/* Performs any initialization of the miniroute layer, if required. */
void
miniroute_initialize()
{
network_get_my_address(hostaddr);
discovery_alarm = -1;
intrpt_buffer = queue_new();
intrpt_sig = semaphore_create();
discovery_mutex = semaphore_create();
discovery_sig = semaphore_create();
route_cache = miniroute_cache_new(65536, SIZE_OF_ROUTE_CACHE, MINIROUTE_CACHED_ROUTE_EXPIRE);
disc_cache = miniroute_cache_new(65536, SIZE_OF_ROUTE_CACHE, MINIROUTE_CACHED_ROUTE_EXPIRE * 10);
if (NULL == intrpt_buffer || NULL == intrpt_sig || NULL == route_cache
|| NULL == discovery_mutex || NULL == discovery_sig) {
queue_free(intrpt_buffer);
semaphore_destroy(intrpt_sig);
semaphore_destroy(discovery_mutex);
semaphore_destroy(discovery_sig);
miniroute_cache_destroy(route_cache);
return;
}
semaphore_initialize(intrpt_sig, 0);
semaphore_initialize(discovery_mutex, 1);
semaphore_initialize(discovery_sig, 0);
network_get_my_address(hostaddr);
minithread_fork(miniroute_control, NULL);
}
/* Initializes the minisocket layer. */
void minisocket_initialize()
{
int i;
sock_array = (minisocket_t*)malloc(sizeof(struct minisocket)*NUM_SOCKETS);
if (!sock_array) {
return;
}
for (i = 0; i < NUM_SOCKETS; i++) {
sock_array[i] = NULL;
}
client_lock = semaphore_create();
if (!client_lock) {
free(sock_array);
return;
}
server_lock = semaphore_create();
if (!server_lock) {
free(sock_array);
semaphore_destroy(client_lock);
return;
}
semaphore_initialize(client_lock, 1);
semaphore_initialize(server_lock, 1);
network_get_my_address(my_addr);
curr_client_idx = CLIENT_START;
//printf("minisocket_initialize complete\n");
}
/* FUNC DEFS
*/
void miniroute_initialize() {
route_cache = miniroute_cache_create();
dcb_table = hash_table_create();
curr_discovery_pkt_id = 1;
network_get_my_address(my_addr); //init my_addr
return;
}
int transmit(int* arg) {
char buffer[BUFFER_SIZE];
int length;
int i;
minithread_t receiver1;
minithread_t receiver2;
miniport_t write_port1;
miniport_t write_port2;
network_address_t my_address;
network_get_my_address(&my_address);
port1 = miniport_create_unbound(0);
port2 = miniport_create_unbound(1);
write_port1 = miniport_create_bound(my_address, 0);
write_port2 = miniport_create_bound(my_address, 1);
receiver1 = minithread_fork(receive1, NULL);
receiver2 = minithread_fork(receive2, NULL);
for (i=0; i<MAX_COUNT; i++) {
printf("Sending packet %d to receiver 1.\n", i+1);
sprintf(buffer, "Count for receiver 1 is %d.\n", i+1);
length = strlen(buffer) + 1;
minimsg_send(port1, write_port1, buffer, length);
minithread_yield();
printf("Sending packet %d to receiver 2.\n", i+1);
sprintf(buffer, "Count for receiver 2 is %d.\n", i+1);
length = strlen(buffer) + 1;
minimsg_send(port2, write_port2, buffer, length);
}
return 0;
}
int receive(int* arg) {
network_address_t my_address;
minisocket_t socket;
minisocket_error error;
printf("starting receive\n");
minithread_yield();
printf("continuing receive\n");
network_get_my_address(my_address);
/* create a network connection to the local machine */
socket = minisocket_client_create(my_address, port,&error);
if (socket==NULL){
printf("ERROR: %s. Exiting. \n",GetErrorDescription(error));
return -1;
}
printf("client connected\n");
minisocket_close(socket);
return 0;
}
int
send(int* arg) {
char buffer[BUFFER_SIZE];
int length = BUFFER_SIZE;
int i;
network_address_t addr;
miniport_t *dest;
miniport_t *equal_test;
network_get_my_address(addr);
equal_test = miniport_create_unbound(100);
if (port != equal_test) {
fprintf(stderr, "miniport_create unbound is duplicating ports \n");
exit(0);
}
dest = miniport_create_bound(addr, 100);
for (i=0; i<MSG_PER_PORT; i++) {
messageCount++;
sprintf(buffer, "Received packet number %d \n", messageCount);
length = strlen(buffer) + 1;
minimsg_send(port, dest, buffer, length);
fprintf(stderr, "sending %d \n", messageCount);
}
miniport_destroy(dest);
return 0;
}
int transmit1(int* arg) {
char buffer[BUFFER_SIZE];
int length;
int i;
minithread_t transmitter2;
minithread_t receiver;
miniport_t write_port;
network_get_my_address(&my_address);
port = miniport_create_unbound(0);
write_port = miniport_create_bound(my_address, 0);
transmitter2 = minithread_fork(transmit2, NULL);
receiver = minithread_fork(receive, NULL);
for (i=0; i<MAX_COUNT; i++) {
printf("Sending packet %d from sender 1.\n", i+1);
sprintf(buffer, "Count from sender 1 is %d.\n", i+1);
length = strlen(buffer) + 1;
minimsg_send(port, write_port, buffer, length);
minithread_yield();
}
return 0;
}
int receive(int* arg) {
char buffer[BUFFER_SIZE];
int i;
int bytes_received;
network_address_t my_address;
minisocket_t socket;
minisocket_error error;
/*
* It is crucial that this minithread_yield() works properly
* (i.e. it really gives the processor to another thread)
* othrevise the client starts before the server and it will
* fail (there is nobody to connect to).
*/
minithread_yield();
network_get_my_address(my_address);
int x;
/* create a network connection to the local machine */
socket = minisocket_client_create(my_address, port,&error);
if (socket==NULL){
printf("3ERROR: %s. Exiting. \n",GetErrorDescription(error));
return -1;
}
//semaphore_P(done_sending);
/* receive the message */
bytes_received=0;
while (bytes_received!=BUFFER_SIZE/20){
int received_bytes;
if ((received_bytes=minisocket_receive(socket,buffer, 2, &error))==-1){
printf("inside, socket status = %d [%p]\n", socket->status, socket);
printf("4ERROR: %s. Exiting. \n",GetErrorDescription(error));
/* close the connection */
minisocket_close(socket);
return -1;
}
/* test the information received */
for (i=0; i<received_bytes; i++){
if (buffer[i]!=(char)( (bytes_received+i)%256 )){
printf("The %d'th byte received is wrong ('%d'-'%d'-'%d'-'%d' vs '%d'-'%d'-'%d'-'%d') [%d].\n",
bytes_received+i, buffer[i-3], buffer[i-2], buffer[i-1], buffer[i],
(bytes_received+i-3)%256, (bytes_received+i-2)%256, (bytes_received+i-1)%256, (bytes_received+i)%256,
received_bytes);
/* close the connection */
minisocket_close(socket);
return -1;
}
}
bytes_received+=received_bytes;
}
printf("All bytes received correctly (received %d bytes).\n", bytes_received);
minisocket_close(socket);
return 0;
}
int receive(int* arg) {
char buffer[BUFFER_SIZE];
int i;
int bytes_received;
network_address_t my_address;
minisocket_t socket;
minisocket_error error;
/*
* It is crucial that this minithread_yield() works properly
* (i.e. it really gives the processor to another thread)
* othrevise the client starts before the server and it will
* fail (there is nobody to connect to).
