linux/fs/afs/rxrpc.c
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   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
  17struct workqueue_struct *afs_async_calls;
  18
  19static void afs_wake_up_call_waiter(struct sock *, struct rxrpc_call *, unsigned long);
  20static void afs_wake_up_async_call(struct sock *, struct rxrpc_call *, unsigned long);
  21static void afs_process_async_call(struct work_struct *);
  22static void afs_rx_new_call(struct sock *, struct rxrpc_call *, unsigned long);
  23static void afs_rx_discard_new_call(struct rxrpc_call *, unsigned long);
  24static int afs_deliver_cm_op_id(struct afs_call *);
  25
  26/* asynchronous incoming call initial processing */
  27static const struct afs_call_type afs_RXCMxxxx = {
  28        .name           = "CB.xxxx",
  29        .deliver        = afs_deliver_cm_op_id,
  30};
  31
  32/*
  33 * open an RxRPC socket and bind it to be a server for callback notifications
  34 * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT
  35 */
  36int afs_open_socket(struct afs_net *net)
  37{
  38        struct sockaddr_rxrpc srx;
  39        struct socket *socket;
  40        int ret;
  41
  42        _enter("");
  43
  44        ret = sock_create_kern(net->net, AF_RXRPC, SOCK_DGRAM, PF_INET6, &socket);
  45        if (ret < 0)
  46                goto error_1;
  47
  48        socket->sk->sk_allocation = GFP_NOFS;
  49
  50        /* bind the callback manager's address to make this a server socket */
  51        memset(&srx, 0, sizeof(srx));
  52        srx.srx_family                  = AF_RXRPC;
  53        srx.srx_service                 = CM_SERVICE;
  54        srx.transport_type              = SOCK_DGRAM;
  55        srx.transport_len               = sizeof(srx.transport.sin6);
  56        srx.transport.sin6.sin6_family  = AF_INET6;
  57        srx.transport.sin6.sin6_port    = htons(AFS_CM_PORT);
  58
  59        ret = rxrpc_sock_set_min_security_level(socket->sk,
  60                                                RXRPC_SECURITY_ENCRYPT);
  61        if (ret < 0)
  62                goto error_2;
  63
  64        ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
  65        if (ret == -EADDRINUSE) {
  66                srx.transport.sin6.sin6_port = 0;
  67                ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
  68        }
  69        if (ret < 0)
  70                goto error_2;
  71
  72        srx.srx_service = YFS_CM_SERVICE;
  73        ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
  74        if (ret < 0)
  75                goto error_2;
  76
  77        /* Ideally, we'd turn on service upgrade here, but we can't because
  78         * OpenAFS is buggy and leaks the userStatus field from packet to
  79         * packet and between FS packets and CB packets - so if we try to do an
  80         * upgrade on an FS packet, OpenAFS will leak that into the CB packet
  81         * it sends back to us.
  82         */
  83
  84        rxrpc_kernel_new_call_notification(socket, afs_rx_new_call,
  85                                           afs_rx_discard_new_call);
  86
  87        ret = kernel_listen(socket, INT_MAX);
  88        if (ret < 0)
  89                goto error_2;
  90
  91        net->socket = socket;
  92        afs_charge_preallocation(&net->charge_preallocation_work);
  93        _leave(" = 0");
  94        return 0;
  95
  96error_2:
  97        sock_release(socket);
  98error_1:
  99        _leave(" = %d", ret);
 100        return ret;
 101}
 102
 103/*
 104 * close the RxRPC socket AFS was using
 105 */
 106void afs_close_socket(struct afs_net *net)
 107{
 108        _enter("");
 109
 110        kernel_listen(net->socket, 0);
 111        flush_workqueue(afs_async_calls);
 112
 113        if (net->spare_incoming_call) {
 114                afs_put_call(net->spare_incoming_call);
 115                net->spare_incoming_call = NULL;
 116        }
 117
 118        _debug("outstanding %u", atomic_read(&net->nr_outstanding_calls));
 119        wait_var_event(&net->nr_outstanding_calls,
 120                       !atomic_read(&net->nr_outstanding_calls));
 121        _debug("no outstanding calls");
 122
 123        kernel_sock_shutdown(net->socket, SHUT_RDWR);
 124        flush_workqueue(afs_async_calls);
 125        sock_release(net->socket);
 126
 127        _debug("dework");
 128        _leave("");
 129}
 130
 131/*
 132 * Allocate a call.
