int udpclient(int argc, char *argv[])
{
char *lhost, *lport, *phost, *pport, *rhost, *rport;
list_t *clients = NULL;
list_t *conn_clients;
client_t *client;
client_t *client2;
socket_t *tcp_serv = NULL;
socket_t *tcp_sock = NULL;
socket_t *udp_sock = NULL;
char data[MSG_MAX_LEN];
char addrstr[ADDRSTRLEN];
struct timeval curr_time;
struct timeval check_time;
struct timeval check_interval;
struct timeval timeout;
fd_set client_fds;
fd_set read_fds;
uint16_t tmp_id;
uint8_t tmp_type;
uint16_t tmp_len;
uint16_t tmp_req_id;
int num_fds;
int ret;
int i;
signal(SIGINT, &signal_handler);
i = 0;
lhost = (argc - i == 5) ? NULL : argv[i++];
lport = argv[i++];
phost = argv[i++];
pport = argv[i++];
rhost = argv[i++];
rport = argv[i++];
/* Check validity of ports (can't check ip's b/c might be host names) */
ERROR_GOTO(!isnum(lport), "Invalid local port.", done);
ERROR_GOTO(!isnum(pport), "Invalid proxy port.", done);
ERROR_GOTO(!isnum(rport), "Invalid remote port.", done);
srand(time(NULL));
next_req_id = rand() % 0xffff;
/* Create an empty list for the clients */
clients = list_create(sizeof(client_t), p_client_cmp, p_client_copy,
p_client_free, 1);
ERROR_GOTO(clients == NULL, "Error creating clients list.", done);
/* Create and empty list for the connecting clients */
conn_clients = list_create(sizeof(client_t), p_client_cmp, p_client_copy,
p_client_free, 1);
ERROR_GOTO(conn_clients == NULL, "Error creating clients list.", done);
/* Create a TCP server socket to listen for incoming connections */
tcp_serv = sock_create(lhost, lport, ipver, SOCK_TYPE_TCP, 1, 1);
ERROR_GOTO(tcp_serv == NULL, "Error creating TCP socket.", done);
if(debug_level >= DEBUG_LEVEL1)
{
printf("Listening on TCP %s\n",
sock_get_str(tcp_serv, addrstr, sizeof(addrstr)));
}
FD_ZERO(&client_fds);
/* Initialize all the timers */
timerclear(&timeout);
check_interval.tv_sec = 0;
check_interval.tv_usec = 500000;
gettimeofday(&check_time, NULL);
while(running)
{
if(!timerisset(&timeout))
timeout.tv_usec = 50000;
read_fds = client_fds;
FD_SET(SOCK_FD(tcp_serv), &read_fds);
ret = select(FD_SETSIZE, &read_fds, NULL, NULL, &timeout);
PERROR_GOTO(ret < 0, "select", done);
num_fds = ret;
gettimeofday(&curr_time, NULL);
/* Go through all the clients and check if didn't get an ACK for sent
data during the timeout period */
if(timercmp(&curr_time, &check_time, >))
{
for(i = 0; i < LIST_LEN(clients); i++)
{
client = list_get_at(clients, i);
ret = client_check_and_resend(client, curr_time);
if(ret == -2)
{
disconnect_and_remove_client(CLIENT_ID(client), clients,
&client_fds, 1);
i--;
continue;
}
ret = client_check_and_send_keepalive(client, curr_time);
if(ret == -2)
{
disconnect_and_remove_client(CLIENT_ID(client), clients,
&client_fds, 1);
i--;
}
}
timeradd(&curr_time, &check_interval, &check_time);
}
if(num_fds == 0)
continue;
/* Check if pending TCP connection to accept and create a new client
and UDP connection if one is ready */
if(FD_ISSET(SOCK_FD(tcp_serv), &read_fds))
{
tcp_sock = sock_accept(tcp_serv);
if(tcp_sock == NULL)
continue;
udp_sock = sock_create(phost, pport, ipver, SOCK_TYPE_UDP, 0, 1);
if(udp_sock == NULL)
{
sock_close(tcp_sock);
