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                 if (call->rxcall) {
 182                         rxrpc_kernel_shutdown_call(net->socket, call->rxcall);
 183                         rxrpc_kernel_put_call(net->socket, call->rxcall);
 184                         call->rxcall = NULL;
 185                 }
 186                 if (call->type->destructor)
 187                         call->type->destructor(call);
 188
 189                 afs_unuse_server_notime(call->net, call->server, afs_server_trace_put_call);
 190                 afs_put_addrlist(call->alist);
 191                 kfree(call->request);
 192
 193                 trace_afs_call(call->debug_id, afs_call_trace_free, 0, o,
 194                                __builtin_return_address(0));
 195                 kfree(call);
 196
 197                 o = atomic_dec_return(&net->nr_outstanding_calls);
 198                 if (o == 0)
 199                         wake_up_var(&net->nr_outstanding_calls);
 200         }
 201 }
 202
 203 static struct afs_call *afs_get_call(struct afs_call *call,
 204                                      enum afs_call_trace why)
 205 {
 206         int r;
 207
 208         __refcount_inc(&call->ref, &r);
 209
 210         trace_afs_call(call->debug_id, why, r + 1,
 211                        atomic_read(&call->net->nr_outstanding_calls),
 212                        __builtin_return_address(0));
 213         return call;
 214 }
 215
 216 /*
 217  * Queue the call for actual work.
 218  */
 219 static void afs_queue_call_work(struct afs_call *call)
 220 {
 221         if (call->type->work) {
 222                 INIT_WORK(&call->work, call->type->work);
 223
 224                 afs_get_call(call, afs_call_trace_work);
 225                 if (!queue_work(afs_wq, &call->work))
 226                         afs_put_call(call);
 227         }
 228 }
 229
 230 /*
 231  * allocate a call with flat request and reply buffers
 232  */
 233 struct afs_call *afs_alloc_flat_call(struct afs_net *net,
 234                                      const struct afs_call_type *type,
 235                                      size_t request_size, size_t reply_max)
 236 {
 237         struct afs_call *call;
 238
 239         call = afs_alloc_call(net, type, GFP_NOFS);
 240         if (!call)
 241                 goto nomem_call;
 242
 243         if (request_size) {
 244                 call->request_size = request_size;
 245                 call->request = kmalloc(request_size, GFP_NOFS);
 246                 if (!call->request)
 247                         goto nomem_free;
 248         }
 249
 250         if (reply_max) {
 251                 call->reply_max = reply_max;
 252                 call->buffer = kmalloc(reply_max, GFP_NOFS);
 253                 if (!call->buffer)
 254                         goto nomem_free;
 255         }
 256
 257         afs_extract_to_buf(call, call->reply_max);
 258         call->operation_ID = type->op;
 259         init_waitqueue_head(&call->waitq);
 260         return call;
 261
 262 nomem_free:
 263         afs_put_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  * Advance the AFS call state when the RxRPC call ends the transmit phase.
 283  */
 284 static void afs_notify_end_request_tx(struct sock *sock,
 285                                       struct rxrpc_call *rxcall,
 286                                       unsigned long call_user_ID)
 287 {
 288         struct afs_call *call = (struct afs_call *)call_user_ID;
 289
 290         afs_set_call_state(call, AFS_CALL_CL_REQUESTING, AFS_CALL_CL_AWAIT_REPLY);
 291 }
 292
 293 /*
 294  * Initiate a call and synchronously queue up the parameters for dispatch.  Any
 295  * error is stored into the call struct, which the caller must check for.
 296  */
 297 void afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call, gfp_t gfp)
 298 {
 299         struct sockaddr_rxrpc *srx = &ac->alist->addrs[ac->index];
 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},", &srx->transport);
 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         call->addr_ix = ac->index;
 317         call->alist = afs_get_addrlist(ac->alist);
 318
 319         /* Work out the length we're going to transmit.  This is awkward for
 320          * calls such as FS.StoreData where there's an extra injection of data
 321          * after the initial fixed part.
 322          */
 323         tx_total_len = call->request_size;
 324         if (call->write_iter)
 325                 tx_total_len += iov_iter_count(call->write_iter);
 326
 327         /* If the call is going to be asynchronous, we need an extra ref for
 328          * the call to hold itself so the caller need not hang on to its ref.
