android_kernel_xiaomi_sm8350/net/sctp/associola.c
Al Viro dd0fc66fb3 [PATCH] gfp flags annotations - part 1
- added typedef unsigned int __nocast gfp_t;

 - replaced __nocast uses for gfp flags with gfp_t - it gives exactly
   the same warnings as far as sparse is concerned, doesn't change
   generated code (from gcc point of view we replaced unsigned int with
   typedef) and documents what's going on far better.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-08 15:00:57 -07:00

1286 lines
35 KiB
C

/* SCTP kernel reference Implementation
* (C) Copyright IBM Corp. 2001, 2004
* Copyright (c) 1999-2000 Cisco, Inc.
* Copyright (c) 1999-2001 Motorola, Inc.
* Copyright (c) 2001 Intel Corp.
* Copyright (c) 2001 La Monte H.P. Yarroll
*
* This file is part of the SCTP kernel reference Implementation
*
* This module provides the abstraction for an SCTP association.
*
* 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@us.ibm.com>
* Xingang Guo <xingang.guo@intel.com>
* Hui Huang <hui.huang@nokia.com>
* Sridhar Samudrala <sri@us.ibm.com>
* Daisy Chang <daisyc@us.ibm.com>
* Ryan Layer <rmlayer@us.ibm.com>
* Kevin Gao <kevin.gao@intel.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/fcntl.h>
#include <linux/poll.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/in.h>
#include <net/ipv6.h>
#include <net/sctp/sctp.h>
#include <net/sctp/sm.h>
/* Forward declarations for internal functions. */
static void sctp_assoc_bh_rcv(struct sctp_association *asoc);
/* 1st Level Abstractions. */
/* Initialize a new association from provided memory. */
static struct sctp_association *sctp_association_init(struct sctp_association *asoc,
const struct sctp_endpoint *ep,
const struct sock *sk,
sctp_scope_t scope,
gfp_t gfp)
{
struct sctp_sock *sp;
int i;
/* Retrieve the SCTP per socket area. */
sp = sctp_sk((struct sock *)sk);
/* Init all variables to a known value. */
memset(asoc, 0, sizeof(struct sctp_association));
/* Discarding const is appropriate here. */
asoc->ep = (struct sctp_endpoint *)ep;
sctp_endpoint_hold(asoc->ep);
/* Hold the sock. */
asoc->base.sk = (struct sock *)sk;
sock_hold(asoc->base.sk);
/* Initialize the common base substructure. */
asoc->base.type = SCTP_EP_TYPE_ASSOCIATION;
/* Initialize the object handling fields. */
atomic_set(&asoc->base.refcnt, 1);
asoc->base.dead = 0;
asoc->base.malloced = 0;
/* Initialize the bind addr area. */
sctp_bind_addr_init(&asoc->base.bind_addr, ep->base.bind_addr.port);
rwlock_init(&asoc->base.addr_lock);
asoc->state = SCTP_STATE_CLOSED;
/* Set these values from the socket values, a conversion between
* millsecons to seconds/microseconds must also be done.
*/
asoc->cookie_life.tv_sec = sp->assocparams.sasoc_cookie_life / 1000;
asoc->cookie_life.tv_usec = (sp->assocparams.sasoc_cookie_life % 1000)
* 1000;
asoc->pmtu = 0;
asoc->frag_point = 0;
/* Set the association max_retrans and RTO values from the
* socket values.
*/
asoc->max_retrans = sp->assocparams.sasoc_asocmaxrxt;
asoc->rto_initial = msecs_to_jiffies(sp->rtoinfo.srto_initial);
asoc->rto_max = msecs_to_jiffies(sp->rtoinfo.srto_max);
asoc->rto_min = msecs_to_jiffies(sp->rtoinfo.srto_min);
asoc->overall_error_count = 0;
/* Initialize the maximum mumber of new data packets that can be sent
* in a burst.
*/
asoc->max_burst = sctp_max_burst;
/* Copy things from the endpoint. */
for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) {
asoc->timeouts[i] = ep->timeouts[i];
init_timer(&asoc->timers[i]);
asoc->timers[i].function = sctp_timer_events[i];
asoc->timers[i].data = (unsigned long) asoc;
}
/* Pull default initialization values from the sock options.
* Note: This assumes that the values have already been
* validated in the sock.
*/
asoc->c.sinit_max_instreams = sp->initmsg.sinit_max_instreams;
asoc->c.sinit_num_ostreams = sp->initmsg.sinit_num_ostreams;
asoc->max_init_attempts = sp->initmsg.sinit_max_attempts;
asoc->max_init_timeo =
msecs_to_jiffies(sp->initmsg.sinit_max_init_timeo);
/* Allocate storage for the ssnmap after the inbound and outbound
* streams have been negotiated during Init.
*/
asoc->ssnmap = NULL;
/* Set the local window size for receive.
