At Thu, 31 Jan 2008 13:15:12 +0100 (CET), Ingo Flaschberger wrote: > > Dear Andre, > > >> 2) linux method: > >> Look for CONFIG_TCP_MD5SIG in linux-2.6.24/net/ipv4/tcp_ipv4.c > >> (sorry no weblink..) > >> They check and block md5-packets early in tcp_v4_do_rcv. > >> afinet.c -> tcp_v4_rcv -> tcp_v4_do_rcv > >> -> for Freebsd: place some logic early in tcp_input function > >> and call a new function to check md5. > > > > IMHO calling a special function that does the check (like in tcp_output) > > is the way to go. This function should be run as late as possible after > > the other segment validity checks to prevent easy cpu exhaustion attacks > > with packets that only get the port numbers right. > > > > In tcp_new there is a natural place to perform the check. tcp_input will > > show up this weekend. This doesn't prevent your work on the current code > > at all as tcp_new won't show up in -current for a long time and when it > > does it will not get MFC'd. > > Ok. > I will do the first patch for freebsd 6.2 (as my system uses it) and do > the a port to current (and I thing 6.3 too). > > Regardding Bruce: > I would prefer to implement md5 via the old setkey api as I also have todo > my daily business. > > >> 3) Bruce extended method: > >> http://lists.freebsd.org/pipermail/freebsd-net/2004-April/003761.html > >> Use his code and add at severall places in tcp_input function > >> similar checks. > >> > >> Options: > >> *) enable disable it via sysctl > >> *) count total, good and bad packets via sysctl > > > > This belongs into struct tcpstat, not a new sysctl. > > Ok. > With which tool can this counters be read? > Should I add the on/off feature? Via which tool? >
Enable/disable via sysctl. Read via netstat. Best, George _______________________________________________ freebsd-net@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "[EMAIL PROTECTED]"
