Re: [PATCH net 1/9] net/tls: Bound time spent on no-data records in tls_sw_read_sock()

[Chuck Lever]

On Thu, Jul 30, 2026, at 5:12 AM, Sabrina Dubroca wrote:
> 2026-07-26, 20:33:29 -0400, Chuck Lever wrote:

>> Bound a run of such records, as net_rx_action() bounds a softirq
>> poll. The first record that delivers no bytes arms a deadline
>> TLS_RX_NODATA_NS ahead; any record that delivers bytes disarms it,
>> so a normal stream never trips it. Breaking out with nothing copied
>
> Another thought here: I think a peer that sends "some" 0-length data
> records followed by one (possibly very small) data record, and then
> repeats that sequence, will not hit this "rate-limiting" of no-data
> records. Is that right? And if so, is that a problem?

That occurred to me too. It's right on the cusp between still
making progress and gumming things up. Neither the packet-count
limit nor the time-bound address this case.

I don't have a good answer.


> [I'm guessing that the caller is doing something equivalent to
> recvmsg(WAITALL), so it could be stuck for a long time even with this
> new bound]

Still digesting your other feedback. I plan to send a v2 to
address it.


-- 
Chuck Lever