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sm_sideeffect.c
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/* SCTP kernel implementation
* (C) Copyright IBM Corp. 2001, 2004
* Copyright (c) 1999 Cisco, Inc.
* Copyright (c) 1999-2001 Motorola, Inc.
*
* This file is part of the SCTP kernel implementation
*
* These functions work with the state functions in sctp_sm_statefuns.c
* to implement that state operations. These functions implement the
* steps which require modifying existing data structures.
*
* This SCTP 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.
*
* This SCTP 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>
* Hui Huang <hui.huang@nokia.com>
* Dajiang Zhang <dajiang.zhang@nokia.com>
* Daisy Chang <daisyc@us.ibm.com>
* Sridhar Samudrala <sri@us.ibm.com>
* Ardelle Fan <ardelle.fan@intel.com>
*
* Any bugs reported given to us we will try to fix... any fixes shared will
* be incorporated into the next SCTP release.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/skbuff.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/ip.h>
#include <linux/gfp.h>
#include <net/sock.h>
#include <net/sctp/sctp.h>
#include <net/sctp/sm.h>
static int sctp_cmd_interpreter(sctp_event_t event_type,
sctp_subtype_t subtype,
sctp_state_t state,
struct sctp_endpoint *ep,
struct sctp_association *asoc,
void *event_arg,
sctp_disposition_t status,
sctp_cmd_seq_t *commands,
gfp_t gfp);
static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
sctp_state_t state,
struct sctp_endpoint *ep,
struct sctp_association *asoc,
void *event_arg,
sctp_disposition_t status,
sctp_cmd_seq_t *commands,
gfp_t gfp);
/********************************************************************
* Helper functions
********************************************************************/
/* A helper function for delayed processing of INET ECN CE bit. */
static void sctp_do_ecn_ce_work(struct sctp_association *asoc,
__u32 lowest_tsn)
{
/* Save the TSN away for comparison when we receive CWR */
asoc->last_ecne_tsn = lowest_tsn;
asoc->need_ecne = 1;
}
/* Helper function for delayed processing of SCTP ECNE chunk. */
/* RFC 2960 Appendix A
*
* RFC 2481 details a specific bit for a sender to send in
* the header of its next outbound TCP segment to indicate to
* its peer that it has reduced its congestion window. This
* is termed the CWR bit. For SCTP the same indication is made
* by including the CWR chunk. This chunk contains one data
* element, i.e. the TSN number that was sent in the ECNE chunk.
* This element represents the lowest TSN number in the datagram
* that was originally marked with the CE bit.
*/
static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
__u32 lowest_tsn,
struct sctp_chunk *chunk)
{
struct sctp_chunk *repl;
/* Our previously transmitted packet ran into some congestion
* so we should take action by reducing cwnd and ssthresh
* and then ACK our peer that we we've done so by
* sending a CWR.
*/
/* First, try to determine if we want to actually lower
* our cwnd variables. Only lower them if the ECNE looks more
* recent than the last response.
*/
if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) {
struct sctp_transport *transport;
/* Find which transport's congestion variables
* need to be adjusted.
*/
transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn);
/* Update the congestion variables. */
if (transport)
sctp_transport_lower_cwnd(transport,
SCTP_LOWER_CWND_ECNE);
asoc->last_cwr_tsn = lowest_tsn;
}
/* Always try to quiet the other end. In case of lost CWR,
* resend last_cwr_tsn.
*/
repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk);
/* If we run out of memory, it will look like a lost CWR. We'll
* get back in sync eventually.
*/
return repl;
}
/* Helper function to do delayed processing of ECN CWR chunk. */
static void sctp_do_ecn_cwr_work(struct sctp_association *asoc,
__u32 lowest_tsn)
{
/* Turn off ECNE getting auto-prepended to every outgoing
* packet
*/
asoc->need_ecne = 0;
}
/* Generate SACK if necessary. We call this at the end of a packet. */
static int sctp_gen_sack(struct sctp_association *asoc, int force,
sctp_cmd_seq_t *commands)
{
__u32 ctsn, max_tsn_seen;
struct sctp_chunk *sack;
struct sctp_transport *trans = asoc->peer.last_data_from;
int error = 0;
if (force ||
(!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) ||
(trans && (trans->param_flags & SPP_SACKDELAY_DISABLE)))
asoc->peer.sack_needed = 1;
ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
/* From 12.2 Parameters necessary per association (i.e. the TCB):
*
* Ack State : This flag indicates if the next received packet
* : is to be responded to with a SACK. ...
