static int qfSeqGapValidate(qfSeq_t *qs) {
int i;
char *err = NULL;
for (i = 0; i < QF_SEQGAP_CT; i++) {
if (qs->gaps[i].a && qs->gaps[i].b) {
if (qfWrapCompare(qs->gaps[i].b, qs->gaps[i].a) < 1) {
err = "invalid";
break;
}
if (i && (qfWrapCompare(qs->gaps[i].a, qs->gaps[i-1].b) >= 0)) {
err = "inverted";
break;
}
}
}
if (!err) return 1;
fprintf(stderr, "%8s gap at %u in %p (nsn %u):\n", err, i, qs, qs->nsn);
for (i = 0; i < QF_SEQGAP_CT; i++) {
fprintf(stderr, "\t%u-%u (%u) (%d)\n",
qs->gaps[i].a, qs->gaps[i].b,
qs->gaps[i].b - qs->gaps[i].a,
i ? (qs->gaps[i-1].b - qs->gaps[i].a) : 0);
}
return 0;
}
void qfAckSegment(qfAck_t *qa,
uint32_t ack,
uint32_t sack,
uint32_t oct,
uint32_t ms)
{
if (!qa->fan || qfWrapCompare(ack, qa->fan) > 0) {
qa->fan = ack;
qa->fanlms = ms;
} else if (!oct) {
qa->dup_ct++;
}
if (sack && qfWrapCompare(sack, ack) > 0) {
qa->sel_ct++;
}
}
void qfRttSegment(qfRtt_t *rtt,
uint32_t seq,
uint32_t ack,
uint32_t tsval,
uint32_t tsecr,
uint32_t ms,
uint8_t tcpflags,
unsigned reverse)
{
qfRttDir_t *fdir, *rdir;
#if QOF_RTT_DEBUG
char *dirname;
#endif
/* select which side we're looking at */
if (reverse) {
fdir = &rtt->rev;
rdir = &rtt->fwd;
#if QOF_RTT_DEBUG
dirname = "rev";
#endif
} else {
fdir = &rtt->fwd;
rdir = &rtt->rev;
#if QOF_RTT_DEBUG
dirname = "fwd";
#endif
}
if (fdir->ackwait && (tcpflags & YF_TF_ACK) &&
qfWrapCompare(ack, fdir->tsack) >= 0)
{
/* got an ACK we were waiting for */
fdir->obs_ms = ms - fdir->lms;
if (qfRttSample(rtt)) {
#if QOF_RTT_DEBUG
fprintf(stderr, "\ton %3s ack %u for seq %u (%u)\n", dirname,
ack, fdir->tsack, ack - fdir->tsack);
#endif
}
fdir->ackwait = 0;
if (tsval) {
qfRttSetEcrWait(rdir, tsval, ms);
}
} else if (fdir->ecrwait && qfWrapCompare(tsecr, fdir->tsack) >= 0) {
/* got a TSECR we were waiting for */
if ((ms - fdir->lms) > fdir->obs_ms) {
/* Minimize measured RTT on TSECR samples */
fdir->obs_ms = ms - fdir->lms;
if (qfRttSample(rtt)) {
#if QOF_RTT_DEBUG
fprintf(stderr, "\ton %s ecr %u for val %u (%u)\n", dirname,
tsecr, fdir->tsack, tsecr - fdir->tsack);
#endif
}
}
fdir->ecrwait = 0;
qfRttSetAckWait(rdir, seq, ms);
} else if (!rdir->ackwait && !rdir->ecrwait) {
qfRttSetAckWait(rdir, seq, ms);
}
}
static int qfSeqGapFill(qfSeq_t *qs, uint32_t a, uint32_t b) {
int i;
uint32_t rtxoct = 0, nexa, nexb;
/* Segment might fill multiple gaps, so iterate until
we've distributed the entire segment */
while (qfWrapCompare(b, a) > 0) {
/* Seek to the next applicable gap */
i = 0;
while ((i < QF_SEQGAP_CT) && !qfSeqGapEmpty(qs->gaps, i) &&
(qfWrapCompare(a, qs->gaps[i].a)) < 0) i++;
/* If we're off the edge of the gapstack, this is pure RTX. */
if (i == QF_SEQGAP_CT || qfSeqGapEmpty(qs->gaps, i)) {
