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)

STANDARDS

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