diff options
Diffstat (limited to 'examples/network/udpserver.c')
| -rw-r--r-- | examples/network/udpserver.c | 114 |
1 files changed, 62 insertions, 52 deletions
diff --git a/examples/network/udpserver.c b/examples/network/udpserver.c index 9fede482fb..d480ff3d14 100644 --- a/examples/network/udpserver.c +++ b/examples/network/udpserver.c @@ -1,74 +1,84 @@ #include <rtthread.h>
-#include <lwip/sockets.h>
+#include <lwip/sockets.h> /* 使用BSD socket，需要包含sockets.h头文件 */
void udpserv(void* paramemter)
{
- int sock;
- int bytes_read;
- char *recv_data;
- rt_uint32_t addr_len;
- struct sockaddr_in server_addr , client_addr;
+ int sock;
+ int bytes_read;
+ char *recv_data;
+ rt_uint32_t addr_len;
+ struct sockaddr_in server_addr, client_addr;
- recv_data = rt_malloc(1024);
- if (recv_data == RT_NULL)
- {
- rt_kprintf("No memory\n");
- return;
- }
+ /* 分配接收用的数据缓冲 */
+ recv_data = rt_malloc(1024);
+ if (recv_data == RT_NULL)
+ {
+ /* 分配内存失败，返回 */
+ rt_kprintf("No memory\n");
+ return;
+ }
- /* create socket */
- if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
- {
- rt_kprintf("Socket error\n");
+ /* 创建一个socket，类型是SOCK_DGRAM，UDP类型 */
+ if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
+ {
+ rt_kprintf("Socket error\n");
- /* release recv buffer */
- rt_free(recv_data);
- return;
- }
+ /* 释放接收用的数据缓冲 */
+ rt_free(recv_data);
+ return;
+ }
- /* init server socket address */
- server_addr.sin_family = AF_INET;
- server_addr.sin_port = htons(5000);
- server_addr.sin_addr.s_addr = INADDR_ANY;
- rt_memset(&(server_addr.sin_zero),0, sizeof(server_addr.sin_zero));
+ /* 初始化服务端地址 */
+ server_addr.sin_family = AF_INET;
+ server_addr.sin_port = htons(5000);
+ server_addr.sin_addr.s_addr = INADDR_ANY;
+ rt_memset(&(server_addr.sin_zero),0, sizeof(server_addr.sin_zero));
- if (bind(sock,(struct sockaddr *)&server_addr,
- sizeof(struct sockaddr)) == -1)
- {
- rt_kprintf("Bind error\n");
+ /* 绑定socket到服务端地址 */
+ if (bind(sock,(struct sockaddr *)&server_addr,
+ sizeof(struct sockaddr)) == -1)
+ {
+ /* 绑定地址失败 */
+ rt_kprintf("Bind error\n");
- /* release recv buffer */
- rt_free(recv_data);
- return;
- }
+ /* 释放接收用的数据缓冲 */
+ rt_free(recv_data);
+ return;
+ }
- addr_len = sizeof(struct sockaddr);
+ addr_len = sizeof(struct sockaddr);
+ rt_kprintf("UDPServer Waiting for client on port 5000...\n");
- rt_kprintf("UDPServer Waiting for client on port 5000...\n");
+ while (1)
+ {
+ /* 从sock中收取最大1024字节数据 */
+ bytes_read = recvfrom(sock, recv_data, 1024, 0,
+ (struct sockaddr *)&client_addr, &addr_len);
+ /* UDP不同于TCP，它基本不会出现收取的数据失败的情况，除非设置了超时等待 */
- while (1)
- {
- bytes_read = recvfrom(sock, recv_data, 1024, 0,
- (struct sockaddr *)&client_addr, &addr_len);
- recv_data[bytes_read] = '\0';
- rt_kprintf("\n(%s , %d) said : ",inet_ntoa(client_addr.sin_addr),
- ntohs(client_addr.sin_port));
- rt_kprintf("%s", recv_data);
+ recv_data[bytes_read] = '\0'; /* 把末端清零 */
- if (strcmp(recv_data, "exit") == 0)
- {
- lwip_close(sock);
+ /* 输出接收的数据 */
+ rt_kprintf("\n(%s , %d) said : ",inet_ntoa(client_addr.sin_addr),
+ ntohs(client_addr.sin_port));
+ rt_kprintf("%s", recv_data);
- /* release recv buffer */
- rt_free(recv_data);
- break;
- }
- }
+ /* 如果接收数据是exit，退出 */
+ if (strcmp(recv_data, "exit") == 0)
+ {
+ lwip_close(sock);
- return;
+ /* 释放接收用的数据缓冲 */
+ rt_free(recv_data);
+ break;
+ }
+ }
+
+ return;
}
#ifdef RT_USING_FINSH
#include <finsh.h>
+/* 输出udpserv函数到finsh shell中 */
FINSH_FUNCTION_EXPORT(udpserv, startup udp server);
#endif
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