 329          */
 330         if (call->async) {
 331                 afs_get_call(call, afs_call_trace_get);
 332                 call->drop_ref = true;
 333         }
 334
 335         /* create a call */
 336         rxcall = rxrpc_kernel_begin_call(call->net->socket, srx, call->key,
 337                                          (unsigned long)call,
 338                                          tx_total_len, gfp,
 339                                          (call->async ?
 340                                           afs_wake_up_async_call :
 341                                           afs_wake_up_call_waiter),
 342                                          call->upgrade,
 343                                          (call->intr ? RXRPC_PREINTERRUPTIBLE :
 344                                           RXRPC_UNINTERRUPTIBLE),
 345                                          call->debug_id);
 346         if (IS_ERR(rxcall)) {
 347                 ret = PTR_ERR(rxcall);
 348                 call->error = ret;
 349                 goto error_kill_call;
 350         }
 351
 352         call->rxcall = rxcall;
 353
 354         if (call->max_lifespan)
 355                 rxrpc_kernel_set_max_life(call->net->socket, rxcall,
 356                                           call->max_lifespan);
 357         call->issue_time = ktime_get_real();
 358
 359         /* send the request */
 360         iov[0].iov_base = call->request;
 361         iov[0].iov_len  = call->request_size;
 362
 363         msg.msg_name            = NULL;
 364         msg.msg_namelen         = 0;
 365         iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, iov, 1, call->request_size);
 366         msg.msg_control         = NULL;
 367         msg.msg_controllen      = 0;
 368         msg.msg_flags           = MSG_WAITALL | (call->write_iter ? MSG_MORE : 0);
 369
 370         ret = rxrpc_kernel_send_data(call->net->socket, rxcall,
 371                                      &msg, call->request_size,
 372                                      afs_notify_end_request_tx);
 373         if (ret < 0)
 374                 goto error_do_abort;
 375
 376         if (call->write_iter) {
 377                 msg.msg_iter = *call->write_iter;
 378                 msg.msg_flags &= ~MSG_MORE;
 379                 trace_afs_send_data(call, &msg);
 380
 381                 ret = rxrpc_kernel_send_data(call->net->socket,
 382                                              call->rxcall, &msg,
 383                                              iov_iter_count(&msg.msg_iter),
 384                                              afs_notify_end_request_tx);
 385                 *call->write_iter = msg.msg_iter;
 386
 387                 trace_afs_sent_data(call, &msg, ret);
 388                 if (ret < 0)
 389                         goto error_do_abort;
 390         }
 391
 392         /* Note that at this point, we may have received the reply or an abort
 393          * - and an asynchronous call may already have completed.
 394          *
 395          * afs_wait_for_call_to_complete(call, ac)
 396          * must be called to synchronously clean up.
 397          */
 398         return;
 399
 400 error_do_abort:
 401         if (ret != -ECONNABORTED) {
 402                 rxrpc_kernel_abort_call(call->net->socket, rxcall,
 403                                         RX_USER_ABORT, ret,
 404                                         afs_abort_send_data_error);
 405         } else {
 406                 len = 0;
 407                 iov_iter_kvec(&msg.msg_iter, ITER_DEST, NULL, 0, 0);
 408                 rxrpc_kernel_recv_data(call->net->socket, rxcall,
 409                                        &msg.msg_iter, &len, false,
 410                                        &call->abort_code, &call->service_id);
 411                 ac->abort_code = call->abort_code;
 412                 ac->responded = true;
 413         }
 414         call->error = ret;
 415         trace_afs_call_done(call);
 416 error_kill_call:
 417         if (call->type->done)
 418                 call->type->done(call);
 419
 420         /* We need to dispose of the extra ref we grabbed for an async call.
 421          * The call, however, might be queued on afs_async_calls and we need to
 422          * make sure we don't get any more notifications that might requeue it.
