socketcall(2) — Linux manual page


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

NAME         top

       socketcall - socket system calls

SYNOPSIS         top

       #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         top

       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         top

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

NOTES         top

       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         top

       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)

COLOPHON         top

       This page is part of release 5.13 of the Linux man-pages project.
       A description of the project, information about reporting bugs,
       and the latest version of this page, can be found at

Linux                          2021-03-22                  SOCKETCALL(2)

Pages that refer to this page: syscalls(2)seccomp_syscall_resolve_name(3)