From 411d6ed93a5d0601980d3e5ce75de07c98e3a7de Mon Sep 17 00:00:00 2001 From: Marek Lindner Date: Wed, 8 May 2013 13:31:59 +0800 Subject: batman-adv: consider network coding overhead when calculating required mtu The module prints a warning when the MTU on the hard interface is too small to transfer payload traffic without fragmentation. The required MTU is calculated based on the encapsulation header size. If network coding is compild into the module its header size is taken into account as well. Signed-off-by: Marek Lindner Signed-off-by: Antonio Quartulli --- net/batman-adv/main.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) (limited to 'net/batman-adv/main.c') diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c index 519138e32fe..7f3a5c42661 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 -- cgit v1.2.3-70-g09d2