socketcall(2)		       System Calls Manual		   socketcall(2)

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  appropri-
     ate call.

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

     tab(:);  l	 l.   call:Man page T{ SYS_SOCKET T}:T{ socket(2) T} T{ SYS_BIND
     T}:T{ bind(2) T} T{ SYS_CONNECT T}:T{ connect(2)  T}  T{  SYS_LISTEN  T}:T{
     listen(2) T} T{ SYS_ACCEPT T}:T{ accept(2) T} T{ SYS_GETSOCKNAME T}:T{ get-
     sockname(2) T} T{ SYS_GETPEERNAME T}:T{ getpeername(2) T} T{ SYS_SOCKETPAIR
     T}:T{  socketpair(2)  T}  T{  SYS_SEND  T}:T{  send(2) T} T{ SYS_RECV T}:T{
     recv(2)  T}  T{  SYS_SENDTO  T}:T{	 sendto(2)  T}	T{  SYS_RECVFROM   T}:T{
     recvfrom(2) T} T{ SYS_SHUTDOWN T}:T{ shutdown(2) T} T{ SYS_SETSOCKOPT T}:T{
     setsockopt(2)  T}	T{  SYS_GETSOCKOPT T}:T{ getsockopt(2) T} T{ SYS_SENDMSG
     T}:T{ sendmsg(2) T} T{ SYS_RECVMSG T}:T{ recvmsg(2) T} T{ SYS_ACCEPT4 T}:T{
     accept4(2) T} T{ SYS_RECVMMSG T}:T{ recvmmsg(2) T}	 T{  SYS_SENDMMSG  T}:T{
     sendmmsg(2) T}

VERSIONS
     On	 some  architectures --for example, x86-64 and ARM-- there is no socket-
     call() 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 sock-
     ets 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), getsock-
     opt(2), listen(2), recv(2), recvfrom(2), recvmsg(2),  send(2),  sendmsg(2),
     sendto(2), setsockopt(2), shutdown(2), socket(2), socketpair(2)

Linux man-pages 6.18		   2026-02-08			   socketcall(2)