Added an optional `c` field in the payment request specifying the
minimum `cltv_expiry` to use for the last htlc in the route. If
not provided, default value is 9.
This commit also clarifies how `channel_update` messages are only
to be used in the context of relaying payments, and how both htlc
amounts and expiries are to be calculated backwards from the values
provided in the payment request.
Not needing the `channel_update` for the first channel in a route also
means that it is possible to make a payment through a channel which
hasn't had any announcements yet.
This is unofficial, since we don't have IANA tag, but it doesn't
clash with any existing one. We'll see if this turns out to be something
people want.
Closes: #206
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* BOLT 11: fix formatting typo, and `r` length value.
The r field is 408 bytes long, which is 82 characters encoded;
this should have been updated when the fee and cltv sizes were
updated (prior to merge into repo).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* BOLT 11: `channel_id`->`short_channel_id`
