ib_cm_handler(9)

📦 version 7.3.1, in nixpkgs unstable

✨ ib_cm_handler(9) ✨

okay bestie, we're in the Kernel API Manual today and this one is ib_cm_handler — the user-defined callback that processes communication events 💅 like, you write it, the kernel calls it, it's giving "you're the main character of this event loop" energy 🎀

🌸 SYNOPSIS 🌸

int ib_cm_handler (struct ib_cm_id *cm_id , const struct ib_cm_event
*event );

literally just one function signature, no cap 🫶

🦋 ARGUMENTS 🦋

  • cm_id — the communication identifier that's associated with the event being reported. that's your girl 💖
  • event — the actual info about the communication event that went down 👑

💜 DESCRIPTION 💜

okay so here's the tea ☕ — when IB_CM_REQ_RECEIVED and IB_CM_SIDR_REQ_RECEIVED communication events get generated as a result of listen requests, that results in the allocation of a new cm_id ✨ and that shiny new cm_id gets returned to the user through this callback. and heads up: clients are responsible for destroying the new cm_id — yes, you, bestie, it's your job 🙈

for peer-to-peer IB_CM_REQ_RECEIVED and all other events, the returned cm_id corresponds to a user's existing communication identifier. so no new allocation, it's just the one you already had 💫

🚨 important safety moment 🚨 users may not call ib_destroy_cm_id while in the context of this callback. like, do not do it, fr fr 😭 however — returning a non-zero value instructs the communication manager to destroy the cm_id after the callback completes. so that's the slay way to do it 👑

🌈 SEE ALSO 🌈

Kernel file ./include/rdma/ib_cm.h and all these iconic siblings:

and that's the whole page, bestie, you ate that 🍓 this came out of ./include/rdma and it's dated October 2026 — yeah, the future, we stay ahead 💀💖 bye pookie, go destroy your cm_id responsibly 🌸✨🫶

📦 where this page comes from