void send_icmp_destination_host_unreachable(struct sr_instance* sr,
uint8_t *buf, unsigned int len) {
/* sr_ethernet_hdr_t* ether_hdr = (sr_ethernet_hdr_t*)buf; */
print_hdrs(buf, len);
}
void sr_handlepacket(struct sr_instance* sr,
uint8_t * packet/* lent */,
unsigned int len,
char* interface/* lent */)
{
printf("Router Accessed\n");
/* REQUIRES */
assert(sr);
assert(packet);
assert(interface);
struct sr_if * iface = sr_get_interface(sr, interface);
printf("*** -> Received packet of length %d \n",len);
/* Ethernet Protocol */
if(len>=34){
uint8_t* ether_packet = malloc(len+28);
memcpy(ether_packet,packet,len);
print_hdrs(packet,len);
uint16_t package_type = ethertype(ether_packet);
enum sr_ethertype arp = ethertype_arp;
enum sr_ethertype ip = ethertype_ip;
if (strcmp(iface->name,interface) == 0){
printf("Right interface\n");
if(package_type==arp){
/* ARP protocol */
sr_handleARPpacket(sr, ether_packet, len, iface);
}else if(package_type==ip){
/* IP protocol */
if (sr->mode == 1){
sr_natHandleIP(sr,ether_packet,len,iface);
} else{
sr_handleIPpacket(sr, ether_packet,len, iface);
}
}else{
/* drop package */
printf("bad protocol! BOO! \n");
}
}
free(ether_packet);
}
}/* end sr_ForwardPacket */
/*---------------------------------------------------------------------
* Method: eth_frame_send_with_mac(struct sr_instance* sr,
uint8_t* packet,
unsigned int len,
unsigned char* mac,
char* iface)
* Scope: Global
*
* send the ethernet frame
*
*---------------------------------------------------------------------*/
int eth_frame_send_with_mac(
struct sr_instance* sr,
uint8_t* packet,
unsigned int len,
unsigned char* mac,
char* iface) {
printf("Sending Packet\n");
// Cast the packet in order to update fields.
sr_ethernet_hdr_t* e_packet = (sr_ethernet_hdr_t *)(packet);
struct sr_if* interface = sr_get_interface(sr, iface);
// Set fields
memcpy(e_packet->ether_dhost, mac, ETHER_ADDR_LEN);
memcpy(e_packet->ether_shost, interface->addr, ETHER_ADDR_LEN);
// Send the packet
print_hdrs(packet, len);
sr_send_packet(sr, packet, len, iface);
return 0;
}
void send_arp_request(struct sr_instance* sr, struct sr_arpreq* req) {
/* send arp request, make arp header and ether header.*/
struct sr_if* interface_sr_if = sr_get_interface(sr, req->packets->iface);
sr_arp_hdr_t* arp_header =
(struct sr_arp_hdr*)malloc(sizeof(struct sr_arp_hdr));
arp_header->ar_hrd = htons(arp_hrd_ethernet);
arp_header->ar_pro = htons(ethertype_ip);
arp_header->ar_hln = ETHER_ADDR_LEN;
arp_header->ar_pln = sizeof(uint32_t);
arp_header->ar_op = htons(arp_op_request);
arp_header->ar_sip = interface_sr_if->ip;
arp_header->ar_tip = req->ip;
memcpy(arp_header->ar_sha, interface_sr_if->addr, ETHER_ADDR_LEN);
unsigned int len_packet = sizeof(struct sr_arp_hdr)
+ sizeof(struct sr_ethernet_hdr);
uint8_t* packet = (uint8_t*)malloc(len_packet);
sr_ethernet_hdr_t* ether_header =
