// SPDX-License-Identifier: GPL-2.0-or-later
/* 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.
*
* Please send any bug reports or fixes you make to the
* email address(es):
* lksctp developers <[email protected]>
*
* Written or modified by:
* La Monte H.P. Yarroll <[email protected]>
* Karl Knutson <[email protected]>
* Jon Grimm <[email protected]>
* Hui Huang <[email protected]>
* Dajiang Zhang <[email protected]>
* Daisy Chang <[email protected]>
* Sridhar Samudrala <[email protected]>
* Ardelle Fan <[email protected]>
*/
#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>
#include <net/sctp/stream_sched.h>
static int sctp_cmd_interpreter(enum sctp_event_type event_type,
union sctp_subtype subtype,
enum sctp_state state,
struct sctp_endpoint *ep,
struct sctp_association *asoc,
void *event_arg,
enum sctp_disposition status,
struct sctp_cmd_seq *commands,
gfp_t gfp);
static int sctp_side_effects(enum sctp_event_type event_type,
union sctp_subtype subtype,
enum sctp_state state,
struct sctp_endpoint *ep,
struct sctp_association **asoc,
void *event_arg,
enum sctp_disposition status,
struct sctp_cmd_seq *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,
struct sctp_cmd_seq *commands)
{
struct sctp_transport *trans = asoc->peer.last_data_from;
__u32 ctsn, max_tsn_seen;
struct sctp_chunk *sack;
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 {
__u32 old_a_rwnd = asoc->a_rwnd;
asoc->a_rwnd = asoc->rwnd;
sack = sctp_make_sack(asoc);
if (!sack) {
asoc->a_rwnd = old_a_rwnd;
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(struct timer_list *t)
{
struct sctp_transport *transport =
from_timer(transport, t, T3_rtx_timer);
struct sctp_association *asoc = transport->asoc;
struct sock *sk = asoc->base.sk;
struct net *net = sock_net(sk);
int error;
/* Check whether a task is in the sock. */
bh_lock_sock(sk);
if (sock_owned_by_user(sk)) {
pr_debug("%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;
}
/* Run through the state machine. */
error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
asoc->state,
asoc->ep, asoc,
transport, GFP_ATOMIC);
if (error)
sk->sk_err = -error;
out_unlock:
bh_unlock_sock(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,
enum sctp_event_timeout timeout_type)
{
struct sock *sk = asoc->base.sk;
struct net *net = sock_net(sk);
int error = 0;
bh_lock_sock(sk);
if (sock_owned_by_user(sk)) {
pr_debug("%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(net, SCTP_EVENT_T_TIMEOUT,
SCTP_ST_TIMEOUT(timeout_type),
asoc->state, asoc->ep, asoc,
(void *)timeout_type, GFP_ATOMIC);
if (error)
sk->sk_err = -error;
out_unlock:
bh_unlock_sock(sk);
sctp_association_put(asoc);
}
static void sctp_generate_t1_cookie_event(struct timer_list *t)
{
struct sctp_association *asoc =
from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T1_COOKIE]);
sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
}
static void sctp_generate_t1_init_event(struct timer_list *t)
{
struct sctp_association *asoc =
from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T1_INIT]);
sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
}
static void sctp_generate_t2_shutdown_event(struct timer_list *t)
{
struct sctp_association *asoc =
from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN]);
sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
}
static void sctp_generate_t4_rto_event(struct timer_list *t)
{
struct sctp_association *asoc =
from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T4_RTO]);
sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
}
static void sctp_generate_t5_shutdown_guard_event(struct timer_list *t)
{
struct sctp_association *asoc =
from_timer(asoc, t,
timers[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]);
sctp_generate_timeout_event(asoc,
SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
} /* sctp_generate_t5_shutdown_guard_event() */
static void sctp_generate_autoclose_event(struct timer_list *t)
{
struct sctp_association *asoc =
from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_AUTOCLOSE]);
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(struct timer_list *t)
{
struct sctp_transport *transport = from_timer(transport, t, hb_timer);
struct sctp_association *asoc = transport->asoc;
struct sock *sk = asoc->base.sk;
struct net *net = sock_net(sk);
u32 elapsed, timeout;
int error = 0;
bh_lock_sock(sk);
if (sock_owned_by_user(sk)) {
pr_debug("%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;
}
/* Check if we should still send the heartbeat or reschedule */
elapsed = jiffies - transport->last_time_sent;
