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SABME flood on backup D-channel in NFAS configuration.

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Made delay restarting the PTP layer 2 link by the T200 time instead of
immediately.  Q.921 does not specify any particular time to restart the
layer 2 link.  Q.921 leaves it up to the upper layers to decide when or if
another attempt to bring layer 2 up is made.  Earlier versions of libpri
used the T200 time to restart the link.

This is a reimplementaion of -r1878.

(closes issue #18255)
Reported by: bklang

JIRA SWP-2508


git-svn-id: https://origsvn.digium.com/svn/libpri/branches/1.4@2111 2fbb986a-6c06-0410-b554-c9c1f0a7f128
This commit is contained in:
Richard Mudgett 2010-11-11 00:30:33 +00:00
parent d2984ee7eb
commit 12805eb71f
2 changed files with 79 additions and 37 deletions
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2
pri_internal.h
View File

@ -119,6 +119,8 @@ struct pri {
int t201_timer;
/*! Number of times T201 has expired. */
int t201_expirycnt;
/*! PTP layer 2 restart delay timer */
int restart_timer;
int cref; /* Next call reference value */

114
q921.c
View File

@ -58,7 +58,6 @@ static void q921_establish_data_link(struct q921_link *link);
static void q921_mdl_error(struct q921_link *link, char error);
static void q921_mdl_remove(struct q921_link *link);
static void q921_mdl_destroy(struct q921_link *link);
static void q921_restart_ptp_link_if_needed(struct q921_link *link);
/*!
* \internal
@ -549,6 +548,72 @@ static void stop_t200(struct q921_link *link)
}
}
static void restart_timer_expire(void *vctrl)
{
struct pri *ctrl = vctrl;
struct q921_link *link;
if (ctrl->debug & PRI_DEBUG_Q921_STATE) {
pri_message(ctrl, "Kick starting layer 2\n");
}
ctrl->restart_timer = 0;
link = &ctrl->link;
switch (link->state) {
case Q921_TEI_ASSIGNED:
/* Try to bring layer 2 up. */
q921_discard_iqueue(link);
q921_establish_data_link(link);
link->l3_initiated = 1;
q921_setstate(link, Q921_AWAITING_ESTABLISHMENT);
break;
default:
/* Looks like someone forgot to stop the restart timer. */
pri_error(ctrl, "Layer 2 restart delay timer expired in state %d(%s)\n",
link->state, q921_state2str(link->state));
break;
}
}
static void restart_timer_stop(struct pri *ctrl)
{
pri_schedule_del(ctrl, ctrl->restart_timer);
ctrl->restart_timer = 0;
}
static void restart_timer_start(struct pri *ctrl)
{
if (ctrl->debug & PRI_DEBUG_Q921_DUMP) {
pri_message(ctrl, "-- Starting layer 2 restart delay timer\n");
}
pri_schedule_del(ctrl, ctrl->restart_timer);
ctrl->restart_timer =
pri_schedule_event(ctrl, ctrl->timers[PRI_TIMER_T200], restart_timer_expire, ctrl);
}
static pri_event *q921_ptp_delay_restart(struct pri *ctrl)
{
pri_event *ev;
if (PTP_MODE(ctrl)) {
/*
* This is where we act a bit like L3 instead of L2, since we've
* got an L3 that depends on us keeping L2 automatically alive
* and happy for PTP links.
*/
restart_timer_start(ctrl);
/* Notify the upper layer that layer 2 is down. */
ctrl->schedev = 1;
ctrl->ev.gen.e = PRI_EVENT_DCHAN_DOWN;
ev = &ctrl->ev;
} else {
ev = NULL;
}
return ev;
}
/* This is the equivalent of the I-Frame queued up path in Figure B.7 in MULTI_FRAME_ESTABLISHED */
static int q921_send_queued_iframes(struct q921_link *link)
{
@ -765,6 +830,7 @@ static void t200_expire(void *vlink)
q921_setstate(link, Q921_TEI_ASSIGNED);
/* DL-RELEASE indication */
q931_dl_event(link, Q931_DL_EVENT_DL_RELEASE_IND);
q921_ptp_delay_restart(ctrl);
}
break;
case Q921_AWAITING_RELEASE:
@ -777,6 +843,7 @@ static void t200_expire(void *vlink)
/* DL-RELEASE confirm */
q931_dl_event(link, Q931_DL_EVENT_DL_RELEASE_CONFIRM);
q921_setstate(link, Q921_TEI_ASSIGNED);
q921_ptp_delay_restart(ctrl);
}
break;
default:
@ -876,6 +943,7 @@ int q921_transmit_iframe(struct q921_link *link, void *buf, int len, int cr)
switch (link->state) {
case Q921_TEI_ASSIGNED:
/* If we aren't in a state compatiable with DL-DATA requests, start getting us there here */
restart_timer_stop(ctrl);
q921_establish_data_link(link);
link->l3_initiated = 1;
q921_setstate(link, Q921_AWAITING_ESTABLISHMENT);
@ -1598,6 +1666,7 @@ static pri_event *q921_sabme_rx(struct q921_link *link, q921_h *h)
}
break;
case Q921_TEI_ASSIGNED:
restart_timer_stop(ctrl);
q921_send_ua(link, h->u.p_f);
q921_clear_exception_conditions(link);
link->v_s = link->v_a = link->v_r = 0;
@ -1658,7 +1727,7 @@ static pri_event *q921_disc_rx(struct q921_link *link, q921_h *h)
if (link->state == Q921_MULTI_FRAME_ESTABLISHED)
stop_t203(link);
q921_setstate(link, Q921_TEI_ASSIGNED);
q921_restart_ptp_link_if_needed(link);
res = q921_ptp_delay_restart(ctrl);
break;
default:
pri_error(ctrl, "Don't know what to do with DISC in state %d(%s)\n",
@ -1691,6 +1760,7 @@ static void q921_mdl_remove(struct q921_link *link)
switch (link->state) {
case Q921_TEI_ASSIGNED:
restart_timer_stop(ctrl);
/* XXX: deviation! Since we don't have a UI queue, we just discard our I-queue */
q921_discard_iqueue(link);
q921_setstate(link, Q921_TEI_UNASSIGNED);
@ -1835,29 +1905,14 @@ static void q921_mdl_handle_ptp_error(struct q921_link *link, char error)
ctrl = link->ctrl;
/* This is where we act a bit like L3 instead of L2, since we've got an L3 that depends on us
* keeping L2 automatically alive and happy for point to point links */
switch (error) {
case 'Z':
/* This is a special MDL error that actually isn't a spec error, but just so we
* have an asynchronous context from the state machine to kick a PTP link back
* up after being requested to drop politely (using DISC or DM) */
case 'G':
/* We pick it back up and put it back together for this case */
q921_discard_iqueue(link);
q921_establish_data_link(link);
q921_setstate(link, Q921_AWAITING_ESTABLISHMENT);
link->l3_initiated = 1;
ctrl->schedev = 1;
ctrl->ev.gen.e = PRI_EVENT_DCHAN_DOWN;
break;
case 'A':
case 'B':
case 'C':
case 'D':
case 'E':
case 'F':
case 'G':
case 'H':
case 'I':
case 'J':
@ -1869,16 +1924,6 @@ static void q921_mdl_handle_ptp_error(struct q921_link *link, char error)
}
}
static void q921_restart_ptp_link_if_needed(struct q921_link *link)
{
struct pri *ctrl;
ctrl = link->ctrl;
if (PTP_MODE(ctrl)) {
q921_mdl_error(&ctrl->link, 'Z');
}
}
static void q921_mdl_handle_error(struct q921_link *link, char error)
{
struct pri *ctrl;
@ -1995,14 +2040,6 @@ static void q921_mdl_error(struct q921_link *link, char error)
pri_error(ctrl, "TEI=%d MDL-ERROR (K): FRMR in state %d(%s)\n",
link->tei, link->state, q921_state2str(link->state));
break;
case 'Z':
if (is_debug_q921_state) {
/* Fake MDL-ERROR to kick start PTP L2 link back up. */
pri_message(ctrl,
"TEI=%d MDL-ERROR (Z): Kick starting L2 link in state %d(%s)\n",
link->tei, link->state, q921_state2str(link->state));
}
break;
default:
pri_message(ctrl, "TEI=%d MDL-ERROR (%c): in state %d(%s)\n",
link->tei, error, link->state, q921_state2str(link->state));
@ -2089,6 +2126,7 @@ static pri_event *q921_ua_rx(struct q921_link *link, q921_h *h)
q931_dl_event(link, Q931_DL_EVENT_DL_RELEASE_CONFIRM);
stop_t200(link);
q921_setstate(link, Q921_TEI_ASSIGNED);
res = q921_ptp_delay_restart(ctrl);
}
break;
default:
@ -2520,6 +2558,7 @@ static pri_event *q921_dm_rx(struct q921_link *link, q921_h *h)
if (h->u.p_f)
break;
/* else */
restart_timer_stop(ctrl);
q921_establish_data_link(link);
link->l3_initiated = 1;
q921_setstate(link, Q921_AWAITING_ESTABLISHMENT);
@ -2533,7 +2572,7 @@ static pri_event *q921_dm_rx(struct q921_link *link, q921_h *h)
q931_dl_event(link, Q931_DL_EVENT_DL_RELEASE_IND);
stop_t200(link);
q921_setstate(link, Q921_TEI_ASSIGNED);
q921_restart_ptp_link_if_needed(link);
res = q921_ptp_delay_restart(ctrl);
break;
case Q921_AWAITING_RELEASE:
if (!h->u.p_f)
@ -2542,6 +2581,7 @@ static pri_event *q921_dm_rx(struct q921_link *link, q921_h *h)
q931_dl_event(link, Q931_DL_EVENT_DL_RELEASE_CONFIRM);
stop_t200(link);
q921_setstate(link, Q921_TEI_ASSIGNED);
res = q921_ptp_delay_restart(ctrl);
break;
case Q921_MULTI_FRAME_ESTABLISHED:
if (h->u.p_f) {