/******************************************************************************
-Author: Samuel Jero
+Utility to convert a DCCP flow to a TCP flow for DCCP analysis via
+ tcptrace.
-Date: 5/2011
+Copyright (C) 2012 Samuel Jero <sj323707@ohio.edu>
-Description: Program to convert a DCCP flow to a TCP flow for DCCP analysis via
- tcptrace.
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+Author: Samuel Jero <sj323707@ohio.edu>
+Date: 11/2012
Notes:
- 1)Supports only a single DCCP contection per capture
- 2)Source Port!=Destination Port
- 3)DCCP MUST use 48 bit sequence numbers
- 4)Checksums are not computed (they are zeroed)
- 5)Only implements those packet types normally used in a session
- 6)DCCP Ack packets show up as TCP packets containing one byte
- 7)Very little error checking of packet headers
+ 1)CCID2 ONLY
+ 2)DCCP MUST use 48 bit sequence numbers
+ 3)DCCP DATA packets are not implemented (Linux doesn't use them)
+ 4)DCCP Ack packets show up as TCP packets containing one byte
******************************************************************************/
#include "dccp2tcp.h"
+#define DCCP2TCP_VERSION 1.6
+#define COPYRIGHT_YEAR 2013
+
+
int debug=0; /*set to 1 to turn on debugging information*/
int yellow=0; /*tcptrace yellow line as currently acked packet*/
int green=0; /*tcptrace green line as currently acked packet*/
int sack=0; /*add TCP SACKS*/
-pcap_t* in; /*libpcap input file discriptor*/
-pcap_dumper_t *out; /*libpcap output file discriptor*/
-struct seq_num *s1; /*sequence number structure for side one of connection*/
-struct seq_num *s2; /*sequence number structure for side two of connection*/
+pcap_t* in; /*libpcap input file discriptor*/
+pcap_dumper_t *out; /*libpcap output file discriptor*/
+struct connection *chead; /*connection list*/
-void PcapSavePacket(struct pcap_pkthdr *h, u_char *data);
-void process_packets();
void handle_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *bytes);
-int convert_packet(struct pcap_pkthdr *h, u_char **nptr, int *nlength, const u_char **optr, int *length);
-unsigned int interp_ack_vect(u_char* hdr);
-u_int32_t initialize_seq(struct seq_num **seq, __be16 source, __be32 initial);
-u_int32_t add_new_seq(struct seq_num *seq, __be32 num, int size, enum dccp_pkt_type type);
-u_int32_t convert_ack(struct seq_num *seq, __be32 num);
-int acked_packet_size(struct seq_num *seq, __be32 num);
-void ack_vect2sack(struct seq_num *seq, struct tcphdr *tcph, u_char* tcpopts, u_char* dccphdr, __be32 dccpack);
+void version();
+void usage();
/*Parse commandline options and open files*/
char *tfile=NULL;
/*parse commandline options*/
- if(argc<3 || argc > 9){
- dbgprintf(0, "Usage: dccp2tcp dccp_file tcp_file [-d] [-y] [-g] [-s]\n");
- exit(1);
+ if(argc > 9){
+ usage();
}
/*loop through commandline options*/
for(int i=1; i < argc; i++){
- if(argv[i][0]!='-'){
- if(dfile==NULL){ /*assign first non-dash argument to the dccp file*/
+ if(argv[i][0]!='-' || (argv[i][0]=='-' && strlen(argv[i])==1)){
+ if(dfile==NULL || argv[i][0]=='-'){
+ /*assign first non-dash (or only dash) argument to the dccp file*/
dfile=argv[i];
}else{
if(tfile==NULL){
tfile=argv[i]; /*assign second non-dash argument to the dccp file*/
}else{
- dbgprintf(0,"Usage: dccp2tcp dccp_file tcp_file [-d] [-y] [-g] [-s]\n");
- exit(1);
+ usage();
}
}
}else{
- if(argv[i][1]=='d' && strlen(argv[i])==2){ /*debug option*/
+ if(argv[i][1]=='d' && strlen(argv[i])==2){ /* -d */
debug++;