*/
minithread_yield();
network_get_my_address(my_address);
/* create a network connection to the local machine */
printf("creating client\n");
socket = minisocket_client_create(my_address, port,&error);
printf("client unblocked\n");
if (socket==NULL){
printf("ERROR: %s. Exiting. \n",GetErrorDescription(error));
return -1;
}
/* receive the message */
bytes_received=0;
while (bytes_received!=BUFFER_SIZE){
int received_bytes;
if ((received_bytes=minisocket_receive(socket,buffer, BUFFER_SIZE-bytes_received, &error))==-1){
printf("ERROR: %s. Exiting. \n",GetErrorDescription(error));
/* close the connection */
minisocket_close(socket);
return -1;
}
printf("checking bytes\n");
/* test the information received */
for (i=0; i<received_bytes; i++){
if (buffer[i]!=(char)( (bytes_received+i)%256 )){
printf("The %d'th byte received is wrong.\n",
bytes_received+i);
/* close the connection */
minisocket_close(socket);
return -1;
}
}
bytes_received+=received_bytes;
}
printf("All bytes received correctly.\n");
minisocket_close(socket);
return 0;
}
int
clientMethod(int* arg) {
char responseBuffer1[10];
char responseBuffer2[10];
minithread_fork(serverMethod, NULL);
network_address_t my_address;
network_get_my_address(my_address);
minisocket_error error;
//create client
client = minisocket_client_create(my_address, PORT_NUM, &error);
assert(client != NULL);
assert(error == SOCKET_NOERROR);
//receive first 10 bytes
int response = minisocket_receive(client, responseBuffer1, 10, &error);
assert(response == 10);
assert(strcmp(responseBuffer1, "aaaaaaaaaa") == 0);
//receive second 10 bytes
response = minisocket_receive(client, responseBuffer2, 10, &error);
assert(response == 10);
assert(strcmp(responseBuffer2, "aaaaaaaaaa") == 0);
minithread_sleep_with_timeout(15000);
//Make sure that the port does not exist
response = minisocket_send(client, aText, strlen(aText), &error);
assert(response == -1);
assert(error == SOCKET_INVALIDPARAMS);
error = SOCKET_NOERROR;
fprintf(stderr, "Test Part 1 Passed \n");
//recreate client
client = minisocket_client_create(my_address, PORT_NUM, &error);
assert(client != NULL);
assert(error == SOCKET_NOERROR);
//send from client
int packets_sent = minisocket_send(client, bText, strlen(bText), &error);
assert(packets_sent == strlen(bText));
assert(error == SOCKET_NOERROR);
minisocket_close(client);
minithread_sleep_with_timeout(15000);
//assert that minisocket has closed
response = minisocket_send(client, aText, strlen(aText), &error);
assert(response == -1);
assert(error == SOCKET_INVALIDPARAMS);
return 0;
}
int transmit_first(int* arg)
{
char buffer[MINIMSG_MAX_MSG_SIZE + 10];
int length = 0;
int i;
network_address_t hostaddr, targetaddr;
miniport_t port;
miniport_t dest;
struct mini_header hdr;
AbortOnCondition(network_translate_hostname(hostname, targetaddr) < 0,
"Could not resolve hostname, exiting.");
port = miniport_create_unbound(0);
dest = miniport_create_bound(targetaddr, 1);
/* Form correct header */
network_get_my_address(hostaddr);
hdr.protocol = PROTOCOL_MINIDATAGRAM;
pack_address(hdr.source_address, hostaddr);
pack_unsigned_short(hdr.source_port, port->num);
pack_address(hdr.destination_address, dest->bound.addr);
pack_unsigned_short(hdr.destination_port, dest->bound.remote);
/* Send packages with short but correct header and zero data */
printf("Sending packages with short headers.\n");
sprintf(buffer, "Receiving packages with short headers.\n");
length = strlen(buffer) + 1;
minimsg_send(port, dest, buffer, length);
for (i = 0; i < MINIMSG_HDRSIZE; i++)
network_send_pkt(targetaddr, i, (char*)&hdr, 0, buffer);
/* Send packages to wrong ports */
printf("Sending packages to wrong destination ports.\n");
sprintf(buffer, "Receiving packages with wrong destination ports.\n");
length = strlen(buffer) + 1;
minimsg_send(port, dest, buffer, length);
sprintf(buffer, "This message is sent to a wrong port.\n");
length = strlen(buffer) + 1;
minimsg_send(port, miniport_create_bound(targetaddr, 0),
buffer, length);
minimsg_send(port, miniport_create_bound(targetaddr, MAX_UNBOUNDED),
buffer, length);
minimsg_send(port, miniport_create_bound(targetaddr, MAX_UNBOUNDED + 1),
buffer, length);
minimsg_send(port, miniport_create_bound(targetaddr, MIN_BOUNDED),
buffer, length);
minimsg_send(port, miniport_create_bound(targetaddr, MAX_BOUNDED),
buffer, length);
printf("Send-first finished.\n");
return 0;
}
void minisocket_initialize()
{
for (int i = 0; i < N_PORTS; i++) {
ports[i] = NULL;
}
ports_mutex = semaphore_create();
semaphore_initialize(ports_mutex, 1);
n_client_ports = MIN_CLIENT_PORT;
network_get_my_address(local_host);
}
/* Construct a (reliable) header to be sent by the given socket. */
void set_header(minisocket_t socket, mini_header_reliable_t hdr, char message_type) {
network_address_t my_address;
hdr->protocol = PROTOCOL_MINISTREAM; // Protocol
network_get_my_address(my_address);
pack_address(hdr->source_address, my_address); // Source address
pack_unsigned_short(hdr->source_port, socket->local_port); // Source port
pack_address(hdr->destination_address, socket->dest_address); // Destination address
pack_unsigned_short(hdr->destination_port, socket->remote_port); // Destination port
hdr->message_type = message_type; // Message type
pack_unsigned_int(hdr->seq_number, socket->seqnum); // Sequence number
pack_unsigned_int(hdr->ack_number, socket->acknum); // Acknowledgment number
}
void
bcast_initialize(char* configfile, bcast_t* bcast) {
FILE* config = fopen(configfile, "r");
char line[BCAST_MAX_LINE_LEN];
int i = 0;
char* rv;
network_address_t my_addr;
unsigned int my_ip_addr;
network_get_my_address(my_addr);
my_ip_addr = my_addr[0];
while ((rv = fgets(line, BCAST_MAX_LINE_LEN, config)) != NULL) {
if (line[0] == '\r' || line[0] == '\n')
break;
line[strlen(line)-1] = '\0';
strcpy(bcast->entries[i].name, line);
bcast->entries[i].n_links = 0;
if (network_translate_hostname(line, bcast->entries[i].addr) != 0) {
kprintf("Error: could not resolve hostname %s.\n", line);
AbortOnCondition(1,"Crashing.");
}
if (bcast->entries[i].addr[0] == my_ip_addr)
bcast->me = i;
i++;
}
bcast->n_entries = i;
if (rv != NULL)
for (i=0; i<bcast->n_entries; i++) {
//int len;
int j;
AbortOnCondition(fgets(line, BCAST_MAX_LINE_LEN, config) == NULL,
"Error: incomplete adjacency matrix.");
//len = strlen(line);
for (j=0; j<bcast->n_entries; j++)
if (i == j)
; /* avoid self-links */
else if (line[j] != '.') {
bcast->entries[i].links[bcast->entries[i].n_links] = j;
bcast->entries[i].n_links++;
}
}
fclose(config);
}
int thread(int* arg) {
char buffer[BUFFER_SIZE];
int length = BUFFER_SIZE;
miniport_t from;
network_address_t my_address;
network_get_my_address(&my_address);
listen_port = miniport_create_unbound(0);
send_port = miniport_create_bound(my_address, 0);
minimsg_send(listen_port, send_port, text, textlen);
minimsg_receive(listen_port, &from, buffer, &length);
printf("%s", buffer);
return 0;
}
/* Sends a message through a locally bound port (the bound port already has an associated
* receiver address so it is sufficient to just supply the bound port number). In order
* for the remote system to correctly create a bound port for replies back to the sending
* system, it needs to know the sender's listening port (specified by local_unbound_port).
* The msg parameter is a pointer to a data payload that the user wishes to send and does not
* include a network header; your implementation of minimsg_send must construct the header
* before calling miniroute_send_pkt(). The return value of this function is the number of
* data payload bytes sent not inclusive of the header.