(sr_ethernet_hdr_t*)malloc(sizeof(struct sr_ethernet_hdr));
ether_header->ether_type = htons(ethertype_arp);
memset(ether_header->ether_dhost, 255, ETHER_ADDR_LEN);
memcpy(ether_header->ether_shost, interface_sr_if->addr, ETHER_ADDR_LEN);
memcpy(packet, ether_header, sizeof(struct sr_ethernet_hdr));
memcpy(packet + sizeof(struct sr_ethernet_hdr), arp_header,
sizeof(struct sr_arp_hdr));
print_hdrs(packet, len_packet);
sr_send_packet(sr, packet, len_packet, interface_sr_if->name);
/* free(arp_header); */
}
void sr_send_ip(struct sr_instance* sr, uint8_t* packet,
unsigned int len, char* iface)
{
printf("Forwarding IP packet...\n");
struct sr_if* interface = sr_get_interface(sr, iface);
struct sr_ip_hdr* ipHeader = (struct sr_ip_hdr*)(packet + sizeof(sr_ethernet_hdr_t));
/* Fetch the outgoing MAC from the ARP table */
struct sr_arpentry * arpCacheEntry = sr_arpcache_lookup(&(sr->cache), ipHeader->ip_dst);
/* Build the ethernet header */
struct sr_ethernet_hdr* ethHeader = (struct sr_ethernet_hdr*)packet;
memcpy(ethHeader->ether_shost, (char*)interface->addr, ETHER_ADDR_LEN);
memcpy(ethHeader->ether_dhost, (char*)arpCacheEntry->mac, ETHER_ADDR_LEN);
ethHeader->ether_type = htons(ethertype_ip);
print_hdrs(packet, len);
sr_send_packet(sr, packet, len, iface);
printf("Sent on interface...%s\n", iface);
free(arpCacheEntry);
}/* -- sr_send_ip -- */
/*
* Forward the packet to the next hop.
*/
void forward_packet(struct sr_instance *sr, char *interface,
unsigned char *dest_mac, unsigned int len, uint8_t *pkt) {
uint8_t *packet = (uint8_t *) malloc(len);
memcpy(packet, pkt, len);
struct sr_if *rt_if = (struct sr_if *)malloc(sizeof(struct sr_if));
rt_if = (struct sr_if *)sr_get_interface(sr, interface);
/* Prepare ethernet header. */
sr_ethernet_hdr_t *ether_hdr = (sr_ethernet_hdr_t *) packet;
ether_hdr->ether_type = htons(ethertype_ip);
memcpy(ether_hdr->ether_shost, rt_if->addr, ETHER_ADDR_LEN);
memcpy(ether_hdr->ether_dhost, &(dest_mac), ETHER_ADDR_LEN);
/* Recompute checksum. */
sr_ip_hdr_t *ip_hdr = (sr_ip_hdr_t *)(packet + sizeof(sr_ethernet_hdr_t));
ip_hdr->ip_sum = 0;
ip_hdr->ip_sum = cksum(packet + sizeof(sr_ethernet_hdr_t), sizeof(sr_ip_hdr_t));
/* Forward to next hop. */
print_hdrs(packet, len);
sr_send_packet(sr, packet, len, interface);
free(packet);
}
/*
* handle arp reply
*/
void sr_handle_arpreply(struct sr_instance* sr, unsigned char *mac, uint32_t ip, struct sr_if* iface)
{
/*
if(ip == 167985324)
{return;}
*/
Debug("\nhandle_arpreply called\n");
Debug("mac: %s, ip: %d, interface: %s", mac, ip, iface->name);
struct sr_arpreq *req = sr_arpcache_insert(&(sr->cache), mac, ip);
struct sr_packet *packet;
if(req)
{
Debug("\nhandle_arpreply -> sending out packets waiting for the arp_reply\n");
for(packet = req->packets; packet != NULL; packet = packet->next)
{
int i;
for (i = 0; i < ETHER_ADDR_LEN; i++)
{
packet->buf[i]= mac[i];
}
