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net: introduce a list of device addresses dev_addr_list (v6)
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v5 -> v6 (current):
-removed so far unused static functions
-corrected dev_addr_del_multiple to call del instead of add

v4 -> v5:
-added device address type (suggested by davem)
-removed refcounting (better to have simplier code then safe potentially few
 bytes)

v3 -> v4:
-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 <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
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Jiri Pirko authored and davem330 committed May 5, 2009
1 parent b6907b0 commit f001fde
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Showing 3 changed files with 312 additions and 2 deletions.
27 changes: 27 additions & 0 deletions include/linux/etherdevice.h
Original file line number Diff line number Diff line change
Expand Up @@ -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__ */

/**
Expand Down
37 changes: 35 additions & 2 deletions include/linux/netdevice.h
Original file line number Diff line number Diff line change
Expand Up @@ -210,6 +210,16 @@ 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];
unsigned char type;
#define NETDEV_HW_ADDR_T_LAN 1
#define NETDEV_HW_ADDR_T_SAN 2
#define NETDEV_HW_ADDR_T_SLAVE 3
struct rcu_head rcu_head;
};

struct hh_cache
{
struct hh_cache *hh_next; /* Next entry */
Expand Down Expand Up @@ -784,8 +794,11 @@ 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 */

Expand Down Expand Up @@ -1791,6 +1804,13 @@ 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);
Expand All @@ -1803,6 +1823,19 @@ 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,
unsigned char addr_type);
extern int dev_addr_del(struct net_device *dev, unsigned char *addr,
unsigned char addr_type);
extern int dev_addr_add_multiple(struct net_device *to_dev,
struct net_device *from_dev,
unsigned char addr_type);
extern int dev_addr_del_multiple(struct net_device *to_dev,
struct net_device *from_dev,
unsigned char addr_type);

/* 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);
Expand Down
250 changes: 250 additions & 0 deletions net/core/dev.c
Original file line number Diff line number Diff line change
Expand Up @@ -3434,6 +3434,252 @@ void dev_set_rx_mode(struct net_device *dev)
netif_addr_unlock_bh(dev);
}

/* hw addresses list handling functions */

static int __hw_addr_add(struct list_head *list, unsigned char *addr,
int addr_len, unsigned char addr_type)
{
struct netdev_hw_addr *ha;
int alloc_size;

if (addr_len > MAX_ADDR_LEN)
return -EINVAL;

alloc_size = sizeof(*ha);
if (alloc_size < L1_CACHE_BYTES)
alloc_size = L1_CACHE_BYTES;
ha = kmalloc(alloc_size, GFP_ATOMIC);
if (!ha)
return -ENOMEM;
memcpy(ha->addr, addr, addr_len);
ha->type = addr_type;
list_add_tail_rcu(&ha->list, list);
return 0;
}

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, unsigned char addr_type,
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) &&
(ha->type == addr_type || !addr_type)) {
list_del_rcu(&ha->list);
call_rcu(&ha->rcu_head, ha_rcu_free);
return 0;
}
}
return -ENOENT;
}

static int __hw_addr_add_multiple_ii(struct list_head *to_list,
struct list_head *from_list,
int addr_len, unsigned char addr_type,
int ignore_index)
{
int err;
struct netdev_hw_addr *ha, *ha2;
unsigned char type;

list_for_each_entry(ha, from_list, list) {
type = addr_type ? addr_type : ha->type;
err = __hw_addr_add(to_list, ha->addr, addr_len, type);
if (err)
goto unroll;
}
return 0;

unroll:
list_for_each_entry(ha2, from_list, list) {
if (ha2 == ha)
break;
type = addr_type ? addr_type : ha2->type;
__hw_addr_del_ii(to_list, ha2->addr, addr_len, type,
ignore_index);
}
return err;
}

static void __hw_addr_del_multiple_ii(struct list_head *to_list,
struct list_head *from_list,
int addr_len, unsigned char addr_type,
int ignore_index)
{
struct netdev_hw_addr *ha;
unsigned char type;

list_for_each_entry(ha, from_list, list) {
type = addr_type ? addr_type : ha->type;
__hw_addr_del_ii(to_list, ha->addr, addr_len, addr_type,
ignore_index);
}
}

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),
NETDEV_HW_ADDR_T_LAN);
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
* @addr_type: address type
*
* 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,
unsigned char addr_type)
{
int err;

ASSERT_RTNL();

err = __hw_addr_add(&dev->dev_addr_list, addr, dev->addr_len,
addr_type);
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
* @addr_type: address type
*
* 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,
unsigned char addr_type)
{
int err;

ASSERT_RTNL();

err = __hw_addr_del_ii(&dev->dev_addr_list, addr, dev->addr_len,
addr_type, 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
* @addr_type: address type - 0 means type will be used from from_dev
*
* 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,
unsigned char addr_type)
{
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, addr_type, 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
* @addr_type: address type - 0 means type will used from from_dev
*
* 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,
unsigned char addr_type)
{
ASSERT_RTNL();

if (from_dev->addr_len != to_dev->addr_len)
return -EINVAL;
__hw_addr_del_multiple_ii(&to_dev->dev_addr_list,
&from_dev->dev_addr_list,
to_dev->addr_len, addr_type, 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)
{
Expand Down Expand Up @@ -4776,6 +5022,7 @@ 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);
Expand All @@ -4801,6 +5048,9 @@ 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);

Expand Down

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