[Toybox] [PATCH] hostname: fix behavior when in jail.

[enh]

On Sun, Jan 20, 2019 at 2:20 PM enh <enh at google.com> wrote:
>
> On Sat, Jan 19, 2019 at 12:43 PM Rob Landley <rob at landley.net> wrote:
> >
> > On 1/19/19 1:41 PM, enh via Toybox wrote:
> > > Only -d and -f should cause a DNS lookup. The rest should just act
> > > directly on the result of gethostname(3). Encountered with the AOSP
> > > buildbots' use of nsjail, but tested with both the Debian hostname and
> > > toybox hostname thus:
> >
> > Applied.
> >
> > I'm rooting on this build work from a distance, sorry I haven't been more direct
> > help.

(also, i'm not sure what could have been more "direct help" than
writing all this stuff in the first place! it's pretty cool that the
majority of the "fixes" needed for the AOSP build have been nothing
more than adding long options corresponding to already-implemented
short options. even looking at the much smaller number of real
"fixes", most of them added missing features rather than fixed some
incorrect behavior.)

> > I'm curious what commands are left that _don't_ point to toybox. (I used
> > to do things like "for i in $(echo $PATH | tr : '\n'); do for i in $(echo $i/* |
> > tr ' ' '\n'); do basename $i; done; done | sort -u" for that...)
>
> the link in the roadmap (the checked-in copy; the web site is too old)
> is, for better or worse, a link to the current status:
> https://android.googlesource.com/platform/build/soong/+/master/ui/build/paths/config.go
>
> i haven't had chance to test your latest cp patch, nor my sed patch or
> yours. assuming they're okay, and ignoring stuff in pending (like dd)
> or that just isn't started yet (like hexdump), patch is probably in
> the worst state: that will need fuzz support (which POSIX describes in
> more detail than i would have expected:
> https://pubs.opengroup.org/onlinepubs/9699919799/utilities/patch.html)
> and support for the `[FILE [PATCH]]` command-line syntax, not just -i.
>
> iirc there's also `realpath --relative-to` but i haven't even looked
> at what that means yet. and when i first used toybox to build AOSP by
> accident there was some issue with find, but that's on the short list
> of things i haven't even looked at yet.
>
> at some point i'll have to go through all the weird and whacky formats
> supplied to date(1), but that one i might try to enlist the help of
> the build folks to get me a complete set off the build servers (aiui
> they've said that's possible but non-trivial, and only date seems like
> it might be hairy enough -- and hard enough to grep for -- to warrant
> that).
>
> but the TL;DR is that more than half of the commands you're allowed to
> run as part of the build (and that list includes stuff like python and
> javac) are switched to toybox. almost all of them that exist in toybox
> at all [minus pending] are switched over (the exceptions being date,
> find, grep/egrep, lsof, patch, realpath, and timeout; at least lsof --
> used only for diagnostics -- should be trivial).
>
> probably a bigger decision right now is whether i want to try to flip
> the switch for the grep family on the device, or whether it's a bit
> late in the cycle for that. i should probably decide one way or the
> other this week. are there any known reasons why i shouldn't give it a
> go?
>
> > Rob