Instead of collecting multicast MAC addresses from the netdev hw mc list collect a node's multicast listeners from the IP lists and convert those to MAC addresses.
This allows to exclude addresses of specific scope later. On a multicast MAC address the IP destination scope is not visible anymore.
Signed-off-by: Linus Lüssing linus.luessing@c0d3.blue --- net/batman-adv/multicast.c | 258 +++++++++++++++++++++++++------------ 1 file changed, 173 insertions(+), 85 deletions(-)
diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c index 86a7f1b8..d38f3808 100644 --- a/net/batman-adv/multicast.c +++ b/net/batman-adv/multicast.c @@ -20,6 +20,7 @@ #include <linux/igmp.h> #include <linux/in.h> #include <linux/in6.h> +#include <linux/inetdevice.h> #include <linux/ip.h> #include <linux/ipv6.h> #include <linux/jiffies.h> @@ -171,91 +172,6 @@ static struct net_device *batadv_mcast_get_bridge(struct net_device *soft_iface) return upper; }
-/** - * batadv_mcast_addr_is_ipv4() - check if multicast MAC is IPv4 - * @addr: the MAC address to check - * - * Return: True, if MAC address is one reserved for IPv4 multicast, false - * otherwise. - */ -static bool batadv_mcast_addr_is_ipv4(const u8 *addr) -{ - static const u8 prefix[] = {0x01, 0x00, 0x5E}; - - return memcmp(prefix, addr, sizeof(prefix)) == 0; -} - -/** - * batadv_mcast_addr_is_ipv6() - check if multicast MAC is IPv6 - * @addr: the MAC address to check - * - * Return: True, if MAC address is one reserved for IPv6 multicast, false - * otherwise. - */ -static bool batadv_mcast_addr_is_ipv6(const u8 *addr) -{ - static const u8 prefix[] = {0x33, 0x33}; - - return memcmp(prefix, addr, sizeof(prefix)) == 0; -} - -/** - * batadv_mcast_mla_softif_get() - get softif multicast listeners - * @dev: the device to collect multicast addresses from - * @mcast_list: a list to put found addresses into - * @flags: flags indicating the new multicast state - * - * Collects multicast addresses of multicast listeners residing - * on this kernel on the given soft interface, dev, in - * the given mcast_list. In general, multicast listeners provided by - * your multicast receiving applications run directly on this node. - * - * If there is a bridge interface on top of dev, collects from that one - * instead. Just like with IP addresses and routes, multicast listeners - * will(/should) register to the bridge interface instead of an - * enslaved bat0. - * - * Return: -ENOMEM on memory allocation error or the number of - * items added to the mcast_list otherwise. - */ -static int -batadv_mcast_mla_softif_get(struct net_device *dev, - struct hlist_head *mcast_list, - struct batadv_mcast_mla_flags *flags) -{ - bool all_ipv4 = flags->tvlv_flags & BATADV_MCAST_WANT_ALL_IPV4; - bool all_ipv6 = flags->tvlv_flags & BATADV_MCAST_WANT_ALL_IPV6; - struct net_device *bridge = batadv_mcast_get_bridge(dev); - struct netdev_hw_addr *mc_list_entry; - struct batadv_hw_addr *new; - int ret = 0; - - netif_addr_lock_bh(bridge ? bridge : dev); - netdev_for_each_mc_addr(mc_list_entry, bridge ? bridge : dev) { - if (all_ipv4 && batadv_mcast_addr_is_ipv4(mc_list_entry->addr)) - continue; - - if (all_ipv6 && batadv_mcast_addr_is_ipv6(mc_list_entry->addr)) - continue; - - new = kmalloc(sizeof(*new), GFP_ATOMIC); - if (!new) { - ret = -ENOMEM; - break; - } - - ether_addr_copy(new->addr, mc_list_entry->addr); - hlist_add_head(&new->list, mcast_list); - ret++; - } - netif_addr_unlock_bh(bridge ? bridge : dev); - - if (bridge) - dev_put(bridge); - - return ret; -} - /** * batadv_mcast_mla_is_duplicate() - check whether an address is in a list * @mcast_addr: the multicast address to check @@ -276,6 +192,178 @@ static bool batadv_mcast_mla_is_duplicate(u8 *mcast_addr, return false; }