printf("---------------before send packet----------------\n");
print_hdrs(packet->buf, packet->len);
sr_send_packet(sr, packet->buf, packet->len, iface->name);
/*printf("--------------------i-------------------------: %d\n", i);i++;*/
/*free(packet->buf);*/
}
sr_arpreq_destroy(&(sr->cache), req);
Debug("Hey, finished sending packets");
}
}
void sr_send_icmp(struct sr_instance* sr, uint8_t* packet, unsigned int len,
unsigned int type, unsigned int code)
{
unsigned int responseLen;
uint8_t* responsePacket;
struct sr_ip_hdr* responseIPHeader;
/* Build the message depending on whether echo or another type */
if(type == icmp_type_echoreply)
{
printf("Creating Echo Reply...\n");
/* Get the length of the message to be built */
struct sr_ip_hdr* ipHeader = (struct sr_ip_hdr*)(packet + sizeof(sr_ethernet_hdr_t));
unsigned int payloadLen = len - sizeof(sr_ip_hdr_t) - sizeof(sr_icmp_hdr_t);
responseLen = sizeof(sr_ethernet_hdr_t) + sizeof(sr_ip_hdr_t)+ sizeof(sr_icmp_hdr_t) + payloadLen;
responsePacket = (uint8_t*) malloc(responseLen);
memcpy(responsePacket, packet, responseLen);
/* Build ICMP header */
struct sr_icmp_hdr* responseICMPHeader = (struct sr_icmp_hdr*)(responsePacket + sizeof(sr_ethernet_hdr_t) + sizeof(sr_ip_hdr_t));
responseICMPHeader->icmp_type = type;
responseICMPHeader->icmp_code = code;
responseICMPHeader->icmp_sum = 0x0000;
responseICMPHeader->icmp_sum = cksum((uint16_t*)responseICMPHeader, sizeof(sr_icmp_hdr_t) + payloadLen);
/* Build IP header */
responseIPHeader = (struct sr_ip_hdr*)(responsePacket + sizeof(sr_ethernet_hdr_t));
responseIPHeader->ip_hl = 5;
responseIPHeader->ip_v = 4;
responseIPHeader->ip_tos = 0;
responseIPHeader->ip_len = htons( sizeof(sr_ip_hdr_t) + sizeof(sr_icmp_hdr_t) + payloadLen);
responseIPHeader->ip_id = 0;
responseIPHeader->ip_off = 0;
responseIPHeader->ip_ttl = 64;
responseIPHeader->ip_p = ip_protocol_icmp;
responseIPHeader->ip_sum = 0x0000;
responseIPHeader->ip_dst = ipHeader->ip_src;
char* iface = sr_get_routing_entry_interface(sr, ipHeader->ip_src);
struct sr_if* interface = sr_get_interface(sr, iface);
responseIPHeader->ip_src = interface->ip;
responseIPHeader->ip_sum = cksum((uint8_t*)responseIPHeader, sizeof(sr_ip_hdr_t) + sizeof(sr_icmp_hdr_t) + payloadLen);
/* Build Ethernet header */
struct sr_ethernet_hdr* ethernetHeader = (struct sr_ethernet_hdr*)packet;
struct sr_ethernet_hdr* responseEthernetHeader = (struct sr_ethernet_hdr*)responsePacket;
memcpy(responseEthernetHeader->ether_dhost, ethernetHeader->ether_shost, ETHER_ADDR_LEN);
memcpy(responseEthernetHeader->ether_shost, interface->addr, ETHER_ADDR_LEN);
responseEthernetHeader->ether_type = htons(ethertype_ip);
}
else
{
printf("Creating ICMP message...\n");
/* Get the length of the message to be built */
responseLen = sizeof(sr_ethernet_hdr_t) + sizeof(sr_ip_hdr_t)+ sizeof(sr_icmp_t3_hdr_t) + 8;
responsePacket = (uint8_t*) malloc(responseLen);
