From 05f95b59c10aec63d3a8f4d9c69f580f25c76818 Mon Sep 17 00:00:00 2001
From: Rusty Russell <rusty@rustcorp.com.au>
Date: Fri, 1 Feb 2019 16:23:38 +1030
Subject: [PATCH] gossipd: take into account risk in final route comparison.
We were only comparing by total msatoshis.
Note, this *still* isn't sufficient to fix our indirect problem, as
our risk values are all 1 (the minimum):
lightning_gossipd(25480): 2 hop solution: 1501990 + 2
lightning_gossipd(25480): 3 hop solution: 1501971 + 3
...
lightning_gossipd(25480): => chose 3 hop solution
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
CHANGELOG.md | 1 +
gossipd/routing.c | 6 +++++-
2 files changed, 6 insertions(+), 1 deletion(-)
diff --git a/CHANGELOG.md b/CHANGELOG.md
index ecbe90f78..47e7a8efb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -39,6 +39,7 @@ changes.
(eg. 4 billion) was slow due to a bug.
- Fixed occasional deadlock with peers when exchanging huge amounts of gossip.
- You can no longer make giant unpayable "wumbo" invoices.
+- CLTV of total route now correctly evaluated when finding best route.
### Security
diff --git a/gossipd/routing.c b/gossipd/routing.c
index 1a23dd8c8..5fcf2a2b8 100644
--- a/gossipd/routing.c
+++ b/gossipd/routing.c
@@ -529,9 +529,13 @@ find_route(const tal_t *ctx, struct routing_state *rstate,
best = 0;
for (i = 1; i <= max_hops; i++) {
- if (dst->bfg[i].total < dst->bfg[best].total)
+ status_trace("%i hop solution: %"PRIu64" + %"PRIu64,
+ i, dst->bfg[i].total, dst->bfg[i].risk);
+ if (dst->bfg[i].total + dst->bfg[i].risk
+ < dst->bfg[best].total + dst->bfg[best].risk)
best = i;
}
+ status_trace("=> chose %i hop solution", best);
/* No route? */
if (dst->bfg[best].total >= INFINITE) {