Fix a number of Q.921 bugs, found doing TBR4 compliance testing, thanks to Tzafrir, Xorcom, and co. (#12861). Thanks!

git-svn-id: https://origsvn.digium.com/svn/libpri/branches/1.4@645 2fbb986a-6c06-0410-b554-c9c1f0a7f128
This commit is contained in:
Matthew Fredrickson 2008-11-22 00:34:26 +00:00
parent e1bfec4b1e
commit 2c104c4dbd

242
q921.c
View File

@ -56,6 +56,7 @@
} while(0)
static void reschedule_t203(struct pri *pri);
static void reschedule_t200(struct pri *pri);
static void q921_restart(struct pri *pri, int now);
static void q921_tei_release_and_reacquire(struct pri *master);
@ -97,7 +98,6 @@ static int q921_transmit(struct pri *pri, q921_h *h, int len)
pri_error(pri, "Short write: %d/%d (%s)\n", res, len + 2, strerror(errno));
return -1;
}
reschedule_t203(pri);
return 0;
}
@ -238,21 +238,6 @@ static int q921_ack_packet(struct pri *pri, int num)
pri->retrans = 0;
/* Decrement window size */
pri->windowlen--;
/* Search for something to send */
f = pri->txqueue;
while(f) {
if (!f->transmitted) {
/* Send it now... */
if (pri->debug & PRI_DEBUG_Q921_DUMP)
pri_message(pri, "-- Finally transmitting %d, since window opened up\n", f->h.n_s);
f->transmitted++;
pri->windowlen++;
f->h.n_r = pri->v_r;
q921_transmit(pri, (q921_h *)(&f->h), f->len);
break;
}
f = f->next;
}
return 1;
}
prev = f;
@ -265,22 +250,30 @@ static void t203_expire(void *);
static void t200_expire(void *);
static pri_event *q921_dchannel_down(struct pri *pri);
static void reschedule_t203(struct pri *pri)
static void reschedule_t200(struct pri *pri)
{
if (pri->t203_timer) {
pri_schedule_del(pri, pri->t203_timer);
if (pri->debug & PRI_DEBUG_Q921_DUMP)
pri_message(pri, "-- Restarting T203 counter\n");
/* Nothing to transmit, start the T203 counter instead */
pri->t203_timer = pri_schedule_event(pri, pri->timers[PRI_TIMER_T203], t203_expire, pri);
}
if (pri->debug & PRI_DEBUG_Q921_DUMP)
pri_message(pri, "-- Restarting T200 timer\n");
if (pri->t200_timer)
pri_schedule_del(pri, pri->t200_timer);
pri->t200_timer = pri_schedule_event(pri, pri->timers[PRI_TIMER_T200], t200_expire, pri);
}
static pri_event *q921_ack_rx(struct pri *pri, int ack)
static void reschedule_t203(struct pri *pri)
{
if (pri->debug & PRI_DEBUG_Q921_DUMP)
pri_message(pri, "-- Restarting T203 timer\n");
if (pri->t203_timer)
pri_schedule_del(pri, pri->t203_timer);
pri->t203_timer = pri_schedule_event(pri, pri->timers[PRI_TIMER_T203], t203_expire, pri);
}
static pri_event *q921_ack_rx(struct pri *pri, int ack, int send_untransmitted_frames)
{
int x;
int cnt=0;
pri_event *ev;
struct q921_frame *f;
/* Make sure the ACK was within our window */
for (x=pri->v_a; (x != pri->v_s) && (x != ack); Q921_INC(x));
if (x != ack) {
@ -300,8 +293,10 @@ static pri_event *q921_ack_rx(struct pri *pri, int ack)
if (pri->debug & PRI_DEBUG_Q921_DUMP)
pri_message(pri, "-- Since there was nothing left, stopping T200 counter\n");
/* Something was ACK'd. Stop T200 counter */
pri_schedule_del(pri, pri->t200_timer);
pri->t200_timer = 0;
if (pri->t200_timer) {
pri_schedule_del(pri, pri->t200_timer);
pri->t200_timer = 0;
}
}
if (pri->t203_timer) {
