BOLT 11: change route to base + millionths.

Doesn't take any more space (we could actually reduce millionths to 24 bits,
but that starts to look silly), but it's simpler and allows for cases where
there's no payment amount.

Closes: #296
Signed-off-by: Rusty Russell <[email protected]>

Author: rustyrussell

11-payment-encoding.md

@@ -114,7 +114,8 @@ Currently defined Tagged Fields are:
 * `r` (3): `data_length` variable.  One or more entries containing extra routing information for a private route; there may be more than one `r` field, too.
    * `pubkey` (264 bits)
    * `short_channel_id` (64 bits)
-   * `fee` (64 bits, big-endian)
+   * `fee_base_msat` (32 bits, big-endian) 
+   * `fee_proportional_millionths` (32 bits, big-endian)
    * `cltv_expiry_delta` (16 bits, big-endian)
 
 ### Requirements
@@ -148,10 +149,7 @@ public channel associated with its public key.  The `r` field MUST contain
 one or more ordered entries, indicating the forward route from a
 public node to the final destination.  For each entry, the `pubkey` is the
 node ID of the start of the channel, `short_channel_id` is the short channel ID
-field to identify the channel, `fee` is the total fee required to use
-that channel to send `amount` to the final node, specified in 10^-11
-currency units, and `cltv_expiry_delta` is the block delta required
-by the channel.  A writer MAY include more than one `r` field to
+field to identify the channel, `fee_base_msat`, `fee_proportional_millionths` and `cltv_expiry_delta` are as specified in [BOLT #7](07-routing-gossip.md#the-channel_update-message).  A writer MAY include more than one `r` field to
 provide multiple routing options.
 
 A writer MUST pad field data to a multiple of 5 bits, using zeroes.
@@ -320,7 +318,7 @@ Breakdown:
 * `wp3f9t`: Bech32 checksum
 
 > ### On mainnet, with fallback address 1RustyRX2oai4EYYDpQGWvEL62BBGqN9T with extra routing info to go via nodes 029e03a901b85534ff1e92c43c74431f7ce72046060fcf7a95c37e148f78c77255 then 039e03a901b85534ff1e92c43c74431f7ce72046060fcf7a95c37e148f78c77255
-> lnbc20m1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqhp58yjmdan79s6qqdhdzgynm4zwqd5d7xmw5fk98klysy043l2ahrqsfpp3qjmp7lwpagxun9pygexvgpjdc4jdj85fr9yq20q82gphp2nflc7jtzrcazrra7wwgzxqc8u7754cdlpfrmccae92qgzqvzq2ps8pqqqqqqqqqqqq9qqqvpeuqafqxu92d8lr6fvg0r5gv0heeeqgcrqlnm6jhphu9y00rrhy4grqszsvpcgpy9qqqqqqqqqqqq7qqzqfnlkwydm8rg30gjku7wmxmk06sevjp53fmvrcfegvwy7d5443jvyhxsel0hulkstws7vqv400q4j3wgpk4crg49682hr4scqvmad43cqd5m7tf
+> lnbc20m1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqhp58yjmdan79s6qqdhdzgynm4zwqd5d7xmw5fk98klysy043l2ahrqsfpp3qjmp7lwpagxun9pygexvgpjdc4jdj85fr9yq20q82gphp2nflc7jtzrcazrra7wwgzxqc8u7754cdlpfrmccae92qgzqvzq2ps8pqqqqqqpqqqqq9qqqvpeuqafqxu92d8lr6fvg0r5gv0heeeqgcrqlnm6jhphu9y00rrhy4grqszsvpcgpy9qqqqqqgqqqqq7qqzqj9n4evl6mr5aj9f58zp6fyjzup6ywn3x6sk8akg5v4tgn2q8g4fhx05wf6juaxu9760yp46454gpg5mtzgerlzezqcqvjnhjh8z3g2qqdhhwkj
 
 Breakdown:
 
@@ -336,9 +334,9 @@ Breakdown:
   * `qjmp7lwpagxun9pygexvgpjdc4jdj85f`: 160 bit P2PKH address
 * `r`: tagged field: route information
   * `9y`: `data_length` (`9` = 5, `y` = 4.  5 * 32 + 4 = 164)
-    `q20q82gphp2nflc7jtzrcazrra7wwgzxqc8u7754cdlpfrmccae92qgzqvzq2ps8pqqqqqqqqqqqq9qqqvpeuqafqxu92d8lr6fvg0r5gv0heeeqgcrqlnm6jhphu9y00rrhy4grqszsvpcgpy9qqqqqqqqqqqq7qqzq`: pubkey `029e03a901b85534ff1e92c43c74431f7ce72046060fcf7a95c37e148f78c77255`, `short_channel_id` 0102030405060708, `fee` 20 millisatoshi, `cltv_expiry_delta` 3.  pubkey `039e03a901b85534ff1e92c43c74431f7ce72046060fcf7a95c37e148f78c77255`, `short_channel_id` 030405060708090a, `fee` 30 millisatoshi, `cltv_expiry_delta` 4.
-* `fnlkwydm8rg30gjku7wmxmk06sevjp53fmvrcfegvwy7d5443jvyhxsel0hulkstws7vqv400q4j3wgpk4crg49682hr4scqvmad43cq`: signature
-* `d5m7tf`: Bech32 checksum
+    `q20q82gphp2nflc7jtzrcazrra7wwgzxqc8u7754cdlpfrmccae92qgzqvzq2ps8pqqqqqqqqqqqq9qqqvpeuqafqxu92d8lr6fvg0r5gv0heeeqgcrqlnm6jhphu9y00rrhy4grqszsvpcgpy9qqqqqqqqqqqq7qqzq`: pubkey `029e03a901b85534ff1e92c43c74431f7ce72046060fcf7a95c37e148f78c77255`, `short_channel_id` 0102030405060708, `fee_base_msat` 1 millisatoshi, `fee_proportional_millionths` 20, `cltv_expiry_delta` 3.  pubkey `039e03a901b85534ff1e92c43c74431f7ce72046060fcf7a95c37e148f78c77255`, `short_channel_id` 030405060708090a, `fee_base_msat` 2 millisatoshi, `fee_proportional_millionths` 30, `cltv_expiry_delta` 4.
+* `j9n4evl6mr5aj9f58zp6fyjzup6ywn3x6sk8akg5v4tgn2q8g4fhx05wf6juaxu9760yp46454gpg5mtzgerlzezqcqvjnhjh8z3g2qq`: signature
+* `dhhwkj`: Bech32 checksum
 
 > ### On mainnet, with fallback (P2SH) address 3EktnHQD7RiAE6uzMj2ZifT9YgRrkSgzQX
 > lnbc20m1pvjluezhp58yjmdan79s6qqdhdzgynm4zwqd5d7xmw5fk98klysy043l2ahrqspp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqfppj3a24vwu6r8ejrss3axul8rxldph2q7z9kmrgvr7xlaqm47apw3d48zm203kzcq357a4ls9al2ea73r8jcceyjtya6fu5wzzpe50zrge6ulk4nvjcpxlekvmxl6qcs9j3tz0469gq5g658y