg,
 329                                                      to - offset);
 330                         kunmap(pages[loop]);
 331                         if (ret < 0)
 332                                 break;
 333                 } while (++loop < count);
 334                 first += count;
 335
 336                 for (loop = 0; loop < count; loop++)
 337                         put_page(pages[loop]);
 338                 if (ret < 0)
 339                         break;
 340         } while (first <= last);
 341
 342         _leave(" = %d", ret);
 343         return ret;
 344 }
 345
 346 /*
 347  * initiate a call
 348  */
 349 int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp,
 350                   const struct afs_wait_mode *wait_mode)
 351 {
 352         struct sockaddr_rxrpc srx;
 353         struct rxrpc_call *rxcall;
 354         struct msghdr msg;
 355         struct kvec iov[1];
 356         int ret;
 357         struct sk_buff *skb;
 358
 359         _enter("%x,{%d},", addr->s_addr, ntohs(call->port));
 360
 361         ASSERT(call->type != NULL);
 362         ASSERT(call->type->name != NULL);
 363
 364         _debug("____MAKE %p{%s,%x} [%d]____",
 365                call, call->type->name, key_serial(call->key),
 366                atomic_read(&afs_outstanding_calls));
 367
 368         call->wait_mode = wait_mode;
 369         call->async_workfn = afs_process_async_call;
 370         INIT_WORK(&call->async_work, afs_async_workfn);
 371
 372         memset(&srx, 0, sizeof(srx));
 373         srx.srx_family = AF_RXRPC;
 374         srx.srx_service = call->service_id;
 375         srx.transport_type = SOCK_DGRAM;
 376         srx.transport_len = sizeof(srx.transport.sin);
 377         srx.transport.sin.sin_family = AF_INET;
 378         srx.transport.sin.sin_port = call->port;
 379         memcpy(&srx.transport.sin.sin_addr, addr, 4);
 380
 381         /* create a call */
 382         rxcall = rxrpc_kernel_begin_call(afs_socket, &srx, call->key,
 383                                          (unsigned long) call, gfp);
 384         call->key = NULL;
 385         if (IS_ERR(rxcall)) {
 386                 ret = PTR_ERR(rxcall);
 387                 goto error_kill_call;
 388         }
 389
 390         call->rxcall = rxcall;
 391
 392         /* send the request */
 393         iov[0].iov_base = call->request;
 394         iov[0].iov_len  = call->request_size;
 395
 396         msg.msg_name            = NULL;
 397         msg.msg_namelen         = 0;
 398         iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1,
 399                       call->request_size);
 400         msg.msg_control         = NULL;
 401         msg.msg_controllen      = 0;
 402         msg.msg_flags           = (call->send_pages ? MSG_MORE : 0);
 403
 404         /* have to change the state *before* sending the last packet as RxRPC
 405          * might give us the reply before it returns from sending the
 406          * request */
 407         if (!call->send_pages)
 408                 call->state = AFS_CALL_AWAIT_REPLY;
 409         ret = rxrpc_kernel_send_data(rxcall, &msg, call->request_size);
 410         if (ret < 0)
 411                 goto error_do_abort;
 412
 413         if (call->send_pages) {
 414                 ret = afs_send_pages(call, &msg, iov);
 415                 if (ret < 0)
 416                         goto error_do_abort;
 417         }
 418
 419         /* at this point, an async call may no longer exist as it may have
 420          * already completed */
 421         return wait_mode->wait(call);
 422
 423 error_do_abort:
 424         rxrpc_kernel_abort_call(rxcall, RX_USER_ABORT);
 425         while ((skb = skb_dequeue(&call->rx_queue)))
 426                 afs_free_skb(skb);
 427 error_kill_call:
 428         afs_end_call(call);
 429         _leave(" = %d", ret);
 430         return ret;
 431 }
 432
 433 /*
 434  * Handles intercepted messages that were arriving in the socket's Rx queue.
 435  *
 436  * Called from the AF_RXRPC call processor in waitqueue process context.  For
 437  * each call, it is guaranteed this will be called in order of packet to be
 438  * delivered.
