fq: support filtering a given tin

Add to the FQ API a way to filter a given tin, in order to
remove frames that fulfil certain criteria according to a
filter function.

This will be used by mac80211 to remove frames belonging to
an AP VLAN interface that's being removed.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/include/net/fq.h b/include/net/fq.h
index 6d8521a30c5cf3951a868aea9b7817ffda749de4..ac944a686840f99b51553511a5d62a1093406118 100644 (file)
--- a/include/net/fq.h
+++ b/include/net/fq.h
@@ -90,6 +90,13 @@ typedef void fq_skb_free_t(struct fq *,
                           struct fq_flow *,
                           struct sk_buff *);
 
+/* Return %true to filter (drop) the frame. */
+typedef bool fq_skb_filter_t(struct fq *,
+                            struct fq_tin *,
+                            struct fq_flow *,
+                            struct sk_buff *,
+                            void *);
+
 typedef struct fq_flow *fq_flow_get_default_t(struct fq *,
                                              struct fq_tin *,
                                              int idx,

diff --git a/include/net/fq_impl.h b/include/net/fq_impl.h
index 4e6131cd3f43dfb711049a1925abbea6074ec25b..8b237e4afee6f6bfeb27de41fb96fd18633d3456 100644 (file)
--- a/include/net/fq_impl.h
+++ b/include/net/fq_impl.h
@@ -12,24 +12,22 @@
 
 /* functions that are embedded into includer */
 
-static struct sk_buff *fq_flow_dequeue(struct fq *fq,
-                                      struct fq_flow *flow)
+static void fq_adjust_removal(struct fq *fq,
+                             struct fq_flow *flow,
+                             struct sk_buff *skb)
 {
        struct fq_tin *tin = flow->tin;
-       struct fq_flow *i;
-       struct sk_buff *skb;
-
-       lockdep_assert_held(&fq->lock);
-
-       skb = __skb_dequeue(&flow->queue);
-       if (!skb)
-               return NULL;
 
        tin->backlog_bytes -= skb->len;
        tin->backlog_packets--;
        flow->backlog -= skb->len;
        fq->backlog--;
        fq->memory_usage -= skb->truesize;
+}
+
+static void fq_rejigger_backlog(struct fq *fq, struct fq_flow *flow)
+{
+       struct fq_flow *i;
 
        if (flow->backlog == 0) {
                list_del_init(&flow->backlogchain);
@@ -43,6 +41,21 @@ static struct sk_buff *fq_flow_dequeue(struct fq *fq,
                list_move_tail(&flow->backlogchain,
                               &i->backlogchain);
        }
+}
+
+static struct sk_buff *fq_flow_dequeue(struct fq *fq,
+                                      struct fq_flow *flow)
+{
+       struct sk_buff *skb;
+
+       lockdep_assert_held(&fq->lock);
+
+       skb = __skb_dequeue(&flow->queue);
+       if (!skb)
+               return NULL;
+
+       fq_adjust_removal(fq, flow, skb);
+       fq_rejigger_backlog(fq, flow);
 
        return skb;
 }
@@ -188,6 +201,45 @@ static void fq_tin_enqueue(struct fq *fq,
        }
 }
 
+static void fq_flow_filter(struct fq *fq,
+                          struct fq_flow *flow,
+                          fq_skb_filter_t filter_func,
+                          void *filter_data,
+                          fq_skb_free_t free_func)
+{
+       struct fq_tin *tin = flow->tin;
+       struct sk_buff *skb, *tmp;
+
+       lockdep_assert_held(&fq->lock);
+
+       skb_queue_walk_safe(&flow->queue, skb, tmp) {
+               if (!filter_func(fq, tin, flow, skb, filter_data))
+                       continue;
+
+               __skb_unlink(skb, &flow->queue);
+               fq_adjust_removal(fq, flow, skb);
+               free_func(fq, tin, flow, skb);
+       }
+
+       fq_rejigger_backlog(fq, flow);
+}
+
+static void fq_tin_filter(struct fq *fq,
+                         struct fq_tin *tin,
+                         fq_skb_filter_t filter_func,
+                         void *filter_data,
+                         fq_skb_free_t free_func)
+{
+       struct fq_flow *flow;
+
+       lockdep_assert_held(&fq->lock);
+
+       list_for_each_entry(flow, &tin->new_flows, flowchain)
+               fq_flow_filter(fq, flow, filter_func, filter_data, free_func);
+       list_for_each_entry(flow, &tin->old_flows, flowchain)
+               fq_flow_filter(fq, flow, filter_func, filter_data, free_func);
+}
+
 static void fq_flow_reset(struct fq *fq,
                          struct fq_flow *flow,
                          fq_skb_free_t free_func)