From: Guus Sliepen <guus@meshlink.io>
Date: Thu, 10 Sep 2020 21:13:39 +0000 (+0200)
Subject: Allow sptps_force_kex() while a key exchange is in progress
X-Git-Url: https://git.meshlink.io/?a=commitdiff_plain;h=38d695b115920c9fb78b596acde817244d0519a6;p=meshlink

Allow sptps_force_kex() while a key exchange is in progress

We should not do anything if we are already exchanging a new key, and
just return true. This change prevents higher layers in MeshLink from
terminating a connection between two nodes if both peers call
sptps_force_kex() at nearly the same time.
---

diff --git a/src/sptps.c b/src/sptps.c
index ed1f67ff..267a47f1 100644
--- a/src/sptps.c
+++ b/src/sptps.c
@@ -374,10 +374,15 @@ static bool receive_sig(sptps_t *s, const char *data, uint16_t len) {
 
 // Force another Key EXchange (for testing purposes).
 bool sptps_force_kex(sptps_t *s) {
-	if(!s->outstate || s->state != SPTPS_SECONDARY_KEX) {
+	if(!s->outstate || s->state < SPTPS_SECONDARY_KEX) {
 		return error(s, EINVAL, "Cannot force KEX in current state");
 	}
 
+	if(s->state > SPTPS_SECONDARY_KEX) {
+		// We are already in the middle of a secondary key exchange
+		return true;
+	}
+
 	s->state = SPTPS_KEX;
 	return send_kex(s);
 }