BATADV_FRAG_MAX_FRAG_SIZE
mtu = min_t(unsigned int, mtu, BATADV_FRAG_MAX_FRAG_SIZE);
int limit = BATADV_FRAG_MAX_FRAG_SIZE;
min_mtu = min_t(int, min_mtu, BATADV_FRAG_MAX_FRAG_SIZE);