patch-2.4.23 linux-2.4.23/net/sctp/sm_sideeffect.c
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- Lines: 1186
- Date:
2003-11-28 10:26:21.000000000 -0800
- Orig file:
linux-2.4.22/net/sctp/sm_sideeffect.c
- Orig date:
1969-12-31 16:00:00.000000000 -0800
diff -urN linux-2.4.22/net/sctp/sm_sideeffect.c linux-2.4.23/net/sctp/sm_sideeffect.c
@@ -0,0 +1,1185 @@
+/* SCTP kernel reference Implementation
+ * Copyright (c) 1999 Cisco, Inc.
+ * Copyright (c) 1999-2001 Motorola, Inc.
+ * Copyright (c) 2001-2002 International Business Machines Corp.
+ *
+ * This file is part of the SCTP kernel reference 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.
+ *
+ * The SCTP reference implementation is free software;
+ * you can redistribute it and/or modify it under the terms of
+ * the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * The SCTP reference implementation is distributed in the hope that it
+ * will be useful, but WITHOUT ANY WARRANTY; without even the implied
+ * ************************
+ * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU CC; see the file COPYING. If not, write to
+ * the Free Software Foundation, 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
+ * Please send any bug reports or fixes you make to the
+ * email address(es):
+ * lksctp developers <lksctp-developers@lists.sourceforge.net>
+ *
+ * Or submit a bug report through the following website:
+ * http://www.sf.net/projects/lksctp
+ *
+ * Written or modified by:
+ * La Monte H.P. Yarroll <piggy@acm.org>
+ * Karl Knutson <karl@athena.chicago.il.us>
+ * Jon Grimm <jgrimm@austin.ibm.com>
+ * 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.
+ */
+
+#include <linux/skbuff.h>
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/ip.h>
+#include <net/sock.h>
+#include <net/sctp/sctp.h>
+#include <net/sctp/sm.h>
+
+/********************************************************************
+ * 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 sctp_chunk_t *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
+ __u32 lowest_tsn,
+ sctp_chunk_t *chunk)
+{
+ sctp_chunk_t *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. */
+int sctp_gen_sack(struct sctp_association *asoc, int force,
+ sctp_cmd_seq_t *commands)
+{
+ __u32 ctsn, max_tsn_seen;
+ struct sctp_chunk *sack;
+ int error = 0;
+
+ if (force)
+ 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) {
+ /* We will need a SACK for the next packet. */
+ asoc->peer.sack_needed = 1;
+ goto out;
+ } else {
+ if (asoc->a_rwnd > asoc->rwnd)
+ asoc->a_rwnd = asoc->rwnd;
+ sack = sctp_make_sack(asoc);
+ if (!sack)
+ goto nomem;
+
+ asoc->peer.sack_needed = 0;
+
+ error = sctp_outq_tail(&asoc->outqueue, sack);
+
+ /* Stop the SACK timer. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
+ }
+out:
+ 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", __FUNCTION__);
+
+ /* 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->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",
+ __FUNCTION__,
+ 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->err = -error;
+
+out_unlock:
+ sctp_bh_unlock_sock(asoc->base.sk);
+ sctp_association_put(asoc);
+}
+
+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);
+}
+
+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);
+}
+
+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);
+}
+
+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() */
+
+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", __FUNCTION__);
+
+ /* 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->err = -error;
+
+out_unlock:
+ sctp_bh_unlock_sock(asoc->base.sk);
+ sctp_transport_put(transport);
+}
+
+/* Inject a SACK Timeout event into the state machine. */
+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_t5_shutdown_guard_event,
+ sctp_generate_heartbeat_event,
+ 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)
+{
+ /* The check for association's overall error counter exceeding the
+ * threshold is done in the state function.
+ */
+ asoc->overall_error_count++;
+
+ if (transport->active &&
+ (transport->error_count++ >= transport->error_threshold)) {
+ SCTP_DEBUG_PRINTK("transport_strike: transport "
+ "IP:%d.%d.%d.%d failed.\n",
+ NIPQUAD(transport->ipaddr.v4.sin_addr));
+ 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.
