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 <linux/crypto.h>
  58 #include <net/sock.h>
  59 #include <net/ipv6.h>
  60 #include <net/sctp/sctp.h>
  61 #include <net/sctp/sm.h>
  62
  63 /* Forward declarations for internal helpers. */
  64 static void sctp_endpoint_bh_rcv(struct sctp_endpoint *ep);
  65
  66 /*
  67  * Initialize the base fields of the endpoint structure.
  68  */
  69 static struct sctp_endpoint *sctp_endpoint_init(struct sctp_endpoint *ep,
  70                                                 struct sock *sk, int gfp)
  71 {
  72         struct sctp_sock *sp = sctp_sk(sk);
  73         memset(ep, 0, sizeof(struct sctp_endpoint));
  74
  75         /* Initialize the base structure. */
  76         /* What type of endpoint are we?  */
  77         ep->base.type = SCTP_EP_TYPE_SOCKET;
  78
  79         /* Initialize the basic object fields. */
  80         atomic_set(&ep->base.refcnt, 1);
  81         ep->base.dead = 0;
  82         ep->base.malloced = 1;
  83
  84         /* Create an input queue.  */
  85         sctp_inq_init(&ep->base.inqueue);
  86
  87         /* Set its top-half handler */
  88         sctp_inq_set_th_handler(&ep->base.inqueue,
  89                                 (void (*)(void *))sctp_endpoint_bh_rcv, ep);
  90
  91         /* Initialize the bind addr area */
  92         sctp_bind_addr_init(&ep->base.bind_addr, 0);
  93         rwlock_init(&ep->base.addr_lock);
  94
  95         /* Remember who we are attached to.  */
  96         ep->base.sk = sk;
  97         sock_hold(ep->base.sk);
  98
  99         /* Create the lists of associations.  */
 100         INIT_LIST_HEAD(&ep->asocs);
 101
 102         /* Set up the base timeout information.  */
 103         ep->timeouts[SCTP_EVENT_TIMEOUT_NONE] = 0;
 104         ep->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
 105                 SCTP_DEFAULT_TIMEOUT_T1_COOKIE;
 106         ep->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
 107                 SCTP_DEFAULT_TIMEOUT_T1_INIT;
 108         ep->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] =
 109                 msecs_to_jiffies(sp->rtoinfo.srto_initial);
 110         ep->timeouts[SCTP_EVENT_TIMEOUT_T3_RTX] = 0;
 111         ep->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = 0;
 112
 113         /* sctpimpguide-05 Section 2.12.2
 114          * If the 'T5-shutdown-guard' timer is used, it SHOULD be set to the
 115          * recommended value of 5 times 'RTO.Max'.
 116          */
 117         ep->timeouts[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]
 118                 = 5 * msecs_to_jiffies(sp->rtoinfo.srto_max);
 119
 120         ep->timeouts[SCTP_EVENT_TIMEOUT_HEARTBEAT] =
 121                 SCTP_DEFAULT_TIMEOUT_HEARTBEAT;
 122         ep->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
 123                 SCTP_DEFAULT_TIMEOUT_SACK;
 124         ep->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] =
 125                 sp->autoclose * HZ;
 126
 127         /* Use SCTP specific send buffer space queues.  */
 128         ep->sndbuf_policy = sctp_sndbuf_policy;
 129         sk->sk_write_space = sctp_write_space;
 130         sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
 131
 132         /* Initialize the secret key used with cookie. */
 133         get_random_bytes(&ep->secret_key[0], SCTP_SECRET_SIZE);
 134         ep->last_key = ep->current_key = 0;
 135         ep->key_changed_at = jiffies;
 136
 137         ep->debug_name = "unnamedEndpoint";
 138         return ep;
 139 }
 140
 141 /* Create a sctp_endpoint with all that boring stuff initialized.
 142  * Returns NULL if there isn't enough memory.
