static int
addseg (tcptrace_context_t *context,
tcb * ptcb,
quadrant * pquad,
seqnum thisseg_firstbyte,
seglen len,
Bool * pout_order)
{
seqnum thisseg_lastbyte = thisseg_firstbyte + len - 1;
segment *pseg;
segment *pseg_new;
int rexlen = 0;
Bool split = FALSE;
/* check each segment in the segment list */
pseg = pquad->seglist_head;
/* (optimize expected case, it just goes at the end) */
if (pquad->seglist_tail &&
(thisseg_firstbyte > pquad->seglist_tail->seq_lastbyte))
pseg = NULL;
for (; pseg != NULL; pseg = pseg->next) {
if (thisseg_firstbyte > pseg->seq_lastbyte) {
/* goes beyond this one */
continue;
}
if (thisseg_firstbyte < pseg->seq_firstbyte) {
/* starts BEFORE this recorded segment */
/* if it also FINISHES before this segment, then it's */
/* out of order (otherwise it's a resend the collapsed */
/* multiple segments into one */
if (thisseg_lastbyte < pseg->seq_lastbyte)
*pout_order = TRUE;
/* make a new segment record for it */
pseg_new = create_seg(context, thisseg_firstbyte, len);
insert_seg_between (pquad, pseg_new, pseg->prev, pseg);
/* see if we overlap the next segment in the list */
if (thisseg_lastbyte < pseg->seq_firstbyte) {
/* we don't overlap, so we're done */
return (rexlen);
} else {
/* overlap him, split myself in 2 */
/* adjust new piece to mate with old piece */
pseg_new->seq_lastbyte = pseg->seq_firstbyte - 1;
/* pretend to be just the second half of this segment */
pseg_new->seq_lastbyte = pseg->seq_firstbyte - 1;
thisseg_firstbyte = pseg->seq_firstbyte;
len = thisseg_lastbyte - thisseg_firstbyte + 1;
/* fall through */
}
}
/* no ELSE, we might have fallen through */
if (thisseg_firstbyte >= pseg->seq_firstbyte) {
/* starts within this recorded sequence */
++pseg->retrans;
if (!split) {
/* must be a retransmission */
rtt_retrans(context, ptcb, pseg);
}
if (thisseg_lastbyte <= pseg->seq_lastbyte) {
/* entirely contained within this sequence */
rexlen += len;
return (rexlen);
}
/* else */
/* we extend beyond this sequence, split ourself in 2 */
/* (pretend to be just the second half of this segment) */
split = TRUE;
rexlen += pseg->seq_lastbyte - thisseg_firstbyte + 1;
thisseg_firstbyte = pseg->seq_lastbyte + 1;
len = thisseg_lastbyte - thisseg_firstbyte + 1;
}
}
/* if we got to the end, then it doesn't go BEFORE anybody, */
/* tack it onto the end */
pseg_new = create_seg(context, thisseg_firstbyte, len);
insert_seg_between (pquad, pseg_new, pquad->seglist_tail, NULL);
return (rexlen);
}
static int
addseg (tcb * ptcb,
quadrant * pquad,
seqnum thisseg_firstbyte, seglen len, Bool * pout_order,
u_short this_ip_id)
{
seqnum thisseg_lastbyte = thisseg_firstbyte + len - 1;
segment *pseg;
segment *pseg_new;
int rexlen = 0;
Bool split = FALSE;
double recovery_time = 0;
/* check each segment in the segment list */
pseg = pquad->seglist_head;
/* LM - all the segments are memorized in the seglist
Here has been implemented the heuristic discussed in
S. Jaiswal, G.Iannaccone, C. Diot, J.F. Kurose, D.Towsley
Measurement and Classification of Out-of-Sequence Packets in a Tier-1 IP Backbone
INFOCOM 2003 http://www.ieee-infocom.org/2003/technical_programs.htm
*/
/* (optimize expected case, it just goes at the end) */
if (pquad->seglist_tail &&
(thisseg_firstbyte > pquad->seglist_tail->seq_lastbyte))
pseg = NULL;
for (; pseg != NULL; pseg = pseg->next)
{
if (thisseg_firstbyte > pseg->seq_lastbyte)
{
/* goes beyond this one */
