Note that it's channeld which calculates the shared secret, too. This
minimizes the work that lightningd has to do, at cost of passing this
through.
We also don't yet save the blinding field(s) to the database.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Instead of making it ourselves, lightningd does it. Now we only have
two cases of failed htlcs: completely malformed (BADONION), and with
an already-wrapped onion reply to send.
This makes channeld's job much simpler.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This makes it clear we're dealing with a message which is a wrapped error
reply (needing unwrap_onionreply), not an already-wrapped one.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Fortunately, we can calculate the sha256 ourselves, so the
outgoing channeld doesn't need to tell us.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This covers all the cases where an onion can be malformed; this means
we know in advance that it's bad. That allows us to distinguish two
cases: where lightningd rejects the onion as bad, and where the next
peer rejects the next onion as bad. Both of those (will) set failcode
to one of the BADONION values.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The master tells us the short_channel_id of the outgoing channel when
failing an HTLC, but channeld didn't store it anywhere. It also
didn't tell channeld the short_channel_id in the case where we're
reconnecting and it's feeding us an array of failed htlcs.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
'struct htlc' in channeld has a 'malformed' field, which is really only
used in the "retransmit updates on reconnect" case. That's quite confusing,
and I'm not entirely convinced that it can only be set to a failcode
with the BADONION bit set.
So generalize it, using the same logic we use in the master daemon:
failcode: a locally generated error, for channeld to turn into the appropriate
error message.
fail: a remotely generated onion error, for forwarding.
Either of these being non-zero/non-NULL means we've failed, and only one
should be set at any time.
We unify the "send htlc fail/fulfill update due to retransmit" and the
normal send update paths, by always calling send_fail_or_fulfill.
This unification revealed that we accidentally skipped the
onion-wrapping stage when we retransmit failed htlcs!
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The bulk of this patch is actually hoisting the get_shared_secret()
function (unchanged) so we can call it earlier.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Rusty Russell
practicalswift