*/
int minimsg_send(miniport_t local_unbound_port, miniport_t local_bound_port, minimsg_t msg, int len) {
network_address_t dest, my_address;
mini_header_t hdr;
// semaphore_P(msgmutex);
// Check for valid arguments
if (local_unbound_port == NULL) {
fprintf(stderr, "ERROR: minimsg_send() passed a NULL local_unbound_port miniport argument\n");
semaphore_V(msgmutex);
return -1;
}
if (local_bound_port == NULL) {
fprintf(stderr, "ERROR: minimsg_send() passed a NULL local_bound_port miniport argument\n");
semaphore_V(msgmutex);
return -1;
}
// Allocate new header for packet
hdr = malloc(sizeof(struct mini_header));
if (hdr == NULL) { // Could not allocate header
fprintf(stderr, "ERROR: minimsg_send() failed to malloc new mini_header\n");
semaphore_V(msgmutex);
return -1;
}
// Assemble packet header
hdr->protocol = PROTOCOL_MINIDATAGRAM; // Protocol
network_get_my_address(my_address);
pack_address(hdr->source_address, my_address); // Source address
pack_unsigned_short(hdr->source_port, local_bound_port->port_num); // Source port
network_address_copy(local_bound_port->u.bound.remote_address, dest);
pack_address(hdr->destination_address, dest); // Destination address
pack_unsigned_short(hdr->destination_port, local_bound_port->u.bound.remote_unbound_port); // Destination port
// Call miniroute_send_pkt() from network.hdr
if (network_send_pkt(dest, sizeof(struct mini_header), (char*) hdr, len, msg) < 0) { // REMOVE THIS LINE
// if (miniroute_send_pkt(dest, sizeof(struct mini_header), (char*) hdr, len, msg) < 0) {
fprintf(stderr, "ERROR: minimsg_send() failed to successfully execute miniroute_send_pkt()\n");
semaphore_V(msgmutex);
return -1;
}
// semaphore_V(msgmutex);
return 0;
}
int
thread(int* arg) {
char buffer[BUFFER_SIZE];
int length = BUFFER_SIZE;
miniport_t *from;
network_address_t my_address;
network_get_my_address(my_address);
listen_port = miniport_create_unbound(0);
send_port = miniport_create_bound(my_address, 0);
minimsg_send(listen_port, send_port, text, textlen);
minimsg_receive(listen_port, &from, buffer, &length);
printf("%s\n", buffer); //newline is to enable printing when truncated before a newline character has been reached
return 0;
}
//Returns a reliable mini header
//TODO: do seq_num and ack_num
void minisocket_create_reliable_header(mini_header_reliable_t* header, minisocket_t* socket, unsigned short dest_port, const network_address_t dest_address, char message_type) {
header->protocol = PROTOCOL_MINISTREAM;
//packs info
pack_address(header->destination_address, dest_address);
pack_unsigned_short(header->destination_port, dest_port);
network_address_t my_address;
network_get_my_address(my_address);
pack_address(header->source_address, my_address);
pack_unsigned_short(header->source_port, socket->local_port_number);
//pack seq and ack numbers
pack_unsigned_int(header->ack_number, socket->ack);
pack_unsigned_int(header->seq_number, socket->seq);
//set message type
header->message_type = message_type;
}
/* performs any required initialization of the minimsg layer.
*/
void
minimsg_initialize() {
unsigned int i;
network_get_my_address(my_addr); //init my_addr
curr_bound_index = BOUND_PORT_START;
miniport_array = (miniport_t*)malloc((MAX_PORT_NUM)*sizeof(miniport_t));
if (miniport_array == NULL) {
return;
}
for (i = 0; i < MAX_PORT_NUM; i++) {
miniport_array[i] = NULL;
}
bound_ports_lock = semaphore_create();
if (!bound_ports_lock){
return;
}
unbound_ports_lock = semaphore_create();
if (!unbound_ports_lock){
semaphore_destroy(bound_ports_lock);
return;
}
pkt_available_sem = semaphore_create();
if (!pkt_available_sem){
semaphore_destroy(bound_ports_lock);
semaphore_destroy(unbound_ports_lock);
return;
}
pkt_q = queue_new();
if (!pkt_q){
semaphore_destroy(bound_ports_lock);
semaphore_destroy(unbound_ports_lock);
semaphore_destroy(pkt_available_sem);
return;
}
semaphore_initialize(bound_ports_lock,1);
semaphore_initialize(unbound_ports_lock,1);
semaphore_initialize(pkt_available_sem,0);
}
int
thread(int* arg) {
char buffer[BUFFER_SIZE];
int length = BUFFER_SIZE;
miniport_t from;
network_address_t my_address;
network_get_my_address(my_address);
receive_port = miniport_create_unbound(0);
send_port = miniport_create_bound(my_address, 0);
minimsg_send(receive_port, send_port, text, textlen);
minithread_sleep_with_timeout(1000);
miniport_destroy(receive_port);
receive_port = miniport_create_unbound(0);
printf("waiting\n");
minimsg_receive(receive_port, &from, buffer, &length);
printf("%s", buffer); //should not print
return 0;
}
int
clientMethod(int* arg) {
char responseBuffer1[1];
char responseBuffer2[20];
char responseBuffer3[10001];
minithread_fork(serverMethod, NULL);
network_address_t my_address;
network_get_my_address(my_address);
minisocket_error error;
//create client
client = minisocket_client_create(my_address, PORT_NUM, &error);
assert(client != NULL);
assert(error == SOCKET_NOERROR);
//Test sending output
int response = minisocket_receive(client, responseBuffer1, 1, &error);
assert(response == 1);
assert(responseBuffer1[0] == 'a');
response = minisocket_receive(client, responseBuffer2, 20, &error);
assert(response == 20);
assert(strcmp(responseBuffer2, "bbbbbbbbbbbbbbbbbbbb") == 0);
int bytes_received = 0;
while (bytes_received != 10000) {
response = minisocket_receive(client, responseBuffer3 + bytes_received, 10000, &error);
assert(response > 0);
bytes_received += response;
}
assert(strcmp(responseBuffer3, cText) == 0);
fprintf(stderr, "All Tests Passed \n");
return 0;
}
int transmit(int* arg) {
char buffer[BUFFER_SIZE];
int length;
// int i;
miniport_t write_port;
network_address_t my_address;
network_get_my_address(my_address);
port = miniport_create_unbound(0);
write_port = miniport_create_bound(my_address, 0);
// write_port = miniport_create_bound("127.111.111.112", 0);
// minithread_fork(receive, NULL);
// for (i=0; i<MAX_COUNT; i++) {
printf("Sending instant message:\n");
sprintf(buffer, "PUT INSTANT MESSAGE HERE\n");
length = strlen(buffer) + 1;
minimsg_send(port, write_port, buffer, length);
// }
return 0;
}
int
transmit(int* arg) {
char buffer[BUFFER_SIZE];
int length;
int i;
miniport_t *write_port;
network_address_t my_address;
network_get_my_address(my_address);
port = miniport_create_unbound(0);
write_port = miniport_create_bound(my_address, 0);
minithread_fork(receive, NULL);
for (i=0; i<MAX_COUNT; i++) {
printf("Sending packet %d.\n", i+1);
sprintf(buffer, "Count is %d.\n", i+1);
length = strlen(buffer) + 1;
minimsg_send(port, write_port, buffer, length);
}
return 0;
}
int
minimsg_send(miniport_t* local_unbound_port, miniport_t* local_bound_port, minimsg_t* msg, int len)
{
assert(g_boundPortCounter >= 0); //sanity check to ensure minimsg_initialize() has been called first
//validate input
if (local_unbound_port == NULL || local_bound_port == NULL || msg == NULL || len < 0 || len > MINIMSG_MAX_MSG_SIZE) return -1;
//generate the header
mini_header_t header;
header.protocol = PROTOCOL_MINIDATAGRAM; //set protocol type
network_address_t my_address;
network_get_my_address(my_address);
pack_address(header.source_address, my_address);
pack_unsigned_short(header.source_port, local_unbound_port->port_number);
pack_address(header.destination_address, local_bound_port->bound_port.remote_addr);
pack_unsigned_short(header.destination_port, local_bound_port->bound_port.remote_unbound_port);
//send message now
int sentBytes = network_send_pkt(local_bound_port->bound_port.remote_addr, sizeof(header), (char*)&header, len, msg);
if (sentBytes == -1) return -1; //we failed to send our message
else return sentBytes - sizeof(header); //else return size of our message not inclusive of header
}
void network_handler(network_interrupt_arg_t* arg)
{
// Used to extract the network address out of the interrupt argument
//network_address_t addr;
// The source port number - this is really the remote unbound port number
int src_port_number;
// The port number the packet was sent to
int dst_port_number;
// Used to store the header data for UDP/minimsgs
mini_header_t header;
// This is used to extract the sender's address from the header
network_address_t src_addr;
// This is used to extract the destination (our) address from the header
network_address_t dst_addr;
// Disable interrupts...
