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                                                 gfp_t 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, gfp_t gfp)
 142 {
 143         struct sctp_endpoint *ep;
 144
 145         /* Build a local endpoint. */
 146         ep = t_new(struct sctp_endpoint, gfp);
 147         if (!ep)
 148                 goto fail;
 149         if (!sctp_endpoint_init(ep, sk, gfp))
 150                 goto fail_init;
 151         ep->base.malloced = 1;
 152         SCTP_DBG_OBJCNT_INC(ep);
 153         return ep;
 154
 155 fail_init:
 156         kfree(ep);
 157 fail:
 158         return NULL;
 159 }
 160
 161 /* Add an association to an endpoint.  */
 162 void sctp_endpoint_add_asoc(struct sctp_endpoint *ep,
 163                             struct sctp_association *asoc)
 164 {
 165         struct sock *sk = ep->base.sk;
 166
 167         /* Now just add it to our list of asocs */
 168         list_add_tail(&asoc->asocs, &ep->asocs);
 169
 170         /* Increment the backlog value for a TCP-style listening socket. */
 171         if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
 172                 sk->sk_ack_backlog++;
 173 }
 174
 175 /* Free the endpoint structure.  Delay cleanup until
 176  * all users have released their reference count on this structure.
 177  */
 178 void sctp_endpoint_free(struct sctp_endpoint *ep)
 179 {
 180         ep->base.dead = 1;
 181         sctp_endpoint_put(ep);
 182 }
 183
 184 /* Final destructor for endpoint.  */
 185 static void sctp_endpoint_destroy(struct sctp_endpoint *ep)
 186 {
 187         SCTP_ASSERT(ep->base.dead, "Endpoint is not dead", return);
 188
 189         ep->base.sk->sk_state = SCTP_SS_CLOSED;
 190
 191         /* Unlink this endpoint, so we can't find it again! */
 192         sctp_unhash_endpoint(ep);
 193
 194         /* Free up the HMAC transform. */
 195         sctp_crypto_free_tfm(sctp_sk(ep->base.sk)->hmac);
 196
 197         /* Cleanup. */
 198         sctp_inq_free(&ep->base.inqueue);
 199         sctp_bind_addr_free(&ep->base.bind_addr);
 200
 201         /* Remove and free the port */
 202         if (sctp_sk(ep->base.sk)->bind_hash)
 203                 sctp_put_port(ep->base.sk);
 204
 205         /* Give up our hold on the sock. */
 206         if (ep->base.sk)
 207                 sock_put(ep->base.sk);
 208
 209         /* Finally, free up our memory. */
 210         if (ep->base.malloced) {
 211                 kfree(ep);
 212                 SCTP_DBG_OBJCNT_DEC(ep);
 213         }
 214 }
 215
 216 /* Hold a reference to an endpoint. */
 217 void sctp_endpoint_hold(struct sctp_endpoint *ep)
 218 {
 219         atomic_inc(&ep->base.refcnt);
 220 }
 221
 222 /* Release a reference to an endpoint and clean up if there are
 223  * no more references.
 224  */
 225 void sctp_endpoint_put(struct sctp_endpoint *ep)
 226 {
 227         if (atomic_dec_and_test(&ep->base.refcnt))
 228                 sctp_endpoint_destroy(ep);
 229 }
 230
 231 /* Is this the endpoint we are looking for?  */
 232 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep,
 233                                                const union sctp_addr *laddr)
 234 {
 235         struct sctp_endpoint *retval;
 236
 237         sctp_read_lock(&ep->base.addr_lock);
 238         if (ep->base.bind_addr.port == laddr->v4.sin_port) {
 239                 if (sctp_bind_addr_match(&ep->base.bind_addr, laddr,
 240                                          sctp_sk(ep->base.sk))) {
 241                         retval = ep;
 242                         goto out;
 243                 }
 244         }
 245
 246         retval = NULL;
 247
 248 out:
 249         sctp_read_unlock(&ep->base.addr_lock);
 250         return retval;
 251 }
 252
 253 /* Find the association that goes with this chunk.
 254  * We do a linear search of the associations for this endpoint.
 255  * We return the matching transport address too.
