void print_packet(const uint8_t *packet, unsigned int len)
{
assert(packet);
printf("\n");
print_eth_hdr(packet, len);
printf("\n");
eth_hdr *eth = (eth_hdr *)packet;
if (ntohs(eth->eth_type) == ETH_TYPE_ARP) {
print_arp_hdr(packet, len);
printf("\n");
} else if (ntohs(eth->eth_type) == ETH_TYPE_IP) {
ip_hdr *ip = get_ip_hdr(packet, len);
indent(1);
printf("IPv4 Packet (%d bytes)\n", len - sizeof(eth_hdr));
print_ip_hdr(packet, len);
switch(ip->ip_p) {
case 1:
{ print_icmp_load(packet, len); break; }
case 6:
{ print_tcp_load(packet, len); break; }
case 89:
{ print_pwospf_load(packet, len); break; }
default:
{ printf("UNRECOGNIZABLE PROTOCOL\n"); break;}
}
}
}
/**@brief This function sends out a fins frame that passes an arp request out to the network
* @param sought_IP_addrs is the IP address whose associated MAC address is sought
* @param fins_arp_out points to the fins frame which will be sent from the module
* */
void arp_out_request(uint32_t sought_IP_addrs, struct finsFrame *fins_arp_out){
gen_requestARP(sought_IP_addrs, &arp_msg);
arp_msg_to_hdr(&arp_msg, packet);
host_to_net(packet);
print_arp_hdr(packet);
arp_to_fins(packet, fins_arp_out); /**arp request to be sent to network*/
}
/**@brief This function sends out a fins frame with a reply arp in response to a request
* from the network
* @param fins_arp_out points to the fins frame which will be sent from the module
* */
void arp_out_reply(struct finsFrame *fins_arp_out){
struct ARP_message arp_msg_reply;
gen_replyARP(&arp_msg, &arp_msg_reply);
arp_msg_to_hdr(&arp_msg_reply, packet);
host_to_net(packet);
print_arp_hdr(packet);
arp_to_fins(packet, fins_arp_out); /**arp reply to be sent to network */
}
/**@brief this function tests a set of functions which are used when
* (1) a host receives an ARP request, and (2) keeps updating its cache based on
* these ARP requests
* @param fileName is the file from which the list of neighbors is drawn
*/
void send_receive_update(char *fileName)
{
extern struct node *ptr_cacheHeader;
struct finsFrame request_fins, reply_fins, *request_fins_ptr, *reply_fins_ptr;
struct ARP_message request_ARP1, request_ARP2, reply_ARP1, reply_ARP2;
struct ARP_message *request_ARP_ptr1, *request_ARP_ptr2, *reply_ARP_ptr1, *reply_ARP_ptr2;
struct arp_hdr hdr_ARP, *hdr_ARP_ptr;
uint64_t MAC_addrs;
uint32_t IP_addrs_read;
int task;
/**Following code generates a list of IP/MAC addresses of 'neighbors' and initializes cache*/
ptr_cacheHeader = init_intface();
gen_neighbor_list(fileName);
init_recordsARP(fileName);
print_cache();
print_neighbors(ptr_neighbor_list);
hdr_ARP_ptr = &hdr_ARP;
IP_addrs_read = 1;
task = 1;
/**Begin Initialize/Instantiate Pointers */
request_fins_ptr = &request_fins;
reply_fins_ptr = &reply_fins;
request_ARP_ptr1 = &request_ARP1;
request_ARP_ptr2 = &request_ARP2;
reply_ARP_ptr1 = &reply_ARP1;
reply_ARP_ptr2 = &reply_ARP2;
/**A host can send update its cache based on its own request or a request from another network host*/
while (IP_addrs_read!=0 && (task==0 || task == 1))
{
PRINT_DEBUG("\nTest send request and update `0' or test receive a request `1' \n");
scanf("%d", &task);
IP_addrs_read = read_IP_addrs();
/**The following functions test the internal operations of the module*/
if (task==0){
gen_requestARP(IP_addrs_read, request_ARP_ptr1);
print_msgARP(request_ARP_ptr1);
arp_to_fins(request_ARP_ptr1, request_fins_ptr);
fins_to_arp(request_fins_ptr, request_ARP_ptr2);
mimic_net_reply(request_ARP_ptr2, reply_ARP_ptr1);
if (check_valid_arp(reply_ARP_ptr1)==1){
arp_to_fins(reply_ARP_ptr1, reply_fins_ptr);
fins_to_arp(reply_fins_ptr, reply_ARP_ptr2);
print_msgARP(reply_ARP_ptr2);
update_cache(reply_ARP_ptr2);}
print_cache();
}
else if (task==1){
MAC_addrs = search_MAC_addrs(IP_addrs_read, ptr_neighbor_list);
mimic_net_request(IP_addrs_read, MAC_addrs,request_ARP_ptr1);
print_msgARP(request_ARP_ptr1);
if (check_valid_arp(request_ARP_ptr1)==1){
arp_to_fins(request_ARP_ptr1, request_fins_ptr);
fins_to_arp(request_fins_ptr, request_ARP_ptr2);
print_msgARP(request_ARP_ptr2);
update_cache(request_ARP_ptr2);}
print_cache();
}
/**The following functions test the external operation of the module*/
if (check_valid_arp(request_ARP_ptr2)==1){
hdr_ARP_ptr = &hdr_ARP;
/**convert ARP message to htons format and generate MAC addresses as unsigned char ptr*/
net_fmt_conversion(request_ARP_ptr2, hdr_ARP_ptr);
print_arp_hdr(hdr_ARP_ptr);/**print some fields of the ARP message in external format*/
host_fmt_conversion(hdr_ARP_ptr, request_ARP_ptr2);/**convert ARP message to ntohs format*/
print_msgARP(request_ARP_ptr2);/**print ARP message internal format*/
}
}
term_intface();
}