 439  */
 440 static void afs_rx_interceptor(struct sock *sk, unsigned long user_call_ID,
 441                                struct sk_buff *skb)
 442 {
 443         struct afs_call *call = (struct afs_call *) user_call_ID;
 444
 445         _enter("%p,,%u", call, skb->mark);
 446
 447         _debug("ICPT %p{%u} [%d]",
 448                skb, skb->mark, atomic_read(&afs_outstanding_skbs));
 449
 450         ASSERTCMP(sk, ==, afs_socket->sk);
 451         atomic_inc(&afs_outstanding_skbs);
 452
 453         if (!call) {
 454                 /* its an incoming call for our callback service */
 455                 skb_queue_tail(&afs_incoming_calls, skb);
 456                 queue_work(afs_wq, &afs_collect_incoming_call_work);
 457         } else {
 458                 /* route the messages directly to the appropriate call */
 459                 skb_queue_tail(&call->rx_queue, skb);
 460                 call->wait_mode->rx_wakeup(call);
 461         }
 462
 463         _leave("");
 464 }
 465
 466 /*
 467  * deliver messages to a call
 468  */
 469 static void afs_deliver_to_call(struct afs_call *call)
 470 {
 471         struct sk_buff *skb;
 472         bool last;
 473         u32 abort_code;
 474         int ret;
 475
 476         _enter("");
 477
 478         while ((call->state == AFS_CALL_AWAIT_REPLY ||
 479                 call->state == AFS_CALL_AWAIT_OP_ID ||
 480                 call->state == AFS_CALL_AWAIT_REQUEST ||
 481                 call->state == AFS_CALL_AWAIT_ACK) &&
 482                (skb = skb_dequeue(&call->rx_queue))) {
 483                 switch (skb->mark) {
 484                 case RXRPC_SKB_MARK_DATA:
 485                         _debug("Rcv DATA");
 486                         last = rxrpc_kernel_is_data_last(skb);
 487                         ret = call->type->deliver(call, skb, last);
 488                         switch (ret) {
 489                         case -EAGAIN:
 490                                 if (last) {
 491                                         _debug("short data");
 492                                         goto unmarshal_error;
 493                                 }
 494                                 break;
 495                         case 0:
 496                                 ASSERT(last);
 497                                 if (call->state == AFS_CALL_AWAIT_REPLY)
 498                                         call->state = AFS_CALL_COMPLETE;
 499                                 break;
 500                         case -ENOTCONN:
 501                                 abort_code = RX_CALL_DEAD;
 502                                 goto do_abort;
 503                         case -ENOTSUPP:
 504                                 abort_code = RX_INVALID_OPERATION;
 505                                 goto do_abort;
 506                         default:
 507                         unmarshal_error:
 508                                 abort_code = RXGEN_CC_UNMARSHAL;
 509                                 if (call->state != AFS_CALL_AWAIT_REPLY)
 510                                         abort_code = RXGEN_SS_UNMARSHAL;
 511                         do_abort:
 512                                 rxrpc_kernel_abort_call(call->rxcall,
 513                                                         abort_code);
 514                                 call->error = ret;
 515                                 call->state = AFS_CALL_ERROR;
 516                                 break;
 517                         }
 518                         break;
 519                 case RXRPC_SKB_MARK_FINAL_ACK:
 520                         _debug("Rcv ACK");
 521                         call->state = AFS_CALL_COMPLETE;
 522                         break;
 523                 case RXRPC_SKB_MARK_BUSY:
 524                         _debug("Rcv BUSY");
 525                         call->error = -EBUSY;
 526                         call->state = AFS_CALL_BUSY;
 527                         break;
 528                 case RXRPC_SKB_MARK_REMOTE_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("Rcv ABORT %u -> %d", abort_code, call->error);
 533                         break;
 534                 case RXRPC_SKB_MARK_LOCAL_ABORT:
 535                         abort_code = rxrpc_kernel_get_abort_code(skb);
 536                         call->error = call->type->abort_to_error(abort_code);
 537                         call->state = AFS_CALL_ABORTED;
 538                         _debug("Loc ABORT %u -> %d", abort_code, call->error);
 539                         break;
 540                 case RXRPC_SKB_MARK_NET_ERROR:
 541                         call->error = -rxrpc_kernel_get_error_number(skb);
 542                         call->state = AFS_CALL_ERROR;
