rt-thread/examples/network/tcpserver.c

287 lines
8.9 KiB
C
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/*
* Copyright (c) 2006-2022, RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date Author Notes
* 2022-01-24 ChungHsuan improve code comments
*/
#include <rtthread.h>
#include <string.h>
#if !defined(SAL_USING_POSIX)
#error "Please enable SAL_USING_POSIX!"
#else
#include <sys/time.h>
#include <sys/select.h>
#endif
#include <sys/socket.h> /* socket.h header file is needed when using BSD socket */ /* 使用BSD socket需要包含socket.h头文件 */
#include "netdb.h"
#define DEBUG_TCP_SERVER
#define DBG_TAG "TCP"
#ifdef DEBUG_TCP_SERVER
#define DBG_LVL DBG_LOG
#else
#define DBG_LVL DBG_INFO /* DBG_ERROR */
#endif
#include <rtdbg.h>
#define BUFSZ (1024)
static int started = 0;
static int is_running = 0;
static int port = 5000;
static const char send_data[] = "This is TCP Server from RT-Thread."; /* The message be sent */ /* 发送用到的数据 */
/**
* @brief This function is for creating a tcp server on RT-Thread
*/
static void tcpserv(void *arg)
{
int ret;
char *recv_data; /* recv_data is a pointer used to receive data */ /* 用于接收的指针,后面会做一次动态分配以请求可用内存 */
int sock, connected, bytes_received;
struct sockaddr_in server_addr, client_addr;
struct timeval timeout;
fd_set readset, readset_c;
socklen_t sin_size = sizeof(struct sockaddr_in);
recv_data = rt_malloc(BUFSZ + 1);/* Allocate space for recv_data */ /* 分配接收用的数据缓冲 */
if (recv_data == RT_NULL)
{
LOG_E("No memory");
return;
}
/* Before making use of socket, socket should be created first and set the socket created to SOCK_STREAM(TCP) */
/* 一个socket在使用前需要预先创建出来指定SOCK_STREAM为TCP的socket */
if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1)
{
LOG_E("Create socket error");
goto __exit;
}
/* Initialize server side address */
/* 初始化服务端地址 */
server_addr.sin_family = AF_INET;
server_addr.sin_port = htons(port); /*Server side port number*//* 服务端工作的端口 */
server_addr.sin_addr.s_addr = INADDR_ANY;
rt_memset(&(server_addr.sin_zero), 0x0, sizeof(server_addr.sin_zero));
/* Bind socket to server side address */
/* 绑定socket到服务端地址 */
if (bind(sock, (struct sockaddr *)&server_addr, sizeof(struct sockaddr)) == -1)
{
LOG_E("Unable to bind");
goto __exit;
}
/* Listen on socket */
/* 在socket上进行监听 */
if (listen(sock, 10) == -1)
{
LOG_E("Listen error");
goto __exit;
}
LOG_I("\nTCPServer Waiting for client on port %d...\n", port);
started = 1;
is_running = 1;
timeout.tv_sec = 3;
timeout.tv_usec = 0;
while (is_running)
{
FD_ZERO(&readset);
FD_SET(sock, &readset);
LOG_I("Waiting for a new connection...");
/* Wait for read or write */
if (select(sock + 1, &readset, RT_NULL, RT_NULL, &timeout) == 0)
continue;
/* Accept a request from client and the function is blocking */
/* 接受一个客户端连接socket的请求这个函数调用是阻塞式的 */
connected = accept(sock, (struct sockaddr *)&client_addr, &sin_size);
/* Return the socket connected sucessfully */
/* 返回的是连接成功的socket */
if (connected < 0)
{
LOG_E("accept connection failed! errno = %d", errno);
continue;
}
/* Accept the message which points by client address */
/* 接受返回的client_addr指向了客户端的地址信息 */
LOG_I("I got a connection from (%s , %d)\n",
inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port));
/* Handle method of client connection */
/* 客户端连接的处理 */
while (is_running)
