socket TCP服务 epoll

// 服务器端  server.c

#include  <unistd.h>
#include  <sys/types.h>       /* basic system data types */
#include  <sys/socket.h>      /* basic socket definitions */
#include  <netinet/in.h>      /* sockaddr_in{} and other Internet defns */
#include  <arpa/inet.h>       /* inet(3) functions */
#include <sys/epoll.h> /* epoll function */
#include <fcntl.h>     /* nonblocking */
#include <sys/resource.h> /*setrlimit */

#include <stdlib.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <signal.h>

#define PORT    6888
#define MAXCLIENT 1000
#define MAXEPOLLSIZE 10000
#define MAXLINE 10240
int handle(int connfd);
int setnonblocking(int sockfd)
{
    if (fcntl(sockfd, F_SETFL, fcntl(sockfd, F_GETFD, 0)|O_NONBLOCK) == -1) {
        return -1;
    }
    return 0;
}

int main(int argc, char **argv)
{
    int listenq = 1024;
    int listenport = PORT;
    int listenfd, connfd, kdpfd, nfds, n, nread, curfds,acceptCount = 0;
    struct sockaddr_in servaddr, cliaddr;
    socklen_t socklen = sizeof(struct sockaddr_in);
    struct epoll_event ev;
    struct epoll_event events[MAXCLIENT];
    struct rlimit rt;
    char buf[MAXLINE];

    if (argc == 2) {
        listenport = atoi(argv[1]);
    }

    /* 设置每个进程允许打开的最大文件数 */
    rt.rlim_max = rt.rlim_cur = MAXEPOLLSIZE;
    if (setrlimit(RLIMIT_NOFILE, &rt) == -1) 
    {
        perror("setrlimit error");
        return -1;
    }


    bzero(&servaddr, sizeof(servaddr));
    servaddr.sin_family = AF_INET; 
    servaddr.sin_addr.s_addr = htonl (INADDR_ANY);
    servaddr.sin_port = htons (listenport);

    listenfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); 
    if (listenfd == -1) {
        perror("can't create socket file");
        return -1;
    }

    int opt = 1;
    setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));

    signal(SIGPIPE,SIG_IGN);
    if (setnonblocking(listenfd) < 0) {
        perror("setnonblock error");
    }

    if (bind(listenfd, (struct sockaddr *) &servaddr, sizeof(struct sockaddr)) == -1) 
    {
        perror("bind error");
        return -1;
    } 
    if (listen(listenfd, MAXCLIENT) == -1) 
    {
        perror("listen error");
        return -1;
    }
    /* 创建 epoll 句柄，把监听 socket 加入到 epoll 集合里 */
    kdpfd = epoll_create(MAXCLIENT);
    ev.events = EPOLLIN | EPOLLET;
    ev.data.fd = listenfd;
    if (epoll_ctl(kdpfd, EPOLL_CTL_ADD, listenfd, &ev) < 0) 
    {
        fprintf(stderr, "epoll set insertion error: fd=%d
", listenfd);
        return -1;
    }
    curfds = 1;

    printf("epollserver startup,port %d, max connection is %d, backlog is %d
", listenport, MAXCLIENT, listenq);

    for (;;) {
        /* 等待有事件发生 */
        nfds = epoll_wait(kdpfd, events, curfds, -1);
        if (nfds == -1)
        {
            perror("epoll_wait");
            continue;
        }
        /* 处理所有事件 */
        for (n = 0; n < nfds; ++n)
        {
            if (events[n].data.fd == listenfd) 
            {
                connfd = accept(listenfd, (struct sockaddr *)&cliaddr,&socklen);
                if (connfd < 0) 
                {
                    perror("accept error");
                    continue;
                }

                sprintf(buf, "accept form %s:%d
", inet_ntoa(cliaddr.sin_addr), cliaddr.sin_port);
                printf("%d:%s", ++acceptCount, buf);

                if (curfds > MAXCLIENT) {
                    fprintf(stderr, "too many connection, more than %d
", MAXCLIENT);
                    close(connfd);
                    continue;
                } 
                if (setnonblocking(connfd) < 0) {
                    perror("setnonblocking error");
                }
                ev.events = EPOLLIN | EPOLLET;
                ev.data.fd = connfd;
                if (epoll_ctl(kdpfd, EPOLL_CTL_ADD, connfd, &ev) < 0)
                {
                    fprintf(stderr, "add socket '%d' to epoll failed: %s
", connfd, strerror(errno));
                    return -1;
                }
                curfds++;
                continue;
            } 
            // 处理客户端请求
            if (handle(events[n].data.fd) < 0) {
                epoll_ctl(kdpfd, EPOLL_CTL_DEL, events[n].data.fd,&ev);
                curfds--;


