linux/net/rxrpc/ar-connection.c
<<
>>
Prefs
   1/* RxRPC virtual connection handler
   2 *
   3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   4 * Written by David Howells (dhowells@redhat.com)
   5 *
   6 * This program is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU General Public License
   8 * as published by the Free Software Foundation; either version
   9 * 2 of the License, or (at your option) any later version.
  10 */
  11
  12#include <linux/module.h>
  13#include <linux/slab.h>
  14#include <linux/net.h>
  15#include <linux/skbuff.h>
  16#include <linux/crypto.h>
  17#include <net/sock.h>
  18#include <net/af_rxrpc.h>
  19#include "ar-internal.h"
  20
  21/*
  22 * Time till a connection expires after last use (in seconds).
  23 */
  24unsigned int rxrpc_connection_expiry = 10 * 60;
  25
  26static void rxrpc_connection_reaper(struct work_struct *work);
  27
  28LIST_HEAD(rxrpc_connections);
  29DEFINE_RWLOCK(rxrpc_connection_lock);
  30static DECLARE_DELAYED_WORK(rxrpc_connection_reap, rxrpc_connection_reaper);
  31
  32/*
  33 * allocate a new client connection bundle
  34 */
  35static struct rxrpc_conn_bundle *rxrpc_alloc_bundle(gfp_t gfp)
  36{
  37        struct rxrpc_conn_bundle *bundle;
  38
  39        _enter("");
  40
  41        bundle = kzalloc(sizeof(struct rxrpc_conn_bundle), gfp);
  42        if (bundle) {
  43                INIT_LIST_HEAD(&bundle->unused_conns);
  44                INIT_LIST_HEAD(&bundle->avail_conns);
  45                INIT_LIST_HEAD(&bundle->busy_conns);
  46                init_waitqueue_head(&bundle->chanwait);
  47                atomic_set(&bundle->usage, 1);
  48        }
  49
  50        _leave(" = %p", bundle);
  51        return bundle;
  52}
  53
  54/*
  55 * compare bundle parameters with what we're looking for
  56 * - return -ve, 0 or +ve
  57 */
  58static inline
  59int rxrpc_cmp_bundle(const struct rxrpc_conn_bundle *bundle,
  60                     struct key *key, u16 service_id)
  61{
  62        return (bundle->service_id - service_id) ?:
  63                ((unsigned long)bundle->key - (unsigned long)key);
  64}
  65
  66/*
  67 * get bundle of client connections that a client socket can make use of
  68 */
  69struct rxrpc_conn_bundle *rxrpc_get_bundle(struct rxrpc_sock *rx,
  70                                           struct rxrpc_transport *trans,
  71                                           struct key *key,
  72                                           u16 service_id,
  73                                           gfp_t gfp)
  74{
  75        struct rxrpc_conn_bundle *bundle, *candidate;
  76        struct rb_node *p, *parent, **pp;
  77
  78        _enter("%p{%x},%x,%hx,",
  79               rx, key_serial(key), trans->debug_id, service_id);
  80
  81        if (rx->trans == trans && rx->bundle) {
  82                atomic_inc(&rx->bundle->usage);
  83                return rx->bundle;
  84        }
  85
  86        /* search the extant bundles first for one that matches the specified
  87         * user ID */
  88        spin_lock(&trans->client_lock);
  89
  90        p = trans->bundles.rb_node;
  91        while (p) {
  92                bundle = rb_entry(p, struct rxrpc_conn_bundle, node);
  93
  94                if (rxrpc_cmp_bundle(bundle, key, service_id) < 0)
  95                        p = p->rb_left;
  96                else if (rxrpc_cmp_bundle(bundle, key, service_id) > 0)
  97                        p = p->rb_right;
  98                else
  99                        goto found_extant_bundle;
 100        }
 101
 102        spin_unlock(&trans->client_lock);
 103
 104        /* not yet present - create a candidate for a new record and then
 105         * redo the search */
 106        candidate = rxrpc_alloc_bundle(gfp);
 107        if (!candidate) {
 108                _leave(" = -ENOMEM");
 109                return ERR_PTR(-ENOMEM);
 110        }
 111
 112        candidate->key = key_get(key);
 113        candidate->service_id = service_id;
 114
 115        spin_lock(&trans->client_lock);
 116
 117        pp = &trans->bundles.rb_node;
 118        parent = NULL;
 119        while (*pp) {
 120                parent = *pp;
 121                bundle = rb_entry(parent, struct rxrpc_conn_bundle, node);
 122
 123                if (rxrpc_cmp_bundle(bundle, key, service_id) < 0)
