sockaddr数据结构

struct sockaddr:用于描述IPV4协议:
目前主要使用sockaddr_in，传参时转换为(sockaddr*)指针
struct sockaddr_in {
sa_family_t sin_family; /* address family: AF_INET /地址结构类型ipv4或者IPv6
in_port_t sin_port; / port in network byte order /
struct in_addr sin_addr; / internet address /
};
/ Internet address. /
struct in_addr
{
uint32_t s_addr; / address in network byte order */
};