timeout = sctp_transport_timeout(transport);
if (elapsed < timeout) {
elapsed = timeout - elapsed;
if (!mod_timer(&transport->hb_timer, jiffies + elapsed))
sctp_transport_hold(transport);
goto out_unlock;
}
error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
asoc->state, asoc->ep, asoc,
transport, GFP_ATOMIC);
if (error)
sk->sk_err = -error;
out_unlock:
bh_unlock_sock(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(struct timer_list *t)
{
struct sctp_transport *transport =
from_timer(transport, t, proto_unreach_timer);
struct sctp_association *asoc = transport->asoc;
struct sock *sk = asoc->base.sk;
struct net *net = sock_net(sk);
bh_lock_sock(sk);
if (sock_owned_by_user(sk)) {
pr_debug("%s: sock is busy\n", __func__);
/* Try again later. */
if (!mod_timer(&transport->proto_unreach_timer,
jiffies + (HZ/20)))
sctp_transport_hold(transport);
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(net, SCTP_EVENT_T_OTHER,
SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
asoc->state, asoc->ep, asoc, transport, GFP_ATOMIC);
out_unlock:
bh_unlock_sock(sk);
sctp_transport_put(transport);
}
/* Handle the timeout of the RE-CONFIG timer. */
void sctp_generate_reconf_event(struct timer_list *t)
{
struct sctp_transport *transport =
from_timer(transport, t, reconf_timer);
struct sctp_association *asoc = transport->asoc;
struct sock *sk = asoc->base.sk;
struct net *net = sock_net(sk);
int error = 0;
bh_lock_sock(sk);
if (sock_owned_by_user(sk)) {
pr_debug("%s: sock is busy\n", __func__);
/* Try again later. */
if (!mod_timer(&transport->reconf_timer, jiffies + (HZ / 20)))
sctp_transport_hold(transport);
goto out_unlock;
}
/* This happens when the response arrives after the timer is triggered. */
if (!asoc->strreset_chunk)
goto out_unlock;
error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_RECONF),
asoc->state, asoc->ep, asoc,
transport, GFP_ATOMIC);
if (error)
sk->sk_err = -error;
out_unlock:
bh_unlock_sock(sk);
sctp_transport_put(transport);
}
/* Handle the timeout of the probe timer. */
void sctp_generate_probe_event(struct timer_list *t)
{
struct sctp_transport *transport = from_timer(transport, t, probe_timer);
struct sctp_association *asoc = transport->asoc;
struct sock *sk = asoc->base.sk;
struct net *net = sock_net(sk);
int error = 0;
bh_lock_sock(sk);
if (sock_owned_by_user(sk)) {
pr_debug("%s: sock is busy\n", __func__);
/* Try again later. */
if (!mod_timer(&transport->probe_timer, jiffies + (HZ / 20)))
sctp_transport_hold(transport);
goto out_unlock;
}
error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_PROBE),
asoc->state, asoc->ep, asoc,
transport, GFP_ATOMIC);
if (error)
sk->sk_err = -error;
out_unlock:
bh_unlock_sock(sk);
sctp_transport_put(transport);
}
/* Inject a SACK Timeout event into the state machine. */
static void sctp_generate_sack_event(struct timer_list *t)
{
struct sctp_association *asoc =
from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_SACK]);
sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
}
sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
[SCTP_EVENT_TIMEOUT_NONE] = NULL,
[SCTP_EVENT_TIMEOUT_T1_COOKIE] = sctp_generate_t1_cookie_event,
[SCTP_EVENT_TIMEOUT_T1_INIT] = sctp_generate_t1_init_event,
[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = sctp_generate_t2_shutdown_event,
[SCTP_EVENT_TIMEOUT_T3_RTX] = NULL,
[SCTP_EVENT_TIMEOUT_T4_RTO] = sctp_generate_t4_rto_event,
[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD] =
sctp_generate_t5_shutdown_guard_event,
[SCTP_EVENT_TIMEOUT_HEARTBEAT] = NULL,
[SCTP_EVENT_TIMEOUT_RECONF] = NULL,
[SCTP_EVENT_TIMEOUT_SACK] = sctp_generate_sack_event,
[SCTP_EVENT_TIMEOUT_AUTOCLOSE] = 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_cmd_seq *commands,
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 the transport error count is greater than the pf_retrans
* threshold, and less than pathmaxrtx, and if the current state
* is SCTP_ACTIVE, then mark this transport as Partially Failed,
* see SCTP Quick Failover Draft, section 5.1
*/
if (asoc->base.net->sctp.pf_enable &&
transport->state == SCTP_ACTIVE &&
transport->error_count < transport->pathmaxrxt &&
transport->error_count > transport->pf_retrans) {
sctp_assoc_control_transport(asoc, transport,
SCTP_TRANSPORT_PF,
0);
/* Update the hb timer to resend a heartbeat every rto */
sctp_transport_reset_hb_timer(transport);
}
if (transport->state != SCTP_INACTIVE &&
(transport->error_count > transport->pathmaxrxt)) {
pr_debug("%s: association:%p transport addr:%pISpc failed\n",
__func__, asoc, &transport->ipaddr.sa);
sctp_assoc_control_transport(asoc, transport,
