Linux平台socks5代理_安全中国_全球最大网络安全培训门户

//printf( "SelectMethod: recv %d bytes\n", ret );

// if client request a wrong version or a wrong number_method
method_request = (METHOD_SELECT_REQUEST *)recv_buffer;
method_response = (METHOD_SELECT_RESPONSE *)reply_buffer;

method_response->version = VERSION;

// if not socks5
if( (int)method_request->version != VERSION )
{
method_response->select_method = 0xff;

send( sock, method_response, sizeof(METHOD_SELECT_RESPONSE), 0 );
close( sock );

return -1;
}

method_response->select_method = AUTH_CODE;
if( -1 == send( sock, method_response, sizeof(METHOD_SELECT_RESPONSE), 0 ) )
{
close( sock );
return -1;
}

return 0;
}

// test password, return 0 for success.
int AuthPassword( int sock )
{
char recv_buffer[BUFF_SIZE] = { 0 };
char reply_buffer[BUFF_SIZE] = { 0 };

AUTH_REQUEST *auth_request;
AUTH_RESPONSE *auth_response;

// auth username and password
int ret = recv( sock, recv_buffer, BUFF_SIZE, 0 );
if( ret <= 0 )
{
perror( "recv username and password error" );
close( sock );
return -1;
}
//printf( "AuthPass: recv %d bytes\n", ret );

auth_request = (AUTH_REQUEST *)recv_buffer;

memset( reply_buffer, 0, BUFF_SIZE );
auth_response = (AUTH_RESPONSE *)reply_buffer;
auth_response->version = 0x01;

char recv_name[256] = { 0 };
char recv_pass[256] = { 0 };

// auth_request->name_len is a char, max number is 0xff
char pwd_str[2] = { 0 };
strncpy( pwd_str, auth_request->name + auth_request->name_len, 1 );
int pwd_len = (int)pwd_str[0];

strncpy( recv_name, auth_request->name, auth_request->name_len );
strncpy( recv_pass, auth_request->name + auth_request->name_len + sizeof(auth_request->pwd_len), pwd_len );

//printf( "username: %s\npassword: %s\n", recv_name, recv_pass );
// check username and password
if( (strncmp( recv_name, USER_NAME, strlen(USER_NAME) ) == 0) &&
(strncmp( recv_pass, PASS_WORD, strlen(PASS_WORD) ) == 0)
)
{
auth_response->result = 0x00;
if( -1 == send( sock, auth_response, sizeof(AUTH_RESPONSE), 0 ) )
{
close( sock );
return -1;
}
else
{
return 0;
}
}
else
{
auth_response->result = 0x01;
send( sock, auth_response, sizeof(AUTH_RESPONSE), 0 );

close( sock );
return -1;
}
}

// parse command, and try to connect real server.
// return socket for success, -1 for failed.
int ParseCommand( int sock )
{
char recv_buffer[BUFF_SIZE] = { 0 };
char reply_buffer[BUFF_SIZE] = { 0 };

SOCKS5_REQUEST *socks5_request;
SOCKS5_RESPONSE *socks5_response;

// recv command
int ret = recv( sock, recv_buffer, BUFF_SIZE, 0 );
if( ret <= 0 )
{
perror( "recv connect command error" );

close( sock );
return -1;
}

socks5_request = (SOCKS5_REQUEST *)recv_buffer;
if( (socks5_request->version != VERSION) || (socks5_request->cmd != CONNECT) ||
(socks5_request->address_type == IPV6) )
{
//printf( "connect command error.\n" );
close( sock );
return -1;
}

// begain process connect request
struct sockaddr_in sin;

memset( (void *)&sin, 0, sizeof(struct sockaddr_in) );
sin.sin_family = AF_INET;

// get real server’s ip address
if( socks5_request->address_type == IPV4 )
{
memcpy( &sin.sin_addr.s_addr, &socks5_request->address_type + sizeof(socks5_request->address_type) , 4 );
memcpy( &sin.sin_port, &socks5_request->address_type + sizeof(socks5_request->address_type) + 4, 2 );

//printf( "Real Server: %s %d\n", inet_ntoa( sin.sin_addr ), ntohs( sin.sin_port ) );
}
else if( socks5_request->address_type == DOMAIN )
{
char domain_length = *(&socks5_request->address_type + sizeof(socks5_request->address_type));
char target_domain[ 256] = { 0 };

strncpy( target_domain, &socks5_request->address_type + 2, (unsigned int)domain_length );

//printf( "target: %s\n", target_domain );

struct hostent *phost = gethostbyname( target_domain );
if( phost == NULL )
{
//printf( "Resolve %s error!\n" , target_domain );

close( sock );
return -1;
}
memcpy( &sin.sin_addr , phost->h_addr_list[0] , phost->h_length );

memcpy( &sin.sin_port, &socks5_request->address_type + sizeof(socks5_request->address_type) +
sizeof(domain_length) + domain_length, 2 );
}

// try to connect to real server
int real_server_sock = socket( AF_INET, SOCK_STREAM, 0 );
if( real_server_sock < 0 )
{
perror( "Socket creation failed\n");

close( sock );
return -1;
}

上一页 1 2 3 4 下一页