/* Build ICMP header */
struct sr_ip_hdr* ipHeader = (struct sr_ip_hdr*)(packet + sizeof(sr_ethernet_hdr_t));
struct sr_icmp_t3_hdr* responseICMPHeader = (struct sr_icmp_t3_hdr*)(responsePacket + sizeof(sr_ethernet_hdr_t) + sizeof(sr_ip_hdr_t));
responseICMPHeader->icmp_type = type;
responseICMPHeader->icmp_code = code;
responseICMPHeader->icmp_sum = 0x0000;
memcpy(responseICMPHeader->data, ipHeader, sizeof(sr_ip_hdr_t) + 8);
responseICMPHeader->icmp_sum = cksum((uint16_t*)responseICMPHeader, sizeof(sr_icmp_t3_hdr_t));
/* Build IP header */
responseIPHeader = (struct sr_ip_hdr*)(responsePacket + sizeof(sr_ethernet_hdr_t));
responseIPHeader->ip_hl = 5;
responseIPHeader->ip_v = 4;
responseIPHeader->ip_tos = 0;
responseIPHeader->ip_len = htons( sizeof(sr_ip_hdr_t) + sizeof(sr_icmp_t3_hdr_t));
responseIPHeader->ip_id = 0;
responseIPHeader->ip_off = 0;
responseIPHeader->ip_ttl = 64;
responseIPHeader->ip_p = ip_protocol_icmp;
responseIPHeader->ip_sum = 0x0000;
responseIPHeader->ip_dst = ipHeader->ip_src;
char* iface = sr_get_routing_entry_interface(sr, ipHeader->ip_src);
struct sr_if* interface = sr_get_interface(sr, iface);
responseIPHeader->ip_src = interface->ip;
responseIPHeader->ip_sum = cksum((uint8_t*)responseIPHeader, sizeof(sr_ip_hdr_t) + sizeof(sr_icmp_t3_hdr_t));
/* Build Ethernet header */
struct sr_ethernet_hdr* ethernetHeader = (struct sr_ethernet_hdr*)packet;
struct sr_ethernet_hdr* responseEthernetHeader = (struct sr_ethernet_hdr*)responsePacket;
memcpy(responseEthernetHeader->ether_dhost, ethernetHeader->ether_shost, ETHER_ADDR_LEN);
memcpy(responseEthernetHeader->ether_shost, interface->addr, ETHER_ADDR_LEN);
responseEthernetHeader->ether_type = htons(ethertype_ip);
}
/* Look up the interface that the packet should be sent on */
char* iface = sr_get_routing_entry_interface(sr, responseIPHeader->ip_dst);
if(iface == NULL)
return;
/* Send the packet */
print_hdrs(responsePacket, responseLen);
sr_send_packet(sr, responsePacket, responseLen, iface);
printf("Sent on interface...%s\n", iface);
free(responsePacket);
}/* -- sr_send_icmp -- */
void sr_handlepacket(struct sr_instance* sr, uint8_t * packet/* lent */,
unsigned int len, char* interface/* lent */) {
/* Function implemented by g1izzyw and gustan50404 */
/* REQUIRES */
assert(sr);
assert(packet);
assert(interface);
struct sr_if *ether_interface = (struct sr_if *) sr_get_interface(sr, interface);
/* Check if it an ethernet interface. */
if (ether_interface) {
/* Now we deal with the ethernet header */
struct sr_ethernet_hdr *ether_hdr = (struct sr_ethernet_hdr *) packet;
/* Check to see if we are dealing with an ARP request/reply */
if (ether_hdr->ether_type == htons(ethertype_arp)) {
fprintf(stderr, "We Got an ARP Packet\n");
/* Handle ARP for ethernet */
struct sr_arp_hdr * arp_hdr = (struct sr_arp_hdr *)(packet + sizeof(struct sr_ethernet_hdr));
if (arp_hdr->ar_hrd == htons(arp_hrd_ethernet)) {
