This is now permitted in the offers PR, so we should support it. But
we can't just look up in the gossmap, since the "short_channel_id"
could be an alias. So we get lightningd to tell us all scid->peer
mappings, and look up in that.
Changelog-Added: Protocol: onion messages can now be forwarded by short_channel_id.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Allows for caller to log, but more importantly, when we add a command to
inject onion messages, allows for us to capture the error.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This was when we handled pre-TLV onions where the first byte was 0. We haven't
done that for a while: you can tell, because process_onionpacket doesn't use
the parameter at all!
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
1. onion-message
2. blinded-payments
3. route-blinding
4. channel-type
5. warnings.
Now they'll be checked correctly, and if the spec changes, we'll know
to reexamine this code.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This has the benefit of being shorter, as well as more reliable (you
will get a link error if we can't print it, not a runtime one!).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
```
make check-source-bolt CHECK_BOLT_PREFIX="--prefix=BOLT-onion-message" BOLTVERSION=guilt/offers
```
Mainly textual, though I neatened the extra fields check for TLVs with
blinding, and implemented the "no other fields" requirement for
non-final onion message hops.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Instead of open coding in connectd/onion_message, we move it to common
with a nice API.
This lets us process the BOLT test vectors.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
