Nmap Development mailing list archives
Re: Nmap/Nping bug on udp checksum calculation
From: David Fifield <david () bamsoftware com>
Date: Sun, 10 Nov 2013 01:14:51 -0800
On Sun, Nov 03, 2013 at 06:49:19PM +0100, Luis MartinGarcia. wrote:
Hi, David. Regarding this bug, I believe it also affects osscan2.cc. See below. What do you think? --- osscan2.cc (revision 32492) +++ osscan2.cc (working copy) @@ -2165,6 +2165,12 @@ /* OK, now we should be able to compute a valid checksum */ realcheck = ipv4_pseudoheader_cksum(source, hss->target->v4hostip(), IPPROTO_UDP, sizeof(struct udp_hdr) + datalen, (char *) udp); + + /* If the computed checksum has a value of zero, we need to set it + * to 0xFFFF (See RFC 768) */ + if(realcheck==0) + realcheck=0xFFFF; + #if STUPID_SOLARIS_CHECKSUM_BUG udp->uh_sum = sizeof(struct udp_hdr) + datalen; #else
Good catch. I agree with you. David Fifield _______________________________________________ Sent through the dev mailing list http://nmap.org/mailman/listinfo/dev Archived at http://seclists.org/nmap-dev/
Current thread:
- Nmap/Nping bug on udp checksum calculation Michael Weber (Nov 02)
- Re: Nmap/Nping bug on udp checksum calculation Luis MartinGarcia. (Nov 03)
- Re: Nmap/Nping bug on udp checksum calculation Luis MartinGarcia. (Nov 03)
- Re: Nmap/Nping bug on udp checksum calculation David Fifield (Nov 10)
- Re: Nmap/Nping bug on udp checksum calculation Daniel Miller (Nov 04)
- Re: Nmap/Nping bug on udp checksum calculation David Fifield (Nov 04)
- AW: Nmap/Nping bug on udp checksum calculation Michael Weber (Nov 05)
- Re: Nmap/Nping bug on udp checksum calculation Luis MartinGarcia (Nov 05)
- Re: Nmap/Nping bug on udp checksum calculation Daniel Miller (Nov 05)
- Re: Nmap/Nping bug on udp checksum calculation David Fifield (Nov 04)