 124                        pp = &(*pp)->rb_left;
 125                else if (rxrpc_cmp_bundle(bundle, key, service_id) > 0)
 126                        pp = &(*pp)->rb_right;
 127                else
 128                        goto found_extant_second;
 129        }
 130
 131        /* second search also failed; add the new bundle */
 132        bundle = candidate;
 133        candidate = NULL;
 134
 135        rb_link_node(&bundle->node, parent, pp);
 136        rb_insert_color(&bundle->node, &trans->bundles);
 137        spin_unlock(&trans->client_lock);
 138        _net("BUNDLE new on trans %d", trans->debug_id);
 139        if (!rx->bundle && rx->sk.sk_state == RXRPC_CLIENT_CONNECTED) {
 140                atomic_inc(&bundle->usage);
 141                rx->bundle = bundle;
 142        }
 143        _leave(" = %p [new]", bundle);
 144        return bundle;
 145
 146        /* we found the bundle in the list immediately */
 147found_extant_bundle:
 148        atomic_inc(&bundle->usage);
 149        spin_unlock(&trans->client_lock);
 150        _net("BUNDLE old on trans %d", trans->debug_id);
 151        if (!rx->bundle && rx->sk.sk_state == RXRPC_CLIENT_CONNECTED) {
 152                atomic_inc(&bundle->usage);
 153                rx->bundle = bundle;
 154        }
 155        _leave(" = %p [extant %d]", bundle, atomic_read(&bundle->usage));
 156        return bundle;
 157
 158        /* we found the bundle on the second time through the list */
 159found_extant_second:
 160        atomic_inc(&bundle->usage);
 161        spin_unlock(&trans->client_lock);
 162        kfree(candidate);
 163        _net("BUNDLE old2 on trans %d", trans->debug_id);
 164        if (!rx->bundle && rx->sk.sk_state == RXRPC_CLIENT_CONNECTED) {
 165                atomic_inc(&bundle->usage);
 166                rx->bundle = bundle;
 167        }
 168        _leave(" = %p [second %d]", bundle, atomic_read(&bundle->usage));
 169        return bundle;
 170}
 171
 172/*
 173 * release a bundle
 174 */
 175void rxrpc_put_bundle(struct rxrpc_transport *trans,
 176                      struct rxrpc_conn_bundle *bundle)
 177{
 178        _enter("%p,%p{%d}",trans, bundle, atomic_read(&bundle->usage));
 179
 180        if (atomic_dec_and_lock(&bundle->usage, &trans->client_lock)) {
 181                _debug("Destroy bundle");
 182                rb_erase(&bundle->node, &trans->bundles);
 183                spin_unlock(&trans->client_lock);
 184                ASSERT(list_empty(&bundle->unused_conns));
 185                ASSERT(list_empty(&bundle->avail_conns));
 186                ASSERT(list_empty(&bundle->busy_conns));
 187                ASSERTCMP(bundle->num_conns, ==, 0);
 188                key_put(bundle->key);
 189                kfree(bundle);
 190        }
 191
 192        _leave("");
 193}
 194
 195/*
 196 * allocate a new connection
 197 */
 198static struct rxrpc_connection *rxrpc_alloc_connection(gfp_t gfp)
 199{
 200        struct rxrpc_connection *conn;
 201
 202        _enter("");
 203
 204        conn = kzalloc(sizeof(struct rxrpc_connection), gfp);
 205        if (conn) {
 206                INIT_WORK(&conn->processor, &rxrpc_process_connection);
 207                INIT_LIST_HEAD(&conn->bundle_link);
 208                conn->calls = RB_ROOT;
 209                skb_queue_head_init(&conn->rx_queue);
 210                conn->security = &rxrpc_no_security;
 211                rwlock_init(&conn->lock);
 212                spin_lock_init(&conn->state_lock);
 213                atomic_set(&conn->usage, 1);
 214                conn->debug_id = atomic_inc_return(&rxrpc_debug_id);
 215                conn->avail_calls = RXRPC_MAXCALLS;
 216                conn->size_align = 4;
 217                conn->header_size = sizeof(struct rxrpc_wire_header);
 218        }
 219
 220        _leave(" = %p{%d}", conn, conn ? conn->debug_id : 0);
 221        return conn;
 222}
 223
 224/*
 225 * assign a connection ID to a connection and add it to the transport's
 226 * connection lookup tree
 227 * - called with transport client lock held
 228 */
 229static void rxrpc_assign_connection_id(struct rxrpc_connection *conn)
 230{
 231        struct rxrpc_connection *xconn;
 232        struct rb_node *parent, **p;
 233        __be32 epoch;
 234        u32 cid;
 235
 236        _enter("");
 237
 238        epoch = conn->epoch;
 239
 240        write_lock_bh(&conn->trans->conn_lock);
 241
 242        conn->trans->conn_idcounter += RXRPC_CID_INC;
 243        if (conn->trans->conn_idcounter < RXRPC_CID_INC)
 244                conn->trans->conn_idcounter = RXRPC_CID_INC;
 245        cid = conn->trans->conn_idcounter;
 246
 247attempt_insertion:
 248        parent = NULL;
 249        p = &conn->trans->client_conns.rb_node;
 250
 251        while (*p) {
 252                parent = *p;
 253                xconn = rb_entry(parent, struct rxrpc_connection, node);
 254
 255                if (epoch < xconn->epoch)
 256                        p = &(*p)->rb_left;
 257                else if (epoch > xconn->epoch)
 258                        p = &(*p)->rb_right;
 259                else if (cid < xconn->cid)
 260                        p = &(*p)->rb_left;
 261                else if (cid > xconn->cid)
 262                        p = &(*p)->rb_right;
 263                else
 264                        goto id_exists;
 265        }
 266
 267        /* we've found a suitable hole - arrange for this connection to occupy
 268         * it */
 269        rb_link_node(&conn->node, parent, p);
 270        rb_insert_color(&conn->node, &conn->trans->client_conns);
 271
 272        conn->cid = cid;
 273        write_unlock_bh(&conn->trans->conn_lock);
 274        _leave(" [CID %x]", cid);
 275        return;
 276
 277        /* we found a connection with the proposed ID - walk the tree from that
 278         * point looking for the next unused ID */
 279id_exists:
 280        for (;;) {
 281                cid += RXRPC_CID_INC;
 282                if (cid < RXRPC_CID_INC) {
 283                        cid = RXRPC_CID_INC;
 284                        conn->trans->conn_idcounter = cid;
 285                        goto attempt_insertion;
 286                }
 287
 288                parent = rb_next(parent);
 289                if (!parent)
 290                        goto attempt_insertion;
 291
 292                xconn = rb_entry(parent, struct rxrpc_connection, node);
 293                if (epoch < xconn->epoch ||
 294                    cid < xconn->cid)
 295                        goto attempt_insertion;
 296        }
 297}
 298
 299/*
 300 * add a call to a connection's call-by-ID tree
 301 */
 302static void rxrpc_add_call_ID_to_conn(struct rxrpc_connection *conn,
 303                                      struct rxrpc_call *call)
 304{
 305        struct rxrpc_call *xcall;
 306        struct rb_node *parent, **p;
 307        __be32 call_id;
 308
 309        write_lock_bh(&conn->lock);
 310
 311        call_id = call->call_id;
 312        p = &conn->calls.rb_node;
 313        parent = NULL;
 314        while (*p) {
 315                parent = *p;
 316                xcall = rb_entry(parent, struct rxrpc_call, conn_node);
 317
 318                if (call_id < xcall->call_id)
 319                        p = &(*p)->rb_left;
 320                else if (call_id > xcall->call_id)
 321                        p = &(*p)->rb_right;
 322                else
 323                        BUG();
 324        }
 325
 326        rb_link_node(&call->conn_node, parent, p);
 327        rb_insert_color(&call->conn_node, &conn->calls);
 328
 329        write_unlock_bh(&conn->lock);
 330}
 331
 332/*
 333 * connect a call on an exclusive connection
 334 */
 335static int rxrpc_connect_exclusive(struct rxrpc_sock *rx,
 336                                   struct rxrpc_transport *trans,
 337                                   u16 service_id,
 338                                   struct rxrpc_call *call,
 339                                   gfp_t gfp)
 340{
 341        struct rxrpc_connection *conn;
 342        int chan, ret;
 343
 344        _enter("");
 345
 346        conn = rx->conn;
 347        if (!conn) {
 348                /* not yet present - create a candidate for a new connection
 349                 * and then redo the check */
 350                conn = rxrpc_alloc_connection(gfp);
 351                if (!conn) {
 352                        _leave(" = -ENOMEM");
 353                        return -ENOMEM;
 354                }
 355
 356                conn->trans = trans;
 357                conn->bundle = NULL;
 358                conn->service_id = service_id;
 359                conn->epoch = rxrpc_epoch;
 360                conn->in_clientflag = 0;