 543                         _debug("Rcv NET ERROR %d", call->error);
 544                         break;
 545                 case RXRPC_SKB_MARK_LOCAL_ERROR:
 546                         call->error = -rxrpc_kernel_get_error_number(skb);
 547                         call->state = AFS_CALL_ERROR;
 548                         _debug("Rcv LOCAL ERROR %d", call->error);
 549                         break;
 550                 default:
 551                         BUG();
 552                         break;
 553                 }
 554
 555                 afs_free_skb(skb);
 556         }
 557
 558         /* make sure the queue is empty if the call is done with (we might have
 559          * aborted the call early because of an unmarshalling error) */
 560         if (call->state >= AFS_CALL_COMPLETE) {
 561                 while ((skb = skb_dequeue(&call->rx_queue)))
 562                         afs_free_skb(skb);
 563                 if (call->incoming)
 564                         afs_end_call(call);
 565         }
 566
 567         _leave("");
 568 }
 569
 570 /*
 571  * wait synchronously for a call to complete
 572  */
 573 static int afs_wait_for_call_to_complete(struct afs_call *call)
 574 {
 575         struct sk_buff *skb;
 576         int ret;
 577
 578         DECLARE_WAITQUEUE(myself, current);
 579
 580         _enter("");
 581
 582         add_wait_queue(&call->waitq, &myself);
 583         for (;;) {
 584                 set_current_state(TASK_INTERRUPTIBLE);
 585
 586                 /* deliver any messages that are in the queue */
 587                 if (!skb_queue_empty(&call->rx_queue)) {
 588                         __set_current_state(TASK_RUNNING);
 589                         afs_deliver_to_call(call);
 590                         continue;
 591                 }
 592
 593                 ret = call->error;
 594                 if (call->state >= AFS_CALL_COMPLETE)
 595                         break;
 596                 ret = -EINTR;
 597                 if (signal_pending(current))
 598                         break;
 599                 schedule();
 600         }
 601
 602         remove_wait_queue(&call->waitq, &myself);
 603         __set_current_state(TASK_RUNNING);
 604
 605         /* kill the call */
 606         if (call->state < AFS_CALL_COMPLETE) {
 607                 _debug("call incomplete");
 608                 rxrpc_kernel_abort_call(call->rxcall, RX_CALL_DEAD);
 609                 while ((skb = skb_dequeue(&call->rx_queue)))
 610                         afs_free_skb(skb);
 611         }
 612
 613         _debug("call complete");
 614         afs_end_call(call);
 615         _leave(" = %d", ret);
 616         return ret;
 617 }
 618
 619 /*
 620  * wake up a waiting call
 621  */
 622 static void afs_wake_up_call_waiter(struct afs_call *call)
 623 {
 624         wake_up(&call->waitq);
 625 }
 626
 627 /*
 628  * wake up an asynchronous call
 629  */
 630 static void afs_wake_up_async_call(struct afs_call *call)
 631 {
 632         _enter("");
 633         queue_work(afs_async_calls, &call->async_work);
 634 }
 635
 636 /*
 637  * put a call into asynchronous mode
 638  * - mustn't touch the call descriptor as the call my have completed by the
 639  *   time we get here
 640  */
 641 static int afs_dont_wait_for_call_to_complete(struct afs_call *call)
 642 {
 643         _enter("");
 644         return -EINPROGRESS;
 645 }
 646
 647 /*
 648  * delete an asynchronous call
 649  */
 650 static void afs_delete_async_call(struct afs_call *call)
 651 {
 652         _enter("");
 653
 654         afs_free_call(call);
 655
 656         _leave("");
 657 }
 658
 659 /*
 660  * perform processing on an asynchronous call
 661  * - on a multiple-thread workqueue this work item may try to run on several
 662  *   CPUs at the same time
 663  */
 664 static void afs_process_async_call(struct afs_call *call)
 665 {
 666         _enter("");
 667
 668         if (!skb_queue_empty(&call->rx_queue))
 669                 afs_deliver_to_call(call);
 670
 671         if (call->state >= AFS_CALL_COMPLETE && call->wait_mode) {
 672                 if (call->wait_mode->async_complete)
 673                         call->wait_mode->async_complete(call->reply,
 674                                                         call->error);
 675                 call->reply = NULL;
 676
 677                 /* kill the call */
 678                 afs_end_call_nofree(call);
 679
 680                 /* we can't just delete the call because the work item may be
 681                  * queued */
 682                 call->async_workfn = afs_delete_async_call;
 683                 queue_work(afs_async_calls, &call->async_work);
 684         }
 685
 686         _leave("");
 687 }
 688
 689 /*
 690  * Empty a socket buffer into a flat reply buffer.