sock_free(tcp_sock);
continue;
}
client = client_create(next_req_id++, tcp_sock, udp_sock, 1);
if(!client || !tcp_sock || !udp_sock)
{
if(tcp_sock)
sock_close(tcp_sock);
if(udp_sock)
sock_close(udp_sock);
}
else
{
client2 = list_add(conn_clients, client, 1);
client_free(client);
client = NULL;
client_send_hello(client2, rhost, rport, CLIENT_ID(client2));
client_add_tcp_fd_to_set(client2, &client_fds);
client_add_udp_fd_to_set(client2, &client_fds);
}
sock_free(tcp_sock);
sock_free(udp_sock);
tcp_sock = NULL;
udp_sock = NULL;
num_fds--;
}
/* Check for pending handshakes from UDP connection */
for(i = 0; i < LIST_LEN(conn_clients) && num_fds > 0; i++)
{
client = list_get_at(conn_clients, i);
if(client_udp_fd_isset(client, &read_fds))
{
num_fds--;
tmp_req_id = CLIENT_ID(client);
ret = client_recv_udp_msg(client, data, sizeof(data),
&tmp_id, &tmp_type, &tmp_len);
if(ret == 0)
ret = handle_message(client, tmp_id, tmp_type,
data, tmp_len);
if(ret < 0)
{
disconnect_and_remove_client(tmp_req_id, conn_clients,
&client_fds, 1);
i--;
}
else
{
client = list_add(clients, client, 1);
list_delete_at(conn_clients, i);
client_remove_udp_fd_from_set(client, &read_fds);
i--;
}
}
}
/* Check if data is ready from any of the clients */
for(i = 0; i < LIST_LEN(clients); i++)
{
client = list_get_at(clients, i);
/* Check for UDP data */
if(num_fds > 0 && client_udp_fd_isset(client, &read_fds))
{
num_fds--;
ret = client_recv_udp_msg(client, data, sizeof(data),
&tmp_id, &tmp_type, &tmp_len);
if(ret == 0)
ret = handle_message(client, tmp_id, tmp_type,
data, tmp_len);
if(ret < 0)
{
disconnect_and_remove_client(CLIENT_ID(client), clients,
&client_fds, 1);
i--;
continue; /* Don't go to check the TCP connection */
}
}
/* Check for TCP data */
if(num_fds > 0 && client_tcp_fd_isset(client, &read_fds))
{
ret = client_recv_tcp_data(client);
if(ret == -1)
{
disconnect_and_remove_client(CLIENT_ID(client), clients,
&client_fds, 1);
i--;
continue;
}
else if(ret == -2)
{
client_mark_to_disconnect(client);
disconnect_and_remove_client(CLIENT_ID(client),
clients, &client_fds, 0);
}
num_fds--;
}
/* send any TCP data that was ready */
ret = client_send_udp_data(client);
if(ret < 0)
{
disconnect_and_remove_client(CLIENT_ID(client), clients,
&client_fds, 1);
i--;
}
}
/* Finally, send any udp data that's still in the queue */
for(i = 0; i < LIST_LEN(clients); i++)
{
client = list_get_at(clients, i);
ret = client_send_udp_data(client);
if(ret < 0 || client_ready_to_disconnect(client))
{
disconnect_and_remove_client(CLIENT_ID(client), clients,
&client_fds, 1);
i--;
}
}
}
done:
if(debug_level >= DEBUG_LEVEL1)
printf("Cleaning up...\n");
if(tcp_serv)
{
sock_close(tcp_serv);
sock_free(tcp_serv);
}
if(udp_sock)
{
sock_close(udp_sock);
sock_free(udp_sock);
}
if(clients)
list_free(clients);
if(conn_clients)
list_free(conn_clients);
if(debug_level >= DEBUG_LEVEL1)
printf("Goodbye.\n");
return 0;
}
int udpclient(int argc, char* argv[])
{
char* lhost, *lport, *phost, *pport, *rhost, *rport;
list_t* clients;
list_t* conn_clients;
client_t* client;
client_t* client2;
socket_t* tcp_serv = NULL;
socket_t* tcp_sock = NULL;
socket_t* udp_sock = NULL;
