[RFC PATCH 4/4] Add a new cache fill API that does a kernel get on each supported family.

[roopa at cumulusnetworks.com]

From: roopa <roopa at cumulusnetworks.com>

The current cache fill API does a get on AF_UNSPEC family.
And a kernel get on AF_UNSPEC family for neigh does not return AF_BRIDGE
objects.

To get objects from all families supported by a cache, this patch adds a
new kind of cache fill api for use during resync and cache creation times.

This new refill api, does a refill for each supported family one at a time.

I have also proposed this change in the context of adding AF_BRIDGE
support to link cache.

Signed-off-by: Roopa Prabhu <roopa at cumulusnetworks.com>
Reviewed-by: Nolan Leake <nolan at cumulusnetworks.com>
Reviewed-by: Shrijeet Mukherjee <shm at cumulusnetworks.com>
Reviewed-by: Wilson Kok <wkok at cumulusnetworks.com>
---
 include/netlink/cache.h |    2 +
 lib/cache.c             |   65 +++++++++++++++++++++++++++++++++++++++-------
 2 files changed, 57 insertions(+), 10 deletions(-)

diff --git a/include/netlink/cache.h b/include/netlink/cache.h
index fd137e1..7acfa40 100644
--- a/include/netlink/cache.h
+++ b/include/netlink/cache.h
@@ -54,6 +54,8 @@ extern int			nl_cache_parse_and_add(struct nl_cache *,
 extern void			nl_cache_remove(struct nl_object *);
 extern int			nl_cache_refill(struct nl_sock *,
 						struct nl_cache *);
+extern int			nl_cache_refill_assoc_families(struct nl_sock *,
+							       struct nl_cache *);
 extern int			nl_cache_pickup(struct nl_sock *,
 						struct nl_cache *);
 extern int			nl_cache_resync(struct nl_sock *,
diff --git a/lib/cache.c b/lib/cache.c
index 45a1a27..9abed0c 100644
--- a/lib/cache.c
+++ b/lib/cache.c
@@ -698,6 +698,7 @@ int nl_cache_resync(struct nl_sock *sk, struct nl_cache *cache,
 		    change_func_t change_cb, void *data)
 {
 	struct nl_object *obj, *next;
+	struct nl_af_group *grp;
 	struct nl_cache_assoc ca = {
 		.ca_cache = cache,
 		.ca_change = change_cb,
@@ -711,19 +712,22 @@ int nl_cache_resync(struct nl_sock *sk, struct nl_cache *cache,
 
 	NL_DBG(1, "Resyncing cache %p <%s>...\n", cache, nl_cache_name(cache));
 
-restart:
 	/* Mark all objects so we can see if some of them are obsolete */
 	nl_cache_mark_all(cache);
 
-	err = nl_cache_request_full_dump(sk, cache);
-	if (err < 0)
-		goto errout;
-
-	err = __cache_pickup(sk, cache, &p);
-	if (err == -NLE_DUMP_INTR)
-		goto restart;
-	else if (err < 0)
-		goto errout;
+        for (grp = cache->c_ops->co_groups; grp->ag_group; grp++) {
+		nl_cache_set_arg1(cache, grp->ag_family);
+restart:
+		err = nl_cache_request_full_dump(sk, cache);
+		if (err < 0)
+			goto errout;
+
+		err = __cache_pickup(sk, cache, &p);
+		if (err == -NLE_DUMP_INTR)
+			goto restart;
+		else if (err < 0)
+			goto errout;
+	}
 
 	nl_list_for_each_entry_safe(obj, next, &cache->c_items, ce_list) {
 		if (nl_object_is_marked(obj)) {
@@ -821,6 +825,47 @@ restart:
 		fprintf(stderr, "dump interrupted, restarting!\n");
 		goto restart;
 	}
+
+	return err;
+}
+
+/**
+ * (Re)fill a cache with the contents in the kernel for all
+ * families the cache is associated with
+ * @arg sk		Netlink socket.
+ * @arg cache		cache to update
+ *
+ * Clears the specified cache and fills it with the current state in
+ * the kernel.
+ *
+ * @return 0 or a negative error code.
+ */
+int nl_cache_refill_assoc_families(struct nl_sock *sk, struct nl_cache *cache)
+{
+	int err = 0;
+	struct nl_af_group *grp;
+
+	nl_cache_clear(cache);
+
+	for (grp = cache->c_ops->co_groups; grp->ag_group; grp++) {
+		nl_cache_set_arg1(cache, grp->ag_family);
+
+restart:
+		err = nl_cache_request_full_dump(sk, cache);
+		if (err < 0)
+			return err;
+
+		NL_DBG(2, "Upading cache %p <%s>, request sent, waiting for dump...\n",
+		       cache, nl_cache_name(cache));
+
+		err = nl_cache_pickup(sk, cache);
+		if (err == -NLE_DUMP_INTR) {
+			fprintf(stderr, "dump interrupted, restarting!\n");
+			goto restart;
+		}
+		else if (err < 0)
+			break;
+	}
 	
 	return err;
 }
-- 
1.7.2.5