_netlbl_catmap_getnode(9)

💅 _netlbl_catmap_getnode — from the Kernel API Manual ✨

okay bestie, pull up a chair, because we're talking about a kernel function and honestly? she's lowkey iconic. this is _netlbl_catmap_getnode(9) and she does exactly one thing, but she does it well. 🎀

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🌸 NAME 🌸

_netlbl_catmap_getnode — get a individual node from a catmap 🫶

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🦋 SYNOPSIS 🦋

struct netlbl_lsm_catmap * _netlbl_catmap_getnode (struct
netlbl_lsm_catmap **catmap , u32 offset , unsigned int cm_flags , gfp_t
gfp_flags );

like… the signature is right there, she's not hiding. four arguments, one return, no cap. 💅

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✨ ARGUMENTS ✨

• catmap — pointer to the category bitmap. yes bestie, it's a double pointer, it's giving main-character energy, we love a pointer-to-pointer. 🫶
• offset — the requested offset. this is the thing you're looking for. the vibe check target, iykyk.
• cm_flags — catmap flags, see _CM_F_*. these little guys change her whole behaviour, so pay attention. 👀
• gfp_flags — memory allocation flags. the "how do i get my memory" instructions, super important if she ends up making a new node. 🧚

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💖 DESCRIPTION 💖

so what she does is: iterate through the catmap looking for the node associated with offset. that's it. that's the whole job. slay. ✨

but here's the tea, and it's a whole two-flavour situation:

• if the _CM_F_ALLOC flag is set in cm_flags and there is no associated node — no worries bestie, one will be created and inserted into the catmap. she literally makes it happen. 👑
• if the _CM_F_WALK flag is set in cm_flags and there is no associated node — the next highest node will be returned instead. so you still get something, she's not gonna leave you hanging. 🌈

and the return values, periodt:

• returns a pointer to the node on success 🎀
• returns NULL on failure 😭

bestie reminder: NULL means failure here. do not pass go, do not dereference it, just accept that it didn't work out this time. 💀

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⭐ SEE ALSO ⭐

the source lives in the kernel file ./net/netlabel/netlabel_kapi.c — go read her in her natural habitat if you want the full lore 💜

and here is the entire extended friend group, all of them, no one left out because we don't do that here:

• netlbl_cfg_map_del(9), netlbl_cfg_unlbl_map_add(9), netlbl_cfg_unlbl_static_add(9), netlbl_cfg_unlbl_static_del(9)
• netlbl_cfg_cipsov4_add(9), netlbl_cfg_cipsov4_del(9), netlbl_cfg_cipsov4_map_add(9)
• netlbl_cfg_calipso_add(9), netlbl_cfg_calipso_del(9), netlbl_cfg_calipso_map_add(9)
• netlbl_catmap_walk(9), netlbl_catmap_walkrng(9), netlbl_catmap_getlong(9)
• netlbl_catmap_setbit(9), netlbl_catmap_setrng(9), netlbl_catmap_setlong(9)
• netlbl_bitmap_walk(9), netlbl_bitmap_setbit(9), netlbl_enabled(9)
• netlbl_sock_setattr(9), netlbl_sock_delattr(9), netlbl_sock_getattr(9), netlbl_sk_lock_check(9)
• netlbl_conn_setattr(9), netlbl_req_setattr(9), netlbl_req_delattr(9)
• netlbl_skbuff_setattr(9), netlbl_skbuff_getattr(9), netlbl_skbuff_err(9)
• netlbl_cache_invalidate(9), netlbl_cache_add(9)
• netlbl_audit_start(9), netlbl_init(9)

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aaaand that's the whole page bestie, you ate that reading it fr fr 🍓

this little love letter came from ./net/netlabel, dated October 2026, and she's filed under _netlbl_catmap_getnode(9). mwah, go touch some kernel code 💋🦋