net/sctp/endpointola.c

   1 /* SCTP kernel reference Implementation
   2  * Copyright (c) 1999-2000 Cisco, Inc.
   3  * Copyright (c) 1999-2001 Motorola, Inc.
   4  * Copyright (c) 2001-2002 International Business Machines, Corp.
   5  * Copyright (c) 2001 Intel Corp.
   6  * Copyright (c) 2001 Nokia, Inc.
   7  * Copyright (c) 2001 La Monte H.P. Yarroll
   8  *
   9  * This file is part of the SCTP kernel reference Implementation
  10  *
  11  * This abstraction represents an SCTP endpoint.
  12  *
  13  * This file is part of the implementation of the add-IP extension,
  14  * based on <draft-ietf-tsvwg-addip-sctp-02.txt> June 29, 2001,
  15  * for the SCTP kernel reference Implementation.
  16  *
  17  * The SCTP reference implementation is free software;
  18  * you can redistribute it and/or modify it under the terms of
  19  * the GNU General Public License as published by
  20  * the Free Software Foundation; either version 2, or (at your option)
  21  * any later version.
  22  *
  23  * The SCTP reference implementation is distributed in the hope that it
  24  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  25  *                 ************************
  26  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  27  * See the GNU General Public License for more details.
  28  *
  29  * You should have received a copy of the GNU General Public License
  30  * along with GNU CC; see the file COPYING.  If not, write to
  31  * the Free Software Foundation, 59 Temple Place - Suite 330,
  32  * Boston, MA 02111-1307, USA.
  33  *
  34  * Please send any bug reports or fixes you make to the
  35  * email address(es):
  36  *    lksctp developers <lksctp-developers@lists.sourceforge.net>
  37  *
  38  * Or submit a bug report through the following website:
  39  *    http://www.sf.net/projects/lksctp
  40  *
  41  * Written or modified by:
  42  *    La Monte H.P. Yarroll <piggy@acm.org>
  43  *    Karl Knutson <karl@athena.chicago.il.us>
  44  *    Jon Grimm <jgrimm@austin.ibm.com>
  45  *    Daisy Chang <daisyc@us.ibm.com>
  46  *    Dajiang Zhang <dajiang.zhang@nokia.com>
  47  *
  48  * Any bugs reported given to us we will try to fix... any fixes shared will
  49  * be incorporated into the next SCTP release.
  50  */
  51
  52 #include <linux/types.h>
  53 #include <linux/sched.h>
  54 #include <linux/slab.h>
  55 #include <linux/in.h>
  56 #include <linux/random.h>       /* get_random_bytes() */
  57 #include <net/sock.h>
  58 #include <net/ipv6.h>
  59 #include <net/sctp/sctp.h>
  60 #include <net/sctp/sm.h>
  61
  62 /* Forward declarations for internal helpers. */
  63 static void sctp_endpoint_bh_rcv(sctp_endpoint_t *ep);
  64
  65 /* Create a sctp_endpoint_t with all that boring stuff initialized.
  66  * Returns NULL if there isn't enough memory.
  67  */
  68 sctp_endpoint_t *sctp_endpoint_new(sctp_protocol_t *proto,
  69                                    struct sock *sk, int priority)
  70 {
  71         sctp_endpoint_t *ep;
  72
  73         /* Build a local endpoint. */
  74         ep = t_new(sctp_endpoint_t, priority);
  75         if (!ep)
  76                 goto fail;
  77         if (!sctp_endpoint_init(ep, proto, sk, priority))
  78                 goto fail_init;
  79         ep->base.malloced = 1;
  80         SCTP_DBG_OBJCNT_INC(ep);
  81         return ep;
  82
  83 fail_init:
  84         kfree(ep);
  85 fail:
  86         return NULL;
  87 }
  88
  89 /*
  90  * Initialize the base fields of the endpoint structure.