 423          */
 424         if (call->rxcall)
 425                 rxrpc_kernel_shutdown_call(call->net->socket, call->rxcall);
 426         if (call->async) {
 427                 if (cancel_work_sync(&call->async_work))
 428                         afs_put_call(call);
 429                 afs_put_call(call);
 430         }
 431
 432         ac->error = ret;
 433         call->state = AFS_CALL_COMPLETE;
 434         _leave(" = %d", ret);
 435 }
 436
 437 /*
 438  * Log remote abort codes that indicate that we have a protocol disagreement
 439  * with the server.
 440  */
 441 static void afs_log_error(struct afs_call *call, s32 remote_abort)
 442 {
 443         static int max = 0;
 444         const char *msg;
 445         int m;
 446
 447         switch (remote_abort) {
 448         case RX_EOF:             msg = "unexpected EOF";        break;
 449         case RXGEN_CC_MARSHAL:   msg = "client marshalling";    break;
 450         case RXGEN_CC_UNMARSHAL: msg = "client unmarshalling";  break;
 451         case RXGEN_SS_MARSHAL:   msg = "server marshalling";    break;
 452         case RXGEN_SS_UNMARSHAL: msg = "server unmarshalling";  break;
 453         case RXGEN_DECODE:       msg = "opcode decode";         break;
 454         case RXGEN_SS_XDRFREE:   msg = "server XDR cleanup";    break;
 455         case RXGEN_CC_XDRFREE:   msg = "client XDR cleanup";    break;
 456         case -32:                msg = "insufficient data";     break;
 457         default:
 458                 return;
 459         }
 460
 461         m = max;
 462         if (m < 3) {
 463                 max = m + 1;
 464                 pr_notice("kAFS: Peer reported %s failure on %s [%pISp]\n",
 465                           msg, call->type->name,
 466                           &call->alist->addrs[call->addr_ix].transport);
 467         }
 468 }
 469
 470 /*
 471  * deliver messages to a call
 472  */
 473 static void afs_deliver_to_call(struct afs_call *call)
 474 {
 475         enum afs_call_state state;
 476         size_t len;
 477         u32 abort_code, remote_abort = 0;
 478         int ret;
 479
 480         _enter("%s", call->type->name);
 481
 482         while (state = READ_ONCE(call->state),
 483                state == AFS_CALL_CL_AWAIT_REPLY ||
 484                state == AFS_CALL_SV_AWAIT_OP_ID ||
 485                state == AFS_CALL_SV_AWAIT_REQUEST ||
 486                state == AFS_CALL_SV_AWAIT_ACK
 487                ) {
 488                 if (state == AFS_CALL_SV_AWAIT_ACK) {
 489                         len = 0;
 490                         iov_iter_kvec(&call->def_iter, ITER_DEST, NULL, 0, 0);
 491                         ret = rxrpc_kernel_recv_data(call->net->socket,
 492                                                      call->rxcall, &call->def_iter,
 493                                                      &len, false, &remote_abort,
 494                                                      &call->service_id);
 495                         trace_afs_receive_data(call, &call->def_iter, false, ret);
 496
 497                         if (ret == -EINPROGRESS || ret == -EAGAIN)
 498                                 return;
 499                         if (ret < 0 || ret == 1) {
 500                                 if (ret == 1)
 501                                         ret = 0;
 502                                 goto call_complete;
 503                         }
 504                         return;
 505                 }
 506
 507                 ret = call->type->deliver(call);
 508                 state = READ_ONCE(call->state);
 509                 if (ret == 0 && call->unmarshalling_error)
 510                         ret = -EBADMSG;
 511                 switch (ret) {
 512                 case 0:
 513                         afs_queue_call_work(call);
 514                         if (state == AFS_CALL_CL_PROC_REPLY) {
 515                                 if (call->op)
 516                                         set_bit(AFS_SERVER_FL_MAY_HAVE_CB,
 517                                                 &call->op->server->flags);
 518                                 goto call_complete;
 519                         }
 520                         ASSERTCMP(state, >, AFS_CALL_CL_PROC_REPLY);
 521                         goto done;
 522                 case -EINPROGRESS:
 523                 case -EAGAIN:
 524                         goto out;
 525                 case -ECONNABORTED:
 526                         ASSERTCMP(state, ==, AFS_CALL_COMPLETE);
 527                         afs_log_error(call, call->abort_code);
 528                         goto done;
 529                 case -ENOTSUPP:
 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 and clean up the call struct.
