bridge: Add netlink interface to configure vlans on bridge ports

Add a netlink interface to add and remove vlan configuration on bridge port.
The interface uses the RTM_SETLINK message and encodes the vlan
configuration inside the IFLA_AF_SPEC.  It is possble to include multiple
vlans to either add or remove in a single message.

Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: Vlad Yasevich

include/linux/netdevice.h

@@ -1020,6 +1020,8 @@ struct net_device_ops {
 	int			(*ndo_bridge_getlink)(struct sk_buff *skb,
 						      u32 pid, u32 seq,
 						      struct net_device *dev);
+	int			(*ndo_bridge_dellink)(struct net_device *dev,
+						      struct nlmsghdr *nlh);
 	int			(*ndo_change_carrier)(struct net_device *dev,
 						      bool new_carrier);
 };

include/uapi/linux/if_bridge.h

@@ -108,15 +108,24 @@ struct __fdb_entry {
  * [IFLA_AF_SPEC] = {
  *     [IFLA_BRIDGE_FLAGS]
  *     [IFLA_BRIDGE_MODE]
+ *     [IFLA_BRIDGE_VLAN_INFO]
  * }
  */
 enum {
 	IFLA_BRIDGE_FLAGS,
 	IFLA_BRIDGE_MODE,
+	IFLA_BRIDGE_VLAN_INFO,
 	__IFLA_BRIDGE_MAX,
 };
 #define IFLA_BRIDGE_MAX (__IFLA_BRIDGE_MAX - 1)
 
+#define BRIDGE_VLAN_INFO_MASTER	(1<<0)	/* Operate on Bridge device as well */
+
+struct bridge_vlan_info {
+	u16 flags;
+	u16 vid;
+};
+
 /* Bridge multicast database attributes
  * [MDBA_MDB] = {
  *     [MDBA_MDB_ENTRY] = {

net/bridge/br_device.c

@@ -316,6 +316,7 @@ static const struct net_device_ops br_netdev_ops = {
 	.ndo_fdb_dump		 = br_fdb_dump,
 	.ndo_bridge_getlink	 = br_getlink,
 	.ndo_bridge_setlink	 = br_setlink,
+	.ndo_bridge_dellink	 = br_dellink,
 };
 
 static void br_dev_free(struct net_device *dev)

net/bridge/br_if.c

@@ -23,6 +23,7 @@
 #include <linux/if_ether.h>
 #include <linux/slab.h>
 #include <net/sock.h>
+#include <linux/if_vlan.h>
 
 #include "br_private.h"
 

net/bridge/br_netlink.c

@@ -16,6 +16,7 @@
 #include <net/rtnetlink.h>
 #include <net/net_namespace.h>
 #include <net/sock.h>
+#include <uapi/linux/if_bridge.h>
 
 #include "br_private.h"
 #include "br_private_stp.h"
@@ -119,10 +120,14 @@ static int br_fill_ifinfo(struct sk_buff *skb, const struct net_bridge_port *por
  */
 void br_ifinfo_notify(int event, struct net_bridge_port *port)
 {
-	struct net *net = dev_net(port->dev);
+	struct net *net;
 	struct sk_buff *skb;
 	int err = -ENOBUFS;
 
+	if (!port)
+		return;
+
+	net = dev_net(port->dev);
 	br_debug(port->br, "port %u(%s) event %d\n",
 		 (unsigned int)port->port_no, port->dev->name, event);
 
@@ -144,6 +149,7 @@ void br_ifinfo_notify(int event, struct net_bridge_port *port)
 		rtnl_set_sk_err(net, RTNLGRP_LINK, err);
 }
 
+
 /*
  * Dump information about all ports, in response to GETLINK
  */
@@ -162,6 +168,64 @@ int br_getlink(struct sk_buff *skb, u32 pid, u32 seq,
 	return err;
 }
 