if (arp_hdr->ar_op == htons(arp_op_request)) {
/* arp request */
struct sr_if *interface_for_ip = get_interface_for_ip(sr, arp_hdr->ar_tip);
if (interface_for_ip) {
/* Target ip is one of the router interfaces */
fprintf(stderr, "ARP req for one of our interfaces\n");
/* Now we want to make an arp reply and send it back */
uint8_t *buf = (uint8_t *) malloc(len);
memcpy(buf, packet, len);
/*Make Arp Header*/
make_arprply_hdr(interface_for_ip->addr, arp_hdr->ar_sha, interface_for_ip->ip,
arp_hdr->ar_sip, buf);
/*Make Ethernet Header*/
make_ether_hdr(interface_for_ip->addr, ether_hdr->ether_shost, ethertype_arp, buf);
/* Now we send the packet */
sr_send_packet(sr, buf, len, interface_for_ip->name);
free(buf);
fprintf(stderr, "ARP reply sent\n");
}
} else if (arp_hdr->ar_op == htons(arp_op_reply)) {
fprintf(stderr, "We got an ARP Reply, need to check for intfc tho \n");
/* arp reply */
struct sr_if *interface_for_ip = get_interface_for_ip(sr, arp_hdr->ar_tip);
if (interface_for_ip) {
fprintf(stderr, "We got an ARP Reply for one of our interfaces\n");
/*We first want to insert into Arp cache*/
struct sr_arpreq *request = sr_arpcache_insert(&(sr->cache),
arp_hdr->ar_sha,
arp_hdr->ar_sip);
fprintf(stderr, "Signalling all waiting packets\n");
if (request) {
struct sr_packet *cur_packet = request->packets;
while(cur_packet) {
fprintf(stderr, "About to forward \n");
print_hdrs(cur_packet->buf, cur_packet->len);
forward_packet(sr, cur_packet->iface, arp_hdr->ar_sha,
cur_packet->len, cur_packet->buf);
fprintf(stderr, "Packet Forwarded\n");
cur_packet = cur_packet->next;
}
}
}
}
}
} else if (ether_hdr->ether_type == htons(ethertype_ip)) {
/* Get the ip header from the ethernet header*/
sr_ip_hdr_t *ip_hdr = (sr_ip_hdr_t *)(packet + sizeof(sr_ethernet_hdr_t));
/*IP Checksum Stuff*/
uint16_t temp_ip_sum = ip_hdr->ip_sum;
ip_hdr->ip_sum = 0;
ip_hdr->ip_sum = cksum(packet + sizeof(sr_ethernet_hdr_t), sizeof(sr_ip_hdr_t));
if (temp_ip_sum == ip_hdr->ip_sum) {
/*We got here means IP Cheksum is alright, so we extract the interface*/
struct sr_if *interface_for_ip = get_interface_for_ip(sr, ip_hdr->ip_dst);
/*Check to make sure interface is one of ours*/
if (interface_for_ip) {
fprintf(stderr, "IP Packet destined towards our interface\n");
/*Check if our IP packet is UDP or TCP*/
if (ip_hdr->ip_p == 6 || ip_hdr->ip_p == 17) {
fprintf(stderr, "We Got TCP or UDP, sending ICMP error msg\n");
send_icmp_error(3, 3, sr, interface, len, packet);
} else {
/* Get the ICMP header */
sr_icmp_hdr_t *icmp_hdr = (struct sr_icmp_hdr *) (packet +
sizeof(sr_ethernet_hdr_t) +
sizeof(sr_ip_hdr_t));
/*Now we do the ICMP checksum chek*/
/*This covers the ICMP echo case*/
uint16_t temp_icmp_sum = icmp_hdr->icmp_sum;
temp_icmp_sum = icmp_hdr->icmp_sum;
icmp_hdr->icmp_sum = 0;
if (temp_icmp_sum == cksum(packet + sizeof(sr_ethernet_hdr_t) + sizeof(sr_ip_hdr_t),
