Function process_channel_update

gossipd/gossmap_manage.c:878–993

This is called both from when we receive the channel update, and if * we had to defer. */

/* This is called both from when we receive the channel update, and if
 * we had to defer. */
static const char *process_channel_update(const tal_t *ctx,
					  struct gossmap_manage *gm,
					  struct short_channel_id scid,
					  const secp256k1_ecdsa_signature *signature,
					  u8 message_flags,
					  u8 channel_flags,
					  u16 cltv_expiry_delta,
					  struct amount_msat htlc_minimum_msat,
					  struct amount_msat htlc_maximum_msat,
					  u32 fee_base_msat,
					  u32 fee_proportional_millionths,
					  u32 timestamp,
					  const u8 *update,
 					  const struct node_id *source_peer)
{
	struct gossmap_chan *chan;
	struct node_id node_id, remote_id;
	const char *err;
	int dir = (channel_flags & ROUTING_FLAGS_DIRECTION);
	struct gossmap *gossmap = gossmap_manage_get_gossmap(gm);
	u64 offset;

	chan = gossmap_find_chan(gossmap, &scid);
	if (!chan) {
		/* Did we explicitly reject announce?  Ignore completely. */
		if (in_txout_failures(gm->txf, scid)) {
			status_debug("Previously-rejected announce for %s",
				     fmt_short_channel_id(tmpctx, scid));
			return NULL;
		}

		/* Seeker may want to ask about this. */
		query_unknown_channel(gm->daemon, source_peer, scid);

		/* Don't send them warning, it can happen. */
		bad_gossip(source_peer,
			   tal_fmt(tmpctx, "Unknown channel %s",
				   fmt_short_channel_id(tmpctx, scid)));
		return NULL;
	}

	/* Now we know node, we can check signature. */
	gossmap_node_get_id(gossmap,
			    gossmap_nth_node(gossmap, chan, dir),
			    &node_id);

	err = sigcheck_channel_update(ctx, &node_id, signature, update);
	if (err)
		return err;

	/* Don't allow private updates on public channels! */
	if (message_flags & ROUTING_OPT_DONT_FORWARD) {
		return tal_fmt(ctx, "Do not set DONT_FORWARD on public channel_updates (%s)",
			       fmt_short_channel_id(tmpctx, scid));
	}

	/* Do we have same or earlier update? */
	if (gossmap_chan_set(chan, dir)) {