[patch v5, kernel version 3.2.1] Source mode for macvlan interface

[patch v5, kernel version 3.2.1] Source mode for macvlan interface

[Stefan Gula]

From: Stefan Gula <steweg@gmail.com>

New mode of macvlan interface called "source" allows one to set a list
of allowed mac address, which is used to match against source mac
address from received frames on underlying interface. This allows
creating mac based VLAN associations, instead of standard port or tag
based. The feature is useful to deploy 802.1x mac based behavior,
where drivers of underlying interfaces doesn't allows that.
Configuration is done through the netlink interface using e.g.:
 ip link add link eth0 name macvlan0 type macvlan mode source
 ip link add link eth0 name macvlan1 type macvlan mode source
 ip link set link macvlan0 type macvlan macaddr add 00:11:11:11:11:11
 ip link set link macvlan0 type macvlan macaddr add 00:22:22:22:22:22
 ip link set link macvlan0 type macvlan macaddr add 00:33:33:33:33:33
 ip link set link macvlan1 type macvlan macaddr add 00:33:33:33:33:33
 ip link set link macvlan1 type macvlan macaddr add 00:44:44:44:44:44
This allows clients with MAC addresses 00:11:11:11:11:11,
00:22:22:22:22:22 to be part of only VLAN associated with macvlan0
interface. Clients with MAC addresses 00:44:44:44:44:44 with only VLAN
associated with macvlan1 interface. And client with MAC address
00:33:33:33:33:33 to be associated with both VLANs.

Signed-off-by: Stefan Gula <steweg@gmail.com>

---

V5: alignment changes and helper function added based on David
    requirements - I hope I fixed all of them

diff -uprN -X linux-3.2.1-orig/Documentation/dontdiff linux-3.2.1-orig/drivers/net/macvlan.c linux-3.2.1-macvlan/drivers/net/macvlan.c
--- linux-3.2.1-orig/drivers/net/macvlan.c	2012-01-27 09:20:02.000000000 +0100
+++ linux-3.2.1-macvlan/drivers/net/macvlan.c	2012-01-27 10:52:29.000000000 +0100
@@ -40,6 +40,7 @@ struct macvlan_port {
 	struct rcu_head		rcu;
 	bool 			passthru;
 	int			count;
+	struct hlist_head	vlan_source_hash[MACVLAN_HASH_SIZE];
 };
 
 static void macvlan_port_destroy(struct net_device *dev);
@@ -155,6 +156,114 @@ static void macvlan_broadcast(struct sk_
 	}
 }
 
+struct macvlan_source_list {
+	struct hlist_node	hlist;
+	struct macvlan_dev	*vlan;
+	unsigned char		addr[ETH_ALEN];
+	struct rcu_head		rcu;
+};
+
+static struct macvlan_source_list *macvlan_hash_lookup_sources_list(
+	const struct macvlan_dev *vlan,
+	const unsigned char *addr)
+{
+	struct macvlan_source_list *list;
+	struct hlist_node *n;
+	struct hlist_head *h = &vlan->port->vlan_source_hash[addr[5]];
+
+	hlist_for_each_entry_rcu(list, n, h, hlist) {
+		if (!compare_ether_addr_64bits(list->addr, addr) &&
+		    list->vlan == vlan)
+			return list;
+	}
+	return NULL;
+}
+
+static int macvlan_hash_add_sources(struct macvlan_dev *vlan,
+				    const unsigned char *addr)
+{
+	struct macvlan_port *port = vlan->port;
+	struct macvlan_source_list *list;
+	struct hlist_head *h;
+
+	list = macvlan_hash_lookup_sources_list(vlan, addr);
+	if (!list) {
+		list = kmalloc(sizeof(*list), GFP_KERNEL);
+		if (list) {
+			memcpy(list->addr, addr, ETH_ALEN);
+			list->vlan = vlan;
+			h = &port->vlan_source_hash[addr[5]];
+			hlist_add_head_rcu(&list->hlist, h);
+		} else
+			return -ENOMEM;
+	}
+	return 0;
+}
+
+static void macvlan_hash_del_sources(struct macvlan_source_list *list)
+{
+	hlist_del_rcu(&list->hlist);
+	kfree_rcu(list, rcu);
+}
+
+static void macvlan_flush_sources(struct macvlan_port *port,
+				struct macvlan_dev *vlan)
+{
+	int i;
+
+	for (i = 0; i < MACVLAN_HASH_SIZE; i++) {
+		struct hlist_node *h, *n;
+
+		hlist_for_each_safe(h, n, &port->vlan_source_hash[i]) {
+			struct macvlan_source_list *list;
+
+			list = hlist_entry(h, struct macvlan_source_list,
+					   hlist);
+			if (list->vlan == vlan)
+				macvlan_hash_del_sources(list);
+		}
+	}
+}
+
+static void macvlan_forward_sources_one(struct sk_buff *skb,
+					struct macvlan_dev *vlan)
+{
+	struct sk_buff *nskb;
+	struct net_device *dev;
+	int len;
+	int ret;
+
+	dev = vlan->dev;
+	if (unlikely(!(dev->flags & IFF_UP)))
+		return;
+
+	nskb = skb_clone(skb, GFP_ATOMIC);
+	if (!nskb)
+		return;
+
+	len = nskb->len + ETH_HLEN;
+	nskb->dev = dev;
+	nskb->pkt_type = PACKET_HOST;
+	ret = vlan->receive(nskb);
+	macvlan_count_rx(vlan, len, ret == NET_RX_SUCCESS, 0);
+}
+
+static void macvlan_forward_sources(struct sk_buff *skb,
+				    struct macvlan_port *port,
+				    const unsigned char *addr)
+{
+	struct macvlan_source_list *list;
+	struct hlist_node *n;
+	struct hlist_head *h = &port->vlan_source_hash[addr[5]];
+
+	hlist_for_each_entry_rcu(list, n, h, hlist) {
+		if (!compare_ether_addr_64bits(list->addr, addr))
+			if (list->vlan->dev->flags & IFF_UP)
+				macvlan_forward_sources_one(skb, list->vlan);
+	}
+	return;
+}
+
 /* called under rcu_read_lock() from netif_receive_skb */
 static rx_handler_result_t macvlan_handle_frame(struct sk_buff **pskb)
 {
@@ -172,6 +281,8 @@ static rx_handler_result_t macvlan_handl
 		skb = ip_check_defrag(skb, IP_DEFRAG_MACVLAN);
 		if (!skb)
 			return RX_HANDLER_CONSUMED;
+
+		macvlan_forward_sources(skb, port, eth->h_source);
 		src = macvlan_hash_lookup(port, eth->h_source);
 		if (!src)
 			/* frame comes from an external address */
@@ -202,6 +313,7 @@ static rx_handler_result_t macvlan_handl
 		return RX_HANDLER_PASS;
 	}
 