* This is also the rcvbuf space per association.
* RFC 6 - A SCTP receiver MUST be able to receive a minimum of
* 1500 bytes in one SCTP packet.
*/
if (sk->sk_rcvbuf < SCTP_DEFAULT_MINWINDOW)
asoc->rwnd = SCTP_DEFAULT_MINWINDOW;
else
asoc->rwnd = sk->sk_rcvbuf;
asoc->a_rwnd = asoc->rwnd;
asoc->rwnd_over = 0;
/* Use my own max window until I learn something better. */
asoc->peer.rwnd = SCTP_DEFAULT_MAXWINDOW;
/* Set the sndbuf size for transmit. */
asoc->sndbuf_used = 0;
init_waitqueue_head(&asoc->wait);
asoc->c.my_vtag = sctp_generate_tag(ep);
asoc->peer.i.init_tag = 0; /* INIT needs a vtag of 0. */
asoc->c.peer_vtag = 0;
asoc->c.my_ttag = 0;
asoc->c.peer_ttag = 0;
asoc->c.my_port = ep->base.bind_addr.port;
asoc->c.initial_tsn = sctp_generate_tsn(ep);
asoc->next_tsn = asoc->c.initial_tsn;
asoc->ctsn_ack_point = asoc->next_tsn - 1;
asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
asoc->highest_sacked = asoc->ctsn_ack_point;
asoc->last_cwr_tsn = asoc->ctsn_ack_point;
asoc->unack_data = 0;
/* ADDIP Section 4.1 Asconf Chunk Procedures
*
* When an endpoint has an ASCONF signaled change to be sent to the
* remote endpoint it should do the following:
* ...
* A2) a serial number should be assigned to the chunk. The serial
* number SHOULD be a monotonically increasing number. The serial
* numbers SHOULD be initialized at the start of the
* association to the same value as the initial TSN.
*/
asoc->addip_serial = asoc->c.initial_tsn;
INIT_LIST_HEAD(&asoc->addip_chunk_list);
/* Make an empty list of remote transport addresses. */
INIT_LIST_HEAD(&asoc->peer.transport_addr_list);
asoc->peer.transport_count = 0;
/* RFC 2960 5.1 Normal Establishment of an Association
*
* After the reception of the first data chunk in an
* association the endpoint must immediately respond with a
* sack to acknowledge the data chunk. Subsequent
* acknowledgements should be done as described in Section
* 6.2.
*
* [We implement this by telling a new association that it
* already received one packet.]
*/
asoc->peer.sack_needed = 1;
/* Assume that the peer recongizes ASCONF until reported otherwise
* via an ERROR chunk.
*/
asoc->peer.asconf_capable = 1;
/* Create an input queue. */
sctp_inq_init(&asoc->base.inqueue);
sctp_inq_set_th_handler(&asoc->base.inqueue,
(void (*)(void *))sctp_assoc_bh_rcv,
asoc);
/* Create an output queue. */
sctp_outq_init(asoc, &asoc->outqueue);
if (!sctp_ulpq_init(&asoc->ulpq, asoc))
goto fail_init;
/* Set up the tsn tracking. */
sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_SIZE, 0);
asoc->need_ecne = 0;
asoc->assoc_id = 0;
/* Assume that peer would support both address types unless we are
* told otherwise.
*/
asoc->peer.ipv4_address = 1;
asoc->peer.ipv6_address = 1;
INIT_LIST_HEAD(&asoc->asocs);
asoc->autoclose = sp->autoclose;
asoc->default_stream = sp->default_stream;
asoc->default_ppid = sp->default_ppid;
asoc->default_flags = sp->default_flags;
asoc->default_context = sp->default_context;
asoc->default_timetolive = sp->default_timetolive;
return asoc;
fail_init:
sctp_endpoint_put(asoc->ep);
sock_put(asoc->base.sk);
return NULL;
}
/* Allocate and initialize a new association */
struct sctp_association *sctp_association_new(const struct sctp_endpoint *ep,
const struct sock *sk,
sctp_scope_t scope,
gfp_t gfp)
{
struct sctp_association *asoc;
asoc = t_new(struct sctp_association, gfp);
if (!asoc)
goto fail;
if (!sctp_association_init(asoc, ep, sk, scope, gfp))
goto fail_init;
asoc->base.malloced = 1;
SCTP_DBG_OBJCNT_INC(assoc);
SCTP_DEBUG_PRINTK("Created asoc %p\n", asoc);
return asoc;
fail_init:
kfree(asoc);
fail:
return NULL;
}
/* Free this association if possible. There may still be users, so
* the actual deallocation may be delayed.
