ron@brl-sem.UUCP (04/30/86)
> I thought that chroot() caused open()s and creat()s and the like to use the > new root, but didn't affect the interpretation of root for exec(). Anybody > know for certain? > > Also, does anybody know if there are brain-damaged implementations of chroot() > out there? > 1. CHROOT is not universal. 2. At least 4.2 CHROOT works for any access, I'd think it would be more difficult to go and modify nami to do something different when looking up different types of objects. 3. If you chroot, you must have an entire duplicate system under the new root including /etc/passwd, and all commands that might want to get run. 4. I think I'll stick to busting apart files from the net with EMACS. 5. Providing leaders the decisive edge.
Unknown@hplabs.UUCP (04/30/86)
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simon@cstvax.UUCP (Simon Brown) (05/09/86)
In article <191@brl-sem.ARPA> ron@brl-sem.UUCP writes: >> I thought that chroot() caused open()s and creat()s and the like to use the >> new root, but didn't affect the interpretation of root for exec(). Anybody >> know for certain? >> >1. CHROOT is not universal. >2. At least 4.2 CHROOT works for any access, I'd think it would be > more difficult to go and modify nami to do something different when > looking up different types of objects. >3. If you chroot, you must have an entire duplicate system under the > new root including /etc/passwd, and all commands that might want > to get run. And Version-7 chroot() is the same - ALL filenames are accessed relative to the new root. Actually, you don't need very much stuff to be duplicated, unless you're doing something complicated... Setting your path to be ( ../../../bin ../../../usr/bin ../../../usr/ucb etc... ) goes quite a long way to fixing stuff so normal commands executed from the shell will still work. Of course /lib and /usr/lib don't exist any more, which is a bit embarrassing sometimes, like if you want to use the C-compiler, or lint, or something... Also, the number of "../"'s you need in the path will depend on where you've chrooted to. Of course, under 4.2BSD, you can always set up symbolic links to all the important directories (/dev, /bin, /usr, /etc, /tmp ...) within the chrooted directory, so everything looks normal, I suppose... -----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+----- Simon Brown ...!mcvax!ukc!cstvax!simon Dept. of computer science University of Edinburgh