SCTP_TRANSPORT_DOWN,
SCTP_FAILED_THRESHOLD);
}
if (transport->error_count > transport->ps_retrans &&
asoc->peer.primary_path == transport &&
asoc->peer.active_path != transport)
sctp_assoc_set_primary(asoc, asoc->peer.active_path);
/* 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);
sctp_max_rto(asoc, transport);
}
}
/* Worker routine to handle INIT command failure. */
static void sctp_cmd_init_failed(struct sctp_cmd_seq *commands,
struct sctp_association *asoc,
unsigned int 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(struct sctp_cmd_seq *commands,
struct sctp_association *asoc,
enum sctp_event_type event_type,
union sctp_subtype subtype,
struct sctp_chunk *chunk,
unsigned int error)
{
struct sctp_ulpevent *event;
struct sctp_chunk *abort;
/* Cancel any partial delivery in progress. */
asoc->stream.si->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));
if (asoc->overall_error_count >= asoc->max_retrans) {
abort = sctp_make_violation_max_retrans(asoc, chunk);
if (abort)
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
SCTP_CHUNK(abort));
}
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(struct sctp_cmd_seq *commands,
struct sctp_association *asoc,
struct sctp_chunk *chunk,
struct sctp_init_chunk *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, 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(struct sctp_cmd_seq *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)
sctp_transport_reset_hb_timer(t);
}
static void sctp_cmd_hb_timers_stop(struct sctp_cmd_seq *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(struct sctp_cmd_seq *cmds,
struct sctp_association *asoc)
{
struct sctp_transport *t;
list_for_each_entry(t, &asoc->peer.transport_addr_list,
transports) {
if (del_timer(&t->T3_rtx_timer))
sctp_transport_put(t);
}
}
/* Helper function to handle the reception of an HEARTBEAT ACK. */
static void sctp_cmd_transport_on(struct sctp_cmd_seq *cmds,
struct sctp_association *asoc,
struct sctp_transport *t,
struct sctp_chunk *chunk)
{
struct sctp_sender_hb_info *hbinfo;
int was_unconfirmed = 0;
/* 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.
*/
t->error_count = 0;
/*
* Although RFC4960 specifies that the overall error count must
* be cleared when a HEARTBEAT ACK is received, we make an
* exception while in SHUTDOWN PENDING. If the peer keeps its
* window shut forever, we may never be able to transmit our
* outstanding data and rely on the retransmission limit be reached
* to shutdown the association.
*/
if (t->asoc->state < SCTP_STATE_SHUTDOWN_PENDING)
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)) {
was_unconfirmed = 1;
sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
SCTP_HEARTBEAT_SUCCESS);
}
if (t->state == SCTP_PF)
sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
SCTP_HEARTBEAT_SUCCESS);
/* HB-ACK was received for a the proper HB. Consider this
* forward progress.
*/
if (t->dst)
sctp_transport_dst_confirm(t);
/* 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 = (struct sctp_sender_hb_info *)chunk->skb->data;
sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
/* Update the heartbeat timer. */
sctp_transport_reset_hb_timer(t);
if (was_unconfirmed && asoc->peer.transport_count == 1)
sctp_transport_immediate_rtx(t);
}
/* Helper function to process the process SACK command. */
static int sctp_cmd_process_sack(struct sctp_cmd_seq *cmds,
struct sctp_association *asoc,
struct sctp_chunk *chunk)
{
int err = 0;
if (sctp_outq_sack(&asoc->outqueue, chunk)) {
/* There are no more TSNs awaiting SACK. */
err = sctp_do_sm(asoc->base.net, 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(struct sctp_cmd_seq *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(struct sctp_cmd_seq *cmds,
struct sctp_association *asoc,
enum sctp_state state)
{
struct sock *sk = asoc->base.sk;
asoc->state = state;
pr_debug("%s: asoc:%p[%s]\n", __func__, 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))
inet_sk_set_state(sk, SCTP_SS_ESTABLISHED);
/* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
sctp_sstate(sk, ESTABLISHED)) {
inet_sk_set_state(sk, SCTP_SS_CLOSING);
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)) {
kfree(asoc->peer.cookie);
asoc->peer.cookie = NULL;
}
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);
}
if (sctp_state(asoc, SHUTDOWN_PENDING) &&
!sctp_outq_is_empty(&asoc->outqueue))
sctp_outq_uncork(&asoc->outqueue, GFP_ATOMIC);
}
/* Helper function to delete an association. */
