diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c index 004017c523fa..d564af295db4 100644 --- a/net/batman-adv/hard-interface.c +++ b/net/batman-adv/hard-interface.c @@ -269,9 +269,10 @@ int batadv_hardif_min_mtu(struct net_device *soft_iface) const struct batadv_priv *bat_priv = netdev_priv(soft_iface); const struct batadv_hard_iface *hard_iface; /* allow big frames if all devices are capable to do so - * (have MTU > 1500 + BAT_HEADER_LEN) + * (have MTU > 1500 + batadv_max_header_len()) */ int min_mtu = ETH_DATA_LEN; + int max_header_len = batadv_max_header_len(); if (atomic_read(&bat_priv->fragmentation)) goto out; @@ -285,8 +286,7 @@ int batadv_hardif_min_mtu(struct net_device *soft_iface) if (hard_iface->soft_iface != soft_iface) continue; - min_mtu = min_t(int, - hard_iface->net_dev->mtu - BATADV_HEADER_LEN, + min_mtu = min_t(int, hard_iface->net_dev->mtu - max_header_len, min_mtu); } rcu_read_unlock(); @@ -380,6 +380,7 @@ int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface, struct batadv_priv *bat_priv; struct net_device *soft_iface, *master; __be16 ethertype = htons(ETH_P_BATMAN); + int max_header_len = batadv_max_header_len(); int ret; if (hard_iface->if_status != BATADV_IF_NOT_IN_USE) @@ -448,18 +449,18 @@ int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface, hard_iface->net_dev->name); if (atomic_read(&bat_priv->fragmentation) && - hard_iface->net_dev->mtu < ETH_DATA_LEN + BATADV_HEADER_LEN) + hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len) batadv_info(hard_iface->soft_iface, - "The MTU of interface %s is too small (%i) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to %zi would solve the problem.\n", + "The MTU of interface %s is too small (%i) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to %i would solve the problem.\n", hard_iface->net_dev->name, hard_iface->net_dev->mtu, - ETH_DATA_LEN + BATADV_HEADER_LEN); + ETH_DATA_LEN + max_header_len); if (!atomic_read(&bat_priv->fragmentation) && - hard_iface->net_dev->mtu < ETH_DATA_LEN + BATADV_HEADER_LEN) + hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len) batadv_info(hard_iface->soft_iface, - "The MTU of interface %s is too small (%i) to handle the transport of batman-adv packets. If you experience problems getting traffic through try increasing the MTU to %zi.\n", + "The MTU of interface %s is too small (%i) to handle the transport of batman-adv packets. If you experience problems getting traffic through try increasing the MTU to %i.\n", hard_iface->net_dev->name, hard_iface->net_dev->mtu, - ETH_DATA_LEN + BATADV_HEADER_LEN); + ETH_DATA_LEN + max_header_len); if (batadv_hardif_is_iface_up(hard_iface)) batadv_hardif_activate_interface(hard_iface); diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c index 519138e32fe6..7f3a5c426615 100644 --- a/net/batman-adv/main.c +++ b/net/batman-adv/main.c @@ -255,6 +255,31 @@ out: return primary_if; } +/** + * batadv_max_header_len - calculate maximum encapsulation overhead for a + * payload packet + * + * Return the maximum encapsulation overhead in bytes. + */ +int batadv_max_header_len(void) +{ + int header_len = 0; + + header_len = max_t(int, header_len, + sizeof(struct batadv_unicast_packet)); + header_len = max_t(int, header_len, + sizeof(struct batadv_unicast_4addr_packet)); + header_len = max_t(int, header_len, + sizeof(struct batadv_bcast_packet)); + +#ifdef CONFIG_BATMAN_ADV_NC + header_len = max_t(int, header_len, + sizeof(struct batadv_coded_packet)); +#endif + + return header_len; +} + /** * batadv_skb_set_priority - sets skb priority according to packet content * @skb: the packet to be sent diff --git a/net/batman-adv/main.h b/net/batman-adv/main.h index 6a74a4225326..54c13d51edbe 100644 --- a/net/batman-adv/main.h +++ b/net/batman-adv/main.h @@ -191,6 +191,7 @@ void batadv_mesh_free(struct net_device *soft_iface); int batadv_is_my_mac(struct batadv_priv *bat_priv, const uint8_t *addr); struct batadv_hard_iface * batadv_seq_print_text_primary_if_get(struct seq_file *seq); +int batadv_max_header_len(void); void batadv_skb_set_priority(struct sk_buff *skb, int offset); int batadv_batman_skb_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *ptype, diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c index 87e7e4ed216d..15c7237f427b 100644 --- a/net/batman-adv/soft-interface.c +++ b/net/batman-adv/soft-interface.c @@ -626,7 +626,7 @@ static void batadv_softif_init_early(struct net_device *dev) */ dev->mtu = ETH_DATA_LEN; /* reserve more space in the skbuff for our header */ - dev->hard_header_len = BATADV_HEADER_LEN; + dev->hard_header_len = batadv_max_header_len(); /* generate random address */ eth_hw_addr_random(dev); diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index d517d5dde6ad..5cbb0d09a9b5 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -24,13 +24,6 @@ #include "bitarray.h" #include -/** - * Maximum overhead for the encapsulation for a payload packet - */ -#define BATADV_HEADER_LEN \ - (ETH_HLEN + max(sizeof(struct batadv_unicast_packet), \ - sizeof(struct batadv_bcast_packet))) - #ifdef CONFIG_BATMAN_ADV_DAT /* batadv_dat_addr_t is the type used for all DHT addresses. If it is changed,