}
- if(argv[i][1]=='y' && strlen(argv[i])==2){ /*yellow option*/
+ if(argv[i][1]=='y' && strlen(argv[i])==2){ /* -y */
yellow=1;
}
- if(argv[i][1]=='g' && strlen(argv[i])==2){ /*green option*/
+ if(argv[i][1]=='g' && strlen(argv[i])==2){ /* -g */
green=1;
}
- if(argv[i][1]=='s' && strlen(argv[i])==2){ /*sack option*/
+ if(argv[i][1]=='s' && strlen(argv[i])==2){ /* -s */
sack++;
}
+ if(argv[i][1]=='h' && strlen(argv[i])==2){ /* -h */
+ usage();
+ }
+ if(argv[i][1]=='V' && strlen(argv[i])==2){ /* -V */
+ version();
+ }
}
}
if(dfile==NULL || tfile==NULL){
- dbgprintf(0,"Usage: dccp2tcp dccp_file tcp_file [-d] [-y] [-g] [-s]\n");
- exit(1);
+ usage();
}
/*all options validated*/
}
/*process packets*/
+ chead=NULL;
u_char *user=(u_char*)out;
pcap_loop(in, -1, handle_packet, user);
/*close files*/
pcap_close(in);
pcap_dump_close(out);
+
+ /*Delete all connections*/
+ cleanup_connections();
return 0;
}
void handle_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *bytes)
{
u_char *ndata;
- u_char *nptr;
- int length;
- int nlength;
struct pcap_pkthdr nh;
int link_type;
+ struct packet new;
+ struct const_packet old;
/*Determine the link type for this packet*/
link_type=pcap_datalink(in);
/*create new libpcap header*/
memcpy(&nh, h, sizeof(struct pcap_pkthdr));
- length=h->caplen;
- nlength=MAX_PACKET;
+
+ /*Setup packet structs*/
+ old.h=h;
+ old.length=h->caplen;
+ old.data=bytes;
+ old.dest_id=NULL;
+ old.src_id=NULL;
+ new.h=&nh;
+ new.length=MAX_PACKET;
+ new.dest_id=NULL;
+ new.src_id=NULL;
/*create buffer for new packet*/
- nptr=ndata=malloc(MAX_PACKET);
+ new.data=ndata=malloc(MAX_PACKET);
if(ndata==NULL){
dbgprintf(0,"Error: Couldn't allocate Memory\n");
exit(1);
}
/*make sure the packet is all zero*/
- memset(nptr, 0, MAX_PACKET);
+ memset(new.data, 0, MAX_PACKET);
/*do all the fancy conversions*/
- if(!do_encap(link_type, &nh, &nptr, &nlength, &bytes, &length)){
+ if(!do_encap(link_type, &new, &old)){
free(ndata);
return;
}
return;
}
-
/*do all the dccp to tcp conversions*/
-int convert_packet(struct pcap_pkthdr *h, u_char **nptr, int *nlength, const u_char **optr, int *length)
-{
- u_char* ncur=*nptr;
- const u_char* ocur=*optr;
- struct tcphdr *tcph;
- struct dccp_hdr *dccph;
- struct dccp_hdr_ext *dccphex;
- struct dccp_hdr_ack_bits *dccphack;
- int datalength;
- int len=0;
- const u_char* pd;
- u_char* npd;
- u_char* tcpopt;
-
- /*cast header pointers*/
- tcph=(struct tcphdr*)ncur;
- tcpopt=ncur+ sizeof(struct tcphdr);
- dccph=(struct dccp_hdr*)ocur;
- dccphex=(struct dccp_hdr_ext*)(ocur+sizeof(struct dccp_hdr));
- dccphack=(struct dccp_hdr_ack_bits*)(ocur+ sizeof(struct dccp_hdr) + sizeof(struct dccp_hdr_ext));
-
- dbgprintf(2,"Sequence Number: %llu\n", (unsigned long long)(((unsigned long)ntohs(dccph->dccph_seq)<<32) + ntohl(dccphex->dccph_seq_low)));
-
- /*determine data length*/
- datalength=*length - dccph->dccph_doff*4;
- pd=*optr + dccph->dccph_doff*4;
-
- /*set tcp standard features*/
- tcph->source=dccph->dccph_sport;
- tcph->dest=dccph->dccph_dport;
- tcph->doff=5;
- tcph->check=htonl(0);
- tcph->urg_ptr=0;
-
- /*Adjust TCP advertised window size*/
- if(!yellow){
- tcph->window=htons(30000);
- }
-
- /*Only accept the first connection*/
- if(s1 && s2 && dccph->dccph_sport!=s1->addr && dccph->dccph_dport!=s1->addr){
- return 0;
- }
-
- /*make changes by packet type*/
- if(dccph->dccph_type==DCCP_PKT_REQUEST){//DCCP REQUEST -->TCP SYN
- dbgprintf(2,"Packet Type: Request\n");
