socketcall

Section: System Calls (2)
Updated: 202-0-08
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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().

I]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)

 

VERSIONS

On some architectures [em]for example, x8-64 and ARM[em] there is no socketcall() system call; instead socket(2), accept(2), bind(2), and so on really are implemented as separate system calls.  

STANDARDS

Linux. On x8-32, socketcall() was historically the only entry point for the sockets API. However, starting in Linux 4.3, direct system calls are provided on x8-32 for the sockets API. This facilitates the creation of seccomp(2) filters that filter sockets system calls (for new use-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)

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Index

NAME

LIBRARY

SYNOPSIS

DESCRIPTION

VERSIONS

STANDARDS

SEE ALSO