 133 */
 134static struct afs_call *afs_alloc_call(struct afs_net *net,
 135                                       const struct afs_call_type *type,
 136                                       gfp_t gfp)
 137{
 138        struct afs_call *call;
 139        int o;
 140
 141        call = kzalloc(sizeof(*call), gfp);
 142        if (!call)
 143                return NULL;
 144
 145        call->type = type;
 146        call->net = net;
 147        call->debug_id = atomic_inc_return(&rxrpc_debug_id);
 148        atomic_set(&call->usage, 1);
 149        INIT_WORK(&call->async_work, afs_process_async_call);
 150        init_waitqueue_head(&call->waitq);
 151        spin_lock_init(&call->state_lock);
 152        call->iter = &call->def_iter;
 153
 154        o = atomic_inc_return(&net->nr_outstanding_calls);
 155        trace_afs_call(call, afs_call_trace_alloc, 1, o,
 156                       __builtin_return_address(0));
 157        return call;
 158}
 159
 160/*
 161 * Dispose of a reference on a call.
 162 */
 163void afs_put_call(struct afs_call *call)
 164{
 165        struct afs_net *net = call->net;
 166        int n = atomic_dec_return(&call->usage);
 167        int o = atomic_read(&net->nr_outstanding_calls);
 168
 169        trace_afs_call(call, afs_call_trace_put, n, o,
 170                       __builtin_return_address(0));
 171
 172        ASSERTCMP(n, >=, 0);
 173        if (n == 0) {
 174                ASSERT(!work_pending(&call->async_work));
 175                ASSERT(call->type->name != NULL);
 176
 177                if (call->rxcall) {
 178                        rxrpc_kernel_end_call(net->socket, call->rxcall);
 179                        call->rxcall = NULL;
 180                }
 181                if (call->type->destructor)
 182                        call->type->destructor(call);
 183
 184                afs_unuse_server_notime(call->net, call->server, afs_server_trace_put_call);
 185                afs_put_addrlist(call->alist);
 186                kfree(call->request);
 187
 188                trace_afs_call(call, afs_call_trace_free, 0, o,
 189                               __builtin_return_address(0));
 190                kfree(call);
 191
 192                o = atomic_dec_return(&net->nr_outstanding_calls);
 193                if (o == 0)
 194                        wake_up_var(&net->nr_outstanding_calls);
 195        }
 196}
 197
 198static struct afs_call *afs_get_call(struct afs_call *call,
 199                                     enum afs_call_trace why)
 200{
 201        int u = atomic_inc_return(&call->usage);
 202
 203        trace_afs_call(call, why, u,
 204                       atomic_read(&call->net->nr_outstanding_calls),
 205                       __builtin_return_address(0));
 206        return call;
 207}
 208
 209/*
 210 * Queue the call for actual work.
