NAME

       socketcall - socket system calls

LIBRARY

       Standard C library (libc, -lc)

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)

VERSIONS

       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.

STANDARDS

       Linux.

       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),  setsockopt(2),  shutdown(2),  socket(2),
       socketpair(2)