*/
void sctp_association_free(struct sctp_association *asoc)
{
struct sock *sk = asoc->base.sk;
struct sctp_transport *transport;
struct list_head *pos, *temp;
int i;
list_del(&asoc->asocs);
/* Decrement the backlog value for a TCP-style listening socket. */
if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
sk->sk_ack_backlog--;
/* Mark as dead, so other users can know this structure is
* going away.
*/
asoc->base.dead = 1;
/* Dispose of any data lying around in the outqueue. */
sctp_outq_free(&asoc->outqueue);
/* Dispose of any pending messages for the upper layer. */
sctp_ulpq_free(&asoc->ulpq);
/* Dispose of any pending chunks on the inqueue. */
sctp_inq_free(&asoc->base.inqueue);
/* Free ssnmap storage. */
sctp_ssnmap_free(asoc->ssnmap);
/* Clean up the bound address list. */
sctp_bind_addr_free(&asoc->base.bind_addr);
/* Do we need to go through all of our timers and
* delete them? To be safe we will try to delete all, but we
* should be able to go through and make a guess based
* on our state.
*/
for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) {
if (timer_pending(&asoc->timers[i]) &&
del_timer(&asoc->timers[i]))
sctp_association_put(asoc);
}
/* Free peer's cached cookie. */
if (asoc->peer.cookie) {
kfree(asoc->peer.cookie);
}
/* Release the transport structures. */
list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
transport = list_entry(pos, struct sctp_transport, transports);
list_del(pos);
sctp_transport_free(transport);
}
asoc->peer.transport_count = 0;
/* Free any cached ASCONF_ACK chunk. */
if (asoc->addip_last_asconf_ack)
sctp_chunk_free(asoc->addip_last_asconf_ack);
/* Free any cached ASCONF chunk. */
if (asoc->addip_last_asconf)
sctp_chunk_free(asoc->addip_last_asconf);
sctp_association_put(asoc);
}
/* Cleanup and free up an association. */
static void sctp_association_destroy(struct sctp_association *asoc)
{
SCTP_ASSERT(asoc->base.dead, "Assoc is not dead", return);
sctp_endpoint_put(asoc->ep);
sock_put(asoc->base.sk);
if (asoc->assoc_id != 0) {
spin_lock_bh(&sctp_assocs_id_lock);
idr_remove(&sctp_assocs_id, asoc->assoc_id);
spin_unlock_bh(&sctp_assocs_id_lock);
}
if (asoc->base.malloced) {
kfree(asoc);
SCTP_DBG_OBJCNT_DEC(assoc);
}
}
/* Change the primary destination address for the peer. */
void sctp_assoc_set_primary(struct sctp_association *asoc,
struct sctp_transport *transport)
{
asoc->peer.primary_path = transport;
/* Set a default msg_name for events. */
memcpy(&asoc->peer.primary_addr, &transport->ipaddr,
sizeof(union sctp_addr));
/* If the primary path is changing, assume that the
* user wants to use this new path.
*/
if (transport->state != SCTP_INACTIVE)
asoc->peer.active_path = transport;
/*
* SFR-CACC algorithm:
* Upon the receipt of a request to change the primary
* destination address, on the data structure for the new
* primary destination, the sender MUST do the following:
*
* 1) If CHANGEOVER_ACTIVE is set, then there was a switch
* to this destination address earlier. The sender MUST set
* CYCLING_CHANGEOVER to indicate that this switch is a
* double switch to the same destination address.
*/
if (transport->cacc.changeover_active)
transport->cacc.cycling_changeover = 1;
/* 2) The sender MUST set CHANGEOVER_ACTIVE to indicate that
* a changeover has occurred.
*/
transport->cacc.changeover_active = 1;
/* 3) The sender MUST store the next TSN to be sent in
* next_tsn_at_change.
*/
transport->cacc.next_tsn_at_change = asoc->next_tsn;
}
/* Remove a transport from an association. */
void sctp_assoc_rm_peer(struct sctp_association *asoc,
struct sctp_transport *peer)
{
struct list_head *pos;
struct sctp_transport *transport;
SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_rm_peer:association %p addr: ",
" port: %d\n",
asoc,
(&peer->ipaddr),
peer->ipaddr.v4.sin_port);
/* If we are to remove the current retran_path, update it
* to the next peer before removing this peer from the list.
*/
if (asoc->peer.retran_path == peer)
sctp_assoc_update_retran_path(asoc);
/* Remove this peer from the list. */
list_del(&peer->transports);
/* Get the first transport of asoc. */
pos = asoc->peer.transport_addr_list.next;
transport = list_entry(pos, struct sctp_transport, transports);
/* Update any entries that match the peer to be deleted. */
if (asoc->peer.primary_path == peer)
sctp_assoc_set_primary(asoc, transport);
if (asoc->peer.active_path == peer)
asoc->peer.active_path = transport;
if (asoc->peer.last_data_from == peer)
asoc->peer.last_data_from = transport;
/* If we remove the transport an INIT was last sent to, set it to
* NULL. Combined with the update of the retran path above, this
* will cause the next INIT to be sent to the next available
* transport, maintaining the cycle.
