[LEDE-DEV] [PATCH umdns 1/3] Access cached records (instead of services) to read list of hosts

[Rafał Miłecki]

From: Rafał Miłecki <rafal at milecki.pl>

We don't need to access hosts stored as services. It's enough to look
for cached A and AAAA DNS records.

Signed-off-by: Rafał Miłecki <rafal at milecki.pl>
---
 cache.c |  2 +-
 cache.h |  1 +
 ubus.c  | 17 +++++++++++------
 3 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/cache.c b/cache.c
index 756ae68..3f3f617 100644
--- a/cache.c
+++ b/cache.c
@@ -42,7 +42,7 @@
 
 static struct uloop_timeout cache_gc;
 struct avl_tree services;
-static AVL_TREE(records, avl_strcmp, true, NULL);
+AVL_TREE(records, avl_strcmp, true, NULL);
 
 static void
 cache_record_free(struct cache_record *r)
diff --git a/cache.h b/cache.h
index 7830b4f..cfd6368 100644
--- a/cache.h
+++ b/cache.h
@@ -47,6 +47,7 @@ struct cache_record {
 };
 
 extern struct avl_tree services;
+extern struct avl_tree records;
 
 int cache_init(void);
 void cache_update(void);
diff --git a/ubus.c b/ubus.c
index 4120fd5..cf2c05b 100644
--- a/ubus.c
+++ b/ubus.c
@@ -96,16 +96,21 @@ umdns_hosts(struct ubus_context *ctx, struct ubus_object *obj,
 		struct ubus_request_data *req, const char *method,
 		struct blob_attr *msg)
 {
-	struct cache_service *s;
+	struct cache_record *prev = NULL;
+	struct cache_record *r;
 	void *c;
 
 	blob_buf_init(&b, 0);
-	avl_for_each_element(&services, s, avl) {
-		if (!cache_service_is_host(s))
+	avl_for_each_element(&records, r, avl) {
+		if (r->type != TYPE_A && r->type != TYPE_AAAA)
 			continue;
-		c = blobmsg_open_table(&b, s->entry);
-		cache_dump_records(&b, s->entry);
-		blobmsg_close_table(&b, c);
+		/* Query each domain just once */
+		if (!prev || strcmp(r->record, prev->record)) {
+			c = blobmsg_open_table(&b, r->record);
+			cache_dump_records(&b, r->record);
+			blobmsg_close_table(&b, c);
+		}
+		prev = r;
 	}
 	ubus_send_reply(ctx, req, b.head);
 
-- 
2.11.0