Re: [PATCH 1/3] net: introduce a list of device addresses dev_addr_list (v4)

Jiri Pirko
2009-04-20T16:15:38Z

How about this (and another 2 patches in patchset)? What's your opinion guys?

Thanks,

Jirka

Sat, Apr 18, 2009 at 10:58:49AM CEST, jpirko@redhat.com wrote:
>v3 -> v4 (current):
>-changed kzalloc to kmalloc in __hw_addr_add_ii()
>-ASSERT_RTNL() avoided in dev_addr_flush() and dev_addr_init()
>
>v2 -> v3:
>-removed unnecessary rcu read locking
>-moved dev_addr_flush() calling to ensure no null dereference of dev_addr
>
>v1 -> v2:
>-added forgotten ASSERT_RTNL to dev_addr_init and dev_addr_flush
>-removed unnecessary rcu_read locking in dev_addr_init
>-use compare_ether_addr_64bits instead of compare_ether_addr
>-use L1_CACHE_BYTES as size for allocating struct netdev_hw_addr
>-use call_rcu instead of rcu_synchronize
>-moved is_etherdev_addr into __KERNEL__ ifdef
>
>This patch introduces a new list in struct net_device and brings a set of
>functions to handle the work with device address list. The list is a replacement
>for the original dev_addr field and because in some situations there is need to
>carry several device addresses with the net device. To be backward compatible,
>dev_addr is made to point to the first member of the list so original drivers
>sees no difference.
>
>Signed-off-by: Jiri Pirko <jpirko@redhat.com>
>---
> include/linux/etherdevice.h | 27 +++++
> include/linux/netdevice.h | 32 +++++-
> net/core/dev.c | 261 +++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 318 insertions(+), 2 deletions(-)
>
>diff --git a/include/linux/etherdevice.h b/include/linux/etherdevice.h
>index a1f17ab..3d7a668 100644
>--- a/include/linux/etherdevice.h
>+++ b/include/linux/etherdevice.h
>@@ -182,6 +182,33 @@ static inline unsigned compare_ether_addr_64bits(const u8 addr1[6+2],
> return compare_ether_addr(addr1, addr2);
> #endif
> }
>+
>+/**
>+ * is_etherdev_addr - Tell if given Ethernet address belongs to the device.
>+ * @dev: Pointer to a device structure
>+ * @addr: Pointer to a six-byte array containing the Ethernet address
>+ *
>+ * Compare passed address with all addresses of the device. Return true if the
>+ * address if one of the device addresses.
>+ *
>+ * Note that this function calls compare_ether_addr_64bits() so take care of
>+ * the right padding.
>+ */
>+static inline bool is_etherdev_addr(const struct net_device *dev,
>+ const u8 addr[6 + 2])
>+{
>+ struct netdev_hw_addr *ha;
>+ int res = 1;
>+
>+ rcu_read_lock();
>+ for_each_dev_addr(dev, ha) {
>+ res = compare_ether_addr_64bits(addr, ha->addr);
>+ if (!res)
>+ break;
>+ }
>+ rcu_read_unlock();
>+ return !res;
>+}
> #endif /* __KERNEL__ */
>
> /**
>diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
>index 2e7783f..89ad6d2 100644
>--- a/include/linux/netdevice.h
>+++ b/include/linux/netdevice.h
>@@ -210,6 +210,13 @@ struct dev_addr_list
> #define dmi_users da_users
> #define dmi_gusers da_gusers
>
>+struct netdev_hw_addr {
>+ struct list_head list;
>+ unsigned char addr[MAX_ADDR_LEN];
>+ int refcount;
>+ struct rcu_head rcu_head;
>+};
>+
> struct hh_cache
> {
> struct hh_cache *hh_next; /* Next entry */
>@@ -776,8 +783,11 @@ struct net_device
> */
> unsigned long last_rx; /* Time of last Rx */
> /* Interface address info used in eth_type_trans() */
>- unsigned char dev_addr[MAX_ADDR_LEN]; /* hw address, (before bcast
>- because most packets are unicast) */
>+ unsigned char *dev_addr; /* hw address, (before bcast
>+ because most packets are
>+ unicast) */
>+
>+ struct list_head dev_addr_list; /* list of device hw addresses */
>
> unsigned char broadcast[MAX_ADDR_LEN]; /* hw bcast add */
>
>@@ -1778,6 +1788,13 @@ static inline void netif_addr_unlock_bh(struct net_device *dev)
> spin_unlock_bh(&dev->addr_list_lock);
> }
>
>+/*
>+ * dev_addr_list walker. Should be used only for read access. Call with
>+ * rcu_read_lock held.
