On Thu, 11 May 2017 15:46:27 +0200 Fredrik Markstrom <fredrik.markstrom@xxxxxxxxx> wrote: > From: Fredrik Markström <fredrik.markstrom@xxxxxxxxx> > > is_skb_forwardable() currently checks if the packet size is <= mtu of > the receiving interface. This is not consistent with most of the hardware > ethernet drivers that happily receives packets larger then MTU. Wrong. Hardware interfaces are free to drop any packet greater than MTU (actually MTU + VLAN). The actual limit is a function of the hardware. Some hardware can only limit by power of 2; some can only limit frames larger than 1500; some have no limiting at all. Any application that should: * not expect packets larger than MTU to be received * not send packets larger than MTU * check actual receive size. IP protocols will do truncation of padded packets
