fs/afs/rxrpc.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* Maintain an RxRPC server socket to do AFS communications through
   3  *
   4  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   5  * Written by David Howells ([email protected])
   6  */
   7
   8 #include <linux/slab.h>
   9 #include <linux/sched/signal.h>
  10
  11 #include <net/sock.h>
  12 #include <net/af_rxrpc.h>
  13 #include "internal.h"
  14 #include "afs_cm.h"
  15 #include "protocol_yfs.h"
  16 #define RXRPC_TRACE_ONLY_DEFINE_ENUMS
  17 #include <trace/events/rxrpc.h>
  18
  19 struct workqueue_struct *afs_async_calls;
  20
  21 static void afs_deferred_free_worker(struct work_struct *work);
  22 static void afs_wake_up_call_waiter(struct sock *, struct rxrpc_call *, unsigned long);
  23 static void afs_wake_up_async_call(struct sock *, struct rxrpc_call *, unsigned long);
  24 static void afs_process_async_call(struct work_struct *);
  25 static void afs_rx_new_call(struct sock *, struct rxrpc_call *, unsigned long);
  26 static void afs_rx_discard_new_call(struct rxrpc_call *, unsigned long);
  27 static int afs_deliver_cm_op_id(struct afs_call *);
  28
  29 /* asynchronous incoming call initial processing */
  30 static const struct afs_call_type afs_RXCMxxxx = {
  31         .name           = "CB.xxxx",
  32         .deliver        = afs_deliver_cm_op_id,
  33 };
  34
  35 /*
  36  * open an RxRPC socket and bind it to be a server for callback notifications
  37  * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT
  38  */
  39 int afs_open_socket(struct afs_net *net)
  40 {
  41         struct sockaddr_rxrpc srx;
  42         struct socket *socket;
  43         int ret;
  44
  45         _enter("");
  46
  47         ret = sock_create_kern(net->net, AF_RXRPC, SOCK_DGRAM, PF_INET6, &socket);
  48         if (ret < 0)
  49                 goto error_1;
  50
  51         socket->sk->sk_allocation = GFP_NOFS;
  52
  53         /* bind the callback manager's address to make this a server socket */
  54         memset(&srx, 0, sizeof(srx));
  55         srx.srx_family                  = AF_RXRPC;
  56         srx.srx_service                 = CM_SERVICE;
  57         srx.transport_type              = SOCK_DGRAM;
  58         srx.transport_len               = sizeof(srx.transport.sin6);
  59         srx.transport.sin6.sin6_family  = AF_INET6;
  60         srx.transport.sin6.sin6_port    = htons(AFS_CM_PORT);
  61
  62         ret = rxrpc_sock_set_min_security_level(socket->sk,
  63                                                 RXRPC_SECURITY_ENCRYPT);
  64         if (ret < 0)
  65                 goto error_2;
  66
  67         ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
  68         if (ret == -EADDRINUSE) {
  69                 srx.transport.sin6.sin6_port = 0;
  70                 ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
  71         }
  72         if (ret < 0)
  73                 goto error_2;
  74
  75         srx.srx_service = YFS_CM_SERVICE;
  76         ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
  77         if (ret < 0)
  78                 goto error_2;
  79
  80         /* Ideally, we'd turn on service upgrade here, but we can't because
  81          * OpenAFS is buggy and leaks the userStatus field from packet to
  82          * packet and between FS packets and CB packets - so if we try to do an
  83          * upgrade on an FS packet, OpenAFS will leak that into the CB packet
  84          * it sends back to us.
  85          */
  86
  87         rxrpc_kernel_new_call_notification(socket, afs_rx_new_call,
  88                                            afs_rx_discard_new_call);
  89
  90         ret = kernel_listen(socket, INT_MAX);
  91         if (ret < 0)
  92                 goto error_2;
  93
  94         net->socket = socket;
  95         afs_charge_preallocation(&net->charge_preallocation_work);
  96         _leave(" = 0");
  97         return 0;
  98
  99 error_2:
 100         sock_release(socket);
 101 error_1:
 102         _leave(" = %d", ret);
 103         return ret;
 104 }
 105
 106 /*
 107  * close the RxRPC socket AFS was using
 108  */
 109 void afs_close_socket(struct afs_net *net)
 110 {
 111         _enter("");
 112
 113         kernel_listen(net->socket, 0);
 114         flush_workqueue(afs_async_calls);
 115
 116         if (net->spare_incoming_call) {
 117                 afs_put_call(net->spare_incoming_call);
 118                 net->spare_incoming_call = NULL;
 119         }
 120
 121         _debug("outstanding %u", atomic_read(&net->nr_outstanding_calls));
 122         wait_var_event(&net->nr_outstanding_calls,
 123                        !atomic_read(&net->nr_outstanding_calls));
 124         _debug("no outstanding calls");
 125
 126         kernel_sock_shutdown(net->socket, SHUT_RDWR);
 127         flush_workqueue(afs_async_calls);
 128         sock_release(net->socket);
 129
 130         _debug("dework");
 131         _leave("");
 132 }
 133
 134 /*
 135  * Allocate a call.