 361                conn->out_clientflag = RXRPC_CLIENT_INITIATED;
 362                conn->cid = 0;
 363                conn->state = RXRPC_CONN_CLIENT;
 364                conn->avail_calls = RXRPC_MAXCALLS - 1;
 365                conn->security_level = rx->min_sec_level;
 366                conn->key = key_get(rx->key);
 367
 368                ret = rxrpc_init_client_conn_security(conn);
 369                if (ret < 0) {
 370                        key_put(conn->key);
 371                        kfree(conn);
 372                        _leave(" = %d [key]", ret);
 373                        return ret;
 374                }
 375
 376                write_lock_bh(&rxrpc_connection_lock);
 377                list_add_tail(&conn->link, &rxrpc_connections);
 378                write_unlock_bh(&rxrpc_connection_lock);
 379
 380                spin_lock(&trans->client_lock);
 381                atomic_inc(&trans->usage);
 382
 383                _net("CONNECT EXCL new %d on TRANS %d",
 384                     conn->debug_id, conn->trans->debug_id);
 385
 386                rxrpc_assign_connection_id(conn);
 387                rx->conn = conn;
 388        } else {
 389                spin_lock(&trans->client_lock);
 390        }
 391
 392        /* we've got a connection with a free channel and we can now attach the
 393         * call to it
 394         * - we're holding the transport's client lock
 395         * - we're holding a reference on the connection
 396         */
 397        for (chan = 0; chan < RXRPC_MAXCALLS; chan++)
 398                if (!conn->channels[chan])
 399                        goto found_channel;
 400        goto no_free_channels;
 401
 402found_channel:
 403        atomic_inc(&conn->usage);
 404        conn->channels[chan] = call;
 405        call->conn = conn;
 406        call->channel = chan;
 407        call->cid = conn->cid | chan;
 408        call->call_id = ++conn->call_counter;
 409
 410        _net("CONNECT client on conn %d chan %d as call %x",
 411             conn->debug_id, chan, call->call_id);
 412
 413        spin_unlock(&trans->client_lock);
 414
 415        rxrpc_add_call_ID_to_conn(conn, call);
 416        _leave(" = 0");
 417        return 0;
 418
 419no_free_channels:
 420        spin_unlock(&trans->client_lock);
 421        _leave(" = -ENOSR");
 422        return -ENOSR;
 423}
 424
 425/*
 426 * find a connection for a call
 427 * - called in process context with IRQs enabled
 428 */
 429int rxrpc_connect_call(struct rxrpc_sock *rx,
 430                       struct rxrpc_transport *trans,
 431                       struct rxrpc_conn_bundle *bundle,
 432                       struct rxrpc_call *call,
 433                       gfp_t gfp)
 434{
 435        struct rxrpc_connection *conn, *candidate;
 436        int chan, ret;
 437
 438        DECLARE_WAITQUEUE(myself, current);
 439
 440        _enter("%p,%lx,", rx, call->user_call_ID);
 441
 442        if (test_bit(RXRPC_SOCK_EXCLUSIVE_CONN, &rx->flags))
 443                return rxrpc_connect_exclusive(rx, trans, bundle->service_id,
 444                                               call, gfp);
 445
 446        spin_lock(&trans->client_lock);
 447        for (;;) {
 448                /* see if the bundle has a call slot available */
 449                if (!list_empty(&bundle->avail_conns)) {
 450                        _debug("avail");
 451                        conn = list_entry(bundle->avail_conns.next,
 452                                          struct rxrpc_connection,
 453                                          bundle_link);
 454                        if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
 455                                list_del_init(&conn->bundle_link);
 456                                bundle->num_conns--;
 457                                continue;
 458                        }
 459                        if (--conn->avail_calls == 0)
 460                                list_move(&conn->bundle_link,
 461                                          &bundle->busy_conns);
 462                        ASSERTCMP(conn->avail_calls, <, RXRPC_MAXCALLS);
 463                        ASSERT(conn->channels[0] == NULL ||
 464                               conn->channels[1] == NULL ||
 465                               conn->channels[2] == NULL ||
