Configuring a better busybox

[twobob]

ah the usbnet provides the sftp

[knc1]

New brain fart about the "telnetd" thingy - - -

Q: Does the alias list include 'init' ?
If so, take it out, reboot, see if the result is "old" or "new".

Why:
Similar reasoning to getting the "old" or "new" busybox shell - -
Differences in the 'init' function provided by the two busybox versions.

[twobob]

okay I'll have a look and will do : )

EDIT: No it does not

My current list. Services at the top. rest in folder / alpha beta order

Spoiler:

alias inetd='busybox inetd'
alias chroot='busybox chroot'
alias crond='busybox crond'
alias ftpd='busybox ftpd'
alias httpd='busybox httpd'
alias loadfont='busybox loadfont'
alias rdate='busybox rdate'
alias sendmail='busybox sendmail'
alias setfont='busybox setfont'
alias telnetd='busybox telnetd'
alias dnsd='busybox dnsd'
# /mnt/us/bin I believe
alias adduser='busybox adduser'
alias addgroup='busybox addgroup'
alias ash='busybox ash'
alias base64='busybox base64'
alias bash='busybox bash'
alias cat='busybox cat'
alias catv='busybox catv'
alias chattr='busybox chattr'
alias chgrp='busybox chgrp'
alias chmod='busybox chmod'
alias chown='busybox chown'
alias cp='busybox cp'
alias cpio='busybox cpio'
alias date='busybox date'
alias dd='busybox dd'
alias delgroup='busybox delgroup'
alias deluser='busybox deluser'
alias df='busybox df'
alias dmesg='busybox dmesg'
alias dnsdomainname='busybox dnsdomainname'
alias dumpkmap='busybox dumpkmap'
alias echo='busybox echo'
alias ed='busybox ed'
alias egrep='busybox egrep'
alias false='busybox false'
alias fdflush='busybox fdflush'
alias fgrep='busybox fgrep'
alias fsync='busybox fsync'
alias getopt='busybox getopt'
alias grep='busybox grep'
alias gunzip='busybox gunzip'
alias gzip='busybox gzip'
alias hostname='busybox hostname'
alias inetd='busybox inetd'
alias ip='busybox ip'
alias ipaddr='busybox ipaddr'
alias iplink='busybox iplink'
alias iproute='busybox iproute'
alias iprule='busybox iprule'
alias iptunnel='busybox iptunnel'
alias kill='busybox kill'
alias linux32='busybox linux32'
alias linux64='busybox linux64'
alias ln='busybox ln'
alias login='busybox login'
alias ls='busybox ls'
alias lsattr='busybox lsattr'
alias lzop='busybox lzop'
alias makemime='busybox makemime'
alias mkdir='busybox mkdir'
alias mknod='busybox mknod'
alias mktemp='busybox mktemp'
alias more='busybox more'
alias mount='busybox mount'
alias mountpoint='busybox mountpoint'
alias mt='busybox mt'
alias mv='busybox mv'
alias netstat='busybox netstat'
alias nice='busybox nice'
alias pidof='busybox pidof'
alias ping='busybox ping'
alias pipe_progress='busybox pipe_progress'
alias printenv='busybox printenv'
alias ps='busybox ps'
alias pwd='busybox pwd'
alias rm='busybox rm'
alias rmdir='busybox rmdir'
alias rpm='busybox rpm'
alias run-parts='busybox run-parts'
alias sed='busybox sed'
alias setarch='busybox setarch'
alias setserial='busybox setserial'
alias sh='busybox sh'
alias sleep='busybox sleep'
alias stat='busybox stat'
alias stty='busybox stty'
alias su='busybox su'
alias sync='busybox sync'
alias tar='busybox tar'
alias touch='busybox touch'
alias true='busybox true'
alias umount='busybox umount'
alias uname='busybox uname'
alias uncompress='busybox uncompress'
alias usleep='busybox usleep'
alias vi='busybox vi'
alias watch='busybox watch'
alias zcat='busybox zcat'
# /mnt/us/sbin
alias adjtimex='busybox adjtimex'
alias blkid='busybox blkid'
alias devmem='busybox devmem'
alias fdisk='busybox fdisk'
alias freeramdisk='busybox freeramdisk'
alias fsck='busybox fsck'
alias getty='busybox getty'
alias hwclock='busybox hwclock'
alias ifconfig='busybox ifconfig'
alias ifdown='busybox ifdown'
alias ifup='busybox ifup'
alias klogd='busybox klogd'
alias loadkmap='busybox loadkmap'
alias logread='busybox logread'
alias losetup='busybox losetup'
alias makedevs='busybox makedevs'
alias man='busybox man'
alias mkdosfs='busybox mkdosfs'
alias mke2fs='busybox mke2fs'
alias output='busybox output'
alias pivot_root='busybox pivot_root'
alias route='busybox route'
alias start-stop-daemon='busybox start-stop-daemon'
alias switch_root='busybox switch_root'
alias syslogd='busybox syslogd'
alias tune2fs='busybox tune2fs'
alias udhcpc='busybox udhcpc'

Note that I did not exhaustively check this list. some stuff is missing from the total offering. it was a 5 second hack to check something. Feel free to point out things I missed.

