bridge: per vlan dst_metadata netlink support

This patch adds support to attach per vlan tunnel info dst
metadata. This enables bridge driver to map vlan to tunnel_info
at ingress and egress. It uses the kernel dst_metadata infrastructure.

The initial use case is vlan to vni bridging, but the api is generic
to extend to any tunnel_info in the future:
    - Uapi to configure/unconfigure/dump per vlan tunnel data
    - netlink functions to configure vlan and tunnel_info mapping
    - Introduces bridge port flag BR_LWT_VLAN to enable attach/detach
    dst_metadata to bridged packets on ports. off by default.
    - changes to existing code is mainly refactor some existing vlan
    handling netlink code + hooks for new vlan tunnel code
    - I have kept the vlan tunnel code isolated in separate files.
    - most of the netlink vlan tunnel code is handling of vlan-tunid
    ranges (follows the vlan range handling code). To conserve space
    vlan-tunid by default are always dumped in ranges if applicable.

Use case:
example use for this is a vxlan bridging gateway or vtep
which maps vlans to vn-segments (or vnis).

iproute2 example (patched and pruned iproute2 output to just show
relevant fdb entries):
example shows same host mac learnt on two vni's and
vlan 100 maps to vni 1000, vlan 101 maps to vni 1001

before (netdev per vni):
$bridge fdb show | grep "00:02:00:00:00:03"
00:02:00:00:00:03 dev vxlan1001 vlan 101 master bridge
00:02:00:00:00:03 dev vxlan1001 dst 12.0.0.8 self
00:02:00:00:00:03 dev vxlan1000 vlan 100 master bridge
00:02:00:00:00:03 dev vxlan1000 dst 12.0.0.8 self

after this patch with collect metdata in bridged mode (single netdev):
$bridge fdb show | grep "00:02:00:00:00:03"
00:02:00:00:00:03 dev vxlan0 vlan 101 master bridge
00:02:00:00:00:03 dev vxlan0 src_vni 1001 dst 12.0.0.8 self
00:02:00:00:00:03 dev vxlan0 vlan 100 master bridge
00:02:00:00:00:03 dev vxlan0 src_vni 1000 dst 12.0.0.8 self

CC: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/bridge/Makefile

@@ -6,7 +6,8 @@ obj-$(CONFIG_BRIDGE) += bridge.o
 
 bridge-y := br.o br_device.o br_fdb.o br_forward.o br_if.o br_input.o \
  br_ioctl.o br_stp.o br_stp_bpdu.o \
- br_stp_if.o br_stp_timer.o br_netlink.o
+ br_stp_if.o br_stp_timer.o br_netlink.o \
+ br_netlink_tunnel.o
 
 bridge-$(CONFIG_SYSFS) += br_sysfs_if.o br_sysfs_br.o
 
@@ -18,7 +19,7 @@ obj-$(CONFIG_BRIDGE_NETFILTER) += br_netfilter.o
 
 bridge-$(CONFIG_BRIDGE_IGMP_SNOOPING) += br_multicast.o br_mdb.o
 
-bridge-$(CONFIG_BRIDGE_VLAN_FILTERING) += br_vlan.o
+bridge-$(CONFIG_BRIDGE_VLAN_FILTERING) += br_vlan.o br_vlan_tunnel.o
 
 bridge-$(CONFIG_NET_SWITCHDEV) += br_switchdev.o
 

net/bridge/br_netlink.c

@@ -20,6 +20,7 @@
 
 #include "br_private.h"
 #include "br_private_stp.h"
+#include "br_private_tunnel.h"
 
 static int __get_num_vlan_infos(struct net_bridge_vlan_group *vg,
  u32 filter_mask)
@@ -95,9 +96,10 @@ static size_t br_get_link_af_size_filtered(const struct net_device *dev,
  u32 filter_mask)
 {
  struct net_bridge_vlan_group *vg = NULL;
- struct net_bridge_port *p;
+ struct net_bridge_port *p = NULL;
  struct net_bridge *br;
  int num_vlan_infos;
+ size_t vinfo_sz = 0;
 
  rcu_read_lock();
  if (br_port_exists(dev)) {
@@ -110,8 +112,13 @@ static size_t br_get_link_af_size_filtered(const struct net_device *dev,
  num_vlan_infos = br_get_num_vlan_infos(vg, filter_mask);
  rcu_read_unlock();
 
