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+ GNU GENERAL PUBLIC LICENSE
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+
+ END OF TERMS AND CONDITIONS
+
+ How to Apply These Terms to Your New Programs
+
+ If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+ To do so, attach the following notices to the program. It is safest
+to attach them to the start of each source file to most effectively
+state the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+ <one line to give the program's name and a brief idea of what it does.>
+ Copyright (C) <year> <name of author>
+
+ 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/>.
+
+Also add information on how to contact you by electronic and paper mail.
+
+ If the program does terminal interaction, make it output a short
+notice like this when it starts in an interactive mode:
+
+ <program> Copyright (C) <year> <name of author>
+ This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+ This is free software, and you are welcome to redistribute it
+ under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License. Of course, your program's commands
+might be different; for a GUI interface, you would use an "about box".
+
+ You should also get your employer (if you work as a programmer) or school,
+if any, to sign a "copyright disclaimer" for the program, if necessary.
+For more information on this, and how to apply and follow the GNU GPL, see
+<http://www.gnu.org/licenses/>.
+
+ The GNU General Public License does not permit incorporating your program
+into proprietary programs. If your program is a subroutine library, you
+may consider it more useful to permit linking proprietary applications with
+the library. If this is what you want to do, use the GNU Lesser General
+Public License instead of this License. But first, please read
+<http://www.gnu.org/philosophy/why-not-lgpl.html>.
--- /dev/null
+/******************************************************************************
+Author: Samuel Jero
+
+Date: 1/2011
+
+Description: Program to convert a DCCP flow to a TCP flow for DCCP analysis via
+ tcptrace.
+
+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
+******************************************************************************/
+#include "dccp2tcp.h"
+
+
+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*/
+
+
+
+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);
+void convert_packet(struct pcap_pkthdr *h, const u_char *odata, u_char *ndata);
+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 ack);
+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);
+
+
+/*Parse commandline options and open files*/
+int main(int argc, char *argv[])
+{
+ char ebuf[200];
+ char *erbuffer=ebuf;
+ char *dfile=NULL;
+ 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);
+ }
+
+ /*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*/
+ 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);
+ }
+ }
+ }else{
+ if(argv[i][1]=='d' && strlen(argv[i])==2){ /*debug option*/
+ debug++;
+ }
+ if(argv[i][1]=='y' && strlen(argv[i])==2){ /*yellow option*/
+ yellow=1;
+ }
+ if(argv[i][1]=='g' && strlen(argv[i])==2){ /*green option*/
+ green=1;
+ }
+ if(argv[i][1]=='s' && strlen(argv[i])==2){ /*sack option*/
+ sack=1;
+ }
+ }
+ }
+
+ if(dfile==NULL || tfile==NULL){
+ dbgprintf(0,"Usage: dccp2tcp dccp_file tcp_file [-d] [-y] [-g] [-s]\n");
+ exit(1);
+ }
+
+ /*all options validated*/
+
+ if(debug){
+ dbgprintf(1,"Debug On\n");
+ if(green){
+ dbgprintf(1,"Tcptrace green line at highest acknowledgment\n");
+ }else{
+ dbgprintf(1,"Tcptrace green line at highest acknowledged acknowledgment\n");
+ }
+ if(yellow){
+ dbgprintf(1,"Tcptrace yellow line at highest acknowledgment\n");
+ }else{
+ dbgprintf(1,"Tcptrace yellow line window value (a made up number)\n");
+ }
+ if(sack){
+ dbgprintf(1,"Adding TCP SACKS\n");
+ }
+ dbgprintf(1,"Input file: %s\n", dfile);
+ dbgprintf(1,"Output file: %s\n", tfile);
+ }
+
+ /*attempt to open input file*/
+ in=pcap_open_offline(dfile, erbuffer);
+ if(in==NULL){
+ dbgprintf(0,"Error opening input file\n");
+ exit(1);
+ }
+
+ /*attempt to open output file*/
+ out=pcap_dump_open(in,tfile);
+ if(out==NULL){
+ dbgprintf(0,"Error opening output file\n");
+ exit(1);
+ }
+
+ /*process packets*/
+ u_char *user=(u_char*)out;
+ pcap_loop(in, -1, handle_packet, user);
+
+ /*close files*/
+ pcap_close(in);
+ pcap_dump_close(out);
+return 0;
+}
+
+
+/*call back function for pcap_loop--do basic packet handling*/
+void handle_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *bytes)
+{
+ u_char *ndata;
+ struct pcap_pkthdr nh;
+
+ /*create new libpcap header*/