- if(!s1){
- if(yellow){
- tcph->window=htons(0);
- }
- tcph->ack_seq=htonl(0);
- tcph->seq=htonl(initialize_seq(&s1, dccph->dccph_sport, ntohl(dccphex->dccph_seq_low)));
- tcph->syn=1;
- tcph->ack=0;
- tcph->fin=0;
- tcph->rst=0;
-
- /* add Sack-permitted option, if relevant*/
- if(sack){
- *tcpopt=4;
- tcpopt++;
- *tcpopt=2;
- tcph->doff++;
- }
-
- /*calculate length*/
- len=tcph->doff*4;
- }
- }
-
- if(dccph->dccph_type==DCCP_PKT_RESPONSE){//DCCP RESPONSE-->TCP SYN,ACK
- dbgprintf(2,"Packet Type: Response\n");
- if(s1 && !s2){
- tcph->ack_seq=htonl(convert_ack(s1,ntohl(dccphack->dccph_ack_nr_low)));
- if(yellow){
- tcph->window=htons(0);
- }
- tcph->seq=htonl(initialize_seq(&s2, dccph->dccph_sport, ntohl(dccphex->dccph_seq_low)));
- tcph->syn=1;
- tcph->ack=1;
- tcph->fin=0;
- tcph->rst=0;
-
- /* add Sack-permitted option, if relevant*/
- if(sack){
- *tcpopt=4;
- *(tcpopt+1)=2;
- tcph->doff++;
- }
-
- /*calculate length*/
- len=tcph->doff*4;
- }
- }
-
- if(dccph->dccph_type==DCCP_PKT_DATA){//DCCP DATA----Never seen in packet capture
- dbgprintf(0,"DCCP Data packet not yet implemented\n");
- exit(1);
- }
-
- if(dccph->dccph_type==DCCP_PKT_DATAACK){//DCCP DATAACK-->TCP ACK with data
- dbgprintf(2,"Packet Type: DataAck\n");
- if(s1 && s2 && dccph->dccph_sport==s1->addr){ //determine which side of connection is sending this packet
- if(green){
- tcph->ack_seq=htonl(convert_ack(s2,ntohl(dccphack->dccph_ack_nr_low)));
- }else{
- tcph->ack_seq=htonl(convert_ack(s2,ntohl(dccphack->dccph_ack_nr_low)+interp_ack_vect((u_char*)dccph)));
- }
- tcph->seq=htonl(add_new_seq(s1, ntohl(dccphex->dccph_seq_low),datalength, dccph->dccph_type));
- if(yellow){
- tcph->window=htons(-interp_ack_vect((u_char*)dccph)*acked_packet_size(s2, ntohl(dccphack->dccph_ack_nr_low)));
- }
- if(sack){
- if(sack!=2 || interp_ack_vect((u_char*)dccph)){
- ack_vect2sack(s2, tcph, tcpopt, (u_char*)dccph, ntohl(dccphack->dccph_ack_nr_low) );
- }
- }
- }else if(s1 && s2 && dccph->dccph_sport==s2->addr){
- if(green){
- tcph->ack_seq=htonl(convert_ack(s1,ntohl(dccphack->dccph_ack_nr_low)));
- }else{
- tcph->ack_seq=htonl(convert_ack(s1,ntohl(dccphack->dccph_ack_nr_low)+interp_ack_vect((u_char*)dccph)));
- }
- tcph->seq=htonl(add_new_seq(s2, ntohl(dccphex->dccph_seq_low),datalength,dccph->dccph_type));
- if(yellow){
- tcph->window=htons(-interp_ack_vect((u_char*)dccph)*acked_packet_size(s1, ntohl(dccphack->dccph_ack_nr_low)));
- }
- if(sack){
- if(sack!=2 || interp_ack_vect((u_char*)dccph)){
- ack_vect2sack(s2, tcph, tcpopt, (u_char*)dccph, ntohl(dccphack->dccph_ack_nr_low) );
-
- }
- }
- }
-
- tcph->syn=0;
- tcph->ack=1;
- tcph->fin=0;
- tcph->rst=0;
-
- /*copy data*/
- npd=*nptr + tcph->doff*4;
- memcpy(npd, pd, datalength);
-
- /*calculate length*/
- len= tcph->doff*4 + datalength;
- }
-
- if(dccph->dccph_type==DCCP_PKT_ACK){ //DCCP ACK -->TCP ACK with no data
- dbgprintf(2,"Packet Type: Ack\n");
- if(s1 && s2 && dccph->dccph_sport==s1->addr){//determine which side of connection is sending this packet
- if(green){
- tcph->ack_seq=htonl(convert_ack(s2,ntohl(dccphack->dccph_ack_nr_low)));
- }else{
- tcph->ack_seq=htonl(convert_ack(s2,ntohl(dccphack->dccph_ack_nr_low)+interp_ack_vect((u_char*)dccph)));
- }
- tcph->seq=htonl(add_new_seq(s1, ntohl(dccphex->dccph_seq_low),1,dccph->dccph_type));
- if(yellow){
- tcph->window=htons(-interp_ack_vect((u_char*)dccph)*1400);
- if(-interp_ack_vect((u_char*)dccph)*1400 > 65535){
