/* return 1 on success.
* return 0 if could not send packet.
* return -1 on failure (connection must be killed).
*/
static int write_packet_TCP_secure_connection(TCP_Secure_Connection *con, const uint8_t *data, uint16_t length,
bool priority)
{
if (length + crypto_box_MACBYTES > MAX_PACKET_SIZE) {
return -1;
}
bool sendpriority = 1;
if (send_pending_data(con) == -1) {
if (priority) {
sendpriority = 0;
} else {
return 0;
}
}
uint8_t packet[sizeof(uint16_t) + length + crypto_box_MACBYTES];
uint16_t c_length = htons(length + crypto_box_MACBYTES);
memcpy(packet, &c_length, sizeof(uint16_t));
int len = encrypt_data_symmetric(con->shared_key, con->sent_nonce, data, length, packet + sizeof(uint16_t));
if ((unsigned int)len != (sizeof(packet) - sizeof(uint16_t))) {
return -1;
}
if (priority) {
len = sendpriority ? send(con->sock, (const char *)packet, sizeof(packet), MSG_NOSIGNAL) : 0;
if (len <= 0) {
len = 0;
}
increment_nonce(con->sent_nonce);
if ((unsigned int)len == sizeof(packet)) {
return 1;
}
return add_priority(con, packet, sizeof(packet), len);
}
len = send(con->sock, (const char *)packet, sizeof(packet), MSG_NOSIGNAL);
if (len <= 0) {
return 0;
}
increment_nonce(con->sent_nonce);
if ((unsigned int)len == sizeof(packet)) {
return 1;
}
memcpy(con->last_packet, packet, sizeof(packet));
con->last_packet_length = sizeof(packet);
con->last_packet_sent = len;
return 1;
}
/* return 1 on success.
* return 0 if could not send packet.
* return -1 on failure (connection must be killed).
*/
static int write_packet_TCP_secure_connection(TCP_Secure_Connection *con, const uint8_t *data, uint16_t length)
{
if (length + crypto_box_MACBYTES > MAX_PACKET_SIZE)
return -1;
if (send_pending_data(con) == -1)
return 0;
uint8_t packet[sizeof(uint16_t) + length + crypto_box_MACBYTES];
uint16_t c_length = htons(length + crypto_box_MACBYTES);
memcpy(packet, &c_length, sizeof(uint16_t));
int len = encrypt_data_symmetric(con->shared_key, con->sent_nonce, data, length, packet + sizeof(uint16_t));
if ((unsigned int)len != (sizeof(packet) - sizeof(uint16_t)))
return -1;
increment_nonce(con->sent_nonce);
len = send(con->sock, packet, sizeof(packet), MSG_NOSIGNAL);
if ((unsigned int)len == sizeof(packet))
return 1;
if (len <= 0)
return 0;
memcpy(con->last_packet, packet, length);
con->last_packet_length = sizeof(packet);
con->last_packet_sent = len;
return 1;
}
void JitteredPacedFlow::send_pending_data() {
if (received_bytes < size) {
//std::cout << "Sending Pending Data" << std::endl;
if (next_seq_no + mss > size) {
next_seq_no = last_unacked_seq;
}
uint32_t seqn = next_seq_no;
if (seqn + mss > size) {
return;
}
next_seq_no = seqn + mss;
if (received.count(seqn) == 0) {
//std::cout << get_current_time() << " Enqueing " << seqn << "\n";
uint32_t priority = get_priority(seqn);
Packet *p = new Packet(get_current_time(), this, seqn, \
priority, mss + hdr_size, \
src, dst);
double td = src->queue->get_transmission_delay(p->size);
double wait = td / rate;
double jitter = (wait - td) * rand() / RAND_MAX;
add_to_event_queue(new PacketQueuingEvent(get_current_time() + jitter,
p, src->queue));
add_to_event_queue(new FlowProcessingEvent(get_current_time() + wait,
this));
} else {
send_pending_data();
}
}
}
static void do_TCP_confirmed(TCP_Server *TCP_server)
{
#ifdef TCP_SERVER_USE_EPOLL
if (TCP_server->last_run_pinged == unix_time()) {
return;
}
TCP_server->last_run_pinged = unix_time();
#endif
uint32_t i;
for (i = 0; i < TCP_server->size_accepted_connections; ++i) {
TCP_Secure_Connection *conn = &TCP_server->accepted_connection_array[i];
if (conn->status != TCP_STATUS_CONFIRMED) {
continue;
}
if (is_timeout(conn->last_pinged, TCP_PING_FREQUENCY)) {
uint8_t ping[1 + sizeof(uint64_t)];
ping[0] = TCP_PACKET_PING;
uint64_t ping_id = random_64b();
if (!ping_id) {
++ping_id;
}
memcpy(ping + 1, &ping_id, sizeof(uint64_t));
int ret = write_packet_TCP_secure_connection(conn, ping, sizeof(ping), 1);
if (ret == 1) {
conn->last_pinged = unix_time();
conn->ping_id = ping_id;
} else {
if (is_timeout(conn->last_pinged, TCP_PING_FREQUENCY + TCP_PING_TIMEOUT)) {
kill_accepted(TCP_server, i);
continue;
}
}
}
if (conn->ping_id && is_timeout(conn->last_pinged, TCP_PING_TIMEOUT)) {
kill_accepted(TCP_server, i);
continue;
}
send_pending_data(conn);
#ifndef TCP_SERVER_USE_EPOLL
