net: bridge: add per-port group_fwd_mask with less restrictions

We need to be able to transparently forward most link-local frames via
tunnels (e.g. vxlan, qinq). Currently the bridge's group_fwd_mask has a
mask which restricts the forwarding of STP and LACP, but we need to be able
to forward these over tunnels and control that forwarding on a per-port
basis thus add a new per-port group_fwd_mask option which only disallows
mac pause frames to be forwarded (they're always dropped anyway).
The patch does not change the current default situation - all of the others
are still restricted unless configured for forwarding.
We have successfully tested this patch with LACP and STP forwarding over
VxLAN and qinq tunnels.

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

diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index 8d062c5..ea87bd7 100644 (file)
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -325,6 +325,7 @@ enum {
        IFLA_BRPORT_MCAST_TO_UCAST,
        IFLA_BRPORT_VLAN_TUNNEL,
        IFLA_BRPORT_BCAST_FLOOD,
+       IFLA_BRPORT_GROUP_FWD_MASK,
        __IFLA_BRPORT_MAX
 };
 #define IFLA_BRPORT_MAX (__IFLA_BRPORT_MAX - 1)

diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index 7637f58..7cb6137 100644 (file)
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -289,6 +289,7 @@ rx_handler_result_t br_handle_frame(struct sk_buff **pskb)
                 *
                 * Others reserved for future standardization
                 */
+               fwd_mask |= p->group_fwd_mask;
                switch (dest[5]) {
                case 0x00:      /* Bridge Group Address */
                        /* If STP is turned off,

diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 3bc8907..dea88a2 100644 (file)
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -152,6 +152,7 @@ static inline size_t br_port_info_size(void)
 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
                + nla_total_size(sizeof(u8))    /* IFLA_BRPORT_MULTICAST_ROUTER */
 #endif
+               + nla_total_size(sizeof(u16))   /* IFLA_BRPORT_GROUP_FWD_MASK */
                + 0;
 }
 
@@ -208,7 +209,8 @@ static int br_port_fill_attrs(struct sk_buff *skb,
                       p->topology_change_ack) ||
            nla_put_u8(skb, IFLA_BRPORT_CONFIG_PENDING, p->config_pending) ||
            nla_put_u8(skb, IFLA_BRPORT_VLAN_TUNNEL, !!(p->flags &
-                                                       BR_VLAN_TUNNEL)))
+                                                       BR_VLAN_TUNNEL)) ||
+           nla_put_u16(skb, IFLA_BRPORT_GROUP_FWD_MASK, p->group_fwd_mask))
                return -EMSGSIZE;
 
        timerval = br_timer_value(&p->message_age_timer);
@@ -637,6 +639,7 @@ static const struct nla_policy br_port_policy[IFLA_BRPORT_MAX + 1] = {
        [IFLA_BRPORT_MCAST_TO_UCAST] = { .type = NLA_U8 },
        [IFLA_BRPORT_MCAST_FLOOD] = { .type = NLA_U8 },
        [IFLA_BRPORT_BCAST_FLOOD] = { .type = NLA_U8 },
+       [IFLA_BRPORT_GROUP_FWD_MASK] = { .type = NLA_U16 },
 };
 
 /* Change the state of the port and notify spanning tree */
@@ -773,6 +776,15 @@ static int br_setport(struct net_bridge_port *p, struct nlattr *tb[])
                        return err;
        }
 #endif
+
+       if (tb[IFLA_BRPORT_GROUP_FWD_MASK]) {
+               u16 fwd_mask = nla_get_u16(tb[IFLA_BRPORT_GROUP_FWD_MASK]);
+
+               if (fwd_mask & BR_GROUPFWD_MACPAUSE)
+                       return -EINVAL;
+               p->group_fwd_mask = fwd_mask;
+       }
+
        br_port_flags_change(p, old_flags ^ p->flags);
        return 0;
 }

diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index e870cfc..020c709 100644 (file)
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -36,7 +36,14 @@
 /* Control of forwarding link local multicast */
 #define BR_GROUPFWD_DEFAULT    0
 /* Don't allow forwarding of control protocols like STP, MAC PAUSE and LACP */
-#define BR_GROUPFWD_RESTRICTED 0x0007u
+enum {
+       BR_GROUPFWD_STP         = BIT(0),
+       BR_GROUPFWD_MACPAUSE    = BIT(1),
+       BR_GROUPFWD_LACP        = BIT(2),
+};
+
+#define BR_GROUPFWD_RESTRICTED (BR_GROUPFWD_STP | BR_GROUPFWD_MACPAUSE | \
+                               BR_GROUPFWD_LACP)
 /* The Nearest Customer Bridge Group Address, 01-80-C2-00-00-[00,0B,0C,0D,0F] */
 #define BR_GROUPFWD_8021AD     0xB801u
 
@@ -268,6 +275,7 @@ struct net_bridge_port {
 #ifdef CONFIG_NET_SWITCHDEV
        int                             offload_fwd_mark;
 #endif
+       u16                             group_fwd_mask;
 };
 
 #define br_auto_port(p) ((p)->flags & BR_AUTO_MASK)

diff --git a/net/bridge/br_sysfs_if.c b/net/bridge/br_sysfs_if.c
index 5d5d413..9110d5e 100644 (file)
--- a/net/bridge/br_sysfs_if.c
+++ b/net/bridge/br_sysfs_if.c
@@ -165,6 +165,23 @@ static int store_flush(struct net_bridge_port *p, unsigned long v)
 }
 static BRPORT_ATTR(flush, S_IWUSR, NULL, store_flush);
 
+static ssize_t show_group_fwd_mask(struct net_bridge_port *p, char *buf)
+{
+       return sprintf(buf, "%#x\n", p->group_fwd_mask);
+}
+
+static int store_group_fwd_mask(struct net_bridge_port *p,
+                               unsigned long v)
+{
+       if (v & BR_GROUPFWD_MACPAUSE)
+               return -EINVAL;
+       p->group_fwd_mask = v;
+
+       return 0;
+}
+static BRPORT_ATTR(group_fwd_mask, S_IRUGO | S_IWUSR, show_group_fwd_mask,
+                  store_group_fwd_mask);
+
 BRPORT_ATTR_FLAG(hairpin_mode, BR_HAIRPIN_MODE);
 BRPORT_ATTR_FLAG(bpdu_guard, BR_BPDU_GUARD);
 BRPORT_ATTR_FLAG(root_block, BR_ROOT_BLOCK);
@@ -223,6 +240,7 @@ static const struct brport_attribute *brport_attrs[] = {
        &brport_attr_proxyarp_wifi,
        &brport_attr_multicast_flood,
        &brport_attr_broadcast_flood,
+       &brport_attr_group_fwd_mask,
        NULL
 };