提问人:Dark Sorrow 提问时间:4/11/2023 最后编辑:dbushDark Sorrow 更新时间:4/11/2023 访问量:93
将 IPv4 地址从 ifaddrs 结构分配给sockaddr_in结构
Assigning IPv4 Address from ifaddrs Structure to sockaddr_in Structure
问:
我正在开发一个 UDP 服务器应用程序。
我希望将我的服务器套接字绑定到特定接口(从配置文件中读取)。在这种情况下.
我用来读取有关当前网络接口的所有信息。
然后,我遍历返回的链表,并根据我想要的接口检查每个接口的名称。
找到匹配项后,我计划从中提取 IPv4 地址并将其分配给对象。
目前我不确定如何传递,或者这是我遵循的正确/推荐的方法。eth0
getifaddrs
getifaddrs
struct ifaddrs
struct sockaddr_in
struct ifaddrs->ifa_addr->sa_data
struct sockaddr_in.sin_addr.s_addr
法典:
bool start_server(void)
{
struct sockaddr_in server_address;
struct ifaddrs *ifaddr;
int return_value;
try
{
this->sock_fd = socket(AF_INET, SOCK_DGRAM, 0);
if (this->sock_fd < 0)
{
//TODO : Log Error
return false;
}
// Initialize and configure struct sockaddr_in server_address
std::memset(&server_address, sizeof(sockaddr_in), 0); // Initialize struct sockaddr_in server_address to 0
server_address.sin_family = AF_INET;
server_address.sin_port = htons(6666); //We are using the port 6666
//Get IP address from the interface (eth0 currently) -> Interface name to be read from the configuration file
return_value = getifaddrs(&ifaddr);
if (return_value < 0) //On error, -1 is returned
{
//TODO : Log Error
return false;
}
for (struct ifaddrs *ifa; ifa != nullptr; ifa = ifaddr->ifa_next)//ifa stand for interface address
{
if (std::strcmp(ifa->ifa_name, "eth0") == 0) //We check the interface name in the linked Strings are exact match
{
if (ifa->ifa_addr == nullptr)
{
//TODO : Log Error - Selected interface doesn't have an assoiciated IP address
break;
}
else
{
server_address.sin_addr.s_addr = inet_addr(ifa->ifa_addr->sa_data); //I am unsure will this work or if this is the right approach
break;
}
}
}
freeifaddrs(ifaddr); //Free up memeory allocated by getifaddrs. Prevents Memory Leaks
}
答:
3赞
dbush
4/11/2023
#1
该成员是指向 .首先,您要通过检查是否设置为 来确保它适用于 IPv4 地址,如果是,则可以将其复制到 .ifa_addr
struct sockaddr
sa_family
AF_INET
memcpy
struct sockadr_in
for (struct ifaddrs *ifa = ifaddr; ifa != nullptr; ifa = ifaddr->ifa_next)
{
if (std::strcmp(ifa->ifa_name, "eth0") == 0)
{
if (ifa->ifa_addr == nullptr)
{
//TODO : Log Error -
//Selected interface doesn't have an assoiciated IP address
break;
}
else if (ifa->ifa_addr->sa_family == AF_INET)
{
memcpy(&server_address.sin_addr, ifa->ifa_addr,
sizeof(server_address.sin_addr));
break;
}
}
}
评论
C
并且是不同的语言。标签需要编辑。C++
this->
std::