*/
if (asoc->init_last_sent_to == peer)
asoc->init_last_sent_to = NULL;
asoc->peer.transport_count--;
sctp_transport_free(peer);
}
/* Add a transport address to an association. */
struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc,
const union sctp_addr *addr,
const gfp_t gfp,
const int peer_state)
{
struct sctp_transport *peer;
struct sctp_sock *sp;
unsigned short port;
sp = sctp_sk(asoc->base.sk);
/* AF_INET and AF_INET6 share common port field. */
port = addr->v4.sin_port;
SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_add_peer:association %p addr: ",
" port: %d state:%s\n",
asoc,
addr,
addr->v4.sin_port,
peer_state == SCTP_UNKNOWN?"UNKNOWN":"ACTIVE");
/* Set the port if it has not been set yet. */
if (0 == asoc->peer.port)
asoc->peer.port = port;
/* Check to see if this is a duplicate. */
peer = sctp_assoc_lookup_paddr(asoc, addr);
if (peer) {
if (peer_state == SCTP_ACTIVE &&
peer->state == SCTP_UNKNOWN)
peer->state = SCTP_ACTIVE;
return peer;
}
peer = sctp_transport_new(addr, gfp);
if (!peer)
return NULL;
sctp_transport_set_owner(peer, asoc);
/* Initialize the pmtu of the transport. */
sctp_transport_pmtu(peer);
/* If this is the first transport addr on this association,
* initialize the association PMTU to the peer's PMTU.
* If not and the current association PMTU is higher than the new
* peer's PMTU, reset the association PMTU to the new peer's PMTU.
*/
if (asoc->pmtu)
asoc->pmtu = min_t(int, peer->pmtu, asoc->pmtu);
else
asoc->pmtu = peer->pmtu;
SCTP_DEBUG_PRINTK("sctp_assoc_add_peer:association %p PMTU set to "
"%d\n", asoc, asoc->pmtu);
asoc->frag_point = sctp_frag_point(sp, asoc->pmtu);
/* The asoc->peer.port might not be meaningful yet, but
* initialize the packet structure anyway.
*/
sctp_packet_init(&peer->packet, peer, asoc->base.bind_addr.port,
asoc->peer.port);
/* 7.2.1 Slow-Start
*
* o The initial cwnd before DATA transmission or after a sufficiently
* long idle period MUST be set to
* min(4*MTU, max(2*MTU, 4380 bytes))
*
* o The initial value of ssthresh MAY be arbitrarily high
* (for example, implementations MAY use the size of the
* receiver advertised window).
*/
peer->cwnd = min(4*asoc->pmtu, max_t(__u32, 2*asoc->pmtu, 4380));
/* At this point, we may not have the receiver's advertised window,
* so initialize ssthresh to the default value and it will be set
* later when we process the INIT.
*/
peer->ssthresh = SCTP_DEFAULT_MAXWINDOW;
peer->partial_bytes_acked = 0;
peer->flight_size = 0;
/* By default, enable heartbeat for peer address. */
peer->hb_allowed = 1;
/* Initialize the peer's heartbeat interval based on the
* sock configured value.
*/
peer->hb_interval = msecs_to_jiffies(sp->paddrparam.spp_hbinterval);
/* Set the path max_retrans. */
peer->max_retrans = sp->paddrparam.spp_pathmaxrxt;
/* Set the transport's RTO.initial value */
peer->rto = asoc->rto_initial;
/* Set the peer's active state. */
peer->state = peer_state;
/* Attach the remote transport to our asoc. */
list_add_tail(&peer->transports, &asoc->peer.transport_addr_list);
asoc->peer.transport_count++;
/* If we do not yet have a primary path, set one. */
if (!asoc->peer.primary_path) {
sctp_assoc_set_primary(asoc, peer);
asoc->peer.retran_path = peer;
}
if (asoc->peer.active_path == asoc->peer.retran_path) {
asoc->peer.retran_path = peer;
}
return peer;
}
/* Delete a transport address from an association. */
void sctp_assoc_del_peer(struct sctp_association *asoc,
const union sctp_addr *addr)
{
struct list_head *pos;
struct list_head *temp;
struct sctp_transport *transport;
list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
transport = list_entry(pos, struct sctp_transport, transports);
if (sctp_cmp_addr_exact(addr, &transport->ipaddr)) {
/* Do book keeping for removing the peer and free it. */
sctp_assoc_rm_peer(asoc, transport);
break;
}
}
}
/* Lookup a transport by address. */
struct sctp_transport *sctp_assoc_lookup_paddr(
const struct sctp_association *asoc,
const union sctp_addr *address)
{
struct sctp_transport *t;
struct list_head *pos;
/* Cycle through all transports searching for a peer address. */
list_for_each(pos, &asoc->peer.transport_addr_list) {
t = list_entry(pos, struct sctp_transport, transports);
if (sctp_cmp_addr_exact(address, &t->ipaddr))
return t;
}
return NULL;
}
/* Engage in transport control operations.
