STRUCT MSGBUF(9)

💅 struct msgbuf — Kernel API Manual, section 9, bestie

okay so before we even get into it: this page lives in section 9 of the Kernel API Manual, and the thing we're talking about is struct msgbuf. that's the whole vibe. now let's go 🫶

✨ NAME ✨

struct msgbuf — the buffer struct you use to construct SSH messages. that's it, that's the job, and she does it slayfully 💖

🌸 SYNOPSIS 🌸

struct msgbuf {
    u8 *begin;
    u8 *end;
    u8 *ptr;
 };

literally just three pointers. three little icons. nothing else. no cap, that's the entire struct 😌

🎀 Members 🎀

• begin — pointer to the beginning of the allocated buffer space. she's the start of the party, the first element, the origin story ✨
• end — pointer to the end (one past last element) of the allocated buffer space. yes bestie, one past the last element — that classic one-past-the-end situation, that's not a typo, that's the whole bit 💅
• ptr — pointer to the first free element in the buffer. this is where the next thing gets written. the empty seat at the table, the available vibe 🌈

👑 SEE ALSO 👑

• Kernel file ./drivers/platform/surface/aggregator/ssh_msgb.h — go read the source, iykyk 🦋

and the whole msgb_ friend group, all iconics, all linked:

• msgb_init(9)
• msgb_bytes_used(9)
• msgb_push_u16(9)
• msgb_push_syn(9)
• msgb_push_buf(9)
• msgb_push_crc(9)
• msgb_push_frame(9)
• msgb_push_ack(9)
• msgb_push_nak(9)
• msgb_push_cmd(9)

ok real talk for a sec: the pointers don't manage themselves, bestie. begin, end and ptr are just describing the space — keeping them honest is on you 🙈

and that's the page!! mwah 💋 this came from the kernel source tree at ./drivers/platform/surface/agg..., dated October 2026, and it's filed under struct msgbuf(9). periodt. 🍓🧚‍♀️