--- /dev/null
+#include <stdlib.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/poll.h>
+#include <fcntl.h>
+
+#include "vtl.h"
+#include "vtl_harness.h"
+
+DEBUG_DECLARE();
+
+
+
+/* Connection List Handling */
+struct VTL_CON g_vtl_cons[MAX_VTL_CONS];
+int g_first_vtl;
+int g_last_vtl;
+int g_num_vtl_cons;
+
+int add_vtl_con(RawEthernetPacket * pkt);
+int find_vtl_con(RawEthernetPacket * pkt);
+
+/* Packet Handlers */
+int handle_local_tcp_pkt(RawEthernetPacket * pkt, iface_t * dev);
+int handle_remote_tcp_pkt(RawEthernetPacket * pkt);
+
+/* Packet functions */
+int make_ack_pkt(RawEthernetPacket * pkt, int vcon_i);
+int init_ack_template(RawEthernetPacket * pkt);
+
+
+unsigned short ip_id_ctr = 1;
+
+int main(int argc, char ** argv) {
+ RawEthernetPacket pkt;
+ RawEthernetPacket ack_pkt;
+ int i = 0;
+ iface_t * dev;
+ unsigned long src_addr;
+
+ debug_init("./vtl.log");
+
+ JRLDBG("Starting VTP Daemon\n");
+
+ for (i = 0; i < MAX_VTL_CONS; i++) {
+ g_vtl_cons[i].con_model.type = TCP_MODEL;
+ g_vtl_cons[i].in_use = false;
+ g_vtl_cons[i].next = -1;
+ g_vtl_cons[i].prev = -1;
+ }
+
+ g_last_vtl = -1;
+ g_first_vtl = -1;
+
+ g_num_vtl_cons = 0;
+
+ src_addr = ToIPAddress(argv[2]);
+ dev = if_connect(argv[1]);
+
+ while (if_read_pkt(dev, &pkt) != -1) {
+
+
+
+ if (is_tcp_pkt(&pkt)) {
+ if (GET_IP_SRC(pkt.data) == src_addr) {
+ handle_local_tcp_pkt(&pkt, dev);
+ } else if (GET_IP_DST(pkt.data) == src_addr) {
+ if (GET_IP_ID(pkt.data) == ip_id_ctr -1) {
+ continue;
+ }
+ handle_remote_tcp_pkt(&pkt);
+ printf("Remote tcp packet\n");
+ }
+ }
+ }
+
+
+ fclose(logfile);
+
+
+ return(0);
+}
+
+
+int handle_local_tcp_pkt(RawEthernetPacket * pkt, iface_t * dev) {
+ printf("local tcp pkt\n");
+ RawEthernetPacket ack_pkt;
+
+ int index = find_vtl_con(pkt);
+
+ if (index != -1) {
+ // packet in the system
+ sync_model(&(g_vtl_cons[index].con_model), pkt);
+
+
+ // dbg_dump_model(&(g_vtl_cons[index].con_model));
+ if (GET_TCP_DATA_LEN(pkt->data) > 0) {
+ create_empty_pkt(&(g_vtl_cons[index].con_model), &ack_pkt, INBOUND_PKT);
+ dbg_print_pkt_info(&ack_pkt);
+ if_write_pkt(dev, &ack_pkt);
+
+ }
+ } else {
+ if (is_syn_pkt(pkt)) {
