From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gary Thomas To: Grant Edwards Cc: ecos-discuss@sources.redhat.com Subject: Re: [ECOS] RedBoot: __eth_install_handler? Date: Mon, 22 Jan 2001 14:51:00 -0000 Message-id: References: <20010122161351.A26689@visi.com> X-SW-Source: 2001-01/msg00376.html On 22-Jan-2001 Grant Edwards wrote: > On Mon, Jan 22, 2001 at 02:57:41PM -0600, Grant Edwards wrote: >> >> > > In RedBoot's net.h file, there's a declaration for >> > > __eth_install_handler(), which would seem from the declaration to >> > > do exactly what I want to do: set a call-back to handle packets >> > > with Ethernet protocol type . >> > > >> > > That functionality hasn't been implemented, so I'm about to >> > > implement it. > > It doesn't look like the packet handler routines verify that > the length of a received Ethernet frame is long enough to > contain the amount of data expected. For example, the IP > handler doesn't check to make sure that the number of bytes in > the Ethernet frame was was large enough to hold the amount of > data claimed in the IP header. > > The only way for that to happen would be for another host to > intentionally send a short Ethernet frame (AFAIK). Even if that > happens it should be caught by the checksum verification, > right? > That would certainly be true - the checksum routines will try and access the advertised length of data. I see no way that the computed value would match if the actual data was too short.