Re: sflt_event_t...
Re: sflt_event_t...
- Subject: Re: sflt_event_t...
- From: Michael Cashwell <email@hidden>
- Date: Thu, 18 Aug 2005 11:00:20 -0400
On Aug 18, 2005, at 10:24 AM, Russell Seehafer (RIT Student) wrote:
I am writing a socket filter NKE that selectively swallows packets,
sends information about that packet to a user process on the
control socket, and waits for a response from the user process
before deciding whether or not to re-inject the packet. The
swallowing / re-injection happens on a per-socket basis. When I
recieve certain sflt_event_t's (sock_evt_disconnecting,
sock_evt_disconnected, and sock_evt_closing) I call a routine that
drops all packets still queued on that socket. I call this routine
when I am attached and detached from a socket as well. The app runs
great for a period of time (I am able to selectively swallow and re-
inject about 4,000 packets) but eventually I recieve the grey
shutdown screen. I realize this could be due to a memory management
problem somewhere in the nke, but I suspect that I am attempting to
re-inject a packet on a socket that is not longer valid. My
question is which of the sflt_event_t's tell me that a socket is no
longer valid and that I should drop all of my remaining packets for
that socket? Also, does the nature of this app raise any red flags,
or bring to mind any key principals that I might be overlooking?
Thanks for your help!
The "grey shutdown screen" is called a kernel panic. The UI you are
seeing is how it's handled for non-developer users/consumers. If you
are working in the kernel then you should set different Open Firmware
options that are more appropriate for such development work. There
are various options including spewing the panic info to the console.
You can also elect to use a second machine to debug it over Ethernet
(2 machine debugging).
These settings are discussed here:
<http://developer.apple.com/documentation/Darwin/Conceptual/
KernelProgramming/build/chapter_18_section_5.html>
Since it sounds like to can (with some effort) reproduce the panic at
will doing this is the next logical step and will probably identify
the problem more quickly than guessing!
The best resource I've found for these things is "Understanding and
Debugging Kernel Panics" found at ADC Home > Reference Library >
Technical Notes > Darwin > Kernel
<http://developer.apple.com/technicalnotes/Darwin/idxKernel-date.html>
Good luck!
-Mike
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| References: | |
| | >sflt_event_t... (From: "Russell Seehafer (RIT Student)" <email@hidden>) |