Socket address structure in lt;syssocket.hgt;struct sockaddr{u_sh.ppt

Socket Programming Socket address structure in sys/socket.h: struct sockaddr{ u_short sa_family; /* address family: AF_xxx value */ char sa_data[14]; /* up to 14 bytes of protocol- */ /* specific address */ } Socket Programming Socket address structure in netinet/in.h: (Internet family) struct in_addr{ u_long s_addr; /* 32-bit netid/hostid */ /* network byte ordered */ } Socket Programming struct sockaddr_in{ short sin_family; /* AF_INET */ u_short sin_port; /* 16-bit port number */ /* network byte ordered */ struct in_addr sin_addr; /* 32-bit netid/hostid */ /* network byte ordered */ char sin_zero[8]; /* unused */ } Socket Programming socket : specify the type of communication protocol desired (TCP, UDP etc.) #include sys/types.h #include sys/socket.h int socket(int family, int type, int protocol); family: AF_UNIX (UNIX internal protocol) AF_INET (Internet protocols) AF_NS (Xerox NS protocols) AF_IMPLINK (IMP link layer) (AF: address family) Socket Programming type: SOCK_STREAM (stream socket, TCP) SOCK_DGRAM (datagram socket, UDP) SOCK_RAW (raw socket) SOCK_SEQPACKET (sequenced packet socket) SOCK_RDM (reliably delivered message socket) (not implemented yet) protocol: typically set to 0 for most user applications The output of the system call is the socket descriptor. Socket Programming bind: assign a name to an unnamed socket #include sys/types.h #include sys/socket.h int bind(int sockfd, struct sockaddr *myaddr, int addrlen); sockfd: socket descriptor (return by*myaddr: a pointer to a protocol-specific address addrlen: the size of this address structure The output 0 if success; otherwise, it fails. Socket Programming connect: establish a connection with a server #include sys/types.h #include sys/socket.h int connect (int sockfd, struct sockaddr *servaddr, int addrlen); same as the system call bind. The output 0 if success; otherwise, it fails. Socket