TCP server

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Introduction

This software package is a TCP server that supports multi-client connection and communication. Using a simple API, you can create a server and communicate with different clients.

This server has the following characteristics:

• Simultaneous operation of multiple servers
• Multiple network card support, support binding to specific IP
• Support blocking reception and non-blocking notification callback reception.
• Support independent exchange of data with different clients.

Instructions for use

Dependence

• RT-Thread 3.1.0+
• SAL
• DFS (select)

Get the package

To use the tcpserver software package, you need to select it in the RT-Thread package management. The specific path is as follows:

RT-Thread online packages --->
    IoT-internet of things --->
        [*] TCP Server:A TCP server that supports multiple clients
            (tcpserv) tcpserver name
            (4096) tcpserver stack size
            (12) tcpserver thread priority
            (512) Maximum possible socket usage
            (5) Number of clients supported
            [] Enable debugging features
            [*] Enable sample
                Version (latest) --->

• tcpserver name: Configure the name of tcpserver
• tcpserver stack size: Configure the size of the thread stack
• tcpserver thread priority: Configure thread priority
• Maximum possible socket usage: the maximum value of sockets that the system may use
• Number of clients supported: The number of clients that support simultaneous connections
• Enable debugging features: Enable debugging features
• Enable sample: Enable sample code
• Version: software package version selection

Using packages

API details

Create server

Create a TCP server and pass in the ip address and port number of the server.

struct tcpserver *tcpserver_create(const char *ip, rt_uint16_t port);

Function Parameters

Parameters	Description
ip	ip address to bind
port	Port number to bind
Back	——
> 0	Success, return a tcp server handle.
= 0	Failure

Destroy the server

Destroy a TCP server and reclaim resources.

rt_err_t tcpserver_destroy(struct tcpserver *server);

Function Parameters

Parameters	Description
server	The handle of the tcp server to be destroyed
Back	——
= 0	Success
<0	Failure

Get the client

Obtain a TCP client, and block a client.

tcpclient_t tcpserver_accept(struct tcpserver *server, rt_int32_t timeout);

Function Parameters

Parameters	Description
server	tcp server handle
timeout	Waiting timeout time, RT_WAITING_FOREVER means waiting forever.
Return	——
> 0	Success, return a tcp client handle.
= 0	Failure

Close the client

Close a TCP client.

rt_err_t tcpserver_close(tcpclient_t client);

Function Parameters

Parameters	Description
client	tcp client handle
Back	——
= 0	Success.
<0	Failure

Receive data from the client

Receive data from the client.

rt_size_t tcpserver_recv(tcpclient_t client, void *buf, rt_size_t size, rt_int32_t timeout);

Function Parameters

Parameters	Description
client	tcp client handle
buf	buffer address
size	Buffer size
timeout	Waiting timeout time, RT_WAITING_FOREVER means waiting forever.
Back	——
> 0	Success, return the received data length.
= 0	Failure

Send data to the client

Send data to the client.

rt_size_t tcpserver_send(tcpclient_t client, void *buf, rt_size_t size, rt_int32_t timeout);

Function Parameters

Parameters	Description
client	tcp client handle
buf	buffer address
size	Buffer size
timeout	Waiting timeout time, not yet implemented
Return	——
> 0	Success, the length of the data sent.
= 0	Failure

Set event notification callback function

Set the event notification callback function of the server.

void tcpserver_set_notify_callback(struct tcpserver *server,
                                   void (*tcpserver_event_notify)(tcpclient_t client, rt_uint8_t event));

Function Parameters

Parameters	Description
server	tcp server handle
tcpserver_event_notify	Function pointer to be set
Back	——

Run the sample program

The software package comes with a sample program for the echo server. After opening the sample program of the software package, you can use it.

Compile, download and run, there will be two commands, tcpserver and tcpserver_stop. They are creating TCP server and closing TCP server.

First enter the IP address and port number to create a server, and then you can use the network debugging assistant to communicate with this server. Enter tcpserver_stop to shut down the server.

 \ | /
-RT-Thread Operating System
 / | \ 3.1.3 build Jul 11 ​​2019
 2006-2019 Copyright by rt-thread team
lwIP-2.0.2 initialized!
[4] I/sal.skt: Socket Abstraction Layer initialize success.
msh />ifconfig
network interface device: e0 (Default)
MTU: 1500
MAC: 00 04 a3 12 34 56
FLAGS: UP LINK_UP INTERNET_UP DHCP_ENABLE ETHARP BROADCAST IGMP
ip address: 192.168.12.117 # Local IP address
gw address: 192.168.10.1
net mask: 255.255.0.0
dns server #0: 192.168.10.1
dns server #1: 223.5.5.5
msh />tcpserver 192.168.12.117 5000 # Create server
msh />[173861] D/tcpserv: client connect:5 # The client connects successfully
[180220] D/tcpserv: client disconnect:5 # The client disconnects
msh />tcpserver_stop # Shut down the server
msh />

Precautions

• The timeout mechanism of the tcpserver_send function has not been implemented yet
• If the number of supported clients has not been reached, but the total connection is wrong, it may be limited by lwip.

contact information

• Maintainer: flybreak
• Homepage: tcpserver