>+ */
>+#define for_each_dev_addr(dev, ha) \
>+ list_for_each_entry_rcu(ha, &dev->dev_addr_list, list)
>+
> /* These functions live elsewhere (drivers/net/net_init.c, but related) */
>
> extern void ether_setup(struct net_device *dev);
>@@ -1790,6 +1807,17 @@ extern struct net_device *alloc_netdev_mq(int sizeof_priv, const char *name,
> alloc_netdev_mq(sizeof_priv, name, setup, 1)
> extern int register_netdev(struct net_device *dev);
> extern void unregister_netdev(struct net_device *dev);
>+
>+/* Functions used for device addresses handling */
>+extern int dev_addr_add(struct net_device *dev,
>+ unsigned char *addr);
>+extern int dev_addr_del(struct net_device *dev,
>+ unsigned char *addr);
>+extern int dev_addr_add_multiple(struct net_device *to_dev,
>+ struct net_device *from_dev);
>+extern int dev_addr_del_multiple(struct net_device *to_dev,
>+ struct net_device *from_dev);
>+
> /* Functions used for secondary unicast and multicast support */
> extern void dev_set_rx_mode(struct net_device *dev);
> extern void __dev_set_rx_mode(struct net_device *dev);
>diff --git a/net/core/dev.c b/net/core/dev.c
>index 343883f..2274294 100644
>--- a/net/core/dev.c
>+++ b/net/core/dev.c
>@@ -3438,6 +3438,263 @@ void dev_set_rx_mode(struct net_device *dev)
> netif_addr_unlock_bh(dev);
> }
>
>+/* hw addresses list handling functions */
>+
>+static int __hw_addr_add_ii(struct list_head *list, unsigned char *addr,
>+ int addr_len, int ignore_index)
>+{
>+ struct netdev_hw_addr *ha;
>+ int i = 0;
>+
>+ if (addr_len > MAX_ADDR_LEN)
>+ return -EINVAL;
>+
>+ list_for_each_entry(ha, list, list) {
>+ if (i++ != ignore_index &&
>+ !memcmp(ha->addr, addr, addr_len)) {
>+ ha->refcount++;
>+ return 0;
>+ }
>+ }
>+
>+ ha = kmalloc(max(sizeof(*ha), L1_CACHE_BYTES), GFP_ATOMIC);
>+ if (!ha)
>+ return -ENOMEM;
>+ memcpy(ha->addr, addr, addr_len);
>+ ha->refcount = 1;
>+ list_add_tail_rcu(&ha->list, list);
>+ return 0;
>+}
>+
>+static int __hw_addr_add(struct list_head *list, unsigned char *addr,
>+ int addr_len)
>+{
>+ return __hw_addr_add_ii(list, addr, addr_len, -1);
>+}
>+
>+static void ha_rcu_free(struct rcu_head *head)
>+{
>+ struct netdev_hw_addr *ha;
>+
>+ ha = container_of(head, struct netdev_hw_addr, rcu_head);
>+ kfree(ha);
>+}
>+
>+static int __hw_addr_del_ii(struct list_head *list, unsigned char *addr,
>+ int addr_len, int ignore_index)
>+{
>+ struct netdev_hw_addr *ha;
>+ int i = 0;
>+
>+ list_for_each_entry(ha, list, list) {
>+ if (i++ != ignore_index &&
>+ !memcmp(ha->addr, addr, addr_len)) {
>+ if (--ha->refcount)
>+ return 0;
>+ list_del_rcu(&ha->list);
>+ call_rcu(&ha->rcu_head, ha_rcu_free);
>+ return 0;
