PROLOG | NAME | SYNOPSIS | DESCRIPTION | APPLICATION USAGE | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT

netinet_in.h(0P)          POSIX Programmer's Manual         netinet_in.h(0P)

PROLOG         top

       This manual page is part of the POSIX Programmer's Manual.  The Linux
       implementation of this interface may differ (consult the
       corresponding Linux manual page for details of Linux behavior), or
       the interface may not be implemented on Linux.

NAME         top

       netinet/in.h — Internet address family

SYNOPSIS         top

       #include <netinet/in.h>

DESCRIPTION         top

       The <netinet/in.h> header shall define the following types:

       in_port_t Equivalent to the type uint16_t as described in
                 <inttypes.h>.

       in_addr_t Equivalent to the type uint32_t as described in
                 <inttypes.h>.

       The <netinet_in.h> header shall define the sa_family_t type as
       described in <sys/socket.h>.

       The <netinet_in.h> header shall define the uint8_t and uint32_t types
       as described in <inttypes.h>.  Inclusion of the <netinet/in.h> header
       may also make visible all symbols from <inttypes.h> and
       <sys/socket.h>.

       The <netinet/in.h> header shall define the in_addr structure, which
       shall include at least the following member:

           in_addr_t  s_addr

       The <netinet/in.h> header shall define the sockaddr_in structure,
       which shall include at least the following members:

           sa_family_t     sin_family   AF_INET.
           in_port_t       sin_port     Port number.
           struct in_addr  sin_addr     IP address.

       The sin_port and sin_addr members shall be in network byte order.

       The sockaddr_in structure is used to store addresses for the Internet
       address family.  Pointers to this type shall be cast by applications
       to struct sockaddr * for use with socket functions.

       The <netinet/in.h> header shall define the in6_addr structure, which
       shall include at least the following member:

           uint8_t s6_addr[16]

       This array is used to contain a 128-bit IPv6 address, stored in
       network byte order.

       The <netinet/in.h> header shall define the sockaddr_in6 structure,
       which shall include at least the following members:

           sa_family_t      sin6_family    AF_INET6.
           in_port_t        sin6_port      Port number.
           uint32_t         sin6_flowinfo  IPv6 traffic class and flow information.
           struct in6_addr  sin6_addr      IPv6 address.
           uint32_t         sin6_scope_id  Set of interfaces for a scope.

       The sin6_port and sin6_addr members shall be in network byte order.

       The sockaddr_in6 structure shall be set to zero by an application
       prior to using it, since implementations are free to have additional,
       implementation-defined fields in sockaddr_in6.

       The sin6_scope_id field is a 32-bit integer that identifies a set of
       interfaces as appropriate for the scope of the address carried in the
       sin6_addr field. For a link scope sin6_addr, the application shall
       ensure that sin6_scope_id is a link index. For a site scope
       sin6_addr, the application shall ensure that sin6_scope_id is a site
       index. The mapping of sin6_scope_id to an interface or set of
       interfaces is implementation-defined.

       The <netinet/in.h> header shall declare the following external
       variable:

           const struct in6_addr in6addr_any

       This variable is initialized by the system to contain the wildcard
       IPv6 address. The <netinet/in.h> header also defines the
       IN6ADDR_ANY_INIT macro. This macro must be constant at compile time
       and can be used to initialize a variable of type struct in6_addr to
       the IPv6 wildcard address.

       The <netinet/in.h> header shall declare the following external
       variable:

           const struct in6_addr in6addr_loopback

       This variable is initialized by the system to contain the loopback
       IPv6 address. The <netinet/in.h> header also defines the
       IN6ADDR_LOOPBACK_INIT macro. This macro must be constant at compile
       time and can be used to initialize a variable of type struct in6_addr
       to the IPv6 loopback address.

       The <netinet/in.h> header shall define the ipv6_mreq structure, which
       shall include at least the following members:

           struct in6_addr  ipv6mr_multiaddr  IPv6 multicast address.
           unsigned         ipv6mr_interface  Interface index.

       The <netinet/in.h> header shall define the following symbolic
       constants for use as values of the level argument of getsockopt() and
       setsockopt():

       IPPROTO_IP      Internet protocol.

       IPPROTO_IPV6    Internet Protocol Version 6.

       IPPROTO_ICMP    Control message protocol.

       IPPROTO_RAW     Raw IP Packets Protocol.

       IPPROTO_TCP     Transmission control protocol.

       IPPROTO_UDP     User datagram protocol.

       The <netinet/in.h> header shall define the following symbolic
       constants for use as destination addresses for connect(), sendmsg(),
       and sendto():

       INADDR_ANY      IPv4 local host address.

       INADDR_BROADCAST
                       IPv4 broadcast address.

       The <netinet/in.h> header shall define the following symbolic
       constant, with the value specified, to help applications declare
       buffers of the proper size to store IPv4 addresses in string form:

       INET_ADDRSTRLEN 16. Length of the string form for IP.

       The htonl(), htons(), ntohl(), and ntohs() functions shall be
       available as described in <arpa/inet.h>.  Inclusion of the
       <netinet/in.h> header may also make visible all symbols from
       <arpa/inet.h>.

       The <netinet/in.h> header shall define the following symbolic
       constant, with the value specified, to help applications declare
       buffers of the proper size to store IPv6 addresses in string form:

       INET6_ADDRSTRLEN
                       46. Length of the string form for IPv6.

       The <netinet/in.h> header shall define the following symbolic
       constants, with distinct integer values, for use in the option_name
       argument in the getsockopt() or setsockopt() functions at protocol
       level IPPROTO_IPV6:

       IPV6_JOIN_GROUP Join a multicast group.

       IPV6_LEAVE_GROUP
                       Quit a multicast group.

       IPV6_MULTICAST_HOPS
                       Multicast hop limit.

       IPV6_MULTICAST_IF
                       Interface to use for outgoing multicast packets.

       IPV6_MULTICAST_LOOP
                       Multicast packets are delivered back to the local
                       application.

       IPV6_UNICAST_HOPS
                       Unicast hop limit.

       IPV6_V6ONLY     Restrict AF_INET6 socket to IPv6 communications only.

       The <netinet/in.h> header shall define the following macros that test
       for special IPv6 addresses. Each macro is of type int and takes a
       single argument of type const struct in6_addr *:

       IN6_IS_ADDR_UNSPECIFIED
             Unspecified address.

       IN6_IS_ADDR_LOOPBACK
             Loopback address.

       IN6_IS_ADDR_MULTICAST
             Multicast address.

       IN6_IS_ADDR_LINKLOCAL
             Unicast link-local address.

       IN6_IS_ADDR_SITELOCAL
             Unicast site-local address.

       IN6_IS_ADDR_V4MAPPED
             IPv4 mapped address.

       IN6_IS_ADDR_V4COMPAT
             IPv4-compatible address.

       IN6_IS_ADDR_MC_NODELOCAL
             Multicast node-local address.

       IN6_IS_ADDR_MC_LINKLOCAL
             Multicast link-local address.

       IN6_IS_ADDR_MC_SITELOCAL
             Multicast site-local address.

       IN6_IS_ADDR_MC_ORGLOCAL
             Multicast organization-local address.

       IN6_IS_ADDR_MC_GLOBAL
             Multicast global address.

       The following sections are informative.

APPLICATION USAGE         top

       None.

RATIONALE         top

       None.

FUTURE DIRECTIONS         top

       None.

SEE ALSO         top

       Section 4.9, Host and Network Byte Orders, arpa_inet.h(0p),
       inttypes.h(0p), sys_socket.h(0p)

       The System Interfaces volume of POSIX.1‐2008, connect(3p),
       getsockopt(3p), htonl(3p), sendmsg(3p), sendto(3p), setsockopt(3p)

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The Open
       Group Base Specifications Issue 7, Copyright (C) 2013 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
       applied.) In the event of any discrepancy between this version and
       the original IEEE and The Open Group Standard, the original IEEE and
       The Open Group Standard is the referee document. The original
       Standard can be obtained online at http://www.unix.org/online.html .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the
       source files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                 2013                    netinet_in.h(0P)