+ */
+ 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,
+ 0, 0, 0, GFP_ATOMIC);
+
+ if (event)
+ sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
+ SCTP_ULPEVENT(event));
+
+ /* 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);
+
+ event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
+ (__u16)error, 0, 0,
+ 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, int 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;
+ struct list_head *pos;
+
+ /* 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(pos, &asoc->peer.transport_addr_list) {
+ t = list_entry(pos, struct sctp_transport, 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;
+ struct list_head *pos;
+
+ /* Stop all heartbeat timers. */
+
+ list_for_each(pos, &asoc->peer.transport_addr_list) {
+ t = list_entry(pos, struct sctp_transport, transports);
+ if (del_timer(&t->hb_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_association *asoc,
+ 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,
+ sctp_chunk_t *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;
+
+ /* Mark the destination transport address as active if it is not so
+ * marked.
+ */
+ if (!t->active)
+ 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.
+ */
+ hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
+ sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
+}
+
+/* Helper function to do a transport reset at the expiry of the hearbeat
+ * timer.
+ */
+static void sctp_cmd_transport_reset(sctp_cmd_seq_t *cmds,
+ struct sctp_association *asoc,
+ struct sctp_transport *t)
+{
+ sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
+
+ /* Mark one strike against a transport. */
+ sctp_do_8_2_transport_strike(asoc, t);
+}
+
+/* Helper function to process the process SACK command. */
+static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
+ struct sctp_association *asoc,
+ sctp_sackhdr_t *sackh)
+{
+ int err;
+
+ 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);
+ } else {
+ /* Windows may have opened, so we need
+ * to check if we have DATA to transmit
+ */
+ err = sctp_outq_flush(&asoc->outqueue, 0);
+ }
+
+ 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,
+ sctp_chunk_t *chunk)
+{
+ struct sctp_transport *t;
+
+ t = sctp_assoc_choose_shutdown_transport(asoc);
+ asoc->shutdown_last_sent_to = t;
+ asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
+ chunk->transport = t;
+}
+
+/* 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;
+ struct sctp_opt *sp = sctp_sk(sk);
+
+ asoc->state = state;
+ asoc->state_timestamp = jiffies;
+
+ if (SCTP_SOCKET_TCP == sp->type) {
+ /* Change the sk->state of a TCP-style socket that has
+ * sucessfully completed a connect() call.
+ */
+ if ((SCTP_STATE_ESTABLISHED == asoc->state) &&
+ (SCTP_SS_CLOSED == sk->state))
+ sk->state = SCTP_SS_ESTABLISHED;
+
+ /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
+ if (SCTP_STATE_SHUTDOWN_RECEIVED == asoc->state)
+ sk->shutdown |= RCV_SHUTDOWN;
+
+ }
+
+ if ((SCTP_STATE_ESTABLISHED == asoc->state) ||
+ (SCTP_STATE_CLOSED == asoc->state) ||
+ (SCTP_STATE_SHUTDOWN_RECEIVED == asoc->state)) {
+ /* 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_SOCKET_UDP != sp->type)
+ 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, do not free it so that accept() can pick it
+ * up later.
+ */
+ if ((SCTP_SOCKET_TCP == sctp_sk(sk)->type) &&
+ (SCTP_SS_LISTENING == sk->state) && (!asoc->temp))
+ return;
+
+ sctp_unhash_established(asoc);
+ sctp_association_free(asoc);
+}
+
+/* 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 \
+ SCTP_DEBUG_PRINTK("sctp_do_sm prefn: " \
+ "ep %p, %s, %s, asoc %p[%s], %s\n", \
+ ep, sctp_evttype_tbl[event_type], \
+ (*debug_fn)(subtype), asoc, \
+ sctp_state_tbl[state], state_fn->name)
+
+#define DEBUG_POST \
+ SCTP_DEBUG_PRINTK("sctp_do_sm postfn: " \
+ "asoc %p, status: %s\n", \
+ asoc, sctp_status_tbl[status])
+
+#define DEBUG_POST_SFX \
+ SCTP_DEBUG_PRINTK("sctp_do_sm post sfx: error %d, asoc %p[%s]\n", \
+ 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(sctp_event_t event_type, sctp_subtype_t subtype,
+ sctp_state_t state,
+ struct sctp_endpoint *ep,
+ struct sctp_association *asoc,
+ void *event_arg,
+ int gfp)
+{
+ sctp_cmd_seq_t commands;
+ sctp_sm_table_entry_t *state_fn;
+ sctp_disposition_t status;
+ int error = 0;
+ typedef const char *(printfn_t)(sctp_subtype_t);
+
+ static printfn_t *table[] = {
+ NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
+ };
+ printfn_t *debug_fn __attribute__ ((unused)) = table[event_type];
+
+ /* 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(event_type, state, subtype);
+
+ sctp_init_cmd_seq(&commands);
+
+ DEBUG_PRE;
+ status = (*state_fn->fn)(ep, asoc, subtype, event_arg, &commands);
+ DEBUG_POST;
+
+ error = sctp_side_effects(event_type, subtype, state,
+ ep, asoc, event_arg, status,
+ &commands, gfp);
+ DEBUG_POST_SFX;
+
+ return error;
+}
+
+#undef DEBUG_PRE
+#undef DEBUG_POST
+
+/*****************************************************************
+ * This the master state function side effect processing function.