interrupt_level_t prev_level = set_interrupt_level(DISABLED);
// This is used to check our own address for sanity checks
network_address_t my_addr;
// This will store the total packet size
int packet_size;
// This will store the size of the data in the packet
int data_len;
// This will store the header of a TCP packet
mini_header_reliable_t header_reliable;
// This will store the ACK number of a TCP packet
int ack_num;
// This will store the Sequence number of a TCP packet
int seq_num;
// This will store the socket
minisocket_t socket;
// This will store the TCP error
minisocket_error error;
// This will be used to indicate whether the TCP packet is a duplicate or not
int duplicate = 0;
// Check the protocol
switch (arg->buffer[0])
{
case (char) PROTOCOL_MINIDATAGRAM:
// Extract data from the network interrupt arg
//network_address_copy(arg->addr, addr);
// Get the header struct, unpack the parameters
header = (mini_header_t) &arg->buffer;
dst_port_number = (int) unpack_unsigned_short(header->destination_port);
// Ensure the port number is valid
if (dst_port_number < MIN_UNBOUND || dst_port_number > MAX_UNBOUND)
{
free(arg);
set_interrupt_level(prev_level);
return;
}
// Then ensure the miniport exists
if (miniports[dst_port_number] == NULL)
{
free(arg);
set_interrupt_level(prev_level);
return;
}
// Add the arg to the queue
queue_append(miniports[dst_port_number]->port_data.unbound.data_queue, arg);
// Wake up thread that's waiting to receive - sem_V()
semaphore_V(miniports[dst_port_number]->port_data.unbound.data_ready);
break;
case PROTOCOL_MINISTREAM:
// Get the total size of the packet and data length
packet_size = arg->size;
data_len = packet_size - sizeof(struct mini_header_reliable);
// Get the header and extract information
header_reliable = (mini_header_reliable_t) arg->buffer;
src_port_number = (int) unpack_unsigned_short(header_reliable->source_port);
dst_port_number = (int) unpack_unsigned_short(header_reliable->destination_port);
unpack_address(header_reliable->source_address, src_addr);
unpack_address(header_reliable->destination_address, dst_addr);
seq_num = (int) unpack_unsigned_int(header_reliable->seq_number);
ack_num = (int) unpack_unsigned_int(header_reliable->ack_number);
// Don't respond if socket doesn't exist - will trigger SOCKET_NOSERVER for client
if (minisockets[dst_port_number] == NULL)
{
set_interrupt_level(prev_level);
return;
}
// Get the socket in question
socket = minisockets[dst_port_number];
// Check if packet was meant for us - ignore if not
network_get_my_address(my_addr);
if (network_compare_network_addresses(my_addr, dst_addr) == 0)
{
set_interrupt_level(prev_level);
return;
}
if (socket->status == TCP_PORT_CLOSING || socket->waiting == TCP_PORT_WAITING_CLOSE)
{
set_interrupt_level(prev_level);
return;
}
// Packet handling for established connections
if (socket->status != TCP_PORT_LISTENING)
{
// Ensure source address is correct - ignore if not
if (network_compare_network_addresses(src_addr, socket->dst_addr) == 0
|| src_port_number != socket->dst_port)
{
if (header_reliable->message_type == MSG_SYN)
{
// A client is trying to connect to an already-connected port
// Send them a FIN, which will result in their client
// returning a SOCKET_BUSY error
transmit_packet(socket, src_addr, src_port_number, 0,
MSG_FIN, 0, NULL, &error);
}
set_interrupt_level(prev_level);
return;
}
/* We got a duplicate SYN and need to ensure that the host gets
* another SYNACK. The thread that sent the SYNACK will currently
* be retransmitting the SYNACKs, as it didn't get an ACK. If it
* was done with the retransmission sequence, the socket would be
* closed, and this would therefore not have gotten this far.
* HOWEVER:
* If the retransmission sequence already sent its LAST
* retransmission and was waiting on it, then this duplicate SYN
* will NOT get a SYNACK, as the retransmission is just waiting
* out the last alarm before it ends. Therefore, if this is the case,
* reset the timeout to the last timeout value so it sends just
* one more SYNACK.
*
* Professor Sirer mentioned that this isn't even necessary,
* but this does seem to make the code follow the specs more.
*/
if (header_reliable->message_type == MSG_SYN)
{
// If the timeout is at 6400, then it's the last transmission
// but it hasn't been doubled yet. If it's 12800, it's just
// been doubled. In each case we want to keep it at 6400
// at the end of the while loop, so we set the timeout to half
// it's current value.
if (socket->timeout >= 6400)
{
socket->timeout /= 2;
}
set_interrupt_level(prev_level);
return;
}
// If we were trying to connect and got a FIN, that means the socket's busy
if (socket->status == TCP_PORT_CONNECTING && header_reliable->message_type == MSG_FIN)
{
// Not connected, got a FIN - that means we couldnt start connection b/c it was busy
// This will let the client function infer that
socket->status = TCP_PORT_COULDNT_CONNECT;
// Wake it up so it can end the retransmission sequence
semaphore_V(socket->wait_for_ack_sem);
set_interrupt_level(prev_level);
return;
}
/* Note: the code below handles ACKs. It also inherently deals with
* duplicate ACKs. We have a status code that indicates whether the socket
* is waiting for an ACK or not. If it's set and we get an ACK (or any
* packet) with the right ACK number, we can process it. However, if our
* status indicates we're NOT waiting for an ACK, we can infer from the
* fact that window_size = 1 that we already got the only ACK we could've
* been expecting, and this new one is therefore a duplicate.
*/
// If we're waiting on an ACK
if (socket->waiting == TCP_PORT_WAITING_ACK /*|| socket->waiting == TCP_PORT_WAITING_ACK_WAKING*/)
{
// This can be an ACK or really any other data packet, we just
// need the ACK number
if (ack_num == socket->seq_num)
{
// Update our status to show we're no longer waiting for an ACK
socket->waiting = TCP_PORT_WAITING_NONE;
// Wake up the thread waiting for the ACK
semaphore_V(socket->wait_for_ack_sem);
}
else if (ack_num == socket->seq_num - 1)
{
// This follows the same logic from the comment block around
// line 170.
if (socket->timeout >= 6400)
{
socket->timeout /= 2;
}
}
}
// If it's an ACK, it requires no further processing
if (header_reliable->message_type == MSG_ACK && data_len == 0)
{
set_interrupt_level(prev_level);
return;
}
// Check if it's a SYNACK we're waiting for
if (socket->waiting == TCP_PORT_WAITING_SYNACK && header_reliable->message_type == MSG_SYNACK)
{
// We're now fully connected in our eyes, handshake complete
socket->waiting = TCP_PORT_WAITING_NONE;
semaphore_V(socket->wait_for_ack_sem);
}
// If we're here, the packet isnt an ACK or SYN, so we should ACK it
// First check if we should increment our ack number
if (seq_num == socket->ack_num + 1)
{
socket->ack_num++;
}
else
{
// It's a duplicate, don't add to queue
duplicate = 1;
}
// Next, perform the ACK, don't incr the seq#
transmit_packet(socket, socket->dst_addr, socket->dst_port,
0, MSG_ACK, 0, NULL, &error);
/* Note: the code below handles FINs, and is also protected against
* duplicate FINs inherently. The seq_num == ack_num check doesn't
* guarantee it's not a duplicate; however, if we process one FIN,
* then the socket's status is set to TCP_PORT_CLOSING. Therefore,
* if we get another FIN, we can tell that the port is already closing
* and we don't need to process it, which also ensures we don't
* process duplicate FINs multiple times. We'll include the
* duplicate == 0 check just for good measure, however.
*/
// We're required to close the conn 15s after we ACK a FIN, so do that here
if (seq_num == socket->ack_num
&& header_reliable->message_type == MSG_FIN
&& socket->status != TCP_PORT_CLOSING
&& duplicate == 0)
{
socket->status = TCP_PORT_CLOSING;
queue_append(sockets_to_delete, socket);
semaphore_V(socket_needs_delete);
}
}
else if (socket->status == TCP_PORT_LISTENING)
{
// Start a connection with the client
if (header_reliable->message_type == MSG_SYN)
{
// Update socket's dst addr & dst port to the client's
network_address_copy(src_addr, socket->dst_addr);
socket->dst_port = src_port_number;
// Set the status to connecting
socket->status = TCP_PORT_CONNECTING;
// Awake the create_server thread, it'll handle the rest
semaphore_V(socket->wait_for_ack_sem);
}
}
// Add the packet to the socket's packet queue if not duplicate & it's a data pkt
if (duplicate == 0 && header_reliable->message_type == MSG_ACK && data_len != 0)
{
queue_append(socket->waiting_packets, arg);
if (socket->data_len == 0)
semaphore_V(socket->packet_ready);
}
// remember to free arg if we dont push this to the tcp recv queue
break;
}
// Restore the interrupt level
set_interrupt_level(prev_level);
return;
}
void network_handler(network_interrupt_arg_t* arg)
{
// Used to extract the network address out of the interrupt argument
//network_address_t addr;
// The source port number - this is really the remote unbound port number
int src_port_number;
// The port number the packet was sent to
int dst_port_number;
// Used to store the header data for UDP/minimsgs
mini_header_t header;
// This is used to extract the sender's address from the header
network_address_t src_addr;
// This is used to extract the destination (our) address from the header
network_address_t dst_addr;
// Disable interrupts...