* : When DATA chunks are out of order, SACK's
* : are not delayed (see Section 6).
*
* [This is actually not mentioned in Section 6, but we
* implement it here anyway. --piggy]
*/
if (max_tsn_seen != ctsn)
asoc->peer.sack_needed = 1;
/* From 6.2 Acknowledgement on Reception of DATA Chunks:
*
* Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
* an acknowledgement SHOULD be generated for at least every
* second packet (not every second DATA chunk) received, and
* SHOULD be generated within 200 ms of the arrival of any
* unacknowledged DATA chunk. ...
*/
if (!asoc->peer.sack_needed) {
asoc->peer.sack_cnt++;
/* Set the SACK delay timeout based on the
* SACK delay for the last transport
* data was received from, or the default
* for the association.
*/
if (trans) {
/* We will need a SACK for the next packet. */
if (asoc->peer.sack_cnt >= trans->sackfreq - 1)
asoc->peer.sack_needed = 1;
asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
trans->sackdelay;
} else {
/* We will need a SACK for the next packet. */
if (asoc->peer.sack_cnt >= asoc->sackfreq - 1)
asoc->peer.sack_needed = 1;
asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
asoc->sackdelay;
}
/* Restart the SACK timer. */
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
} else {
asoc->a_rwnd = asoc->rwnd;
sack = sctp_make_sack(asoc);
if (!sack)
goto nomem;
asoc->peer.sack_needed = 0;
asoc->peer.sack_cnt = 0;
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack));
/* Stop the SACK timer. */
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
}
return error;
nomem:
error = -ENOMEM;
return error;
}
/* When the T3-RTX timer expires, it calls this function to create the
* relevant state machine event.
*/
void sctp_generate_t3_rtx_event(unsigned long peer)
{
int error;
struct sctp_transport *transport = (struct sctp_transport *) peer;
struct sctp_association *asoc = transport->asoc;
/* Check whether a task is in the sock. */
sctp_bh_lock_sock(asoc->base.sk);
if (sock_owned_by_user(asoc->base.sk)) {
SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __func__);
/* Try again later. */
if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
sctp_transport_hold(transport);
goto out_unlock;
}
/* Is this transport really dead and just waiting around for
* the timer to let go of the reference?
*/
if (transport->dead)
goto out_unlock;
/* Run through the state machine. */
error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
asoc->state,
asoc->ep, asoc,
transport, GFP_ATOMIC);
if (error)
asoc->base.sk->sk_err = -error;
out_unlock:
sctp_bh_unlock_sock(asoc->base.sk);
sctp_transport_put(transport);
}
/* This is a sa interface for producing timeout events. It works
* for timeouts which use the association as their parameter.
*/
static void sctp_generate_timeout_event(struct sctp_association *asoc,
sctp_event_timeout_t timeout_type)
{
int error = 0;
sctp_bh_lock_sock(asoc->base.sk);
if (sock_owned_by_user(asoc->base.sk)) {
SCTP_DEBUG_PRINTK("%s:Sock is busy: timer %d\n",
__func__,
timeout_type);
/* Try again later. */
if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
sctp_association_hold(asoc);
goto out_unlock;
}
/* Is this association really dead and just waiting around for
* the timer to let go of the reference?
*/
if (asoc->base.dead)
goto out_unlock;
/* Run through the state machine. */
error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
SCTP_ST_TIMEOUT(timeout_type),
asoc->state, asoc->ep, asoc,
(void *)timeout_type, GFP_ATOMIC);
if (error)
asoc->base.sk->sk_err = -error;
out_unlock:
sctp_bh_unlock_sock(asoc->base.sk);
sctp_association_put(asoc);
}
static void sctp_generate_t1_cookie_event(unsigned long data)
{
struct sctp_association *asoc = (struct sctp_association *) data;
sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
}
static void sctp_generate_t1_init_event(unsigned long data)
{
struct sctp_association *asoc = (struct sctp_association *) data;
sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
}
static void sctp_generate_t2_shutdown_event(unsigned long data)
{
struct sctp_association *asoc = (struct sctp_association *) data;
sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
}
static void sctp_generate_t4_rto_event(unsigned long data)
{
struct sctp_association *asoc = (struct sctp_association *) data;
sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
}
static void sctp_generate_t5_shutdown_guard_event(unsigned long data)
{
struct sctp_association *asoc = (struct sctp_association *)data;
sctp_generate_timeout_event(asoc,
SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
} /* sctp_generate_t5_shutdown_guard_event() */
static void sctp_generate_autoclose_event(unsigned long data)
{
struct sctp_association *asoc = (struct sctp_association *) data;
sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
}
/* Generate a heart beat event. If the sock is busy, reschedule. Make
* sure that the transport is still valid.