 211 */
 212static void afs_queue_call_work(struct afs_call *call)
 213{
 214        if (call->type->work) {
 215                INIT_WORK(&call->work, call->type->work);
 216
 217                afs_get_call(call, afs_call_trace_work);
 218                if (!queue_work(afs_wq, &call->work))
 219                        afs_put_call(call);
 220        }
 221}
 222
 223/*
 224 * allocate a call with flat request and reply buffers
 225 */
 226struct afs_call *afs_alloc_flat_call(struct afs_net *net,
 227                                     const struct afs_call_type *type,
 228                                     size_t request_size, size_t reply_max)
 229{
 230        struct afs_call *call;
 231
 232        call = afs_alloc_call(net, type, GFP_NOFS);
 233        if (!call)
 234                goto nomem_call;
 235
 236        if (request_size) {
 237                call->request_size = request_size;
 238                call->request = kmalloc(request_size, GFP_NOFS);
 239                if (!call->request)
 240                        goto nomem_free;
 241        }
 242
 243        if (reply_max) {
 244                call->reply_max = reply_max;
 245                call->buffer = kmalloc(reply_max, GFP_NOFS);
 246                if (!call->buffer)
 247                        goto nomem_free;
 248        }
 249
 250        afs_extract_to_buf(call, call->reply_max);
 251        call->operation_ID = type->op;
 252        init_waitqueue_head(&call->waitq);
 253        return call;
 254
 255nomem_free:
 256        afs_put_call(call);
 257nomem_call:
 258        return NULL;
 259}
 260
 261/*
 262 * clean up a call with flat buffer
 263 */
 264void afs_flat_call_destructor(struct afs_call *call)
 265{
 266        _enter("");
 267
 268        kfree(call->request);
 269        call->request = NULL;
 270        kfree(call->buffer);
 271        call->buffer = NULL;
 272}
 273
 274/*
 275 * Advance the AFS call state when the RxRPC call ends the transmit phase.
 276 */
 277static void afs_notify_end_request_tx(struct sock *sock,
 278                                      struct rxrpc_call *rxcall,
 279                                      unsigned long call_user_ID)
 280{
 281        struct afs_call *call = (struct afs_call *)call_user_ID;
 282
 283        afs_set_call_state(call, AFS_CALL_CL_REQUESTING, AFS_CALL_CL_AWAIT_REPLY);
 284}
 285
 286/*
 287 * Initiate a call and synchronously queue up the parameters for dispatch.  Any
 288 * error is stored into the call struct, which the caller must check for.
 289 */
 290void afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call, gfp_t gfp)
 291{
 292        struct sockaddr_rxrpc *srx = &ac->alist->addrs[ac->index];
 293        struct rxrpc_call *rxcall;
 294        struct msghdr msg;
 295        struct kvec iov[1];
 296        size_t len;
 297        s64 tx_total_len;
 298        int ret;
 299
 300        _enter(",{%pISp},", &srx->transport);
 301
 302        ASSERT(call->type != NULL);
 303        ASSERT(call->type->name != NULL);
 304
 305        _debug("____MAKE %p{%s,%x} [%d]____",
 306               call, call->type->name, key_serial(call->key),
 307               atomic_read(&call->net->nr_outstanding_calls));
 308
 309        call->addr_ix = ac->index;
 310        call->alist = afs_get_addrlist(ac->alist);
 311
 312        /* Work out the length we're going to transmit.  This is awkward for
 313         * calls such as FS.StoreData where there's an extra injection of data
 314         * after the initial fixed part.
 315         */
 316        tx_total_len = call->request_size;
 317        if (call->write_iter)
 318                tx_total_len += iov_iter_count(call->write_iter);
 319
 320        /* If the call is going to be asynchronous, we need an extra ref for
 321         * the call to hold itself so the caller need not hang on to its ref.
 322         */
 323        if (call->async) {
 324                afs_get_call(call, afs_call_trace_get);
 325                call->drop_ref = true;
 326        }
 327
 328        /* create a call */
 329        rxcall = rxrpc_kernel_begin_call(call->net->socket, srx, call->key,
 330                                         (unsigned long)call,
 331                                         tx_total_len, gfp,
 332                                         (call->async ?
