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/*
* TCP_client.c -- Implementation of the TCP relay client part of Tox.
*
* Copyright (C) 2014 Tox project All Rights Reserved.
*
* This file is part of Tox.
*
* Tox is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Tox is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Tox. If not, see <http://www.gnu.org/licenses/>.
*
*/
#include "TCP_client.h"
#if !defined(_WIN32) && !defined(__WIN32__) && !defined (WIN32)
#include <sys/ioctl.h>
#endif
#include "util.h"
/* return 1 on success
* return 0 on failure
*/
static int connect_sock_to(sock_t sock, IP_Port ip_port)
{
struct sockaddr_storage addr = {0};
size_t addrsize;
if (ip_port.ip.family == AF_INET) {
struct sockaddr_in *addr4 = (struct sockaddr_in *)&addr;
addrsize = sizeof(struct sockaddr_in);
addr4->sin_family = AF_INET;
addr4->sin_addr = ip_port.ip.ip4.in_addr;
addr4->sin_port = ip_port.port;
} else if (ip_port.ip.family == AF_INET6) {
struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&addr;
addrsize = sizeof(struct sockaddr_in6);
addr6->sin6_family = AF_INET6;
addr6->sin6_addr = ip_port.ip.ip6.in6_addr;
addr6->sin6_port = ip_port.port;
} else {
return 0;
}
/* nonblocking socket, connect will never return success */
connect(sock, (struct sockaddr *)&addr, addrsize);
return 1;
}
/* return 0 on success.
* return -1 on failure.
*/
static int generate_handshake(TCP_Client_Connection *TCP_conn, uint8_t *self_public_key, uint8_t *self_secret_key)
{
uint8_t plain[crypto_box_PUBLICKEYBYTES + crypto_box_NONCEBYTES];
crypto_box_keypair(plain, TCP_conn->temp_secret_key);
encrypt_precompute(TCP_conn->public_key, self_secret_key, TCP_conn->shared_key);
random_nonce(TCP_conn->sent_nonce);
memcpy(plain + crypto_box_PUBLICKEYBYTES, TCP_conn->sent_nonce, crypto_box_NONCEBYTES);
memcpy(TCP_conn->last_packet, self_public_key, crypto_box_PUBLICKEYBYTES);
new_nonce(TCP_conn->last_packet + crypto_box_PUBLICKEYBYTES);
int len = encrypt_data_fast(TCP_conn->shared_key, TCP_conn->last_packet + crypto_box_PUBLICKEYBYTES, plain,
sizeof(plain), TCP_conn->last_packet + crypto_box_PUBLICKEYBYTES + crypto_box_NONCEBYTES);
if (len != sizeof(plain) + crypto_box_MACBYTES)
return -1;
TCP_conn->last_packet_length = crypto_box_PUBLICKEYBYTES + crypto_box_NONCEBYTES + sizeof(plain) + crypto_box_MACBYTES;
TCP_conn->last_packet_sent = 0;
return 0;
}
/* data must be of length TCP_SERVER_HANDSHAKE_SIZE
*
* return 0 on success.
* return -1 on failure.
*/
static int handle_handshake(TCP_Client_Connection *TCP_conn, uint8_t *data)
{
uint8_t plain[crypto_box_PUBLICKEYBYTES + crypto_box_NONCEBYTES];
int len = decrypt_data_fast(TCP_conn->shared_key, data, data + crypto_box_NONCEBYTES,
TCP_SERVER_HANDSHAKE_SIZE - crypto_box_NONCEBYTES, plain);
if (len != sizeof(plain))
return -1;
memcpy(TCP_conn->recv_nonce, plain + crypto_box_PUBLICKEYBYTES, crypto_box_NONCEBYTES);
encrypt_precompute(plain, TCP_conn->temp_secret_key, TCP_conn->shared_key);
memset(TCP_conn->temp_secret_key, 0, crypto_box_SECRETKEYBYTES);
return 0;
}
/* return 0 if pending data was sent completely
* return -1 if it wasn't
*/
static int send_pending_data(TCP_Client_Connection *con)
{
if (con->last_packet_length == 0) {
return 0;
}
uint16_t left = con->last_packet_length - con->last_packet_sent;
int len = send(con->sock, con->last_packet + con->last_packet_sent, left, MSG_NOSIGNAL);
if (len <= 0)
return -1;
if (len == left) {
con->last_packet_length = 0;
con->last_packet_sent = 0;
return 0;
}
if (len > left)
return -1;
con->last_packet_sent += len;
return -1;
}
/* Create new TCP connection to ip_port/public_key
*/
TCP_Client_Connection *new_TCP_connection(IP_Port ip_port, uint8_t *public_key, uint8_t *self_public_key,
uint8_t *self_secret_key)
{
if (networking_at_startup() != 0) {
return NULL;
}
if (ip_port.ip.family != AF_INET && ip_port.ip.family != AF_INET6)
return NULL;
sock_t sock = socket(ip_port.ip.family, SOCK_STREAM, IPPROTO_TCP);
if (!sock_valid(sock)) {
printf("fail1 %u\n", sock);
return NULL;
}
if (!(set_socket_nonblock(sock) && connect_sock_to(sock, ip_port))) {
kill_sock(sock);
return NULL;
}
TCP_Client_Connection *temp = calloc(sizeof(TCP_Client_Connection), 1);
if (temp == NULL) {
kill_sock(sock);
return NULL;
}
temp->status = TCP_CLIENT_CONNECTING;
temp->sock = sock;
memcpy(temp->public_key, public_key, crypto_box_PUBLICKEYBYTES);
if (generate_handshake(temp, self_public_key, self_secret_key) == -1) {
kill_sock(sock);
free(temp);
return NULL;
}
temp->kill_at = unix_time() + TCP_CONNECTION_TIMEOUT;
return temp;
}
static int do_confirmed_TCP(TCP_Client_Connection *TCP_connection)
{
return 0;
}
/* Run the TCP connection
*/
void do_TCP_connection(TCP_Client_Connection *TCP_connection)
{
unix_time_update();
if (TCP_connection->status == TCP_CLIENT_DISCONNECTED) {
return;
}
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->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);
}
if (TCP_connection->kill_at <= unix_time()) {
TCP_connection->status = TCP_CLIENT_DISCONNECTED;
}
}
/* Kill the TCP connection
*/
void kill_TCP_connection(TCP_Client_Connection *TCP_connection)
{
kill_sock(TCP_connection->sock);
memset(TCP_connection, 0, sizeof(TCP_Client_Connection));
free(TCP_connection);
}
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