+	macvlan_forward_sources(skb, port, eth->h_source);
 	if (port->passthru)
 		vlan = list_first_entry(&port->vlans, struct macvlan_dev, list);
 	else
@@ -474,6 +586,7 @@ static void macvlan_uninit(struct net_de
 
 	free_percpu(vlan->pcpu_stats);
 
+	macvlan_flush_sources(port, vlan);
 	port->count -= 1;
 	if (!port->count)
 		macvlan_port_destroy(port->dev);
@@ -615,7 +728,8 @@ static int macvlan_port_create(struct ne
 	INIT_LIST_HEAD(&port->vlans);
 	for (i = 0; i < MACVLAN_HASH_SIZE; i++)
 		INIT_HLIST_HEAD(&port->vlan_hash[i]);
-
+	for (i = 0; i < MACVLAN_HASH_SIZE; i++)
+		INIT_HLIST_HEAD(&port->vlan_source_hash[i]);
 	err = netdev_rx_handler_register(dev, macvlan_handle_frame, port);
 	if (err)
 		kfree(port);
@@ -648,11 +762,31 @@ static int macvlan_validate(struct nlatt
 		case MACVLAN_MODE_VEPA:
 		case MACVLAN_MODE_BRIDGE:
 		case MACVLAN_MODE_PASSTHRU:
+		case MACVLAN_MODE_SOURCE:
 			break;
 		default:
 			return -EINVAL;
 		}
 	}
+
+	if (data && data[IFLA_MACVLAN_MACADDR_MODE]) {
+		switch (nla_get_u32(data[IFLA_MACVLAN_MACADDR_MODE])) {
+		case MACVLAN_MACADDR_ADD:
+		case MACVLAN_MACADDR_DEL:
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+
+	if (data && data[IFLA_MACVLAN_MACADDR]) {
+		if (nla_len(data[IFLA_MACVLAN_MACADDR]) != ETH_ALEN)
+			return -EINVAL;
+
+		if (!is_valid_ether_addr(nla_data(data[IFLA_MACVLAN_MACADDR])))
+			return -EADDRNOTAVAIL;
+	}
+
 	return 0;
 }
 
@@ -749,39 +883,141 @@ void macvlan_dellink(struct net_device *
 {
 	struct macvlan_dev *vlan = netdev_priv(dev);
 
+	if (vlan->mode == MACVLAN_MODE_SOURCE)
+		macvlan_flush_sources(vlan->port, vlan);
 	list_del(&vlan->list);
 	unregister_netdevice_queue(dev, head);
 }
 EXPORT_SYMBOL_GPL(macvlan_dellink);
 
