/* SCTP kernel reference Implementation
* Copyright (c) 1999-2000 Cisco, Inc.
* Copyright (c) 1999-2001 Motorola, Inc.
* Copyright (c) 2001-2002 International Business Machines, Corp.
* Copyright (c) 2001 Intel Corp.
* Copyright (c) 2001 Nokia, Inc.
* Copyright (c) 2001 La Monte H.P. Yarroll
*
* This file is part of the SCTP kernel reference Implementation
*
* This abstraction represents an SCTP endpoint.
*
* This file is part of the implementation of the add-IP extension,
* based on <draft-ietf-tsvwg-addip-sctp-02.txt> June 29, 2001,
* for the SCTP kernel reference Implementation.
*
* The SCTP reference implementation is free software;
* you can redistribute it and/or modify it under the terms of
* the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* The SCTP reference implementation is distributed in the hope that it
* will be useful, but WITHOUT ANY WARRANTY; without even the implied
* ************************
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNU CC; see the file COPYING. If not, write to
* the Free Software Foundation, 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*
* Please send any bug reports or fixes you make to the
* email address(es):
* lksctp developers <lksctp-developers@lists.sourceforge.net>
*
* Or submit a bug report through the following website:
* http://www.sf.net/projects/lksctp
*
* Written or modified by:
* La Monte H.P. Yarroll <piggy@acm.org>
* Karl Knutson <karl@athena.chicago.il.us>
* Jon Grimm <jgrimm@austin.ibm.com>
* Daisy Chang <daisyc@us.ibm.com>
* Dajiang Zhang <dajiang.zhang@nokia.com>
*
* Any bugs reported given to us we will try to fix... any fixes shared will
* be incorporated into the next SCTP release.
*/
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/in.h>
#include <linux/random.h> /* get_random_bytes() */
#include <linux/crypto.h>
#include <net/sock.h>
#include <net/ipv6.h>
#include <net/sctp/sctp.h>
#include <net/sctp/sm.h>
/* Forward declarations for internal helpers. */
static void sctp_endpoint_bh_rcv(struct sctp_endpoint *ep);
/*
* Initialize the base fields of the endpoint structure.
*/
static struct sctp_endpoint *sctp_endpoint_init(struct sctp_endpoint *ep,
struct sock *sk,
gfp_t gfp)
{
memset(ep, 0, sizeof(struct sctp_endpoint));
ep->digest = kzalloc(SCTP_SIGNATURE_SIZE, gfp);
if (!ep->digest)
return NULL;
/* Initialize the base structure. */
/* What type of endpoint are we? */
ep->base.type = SCTP_EP_TYPE_SOCKET;
/* Initialize the basic object fields. */
atomic_set(&ep->base.refcnt, 1);
ep->base.dead = 0;
ep->base.malloced = 1;
/* Create an input queue. */
sctp_inq_init(&ep->base.inqueue);
/* Set its top-half handler */
sctp_inq_set_th_handler(&ep->base.inqueue,
(void (*)(void *))sctp_endpoint_bh_rcv, ep);
/* Initialize the bind addr area */
sctp_bind_addr_init(&ep->base.bind_addr, 0);
rwlock_init(&ep->base.addr_lock);
/* Remember who we are attached to. */
ep->base.sk = sk;
sock_hold(ep->base.sk);
/* Create the lists of associations. */
INIT_LIST_HEAD(&ep->asocs);
/* Use SCTP specific send buffer space queues. */
ep->sndbuf_policy = sctp_sndbuf_policy;
sk->sk_write_space = sctp_write_space;
sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
/* Get the receive buffer policy for this endpoint */
ep->rcvbuf_policy = sctp_rcvbuf_policy;
/* Initialize the secret key used with cookie. */
get_random_bytes(&ep->secret_key[0], SCTP_SECRET_SIZE);
ep->last_key = ep->current_key = 0;
ep->key_changed_at = jiffies;
return ep;
}
/* Create a sctp_endpoint with all that boring stuff initialized.
* Returns NULL if there isn't enough memory.
*/
struct sctp_endpoint *sctp_endpoint_new(struct sock *sk, gfp_t gfp)
{
struct sctp_endpoint *ep;
/* Build a local endpoint. */
ep = t_new(struct sctp_endpoint, gfp);
if (!ep)
goto fail;
if (!sctp_endpoint_init(ep, sk, gfp))
goto fail_init;
ep->base.malloced = 1;
SCTP_DBG_OBJCNT_INC(ep);
return ep;
fail_init:
kfree(ep);
fail:
return NULL;
}
/* Add an association to an endpoint. */
void sctp_endpoint_add_asoc(struct sctp_endpoint *ep,
struct sctp_association *asoc)
{
struct sock *sk = ep->base.sk;
/* If this is a temporary association, don't bother
* since we'll be removing it shortly and don't
* want anyone to find it anyway.
*/
if (asoc->temp)
return;
/* Now just add it to our list of asocs */
list_add_tail(&asoc->asocs, &ep->asocs);
/* Increment the backlog value for a TCP-style listening socket. */
if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
sk->sk_ack_backlog++;
}
/* Free the endpoint structure. Delay cleanup until
* all users have released their reference count on this structure.
