Date: Wed, 12 May 2004 11:31:48 +0400 From: "Mikhail E. Zakharov" <zakharov@ipb.redline.ru> To: freebsd-questions@freebsd.org Subject: NFS-bug or not ? Message-ID: <1672830687.20040512113148@ipb.redline.ru>
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Hi! When playing with NFS under FreeBSD, I've noticed something strange. You know it's impossible to export 2 directories of the same file system on the server to the 1 nfs-client: server# cat /etc/exports /usr/c client /usr/d client server# killall -HUP mountd server# showmount -e /usr/c Everyone There is no /usr/d exported. And we got errors in /var/log/messages: mountd[377]: can't change attributes for /usr/d mountd[377]: bad exports list line /usr/d But it's possible(!) to fool mountd when using the -network key. Let's try to export /usr/a as read-only system for the whole network, and /usr/b writable for one host, and not readable for other. NB! Our NFS-client (192.168.12.98) is from 192.168.0.0/16 network. See this example: server# cat /etc/exports /usr/a -ro -network 192.168.0.0 -mask 255.255.0.0 /usr/b -mapall=root 192.168.12.98 server# killall -HUP mountd server# showmount -e Exports list on localhost: /usr/b 192.168.12.98 /usr/a 192.168.0.0 As you see /usr/a and /usr/b successfully exported without errors. Now, from the client (192.168.12.98) we can mount both of them: client# mount server:/usr/b /mnt1 client# mount server:/usr/a /mnt client# mount server:/usr/b on /mnt1 (nfs) server:/usr/a on /mnt (nfs) When we mounted them on client. Let's make additional tests: client# echo "something stupid" > /mnt/test.txt client# echo "something stupid1" > /mnt1/test1.txt client# cat /mnt/test.txt something stupid client# cat /mnt1/test1.txt something stupid1 Oh, my God! Both of the exported directories are writable. Best regards, Mikhail Zakharov
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