Definition for what happens to packets experiencing parser errors?

[jafingerhut]

Here is a PR to address this same question for the PSA specification in one particular way, which we should review and think about whether we want something similar for PNA, too: p4lang/p4-spec#1026

[mariobaldi]

I wonder if it would make sense to make the behavior for packets experiencing parsing errors configurable.
Even though it makes sense that the P4 program running in the Control is able to decide what to do with such packets, there may be cases where such packets should be discarded to reduce the load on the match-action pipeline.
External configuration means could fulfil this purpose.
If we agreed to have such means, I would guess we wouldn't need to define exactly what they are, but just say that they are available.

[jafingerhut]

@mariobaldi Looks like a reasonable idea to me. Should we consider it for the PSA specification as well, while we are at it?