 466                               conn->channels[3] == NULL);
 467                        atomic_inc(&conn->usage);
 468                        break;
 469                }
 470
 471                if (!list_empty(&bundle->unused_conns)) {
 472                        _debug("unused");
 473                        conn = list_entry(bundle->unused_conns.next,
 474                                          struct rxrpc_connection,
 475                                          bundle_link);
 476                        if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
 477                                list_del_init(&conn->bundle_link);
 478                                bundle->num_conns--;
 479                                continue;
 480                        }
 481                        ASSERTCMP(conn->avail_calls, ==, RXRPC_MAXCALLS);
 482                        conn->avail_calls = RXRPC_MAXCALLS - 1;
 483                        ASSERT(conn->channels[0] == NULL &&
 484                               conn->channels[1] == NULL &&
 485                               conn->channels[2] == NULL &&
 486                               conn->channels[3] == NULL);
 487                        atomic_inc(&conn->usage);
 488                        list_move(&conn->bundle_link, &bundle->avail_conns);
 489                        break;
 490                }
 491
 492                /* need to allocate a new connection */
 493                _debug("get new conn [%d]", bundle->num_conns);
 494
 495                spin_unlock(&trans->client_lock);
 496
 497                if (signal_pending(current))
 498                        goto interrupted;
 499
 500                if (bundle->num_conns >= 20) {
 501                        _debug("too many conns");
 502
 503                        if (!gfpflags_allow_blocking(gfp)) {
 504                                _leave(" = -EAGAIN");
 505                                return -EAGAIN;
 506                        }
 507
 508                        add_wait_queue(&bundle->chanwait, &myself);
 509                        for (;;) {
 510                                set_current_state(TASK_INTERRUPTIBLE);
 511                                if (bundle->num_conns < 20 ||
 512                                    !list_empty(&bundle->unused_conns) ||
 513                                    !list_empty(&bundle->avail_conns))
 514                                        break;
 515                                if (signal_pending(current))
 516                                        goto interrupted_dequeue;
 517                                schedule();
 518                        }
 519                        remove_wait_queue(&bundle->chanwait, &myself);
 520                        __set_current_state(TASK_RUNNING);
 521                        spin_lock(&trans->client_lock);
 522                        continue;
 523                }
 524
 525                /* not yet present - create a candidate for a new connection and then
 526                 * redo the check */
 527                candidate = rxrpc_alloc_connection(gfp);
 528                if (!candidate) {
 529                        _leave(" = -ENOMEM");
 530                        return -ENOMEM;
 531                }
 532
 533                candidate->trans = trans;
 534                candidate->bundle = bundle;
 535                candidate->service_id = bundle->service_id;
 536                candidate->epoch = rxrpc_epoch;
 537                candidate->in_clientflag = 0;
 538                candidate->out_clientflag = RXRPC_CLIENT_INITIATED;
 539                candidate->cid = 0;
 540                candidate->state = RXRPC_CONN_CLIENT;
 541                candidate->avail_calls = RXRPC_MAXCALLS;
 542                candidate->security_level = rx->min_sec_level;
 543                candidate->key = key_get(bundle->key);
 544
 545                ret = rxrpc_init_client_conn_security(candidate);
 546                if (ret < 0) {
 547                        key_put(candidate->key);
 548                        kfree(candidate);
 549                        _leave(" = %d [key]", ret);
 550                        return ret;
 551                }
 552
 553                write_lock_bh(&rxrpc_connection_lock);
 554                list_add_tail(&candidate->link, &rxrpc_connections);
 555                write_unlock_bh(&rxrpc_connection_lock);