+ memcpy(&nh, h, sizeof(struct pcap_pkthdr));
+
+ /*create buffer for new packet*/
+ 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(ndata, 0, MAX_PACKET);
+
+ /*do all the fancy conversions*/
+ convert_packet(&nh, bytes, ndata);
+
+ /*save packet*/
+ pcap_dump(user,&nh, ndata);
+
+ free(ndata);
+return;
+}
+
+
+/*do all the dccp to tcp conversions*/
+void convert_packet(struct pcap_pkthdr *h, const u_char *odata, u_char *ndata)
+{
+ u_char* ncur=ndata;
+ const u_char* ocur=odata;
+ int length=h->caplen;
+ struct iphdr *iph;
+ struct tcphdr *tcph;
+ struct dccp_hdr *dccph;
+ struct dccp_hdr_ext *dccphex;
+ struct dccp_hdr_ack_bits *dccphack;
+ int datalength;
+ const u_char* pd;
+ u_char* npd;
+ u_char* tcpopt;
+
+ /*copy ethernet and ip headers over*/
+ memcpy(ncur, ocur, sizeof(struct ether_header)+sizeof(struct iphdr) );
+ ocur+=sizeof(struct ether_header)+ sizeof(struct iphdr);
+ ncur+=sizeof(struct ether_header) +sizeof(struct iphdr);
+ length-=sizeof(struct ether_header) +sizeof(struct iphdr);
+
+ /*set ip to indicate that tcp is next protocol*/
+ iph= (struct iphdr *) (ncur - sizeof(struct iphdr));
+ iph->protocol=6;
+ iph->check=htonl(0);
+
+ /*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=ntohs(iph->tot_len) - sizeof(struct iphdr) - dccph->dccph_doff*4;
+ pd=odata + sizeof(struct ether_header)+sizeof(struct iphdr) + 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);
+ }
+
+ /*make changes by packet type*/
+ if(dccph->dccph_type==DCCP_PKT_REQUEST){//DCCP REQUEST -->TCP SYN
+ dbgprintf(2,"Packet Type: Request\n");
+
+ 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++;
+ }
+
+ /*set libpcap header lengths*/
+ h->len=sizeof(struct ether_header) + sizeof(struct iphdr) + tcph->doff*4;
+ h->caplen=sizeof(struct ether_header) + sizeof(struct iphdr) + tcph->doff*4;
+
+ /*set length in ip header*/
+ iph->tot_len=htons(sizeof(struct iphdr) + tcph->doff*4);
+ }
+
+ if(dccph->dccph_type==DCCP_PKT_RESPONSE){//DCCP RESPONSE-->TCP SYN,ACK
+ dbgprintf(2,"Packet Type: Response\n");
+ 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++;
+ }
+
+ /*set libpcap header lengths*/
+ h->len=sizeof(struct ether_header) + sizeof(struct iphdr) + tcph->doff*4;
+ h->caplen=sizeof(struct ether_header) + sizeof(struct iphdr) + tcph->doff*4;
+
+ /*set length in ip header*/
+ iph->tot_len=htons(sizeof(struct iphdr) + 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 && 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));
+ if(yellow){
+ tcph->window=htons(-interp_ack_vect((u_char*)dccph)*acked_packet_size(s2, ntohl(dccphack->dccph_ack_nr_low)));
+ }
+ if(sack){
+ ack_vect2sack(s2, tcph, tcpopt, (u_char*)dccph, ntohl(dccphack->dccph_ack_nr_low) );
+ }
+ }else{
+ 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));
+ if(yellow){
+ tcph->window=htons(-interp_ack_vect((u_char*)dccph)*acked_packet_size(s1, ntohl(dccphack->dccph_ack_nr_low)));
+ }
+ if(sack){
+ 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=ndata+ sizeof(struct ether_header)+sizeof(struct iphdr)+ tcph->doff*4;
+ memcpy(npd, pd, datalength);
+
+ /*set libpcap header lengths*/
+ h->len=sizeof(struct ether_header) + sizeof(struct iphdr) + tcph->doff*4 + datalength;
+ h->caplen=sizeof(struct ether_header) + sizeof(struct iphdr) + tcph->doff*4 + datalength;
+
+ /*set length in ip header*/
+ iph->tot_len=htons(sizeof(struct iphdr) + sizeof(struct tcphdr) + datalength);
+ }
+
+ if(dccph->dccph_type==DCCP_PKT_ACK){ //DCCP ACK -->TCP ACK with no data
+ dbgprintf(2,"Packet Type: Ack\n");
+ if(s1 && 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));
+ 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){
+ ack_vect2sack(s2, tcph, tcpopt, (u_char*)dccph, ntohl(dccphack->dccph_ack_nr_low) );
+ }
+ }else{
+ 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));
+ 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){
+ 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;
+
+ /*set libpcap header lengths*/
+ h->len=sizeof(struct ether_header) + sizeof(struct iphdr) + tcph->doff*4+ 1;
+ h->caplen=sizeof(struct ether_header) + sizeof(struct iphdr) + tcph->doff*4+ 1;
+
+ /*set length in ip header*/
+ iph->tot_len=htons(sizeof(struct iphdr) + 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");
+ exit(1);
+ }
+
+ if(dccph->dccph_type==DCCP_PKT_CLOSE){//DCCP CLOSE-->TCP FIN,ACK
+ dbgprintf(2,"Packet Type: Close\n");
+ if(s1 && 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));
+ if(yellow){
+ tcph->window=htons(-interp_ack_vect((u_char*)dccph)*acked_packet_size(s2, ntohl(dccphack->dccph_ack_nr_low)));
+ }
+ if(sack){
+ ack_vect2sack(s2, tcph, tcpopt, (u_char*)dccph, ntohl(dccphack->dccph_ack_nr_low) );
