Tribblix: manual page: socket.h.3head

SOCKET.H(3HEAD) Headers SOCKET.H(3HEAD)

NAME

socket.h, socket, CMSG_DATA, CMSG_FIRSTHDR, CMSG_LEN, CMSG_NXTHDR,
CMSG_SPACE - Internet Protocol family

SYNOPSIS

#include <sys/socket.h>

DESCRIPTION

The <sys/socket.h> header defines the unsigned integral type
sa_family_t through typedef.

The <sys/socket.h> header defines the sockaddr structure that
includes the following members:

sa_family_t sa_family /* address family */
char sa_data[] /* socket address (variable-length
data) */

libxnet Interfaces
The <sys/socket.h> header defines the msghdr structure for libxnet
interfaces that includes the following members:

void *msg_name /* optional address */
socklen_t msg_namelen /* size of address */
struct iovec *msg_iov /* scatter/gather array */
int msg_iovlen /* members in msg_iov */
void *msg_control /* ancillary data, see below */
socklen_t msg_controllen /* ancillary data buffer len */
int msg_flags /* flags on received message */

The <sys/socket.h> header defines the cmsghdr structure for libxnet
that includes the following members:

socklen_t cmsg_len /* data byte count, including hdr */
int cmsg_level /* originating protocol */
int cmsg_type /* protocol-specific type */

Ancillary data consists of a sequence of pairs, each consisting of a
cmsghdr structure followed by a data array. The data array contains
the ancillary data message, and the cmsghdr structure contains
descriptive information that allows an application to correctly parse
the data.

The values for cmsg_level will be legal values for the level argument
to the getsockopt() and setsockopt() functions. The SCM_RIGHTS type
is supported for level SOL_SOCKET.

Ancillary data is also possible at the socket level. The
<sys/socket.h> header defines the following macros for use as the
cmsg_type values when cmsg_level is SOL_SOCKET.

SCM_RIGHTS
Indicates that the data array contains the access
rights (set of open file descriptors) to be sent or
received. Each file descriptor requires one int to send
or receive.

SCM_UCRED
Indicates that the data array contains a ucred_t to be
received. The ucred_t is the credential of the sending
process at the time the message was sent. This is a
Sun-specific, Evolving interface. See ucred_get(3C).

The IPv4 ancillary data formats are listed below by cmsg_level and
cmsg_type, along with the associated payload for each.

IPPROTO_IP, IP_RECVDSTADDR -- SOCK_DGRAM only

ipaddr_t, IP address

IPPROTO_IP, IP_RECVIF

uint_t, ifIndex number

IPPROTO_IP, IP_RECVOPTS -- SOCK_DGRAM only

variable-length IP options, up to 40 bytes

IPPROTO_IP, IP_RECVPKTINFO -- SOCK_DGRAM only

in_pktinfo_t

IPPROTO_IP, IP_RECVSLLA -- SOCK_DGRAM only

struct sockaddr_dl, link layer address

IPPROTO_IP, IP_RECVTTL -- SOCK_DGRAM only

uint8_t, the IP TTL (time to live)

IPPROTO_IP, IP_RECVTOS

uint8_t, the IP TOS (type of service)

SOL_SOCKET, SO_UCRED

ucred_t

The IPv6 ancillary data formats are listed below by cmsg_level and
cmsg_type, along with the associated payload for each.

IPPROTO_IPV6, IPV6_PKTINFO

in_pktinfo_t

IPPROTO_IPV6, IPV6_TCLASS

uint_t

IPPROTO_IPV6, IPV6_PATHMTU

ip6_mtuinfo

IPPROTO_IPV6, IPV6_HOPLIMIT

uint_t

IPPROTO_IPV6, IPV6_HOPOPTS

variable-length IPv6 options

IPPROTO_IPV6, IPV6_DSTOPTS

variable-length IPv6 options

IPPROTO_IPV6, IPV6_RTHDR

variable-length IPv6 options

IPPROTO_IPV6, IPV6_DSTOPTS

variable-length IPv6 options

The <sys/socket.h> header defines the following macros to gain access
to the data arrays in the ancillary data associated with a message
header:

CMSG_DATA(cmsg)

If the argument is a pointer to a cmsghdr structure, this macro
returns an unsigned character pointer to the data array
associated with the cmsghdr structure.

CMSG_NXTHDR(mhdr, cmsg)

If the first argument is a pointer to a msghdr structure and the
second argument is a pointer to a cmsghdr structure in the
ancillary data, pointed to by the msg_control field of that
msghdr structure, this macro returns a pointer to the next
cmsghdr structure, or a null pointer if this structure is the
last cmsghdr in the ancillary data.

CMSG_FIRSTHDR(mhdr)

If the argument is a pointer to a msghdr structure, this macro
returns a pointer to the first cmsghdr structure in the ancillary
data associated with this msghdr structure, or a null pointer if
there is no ancillary data associated with the msghdr structure.

CMSG_SPACE(len)

Given the length of an ancillary data object, CMSG_SPACE()
returns the space required by the object and its cmsghdr
structure, including any padding needed to satisfy alignment
requirements. This macro can be used, for example, to allocate
space dynamically for the ancillary data. This macro should not
be used to initialize the cmsg_len member of a cmsghdr structure.
Use the CMSG_LEN() macro instead.

