Helper function bpf_xdp_adjust_head
Definition
Copyright (c) 2015 The Libbpf Authors. All rights reserved.
Adjust (move) xdp_md->data by delta bytes. Note that it is possible to use a negative value for delta. This helper can be used to prepare the packet for pushing or popping headers.
A call to this helper is susceptible to change the underlying packet buffer. Therefore, at load time, all checks on pointers previously done by the verifier are invalidated and must be performed again, if the helper is used in combination with direct packet access.
Returns
0 on success, or a negative error in case of failure.
static long (* const bpf_xdp_adjust_head)(struct xdp_md *xdp_md, int delta) = (void *) 44;
Usage
Docs could be improved
This part of the docs is incomplete, contributions are very welcome
Program types
This helper call can be used in the following program types:
Example
Docs could be improved
This part of the docs is incomplete, contributions are very welcome