优化iproute2中的tc流控规则下发机制

设备基于IP对每个用户配置流量控制规则，规则如下：

tc filter add dev eth0 protocol ip parent 1:0 prio 1 u32 match ip src 192.168.0.10 flowid 1:10

上面的tc 是一个配置工具，本身是一个应用程序，tc后面的参数通过应用程序参数形式传递给tc工具

业务程序通过system方式调用tc，当并发用户量比较大时，业务进程会fork出大量tc,影响系统性能

优化的思路是用一个tc守护进程代替并发的多个tc，业务程序通过socket将配置参数发送给tc手机进程

 tc守护进程是在tc进程外面套一个壳，增加一个socket 服务端，用来接收业务程序发送的tc 配置规则

源码：

int main(int argc, char **argv)
{
	int socket = sock_init();
    {
        char cmd[256];
        sprintf(cmd, "echo \"TC CONFIGSERVER RUNNING %d\" >> /var/log/tc.log", socket);
        system(cmd);
    }
	while (socket > 0)
	{
		socket_monitor(socket);
	}


	fprintf(stderr, "TC-SERVER EXIT !\n");

	return 0;
}

void socket_monitor(int sock)
{
	fd_set set;
	struct	timeval timeout = {0};
	int ret;
	struct tc_rule_options_t *p_req	= (struct tc_rule_options_t *)s_request_buff;

	timeout.tv_sec = 0;
	timeout.tv_usec = 10000; //10ms

	FD_ZERO(&set);
	FD_SET(sock, &set);

	ret = select(sock + 1, &set, NULL, NULL, &timeout);
	if (!((ret > 0) && FD_ISSET(sock, &set)))
	{
		return;
	}

	struct sockaddr_in client_socket_addr = {0};
	unsigned int addr_size = sizeof(client_socket_addr);
	int accept_socket = accept(sock,
									(struct sockaddr *)&client_socket_addr,
									&addr_size);
	if (-1 == accept_socket)
	{
		fprintf(stderr, "tc server socket accept Failure!!!\n");
		return;
	}

	timeout.tv_sec = 30;
    timeout.tv_usec = 0;
	setsockopt(accept_socket, SOL_SOCKET, SO_RCVTIMEO, (char *)&timeout, sizeof(struct timeval));

	unsigned int ul_rcved_len = 0;
RCV:
	ret = recv(accept_socket, s_request_buff + ul_rcved_len
			,sizeof(s_request_buff) - ul_rcved_len, MSG_NOSIGNAL);
	if (ret <= 0)
	{
		if ((-1 == ret) && (EINTR == errno))
		{
			goto RCV;
		}
	}
	else
	{
		ul_rcved_len += ret;
		if (ul_rcved_len < sizeof(struct tc_rule_options_t))
		{
			goto RCV;
		}

		//*change_point(p_req)
		//char (*aaa)[32] = (char(*)[32])p_req->argv;
		tc_main(p_req->argc, change_point(p_req));
		close(accept_socket);
	}
	accept_socket = -1;
}