extern "C" int RTinet_lookup( const char * host,RTinet_address *address,RTinet_port port)
{
struct addrinfo,*res;
int errcode;
char addrstr[INET6_ADDRSTRLEN];
memset (&hints, 0, sizeof (hints));
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = IPPROTO_TCP;
hints.ai_flags |= AI_CANONNAME;
errcode = getaddrinfo (host, NULL , &hints, &res);
if (errcode != 0)
{
INFO("getaddrinfo");
return -1;
}
INFO(STR("Host: %s", host));
if(res == NULL)
{
INFO(STR("NULL VALUE OF RES"));
}
else
{INFO(STR("IN ELSE PART"));
while (res)
{
INFO(STR("Inside while condition with res "));
switch (res->ai_family)
{
case AF_INET:
inet_ntop(AF_INET, &((struct sockaddr_in *) res->ai_addr)->sin_addr,addrstr, INET_ADDRSTRLEN);
break;
case AF_INET6:
inet_ntop(AF_INET6, &((struct sockaddr_in6 *) res->ai_addr)->sin6_addr ,addrstr, INET6_ADDRSTRLEN);
break;
}
res = res->ai_next;
}
}
INFO(STR("IPv%d address: %s ", res->ai_family == AF_INET6 ? 6 : 4, addrstr));
return 1;
}
这里我传递"::1"
作为主机地址,这是一个IPV6表单。但是我正在追踪
Host: ::1
IPv4 address: ::1
为什么选择IPv4 ???应该使用IPv6,因为在这种情况下地址族应该是AF_INET6
答案 0 :(得分:1)
res
指向NULL,因此您的上一个print语句无效,因为您认为ai_family != AF_INET6
必须为AF_INET
。
编辑:为了进一步解释,这里是你的代码问题,删除了不相关的点:
while (res)
{
res = res->ai_next;
}
INFO(STR("IPv%d address: %s ", res->ai_family == AF_INET6 ? 6 : 4, addrstr));
当res
循环结束时,问问自己while
的价值是什么。