+ int index = -1;
+
+ index = add_vtl_con(pkt);
+ printf("Connection added at %d\n", index);
+
+
+ }
+ }
+
+ return 0;
+
+}
+
+int handle_remote_tcp_pkt(RawEthernetPacket * pkt) {
+ int index;
+
+ index = find_vtl_con(pkt);
+
+ if (index != -1) {
+ sync_model(&(g_vtl_cons[index].con_model), pkt);
+ g_vtl_cons[index].con_model.model.ip_model.dst.ip_id = ip_id_ctr++;
+ }
+
+ return 0;
+}
+
+
+
+int find_vtl_con(RawEthernetPacket * pkt) {
+ int index = -1;
+ int i = 0;
+
+
+ FOREACH_VTL_CON(i,g_vtl_cons) {
+ if (is_model_pkt(&(g_vtl_cons[i].con_model), pkt)) {
+ index = i;
+ break;
+ }
+ }
+ return index;
+}
+
+
+
+int add_vtl_con(RawEthernetPacket * pkt) {
+ int i;
+
+ for (i = 0; i < MAX_VTL_CONS; i++) {
+ if (!(g_vtl_cons[i].in_use)) {
+ JRLDBG("Adding connection in slot %d\n", i);
+
+ initialize_model(&(g_vtl_cons[i].con_model), pkt);
+ g_vtl_cons[i].in_use = true;
+
+ dbg_dump_model(&(g_vtl_cons[i].con_model));
+
+ if (g_first_vtl == -1)
+ g_first_vtl = i;
+
+ g_vtl_cons[i].prev = g_last_vtl;
+ g_vtl_cons[i].next = -1;
+
+ if (g_last_vtl != -1) {
+ g_vtl_cons[g_last_vtl].next = i;
+ }
+
+ g_last_vtl = i;
+
+ g_num_vtl_cons++;
+ return 0;
+ }
+ }
+ return -1;
+}
+
+
+
+/*
+
+
+int handle_tcp_pkt(RawEthernetPacket *pkt) {
+
+
+ unsigned short ip_pkt_len = 0;
+ // unsigned char ip_hdr_len = (*(pkt->data + ETH_HDR_LEN) & 0x0f) << 2;
+ unsigned char ip_hdr_len = IP_HDR_LEN(pkt->data);
+ unsigned short * ip_pkt_len_ptr = (unsigned short *)(pkt->data + ETH_HDR_LEN + 2);
+ ip_pkt_len = ntohs(*ip_pkt_len_ptr);
+
+ JRLDBG("IP Header Length = %d(%x)\n", ip_hdr_len, *(pkt->data + ETH_HDR_LEN));
+ JRLDBG("IP Packet Length = %hu\n", ip_pkt_len);
+
+ if (is_syn_pkt(pkt) == 0) {
+ // we don't mess with connection establishment
+ int vcon_i;
+ unsigned long payload_len = 0;
+ unsigned short tcp_hdr_len = 0;
+ struct in_addr tmp;
+
+
+ tcp_hdr_len = (*(pkt->data + ETH_HDR_LEN + ip_hdr_len + 12) & 0xf0) >> 2;
+ payload_len = ip_pkt_len - (ip_hdr_len + tcp_hdr_len);
+
+ if ((payload_len == 0) && (is_ack_pkt(pkt) == 1)) {
+ // we just kill empty acks.
+ //return 0;
+ }
+
+ vcon_i = find_remote_vtp_con(pkt);
+
+ // Create ACK and send it.