+ }
+ }else{
+ 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));
+ if(yellow){
+ tcph->window=htons(-interp_ack_vect((u_char*)dccph)*acked_packet_size(s1, ntohl(dccphack->dccph_ack_nr_low)));
+ }
+ if(sack){
+ 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;
+
+ /*set libpcap header lengths*/
+ h->len=sizeof(struct ether_header) + sizeof(struct iphdr) + tcph->doff*4;
+ h->caplen=sizeof(struct ether_header) + sizeof(struct iphdr) + tcph->doff*4;
+
+ /*set length in ip header*/
+ iph->tot_len=htons(sizeof(struct iphdr) + 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 && 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));
+ if(yellow){
+ tcph->window=htons(-interp_ack_vect((u_char*)dccph)*acked_packet_size(s2, ntohl(dccphack->dccph_ack_nr_low)));
+ }
+ if(sack){
+ ack_vect2sack(s2, tcph, tcpopt, (u_char*)dccph, ntohl(dccphack->dccph_ack_nr_low) );
+ }
+ }else{
+ 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));
+ if(yellow){
+ tcph->window=htons(-interp_ack_vect((u_char*)dccph)*acked_packet_size(s1, ntohl(dccphack->dccph_ack_nr_low)));
+ }
+ if(sack){
+ 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;
+
+ /*set libpcap header lengths*/
+ h->len=sizeof(struct ether_header) + sizeof(struct iphdr) + tcph->doff*4;
+ h->caplen=sizeof(struct ether_header) + sizeof(struct iphdr) + tcph->doff*4;
+
+ /*set length in ip header*/
+ iph->tot_len=htons(sizeof(struct iphdr) + tcph->doff*4);
+ }
+
+ if(dccph->dccph_type==DCCP_PKT_SYNC){//DCCP SYNC
+ dbgprintf(2,"Packet Type: Sync\n");
+ if(s1 && 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));
+ 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){
+ ack_vect2sack(s2, tcph, tcpopt, (u_char*)dccph, ntohl(dccphack->dccph_ack_nr_low) );
+ }
+ }else{
+ 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));
+ 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){
+ 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;
+
+ /*set libpcap header lengths*/
+ h->len=sizeof(struct ether_header) + sizeof(struct iphdr) + tcph->doff*4+ 0;
+ h->caplen=sizeof(struct ether_header) + sizeof(struct iphdr) + tcph->doff*4+ 0;
+
+ /*set length in ip header*/
+ iph->tot_len=htons(sizeof(struct iphdr) + tcph->doff*4+0);
+ }
+
+ if(dccph->dccph_type==DCCP_PKT_SYNCACK){//DCCP SYNACK
+ dbgprintf(2,"Packet Type: SyncAck\n");
+ if(s1 && 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));
+ 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){
+ ack_vect2sack(s2, tcph, tcpopt, (u_char*)dccph, ntohl(dccphack->dccph_ack_nr_low) );
+ }
+ }else{
+ 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));
+ 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){
+ 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;
+
+ /*set libpcap header lengths*/
+ h->len=sizeof(struct ether_header) + sizeof(struct iphdr) + tcph->doff*4+0;
+ h->caplen=sizeof(struct ether_header) + sizeof(struct iphdr) + tcph->doff*4+0;
+
+ /*set length in ip header*/
+ iph->tot_len=htons(sizeof(struct iphdr) + tcph->doff*4+0);
+ }
+
+ if(dccph->dccph_type==DCCP_PKT_INVALID){//DCCP INVALID----Never seen in packet capture
+ dbgprintf(0,"Invalid DCCP Packet!!\n");
+ exit(1);
+ }
+return;
+}
+
+
+/*Parse Ack Vector Options*/
+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++;
+ }
+ }
+
+ 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);
+ }
+
+ /*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);
+ }
+
+ /*add first sequence number*/
+ (*seq)->table[0].old=initial;
+ (*seq)->table[0].new=initial;
+ (*seq)->table[0].size=1; /* size is actually zero; this is a convient way to get
+ these packets counted in the sequence number space*/
+return initial;
+}
+
+
+/*Convert Sequence Numbers*/
+u_int32_t add_new_seq(struct seq_num *seq, __be32 num, int size)
+{
+ 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;
+ }
+
+ 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].new=seq->table[prev].new + seq->table[prev].size;
+ seq->table[seq->cur].size=size;
+return seq->table[seq->cur].new;
+}
+
+
+/*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 +1; /*TCP acks the sequence number plus 1*/
+ }
+ }
+
+ dbgprintf(1, "Error: Address Not Found! looking for: %X\n", num);
+return 0;
+}
+
+
+/* Get size of packet being acked*/
+int acked_packet_size(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].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;
+}
+
+/*Debug Printf*/
+void dbgprintf(int level, const char *fmt, ...)
+{
+ va_list args;
+ if(debug>=level){
+ va_start(args, fmt);
+ vfprintf(stderr, fmt, args);
+ va_end(args);
+ }
+}
projects / dccp2tcp / commitdiff