diff options
Diffstat (limited to 'net/batman-adv/multicast.c')
| -rw-r--r-- | net/batman-adv/multicast.c | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c index 3ba9a18a906c..1d1627fe0de0 100644 --- a/net/batman-adv/multicast.c +++ b/net/batman-adv/multicast.c @@ -20,6 +20,7 @@ #include "originator.h" #include "hard-interface.h" #include "translation-table.h" +#include "multicast.h" /** * batadv_mcast_mla_softif_get - get softif multicast listeners @@ -247,6 +248,131 @@ out: } /** + * batadv_mcast_forw_mode_check_ipv6 - check for optimized forwarding potential + * @bat_priv: the bat priv with all the soft interface information + * @skb: the IPv6 packet to check + * + * Checks whether the given IPv6 packet has the potential to be forwarded with a + * mode more optimal than classic flooding. + * + * If so then returns 0. Otherwise -EINVAL is returned or -ENOMEM if we are out + * of memory. + */ +static int batadv_mcast_forw_mode_check_ipv6(struct batadv_priv *bat_priv, + struct sk_buff *skb) +{ + struct ipv6hdr *ip6hdr; + + /* We might fail due to out-of-memory -> drop it */ + if (!pskb_may_pull(skb, sizeof(struct ethhdr) + sizeof(*ip6hdr))) + return -ENOMEM; + + ip6hdr = ipv6_hdr(skb); + + /* TODO: Implement Multicast Router Discovery (RFC4286), + * then allow scope > link local, too + */ + if (IPV6_ADDR_MC_SCOPE(&ip6hdr->daddr) != IPV6_ADDR_SCOPE_LINKLOCAL) + return -EINVAL; + + /* link-local-all-nodes multicast listeners behind a bridge are + * not snoopable (see RFC4541, section 3, paragraph 3) + */ + if (ipv6_addr_is_ll_all_nodes(&ip6hdr->daddr)) + return -EINVAL; + + return 0; +} + +/** + * batadv_mcast_forw_mode_check - check for optimized forwarding potential + * @bat_priv: the bat priv with all the soft interface information + * @skb: the multicast frame to check + * + * Checks whether the given multicast ethernet frame has the potential to be + * forwarded with a mode more optimal than classic flooding. + * + * If so then returns 0. Otherwise -EINVAL is returned or -ENOMEM if we are out + * of memory. + */ +static int batadv_mcast_forw_mode_check(struct batadv_priv *bat_priv, + struct sk_buff *skb) +{ + struct ethhdr *ethhdr = eth_hdr(skb); + + if (!atomic_read(&bat_priv->multicast_mode)) + return -EINVAL; + + if (atomic_read(&bat_priv->mcast.num_disabled)) + return -EINVAL; + + switch (ntohs(ethhdr->h_proto)) { + case ETH_P_IPV6: + return batadv_mcast_forw_mode_check_ipv6(bat_priv, skb); + default: + return -EINVAL; + } +} + +/** + * batadv_mcast_forw_tt_node_get - get a multicast tt node + * @bat_priv: the bat priv with all the soft interface information + * @ethhdr: the ether header containing the multicast destination + * + * Returns an orig_node matching the multicast address provided by ethhdr + * via a translation table lookup. This increases the returned nodes refcount. + */ +static struct batadv_orig_node * +batadv_mcast_forw_tt_node_get(struct batadv_priv *bat_priv, + struct ethhdr *ethhdr) +{ + return batadv_transtable_search(bat_priv, ethhdr->h_source, + ethhdr->h_dest, BATADV_NO_FLAGS); +} + +/** + * batadv_mcast_forw_mode - check on how to forward a multicast packet + * @bat_priv: the bat priv with all the soft interface information + * @skb: The multicast packet to check + * @orig: an originator to be set to forward the skb to + * + * Returns the forwarding mode as enum batadv_forw_mode and in case of + * BATADV_FORW_SINGLE set the orig to the single originator the skb + * should be forwarded to. + */ +enum batadv_forw_mode +batadv_mcast_forw_mode(struct batadv_priv *bat_priv, struct sk_buff *skb, + struct batadv_orig_node **orig) +{ + struct ethhdr *ethhdr; + int ret, tt_count; + + ret = batadv_mcast_forw_mode_check(bat_priv, skb); + if (ret == -ENOMEM) + return BATADV_FORW_NONE; + else if (ret < 0) + return BATADV_FORW_ALL; + + ethhdr = eth_hdr(skb); + + tt_count = batadv_tt_global_hash_count(bat_priv, ethhdr->h_dest, + BATADV_NO_FLAGS); + + switch (tt_count) { + case 1: + *orig = batadv_mcast_forw_tt_node_get(bat_priv, ethhdr); + if (*orig) + return BATADV_FORW_SINGLE; + + /* fall through */ + case 0: + return BATADV_FORW_NONE; + default: + return BATADV_FORW_ALL; + } +} + +/** * batadv_mcast_tvlv_ogm_handler_v1 - process incoming multicast tvlv container * @bat_priv: the bat priv with all the soft interface information * @orig: the orig_node of the ogm |
