RDMA_SET_OPTION(3)

💖 RDMA_SET_OPTION 💖

okay bestie, gather round, because this is a lil function from the Librdmacm Programmer's Manual and she is lowkey iconic 👑

✨ NAME ✨

rdma_set_option — sets communication options for an rdma_cm_id. that's it, that's the job, and she does it flawlessly 💅

🌸 SYNOPSIS 🌸

#include <rdma/rdma_cma.h>

int rdma_set_option (struct rdma_cm_id *id, int level, int optname, void
*optval, size_t optlen);

like yes, five arguments, we love a main character with a full ensemble cast 🫶

🎀 ARGUMENTS 🎀

• id — the RDMA identifier. your lil handle on the whole situation fr.
• level — the protocol level of the option you're setting. which floor of the building are we on, bestie.
• optname — the name of the option, relative to the level, that you wanna set. it's giving "address, but make it relative" 🏠
• optval — a reference to the option data. what's actually in there depends on the level and the optname, so no, there's no single answer, it's dependent 😌
• optlen — the size of the optval buffer. know your sizes, queen.

🌈 DESCRIPTION 🌈

Sets communication options for an rdma_cm_id. the whole point of this call is to override the default system settings — you're basically saying "thanks for the defaults but I'll take it from here" 💁♀️

optname can be one of these:

• RDMA_OPTION_ID_TOS — specify the quality of service provided by a connection. the expected optlen is size of uint8_t. tiny buffer, big service energy ✨
• RDMA_OPTION_ID_REUSEADDR — bound the rdma_cm_id to a reuseable address. this will allow other users to bind to that same address. the expected optlen is size of int. sharing is caring, no cap 🤝
• RDMA_OPTION_ID_AFONLY — set IPV6_V6ONLY socket. the expected optlen is size of int. v6 only, v6 forever, periodt 🦋
• RDMA_OPTION_IB_PATH — set IB path record data. the expected optlen is size of struct ibv_path_data[]. yes it's an array, yes that's on purpose 💀
• RDMA_OPTION_ID_ACK_TIMEOUT — set QP ACK timeout. the value is calculated according to the formula 4.096 * 2^(ack_timeout) usec. math girlies rise, we love a formula 🔥

⭐ RETURN VALUE ⭐

Returns 0 on success, or -1 on error. and if an error happens, errno will be set to indicate the failure reason. so like, always check errno, bestie, she's the one telling you what went wrong 😭

💜 NOTES 💜

Option details may be found in the relevant header files. iykyk — go read the headers, they're the receipts 📜

🧚 SEE ALSO 🧚

rdma_create_id(3)

not me being obsessed with a C function. anyway, this page is brought to you by librdmacm, dated 2007-08-06 — vintage but still slaying 💖 go forth and set those options, angel 🎀