if (pri->debug & PRI_DEBUG_Q921_DUMP)
@ -311,10 +306,27 @@ static pri_event *q921_ack_rx(struct pri *pri, int ack)
}
if (pri->txqueue) {
/* Something left to transmit, Start the T200 counter again if we stopped it */
if (!pri->busy && send_untransmitted_frames) {
pri->retrans = 0;
/* Search for something to send */
f = pri->txqueue;
while(f && (pri->windowlen < pri->window)) {
if (!f->transmitted) {
/* Send it now... */
if (pri->debug & PRI_DEBUG_Q921_DUMP)
pri_message(pri, "-- Finally transmitting %d, since window opened up (%d)\n", f->h.n_s, pri->windowlen);
f->transmitted++;
pri->windowlen++;
f->h.n_r = pri->v_r;
f->h.p_f = 0;
q921_transmit(pri, (q921_h *)(&f->h), f->len);
}
f = f->next;
}
}
if (pri->debug & PRI_DEBUG_Q921_DUMP)
pri_message(pri, "-- Something left to transmit (%d), restarting T200 counter\n", pri->txqueue->h.n_s);
if (!pri->t200_timer)
pri->t200_timer = pri_schedule_event(pri, pri->timers[PRI_TIMER_T200], t200_expire, pri);
pri_message(pri, "-- Waiting for acknowledge, restarting T200 counter\n");
reschedule_t200(pri);
} else {
if (pri->debug & PRI_DEBUG_Q921_DUMP)
pri_message(pri, "-- Nothing left, starting T203 counter\n");
@ -384,20 +396,16 @@ static void q921_rr(struct pri *pri, int pbit, int cmd) {
static void t200_expire(void *vpri)
{
struct pri *pri = vpri;
q921_frame *f, *lastframe=NULL;
if (pri->txqueue) {
/* Retransmit first packet in the queue, setting the poll bit */
if (pri->debug & PRI_DEBUG_Q921_DUMP)
pri_message(pri, "-- T200 counter expired, What to do...\n");
/* Force Poll bit */
pri->txqueue->h.p_f = 1;
/* Update nr */
pri->txqueue->h.n_r = pri->v_r;
pri->v_na = pri->v_r;
pri->solicitfbit = 1;
pri->retrans++;
/* Up to three retransmissions */
if (pri->retrans < pri->timers[PRI_TIMER_N200]) {
pri->retrans++;
/* Reschedule t200_timer */
if (pri->debug & PRI_DEBUG_Q921_DUMP)
pri_message(pri, "-- Retransmitting %d bytes\n", pri->txqueue->len);
@ -406,7 +414,19 @@ static void t200_expire(void *vpri)
else {
if (!pri->txqueue->transmitted)
pri_error(pri, "!! Not good - head of queue has not been transmitted yet\n");
q921_transmit(pri, (q921_h *)&pri->txqueue->h, pri->txqueue->len);
/*Actually we need to retransmit the last transmitted packet, setting the poll bit */
for (f=pri->txqueue; f; f = f->next) {
if (f->transmitted)
lastframe = f;
}
if (lastframe) {
/* Force Poll bit */
lastframe->h.p_f = 1;
/* Update nr */
lastframe->h.n_r = pri->v_r;
pri->v_na = pri->v_r;
q921_transmit(pri, (q921_h *)&lastframe->h, lastframe->len);
}
}
if (pri->debug & PRI_DEBUG_Q921_DUMP)
pri_message(pri, "-- Rescheduling retransmission (%d)\n", pri->retrans);
@ -425,8 +445,8 @@ static void t200_expire(void *vpri)
} else if (pri->solicitfbit) {
if (pri->debug & PRI_DEBUG_Q921_DUMP)
pri_message(pri, "-- Retrying poll with f-bit\n");
pri->retrans++;
if (pri->retrans < pri->timers[PRI_TIMER_N200]) {
pri->retrans++;
pri->solicitfbit = 1;
q921_rr(pri, 1, 1);
pri->t200_timer = pri_schedule_event(pri, pri->timers[PRI_TIMER_T200], t200_expire, pri);
@ -507,14 +527,9 @@ int q921_transmit_iframe(struct pri *pri, void *buf, int len, int cr)
pri_schedule_del(pri, pri->t203_timer);
pri->t203_timer = 0;
}
if (!pri->t200_timer) {
if (pri->debug & PRI_DEBUG_Q921_DUMP)
pri_message(pri, "Starting T_200 timer\n");
pri->t200_timer = pri_schedule_event(pri, pri->timers[PRI_TIMER_T200], t200_expire, pri);
} else
if (pri->debug & PRI_DEBUG_Q921_DUMP)
pri_message(pri, "T_200 timer already going (%d)\n", pri->t200_timer);
if (pri->debug & PRI_DEBUG_Q921_DUMP)
pri_message(pri, "Starting T_200 timer\n");
reschedule_t200(pri);
} else {
pri_error(pri, "!! Out of memory for Q.921 transmit\n");
return -1;
@ -540,25 +555,26 @@ static void t203_expire(void *vpri)
pri->t203_timer = 0;
}
}
static pri_event *q921_handle_iframe(struct pri *pri, q921_i *i, int len)
{
int res;
pri_event *ev;
pri->solicitfbit = 0;
/* Make sure this is a valid packet */
if (i->n_s == pri->v_r) {
/* Increment next expected I-frame */
Q921_INC(pri->v_r);
/* Handle their ACK */
pri->sentrej = 0;
ev = q921_ack_rx(pri, i->n_r);
ev = q921_ack_rx(pri, i->n_r, 0);
if (ev)
return ev;
if (i->p_f) {
/* If the Poll/Final bit is set, immediate send the RR */
q921_rr(pri, 1, 0);
} else if (pri->busy) {
q921_rr(pri, 0, 0);
} else if (pri->busy || pri->retrans) {
q921_rr(pri, 0, 0);
}
/* Receive Q.931 data */
res = q931_receive(pri, (q931_h *)i->data, len - 4);
@ -883,6 +899,18 @@ static pri_event *q921_receive_MDL(struct pri *pri, q921_u *h, int len)
return NULL; /* Do we need to return something??? */
}
static int is_command(struct pri *pri, q921_h *h)
{
int command =0;
int c_r = h->s.h.c_r;
if ((pri->localtype == PRI_NETWORK && c_r == 0) ||
(pri->localtype == PRI_CPE && c_r == 1))
command = 1;
return( command );
}
static pri_event *__q921_receive_qualified(struct pri *pri, q921_h *h, int len)
{
q921_frame *f;
@ -917,74 +945,98 @@ static pri_event *__q921_receive_qualified(struct pri *pri, q921_h *h, int len)
/* Receiver Ready */
pri->busy = 0;
/* Acknowledge frames as necessary */
ev = q921_ack_rx(pri, h->s.n_r);
ev = q921_ack_rx(pri, h->s.n_r, 1);
if (ev)
return ev;
if (is_command(pri, h))
pri->solicitfbit = 0;
if (h->s.p_f) {
/* If it's a p/f one then send back a RR in return with the p/f bit set */
if (pri->solicitfbit) {
if (!is_command(pri, h)) {
if (pri->debug & PRI_DEBUG_Q921_DUMP)
pri_message(pri, "-- Got RR response to our frame\n");
pri->retrans = 0;
} else {
if (pri->debug & PRI_DEBUG_Q921_DUMP)
pri_message(pri, "-- Unsolicited RR with P/F bit, responding\n");
q921_rr(pri, 1, 0);
}
pri->solicitfbit = 0;
}
break;
case 1:
/* Receiver not ready */
if (pri->debug & PRI_DEBUG_Q921_STATE)
pri_message(pri, "-- Got receiver not ready\n");
if(h->s.p_f) {
/* Send RR if poll bit set */
q921_rr(pri, h->s.p_f, 0);
}
pri->busy = 1;
ev = q921_ack_rx(pri, h->s.n_r, 0);
if (ev)
return ev;
if (h->s.p_f && is_command(pri, h))
q921_rr(pri, 1, 0);
pri->solicitfbit = 1;
pri->retrans = 0;
if (pri->t203_timer) {
if (pri->debug & PRI_DEBUG_Q921_DUMP)
pri_message(pri, "Stopping T_203 timer\n");
pri_schedule_del(pri, pri->t203_timer);
pri->t203_timer = 0;
}
if (pri->debug & PRI_DEBUG_Q921_DUMP)
pri_message(pri, "Restarting T_200 timer\n");
reschedule_t200(pri);
break;
case 2:
/* Just retransmit */