static void sctp_cmd_delete_tcb(struct sctp_cmd_seq *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_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(struct sctp_cmd_seq *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(struct sctp_cmd_seq *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;
asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
switch (err_hdr->cause) {
case SCTP_ERROR_UNKNOWN_CHUNK:
{
struct sctp_chunkhdr *unk_chunk_hdr;
unk_chunk_hdr = (struct sctp_chunkhdr *)(err_hdr + 1);
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;
}
}
}
/* 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 *temp;
struct list_head *pos;
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_rm_peer(asoc, t);
}
}
}
/* 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(struct sctp_cmd_seq *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)
asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
}
static void sctp_cmd_peer_no_auth(struct sctp_cmd_seq *commands,
struct sctp_association *asoc)
{
struct sctp_ulpevent *ev;
ev = sctp_ulpevent_make_authkey(asoc, 0, SCTP_AUTH_NO_AUTH, GFP_ATOMIC);
if (ev)
asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
}
/* Helper function to generate an adaptation indication event */
static void sctp_cmd_adaptation_ind(struct sctp_cmd_seq *commands,
struct sctp_association *asoc)
{
struct sctp_ulpevent *ev;
ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
if (ev)
asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
}
static void sctp_cmd_t1_timer_update(struct sctp_association *asoc,
enum sctp_event_timeout 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++;
pr_debug("%s: T1[%s] timeout adjustment init_err_counter:%d"
" cycle:%d timeout:%ld\n", __func__, 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 void sctp_cmd_send_msg(struct sctp_association *asoc,
struct sctp_datamsg *msg, gfp_t gfp)
{
struct sctp_chunk *chunk;
list_for_each_entry(chunk, &msg->chunks, frag_list)
sctp_outq_tail(&asoc->outqueue, chunk, gfp);
asoc->outqueue.sched->enqueue(&asoc->outqueue, msg);
}
/* These three macros allow us to pull the debugging code out of the
* main flow of sctp_do_sm() to keep attention focused on the real
* functionality there.
*/
#define debug_pre_sfn() \
pr_debug("%s[pre-fn]: ep:%p, %s, %s, asoc:%p[%s], %s\n", __func__, \
ep, sctp_evttype_tbl[event_type], (*debug_fn)(subtype), \
asoc, sctp_state_tbl[state], state_fn->name)
#define debug_post_sfn() \
pr_debug("%s[post-fn]: asoc:%p, status:%s\n", __func__, asoc, \
sctp_status_tbl[status])
#define debug_post_sfx() \
pr_debug("%s[post-sfx]: error:%d, asoc:%p[%s]\n", __func__, error, \
asoc, sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
sctp_assoc2id(asoc))) ? asoc->state : SCTP_STATE_CLOSED])
/*
* This is the master state machine processing function.
*
* If you want to understand all of lksctp, this is a
* good place to start.
*/
int sctp_do_sm(struct net *net, enum sctp_event_type event_type,
union sctp_subtype subtype, enum sctp_state state,
struct sctp_endpoint *ep, struct sctp_association *asoc,
void *event_arg, gfp_t gfp)
{
typedef const char *(printfn_t)(union sctp_subtype);
static printfn_t *table[] = {
NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
};
printfn_t *debug_fn __attribute__ ((unused)) = table[event_type];
const struct sctp_sm_table_entry *state_fn;
struct sctp_cmd_seq commands;
enum sctp_disposition status;
int error = 0;
/* Look up the state function, run it, and then process the
* side effects. These three steps are the heart of lksctp.
*/
state_fn = sctp_sm_lookup_event(net, event_type, state, subtype);
sctp_init_cmd_seq(&commands);
debug_pre_sfn();
status = state_fn->fn(net, ep, asoc, subtype, event_arg, &commands);
debug_post_sfn();
error = sctp_side_effects(event_type, subtype, state,
ep, &asoc, event_arg, status,
&commands, gfp);
debug_post_sfx();
return error;
}
/*****************************************************************
* This the master state function side effect processing function.
*****************************************************************/
static int sctp_side_effects(enum sctp_event_type event_type,
union sctp_subtype subtype,
enum sctp_state state,
struct sctp_endpoint *ep,
struct sctp_association **asoc,
void *event_arg,
enum sctp_disposition status,
struct sctp_cmd_seq *commands,
gfp_t gfp)
{
int error;
/* FIXME - Most of the dispositions left today would be categorized
* as "exceptional" dispositions. For those dispositions, it
* may not be proper to run through any of the commands at all.
* For example, the command interpreter might be run only with
* disposition SCTP_DISPOSITION_CONSUME.
