socketcall (2)

Leading comments

Copyright (c) 1995 Michael Chastain (mec@shell.portal.com), 15 April 1995.

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(The comments found at the beginning of the groff file "man2/socketcall.2".)

NAME

socketcall - socket system calls

SYNOPSIS

int socketcall(int call, unsigned long *args);

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().

CONFORMING TO

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

NOTES

On 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.

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)

COLOPHON

This page is part of release 4.04 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 www.kernel.org/doc/man-pages