*/
void sctp_endpoint_free(struct sctp_endpoint *ep)
{
ep->base.dead = 1;
ep->base.sk->sk_state = SCTP_SS_CLOSED;
/* Unlink this endpoint, so we can't find it again! */
sctp_unhash_endpoint(ep);
sctp_endpoint_put(ep);
}
/* Final destructor for endpoint. */
static void sctp_endpoint_destroy(struct sctp_endpoint *ep)
{
SCTP_ASSERT(ep->base.dead, "Endpoint is not dead", return);
/* Free up the HMAC transform. */
crypto_free_hash(sctp_sk(ep->base.sk)->hmac);
/* Free the digest buffer */
kfree(ep->digest);
/* Cleanup. */
sctp_inq_free(&ep->base.inqueue);
sctp_bind_addr_free(&ep->base.bind_addr);
/* Remove and free the port */
if (sctp_sk(ep->base.sk)->bind_hash)
sctp_put_port(ep->base.sk);
/* Give up our hold on the sock. */
if (ep->base.sk)
sock_put(ep->base.sk);
/* Finally, free up our memory. */
if (ep->base.malloced) {
kfree(ep);
SCTP_DBG_OBJCNT_DEC(ep);
}
}
/* Hold a reference to an endpoint. */
void sctp_endpoint_hold(struct sctp_endpoint *ep)
{
atomic_inc(&ep->base.refcnt);
}
/* Release a reference to an endpoint and clean up if there are
* no more references.
*/
void sctp_endpoint_put(struct sctp_endpoint *ep)
{
if (atomic_dec_and_test(&ep->base.refcnt))
sctp_endpoint_destroy(ep);
}
/* Is this the endpoint we are looking for? */
struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep,
const union sctp_addr *laddr)
{
struct sctp_endpoint *retval;
sctp_read_lock(&ep->base.addr_lock);
if (htons(ep->base.bind_addr.port) == laddr->v4.sin_port) {
if (sctp_bind_addr_match(&ep->base.bind_addr, laddr,
sctp_sk(ep->base.sk))) {
retval = ep;
goto out;
}
}
retval = NULL;
out:
sctp_read_unlock(&ep->base.addr_lock);
return retval;
}
/* Find the association that goes with this chunk.
* We do a linear search of the associations for this endpoint.
* We return the matching transport address too.
*/
static struct sctp_association *__sctp_endpoint_lookup_assoc(
const struct sctp_endpoint *ep,
const union sctp_addr *paddr,
struct sctp_transport **transport)
{
int rport;
struct sctp_association *asoc;
struct list_head *pos;
rport = ntohs(paddr->v4.sin_port);
list_for_each(pos, &ep->asocs) {
asoc = list_entry(pos, struct sctp_association, asocs);
if (rport == asoc->peer.port) {
sctp_read_lock(&asoc->base.addr_lock);
*transport = sctp_assoc_lookup_paddr(asoc, paddr);
sctp_read_unlock(&asoc->base.addr_lock);
if (*transport)
return asoc;
}
}
*transport = NULL;
return NULL;
}
/* Lookup association on an endpoint based on a peer address. BH-safe. */
struct sctp_association *sctp_endpoint_lookup_assoc(
const struct sctp_endpoint *ep,
const union sctp_addr *paddr,
struct sctp_transport **transport)
{
struct sctp_association *asoc;
sctp_local_bh_disable();
asoc = __sctp_endpoint_lookup_assoc(ep, paddr, transport);
sctp_local_bh_enable();
return asoc;
}
/* Look for any peeled off association from the endpoint that matches the
* given peer address.
*/
int sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
const union sctp_addr *paddr)
{
struct list_head *pos;
struct sctp_sockaddr_entry *addr;
struct sctp_bind_addr *bp;
sctp_read_lock(&ep->base.addr_lock);
bp = &ep->base.bind_addr;
list_for_each(pos, &bp->address_list) {
addr = list_entry(pos, struct sctp_sockaddr_entry, list);
if (sctp_has_association(&addr->a_h, paddr)) {
sctp_read_unlock(&ep->base.addr_lock);
return 1;
}
}
sctp_read_unlock(&ep->base.addr_lock);
return 0;
}
/* Do delayed input processing. This is scheduled by sctp_rcv().
* This may be called on BH or task time.
*/
static void sctp_endpoint_bh_rcv(struct sctp_endpoint *ep)
{
struct sctp_association *asoc;
struct sock *sk;
struct sctp_transport *transport;
struct sctp_chunk *chunk;
struct sctp_inq *inqueue;
sctp_subtype_t subtype;
sctp_state_t state;
int error = 0;
if (ep->base.dead)
return;
asoc = NULL;
inqueue = &ep->base.inqueue;
sk = ep->base.sk;
while (NULL != (chunk = sctp_inq_pop(inqueue))) {
subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
/* We might have grown an association since last we
* looked, so try again.
*
* This happens when we've just processed our
* COOKIE-ECHO chunk.
*/
if (NULL == chunk->asoc) {
union sctp_addr tmp;
flip_to_n(&tmp, sctp_source(chunk));
asoc = sctp_endpoint_lookup_assoc(ep,
&tmp,
&transport);
chunk->asoc = asoc;
chunk->transport = transport;
}
state = asoc ? asoc->state : SCTP_STATE_CLOSED;
/* Remember where the last DATA chunk came from so we
* know where to send the SACK.
*/
if (asoc && sctp_chunk_is_data(chunk))
asoc->peer.last_data_from = chunk->transport;
else
SCTP_INC_STATS(SCTP_MIB_INCTRLCHUNKS);
if (chunk->transport)
chunk->transport->last_time_heard = jiffies;
error = sctp_do_sm(SCTP_EVENT_T_CHUNK, subtype, state,
ep, asoc, chunk, GFP_ATOMIC);
if (error && chunk)
chunk->pdiscard = 1;
/* Check to see if the endpoint is freed in response to
* the incoming chunk. If so, get out of the while loop.
*/
if (!sctp_sk(sk)->ep)
break;
}
}