{
FD_ZERO(&readset_c);
FD_SET(connected, &readset_c);
/* Wait for read or write */
if (select(connected + 1, &readset_c, RT_NULL, RT_NULL, &timeout) == 0)
continue;
/* Receive message from connected socket. Buffer size is 1024 bytes,but it's not guranteed to receive size exactly 1024 */
/* 从connected socket中接收数据接收buffer是1024大小但并不一定能够收到1024大小的数据 */
bytes_received = recv(connected, recv_data, BUFSZ, 0);
if (bytes_received < 0)
{
LOG_E("Received error, close the connect.");
closesocket(connected);
connected = -1;
break;
}
else if (bytes_received == 0)
{
/* Print warning message when recv function return 0 */
/* 打印recv函数返回值为0的警告信息 */
LOG_W("Received warning, recv function return 0.");
continue;
}
else
{ /* Receive data sucessfully and append '\0' at the end of message */
/* 有接收到数据,把末端清零 */
recv_data[bytes_received] = '\0';
if (strcmp(recv_data, "q") == 0 || strcmp(recv_data, "Q") == 0)
{
/* If the first letter is 'q' or 'Q', close the connection */
/* 如果是首字母是q或Q关闭这个连接 */
LOG_I("Got a 'q' or 'Q', close the connect.");
closesocket(connected);
connected = -1;
break;
}
else if (strcmp(recv_data, "exit") == 0)
{
/* If the message received is 'exit', close the whole server side. */
/* 如果接收的是exit则关闭整个服务端 */
closesocket(connected);
connected = -1;
goto __exit;
}
else
{
/* Show the message in terminal */
/* 在控制终端显示收到的数据 */
LOG_D("Received data = %s", recv_data);
}
}
/* Send message to connected socket */
/* 发送数据到connected socket */
ret = send(connected, send_data, rt_strlen(send_data), 0);
if (ret < 0)
{
LOG_E("send error, close the connect.");
closesocket(connected);
connected = -1;
break;
}
else if (ret == 0)
{
/* Print warning message when send function return 0 */
/* 打印send函数返回值为0的警告信息 */
LOG_W("Send warning, send function return 0.");
}
}
}
__exit:
if (recv_data)
{
rt_free(recv_data);
recv_data = RT_NULL;
}
if (connected >= 0)
{
closesocket(connected);
connected = -1;
}
if (sock >= 0)
{
closesocket(sock);
sock = -1;
}
started = 0;
is_running = 0;
return;
}
/**
* @brief The usage description of tcp server on rt-Thread
*/
static void usage(void)
{
rt_kprintf("Usage: tcpserver -p <port>\n");
rt_kprintf(" tcpserver --stop\n");
rt_kprintf(" tcpserver --help\n");
rt_kprintf("\n");
rt_kprintf("Miscellaneous:\n");
rt_kprintf(" -p Specify the host port number\n");
rt_kprintf(" --stop Stop tcpserver program\n");
rt_kprintf(" --help Print help information\n");
}
/**
* @brief This function is for testing tcp server on rt-Thread
*/
static void tcpserver_test(int argc, char** argv)
{
rt_thread_t tid;
if (argc == 1 || argc > 3)
{
LOG_I("Please check the command you entered!\n");
goto __usage;
}
else
{
if (rt_strcmp(argv[1], "--help") == 0)
{
goto __usage;
}
else if (rt_strcmp(argv[1], "--stop") == 0)
{
is_running = 0;
return;
}
else if (rt_strcmp(argv[1], "-p") == 0)
{
if (started)
{
LOG_I("The tcpserver has started!");
LOG_I("Please stop tcpserver firstly, by: tcpserver --stop");
return;
}
port = atoi(argv[2]);
}
else
{
goto __usage;
}
}
tid = rt_thread_create("tcp_serv",
tcpserv, RT_NULL,
2048, RT_THREAD_PRIORITY_MAX/3, 20);
if (tid != RT_NULL)
{
rt_thread_startup(tid);
}
return;
__usage:
usage();
}
#ifdef RT_USING_FINSH
MSH_CMD_EXPORT_ALIAS(tcpserver_test, tcpserver,
Start a tcp server. Help: tcpserver --help);
#endif