Gentoo Weekly Newsletter: August 8th, 2005
1.
Gentoo News
First alpha release of the Gentoo Installer
Gentoo
Installer Project lead Andrew
Gaffney made an announcement
this week about version 0.1 of GLI! This is a milestone in Gentoo's
history as it was installer-free before and the user had to do every
step manually with the help of the Gentoo Handbook.
There will be an x86 LiveCD with the installer included in the
/experimental branch on the mirrors. More
information is available on the Installer
Project's website.
Tor network servers banned on the Forums
The Tor Network is an anonymous
Internet communication system that uses a distributed network of servers
to bounce communications around. People were able to use tor to browse
the Gentoo Forums until some
malicious users started abusing the forums. As you might have already
guessed, using tor hides your IP address, so it works similarly to a
kind of anonymous posting. The gentoo forums
staff, due to this abusive use of tor servers, has decided to
ban all tor servers that have an exit policy allowing connections to
forums.gentoo.org on ports 80 (HTTP) and/or 443 (HTTPS). We are
concerned that our users might want to preserve their anonymity, however
there doesn't seem to be a good technical or legitimate reason
to use tor on the Gentoo Forums.
In an effort to purge the abuse of the Tor Network generating the
least problem to our users, only Tor servers with an exit to
forums.gentoo.org on the ports above stated will be banned. If they have
those exits removed, they'll automatically be unbanned. Please, notice
that this process of retrieving the list of Tor servers is performed
automatically and that it might take a while to have the ban-list
synced.
2.
Developer of the week
”Gentoo is something you learn once and apply wherever you want…
just port it there ;)“
Figure 2.1: Diego Pettenò |
 |
This week's developer special is Diego
Pettenò, better known as Flameeyes. He is one of the Gentoo/FreeBSD
hackers and a media-video and sound bugfixer, so he usually does ebuild
maintenance, patches for media apps and of course Gentoo/FreeBSD things
in general.
Diego lives somewhere near Venice, Italy, where he tries to study
Computer Science at the Ca' Foscari university and does translations to
pay for his studies. Before he got assimilated into the Gentoo
collective he worked on a few small open-source projects, but as he said
”nothing that takes someone else“. Gentoo/BSD is the thing he
is most proud of: ”When I joined in march it was an overlay over
FreeBSD, now it can be considered a full distribution on its own, so
it's the first time I can really see something actually usable where I
worked on :)“
Obviously KDE is the best thing since sliced bread, so Diego uses it
and only needs vim and ssh to be happy. The first thing that gets
started is usually amaroK to wake up… but usually the computers just
keep running 24/7.
Diego uses an Athlon64 3500+, an iBook (with Gentoo/OSX) and an old
Athlon-tbird headless for Gentoo/FreeBSD. When not in front of his
computers (unlikely as that may appear) he is usually reading fantasy
books or doing bricolage.
Quote: ”I'd like to thank all the devs who allowed me to be here right
now :)“
3.
Heard in the community
gentoo-dev
Food For Thought: Bugzilla Localization?
Chris White starts a
discussion whether bugzilla should be localized. This would be a great
asset for non-English Gentoo users, but it would complicate bug
management to the point where it seems unreasonable to implement it.
Especially duplicate bugs and translation issues can't be managed
sanely.
4.
Gentoo International
Germany: Reminder for the national user meeting
Just a quick reminder for the national user meeting
in Wissen (Westerwald) next weekend. If you like camping and
want to meet some other Gentoo users, this is the perfect event for
you.
5.
Gentoo in the press
Gentoo in Windows
This month's issue of the Redmondmag.com, ’The independent voice of
the Microsoft IT community‘, features an article entitled ”Make
Room for Linux Apps“. The author describes how a Windows user
can run Linux application in Windows and describes his experiences with
Gentoo in combination with coLinux.
6.
Tips and Tricks
ulimit and sysctl
The ulimit and sysctl programs allow to limit system-wide
resource use. This can help a lot in system administration, e.g. when
a user starts too many processes and therefore makes the system
unresponsive for other users.