 333                                          afs_wake_up_async_call :
 334                                          afs_wake_up_call_waiter),
 335                                         call->upgrade,
 336                                         (call->intr ? RXRPC_PREINTERRUPTIBLE :
 337                                          RXRPC_UNINTERRUPTIBLE),
 338                                         call->debug_id);
 339        if (IS_ERR(rxcall)) {
 340                ret = PTR_ERR(rxcall);
 341                call->error = ret;
 342                goto error_kill_call;
 343        }
 344
 345        call->rxcall = rxcall;
 346
 347        if (call->max_lifespan)
 348                rxrpc_kernel_set_max_life(call->net->socket, rxcall,
 349                                          call->max_lifespan);
 350
 351        /* send the request */
 352        iov[0].iov_base = call->request;
 353        iov[0].iov_len  = call->request_size;
 354
 355        msg.msg_name            = NULL;
 356        msg.msg_namelen         = 0;
 357        iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, call->request_size);
 358        msg.msg_control         = NULL;
 359        msg.msg_controllen      = 0;
 360        msg.msg_flags           = MSG_WAITALL | (call->write_iter ? MSG_MORE : 0);
 361
 362        ret = rxrpc_kernel_send_data(call->net->socket, rxcall,
 363                                     &msg, call->request_size,
 364                                     afs_notify_end_request_tx);
 365        if (ret < 0)
 366                goto error_do_abort;
 367
 368        if (call->write_iter) {
 369                msg.msg_iter = *call->write_iter;
 370                msg.msg_flags &= ~MSG_MORE;
 371                trace_afs_send_data(call, &msg);
 372
 373                ret = rxrpc_kernel_send_data(call->net->socket,
 374                                             call->rxcall, &msg,
 375                                             iov_iter_count(&msg.msg_iter),
 376                                             afs_notify_end_request_tx);
 377                *call->write_iter = msg.msg_iter;
 378
 379                trace_afs_sent_data(call, &msg, ret);
 380                if (ret < 0)
 381                        goto error_do_abort;
 382        }
 383
 384        /* Note that at this point, we may have received the reply or an abort
 385         * - and an asynchronous call may already have completed.
 386         *
 387         * afs_wait_for_call_to_complete(call, ac)
 388         * must be called to synchronously clean up.
 389         */
 390        return;
 391
 392error_do_abort:
 393        if (ret != -ECONNABORTED) {
 394                rxrpc_kernel_abort_call(call->net->socket, rxcall,
 395                                        RX_USER_ABORT, ret, "KSD");
 396        } else {
 397                len = 0;
 398                iov_iter_kvec(&msg.msg_iter, READ, NULL, 0, 0);
 399                rxrpc_kernel_recv_data(call->net->socket, rxcall,
 400                                       &msg.msg_iter, &len, false,
 401                                       &call->abort_code, &call->service_id);
 402                ac->abort_code = call->abort_code;
 403                ac->responded = true;
 404        }
 405        call->error = ret;
 406        trace_afs_call_done(call);
 407error_kill_call:
 408        if (call->type->done)
 409                call->type->done(call);
 410
 411        /* We need to dispose of the extra ref we grabbed for an async call.
 412         * The call, however, might be queued on afs_async_calls and we need to
 413         * make sure we don't get any more notifications that might requeue it.
 414         */
 415        if (call->rxcall) {
 416                rxrpc_kernel_end_call(call->net->socket, call->rxcall);
 417                call->rxcall = NULL;
 418        }
 419        if (call->async) {
 420                if (cancel_work_sync(&call->async_work))
 421                        afs_put_call(call);
 422                afs_put_call(call);
 423        }
 424
 425        ac->error = ret;
 426        call->state = AFS_CALL_COMPLETE;
 427        _leave(" = %d", ret);
 428}
 429
 430/*
 431 * Log remote abort codes that indicate that we have a protocol disagreement
 432 * with the server.
