socket_fastopen(3)

✨ socket_fastopen ✨

okay bestie, so this is a lil page from the Library Functions Manual about socket_fastopen(3) — yes that's the whole vibe, we're doing TCP Fast Open on the server side today, and honestly? iconic. 💅

---

🎀 NAME 🎀

socket_fastopen — turning on TCP Fast Open for a server-side TCP socket, no cap ✨

---

🦋 SYNTAX 🦋

#include <libowfat/socket.h>

int socket_fastopen(int s);

like literally just that. one include, one call, we're so back 🫶

---

🌸 DESCRIPTION 🌸

okay so socket_fastopen does exactly what it says on the tin: it enables TCP Fast Open support on a server-side TCP socket. that's the whole job. main character energy fr fr 👑

the timing matters though!! you gotta call this before socket_listen(). like, before. not after. not during. before. the way that order is non-negotiable 😭

now, plot twist: if your platform just does not support this functionality, it returns -1 and sets errno to ENOPROTOOPT — or ENOSYS if the platform doesn't even define ENOPROTOOPT. so yeah, sometimes the platform is the problem, not you. 💀

normally though? socket_fastopen returns 0. and if anything goes wrong, it returns -1 and sets errno appropriately. simple as that, periodt ✨

ngl, that -1 return is your vibe check — if you see it, something said no. go check errno, bestie. 🔥

---

🌈 EXAMPLE 🌈

here's the whole lil routine, exactly as it's written:

#include <libowfat/socket.h>

int s;
char ip[4];
uint16 p;

s = socket_tcp4b();
socket_fastopen(s);
socket_bind4_reuse(s,ip,p);
socket_listen(16);

see how socket_fastopen(s) comes in before socket_listen(16)? that's the order, bestie. we love a sequence 🎀

---

💖 SEE ALSO 💖

• socket_fastopen_connect4(3)
• socket_fastopen_connect6(3)

go read those too, they're the client-side besties 🦋

---

and that's the page!! this one lives in the Library Functions Manual and it's filed under socket_fastopen(3) — shoutout to the man page for being short, sweet, and to the point. ily, go enable TCP Fast Open responsibly 🫶✨💖