net: bridge: vlan: include stats in dumps if requested

This patch adds support for vlan stats to be included when dumping vlan
information. We have to dump them only when explicitly requested (thus the
flag below) because that disables the vlan range compression and will make
the dump significantly larger. In order to request the stats to be
included we add a new dump attribute called BRIDGE_VLANDB_DUMP_FLAGS which
can affect dumps with the following first flag:
  - BRIDGE_VLANDB_DUMPF_STATS
The stats are intentionally nested and put into separate attributes to make
it easier for extending later since we plan to add per-vlan mcast stats,
drop stats and possibly STP stats. This is the last missing piece from the
new vlan API which makes the dumped vlan information complete.

A dump request which should include stats looks like:
 [BRIDGE_VLANDB_DUMP_FLAGS] |= BRIDGE_VLANDB_DUMPF_STATS

A vlandb entry attribute with stats looks like:
 [BRIDGE_VLANDB_ENTRY] = {
     [BRIDGE_VLANDB_ENTRY_STATS] = {
         [BRIDGE_VLANDB_STATS_RX_BYTES]
         [BRIDGE_VLANDB_STATS_RX_PACKETS]
         ...
     }
 }
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/uapi/linux/if_bridge.h

@@ -175,6 +175,16 @@ struct br_vlan_msg {
 	__u32 ifindex;
 };
 
+enum {
+	BRIDGE_VLANDB_DUMP_UNSPEC,
+	BRIDGE_VLANDB_DUMP_FLAGS,
+	__BRIDGE_VLANDB_DUMP_MAX,
+};
+#define BRIDGE_VLANDB_DUMP_MAX (__BRIDGE_VLANDB_DUMP_MAX - 1)
+
+/* flags used in BRIDGE_VLANDB_DUMP_FLAGS attribute to affect dumps */
+#define BRIDGE_VLANDB_DUMPF_STATS	(1 << 0) /* Include stats in the dump */
+
 /* Bridge vlan RTM attributes
  * [BRIDGE_VLANDB_ENTRY] = {
  *     [BRIDGE_VLANDB_ENTRY_INFO]
@@ -194,10 +204,30 @@ enum {
 	BRIDGE_VLANDB_ENTRY_RANGE,
 	BRIDGE_VLANDB_ENTRY_STATE,
 	BRIDGE_VLANDB_ENTRY_TUNNEL_ID,
+	BRIDGE_VLANDB_ENTRY_STATS,
 	__BRIDGE_VLANDB_ENTRY_MAX,
 };
 #define BRIDGE_VLANDB_ENTRY_MAX (__BRIDGE_VLANDB_ENTRY_MAX - 1)
 
+/* [BRIDGE_VLANDB_ENTRY] = {
+ *     [BRIDGE_VLANDB_ENTRY_STATS] = {
+ *         [BRIDGE_VLANDB_STATS_RX_BYTES]
+ *         ...
+ *     }
+ *     ...
+ * }
+ */
+enum {
+	BRIDGE_VLANDB_STATS_UNSPEC,
+	BRIDGE_VLANDB_STATS_RX_BYTES,
+	BRIDGE_VLANDB_STATS_RX_PACKETS,
+	BRIDGE_VLANDB_STATS_TX_BYTES,
+	BRIDGE_VLANDB_STATS_TX_PACKETS,
+	BRIDGE_VLANDB_STATS_PAD,
+	__BRIDGE_VLANDB_STATS_MAX,
+};
+#define BRIDGE_VLANDB_STATS_MAX (__BRIDGE_VLANDB_STATS_MAX - 1)
+
 /* Bridge multicast database attributes
  * [MDBA_MDB] = {
  *     [MDBA_MDB_ENTRY] = {

net/bridge/br_vlan.c

@@ -1569,10 +1569,41 @@ void br_vlan_port_event(struct net_bridge_port *p, unsigned long event)
 	}
 }
 
+static bool br_vlan_stats_fill(struct sk_buff *skb,
+			       const struct net_bridge_vlan *v)
+{
+	struct br_vlan_stats stats;
+	struct nlattr *nest;
+
+	nest = nla_nest_start(skb, BRIDGE_VLANDB_ENTRY_STATS);
+	if (!nest)
+		return false;
+
+	br_vlan_get_stats(v, &stats);
+	if (nla_put_u64_64bit(skb, BRIDGE_VLANDB_STATS_RX_BYTES, stats.rx_bytes,
+			      BRIDGE_VLANDB_STATS_PAD) ||
+	    nla_put_u64_64bit(skb, BRIDGE_VLANDB_STATS_RX_PACKETS,
+			      stats.rx_packets, BRIDGE_VLANDB_STATS_PAD) ||
+	    nla_put_u64_64bit(skb, BRIDGE_VLANDB_STATS_TX_BYTES, stats.tx_bytes,
+			      BRIDGE_VLANDB_STATS_PAD) ||
+	    nla_put_u64_64bit(skb, BRIDGE_VLANDB_STATS_TX_PACKETS,
+			      stats.tx_packets, BRIDGE_VLANDB_STATS_PAD))
+		goto out_err;
+
+	nla_nest_end(skb, nest);
+
+	return true;
+
+out_err:
+	nla_nest_cancel(skb, nest);
+	return false;
+}
+
 /* v_opts is used to dump the options which must be equal in the whole range */
 static bool br_vlan_fill_vids(struct sk_buff *skb, u16 vid, u16 vid_range,
 			      const struct net_bridge_vlan *v_opts,
-			      u16 flags)
+			      u16 flags,
+			      bool dump_stats)
 {
 	struct bridge_vlan_info info;
 	struct nlattr *nest;
@@ -1596,9 +1627,14 @@ static bool br_vlan_fill_vids(struct sk_buff *skb, u16 vid, u16 vid_range,
 	    nla_put_u16(skb, BRIDGE_VLANDB_ENTRY_RANGE, vid_range))
 		goto out_err;
 