if (pri->debug & PRI_DEBUG_Q921_STATE)
pri_message(pri, "-- Got reject requesting packet %d... Retransmitting.\n", h->s.n_r);
if (h->s.p_f) {
/* If it has the poll bit set, send an appropriate supervisory response */
q921_rr(pri, 1, 0);
}
sendnow = 0;
/* Resend the proper I-frame */
for(f=pri->txqueue;f;f=f->next) {
if ((sendnow || (f->h.n_s == h->s.n_r)) && f->transmitted) {
/* Matches the request, or follows in our window, and has
already been transmitted. */
sendnow = 1;
pri_error(pri, "!! Got reject for frame %d, retransmitting frame %d now, updating n_r!\n", h->s.n_r, f->h.n_s);
f->h.n_r = pri->v_r;
q921_transmit(pri, (q921_h *)(&f->h), f->len);
}
}
if (!sendnow) {
if (pri->txqueue) {
/* This should never happen */
if (!h->s.p_f || h->s.n_r) {
pri_error(pri, "!! Got reject for frame %d, but we only have others!\n", h->s.n_r);
}
} else {
/* Hrm, we have nothing to send, but have been REJ'd. Reset v_a, v_s, etc */
pri_error(pri, "!! Got reject for frame %d, but we have nothing -- resetting!\n", h->s.n_r);
pri->v_a = h->s.n_r;
pri->v_s = h->s.n_r;
/* Reset t200 timer if it was somehow going */
if (pri->t200_timer) {
pri_schedule_del(pri, pri->t200_timer);
pri->t200_timer = 0;
}
/* Reset and restart t203 timer */
if (pri->t203_timer)
pri_schedule_del(pri, pri->t203_timer);
pri->t203_timer = pri_schedule_event(pri, pri->timers[PRI_TIMER_T203], t203_expire, pri);
}
}
if (pri->busy && !is_command(pri, h))
pri->solicitfbit = 0;
pri->busy = 0;
if (is_command(pri, h) && h->s.p_f)
q921_rr(pri, 1, 0);
q921_ack_rx(pri, h->s.n_r, 0);
/*Resend only if we are in the Multiple Frame Established state or when
we are in the Time Recovery state and received responce with bit F=1*/
if ((pri->solicitfbit == 0) || (pri->solicitfbit && !is_command(pri, h) && h->s.p_f)) {
pri->solicitfbit = 0;
pri->retrans = 0;
sendnow = 0;
/* Resend I-frames starting from frame where f->h.n_s == h->s.n_r */
for (f = pri->txqueue; f && (f->h.n_s != h->s.n_r); f = f->next);
while (f) {
sendnow = 1;
if (f->transmitted || (!f->transmitted && (pri->windowlen < pri->window))) {
if (pri->debug & PRI_DEBUG_Q921_STATE)
pri_error(pri, "!! Got reject for frame %d, retransmitting frame %d now, updating n_r!\n", h->s.n_r, f->h.n_s);
f->h.n_r = pri->v_r;
f->h.p_f = 0;
if (!f->transmitted && (pri->windowlen < pri->window))
pri->windowlen++;
q921_transmit(pri, (q921_h *)(&f->h), f->len);
}
f = f->next;
}
if (!sendnow) {
if (pri->txqueue) {
/* This should never happen */
if (!h->s.p_f || h->s.n_r) {
pri_error(pri, "!! Got reject for frame %d, but we only have others!\n", h->s.n_r);
}
} else {
/* Hrm, we have nothing to send, but have been REJ'd. Reset v_a, v_s, etc */
pri_error(pri, "!! Got reject for frame %d, but we have nothing -- resetting!\n", h->s.n_r);
pri->v_a = h->s.n_r;
pri->v_s = h->s.n_r;
}
}
/* Reset t200 timer if it was somehow going */
if (pri->t200_timer) {
pri_schedule_del(pri, pri->t200_timer);
pri->t200_timer = 0;
}
/* Reset and restart t203 timer */
reschedule_t203(pri);
}
break;
default:
pri_error(pri, "!! XXX Unknown Supervisory frame ss=0x%02x,pf=%02xnr=%02x vs=%02x, va=%02x XXX\n", h->s.ss, h->s.p_f, h->s.n_r,