+const struct nla_policy ifla_br_policy[IFLA_MAX+1] = {
+	[IFLA_BRIDGE_FLAGS]	= { .type = NLA_U16 },
+	[IFLA_BRIDGE_MODE]	= { .type = NLA_U16 },
+	[IFLA_BRIDGE_VLAN_INFO]	= { .type = NLA_BINARY,
+				    .len = sizeof(struct bridge_vlan_info), },
+};
+
+static int br_afspec(struct net_bridge *br,
+		     struct net_bridge_port *p,
+		     struct nlattr *af_spec,
+		     int cmd)
+{
+	struct nlattr *tb[IFLA_BRIDGE_MAX+1];
+	int err = 0;
+
+	err = nla_parse_nested(tb, IFLA_BRIDGE_MAX, af_spec, ifla_br_policy);
+	if (err)
+		return err;
+
+	if (tb[IFLA_BRIDGE_VLAN_INFO]) {
+		struct bridge_vlan_info *vinfo;
+
+		vinfo = nla_data(tb[IFLA_BRIDGE_VLAN_INFO]);
+
+		if (vinfo->vid >= VLAN_N_VID)
+			return -EINVAL;
+
+		switch (cmd) {
+		case RTM_SETLINK:
+			if (p) {
+				err = nbp_vlan_add(p, vinfo->vid);
+				if (err)
+					break;
+
+				if (vinfo->flags & BRIDGE_VLAN_INFO_MASTER)
+					err = br_vlan_add(p->br, vinfo->vid);
+			} else
+				err = br_vlan_add(br, vinfo->vid);
+
+			if (err)
+				break;
+
+			break;
+
+		case RTM_DELLINK:
+			if (p) {
+				nbp_vlan_delete(p, vinfo->vid);
+				if (vinfo->flags & BRIDGE_VLAN_INFO_MASTER)
+					br_vlan_delete(p->br, vinfo->vid);
+			} else
+				br_vlan_delete(br, vinfo->vid);
+			break;
+		}
+	}
+
+	return err;
+}
+
 static const struct nla_policy ifla_brport_policy[IFLA_BRPORT_MAX + 1] = {
 	[IFLA_BRPORT_STATE]	= { .type = NLA_U8 },
 	[IFLA_BRPORT_COST]	= { .type = NLA_U32 },
@@ -241,45 +305,84 @@ int br_setlink(struct net_device *dev, struct nlmsghdr *nlh)
 {
 	struct ifinfomsg *ifm;
 	struct nlattr *protinfo;
+	struct nlattr *afspec;
 	struct net_bridge_port *p;
 	struct nlattr *tb[IFLA_BRPORT_MAX + 1];
 	int err;
 
 	ifm = nlmsg_data(nlh);
 
 	protinfo = nlmsg_find_attr(nlh, sizeof(*ifm), IFLA_PROTINFO);
-	if (!protinfo)
+	afspec = nlmsg_find_attr(nlh, sizeof(*ifm), IFLA_AF_SPEC);
+	if (!protinfo && !afspec)
 		return 0;
 
 	p = br_port_get_rtnl(dev);
-	if (!p)
+	/* We want to accept dev as bridge itself if the AF_SPEC
+	 * is set to see if someone is setting vlan info on the brigde
+	 */
+	if (!p && ((dev->priv_flags & IFF_EBRIDGE) && !afspec))
 		return -EINVAL;
 
-	if (protinfo->nla_type & NLA_F_NESTED) {
-		err = nla_parse_nested(tb, IFLA_BRPORT_MAX,
-				       protinfo, ifla_brport_policy);
+	if (p && protinfo) {
+		if (protinfo->nla_type & NLA_F_NESTED) {
+			err = nla_parse_nested(tb, IFLA_BRPORT_MAX,
+					       protinfo, ifla_brport_policy);
+			if (err)
+				return err;
+
+			spin_lock_bh(&p->br->lock);
+			err = br_setport(p, tb);
+			spin_unlock_bh(&p->br->lock);
+		} else {
+			/* Binary compatability with old RSTP */
+			if (nla_len(protinfo) < sizeof(u8))
+				return -EINVAL;
+
+			spin_lock_bh(&p->br->lock);
+			err = br_set_port_state(p, nla_get_u8(protinfo));
+			spin_unlock_bh(&p->br->lock);
+		}
 		if (err)
-			return err;
-
-		spin_lock_bh(&p->br->lock);
-		err = br_setport(p, tb);
-		spin_unlock_bh(&p->br->lock);
-	} else {
-		/* Binary compatability with old RSTP */
-		if (nla_len(protinfo) < sizeof(u8))
-			return -EINVAL;
+			goto out;
+	}
 
-		spin_lock_bh(&p->br->lock);
-		err = br_set_port_state(p, nla_get_u8(protinfo));
-		spin_unlock_bh(&p->br->lock);
+	if (afspec) {
+		err = br_afspec((struct net_bridge *)netdev_priv(dev), p,
+				afspec, RTM_SETLINK);
 	}
 
 	if (err == 0)
 		br_ifinfo_notify(RTM_NEWLINK, p);
 