*/
if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
ep, *asoc,
event_arg, status,
commands, gfp)))
goto bail;
switch (status) {
case SCTP_DISPOSITION_DISCARD:
pr_debug("%s: ignored sctp protocol event - state:%d, "
"event_type:%d, event_id:%d\n", __func__, state,
event_type, subtype.chunk);
break;
case SCTP_DISPOSITION_NOMEM:
/* We ran out of memory, so we need to discard this
* packet.
*/
/* BUG--we should now recover some memory, probably by
* reneging...
*/
error = -ENOMEM;
break;
case SCTP_DISPOSITION_DELETE_TCB:
case SCTP_DISPOSITION_ABORT:
/* This should now be a command. */
*asoc = NULL;
break;
case SCTP_DISPOSITION_CONSUME:
/*
* We should no longer have much work to do here as the
* real work has been done as explicit commands above.
*/
break;
case SCTP_DISPOSITION_VIOLATION:
net_err_ratelimited("protocol violation state %d chunkid %d\n",
state, subtype.chunk);
break;
case SCTP_DISPOSITION_NOT_IMPL:
pr_warn("unimplemented feature in state %d, event_type %d, event_id %d\n",
state, event_type, subtype.chunk);
break;
case SCTP_DISPOSITION_BUG:
pr_err("bug in state %d, event_type %d, event_id %d\n",
state, event_type, subtype.chunk);
BUG();
break;
default:
pr_err("impossible disposition %d in state %d, event_type %d, event_id %d\n",
status, state, event_type, subtype.chunk);
error = status;
if (error >= 0)
error = -EINVAL;
WARN_ON_ONCE(1);
break;
}
bail:
return error;
}
/********************************************************************
* 2nd Level Abstractions
********************************************************************/
/* This is the side-effect interpreter. */
static int sctp_cmd_interpreter(enum sctp_event_type event_type,
union sctp_subtype subtype,
enum sctp_state state,
struct sctp_endpoint *ep,
struct sctp_association *asoc,
void *event_arg,
enum sctp_disposition status,
struct sctp_cmd_seq *commands,
gfp_t gfp)
{
struct sctp_sock *sp = sctp_sk(ep->base.sk);
struct sctp_chunk *chunk = NULL, *new_obj;
struct sctp_packet *packet;
struct sctp_sackhdr sackh;
struct timer_list *timer;
struct sctp_transport *t;
unsigned long timeout;
struct sctp_cmd *cmd;
int local_cork = 0;
int error = 0;
int force;
if (SCTP_EVENT_T_TIMEOUT != event_type)
chunk = event_arg;
/* Note: This whole file is a huge candidate for rework.
* For example, each command could either have its own handler, so
* the loop would look like:
* while (cmds)
* cmd->handle(x, y, z)
* --jgrimm
*/
while (NULL != (cmd = sctp_next_cmd(commands))) {
switch (cmd->verb) {
case SCTP_CMD_NOP:
/* Do nothing. */
break;
case SCTP_CMD_NEW_ASOC:
/* Register a new association. */
if (local_cork) {
sctp_outq_uncork(&asoc->outqueue, gfp);
local_cork = 0;
}
/* Register with the endpoint. */
asoc = cmd->obj.asoc;
BUG_ON(asoc->peer.primary_path == NULL);
sctp_endpoint_add_asoc(ep, asoc);
break;
case SCTP_CMD_PURGE_OUTQUEUE:
sctp_outq_teardown(&asoc->outqueue);
break;
case SCTP_CMD_DELETE_TCB:
if (local_cork) {
sctp_outq_uncork(&asoc->outqueue, gfp);
local_cork = 0;
}
/* Delete the current association. */
sctp_cmd_delete_tcb(commands, asoc);
asoc = NULL;
break;
case SCTP_CMD_NEW_STATE:
/* Enter a new state. */
sctp_cmd_new_state(commands, asoc, cmd->obj.state);
break;
case SCTP_CMD_REPORT_TSN:
/* Record the arrival of a TSN. */
error = sctp_tsnmap_mark(&asoc->peer.tsn_map,
cmd->obj.u32, NULL);
break;
case SCTP_CMD_REPORT_FWDTSN:
asoc->stream.si->report_ftsn(&asoc->ulpq, cmd->obj.u32);
break;
case SCTP_CMD_PROCESS_FWDTSN:
asoc->stream.si->handle_ftsn(&asoc->ulpq,
cmd->obj.chunk);
break;
case SCTP_CMD_GEN_SACK:
/* Generate a Selective ACK.
* The argument tells us whether to just count
* the packet and MAYBE generate a SACK, or
* force a SACK out.