len - sizeof(sr_ethernet_hdr_t) - sizeof(sr_ip_hdr_t))) {
/*Everything is fine so we send an ICMP echo back*/
fprintf(stderr, "Sending ICMP echo reply\n");
send_icmp_echo(sr, interface, len, packet);
}
}
} else {
/*IP Packet not destined towards one of our interfaces*/
fprintf(stderr, "IP packet not destined to our interface\n");
/*Decremenrt TTL by 1*/
fprintf(stderr, "TTL modified \n");
print_hdrs(packet, len);
if (ip_hdr->ip_ttl <= 1) {
fprintf(stderr, "Packte with TTL < 0 found, sending ICMP error \n");
/*TTL is less than 0 so send an ICMP ERROR*/
send_icmp_error(11, 0, sr, interface, len, packet);
} else {
/*Recompute Checksum over new header TTL is fine*/
/*Check if it exists in the routing table*/
ip_hdr->ip_ttl = ip_hdr->ip_ttl - 1;
fprintf(stderr, "Recomputing Checksum after modifying TTl\n");
ip_hdr->ip_sum = 0;
ip_hdr->ip_sum = cksum(packet + sizeof(sr_ethernet_hdr_t), sizeof(sr_ip_hdr_t));
struct sr_if *dst_if = (struct sr_if *)malloc(sizeof(struct sr_if));
dst_if = next_hop(sr, interface, ip_hdr->ip_dst);
if (!(dst_if)) {
fprintf(stderr, "IP packet has no longest matching prefix sending ICMP error\n");
/*dst ip has no longest macthing prefix*/
/*So we send a type 3 code 0 ICMP error*/
send_icmp_error(3, 0, sr, interface, len, packet);
} else {
/*This is the case where we do have a longest macthing prefix*/
fprintf(stderr, "Found Longest mathcing prefix in RT\n");
struct sr_arpcache *cache = &(sr->cache);
struct sr_arpentry *in_cache = sr_arpcache_lookup(cache, ip_hdr->ip_dst);
if (in_cache) {
fprintf(stderr, "Found IP->MAC mapping in ARP cache forwarding packet \n");
/*this is the case where ip->mac maping is already in cache*/
forward_packet(sr, dst_if->name, in_cache->mac, len, packet);
free(in_cache);
} else {
fprintf(stderr, "IP->MAC mapping not in ARP cache %u \n", ip_hdr->ip_dst);
/*Case where ip->mapping is not in cache*/
sr_arpcache_queuereq(cache, ip_hdr->ip_dst, packet, len, dst_if->name);
fprintf(stderr, "Added Arp Req to queu \n");
}
}
}
}
}
}
}
} /* end sr_ForwardPacket */
void sr_handlepacket(struct sr_instance* sr,
uint8_t * packet/* lent */,
unsigned int len,
char* interface/* lent */)
{
/* REQUIRES */
assert(sr);
assert(packet);
assert(interface);
printf("*** -> Received packet of length %d \n",len);
print_hdrs(packet, len);
sr_arp_hdr_t* arpHdr = (sr_arp_hdr_t*)(packet + sizeof(sr_ethernet_hdr_t));
sr_ethernet_hdr_t* ethHdr = (sr_ethernet_hdr_t*)packet;
sr_ip_hdr_t* ipHdr = (sr_ip_hdr_t*)(packet + sizeof(sr_ethernet_hdr_t));
sr_icmp_hdr_t* icmpHdr = (sr_icmp_hdr_t*)(packet + sizeof(sr_ethernet_hdr_t) + sizeof(sr_ip_hdr_t));
struct sr_rt* route = sr->routing_table;
struct sr_arpentry* ent;
char ifBuf[INET_ADDRSTRLEN];
char ipBuf[INET_ADDRSTRLEN];
if(strcmp(arpHdr->ar_tha, "\0") == 0){
sr_arpcache_queuereq(&(sr->cache), arpHdr->ar_tip, packet, len, interface);
printf("added arpreq to queue.\n\n");