 691  */
 692 int afs_transfer_reply(struct afs_call *call, struct sk_buff *skb, bool last)
 693 {
 694         size_t len = skb->len;
 695
 696         if (len > call->reply_max - call->reply_size) {
 697                 _leave(" = -EBADMSG [%zu > %u]",
 698                        len, call->reply_max - call->reply_size);
 699                 return -EBADMSG;
 700         }
 701
 702         if (len > 0) {
 703                 if (skb_copy_bits(skb, 0, call->buffer + call->reply_size,
 704                                   len) < 0)
 705                         BUG();
 706                 call->reply_size += len;
 707         }
 708
 709         afs_data_consumed(call, skb);
 710         if (!last)
 711                 return -EAGAIN;
 712
 713         if (call->reply_size != call->reply_max) {
 714                 _leave(" = -EBADMSG [%u != %u]",
 715                        call->reply_size, call->reply_max);
 716                 return -EBADMSG;
 717         }
 718         return 0;
 719 }
 720
 721 /*
 722  * accept the backlog of incoming calls
 723  */
 724 static void afs_collect_incoming_call(struct work_struct *work)
 725 {
 726         struct rxrpc_call *rxcall;
 727         struct afs_call *call = NULL;
 728         struct sk_buff *skb;
 729
 730         while ((skb = skb_dequeue(&afs_incoming_calls))) {
 731                 _debug("new call");
 732
 733                 /* don't need the notification */
 734                 afs_free_skb(skb);
 735
 736                 if (!call) {
 737                         call = kzalloc(sizeof(struct afs_call), GFP_KERNEL);
 738                         if (!call) {
 739                                 rxrpc_kernel_reject_call(afs_socket);
 740                                 return;
 741                         }
 742
 743                         call->async_workfn = afs_process_async_call;
 744                         INIT_WORK(&call->async_work, afs_async_workfn);
 745                         call->wait_mode = &afs_async_incoming_call;
 746                         call->type = &afs_RXCMxxxx;
 747                         init_waitqueue_head(&call->waitq);
 748                         skb_queue_head_init(&call->rx_queue);
 749                         call->state = AFS_CALL_AWAIT_OP_ID;
 750
 751                         _debug("CALL %p{%s} [%d]",
 752                                call, call->type->name,
 753                                atomic_read(&afs_outstanding_calls));
 754                         atomic_inc(&afs_outstanding_calls);
 755                 }
 756
 757                 rxcall = rxrpc_kernel_accept_call(afs_socket,
 758                                                   (unsigned long) call);
 759                 if (!IS_ERR(rxcall)) {
 760                         call->rxcall = rxcall;
 761                         call = NULL;
 762                 }
 763         }
 764
 765         if (call)
 766                 afs_free_call(call);
 767 }
 768
 769 /*
 770  * Grab the operation ID from an incoming cache manager call.  The socket
 771  * buffer is discarded on error or if we don't yet have sufficient data.
