SOCKETCALL(2)                                                           Linux Programmer's Manual                                                          SOCKETCALL(2)

NAME
       socketcall - socket system calls

SYNOPSIS
       #include <linux/net.h>        /* Definition of SYS_* constants */
       #include <sys/syscall.h>      /* Definition of SYS_socketcall */
       #include <unistd.h>

       int syscall(SYS_socketcall, int call, unsigned long *args);

       Note: glibc provides no wrapper for socketcall(), necessitating the use of syscall(2).

DESCRIPTION
       socketcall() is a common kernel entry point for the socket system calls.  call determines which socket function to invoke.  args points to a block containing the
       actual arguments, which are passed through to the appropriate call.

       User programs should call the appropriate functions by their usual names.  Only standard library implementors and kernel hackers need to know about socketcall().

       call              Man page
       SYS_SOCKET        socket(2)
       SYS_BIND          bind(2)
       SYS_CONNECT       connect(2)
       SYS_LISTEN        listen(2)
       SYS_ACCEPT        accept(2)
       SYS_GETSOCKNAME   getsockname(2)
       SYS_GETPEERNAME   getpeername(2)
       SYS_SOCKETPAIR    socketpair(2)
       SYS_SEND          send(2)
       SYS_RECV          recv(2)
       SYS_SENDTO        sendto(2)
       SYS_RECVFROM      recvfrom(2)
       SYS_SHUTDOWN      shutdown(2)
       SYS_SETSOCKOPT    setsockopt(2)
       SYS_GETSOCKOPT    getsockopt(2)
       SYS_SENDMSG       sendmsg(2)
       SYS_RECVMSG       recvmsg(2)
       SYS_ACCEPT4       accept4(2)
       SYS_RECVMMSG      recvmmsg(2)
       SYS_SENDMMSG      sendmmsg(2)

CONFORMING TO
       This call is specific to Linux, and should not be used in programs intended to be portable.

NOTES
       On some architectures—for example, x86-64 and ARM—there is no socketcall() system call; instead socket(2), accept(2), bind(2), and so on really  are  implemented
       as separate system calls.

       On  x86-32,  socketcall()  was historically the only entry point for the sockets API.  However, starting in Linux 4.3, direct system calls are provided on x86-32
       for the sockets API.  This facilitates the creation of seccomp(2) filters that filter sockets system calls (for new user-space binaries that are compiled to  use
       the new entry points) and also provides a (very) small performance improvement.

SEE ALSO
       accept(2),  bind(2), connect(2), getpeername(2), getsockname(2), getsockopt(2), listen(2), recv(2), recvfrom(2), recvmsg(2), send(2), sendmsg(2), sendto(2), set‐
       sockopt(2), shutdown(2), socket(2), socketpair(2)

Linux                                                                          2021-03-22                                                                  SOCKETCALL(2)