From a0a400d79e3dd7843e7e81baa3ef2957bdc292d0 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Sat, 14 Jul 2007 18:52:02 -0700 Subject: [PATCH] [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: Patrick McHardy Signed-off-by: David S. Miller --- include/linux/netdevice.h | 3 ++ net/core/dev_mcast.c | 75 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 78 insertions(+) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index f193aba3038..e5af458ab04 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -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); diff --git a/net/core/dev_mcast.c b/net/core/dev_mcast.c index aa38100601f..235a2a8a0d0 100644 --- a/net/core/dev_mcast.c +++ b/net/core/dev_mcast.c @@ -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 */ -- 2.32.0.93.g670b81a890