>+ }
>+ }
>+ return -ENOENT;
>+}
>+
>+static int __hw_addr_del(struct list_head *list, unsigned char *addr,
>+ int addr_len)
>+{
>+ return __hw_addr_del_ii(list, addr, addr_len, -1);
>+}
>+
>+static int __hw_addr_add_multiple_ii(struct list_head *to_list,
>+ struct list_head *from_list,
>+ int addr_len, int ignore_index)
>+{
>+ int err;
>+ struct netdev_hw_addr *ha, *ha2;
>+
>+ list_for_each_entry(ha, from_list, list) {
>+ err = __hw_addr_add_ii(to_list, ha->addr, addr_len, 0);
>+ if (err)
>+ goto unroll;
>+ }
>+ return 0;
>+
>+unroll:
>+ list_for_each_entry(ha2, from_list, list) {
>+ if (ha2 == ha)
>+ break;
>+ __hw_addr_del_ii(to_list, ha2->addr, addr_len, 0);
>+ }
>+ return err;
>+}
>+
>+static int __hw_addr_add_multiple(struct list_head *to_list,
>+ struct list_head *from_list,
>+ int addr_len)
>+{
>+ return __hw_addr_add_multiple_ii(to_list, from_list, addr_len, -1);
>+}
>+
>+static void __hw_addr_del_multiple_ii(struct list_head *to_list,
>+ struct list_head *from_list,
>+ int addr_len, int ignore_index)
>+{
>+ struct netdev_hw_addr *ha;
>+
>+ list_for_each_entry(ha, from_list, list) {
>+ __hw_addr_del_ii(to_list, ha->addr, addr_len, 0);
>+ }
>+}
>+
>+static void __hw_addr_del_multiple(struct list_head *to_list,
>+ struct list_head *from_list,
>+ int addr_len)
>+{
>+ __hw_addr_del_multiple_ii(to_list, from_list, addr_len, -1);
>+}
>+
>+static void __hw_addr_flush(struct list_head *list)
>+{
>+ struct netdev_hw_addr *ha, *tmp;
>+
>+ list_for_each_entry_safe(ha, tmp, list, list) {
>+ list_del_rcu(&ha->list);
>+ call_rcu(&ha->rcu_head, ha_rcu_free);
>+ }
>+}
>+
>+/* Device addresses handling functions */
>+
>+static void dev_addr_flush(struct net_device *dev)
>+{
>+ /* rtnl_mutex must be held here */
>+
>+ __hw_addr_flush(&dev->dev_addr_list);
>+ dev->dev_addr = NULL;
>+}
>+
>+static int dev_addr_init(struct net_device *dev)
>+{
>+ unsigned char addr[MAX_ADDR_LEN];
>+ struct netdev_hw_addr *ha;
>+ int err;
>+
>+ /* rtnl_mutex must be held here */
>+
>+ INIT_LIST_HEAD(&dev->dev_addr_list);
>+ memset(addr, 0, sizeof(*addr));
>+ err = __hw_addr_add(&dev->dev_addr_list, addr, sizeof(*addr));
>+ if (!err) {
>+ /*
>+ * Get the first (previously created) address from the list
>+ * and set dev_addr pointer to this location.
>+ */
>+ ha = list_first_entry(&dev->dev_addr_list,
>+ struct netdev_hw_addr, list);
>+ dev->dev_addr = ha->addr;
>+ }
>+ return err;
>+}
>+
>+/**
>+ * dev_addr_add - Add a device address
>+ * @dev: device
>+ * @addr: address to add
>+ *
>+ * Add a device address to the device or increase the reference count if
>+ * it already exists.
>+ *
>+ * The caller must hold the rtnl_mutex.
