[LEDE-DEV] [PATCH] Fix refreshing cached A(AAA) records that expire

[John Crispin]

On 20/03/17 11:45, Rafał Miłecki wrote:
> From: Rafał Miłecki <rafal at milecki.pl>
>
> Old code was trying to refresh record after it has already expired. Now
> it tries after 50% of TTL has passed - we do the same for other records.
>
> Fixes: 80dd24602480 ("Refresh DNS records A and AAAA directly")
> Signed-off-by: Rafał Miłecki <rafal at milecki.pl>
Acked-by: John Crispin <john at phrozen.org>

> ---
>   cache.c | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/cache.c b/cache.c
> index 0e92137..921e612 100644
> --- a/cache.c
> +++ b/cache.c
> @@ -76,7 +76,7 @@ cache_gc_timer(struct uloop_timeout *timeout)
>   	struct cache_service *s, *t;
>   
>   	avl_for_each_element_safe(&records, r, avl, p) {
> -		if (!cache_is_expired(r->time, r->ttl, 100))
> +		if (!cache_is_expired(r->time, r->ttl, r->refresh))
>   			continue;
>   		/* Records other and A(AAA) are handled as services */
>   		if (r->type != TYPE_A && r->type != TYPE_AAAA) {
> @@ -336,9 +336,11 @@ cache_answer(struct interface *iface, uint8_t *base, int blen, char *name, struc
>   		if (!a->ttl) {
>   			DBG(1, "D -> %s %s ttl:%d\n", dns_type_string(r->type), r->record, r->ttl);
>   			r->time = now + 1 - r->ttl;
> +			r->refresh = 100;
>   		} else {
>   			r->ttl = a->ttl;
>   			r->time = now;
> +			r->refresh = 50;
>   			DBG(1, "A -> %s %s ttl:%d\n", dns_type_string(r->type), r->record, r->ttl);
>   		}
>   		return;
> @@ -359,6 +361,7 @@ cache_answer(struct interface *iface, uint8_t *base, int blen, char *name, struc
>   	r->rdlength = dlen;
>   	r->time = now;
>   	r->iface = iface;
> +	r->refresh = 50;
>   
>   	if (tlen)
>   		r->txt = memcpy(txt_ptr, rdata_buffer, tlen);