On Wed, Mar 11, 2009 at 3:00 AM, Allan McRae <allan@archlinux.org> wrote:

Gerardo Exequiel Pozzi wrote:

...

Tobias Powalowski wrote:

...

Am Mittwoch 11 März 2009 schrieb Allan McRae:

...

Gerardo Exequiel Pozzi wrote:

...

Pierre Schmitz wrote:

...

Does anybody know what this message in dmesg is about? Was syslog-ng compiled for i686?

warning: `syslog-ng' uses 32-bit capabilities (legacy support in use)

Very out-of-date libcap, not only syslog-ng, also proftpd, vsftpd, pulseaudio, ntpd, virtualbox, etc, etc...

http://www.archlinux.org/packages/extra/i686/libcap/ (for linux 2.4)

Need to have libcap2 package for kernel 2.6 in Arch Linux http://www.kernel.org/pub/linux/libs/security/linux-privs/

I was confused about this as libcap is in [extra] so how can it make problems with a package in [core]?

So going from this comment in the bug report about libcap (http://bugs.archlinux.org/task/11917#comment41046) I get...

...

readelf -s /usr/sbin/syslog-ng | grep cap

   33: 00000000     0 FUNC    GLOBAL DEFAULT  UND capset@GLIBC_2.1 (4)   177: 00000000     0 FUNC    GLOBAL DEFAULT  UND capget@GLIBC_2.1 (4)   473: 08228bd8     4 OBJECT  GLOBAL DEFAULT   26 OPENSSL_ia32cap_P

Looks like libcap is a soft dep there.  How?

Then rebuild in clean chroot:

...

readelf -s syslog-ng | grep cap

  467: 08221b18     4 OBJECT  GLOBAL DEFAULT   26 OPENSSL_ia32cap_P

And then the dmesg warning goes away...  So, the lesson to learn is to _always build in a clean chroot_!

Allan

hrm i normally build in chroots, seems somehow this one slipped into it. Shall i add it as makedepend?

Yes, is a makedepends, capget, capset are glibc symbols.

But these symbols are defined in sys/capability.h (that are part of libcap) don't confuse with linux/capability.h

So you can make syslog-ng with capabilities, and don't have libcap installed. ;)

See libc.so ;) # readelf -s /lib/libc.so.6 | grep cap  1745: 000d10e0    67 FUNC    GLOBAL DEFAULT   11 capset@@GLIBC_2.1  1923: 000d1090    67 FUNC    GLOBAL DEFAULT   11 capget@@GLIBC_2.1  3801: 000d1090    67 FUNC    LOCAL  DEFAULT   11 __GI_capget  4043: 000d10e0    67 FUNC    LOCAL  DEFAULT   11 __GI_capset  5388: 000d10e0    67 FUNC    GLOBAL DEFAULT   11 capset  6337: 000d1090    67 FUNC    GLOBAL DEFAULT   11 capget

Allan: I hope you have cleared up the confusion.

Not really.....  so I did some research.  Here we go:

From the release announcement for syslog-ng OSE 3.0:

* support for capabilities under Linux, this running syslog-ng as non-root is possible,  also with reload support, see the documentation of Linux capabilities in capabilities(7),  for the syntax of the --caps option, see cap_from_text(3)

And from capabilities(7):

For the purpose of performing permission checks, traditional Unix implementations distinguish two categories of processes: /privileged/ processes (whose effective user ID is 0, referred to as superuser or root), and /unprivileged/ processes (whose effective UID is non-zero). Privileged processes bypass all kernel permission checks, while unprivileged processes are subject to full permission checking based on the process's credentials (usually: effective UID, effective GID, and supplementary group list).

So my conclusion is that it would probably be a good idea to add the makedepends on libcap.

Then we should probably upgrade libcap first