tcpdump mailing list archives
tcpdump -z: command execution
From: ef <blob.bb.a () gmail com>
Date: Fri, 27 Aug 2010 09:33:48 +0200
Hello, Thx for tcpdump, very valuable tool! Was looking at the new version of tcpdump a few days ago and saw this option: " -z Used in conjunction with the -C or -G options, this will make tcpdump run " command file " where file is the savefile being closed after each rotation. For example, specifying -z gzip or -z bzip2 will compress each savefile using gzip or bzip2. Note that tcpdump will run the command in parallel to the capture, using the lowest priority so that this doesn't disturb the capture process. And in case you would like to use a command that itself takes flags or different arguments, you can always write a shell script that will take the savefile name as the only argument, make the flags & arguments arrangements and execute the command that you want. " I think there are many environments that restrict users but give access to tcpdump via sudo. With this option tcpdump can execute any command: $ ./tcpdump -V tcpdump version 4.1.1 $ sudo ./tcpdump -i any -G 1 -z ./test.sh -w dump port 55555 [sudo] password for user: tcpdump: listening on any, link-type LINUX_SLL (Linux cooked), capture size 65535 bytes (generate some traffic on port 55555) root@blaa ~/temp/tcpdump-4.1.1$ id uid=0(root) gid=0(root) groups=0(root) $ cat test.sh: #!/bin/bash /bin/bash Is this known and accepted? Could this option maybe be implemented differently? Regards, tazo P.S. glad to see the DEFAULT_SNAPLEN has become MAXIMUM_SNAPLEN, I always forgot -s0 when I was dumping ;-) - This is the tcpdump-workers list. Visit https://cod.sandelman.ca/ to unsubscribe.
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- tcpdump -z: command execution ef (Aug 27)