Structures

Structures of the BSD Socket. More...

Structures
struct	SOCKADDR
	Generic Socket Address structure. More...
struct	IN_ADDR
	Generic IPv4 Address structure. More...
struct	IN6_ADDR
	Generic IPv6 Address structure. More...
struct	SOCKADDR_IN
	IPv4 Socket Address structure. More...
struct	SOCKADDR_IN6
	IPv6 Socket Address structure. More...
struct	SOCKADDR_STORAGE
	Socket Address storage structure. More...
struct	HOSTENT
	BSD Host Entry structure. More...
struct	timeval
	BSD timeval structure. More...
struct	fd_set
	BSD fd_set structure. More...
struct	IOVEC
	BSD scatter/gather array of items. More...
struct	MSGHDR
	BSD message header structure. More...
struct	CMSGHDR
	BSD cmsg header structure. More...
union	IN_ADDR.u
	Union members for different data accesses. More...
struct	IN_ADDR.u.s_b
	IP address, byte access. More...
struct	IN_ADDR.u.s_w
	IP address, unsigned short integer access. More...
union	IN6_ADDR.u
	Union members for different data accesses. More...

Description

Structures of the BSD Socket.

---

Data Structure Documentation

SOCKADDR

struct SOCKADDR

Generic Socket Address structure.

Parameter for:

• accept, bind, connect, getpeername, getsockname, recvfrom, sendto

Data Fields
int8_t	sa_data[14]	Direct address (up to 14 bytes)
uint16_t	sa_family	Address family.

IN_ADDR

struct IN_ADDR

Generic IPv4 Address structure.

Parameter for:

• SOCKADDR_IN structure
• inet_ntoa
• inet_aton

Data Fields
union IN_ADDR.u	u	Union members for different data accesses.

IN6_ADDR

struct IN6_ADDR

Generic IPv6 Address structure.

Parameter for:

• SOCKADDR_IN6 structure

Data Fields
union IN6_ADDR.u	u	Union members for different data accesses.

SOCKADDR_IN

struct SOCKADDR_IN

IPv4 Socket Address structure.

Used in:

• bind, connect, sendto

Data Fields
IN_ADDR	sin_addr	IP address.
int16_t	sin_family	Socket domain.
uint16_t	sin_port	Port.
int8_t	sin_zero[8]	reserved

SOCKADDR_IN6

struct SOCKADDR_IN6

IPv6 Socket Address structure.

Used in:

• bind, connect, sendto

Data Fields
IN6_ADDR	sin6_addr	IP6 address.
int16_t	sin6_family	Socket domain.
uint32_t	sin6_flowinfo	IP6 flow information.
uint16_t	sin6_port	Port.

SOCKADDR_STORAGE

struct SOCKADDR_STORAGE

Socket Address storage structure.

The structure is sufficiently large to store SOCKADDR_IN or SOCKADDR_IN6 address information.

Data Fields
int32_t	__ss_align	reserved, structure alignment
int8_t	__ss_pad1[2]	reserved
int8_t	__ss_pad2[16]	reserved
int16_t	ss_family	Address family.

HOSTENT

struct HOSTENT

BSD Host Entry structure.

Returned by:

• gethostbyname

Data Fields
char **	h_addr_list	Pointer to an array of IPv4 addresses.
int16_t	h_addrtype	Address Type: AF_INET, AF_NETBIOS.
char **	h_aliases	Pointer to an array of alias names.
int16_t	h_length	Length of address in bytes.
char *	h_name	Official name of host.

timeval

struct timeval

BSD timeval structure.

Used in:

• select

Data Fields
uint32_t	tv_sec	Time interval: seconds.
uint32_t	tv_usec	Time interval: microseconds.

fd_set

struct fd_set

BSD fd_set structure.

Used in:

• select

Data Fields
uint32_t	fd_bits[(FD_SETSIZE+31)> >5]	Set of sockets bit-mask.

IOVEC

struct IOVEC

BSD scatter/gather array of items.

Used in:

• recvmsg
• sendmsg

Data Fields
void *	iov_base	Starting address.
uint32_t	iov_len	Number of bytes to transfer.

MSGHDR

struct MSGHDR

BSD message header structure.

Used in:

• recvmsg
• sendmsg

Data Fields
void *	msg_control	Ancillary data.
uint32_t	msg_controllen	Ancillary data buffer length.
int32_t	msg_flags	Flags on received message.
IOVEC *	msg_iov	An array of iovec buffers for the message.
int32_t	msg_iovlen	Number of elements in msg_iov.
void *	msg_name	Optional pointer to source address.
uint32_t	msg_namelen	Size of address buffer.

CMSGHDR

struct CMSGHDR

BSD cmsg header structure.

Used in:

• recvmsg
• sendmsg

Data Fields
uint32_t	cmsg_len	Data byte count, including the cmsghdr.
int32_t	cmsg_level	Originating protocol.
int32_t	cmsg_type	Protocol-specific type.

IN_ADDR.u

union IN_ADDR.u

Union members for different data accesses.

Data Fields
uint32_t	s_addr	IP address, unsigned integer access in network byte order.
struct IN_ADDR.u.s_b	s_b	IP address, byte access.
struct IN_ADDR.u.s_w	s_w	IP address, unsigned short integer access.

IN_ADDR.u.s_b

struct IN_ADDR.u.s_b

IP address, byte access.

Data Fields
uint8_t	s_b1	byte 1
uint8_t	s_b2	byte 2
uint8_t	s_b3	byte 3
uint8_t	s_b4	byte 4

IN_ADDR.u.s_w

struct IN_ADDR.u.s_w

IP address, unsigned short integer access.

Data Fields
uint16_t	s_w1	unsigned short integer 1
uint16_t	s_w2	unsigned short integer 2

IN6_ADDR.u

union IN6_ADDR.u

Union members for different data accesses.

Data Fields
uint8_t	s6_b[16]	IP6 address, array for byte access.
uint16_t	s6_w[8]	IP6 address, array for unsigned short integer access.