Happy days : )

[knc1]

A long list.
But certainly takes up less room than that many copies of busybox in place of symbolic links.

Hmm...
you have 'sendmail' now . . .
just in case you need to send an e-mail message about the book your reading, I guess.
a new toy for the end-users to play with.

Who would have thought that we could replace most of the basic system functions without touching the main file system tree.
(other than those couple of shell related config files)

[twobob]

yeah. however I am still in same situation...

need to convince subshells - all of them - to honour -l somehow.

hmm..

vi

:!su -version

would fail for example and find the old version ... hmm

~
~
su: invalid option -- v
BusyBox v1.7.2 (2011-09-08 21:57:14 PDT) multi-call binary

Usage: su [OPTION]... [-] [username]

Change user id or become root

Options:
-p, -m Preserve environment
-c Command to pass to 'sh -c'
-s Shell to use instead of default shell


shell returned 256

[Hit return to continue]

[knc1]

Naw - -
Just find the shell config file that is read by **both** login and non-login shells.

Not part of my Busybox Foo, but it is there, somewhere.
Hmm...
You might have to 'strace -fF ash' a few times. Check what files it is trying to open.

[twobob]

Originally Posted by knc1

A long list.
But certainly takes up less room than that many copies of busybox in place of symbolic links.

...

Who would have thought that we could replace most of the basic system functions without touching the main file system tree.
(other than those couple of shell related config files)

Yeah, damn right. 30ish (* 140 odd) bytes as opposed to 2MB (* 140 odd). err quite the saving. plus we can probably bastardise the process, as you say, to serve us in other ways.

I never would have thought this much possible and to be fair with more thought we can probably not even touch the default config files.

some simple scripted injection of those values somewhere 'just before' w/e runtime is needed would probably suffice for the non-system bits

and a similar method may be employed perhaps in 'var' at boot or something for the system bits.. unsure about that however.

Simply put a large %age of the nice to haves are now seemingly within reach. if we had a million monkeys I suspect we could start to catch up quite rapidly now with the raspbian crew.

there are only a couple of gotchas preventing utter kindle domination.

A correctly configured injection of the awesome window manager in Buildroot sounds like a fairly awesome idea. Zomg I don't vote I do that. Gah...
I shouldn't type out loud.

Anyways... back to the underlying injection issue.

If ANYONE reading this has any ideas - jump in right now - if you don't want to go public simply PM me.

No one person comprehends all of the possibilities that are afforded to us:
Some of us don't even get the basics

Much obliged.

[twobob]

Originally Posted by knc1

Naw - -
Just find the shell config file that is read by **both** login and non-login shells.

Not part of my Busybox Foo, but it is there, somewhere.
Hmm...
You might have to 'strace -fF ash' a few times. Check what files it is trying to open.

ooh okay then : )

Thanks mate

*wields hammer*

[twobob]

heh. brilliant. sorted it. TBC

Okay, seemingly the OOTB config does not have a ENV value defined

Ash honours this. and a strace confirms that it now reads /home/root/.bashrc

Setting ENV in a .bashrc has it's drawbacks as it will be processed twice.

So - more sensibly - we should probably just set the ENV value at boot to another filename and populate that with the current current .bashrc noise.

Anyways - that is by the by and will be decided in the wash.

Here are some tests.

[root@kindle root]# echo $ENV
(nothing)
[root@kindle root]# su
[root@kindle root]# grep -v

BusyBox v1.7.2 (2011-09-08 21:57:14 PDT) multi-call binary

[root@kindle root]# exit


[root@kindle root]# echo $ENV
/home/root/.bashrc
[root@kindle root]# su
[root@kindle root]# grep -v

BusyBox v1.20.2 (2012-09-03 02:06:04 BST) multi-call binary.

[root@kindle root]# exit


The ENV value is NOT honored though when calling a single command as is shown here:

[root@kindle root]# echo $ENV
(nothing)
[root@kindle root]# su -c 'grep -v'

BusyBox v1.7.2 (2011-09-08 21:57:14 PDT) multi-call binary

[root@kindle root]# echo $ENV
/home/root/.bashrc
[root@kindle root]# su -c 'grep -v'

BusyBox v1.7.2 (2011-09-08 21:57:14 PDT) multi-call binary

which is worth noting now, for the future.

however explicitly informing it to use -l does work

[root@kindle root]# su -c 'su -v' -l
su: invalid option -- v

BusyBox v1.20.2 (2012-09-03 02:06:04 BST) multi-call binary.