- printf("Note: TCP Window Overflow @ %d.%d\n", (int)h->ts.tv_sec, (int)h->ts.tv_usec);
- }
- }
- if(sack){
- if(sack!=2 || interp_ack_vect((u_char*)dccph)){
- ack_vect2sack(s2, tcph, tcpopt, (u_char*)dccph, ntohl(dccphack->dccph_ack_nr_low) );
- }
- }
- }else if(s1 && s2 && dccph->dccph_sport==s2->addr){
- if(green){
- tcph->ack_seq=htonl(convert_ack(s1,ntohl(dccphack->dccph_ack_nr_low)));
- }else{
- tcph->ack_seq=htonl(convert_ack(s1,ntohl(dccphack->dccph_ack_nr_low)+interp_ack_vect((u_char*)dccph)));
- }
- tcph->seq=htonl(add_new_seq(s2, ntohl(dccphex->dccph_seq_low),1,dccph->dccph_type));
- if(yellow){
- tcph->window=htons(-interp_ack_vect((u_char*)dccph)*1400);
- if(-interp_ack_vect((u_char*)dccph)*1400 > 65535){
- printf("Note: TCP Window Overflow @ %d.%d\n", (int)h->ts.tv_sec, (int)h->ts.tv_usec);
- }
- }
- if(sack){
- if(sack!=2 || interp_ack_vect((u_char*)dccph)){
- ack_vect2sack(s1, tcph, tcpopt, (u_char*)dccph, ntohl(dccphack->dccph_ack_nr_low) );
- }
- }
- }
-
- tcph->syn=0;
- tcph->ack=1;
- tcph->fin=0;
- tcph->rst=0;
-
- /*calculate length*/
- len=tcph->doff*4 + 1;
- }
-
- if(dccph->dccph_type==DCCP_PKT_CLOSEREQ){//DCCP CLOSEREQ----Never seen in packet capture
- dbgprintf(0,"DCCP CloseReq not yet implemented\n");
+int convert_packet(struct packet *new, const struct const_packet* old)
+{
+ struct tcphdr *tcph;
+ struct dccp_hdr *dccph;
+ struct dccp_hdr_ext *dccphex;
+ struct host *h1=NULL;
+ struct host *h2=NULL;
+
+ /*Safety checks*/
+ if(!new || !old || !new->data || !old->data || !new->h || !old->h){
+ dbgprintf(0,"Error: Convert Packet Function given bad data!\n");
exit(1);
+ return 0;
}
-
- if(dccph->dccph_type==DCCP_PKT_CLOSE){//DCCP CLOSE-->TCP FIN,ACK
- dbgprintf(2,"Packet Type: Close\n");
- if(s1 && s2 && dccph->dccph_sport==s1->addr){//determine which side of connection is sending this packet
- if(green){
- tcph->ack_seq=htonl(convert_ack(s2,ntohl(dccphack->dccph_ack_nr_low)));
- }else{
- tcph->ack_seq=htonl(convert_ack(s2,ntohl(dccphack->dccph_ack_nr_low)+interp_ack_vect((u_char*)dccph)));
- }
- tcph->seq=htonl(add_new_seq(s1, ntohl(dccphex->dccph_seq_low),1,dccph->dccph_type));
- if(yellow){
- tcph->window=htons(-interp_ack_vect((u_char*)dccph)*acked_packet_size(s2, ntohl(dccphack->dccph_ack_nr_low)));
- }
- if(sack){
- if(sack!=2 || interp_ack_vect((u_char*)dccph)){
- ack_vect2sack(s2, tcph, tcpopt, (u_char*)dccph, ntohl(dccphack->dccph_ack_nr_low) );
- }
- }
- }else if(s1 && s2 && dccph->dccph_sport==s2->addr){
- if(green){
- tcph->ack_seq=htonl(convert_ack(s1,ntohl(dccphack->dccph_ack_nr_low)));
- }else{
- tcph->ack_seq=htonl(convert_ack(s1,ntohl(dccphack->dccph_ack_nr_low)+interp_ack_vect((u_char*)dccph)));
- }
- tcph->seq=htonl(add_new_seq(s2, ntohl(dccphex->dccph_seq_low),1,dccph->dccph_type));
- if(yellow){
- tcph->window=htons(-interp_ack_vect((u_char*)dccph)*acked_packet_size(s1, ntohl(dccphack->dccph_ack_nr_low)));
- }
- if(sack){
- if(sack!=2 || interp_ack_vect((u_char*)dccph)){
- ack_vect2sack(s1, tcph, tcpopt, (u_char*)dccph, ntohl(dccphack->dccph_ack_nr_low) );
- }
- }
- }
-
- tcph->syn=0;
- tcph->ack=1;
- tcph->fin=1;
- tcph->rst=0;
-
- /*calculate length*/
- len=tcph->doff*4;
- }
-
- if(dccph->dccph_type==DCCP_PKT_RESET){//DCCP RESET-->TCP FIN,ACK (only seen at end of connection as CLOSE ACK)
- dbgprintf(2,"Packet Type: Reset\n");
- if(s1 && s2 && dccph->dccph_sport==s1->addr){//determine which side of connection is sending this packet
