On Saturday 05 March 2011 16:51:11 Tito wrote:
> 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
>
>
Minor fix to catch ./busybox.
Attached patch v2.
if (ENABLE_FEATURE_INSTALLER && strcmp(argv[1], "--install") == 0) {
int use_symbolic_links = (argv[2] && strcmp(argv[2], "-s") ==
0);
if (strncmp(argv[0], "./", 2) == 0 || !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;
}
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 18:05:16.000000000 +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 (strncmp(argv[0], "./", 2) == 0 || !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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