[Ethernet]网卡驱动 -- TCP通信传输字符

最近在搞网络驱动，在网上找到几个比较好的例程，自己又整理了下，代码贴在下面：
原帖地址

// server.c
#include <stdio.h>
#include <netdb.h>
#include <netinet/in.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/types.h>

#define MAX 80
#define PORT 1234
#define SA struct sockaddr
  
// Function designed for chat between client and server.
void func(int sockfd)
{
    char buff[MAX];
    int n;
    // infinite loop for chat
    for (;;) {
        bzero(buff, MAX);
  
        // read the message from client and copy it in buffer
        read(sockfd, buff, sizeof(buff));
        // print buffer which contains the client contents
        printf("From client: %s\t To client : ", buff);
        bzero(buff, MAX);
        n = 0;
        // copy server message in the buffer
        while ((buff[n++] = getchar()) != '\n')
            ;
  
        // and send that buffer to client
        write(sockfd, buff, sizeof(buff));
  
        // if msg contains "Exit" then server exit and chat ended.
        if (strncmp("exit", buff, 4) == 0) {
            printf("Server Exit...\n");
            break;
        }
    }
}
  
// Driver function
int main()
{
    int sockfd, connfd, len;
    struct sockaddr_in servaddr, cli;
  
    // socket create and verification
    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd == -1) {
        printf("socket creation failed...\n");
        exit(0);
    }
    else
        printf("Socket successfully created..\n");
    bzero(&servaddr, sizeof(servaddr));
  
    int on = 1;
    setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));

    // assign IP, PORT
    servaddr.sin_family = AF_INET;
    servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
    servaddr.sin_port = htons(PORT);
  
    // Binding newly created socket to given IP and verification
    if ((bind(sockfd, (SA*)&servaddr, sizeof(servaddr))) != 0) {
        printf("socket bind failed...\n");
        exit(0);
    }
    else
        printf("Socket successfully binded..\n");
  
    // Now server is ready to listen and verification
    if ((listen(sockfd, 5)) != 0) {
        printf("Listen failed...\n");
        exit(0);
    }
    else
        printf("Server listening..\n");
    len = sizeof(cli);
  
    // Accept the data packet from client and verification
    connfd = accept(sockfd, (SA*)&cli, &len);
    if (connfd < 0) {
        printf("server acccept failed...\n");
        exit(0);
    }
    else
        printf("server acccept the client...\n");
  
    // Function for chatting between client and server
    func(connfd);
  
    // After chatting close the socket
    close(sockfd);
}

// client.c
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>

#define MAX 80
#define PORT 1234
#define SA struct sockaddr

void func(int sockfd)
{
    char buff[MAX];
    int n;
    for (;;) {
        bzero(buff, sizeof(buff));
        printf("Enter the string : ");
        n = 0;
        while ((buff[n++] = getchar()) != '\n')
            ;
        write(sockfd, buff, sizeof(buff));
        bzero(buff, sizeof(buff));
        read(sockfd, buff, sizeof(buff));
        printf("From Server : %s", buff);
        if ((strncmp(buff, "exit", 4)) == 0) {
            printf("Client Exit...\n");
            break;
        }
    }
}
  
int main(int argc, int *argv)
{
    int sockfd, connfd;
    struct sockaddr_in servaddr;

    if (argc != 2)
    {
        printf("usage: ./client <ipaddress>\n");
        exit(0);
    }
  
    // socket create and varification
    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd == -1) {
        printf("socket creation failed...\n");
        exit(0);
    }else
        printf("Socket successfully created..\n");
    bzero(&servaddr, sizeof(servaddr));
  
    // assign IP, PORT
    servaddr.sin_family = AF_INET;
    servaddr.sin_port = htons(PORT);
#if 0
    if (inet_pton(AF_INET, argv[1], &servaddr.sin_addr) <= 0)
    {
        printf("inet_pton error for %s\n", argv[1]);
        exit(1);
    }
#else
    servaddr.sin_addr.s_addr = inet_addr("10.10.177.13");
#endif
    
    // connect the client socket to server socket
    if (connect(sockfd, (SA*)&servaddr, sizeof(servaddr)) != 0) {
        printf("connection with the server failed...\n");
        exit(0);
    }
    else
        printf("connected to the server..\n");
  
    // function for chat
    func(sockfd);
  
    // close the socket
    close(sockfd);
}