* Mark the transport up or down and send a notification to the user.
* Select and update the new active and retran paths.
*/
void sctp_assoc_control_transport(struct sctp_association *asoc,
struct sctp_transport *transport,
sctp_transport_cmd_t command,
sctp_sn_error_t error)
{
struct sctp_transport *t = NULL;
struct sctp_transport *first;
struct sctp_transport *second;
struct sctp_ulpevent *event;
struct list_head *pos;
int spc_state = 0;
/* Record the transition on the transport. */
switch (command) {
case SCTP_TRANSPORT_UP:
transport->state = SCTP_ACTIVE;
spc_state = SCTP_ADDR_AVAILABLE;
break;
case SCTP_TRANSPORT_DOWN:
transport->state = SCTP_INACTIVE;
spc_state = SCTP_ADDR_UNREACHABLE;
break;
default:
return;
};
/* Generate and send a SCTP_PEER_ADDR_CHANGE notification to the
* user.
*/
event = sctp_ulpevent_make_peer_addr_change(asoc,
(struct sockaddr_storage *) &transport->ipaddr,
0, spc_state, error, GFP_ATOMIC);
if (event)
sctp_ulpq_tail_event(&asoc->ulpq, event);
/* Select new active and retran paths. */
/* Look for the two most recently used active transports.
*
* This code produces the wrong ordering whenever jiffies
* rolls over, but we still get usable transports, so we don't
* worry about it.
*/
first = NULL; second = NULL;
list_for_each(pos, &asoc->peer.transport_addr_list) {
t = list_entry(pos, struct sctp_transport, transports);
if (t->state == SCTP_INACTIVE)
continue;
if (!first || t->last_time_heard > first->last_time_heard) {
second = first;
first = t;
}
if (!second || t->last_time_heard > second->last_time_heard)
second = t;
}
/* RFC 2960 6.4 Multi-Homed SCTP Endpoints
*
* By default, an endpoint should always transmit to the
* primary path, unless the SCTP user explicitly specifies the
* destination transport address (and possibly source
* transport address) to use.
*
* [If the primary is active but not most recent, bump the most
* recently used transport.]
*/
if (asoc->peer.primary_path->state != SCTP_INACTIVE &&
first != asoc->peer.primary_path) {
second = first;
first = asoc->peer.primary_path;
}
/* If we failed to find a usable transport, just camp on the
* primary, even if it is inactive.
*/
if (!first) {
first = asoc->peer.primary_path;
second = asoc->peer.primary_path;
}
/* Set the active and retran transports. */
asoc->peer.active_path = first;
asoc->peer.retran_path = second;
}
/* Hold a reference to an association. */
void sctp_association_hold(struct sctp_association *asoc)
{
atomic_inc(&asoc->base.refcnt);
}
/* Release a reference to an association and cleanup
* if there are no more references.
*/
void sctp_association_put(struct sctp_association *asoc)
{
if (atomic_dec_and_test(&asoc->base.refcnt))
sctp_association_destroy(asoc);
}
/* Allocate the next TSN, Transmission Sequence Number, for the given
* association.
*/
__u32 sctp_association_get_next_tsn(struct sctp_association *asoc)
{
/* From Section 1.6 Serial Number Arithmetic:
* Transmission Sequence Numbers wrap around when they reach
* 2**32 - 1. That is, the next TSN a DATA chunk MUST use
* after transmitting TSN = 2*32 - 1 is TSN = 0.
*/
__u32 retval = asoc->next_tsn;
asoc->next_tsn++;
asoc->unack_data++;
return retval;
}
/* Compare two addresses to see if they match. Wildcard addresses
* only match themselves.
*/
int sctp_cmp_addr_exact(const union sctp_addr *ss1,
const union sctp_addr *ss2)
{
struct sctp_af *af;
af = sctp_get_af_specific(ss1->sa.sa_family);
if (unlikely(!af))
return 0;
return af->cmp_addr(ss1, ss2);
}
/* Return an ecne chunk to get prepended to a packet.
* Note: We are sly and return a shared, prealloced chunk. FIXME:
* No we don't, but we could/should.
*/
struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc)
{
struct sctp_chunk *chunk;
/* Send ECNE if needed.
* Not being able to allocate a chunk here is not deadly.
*/
if (asoc->need_ecne)
chunk = sctp_make_ecne(asoc, asoc->last_ecne_tsn);
else
chunk = NULL;
return chunk;
}
/*
* Find which transport this TSN was sent on.