 577  */
 578 long afs_wait_for_call_to_complete(struct afs_call *call,
 579                                    struct afs_addr_cursor *ac)
 580 {
 581         long ret;
 582         bool rxrpc_complete = false;
 583
 584         DECLARE_WAITQUEUE(myself, current);
 585
 586         _enter("");
 587
 588         ret = call->error;
 589         if (ret < 0)
 590                 goto out;
 591
 592         add_wait_queue(&call->waitq, &myself);
 593         for (;;) {
 594                 set_current_state(TASK_UNINTERRUPTIBLE);
 595
 596                 /* deliver any messages that are in the queue */
 597                 if (!afs_check_call_state(call, AFS_CALL_COMPLETE) &&
 598                     call->need_attention) {
 599                         call->need_attention = false;
 600                         __set_current_state(TASK_RUNNING);
 601                         afs_deliver_to_call(call);
 602                         continue;
 603                 }
 604
 605                 if (afs_check_call_state(call, AFS_CALL_COMPLETE))
 606                         break;
 607
 608                 if (!rxrpc_kernel_check_life(call->net->socket, call->rxcall)) {
 609                         /* rxrpc terminated the call. */
 610                         rxrpc_complete = true;
 611                         break;
 612                 }
 613
 614                 schedule();
 615         }
 616
 617         remove_wait_queue(&call->waitq, &myself);
 618         __set_current_state(TASK_RUNNING);
 619
 620         if (!afs_check_call_state(call, AFS_CALL_COMPLETE)) {
 621                 if (rxrpc_complete) {
 622                         afs_set_call_complete(call, call->error, call->abort_code);
 623                 } else {
 624                         /* Kill off the call if it's still live. */
 625                         _debug("call interrupted");
 626                         if (rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 627                                                     RX_USER_ABORT, -EINTR,
 628                                                     afs_abort_interrupted))
 629                                 afs_set_call_complete(call, -EINTR, 0);
 630                 }
 631         }
 632
 633         spin_lock_bh(&call->state_lock);
 634         ac->abort_code = call->abort_code;
 635         ac->error = call->error;
 636         spin_unlock_bh(&call->state_lock);
 637
 638         ret = ac->error;
 639         switch (ret) {
 640         case 0:
 641                 ret = call->ret0;
 642                 call->ret0 = 0;
 643
 644                 fallthrough;
 645         case -ECONNABORTED:
 646                 ac->responded = true;
 647                 break;
 648         }
 649
 650 out:
 651         _debug("call complete");
 652         afs_put_call(call);
 653         _leave(" = %p", (void *)ret);
 654         return ret;
 655 }
 656
 657 /*
 658  * wake up a waiting call
 659  */
 660 static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall,
 661                                     unsigned long call_user_ID)
 662 {
 663         struct afs_call *call = (struct afs_call *)call_user_ID;
 664
 665         call->need_attention = true;
 666         wake_up(&call->waitq);
 667 }
 668
 669 /*
 670  * wake up an asynchronous call
 671  */
 672 static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
 673                                    unsigned long call_user_ID)
 674 {
 675         struct afs_call *call = (struct afs_call *)call_user_ID;
 676         int r;
 677
 678         trace_afs_notify_call(rxcall, call);
 679         call->need_attention = true;
 680
 681         if (__refcount_inc_not_zero(&call->ref, &r)) {
 682                 trace_afs_call(call->debug_id, afs_call_trace_wake, r + 1,
 683                                atomic_read(&call->net->nr_outstanding_calls),
 684                                __builtin_return_address(0));
 685
 686                 if (!queue_work(afs_async_calls, &call->async_work))
 687                         afs_put_call(call);
 688         }
 689 }
 690
 691 /*
 692  * Perform I/O processing on an asynchronous call.  The work item carries a ref
 693  * to the call struct that we either need to release or to pass on.
 694  */
 695 static void afs_process_async_call(struct work_struct *work)
 696 {
 697         struct afs_call *call = container_of(work, struct afs_call, async_work);
 698
 699         _enter("");
 700
 701         if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
 702                 call->need_attention = false;
 703                 afs_deliver_to_call(call);
 704         }
 705
 706         afs_put_call(call);
 707         _leave("");
 708 }
 709
 710 static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)
 711 {
 712         struct afs_call *call = (struct afs_call *)user_call_ID;
 713
 714         call->rxcall = rxcall;
 715 }
 716
 717 /*
 718  * Charge the incoming call preallocation.
 719  */
 720 void afs_charge_preallocation(struct work_struct *work)
 721 {
 722         struct afs_net *net =
 723                 container_of(work, struct afs_net, charge_preallocation_work);
 724         struct afs_call *call = net->spare_incoming_call;
 725
 726         for (;;) {
 727                 if (!call) {
 728                         call = afs_alloc_call(net, &afs_RXCMxxxx, GFP_KERNEL);
 729                         if (!call)
 730                                 break;
 731
 732                         call->drop_ref = true;
 733                         call->async = true;
 734                         call->state = AFS_CALL_SV_AWAIT_OP_ID;
 735                         init_waitqueue_head(&call->waitq);
 736                         afs_extract_to_tmp(call);
 737                 }
 738
 739                 if (rxrpc_kernel_charge_accept(net->socket,
 740                                                afs_wake_up_async_call,
 741                                                afs_rx_attach,
 742                                                (unsigned long)call,
 743                                                GFP_KERNEL,
 744                                                call->debug_id) < 0)
 745                         break;
 746                 call = NULL;
 747         }
 748         net->spare_incoming_call = call;
 749 }
 750
 751 /*
 752  * Discard a preallocated call when a socket is shut down.
 753  */
 754 static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
 755                                     unsigned long user_call_ID)
 756 {
 757         struct afs_call *call = (struct afs_call *)user_call_ID;
 758
 759         call->rxcall = NULL;
 760         afs_put_call(call);
 761 }
 762
 763 /*
 764  * Notification of an incoming call.
 765  */
 766 static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
 767                             unsigned long user_call_ID)
 768 {
 769         struct afs_net *net = afs_sock2net(sk);
 770
 771         queue_work(afs_wq, &net->charge_preallocation_work);
 772 }
 773
 774 /*
 775  * Grab the operation ID from an incoming cache manager call.  The socket
 776  * buffer is discarded on error or if we don't yet have sufficient data.
 777  */
 778 static int afs_deliver_cm_op_id(struct afs_call *call)
 779 {
 780         int ret;
 781
 782         _enter("{%zu}", iov_iter_count(call->iter));
 783
 784         /* the operation ID forms the first four bytes of the request data */
 785         ret = afs_extract_data(call, true);
 786         if (ret < 0)
 787                 return ret;
 788
 789         call->operation_ID = ntohl(call->tmp);
 790         afs_set_call_state(call, AFS_CALL_SV_AWAIT_OP_ID, AFS_CALL_SV_AWAIT_REQUEST);
 791
 792         /* ask the cache manager to route the call (it'll change the call type
 793          * if successful) */
 794         if (!afs_cm_incoming_call(call))
 795                 return -ENOTSUPP;
 796
 797         trace_afs_cb_call(call);
 798
 799         /* pass responsibility for the remainer of this message off to the
 800          * cache manager op */
 801         return call->type->deliver(call);
 802 }
 803
 804 /*
 805  * Advance the AFS call state when an RxRPC service call ends the transmit
 806  * phase.
 807  */
 808 static void afs_notify_end_reply_tx(struct sock *sock,
 809                                     struct rxrpc_call *rxcall,
 810                                     unsigned long call_user_ID)
 811 {
 812         struct afs_call *call = (struct afs_call *)call_user_ID;
 813
 814         afs_set_call_state(call, AFS_CALL_SV_REPLYING, AFS_CALL_SV_AWAIT_ACK);
 815 }
 816
 817 /*
 818  * send an empty reply
 819  */
 820 void afs_send_empty_reply(struct afs_call *call)
 821 {
 822         struct afs_net *net = call->net;
 823         struct msghdr msg;
 824
 825         _enter("");
 826
 827         rxrpc_kernel_set_tx_length(net->socket, call->rxcall, 0);
 828
 829         msg.msg_name            = NULL;
 830         msg.msg_namelen         = 0;
 831         iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, NULL, 0, 0);
 832         msg.msg_control         = NULL;
 833         msg.msg_controllen      = 0;
 834         msg.msg_flags           = 0;
 835
 836         switch (rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, 0,
 837                                        afs_notify_end_reply_tx)) {
 838         case 0:
 839                 _leave(" [replied]");
 840                 return;
 841
 842         case -ENOMEM:
 843                 _debug("oom");
 844                 rxrpc_kernel_abort_call(net->socket, call->rxcall,
 845                                         RXGEN_SS_MARSHAL, -ENOMEM,
 846                                         afs_abort_oom);
 847                 fallthrough;
 848         default:
 849                 _leave(" [error]");
 850                 return;
 851         }
 852 }
 853
 854 /*
 855  * send a simple reply
 856  */
 857 void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
 858 {
 859         struct afs_net *net = call->net;
 860         struct msghdr msg;
 861         struct kvec iov[1];
 862         int n;
 863
 864         _enter("");
 865
 866         rxrpc_kernel_set_tx_length(net->socket, call->rxcall, len);
 867
 868         iov[0].iov_base         = (void *) buf;
 869         iov[0].iov_len          = len;
 870         msg.msg_name            = NULL;
 871         msg.msg_namelen         = 0;
 872         iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, iov, 1, len);
 873         msg.msg_control         = NULL;
 874         msg.msg_controllen      = 0;
 875         msg.msg_flags           = 0;
 876
 877         n = rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, len,
 878                                    afs_notify_end_reply_tx);
 879         if (n >= 0) {
 880                 /* Success */
 881                 _leave(" [replied]");
 882                 return;
 883         }
 884
 885         if (n == -ENOMEM) {
 886                 _debug("oom");
 887                 rxrpc_kernel_abort_call(net->socket, call->rxcall,
 888                                         RXGEN_SS_MARSHAL, -ENOMEM,
 889                                         afs_abort_oom);
 890         }
 891         _leave(" [error]");
 892 }
 893
 894 /*
 895  * Extract a piece of data from the received data socket buffers.
 896  */
 897 int afs_extract_data(struct afs_call *call, bool want_more)
 898 {
 899         struct afs_net *net = call->net;
 900         struct iov_iter *iter = call->iter;
 901         enum afs_call_state state;
 902         u32 remote_abort = 0;
 903         int ret;
 904
 905         _enter("{%s,%zu,%zu},%d",
 906                call->type->name, call->iov_len, iov_iter_count(iter), want_more);
 907
 908         ret = rxrpc_kernel_recv_data(net->socket, call->rxcall, iter,
 909                                      &call->iov_len, want_more, &remote_abort,
 910                                      &call->service_id);
 911         trace_afs_receive_data(call, call->iter, want_more, ret);
 912         if (ret == 0 || ret == -EAGAIN)
 913                 return ret;
 914
 915         state = READ_ONCE(call->state);
 916         if (ret == 1) {
 917                 switch (state) {
 918                 case AFS_CALL_CL_AWAIT_REPLY:
 919                         afs_set_call_state(call, state, AFS_CALL_CL_PROC_REPLY);
 920                         break;
 921                 case AFS_CALL_SV_AWAIT_REQUEST:
 922                         afs_set_call_state(call, state, AFS_CALL_SV_REPLYING);
 923                         break;
 924                 case AFS_CALL_COMPLETE:
 925                         kdebug("prem complete %d", call->error);
 926                         return afs_io_error(call, afs_io_error_extract);
 927                 default:
 928                         break;
 929                 }
 930                 return 0;
 931         }
 932
 933         afs_set_call_complete(call, ret, remote_abort);
 934         return ret;
 935 }
 936
 937 /*
 938  * Log protocol error production.
 939  */
 940 noinline int afs_protocol_error(struct afs_call *call,
 941                                 enum afs_eproto_cause cause)
 942 {
 943         trace_afs_protocol_error(call, cause);
 944         if (call)
 945                 call->unmarshalling_error = true;
 946         return -EBADMSG;
 947 }