continue;
}
if (thisseg_firstbyte < pseg->seq_firstbyte)
{
/* starts BEFORE this recorded segment */
/* if it also FINISHES before this segment, then it's */
/* out of order (otherwise it's a resend the collapsed */
/* multiple segments into one */
if (thisseg_lastbyte < pseg->seq_lastbyte)
*pout_order = TRUE;
/* make a new segment record for it */
pseg_new = create_seg (thisseg_firstbyte, len, this_ip_id);
insert_seg_between (pquad, pseg_new, pseg->prev, pseg);
/* see if we overlap the next segment in the list */
if (thisseg_lastbyte <= pseg->seq_firstbyte)
{
/* we don't overlap, so we're done */
// LM start
rules_test (ptcb, pseg, len, pquad, this_ip_id, FALSE,
recovery_time);
return (rexlen);
}
else
{
/* overlap him, split myself in 2 */
//fprintf(fp_stdout, "split %lu %lu\n",
// len, pseg_new->seq_lastbyte-pseg_new->seq_firstbyte);
/* adjust new piece to mate with old piece */
pseg_new->seq_lastbyte = pseg->seq_firstbyte - 1;
// LM start
rules_test (ptcb, pseg,
pseg_new->seq_lastbyte - pseg_new->seq_firstbyte,
pquad, this_ip_id, FALSE, recovery_time);
/* pretend to be just the second half of this segment */
thisseg_firstbyte = pseg->seq_firstbyte;
len = thisseg_lastbyte - thisseg_firstbyte + 1;
/* fall through */
}
}
/* no ELSE, we might have fallen through */
if (thisseg_firstbyte >= pseg->seq_firstbyte)
{
/* starts within this recorded sequence */
++pseg->retrans;
recovery_time =
time2double (current_time) - time2double (pseg->time);
if (!split)
rtt_retrans (ptcb, pseg); /* must be a retransmission */
if (thisseg_lastbyte <= pseg->seq_lastbyte)
{
/* entirely contained within this sequence */
rexlen += len;
// LM start
rules_test (ptcb, pseg, len, pquad, this_ip_id, TRUE,
recovery_time);
return (rexlen);
}
/* else */
/* we extend beyond this sequence, split ourself in 2 */
/* (pretend to be just the second half of this segment) */
split = TRUE;
rexlen += pseg->seq_lastbyte - thisseg_firstbyte + 1;
thisseg_firstbyte = pseg->seq_lastbyte + 1;
// LM start
rules_test (ptcb, pseg, rexlen, pquad, this_ip_id, TRUE,
recovery_time);
len = thisseg_lastbyte - thisseg_firstbyte + 1;
}
}
/* if we got to the end, then it doesn't go BEFORE anybody, */
/* tack it onto the end */
pseg_new = create_seg (thisseg_firstbyte, len, this_ip_id);
insert_seg_between (pquad, pseg_new, pquad->seglist_tail, NULL);
/* MGM - management of the number of segments within this quadrant */
if (pquad->no_of_segments > MAX_SEG_PER_QUAD)
{
/* free up the first segment in this quadrant */
segment *tmp_pseg = pquad->seglist_head;
/* rebuild the list */
if (tmp_pseg->next != NULL)
tmp_pseg->next->prev = tmp_pseg->prev;
pquad->seglist_head = tmp_pseg->next;
/* recall the initial segment byte */
pquad->seglist_head->seq_firstbyte = tmp_pseg->seq_firstbyte;
/* remove the segment */
segment_release (tmp_pseg);
pquad->no_of_segments--;
}
pseg_new->type_of_segment = IN_SEQUENCE;
/* LM : This is an IN_SEQUENCE segment */
if (internal_src && !internal_dst)
{
add_histo (tcp_anomalies_out, IN_SEQUENCE);
}
else if (!internal_src && internal_dst)
{
add_histo (tcp_anomalies_in, IN_SEQUENCE);
}
#ifndef LOG_UNKNOWN
else if (internal_src && internal_dst)
#else
else
#endif
{
add_histo (tcp_anomalies_loc, IN_SEQUENCE);
}
if ((&(ptcb->ptp->c2s)) == ptcb) //(dir == C2S)
{
add_histo (tcp_anomalies_c2s, IN_SEQUENCE);
}
else
{
add_histo (tcp_anomalies_s2c, IN_SEQUENCE);
}
return (rexlen);
}