 433 */
 434static void afs_log_error(struct afs_call *call, s32 remote_abort)
 435{
 436        static int max = 0;
 437        const char *msg;
 438        int m;
 439
 440        switch (remote_abort) {
 441        case RX_EOF:             msg = "unexpected EOF";        break;
 442        case RXGEN_CC_MARSHAL:   msg = "client marshalling";    break;
 443        case RXGEN_CC_UNMARSHAL: msg = "client unmarshalling";  break;
 444        case RXGEN_SS_MARSHAL:   msg = "server marshalling";    break;
 445        case RXGEN_SS_UNMARSHAL: msg = "server unmarshalling";  break;
 446        case RXGEN_DECODE:       msg = "opcode decode";         break;
 447        case RXGEN_SS_XDRFREE:   msg = "server XDR cleanup";    break;
 448        case RXGEN_CC_XDRFREE:   msg = "client XDR cleanup";    break;
 449        case -32:                msg = "insufficient data";     break;
 450        default:
 451                return;
 452        }
 453
 454        m = max;
 455        if (m < 3) {
 456                max = m + 1;
 457                pr_notice("kAFS: Peer reported %s failure on %s [%pISp]\n",
 458                          msg, call->type->name,
 459                          &call->alist->addrs[call->addr_ix].transport);
 460        }
 461}
 462
 463/*
 464 * deliver messages to a call
 465 */
 466static void afs_deliver_to_call(struct afs_call *call)
 467{
 468        enum afs_call_state state;
 469        size_t len;
 470        u32 abort_code, remote_abort = 0;
 471        int ret;
 472
 473        _enter("%s", call->type->name);
 474
 475        while (state = READ_ONCE(call->state),
 476               state == AFS_CALL_CL_AWAIT_REPLY ||
 477               state == AFS_CALL_SV_AWAIT_OP_ID ||
 478               state == AFS_CALL_SV_AWAIT_REQUEST ||
 479               state == AFS_CALL_SV_AWAIT_ACK
 480               ) {
 481                if (state == AFS_CALL_SV_AWAIT_ACK) {
 482                        len = 0;
 483                        iov_iter_kvec(&call->def_iter, READ, NULL, 0, 0);
 484                        ret = rxrpc_kernel_recv_data(call->net->socket,
 485                                                     call->rxcall, &call->def_iter,
 486                                                     &len, false, &remote_abort,
 487                                                     &call->service_id);
 488                        trace_afs_receive_data(call, &call->def_iter, false, ret);
 489
 490                        if (ret == -EINPROGRESS || ret == -EAGAIN)
 491                                return;
 492                        if (ret < 0 || ret == 1) {
 493                                if (ret == 1)
 494                                        ret = 0;
 495                                goto call_complete;
 496                        }
 497                        return;
 498                }
 499
 500                if (!call->have_reply_time &&
 501                    rxrpc_kernel_get_reply_time(call->net->socket,
 502                                                call->rxcall,
 503                                                &call->reply_time))
 504                        call->have_reply_time = true;
 505
 506                ret = call->type->deliver(call);
 507                state = READ_ONCE(call->state);
 508                if (ret == 0 && call->unmarshalling_error)
 509                        ret = -EBADMSG;
 510                switch (ret) {
 511                case 0:
 512                        afs_queue_call_work(call);
 513                        if (state == AFS_CALL_CL_PROC_REPLY) {
 514                                if (call->op)
 515                                        set_bit(AFS_SERVER_FL_MAY_HAVE_CB,
 516                                                &call->op->server->flags);
 517                                goto call_complete;
 518                        }
 519                        ASSERTCMP(state, >, AFS_CALL_CL_PROC_REPLY);
 520                        goto done;
 521                case -EINPROGRESS:
 522                case -EAGAIN:
 523                        goto out;
 524                case -ECONNABORTED:
 525                        ASSERTCMP(state, ==, AFS_CALL_COMPLETE);
 526                        afs_log_error(call, call->abort_code);
 527                        goto done;
 528                case -ENOTSUPP:
 529                        abort_code = RXGEN_OPCODE;
 530                        rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 531                                                abort_code, ret, "KIV");
 532                        goto local_abort;
 533                case -EIO:
 534                        pr_err("kAFS: Call %u in bad state %u\n",
 535                               call->debug_id, state);
 536                        fallthrough;
 537                case -ENODATA:
 538                case -EBADMSG:
 539                case -EMSGSIZE:
 540                        abort_code = RXGEN_CC_UNMARSHAL;
 541                        if (state != AFS_CALL_CL_AWAIT_REPLY)
 542                                abort_code = RXGEN_SS_UNMARSHAL;
 543                        rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 544                                                abort_code, ret, "KUM");
 545                        goto local_abort;
 546                default:
 547                        abort_code = RX_USER_ABORT;
 548                        rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 549                                                abort_code, ret, "KER");
 550                        goto local_abort;
 551                }
 552        }
 553
 554done:
 555        if (call->type->done)
 556                call->type->done(call);
 557out:
 558        _leave("");
 559        return;
 560
 561local_abort:
 562        abort_code = 0;
 563call_complete:
 564        afs_set_call_complete(call, ret, remote_abort);
 565        state = AFS_CALL_COMPLETE;
 566        goto done;
 567}
 568
 569/*
 570 * Wait synchronously for a call to complete and clean up the call struct.