+static int macvlan_changelink_sources(struct macvlan_dev *vlan, u32 mode,
+				      unsigned char *addr)
+{
+	if (mode == MACVLAN_MACADDR_ADD)
+		return macvlan_hash_add_sources(vlan, addr);
+
+	else if (mode == MACVLAN_MACADDR_DEL) {
+		struct macvlan_source_list *list;
+
+		list = macvlan_hash_lookup_sources_list(vlan, addr);
+		if (list)
+			macvlan_hash_del_sources(list);
+	} else
+		return -EINVAL;
+
+	return 0;
+}
+
 static int macvlan_changelink(struct net_device *dev,
 		struct nlattr *tb[], struct nlattr *data[])
 {
 	struct macvlan_dev *vlan = netdev_priv(dev);
-	if (data && data[IFLA_MACVLAN_MODE])
+	u32 mode;
+	unsigned char *addr;
+
+	if (data && data[IFLA_MACVLAN_MODE]) {
+		if (vlan->mode == MACVLAN_MODE_SOURCE &&
+		    vlan->mode != nla_get_u32(data[IFLA_MACVLAN_MODE]))
+			macvlan_flush_sources(vlan->port, vlan);
 		vlan->mode = nla_get_u32(data[IFLA_MACVLAN_MODE]);
+	}
+
+	if (data && data[IFLA_MACVLAN_MACADDR_MODE] &&
+	    data[IFLA_MACVLAN_MACADDR]) {
+		mode = nla_get_u32(data[IFLA_MACVLAN_MACADDR_MODE]);
+		addr = nla_data(nla_data(data[IFLA_MACVLAN_MACADDR]));
+		if (vlan->mode == MACVLAN_MODE_SOURCE)
+			return macvlan_changelink_sources(vlan, mode, addr);
+		else
+			return -EINVAL;
+	}
+
 	return 0;
 }
 
 static size_t macvlan_get_size(const struct net_device *dev)
 {
-	return nla_total_size(4);
+	struct macvlan_dev *vlan = netdev_priv(dev);
+	struct macvlan_port *port = vlan->port;
+	u16 source_size = 0;
+	int count = 0;
+
+	if (vlan->mode == MACVLAN_MODE_SOURCE) {
+		int i;
+		for (i = 0; i < MACVLAN_HASH_SIZE; i++) {
+			struct hlist_node *n;
+			struct hlist_head *h = &port->vlan_source_hash[i];
+			struct macvlan_source_list *list;
+
+			hlist_for_each_entry_rcu(list, n, h, hlist) {
+				if (list->vlan == vlan)
+					count++;
+			}
+		}
+		if (count)
+			source_size = nla_total_size(sizeof(struct nlattr))
+				+ nla_total_size(sizeof(u8) * ETH_ALEN) * count;
+	}
+
+	return nla_total_size(4) + source_size;
+}
+
+static int macvlan_fill_nested(struct sk_buff *skb, const char *addr)
+{
+	NLA_PUT(skb, IFLA_MACVLAN_MACADDR, ETH_ALEN, addr);
+
+	return 0;
+
+nla_put_failure:
+	return -EMSGSIZE;
 }
 
 static int macvlan_fill_info(struct sk_buff *skb,
 				const struct net_device *dev)
 {
 	struct macvlan_dev *vlan = netdev_priv(dev);
+	struct macvlan_port *port = vlan->port;
+	struct nlattr *adt;
 
 	NLA_PUT_U32(skb, IFLA_MACVLAN_MODE, vlan->mode);
+
+	if (vlan->mode == MACVLAN_MODE_SOURCE) {
+		int i;
+
+		adt = nla_nest_start(skb, IFLA_MACVLAN_MACADDR_DATA);
+		if (!adt)
+			goto nla_put_failure;
+
+		for (i = 0; i < MACVLAN_HASH_SIZE; i++) {
+			struct hlist_node *n;
+			struct hlist_head *h = &port->vlan_source_hash[i];
+			struct macvlan_source_list *list;
+
+			hlist_for_each_entry_rcu(list, n, h, hlist) {
+				if (list->vlan == vlan)
+					if (macvlan_fill_nested(skb,
+								list->addr))
+						goto nla_nested_failure;
+			}
+		}
+		nla_nest_end(skb, adt);
+	}
+
 	return 0;
 
