Crash When remote server goes down

[eroom1966]

I have a strange scenario.
I am connected to a server/endpoint and all is working as expected.
The server/endpoint then goes down, and I stop receiving traffic.

I then call esp_wireguardif_peer_is_up() to see if it is still available, but this causes a crash
The crash is due to the following assert failing

esp_wireguardif_peer_is_up() -> wireguardif_peer_is_up()
wireguardif_peer_is_up() -> wireguardif_lookup_peer()

This assert fails due to netif being NULL

static err_t wireguardif_lookup_peer(struct netif *netif, u8_t peer_index, struct wireguard_peer **out) {
	LWIP_ASSERT("netif != NULL", (netif != NULL));

I put a simple fix into this function, to check that ctx->netif is non NULL

esp_err_t esp_wireguardif_peer_is_up(wireguard_ctx_t *ctx)
{
...
    if (!ctx->netif) {
        err = ESP_ERR_INVALID_ARG;
        goto fail;
    }

I don't understand enough about this code, but this solves my problem, what I do not understand is why is ctx->netif==NULL ?
All I do to get to this state, is to take down the remote wireguard after connection has been established

Thx
Lee

[eroom1966]

Hmm, I think I see my problem.
When I see that the remote end has gone away, I call esp_wireguard_disconnect(), this results in setting ctx->netif to NULL
a subsequent call to esp_wireguardif_peer_is_up, then causes the crash.

Ultimately what I want to do is install a new certificate when it is no longer valid, I cannot figure out the sequence of calls.
Effectively I have this

setup wg_config
call esp_wireguard_init()
call esp_wireguard_connect(&ctx);
check esp_wireguardif_peer_is_up(&ctx)

// all is now running as expected

at some point later, the certificate becomes invalid, and I need to install a new certificate and force a re-connect.

What calls should I make ?