 571 */
 572long afs_wait_for_call_to_complete(struct afs_call *call,
 573                                   struct afs_addr_cursor *ac)
 574{
 575        long ret;
 576        bool rxrpc_complete = false;
 577
 578        DECLARE_WAITQUEUE(myself, current);
 579
 580        _enter("");
 581
 582        ret = call->error;
 583        if (ret < 0)
 584                goto out;
 585
 586        add_wait_queue(&call->waitq, &myself);
 587        for (;;) {
 588                set_current_state(TASK_UNINTERRUPTIBLE);
 589
 590                /* deliver any messages that are in the queue */
 591                if (!afs_check_call_state(call, AFS_CALL_COMPLETE) &&
 592                    call->need_attention) {
 593                        call->need_attention = false;
 594                        __set_current_state(TASK_RUNNING);
 595                        afs_deliver_to_call(call);
 596                        continue;
 597                }
 598
 599                if (afs_check_call_state(call, AFS_CALL_COMPLETE))
 600                        break;
 601
 602                if (!rxrpc_kernel_check_life(call->net->socket, call->rxcall)) {
 603                        /* rxrpc terminated the call. */
 604                        rxrpc_complete = true;
 605                        break;
 606                }
 607
 608                schedule();
 609        }
 610
 611        remove_wait_queue(&call->waitq, &myself);
 612        __set_current_state(TASK_RUNNING);
 613
 614        if (!afs_check_call_state(call, AFS_CALL_COMPLETE)) {
 615                if (rxrpc_complete) {
 616                        afs_set_call_complete(call, call->error, call->abort_code);
 617                } else {
 618                        /* Kill off the call if it's still live. */
 619                        _debug("call interrupted");
 620                        if (rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 621                                                    RX_USER_ABORT, -EINTR, "KWI"))
 622                                afs_set_call_complete(call, -EINTR, 0);
 623                }
 624        }
 625
 626        spin_lock_bh(&call->state_lock);
 627        ac->abort_code = call->abort_code;
 628        ac->error = call->error;
 629        spin_unlock_bh(&call->state_lock);
 630
 631        ret = ac->error;
 632        switch (ret) {
 633        case 0:
 634                ret = call->ret0;
 635                call->ret0 = 0;
 636
 637                fallthrough;
 638        case -ECONNABORTED:
 639                ac->responded = true;
 640                break;
 641        }
 642
 643out:
 644        _debug("call complete");
 645        afs_put_call(call);
 646        _leave(" = %p", (void *)ret);
 647        return ret;
 648}
 649
 650/*
 651 * wake up a waiting call
 652 */
 653static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall,
 654                                    unsigned long call_user_ID)
 655{
 656        struct afs_call *call = (struct afs_call *)call_user_ID;
 657
 658        call->need_attention = true;
 659        wake_up(&call->waitq);
 660}
 661
 662/*
 663 * wake up an asynchronous call
 664 */
 665static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
 666                                   unsigned long call_user_ID)
 667{
 668        struct afs_call *call = (struct afs_call *)call_user_ID;
 669        int u;
 670
 671        trace_afs_notify_call(rxcall, call);
 672        call->need_attention = true;
 673
 674        u = atomic_fetch_add_unless(&call->usage, 1, 0);
 675        if (u != 0) {
 676                trace_afs_call(call, afs_call_trace_wake, u + 1,
 677                               atomic_read(&call->net->nr_outstanding_calls),
 678                               __builtin_return_address(0));
 679
 680                if (!queue_work(afs_async_calls, &call->async_work))
 681                        afs_put_call(call);
 682        }
 683}
 684
 685/*
 686 * Perform I/O processing on an asynchronous call.  The work item carries a ref
 687 * to the call struct that we either need to release or to pass on.