*/
struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *asoc,
__u32 tsn)
{
struct sctp_transport *active;
struct sctp_transport *match;
struct list_head *entry, *pos;
struct sctp_transport *transport;
struct sctp_chunk *chunk;
__u32 key = htonl(tsn);
match = NULL;
/*
* FIXME: In general, find a more efficient data structure for
* searching.
*/
/*
* The general strategy is to search each transport's transmitted
* list. Return which transport this TSN lives on.
*
* Let's be hopeful and check the active_path first.
* Another optimization would be to know if there is only one
* outbound path and not have to look for the TSN at all.
*
*/
active = asoc->peer.active_path;
list_for_each(entry, &active->transmitted) {
chunk = list_entry(entry, struct sctp_chunk, transmitted_list);
if (key == chunk->subh.data_hdr->tsn) {
match = active;
goto out;
}
}
/* If not found, go search all the other transports. */
list_for_each(pos, &asoc->peer.transport_addr_list) {
transport = list_entry(pos, struct sctp_transport, transports);
if (transport == active)
break;
list_for_each(entry, &transport->transmitted) {
chunk = list_entry(entry, struct sctp_chunk,
transmitted_list);
if (key == chunk->subh.data_hdr->tsn) {
match = transport;
goto out;
}
}
}
out:
return match;
}
/* Is this the association we are looking for? */
struct sctp_transport *sctp_assoc_is_match(struct sctp_association *asoc,
const union sctp_addr *laddr,
const union sctp_addr *paddr)
{
struct sctp_transport *transport;
sctp_read_lock(&asoc->base.addr_lock);
if ((asoc->base.bind_addr.port == laddr->v4.sin_port) &&
(asoc->peer.port == paddr->v4.sin_port)) {
transport = sctp_assoc_lookup_paddr(asoc, paddr);
if (!transport)
goto out;
if (sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
sctp_sk(asoc->base.sk)))
goto out;
}
transport = NULL;
out:
sctp_read_unlock(&asoc->base.addr_lock);
return transport;
}
/* Do delayed input processing. This is scheduled by sctp_rcv(). */
static void sctp_assoc_bh_rcv(struct sctp_association *asoc)
{
struct sctp_endpoint *ep;
struct sctp_chunk *chunk;
struct sock *sk;
struct sctp_inq *inqueue;
int state;
sctp_subtype_t subtype;
int error = 0;
/* The association should be held so we should be safe. */
ep = asoc->ep;
sk = asoc->base.sk;
inqueue = &asoc->base.inqueue;
sctp_association_hold(asoc);
while (NULL != (chunk = sctp_inq_pop(inqueue))) {
state = asoc->state;
subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
/* Remember where the last DATA chunk came from so we
* know where to send the SACK.
*/
if (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;
/* Run through the state machine. */
error = sctp_do_sm(SCTP_EVENT_T_CHUNK, subtype,
state, ep, asoc, chunk, GFP_ATOMIC);
/* Check to see if the association is freed in response to
* the incoming chunk. If so, get out of the while loop.
*/
if (asoc->base.dead)
break;
/* If there is an error on chunk, discard this packet. */
if (error && chunk)
chunk->pdiscard = 1;
}
sctp_association_put(asoc);
}
/* This routine moves an association from its old sk to a new sk. */
void sctp_assoc_migrate(struct sctp_association *assoc, struct sock *newsk)
{
struct sctp_sock *newsp = sctp_sk(newsk);
struct sock *oldsk = assoc->base.sk;
/* Delete the association from the old endpoint's list of
* associations.
*/
list_del_init(&assoc->asocs);
/* Decrement the backlog value for a TCP-style socket. */
if (sctp_style(oldsk, TCP))
oldsk->sk_ack_backlog--;
/* Release references to the old endpoint and the sock. */
sctp_endpoint_put(assoc->ep);
sock_put(assoc->base.sk);
/* Get a reference to the new endpoint. */
assoc->ep = newsp->ep;
sctp_endpoint_hold(assoc->ep);
/* Get a reference to the new sock. */
assoc->base.sk = newsk;
sock_hold(assoc->base.sk);
/* Add the association to the new endpoint's list of associations. */
sctp_endpoint_add_asoc(newsp->ep, assoc);
}
/* Update an association (possibly from unexpected COOKIE-ECHO processing). */
void sctp_assoc_update(struct sctp_association *asoc,
struct sctp_association *new)
{
struct sctp_transport *trans;
struct list_head *pos, *temp;
/* Copy in new parameters of peer. */
asoc->c = new->c;
asoc->peer.rwnd = new->peer.rwnd;
asoc->peer.sack_needed = new->peer.sack_needed;
asoc->peer.i = new->peer.i;
sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_SIZE,
asoc->peer.i.initial_tsn);
/* Remove any peer addresses not present in the new association. */
list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
trans = list_entry(pos, struct sctp_transport, transports);
if (!sctp_assoc_lookup_paddr(new, &trans->ipaddr))
sctp_assoc_del_peer(asoc, &trans->ipaddr);
}
/* If the case is A (association restart), use
* initial_tsn as next_tsn. If the case is B, use
* current next_tsn in case data sent to peer
* has been discarded and needs retransmission.
