---
name: "mlx5dv_create_flow_action_modify_header"
section: "3"
platform: "linux"
package: "rdma-core"
version: "65.0-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/mlx5dv_create_flow_action_modify_header"
---

# mlx5dv\_create\_flow\_action\_modify\_header(3)

Flow action modify header for mlx5 provider

## NAME

mlx5dv\_create\_flow\_action\_modify\_header - Flow action modify header for mlx5 provider

## SYNOPSIS

-

  ```
  #include <infiniband/mlx5dv.h>
  struct ibv_flow_action *
  mlx5dv_create_flow_action_modify_header(struct ibv_context *ctx,
                      size_t actions_sz,
                      uint64_t actions[],
                      enum mlx5dv_flow_table_type ft_type)
  ```

## DESCRIPTION

Create a modify header flow steering action, it allows mutating a packet header.

## ARGUMENTS

- *ctx*

  RDMA device context to create the action on.

- *actions\_sz*

  The size of *actions* buffer in bytes.

- *actions*

  A buffer which contains modify actions provided in device spec format (i.e. be64).

- *ft\_type*

  Defines the flow table type to which the modify header action will be attached.

  MLX5DV\_FLOW\_TABLE\_TYPE\_NIC\_RX: RX FLOW TABLE MLX5DV\_FLOW\_TABLE\_TYPE\_NIC\_TX: TX FLOW TABLE

## RETURN VALUE

Upon success *mlx5dv\_create\_flow\_action\_modify\_header* will return a new *struct ibv\_flow\_action* object, on error NULL will be returned and errno will be set.

## SEE ALSO

*[ibv\_create\_flow(3)](/ibv_create_flow/3.md)*, *[ibv\_create\_flow\_action(3)](/ibv_create_flow_action/3.md)*