+/** + * batadv_mcast_mla_softif_get_ipv4() - get softif IPv4 multicast listeners + * @dev: the device to collect multicast addresses from + * @mcast_list: a list to put found addresses into + * @flags: flags indicating the new multicast state + * + * Collects multicast addresses of IPv4 multicast listeners residing + * on this kernel on the given soft interface, dev, in + * the given mcast_list. In general, multicast listeners provided by + * your multicast receiving applications run directly on this node. + * + * Return: -ENOMEM on memory allocation error or the number of + * items added to the mcast_list otherwise. + */ +static int +batadv_mcast_mla_softif_get_ipv4(struct net_device *dev, + struct hlist_head *mcast_list, + struct batadv_mcast_mla_flags *flags) +{ + struct batadv_hw_addr *new; + struct in_device *in_dev; + u8 mcast_addr[ETH_ALEN]; + struct ip_mc_list *pmc; + int ret = 0; + + if (flags->tvlv_flags & BATADV_MCAST_WANT_ALL_IPV4) + return 0; + + in_dev = in_dev_get(dev); + if (!in_dev) + return 0; + + rcu_read_lock(); + for (pmc = rcu_dereference(in_dev->mc_list); pmc; + pmc = rcu_dereference(pmc->next_rcu)) { + ip_eth_mc_map(pmc->multiaddr, mcast_addr); + + if (batadv_mcast_mla_is_duplicate(mcast_addr, mcast_list)) + continue; + + new = kmalloc(sizeof(*new), GFP_ATOMIC); + if (!new) { + ret = -ENOMEM; + break; + } + + ether_addr_copy(new->addr, mcast_addr); + hlist_add_head(&new->list, mcast_list); + ret++; + } + rcu_read_unlock(); + in_dev_put(in_dev); + + return ret; +} + +/** + * batadv_mcast_mla_softif_get_ipv6() - get softif IPv6 multicast listeners + * @dev: the device to collect multicast addresses from + * @mcast_list: a list to put found addresses into + * @flags: flags indicating the new multicast state + * + * Collects multicast addresses of IPv6 multicast listeners residing + * on this kernel on the given soft interface, dev, in + * the given mcast_list. In general, multicast listeners provided by + * your multicast receiving applications run directly on this node. + * + * Return: -ENOMEM on memory allocation error or the number of + * items added to the mcast_list otherwise. + */ +#if IS_ENABLED(CONFIG_IPV6) +static int +batadv_mcast_mla_softif_get_ipv6(struct net_device *dev, + struct hlist_head *mcast_list, + struct batadv_mcast_mla_flags *flags) +{ + struct batadv_hw_addr *new; + struct inet6_dev *in6_dev; + u8 mcast_addr[ETH_ALEN]; + struct ifmcaddr6 *pmc6; + int ret = 0; + + if (flags->tvlv_flags & BATADV_MCAST_WANT_ALL_IPV6) + return 0; + + in6_dev = in6_dev_get(dev); + if (!in6_dev) + return 0; + + read_lock_bh(&in6_dev->lock); + for (pmc6 = in6_dev->mc_list; pmc6; pmc6 = pmc6->next) { + if (IPV6_ADDR_MC_SCOPE(&pmc6->mca_addr) < + IPV6_ADDR_SCOPE_LINKLOCAL) + continue; + + ipv6_eth_mc_map(&pmc6->mca_addr, mcast_addr); + + if (batadv_mcast_mla_is_duplicate(mcast_addr, mcast_list)) + continue; + + new = kmalloc(sizeof(*new), GFP_ATOMIC); + if (!new) { + ret = -ENOMEM; + break; + } + + ether_addr_copy(new->addr, mcast_addr); + hlist_add_head(&new->list, mcast_list); + ret++; + } + read_unlock_bh(&in6_dev->lock); + in6_dev_put(in6_dev); + + return ret; +} +#else +static inline int +batadv_mcast_mla_softif_get_ipv6(struct batadv_priv *bat_priv, + struct net_device *dev, + struct hlist_head *mcast_list) +{ + return 0; +} +#endif + +/** + * batadv_mcast_mla_softif_get() - get softif multicast listeners + * @dev: the device to collect multicast addresses from + * @mcast_list: a list to put found addresses into + * @flags: flags indicating the new multicast state + * + * Collects multicast addresses of multicast listeners residing + * on this kernel on the given soft interface, dev, in + * the given mcast_list. In general, multicast listeners provided by + * your multicast receiving applications run directly on this node. + * + * If there is a bridge interface on top of dev, collects from that one + * instead. Just like with IP addresses and routes, multicast listeners + * will(/should) register to the bridge interface instead of an + * enslaved bat0. + * + * Return: -ENOMEM on memory allocation error or the number of + * items added to the mcast_list otherwise. + */ +static int +batadv_mcast_mla_softif_get(struct net_device *dev, + struct hlist_head *mcast_list, + struct batadv_mcast_mla_flags *flags) +{ + struct net_device *bridge = batadv_mcast_get_bridge(dev); + int ret4, ret6 = 0; + + if (bridge) + dev = bridge; + + ret4 = batadv_mcast_mla_softif_get_ipv4(dev, mcast_list, flags); + if (ret4 < 0) + goto out; + + ret6 = batadv_mcast_mla_softif_get_ipv6(dev, mcast_list, flags); + if (ret6 < 0) { + ret4 = 0; + goto out; + } + +out: + if (bridge) + dev_put(bridge); + + return ret4 + ret6; +} + /** * batadv_mcast_mla_br_addr_cpy() - copy a bridge multicast address * @dst: destination to write to - a multicast MAC address