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浅谈linux 内核网络 sk_buff 之克隆与复制

深入linux内核架构--进程&线程

了解Docker 依赖的linux内核技术

1.client端（读）

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>void error_handling(char *msg);int main(int argc, char *argv[])
{int sock_fd;struct sockaddr_in serv_addr;char message[30] = {0};int rcv_len;if (argc != 3){printf("Usage: %s <IP> <port>\n", argv[0]);exit(1);}sock_fd = socket(AF_INET, SOCK_STREAM, 0);if (sock_fd == -1)error_handling("sock() error");memset(&serv_addr, 0, sizeof(serv_addr));serv_addr.sin_family = AF_INET;serv_addr.sin_addr.s_addr = inet_addr(argv[1]);// server's IP addrserv_addr.sin_port = htons(atoi(argv[2]));//portif (connect(sock_fd, (struct sockaddr*)&serv_addr, sizeof(serv_addr)) == -1)error_handling("connect() error!");rcv_len = read(sock_fd, message, sizeof(message) - 1);if (rcv_len == -1)error_handling("read() error!");printf("Message from server: %s\n", message);printf("read length : %d\n",rcv_len);close(sock_fd);return 0;
}void error_handling(char *message)
{fputs(message, stderr);fputc('\n', stderr);exit(1);
}

如果是在client中发送数据，只需将read修改为write即可。

2.server（发送）

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>void error_handling(char *msg);int main(int argc, char *argv[])
{int serv_sock_fd;int clnt_sock_fd;struct sockaddr_in serv_addr;struct sockaddr_in clnt_addr;socklen_t clnt_addr_size;char message[] = "This is a sample TCP¡sserver!";if (argc != 2){printf("Usage: %s <port>\n", argv[0]);exit(1);}serv_sock_fd = socket(AF_INET, SOCK_STREAM, 0);if (serv_sock_fd == -1)error_handling("sock() error");memset(&serv_addr, 0, sizeof(serv_addr));serv_addr.sin_family = AF_INET;serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);serv_addr.sin_port = htons(atoi(argv[1]));if (bind(serv_sock_fd, (struct sockaddr*)&serv_addr, sizeof(serv_addr)) == -1)error_handling("bind() error");if (listen(serv_sock_fd, 5) == -1)error_handling("listen() error");clnt_addr_size = sizeof(clnt_addr);clnt_sock_fd = accept(serv_sock_fd, (struct sockaddr*)&clnt_addr, &clnt_addr_size);if (clnt_sock_fd == -1)error_handling("accept() error");write(clnt_sock_fd, message, sizeof(message));close(clnt_sock_fd);close(serv_sock_fd);return 0;
}void error_handling(char *message)
{fputs(message, stderr);fputc('\n', stderr);exit(1);
}

如果是在server端接收数据，只需将write修改为read即可。

3，以上，在Linux下分别gcc编译，先运行server程序，然后运行client程序，server端等待client的连接，一旦连接并完成数据发送，server关闭。

4，示例程序的server只能连接一个client端，并且未进行数据收发的正确性验证。