Bugzilla Bug 134187

i386-gentoo-linux-uclibc-gcc -I/usr/kerberos/include -march=i386 -Os -pipe
-fomit-frame-pointer -L/usr/lib  -o fetchmail  socket.o getpass.o pop2.o pop3.o
imap.o etrn.o odmr.o fetchmail.o env.o idle.o options.o daemon.o driver.o
transact.o sink.o smtp.o uid.o mxget.o md5ify.o cram.o kerberos.o gssapi.o
opie.o rpa.o interface.o netrc.o unmime.o conf.o checkalias.o lock.o rcfile_l.o
rcfile_y.o norm_charmap.o getaddrinfo.o getnameinfo.o libfm.a    -lcrypt  
-lssl -lcrypto
mxget.o: In function `getmxrecords':
mxget.c:(.text+0xab): undefined reference to `__dn_skipname'
collect2: ld returned 1 exit status
make[2]: *** [fetchmail] Error 1
make[2]: Leaving directory
`/var/tmp/portage/fetchmail-6.3.4/work/fetchmail-6.3.4'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory
`/var/tmp/portage/fetchmail-6.3.4/work/fetchmail-6.3.4'
make: *** [all] Error 2

hardened ~ # emerge --info
Portage 2.0.54-r2 (uclibc/x86/hardened, gcc-3.4.5, uclibc-0.9.28-r0,
2.6.16-gentoo-r8 i686)
=================================================================
System uname: 2.6.16-gentoo-r8 i686 Intel(R) Pentium(R) D CPU 3.00GHz
Gentoo Base System version 1.6.14
distcc 2.18.3 i386-gentoo-linux-uclibc (protocols 1 and 2) (default port 3632)
[disabled]
dev-lang/python:     2.4.2
dev-python/pycrypto: [Not Present]
dev-util/ccache:     [Not Present]
dev-util/confcache:  [Not Present]
sys-apps/sandbox:    1.2.17
sys-devel/autoconf:  2.13, 2.59-r7
sys-devel/automake:  1.4_p6, 1.5, 1.6.3, 1.7.9-r1, 1.8.5-r3, 1.9.6-r1
sys-devel/binutils:  2.16.1
sys-devel/libtool:   1.5.22
virtual/os-headers:  2.6.11-r2
ACCEPT_KEYWORDS="x86"
AUTOCLEAN="yes"
CBUILD="i386-gentoo-linux-uclibc"
CFLAGS="-march=i386 -Os -pipe -fomit-frame-pointer"
CHOST="i386-gentoo-linux-uclibc"
CONFIG_PROTECT="/etc /usr/kde/2/share/config /usr/kde/3/share/config
/usr/share/config /var/bind /var/qmail/control"
CONFIG_PROTECT_MASK="/etc/eselect/compiler /etc/gconf /etc/terminfo /etc/env.d"
CXXFLAGS="-Os -pipe"
DISTDIR="/var/cache/distfiles"
FEATURES="autoconfig buildpkg distlocks nodoc noinfo noman sandbox sfperms
strict"
GENTOO_MIRRORS="http://distfiles.gentoo.org
http://distro.ibiblio.org/pub/linux/distributions/gentoo"
MAKEOPTS="-j3"
PKGDIR="/var/cache/packages/default"
PORTAGE_TMPDIR="/var/tmp"
PORTDIR="/usr/portage"
PORTDIR_OVERLAY="/usr/alpine-portage"
SYNC="rsync://rsync.gentoo.org/gentoo-portage"
USE="x86 X509 bitmap-fonts bri bzip2 cdr cli cracklib curl dri encode expat gd
gmp hardened iproute2 ipv6 jpeg mad mhash minimal ncurses netboot ogg oss pci
pcmcia pic png pppd readline reflection rrdtool sensord session snmp speex spl
ssl tdb truetype truetype-fonts type1-fonts uclibc udev usb userlocales vorbis
winbind xorg zlib userland_GNU kernel_linux elibc_uclibc"
Unset:  ASFLAGS, CTARGET, INSTALL_MASK, LANG, LC_ALL, LDFLAGS, LINGUAS,
PORTAGE_RSYNC_EXTRA_OPTS, PORTAGE_RSYNC_OPTS

dn_skipname does not exist in uClibc. It's documented as far back as 2004 as
not existing. You will probably need to patch around it.
http://www.google.com/search?q=fetchmail+uclibc

They must have added calls to dn_skipname in recent releases.
fetchmail-6.3.2-r1 (stable) compiles without problems and I am using that
version. 

I just wanted to report this before 6.3.4 is marked stable to tell that there
are problems ahead for uclibc users.

Embedded, what do you suggest to work around this uClibc issue?

fix it in uClibc

I just tested fetchmail-6.3.6 against the latest uclibc (0.9.28-r2) and it
fails with the same linker error.

Could we please get back any of the pre 6.3.4 versions to the portage tree
until this is fixed?

This is weird, because 6.3.2 already contains a call to dn_skipname(). Even
6.3.0 had it.

