tcpdump mailing list archives
Max OS-X issues: read privledges / bpf buffer size
From: "Eric St.John" <estjohn () umich edu>
Date: Fri, 03 Sep 2004 12:39:19 -0400
I'm trying to use libpcap in Darwin (uses bpf). In order to capture the packets, I must have read acess to the /dev/bpf* files. I can chmod these, but as soon as I reboot their privledges are reset! Any ideas?
I would also like to get a larger bpf buffer size. I call ioctl(fd, BIOCSBLEN, (caddr_t)&v); with v initially equal to 64 MB. After the call v is changed to 32 K and a call with BIOCGBLEN confirms this. Is there anything I can do (short of recompiling Darwin) to get around this? I am trying to capture at sustained speeds of 80Mbps - 320Mbps. With these speeds I need a larger buffer for when the OS wanders off to do other stuff.
One last thing, I noticed in some other mails this month that eliminating timestamping will increase performance of bpf. I don't use this feature of bpf, is there a way for me to turn it off in Darwin?
Thanks, Eric - This is the tcpdump-workers list. Visit https://lists.sandelman.ca/ to unsubscribe.
Current thread:
- Max OS-X issues: read privledges / bpf buffer size Eric St.John (Sep 03)
- Re: Max OS-X issues: read privledges / bpf buffer Guy Harris (Sep 03)
- Re: Max OS-X issues: read privledges / bpf buffer Bruce M Simpson (Sep 03)
- Re: Max OS-X issues: read privledges / bpf buffer Guy Harris (Sep 03)