On 16-09-25 12:26 PM, Daniel Borkmann wrote:
On 09/25/2016 03:05 PM, Jamal Hadi Salim wrote:
[..]
MAX_RED_LOOP (stands for "Maximum Redirect loop") still exists in
current code. The idea above was that we would increment the rttl
counter once and if we saw it again upto MAX_RED_LOOP we would assume
a loop and drop the packet (at the time i didnt think it was wise to
let the actions be in charge of setting the RTTL; it had to be central
core code - but it may not be neccessary)
Florian, when we discussed I said it was fine to reclaim those 3 bits
on tc verdict for RTTL at the time because i had taken out the
feature and never added it back. Your comment at the time was we can
add it back when someone shows up with the feature.
Shmulik is looking to add it.
Why not just reuse xmit_recursion, which is what we did in tc cls_bpf
programs f.e. see __bpf_tx_skb()? Would be a pity to waste 3 bits on
this in the skb.
If it is going to work, I'd be happy to save those bits.
xmit_recursion is going to prevent recursing into
dev_xmit(), no?
In our case we want to preventing looping of a singular
skb.
cheers,
jamal
