11.1客戶端-伺服器程式設計模型

11.2網路

11.3全球IP因特網

13.3.1 IP地址

11.3.2因特網域名

11.3.3因特網連線

11.4套接字介面

11.4.1套接字地址結構

11.4.2socket函式

11.4.3connect函式

11.4.4bind函式

11.4.5listen函式

11.4.6accept函式

11.4.7主機和服務的轉換

1.getaddrinfo函式

2.getnameinfo

11.4.8套接字介面的輔助函式

1.open_clientfd函式

/* $begin open_clientfd */
int open_clientfd(char *hostname, char *port) {
    int clientfd, rc;
    struct addrinfo hints, *listp, *p;

    /* Get a list of potential server addresses */
    memset(&hints, 0, sizeof(struct addrinfo));
    hints.ai_socktype = SOCK_STREAM;  /* Open a connection 
 
*/
    hints.ai_flags = AI_NUMERICSERV;  /* ... using a numeric port arg. */
    hints.ai_flags |= AI_ADDRCONFIG;  /* Recommended for connections */
    if ((rc = getaddrinfo(hostname, port, &hints, &listp)) != 0) {
        fprintf(stderr, "getaddrinfo failed (%s:%s): %s\n", hostname, port, gai_strerror(rc));
        
 
return -2;
    }
  
    /* Walk the list for one that we can successfully connect to */
    for (p = listp; p; p = p->ai_next) {
        /* Create a socket descriptor */
        if ((clientfd = socket(p->ai_family, p->ai_socktype, p->ai_protocol)) < 0) 
            continue; /* Socket failed, try the next */

        /* Connect to the server */
        if (connect(clientfd, p->ai_addr, p->ai_addrlen) != -1) 
            break; /* Success */
        if (close(clientfd) < 0) { /* Connect failed, try another */  //line:netp:openclientfd:closefd
            fprintf(stderr, "open_clientfd: close failed: %s\n", strerror(errno));
            return -1;
        } 
    } 

    /* Clean up */
    freeaddrinfo(listp);
    if (!p) /* All connects failed */
        return -1;
    else    /* The last connect succeeded */
        return clientfd;
}
/* $end open_clientfd */

2.open_listenfd函式

/* $begin open_listenfd */
int open_listenfd(char *port) 
{
    struct addrinfo hints, *listp, *p;
    int listenfd, rc, optval=1;

    /* Get a list of potential server addresses */
    memset(&hints, 0, sizeof(struct addrinfo));
    hints.ai_socktype = SOCK_STREAM;             /* Accept connections */
    hints.ai_flags = AI_PASSIVE | AI_ADDRCONFIG; /* ... on any IP address */
    hints.ai_flags |= AI_NUMERICSERV;            /* ... using port number */
    if ((rc = getaddrinfo(NULL, port, &hints, &listp)) != 0) {
        fprintf(stderr, "getaddrinfo failed (port %s): %s\n", port, gai_strerror(rc));
        return -2;
    }

    /* Walk the list for one that we can bind to */
    for (p = listp; p; p = p->ai_next) {
        /* Create a socket descriptor */
        if ((listenfd = socket(p->ai_family, p->ai_socktype, p->ai_protocol)) < 0) 
            continue;  /* Socket failed, try the next */

        /* Eliminates "Address already in use" error from bind */
        setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR,    //line:netp:csapp:setsockopt
                   (const void *)&optval , sizeof(int));

        /* Bind the descriptor to the address */
        if (bind(listenfd, p->ai_addr, p->ai_addrlen) == 0)
            break; /* Success */
        if (close(listenfd) < 0) { /* Bind failed, try the next */
            fprintf(stderr, "open_listenfd close failed: %s\n", strerror(errno));
            return -1;
        }
    }


    /* Clean up */
    freeaddrinfo(listp);
    if (!p) /* No address worked */
        return -1;

    /* Make it a listening socket ready to accept connection requests */
    if (listen(listenfd, LISTENQ) < 0) {
        close(listenfd);
    return -1;
    }
    return listenfd;
}/* $end open_listenfd */

11.4.9echo客戶端和伺服器的示例

11.5Web伺服器

11.5.1Web基礎

11.5.2Web內容

11.5.3HTTP事務

1.HTTP請求

2.HTTP響應

11.5.4服務動態內容

1.客戶端如何將程式引數傳遞給伺服器

2.伺服器如何將引數傳遞給子程序

3.伺服器如何將其他資訊傳遞給子程序

4.子程序將它的輸出傳送到哪裡

11.6綜合：TINY Web伺服器