 772  */
 773 static int afs_deliver_cm_op_id(struct afs_call *call, struct sk_buff *skb,
 774                                 bool last)
 775 {
 776         size_t len = skb->len;
 777         void *oibuf = (void *) &call->operation_ID;
 778
 779         _enter("{%u},{%zu},%d", call->offset, len, last);
 780
 781         ASSERTCMP(call->offset, <, 4);
 782
 783         /* the operation ID forms the first four bytes of the request data */
 784         len = min_t(size_t, len, 4 - call->offset);
 785         if (skb_copy_bits(skb, 0, oibuf + call->offset, len) < 0)
 786                 BUG();
 787         if (!pskb_pull(skb, len))
 788                 BUG();
 789         call->offset += len;
 790
 791         if (call->offset < 4) {
 792                 afs_data_consumed(call, skb);
 793                 _leave(" = -EAGAIN");
 794                 return -EAGAIN;
 795         }
 796
 797         call->state = AFS_CALL_AWAIT_REQUEST;
 798
 799         /* ask the cache manager to route the call (it'll change the call type
 800          * if successful) */
 801         if (!afs_cm_incoming_call(call))
 802                 return -ENOTSUPP;
 803
 804         /* pass responsibility for the remainer of this message off to the
 805          * cache manager op */
 806         return call->type->deliver(call, skb, last);
 807 }
 808
 809 /*
 810  * send an empty reply
 811  */
 812 void afs_send_empty_reply(struct afs_call *call)
 813 {
 814         struct msghdr msg;
 815
 816         _enter("");
 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         call->state = AFS_CALL_AWAIT_ACK;
 826         switch (rxrpc_kernel_send_data(call->rxcall, &msg, 0)) {
 827         case 0:
 828                 _leave(" [replied]");
 829                 return;
 830
 831         case -ENOMEM:
 832                 _debug("oom");
 833                 rxrpc_kernel_abort_call(call->rxcall, RX_USER_ABORT);
 834         default:
 835                 afs_end_call(call);
 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 msghdr msg;
 847         struct kvec iov[1];
 848         int n;
 849
 850         _enter("");
 851
 852         iov[0].iov_base         = (void *) buf;
 853         iov[0].iov_len          = len;
 854         msg.msg_name            = NULL;
 855         msg.msg_namelen         = 0;
 856         iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1, len);
 857         msg.msg_control         = NULL;
 858         msg.msg_controllen      = 0;
 859         msg.msg_flags           = 0;
 860
 861         call->state = AFS_CALL_AWAIT_ACK;
 862         n = rxrpc_kernel_send_data(call->rxcall, &msg, len);
 863         if (n >= 0) {
 864                 /* Success */
 865                 _leave(" [replied]");
 866                 return;
 867         }
 868
 869         if (n == -ENOMEM) {
 870                 _debug("oom");
 871                 rxrpc_kernel_abort_call(call->rxcall, RX_USER_ABORT);
 872         }
 873         afs_end_call(call);
 874         _leave(" [error]");
 875 }
 876
 877 /*
 878  * Extract a piece of data from the received data socket buffers.
 879  */
 880 int afs_extract_data(struct afs_call *call, struct sk_buff *skb,
 881                      bool last, void *buf, size_t count)
 882 {
 883         size_t len = skb->len;
 884
 885         _enter("{%u},{%zu},%d,,%zu", call->offset, len, last, count);
 886
 887         ASSERTCMP(call->offset, <, count);
 888
 889         len = min_t(size_t, len, count - call->offset);
 890         if (skb_copy_bits(skb, 0, buf + call->offset, len) < 0 ||
 891             !pskb_pull(skb, len))
 892                 BUG();
 893         call->offset += len;
 894
 895         if (call->offset < count) {
 896                 afs_data_consumed(call, skb);
 897                 _leave(" = -EAGAIN");
 898                 return -EAGAIN;
 899         }
 900         return 0;
 901 }