sockaddr(3type) - Linux manual page (original) (raw)

sockaddr(3type) sockaddr(3type)

NAME top

   sockaddr, sockaddr_storage, sockaddr_in, sockaddr_in6,
   sockaddr_un, socklen_t, in_addr, in6_addr, in_addr_t, in_port_t, -
   socket address

LIBRARY top

   Standard C library (_libc_)

SYNOPSIS top

   **#include <sys/socket.h>**

   **struct sockaddr {**
       **sa_family_t     sa_family;** /* Address family */
       **char            sa_data[];** /* Socket address */
   **};**

   **struct sockaddr_storage {**
       **sa_family_t     ss_family;** /* Address family */
   **};**

   **typedef** /* ... */ **socklen_t;**
   **typedef** /* ... */ **sa_family_t;**

Internet domain sockets #include <netinet/in.h>

   **struct sockaddr_in {**
       **sa_family_t     sin_family;** /* **AF_INET** */
       **in_port_t       sin_port;** /* Port number */
       **struct in_addr  sin_addr;** /* IPv4 address */
   **};**

   **struct sockaddr_in6 {**
       **sa_family_t     sin6_family;** /* **AF_INET6** */
       **in_port_t       sin6_port;** /* Port number */
       **uint32_t        sin6_flowinfo;** /* IPv6 flow info */
       **struct in6_addr sin6_addr;** /* IPv6 address */
       **uint32_t        sin6_scope_id;** /* Set of interfaces for a scope */
   **};**

   **struct in_addr {**
       **in_addr_t s_addr;**
   **};**

   **struct in6_addr {**
       **uint8_t   s6_addr[16];**
   **};**

   **typedef uint32_t in_addr_t;**
   **typedef uint16_t in_port_t;**

UNIX domain sockets #include <sys/un.h>

   **struct sockaddr_un {**
       **sa_family_t     sun_family;** /* Address family */
       **char            sun_path[];** /* Socket pathname */
   **};**

DESCRIPTION top

   _sockaddr_
          Describes a socket address.

   _sockaddrstorage_
          A structure at least as large as any other _sockaddr_*
          address structures.  It's aligned so that a pointer to it
          can be cast as a pointer to other _sockaddr_* structures and
          used to access its fields.

   _socklent_
          Describes the length of a socket address.  This is an
          integer type of at least 32 bits.

   _safamilyt_
          Describes a socket's protocol family.  This is an unsigned
          integer type.

Internet domain sockets sockaddrin Describes an IPv4 Internet domain socket address. The sinport and sinaddr members are stored in network byte order.

   _sockaddrin6_
          Describes an IPv6 Internet domain socket address.  The
          _sin6addr.s6addr_ array is used to contain a 128-bit IPv6
          address, stored in network byte order.

UNIX domain sockets sockaddrun Describes a UNIX domain socket address.

STANDARDS top

   POSIX.1-2008.

HISTORY top

   POSIX.1-2001.

   _socklent_ was invented by POSIX.  See also [accept(2)](../man2/accept.2.html).

   These structures were invented before modern ISO C strict-aliasing
   rules.  If aliasing rules are applied strictly, these structures
   would be extremely difficult to use without invoking undefined
   behavior.  POSIX Issue 8 will fix this by requiring that
   implementations make sure that these structures can be safely used
   as they were designed.

NOTES top

   _socklent_ is also defined in _<netdb.h>_.

   _safamilyt_ is also defined in _<netinet/in.h>_ and _<sys/un.h>_.

SEE ALSO top

   [accept(2)](../man2/accept.2.html), [bind(2)](../man2/bind.2.html), [connect(2)](../man2/connect.2.html), [getpeername(2)](../man2/getpeername.2.html), [getsockname(2)](../man2/getsockname.2.html),
   [getsockopt(2)](../man2/getsockopt.2.html), [sendto(2)](../man2/sendto.2.html), [setsockopt(2)](../man2/setsockopt.2.html), [socket(2)](../man2/socket.2.html), [socketpair(2)](../man2/socketpair.2.html),
   [getaddrinfo(3)](../man3/getaddrinfo.3.html), [gethostbyaddr(3)](../man3/gethostbyaddr.3.html), [getnameinfo(3)](../man3/getnameinfo.3.html), [htonl(3)](../man3/htonl.3.html),
   [ipv6(7)](../man7/ipv6.7.html), [socket(7)](../man7/socket.7.html)

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Linux man-pages 6.10 2024-11-17 sockaddr(3type)