 556
 557                spin_lock(&trans->client_lock);
 558
 559                list_add(&candidate->bundle_link, &bundle->unused_conns);
 560                bundle->num_conns++;
 561                atomic_inc(&bundle->usage);
 562                atomic_inc(&trans->usage);
 563
 564                _net("CONNECT new %d on TRANS %d",
 565                     candidate->debug_id, candidate->trans->debug_id);
 566
 567                rxrpc_assign_connection_id(candidate);
 568                candidate->security->prime_packet_security(candidate);
 569
 570                /* leave the candidate lurking in zombie mode attached to the
 571                 * bundle until we're ready for it */
 572                rxrpc_put_connection(candidate);
 573                candidate = NULL;
 574        }
 575
 576        /* we've got a connection with a free channel and we can now attach the
 577         * call to it
 578         * - we're holding the transport's client lock
 579         * - we're holding a reference on the connection
 580         * - we're holding a reference on the bundle
 581         */
 582        for (chan = 0; chan < RXRPC_MAXCALLS; chan++)
 583                if (!conn->channels[chan])
 584                        goto found_channel;
 585        ASSERT(conn->channels[0] == NULL ||
 586               conn->channels[1] == NULL ||
 587               conn->channels[2] == NULL ||
 588               conn->channels[3] == NULL);
 589        BUG();
 590
 591found_channel:
 592        conn->channels[chan] = call;
 593        call->conn = conn;
 594        call->channel = chan;
 595        call->cid = conn->cid | chan;
 596        call->call_id = ++conn->call_counter;
 597
 598        _net("CONNECT client on conn %d chan %d as call %x",
 599             conn->debug_id, chan, call->call_id);
 600
 601        ASSERTCMP(conn->avail_calls, <, RXRPC_MAXCALLS);
 602        spin_unlock(&trans->client_lock);
 603
 604        rxrpc_add_call_ID_to_conn(conn, call);
 605
 606        _leave(" = 0");
 607        return 0;
 608
 609interrupted_dequeue:
 610        remove_wait_queue(&bundle->chanwait, &myself);
 611        __set_current_state(TASK_RUNNING);
 612interrupted:
 613        _leave(" = -ERESTARTSYS");
 614        return -ERESTARTSYS;
 615}
 616
 617/*
 618 * get a record of an incoming connection
 619 */
 620struct rxrpc_connection *
 621rxrpc_incoming_connection(struct rxrpc_transport *trans,
 622                          struct rxrpc_host_header *hdr)
 623{
 624        struct rxrpc_connection *conn, *candidate = NULL;
 625        struct rb_node *p, **pp;
 626        const char *new = "old";
 627        __be32 epoch;
 628        u32 cid;
 629
 630        _enter("");
 631
 632        ASSERT(hdr->flags & RXRPC_CLIENT_INITIATED);
 633
 634        epoch = hdr->epoch;
 635        cid = hdr->cid & RXRPC_CIDMASK;
 636
 637        /* search the connection list first */
 638        read_lock_bh(&trans->conn_lock);
 639
 640        p = trans->server_conns.rb_node;
 641        while (p) {
 642                conn = rb_entry(p, struct rxrpc_connection, node);
 643
 644                _debug("maybe %x", conn->cid);
 645
 646                if (epoch < conn->epoch)
 647                        p = p->rb_left;
 648                else if (epoch > conn->epoch)
 649                        p = p->rb_right;
 650                else if (cid < conn->cid)
 651                        p = p->rb_left;
 652                else if (cid > conn->cid)
 653                        p = p->rb_right;
 654                else
 655                        goto found_extant_connection;
 656        }
 657        read_unlock_bh(&trans->conn_lock);
 658
 659        /* not yet present - create a candidate for a new record and then
 660         * redo the search */
 661        candidate = rxrpc_alloc_connection(GFP_NOIO);
 662        if (!candidate) {
 663                _leave(" = -ENOMEM");
 664                return ERR_PTR(-ENOMEM);
 665        }
 666
 667        candidate->trans = trans;
 668        candidate->epoch = hdr->epoch;
 669        candidate->cid = hdr->cid & RXRPC_CIDMASK;
 670        candidate->service_id = hdr->serviceId;
 671        candidate->security_ix = hdr->securityIndex;
 672        candidate->in_clientflag = RXRPC_CLIENT_INITIATED;
 673        candidate->out_clientflag = 0;
 674        candidate->state = RXRPC_CONN_SERVER;