+ *****************************************************************/
+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,
+ int 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:
+ SCTP_DEBUG_PRINTK("Ignored sctp protocol event - state %d, "
+ "event_type %d, event_id %d\n",
+ 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:
+ /* This should now be a command. */
+ break;
+
+ case SCTP_DISPOSITION_CONSUME:
+ case SCTP_DISPOSITION_ABORT:
+ /*
+ * 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:
+ printk(KERN_ERR "sctp protocol violation state %d "
+ "chunkid %d\n", state, subtype.chunk);
+ break;
+
+ case SCTP_DISPOSITION_NOT_IMPL:
+ printk(KERN_WARNING "sctp unimplemented feature in state %d, "
+ "event_type %d, event_id %d\n",
+ state, event_type, subtype.chunk);
+ break;
+
+ case SCTP_DISPOSITION_BUG:
+ printk(KERN_ERR "sctp bug in state %d, "
+ "event_type %d, event_id %d\n",
+ state, event_type, subtype.chunk);
+ BUG();
+ break;
+
+ default:
+ printk(KERN_ERR "sctp impossible disposition %d "
+ "in state %d, event_type %d, event_id %d\n",
+ status, state, event_type, subtype.chunk);
+ BUG();
+ break;
+ };
+
+bail:
+ return error;
+}
+
+/********************************************************************
+ * 2nd Level Abstractions
+ ********************************************************************/
+
+/* This is the side-effect interpreter. */
+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,
+ int gfp)
+{
+ int error = 0;
+ int force;
+ sctp_cmd_t *cmd;
+ sctp_chunk_t *new_obj;
+ sctp_chunk_t *chunk = NULL;
+ struct sctp_packet *packet;
+ struct list_head *pos;
+ struct timer_list *timer;
+ unsigned long timeout;
+ struct sctp_transport *t;
+ sctp_sackhdr_t sackh;
+
+ if(SCTP_EVENT_T_TIMEOUT != event_type)
+ chunk = (sctp_chunk_t *) 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. */
+ asoc = cmd->obj.ptr;
+ /* Register with the endpoint. */
+ sctp_endpoint_add_asoc(ep, asoc);
+ sctp_hash_established(asoc);
+ break;
+
+ case SCTP_CMD_UPDATE_ASSOC:
+ sctp_assoc_update(asoc, cmd->obj.ptr);
+ break;
+
+ case SCTP_CMD_PURGE_OUTQUEUE:
+ sctp_outq_teardown(&asoc->outqueue);
+ break;
+
+ case SCTP_CMD_DELETE_TCB:
+ /* 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. */
+ sctp_tsnmap_mark(&asoc->peer.tsn_map, cmd->obj.u32);
+ 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.ptr);
+ 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)
+ goto nomem;
+
+ 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.ptr, 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.ptr)
+ sctp_free_chunk(cmd->obj.ptr);
+ goto nomem;
+ }
+ 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.ptr)
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
+ SCTP_CHUNK(cmd->obj.ptr));
+ 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);
+ if (!new_obj)
+ goto nomem;
+ 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. */
+ SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
+ "chunk_up:", cmd->obj.ptr,
+ "ulpq:", &asoc->ulpq);
+ sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.ptr,
+ GFP_ATOMIC);
+ break;
+
+ case SCTP_CMD_EVENT_ULP:
+ /* Send a notification to the sockets layer. */
+ SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
+ "event_up:",cmd->obj.ptr,
+ "ulpq:",&asoc->ulpq);
+ sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ptr);
+ break;
+
+ case SCTP_CMD_REPLY:
+ /* Send a chunk to our peer. */
+ error = sctp_outq_tail(&asoc->outqueue,
+ cmd->obj.ptr);
+ break;
+
+ case SCTP_CMD_SEND_PKT:
+ /* Send a full packet to our peer. */
+ packet = cmd->obj.ptr;
+ sctp_packet_transmit(packet);
+ sctp_ootb_pkt_free(packet);
+ 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_TRANSMIT:
+ /* Kick start transmission. */
+ error = sctp_outq_flush(&asoc->outqueue, 0);
+ 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.ptr);
+ break;
+
+ case SCTP_CMD_TIMER_START:
+ timer = &asoc->timers[cmd->obj.to];
+ timeout = asoc->timeouts[cmd->obj.to];
+ if (!timeout)
+ BUG();
+
+ timer->expires = jiffies + timeout;
+ sctp_association_hold(asoc);
+ add_timer(timer);
+ 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 (timer_pending(timer) && del_timer(timer))
+ sctp_association_put(asoc);
+ break;
+
+ case SCTP_CMD_INIT_RESTART:
+ /* Do the needed accounting and updates
+ * associated with restarting an initialization
+ * timer.
