Commit a0a400d7 authored by Patrick McHardy's avatar Patrick McHardy Committed by David S. Miller
Browse files

[NET]: dev_mcast: add multicast list synchronization helpers



The method drivers currently use to synchronize multicast lists is not
very pretty:

- walk the multicast list
- search each entry on a copy of the previous list
- if new add to lower device
- walk the copy of the previous list
- search each entry on the current list
- if removed delete from lower device
- copy entire list

This patch adds a new field to struct dev_addr_list to store the
synchronization state and adds two helper functions for synchronization
and cleanup.
Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 24023451
......@@ -190,6 +190,7 @@ struct dev_addr_list
struct dev_addr_list *next;
u8 da_addr[MAX_ADDR_LEN];
u8 da_addrlen;
u8 da_synced;
int da_users;
int da_gusers;
};
......@@ -1103,6 +1104,8 @@ extern int dev_unicast_delete(struct net_device *dev, void *addr, int alen);
extern int dev_unicast_add(struct net_device *dev, void *addr, int alen);
extern int dev_mc_delete(struct net_device *dev, void *addr, int alen, int all);
extern int dev_mc_add(struct net_device *dev, void *addr, int alen, int newonly);
extern int dev_mc_sync(struct net_device *to, struct net_device *from);
extern void dev_mc_unsync(struct net_device *to, struct net_device *from);
extern void dev_mc_discard(struct net_device *dev);
extern int __dev_addr_delete(struct dev_addr_list **list, int *count, void *addr, int alen, int all);
extern int __dev_addr_add(struct dev_addr_list **list, int *count, void *addr, int alen, int newonly);
......
......@@ -102,6 +102,81 @@ int dev_mc_add(struct net_device *dev, void *addr, int alen, int glbl)
return err;
}
/**
* dev_mc_sync - Synchronize device's multicast list to another device
* @to: destination device
* @from: source device
*
* Add newly added addresses to the destination device and release
* addresses that have no users left. The source device must be
* locked by netif_tx_lock_bh.
*
* This function is intended to be called from the dev->set_multicast_list
* function of layered software devices.
*/
int dev_mc_sync(struct net_device *to, struct net_device *from)
{
struct dev_addr_list *da;
int err = 0;
netif_tx_lock_bh(to);
for (da = from->mc_list; da != NULL; da = da->next) {
if (!da->da_synced) {
err = __dev_addr_add(&to->mc_list, &to->mc_count,
da->da_addr, da->da_addrlen, 0);
if (err < 0)
break;
da->da_synced = 1;
da->da_users++;
} else if (da->da_users == 1) {
__dev_addr_delete(&to->mc_list, &to->mc_count,
da->da_addr, da->da_addrlen, 0);
__dev_addr_delete(&from->mc_list, &from->mc_count,
da->da_addr, da->da_addrlen, 0);
}
}
if (!err)
__dev_set_rx_mode(to);
netif_tx_unlock_bh(to);
return err;
}
EXPORT_SYMBOL(dev_mc_sync);
/**
* dev_mc_unsync - Remove synchronized addresses from the destination
* device
* @to: destination device
* @from: source device
*
* Remove all addresses that were added to the destination device by
* dev_mc_sync(). This function is intended to be called from the
* dev->stop function of layered software devices.
*/
void dev_mc_unsync(struct net_device *to, struct net_device *from)
{
struct dev_addr_list *da;
netif_tx_lock_bh(from);
netif_tx_lock_bh(to);
for (da = from->mc_list; da != NULL; da = da->next) {
if (!da->da_synced)
continue;
__dev_addr_delete(&to->mc_list, &to->mc_count,
da->da_addr, da->da_addrlen, 0);
da->da_synced = 0;
__dev_addr_delete(&from->mc_list, &from->mc_count,
da->da_addr, da->da_addrlen, 0);
}
__dev_set_rx_mode(to);
netif_tx_unlock_bh(to);
netif_tx_unlock_bh(from);
}
EXPORT_SYMBOL(dev_mc_unsync);
/*
* Discard multicast list when a device is downed
*/
......
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