 688 */
 689static void afs_process_async_call(struct work_struct *work)
 690{
 691        struct afs_call *call = container_of(work, struct afs_call, async_work);
 692
 693        _enter("");
 694
 695        if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
 696                call->need_attention = false;
 697                afs_deliver_to_call(call);
 698        }
 699
 700        afs_put_call(call);
 701        _leave("");
 702}
 703
 704static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)
 705{
 706        struct afs_call *call = (struct afs_call *)user_call_ID;
 707
 708        call->rxcall = rxcall;
 709}
 710
 711/*
 712 * Charge the incoming call preallocation.
 713 */
 714void afs_charge_preallocation(struct work_struct *work)
 715{
 716        struct afs_net *net =
 717                container_of(work, struct afs_net, charge_preallocation_work);
 718        struct afs_call *call = net->spare_incoming_call;
 719
 720        for (;;) {
 721                if (!call) {
 722                        call = afs_alloc_call(net, &afs_RXCMxxxx, GFP_KERNEL);
 723                        if (!call)
 724                                break;
 725
 726                        call->drop_ref = true;
 727                        call->async = true;
 728                        call->state = AFS_CALL_SV_AWAIT_OP_ID;
 729                        init_waitqueue_head(&call->waitq);
 730                        afs_extract_to_tmp(call);
 731                }
 732
 733                if (rxrpc_kernel_charge_accept(net->socket,
 734                                               afs_wake_up_async_call,
 735                                               afs_rx_attach,
 736                                               (unsigned long)call,
 737                                               GFP_KERNEL,
 738                                               call->debug_id) < 0)
 739                        break;
 740                call = NULL;
 741        }
 742        net->spare_incoming_call = call;
 743}
 744
 745/*
 746 * Discard a preallocated call when a socket is shut down.
 747 */
 748static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
 749                                    unsigned long user_call_ID)
 750{
 751        struct afs_call *call = (struct afs_call *)user_call_ID;
 752
 753        call->rxcall = NULL;
 754        afs_put_call(call);
 755}
 756
 757/*
 758 * Notification of an incoming call.
 759 */
 760static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
 761                            unsigned long user_call_ID)
 762{
 763        struct afs_net *net = afs_sock2net(sk);
 764
 765        queue_work(afs_wq, &net->charge_preallocation_work);
 766}
 767
 768/*
 769 * Grab the operation ID from an incoming cache manager call.  The socket
 770 * buffer is discarded on error or if we don't yet have sufficient data.
 771 */
 772static int afs_deliver_cm_op_id(struct afs_call *call)
 773{
 774        int ret;
 775
 776        _enter("{%zu}", iov_iter_count(call->iter));
 777
 778        /* the operation ID forms the first four bytes of the request data */
 779        ret = afs_extract_data(call, true);
 780        if (ret < 0)
 781                return ret;
 782
 783        call->operation_ID = ntohl(call->tmp);
 784        afs_set_call_state(call, AFS_CALL_SV_AWAIT_OP_ID, AFS_CALL_SV_AWAIT_REQUEST);
 785
 786        /* ask the cache manager to route the call (it'll change the call type
 787         * if successful) */
 788        if (!afs_cm_incoming_call(call))
 789                return -ENOTSUPP;
 790
 791        trace_afs_cb_call(call);
 792
 793        /* pass responsibility for the remainer of this message off to the
 794         * cache manager op */
 795        return call->type->deliver(call);
 796}
 797
 798/*
 799 * Advance the AFS call state when an RxRPC service call ends the transmit
 800 * phase.