 136  */
 137 static struct afs_call *afs_alloc_call(struct afs_net *net,
 138                                        const struct afs_call_type *type,
 139                                        gfp_t gfp)
 140 {
 141         struct afs_call *call;
 142         int o;
 143
 144         call = kzalloc(sizeof(*call), gfp);
 145         if (!call)
 146                 return NULL;
 147
 148         call->type = type;
 149         call->net = net;
 150         call->debug_id = atomic_inc_return(&rxrpc_debug_id);
 151         refcount_set(&call->ref, 1);
 152         INIT_WORK(&call->async_work, afs_process_async_call);
 153         INIT_WORK(&call->free_work, afs_deferred_free_worker);
 154         init_waitqueue_head(&call->waitq);
 155         spin_lock_init(&call->state_lock);
 156         call->iter = &call->def_iter;
 157
 158         o = atomic_inc_return(&net->nr_outstanding_calls);
 159         trace_afs_call(call->debug_id, afs_call_trace_alloc, 1, o,
 160                        __builtin_return_address(0));
 161         return call;
 162 }
 163
 164 static void afs_free_call(struct afs_call *call)
 165 {
 166         struct afs_net *net = call->net;
 167         int o;
 168
 169         ASSERT(!work_pending(&call->async_work));
 170
 171         rxrpc_kernel_put_peer(call->peer);
 172
 173         if (call->rxcall) {
 174                 rxrpc_kernel_shutdown_call(net->socket, call->rxcall);
 175                 rxrpc_kernel_put_call(net->socket, call->rxcall);
 176                 call->rxcall = NULL;
 177         }
 178         if (call->type->destructor)
 179                 call->type->destructor(call);
 180
 181         afs_unuse_server_notime(call->net, call->server, afs_server_trace_put_call);
 182         kfree(call->request);
 183
 184         o = atomic_read(&net->nr_outstanding_calls);
 185         trace_afs_call(call->debug_id, afs_call_trace_free, 0, o,
 186                        __builtin_return_address(0));
 187         kfree(call);
 188
 189         o = atomic_dec_return(&net->nr_outstanding_calls);
 190         if (o == 0)
 191                 wake_up_var(&net->nr_outstanding_calls);
 192 }
 193
 194 /*
 195  * Dispose of a reference on a call.
 196  */
 197 void afs_put_call(struct afs_call *call)
 198 {
 199         struct afs_net *net = call->net;
 200         unsigned int debug_id = call->debug_id;
 201         bool zero;
 202         int r, o;
 203
 204         zero = __refcount_dec_and_test(&call->ref, &r);
 205         o = atomic_read(&net->nr_outstanding_calls);
 206         trace_afs_call(debug_id, afs_call_trace_put, r - 1, o,
 207                        __builtin_return_address(0));
 208         if (zero)
 209                 afs_free_call(call);
 210 }
 211
 212 static void afs_deferred_free_worker(struct work_struct *work)
 213 {
 214         struct afs_call *call = container_of(work, struct afs_call, free_work);
 215
 216         afs_free_call(call);
 217 }
 218
 219 /*
 220  * Dispose of a reference on a call, deferring the cleanup to a workqueue
 221  * to avoid lock recursion.