 143  */
 144 struct sctp_endpoint *sctp_endpoint_new(struct sock *sk, int gfp)
 145 {
 146         struct sctp_endpoint *ep;
 147
 148         /* Build a local endpoint. */
 149         ep = t_new(struct sctp_endpoint, gfp);
 150         if (!ep)
 151                 goto fail;
 152         if (!sctp_endpoint_init(ep, sk, gfp))
 153                 goto fail_init;
 154         ep->base.malloced = 1;
 155         SCTP_DBG_OBJCNT_INC(ep);
 156         return ep;
 157
 158 fail_init:
 159         kfree(ep);
 160 fail:
 161         return NULL;
 162 }
 163
 164 /* Add an association to an endpoint.  */
 165 void sctp_endpoint_add_asoc(struct sctp_endpoint *ep,
 166                             struct sctp_association *asoc)
 167 {
 168         struct sock *sk = ep->base.sk;
 169
 170         /* Now just add it to our list of asocs */
 171         list_add_tail(&asoc->asocs, &ep->asocs);
 172
 173         /* Increment the backlog value for a TCP-style listening socket. */
 174         if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
 175                 sk->sk_ack_backlog++;
 176 }
 177
 178 /* Free the endpoint structure.  Delay cleanup until
 179  * all users have released their reference count on this structure.
 180  */
 181 void sctp_endpoint_free(struct sctp_endpoint *ep)
 182 {
 183         ep->base.dead = 1;
 184         sctp_endpoint_put(ep);
 185 }
 186
 187 /* Final destructor for endpoint.  */
 188 static void sctp_endpoint_destroy(struct sctp_endpoint *ep)
 189 {
 190         SCTP_ASSERT(ep->base.dead, "Endpoint is not dead", return);
 191
 192         ep->base.sk->sk_state = SCTP_SS_CLOSED;
 193
 194         /* Unlink this endpoint, so we can't find it again! */
 195         sctp_unhash_endpoint(ep);
 196
 197         /* Free up the HMAC transform. */
 198         if (sctp_sk(ep->base.sk)->hmac)
 199                 sctp_crypto_free_tfm(sctp_sk(ep->base.sk)->hmac);
 200
 201         /* Cleanup. */
 202         sctp_inq_free(&ep->base.inqueue);
 203         sctp_bind_addr_free(&ep->base.bind_addr);
 204
 205         /* Remove and free the port */
 206         if (sctp_sk(ep->base.sk)->bind_hash)
 207                 sctp_put_port(ep->base.sk);
 208
 209         /* Give up our hold on the sock. */
 210         if (ep->base.sk)
 211                 sock_put(ep->base.sk);
 212
 213         /* Finally, free up our memory. */
 214         if (ep->base.malloced) {
 215                 kfree(ep);
 216                 SCTP_DBG_OBJCNT_DEC(ep);
 217         }
 218 }
 219
 220 /* Hold a reference to an endpoint. */
 221 void sctp_endpoint_hold(struct sctp_endpoint *ep)
 222 {
 223         atomic_inc(&ep->base.refcnt);
 224 }
 225
 226 /* Release a reference to an endpoint and clean up if there are
 227  * no more references.
 228  */
 229 void sctp_endpoint_put(struct sctp_endpoint *ep)
 230 {
 231         if (atomic_dec_and_test(&ep->base.refcnt))
 232                 sctp_endpoint_destroy(ep);
 233 }
 234
 235 /* Is this the endpoint we are looking for?  */
 236 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep,
 237                                                const union sctp_addr *laddr)
 238 {
 239         struct sctp_endpoint *retval;
 240
 241         sctp_read_lock(&ep->base.addr_lock);
 242         if (ep->base.bind_addr.port == laddr->v4.sin_port) {
 243                 if (sctp_bind_addr_match(&ep->base.bind_addr, laddr,
 244                                          sctp_sk(ep->base.sk))) {
 245                         retval = ep;
 246                         goto out;
 247                 }
 248         }
 249
 250         retval = NULL;
 251
 252 out:
 253         sctp_read_unlock(&ep->base.addr_lock);
 254         return retval;
 255 }
 256
 257 /* Find the association that goes with this chunk.
 258  * We do a linear search of the associations for this endpoint.
 259  * We return the matching transport address too.
