Copyright (c) 1995 Michael Chastain (firstname.lastname@example.org), 15 April 1995. %%%LICENSE_START(GPLv2+_DOC_FULL) This is free documentation; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. The GNU General Public License's references to "object code" and "executables" are to be interpreted as the output of any document formatting or type...
NAMEsocketcall - socket system calls
int socketcall(int call, unsigned long *args);
DESCRIPTIONsocketcall() 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().
CONFORMING TOThis call is specific to Linux, and should not be used in programs intended to be portable.
NOTESOn a 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.