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,
  71                                                 unsigned int __nocast gfp)
  72 {
  73         struct sctp_sock *sp = sctp_sk(sk);
  74         memset(ep, 0, sizeof(struct sctp_endpoint));
  75
  76         /* Initialize the base structure. */
  77         /* What type of endpoint are we?  */
  78         ep->base.type = SCTP_EP_TYPE_SOCKET;
  79
  80         /* Initialize the basic object fields. */
  81         atomic_set(&ep->base.refcnt, 1);
  82         ep->base.dead = 0;
  83         ep->base.malloced = 1;
  84
  85         /* Create an input queue.  */
  86         sctp_inq_init(&ep->base.inqueue);
  87
  88         /* Set its top-half handler */
  89         sctp_inq_set_th_handler(&ep->base.inqueue,
  90                                 (void (*)(void *))sctp_endpoint_bh_rcv, ep);
  91
  92         /* Initialize the bind addr area */
  93         sctp_bind_addr_init(&ep->base.bind_addr, 0);
  94         rwlock_init(&ep->base.addr_lock);
  95
  96         /* Remember who we are attached to.  */
  97         ep->base.sk = sk;
  98         sock_hold(ep->base.sk);
  99
 100         /* Create the lists of associations.  */
 101         INIT_LIST_HEAD(&ep->asocs);
 102
 103         /* Set up the base timeout information.  */
 104         ep->timeouts[SCTP_EVENT_TIMEOUT_NONE] = 0;
 105         ep->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
 106                 msecs_to_jiffies(sp->rtoinfo.srto_initial);
 107         ep->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
 108                 msecs_to_jiffies(sp->rtoinfo.srto_initial);
 109         ep->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] =
 110                 msecs_to_jiffies(sp->rtoinfo.srto_initial);
 111         ep->timeouts[SCTP_EVENT_TIMEOUT_T3_RTX] = 0;
 112         ep->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = 0;
 113
 114         /* sctpimpguide-05 Section 2.12.2
 115          * If the 'T5-shutdown-guard' timer is used, it SHOULD be set to the
 116          * recommended value of 5 times 'RTO.Max'.
 117          */
 118         ep->timeouts[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]
 119                 = 5 * msecs_to_jiffies(sp->rtoinfo.srto_max);
 120
 121         ep->timeouts[SCTP_EVENT_TIMEOUT_HEARTBEAT] = 0;
 122         ep->timeouts[SCTP_EVENT_TIMEOUT_SACK] = sctp_sack_timeout;
 123         ep->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] = sp->autoclose * HZ;
 124
 125         /* Use SCTP specific send buffer space queues.  */
 126         ep->sndbuf_policy = sctp_sndbuf_policy;
 127         sk->sk_write_space = sctp_write_space;
 128         sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
 129
 130         /* Initialize the secret key used with cookie. */
 131         get_random_bytes(&ep->secret_key[0], SCTP_SECRET_SIZE);
 132         ep->last_key = ep->current_key = 0;
 133         ep->key_changed_at = jiffies;
 134
 135         return ep;
 136 }
 137
 138 /* Create a sctp_endpoint with all that boring stuff initialized.
 139  * Returns NULL if there isn't enough memory.
 140  */
 141 struct sctp_endpoint *sctp_endpoint_new(struct sock *sk,
 142                                         unsigned int __nocast gfp)
 143 {
 144         struct sctp_endpoint *ep;
 145
 146         /* Build a local endpoint. */
 147         ep = t_new(struct sctp_endpoint, gfp);
 148         if (!ep)
 149                 goto fail;
 150         if (!sctp_endpoint_init(ep, sk, gfp))
 151                 goto fail_init;
 152         ep->base.malloced = 1;
 153         SCTP_DBG_OBJCNT_INC(ep);
 154         return ep;
 155
 156 fail_init:
 157         kfree(ep);
 158 fail:
 159         return NULL;
 160 }
 161
 162 /* Add an association to an endpoint.  */
 163 void sctp_endpoint_add_asoc(struct sctp_endpoint *ep,
 164                             struct sctp_association *asoc)
 165 {
 166         struct sock *sk = ep->base.sk;
 167
 168         /* Now just add it to our list of asocs */
 169         list_add_tail(&asoc->asocs, &ep->asocs);
 170
 171         /* Increment the backlog value for a TCP-style listening socket. */
 172         if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
 173                 sk->sk_ack_backlog++;
 174 }
 175
 176 /* Free the endpoint structure.  Delay cleanup until
 177  * all users have released their reference count on this structure.