 675        if (candidate->service_id)
 676                candidate->state = RXRPC_CONN_SERVER_UNSECURED;
 677
 678        write_lock_bh(&trans->conn_lock);
 679
 680        pp = &trans->server_conns.rb_node;
 681        p = NULL;
 682        while (*pp) {
 683                p = *pp;
 684                conn = rb_entry(p, struct rxrpc_connection, node);
 685
 686                if (epoch < conn->epoch)
 687                        pp = &(*pp)->rb_left;
 688                else if (epoch > conn->epoch)
 689                        pp = &(*pp)->rb_right;
 690                else if (cid < conn->cid)
 691                        pp = &(*pp)->rb_left;
 692                else if (cid > conn->cid)
 693                        pp = &(*pp)->rb_right;
 694                else
 695                        goto found_extant_second;
 696        }
 697
 698        /* we can now add the new candidate to the list */
 699        conn = candidate;
 700        candidate = NULL;
 701        rb_link_node(&conn->node, p, pp);
 702        rb_insert_color(&conn->node, &trans->server_conns);
 703        atomic_inc(&conn->trans->usage);
 704
 705        write_unlock_bh(&trans->conn_lock);
 706
 707        write_lock_bh(&rxrpc_connection_lock);
 708        list_add_tail(&conn->link, &rxrpc_connections);
 709        write_unlock_bh(&rxrpc_connection_lock);
 710
 711        new = "new";
 712
 713success:
 714        _net("CONNECTION %s %d {%x}", new, conn->debug_id, conn->cid);
 715
 716        _leave(" = %p {u=%d}", conn, atomic_read(&conn->usage));
 717        return conn;
 718
 719        /* we found the connection in the list immediately */
 720found_extant_connection:
 721        if (hdr->securityIndex != conn->security_ix) {
 722                read_unlock_bh(&trans->conn_lock);
 723                goto security_mismatch;
 724        }
 725        atomic_inc(&conn->usage);
 726        read_unlock_bh(&trans->conn_lock);
 727        goto success;
 728
 729        /* we found the connection on the second time through the list */
 730found_extant_second:
 731        if (hdr->securityIndex != conn->security_ix) {
 732                write_unlock_bh(&trans->conn_lock);
 733                goto security_mismatch;
 734        }
 735        atomic_inc(&conn->usage);
 736        write_unlock_bh(&trans->conn_lock);
 737        kfree(candidate);
 738        goto success;
 739
 740security_mismatch:
 741        kfree(candidate);
 742        _leave(" = -EKEYREJECTED");
 743        return ERR_PTR(-EKEYREJECTED);
 744}
 745
 746/*
 747 * find a connection based on transport and RxRPC connection ID for an incoming
 748 * packet
 749 */
 750struct rxrpc_connection *rxrpc_find_connection(struct rxrpc_transport *trans,
 751                                               struct rxrpc_host_header *hdr)
 752{
 753        struct rxrpc_connection *conn;
 754        struct rb_node *p;
 755        u32 epoch, cid;
 756
 757        _enter(",{%x,%x}", hdr->cid, hdr->flags);
 758
 759        read_lock_bh(&trans->conn_lock);
 760
 761        cid = hdr->cid & RXRPC_CIDMASK;
 762        epoch = hdr->epoch;
 763
 764        if (hdr->flags & RXRPC_CLIENT_INITIATED)
 765                p = trans->server_conns.rb_node;
 766        else
 767                p = trans->client_conns.rb_node;
 768
 769        while (p) {
 770                conn = rb_entry(p, struct rxrpc_connection, node);
 771
 772                _debug("maybe %x", conn->cid);
 773
 774                if (epoch < conn->epoch)
 775                        p = p->rb_left;
 776                else if (epoch > conn->epoch)
 777                        p = p->rb_right;
 778                else if (cid < conn->cid)
 779                        p = p->rb_left;
 780                else if (cid > conn->cid)
 781                        p = p->rb_right;
 782                else
 783                        goto found;
 784        }
 785
 786        read_unlock_bh(&trans->conn_lock);
 787        _leave(" = NULL");
 788        return NULL;
 789
 790found:
 791        atomic_inc(&conn->usage);
 792        read_unlock_bh(&trans->conn_lock);
 793        _leave(" = %p", conn);
 794        return conn;
 795}
 796
 797/*
 798 * release a virtual connection
 799 */
 800void rxrpc_put_connection(struct rxrpc_connection *conn)
 801{
 802        _enter("%p{u=%d,d=%d}",