 222  */
 223 void afs_deferred_put_call(struct afs_call *call)
 224 {
 225         struct afs_net *net = call->net;
 226         unsigned int debug_id = call->debug_id;
 227         bool zero;
 228         int r, o;
 229
 230         zero = __refcount_dec_and_test(&call->ref, &r);
 231         o = atomic_read(&net->nr_outstanding_calls);
 232         trace_afs_call(debug_id, afs_call_trace_put, r - 1, o,
 233                        __builtin_return_address(0));
 234         if (zero)
 235                 schedule_work(&call->free_work);
 236 }
 237
 238 static struct afs_call *afs_get_call(struct afs_call *call,
 239                                      enum afs_call_trace why)
 240 {
 241         int r;
 242
 243         __refcount_inc(&call->ref, &r);
 244
 245         trace_afs_call(call->debug_id, why, r + 1,
 246                        atomic_read(&call->net->nr_outstanding_calls),
 247                        __builtin_return_address(0));
 248         return call;
 249 }
 250
 251 /*
 252  * Queue the call for actual work.
 253  */
 254 static void afs_queue_call_work(struct afs_call *call)
 255 {
 256         if (call->type->work) {
 257                 INIT_WORK(&call->work, call->type->work);
 258
 259                 afs_get_call(call, afs_call_trace_work);
 260                 if (!queue_work(afs_wq, &call->work))
 261                         afs_put_call(call);
 262         }
 263 }
 264
 265 /*
 266  * allocate a call with flat request and reply buffers
 267  */
 268 struct afs_call *afs_alloc_flat_call(struct afs_net *net,
 269                                      const struct afs_call_type *type,
 270                                      size_t request_size, size_t reply_max)
 271 {
 272         struct afs_call *call;
 273
 274         call = afs_alloc_call(net, type, GFP_NOFS);
 275         if (!call)
 276                 goto nomem_call;
 277
 278         if (request_size) {
 279                 call->request_size = request_size;
 280                 call->request = kmalloc(request_size, GFP_NOFS);
 281                 if (!call->request)
 282                         goto nomem_free;
 283         }
 284
 285         if (reply_max) {
 286                 call->reply_max = reply_max;
 287                 call->buffer = kmalloc(reply_max, GFP_NOFS);
 288                 if (!call->buffer)
 289                         goto nomem_free;
 290         }
 291
 292         afs_extract_to_buf(call, call->reply_max);
 293         call->operation_ID = type->op;
 294         init_waitqueue_head(&call->waitq);
 295         return call;
 296
 297 nomem_free:
 298         afs_put_call(call);
 299 nomem_call:
 300         return NULL;
 301 }
 302
 303 /*
 304  * clean up a call with flat buffer
 305  */
 306 void afs_flat_call_destructor(struct afs_call *call)
 307 {
 308         _enter("");
 309
 310         kfree(call->request);
 311         call->request = NULL;
 312         kfree(call->buffer);
 313         call->buffer = NULL;
 314 }
 315
 316 /*
 317  * Advance the AFS call state when the RxRPC call ends the transmit phase.
 318  */
 319 static void afs_notify_end_request_tx(struct sock *sock,
 320                                       struct rxrpc_call *rxcall,
 321                                       unsigned long call_user_ID)
 322 {
 323         struct afs_call *call = (struct afs_call *)call_user_ID;
 324
 325         afs_set_call_state(call, AFS_CALL_CL_REQUESTING, AFS_CALL_CL_AWAIT_REPLY);
 326 }
 327
 328 /*
 329  * Initiate a call and synchronously queue up the parameters for dispatch.  Any
 330  * error is stored into the call struct, which the caller must check for.
 331  */
 332 void afs_make_call(struct afs_call *call, gfp_t gfp)
 333 {
 334         struct rxrpc_call *rxcall;
 335         struct msghdr msg;
 336         struct kvec iov[1];
 337         size_t len;
 338         s64 tx_total_len;
 339         int ret;
 340
 341         _enter(",{%pISp+%u},", rxrpc_kernel_remote_addr(call->peer), call->service_id);
 342
 343         ASSERT(call->type != NULL);
 344         ASSERT(call->type->name != NULL);
 345
 346         _debug("____MAKE %p{%s,%x} [%d]____",
 347                call, call->type->name, key_serial(call->key),
 348                atomic_read(&call->net->nr_outstanding_calls));
 349
 350         trace_afs_make_call(call);
 351
 352         /* Work out the length we're going to transmit.  This is awkward for
 353          * calls such as FS.StoreData where there's an extra injection of data
 354          * after the initial fixed part.