+out:
 	return err;
 }
 
+/* Delete port information */
+int br_dellink(struct net_device *dev, struct nlmsghdr *nlh)
+{
+	struct ifinfomsg *ifm;
+	struct nlattr *afspec;
+	struct net_bridge_port *p;
+	int err;
+
+	ifm = nlmsg_data(nlh);
+
+	afspec = nlmsg_find_attr(nlh, sizeof(*ifm), IFLA_AF_SPEC);
+	if (!afspec)
+		return 0;
+
+	p = br_port_get_rtnl(dev);
+	/* We want to accept dev as bridge itself as well */
+	if (!p && !(dev->priv_flags & IFF_EBRIDGE))
+		return -EINVAL;
+
+	err = br_afspec((struct net_bridge *)netdev_priv(dev), p,
+			afspec, RTM_DELLINK);
+
+	return err;
+}
 static int br_validate(struct nlattr *tb[], struct nlattr *data[])
 {
 	if (tb[IFLA_ADDRESS]) {

net/bridge/br_private.h

@@ -713,6 +713,7 @@ extern int br_netlink_init(void);
 extern void br_netlink_fini(void);
 extern void br_ifinfo_notify(int event, struct net_bridge_port *port);
 extern int br_setlink(struct net_device *dev, struct nlmsghdr *nlmsg);
+extern int br_dellink(struct net_device *dev, struct nlmsghdr *nlmsg);
 extern int br_getlink(struct sk_buff *skb, u32 pid, u32 seq,
 		      struct net_device *dev);
 

net/core/rtnetlink.c

@@ -2464,6 +2464,77 @@ static int rtnl_bridge_setlink(struct sk_buff *skb, struct nlmsghdr *nlh,
 	return err;
 }
 
+static int rtnl_bridge_dellink(struct sk_buff *skb, struct nlmsghdr *nlh,
+			       void *arg)
+{
+	struct net *net = sock_net(skb->sk);
+	struct ifinfomsg *ifm;
+	struct net_device *dev;
+	struct nlattr *br_spec, *attr = NULL;
+	int rem, err = -EOPNOTSUPP;
+	u16 oflags, flags = 0;
+	bool have_flags = false;
+
+	if (nlmsg_len(nlh) < sizeof(*ifm))
+		return -EINVAL;
+
+	ifm = nlmsg_data(nlh);
+	if (ifm->ifi_family != AF_BRIDGE)
+		return -EPFNOSUPPORT;
+
+	dev = __dev_get_by_index(net, ifm->ifi_index);
+	if (!dev) {
+		pr_info("PF_BRIDGE: RTM_SETLINK with unknown ifindex\n");
+		return -ENODEV;
+	}
+
+	br_spec = nlmsg_find_attr(nlh, sizeof(struct ifinfomsg), IFLA_AF_SPEC);
+	if (br_spec) {
+		nla_for_each_nested(attr, br_spec, rem) {
+			if (nla_type(attr) == IFLA_BRIDGE_FLAGS) {
+				have_flags = true;
+				flags = nla_get_u16(attr);
+				break;
+			}
+		}
+	}
+
+	oflags = flags;
+
+	if (!flags || (flags & BRIDGE_FLAGS_MASTER)) {
+		struct net_device *br_dev = netdev_master_upper_dev_get(dev);
+
+		if (!br_dev || !br_dev->netdev_ops->ndo_bridge_dellink) {
+			err = -EOPNOTSUPP;
+			goto out;
+		}
+
+		err = br_dev->netdev_ops->ndo_bridge_dellink(dev, nlh);
+		if (err)
+			goto out;
+
+		flags &= ~BRIDGE_FLAGS_MASTER;
+	}
+
+	if ((flags & BRIDGE_FLAGS_SELF)) {
+		if (!dev->netdev_ops->ndo_bridge_dellink)
+			err = -EOPNOTSUPP;
+		else
+			err = dev->netdev_ops->ndo_bridge_dellink(dev, nlh);
+
+		if (!err)
+			flags &= ~BRIDGE_FLAGS_SELF;
+	}
+
+	if (have_flags)
+		memcpy(nla_data(attr), &flags, sizeof(flags));
+	/* Generate event to notify upper layer of bridge change */
+	if (!err)
+		err = rtnl_bridge_notify(dev, oflags);
+out:
+	return err;
+}
+
 /* Protected by RTNL sempahore.  */
 static struct rtattr **rta_buf;
 static int rtattr_max;
@@ -2647,6 +2718,7 @@ void __init rtnetlink_init(void)
 	rtnl_register(PF_BRIDGE, RTM_GETNEIGH, NULL, rtnl_fdb_dump, NULL);
 
 	rtnl_register(PF_BRIDGE, RTM_GETLINK, NULL, rtnl_bridge_getlink, NULL);
+	rtnl_register(PF_BRIDGE, RTM_DELLINK, rtnl_bridge_dellink, NULL, NULL);
 	rtnl_register(PF_BRIDGE, RTM_SETLINK, rtnl_bridge_setlink, NULL, NULL);
 }