Natanael, can you please grab ebuilds from
http://sources.gentoo.org/viewcvs.py/gentoo-x86/net-mail/fetchmail/?hideattic=0
and test which will and which won't work?

embedded@: Alternatively, can I get access to some Gentoo uclibc system to test
this myself? I'm not sure if you have some available for tests like this...

(In reply to comment #6)

> Natanael, can you please grab ebuilds from
> http://sources.gentoo.org/viewcvs.py/gentoo-x86/net-mail/fetchmail/?hideattic=0
> and test which will and which won't work?

fetchmail-6.3.2-r1 works
fetchmail-6.3.3 works
fetchmail-6.3.4 fails
fetchmail-6.3.6 fails

Portage 2.1.1-r2 (uclibc/x86/hardened, gcc-3.4.6, uclibc-0.9.28-r2,
2.6.19-gentoo-r4 i686)
=================================================================
System uname: 2.6.19-gentoo-r4 i686 Intel(R) Pentium(R) D CPU 3.00GHz
Gentoo Base System version 1.12.6
Last Sync: Tue, 16 Jan 2007 09:30:01 +0000
distcc 2.18.3 i386-gentoo-linux-uclibc (protocols 1 and 2) (default port 3632)
[disabled]
app-admin/eselect-compiler: [Not Present]
dev-java/java-config: 1.3.7, 2.0.30
dev-lang/python:     2.4.3-r4
dev-python/pycrypto: 2.0.1-r5
dev-util/ccache:     [Not Present]
dev-util/confcache:  [Not Present]
sys-apps/sandbox:    1.2.17
sys-devel/autoconf:  2.13, 2.61
sys-devel/automake:  1.4_p6, 1.5, 1.6.3, 1.7.9-r1, 1.8.5-r3, 1.9.6-r2, 1.10
sys-devel/binutils:  2.16.1-r3
sys-devel/gcc-config: 1.3.14
sys-devel/libtool:   1.5.22
virtual/os-headers:  2.6.17-r2
ACCEPT_KEYWORDS="x86"
AUTOCLEAN="yes"
CBUILD="i386-gentoo-linux-uclibc"
CFLAGS="-march=i386 -Os -pipe -fomit-frame-pointer"
CHOST="i386-gentoo-linux-uclibc"
CONFIG_PROTECT="/etc /var/bind"
CONFIG_PROTECT_MASK="/etc/env.d /etc/env.d/java/ /etc/gconf
/etc/java-config/vms/ /etc/revdep-rebuild /etc/terminfo"
CXXFLAGS="-Os -pipe"
DISTDIR="/var/cache/distfiles"
FEATURES="autoconfig buildpkg distlocks metadata-transfer nodoc noinfo noman
sandbox sfperms strict"
GENTOO_MIRRORS="http://distfiles.gentoo.org
http://distro.ibiblio.org/pub/linux/distributions/gentoo"
MAKEOPTS="-j3"
PKGDIR="/var/cache/packages/default"
PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --compress
--force --whole-file --delete --delete-after --stats --timeout=180
--exclude='/distfiles' --exclude='/local' --exclude='/packages'"
PORTAGE_TMPDIR="/var/tmp"
PORTDIR="/usr/portage"
PORTDIR_OVERLAY="/usr/alpine-portage"
SYNC="rsync://rsync.gentoo.org/gentoo-portage"
USE="x86 X509 alsa_pcm_plugins_adpcm alsa_pcm_plugins_alaw
alsa_pcm_plugins_asym alsa_pcm_plugins_copy alsa_pcm_plugins_dmix
alsa_pcm_plugins_dshare alsa_pcm_plugins_dsnoop alsa_pcm_plugins_empty
alsa_pcm_plugins_extplug alsa_pcm_plugins_file alsa_pcm_plugins_hooks
alsa_pcm_plugins_iec958 alsa_pcm_plugins_ioplug alsa_pcm_plugins_ladspa
alsa_pcm_plugins_lfloat alsa_pcm_plugins_linear alsa_pcm_plugins_meter
alsa_pcm_plugins_mulaw alsa_pcm_plugins_multi alsa_pcm_plugins_null
alsa_pcm_plugins_plug alsa_pcm_plugins_rate alsa_pcm_plugins_route
alsa_pcm_plugins_share alsa_pcm_plugins_shm alsa_pcm_plugins_softvol
bitmap-fonts bri bzip2 cli cracklib dlloader dri elibc_uclibc encode expat
extensions hardened input_devices_evdev input_devices_keyboard
input_devices_mouse iproute2 ipv6 jpeg kernel_linux lua mad minimal
misdn_cards_avmfritz misdn_cards_hfcmulti misdn_cards_hfcpci
misdn_cards_hfcsmini misdn_cards_hfcsusb misdn_cards_netjetpci
misdn_cards_sedlfax misdn_cards_w6692pci misdn_cards_xhfc ncurses netboot ntfs
ogg oss pci pcmcia pic png pppd pri readline reflection rrdtool sensord session
snmp speex spl ssl tdb truetype truetype-fonts type1-fonts uclibc uclibc++ udev
usb userland_GNU userlocales video_cards_dummy video_cards_fbdev
video_cards_v4l winbind wordexp xorg zaptel zlib"
Unset:  CTARGET, EMERGE_DEFAULT_OPTS, INSTALL_MASK, LANG, LC_ALL, LDFLAGS,
LINGUAS, PORTAGE_RSYNC_EXTRA_OPTS

6.3.3 is back in CVS. Thanks for testing!

I'd suggest not to use older versions because of security bug CVE-2006-5867.

(In reply to comment #9)
> I'd suggest not to use older versions because of security bug CVE-2006-5867.
> 

Which puts me in an interesting situation. Newer fetchmail fails to compile due
to missing features in uclibc. Old version has security problems.

What to do?

Basically, strip the alias detection code (which is AFAIR the only part using
the resolver functions directly, look for res_* and dn_*), which is of limited
use in real-life deployment scenarios because it relies on (bold) assumptions
that are typically no longer true today: it assumes that the server listed as
the MX for a given domain, that is the SMTP server, were also the IMAP/POP3
server. It still is on some sites, but that's not a general rule. In fact, this
alias detection code is scheduled for removal in a later version (not on the
6.3 branch though) because of these assumptions, the non-portability to IPv6
and other issues with it.

The interesting fix underneath in one of the recent 6.3.X versions however was
calling res_init() as well at the beginning of a poll loop to cater for systems
that change /etc/resolv.conf but still let fetchmail run extended amounts of
time. We need to make sure this res_init() alone does not break with the
µC-oriented libc spinoffs.

Does it work to compile fetchmail with dietlibc?

A workaround to this used by nslu2 linux [1] is to set undef those macros that
cause the code to be included:

/* Define to 1 if you have the <resolv.h> header file. */
#undef HAVE_RESOLV_H

/* Define to 1 if you have the 'res_search' function. */
#undef HAVE_RES_SEARCH

[1] http://trac.nslu2-linux.org/optware/browser/trunk/make/fetchmail.mk

Created an attachment (id=121645) [details]
Fix mxget.o linker failures (dn_skipname) for µClibc

The attached patch extends the configure check for res_search() by another
check for dn_skipname() which µClibc doesn't provide.

This fixes the link failures for dn_skipname() by disabling the DNS feature
automatically on systems that don't provide a BSD/BIND9 compatible libresolv.a. 

Please file a feature request for µClibc to enable dn_skipname() and once
that's added, rebuilding fetchmail should pick it up and enable DNS
automatically.

The patch from comment #13 has been committed to the upstream fetchmail SVN
repository and is scheduled to appear in 6.3.9.

sounds like newer fetchmail's are fixed

This is still an issue in net-mail/fetchmail-6.3.8-r2.

i386-gentoo-linux-uclibc-gcc -I/usr/kerberos/include -march=i386 -Os -pipe
-fomit-frame-pointer -L/usr/lib  -o fetchmail  socket.o getpass.o fetchmail.o
env.o idle.o options.o daemon.o driver.o transact.o sink.o smtp.o uid.o mxget.o
md5ify.o cram.o gssapi.o opie.o interface.o netrc.o unmime.o conf.o
checkalias.o lock.o rcfile_l.o rcfile_y.o norm_charmap.o  pop3.o imap.o etrn.o
odmr.o  rpa.o   libfm.a    -lcrypt   -lssl -lcrypto 
mxget.o: In function `getmxrecords':
mxget.c:(.text+0xab): undefined reference to `__dn_skipname'
collect2: ld returned 1 exit status
make[2]: *** [fetchmail] Error 1
make[2]: Leaving directory
`/var/tmp/portage/net-mail/fetchmail-6.3.8-r2/work/fetchmail-6.3.8'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory
`/var/tmp/portage/net-mail/fetchmail-6.3.8-r2/work/fetchmail-6.3.8'
make: *** [all] Error 2

the patch from comment #13 (renamed to fethcmail-6.3.8-dn_skipname.patch) and
the change below fixes the issue.

--- fetchmail-6.3.8-r2.ebuild.orig      2008-06-17 09:35:41 +0000
+++ fetchmail-6.3.8-r2.ebuild   2008-06-17 09:29:18 +0000
@@ -2,7 +2,7 @@
 # Distributed under the terms of the GNU General Public License v2
 # $Header:
/var/cvsroot/gentoo-x86/net-mail/fetchmail/fetchmail-6.3.8-r2.ebuild,v 1.7
2008/06/16 18:34:59 jer Exp $

-inherit eutils
+inherit eutils autotools

 DESCRIPTION="the legendary remote-mail retrieval and forwarding utility"
 HOMEPAGE="http://fetchmail.berlios.de"
@@ -33,6 +33,10 @@

        # this patch fixes bug #34788 (ticho@gentoo.org 2004-09-03)
        epatch "${FILESDIR}"/${PN}-6.2.5-broken-headers.patch
+
+       # bug #134187
+       epatch "${FILESDIR}"/${P}-dn_skipname.patch
+       eautoreconf
 }

 src_compile() {