+ make_ack_pkt(pkt, vcon_i);
+
+ g_vtl_cons[vcon_i].ack_template.VtpSerialize(vtp_in_fd, &tmp);
+
+ } else {
+ if(is_ack_pkt(pkt) == 1) {
+ int vcon_i = find_remote_vtp_con(pkt);
+ struct in_addr tmp;
+ make_ack_pkt(pkt, vcon_i);
+
+ g_vtl_cons[vcon_i].ack_template.VtpSerialize(vtp_in_fd, &tmp);
+ }
+#ifdef DEBUG
+ unsigned long * seq_num_ptr ;
+ unsigned long seq_num = 0;
+ unsigned long payload_len = 0;
+ unsigned short tcp_hdr_len = 0;
+ unsigned long ack = 0;
+
+ JRLDBG("Packet is a Syn Packet\n");
+
+ seq_num_ptr = (unsigned long *)(pkt->data + ETH_HDR_LEN + ip_hdr_len + 4);
+ seq_num = ntohl(*seq_num_ptr);
+ JRLDBG("Sequence Number = %lu\n", seq_num);
+
+ tcp_hdr_len = (*(pkt->data + ETH_HDR_LEN + ip_hdr_len + 12) & 0xf0) >> 2;
+ payload_len = ip_pkt_len - (ip_hdr_len + tcp_hdr_len);
+
+ JRLDBG("TCP Header Length = %hu\n", tcp_hdr_len);
+ JRLDBG("Payload Length = %lu\n", payload_len);
+
+
+
+ ack = (payload_len > 0) ? (seq_num + payload_len) : (seq_num + 1);
+ JRLDBG("Ack Num = %lu\n", ack);
+#endif
+ }
+
+ return 0;
+}
+
+int handle_rem_tcp_pkt(RawEthernetPacket * pkt) {
+ unsigned long * seq_num_ptr;
+ unsigned long seq_num;
+ unsigned char ip_hdr_len = IP_HDR_LEN(pkt->data);
+
+ seq_num_ptr = (unsigned long *)(pkt->data + ETH_HDR_LEN + ip_hdr_len + 4);
+ seq_num = ntohl(*seq_num_ptr);
+ JRLDBG("Received Packet, SeqNum = %lu\n", seq_num);
+
+ if (is_syn_pkt(pkt) == 1) {
+ // syn packet
+ seq_num++;
+ add_vtp_con(pkt, seq_num);
+ JRLDBG("Received Syn Packet, SeqNum = %lu\n", seq_num);
+ } else {
+ unsigned short ip_pkt_len = 0;
+ unsigned short * ip_pkt_len_ptr = (unsigned short *)(pkt->data + ETH_HDR_LEN + 2);
+ unsigned long payload_len = 0;
+ unsigned short tcp_hdr_len = 0;
+ int i_vcon = find_vtp_con(pkt);
+
+ ip_pkt_len = ntohs(*ip_pkt_len_ptr);
+
+ tcp_hdr_len = (*(pkt->data + ETH_HDR_LEN + ip_hdr_len + 12) & 0xf0) >> 2;
+
+ if (tcp_hdr_len > 20) {
+ unsigned long ts = get_tcp_timestamp(pkt->data + ETH_HDR_LEN + ip_hdr_len + 20, tcp_hdr_len - 20);
+ JRLDBG("TCP Timestamp = %lu(%lu)\n", ts, (unsigned long)ntohl(ts));
+ g_vtl_cons[i_vcon].tcp_timestamp = ts;
+ }
+
+ payload_len = ip_pkt_len - (ip_hdr_len + tcp_hdr_len);
+ seq_num += payload_len;
+ JRLDBG("Received Data Packet, SeqNum = %lu\n", seq_num);
+ g_vtl_cons[i_vcon].rem_seq_num = seq_num;
+ JRLDBG("Remote Sequence Number (con: %d) = %lu\n", i_vcon, seq_num);
+
+#if 0
+ {
+ int offset = 0;
+ unsigned short tcp_cksum = 0;
+ // Zero Ack Field
+ *(unsigned long *)(pkt->data + ETH_HDR_LEN + ip_hdr_len + 8) = 0;
+
+ // Zero Ack Flag
+ offset = ETH_HDR_LEN + ip_hdr_len + 13;
+ *(pkt->data + offset) &= 0xef;
+
+ // Zero TCP chksum
+ *(unsigned short *)(pkt->data + ETH_HDR_LEN + ip_hdr_len + 16) = 0;
+
+ // Get TCP chksum
+ tcp_cksum = get_tcp_checksum(pkt, ip_pkt_len - ip_hdr_len);
+
+ // Set TCP chksum
+ *(unsigned short *)(pkt->data + ETH_HDR_LEN + ip_hdr_len + 16) = tcp_cksum;
+ }
+#endif
+
+
+ }
+ return 0;
+}
+
+
+
+int make_ack_pkt(RawEthernetPacket * pkt, int vcon_i) {