char data[MSG_MAX_LEN];
char addrstr[ADDRSTRLEN];
char pport_s[6];
struct timeval curr_time;
struct timeval check_time;
struct timeval check_interval;
struct timeval timeout;
fd_set client_fds;
fd_set read_fds;
uint16_t tmp_id;
uint8_t tmp_type;
uint16_t tmp_len;
uint16_t tmp_req_id;
int num_fds;
int ret;
int i;
int icmp_sock ;
int timeexc = -1;
struct sockaddr_in src, dest, rsrc;
struct hostent* hp;
uint32_t timeexc_ip;
signal(SIGINT, &signal_handler);
i = 0;
if(index(argv[i], 58) || index(argv[i], 46))
lhost = argv[i++];
else
lhost = NULL;
lport = argv[i++];
phost = argv[i++];
if(index(argv[i], 58) || index(argv[i], 46)) {
snprintf(pport_s, 5, "2222");
pport = pport_s;
} else
pport = argv[i++];
rhost = argv[i++];
rport = argv[i++];
/* Get info about localhost IP */
if(!lhost){
char szHostName[255];
gethostname(szHostName, 255);
hp = gethostbyname(szHostName);
}else{
hp = gethostbyname(lhost);
}
memset(&rsrc, 0, sizeof(struct sockaddr_in));
timeexc_ip = *(uint32_t*)hp->h_addr_list[0];
rsrc.sin_family = AF_INET;
rsrc.sin_port = 0;
rsrc.sin_addr.s_addr = timeexc_ip;
/* IP of destination */
memset(&src, 0, sizeof(struct sockaddr_in));
hp = gethostbyname(phost);
timeexc_ip = *(uint32_t*)hp->h_addr_list[0];
src.sin_family = AF_INET;
src.sin_port = 0;
src.sin_addr.s_addr = timeexc_ip;
/* IP of where the fake packet (echo request) was going */
hp = gethostbyname("3.3.3.3");
memcpy(&dest.sin_addr, hp->h_addr, hp->h_length);
inet_pton(AF_INET, "3.3.3.3", &(dest.sin_addr));
srand(time(NULL));
next_req_id = rand() % 0xffff;
/* Create an empty list for the clients */
clients = list_create(sizeof(client_t), p_client_cmp, p_client_copy,
p_client_free);
ERROR_GOTO(clients == NULL, "Error creating clients list.", done);
/* Create and empty list for the connecting clients */
conn_clients = list_create(sizeof(client_t), p_client_cmp, p_client_copy,
p_client_free);
ERROR_GOTO(conn_clients == NULL, "Error creating clients list.", done);
/* Create a TCP server socket to listen for incoming connections */
tcp_serv = sock_create(lhost, lport, ipver, SOCK_TYPE_TCP, 1, 1);
ERROR_GOTO(tcp_serv == NULL, "Error creating TCP socket.", done);
if(debug_level >= DEBUG_LEVEL1) {
printf("Listening on TCP %s\n",
sock_get_str(tcp_serv, addrstr, sizeof(addrstr)));
}
FD_ZERO(&client_fds);
/* Initialize all the timers */
timerclear(&timeout);
check_interval.tv_sec = 0;
check_interval.tv_usec = 500000;
gettimeofday(&check_time, NULL);
/* open raw socket */
create_icmp_socket(&icmp_sock);
if(icmp_sock == -1) {
printf("[main] can't open raw socket\n");
exit(1);
}
while(running) {
if(!timerisset(&timeout))
timeout.tv_usec = 50000;
if(++timeexc==100) {
timeexc=0;
/* Send ICMP TTL exceeded to penetrate remote NAT */
send_icmp(icmp_sock, &rsrc, &src, &dest, 0);
}
read_fds = client_fds;
FD_SET(SOCK_FD(tcp_serv), &read_fds);
ret = select(FD_SETSIZE, &read_fds, NULL, NULL, &timeout);
PERROR_GOTO(ret < 0, "select", done);
num_fds = ret;
gettimeofday(&curr_time, NULL);
/* Go through all the clients and check if didn't get an ACK for sent
data during the timeout period */
if(timercmp(&curr_time, &check_time, >)) {
for(i = 0; i < LIST_LEN(clients); i++) {
