On Wednesday 02 March 2011 02:19:02 Denys Vlasenko wrote:
> On Tuesday 01 March 2011 22:08, Tobias Poschwatta wrote:
> > The attached patch allows to change the name of the main busybox binary
> > to something other than "busybox". This makes it easy to have two or
> > more busybox binaries (different versions, different feature sets, etc.)
> > installed in the same filesystem.
>
> It is already possible by using a suffix:
>
> # cp busybox busybox2
> # ./busybox2
> BusyBox v1.19.0.git (2011-03-01 16:23:40 CET) multi-call binary.
> Copyright (C) 1998-2009 Erik Andersen, Rob Landley, Denys Vlasenko
> and others. Licensed under GPLv2.
> See source distribution for full notice.
>
> Usage: busybox [function] [arguments]...
> or: busybox --list[-full]
> or: function [arguments]...
>
> BusyBox is a multi-call binary that combines many common Unix
> utilities into a single executable. Most people will create a
> link to busybox for each function they wish to use and BusyBox
> will act like whatever it was invoked as.
>
> Currently defined functions:
> [, [[, acpid, add-shell, addgroup, adduser ...
>
Hi,
while inspecting the behaviour of busybox --install -s in a chroot
environment I've noticed something that looks wrong to me:
lrwxrwxrwx 1 0 0 14 Mar 5 14:02 addgroup -> /proc/self/exe
lrwxrwxrwx 1 0 0 14 Mar 5 14:02 adduser -> /proc/self/exe
lrwxrwxrwx 1 0 0 14 Mar 5 14:02 ash -> /proc/self/exe
lrwxrwxrwx 1 0 0 14 Mar 5 14:02 base64 -> /proc/self/exe
-rwxr-xr-x 1 0 0 700492 Mar 5 13:55 bash
-rwxr-xr-x 1 0 0 724192 Mar 5 13:56 busybox
lrwxrwxrwx 1 0 0 14 Mar 5 14:02 cat -> /proc/self/exe
lrwxrwxrwx 1 0 0 14 Mar 5 14:02 catv -> /proc/self/exe
lrwxrwxrwx 1 0 0 14 Mar 5 14:02 chattr -> /proc/self/exe
lrwxrwxrwx 1 0 0 14 Mar 5 14:02 chgrp -> /proc/self/exe
lrwxrwxrwx 1 0 0 14 Mar 5 14:02 chmod -> /proc/self/exe
lrwxrwxrwx 1 0 0 14 Mar 5 14:02 chown -> /proc/self/exe
lrwxrwxrwx 1 0 0 14 Mar 5 14:02 cp -> /proc/self/exe
lrwxrwxrwx 1 0 0 14 Mar 5 14:02 cpio -> /proc/self/exe
lrwxrwxrwx 1 0 0 14 Mar 5 14:02 cttyhack -> /proc/self/exe
lrwxrwxrwx 1 0 0 14 Mar 5 14:02 date -> /proc/self/exe
all links point to /proc/self/exe as bb_busybox_exec_path is used :
config BUSYBOX_EXEC_PATH
string "Path to BusyBox executable"
default "/proc/self/exe"
help
When Busybox applets need to run other busybox applets, BusyBox
sometimes needs to exec() itself. When the /proc filesystem is
mounted, /proc/self/exe always points to the currently running
executable. If you haven't got /proc, set this to wherever you
want to run BusyBox from.
This seems not to be a sane default here as
1) was not able to make this work in a chrooted env
2) in case of failure xmalloc_readlink symlinks
point to /proc/self/exe
3) it works only if /proc/ is mounted
I would suggest rather than doing it automagically
as this setp is done only at setup time (from a known path i suppose)
to enforce that the busybox binary is called on the command line
with the full path, the pros are:
1) no need for /proc
2) name of busybox could be changed and different busybox
executables could be used at the same time.
3) works in my chroot env.
4) it is simple.
if (ENABLE_FEATURE_INSTALLER && strcmp(argv[1], "--install") == 0) {
int use_symbolic_links = (argv[2] && strcmp(argv[2], "-s") ==
0);
if (!strchr(argv[0], '/'))
bb_error_msg_and_die("Please call %s with the full
path", argv[0]);
/* busybox --install [-s] [DIR]: */
/* -s: make symlinks */
/* DIR: directory to install links to */
install_links(argv[0], use_symbolic_links, (argv[3]) ? argv[3]
: NULL);
return 0;
}
Hints, critics, improvements are welcome.
Ciao,
Tito
Simplify --install logic.
Signed-off by Tito Ragusa <[email protected]>
--- libbb/appletlib.c.original 2011-03-05 16:43:05.000000000 +0100
+++ libbb/appletlib.c 2011-03-05 16:43:37.000000000 +0100
@@ -711,16 +711,13 @@
}
if (ENABLE_FEATURE_INSTALLER && strcmp(argv[1], "--install") == 0) {
- int use_symbolic_links;
- const char *busybox;
- busybox = xmalloc_readlink(bb_busybox_exec_path);
- if (!busybox)
- busybox = bb_busybox_exec_path;
+ int use_symbolic_links = (argv[2] && strcmp(argv[2], "-s") == 0);
+ if (!strchr(argv[0], '/'))
+ bb_error_msg_and_die("Please call %s with the full path", argv[0]);
/* busybox --install [-s] [DIR]: */
/* -s: make symlinks */
/* DIR: directory to install links to */
- use_symbolic_links = (argv[2] && strcmp(argv[2], "-s") == 0 && argv++);
- install_links(busybox, use_symbolic_links, argv[2]);
+ install_links(argv[0], use_symbolic_links, (argv[3]) ? argv[3] : NULL);
return 0;
}
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