CMSG_LEN(len)

Given the length of an ancillary data object, CMSG_LEN() returns
the value to store in the cmsg_len member of the cmsghdr
structure, taking into account any padding needed to satisfy
alignment requirements.

The <sys/socket.h> header defines the linger structure that includes
the following members:

int l_onoff /* indicates whether linger option is enabled */
int l_linger /* linger time, in seconds */

The <sys/socket.h> header defines the following macros which indicate
types of sockets:

SOCK_DGRAM
Datagram socket

SOCK_STREAM
Byte-stream socket

SOCK_RAW
Raw protocol interface

SOCK_RDM
Reliably delivered message

SOCK_SEQPACKET
Sequenced-packet socket

In some cases, the above types are bitwise-inclusive-ORed with zero
or more of the following macros which modify the socket's default
behavior:

SOCK_CLOEXEC
The socket should have the close-on-exec,
FD_CLOEXEC file descriptor flag set on it. The
socket will be closed when the process calls any of
the exec(2) family of functions.

SOCK_CLOFORK
The socket should have the close-on-fork,
FD_CLOFORK file descriptor flag set on it. The
socket will be closed in any child process created
with the fork(2) family of functions.

SOCK_NDELAY
The socket should have the O_NDELAY flag set. See
open(2) for a discussion of the specific non-
blocking behavior this implies.

SOCK_NONBLOCK
The socket should have the O_NONBLOCK flag set. See
open(2) for a discussion of the specific non-
blocking behavior this implies.

The <sys/socket.h> header defines the following macros for use as the
level argument of setsockopt() and getsockopt().

SOL_SOCKET
Options to be accessed at the socket level, not the
protocol level.

SOL_ROUTE
Options to be accessed at the routing socket level, not
the protocol level.

The <sys/socket.h> header defines the following macros for use as the
option_name argument of getsockopt() or setsockopt() calls:

SO_DEBUG
Debugging information is being recorded.

SO_ACCEPTCONN
Socket is accepting connections.

SO_BROADCAST
Transmission of broadcast messages is supported.

SO_REUSEADDR
Reuse of local addresses is supported.

SO_KEEPALIVE
Connections are kept alive with periodic messages.

SO_LINGER
Socket lingers on close.

SO_OOBINLINE
Out-of-band data is transmitted in line.

SO_SNDBUF
Send buffer size.

SO_RCVBUF
Receive buffer size.

SO_ERROR
Socket error status.

SO_DOMAIN
Socket family.

SO_TYPE
Socket type.

SO_PROTOCOL, SO_PROTOTYPE
Socket protocol.

SO_RECVUCRED
Request the reception of user credential ancillary
data. This is a Sun-specific, Evolving interface.
See ucred_get(3C).

SO_MAC_EXEMPT
Mandatory Access Control (MAC) exemption for
unlabeled peers. This option is available only if
the system is configured with Trusted Extensions.

SO_ALLZONES
Bypass zone boundaries (privileged).

The <sys/socket.h> header defines the following macros for use as the
valid values for the msg_flags field in the msghdr structure, or the
flags parameter in recvfrom(), recvmsg(), sendto(), or sendmsg()
calls:

MSG_CTRUNC
Control data truncated.

MSG_EOR
Terminates a record (if supported by the protocol).

MSG_OOB
Out-of-band data.

MSG_PEEK
Leave received data in queue.

MSG_TRUNC
Normal data truncated.

MSG_WAITALL
Wait for complete message.

MSG_NOSIGNAL
Do not generate SIGPIPE signal.

MSG_CMSG_CLOEXEC
When receiving a message with the SCM_RIGHTS ancillary
data present, all file descriptors should have the
close-on-exec, FD_CLOEXEC flag set on them. They will
be closed when the process successfully calls any of
the exec(2) family of functions. This has no effect
when sending SCM_RIGHTS ancillary data.

MSG_CMSG_CLOFORK
When receiving a message with the SCM_RIGHTS ancillary
data present, all file descriptors should have the
close-on-fork, FD_CLOFORK flag set on them. They will
be closed in any child processes created with the
fork(2) family of functions. This has no effect when
sending SCM_RIGHTS ancillary data.

The <sys/socket.h> header defines the following macros:

AF_UNIX
UNIX domain sockets

AF_INET
Internet domain sockets

The <sys/socket.h> header defines the following macros:

SHUT_RD
Disables further receive operations.

SHUT_WR
Disables further send operations.

SHUT_RDWR
Disables further send and receive operations.

libsocket Interfaces
The <sys/socket.h> header defines the msghdr structure for libsocket
interfaces that includes the following members:

void *msg_name /* optional address */
socklen_t msg_namelen /* size of address */
struct iovec *msg_iov /* scatter/gather array */
int msg_iovlen /* # elements in msg_iov */
caddr_t msg_accrights /* access rights sent/received */

The msg_name and msg_namelen parameters specify the destination
address when the socket is unconnected The msg_name can be specified
as a NULL pointer if no names are desired or required. The msg_iov
and msg_iovlen parameters describe the scatter-gather locations, as
described in read(2). The msg_accrights parameter specifies the
buffer in which access rights sent along with the message are
received. The msg_accrightslen specifies the length of the buffer.

ATTRIBUTES

NAME

SYNOPSIS

DESCRIPTION

ATTRIBUTES

SEE ALSO