Snort mailing list archives
Re: Re: [Snort-users] Bus error on sparc
From: "Andrew R. Baker" <andrewb () snort org>
Date: Fri, 16 May 2003 08:32:08 -0400
Michael Bell wrote: > Andrew R. Baker wrote: > >> A better fix may be to do what pcap does for these cases. When >> constructing the pseudo packet, offset the start of the packet by N >> bytes (where N = number of bytes to make the link layer portion *end* >> on a word boundary). I do this in Barnyard for *all* packets >> regardless of what platform we are running on > > > Is there no other way? This would require several fixes in decode.c. > > If you read decode.c carefully then you will see that there are several > calls of this type: > > DecodeXYZ (p->pkt + ABC_HEADER_LEN, ...) It is not quite as bad as it seems. First, we only need to do this when allocating memory to store a packet in (ie only in packets created by stream4 and frag2). Second, since all of the protocols above the link layer are nicely aligned, it only needs to be done once. Creating a new packet would go something like this. pkt_buffer = calloc(pkt_len + offset, sizeof(uchar)); pkt = pkt_buffer + offset; offset is calculated by determing how many bytes shy of being word aligned the link layer header is. The packet is stored starting at pkt. The only trick is to remember to free appropriately (ie free(pkt_buffer) or free(pkt - offset)). -A ------------------------------------------------------- Enterprise Linux Forum Conference & Expo, June 4-6, 2003, Santa Clara The only event dedicated to issues related to Linux enterprise solutions www.enterpriselinuxforum.com _______________________________________________ Snort-users mailing list Snort-users () lists sourceforge net Go to this URL to change user options or unsubscribe: https://lists.sourceforge.net/lists/listinfo/snort-users Snort-users list archive: http://www.geocrawler.com/redir-sf.php3?list=snort-users
Current thread:
- Bus error on sparc Michael Bell (May 12)
- Re: Bus error on sparc Michael Bell (May 13)
- Re: Bus error on sparc Michael Bell (May 14)
- Re: Bus error on sparc Michael Bell (May 14)
- Re: Bus error on sparc Michael Bell (May 14)
- Re: Bus error on sparc Andrew R. Baker (May 15)
- Re: Bus error on sparc Michael Bell (May 16)
- Re: Re: [Snort-users] Bus error on sparc Andrew R. Baker (May 16)
- Re: Bus error on sparc Michael Bell (May 14)
- Re: Bus error on sparc Michael Bell (May 13)