*/
void sctp_generate_heartbeat_event(unsigned long data)
{
int error = 0;
struct sctp_transport *transport = (struct sctp_transport *) data;
struct sctp_association *asoc = transport->asoc;
sctp_bh_lock_sock(asoc->base.sk);
if (sock_owned_by_user(asoc->base.sk)) {
SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __func__);
/* Try again later. */
if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
sctp_transport_hold(transport);
goto out_unlock;
}
/* Is this structure just waiting around for us to actually
* get destroyed?
*/
if (transport->dead)
goto out_unlock;
error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
asoc->state, asoc->ep, asoc,
transport, GFP_ATOMIC);
if (error)
asoc->base.sk->sk_err = -error;
out_unlock:
sctp_bh_unlock_sock(asoc->base.sk);
sctp_transport_put(transport);
}
/* Handle the timeout of the ICMP protocol unreachable timer. Trigger
* the correct state machine transition that will close the association.
*/
void sctp_generate_proto_unreach_event(unsigned long data)
{
struct sctp_transport *transport = (struct sctp_transport *) data;
struct sctp_association *asoc = transport->asoc;
sctp_bh_lock_sock(asoc->base.sk);
if (sock_owned_by_user(asoc->base.sk)) {
SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __func__);
/* Try again later. */
if (!mod_timer(&transport->proto_unreach_timer,
jiffies + (HZ/20)))
sctp_association_hold(asoc);
goto out_unlock;
}
/* Is this structure just waiting around for us to actually
* get destroyed?
*/
if (asoc->base.dead)
goto out_unlock;
sctp_do_sm(SCTP_EVENT_T_OTHER,
SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
asoc->state, asoc->ep, asoc, transport, GFP_ATOMIC);
out_unlock:
sctp_bh_unlock_sock(asoc->base.sk);
sctp_association_put(asoc);
}
/* Inject a SACK Timeout event into the state machine. */
static void sctp_generate_sack_event(unsigned long data)
{
struct sctp_association *asoc = (struct sctp_association *) data;
sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
}
sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
NULL,
sctp_generate_t1_cookie_event,
sctp_generate_t1_init_event,
sctp_generate_t2_shutdown_event,
NULL,
sctp_generate_t4_rto_event,
sctp_generate_t5_shutdown_guard_event,
NULL,
sctp_generate_sack_event,
sctp_generate_autoclose_event,
};
/* RFC 2960 8.2 Path Failure Detection
*
* When its peer endpoint is multi-homed, an endpoint should keep a
* error counter for each of the destination transport addresses of the
* peer endpoint.
*
* Each time the T3-rtx timer expires on any address, or when a
* HEARTBEAT sent to an idle address is not acknowledged within a RTO,
* the error counter of that destination address will be incremented.
* When the value in the error counter exceeds the protocol parameter
* 'Path.Max.Retrans' of that destination address, the endpoint should
* mark the destination transport address as inactive, and a
* notification SHOULD be sent to the upper layer.
*
*/
static void sctp_do_8_2_transport_strike(struct sctp_association *asoc,
struct sctp_transport *transport,
int is_hb)
{
/* The check for association's overall error counter exceeding the
* threshold is done in the state function.
*/
/* We are here due to a timer expiration. If the timer was
* not a HEARTBEAT, then normal error tracking is done.
* If the timer was a heartbeat, we only increment error counts
* when we already have an outstanding HEARTBEAT that has not
* been acknowledged.
* Additionally, some tranport states inhibit error increments.