 355          */
 356         tx_total_len = call->request_size;
 357         if (call->write_iter)
 358                 tx_total_len += iov_iter_count(call->write_iter);
 359
 360         /* If the call is going to be asynchronous, we need an extra ref for
 361          * the call to hold itself so the caller need not hang on to its ref.
 362          */
 363         if (call->async) {
 364                 afs_get_call(call, afs_call_trace_get);
 365                 call->drop_ref = true;
 366         }
 367
 368         /* create a call */
 369         rxcall = rxrpc_kernel_begin_call(call->net->socket, call->peer, call->key,
 370                                          (unsigned long)call,
 371                                          tx_total_len,
 372                                          call->max_lifespan,
 373                                          gfp,
 374                                          (call->async ?
 375                                           afs_wake_up_async_call :
 376                                           afs_wake_up_call_waiter),
 377                                          call->service_id,
 378                                          call->upgrade,
 379                                          (call->intr ? RXRPC_PREINTERRUPTIBLE :
 380                                           RXRPC_UNINTERRUPTIBLE),
 381                                          call->debug_id);
 382         if (IS_ERR(rxcall)) {
 383                 ret = PTR_ERR(rxcall);
 384                 call->error = ret;
 385                 goto error_kill_call;
 386         }
 387
 388         call->rxcall = rxcall;
 389         call->issue_time = ktime_get_real();
 390
 391         /* send the request */
 392         iov[0].iov_base = call->request;
 393         iov[0].iov_len  = call->request_size;
 394
 395         msg.msg_name            = NULL;
 396         msg.msg_namelen         = 0;
 397         iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, iov, 1, call->request_size);
 398         msg.msg_control         = NULL;
 399         msg.msg_controllen      = 0;
 400         msg.msg_flags           = MSG_WAITALL | (call->write_iter ? MSG_MORE : 0);
 401
 402         ret = rxrpc_kernel_send_data(call->net->socket, rxcall,
 403                                      &msg, call->request_size,
 404                                      afs_notify_end_request_tx);
 405         if (ret < 0)
 406                 goto error_do_abort;
 407
 408         if (call->write_iter) {
 409                 msg.msg_iter = *call->write_iter;
 410                 msg.msg_flags &= ~MSG_MORE;
 411                 trace_afs_send_data(call, &msg);
 412
 413                 ret = rxrpc_kernel_send_data(call->net->socket,
 414                                              call->rxcall, &msg,
 415                                              iov_iter_count(&msg.msg_iter),
 416                                              afs_notify_end_request_tx);
 417                 *call->write_iter = msg.msg_iter;
 418
 419                 trace_afs_sent_data(call, &msg, ret);
 420                 if (ret < 0)
 421                         goto error_do_abort;
 422         }
 423
 424         /* Note that at this point, we may have received the reply or an abort
 425          * - and an asynchronous call may already have completed.
 426          *
 427          * afs_wait_for_call_to_complete(call)
 428          * must be called to synchronously clean up.
 429          */
 430         return;
 431
 432 error_do_abort:
 433         if (ret != -ECONNABORTED) {
 434                 rxrpc_kernel_abort_call(call->net->socket, rxcall,
 435                                         RX_USER_ABORT, ret,
 436                                         afs_abort_send_data_error);
 437         } else {
 438                 len = 0;
 439                 iov_iter_kvec(&msg.msg_iter, ITER_DEST, NULL, 0, 0);
 440                 rxrpc_kernel_recv_data(call->net->socket, rxcall,
 441                                        &msg.msg_iter, &len, false,
 442                                        &call->abort_code, &call->service_id);
 443                 call->responded = true;
 444         }
 445         call->error = ret;
 446         trace_afs_call_done(call);
 447 error_kill_call:
 448         if (call->type->done)
 449                 call->type->done(call);
 450
 451         /* We need to dispose of the extra ref we grabbed for an async call.
 452          * The call, however, might be queued on afs_async_calls and we need to
 453          * make sure we don't get any more notifications that might requeue it.
 454          */
 455         if (call->rxcall)
 456                 rxrpc_kernel_shutdown_call(call->net->socket, call->rxcall);
 457         if (call->async) {
 458                 if (cancel_work_sync(&call->async_work))
 459                         afs_put_call(call);
 460                 afs_set_call_complete(call, ret, 0);
 461         }
 462
 463         call->error = ret;
 464         call->state = AFS_CALL_COMPLETE;
 465         _leave(" = %d", ret);
 466 }
 467
 468 /*
 469  * Log remote abort codes that indicate that we have a protocol disagreement
 470  * with the server.
