Socket

SOCKET WSAAPI socket(

  int af,//协议地址族

  int type,//协议套接字类型

  int protocol//传输层协议

);

Af	Meaning
AF_UNSPEC 0	The address family is unspecified.
AF_INET 2	The Internet Protocol version 4 (IPv4) address family.
AF_NETBIOS 17	The NetBIOS address family. This address family is only supported if a Windows Sockets provider for NetBIOS is installed.
AF_INET6 23	The Internet Protocol version 6 (IPv6) address family.
AF_IRDA 26	The Infrared Data Association (IrDA) address family. This address family is only supported if the computer has an infrared port and driver installed.
AF_BTM 32	The Bluetooth address family. This address family is only supported if a Bluetooth adapter is installed on Windows Server 2003 or later.

 

 

Type	Meaning
SOCK_STREAM 1	Provides sequenced, reliable, two-way, connection-based byte streams with an OOB data transmission mechanism. Uses the Transmission Control Protocol (TCP) for the Internet address family (AF_INET or AF_INET6).
SOCK_DGRAM 2	Supports datagrams, which are connectionless, unreliable buffers of a fixed (typically small) maximum length. Uses the User Datagram Protocol (UDP) for the Internet address family (AF_INET or AF_INET6).
SOCK_RAW 3	Provides a raw socket that allows an application to manipulate the next upper-layer protocol header. To manipulate the IPv4 header, the IP_HDRINCL socket option must be set on the socket. To manipulate the IPv6 header, the IPV6_HDRINCL socket option must be set on the socket.
SOCK_RDM 4	Provides a reliable message datagram. An example of this type is the Pragmatic General Multicast (PGM) multicast protocol implementation in Windows, often referred to as reliable multicast programming.
SOCK_SEQPACKET 5	Provides a pseudo-stream packet based on datagrams.

 

 

protocol	Meaning
IPPROTO_TCP 6	The Transmission Control Protocol (TCP). This is a possible value when the af parameter is AF_INET or AF_INET6 and the type parameter is SOCK_STREAM.
IPPROTO_UDP 17	The User Datagram Protocol (UDP). This is a possible value when the af parameter is AF_INET or AF_INET6 and the type parameter is SOCK_DGRAM.
IPPROTO_RM 113	The PGM protocol for reliable multicast. This is a possible value when the af parameter is AF_INET and the type parameter is SOCK_RDM. On the Windows SDK released for Windows Vista and later, this value is also called IPPROTO_PGM.

 

 

struct sockaddr {

        ushort  sa_family;

        char    sa_data[14];

};

struct sockaddr_in {

        short   sin_family;

        u_short sin_port;

        struct  in_addr sin_addr;//把IP地址保存为4字节数

        char    sin_zero[8];//填充项，使其与sockaddr结构一样长

};

//字节排序：主机对字节编号方式和网络不同
net to host long short

ntohl() ntohs()

htons() htonl()

 

sockaddr_in inter;

int nport=5050;

inter.sin_family=AF_INET;

inter.sin_addr.s_addr=inet_addr("127.0.0.1");

//IP地址→位无符长整形

inter.sin_port=htons(nport);

cout<<inter.sin_port;