interrupt_level_t prev_level = set_interrupt_level(DISABLED);
// This is used to check our own address for sanity checks
network_address_t my_addr;
// This will store the total packet size
int packet_size;
// This will store the size of the data in the packet
int data_len;
// This will store the header of a TCP packet
mini_header_reliable_t header_reliable;
// This will store the ACK number of a TCP packet
int ack_num;
// This will store the Sequence number of a TCP packet
int seq_num;
// This will store the socket
minisocket_t socket;
// This will store the TCP error
minisocket_error error;
// This will be used to indicate whether the TCP packet is a duplicate or not
int duplicate = 0;
// This will tell us if we need to free the arg or not
int enqueued;
// Used for general for loops
int i;
// Used to check if we've already broadcasted a route discovery req
int* last_seen_req_id;
// Used for various tasks
network_address_t tmp_addr;
network_address_t tmp_addr2;
// Used to handle routing and discovery requests
route_request_t route_request;
int current_req_id;
int path_len;
int ttl;
// Get the buffer without the routing header
char* buffer_without_routing = (char*) (arg->buffer + sizeof(struct routing_header));
// Used to get the data buffer
char* data_buffer;
// Handle the mini route stuff
// Extract the information from the routing header
routing_header_t routing_header = (routing_header_t) arg->buffer;
char routing_packet_type = routing_header->routing_packet_type;
unpack_address(routing_header->destination, dst_addr);
current_req_id = unpack_unsigned_int(routing_header->id);
ttl = unpack_unsigned_int(routing_header->ttl);
path_len = unpack_unsigned_int(routing_header->path_len);
// Get the data buffer & data length
switch(buffer_without_routing[0])
{
case (char) PROTOCOL_MINISTREAM:
data_buffer = (char*) (buffer_without_routing + sizeof(struct mini_header_reliable));
data_len = arg->size - sizeof(struct routing_header) - sizeof(struct mini_header_reliable);
break;
//default: todo: put this back in, but leave w/o it for testing
case (char) PROTOCOL_MINIDATAGRAM:
data_buffer = (char*) (buffer_without_routing + sizeof(struct mini_header));
data_len = arg->size - sizeof(struct routing_header) - sizeof(struct mini_header);
break;
}
network_get_my_address(my_addr);
//if (network_compare_network_addresses(my_addr, dst_addr) == 0 && ttl == 0)
if (my_addr[0] != dst_addr[0] && ttl == 0)
{
free(arg);
set_interrupt_level(prev_level);
return;
}
switch (routing_packet_type)
{
// If this is a data packet
case ROUTING_DATA:
// If the data packet is meant for us, then break and let the higher
// protocols get the data
unpack_address(routing_header->path[path_len-1], tmp_addr);
if (network_compare_network_addresses(my_addr, tmp_addr) != 0)
{
break;
}
else
{
// If it's not meant for us, we must pass it along
// Go through the path and find the next node
for (i = 0; i < path_len; i++)
{
unpack_address(routing_header->path[i], tmp_addr);
// If this node is us, break - the node we need to send to is next
if (network_compare_network_addresses(tmp_addr, my_addr) != 0)
{
break;
}
}
// If we're the last node (i == path_len-1) or we weren't found in it, quit
if (i >= path_len - 1)
{
free(arg);
set_interrupt_level(prev_level);
return;
}
// Now we'll forward the packet by reusing the headers we have
// Get the next host in the path and set it as the packet's dst
unpack_address(routing_header->path[i+1], tmp_addr);
pack_unsigned_int(routing_header->ttl, ttl - 1);
// Send the packet onward in the route
network_send_pkt(tmp_addr, arg->size - data_len,
(char*) arg->buffer, data_len, data_buffer);
// Revert the header back (not entirely necessary)
//pack_unsigned_int(routing_header->ttl, ttl);
}
free(arg);
set_interrupt_level(prev_level);
return;
break;
case ROUTING_ROUTE_DISCOVERY:
// We're not the dst, so just forward this packet along
//if (network_compare_network_addresses(my_addr, dst_addr) == 0)
if (my_addr[0] != dst_addr[0])
{
// Check if we're in the path, if so, no need to send again (no loops)
for (i = 0; i < path_len; i++)
{
unpack_address(routing_header->path[i], tmp_addr);
if (network_compare_network_addresses(tmp_addr, my_addr) != 0)
{
break;
}
}
// If we were in the path, return - no need to do anything else
if (i < path_len)
{
free(arg);
set_interrupt_level(prev_level);
return;
}
// todo: this next part w/ the discovery packets seen is probably wrong...
// also, lookup the "explain" part in my txt
// todo: need something to clean up old discovery packets
// Check if we've already seen this discovery request - if so, don't resend
last_seen_req_id = (int*) hashmap_get(discovery_packets_seen, current_req_id);
if (last_seen_req_id != NULL)
{
// If this exists, then we've already seen this packet - no need to resend
free(arg);
set_interrupt_level(prev_level);
return;
}
// Now we'll rebroadcast the discovery packet by reusing the header we have
// Modify the header as needed
pack_unsigned_int(routing_header->path_len, path_len+1);
pack_address(routing_header->path[path_len], my_addr);
pack_unsigned_int(routing_header->ttl, ttl - 1);
// Broadcast this packet
network_bcast_pkt(arg->size - data_len, (char*) arg->buffer, data_len, data_buffer);
// Revert the header - dont need to actually remove from route
/*pack_unsigned_int(routing_header->path_len, path_len);
pack_unsigned_int(routing_header->ttl, ttl);
// update already broadcasted hashmap - just put a garbage ptr in
hashmap_insert(discovery_packets_seen, current_req_id, (void*) 0x555555);
*/
free(arg);
set_interrupt_level(prev_level);
return;
}
else
{
// If we were the host being sought, send a reply packet back
// and ensure the higher protocols get the data sent
// reverse the path so we can send a packet back to the host
// Don't forget to add ourselves to the route
path_len++;
pack_unsigned_int(routing_header->path_len, path_len);
pack_address(routing_header->path[path_len-1], my_addr);
for (i = 0; i < path_len/2; i++)
{
unpack_address(routing_header->path[path_len-1-i], tmp_addr);
unpack_address(routing_header->path[i], tmp_addr2);
pack_address(routing_header->path[i], tmp_addr);
pack_address(routing_header->path[path_len-1-i], tmp_addr2);
}
// We'll start sending the packet back now by reusing the header we have
// Prepare the headers
pack_unsigned_int(routing_header->ttl, MAX_ROUTE_LENGTH);
routing_header->routing_packet_type = ROUTING_ROUTE_REPLY;
// send a route reply packet, starting from the next host in the reversed route
unpack_address(routing_header->path[1], tmp_addr);
pack_address(routing_header->destination, tmp_addr);
network_send_pkt(tmp_addr, arg->size - data_len,
(char*) arg->buffer, 0, NULL);
// Revert the header
/*pack_unsigned_int(routing_header->ttl, ttl);
routing_header->routing_packet_type = ROUTING_ROUTE_DISCOVERY;
// Reverse the path back
for (i = 0; i < path_len/2; i++)
{
unpack_address(routing_header->path[path_len-1-i], tmp_addr);
unpack_address(routing_header->path[i], tmp_addr2);
pack_address(routing_header->path[i], tmp_addr);
pack_address(routing_header->path[path_len-1-i], tmp_addr);
}
*/
// DONT return, ensure that the higher protocols will get the data
// ^ never mind. return, it will send a data packet later.