 471  */
 472 static void afs_log_error(struct afs_call *call, s32 remote_abort)
 473 {
 474         static int max = 0;
 475         const char *msg;
 476         int m;
 477
 478         switch (remote_abort) {
 479         case RX_EOF:             msg = "unexpected EOF";        break;
 480         case RXGEN_CC_MARSHAL:   msg = "client marshalling";    break;
 481         case RXGEN_CC_UNMARSHAL: msg = "client unmarshalling";  break;
 482         case RXGEN_SS_MARSHAL:   msg = "server marshalling";    break;
 483         case RXGEN_SS_UNMARSHAL: msg = "server unmarshalling";  break;
 484         case RXGEN_DECODE:       msg = "opcode decode";         break;
 485         case RXGEN_SS_XDRFREE:   msg = "server XDR cleanup";    break;
 486         case RXGEN_CC_XDRFREE:   msg = "client XDR cleanup";    break;
 487         case -32:                msg = "insufficient data";     break;
 488         default:
 489                 return;
 490         }
 491
 492         m = max;
 493         if (m < 3) {
 494                 max = m + 1;
 495                 pr_notice("kAFS: Peer reported %s failure on %s [%pISp]\n",
 496                           msg, call->type->name,
 497                           rxrpc_kernel_remote_addr(call->peer));
 498         }
 499 }
 500
 501 /*
 502  * deliver messages to a call
 503  */
 504 static void afs_deliver_to_call(struct afs_call *call)
 505 {
 506         enum afs_call_state state;
 507         size_t len;
 508         u32 abort_code, remote_abort = 0;
 509         int ret;
 510
 511         _enter("%s", call->type->name);
 512
 513         while (state = READ_ONCE(call->state),
 514                state == AFS_CALL_CL_AWAIT_REPLY ||
 515                state == AFS_CALL_SV_AWAIT_OP_ID ||
 516                state == AFS_CALL_SV_AWAIT_REQUEST ||
 517                state == AFS_CALL_SV_AWAIT_ACK
 518                ) {
 519                 if (state == AFS_CALL_SV_AWAIT_ACK) {
 520                         len = 0;
 521                         iov_iter_kvec(&call->def_iter, ITER_DEST, NULL, 0, 0);
 522                         ret = rxrpc_kernel_recv_data(call->net->socket,
 523                                                      call->rxcall, &call->def_iter,
 524                                                      &len, false, &remote_abort,
 525                                                      &call->service_id);
 526                         trace_afs_receive_data(call, &call->def_iter, false, ret);
 527
 528                         if (ret == -EINPROGRESS || ret == -EAGAIN)
 529                                 return;
 530                         if (ret < 0 || ret == 1) {
 531                                 if (ret == 1)
 532                                         ret = 0;
 533                                 goto call_complete;
 534                         }
 535                         return;
 536                 }
 537
 538                 ret = call->type->deliver(call);
 539                 state = READ_ONCE(call->state);
 540                 if (ret == 0 && call->unmarshalling_error)
 541                         ret = -EBADMSG;
 542                 switch (ret) {
 543                 case 0:
 544                         call->responded = true;
 545                         afs_queue_call_work(call);
 546                         if (state == AFS_CALL_CL_PROC_REPLY) {
 547                                 if (call->op)
 548                                         set_bit(AFS_SERVER_FL_MAY_HAVE_CB,
 549                                                 &call->op->server->flags);
 550                                 goto call_complete;
 551                         }
 552                         ASSERTCMP(state, >, AFS_CALL_CL_PROC_REPLY);
 553                         goto done;
 554                 case -EINPROGRESS:
 555                 case -EAGAIN:
 556                         goto out;
 557                 case -ECONNABORTED:
 558                         ASSERTCMP(state, ==, AFS_CALL_COMPLETE);
 559                         call->responded = true;
 560                         afs_log_error(call, call->abort_code);
 561                         goto done;
 562                 case -ENOTSUPP:
 563                         call->responded = true;
 564                         abort_code = RXGEN_OPCODE;
 565                         rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 566                                                 abort_code, ret,
 567                                                 afs_abort_op_not_supported);
 568                         goto local_abort;
 569                 case -EIO:
 570                         pr_err("kAFS: Call %u in bad state %u\n",
 571                                call->debug_id, state);
 572                         fallthrough;
 573                 case -ENODATA:
 574                 case -EBADMSG:
 575                 case -EMSGSIZE:
 576                 case -ENOMEM:
 577                 case -EFAULT:
 578                         abort_code = RXGEN_CC_UNMARSHAL;
 579                         if (state != AFS_CALL_CL_AWAIT_REPLY)
 580                                 abort_code = RXGEN_SS_UNMARSHAL;
 581                         rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 582                                                 abort_code, ret,
 583                                                 afs_abort_unmarshal_error);
 584                         goto local_abort;
 585                 default:
 586                         abort_code = RX_CALL_DEAD;
 587                         rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 588                                                 abort_code, ret,
 589                                                 afs_abort_general_error);
 590                         goto local_abort;
 591                 }
 592         }
 593
 594 done:
 595         if (call->type->done)
 596                 call->type->done(call);
 597 out:
 598         _leave("");
 599         return;
 600
 601 local_abort:
 602         abort_code = 0;
 603 call_complete:
 604         afs_set_call_complete(call, ret, remote_abort);
 605         state = AFS_CALL_COMPLETE;
 606         goto done;
 607 }
 608
 609 /*
 610  * Wait synchronously for a call to complete.
