无法通过套接字连接到HTTP服务C

我正在编写一个客户端程序，它建立套接字，连接到远程服务器并发出HTTP请求。但是，我似乎无法连接到远程服务器。无法通过套接字连接到HTTP服务C

我相信我所做的一切都对，甚至为sockaddr_in设置了正确的端口号，但仍然无法连接。

我错过了什么？

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

int main(int argc, char *argv[]) 
{ 
    FILE *fout; 

    int i, c, sk; 
    char *tk, host[64], path[64], fname[64], http_msg[256], buf[1024]; 

    struct sockaddr_in remote; 
    struct hostent *hp; 
    struct servent *se; 

    if(argc != 2) 
    { 
     printf("Invalid number of arguments. Program terminating...\n"); 
     exit(1); 
    } 

    sk = socket(AF_INET, SOCK_STREAM, 0); 
    remote.sin_family = AF_INET; 

    c = 0; 
    tk = strtok(argv[1], "/"); 
    while(tk != NULL) 
    { 
     if(c == 0) 
      strcpy(host, tk); 
     else if(c == 1) 
      strcpy(path, tk); 
     else 
      strcpy(fname, tk); 
     ++c; 
     tk = strtok(NULL, "/"); 
    } 

    snprintf(http_msg, 256, "GET /%s/%s HTTP/1.1\r\nHost: %s\r\nConnection: close\r\n\n", path, fname, host); 

    hp = gethostbyname(host); 
    if(hp == NULL) 
    { 
     printf("Can't find host %s. Program terminating...\n", host); 
     exit(1); 
    } 

    se = getservbyname("http", "tcp"); 
    remote.sin_port = ntohs(se->s_port); 

    if(connect(sk, (struct sockaddr*)&remote, sizeof(remote)) < 0) 
    { 
     printf("Connection attempt failed. Program terminating...\n"); 
     exit(1); 
    } 

    send(sk, http_msg, sizeof(http_msg) + 1, 0); 
    recv(sk, buf, sizeof(buf), 0); 
    printf("%s\n", buf); 

    return 0; 
}

来源

2015-04-07 Delfino

你错过了注射马力到远程：'BCOPY（（字符*）HP-> H_ADDR，（字符*）＆remote.sin_addr.s_addr，HP- >长度h_length）; ' –

我刚刚尝试过，但仍无法连接。如果我使用'memcpy'而不是重要吗？ – Delfino

就在连接之前，连接完成。你如何检查你是否连接？ –

我得到了它

问题是与线

remote.sin_port = ntohs(se->s_port);

你并不需要将其转换。此代码的工作对我来说：

if(argc != 2)                
{                   
    printf("Invalid number of arguments. Program terminating...\n");  
    exit(1);                
}                   

bzero(&remote, sizeof(remote));            
sk = socket(AF_INET, SOCK_STREAM, 0);          
remote.sin_family = AF_INET;            

c = 0;                  
tk = strtok(argv[1], "/");             
while(tk != NULL)               
{                   
    if(c == 0)                
     strcpy(host, tk);             
    else if(c == 1)               
     strcpy(path, tk);             
    else                 
     strcpy(fname, tk);             
    ++c;                 
    tk = strtok(NULL, "/");             
}                   

snprintf(http_msg, 256, "GET /%s/%s HTTP/1.1\r\nHost: %s\r\nConnection: close\r\n\r\n", path, fname, host); 

hp = gethostbyname(host);             
if(hp == NULL)                
{                   
    printf("Can't find host %s. Program terminating...\n", host);   
    exit(1);                
}                   

se = getservbyname("http", "tcp");           
printf("%d port\n", ntohs(se->s_port));          
remote.sin_port = se->s_port;            
bcopy((char *)hp->h_addr, (char *)&remote.sin_addr.s_addr, hp->h_length); 

if(connect(sk, (struct sockaddr*)&remote, sizeof(remote)) < 0)    
{                   
    printf("Connection attempt failed. Program terminating...\n");   
    exit(1);                
}                   

send(sk, http_msg, sizeof(http_msg) + 1, 0);        
recv(sk, buf, sizeof(buf), 0);            
printf("%s\n", buf);              

return 0;

}

来源

2015-04-07 05:06:42

为什么在'remote'中使用'bzero'？我会尝试。不幸的是我现在不在我的电脑上。 – Delfino

堆栈值未初始化，因此您必须初始化它。默认情况下，我更愿意重置为0 –

这样做：

remote.sin_port = ntohs(se->s_port); 
remote.sin_family = AF_INET; 
remote.sin_addr = *((struct in_addr *) hp->h_addr);

这shoul'd做到这一点。连接后请查看\ r \ n \ r \ n：关闭。

snprintf(http_msg, 256, "GET /%s/%s HTTP/1.1\r\nHost: %s\r\nConnection: close\r\n\r\n", path, fname, host);

来源

2015-04-07 04:16:23

无法通过套接字连接到HTTP服务C

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