 256  */
 257 static struct sctp_association *__sctp_endpoint_lookup_assoc(
 258         const struct sctp_endpoint *ep,
 259         const union sctp_addr *paddr,
 260         struct sctp_transport **transport)
 261 {
 262         int rport;
 263         struct sctp_association *asoc;
 264         struct list_head *pos;
 265
 266         rport = paddr->v4.sin_port;
 267
 268         list_for_each(pos, &ep->asocs) {
 269                 asoc = list_entry(pos, struct sctp_association, asocs);
 270                 if (rport == asoc->peer.port) {
 271                         sctp_read_lock(&asoc->base.addr_lock);
 272                         *transport = sctp_assoc_lookup_paddr(asoc, paddr);
 273                         sctp_read_unlock(&asoc->base.addr_lock);
 274
 275                         if (*transport)
 276                                 return asoc;
 277                 }
 278         }
 279
 280         *transport = NULL;
 281         return NULL;
 282 }
 283
 284 /* Lookup association on an endpoint based on a peer address.  BH-safe.  */
 285 struct sctp_association *sctp_endpoint_lookup_assoc(
 286         const struct sctp_endpoint *ep,
 287         const union sctp_addr *paddr,
 288         struct sctp_transport **transport)
 289 {
 290         struct sctp_association *asoc;
 291
 292         sctp_local_bh_disable();
 293         asoc = __sctp_endpoint_lookup_assoc(ep, paddr, transport);
 294         sctp_local_bh_enable();
 295
 296         return asoc;
 297 }
 298
 299 /* Look for any peeled off association from the endpoint that matches the
 300  * given peer address.
 301  */
 302 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
 303                                 const union sctp_addr *paddr)
 304 {
 305         struct list_head *pos;
 306         struct sctp_sockaddr_entry *addr;
 307         struct sctp_bind_addr *bp;
 308
 309         sctp_read_lock(&ep->base.addr_lock);
 310         bp = &ep->base.bind_addr;
 311         list_for_each(pos, &bp->address_list) {
 312                 addr = list_entry(pos, struct sctp_sockaddr_entry, list);
 313                 if (sctp_has_association(&addr->a, paddr)) {
 314                         sctp_read_unlock(&ep->base.addr_lock);
 315                         return 1;
 316                 }
 317         }
 318         sctp_read_unlock(&ep->base.addr_lock);
 319
 320         return 0;
 321 }
 322
 323 /* Do delayed input processing.  This is scheduled by sctp_rcv().
 324  * This may be called on BH or task time.
 325  */
 326 static void sctp_endpoint_bh_rcv(struct sctp_endpoint *ep)
 327 {
 328         struct sctp_association *asoc;
 329         struct sock *sk;
 330         struct sctp_transport *transport;
 331         struct sctp_chunk *chunk;
 332         struct sctp_inq *inqueue;
 333         sctp_subtype_t subtype;
 334         sctp_state_t state;
 335         int error = 0;
 336
 337         if (ep->base.dead)
 338                 return;
 339
 340         asoc = NULL;
 341         inqueue = &ep->base.inqueue;
 342         sk = ep->base.sk;
 343
 344         while (NULL != (chunk = sctp_inq_pop(inqueue))) {
 345                 subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
 346
 347                 /* We might have grown an association since last we
 348                  * looked, so try again.
 349                  *
 350                  * This happens when we've just processed our
 351                  * COOKIE-ECHO chunk.
 352                  */
 353                 if (NULL == chunk->asoc) {
 354                         asoc = sctp_endpoint_lookup_assoc(ep,
 355                                                           sctp_source(chunk),
 356                                                           &transport);
 357                         chunk->asoc = asoc;
 358                         chunk->transport = transport;
 359                 }
 360
 361                 state = asoc ? asoc->state : SCTP_STATE_CLOSED;
 362
 363                 /* Remember where the last DATA chunk came from so we
 364                  * know where to send the SACK.
 365                  */
 366                 if (asoc && sctp_chunk_is_data(chunk))
 367                         asoc->peer.last_data_from = chunk->transport;
 368                 else
 369                         SCTP_INC_STATS(SCTP_MIB_INCTRLCHUNKS);
 370
 371                 if (chunk->transport)
 372                         chunk->transport->last_time_heard = jiffies;
 373
 374                 error = sctp_do_sm(SCTP_EVENT_T_CHUNK, subtype, state,
 375                                    ep, asoc, chunk, GFP_ATOMIC);
 376
 377                 if (error && chunk)
 378                         chunk->pdiscard = 1;
 379
 380                 /* Check to see if the endpoint is freed in response to
 381                  * the incoming chunk. If so, get out of the while loop.
 382                  */
 383                 if (!sctp_sk(sk)->ep)
 384                         break;
 385         }
 386 }