+ unsigned long * seq_num_ptr ;
+ unsigned long seq_num = 0;
+ unsigned long rem_seq_num = 0;
+ unsigned long payload_len = 0;
+ unsigned short tcp_hdr_len = 0;
+ unsigned long ack = 0;
+ unsigned long local_ts = 0;
+ unsigned short tcp_cksum = 0;
+ unsigned char ip_hdr_len = IP_HDR_LEN(pkt->data);
+ unsigned short ip_pkt_len = *(unsigned short *)(pkt->data + ETH_HDR_LEN + 2);
+ RawEthernetPacket * ack_pkt = &(g_vtl_cons[vcon_i].ack_template);
+ unsigned short ack_ip_pkt_len = *(unsigned short *)(ack_pkt->data + ETH_HDR_LEN + 2);
+ unsigned char ack_ip_hdr_len = IP_HDR_LEN(ack_pkt->data);
+
+ ip_pkt_len = ntohs(ip_pkt_len);
+ ack_ip_pkt_len = ntohs(ack_ip_pkt_len);
+
+ seq_num_ptr = (unsigned long *)(pkt->data + ETH_HDR_LEN + ip_hdr_len + 4);
+ seq_num = ntohl(*seq_num_ptr);
+ JRLDBG("Sequence Number = %lu\n", seq_num);
+
+ tcp_hdr_len = (*(pkt->data + ETH_HDR_LEN + ip_hdr_len + 12) & 0xf0) >> 2;
+
+ if (is_syn_pkt(pkt) == 1) {
+ ack = seq_num + 1;
+ } else {
+ payload_len = ip_pkt_len - (ip_hdr_len + tcp_hdr_len);
+
+ JRLDBG("TCP Header Length = %hu\n", tcp_hdr_len);
+ JRLDBG("Payload Length = %lu\n", payload_len);
+
+ ack = seq_num + payload_len;
+ JRLDBG("Ack Num = %lu\n", ack);
+ }
+
+ // Set IP id
+ g_vtl_cons[vcon_i].ip_id--;
+ *(unsigned short *)(ack_pkt->data + ETH_HDR_LEN + 4) = htons(g_vtl_cons[vcon_i].ip_id);
+
+ // Recompute IP checksum
+ *(unsigned short *)(ack_pkt->data + ETH_HDR_LEN + 10) = 0;
+ *(unsigned short *)(ack_pkt->data + ETH_HDR_LEN + 10) = get_ip_checksum(ack_pkt);
+
+ //return 0;
+ // Set Sequence Number
+ rem_seq_num = htonl(g_vtl_cons[vcon_i].rem_seq_num);
+ *(unsigned long *)(ack_pkt->data + ETH_HDR_LEN + ack_ip_hdr_len + 4) = rem_seq_num;
+
+ // Set ACK Number
+ ack = htonl(ack);
+ *(unsigned long *)(ack_pkt->data + ETH_HDR_LEN + ack_ip_hdr_len + 8) = ack;
+
+ // Set TCP Timestamp option
+ local_ts = get_tcp_timestamp(pkt->data + ETH_HDR_LEN + ack_ip_hdr_len + 20, tcp_hdr_len - 20);
+
+ // We use this for debugging:
+ // If the TCPDump trace shows timestamps with the value of '5' then they are our packets
+ //
+
+ *(unsigned long *)(ack_pkt->data + ETH_HDR_LEN + ack_ip_hdr_len + 24) = g_vtl_cons[vcon_i].tcp_timestamp;
+// *(unsigned long *)(ack_pkt->data + ETH_HDR_LEN + ip_hdr_len + 24) = htonl(5);
+
+
+ *(unsigned long *)(ack_pkt->data + ETH_HDR_LEN + ack_ip_hdr_len + 28) = local_ts;
+
+ // Zero TCP chksum
+ *(unsigned short *)(ack_pkt->data + ETH_HDR_LEN + ack_ip_hdr_len + 16) = 0;
+
+ // Get TCP chksum
+ tcp_cksum = get_tcp_checksum(ack_pkt, ack_ip_pkt_len - ack_ip_hdr_len);
+
+ // Set TCP chksum
+ *(unsigned short *)(ack_pkt->data + ETH_HDR_LEN + ack_ip_hdr_len + 16) = tcp_cksum;
+
+ return 0;
+}
+
+
+
+
+
+// Connection List Handling //
+
+
+
+int init_ack_template(RawEthernetPacket * pkt) {
+ // We assume here that the ethernet and ip headers are ok, except for ip pkt length
+ // TCP is mostly right because its pulled off of a syn packet
+ // we need to zero the data, and reset the syn flag.
