mlx5hws_act...odify_header(9)

💅 mlx5hws_act...odify_header(9) — Kernel API Manual 💅

okay bestie, buckle up, because this is the page for mlx5hws_action_create_modify_header from the Kernel API Manual, section 9. yeah. that's the one. she's a little niche but she's iconic 🎀

---

✨ NAME ✨

mlx5hws_action_create_modify_header — create a direct rule modify header action. that's it, that's the whole thing, but like... explained properly below 🫶

---

🌸 SYNOPSIS 🌸

struct mlx5hws_action * mlx5hws_action_create_modify_header (struct
mlx5hws_context *ctx , u8 num_of_patterns , struct
mlx5hws_action_mh_pattern *patterns , u32 log_bulk_size , u32 flags );

literally just one function, no cap, and it returns a pointer to struct mlx5hws_action 💖

---

🦋 ARGUMENTS 🦋

okay so here's the tea on every single parameter, and yes you need all of them:

• ctx — the context where your brand new action is gonna live. think of it as the group chat this action gets added to 💬
• num_of_patterns — how many patterns you actually put in the patterns array. like, count them. don't lie to her.
• patterns — the array itself, carrying all the pattern info. this is the main character of the whole function ngl 👑
• log_bulk_size — the number of unique values used with this pattern. yes that's the description, no I'm not elaborating, it means what it says ✨
• flags — the action creation flags, and they come from enum mlx5hws_action_flags. real ones know.

---

⭐ RETURN ⭐

she gives you a pointer to mlx5hws_action on success 💖

and NULL otherwise 🙈 that's it. no in-between. no "maybe". it's giving all or nothing, periodt.

---

🌈 SEE ALSO 🌈

first up, the Kernel file itself, go read the source bestie, it's right here:

./drivers/net/ethernet/mellanox/mlx5/core/steering/hws/mlx5hws.h

and then the whole extended friend group of pages, in the exact order they were listed, no gatekeeping:

• mlx5hws_is_supported(9)
• mlx5hws_context_open(9)
• mlx5hws_context_close(9)
• mlx5hws_context_set_peer(9)
• mlx5hws_table_create(9)
• mlx5hws_table_destroy(9)
• mlx5hws_table_get_id(9)
• mlx5hws_table_set_default_miss(9)
• mlx5hws_match_template_create(9)
• mlx5hws_match_template_destroy(9)
• mlx5hws_action_template_create(9)
• mlx5hws_action_template_destroy(9)
• mlx5hws_matcher_create(9)
• mlx5hws_matcher_destroy(9)
• mlx5hws_matcher_attach_at(9)
• mlx5hws_matcher_resize_set_target(9)
• mlx5hws_matcher_resize_rule_move(9)
• mlx5hws_rule_create(9)
• mlx5hws_rule_destroy(9)
• mlx5hws_rule_action_update(9)
• mlx5hws_action_get_type(9)
• mlx5hws_action_get_dev(9)
• mlx5hws_action_create_dest_drop(9)
• mlx5hws_action_create_default_miss(9)
• mlx5hws_action_create_dest_table(9)
• mlx5hws_action_create_dest_table_num(9)
• mlx5hws_action_create_dest_match_range(9)
• mlx5hws_action_create_flow_sampler(9)
• mlx5hws_action_create_dest_vport(9)
• mlx5hws_action_create_tag(9)
• mlx5hws_action_create_counter(9)
• mlx5hws_action_create_reformat(9)
• mlx5hws_action_create_aso_meter(9)
• mlx5hws_action_create_pop_vlan(9)
• mlx5hws_action_create_push_vlan(9)
• mlx5hws_action_create_dest_array(9)
• mlx5hws_action_create_insert_header(9)
• mlx5hws_action_create_remove_header(9)
• mlx5hws_action_create_last(9)
• mlx5hws_action_destroy(9)
• mlx5hws_send_queue_poll(9)
• mlx5hws_send_queue_action(9)
• mlx5hws_debug_dump(9)
• mlx5hws_bwc_matcher_create(9)
• mlx5hws_bwc_matcher_destroy(9)
• mlx5hws_bwc_rule_create(9)
• mlx5hws_bwc_rule_destroy(9)
• mlx5hws_bwc_rule_action_update(9)

that's the whole roster, go follow them all, they all post good content 💜

---

💀 tiny reminder bestie: the return value can be NULL, and that is not a vibe. check it before you dereference, or the kernel will humble you in front of everyone. fr fr.

---

and that's the page!! 🎀 source and version live at ./drivers/net/ethernet/mellano... and she was dated October 2026 — mwah, sending you off with a kiss, go modify some headers responsibly 💅✨🦋