free(arg);
set_interrupt_level(prev_level);
return;
}
break;
case ROUTING_ROUTE_REPLY:
unpack_address(routing_header->path[path_len-1], tmp_addr);
// If we were the initiator of the request and just got our response
//if (network_compare_network_addresses(my_addr, tmp_addr) != 0)
if (my_addr[0] == tmp_addr[0])
{
// Get the addr of the host we were trying to discover
unpack_address(routing_header->path[0], tmp_addr);
// find the discovery request struct for this dst addr
//route_request = (route_request_t) hashmap_get(current_discovery_requests, hash_address(tmp_addr));
route_request = (route_request_t) hashmap_get(current_discovery_requests, tmp_addr[0]);
if (route_request == NULL)
{
free(arg);
set_interrupt_level(prev_level);
return;
// it could be we already got this path
break;
}
// Check if we already got this path, but miniroute_send_pkt() hasn't deleted the req struct yet
if (route_request->interrupt_arg != NULL)
{
free(arg);
set_interrupt_level(prev_level);
return;
break;
}
route_request->interrupt_arg = arg;
semaphore_V(route_request->initiator_sem);
set_interrupt_level(prev_level);
return;
}
else
{
// Find the next node in the route
for (i = 0; i < path_len; i++)
{
unpack_address(routing_header->path[i], tmp_addr);
// Stop if we found ourselves - we need to send to the next node
if (network_compare_network_addresses(tmp_addr, my_addr) != 0)
{
break;
}
}
// If we were the last node OR not in the route at all
if (i >= path_len - 1)
{
free(arg);
set_interrupt_level(prev_level);
return;
}
// We'll forward the reply along by reusing the header
// Get the next host in the path and set it as the packet's dst
unpack_address(routing_header->path[i+1], tmp_addr);
pack_unsigned_int(routing_header->ttl, ttl - 1);
pack_address(routing_header->destination, tmp_addr);
// Send the packet onward in the route
network_send_pkt(tmp_addr, arg->size - data_len,
(char*) arg->buffer, 0, NULL);
// Make sure we set the header back
//pack_unsigned_int(routing_header->ttl, ttl);
}
free(arg);
set_interrupt_level(prev_level);
return;
break;
}
// If we're here, the packet was meant for us
// The "normal" packet without the routing header is in buffer_without_routing
// Adjust arg->size in case something uses it
arg->size -= sizeof(struct routing_header);
// Check the protocol
switch (buffer_without_routing[0])
{
case (char) PROTOCOL_MINIDATAGRAM:
// Extract data from the network interrupt arg
//network_address_copy(arg->addr, addr);
// Get the header struct, unpack the parameters
header = (mini_header_t) buffer_without_routing;
dst_port_number = (int) unpack_unsigned_short(header->destination_port);
// Ensure the port number is valid
if (dst_port_number < MIN_UNBOUND || dst_port_number > MAX_UNBOUND)
{
free(arg);
set_interrupt_level(prev_level);
return;
}
// Then ensure the miniport exists
if (miniports[dst_port_number] == NULL)
{
free(arg);
set_interrupt_level(prev_level);
return;
}
// Add the arg to the queue
queue_append(miniports[dst_port_number]->port_data.unbound.data_queue, arg);
// Wake up thread that's waiting to receive - sem_V()
semaphore_V(miniports[dst_port_number]->port_data.unbound.data_ready);
// Ensure the argument isn't free'd
enqueued = 1;
set_interrupt_level(prev_level);
return;
break;
case PROTOCOL_MINISTREAM:
// Get the total size of the packet and data length
packet_size = arg->size;
data_len = packet_size - sizeof(struct mini_header_reliable);
// Get the header and extract information
header_reliable = (mini_header_reliable_t) buffer_without_routing;
src_port_number = (int) unpack_unsigned_short(header_reliable->source_port);
dst_port_number = (int) unpack_unsigned_short(header_reliable->destination_port);
unpack_address(header_reliable->source_address, src_addr);
unpack_address(header_reliable->destination_address, dst_addr);
seq_num = (int) unpack_unsigned_int(header_reliable->seq_number);
ack_num = (int) unpack_unsigned_int(header_reliable->ack_number);
// Don't respond if socket doesn't exist - will trigger SOCKET_NOSERVER for client
if (minisockets[dst_port_number] == NULL)
{
free(arg);
set_interrupt_level(prev_level);
return;
}
// Get the socket in question
socket = minisockets[dst_port_number];
// Check if packet was meant for us - ignore if not
network_get_my_address(my_addr);
if (network_compare_network_addresses(my_addr, dst_addr) == 0)
{
free(arg);
set_interrupt_level(prev_level);
return;
}
if (socket->status == TCP_PORT_CLOSING || socket->waiting == TCP_PORT_WAITING_CLOSE)
{
free(arg);
set_interrupt_level(prev_level);
return;
}
// Packet handling for established connections
if (socket->status != TCP_PORT_LISTENING)
{
// Ensure source address is correct - ignore if not
if (network_compare_network_addresses(src_addr, socket->dst_addr) == 0
|| src_port_number != socket->dst_port)
{
if (header_reliable->message_type == MSG_SYN)
{
// A client is trying to connect to an already-connected port
// Send them a FIN, which will result in their client
// returning a SOCKET_BUSY error
transmit_packet(socket, src_addr, src_port_number, 0,
MSG_FIN, 0, NULL, &error);
}
free(arg);
set_interrupt_level(prev_level);
return;
}
/* We got a duplicate SYN and need to ensure that the host gets
* another SYNACK. The thread that sent the SYNACK will currently
* be retransmitting the SYNACKs, as it didn't get an ACK. If it
* was done with the retransmission sequence, the socket would be
* closed, and this would therefore not have gotten this far.
* HOWEVER:
* If the retransmission sequence already sent its LAST
* retransmission and was waiting on it, then this duplicate SYN
* will NOT get a SYNACK, as the retransmission is just waiting
* out the last alarm before it ends. Therefore, if this is the case,
* reset the timeout to the last timeout value so it sends just
* one more SYNACK.
*
* Professor Sirer mentioned that this isn't even necessary,
* but this does seem to make the code follow the specs more.
*/
if (header_reliable->message_type == MSG_SYN)
{
// If the timeout is at 6400, then it's the last transmission
// but it hasn't been doubled yet. If it's 12800, it's just
// been doubled. In each case we want to keep it at 6400
// at the end of the while loop, so we set the timeout to half
// it's current value.
if (socket->timeout >= 6400)
{
socket->timeout /= 2;
}
free(arg);
set_interrupt_level(prev_level);
return;
}
// If we were trying to connect and got a FIN, that means the socket's busy
if (socket->status == TCP_PORT_CONNECTING && header_reliable->message_type == MSG_FIN)
{
// Not connected, got a FIN - that means we couldnt start connection b/c it was busy
// This will let the client function infer that
socket->status = TCP_PORT_COULDNT_CONNECT;
// Wake it up so it can end the retransmission sequence
semaphore_V(socket->wait_for_ack_sem);
free(arg);
set_interrupt_level(prev_level);
return;
}
/* Note: the code below handles ACKs. It also inherently deals with
* duplicate ACKs. We have a status code that indicates whether the socket
* is waiting for an ACK or not. If it's set and we get an ACK (or any
* packet) with the right ACK number, we can process it. However, if our
* status indicates we're NOT waiting for an ACK, we can infer from the
* fact that window_size = 1 that we already got the only ACK we could've
* been expecting, and this new one is therefore a duplicate.
*/
// If we're waiting on an ACK
if (socket->waiting == TCP_PORT_WAITING_ACK /*|| socket->waiting == TCP_PORT_WAITING_ACK_WAKING*/)
{
// This can be an ACK or really any other data packet, we just
// need the ACK number
if (ack_num == socket->seq_num)
{
// Update our status to show we're no longer waiting for an ACK
socket->waiting = TCP_PORT_WAITING_NONE;
// Wake up the thread waiting for the ACK
semaphore_V(socket->wait_for_ack_sem);
}
else if (ack_num == socket->seq_num - 1)
{
// This follows the same logic from the comment block around
// line 170.
if (socket->timeout >= 6400)
{
socket->timeout /= 2;
}
}
}
// If it's an ACK, it requires no further processing
if (header_reliable->message_type == MSG_ACK && data_len == 0)
{
free(arg);
set_interrupt_level(prev_level);
return;
}
// Check if it's a SYNACK we're waiting for
if (socket->waiting == TCP_PORT_WAITING_SYNACK && header_reliable->message_type == MSG_SYNACK)
{
// We're now fully connected in our eyes, handshake complete
socket->waiting = TCP_PORT_WAITING_NONE;
semaphore_V(socket->wait_for_ack_sem);
}
// If we're here, the packet isnt an ACK or SYN, so we should ACK it
// First check if we should increment our ack number
if (seq_num == socket->ack_num + 1)
{
socket->ack_num++;
}
else
{
// It's a duplicate, don't add to queue
duplicate = 1;
}
// Next, perform the ACK, don't incr the seq#
transmit_packet(socket, socket->dst_addr, socket->dst_port,
0, MSG_ACK, 0, NULL, &error);
/* Note: the code below handles FINs, and is also protected against
* duplicate FINs inherently. The seq_num == ack_num check doesn't
* guarantee it's not a duplicate; however, if we process one FIN,
* then the socket's status is set to TCP_PORT_CLOSING. Therefore,
* if we get another FIN, we can tell that the port is already closing
* and we don't need to process it, which also ensures we don't
* process duplicate FINs multiple times. We'll include the
* duplicate == 0 check just for good measure, however.