 260  */
 261 static struct sctp_association *__sctp_endpoint_lookup_assoc(
 262         const struct sctp_endpoint *ep,
 263         const union sctp_addr *paddr,
 264         struct sctp_transport **transport)
 265 {
 266         int rport;
 267         struct sctp_association *asoc;
 268         struct list_head *pos;
 269
 270         rport = paddr->v4.sin_port;
 271
 272         list_for_each(pos, &ep->asocs) {
 273                 asoc = list_entry(pos, struct sctp_association, asocs);
 274                 if (rport == asoc->peer.port) {
 275                         sctp_read_lock(&asoc->base.addr_lock);
 276                         *transport = sctp_assoc_lookup_paddr(asoc, paddr);
 277                         sctp_read_unlock(&asoc->base.addr_lock);
 278
 279                         if (*transport)
 280                                 return asoc;
 281                 }
 282         }
 283
 284         *transport = NULL;
 285         return NULL;
 286 }
 287
 288 /* Lookup association on an endpoint based on a peer address.  BH-safe.  */
 289 struct sctp_association *sctp_endpoint_lookup_assoc(
 290         const struct sctp_endpoint *ep,
 291         const union sctp_addr *paddr,
 292         struct sctp_transport **transport)
 293 {
 294         struct sctp_association *asoc;
 295
 296         sctp_local_bh_disable();
 297         asoc = __sctp_endpoint_lookup_assoc(ep, paddr, transport);
 298         sctp_local_bh_enable();
 299
 300         return asoc;
 301 }
 302
 303 /* Look for any peeled off association from the endpoint that matches the
 304  * given peer address.
 305  */
 306 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
 307                                 const union sctp_addr *paddr)
 308 {
 309         struct list_head *pos;
 310         struct sctp_sockaddr_entry *addr;
 311         struct sctp_bind_addr *bp;
 312
 313         sctp_read_lock(&ep->base.addr_lock);
 314         bp = &ep->base.bind_addr;
 315         list_for_each(pos, &bp->address_list) {
 316                 addr = list_entry(pos, struct sctp_sockaddr_entry, list);
 317                 if (sctp_has_association(&addr->a, paddr)) {
 318                         sctp_read_unlock(&ep->base.addr_lock);
 319                         return 1;
 320                 }
 321         }
 322         sctp_read_unlock(&ep->base.addr_lock);
 323
 324         return 0;
 325 }
 326
 327 /* Do delayed input processing.  This is scheduled by sctp_rcv().
 328  * This may be called on BH or task time.
 329  */
 330 static void sctp_endpoint_bh_rcv(struct sctp_endpoint *ep)
 331 {
 332         struct sctp_association *asoc;
 333         struct sock *sk;
 334         struct sctp_transport *transport;
 335         struct sctp_chunk *chunk;
 336         struct sctp_inq *inqueue;
 337         sctp_subtype_t subtype;
 338         sctp_state_t state;
 339         int error = 0;
 340
 341         if (ep->base.dead)
 342                 return;
 343
 344         asoc = NULL;
 345         inqueue = &ep->base.inqueue;
 346         sk = ep->base.sk;
 347
 348         while (NULL != (chunk = sctp_inq_pop(inqueue))) {
 349                 subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
 350
 351                 /* We might have grown an association since last we
 352                  * looked, so try again.
 353                  *
 354                  * This happens when we've just processed our
 355                  * COOKIE-ECHO chunk.
 356                  */
 357                 if (NULL == chunk->asoc) {
 358                         asoc = sctp_endpoint_lookup_assoc(ep,
 359                                                           sctp_source(chunk),
 360                                                           &transport);
 361                         chunk->asoc = asoc;
 362                         chunk->transport = transport;
 363                 }
 364
 365                 state = asoc ? asoc->state : SCTP_STATE_CLOSED;
 366
 367                 /* Remember where the last DATA chunk came from so we
 368                  * know where to send the SACK.
 369                  */
 370                 if (asoc && sctp_chunk_is_data(chunk))
 371                         asoc->peer.last_data_from = chunk->transport;
 372                 else
 373                         SCTP_INC_STATS(SCTP_MIB_INCTRLCHUNKS);
 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 }