Launchpad has imported 13 comments from the remote bug at
https://support.ntp.org/bugs/show_bug.cgi?id=1071.
If you reply to an imported comment from within Launchpad, your comment
will be sent to the remote bug automatically. Read more about
Launchpad's inter-bugtracker facilities at
https://help.launchpad.net/InterBugTracking.
On 2008-09-19T01:40:42+00:00 Jw-ntp wrote:
Hi:
We're running into the same problem on a redhat system that was previously
reported against ubuntu.
I don't think I could write a better bug report, so I'll just include/reference
it here:
http://www.mail-archive.com/ubuntu-bugs@lists.ubuntu.com/msg858457.html
$ uname -a
Linux x 2.6.24-17-generic #1 SMP Thu May 1 13:57:17 UTC 2008 x86_64
GNU/Linux
$ lsb_release -rd
Description:Ubuntu 8.04
Release:8.04
$ apt-cache policy ntp
ntp:
Installed: 1:4.2.4p4+dfsg-3ubuntu2
Candidate: 1:4.2.4p4+dfsg-3ubuntu2
Version table:
*** 1:4.2.4p4+dfsg-3ubuntu2 0
500 http://gb.archive.ubuntu.com hardy/main Packages
100 /var/lib/dpkg/status
On a system which has any more than 1134 interface addresses (counting
both IPv4 and IPv6 address thus: 'ip addr ls | grep inet | wc -l') ntpd
fails with a segmentation fault.
I run a large network for a university (20,000 people), and we routinely
operate open-source routers with several thousand interface addresses
(every client machine lives in it's own /30 subnet).
Whilst examining the problem I used this script to add interface addresses:
$ cat breakit.sh
#!/bin/sh
set -e
dev=vlan252
sudo ifdown ${dev}# clears all old addr
naddr=`ip add ls | grep inet | wc -l` # number of addr already on system
echo Pre-existing addresses on system: ${naddr}
: ${nbreakit:=1217} # number of addr required to break ntp
sudo ifup ${dev}
total=${naddr}
for I in `seq 1 5` ; do
for J in `seq 0 255` ; do
sudo ip addr add 10.0.${I}.${J}/32 dev ${dev}
total=$((${total}+1))
if [ ${total} -ge ${nbreakit} ]; then break ; fi
done
if [ ${total} -ge ${nbreakit} ]; then break ; fi
done
echo Added extra addresses: $((${total}-${naddr}))
echo Total addresses on system now: $(ip add ls | grep inet | wc -l)
exit 0
$ grep -B1 -A2 vlan252 /etc/network/interfaces
#auto vlan252
iface vlan252 inet manual
vlan-raw-device eth0
I could then add the desired number of interfaces by doing:
$ nbreakit=1135 ../breakit.sh
and then run ntpd [1][2] under gdb by doing:
sudo sh -c ulimit -n 8192 ; gdb --args /usr/sbin/ntpd -n -d -D3 -p
/var/run/ntpd.pid -u 115:126 -g
[1] You can't use '-d -D3' on the standard ubuntu package - debugging is
disabled.
[2] It is necessary to raise the number of open files ulimit of 1024 in order
to run ntpd with this many addresses.
In order to help me understand what was going wrong with the standard
package, I rebuilt it with debugging enabled and symbols not stripped:
$ mkdir work
$ cd work/
$ apt-get source ntp
Reading package lists... Done
Building dependency tree
Reading state information... Done
NOTICE: 'ntp' packaging is maintained in the 'Svn' version control system at:
svn://svn.debian.org/pkg-ntp/ntp/
Need to get 3120kB of source archives.
Get: 1 http://gb.archive.ubuntu.com hardy/main ntp 1:4.2.4p4+dfsg-3ubuntu2
(dsc) [1034B]
Get: 2 http://gb.archive.ubuntu.com hardy/main ntp 1:4.2.4p4+dfsg-3ubuntu2
(tar) [2835kB]
Get: 3 http://gb.archive.ubuntu.com hardy/main ntp 1:4.2.4p4+dfsg-3ubuntu2
(diff) [284kB]
Fetched 3120kB in 0s (7433kB/s)
dpkg-source: extracting ntp in ntp-4.2.4p4+dfsg
dpkg-source: unpacking ntp_4.2.4p4+dfsg.orig.tar.gz
dpkg-source: applying ./ntp_4.2.4p4+dfsg-3ubuntu2.diff.gz
$ cd ntp-4.2.4p4+dfsg/
$ cp -p debian/rules{,.orig}
$ vi debian/rules
$ diff -u debian/rules{.orig,}
--- debian/rules.orig 2008-05-28 17:52:21.0 +0100
+++ debian/rules2008-05-28 17:53:21.0 +0100
@@ -21,7 +21,7 @@
./configure CFLAGS='$(CFLAGS)' \
--prefix=/usr \
--enable-all-clocks --enable-parse-clocks --enable-SHM \
- --disable-debugging --sysconfdir=/var/lib/ntp \
+ --enable-debugging --sysconfdir=/var/lib/ntp \
--with-sntp=no \
--enable-linuxcaps \
--disable-dependency-tracking
@@ -104,7 +104,7 @@
dh_installlogcheck -a
dh_installchangelogs -a
dh_perl -a
- dh_strip -a
+ #dh_strip -a
dh_compress -a
dh_fixperms -a
dh_installdeb -a
$ dpkg-buildpackage -us -uc
...
dpkg-buildpackage: binary and diff upload (original source NOT included)
$ sudo dpkg -i ../ntp_4.2.4p4+dfsg-3ubuntu2_amd64.deb
Once one has 1135 interface addresses on the system you get this
segmentation fault:
0x0040c9d2 in update_interfaces (port=value optimized out,
receiver=0, data=0x0) at ntp_io.c:769
769 ISC_LIST_UNLINK_TYPE(inter_list, interface, link, struct