+nla_nested_failure:
+	nla_nest_end(skb, adt);
+	return -EMSGSIZE;
+
 nla_put_failure:
 	return -EMSGSIZE;
 }
 
 static const struct nla_policy macvlan_policy[IFLA_MACVLAN_MAX + 1] = {
 	[IFLA_MACVLAN_MODE] = { .type = NLA_U32 },
+	[IFLA_MACVLAN_MACADDR_MODE] = { .type = NLA_U32 },
+	[IFLA_MACVLAN_MACADDR] = { .type = NLA_BINARY, .len = MAX_ADDR_LEN },
+	[IFLA_MACVLAN_MACADDR_DATA] = { .type = NLA_NESTED },
 };
 
 int macvlan_link_register(struct rtnl_link_ops *ops)
diff -uprN -X linux-3.2.1-orig/Documentation/dontdiff linux-3.2.1-orig/include/linux/if_link.h linux-3.2.1-macvlan/include/linux/if_link.h
--- linux-3.2.1-orig/include/linux/if_link.h	2012-01-27 09:20:24.000000000 +0100
+++ linux-3.2.1-macvlan/include/linux/if_link.h	2012-01-27 09:23:38.000000000 +0100
@@ -252,6 +252,9 @@ struct ifla_vlan_qos_mapping {
 enum {
 	IFLA_MACVLAN_UNSPEC,
 	IFLA_MACVLAN_MODE,
+	IFLA_MACVLAN_MACADDR_MODE,
+	IFLA_MACVLAN_MACADDR,
+	IFLA_MACVLAN_MACADDR_DATA,
 	__IFLA_MACVLAN_MAX,
 };
 
@@ -262,6 +265,12 @@ enum macvlan_mode {
 	MACVLAN_MODE_VEPA    = 2, /* talk to other ports through ext bridge */
 	MACVLAN_MODE_BRIDGE  = 4, /* talk to bridge ports directly */
 	MACVLAN_MODE_PASSTHRU = 8,/* take over the underlying device */
+	MACVLAN_MODE_SOURCE  = 16,/* use source MAC address list to assign */
+};
+
+enum macvlan_macaddr_mode {
+	MACVLAN_MACADDR_ADD,
+	MACVLAN_MACADDR_DEL,
 };
 
 /* SR-IOV virtual function management section */

Re: [patch v5, kernel version 3.2.1] Source mode for macvlan interface

[Eric Dumazet]

Le vendredi 27 janvier 2012 à 10:58 +0100, Stefan Gula a écrit :
> From: Stefan Gula <steweg@gmail.com>
> 

...

> +static struct macvlan_source_list *macvlan_hash_lookup_sources_list(
> +	const struct macvlan_dev *vlan,
> +	const unsigned char *addr)
> +{
> +	struct macvlan_source_list *list;
> +	struct hlist_node *n;
> +	struct hlist_head *h = &vlan->port->vlan_source_hash[addr[5]];
> +
> +	hlist_for_each_entry_rcu(list, n, h, hlist) {

You dont hold rcu_read_lock() here, and dont need to, since you are in
the controler path, rtnl is locked :

	hlist_for_each_entry(...)

> +		if (!compare_ether_addr_64bits(list->addr, addr) &&
> +		    list->vlan == vlan)
> +			return list;
> +	}
> +	return NULL;
> +}
> +
> +static int macvlan_hash_add_sources(struct macvlan_dev *vlan,
> +				    const unsigned char *addr)
> +{
> +	struct macvlan_port *port = vlan->port;
> +	struct macvlan_source_list *list;
> +	struct hlist_head *h;
> +
> +	list = macvlan_hash_lookup_sources_list(vlan, addr);
> +	if (!list) {
> +		list = kmalloc(sizeof(*list), GFP_KERNEL);

By the way, use of GFP_KERNEL here is a proof you dont hold
rcu_read_lock().

(If you were, you would not be allowed to sleep in kmalloc())

> +		if (list) {
> +			memcpy(list->addr, addr, ETH_ALEN);
> +			list->vlan = vlan;
> +			h = &port->vlan_source_hash[addr[5]];
> +			hlist_add_head_rcu(&list->hlist, h);
> +		} else
> +			return -ENOMEM;

	if (cond) {
		foo;
		bar;
	} else {
		blip;
	}


> +	}
> +	return 0;
> +}
> +
> +static void macvlan_hash_del_sources(struct macvlan_source_list *list)
> +{
> +	hlist_del_rcu(&list->hlist);
> +	kfree_rcu(list, rcu);
> +}
> +

...

> +static int macvlan_changelink_sources(struct macvlan_dev *vlan, u32 mode,
> +				      unsigned char *addr)
> +{
> +	if (mode == MACVLAN_MACADDR_ADD)
> +		return macvlan_hash_add_sources(vlan, addr);
> +

Same codestyle here...

	if (cond) {
		foo;
	} else if (cond2) {
	} else {
		blip;
	}


> +	else if (mode == MACVLAN_MACADDR_DEL) {
> +		struct macvlan_source_list *list;
> +
> +		list = macvlan_hash_lookup_sources_list(vlan, addr);
> +		if (list)
> +			macvlan_hash_del_sources(list);
> +	} else
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +