socketcall(2)

💖 socketcall(2) — the group chat of socket syscalls 💖

okay bestie, buckle up, because this is a System Calls Manual page and the star of the show is socketcall(2). no cap.

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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). 💅 like, glibc said "not my job" and honestly? fair.

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🦋 DESCRIPTION 🦋

so socketcall() is literally the common kernel entry point for the socket system calls. it's giving main character energy for the whole sockets API. 🌈

call tells it which socket function to invoke. args points to a block containing the actual arguments, which get 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(). that's the vibe check — if that's not you, keep scrolling, iykyk. 🙈

here's the whole roster, the entire friend group, no one left out:

• 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)

twenty entries, all accounted for, we ate that. 🍓

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🧚 VERSIONS 🧚

on some architectures — for example, x86-64 and ARM — there is no socketcall() system call at all. 😭 instead socket(2), accept(2), bind(2), and so on really are implemented as separate system calls. so they're not doing the group-chat thing, they're all individual main characters. 💀

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👑 STANDARDS 👑

Linux.

On x86-32, socketcall() was historically the only entry point for the sockets API. but 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. like, microscopic. a crumb of speed. but we respect it. 💜

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🌸 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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okay that's the whole page, you understood it perfectly, slay. 🎀

this icon was brought to you by Linux man-pages 6.20, dated 2026-02-08 — shoutout to the man-pages girlies keeping the docs ✨ immaculate ✨. periodt. 💅🔥