            }
        }
    }
    close(listenfd);
    return 0;
}
int handle(int connfd) {
    int nread;
    char buf[MAXLINE];
    memset(buf,0,sizeof(buf));
    nread = read(connfd, buf, MAXLINE);//读取客户端socket流　
    struct sockaddr_in serv,guest;
    char serv_ip[20];
    char guest_ip[20];
    socklen_t serv_len = sizeof(serv);
    socklen_t guest_len = sizeof(guest);
    getsockname(connfd, (struct sockaddr *)&serv, &serv_len);
    getpeername(connfd, (struct sockaddr *)&guest, &guest_len);
    inet_ntop(AF_INET, &serv.sin_addr, serv_ip, sizeof(serv_ip));
    inet_ntop(AF_INET, &guest.sin_addr, guest_ip, sizeof(guest_ip));
    printf("guest %s:%d ",guest_ip, ntohs(guest.sin_port));

    if (nread == 0) {
        printf("client close the connection
");
        close(connfd);
        return -1;
    } 
    if (nread < 0) {
        perror("read error");
        close(connfd);
        return -1;
    }  
    printf(">> %s",buf);  
    fflush(stdout);
    write(connfd, buf, nread);//响应客户端  
    return 0;
}

客户端 client.c

#include  <unistd.h>
#include  <sys/types.h>       /* basic system data types */
#include  <sys/socket.h>      /* basic socket definitions */
#include  <netinet/in.h>      /* sockaddr_in{} and other Internet defns */
#include  <arpa/inet.h>       /* inet(3) functions */
#include <netdb.h> /*gethostbyname function */

#include <stdlib.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>

#define MAXLINE 1024

void handle(int connfd);

int main(int argc, char **argv)
{
    char * servInetAddr = "127.0.0.1";
    int servPort = 6888;
    char buf[MAXLINE];
    int connfd;
    struct sockaddr_in servaddr;

    if (argc == 2) {
        servInetAddr = argv[1];
    }
    if (argc == 3) {
        servInetAddr = argv[1];
        servPort = atoi(argv[2]);
    }
    if (argc > 3) {
        printf("usage: echoclient <IPaddress> <Port>
");
        return -1;
    }

    connfd = socket(AF_INET, SOCK_STREAM, 0);

    bzero(&servaddr, sizeof(servaddr));
    servaddr.sin_family = AF_INET;
    servaddr.sin_port = htons(servPort);
    inet_pton(AF_INET, servInetAddr, &servaddr.sin_addr);

    if (connect(connfd, (struct sockaddr *) &servaddr, sizeof(servaddr)) < 0) {
        perror("connect error");
        return -1;
    }
    printf("welcome to echoclient
");
    handle(connfd);     /* do it all */
    close(connfd);
    printf("exit
");
    exit(0);
}

void handle(int sockfd)
{
    char sendline[MAXLINE], recvline[MAXLINE];
    int n;
    for (;;) {
        if (fgets(sendline, MAXLINE, stdin) == NULL) {
            break;//read eof
        }
        /*
        //也可以不用标准库的缓冲流,直接使用系统函数无缓存操作
        if (read(STDIN_FILENO, sendline, MAXLINE) == 0) {
            break;//read eof
        }
        */

        n = write(sockfd, sendline, strlen(sendline));
        n = read(sockfd, recvline, MAXLINE);
        if (n == 0) {
            printf("echoclient: server terminated prematurely
");
            break;
        }
        write(STDOUT_FILENO, recvline, n);
        //如果用标准库的缓存流输出有时会出现问题
        //fputs(recvline, stdout);
    }
}