 178  */
 179 void sctp_endpoint_free(struct sctp_endpoint *ep)
 180 {
 181         ep->base.dead = 1;
 182         sctp_endpoint_put(ep);
 183 }
 184
 185 /* Final destructor for endpoint.  */
 186 static void sctp_endpoint_destroy(struct sctp_endpoint *ep)
 187 {
 188         SCTP_ASSERT(ep->base.dead, "Endpoint is not dead", return);
 189
 190         ep->base.sk->sk_state = SCTP_SS_CLOSED;
 191
 192         /* Unlink this endpoint, so we can't find it again! */
 193         sctp_unhash_endpoint(ep);
 194
 195         /* Free up the HMAC transform. */
 196         sctp_crypto_free_tfm(sctp_sk(ep->base.sk)->hmac);
 197
 198         /* Cleanup. */
 199         sctp_inq_free(&ep->base.inqueue);
 200         sctp_bind_addr_free(&ep->base.bind_addr);
 201
 202         /* Remove and free the port */
 203         if (sctp_sk(ep->base.sk)->bind_hash)
 204                 sctp_put_port(ep->base.sk);
 205
 206         /* Give up our hold on the sock. */
 207         if (ep->base.sk)
 208                 sock_put(ep->base.sk);
 209
 210         /* Finally, free up our memory. */
 211         if (ep->base.malloced) {
 212                 kfree(ep);
 213                 SCTP_DBG_OBJCNT_DEC(ep);
 214         }
 215 }
 216
 217 /* Hold a reference to an endpoint. */
 218 void sctp_endpoint_hold(struct sctp_endpoint *ep)
 219 {
 220         atomic_inc(&ep->base.refcnt);
 221 }
 222
 223 /* Release a reference to an endpoint and clean up if there are
 224  * no more references.
 225  */
 226 void sctp_endpoint_put(struct sctp_endpoint *ep)
 227 {
 228         if (atomic_dec_and_test(&ep->base.refcnt))
 229                 sctp_endpoint_destroy(ep);
 230 }
 231
 232 /* Is this the endpoint we are looking for?  */
 233 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep,
 234                                                const union sctp_addr *laddr)
 235 {
 236         struct sctp_endpoint *retval;
 237
 238         sctp_read_lock(&ep->base.addr_lock);
 239         if (ep->base.bind_addr.port == laddr->v4.sin_port) {
 240                 if (sctp_bind_addr_match(&ep->base.bind_addr, laddr,
 241                                          sctp_sk(ep->base.sk))) {
 242                         retval = ep;
 243                         goto out;
 244                 }
 245         }
 246
 247         retval = NULL;
 248
 249 out:
 250         sctp_read_unlock(&ep->base.addr_lock);
 251         return retval;
 252 }
 253
 254 /* Find the association that goes with this chunk.
 255  * We do a linear search of the associations for this endpoint.
 256  * We return the matching transport address too.
