Nmap Development mailing list archives
Re: Bad IP-checksums
From: Fyodor <fyodor () insecure org>
Date: Fri, 15 Aug 2008 13:07:38 -0700
On Fri, Aug 15, 2008 at 03:11:02PM +0200, Gisle Vanem wrote:
After some digging, I found two places where 'ip->ip_sum' wasn't cleared before calculating the sum. I believe the omission in osscan2.cc that was causing me trouble. A patch against today's svn:
Did this actually fix the problem for you? For osscan2.cc, it looks at first glance like ip_sum should already be zero because of line 3064: memset((char *) packet, 0, sizeof(struct ip) + sizeof(struct udp_hdr)); Your tcpip.cc change looks like it only relates to fragmented packets. I'm not sure if resetting ip_sum to 0 is needed there, but I'll probably add it because it is easy and shouldn't hurt anything. Cheers, -F _______________________________________________ Sent through the nmap-dev mailing list http://cgi.insecure.org/mailman/listinfo/nmap-dev Archived at http://SecLists.Org
Current thread:
- Bad IP-checksums Gisle Vanem (Jul 25)
- Re: Bad IP-checksums Brandon Enright (Jul 25)
- Re: Bad IP-checksums David Fifield (Jul 25)
- Re: Bad IP-checksums Brandon Enright (Jul 25)
- Re: Bad IP-checksums Gisle Vanem (Jul 26)
- Re: Bad IP-checksums Gisle Vanem (Jul 26)
- Re: Bad IP-checksums Gisle Vanem (Aug 15)
- Re: Bad IP-checksums Fyodor (Aug 15)
- Re: Bad IP-checksums Gisle Vanem (Aug 15)
- Re: Bad IP-checksums Michael Pattrick (Aug 15)
- Re: Bad IP-checksums Gisle Vanem (Aug 16)
- Re: Bad IP-checksums David Fifield (Aug 20)
- Re: Bad IP-checksums Michael Pattrick (Aug 20)
- Re: Bad IP-checksums Gisle Vanem (Aug 21)
- Re: Bad IP-checksums David Fifield (Aug 21)
- Re: Bad IP-checksums David Fifield (Jul 25)
- Re: Bad IP-checksums Brandon Enright (Jul 25)