*/
// We're required to close the conn 15s after we ACK a FIN, so do that here
if (seq_num == socket->ack_num
&& header_reliable->message_type == MSG_FIN
&& socket->status != TCP_PORT_CLOSING
&& duplicate == 0)
{
socket->status = TCP_PORT_CLOSING;
queue_append(sockets_to_delete, socket);
semaphore_V(socket_needs_delete);
}
}
else if (socket->status == TCP_PORT_LISTENING)
{
// Start a connection with the client
if (header_reliable->message_type == MSG_SYN)
{
// Update socket's dst addr & dst port to the client's
network_address_copy(src_addr, socket->dst_addr);
socket->dst_port = src_port_number;
// Set the status to connecting
socket->status = TCP_PORT_CONNECTING;
// Awake the create_server thread, it'll handle the rest
semaphore_V(socket->wait_for_ack_sem);
}
}
// Add the packet to the socket's packet queue if not duplicate & it's a data pkt
if (duplicate == 0 && header_reliable->message_type == MSG_ACK && data_len != 0)
{
enqueued = 1;
queue_append(socket->waiting_packets, arg);
if (socket->data_len == 0)
semaphore_V(socket->packet_ready);
}
// remember to free arg if we dont push this to the tcp recv queue
break;
}
if (enqueued == 0)
{
free(arg);
}
// Restore the interrupt level
set_interrupt_level(prev_level);
return;
}
minisocket_t* minisocket_server_create(int port, minisocket_error *error) {
//Check socket number first
if (valid_server_port(port) == 0) {
*error = SOCKET_INVALIDPARAMS;
return NULL;
}
//check if socket is already in use
if (mini_socket_data[port] != NULL) {
*error = SOCKET_PORTINUSE;
return NULL;
}
minisocket_t* socket = (minisocket_t *) malloc(sizeof(minisocket_t));
if (socket == NULL) {
*error = SOCKET_OUTOFMEMORY;
return NULL;
}
socket->state = LISTENING;
socket->socket_type = SERVER_TYPE;
socket->local_port_number = port;
network_address_t my_address;
network_get_my_address(my_address);
network_address_copy(my_address, socket->local_address);
socket->datagrams_ready = semaphore_create();
semaphore_initialize(socket->datagrams_ready, 0);
socket->ack_ready = semaphore_create();
semaphore_initialize(socket->ack_ready, 0);
socket->incoming_data = queue_new();
socket->acknowledgements = queue_new();
socket->seq = 0;
socket->ack = 0;
socket->next_read = 0;
//add socket to global array
mini_socket_data[socket->local_port_number] = socket;
char connection_established = 0;
mini_header_reliable_t header;
minisocket_create_reliable_header((mini_header_reliable_t *) &header, socket, socket->remote_port_number, socket->remote_address, MSG_SYNACK);
network_address_t dest;
pack_unsigned_int(header.seq_number, socket->seq);
pack_unsigned_int(header.ack_number, socket->ack);
//loop until a full connection is established
while (connection_established == 0) {
//sleep until initial MSG_SYN arrives from client
char message_received = 0;
while (message_received == 0) {
//Waits until it receives a packet
semaphore_P(socket->ack_ready);
interrupt_level_t old_level = set_interrupt_level(DISABLED);
network_interrupt_arg_t* interrupt_message = NULL;
queue_dequeue(socket->acknowledgements, (void **) &interrupt_message);
set_interrupt_level(old_level);
//TODO: check more contents of message? change seq and ack values in response??}
if (interrupt_message != NULL ) {
mini_header_reliable_t* received_header = (mini_header_reliable_t *) interrupt_message->buffer;
unpack_address(received_header->source_address, dest);
pack_address(header.destination_address, dest);
pack_unsigned_short(header.destination_port, unpack_unsigned_short(received_header->source_port));
if (valid_client_port(unpack_unsigned_short(received_header->source_port)) == 1) { //check valid port number
if (received_header->message_type != MSG_SYN) { //check valid message type
header.message_type = MSG_FIN;
network_send_pkt(dest, sizeof(mini_header_reliable_t), (char *) &header, 0, empty_message);
free(interrupt_message);
}
else {
//set remote port values
printf("server got the SYN message\n");
socket->remote_port_number = unpack_unsigned_short(received_header->source_port);
network_address_copy(dest, socket->remote_address);
socket->seq = unpack_unsigned_int(received_header->seq_number);
message_received = 1; //will break loop
free(interrupt_message);
socket->state = CONNECTING;
break;
}
}
}
}
//reset loop value for return
message_received = 0;
//otherwise the message was the correct type and format
int timeout = START_TIMEOUT / 2; //this way first timeout will be at START_TIMEOUT
for (int i = 0; i < MAX_FAILURES; i++) {
printf("sending MSG_SYNACK in server, i: %d\n", i);
timeout = timeout * 2;
header.message_type = MSG_SYNACK;
network_send_pkt(dest, sizeof(mini_header_reliable_t), (char *) &header, 0, empty_message);
alarm_id timeout_alarm_id = register_alarm(timeout, handshake_timeout_handler, (void *) socket->ack_ready);
int alarm_fired = 0;
//keep looking through received packets until either the alarm fires or it finds the correct packet
while (!connection_established && !alarm_fired) {
semaphore_P(socket->ack_ready);
//alarm has fired, since there are no packets to be received
if (queue_length(socket->acknowledgements) == 0) {
alarm_fired = 1; //goes to next iteration of for loop
}
//There is a packet (alarm hasnt fired yet)
else {
network_interrupt_arg_t* interrupt_message = NULL;
interrupt_level_t old_level = set_interrupt_level(DISABLED);
queue_dequeue(socket->acknowledgements, (void **) &interrupt_message);
set_interrupt_level(old_level);
// verify non null message
if (interrupt_message != NULL) {
mini_header_reliable_t* received_header = (mini_header_reliable_t *) interrupt_message->buffer;
network_address_t temp_address;
unpack_address(received_header->source_address, temp_address);
if (socket->remote_port_number == unpack_unsigned_short(received_header->source_port) &&
network_compare_network_addresses(socket->remote_address, temp_address) != 0 &&
received_header->message_type == MSG_ACK) {
//same address, same ports, right message
deregister_alarm(timeout_alarm_id); //only deregister alarm when the right packet is found
connection_established = 1;
//queue_prepend(socket->acknowledgements, interrupt_message); //ack works as well when there is data
break;
}
else {
free(interrupt_message);
}
}
}
}
if (connection_established) {
//correct response has been found, get out of this timeout loop!