  91  */
  92 sctp_endpoint_t *sctp_endpoint_init(sctp_endpoint_t *ep, sctp_protocol_t *proto,
  93                                     struct sock *sk, int priority)
  94 {
  95         sctp_opt_t *sp = sctp_sk(sk);
  96         memset(ep, 0, sizeof(sctp_endpoint_t));
  97
  98         /* Initialize the base structure. */
  99         /* What type of endpoint are we?  */
 100         ep->base.type = SCTP_EP_TYPE_SOCKET;
 101
 102         /* Initialize the basic object fields. */
 103         atomic_set(&ep->base.refcnt, 1);
 104         ep->base.dead = 0;
 105         ep->base.malloced = 1;
 106
 107         /* Create an input queue.  */
 108         sctp_inqueue_init(&ep->base.inqueue);
 109
 110         /* Set its top-half handler */
 111         sctp_inqueue_set_th_handler(&ep->base.inqueue,
 112                                     (void (*)(void *))sctp_endpoint_bh_rcv,
 113                                     ep);
 114
 115         /* Initialize the bind addr area */
 116         sctp_bind_addr_init(&ep->base.bind_addr, 0);
 117         ep->base.addr_lock = RW_LOCK_UNLOCKED;
 118
 119         /* Remember who we are attached to.  */
 120         ep->base.sk = sk;
 121         sock_hold(ep->base.sk);
 122
 123         /* This pointer is useful to access the default protocol parameter
 124          * values.
 125          */
 126         ep->proto = proto;
 127
 128         /* Create the lists of associations.  */
 129         INIT_LIST_HEAD(&ep->asocs);
 130
 131         /* Set up the base timeout information.  */
 132         ep->timeouts[SCTP_EVENT_TIMEOUT_NONE] = 0;
 133         ep->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
 134                 SCTP_DEFAULT_TIMEOUT_T1_COOKIE;
 135         ep->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
 136                 SCTP_DEFAULT_TIMEOUT_T1_INIT;
 137         ep->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] =
 138                 sp->rtoinfo.srto_initial;
 139         ep->timeouts[SCTP_EVENT_TIMEOUT_T3_RTX] = 0;
 140         ep->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = 0;
 141
 142         /* sctpimpguide-05 Section 2.12.2
 143          * If the 'T5-shutdown-guard' timer is used, it SHOULD be set to the
 144          * recommended value of 5 times 'RTO.Max'.
 145          */
 146         ep->timeouts[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]
 147                 = 5 * sp->rtoinfo.srto_max;
 148
 149         ep->timeouts[SCTP_EVENT_TIMEOUT_HEARTBEAT] =
 150                 SCTP_DEFAULT_TIMEOUT_HEARTBEAT;
 151         ep->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
 152                 SCTP_DEFAULT_TIMEOUT_SACK;
 153         ep->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] =
 154                 sp->autoclose * HZ;
 155         ep->timeouts[SCTP_EVENT_TIMEOUT_PMTU_RAISE] =
 156                 SCTP_DEFAULT_TIMEOUT_PMTU_RAISE;
 157
 158         /* Set up the default send/receive buffer space.  */
 159
 160         /* FIXME - Should the min and max window size be configurable
 161          * sysctl parameters as opposed to be constants?
 162          */
 163         sk->rcvbuf = SCTP_DEFAULT_MAXWINDOW;
 164         sk->sndbuf = SCTP_DEFAULT_MAXWINDOW * 2;
 165
 166         /* Use SCTP specific send buffer space queues.  */
 167         sk->write_space = sctp_write_space;
 168         sk->use_write_queue = 1;
 169
 170         /* Initialize the secret key used with cookie. */
 171         get_random_bytes(&ep->secret_key[0], SCTP_SECRET_SIZE);
 172         ep->last_key = ep->current_key = 0;
 173         ep->key_changed_at = jiffies;
 174
 175         ep->debug_name = "unnamedEndpoint";
 176         return ep;
 177 }
 178
 179 /* Add an association to an endpoint.  */
 180 void sctp_endpoint_add_asoc(sctp_endpoint_t *ep, sctp_association_t *asoc)
 181 {
 182         /* Now just add it to our list of asocs */
 183         list_add_tail(&asoc->asocs, &ep->asocs);
 184 }
 185
 186 /* Free the endpoint structure.  Delay cleanup until
 187  * all users have released their reference count on this structure.