*/
if (asoc->state >= SCTP_STATE_ESTABLISHED) {
asoc->next_tsn = new->next_tsn;
asoc->ctsn_ack_point = new->ctsn_ack_point;
asoc->adv_peer_ack_point = new->adv_peer_ack_point;
/* Reinitialize SSN for both local streams
* and peer's streams.
*/
sctp_ssnmap_clear(asoc->ssnmap);
} else {
/* Add any peer addresses from the new association. */
list_for_each(pos, &new->peer.transport_addr_list) {
trans = list_entry(pos, struct sctp_transport,
transports);
if (!sctp_assoc_lookup_paddr(asoc, &trans->ipaddr))
sctp_assoc_add_peer(asoc, &trans->ipaddr,
GFP_ATOMIC, SCTP_ACTIVE);
}
asoc->ctsn_ack_point = asoc->next_tsn - 1;
asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
if (!asoc->ssnmap) {
/* Move the ssnmap. */
asoc->ssnmap = new->ssnmap;
new->ssnmap = NULL;
}
}
}
/* Update the retran path for sending a retransmitted packet.
* Round-robin through the active transports, else round-robin
* through the inactive transports as this is the next best thing
* we can try.
*/
void sctp_assoc_update_retran_path(struct sctp_association *asoc)
{
struct sctp_transport *t, *next;
struct list_head *head = &asoc->peer.transport_addr_list;
struct list_head *pos;
/* Find the next transport in a round-robin fashion. */
t = asoc->peer.retran_path;
pos = &t->transports;
next = NULL;
while (1) {
/* Skip the head. */
if (pos->next == head)
pos = head->next;
else
pos = pos->next;
t = list_entry(pos, struct sctp_transport, transports);
/* Try to find an active transport. */
if (t->state != SCTP_INACTIVE) {
break;
} else {
/* Keep track of the next transport in case
* we don't find any active transport.
*/
if (!next)
next = t;
}
/* We have exhausted the list, but didn't find any
* other active transports. If so, use the next
* transport.
*/
if (t == asoc->peer.retran_path) {
t = next;
break;
}
}
asoc->peer.retran_path = t;
SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_update_retran_path:association"
" %p addr: ",
" port: %d\n",
asoc,
(&t->ipaddr),
t->ipaddr.v4.sin_port);
}
/* Choose the transport for sending a INIT packet. */
struct sctp_transport *sctp_assoc_choose_init_transport(
struct sctp_association *asoc)
{
struct sctp_transport *t;
/* Use the retran path. If the last INIT was sent over the
* retran path, update the retran path and use it.
*/
if (!asoc->init_last_sent_to) {
t = asoc->peer.active_path;
} else {
if (asoc->init_last_sent_to == asoc->peer.retran_path)
sctp_assoc_update_retran_path(asoc);
t = asoc->peer.retran_path;
}
SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_update_retran_path:association"
" %p addr: ",
" port: %d\n",
asoc,
(&t->ipaddr),
t->ipaddr.v4.sin_port);
return t;
}
/* Choose the transport for sending a SHUTDOWN packet. */
struct sctp_transport *sctp_assoc_choose_shutdown_transport(
struct sctp_association *asoc)
{
/* If this is the first time SHUTDOWN is sent, use the active path,
* else use the retran path. If the last SHUTDOWN was sent over the
* retran path, update the retran path and use it.
*/
if (!asoc->shutdown_last_sent_to)
return asoc->peer.active_path;
else {
if (asoc->shutdown_last_sent_to == asoc->peer.retran_path)
sctp_assoc_update_retran_path(asoc);
return asoc->peer.retran_path;
}
}
/* Update the association's pmtu and frag_point by going through all the
* transports. This routine is called when a transport's PMTU has changed.