client = list_get_at(clients, i);
ret = client_check_and_resend(client, curr_time);
if(ret == -2) {
disconnect_and_remove_client(CLIENT_ID(client), clients,
&client_fds);
i--;
continue;
}
ret = client_check_and_send_keepalive(client, curr_time);
if(ret == -2) {
disconnect_and_remove_client(CLIENT_ID(client), clients,
&client_fds);
i--;
}
}
timeradd(&curr_time, &check_interval, &check_time);
}
if(num_fds == 0) continue;
timeexc=0;
/* Check if pending TCP connection to accept and create a new client
and UDP connection if one is ready */
if(FD_ISSET(SOCK_FD(tcp_serv), &read_fds)) {
tcp_sock = sock_accept(tcp_serv);
udp_sock = sock_create(phost, pport, ipver,
SOCK_TYPE_UDP, 0, 1);
client = client_create(next_req_id++, tcp_sock, udp_sock, 1);
if(!client || !tcp_sock || !udp_sock) {
if(tcp_sock)
sock_close(tcp_sock);
if(udp_sock)
sock_close(udp_sock);
} else {
client2 = list_add(conn_clients, client);
client_free(client);
client = NULL;
client_send_hello(client2, rhost, rport, CLIENT_ID(client2));
client_add_tcp_fd_to_set(client2, &client_fds);
client_add_udp_fd_to_set(client2, &client_fds);
}
sock_free(tcp_sock);
sock_free(udp_sock);
tcp_sock = NULL;
udp_sock = NULL;
num_fds--;
}
/* Check for pending handshakes from UDP connection */
for(i = 0; i < LIST_LEN(conn_clients) && num_fds > 0; i++) {
client = list_get_at(conn_clients, i);
if(client_udp_fd_isset(client, &read_fds)) {
num_fds--;
tmp_req_id = CLIENT_ID(client);
ret = client_recv_udp_msg(client, data, sizeof(data),
&tmp_id, &tmp_type, &tmp_len);
if(ret == 0)
ret = handle_message(client, tmp_id, tmp_type,
data, tmp_len);
if(ret < 0) {
disconnect_and_remove_client(tmp_req_id, conn_clients,
&client_fds);
i--;
} else {
client = list_add(clients, client);
list_delete_at(conn_clients, i);
client_remove_udp_fd_from_set(client, &read_fds);
i--;
}
}
}
/* Check if data is ready from any of the clients */
for(i = 0; i < LIST_LEN(clients) && num_fds > 0; i++) {
client = list_get_at(clients, i);
/* Check for UDP data */
if(client_udp_fd_isset(client, &read_fds)) {
num_fds--;
ret = client_recv_udp_msg(client, data, sizeof(data),
&tmp_id, &tmp_type, &tmp_len);
if(ret == 0)
ret = handle_message(client, tmp_id, tmp_type,
data, tmp_len);
if(ret < 0) {
disconnect_and_remove_client(CLIENT_ID(client), clients,
&client_fds);
i--;
continue; /* Don't go to check the TCP connection */
}
}
/* Check for TCP data */
if(client_tcp_fd_isset(client, &read_fds)) {
num_fds--;
ret = client_recv_tcp_data(client);
if(ret == 0)
ret = client_send_udp_data(client);
#if 0 /* if udptunnel is taking up 100% of cpu, try including this */
else if(ret == 1)
#ifdef _WIN32
_sleep(1);
#else
usleep(1000); /* Quick hack so doesn't use 100% of CPU if
data wasn't ready yet (waiting for ack) */
#endif /*WIN32*/
#endif /*0*/
if(ret < 0) {
disconnect_and_remove_client(CLIENT_ID(client), clients,
&client_fds);
i--;
}
}
}
}
done:
if(debug_level >= DEBUG_LEVEL1)
printf("Cleaning up...\n");
if(tcp_serv) {
sock_close(tcp_serv);
sock_free(tcp_serv);
}
if(udp_sock) {
sock_close(udp_sock);
sock_free(udp_sock);
}
if(clients)
list_free(clients);
if(debug_level >= DEBUG_LEVEL1)
printf("Goodbye.\n");
return 0;
}