-	if (v_opts && !br_vlan_opts_fill(skb, v_opts))
+	if (v_opts) {
+		if (!br_vlan_opts_fill(skb, v_opts))
 			goto out_err;
 
+		if (dump_stats && !br_vlan_stats_fill(skb, v_opts))
+			goto out_err;
+	}
+
 	nla_nest_end(skb, nest);
 
 	return true;
@@ -1675,7 +1711,7 @@ void br_vlan_notify(const struct net_bridge *br,
 		goto out_kfree;
 	}
 
-	if (!br_vlan_fill_vids(skb, vid, vid_range, v, flags))
+	if (!br_vlan_fill_vids(skb, vid, vid_range, v, flags, false))
 		goto out_err;
 
 	nlmsg_end(skb, nlh);
@@ -1699,9 +1735,11 @@ bool br_vlan_can_enter_range(const struct net_bridge_vlan *v_curr,
 
 static int br_vlan_dump_dev(const struct net_device *dev,
 			    struct sk_buff *skb,
-			    struct netlink_callback *cb)
+			    struct netlink_callback *cb,
+			    u32 dump_flags)
 {
 	struct net_bridge_vlan *v, *range_start = NULL, *range_end = NULL;
+	bool dump_stats = !!(dump_flags & BRIDGE_VLANDB_DUMPF_STATS);
 	struct net_bridge_vlan_group *vg;
 	int idx = 0, s_idx = cb->args[1];
 	struct nlmsghdr *nlh = NULL;
@@ -1754,12 +1792,13 @@ static int br_vlan_dump_dev(const struct net_device *dev,
 			continue;
 		}
 
-		if (v->vid == pvid || !br_vlan_can_enter_range(v, range_end)) {
-			u16 flags = br_vlan_flags(range_start, pvid);
+		if (dump_stats || v->vid == pvid ||
+		    !br_vlan_can_enter_range(v, range_end)) {
+			u16 vlan_flags = br_vlan_flags(range_start, pvid);
 
 			if (!br_vlan_fill_vids(skb, range_start->vid,
 					       range_end->vid, range_start,
-					       flags)) {
+					       vlan_flags, dump_stats)) {
 				err = -EMSGSIZE;
 				break;
 			}
@@ -1778,7 +1817,8 @@ static int br_vlan_dump_dev(const struct net_device *dev,
 	 */
 	if (!err && range_start &&
 	    !br_vlan_fill_vids(skb, range_start->vid, range_end->vid,
-			       range_start, br_vlan_flags(range_start, pvid)))
+			       range_start, br_vlan_flags(range_start, pvid),
+			       dump_stats))
 		err = -EMSGSIZE;
 
 	cb->args[1] = err ? idx : 0;
@@ -1788,18 +1828,27 @@ static int br_vlan_dump_dev(const struct net_device *dev,
 	return err;
 }
 
+static const struct nla_policy br_vlan_db_dump_pol[BRIDGE_VLANDB_DUMP_MAX + 1] = {
+	[BRIDGE_VLANDB_DUMP_FLAGS] = { .type = NLA_U32 },
+};
+
 static int br_vlan_rtm_dump(struct sk_buff *skb, struct netlink_callback *cb)
 {
+	struct nlattr *dtb[BRIDGE_VLANDB_DUMP_MAX + 1];
 	int idx = 0, err = 0, s_idx = cb->args[0];
 	struct net *net = sock_net(skb->sk);
 	struct br_vlan_msg *bvm;
 	struct net_device *dev;
+	u32 dump_flags = 0;
 
-	err = nlmsg_parse(cb->nlh, sizeof(*bvm), NULL, 0, NULL, cb->extack);
+	err = nlmsg_parse(cb->nlh, sizeof(*bvm), dtb, BRIDGE_VLANDB_DUMP_MAX,
+			  br_vlan_db_dump_pol, cb->extack);
 	if (err < 0)
 		return err;
 
 	bvm = nlmsg_data(cb->nlh);
+	if (dtb[BRIDGE_VLANDB_DUMP_FLAGS])
+		dump_flags = nla_get_u32(dtb[BRIDGE_VLANDB_DUMP_FLAGS]);
 
 	rcu_read_lock();
 	if (bvm->ifindex) {
@@ -1808,7 +1857,7 @@ static int br_vlan_rtm_dump(struct sk_buff *skb, struct netlink_callback *cb)
 			err = -ENODEV;
 			goto out_err;
 		}
-		err = br_vlan_dump_dev(dev, skb, cb);
+		err = br_vlan_dump_dev(dev, skb, cb, dump_flags);
 		if (err && err != -EMSGSIZE)
 			goto out_err;
 	} else {
@@ -1816,7 +1865,7 @@ static int br_vlan_rtm_dump(struct sk_buff *skb, struct netlink_callback *cb)
 			if (idx < s_idx)
 				goto skip;
 
-			err = br_vlan_dump_dev(dev, skb, cb);
+			err = br_vlan_dump_dev(dev, skb, cb, dump_flags);
 			if (err == -EMSGSIZE)
 				break;
 skip: