From ca8864a6709da9c6a603465e37e31b58e69c2e82 Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Tue, 18 Jul 2023 11:09:18 +0200 Subject: [RFC PATCH v1] batman-adv: Add support for jumbo frames TODO: write a commit message Signed-off-by: Sven Eckelmann --- net/batman-adv/hard-interface.c | 17 ++++++++--------- net/batman-adv/hard-interface.h | 2 +- net/batman-adv/main.h | 2 ++ net/batman-adv/soft-interface.c | 8 ++++++-- 4 files changed, 17 insertions(+), 12 deletions(-) diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c index 41c1ad33..3b0df9fb 100644 --- a/net/batman-adv/hard-interface.c +++ b/net/batman-adv/hard-interface.c @@ -573,11 +573,12 @@ static void batadv_hardif_recalc_extra_skbroom(struct net_device *soft_iface) /** * batadv_hardif_min_mtu() - Calculate maximum MTU for soft interface * @soft_iface: netdev struct of the soft interface + * @max_mtu: limit for maximum returned MTU * * Return: MTU for the soft-interface (limited by the minimal MTU of all active * slave interfaces) */ -int batadv_hardif_min_mtu(struct net_device *soft_iface) +int batadv_hardif_min_mtu(struct net_device *soft_iface, unsigned int max_mtu) { struct batadv_priv *bat_priv = netdev_priv(soft_iface); const struct batadv_hard_iface *hard_iface; @@ -617,10 +618,8 @@ int batadv_hardif_min_mtu(struct net_device *soft_iface) /* the real soft-interface MTU is computed by removing the payload * overhead from the maximum amount of bytes that was just computed. - * - * However batman-adv does not support MTUs bigger than ETH_DATA_LEN */ - return min_t(int, min_mtu - batadv_max_header_len(), ETH_DATA_LEN); + return min_t(int, min_mtu - batadv_max_header_len(), max_mtu); } /** @@ -630,7 +629,7 @@ int batadv_hardif_min_mtu(struct net_device *soft_iface) */ void batadv_update_min_mtu(struct net_device *soft_iface) { - soft_iface->mtu = batadv_hardif_min_mtu(soft_iface); + soft_iface->mtu = batadv_hardif_min_mtu(soft_iface, soft_iface->mtu); /* Check if the local translate table should be cleaned up to match a * new (and smaller) MTU. @@ -734,18 +733,18 @@ 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 + max_header_len) + hard_iface->net_dev->mtu < BATADV_MAX_MTU + 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 %i would solve the problem.\n", hard_iface->net_dev->name, hard_iface->net_dev->mtu, - ETH_DATA_LEN + max_header_len); + BATADV_MAX_MTU + max_header_len); if (!atomic_read(&bat_priv->fragmentation) && - hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len) + hard_iface->net_dev->mtu < BATADV_MAX_MTU + 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 %i.\n", hard_iface->net_dev->name, hard_iface->net_dev->mtu, - ETH_DATA_LEN + max_header_len); + BATADV_MAX_MTU + max_header_len); if (batadv_hardif_is_iface_up(hard_iface)) batadv_hardif_activate_interface(hard_iface); diff --git a/net/batman-adv/hard-interface.h b/net/batman-adv/hard-interface.h index 64f660db..d5525483 100644 --- a/net/batman-adv/hard-interface.h +++ b/net/batman-adv/hard-interface.h @@ -76,7 +76,7 @@ batadv_hardif_get_by_netdev(const struct net_device *net_dev); int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface, struct net_device *soft_iface); void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface); -int batadv_hardif_min_mtu(struct net_device *soft_iface); +int batadv_hardif_min_mtu(struct net_device *soft_iface, unsigned int max_mtu); void batadv_update_min_mtu(struct net_device *soft_iface); void batadv_hardif_release(struct kref *ref); int batadv_hardif_no_broadcast(struct batadv_hard_iface *if_outgoing, diff --git a/net/batman-adv/main.h b/net/batman-adv/main.h index e0d53273..4dc81ddb 100644 --- a/net/batman-adv/main.h +++ b/net/batman-adv/main.h @@ -22,6 +22,8 @@ #define BATADV_THROUGHPUT_MAX_VALUE 0xFFFFFFFF #define BATADV_JITTER 20 +#define BATADV_MAX_MTU (ETH_MAX_MTU - batadv_max_header_len()) + /* Time To Live of broadcast messages */ #define BATADV_TTL 50 diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c index d3fdf822..f173f090 100644 --- a/net/batman-adv/soft-interface.c +++ b/net/batman-adv/soft-interface.c @@ -154,7 +154,10 @@ static int batadv_interface_set_mac_addr(struct net_device *dev, void *p) static int batadv_interface_change_mtu(struct net_device *dev, int new_mtu) { /* check ranges */ - if (new_mtu < 68 || new_mtu > batadv_hardif_min_mtu(dev)) + if (new_mtu < ETH_MIN_MTU) + return -EINVAL; + + if (new_mtu > batadv_hardif_min_mtu(dev, BATADV_MAX_MTU)) return -EINVAL; dev->mtu = new_mtu; @@ -769,7 +772,7 @@ static int batadv_softif_init_late(struct net_device *dev) atomic_set(&bat_priv->log_level, 0); #endif atomic_set(&bat_priv->fragmentation, 1); - atomic_set(&bat_priv->packet_size_max, ETH_DATA_LEN); + atomic_set(&bat_priv->packet_size_max, BATADV_MAX_MTU); atomic_set(&bat_priv->bcast_queue_left, BATADV_BCAST_QUEUE_LEN); atomic_set(&bat_priv->batman_queue_left, BATADV_BATMAN_QUEUE_LEN); @@ -1009,6 +1012,7 @@ static void batadv_softif_init_early(struct net_device *dev) * have not been initialized yet */ dev->mtu = ETH_DATA_LEN; + dev->max_mtu = BATADV_MAX_MTU; /* generate random address */ eth_hw_addr_random(dev); -- 2.39.2