 188  */
 189 void sctp_endpoint_free(sctp_endpoint_t *ep)
 190 {
 191         ep->base.dead = 1;
 192         sctp_endpoint_put(ep);
 193 }
 194
 195 /* Final destructor for endpoint.  */
 196 void sctp_endpoint_destroy(sctp_endpoint_t *ep)
 197 {
 198         SCTP_ASSERT(ep->base.dead, "Endpoint is not dead", return);
 199
 200         /* Unlink this endpoint, so we can't find it again! */
 201         sctp_unhash_endpoint(ep);
 202
 203         /* Cleanup the inqueue. */
 204         sctp_inqueue_free(&ep->base.inqueue);
 205
 206         sctp_bind_addr_free(&ep->base.bind_addr);
 207
 208         /* Remove and free the port */
 209         if (ep->base.sk->prev != NULL)
 210                 sctp_put_port(ep->base.sk);
 211
 212         /* Give up our hold on the sock. */
 213         if (ep->base.sk)
 214                 sock_put(ep->base.sk);
 215
 216         /* Finally, free up our memory. */
 217         if (ep->base.malloced) {
 218                 kfree(ep);
 219                 SCTP_DBG_OBJCNT_DEC(ep);
 220         }
 221 }
 222
 223 /* Hold a reference to an endpoint. */
 224 void sctp_endpoint_hold(sctp_endpoint_t *ep)
 225 {
 226         atomic_inc(&ep->base.refcnt);
 227 }
 228
 229 /* Release a reference to an endpoint and clean up if there are
 230  * no more references.
 231  */
 232 void sctp_endpoint_put(sctp_endpoint_t *ep)
 233 {
 234         if (atomic_dec_and_test(&ep->base.refcnt))
 235                 sctp_endpoint_destroy(ep);
 236 }
 237
 238 /* Is this the endpoint we are looking for?  */
 239 sctp_endpoint_t *sctp_endpoint_is_match(sctp_endpoint_t *ep,
 240                                         const union sctp_addr *laddr)
 241 {
 242         sctp_endpoint_t *retval;
 243
 244         sctp_read_lock(&ep->base.addr_lock);
 245         if (ep->base.bind_addr.port == laddr->v4.sin_port) {
 246                 if (sctp_bind_addr_match(&ep->base.bind_addr, laddr,
 247                                          sctp_sk(ep->base.sk))) {
 248                         retval = ep;
 249                         goto out;
 250                 }
 251         }
 252
 253         retval = NULL;
 254
 255 out:
 256         sctp_read_unlock(&ep->base.addr_lock);
 257         return retval;
 258 }
 259
 260 /* Find the association that goes with this chunk.
 261  * We do a linear search of the associations for this endpoint.
 262  * We return the matching transport address too.
 263  */
 264 sctp_association_t *__sctp_endpoint_lookup_assoc(
 265         const sctp_endpoint_t *endpoint,
 266         const union sctp_addr *paddr,
 267         sctp_transport_t **transport)
 268 {
 269         int rport;
 270         sctp_association_t *asoc;
 271         struct list_head *pos;
 272
 273         rport = paddr->v4.sin_port;
 274
 275         list_for_each(pos, &endpoint->asocs) {
 276                 asoc = list_entry(pos, sctp_association_t, asocs);
 277                 if (rport == asoc->peer.port) {
 278                         sctp_read_lock(&asoc->base.addr_lock);
 279                         *transport = sctp_assoc_lookup_paddr(asoc, paddr);
 280                         sctp_read_unlock(&asoc->base.addr_lock);
 281
 282                         if (*transport)
 283                                 return asoc;
 284                 }
 285         }
 286
 287         *transport = NULL;
 288         return NULL;
 289 }
 290
 291 /* Lookup association on an endpoint based on a peer address.  BH-safe.  */
 292 sctp_association_t *sctp_endpoint_lookup_assoc(const sctp_endpoint_t *ep,
 293                                                const union sctp_addr *paddr,
 294                                                sctp_transport_t **transport)
 295 {
 296         sctp_association_t *asoc;
 297
 298         sctp_local_bh_disable();
 299         asoc = __sctp_endpoint_lookup_assoc(ep, paddr, transport);
 300         sctp_local_bh_enable();
 301
 302         return asoc;
 303 }
 304
 305 /* Look for any peeled off association from the endpoint that matches the
 306  * given peer address.