*/
force = cmd->obj.i32;
error = sctp_gen_sack(asoc, force, commands);
break;
case SCTP_CMD_PROCESS_SACK:
/* Process an inbound SACK. */
error = sctp_cmd_process_sack(commands, asoc,
cmd->obj.chunk);
break;
case SCTP_CMD_GEN_INIT_ACK:
/* Generate an INIT ACK chunk. */
new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
0);
if (!new_obj) {
error = -ENOMEM;
break;
}
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
SCTP_CHUNK(new_obj));
break;
case SCTP_CMD_PEER_INIT:
/* Process a unified INIT from the peer.
* Note: Only used during INIT-ACK processing. If
* there is an error just return to the outter
* layer which will bail.
*/
error = sctp_cmd_process_init(commands, asoc, chunk,
cmd->obj.init, gfp);
break;
case SCTP_CMD_GEN_COOKIE_ECHO:
/* Generate a COOKIE ECHO chunk. */
new_obj = sctp_make_cookie_echo(asoc, chunk);
if (!new_obj) {
if (cmd->obj.chunk)
sctp_chunk_free(cmd->obj.chunk);
error = -ENOMEM;
break;
}
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
SCTP_CHUNK(new_obj));
/* If there is an ERROR chunk to be sent along with
* the COOKIE_ECHO, send it, too.
*/
if (cmd->obj.chunk)
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
SCTP_CHUNK(cmd->obj.chunk));
if (new_obj->transport) {
new_obj->transport->init_sent_count++;
asoc->init_last_sent_to = new_obj->transport;
}
/* FIXME - Eventually come up with a cleaner way to
* enabling COOKIE-ECHO + DATA bundling during
* multihoming stale cookie scenarios, the following
* command plays with asoc->peer.retran_path to
* avoid the problem of sending the COOKIE-ECHO and
* DATA in different paths, which could result
* in the association being ABORTed if the DATA chunk
* is processed first by the server. Checking the
* init error counter simply causes this command
* to be executed only during failed attempts of
* association establishment.
*/
if ((asoc->peer.retran_path !=
asoc->peer.primary_path) &&
(asoc->init_err_counter > 0)) {
sctp_add_cmd_sf(commands,
SCTP_CMD_FORCE_PRIM_RETRAN,
SCTP_NULL());
}
break;
case SCTP_CMD_GEN_SHUTDOWN:
/* Generate SHUTDOWN when in SHUTDOWN_SENT state.
* Reset error counts.
*/
asoc->overall_error_count = 0;
/* Generate a SHUTDOWN chunk. */
new_obj = sctp_make_shutdown(asoc, chunk);
if (!new_obj) {
error = -ENOMEM;
break;
}
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
SCTP_CHUNK(new_obj));
break;
case SCTP_CMD_CHUNK_ULP:
/* Send a chunk to the sockets layer. */
pr_debug("%s: sm_sideff: chunk_up:%p, ulpq:%p\n",
__func__, cmd->obj.chunk, &asoc->ulpq);
asoc->stream.si->ulpevent_data(&asoc->ulpq,
cmd->obj.chunk,
GFP_ATOMIC);
break;
case SCTP_CMD_EVENT_ULP:
/* Send a notification to the sockets layer. */
pr_debug("%s: sm_sideff: event_up:%p, ulpq:%p\n",
__func__, cmd->obj.ulpevent, &asoc->ulpq);
asoc->stream.si->enqueue_event(&asoc->ulpq,
cmd->obj.ulpevent);
break;
case SCTP_CMD_REPLY:
/* If an caller has not already corked, do cork. */
if (!asoc->outqueue.cork) {
sctp_outq_cork(&asoc->outqueue);
local_cork = 1;
}
/* Send a chunk to our peer. */
sctp_outq_tail(&asoc->outqueue, cmd->obj.chunk, gfp);
break;
case SCTP_CMD_SEND_PKT:
/* Send a full packet to our peer. */
packet = cmd->obj.packet;
sctp_packet_transmit(packet, gfp);
sctp_ootb_pkt_free(packet);
break;
case SCTP_CMD_T1_RETRAN:
/* Mark a transport for retransmission. */
sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
SCTP_RTXR_T1_RTX);
break;
case SCTP_CMD_RETRAN:
/* Mark a transport for retransmission. */
sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
SCTP_RTXR_T3_RTX);
break;
case SCTP_CMD_ECN_CE:
/* Do delayed CE processing. */
sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
break;
case SCTP_CMD_ECN_ECNE:
/* Do delayed ECNE processing. */
new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
chunk);
if (new_obj)
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
SCTP_CHUNK(new_obj));
break;
case SCTP_CMD_ECN_CWR:
/* Do delayed CWR processing. */
sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
break;
case SCTP_CMD_SETUP_T2:
sctp_cmd_setup_t2(commands, asoc, cmd->obj.chunk);
break;
case SCTP_CMD_TIMER_START_ONCE:
timer = &asoc->timers[cmd->obj.to];
if (timer_pending(timer))