+ if (p && (p->flags & BR_VLAN_TUNNEL))
+ vinfo_sz += br_get_vlan_tunnel_info_size(vg);
+
  /* Each VLAN is returned in bridge_vlan_info along with flags */
- return num_vlan_infos * nla_total_size(sizeof(struct bridge_vlan_info));
+ vinfo_sz += num_vlan_infos * nla_total_size(sizeof(struct bridge_vlan_info));
+
+ return vinfo_sz;
 }
 
 static inline size_t br_port_info_size(void)
@@ -128,6 +135,7 @@ static inline size_t br_port_info_size(void)
  + nla_total_size(1) /* IFLA_BRPORT_UNICAST_FLOOD */
  + nla_total_size(1) /* IFLA_BRPORT_PROXYARP */
  + nla_total_size(1) /* IFLA_BRPORT_PROXYARP_WIFI */
+ + nla_total_size(1) /* IFLA_BRPORT_VLAN_TUNNEL */
  + nla_total_size(sizeof(struct ifla_bridge_id)) /* IFLA_BRPORT_ROOT_ID */
  + nla_total_size(sizeof(struct ifla_bridge_id)) /* IFLA_BRPORT_BRIDGE_ID */
  + nla_total_size(sizeof(u16)) /* IFLA_BRPORT_DESIGNATED_PORT */
@@ -194,7 +202,9 @@ static int br_port_fill_attrs(struct sk_buff *skb,
  nla_put_u16(skb, IFLA_BRPORT_NO, p->port_no) ||
  nla_put_u8(skb, IFLA_BRPORT_TOPOLOGY_CHANGE_ACK,
  p->topology_change_ack) ||
- nla_put_u8(skb, IFLA_BRPORT_CONFIG_PENDING, p->config_pending))
+ nla_put_u8(skb, IFLA_BRPORT_CONFIG_PENDING, p->config_pending) ||
+ nla_put_u8(skb, IFLA_BRPORT_VLAN_TUNNEL, !!(p->flags &
+ BR_VLAN_TUNNEL)))
  return -EMSGSIZE;
 
  timerval = br_timer_value(&p->message_age_timer);
@@ -417,6 +427,9 @@ static int br_fill_ifinfo(struct sk_buff *skb,
  err = br_fill_ifvlaninfo_compressed(skb, vg);
  else
  err = br_fill_ifvlaninfo(skb, vg);
+
+ if (port && (port->flags & BR_VLAN_TUNNEL))
+ err = br_fill_vlan_tunnel_info(skb, vg);
  rcu_read_unlock();
  if (err)
  goto nla_put_failure;
@@ -517,60 +530,91 @@ static int br_vlan_info(struct net_bridge *br, struct net_bridge_port *p,
  return err;
 }
 
+static int br_process_vlan_info(struct net_bridge *br,
+ struct net_bridge_port *p, int cmd,
+ struct bridge_vlan_info *vinfo_curr,
+ struct bridge_vlan_info **vinfo_last)
+{
+ if (!vinfo_curr->vid || vinfo_curr->vid >= VLAN_VID_MASK)
+ return -EINVAL;
+
+ if (vinfo_curr->flags & BRIDGE_VLAN_INFO_RANGE_BEGIN) {
+ /* check if we are already processing a range */
+ if (*vinfo_last)
+ return -EINVAL;
+ *vinfo_last = vinfo_curr;
+ /* don't allow range of pvids */
+ if ((*vinfo_last)->flags & BRIDGE_VLAN_INFO_PVID)
+ return -EINVAL;
+ return 0;
+ }
+
+ if (*vinfo_last) {
+ struct bridge_vlan_info tmp_vinfo;
+ int v, err;
+
+ if (!(vinfo_curr->flags & BRIDGE_VLAN_INFO_RANGE_END))
+ return -EINVAL;
+
+ if (vinfo_curr->vid <= (*vinfo_last)->vid)
+ return -EINVAL;
+
+ memcpy(&tmp_vinfo, *vinfo_last,
+ sizeof(struct bridge_vlan_info));
+ for (v = (*vinfo_last)->vid; v <= vinfo_curr->vid; v++) {
+ tmp_vinfo.vid = v;
+ err = br_vlan_info(br, p, cmd, &tmp_vinfo);
+ if (err)
+ break;
+ }
+ *vinfo_last = NULL;
+
+ return 0;
+ }
+
+ return br_vlan_info(br, p, cmd, vinfo_curr);
+}
+
 static int br_afspec(struct net_bridge *br,
  struct net_bridge_port *p,
  struct nlattr *af_spec,
  int cmd)
 {
- struct bridge_vlan_info *vinfo_start = NULL;
- struct bridge_vlan_info *vinfo = NULL;
+ struct bridge_vlan_info *vinfo_curr = NULL;
+ struct bridge_vlan_info *vinfo_last = NULL;
  struct nlattr *attr;
- int err = 0;
- int rem;
+ struct vtunnel_info tinfo_last = {};
+ struct vtunnel_info tinfo_curr = {};
+ int err = 0, rem;
 