break;
}
}
//if timeout occurs, will loop back to initial waiting phase for MSG_SYN from client
}
printf("leaving server create\n");
//update server socket values with client connection
socket->state = CONNECTED;
assert(socket != NULL);
return socket;
}
//Transmit a packet and handle retransmission attempts
int transmit_packet(minisocket_t socket, network_address_t dst_addr, int dst_port,
short incr_seq, char message_type, int data_len, char* data,
minisocket_error* error)
{
mini_header_reliable_t newReliableHeader;
void *alarmId;
int sendSucessful;
network_address_t my_addr;
int success = 0;
int connected = 0;
if (message_type == MSG_ACK)
connected = 1;
network_get_my_address(my_addr);
if (socket == NULL)
{
*error = SOCKET_INVALIDPARAMS;
return -1;
}
if (socket->status == TCP_PORT_CLOSING)
{
*error = SOCKET_SENDERROR;
return -1;
}
newReliableHeader = create_reliable_header(my_addr, socket->port_number, dst_addr,
dst_port, message_type, socket->seq_number, socket->ack_number);
socket->timeout = 100;
while(socket->timeout <= 6400)
{
printf("sending packet to %d, seq=%d, ack=%d, type=%d\n", dst_port, socket->seq_number, socket->ack_number, message_type);
sendSucessful = network_send_pkt(dst_addr, sizeof(struct mini_header_reliable),
(char*) newReliableHeader, data_len, (char*) data);
if (sendSucessful == -1)
{
socket->timeout *= 2;
continue;
}
alarmId = register_alarm(socket->timeout, &wake_up_semaphore, socket);
if (message_type == MSG_SYN)
{
socket->waiting = TCP_PORT_WAITING_SYNACK;
semaphore_P(socket->wait_for_ack_semaphore);
}
else if (!connected)
{
socket->waiting = TCP_PORT_WAITING_ACK;
semaphore_P(socket->wait_for_ack_semaphore);
}
else {
socket->waiting = TCP_PORT_WAITING_NONE;
}
semaphore_P(socket->mutex);
if (socket->waiting == TCP_PORT_WAITING_NONE)
{
/* I think incr_seq belongs before the _P on wait_for_ack, but that breaks it for now :/
if (incr_seq)
{
semaphore_P(socket->mutex);
socket->seq_number++;
semaphore_V(socket->mutex);
}
*/ if (message_type == MSG_SYN)
{
//we got a synack back, so we need to make sure to send an ack to the server
newReliableHeader = create_reliable_header(my_addr, socket->port_number, dst_addr,
dst_port, MSG_ACK, socket->seq_number, socket->ack_number);
socket->timeout = 100;
message_type = MSG_ACK;
connected = 1;
semaphore_V(socket->mutex);
continue;
}
deregister_alarm(alarmId);
success = 1;
semaphore_V(socket->mutex);
break;
}
else
{
if (socket->status == TCP_PORT_UNABLE_TO_CONNECT)
{
deregister_alarm(alarmId);
success = 0;
semaphore_V(socket->mutex);
break;
}
socket->timeout *= 2;
semaphore_V(socket->mutex);
}
}
semaphore_P(socket->mutex);
socket->timeout = 100;
if (success == 0)
{
socket->waiting = TCP_PORT_WAITING_NONE;
*error = SOCKET_NOSERVER;
}
semaphore_V(socket->mutex);
*error = SOCKET_NOERROR;
free(newReliableHeader);
return 0;
}
int
network_initialize(interrupt_handler_t network_handler) {
int arg = 1;
/* initialise the NT socket library, inexplicably required by NT */
assert(WSAStartup(MAKEWORD(2, 0), &winsock_version_data) == 0);
if (atomic_test_and_set(&initialized)) {
return -1;
}
memset(&if_info, 0, sizeof(if_info));
if_info.sock = socket(PF_INET, SOCK_DGRAM, 0);
if (if_info.sock < 0) {
perror("socket");
return -1;
}
if_info.sin.sin_family = SOCK_DGRAM;
if_info.sin.sin_addr.s_addr = htonl(0);
if_info.sin.sin_port = htons(my_udp_port);
if (bind(if_info.sock, (struct sockaddr *) &if_info.sin,
sizeof(if_info.sin)) < 0) {
/* kprintf("Error: code %ld.\n", GetLastError());*/
AbortOnError(0);
perror("bind");
return -1;
}
/* set for fast reuse */
assert(setsockopt(if_info.sock, SOL_SOCKET, SO_REUSEADDR,
(char *) &arg, sizeof(int)) == 0);
if (BCAST_ENABLED){
if (BCAST_USE_TOPOLOGY_FILE){
bcast_initialize(BCAST_TOPOLOGY_FILE, &topology);
} else {
assert(setsockopt(if_info.sock, SOL_SOCKET, SO_BROADCAST,
(char *) &arg, sizeof(int)) == 0);
network_translate_hostname(BCAST_ADDRESS,broadcast_addr);
}
}
/*
* Print network information on the screen (mostly for Joranda).
*/
{
network_address_t my_address;
char my_hostname[256];
network_get_my_address(my_address);
network_format_address(my_address, my_hostname, 256);
kprintf("Hostname of local machine: %s.\n",my_hostname);
}
/*
* Interrupts are handled through the caller's handler.
*/
start_network_poll(network_handler, &if_info.sock);
return 0;
}
minisocket_t* minisocket_client_create(const network_address_t addr, int port, minisocket_error *error) {
//Check socket number first
if (valid_server_port(port) == 0) {
*error = SOCKET_INVALIDPARAMS;
return NULL;
}
//Then check if we can make another client
if (client_count >= MAX_CLIENTS) {
*error = SOCKET_NOMOREPORTS;
return NULL;
}
//create new minisocket
minisocket_t* socket = (minisocket_t *) malloc(sizeof(minisocket_t));
if (socket == NULL) {
*error = SOCKET_OUTOFMEMORY;
return NULL; //OOM
}
while (mini_socket_data[next_port]) {
next_port = ((next_port + 1) % PORT_RANGE);
}
socket->socket_type = CLIENT_TYPE;
socket->local_port_number = next_port;
next_port = ((next_port + 1) % PORT_RANGE);
socket->state = CONNECTING;
socket->seq = 0;
socket->ack = 0;
network_address_copy(addr, socket->remote_address);
socket->remote_port_number = (unsigned short) port;
network_address_copy(addr, socket->remote_address);
socket->next_read = 0;
network_address_t my_address;
network_get_my_address(my_address);
network_address_copy(my_address, socket->local_address);
socket->datagrams_ready = semaphore_create();
semaphore_initialize(socket->datagrams_ready, 0);
socket->ack_ready = semaphore_create();
semaphore_initialize(socket->ack_ready, 0);
socket->incoming_data = queue_new();
socket->acknowledgements = queue_new();
//add socket to global array
mini_socket_data[socket->local_port_number] = socket;
mini_header_reliable_t header;
minisocket_create_reliable_header((mini_header_reliable_t *) &header, socket, socket->remote_port_number, addr, MSG_SYN);
//minisocket and header now created, try to establish connection
pack_unsigned_int(header.seq_number, socket->seq);
pack_unsigned_int(header.ack_number, socket->ack);
//send first message and wait for response
int response = 0; //no response yet
int timeout = START_TIMEOUT / 2; //this way first timeout will be at START_TIMEOUT
for (int i = 0; i < MAX_FAILURES; i++) {
printf("sending MSG_SYN in client, i: %d\n", i);
timeout = timeout * 2;
network_send_pkt(addr, sizeof(mini_header_reliable_t), (char *) &header, 0, empty_message);
alarm_id timeout_alarm_id = register_alarm(timeout, handshake_timeout_handler, (void *) socket->ack_ready);
int alarm_fired = 0;
while (!response && !alarm_fired) {
semaphore_P(socket->ack_ready);
//If queue length == 0, then the alarm must have fired
if (queue_length(socket->acknowledgements) == 0) {
alarm_fired = 1; //goes to next iteration of for loop
}
//otherwise, we received a packet
else {
network_interrupt_arg_t *interrupt_message;
interrupt_level_t old_level = set_interrupt_level(DISABLED);
queue_dequeue(socket->acknowledgements, (void **) &interrupt_message);
set_interrupt_level(old_level);
// if message not null
if (interrupt_message != NULL) {
mini_header_reliable_t* received_header = (mini_header_reliable_t *) interrupt_message->buffer;
network_address_t temp_address;
unpack_address(received_header->source_address, temp_address);
if (socket->remote_port_number == unpack_unsigned_short(received_header->source_port) &&
network_compare_network_addresses(socket->remote_address, temp_address) != 0) {
//if SYNACK
printf("CLIENT\n");
if (received_header->message_type == MSG_SYNACK) {
printf("GOT message SYN_ACK\n");
deregister_alarm(timeout_alarm_id);
response = 1;
break;
}
//if MSG_FIN
else if (received_header->message_type == MSG_FIN) {
printf("got message MSG_FIN in client\n");
//server already in use
deregister_alarm(timeout_alarm_id);
*error = SOCKET_BUSY;
response = 1;
minisocket_destroy(socket);
return NULL;
}
//WRONG MESSAGE TYPE
else {
printf("wrong message type received in client\n");
//TODO : try another message type, maybe do nothing?
}
}
}
}
}
if (response) {
break;
}
}
// timeout after 12.8s occured, close down socket
if (response != 1) {
printf("full timeout in client sending SYN\n");
*error = SOCKET_NOSERVER;
minisocket_destroy(socket);
return NULL;
}
// send final MSG_ACK once to server (future data packets will also have MSG_ACK as header type)
header.message_type = MSG_ACK;
printf("sending final MSG_ACK and leaving client create\n");
network_send_pkt(addr, sizeof(mini_header_reliable_t), (char *) &header, 0, empty_message);
socket->state = CONNECTED;
client_count++;
return socket;
}