>+ */
>+int dev_addr_add(struct net_device *dev, unsigned char *addr)
>+{
>+ int err;
>+
>+ ASSERT_RTNL();
>+
>+ err = __hw_addr_add_ii(&dev->dev_addr_list, addr, dev->addr_len, 0);
>+ if (!err)
>+ call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
>+ return err;
>+}
>+EXPORT_SYMBOL(dev_addr_add);
>+
>+/**
>+ * dev_addr_del - Release a device address.
>+ * @dev: device
>+ * @addr: address to delete
>+ *
>+ * Release reference to a device address and remove it from the device
>+ * if the reference count drops to zero.
>+ *
>+ * The caller must hold the rtnl_mutex.
>+ */
>+int dev_addr_del(struct net_device *dev, unsigned char *addr)
>+{
>+ int err;
>+
>+ ASSERT_RTNL();
>+
>+ err = __hw_addr_del_ii(&dev->dev_addr_list, addr, dev->addr_len, 0);
>+ if (!err)
>+ call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
>+ return err;
>+}
>+EXPORT_SYMBOL(dev_addr_del);
>+
>+/**
>+ * dev_addr_add_multiple - Add device addresses from another device
>+ * @to_dev: device to which addresses will be added
>+ * @from_dev: device from which addresses will be added
>+ *
>+ * Add device addresses of the one device to another.
>+ *
>+ * The caller must hold the rtnl_mutex.
>+ */
>+int dev_addr_add_multiple(struct net_device *to_dev,
>+ struct net_device *from_dev)
>+{
>+ int err;
>+
>+ ASSERT_RTNL();
>+
>+ if (from_dev->addr_len != to_dev->addr_len)
>+ return -EINVAL;
>+ err = __hw_addr_add_multiple_ii(&to_dev->dev_addr_list,
>+ &from_dev->dev_addr_list,
>+ to_dev->addr_len, 0);
>+ if (!err)
>+ call_netdevice_notifiers(NETDEV_CHANGEADDR, to_dev);
>+ return err;
>+}
>+EXPORT_SYMBOL(dev_addr_add_multiple);
>+
>+/**
>+ * dev_addr_del_multiple - Delete device addresses by another device
>+ * @to_dev: device where the addresses will be deleted
>+ * @from_dev: device by which addresses the addresses will be deleted
>+ *
>+ * Deletes addresses in to device by the list of addresses in from device.
>+ *
>+ * The caller must hold the rtnl_mutex.
>+ */
>+int dev_addr_del_multiple(struct net_device *to_dev,
>+ struct net_device *from_dev)
>+{
>+ ASSERT_RTNL();
>+
>+ if (from_dev->addr_len != to_dev->addr_len)
>+ return -EINVAL;
>+ __hw_addr_add_multiple_ii(&to_dev->dev_addr_list,
>+ &from_dev->dev_addr_list,
>+ to_dev->addr_len, 0);
>+ call_netdevice_notifiers(NETDEV_CHANGEADDR, to_dev);
>+ return 0;
>+}
>+EXPORT_SYMBOL(dev_addr_del_multiple);
>+
>+/* unicast and multicast addresses handling functions */
>+
> int __dev_addr_delete(struct dev_addr_list **list, int *count,
> void *addr, int alen, int glbl)
> {
>@@ -4780,6 +5037,7 @@ struct net_device *alloc_netdev_mq(int sizeof_priv, const char *name,
>
> dev->gso_max_size = GSO_MAX_SIZE;
>
>+ dev_addr_init(dev);
> netdev_init_queues(dev);
>
> INIT_LIST_HEAD(&dev->napi_list);
>@@ -4805,6 +5063,9 @@ void free_netdev(struct net_device *dev)
>
> kfree(dev->_tx);
>
>+ /* Flush device addresses */
>+ dev_addr_flush(dev);
>+
> list_for_each_entry_safe(p, n, &dev->napi_list, dev_list)
> netif_napi_del(p);
>
>--
>1.6.0.6
>