*/
if (!is_hb) {
asoc->overall_error_count++;
if (transport->state != SCTP_INACTIVE)
transport->error_count++;
} else if (transport->hb_sent) {
if (transport->state != SCTP_UNCONFIRMED)
asoc->overall_error_count++;
if (transport->state != SCTP_INACTIVE)
transport->error_count++;
}
if (transport->state != SCTP_INACTIVE &&
(transport->error_count > transport->pathmaxrxt)) {
SCTP_DEBUG_PRINTK_IPADDR("transport_strike:association %p",
" transport IP: port:%d failed.\n",
asoc,
(&transport->ipaddr),
ntohs(transport->ipaddr.v4.sin_port));
sctp_assoc_control_transport(asoc, transport,
SCTP_TRANSPORT_DOWN,
SCTP_FAILED_THRESHOLD);
}
/* E2) For the destination address for which the timer
* expires, set RTO <- RTO * 2 ("back off the timer"). The
* maximum value discussed in rule C7 above (RTO.max) may be
* used to provide an upper bound to this doubling operation.
*
* Special Case: the first HB doesn't trigger exponential backoff.
* The first unacknowledged HB triggers it. We do this with a flag
* that indicates that we have an outstanding HB.
*/
if (!is_hb || transport->hb_sent) {
transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
}
}
/* Worker routine to handle INIT command failure. */
static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands,
struct sctp_association *asoc,
unsigned error)
{
struct sctp_ulpevent *event;
event = sctp_ulpevent_make_assoc_change(asoc,0, SCTP_CANT_STR_ASSOC,
(__u16)error, 0, 0, NULL,
GFP_ATOMIC);
if (event)
sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
SCTP_ULPEVENT(event));
sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
SCTP_STATE(SCTP_STATE_CLOSED));
/* SEND_FAILED sent later when cleaning up the association. */
asoc->outqueue.error = error;
sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
}
/* Worker routine to handle SCTP_CMD_ASSOC_FAILED. */
static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
struct sctp_association *asoc,
sctp_event_t event_type,
sctp_subtype_t subtype,
struct sctp_chunk *chunk,
unsigned error)
{
struct sctp_ulpevent *event;
/* Cancel any partial delivery in progress. */
sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
(__u16)error, 0, 0, chunk,
GFP_ATOMIC);
else
event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
(__u16)error, 0, 0, NULL,
GFP_ATOMIC);
if (event)
sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
SCTP_ULPEVENT(event));
sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
SCTP_STATE(SCTP_STATE_CLOSED));
/* SEND_FAILED sent later when cleaning up the association. */
asoc->outqueue.error = error;
sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
}
/* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
* inside the cookie. In reality, this is only used for INIT-ACK processing
* since all other cases use "temporary" associations and can do all
* their work in statefuns directly.
*/
static int sctp_cmd_process_init(sctp_cmd_seq_t *commands,
struct sctp_association *asoc,
struct sctp_chunk *chunk,
sctp_init_chunk_t *peer_init,
gfp_t gfp)
{
int error;
/* We only process the init as a sideeffect in a single
* case. This is when we process the INIT-ACK. If we
* fail during INIT processing (due to malloc problems),
* just return the error and stop processing the stack.
*/
if (!sctp_process_init(asoc, chunk->chunk_hdr->type,
sctp_source(chunk), peer_init, gfp))
error = -ENOMEM;
else
error = 0;
return error;
}
/* Helper function to break out starting up of heartbeat timers. */
static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
struct sctp_association *asoc)
{
struct sctp_transport *t;
/* Start a heartbeat timer for each transport on the association.
* hold a reference on the transport to make sure none of
* the needed data structures go away.
*/
list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) {
if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
sctp_transport_hold(t);
}
}
static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
struct sctp_association *asoc)
{
struct sctp_transport *t;
/* Stop all heartbeat timers. */
list_for_each_entry(t, &asoc->peer.transport_addr_list,
transports) {
if (del_timer(&t->hb_timer))
sctp_transport_put(t);
}
}
/* Helper function to stop any pending T3-RTX timers */
static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds,
struct sctp_association *asoc)
{
struct sctp_transport *t;
list_for_each_entry(t, &asoc->peer.transport_addr_list,
transports) {
if (timer_pending(&t->T3_rtx_timer) &&
del_timer(&t->T3_rtx_timer)) {
sctp_transport_put(t);
}
}
}
/* Helper function to update the heartbeat timer. */
static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
struct sctp_transport *t)
{
/* Update the heartbeat timer. */
if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
sctp_transport_hold(t);
}
/* Helper function to handle the reception of an HEARTBEAT ACK. */
static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
struct sctp_association *asoc,
struct sctp_transport *t,
struct sctp_chunk *chunk)
{
sctp_sender_hb_info_t *hbinfo;
/* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
* HEARTBEAT should clear the error counter of the destination
* transport address to which the HEARTBEAT was sent.