- if(green){
- tcph->ack_seq=htonl(convert_ack(s2,ntohl(dccphack->dccph_ack_nr_low)));
- }else{
- tcph->ack_seq=htonl(convert_ack(s2,ntohl(dccphack->dccph_ack_nr_low)+interp_ack_vect((u_char*)dccph)));
- }
- tcph->seq=htonl(add_new_seq(s1, ntohl(dccphex->dccph_seq_low),1,dccph->dccph_type));
- if(yellow){
- tcph->window=htons(-interp_ack_vect((u_char*)dccph)*acked_packet_size(s2, ntohl(dccphack->dccph_ack_nr_low)));
- }
- if(sack){
- if(sack!=2 || interp_ack_vect((u_char*)dccph)){
- ack_vect2sack(s2, tcph, tcpopt, (u_char*)dccph, ntohl(dccphack->dccph_ack_nr_low) );
- }
- }
- }else if(s1 && s2 && dccph->dccph_sport==s2->addr){
- if(green){
- tcph->ack_seq=htonl(convert_ack(s1,ntohl(dccphack->dccph_ack_nr_low)));
- }else{
- tcph->ack_seq=htonl(convert_ack(s1,ntohl(dccphack->dccph_ack_nr_low)+interp_ack_vect((u_char*)dccph)));
- }
- tcph->seq=htonl(add_new_seq(s2, ntohl(dccphex->dccph_seq_low),1,dccph->dccph_type));
- if(yellow){
- tcph->window=htons(-interp_ack_vect((u_char*)dccph)*acked_packet_size(s1, ntohl(dccphack->dccph_ack_nr_low)));
- }
- if(sack){
- if(sack!=2 || interp_ack_vect((u_char*)dccph)){
- ack_vect2sack(s1, tcph, tcpopt, (u_char*)dccph, ntohl(dccphack->dccph_ack_nr_low) );
- }
- }
- }
-
- tcph->syn=0;
- tcph->ack=1;
- tcph->fin=1;
- tcph->rst=0;
-
- /*calculate length*/
- len=tcph->doff*4;
+ if(old->length < (sizeof(struct dccp_hdr) + sizeof(struct dccp_hdr_ext)) || new->length < sizeof(struct dccp_hdr)){
+ dbgprintf(0, "Error: DCCP Packet Too short!\n");
+ return 0;
}
- if(dccph->dccph_type==DCCP_PKT_SYNC){//DCCP SYNC
- dbgprintf(2,"Packet Type: Sync\n");
- if(s1 && s2 && dccph->dccph_sport==s1->addr){//determine which side of connection is sending this packet
- if(green){
- tcph->ack_seq=htonl(convert_ack(s2,ntohl(dccphack->dccph_ack_nr_low)));
- }else{
- tcph->ack_seq=htonl(convert_ack(s2,ntohl(dccphack->dccph_ack_nr_low)+interp_ack_vect((u_char*)dccph)));
- }
- tcph->seq=htonl(add_new_seq(s1, ntohl(dccphex->dccph_seq_low),0,dccph->dccph_type));
- if(yellow){
- tcph->window=htons(-interp_ack_vect((u_char*)dccph)*acked_packet_size(s2, ntohl(dccphack->dccph_ack_nr_low)));
- }else{
- tcph->window=htons(0);
- }
- if(sack){
- if(sack!=2 || interp_ack_vect((u_char*)dccph)){
- ack_vect2sack(s2, tcph, tcpopt, (u_char*)dccph, ntohl(dccphack->dccph_ack_nr_low) );
- }
- }
- }else if(s1 && s2 && dccph->dccph_sport==s2->addr){
- if(green){
- tcph->ack_seq=htonl(convert_ack(s1,ntohl(dccphack->dccph_ack_nr_low)));
- }else{
- tcph->ack_seq=htonl(convert_ack(s1,ntohl(dccphack->dccph_ack_nr_low)+interp_ack_vect((u_char*)dccph)));
- }
- tcph->seq=htonl(add_new_seq(s2, ntohl(dccphex->dccph_seq_low),0,dccph->dccph_type));
- if(yellow){
- tcph->window=htons(-interp_ack_vect((u_char*)dccph)*acked_packet_size(s1, ntohl(dccphack->dccph_ack_nr_low)));
- }else{
- tcph->window=htons(0);
- }
- if(sack){
- if(sack!=2 || interp_ack_vect((u_char*)dccph)){
- ack_vect2sack(s1, tcph, tcpopt, (u_char*)dccph, ntohl(dccphack->dccph_ack_nr_low) );
- }
- }
- }
+ /*cast header pointers*/
+ tcph=(struct tcphdr*)new->data;
+ dccph=(struct dccp_hdr*)old->data;
+ dccphex=(struct dccp_hdr_ext*)(old->data+sizeof(struct dccp_hdr));
- tcph->syn=0;
- tcph->ack=1;
- tcph->fin=0;
- tcph->rst=0;
+ dbgprintf(2,"Sequence Number: %llu\n", (unsigned long long)
+ (((unsigned long)ntohs(dccph->dccph_seq)<<32) + ntohl(dccphex->dccph_seq_low)));
- /*calculate length*/
- len=tcph->doff*4;
+ /*Ensure packet is at least as large as DCCP header*/