  nla_for_each_nested(attr, af_spec, rem) {
- if (nla_type(attr) != IFLA_BRIDGE_VLAN_INFO)
- continue;
- if (nla_len(attr) != sizeof(struct bridge_vlan_info))
- return -EINVAL;
- vinfo = nla_data(attr);
- if (!vinfo->vid || vinfo->vid >= VLAN_VID_MASK)
- return -EINVAL;
- if (vinfo->flags & BRIDGE_VLAN_INFO_RANGE_BEGIN) {
- if (vinfo_start)
+ err = 0;
+ switch (nla_type(attr)) {
+ case IFLA_BRIDGE_VLAN_TUNNEL_INFO:
+ if (!(p->flags & BR_VLAN_TUNNEL))
  return -EINVAL;
- vinfo_start = vinfo;
- /* don't allow range of pvids */
- if (vinfo_start->flags & BRIDGE_VLAN_INFO_PVID)
+ err = br_parse_vlan_tunnel_info(attr, &tinfo_curr);
+ if (err)
+ return err;
+ err = br_process_vlan_tunnel_info(br, p, cmd,
+ &tinfo_curr,
+ &tinfo_last);
+ if (err)
+ return err;
+ break;
+ case IFLA_BRIDGE_VLAN_INFO:
+ if (nla_len(attr) != sizeof(struct bridge_vlan_info))
  return -EINVAL;
- continue;
+ vinfo_curr = nla_data(attr);
+ err = br_process_vlan_info(br, p, cmd, vinfo_curr,
+ &vinfo_last);
+ if (err)
+ return err;
+ break;
  }
 
- if (vinfo_start) {
- struct bridge_vlan_info tmp_vinfo;
- int v;
-
- if (!(vinfo->flags & BRIDGE_VLAN_INFO_RANGE_END))
- return -EINVAL;
-
- if (vinfo->vid <= vinfo_start->vid)
- return -EINVAL;
-
- memcpy(&tmp_vinfo, vinfo_start,
- sizeof(struct bridge_vlan_info));
-
- for (v = vinfo_start->vid; v <= vinfo->vid; v++) {
- tmp_vinfo.vid = v;
- err = br_vlan_info(br, p, cmd, &tmp_vinfo);
- if (err)
- break;
- }
- vinfo_start = NULL;
- } else {
- err = br_vlan_info(br, p, cmd, vinfo);
- }
  if (err)
- break;
+ return err;
  }
 
  return err;
@@ -630,8 +674,9 @@ static void br_set_port_flag(struct net_bridge_port *p, struct nlattr *tb[],
 /* Process bridge protocol info on port */
 static int br_setport(struct net_bridge_port *p, struct nlattr *tb[])
 {
- int err;
  unsigned long old_flags = p->flags;
+ bool br_vlan_tunnel_old = false;
+ int err;
 
  br_set_port_flag(p, tb, IFLA_BRPORT_MODE, BR_HAIRPIN_MODE);
  br_set_port_flag(p, tb, IFLA_BRPORT_GUARD, BR_BPDU_GUARD);
@@ -644,6 +689,11 @@ static int br_setport(struct net_bridge_port *p, struct nlattr *tb[])
  br_set_port_flag(p, tb, IFLA_BRPORT_PROXYARP, BR_PROXYARP);
  br_set_port_flag(p, tb, IFLA_BRPORT_PROXYARP_WIFI, BR_PROXYARP_WIFI);
 
+ br_vlan_tunnel_old = (p->flags & BR_VLAN_TUNNEL) ? true : false;
+ br_set_port_flag(p, tb, IFLA_BRPORT_VLAN_TUNNEL, BR_VLAN_TUNNEL);
+ if (br_vlan_tunnel_old && !(p->flags & BR_VLAN_TUNNEL))
+ nbp_vlan_tunnel_info_flush(p);
+
  if (tb[IFLA_BRPORT_COST]) {
  err = br_stp_set_path_cost(p, nla_get_u32(tb[IFLA_BRPORT_COST]));
  if (err)