sockaddr, sockaddr_storage, sockaddr_in, sockaddr_in6, sockaddr_un, socklen_t, in_addr, in6_addr,

sockaddr
              Describes a socket address.

       sockaddr_storage
              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.

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

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

   Internetdomainsocketssockaddr_in
              Describes an IPv4 Internet domain socket address.  The sin_port and sin_addr members are stored in
              network byte order.

       sockaddr_in6
              Describes an IPv6 Internet domain socket address.  The sin6_addr.s6_addr array is used to  contain
              a 128-bit IPv6 address, stored in network byte order.

   UNIXdomainsocketssockaddr_un
              Describes a UNIX domain socket address.

       POSIX.1-2001.

       socklen_t was invented by POSIX.  See also accept(2).

       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.

       Standard C library (libc)

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

socklen_t is also defined in <netdb.h>.

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

accept(2), bind(2), connect(2), getpeername(2), getsockname(2), getsockopt(2), sendto(2),  setsockopt(2),
       socket(2), socketpair(2), getaddrinfo(3), gethostbyaddr(3), getnameinfo(3), htonl(3), ipv6(7), socket(7)

Linux man-pages 6.9.1                              2024-05-02                                    sockaddr(3type)

       POSIX.1-2008.

#include<sys/socket.h>structsockaddr{sa_family_tsa_family;      /* Address family */
           charsa_data[];      /* Socket address */
       };structsockaddr_storage{sa_family_tss_family;      /* Address family */
       };typedef /* ... */ socklen_t;typedef /* ... */ sa_family_t;Internetdomainsockets#include<netinet/in.h>structsockaddr_in{sa_family_tsin_family;     /* AF_INET */
           in_port_tsin_port;       /* Port number */
           structin_addrsin_addr;       /* IPv4 address */
       };structsockaddr_in6{sa_family_tsin6_family;    /* AF_INET6 */
           in_port_tsin6_port;      /* Port number */
           uint32_tsin6_flowinfo;  /* IPv6 flow info */
           structin6_addrsin6_addr;      /* IPv6 address */
           uint32_tsin6_scope_id;  /* Set of interfaces for a scope */
       };structin_addr{in_addr_ts_addr;};structin6_addr{uint8_ts6_addr[16];};typedefuint32_tin_addr_t;typedefuint16_tin_port_t;UNIXdomainsockets#include<sys/un.h>structsockaddr_un{sa_family_tsun_family;     /* Address family */
           charsun_path[];     /* Socket pathname */
       };