Bluetooth: Mesh: Assert in bt_mesh_adv_unref when sending 2 messages in a row to a proxy client

[PavelVPV]

Describe the bug
After Bluetooth: Mesh: Introduce separate workq for ADV EXT by LingaoM · Pull Request #78914 · zephyrproject-rtos/zephyr the mesh device asserts in bt_mesh_adv_unref when sending 2 messages in a row to a proxy client: ASSERTION FAIL @ WEST_TOPDIR/zephyr/subsys/bluetooth/mesh/adv.c

There are 2 issues here. First, struct bt_mesh_adv::node variable is shared among 2 FIFOs: one in adv.c and the other one in proxy_msg.c. Second, is the node type should be void * : FIFOs — Zephyr Project Documentation, zephyr/include/zephyr/kernel.h at 0728f5d0e27ed1d1274f1c82b2bdc0ffd31d2aee · zephyrproject-rtos/zephyr but not sys_snode_t (or at least sys_sfnode_t).

The temporary fix is to define a separate variable for the proxy FIFO.

To Reproduce

1. Provision a mesh device using nRF Mesh app for smartphone
2. Send any 2 messages in a row to the proxy client (smartphone)
3. Observe the assertion

Expected behavior
No assertion happens and all messages are sent to the proxy client.

Impact
Proxy feature is broken in Zephyr 4.0.0+

[PavelVPV]

@LingaoM , any ideas how to fix this?

[LingaoM]

The temporary fix is to define a separate variable for the proxy FIFO.

bool bt_mesh_proxy_relay(struct bt_mesh_adv *adv, uint16_t dst)
{
	bool relayed = false;
	int i;

	LOG_DBG("%u bytes to dst 0x%04x", adv->b.len, dst);

	for (i = 0; i < ARRAY_SIZE(clients); i++) {
		struct bt_mesh_proxy_client *client = &clients[i];

		if (!client->cli) {
			continue;
		}

		if (!client_filter_match(client, dst)) {
			continue;
		}

		if (bt_mesh_proxy_relay_send(client->cli->conn, adv)) {
			continue;
		}

		relayed = true;
	}

	return relayed;
}

For ARRAY_SIZE(clients) > 1, also have problem.