 611  */
 612 void afs_wait_for_call_to_complete(struct afs_call *call)
 613 {
 614         bool rxrpc_complete = false;
 615
 616         _enter("");
 617
 618         if (!afs_check_call_state(call, AFS_CALL_COMPLETE)) {
 619                 DECLARE_WAITQUEUE(myself, current);
 620
 621                 add_wait_queue(&call->waitq, &myself);
 622                 for (;;) {
 623                         set_current_state(TASK_UNINTERRUPTIBLE);
 624
 625                         /* deliver any messages that are in the queue */
 626                         if (!afs_check_call_state(call, AFS_CALL_COMPLETE) &&
 627                             call->need_attention) {
 628                                 call->need_attention = false;
 629                                 __set_current_state(TASK_RUNNING);
 630                                 afs_deliver_to_call(call);
 631                                 continue;
 632                         }
 633
 634                         if (afs_check_call_state(call, AFS_CALL_COMPLETE))
 635                                 break;
 636
 637                         if (!rxrpc_kernel_check_life(call->net->socket, call->rxcall)) {
 638                                 /* rxrpc terminated the call. */
 639                                 rxrpc_complete = true;
 640                                 break;
 641                         }
 642
 643                         schedule();
 644                 }
 645
 646                 remove_wait_queue(&call->waitq, &myself);
 647                 __set_current_state(TASK_RUNNING);
 648         }
 649
 650         if (!afs_check_call_state(call, AFS_CALL_COMPLETE)) {
 651                 if (rxrpc_complete) {
 652                         afs_set_call_complete(call, call->error, call->abort_code);
 653                 } else {
 654                         /* Kill off the call if it's still live. */
 655                         _debug("call interrupted");
 656                         if (rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 657                                                     RX_USER_ABORT, -EINTR,
 658                                                     afs_abort_interrupted))
 659                                 afs_set_call_complete(call, -EINTR, 0);
 660                 }
 661         }
 662 }
 663
 664 /*
 665  * wake up a waiting call
 666  */
 667 static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall,
 668                                     unsigned long call_user_ID)
 669 {
 670         struct afs_call *call = (struct afs_call *)call_user_ID;
 671
 672         call->need_attention = true;
 673         wake_up(&call->waitq);
 674 }
 675
 676 /*
 677  * Wake up an asynchronous call.  The caller is holding the call notify
 678  * spinlock around this, so we can't call afs_put_call().
 679  */
 680 static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
 681                                    unsigned long call_user_ID)
 682 {
 683         struct afs_call *call = (struct afs_call *)call_user_ID;
 684         int r;
 685
 686         trace_afs_notify_call(rxcall, call);
 687         call->need_attention = true;
 688
 689         if (__refcount_inc_not_zero(&call->ref, &r)) {
 690                 trace_afs_call(call->debug_id, afs_call_trace_wake, r + 1,
 691                                atomic_read(&call->net->nr_outstanding_calls),
 692                                __builtin_return_address(0));
 693
 694                 if (!queue_work(afs_async_calls, &call->async_work))
 695                         afs_deferred_put_call(call);
 696         }
 697 }
 698
 699 /*
 700  * Perform I/O processing on an asynchronous call.  The work item carries a ref
 701  * to the call struct that we either need to release or to pass on.
