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Diffstat (limited to 'net/sctp/sm_sideeffect.c')
| -rw-r--r-- | net/sctp/sm_sideeffect.c | 1825 |
1 files changed, 1825 insertions, 0 deletions
diff --git a/net/sctp/sm_sideeffect.c b/net/sctp/sm_sideeffect.c new file mode 100644 index 000000000..970c6a486 --- /dev/null +++ b/net/sctp/sm_sideeffect.c @@ -0,0 +1,1825 @@ +// 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 <linux-sctp@vger.kernel.org> + * + * 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> + */ + +#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->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; + } + } +} + +/* 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; +} |