+
+ unsigned short IP_PACKET_LEN = 52;
+ unsigned short TCP_HEADER_LEN = 32;
+ unsigned char ip_hdr_len = IP_HDR_LEN(pkt->data);
+ unsigned short ip_pkt_len = 0;
+ unsigned short tcp_hdr_len = 0;
+ unsigned short payload_len = 0;
+ unsigned short * ip_pkt_len_ptr = (unsigned short *)(pkt->data + ETH_HDR_LEN + 2);
+ unsigned int offset = 0;
+ unsigned short ip_chksum = 0;
+
+ JRLDBG("--> Initializing ACK Template <--\n");
+
+ ip_pkt_len = ntohs(*ip_pkt_len_ptr);
+ JRLDBG("ip_pkt_len = %hu\n", ip_pkt_len);
+
+ tcp_hdr_len = (*(pkt->data + ETH_HDR_LEN + ip_hdr_len + 12) & 0xf0) >> 2;
+ payload_len = ip_pkt_len - (ip_hdr_len + tcp_hdr_len);
+ JRLDBG("tcp_hdr_len = %hu\n", tcp_hdr_len);
+ JRLDBG("payload_len = %hu\n", payload_len);
+
+ // set only the ack flags
+ offset = ETH_HDR_LEN + ip_hdr_len + 13;
+ *(pkt->data + offset) |= 0x10;
+ *(pkt->data + offset) &= 0xd0;
+
+ // set up tcp options
+ offset = ETH_HDR_LEN + ip_hdr_len + 20;
+ *(pkt->data + offset) = 0x01;
+ offset++;
+ *(pkt->data + offset) = 0x01;
+ offset++;
+ *(pkt->data + offset) = 0x08;
+ offset++;
+ *(pkt->data + offset) = 0x0a;
+
+ // Set Header Lengths
+ // IP HEADER = 20 (same)
+ // IP PACKET LEN = 52
+ // TCP Header len = 32
+
+ ip_pkt_len = htons(IP_PACKET_LEN);
+ memcpy(pkt->data + ETH_HDR_LEN + 2, &ip_pkt_len, 2);
+ tcp_hdr_len = (TCP_HEADER_LEN << 2);
+ *(pkt->data + ETH_HDR_LEN + ip_hdr_len + 12) &= 0x0f;
+ *(pkt->data + ETH_HDR_LEN + ip_hdr_len + 12) |= tcp_hdr_len;
+
+ JRLDBG("Setting TEMPLATE TCPLEN = %2x\n", *(pkt->data + ETH_HDR_LEN +ip_hdr_len + 12));
+
+ // Set IP Header chksum
+ *(unsigned short *)(pkt->data + ETH_HDR_LEN + 10) = 0;
+ ip_chksum = get_ip_checksum(pkt);
+ *(unsigned short *)(pkt->data + ETH_HDR_LEN + 10) = ip_chksum;
+
+
+ // Set RawEthernetPacket size
+ pkt->set_size(IP_PACKET_LEN + ETH_HDR_LEN);
+ pkt->set_type("et");
+
+ JRLDBG("--> ACK Template Initialized <--\n");
+
+
+ return 0;
+}
+
+*/