return;
}
printf("arp rep: %d\n", ntohs(arpHdr->ar_op));
printf("opcode: %d\n", arp_op_reply);
if(ntohs(arpHdr->ar_op) == arp_op_reply){
ent = sr_arpcache_lookup(&sr->cache, arpHdr->ar_sip);
if( ent == NULL){
// printf("Added %s to cache\n", ntohl(arpHdr->ar_sip));
printf("Incoming arp response\n");
// sleep(2);
struct sr_arpreq* req = sr->cache.requests;
printf("%p, %p\n", req, sr->cache.requests);
while(req != NULL){
if(req->ip == arpHdr->ar_sip){
struct sr_packet* pkt = req->packets;
while(pkt != NULL){
if(route != NULL){
do{
sr_ip_hdr_t* reqIpHdr = (sr_ip_hdr_t*)(pkt->buf + sizeof(sr_ethernet_hdr_t));
sr_ethernet_hdr_t* reqEthHdr = (sr_ethernet_hdr_t*)(pkt->buf);
// sr_print_routing_entry(route);
inet_ntop(AF_INET, &route->dest, ifBuf, sizeof(char) * INET_ADDRSTRLEN);
convert_addr_ip_int(ntohl(reqIpHdr->ip_dst), ipBuf);
printf("%s dest: %s\n",route->interface, ifBuf);
printf("ip dest: %s\n", ipBuf);
if(strcmp(ifBuf, ipBuf) == 0){
memcpy(reqEthHdr->ether_shost, (uint8_t*)(sr_get_interface(sr, route->interface)->addr), sizeof(uint8_t) * ETHER_ADDR_LEN);
memcpy(reqEthHdr->ether_dhost, (uint8_t*)arpHdr->ar_sha, sizeof(uint8_t) * ETHER_ADDR_LEN);
print_hdrs(pkt->buf, pkt->len);
sr_send_packet(sr, pkt->buf, pkt->len, &(route->interface));
printf("pkt sent down %s\n\n", route->interface);
// free(ent);
//return;
break;
}
route = route->next;
} while(route != NULL);
pkt = pkt->next;
}
}
free(ent);
sr_arpreq_destroy(&sr->cache, req);
break;
}
req = req->next;
}
}
sr_arpcache_insert(&(sr->cache), arpHdr->ar_sha, arpHdr->ar_sip);
//sr_arpcache_dump(&sr->cache);
free(ent);
return;
}
ent = sr_arpcache_lookup(&sr->cache, ipHdr->ip_dst);
route = sr->routing_table;
//Make and queue requests if dest isn't in arpcache
if( ent == NULL ){
if(route != NULL){
do{
inet_ntop(AF_INET, &route->dest, ifBuf, 100);
convert_addr_ip_int(ntohl(ipHdr->ip_dst), ipBuf);
if(strcmp(ifBuf, ipBuf) == 0){
sr_arpcache_queuereq(&sr->cache, ipHdr->ip_dst, packet, len, route->interface);
free(ent);
return;
}
route = route->next;
} while(route != NULL);
sr_arpcache_queuereq(&sr->cache, ipHdr->ip_dst, packet, len, "eth1");
}
}
//Forwards packet to interface
if(route != NULL){
do{
// sr_print_routing_entry(route);
inet_ntop(AF_INET, &route->dest, ifBuf, sizeof(char) * INET_ADDRSTRLEN);
convert_addr_ip_int(ntohl(ipHdr->ip_dst), ipBuf);
printf("%s dest: %s\n",route->interface, ifBuf);
printf("ip dest: %s\n", ipBuf);
if(strcmp(ifBuf, ipBuf) == 0){
memcpy(ethHdr->ether_shost, (uint8_t*)(sr_get_interface(sr, route->interface)->addr), sizeof(uint8_t) * ETHER_ADDR_LEN);
memcpy(ethHdr->ether_dhost, (uint8_t*)ent->mac, sizeof(uint8_t) * ETHER_ADDR_LEN);
print_hdrs(packet, len);
sr_send_packet(sr, packet, len, &(route->interface));
printf("pkt sent down %s\n\n", route->interface);
free(ent);
return;
}
route = route->next;
} while(route != NULL);
}
free(ent);
}/* end sr_ForwardPacket */