uapi: bpf.h update from upstream

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
This commit is contained in:
Stephen Hemminger 2021-03-30 16:38:05 -07:00
parent 7384c15e0e
commit e77a0d3dc9
1 changed files with 11 additions and 5 deletions

View File

@ -3850,7 +3850,7 @@ union bpf_attr {
*
* long bpf_check_mtu(void *ctx, u32 ifindex, u32 *mtu_len, s32 len_diff, u64 flags)
* Description
* Check ctx packet size against exceeding MTU of net device (based
* Check packet size against exceeding MTU of net device (based
* on *ifindex*). This helper will likely be used in combination
* with helpers that adjust/change the packet size.
*
@ -3867,6 +3867,14 @@ union bpf_attr {
* against the current net device. This is practical if this isn't
* used prior to redirect.
*
* On input *mtu_len* must be a valid pointer, else verifier will
* reject BPF program. If the value *mtu_len* is initialized to
* zero then the ctx packet size is use. When value *mtu_len* is
* provided as input this specify the L3 length that the MTU check
* is done against. Remember XDP and TC length operate at L2, but
* this value is L3 as this correlate to MTU and IP-header tot_len
* values which are L3 (similar behavior as bpf_fib_lookup).
*
* The Linux kernel route table can configure MTUs on a more
* specific per route level, which is not provided by this helper.
* For route level MTU checks use the **bpf_fib_lookup**\ ()
@ -3891,11 +3899,9 @@ union bpf_attr {
*
* On return *mtu_len* pointer contains the MTU value of the net
* device. Remember the net device configured MTU is the L3 size,
* which is returned here and XDP and TX length operate at L2.
* which is returned here and XDP and TC length operate at L2.
* Helper take this into account for you, but remember when using
* MTU value in your BPF-code. On input *mtu_len* must be a valid
* pointer and be initialized (to zero), else verifier will reject
* BPF program.
* MTU value in your BPF-code.
*
* Return
* * 0 on success, and populate MTU value in *mtu_len* pointer.