Code Listing 6.1: ulimit example |
# ulimit -a
core file size (blocks, -c) 0
data seg size (kbytes, -d) unlimited
file size (blocks, -f) unlimited
pending signals (-i) 8191
max locked memory (kbytes, -l) 32
max memory size (kbytes, -m) unlimited
open files (-n) 1024
pipe size (512 bytes, -p) 8
POSIX message queues (bytes, -q) 819200
stack size (kbytes, -s) 8192
cpu time (seconds, -t) unlimited
max user processes (-u) 8191
virtual memory (kbytes, -v) unlimited
file locks (-x) unlimited
|
All these settings can be manipulated. A good example is this bash
forkbomb that forks as many processes as possible and can crash systems
where no user limits are set:
Warning: Do not run this in a shell! If no limits are set your system will
either become unresponsive or might even crash. |
Code Listing 6.2: A bash forkbomb |
$ :(){ :|:& };:
|
Now this is not good - any user with shell access to your box could
take it down. But if that user can only start 30 processes the damage
will be minimal. So let's set a process limit:
Note: A too small number of processes can break the use of portage. So,
don't be too strict. |
Code Listing 6.3: Setting a process limit |
# ulimit -u 30
# ulimit -a
…
max user processes (-u) 30
…
|
If you try to run the forkbomb now it should run, but throw error
messages "fork: resource temporarily unavailable". This means
that your system has not allowed the forkbomb to start more processes.
The other options of ulimit can help with similar problems, but you
should be careful that you don't lock yourself out - setting data seg
size too small will even prevent bash from starting!
sysctl is a similar tool: It allows to configure kernel
parameters at runtime. If you wish to keep settings persistent across
reboots you should edit /etc/sysctl.conf - be aware that
wrong settings may break things in unforeseen ways.
Code Listing 6.4: Exploring sysctl variables |
# sysctl -a
…
vm.swappiness = 60
…
|
The list of variables is quite long (367 lines on my system), but I
picked out vm.swappiness here. It controls how aggressive
swapping will be, the higher it is (with a maximum of 100) the more swap
will be used. This can affect performance a lot on systems with little
memory, depending on load and other factors.
Code Listing 6.5: Reducing swappiness |
# sysctl vm.swappiness=0
vm.swappiness = 0
|
The effects of changing this setting are usually not felt instantly.
But you can change many settings, especially network-related, this way.
For servers this can offer a nice performance boost, but as with ulimit
careless usage might cause your system to misbehave or slow down. If
you don't know what a variable controls, you should not modify it!
7.
Moves, adds, and changes
Moves
The following developers recently left the Gentoo team:
- Benjamin Judas (beejay) (Gentoo/X86 Release manager)
Adds
The following developers recently joined the Gentoo Linux team:
- New developer: Christian Heim (phreak) (vserver)
- New forums staff: Jonathan Coome (Maedhros)
- New forums staff: Anders Hellgren (Kallamej)
- New forums staff: Robert Muchacki (Muchar)
Changes
The following developers recently changed roles within the
Gentoo Linux project:
- Mike Doty (kingtaco) (stepped back from Arch Tester lead)
- Homer Parker (hparker) (New Arch Tester lead)
8.
Gentoo Security
Compress::Zlib: Buffer overflow
Compress::Zlib is vulnerable to a buffer overflow which could potentially
lead to execution of arbitrary code.
For more information, please see the GLSA Announcement
ProFTPD: Format string vulnerabilities
Under specific circumstances, ProFTPD is vulnerable to format string
vulnerabilities, potentially resulting in the execution of arbitrary code.
For more information, please see the GLSA Announcement
nbSMTP: Format string vulnerability
nbSMTP is vulnerable to a format string vulnerability which may result in
remote execution of arbitrary code.
For more information, please see the GLSA Announcement
Netpbm: Arbitrary code execution in pstopnm
The pstopnm utility, part of the Netpbm tools, contains a vulnerability
which can potentially result in the execution of arbitrary code.
For more information, please see the GLSA Announcement
Heartbeat: Insecure temporary file creation
Heartbeat is vulnerable to symlink attacks, potentially allowing a local
user to overwrite arbitrary files.
For more information, please see the GLSA Announcement
9.
Bugzilla
Summary
Statistics
The Gentoo community uses Bugzilla (bugs.gentoo.org) to record and track
bugs, notifications, suggestions and other interactions with the
development team. Between 30 July 2005
and 06 August 2005, activity on the site has resulted in:
- 725 new bugs during this period
- 459 bugs closed or resolved during this period
- 38 previously closed bugs were reopened this period
Of the 8042 currently open bugs: 107 are labeled 'blocker', 200 are labeled 'critical', and 539 are labeled 'major'.
Closed bug rankings
The developers and teams who have closed the most bugs during this period are:
New bug rankings
The developers and teams who have been assigned the most new bugs during this period are:
10.
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11.
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12.
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