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/*
Copyright (c) 2000
International Computer Science Institute
All rights reserved.
This file may contain software code originally developed for the
Sting project. The Sting software carries the following copyright:
Copyright (c) 1998, 1999
Stefan Savage and the University of Washington.
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
3. All advertising materials mentioning features or use of this software
must display the following acknowledgment:
This product includes software developed by ACIRI, the AT&T
Center for Internet Research at ICSI (the International Computer
Science Institute). This product may also include software developed
by Stefan Savage at the University of Washington.
4. The names of ACIRI, ICSI, Stefan Savage and University of Washington
may not be used to endorse or promote products derived from this software
without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY ICSI AND CONTRIBUTORS ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL ICSI OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.
*/
#include <sys/types.h>
#include <sys/param.h>
#include <sys/time.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>
#include "base.h"
#include "inet.h"
#include "session.h"
#include "support.h"
#include "history.h"
extern struct TcpSession session;
struct History history[MAXHSZ];
void StorePacket (struct IPPacket *p) {
uint32 src, dst, seq, ack ;
uint16 sport, dport, win, urp, datalen, optlen;
uint16 ip_optlen;
uint8 flags;
ReadIPPacket(p,
&src, &dst,
&sport, &dport,
&seq,
&ack,
&flags,
&win,
&urp,
&datalen,
&ip_optlen,
&optlen);
if (src == session.src) {
history[session.hsz].type = SENT;
} else {
history[session.hsz].type = RCVD ;
}
history[session.hsz].timestamp = GetTime () - session.epochTime;
history[session.hsz].seqno = seq;
history[session.hsz].nextbyte = seq + datalen;
history[session.hsz].ackno = ack ;
history[session.hsz].fin = (flags & TCPFLAGS_FIN) ? 1 : 0;
history[session.hsz].syn = (flags & TCPFLAGS_SYN) ? 1 : 0;
history[session.hsz].rst = (flags & TCPFLAGS_RST) ? 1 : 0;
history[session.hsz].psh = (flags & TCPFLAGS_PSH) ? 1 : 0;
history[session.hsz].ack = (flags & TCPFLAGS_ACK) ? 1 : 0;
history[session.hsz].urg = (flags & TCPFLAGS_URG) ? 1 : 0;
history[session.hsz].ecn_echo = (flags & TCPFLAGS_ECN_ECHO) ? 1:0;
history[session.hsz].cwr = (flags & TCPFLAGS_CWR) ? 1 : 0;
history[session.hsz].ip_optlen = ip_optlen;
history[session.hsz].optlen = optlen ;
/* Grab IP Options from Ip Header - New */
if (ip_optlen > 0) {
if ((history[session.hsz].ip_opt = calloc(sizeof(uint8), ip_optlen)) == NULL) {
printf("StorePacket Error: Could not allocate history memory\nRETURN CODE: %d\n", ERR_MEM_ALLOC);
Quit (ERR_MEM_ALLOC);
}
memcpy(history[session.hsz].ip_opt, (char *)p->ip + sizeof(struct IpHeader), ip_optlen);
}
/* Grab TCP options from TCP Header */
if (optlen > 0) {
if ((history[session.hsz].opt = calloc(sizeof(uint8), optlen)) == NULL) {
Quit (ERR_MEM_ALLOC);
}
memcpy(history[session.hsz].opt, (char *)p->tcp + sizeof(struct TcpHeader), optlen);
}
history[session.hsz].dlen = datalen;
if ((history[session.hsz].data = calloc(sizeof(uint8), datalen)) == NULL) {
Quit (ERR_MEM_ALLOC);
}
/* Copy data bytes */
memcpy(history[session.hsz].data,
(char *)p->tcp + sizeof(struct TcpHeader) + optlen,
datalen);
session.hsz++;
if (session.hsz >= MAXHSZ) {
Quit(TOO_MANY_PKTS);
}
}
int reordered(struct IPPacket *p) {
int i;
int count = 0;
double ts = -99999;
/*
* This might be either an unwanted packet drop, or just a reordering.
* Test:
* If we have not sent three acks for this packet
* AND the gap between this packet and previous one is "small" (i.e. not a timeout)
* then its a reordering, and not a retransmission.
*/
/* count the number of (dup) ACKs sent */
for (i = 0; i < session.hsz; i++) {
if ((history[i].type == SENT) &&
(history[i].ack)) {
if (history[i].ackno == history[session.hsz - 1].seqno)
count += 1;
}
}
if (count > 0) {
session.num_dup_acks += count - 1;
switch (count) {
case 1: /* no dup acks */
session.num_pkts_0_dup_acks += 1;
break;
case 2: /* 1 dup acks */
session.num_pkts_1_dup_acks += 1;
break;
case 3: /* 2 dup acks */
session.num_pkts_2_dup_acks += 1;
break;
case 4: /* 3 dup acks */
session.num_pkts_3_dup_acks += 1;
break;
default:
session.num_pkts_4_or_more_dup_acks += 1;
break;
}
}
/* 3 dup acks? => Fast retransmission */
if (count > 3) {
printf("Fast retransmit...\n");
return 3;
}
/* Compute elapsed time between this packet and the previously RCVD packet */
for (i = (session.hsz - 2); i >= 0; i--) {
if ((history[i].type == RCVD) && (history[i].dlen > 0)) {
ts = history[i].timestamp;
break;
}
}
if ((history[session.hsz - 1].timestamp - ts) > RTT_TO_MULT * (session.rtt + PLOTDIFF)) {
printf ("RTO ===> %f %f\n", history[session.hsz - 1].timestamp, ts);
return 2;
}
printf ("#### Acks %d\n", count);
printf ("#### reordering detected\n");
session.num_reordered++;
return 1;
}
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