cs

hostinfo.c

#include <csapp.h>
#include <execinfo.h>

void print_stack(); 

int main(int argc, char ** argv)
{
#if 0
     /*测试main函数入参*/
    printf("argc = %d\n", argc);
    int counter = 0;
    printf("%p\n", argv);
    printf("%s,%p,%p\n", *argv, *argv, argv[0]);
    printf("%c\n", **argv);
    printf("MAXLINE = %d\n", MAXLINE);
#endif
    //atexit(print_stack); 
    
    struct addrinfo *p, *listp, hints;
    char bufhost[MAXLINE], bufserv[MAXLINE],bufinetntop[MAXLINE];
    int res, flags;
    struct sockaddr_in *temp;

    /*main函数入参校验*/
    if(3 != argc)
    {
        fprintf(stderr,"%s <domin name> <service>\n", argv[0]);
        exit(EXIT_FAILURE);
    }

    /*调用getaddrinfo函数，获取*/ 
    memset(&hints, 0, sizeof(struct addrinfo));
    hints.ai_family = AF_INET;
    hints.ai_socktype = SOCK_STREAM;
    hints.ai_flags = AI_CANONNAME;
    if(0 != (res = getaddrinfo(argv[1], argv[2], &hints, &listp)))
    {
        fprintf(stderr,"%s %s getaddrinfo return errcode is %s\n", argv[0],argv[1], 
            gai_strerror(res));
        exit(EXIT_FAILURE);
    }
   
    flags = NI_NUMERICSERV;
    //flags = 0;
    for(p = listp; p != NULL ; p = p -> ai_next)
    {
        if(0 !=(res = getnameinfo(p -> ai_addr, p -> ai_addrlen,
            bufhost, MAXLINE, bufserv, MAXLINE, flags)))
        {
            fprintf(stderr, "%s %s getnameinfo return error\n");
            exit(EXIT_FAILURE);
        }
        printf("print the args from getnameinfo function:\n");
        printf("host : %s, service : %s\n\n", bufhost, bufserv);

        printf("print the ai_canonname and ai_addrlen:\n");
        printf("ai_canonname is %s and ai_addrlen is %d\n\n",p->ai_canonname,p->ai_addrlen);

        printf("print the result from p->ai_addr:\n");
        temp = (struct sockaddr_in *)p -> ai_addr;
        struct in_addr tem = temp -> sin_addr;
        inet_ntop(AF_INET, &tem, bufinetntop, MAXLINE);
        uint16_t portnumber = ((struct sockaddr_in *)(p->ai_addr))->sin_port;
        portnumber = ntohs(portnumber);
        printf("p->ai_addr->sin_addr:%s,p->ai_addr->sin_port:%d\n=======================================\n",bufinetntop, portnumber);
    }
    
    

    freeaddrinfo(listp);

    exit(EXIT_SUCCESS);
    
}


void print_stack()  
{  
    int size = 16;  
    int i;    
    void *array[16];  
    int stack_num = backtrace(array, size);  
    char **stacktrace = NULL;  
          
    stacktrace = (char**)backtrace_symbols(array, stack_num);  
    printf("==========begin print backtrace================\n");
    for(i = 0; i < stack_num; i++)  
    {  
        printf("%d------>%s\n",i, stacktrace[i]);  
    }  
    free(stacktrace);  
}  

servermain.c

#include <csapp.h>

int open_listenfd_created_by_myself(char * hostname, char * port);

int main(int argc, char ** argv)
{   
    int listenfd, connfd;
    struct sockaddr clientaddr;
    char buf[MAXLINE];
    rio_t rio;
    size_t n;
    
    if(3 != argc)
    {
        fprintf(stderr, "%s <hostname><numeric port>", argv[0]);
        exit(EXIT_FAILURE);
    }

    int clientaddrlen = sizeof(struct sockaddr);
    
    listenfd = open_listenfd_created_by_myself(argv[1], argv[2]);

    while(1)
    {
        if(0 < (connfd = accept(listenfd, &clientaddr, &clientaddrlen)))
        {
            printf("the connection has builded.\n");
            
            rio_readinitb(&rio, connfd);

            while(0 != (n = rio_readlineb(&rio, buf, MAXLINE)))
            {
                printf("===========\nreceive the\n%sfrom the client.\n============\n",buf);
            }
        }
        Close(connfd);
        break;
    }
    Close(listenfd);
    exit(EXIT_SUCCESS);