*/
void sctp_assoc_sync_pmtu(struct sctp_association *asoc)
{
struct sctp_transport *t;
struct list_head *pos;
__u32 pmtu = 0;
if (!asoc)
return;
/* Get the lowest pmtu of all the transports. */
list_for_each(pos, &asoc->peer.transport_addr_list) {
t = list_entry(pos, struct sctp_transport, transports);
if (!pmtu || (t->pmtu < pmtu))
pmtu = t->pmtu;
}
if (pmtu) {
struct sctp_sock *sp = sctp_sk(asoc->base.sk);
asoc->pmtu = pmtu;
asoc->frag_point = sctp_frag_point(sp, pmtu);
}
SCTP_DEBUG_PRINTK("%s: asoc:%p, pmtu:%d, frag_point:%d\n",
__FUNCTION__, asoc, asoc->pmtu, asoc->frag_point);
}
/* Should we send a SACK to update our peer? */
static inline int sctp_peer_needs_update(struct sctp_association *asoc)
{
switch (asoc->state) {
case SCTP_STATE_ESTABLISHED:
case SCTP_STATE_SHUTDOWN_PENDING:
case SCTP_STATE_SHUTDOWN_RECEIVED:
case SCTP_STATE_SHUTDOWN_SENT:
if ((asoc->rwnd > asoc->a_rwnd) &&
((asoc->rwnd - asoc->a_rwnd) >=
min_t(__u32, (asoc->base.sk->sk_rcvbuf >> 1), asoc->pmtu)))
return 1;
break;
default:
break;
}
return 0;
}
/* Increase asoc's rwnd by len and send any window update SACK if needed. */
void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned len)
{
struct sctp_chunk *sack;
struct timer_list *timer;
if (asoc->rwnd_over) {
if (asoc->rwnd_over >= len) {
asoc->rwnd_over -= len;
} else {
asoc->rwnd += (len - asoc->rwnd_over);
asoc->rwnd_over = 0;
}
} else {
asoc->rwnd += len;
}
SCTP_DEBUG_PRINTK("%s: asoc %p rwnd increased by %d to (%u, %u) "
"- %u\n", __FUNCTION__, asoc, len, asoc->rwnd,
asoc->rwnd_over, asoc->a_rwnd);
/* Send a window update SACK if the rwnd has increased by at least the
* minimum of the association's PMTU and half of the receive buffer.
* The algorithm used is similar to the one described in
* Section 4.2.3.3 of RFC 1122.
*/
if (sctp_peer_needs_update(asoc)) {
asoc->a_rwnd = asoc->rwnd;
SCTP_DEBUG_PRINTK("%s: Sending window update SACK- asoc: %p "
"rwnd: %u a_rwnd: %u\n", __FUNCTION__,
asoc, asoc->rwnd, asoc->a_rwnd);
sack = sctp_make_sack(asoc);
if (!sack)
return;
asoc->peer.sack_needed = 0;
sctp_outq_tail(&asoc->outqueue, sack);
/* Stop the SACK timer. */
timer = &asoc->timers[SCTP_EVENT_TIMEOUT_SACK];
if (timer_pending(timer) && del_timer(timer))
sctp_association_put(asoc);
}
}
/* Decrease asoc's rwnd by len. */
void sctp_assoc_rwnd_decrease(struct sctp_association *asoc, unsigned len)
{
SCTP_ASSERT(asoc->rwnd, "rwnd zero", return);
SCTP_ASSERT(!asoc->rwnd_over, "rwnd_over not zero", return);
if (asoc->rwnd >= len) {
asoc->rwnd -= len;
} else {
asoc->rwnd_over = len - asoc->rwnd;
asoc->rwnd = 0;
}
SCTP_DEBUG_PRINTK("%s: asoc %p rwnd decreased by %d to (%u, %u)\n",
__FUNCTION__, asoc, len, asoc->rwnd,
asoc->rwnd_over);
}
/* Build the bind address list for the association based on info from the
* local endpoint and the remote peer.
*/
int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
gfp_t gfp)
{
sctp_scope_t scope;
int flags;
/* Use scoping rules to determine the subset of addresses from
* the endpoint.
*/
scope = sctp_scope(&asoc->peer.active_path->ipaddr);
flags = (PF_INET6 == asoc->base.sk->sk_family) ? SCTP_ADDR6_ALLOWED : 0;
if (asoc->peer.ipv4_address)
flags |= SCTP_ADDR4_PEERSUPP;
if (asoc->peer.ipv6_address)
flags |= SCTP_ADDR6_PEERSUPP;
return sctp_bind_addr_copy(&asoc->base.bind_addr,
&asoc->ep->base.bind_addr,
scope, gfp, flags);
}
/* Build the association's bind address list from the cookie. */
int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *asoc,
struct sctp_cookie *cookie,
gfp_t gfp)
{
int var_size2 = ntohs(cookie->peer_init->chunk_hdr.length);
int var_size3 = cookie->raw_addr_list_len;
__u8 *raw = (__u8 *)cookie->peer_init + var_size2;
return sctp_raw_to_bind_addrs(&asoc->base.bind_addr, raw, var_size3,
asoc->ep->base.bind_addr.port, gfp);
}
/* Lookup laddr in the bind address list of an association. */
int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
const union sctp_addr *laddr)
{
int found;
sctp_read_lock(&asoc->base.addr_lock);
if ((asoc->base.bind_addr.port == ntohs(laddr->v4.sin_port)) &&
sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
sctp_sk(asoc->base.sk))) {
found = 1;
goto out;
}
found = 0;
out:
sctp_read_unlock(&asoc->base.addr_lock);
return found;
}