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