+ if(old->length < dccph->dccph_doff*4){
+ dbgprintf(0, "Error: DCCP Header truncated\n");
+ return 0;
}
- if(dccph->dccph_type==DCCP_PKT_SYNCACK){//DCCP SYNACK
- dbgprintf(2,"Packet Type: SyncAck\n");
- if(s1 && s2 && dccph->dccph_sport==s1->addr){//determine which side of connection is sending this packet
- if(green){
- tcph->ack_seq=htonl(convert_ack(s2,ntohl(dccphack->dccph_ack_nr_low)));
- }else{
- tcph->ack_seq=htonl(convert_ack(s2,ntohl(dccphack->dccph_ack_nr_low)+interp_ack_vect((u_char*)dccph)));
- }
- tcph->seq=htonl(add_new_seq(s1, ntohl(dccphex->dccph_seq_low),0,dccph->dccph_type));
- if(yellow){
- tcph->window=htons(-interp_ack_vect((u_char*)dccph)*acked_packet_size(s2, ntohl(dccphack->dccph_ack_nr_low)));
- }else{
- tcph->window=htons(0);
- }
- if(sack){
- if(sack!=2 || interp_ack_vect((u_char*)dccph)){
- ack_vect2sack(s2, tcph, tcpopt, (u_char*)dccph, ntohl(dccphack->dccph_ack_nr_low));
- }
- }
- }else if(s1 && s2 && dccph->dccph_sport==s2->addr){
- if(green){
- tcph->ack_seq=htonl(convert_ack(s1,ntohl(dccphack->dccph_ack_nr_low)));
- }else{
- tcph->ack_seq=htonl(convert_ack(s1,ntohl(dccphack->dccph_ack_nr_low)+interp_ack_vect((u_char*)dccph)));
- }
- tcph->seq=htonl(add_new_seq(s2, ntohl(dccphex->dccph_seq_low),0,dccph->dccph_type));
- if(yellow){
- tcph->window=htons(-interp_ack_vect((u_char*)dccph)*acked_packet_size(s1, ntohl(dccphack->dccph_ack_nr_low)));
- }else{
- tcph->window=htons(0);
- }
- if(sack){
- if(sack!=2 || interp_ack_vect((u_char*)dccph)){
- ack_vect2sack(s1, tcph, tcpopt, (u_char*)dccph, ntohl(dccphack->dccph_ack_nr_low) );
- }
- }
- }
-
- tcph->syn=0;
- tcph->ack=1;
- tcph->fin=0;
- tcph->rst=0;
-
- /*calculate length*/
- len=tcph->doff*4;
+ /*Get Hosts*/
+ if(get_host(new->src_id, new->dest_id, new->id_len,
+ dccph->dccph_sport, dccph->dccph_dport, &h1, &h2)){
+ dbgprintf(0,"Error: Can't Get Hosts!\n");
+ return 0;
}
-
- if(dccph->dccph_type==DCCP_PKT_INVALID){//DCCP INVALID----Never seen in packet capture
- dbgprintf(0,"Invalid DCCP Packet!!\n");
+ if(h1==NULL || h2==NULL){
+ dbgprintf(0, "Error: Can't Get Hosts!\n");
return 0;
}
- *nlength=len;
-return 1;
-}
-
-
-/*Parse Ack Vector Options
- * Returns the Number of packets since last recorded loss*/
-unsigned int interp_ack_vect(u_char* hdr)
-{
- int hdrlen=((struct dccp_hdr*)hdr)->dccph_doff*4;
- //struct dccp_hdr_ext* e=(struct dccp_hdr_ext*)hdr + sizeof(struct dccp_hdr);
- int optlen;
- int len;
- int tmp;
- int bp=0;
- int additional=0;
- u_char* opt;
- u_char* cur;
-
- /*setup pointer to DCCP options and determine how long the options are*/
- optlen=hdrlen-sizeof(struct dccp_hdr) - sizeof(struct dccp_hdr_ext) - sizeof(struct dccp_hdr_ack_bits);
- opt=hdr + sizeof(struct dccp_hdr) + sizeof(struct dccp_hdr_ext) + sizeof(struct dccp_hdr_ack_bits);
-
- /*parse options*/
- while(optlen > 0){
- len=*(opt+1);
-
- /*One byte options (no length)*/
- if(*opt< 32){
- optlen--;
- opt++;
- continue;
- }
-
- /*Ack Vector Option*/
- if(*opt==38 || *opt==39){
- tmp=len-2;
- cur=opt+2;
- /*loop through Vector*/
- while(tmp > 0){
- /*ack vector works BACKWARDS through time*/
-
- /*keep track of total packets recieved and if
- a packet is lost, subtract all packets received
- after that*/
- if((*cur & 0xC0)==0xC0 || (*cur & 0xC0)==0x40){ //lost packet
- bp+=(*cur & 0x3F)+1;
- additional= -bp;
- }
-
- if((*cur & 0xC0)==0x00){ //received packet
- bp+= (*cur & 0x3F)+1;
- }
- tmp--;
- cur++;
- }