So, this in mind - I'll go hunting down some use cases.
But ostensibly setting the ENV value should do the trick, wherever it one day ends up being done.

[twobob]

This in mind I'll try another reboot.

May possibly cause a few more calls to point to the 1.20.x versions of things.

That is utter speculation, but I'm doing it anyway.

: )

EDIT: PLUS If I don't someone else will. May as well brick mine first.

[twobob]

100% fine. the telnetd is still there so I'm going to have a quick play with that

[twobob]

[root@kindle root]# find / -name iptables
/usr/lib/iptables
/usr/sbin/iptables
/etc/sysconfig/iptables

[root@kindle root]# iptables -L

Chain INPUT (policy DROP)
target prot opt source destination
ACCEPT tcp -- anywhere anywhere tcp dpt:40317
ACCEPT tcp -- anywhere anywhere state RELATED,ESTABLISHED
ACCEPT tcp -- anywhere anywhere state RELATED,ESTABLISHED
ACCEPT udp -- anywhere anywhere state ESTABLISHED
ACCEPT udp -- anywhere anywhere state ESTABLISHED
ACCEPT all -- localhost.localdomain anywhere
ACCEPT all -- anywhere anywhere
ACCEPT icmp -- anywhere anywhere state RELATED,ESTABLISHED
ACCEPT tcp -- anywhere anywhere tcp dpt:ssh

Chain FORWARD (policy ACCEPT)
target prot opt source destination

Chain OUTPUT (policy ACCEPT)
target prot opt source destination
ACCEPT all -- anywhere localhost.localdomain

OPTIONAL TO MAKE IT PERMANENT

Spoiler:

mntroot rw

[root@kindle root]# nano /etc/sysconfig/iptables

(don't mess this up!!!)

add a line

-A INPUT -i wlan0 -p tcp --dport 23 -j ACCEPT

save it

mntroot ro

[root@kindle root]# iptables -A INPUT -i wlan0 -p tcp --dport 23 -j ACCEPT
(just until we reboot, to finish our testing without rebooting...)

now on our main machine:

me@dev ~ $ telnet k

Trying 192.168.1.999...
Connected to k.
Escape character is '^]'.

Welcome to Kindle!

#################################################
# N O T I C E * N O T I C E * N O T I C E #
#################################################
Rootfs is mounted read-only. Invoke mntroot rw to
switch back to a writable rootfs.
#################################################
[root@kindle root]#

Heh... sweet.

[root@kindle root]# grep -v

BusyBox v1.20.2 (2012-09-03 02:06:04 BST) multi-call binary.

Excellent

[twobob]

well. that's ssh out the window.

Telnet is pretty convenient. No doubt there are a few gotchas, like maybe Niluje fixed up some terminfo and environment variables - I'll have a dig around but seems 100% and now I can always ^] to shove extra stuff to the term and ^z to suspend the session which is nice of course.

Dunno. seems bloody handy mate.

[knc1]

Without the hardware restriction (-i wlan0 -- input from wlan0) you could telnet from any connected source (usbnet, 3G, etc).

Hmm...
Sorry for getting the port number wrong for telnet - ports 20/21 are ftp

Now, you mentioned losing sftp if tossing out the dropbear stuff - - -

No hurry on these things, but
To do passive-mode ftp you need to load the ftp-conntrack module ;
But to do active-mode ftp (since the output default is ACCEPT) you only need to open port 21 in-bound (I looked it up this time).

Now, about all that ram in use (90Mbyte) - -
Only load and run ftpd when there is a connection request for it (uses inetd).
This one should help:
http://www.gnu.org/software/libc/man...ing-Inetd.html

It isn't specifically about the busybox inetd, but they should be very similar.

Same can be done for the httpd and telnetd servers (well, for any server).
No need to convert the lab126 telnetd setup now, just noting that it can be run from inetd also.
I am pretty sure the Busybox httpd will do cgi-bin - - WARNING: I am guessing at that one, we may need a light weight httpd that does.

[twobob]

Enabled the CGI stuff I believe.
and in all the underlying things that support cgi that I have touched.
like microperl at el...

Rather planning on using some of that

Hah. yeah port numbers, phooey, There are too many, I once had to remember a large swath of them (the lower 1000 or so) for some stupid exam or interview, fortunately I have managed to forget most of them again now in favour of more interesting information that gurgle doesn't return at the touch of a mouse.

it's been about 10, 15??? years since I last used inetd but it will all no doubt be exactly the same with some bells on. I'll have a play.

It's odd I did have a hunt to see where the ram was going.

Busybox enables tftp in this build. it could serve perhaps as a whorey host in some black-hole interim if it ever came to pass. I actually see no need to ditch ssh, merely no need to not use telnet by the same token. If the cap fits and all that.

ah find another alias I missed...

My Firewall is considerably more "setup" than that list expounds
(no need to make it too easy for the casual goon to find my attack vectors)

: ) more testing for me I think. and tea : )