do_confirmed_recv(TCP_server, i);
#endif
}
}
static void do_TCP_confirmed(TCP_Server *TCP_server)
{
uint32_t i;
for (i = 0; i < TCP_server->size_accepted_connections; ++i) {
TCP_Secure_Connection *conn = &TCP_server->accepted_connection_array[i];
if (conn->status != TCP_STATUS_CONFIRMED)
continue;
if (is_timeout(conn->last_pinged, TCP_PING_FREQUENCY)) {
uint8_t ping[1 + sizeof(uint64_t)];
ping[0] = TCP_PACKET_PING;
uint64_t ping_id = random_64b();
if (!ping_id)
++ping_id;
memcpy(ping + 1, &ping_id, sizeof(uint64_t));
int ret = write_packet_TCP_secure_connection(conn, ping, sizeof(ping));
if (ret == 1) {
conn->last_pinged = unix_time();
conn->ping_id = ping_id;
}
}
if (conn->ping_id && is_timeout(conn->last_pinged, TCP_PING_TIMEOUT)) {
kill_TCP_connection(conn);
del_accepted(TCP_server, i);
continue;
}
send_pending_data(conn);
uint8_t packet[MAX_PACKET_SIZE];
int len;
while ((len = read_packet_TCP_secure_connection(conn->sock, &conn->next_packet_length, conn->shared_key,
conn->recv_nonce, packet, sizeof(packet)))) {
if (len == -1) {
kill_TCP_connection(conn);
del_accepted(TCP_server, i);
break;
}
if (handle_TCP_packet(TCP_server, i, packet, len) == -1) {
kill_TCP_connection(conn);
del_accepted(TCP_server, i);
break;
}
}
}
}
static int do_confirmed_TCP(TCP_Client_Connection *conn, void *userdata)
{
send_pending_data(conn);
send_ping_response(conn);
send_ping_request(conn);
uint8_t packet[MAX_PACKET_SIZE];
int len;
if (is_timeout(conn->last_pinged, TCP_PING_FREQUENCY)) {
uint64_t ping_id = random_64b();
if (!ping_id) {
++ping_id;
}
conn->ping_request_id = conn->ping_id = ping_id;
send_ping_request(conn);
conn->last_pinged = unix_time();
}
if (conn->ping_id && is_timeout(conn->last_pinged, TCP_PING_TIMEOUT)) {
conn->status = TCP_CLIENT_DISCONNECTED;
return 0;
}
while ((len = read_packet_TCP_secure_connection(conn->sock, &conn->next_packet_length, conn->shared_key,
conn->recv_nonce, packet, sizeof(packet)))) {
if (len == -1) {
conn->status = TCP_CLIENT_DISCONNECTED;
break;
}
if (handle_TCP_packet(conn, packet, len, userdata) == -1) {
conn->status = TCP_CLIENT_DISCONNECTED;
break;
}
}
return 0;
}
/* Run the TCP connection
*/
void do_TCP_connection(TCP_Client_Connection *TCP_connection, void *userdata)
{
unix_time_update();
if (TCP_connection->status == TCP_CLIENT_DISCONNECTED) {
return;
}
if (TCP_connection->status == TCP_CLIENT_PROXY_HTTP_CONNECTING) {
if (send_pending_data(TCP_connection) == 0) {
int ret = proxy_http_read_connection_response(TCP_connection);
if (ret == -1) {
TCP_connection->kill_at = 0;
TCP_connection->status = TCP_CLIENT_DISCONNECTED;
}
if (ret == 1) {
generate_handshake(TCP_connection);
TCP_connection->status = TCP_CLIENT_CONNECTING;
}
}
}
if (TCP_connection->status == TCP_CLIENT_PROXY_SOCKS5_CONNECTING) {
if (send_pending_data(TCP_connection) == 0) {
int ret = socks5_read_handshake_response(TCP_connection);
if (ret == -1) {
TCP_connection->kill_at = 0;
TCP_connection->status = TCP_CLIENT_DISCONNECTED;
}
if (ret == 1) {
proxy_socks5_generate_connection_request(TCP_connection);
TCP_connection->status = TCP_CLIENT_PROXY_SOCKS5_UNCONFIRMED;
}
}
}
if (TCP_connection->status == TCP_CLIENT_PROXY_SOCKS5_UNCONFIRMED) {
if (send_pending_data(TCP_connection) == 0) {
int ret = proxy_socks5_read_connection_response(TCP_connection);
if (ret == -1) {
TCP_connection->kill_at = 0;
TCP_connection->status = TCP_CLIENT_DISCONNECTED;
}
if (ret == 1) {
generate_handshake(TCP_connection);
TCP_connection->status = TCP_CLIENT_CONNECTING;
}
}
}
if (TCP_connection->status == TCP_CLIENT_CONNECTING) {
if (send_pending_data(TCP_connection) == 0) {
TCP_connection->status = TCP_CLIENT_UNCONFIRMED;
}
}
if (TCP_connection->status == TCP_CLIENT_UNCONFIRMED) {
uint8_t data[TCP_SERVER_HANDSHAKE_SIZE];
int len = read_TCP_packet(TCP_connection->sock, data, sizeof(data));
if (sizeof(data) == len) {
if (handle_handshake(TCP_connection, data) == 0) {
TCP_connection->kill_at = ~0;
TCP_connection->status = TCP_CLIENT_CONFIRMED;
} else {
TCP_connection->kill_at = 0;
TCP_connection->status = TCP_CLIENT_DISCONNECTED;
}
}
}
if (TCP_connection->status == TCP_CLIENT_CONFIRMED) {
do_confirmed_TCP(TCP_connection, userdata);
}
if (TCP_connection->kill_at <= unix_time()) {
TCP_connection->status = TCP_CLIENT_DISCONNECTED;
}
}