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#include "os_calls.h"
int g_loc_io_count = 0; // bytes read from local port
int g_rem_io_count = 0; // bytes read from remote port
static int g_terminated = 0;
static char g_buf[1024 * 32];
/*****************************************************************************/
static int
main_loop(char* local_port, char* remote_ip, char* remote_port, int hexdump)
{
int lis_sck;
int acc_sck;
int con_sck;
int sel;
int count;
int sent;
int error;
int i;
int acc_to_con;
int con_to_acc;
acc_to_con = 0;
con_to_acc = 0;
acc_sck = 0;
/* create the listening socket and setup options */
lis_sck = g_tcp_socket();
g_tcp_set_non_blocking(lis_sck);
error = g_tcp_bind(lis_sck, local_port);
if (error != 0)
{
g_writeln("bind failed");
}
/* listen for an incomming connection */
if (error == 0)
{
error = g_tcp_listen(lis_sck);
if (error == 0)
{
g_writeln("listening for connection");
}
}
/* accept an incomming connection */
if (error == 0)
{
while ((!g_terminated) && (error == 0))
{
acc_sck = g_tcp_accept(lis_sck);
if ((acc_sck == -1) && g_tcp_last_error_would_block(lis_sck))
{
g_sleep(100);
}
else if (acc_sck == -1)
{
error = 1;
}
else
{
break;
}
}
if (error == 0)
{
error = g_terminated;
}
/* stop listening */
g_tcp_close(lis_sck);
lis_sck = 0;
if (error == 0)
{
g_writeln("got connection");
}
}
/* connect outgoing socket */
con_sck = 0;
if (error == 0)
{
con_sck = g_tcp_socket();
g_tcp_set_non_blocking(con_sck);
error = g_tcp_connect(con_sck, remote_ip, remote_port);
if ((error == -1) && g_tcp_last_error_would_block(con_sck))
{
error = 0;
i = 0;
while ((!g_tcp_can_send(con_sck, 100)) && (!g_terminated) && (i < 100))
{
g_sleep(100);
i++;
}
if (i > 99)
{
g_writeln("timout connecting");
error = 1;
}
if (g_terminated)
{
error = 1;
}
}
if ((error != 0) && (!g_terminated))
{
g_writeln("error connecting to remote\r\n");
}
}
while ((!g_terminated) && (error == 0))
{
sel = g_tcp_select(con_sck, acc_sck);
if (sel == 0)
{
g_sleep(10);
continue;
}
if (sel & 1)
{
// can read from con_sck w/o blocking
count = g_tcp_recv(con_sck, g_buf, 1024 * 16, 0);
error = count < 1;
if (error == 0)
{
g_loc_io_count += count;
con_to_acc += count;
if (hexdump)
{
g_writeln("from remove, the socket from connect");
g_hexdump(g_buf, count);
}
#if 0
g_writeln("local_io_count: %d\tremote_io_count: %d",
g_loc_io_count, g_rem_io_count);
#endif
sent = 0;
while ((sent < count) && (error == 0) && (!g_terminated))
{
i = g_tcp_send(acc_sck, g_buf + sent, count - sent, 0);
if ((i == -1) && g_tcp_last_error_would_block(acc_sck))
{
g_tcp_can_send(acc_sck, 1000);
}
else if (i < 1)
{
error = 1;
}
else
{
sent += i;
}
}
}
}
if (sel & 2)
{
// can read from acc_sck w/o blocking
count = g_tcp_recv(acc_sck, g_buf, 1024 * 16, 0);
error = count < 1;
if (error == 0)
{
g_rem_io_count += count;
acc_to_con += count;
if (hexdump)
{
g_writeln("from accepted, the socket from accept");
g_hexdump(g_buf, count);
}
#if 0
g_writeln("local_io_count: %d\tremote_io_count: %d",
g_loc_io_count, g_rem_io_count);
#endif
sent = 0;
while ((sent < count) && (error == 0) && (!g_terminated))
{
i = g_tcp_send(con_sck, g_buf + sent, count - sent, 0);
if ((i == -1) && g_tcp_last_error_would_block(con_sck))
{
g_tcp_can_send(con_sck, 1000);
}
else if (i < 1)
{
error = 1;
}
else
{
sent += i;
}
}
}
}
}
g_tcp_close(lis_sck);
g_tcp_close(con_sck);
g_tcp_close(acc_sck);
g_writeln("acc_to_con %d", acc_to_con);
g_writeln("con_to_acc %d", con_to_acc);
return 0;
}
/*****************************************************************************/
static int
usage(void)
{
g_writeln("tcp_proxy <local-port> <remote-ip> <remote-port> [dump]");
return 0;
}
/*****************************************************************************/
void
proxy_shutdown(int sig)
{
g_writeln("shutting down");
g_terminated = 1;
}
void
clear_counters(int sig)
{
g_writeln("cleared counters at: local_io_count: %d remote_io_count: %d",
g_loc_io_count, g_rem_io_count);
g_loc_io_count = 0;
g_rem_io_count = 0;
}
/*****************************************************************************/
int
main(int argc, char** argv)
{
int dump;
if (argc < 4)
{
usage();
return 0;
}
g_init();
g_signal(2, proxy_shutdown); /* SIGINT */
g_signal(9, proxy_shutdown); /* SIGKILL */
g_signal(10, clear_counters);/* SIGUSR1*/
g_signal(15, proxy_shutdown);/* SIGTERM */
if (argc < 5)
{
while (!g_terminated)
{
g_loc_io_count = 0;
g_rem_io_count = 0;
main_loop(argv[1], argv[2], argv[3], 0);
}
}
else
{
dump = g_strcasecmp(argv[4], "dump") == 0;
while (!g_terminated)
{
main_loop(argv[1], argv[2], argv[3], dump);
}
}
g_deinit();
return 0;
}
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