怎样获取socket server的网络地址？

[frankspy]

我用getaddrinfo通过hostname获取server的ip地址。在3台其他的UNIX服务器上都可以获取各自的网络地址，但是在现在这台linux上就无法获取其网络地址，获取只有127.0.0.1的本地地址，socket绑定本地地址，其他的机器就不能访问该socket serve。请问如何才能获取网络地址（而不是127.0.0.1）？谢谢！

[do_fork]

#include <arpa/inet.h>
#include <sys/socket.h>
#include <netdb.h>
#include <ifaddrs.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

int main(int argc, char *argv[])
{
        struct ifaddrs *ifaddr, *ifa;
        int family, s;
        char host[NI_MAXHOST];

        if (getifaddrs(&ifaddr) == -1) {
                perror("getifaddrs");
                exit(EXIT_FAILURE);
        }   

        for (ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next) {
                family = ifa->ifa_addr->sa_family;
                printf("%s  address family: %d%s\n",
                                ifa->ifa_name, family,
                                (family == AF_PACKET) ? " (AF_PACKET)" :
                                (family == AF_INET) ?   " (AF_INET)" :
                                (family == AF_INET6) ?  " (AF_INET6)" : "");

                if (family == AF_INET || family == AF_INET6) {
                        s = getnameinfo(ifa->ifa_addr,
                                        (family == AF_INET) ? sizeof(struct sockaddr_in) :
                                        sizeof(struct sockaddr_in6),
                                        host, NI_MAXHOST, NULL, 0, NI_NUMERICHOST);
                        if (s != 0) {
                                printf("getnameinfo() failed: %s\n", gai_strerror(s));
                                exit(EXIT_FAILURE);
                        }   
                        printf("\taddress: <%s>\n", host);
                }   
        }   
        freeifaddrs(ifaddr);
        exit(EXIT_SUCCESS);
}

执行结果:

lo  address family: 17 (AF_PACKET)
eth0  address family: 17 (AF_PACKET)
lo  address family: 2 (AF_INET)
        address: <127.0.0.1>
eth0  address family: 2 (AF_INET)
        address: <10.0.2.15>
lo  address family: 10 (AF_INET6)
        address: <::1>
eth0  address family: 10 (AF_INET6)
        address: <fe80::a00:27ff:fee4:2237%eth0>

源码不是我写的，是
man getifaddrs
自带例子

[wanghao111]

友情up

[diablox0147]

登陆这个网站，就能看到自己的IP了
http://www.whatismyip.com/

[frankspy]

我是想用c来实现，谢谢！

[Quote=引用 2 楼 diablox0147 的回复:]
登陆这个网站，就能看到自己的IP了
http://www.whatismyip.com/
[/Quote]

[lklwlklw]

char szHostName[256];

if(gethostname(szHostName, sizeof(szHostName)))
{
strHostName = _T("");
MessageBox(GetError(GetLastError()), _T("错误"), MB_ICONHAND|MB_OK);
return -1;
}

PHOSTENT hostinfo;
if((hostinfo = gethostbyname(szHostName)) == NULL)
return GetLastError();

LPCSTR ip = inet_ntoa (*(struct in_addr *)*hostinfo->h_addr_list);

strIPAddress = ip;
strHostName = szHostName;

return 0;

[sxsong_04]

把server的地址写到配置文件里，每次读文件获取server ip

[frankspy]

谢谢，但是这样仍然获得的是127.0.0.1, 我想获取的不是本地地址，而是外部地址。

[Quote=引用 4 楼 lklwlklw 的回复:]
char szHostName[256];

if(gethostname(szHostName, sizeof(szHostName)))
{
strHostName = _T("");
MessageBox(GetError(GetLastError()), _T("错误"), MB_ICONHAND|MB_OK);
return -1;
}

PHOSTENT hostinfo;
if((hostinfo = gethostbyname(szHostName)) == NULL)
return GetLastError();

LPCSTR ip = inet_ntoa (*(struct in_addr *)*hostinfo->h_addr_list);

strIPAddress = ip;
strHostName = szHostName;

return 0;
[/Quote]

[zhenjiangge]

我遇到这样的问题时，一般是通过写配置文件解决的，方便修改，测试