break;
fallthrough;
case SCTP_CMD_TIMER_START:
timer = &asoc->timers[cmd->obj.to];
timeout = asoc->timeouts[cmd->obj.to];
BUG_ON(!timeout);
/*
* SCTP has a hard time with timer starts. Because we process
* timer starts as side effects, it can be hard to tell if we
* have already started a timer or not, which leads to BUG
* halts when we call add_timer. So here, instead of just starting
* a timer, if the timer is already started, and just mod
* the timer with the shorter of the two expiration times
*/
if (!timer_pending(timer))
sctp_association_hold(asoc);
timer_reduce(timer, jiffies + timeout);
break;
case SCTP_CMD_TIMER_RESTART:
timer = &asoc->timers[cmd->obj.to];
timeout = asoc->timeouts[cmd->obj.to];
if (!mod_timer(timer, jiffies + timeout))
sctp_association_hold(asoc);
break;
case SCTP_CMD_TIMER_STOP:
timer = &asoc->timers[cmd->obj.to];
if (del_timer(timer))
sctp_association_put(asoc);
break;
case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
chunk = cmd->obj.chunk;
t = sctp_assoc_choose_alter_transport(asoc,
asoc->init_last_sent_to);
asoc->init_last_sent_to = t;
chunk->transport = t;
t->init_sent_count++;
/* Set the new transport as primary */
sctp_assoc_set_primary(asoc, t);
break;
case SCTP_CMD_INIT_RESTART:
/* Do the needed accounting and updates
* associated with restarting an initialization
* timer. Only multiply the timeout by two if
* all transports have been tried at the current
* timeout.
*/
sctp_cmd_t1_timer_update(asoc,
SCTP_EVENT_TIMEOUT_T1_INIT,
"INIT");
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
break;
case SCTP_CMD_COOKIEECHO_RESTART:
/* Do the needed accounting and updates
* associated with restarting an initialization
* timer. Only multiply the timeout by two if
* all transports have been tried at the current
* timeout.
*/
sctp_cmd_t1_timer_update(asoc,
SCTP_EVENT_TIMEOUT_T1_COOKIE,
"COOKIE");
/* If we've sent any data bundled with
* COOKIE-ECHO we need to resend.
*/
list_for_each_entry(t, &asoc->peer.transport_addr_list,
transports) {
sctp_retransmit_mark(&asoc->outqueue, t,
SCTP_RTXR_T1_RTX);
}
sctp_add_cmd_sf(commands,
SCTP_CMD_TIMER_RESTART,
SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
break;
case SCTP_CMD_INIT_FAILED:
sctp_cmd_init_failed(commands, asoc, cmd->obj.u16);
break;
case SCTP_CMD_ASSOC_FAILED:
sctp_cmd_assoc_failed(commands, asoc, event_type,
subtype, chunk, cmd->obj.u16);
break;
case SCTP_CMD_INIT_COUNTER_INC:
asoc->init_err_counter++;
break;
case SCTP_CMD_INIT_COUNTER_RESET:
asoc->init_err_counter = 0;
asoc->init_cycle = 0;
list_for_each_entry(t, &asoc->peer.transport_addr_list,
transports) {
t->init_sent_count = 0;
}
break;
case SCTP_CMD_REPORT_DUP:
sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
cmd->obj.u32);
break;
case SCTP_CMD_REPORT_BAD_TAG:
pr_debug("%s: vtag mismatch!\n", __func__);
break;
case SCTP_CMD_STRIKE:
/* Mark one strike against a transport. */
sctp_do_8_2_transport_strike(commands, asoc,
cmd->obj.transport, 0);
break;
case SCTP_CMD_TRANSPORT_IDLE:
t = cmd->obj.transport;
sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
break;
case SCTP_CMD_TRANSPORT_HB_SENT:
t = cmd->obj.transport;
sctp_do_8_2_transport_strike(commands, asoc,
t, 1);
t->hb_sent = 1;
break;
case SCTP_CMD_TRANSPORT_ON:
t = cmd->obj.transport;
sctp_cmd_transport_on(commands, asoc, t, chunk);
break;
case SCTP_CMD_HB_TIMERS_START:
sctp_cmd_hb_timers_start(commands, asoc);
break;
case SCTP_CMD_HB_TIMER_UPDATE:
t = cmd->obj.transport;
sctp_transport_reset_hb_timer(t);
break;
case SCTP_CMD_HB_TIMERS_STOP:
sctp_cmd_hb_timers_stop(commands, asoc);
break;
case SCTP_CMD_PROBE_TIMER_UPDATE:
t = cmd->obj.transport;
sctp_transport_reset_probe_timer(t);
break;
case SCTP_CMD_REPORT_ERROR:
error = cmd->obj.error;
break;
case SCTP_CMD_PROCESS_CTSN:
/* Dummy up a SACK for processing. */
sackh.cum_tsn_ack = cmd->obj.be32;
sackh.a_rwnd = htonl(asoc->peer.rwnd +
asoc->outqueue.outstanding_bytes);
sackh.num_gap_ack_blocks = 0;
sackh.num_dup_tsns = 0;
chunk->subh.sack_hdr = &sackh;
sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
SCTP_CHUNK(chunk));
break;
case SCTP_CMD_DISCARD_PACKET:
/* We need to discard the whole packet.