* The association's overall error count is also cleared.
*/
t->error_count = 0;
t->asoc->overall_error_count = 0;
/* Clear the hb_sent flag to signal that we had a good
* acknowledgement.
*/
t->hb_sent = 0;
/* Mark the destination transport address as active if it is not so
* marked.
*/
if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED))
sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
SCTP_HEARTBEAT_SUCCESS);
/* The receiver of the HEARTBEAT ACK should also perform an
* RTT measurement for that destination transport address
* using the time value carried in the HEARTBEAT ACK chunk.
* If the transport's rto_pending variable has been cleared,
* it was most likely due to a retransmit. However, we want
* to re-enable it to properly update the rto.
*/
if (t->rto_pending == 0)
t->rto_pending = 1;
hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
/* Update the heartbeat timer. */
if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
sctp_transport_hold(t);
}
/* Helper function to process the process SACK command. */
static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
struct sctp_association *asoc,
struct sctp_sackhdr *sackh)
{
int err = 0;
if (sctp_outq_sack(&asoc->outqueue, sackh)) {
/* There are no more TSNs awaiting SACK. */
err = sctp_do_sm(SCTP_EVENT_T_OTHER,
SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
asoc->state, asoc->ep, asoc, NULL,
GFP_ATOMIC);
}
return err;
}
/* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
* the transport for a shutdown chunk.
*/
static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds,
struct sctp_association *asoc,
struct sctp_chunk *chunk)
{
struct sctp_transport *t;
if (chunk->transport)
t = chunk->transport;
else {
t = sctp_assoc_choose_alter_transport(asoc,
asoc->shutdown_last_sent_to);
chunk->transport = t;
}
asoc->shutdown_last_sent_to = t;
asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
}
/* Helper function to change the state of an association. */
static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds,
struct sctp_association *asoc,
sctp_state_t state)
{
struct sock *sk = asoc->base.sk;
asoc->state = state;
SCTP_DEBUG_PRINTK("sctp_cmd_new_state: asoc %p[%s]\n",
asoc, sctp_state_tbl[state]);
if (sctp_style(sk, TCP)) {
/* Change the sk->sk_state of a TCP-style socket that has
* successfully completed a connect() call.
*/
if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
sk->sk_state = SCTP_SS_ESTABLISHED;
/* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
sctp_sstate(sk, ESTABLISHED))
sk->sk_shutdown |= RCV_SHUTDOWN;
}
if (sctp_state(asoc, COOKIE_WAIT)) {
/* Reset init timeouts since they may have been
* increased due to timer expirations.
*/
asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
asoc->rto_initial;
asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
asoc->rto_initial;
}
if (sctp_state(asoc, ESTABLISHED) ||
sctp_state(asoc, CLOSED) ||
sctp_state(asoc, SHUTDOWN_RECEIVED)) {
/* Wake up any processes waiting in the asoc's wait queue in
* sctp_wait_for_connect() or sctp_wait_for_sndbuf().
*/
if (waitqueue_active(&asoc->wait))
wake_up_interruptible(&asoc->wait);
/* Wake up any processes waiting in the sk's sleep queue of
* a TCP-style or UDP-style peeled-off socket in
* sctp_wait_for_accept() or sctp_wait_for_packet().
* For a UDP-style socket, the waiters are woken up by the
* notifications.
*/
if (!sctp_style(sk, UDP))
sk->sk_state_change(sk);
}
}
/* Helper function to delete an association. */
static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
struct sctp_association *asoc)
{
struct sock *sk = asoc->base.sk;
/* If it is a non-temporary association belonging to a TCP-style
* listening socket that is not closed, do not free it so that accept()
* can pick it up later.
*/
if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
(!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
return;
sctp_unhash_established(asoc);
sctp_association_free(asoc);
}
/*
* ADDIP Section 4.1 ASCONF Chunk Procedures
* A4) Start a T-4 RTO timer, using the RTO value of the selected
* destination address (we use active path instead of primary path just
* because primary path may be inactive.