rtxoct += b - a;
break;
}
/* Everything greater than the gap is also RTX */
if (qfWrapCompare(b, qs->gaps[i].b) > 0) {
if (qfWrapCompare(a, qs->gaps[i].b) > 0) {
rtxoct += b - a;
break;
} else {
rtxoct += b - qs->gaps[i].b;
b = qs->gaps[i].b;
}
}
/* Check to see if we'll need to iterate */
if (qfWrapCompare(a, qs->gaps[i].a) < 0) {
/* A is less than the gap; prepare to iterate */
nexa = a;
nexb = b;
a = qs->gaps[i].a;
} else {
/* A and B within or on gap edge; terminate iteration */
nexa = 0;
nexb = 0;
}
/* Check for overlap within gap and fill */
if ((a == qs->gaps[i].a) && (b == qs->gaps[i].b)) {
/* Completely fill gap */
qfSeqGapShift(qs->gaps, i);
break;
} else if (b == qs->gaps[i].b) {
/* A within gap, B on edge; fill on the high side */
qs->gaps[i].b = a;
break;
} else if (a == qs->gaps[i].a) {
/* B within gap, A on edge; fill on the high side */
qs->gaps[i].a = b;
break;
} else {
/* A and B within gap; split the gap */
qs->seqlost += qfSeqGapUnshift(qs->gaps, i);
qs->gaps[i].a = b;
qs->gaps[i+1].b = a;
}
/* Modify segment and iterate */
a = nexa;
b = nexb;
}
/* Done. Count retransmit */
if (rtxoct) {
qs->rtx++;
return 1;
} else {
return 0;
}
}
int qfSeqSegment(qfSeq_t *qs, qfRtt_t *rtt, uint16_t mss,
uint8_t flags, uint32_t seq, uint32_t oct,
uint32_t ms, uint32_t tsval,
gboolean do_ts, gboolean do_iat) {
uint32_t lastms = 0;
/* Empty segments don't count */
if (!oct) return 0;
if (qfWrapCompare(seq, qs->nsn) < 0) {
/* Sequence less than NSN: fill */
if (seq - qs->nsn > qs->maxooo) {
qs->maxooo = seq - qs->nsn;
}
if (qfSeqGapFill(qs, seq, seq + oct)) {
qfCountLoss(qs, rtt, ms);
}
} else {
/* Sequence beyond NSN: push */
if (seq != qs->nsn) {
qfSeqGapPush(qs, qs->nsn, seq, mss);
/* signal loss for burst tracking */
qfCountLoss(qs, rtt, ms);
/* track max out of order */
if (seq - qs->nsn > qs->maxooo) {
qs->maxooo = seq - qs->nsn;
}
}
/* Detect wrap */
if (seq + oct < qs->nsn) {
qs->wrapct++;
}
/* Determine next sequence number */
qs->nsn = seq + oct;
/* track timestamp frequency */
if (do_ts && tsval) {
/* increment wrap counters if necessary */
if (tsval < qs->advtsval) {
qs->tsvalwrap++;
}
if (ms < qs->advlms) {
qs->lmswrap++;
}
/* save current value */
qs->advtsval = tsval;
}
/* and advance time */
lastms = qs->advlms;
qs->advlms = ms;
/* calculate interarrival/interdeparture time of advancing segments */
if (do_iat) {
uint32_t iat = 0, idt = 0, hz = 0;
iat = ms - lastms;
sstMeanAdd(&qs->seg_iat, iat);
if (do_ts && tsval && (hz = qfTimestampHz(qs))) {
idt = (1000 * (tsval - qs->advtsval)) / hz;
sstMeanAdd(&qs->seg_variat, iat - idt);
}
}
return 1;
}
/* if we're here, we didn't advance */
return 0;
}