}


int open_listenfd_created_by_myself(char * hostname, char * port)
{
    struct addrinfo *p, *plist, hints;
    int res;
    int listenfd;
    struct sockaddr_in6 *temp;
    char bufinetntop[MAXLINE];


    
    memset(&hints, 0, sizeof(struct addrinfo));
    hints.ai_flags = AI_ADDRCONFIG;
    hints.ai_flags |= AI_NUMERICSERV;
    //hints.ai_family = AF_UNSPEC;
    hints.ai_socktype = SOCK_STREAM;
    
    if(0 != (res = getaddrinfo(hostname, port, &hints, &plist)))
    {
        fprintf(stderr, "call getaddrinfo() function failed the errcode is %d.\n",gai_strerror(res));
        exit(EXIT_FAILURE);
    }
    
    for(p = plist; p; p = p->ai_next)
    {
        if(0 >= (listenfd = socket(p->ai_family, p->ai_socktype, p->ai_protocol)))
        {
            continue;
        }

        if(0 !=(res = bind(listenfd, p->ai_addr, p->ai_addrlen)))
        {
            continue;
        }
        /*
        temp = (struct sockaddr_in6 *)p -> ai_addr;
        struct in6_addr tem = temp -> sin6_addr;
        inet_ntop(AF_INET6, &tem, bufinetntop, MAXLINE);
        uint16_t portnumber = ((struct sockaddr_in6 *)(p->ai_addr))->sin6_port;
        portnumber = ntohs(portnumber);
        printf("p->ai_addr->sin_addr:%s,p->ai_addr->sin_port:%d\n",bufinetntop, portnumber);
        */


        
        if(0 == listen(listenfd , 1024))
        {
            freeaddrinfo(plist);        
            return listenfd;
        }
    }
    Close(listenfd);
    freeaddrinfo(plist);
    exit(EXIT_FAILURE);
}

clientmain.c

#include <csapp.h>
#include <execinfo.h>

int open_clientfd_created_by_myself(char * hostname, char * port);


int main(int argc, char ** argv)
{   
    int res, clientfd;
    char buf[MAXLINE];
    
    if(3 != argc)
    {
        fprintf(stderr, "%s <server host name><numeric port number>\n",argv[0]);
        exit(EXIT_FAILURE);
    }

    clientfd = open_clientfd_created_by_myself(argv[1], argv[2]);
 
    while(fgets(buf ,MAXLINE, stdin)!=NULL)
    {
        rio_writen(clientfd, buf, strlen(buf));
    }
    Close(clientfd);
    exit(EXIT_SUCCESS);
    
}


int open_clientfd_created_by_myself(char * hostname, char * port)
{
    int clientfd;
    int res, flags;
    struct addrinfo  hints, *p, * plist;
    char bufhost[MAXLINE], bufport[MAXLINE];
    char bufinetntop[MAXLINE];

    struct sockaddr_in6 * temp;
    
    memset(&hints, 0, sizeof(struct addrinfo));
    hints.ai_flags = AI_NUMERICSERV;
    hints.ai_flags |= AI_ADDRCONFIG;
    hints.ai_socktype = SOCK_STREAM;
    //hints.ai_family = AF_UNSPEC;
    if(0 != (res = getaddrinfo(hostname, port, &hints, &plist)))
    {
        fprintf(stderr, "call getaddrinfo func failed and the error code is %d\n",gai_strerror(res));
        exit(EXIT_FAILURE);
    }
    if(NULL == plist)
    {
        fprintf(stderr, "NULL == plist\n");
        exit(EXIT_FAILURE);
    }

    for(p = plist; p; p=p->ai_next)
    {   
        flags = 0;
        if(0 == (res=getnameinfo(p->ai_addr, p->ai_addrlen, bufhost, MAXLINE, bufport, MAXLINE, flags)))
        {
            printf("server hostname is %s, and the server port is %s\n", bufhost, bufport);
        }
        /*
        temp = (struct sockaddr_in6 *)p -> ai_addr;
        struct in6_addr tem = temp -> sin6_addr;
        inet_ntop(AF_INET6, &tem, bufinetntop, MAXLINE);
        uint16_t portnumber = ((struct sockaddr_in6 *)(p->ai_addr))->sin6_port;
        portnumber = ntohs(portnumber);
        printf("p->ai_addr->sin_addr:%s,p->ai_addr->sin_port:%d\n",bufinetntop, portnumber);
        */

        if(0 >= (clientfd = socket(p->ai_family ,p->ai_socktype,p->ai_protocol)))
        {
            continue;
        }

        if(0 == (res = connect(clientfd, p -> ai_addr, p->ai_addrlen)))
        {
            freeaddrinfo(plist);
            return clientfd; 
        }
        printf("res = %d,p->ai_addrlen=%d\n",res,p->ai_addrlen);
        Close(clientfd);
    }
    freeaddrinfo(plist);
    fprintf(stderr, "call open_clientfd_created_by_myself() function failed.\n");
    exit(EXIT_FAILURE);
}