 801 */
 802static void afs_notify_end_reply_tx(struct sock *sock,
 803                                    struct rxrpc_call *rxcall,
 804                                    unsigned long call_user_ID)
 805{
 806        struct afs_call *call = (struct afs_call *)call_user_ID;
 807
 808        afs_set_call_state(call, AFS_CALL_SV_REPLYING, AFS_CALL_SV_AWAIT_ACK);
 809}
 810
 811/*
 812 * send an empty reply
 813 */
 814void afs_send_empty_reply(struct afs_call *call)
 815{
 816        struct afs_net *net = call->net;
 817        struct msghdr msg;
 818
 819        _enter("");
 820
 821        rxrpc_kernel_set_tx_length(net->socket, call->rxcall, 0);
 822
 823        msg.msg_name            = NULL;
 824        msg.msg_namelen         = 0;
 825        iov_iter_kvec(&msg.msg_iter, WRITE, NULL, 0, 0);
 826        msg.msg_control         = NULL;
 827        msg.msg_controllen      = 0;
 828        msg.msg_flags           = 0;
 829
 830        switch (rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, 0,
 831                                       afs_notify_end_reply_tx)) {
 832        case 0:
 833                _leave(" [replied]");
 834                return;
 835
 836        case -ENOMEM:
 837                _debug("oom");
 838                rxrpc_kernel_abort_call(net->socket, call->rxcall,
 839                                        RX_USER_ABORT, -ENOMEM, "KOO");
 840                fallthrough;
 841        default:
 842                _leave(" [error]");
 843                return;
 844        }
 845}
 846
 847/*
 848 * send a simple reply
 849 */
 850void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
 851{
 852        struct afs_net *net = call->net;
 853        struct msghdr msg;
 854        struct kvec iov[1];
 855        int n;
 856
 857        _enter("");
 858
 859        rxrpc_kernel_set_tx_length(net->socket, call->rxcall, len);
 860
 861        iov[0].iov_base         = (void *) buf;
 862        iov[0].iov_len          = len;
 863        msg.msg_name            = NULL;
 864        msg.msg_namelen         = 0;
 865        iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, len);
 866        msg.msg_control         = NULL;
 867        msg.msg_controllen      = 0;
 868        msg.msg_flags           = 0;
 869
 870        n = rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, len,
 871                                   afs_notify_end_reply_tx);
 872        if (n >= 0) {
 873                /* Success */
 874                _leave(" [replied]");
 875                return;
 876        }
 877
 878        if (n == -ENOMEM) {
 879                _debug("oom");
 880                rxrpc_kernel_abort_call(net->socket, call->rxcall,
 881                                        RX_USER_ABORT, -ENOMEM, "KOO");
 882        }
 883        _leave(" [error]");
 884}
 885
 886/*
 887 * Extract a piece of data from the received data socket buffers.
 888 */
 889int afs_extract_data(struct afs_call *call, bool want_more)
 890{
 891        struct afs_net *net = call->net;
 892        struct iov_iter *iter = call->iter;
 893        enum afs_call_state state;
 894        u32 remote_abort = 0;
 895        int ret;
 896
 897        _enter("{%s,%zu,%zu},%d",
 898               call->type->name, call->iov_len, iov_iter_count(iter), want_more);
 899
 900        ret = rxrpc_kernel_recv_data(net->socket, call->rxcall, iter,
 901                                     &call->iov_len, want_more, &remote_abort,
 902                                     &call->service_id);
 903        if (ret == 0 || ret == -EAGAIN)
 904                return ret;
 905
 906        state = READ_ONCE(call->state);
 907        if (ret == 1) {
 908                switch (state) {
 909                case AFS_CALL_CL_AWAIT_REPLY:
 910                        afs_set_call_state(call, state, AFS_CALL_CL_PROC_REPLY);
 911                        break;
 912                case AFS_CALL_SV_AWAIT_REQUEST:
 913                        afs_set_call_state(call, state, AFS_CALL_SV_REPLYING);
 914                        break;
 915                case AFS_CALL_COMPLETE:
 916                        kdebug("prem complete %d", call->error);
 917                        return afs_io_error(call, afs_io_error_extract);
 918                default:
 919                        break;
 920                }
 921                return 0;
 922        }
 923
 924        afs_set_call_complete(call, ret, remote_abort);
 925        return ret;
 926}
 927
 928/*
 929 * Log protocol error production.
 930 */
 931noinline int afs_protocol_error(struct afs_call *call,
 932                                enum afs_eproto_cause cause)
 933{
 934        trace_afs_protocol_error(call, cause);
 935        if (call)
 936                call->unmarshalling_error = true;
 937        return -EBADMSG;
 938}
 939
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