+ /*TODO: Add CCID detection*/
+ if(h1->type==CCID2 && h2->type==CCID2){
+ if(ccid2_convert_packet(new,old)==0){
+ return 0;
}
-
- optlen-=len;
- opt+=len;
}
-
- dbgprintf(2,"Ack vector adding: %i\n", additional);
-return additional;
-}
-
-
-/* Setup Sequence Number Structure*/
-u_int32_t initialize_seq(struct seq_num **seq, __be16 source, __be32 initial)
-{
- /*allocate structure*/
- *seq=(struct seq_num*)malloc(sizeof(struct seq_num));
- if(*seq==NULL){
- dbgprintf(0,"Can't Allocate Memory!\n");
- exit(1);
+ if(h1->type==CCID3 && h2->type==CCID3){
+ //ccid3_convert_packet(new,old);
}
-
- /*set default values*/
- (*seq)->cur=0;
- (*seq)->addr=source;
- (*seq)->size=TBL_SZ;
-
- /*allocate table*/
- (*seq)->table=(struct tbl*)malloc(sizeof(struct tbl)*TBL_SZ);
- if((*seq)->table==NULL){
- dbgprintf(0,"Can't Allocate Memory!\n");
- exit(1);
+ if(ccid2_convert_packet(new,old)==0){
+ return 0;
}
- /*add first sequence number*/
- (*seq)->table[0].old=initial;
- (*seq)->table[0].new=initial;
- (*seq)->table[0].type=DCCP_PKT_REQUEST;
- (*seq)->table[0].size=0;
-return initial;
-}
-
-
-/*Convert Sequence Numbers*/
-u_int32_t add_new_seq(struct seq_num *seq, __be32 num, int size, enum dccp_pkt_type type)
-{
- int prev;
- if(seq==NULL){
- dbgprintf(0,"ERROR NULL POINTER!\n");
- exit(1);
- }
-
- /*account for missing packets*/
- while(seq->table[seq->cur].old +1 < num && seq->table[seq->cur].old +1 > 0){
- prev=seq->cur;
- dbgprintf(1,"Missing Packet: %X\n",seq->table[prev].new+1);
- seq->cur=(seq->cur+1)%(seq->size);/*find next available table slot*/
- seq->table[seq->cur].old=seq->table[prev].old+1;
- seq->table[seq->cur].new=seq->table[prev].new + seq->table[prev].size;
- seq->table[seq->cur].size=size;
- seq->table[seq->cur].type=type;
+ /*Compute TCP checksums*/
+ if(new->id_len==IP4_ADDR_LEN){
+ tcph->check=0;
+ tcph->check=ipv4_pseudohdr_chksum(new->data,
+ new->length, new->dest_id, new->src_id, 6);
+ }else if(new->id_len==IP6_ADDR_LEN){
+ tcph->check=0;
+ tcph->check=ipv6_pseudohdr_chksum(new->data,
+ new->length, new->dest_id, new->src_id, 6);
+ }else{
+ tcph->check=0;
+ dbgprintf(2,"Unknown ID Length, can't do checksums");
}
- prev=seq->cur;
- seq->cur=(seq->cur+1)%(seq->size);/*find next available table slot*/
- seq->table[seq->cur].old=num;
- seq->table[seq->cur].size=size;
- seq->table[seq->cur].type=type;
- if(seq->table[prev].type==DCCP_PKT_REQUEST || seq->table[prev].type==DCCP_PKT_RESPONSE){
- seq->table[seq->cur].new=seq->table[prev].new + seq->table[prev].size;
- seq->table[seq->cur].size=1;
- return seq->table[prev].new + seq->table[prev].size+1;
- }
- if(type==DCCP_PKT_DATA || type==DCCP_PKT_DATAACK || type==DCCP_PKT_ACK){
- seq->table[seq->cur].new=seq->table[prev].new + seq->table[prev].size;
- return seq->table[seq->cur].new+1;
- }
- if(type==DCCP_PKT_SYNC || type==DCCP_PKT_SYNCACK){
- seq->table[seq->cur].new=seq->table[prev].new + seq->table[prev].size;
- return seq->table[seq->cur].new;
- }
- seq->table[seq->cur].new=seq->table[prev].new + seq->table[prev].size;
-return seq->table[seq->cur].new +1;
+ return 1;
}
-
-/*Convert Ack Numbers*/
-u_int32_t convert_ack(struct seq_num *seq, __be32 num)
-{
- if(seq==NULL){
- dbgprintf(0,"ERROR NULL POINTER!\n");
- exit(1);
- }
-
- /*loop through table looking for the DCCP ack number*/
- for(int i=0; i < seq->size; i++){
- if(seq->table[i].old==num){
- return seq->table[i].new + seq->table[i].size + 1; /*TCP acks the sequence number plus 1*/