 702  */
 703 static void afs_process_async_call(struct work_struct *work)
 704 {
 705         struct afs_call *call = container_of(work, struct afs_call, async_work);
 706
 707         _enter("");
 708
 709         if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
 710                 call->need_attention = false;
 711                 afs_deliver_to_call(call);
 712         }
 713
 714         afs_put_call(call);
 715         _leave("");
 716 }
 717
 718 static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)
 719 {
 720         struct afs_call *call = (struct afs_call *)user_call_ID;
 721
 722         call->rxcall = rxcall;
 723 }
 724
 725 /*
 726  * Charge the incoming call preallocation.
 727  */
 728 void afs_charge_preallocation(struct work_struct *work)
 729 {
 730         struct afs_net *net =
 731                 container_of(work, struct afs_net, charge_preallocation_work);
 732         struct afs_call *call = net->spare_incoming_call;
 733
 734         for (;;) {
 735                 if (!call) {
 736                         call = afs_alloc_call(net, &afs_RXCMxxxx, GFP_KERNEL);
 737                         if (!call)
 738                                 break;
 739
 740                         call->drop_ref = true;
 741                         call->async = true;
 742                         call->state = AFS_CALL_SV_AWAIT_OP_ID;
 743                         init_waitqueue_head(&call->waitq);
 744                         afs_extract_to_tmp(call);
 745                 }
 746
 747                 if (rxrpc_kernel_charge_accept(net->socket,
 748                                                afs_wake_up_async_call,
 749                                                afs_rx_attach,
 750                                                (unsigned long)call,
 751                                                GFP_KERNEL,
 752                                                call->debug_id) < 0)
 753                         break;
 754                 call = NULL;
 755         }
 756         net->spare_incoming_call = call;
 757 }
 758
 759 /*
 760  * Discard a preallocated call when a socket is shut down.
 761  */
 762 static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
 763                                     unsigned long user_call_ID)
 764 {
 765         struct afs_call *call = (struct afs_call *)user_call_ID;
 766
 767         call->rxcall = NULL;
 768         afs_put_call(call);
 769 }
 770
 771 /*
 772  * Notification of an incoming call.
 773  */
 774 static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
 775                             unsigned long user_call_ID)
 776 {
 777         struct afs_net *net = afs_sock2net(sk);
 778
 779         queue_work(afs_wq, &net->charge_preallocation_work);
 780 }
 781
 782 /*
 783  * Grab the operation ID from an incoming cache manager call.  The socket
 784  * buffer is discarded on error or if we don't yet have sufficient data.
 785  */
 786 static int afs_deliver_cm_op_id(struct afs_call *call)
 787 {
 788         int ret;
 789
 790         _enter("{%zu}", iov_iter_count(call->iter));
 791
 792         /* the operation ID forms the first four bytes of the request data */
 793         ret = afs_extract_data(call, true);
 794         if (ret < 0)
 795                 return ret;
 796
 797         call->operation_ID = ntohl(call->tmp);
 798         afs_set_call_state(call, AFS_CALL_SV_AWAIT_OP_ID, AFS_CALL_SV_AWAIT_REQUEST);
 799
 800         /* ask the cache manager to route the call (it'll change the call type
 801          * if successful) */
 802         if (!afs_cm_incoming_call(call))
 803                 return -ENOTSUPP;
 804
 805         trace_afs_cb_call(call);
 806
 807         /* pass responsibility for the remainer of this message off to the
 808          * cache manager op */
 809         return call->type->deliver(call);
 810 }
 811
 812 /*
 813  * Advance the AFS call state when an RxRPC service call ends the transmit
 814  * phase.