 803               conn, atomic_read(&conn->usage), conn->debug_id);
 804
 805        ASSERTCMP(atomic_read(&conn->usage), >, 0);
 806
 807        conn->put_time = ktime_get_seconds();
 808        if (atomic_dec_and_test(&conn->usage)) {
 809                _debug("zombie");
 810                rxrpc_queue_delayed_work(&rxrpc_connection_reap, 0);
 811        }
 812
 813        _leave("");
 814}
 815
 816/*
 817 * destroy a virtual connection
 818 */
 819static void rxrpc_destroy_connection(struct rxrpc_connection *conn)
 820{
 821        _enter("%p{%d}", conn, atomic_read(&conn->usage));
 822
 823        ASSERTCMP(atomic_read(&conn->usage), ==, 0);
 824
 825        _net("DESTROY CONN %d", conn->debug_id);
 826
 827        if (conn->bundle)
 828                rxrpc_put_bundle(conn->trans, conn->bundle);
 829
 830        ASSERT(RB_EMPTY_ROOT(&conn->calls));
 831        rxrpc_purge_queue(&conn->rx_queue);
 832
 833        conn->security->clear(conn);
 834        key_put(conn->key);
 835        key_put(conn->server_key);
 836
 837        rxrpc_put_transport(conn->trans);
 838        kfree(conn);
 839        _leave("");
 840}
 841
 842/*
 843 * reap dead connections
 844 */
 845static void rxrpc_connection_reaper(struct work_struct *work)
 846{
 847        struct rxrpc_connection *conn, *_p;
 848        unsigned long now, earliest, reap_time;
 849
 850        LIST_HEAD(graveyard);
 851
 852        _enter("");
 853
 854        now = ktime_get_seconds();
 855        earliest = ULONG_MAX;
 856
 857        write_lock_bh(&rxrpc_connection_lock);
 858        list_for_each_entry_safe(conn, _p, &rxrpc_connections, link) {
 859                _debug("reap CONN %d { u=%d,t=%ld }",
 860                       conn->debug_id, atomic_read(&conn->usage),
 861                       (long) now - (long) conn->put_time);
 862
 863                if (likely(atomic_read(&conn->usage) > 0))
 864                        continue;
 865
 866                spin_lock(&conn->trans->client_lock);
 867                write_lock(&conn->trans->conn_lock);
 868                reap_time = conn->put_time + rxrpc_connection_expiry;
 869
 870                if (atomic_read(&conn->usage) > 0) {
 871                        ;
 872                } else if (reap_time <= now) {
 873                        list_move_tail(&conn->link, &graveyard);
 874                        if (conn->out_clientflag)
 875                                rb_erase(&conn->node,
 876                                         &conn->trans->client_conns);
 877                        else
 878                                rb_erase(&conn->node,
 879                                         &conn->trans->server_conns);
 880                        if (conn->bundle) {
 881                                list_del_init(&conn->bundle_link);
 882                                conn->bundle->num_conns--;
 883                        }
 884
 885                } else if (reap_time < earliest) {
 886                        earliest = reap_time;
 887                }
 888
 889                write_unlock(&conn->trans->conn_lock);
 890                spin_unlock(&conn->trans->client_lock);
 891        }
 892        write_unlock_bh(&rxrpc_connection_lock);
 893
 894        if (earliest != ULONG_MAX) {
 895                _debug("reschedule reaper %ld", (long) earliest - now);
 896                ASSERTCMP(earliest, >, now);
 897                rxrpc_queue_delayed_work(&rxrpc_connection_reap,
 898                                         (earliest - now) * HZ);
 899        }
 900
 901        /* then destroy all those pulled out */
 902        while (!list_empty(&graveyard)) {
 903                conn = list_entry(graveyard.next, struct rxrpc_connection,
 904                                  link);
 905                list_del_init(&conn->link);
 906
 907                ASSERTCMP(atomic_read(&conn->usage), ==, 0);
 908                rxrpc_destroy_connection(conn);
 909        }
 910
 911        _leave("");
 912}
 913
 914/*
 915 * preemptively destroy all the connection records rather than waiting for them
 916 * to time out
 917 */
 918void __exit rxrpc_destroy_all_connections(void)
 919{
 920        _enter("");
 921
 922        rxrpc_connection_expiry = 0;
 923        cancel_delayed_work(&rxrpc_connection_reap);
 924        rxrpc_queue_delayed_work(&rxrpc_connection_reap, 0);
 925
 926        _leave("");
 927}
 928