 307  */
 308 int sctp_endpoint_is_peeled_off(sctp_endpoint_t *ep,
 309                                 const union sctp_addr *paddr)
 310 {
 311         struct list_head *pos;
 312         struct sockaddr_storage_list *addr;
 313         sctp_bind_addr_t *bp;
 314
 315         sctp_read_lock(&ep->base.addr_lock);
 316         bp = &ep->base.bind_addr;
 317         list_for_each(pos, &bp->address_list) {
 318                 addr = list_entry(pos, struct sockaddr_storage_list, list);
 319                 if (sctp_has_association(&addr->a, paddr)) {
 320                         sctp_read_unlock(&ep->base.addr_lock);
 321                         return 1;
 322                 }
 323         }
 324         sctp_read_unlock(&ep->base.addr_lock);
 325
 326         return 0;
 327 }
 328
 329 /* Do delayed input processing.  This is scheduled by sctp_rcv().
 330  * This may be called on BH or task time.
 331  */
 332 static void sctp_endpoint_bh_rcv(sctp_endpoint_t *ep)
 333 {
 334         sctp_association_t *asoc;
 335         struct sock *sk;
 336         sctp_transport_t *transport;
 337         sctp_chunk_t *chunk;
 338         sctp_inqueue_t *inqueue;
 339         sctp_subtype_t subtype;
 340         sctp_state_t state;
 341         int error = 0;
 342
 343         if (ep->base.dead)
 344                 return;
 345
 346         asoc = NULL;
 347         inqueue = &ep->base.inqueue;
 348         sk = ep->base.sk;
 349
 350         while (NULL != (chunk = sctp_pop_inqueue(inqueue))) {
 351                 subtype.chunk = chunk->chunk_hdr->type;
 352
 353                 /* We might have grown an association since last we
 354                  * looked, so try again.
 355                  *
 356                  * This happens when we've just processed our
 357                  * COOKIE-ECHO chunk.
 358                  */
 359                 if (NULL == chunk->asoc) {
 360                         asoc = sctp_endpoint_lookup_assoc(ep,
 361                                                           sctp_source(chunk),
 362                                                           &transport);
 363                         chunk->asoc = asoc;
 364                         chunk->transport = transport;
 365                 }
 366
 367                 state = asoc ? asoc->state : SCTP_STATE_CLOSED;
 368
 369                 /* Remember where the last DATA chunk came from so we
 370                  * know where to send the SACK.
 371                  */
 372                 if (asoc && sctp_chunk_is_data(chunk))
 373                         asoc->peer.last_data_from = chunk->transport;
 374
 375                 if (chunk->transport)
 376                         chunk->transport->last_time_heard = jiffies;
 377
 378                 error = sctp_do_sm(SCTP_EVENT_T_CHUNK, subtype, state,
 379                                    ep, asoc, chunk, GFP_ATOMIC);
 380
 381                 if (error && chunk)
 382                         chunk->pdiscard = 1;
 383
 384                 /* Check to see if the endpoint is freed in response to
 385                  * the incoming chunk. If so, get out of the while loop.
 386                  */
 387                 if (!sctp_sk(sk)->ep)
 388                         break;
 389         }
 390 }