- }
- }
-
- dbgprintf(1, "Error: Address Not Found! looking for: %X\n", num);
-return 0;
+void version(){
+ dbgprintf(0, "dccp2tcp version %.1f\nCopyright (C) %i Samuel Jero <sj323707@ohio.edu>\n", DCCP2TCP_VERSION,COPYRIGHT_YEAR);
+ dbgprintf(0, "This program comes with ABSOLUTELY NO WARRANTY.\n");
+ dbgprintf(0, "This is free software, and you are welcome to\nredistribute it under certain conditions.\n");
+ exit(0);
}
-
-/* Get size of packet being acked*/
-int acked_packet_size(struct seq_num *seq, __be32 num)
+/*Usage information for program*/
+void usage()
{
- if(seq==NULL){
- dbgprintf(0,"ERROR NULL POINTER!\n");
- exit(1);
- }
-
- /*loop through table looking for the DCCP ack number*/
- for(int i=0; i < seq->size; i++){
- if(seq->table[i].old==num){
- return seq->table[i].size;
- }
- }
-
- dbgprintf(1, "Error: Address Not Found! looking for: %X\n", num);
-return 0;
-}
-
-
-/*Ack Vector to SACK Option*/
-void ack_vect2sack(struct seq_num *seq, struct tcphdr *tcph, u_char* tcpopts, u_char* dccphdr, __be32 dccpack)
-{
- int hdrlen=((struct dccp_hdr*)dccphdr)->dccph_doff*4;
- int optlen;
- int len;
- int tmp;
- __be32 bp;
- u_char* temp;
- u_char* opt;
- u_char* cur;
- u_char* tlen;
- u_int32_t bL=0;
- u_int32_t bR;
- u_int32_t* pL;
- u_int32_t* pR;
- int num_blocks;
- int cont;
- int isopt;
-
- /*setup pointer to DCCP options and determine how long the options are*/
- optlen=hdrlen-sizeof(struct dccp_hdr) - sizeof(struct dccp_hdr_ext) - sizeof(struct dccp_hdr_ack_bits);
- opt=dccphdr + sizeof(struct dccp_hdr) + sizeof(struct dccp_hdr_ext) + sizeof(struct dccp_hdr_ack_bits);
-
- /*setup tcp pointers*/
- num_blocks=2;
- *tcpopts=5;
- tlen=tcpopts+1;
- temp=tlen;
- temp++;
- pL=(u_int32_t*)temp;
- pR=pL+1;
-
- /*setup tcp control variables*/
- bp=dccpack;
- cont=0;
- *tlen=2;
- isopt=0;
-
- /*parse options*/
- while(optlen > 0){
- len=*(opt+1);
-
- /*One byte options (no length)*/
- if(*opt< 32){
- optlen--;
- opt++;
- continue;
- }
-
- /*Ack Vector Option*/
- if(*opt==38 || *opt==39){
- tmp=len-2;
- cur=opt+2;
- /*loop through Vector*/
- while(tmp > 0){
- /*ack vector works BACKWARDS through time*/
-
- if((*cur & 0xC0)==0xC0 || (*cur & 0xC0)==0x40){ //lost packet
- if(cont){ /*end a SACK run, if one is started*/
- bR=convert_ack(seq, bp);
- cont=0;
- num_blocks--;
- *pR=htonl(bR);
- *pL=htonl(bL);
- tcph->doff+=2;
- *tlen+=8;
- pL=pR+1;
- pR=pL+1;
- }
- bp= bp - (*cur & 0x3F)- 1;
- }
-
- if((*cur & 0xC0)==0x00){ //received packet
- if(!cont){ /*if no SACK run and we can start another one, do so*/
- if(num_blocks>0){
- bL=convert_ack(seq, bp);
- isopt=1;
- cont=1;
-
- }
- }
- bp = bp -(*cur & 0x3F)- 1;
- }
- tmp--;
- cur++;
- }
- }
-
- optlen-=len;
- opt+=len;
- }
-
- /*if we are in the middle of a SACK run, close it*/
- if(cont){
- bR=convert_ack(seq, bp);
- *pR=htonl(bR);
- *pL=htonl(bL);
- tcph->doff+=2;
- *tlen+=8;
- cont=0;
- }
-
- /*adjust length if the option is actually added*/
- if(isopt){
- tcph->doff+=1;
- }
-return;
+ dbgprintf(0,"Usage: dccp2tcp dccp_file tcp_file [-d] [-h] [-V] [-y] [-g] [-s]\n");
+ dbgprintf(0, " -d Debug. May be repeated for aditional verbosity.\n");
+ dbgprintf(0, " -V Version information\n");
+ dbgprintf(0, " -h Help\n");
+ dbgprintf(0, " -y Yellow line is highest ACK\n");
+ dbgprintf(0, " -g Green line is highest ACK\n");
+ dbgprintf(0, " -s convert ACK Vectors to SACKS\n");
+ exit(0);
}
/*Debug Printf*/
projects / dccp2tcp / blobdiff