netlink: Use ifindex of parent TC object when searching leaf qdiscs

The qdisc cache is host wide, the parent classid is not unique
so the ifindex of the parent tc object must be set in the filter
otherwise a leaf qdisc with an identical parent id in another
device can be mistaken.

This also converts the class_cache to be passed up through the
stack to make clear it is not system wide but specific to the
ifindex we are currently handling.

Signed-off-by: Thomas Graf <tgraf@suug.ch>

1 files changed, 15 insertions, 8 deletions

diff --git a/src/in_netlink.c b/src/in_netlink.c
index 84a841a..43019d3 100644
--- a/src/in_netlink.c
+++ b/src/in_netlink.c
@@ -491,12 +491,13 @@ static struct attr_map tc_attrs[] = {
 };
 
 struct rdata {
+	struct nl_cache *	class_cache;
 	struct element *	parent;
 	int 			level;
 };
 
 static struct nl_sock *sock;
-static struct nl_cache *link_cache, *qdisc_cache, *class_cache;
+static struct nl_cache *link_cache, *qdisc_cache;
 
 static void update_tc_attrs(struct element *e, struct rtnl_tc *tc)
 {
@@ -531,10 +532,10 @@ static void update_tc_infos(struct element *e, struct rtnl_tc *tc)
 
 static void handle_qdisc(struct nl_object *obj, void *);
 static void find_classes(uint32_t, struct rdata *);
-static void find_qdiscs(uint32_t, struct rdata *);
+static void find_qdiscs(int, uint32_t, struct rdata *);
 
 static struct element *handle_tc_obj(struct rtnl_tc *tc, const char *prefix,
-				     struct rdata *rdata)
+				     const struct rdata *rdata)
 {
 	char buf[IFNAME_MAX], name[IFNAME_MAX];
 	uint32_t id = rtnl_tc_get_handle(tc);
@@ -579,8 +580,9 @@ static void handle_class(struct nl_object *obj, void *arg)
 {
 	struct rtnl_tc *tc = (struct rtnl_tc *) obj;
 	struct element *e;
-	struct rdata *rdata = arg;
+	const struct rdata *rdata = arg;
 	struct rdata ndata = {
+		.class_cache = rdata->class_cache,
 		.level = rdata->level + 1,
 	};
 
@@ -593,10 +595,10 @@ static void handle_class(struct nl_object *obj, void *arg)
 		element_set_txmax(e, rtnl_htb_get_rate((struct rtnl_class *) tc));
 
 	find_classes(rtnl_tc_get_handle(tc), &ndata);
-	find_qdiscs(rtnl_tc_get_handle(tc), &ndata);
+	find_qdiscs(rtnl_tc_get_ifindex(tc), rtnl_tc_get_handle(tc), &ndata);
 }
 
-static void find_qdiscs(uint32_t parent, struct rdata *rdata)
+static void find_qdiscs(int ifindex, uint32_t parent, struct rdata *rdata)
 {
 	struct rtnl_qdisc *filter;
 
@@ -604,6 +606,7 @@ static void find_qdiscs(uint32_t parent, struct rdata *rdata)
 		return;
 
 	rtnl_tc_set_parent((struct rtnl_tc *) filter, parent);
+	rtnl_tc_set_ifindex((struct rtnl_tc *) filter, ifindex);
 
 	nl_cache_foreach_filter(qdisc_cache, OBJ_CAST(filter),
 				handle_qdisc, rdata);
@@ -632,7 +635,7 @@ static void find_classes(uint32_t parent, struct rdata *rdata)
 
 	rtnl_tc_set_parent((struct rtnl_tc *) filter, parent);
 
-	nl_cache_foreach_filter(class_cache, OBJ_CAST(filter),
+	nl_cache_foreach_filter(rdata->class_cache, OBJ_CAST(filter),
 				handle_class, rdata);
 
 	rtnl_class_put(filter);
@@ -642,8 +645,9 @@ static void handle_qdisc(struct nl_object *obj, void *arg)
 {
 	struct rtnl_tc *tc = (struct rtnl_tc *) obj;
 	struct element *e;
-	struct rdata *rdata = arg;
+	const struct rdata *rdata = arg;
 	struct rdata ndata = {
+		.class_cache = rdata->class_cache,
 		.level = rdata->level + 1,
 	};
 
@@ -665,6 +669,7 @@ static void handle_qdisc(struct nl_object *obj, void *arg)
 static void handle_tc(struct element *e, struct rtnl_link *link)
 {
 	struct rtnl_qdisc *qdisc;
+	struct nl_cache *class_cache;
 	int ifindex = rtnl_link_get_ifindex(link);
 	struct rdata rdata = {
 		.level = 1,
@@ -674,6 +679,8 @@ static void handle_tc(struct element *e, struct rtnl_link *link)
 	if (rtnl_class_alloc_cache(sock, ifindex, &class_cache) < 0)
 		return;
 
+	rdata.class_cache = class_cache;
+
 	qdisc = rtnl_qdisc_get_by_parent(qdisc_cache, ifindex, TC_H_ROOT);
 	if (qdisc) {
 		handle_qdisc(OBJ_CAST(qdisc), &rdata);