 815  */
 816 static void afs_notify_end_reply_tx(struct sock *sock,
 817                                     struct rxrpc_call *rxcall,
 818                                     unsigned long call_user_ID)
 819 {
 820         struct afs_call *call = (struct afs_call *)call_user_ID;
 821
 822         afs_set_call_state(call, AFS_CALL_SV_REPLYING, AFS_CALL_SV_AWAIT_ACK);
 823 }
 824
 825 /*
 826  * send an empty reply
 827  */
 828 void afs_send_empty_reply(struct afs_call *call)
 829 {
 830         struct afs_net *net = call->net;
 831         struct msghdr msg;
 832
 833         _enter("");
 834
 835         rxrpc_kernel_set_tx_length(net->socket, call->rxcall, 0);
 836
 837         msg.msg_name            = NULL;
 838         msg.msg_namelen         = 0;
 839         iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, NULL, 0, 0);
 840         msg.msg_control         = NULL;
 841         msg.msg_controllen      = 0;
 842         msg.msg_flags           = 0;
 843
 844         switch (rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, 0,
 845                                        afs_notify_end_reply_tx)) {
 846         case 0:
 847                 _leave(" [replied]");
 848                 return;
 849
 850         case -ENOMEM:
 851                 _debug("oom");
 852                 rxrpc_kernel_abort_call(net->socket, call->rxcall,
 853                                         RXGEN_SS_MARSHAL, -ENOMEM,
 854                                         afs_abort_oom);
 855                 fallthrough;
 856         default:
 857                 _leave(" [error]");
 858                 return;
 859         }
 860 }
 861
 862 /*
 863  * send a simple reply
 864  */
 865 void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
 866 {
 867         struct afs_net *net = call->net;
 868         struct msghdr msg;
 869         struct kvec iov[1];
 870         int n;
 871
 872         _enter("");
 873
 874         rxrpc_kernel_set_tx_length(net->socket, call->rxcall, len);
 875
 876         iov[0].iov_base         = (void *) buf;
 877         iov[0].iov_len          = len;
 878         msg.msg_name            = NULL;
 879         msg.msg_namelen         = 0;
 880         iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, iov, 1, len);
 881         msg.msg_control         = NULL;
 882         msg.msg_controllen      = 0;
 883         msg.msg_flags           = 0;
 884
 885         n = rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, len,
 886                                    afs_notify_end_reply_tx);
 887         if (n >= 0) {
 888                 /* Success */
 889                 _leave(" [replied]");
 890                 return;
 891         }
 892
 893         if (n == -ENOMEM) {
 894                 _debug("oom");
 895                 rxrpc_kernel_abort_call(net->socket, call->rxcall,
 896                                         RXGEN_SS_MARSHAL, -ENOMEM,
 897                                         afs_abort_oom);
 898         }
 899         _leave(" [error]");
 900 }
 901
 902 /*
 903  * Extract a piece of data from the received data socket buffers.
 904  */
 905 int afs_extract_data(struct afs_call *call, bool want_more)
 906 {
 907         struct afs_net *net = call->net;
 908         struct iov_iter *iter = call->iter;
 909         enum afs_call_state state;
 910         u32 remote_abort = 0;
 911         int ret;
 912
 913         _enter("{%s,%zu,%zu},%d",
 914                call->type->name, call->iov_len, iov_iter_count(iter), want_more);
 915
 916         ret = rxrpc_kernel_recv_data(net->socket, call->rxcall, iter,
 917                                      &call->iov_len, want_more, &remote_abort,
 918                                      &call->service_id);
 919         trace_afs_receive_data(call, call->iter, want_more, ret);
 920         if (ret == 0 || ret == -EAGAIN)
 921                 return ret;
 922
 923         state = READ_ONCE(call->state);
 924         if (ret == 1) {
 925                 switch (state) {
 926                 case AFS_CALL_CL_AWAIT_REPLY:
 927                         afs_set_call_state(call, state, AFS_CALL_CL_PROC_REPLY);
 928                         break;
 929                 case AFS_CALL_SV_AWAIT_REQUEST:
 930                         afs_set_call_state(call, state, AFS_CALL_SV_REPLYING);
 931                         break;
 932                 case AFS_CALL_COMPLETE:
 933                         kdebug("prem complete %d", call->error);
 934                         return afs_io_error(call, afs_io_error_extract);
 935                 default:
 936                         break;
 937                 }
 938                 return 0;
 939         }
 940
 941         afs_set_call_complete(call, ret, remote_abort);
 942         return ret;
 943 }
 944
 945 /*
 946  * Log protocol error production.
 947  */
 948 noinline int afs_protocol_error(struct afs_call *call,
 949                                 enum afs_eproto_cause cause)
 950 {
 951         trace_afs_protocol_error(call, cause);
 952         if (call)
 953                 call->unmarshalling_error = true;
 954         return -EBADMSG;
 955 }