+ */
+ asoc->counters[SCTP_COUNTER_INIT_ERROR]++;
+ asoc->timeouts[cmd->obj.to] *= 2;
+ if (asoc->timeouts[cmd->obj.to] >
+ asoc->max_init_timeo) {
+ asoc->timeouts[cmd->obj.to] =
+ asoc->max_init_timeo;
+ }
+
+ /* If we've sent any data bundled with
+ * COOKIE-ECHO we need to resend.
+ */
+ list_for_each(pos, &asoc->peer.transport_addr_list) {
+ t = list_entry(pos, struct sctp_transport,
+ transports);
+ sctp_retransmit_mark(&asoc->outqueue, t, 0);
+ }
+
+ sctp_add_cmd_sf(commands,
+ SCTP_CMD_TIMER_RESTART,
+ SCTP_TO(cmd->obj.to));
+ break;
+
+ case SCTP_CMD_INIT_FAILED:
+ sctp_cmd_init_failed(commands, asoc, cmd->obj.u32);
+ break;
+
+ case SCTP_CMD_ASSOC_FAILED:
+ sctp_cmd_assoc_failed(commands, asoc, event_type,
+ subtype, chunk, cmd->obj.u32);
+ break;
+
+ case SCTP_CMD_COUNTER_INC:
+ asoc->counters[cmd->obj.counter]++;
+ break;
+
+ case SCTP_CMD_COUNTER_RESET:
+ asoc->counters[cmd->obj.counter] = 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:
+ SCTP_DEBUG_PRINTK("vtag mismatch!\n");
+ break;
+
+ case SCTP_CMD_STRIKE:
+ /* Mark one strike against a transport. */
+ sctp_do_8_2_transport_strike(asoc, cmd->obj.transport);
+ break;
+
+ case SCTP_CMD_TRANSPORT_RESET:
+ t = cmd->obj.transport;
+ sctp_cmd_transport_reset(commands, asoc, t);
+ 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_cmd_hb_timer_update(commands, asoc, t);
+ break;
+
+ case SCTP_CMD_HB_TIMERS_STOP:
+ sctp_cmd_hb_timers_stop(commands, asoc);
+ 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.u32;
+ sackh.a_rwnd = 0;
+ sackh.num_gap_ack_blocks = 0;
+ sackh.num_dup_tsns = 0;
+ sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
+ SCTP_SACKH(&sackh));
+ break;
+
+ case SCTP_CMD_DISCARD_PACKET:
+ /* We need to discard the whole packet. */
+ chunk->pdiscard = 1;
+ break;
+
+ case SCTP_CMD_RTO_PENDING:
+ t = cmd->obj.transport;
+ t->rto_pending = 1;
+ break;
+
+ case SCTP_CMD_PART_DELIVER:
+ sctp_ulpq_partial_delivery(&asoc->ulpq, cmd->obj.ptr,
+ GFP_ATOMIC);
+ break;
+
+ case SCTP_CMD_RENEGE:
+ sctp_ulpq_renege(&asoc->ulpq, cmd->obj.ptr,
+ GFP_ATOMIC);
+ break;
+
+ default:
+ printk(KERN_WARNING "Impossible command: %u, %p\n",
+ cmd->verb, cmd->obj.ptr);
+ break;
+ };
+ if (error)
+ return error;
+ }
+
+ return error;
+
+nomem:
+ error = -ENOMEM;
+ return error;
+}
+
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)