 257  */
 258 static struct sctp_association *__sctp_endpoint_lookup_assoc(
 259         const struct sctp_endpoint *ep,
 260         const union sctp_addr *paddr,
 261         struct sctp_transport **transport)
 262 {
 263         int rport;
 264         struct sctp_association *asoc;
 265         struct list_head *pos;
 266
 267         rport = paddr->v4.sin_port;
 268
 269         list_for_each(pos, &ep->asocs) {
 270                 asoc = list_entry(pos, struct sctp_association, asocs);
 271                 if (rport == asoc->peer.port) {
 272                         sctp_read_lock(&asoc->base.addr_lock);
 273                         *transport = sctp_assoc_lookup_paddr(asoc, paddr);
 274                         sctp_read_unlock(&asoc->base.addr_lock);
 275
 276                         if (*transport)
 277                                 return asoc;
 278                 }
 279         }
 280
 281         *transport = NULL;
 282         return NULL;
 283 }
 284
 285 /* Lookup association on an endpoint based on a peer address.  BH-safe.  */
 286 struct sctp_association *sctp_endpoint_lookup_assoc(
 287         const struct sctp_endpoint *ep,
 288         const union sctp_addr *paddr,
 289         struct sctp_transport **transport)
 290 {
 291         struct sctp_association *asoc;
 292
 293         sctp_local_bh_disable();
 294         asoc = __sctp_endpoint_lookup_assoc(ep, paddr, transport);
 295         sctp_local_bh_enable();
 296
 297         return asoc;
 298 }
 299
 300 /* Look for any peeled off association from the endpoint that matches the
 301  * given peer address.
 302  */
 303 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
 304                                 const union sctp_addr *paddr)
 305 {
 306         struct list_head *pos;
 307         struct sctp_sockaddr_entry *addr;
 308         struct sctp_bind_addr *bp;
 309
 310         sctp_read_lock(&ep->base.addr_lock);
 311         bp = &ep->base.bind_addr;
 312         list_for_each(pos, &bp->address_list) {
 313                 addr = list_entry(pos, struct sctp_sockaddr_entry, list);
 314                 if (sctp_has_association(&addr->a, paddr)) {
 315                         sctp_read_unlock(&ep->base.addr_lock);
 316                         return 1;
 317                 }
 318         }
 319         sctp_read_unlock(&ep->base.addr_lock);
 320
 321         return 0;
 322 }
 323
 324 /* Do delayed input processing.  This is scheduled by sctp_rcv().
 325  * This may be called on BH or task time.
 326  */
 327 static void sctp_endpoint_bh_rcv(struct sctp_endpoint *ep)
 328 {
 329         struct sctp_association *asoc;
 330         struct sock *sk;
 331         struct sctp_transport *transport;
 332         struct sctp_chunk *chunk;
 333         struct sctp_inq *inqueue;
 334         sctp_subtype_t subtype;
 335         sctp_state_t state;
 336         int error = 0;
 337
 338         if (ep->base.dead)
 339                 return;
 340
 341         asoc = NULL;
 342         inqueue = &ep->base.inqueue;
 343         sk = ep->base.sk;
 344
 345         while (NULL != (chunk = sctp_inq_pop(inqueue))) {
 346                 subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
 347
 348                 /* We might have grown an association since last we
 349                  * looked, so try again.
 350                  *
 351                  * This happens when we've just processed our
 352                  * COOKIE-ECHO chunk.
 353                  */
 354                 if (NULL == chunk->asoc) {
 355                         asoc = sctp_endpoint_lookup_assoc(ep,
 356                                                           sctp_source(chunk),
 357                                                           &transport);
 358                         chunk->asoc = asoc;
 359                         chunk->transport = transport;
 360                 }
 361
 362                 state = asoc ? asoc->state : SCTP_STATE_CLOSED;
 363
 364                 /* Remember where the last DATA chunk came from so we
 365                  * know where to send the SACK.
 366                  */
 367                 if (asoc && sctp_chunk_is_data(chunk))
 368                         asoc->peer.last_data_from = chunk->transport;
 369                 else
 370                         SCTP_INC_STATS(SCTP_MIB_INCTRLCHUNKS);
 371
 372                 if (chunk->transport)
 373                         chunk->transport->last_time_heard = jiffies;
 374
 375                 error = sctp_do_sm(SCTP_EVENT_T_CHUNK, subtype, state,
 376                                    ep, asoc, chunk, GFP_ATOMIC);
 377
 378                 if (error && chunk)
 379                         chunk->pdiscard = 1;
 380
 381                 /* Check to see if the endpoint is freed in response to
 382                  * the incoming chunk. If so, get out of the while loop.
 383                  */
 384                 if (!sctp_sk(sk)->ep)
 385                         break;
 386         }
 387 }