socketcall(2) System Calls Manual socketcall(2)
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)
VERSIONS
On some architectures—for example, x86-64 and ARM—there is no socket-
call() system call; instead socket(2), accept(2), bind(2), and so on
really are implemented as separate system calls.
STANDARDS
Linux.
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), get-
sockopt(2), listen(2), recv(2), recvfrom(2), recvmsg(2), send(2),
sendmsg(2), sendto(2), setsockopt(2), shutdown(2), socket(2), socket-
pair(2)
Linux man-pages 6.7 2023-10-31 socketcall(2)
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