bpf_strnstr(9)

📦 version 7.3.1, in nixpkgs unstable

💅 bpf_strnstr(9)

ok so this is a page from the Kernel API Manual (section 9, the kernel-funcs girlies ✨), and it's all about bpf_strnstr — the function that finds the first substring in a length-limited string. like strnstr but make it BPF 🎀

✨ NAME ✨

bpf_strnstr — find the first substring in a length-limited string 🔍

🌸 SYNOPSIS 🌸

__bpf_kfunc int bpf_strnstr (const char *s1__ign , const char *s2__ign ,
       size_t len );

🦋 ARGUMENTS 🦋

  • s1__ign — the string you're searching in, i.e. the one getting snooped through 🕵️‍♀️
  • s2__ign — the string you're searching for, the one you're hoping to find 🎯
  • len — the maximum number of characters to search, so bestie you're only looking at the first len chars and nothing past that, periodt ✋

💖 RETURN 💖

  • >=0 — the index of the first character of the first occurrence of s2__ign within the first len characters of s1__ign 🥳 found it!!
  • -ENOENT — s2__ign was not found in the first len characters of s1__ign 😭 it's not there, bestie
  • -EFAULT — cannot read one of the strings 💀 something's unreachable
  • -E2BIG — one of the strings is too large, like it's giving too much 🫠
  • -ERANGE — one of the strings is outside of kernel address space 🚫 not our territory

👑 SEE ALSO 👑

Kernel file ./kernel/bpf/helpers.c — and honestly the whole friend group is here, so let's give them all their moment 💅

ok that's the whole page bestie, no skips, no gatekeeping 🫶

and that's a wrap!! this one lives in ./kernel/bpf and the version date on it is October 2026 — so yeah, bookmark it, screenshot it, send it to the group chat 🌈💜 mwah 💋

📦 where this page comes from