*/
static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
struct sctp_association *asoc,
struct sctp_chunk *chunk)
{
struct sctp_transport *t;
t = sctp_assoc_choose_alter_transport(asoc, chunk->transport);
asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
chunk->transport = t;
}
/* Process an incoming Operation Error Chunk. */
static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
struct sctp_association *asoc,
struct sctp_chunk *chunk)
{
struct sctp_errhdr *err_hdr;
struct sctp_ulpevent *ev;
while (chunk->chunk_end > chunk->skb->data) {
err_hdr = (struct sctp_errhdr *)(chunk->skb->data);
ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
GFP_ATOMIC);
if (!ev)
return;
sctp_ulpq_tail_event(&asoc->ulpq, ev);
switch (err_hdr->cause) {
case SCTP_ERROR_UNKNOWN_CHUNK:
{
sctp_chunkhdr_t *unk_chunk_hdr;
unk_chunk_hdr = (sctp_chunkhdr_t *)err_hdr->variable;
switch (unk_chunk_hdr->type) {
/* ADDIP 4.1 A9) If the peer responds to an ASCONF with
* an ERROR chunk reporting that it did not recognized
* the ASCONF chunk type, the sender of the ASCONF MUST
* NOT send any further ASCONF chunks and MUST stop its
* T-4 timer.
*/
case SCTP_CID_ASCONF:
if (asoc->peer.asconf_capable == 0)
break;
asoc->peer.asconf_capable = 0;
sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
break;
default:
break;
}
break;
}
default:
break;
}
}
}
/* Process variable FWDTSN chunk information. */
static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
struct sctp_chunk *chunk)
{
struct sctp_fwdtsn_skip *skip;
/* Walk through all the skipped SSNs */
sctp_walk_fwdtsn(skip, chunk) {
sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
}
}
/* Helper function to remove the association non-primary peer
* transports.
*/
static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
{
struct sctp_transport *t;
struct list_head *pos;
struct list_head *temp;
list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
t = list_entry(pos, struct sctp_transport, transports);
if (!sctp_cmp_addr_exact(&t->ipaddr,
&asoc->peer.primary_addr)) {
sctp_assoc_del_peer(asoc, &t->ipaddr);
}
}
}
/* Helper function to set sk_err on a 1-1 style socket. */
static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
{
struct sock *sk = asoc->base.sk;
if (!sctp_style(sk, UDP))
sk->sk_err = error;
}
/* Helper function to generate an association change event */
static void sctp_cmd_assoc_change(sctp_cmd_seq_t *commands,
struct sctp_association *asoc,
u8 state)
{
struct sctp_ulpevent *ev;
ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
asoc->c.sinit_num_ostreams,
asoc->c.sinit_max_instreams,
NULL, GFP_ATOMIC);
if (ev)
sctp_ulpq_tail_event(&asoc->ulpq, ev);
}
/* Helper function to generate an adaptation indication event */
static void sctp_cmd_adaptation_ind(sctp_cmd_seq_t *commands,
struct sctp_association *asoc)
{
struct sctp_ulpevent *ev;
ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
if (ev)
sctp_ulpq_tail_event(&asoc->ulpq, ev);
}
static void sctp_cmd_t1_timer_update(struct sctp_association *asoc,
sctp_event_timeout_t timer,
char *name)
{
struct sctp_transport *t;
t = asoc->init_last_sent_to;
asoc->init_err_counter++;
if (t->init_sent_count > (asoc->init_cycle + 1)) {
asoc->timeouts[timer] *= 2;
if (asoc->timeouts[timer] > asoc->max_init_timeo) {
asoc->timeouts[timer] = asoc->max_init_timeo;
}
asoc->init_cycle++;
SCTP_DEBUG_PRINTK(
"T1 %s Timeout adjustment"
" init_err_counter: %d"
" cycle: %d"
" timeout: %ld\n",
name,
asoc->init_err_counter,
asoc->init_cycle,
asoc->timeouts[timer]);
}
}
/* Send the whole message, chunk by chunk, to the outqueue.
* This way the whole message is queued up and bundling if
* encouraged for small fragments.
*/
static int sctp_cmd_send_msg(struct sctp_association *asoc,
struct sctp_datamsg *msg)
{
struct sctp_chunk *chunk;
int error = 0;
list_for_each_entry(chunk, &msg->chunks, frag_list) {
error = sctp_outq_tail(&asoc->outqueue, chunk);
if (error)
break;
}
return error;
}