* Uncork the queue since there might be
* responses pending
*/
chunk->pdiscard = 1;
if (asoc) {
sctp_outq_uncork(&asoc->outqueue, gfp);
local_cork = 0;
}
break;
case SCTP_CMD_RTO_PENDING:
t = cmd->obj.transport;
t->rto_pending = 1;
break;
case SCTP_CMD_PART_DELIVER:
asoc->stream.si->start_pd(&asoc->ulpq, GFP_ATOMIC);
break;
case SCTP_CMD_RENEGE:
asoc->stream.si->renege_events(&asoc->ulpq,
cmd->obj.chunk,
GFP_ATOMIC);
break;
case SCTP_CMD_SETUP_T4:
sctp_cmd_setup_t4(commands, asoc, cmd->obj.chunk);
break;
case SCTP_CMD_PROCESS_OPERR:
sctp_cmd_process_operr(commands, asoc, chunk);
break;
case SCTP_CMD_CLEAR_INIT_TAG:
asoc->peer.i.init_tag = 0;
break;
case SCTP_CMD_DEL_NON_PRIMARY:
sctp_cmd_del_non_primary(asoc);
break;
case SCTP_CMD_T3_RTX_TIMERS_STOP:
sctp_cmd_t3_rtx_timers_stop(commands, asoc);
break;
case SCTP_CMD_FORCE_PRIM_RETRAN:
t = asoc->peer.retran_path;
asoc->peer.retran_path = asoc->peer.primary_path;
sctp_outq_uncork(&asoc->outqueue, gfp);
local_cork = 0;
asoc->peer.retran_path = t;
break;
case SCTP_CMD_SET_SK_ERR:
sctp_cmd_set_sk_err(asoc, cmd->obj.error);
break;
case SCTP_CMD_ASSOC_CHANGE:
sctp_cmd_assoc_change(commands, asoc,
cmd->obj.u8);
break;
case SCTP_CMD_ADAPTATION_IND:
sctp_cmd_adaptation_ind(commands, asoc);
break;
case SCTP_CMD_PEER_NO_AUTH:
sctp_cmd_peer_no_auth(commands, asoc);
break;
case SCTP_CMD_ASSOC_SHKEY:
error = sctp_auth_asoc_init_active_key(asoc,
GFP_ATOMIC);
break;
case SCTP_CMD_UPDATE_INITTAG:
asoc->peer.i.init_tag = cmd->obj.u32;
break;
case SCTP_CMD_SEND_MSG:
if (!asoc->outqueue.cork) {
sctp_outq_cork(&asoc->outqueue);
local_cork = 1;
}
sctp_cmd_send_msg(asoc, cmd->obj.msg, gfp);
break;
case SCTP_CMD_PURGE_ASCONF_QUEUE:
sctp_asconf_queue_teardown(asoc);
break;
case SCTP_CMD_SET_ASOC:
if (asoc && local_cork) {
sctp_outq_uncork(&asoc->outqueue, gfp);
local_cork = 0;
}
asoc = cmd->obj.asoc;
break;
default:
pr_warn("Impossible command: %u\n",
cmd->verb);
break;
}
if (error) {
cmd = sctp_next_cmd(commands);
while (cmd) {
if (cmd->verb == SCTP_CMD_REPLY)
sctp_chunk_free(cmd->obj.chunk);
cmd = sctp_next_cmd(commands);
}
break;
}
}
/* If this is in response to a received chunk, wait until
* we are done with the packet to open the queue so that we don't
* send multiple packets in response to a single request.
*/
if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) {
if (chunk->end_of_packet || chunk->singleton)
sctp_outq_uncork(&asoc->outqueue, gfp);
} else if (local_cork)
sctp_outq_uncork(&asoc->outqueue, gfp);
if (sp->data_ready_signalled)
sp->data_ready_signalled = 0;
return error;
}
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