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FreeBSD Summer of Code 2007

The FreeBSD Project is proud to have taken part in the Google Summer of Code 2007. We received more high quality applications this year than ever before. In the end it was a very tough decision to narrow it down to the 25 students selected for funding by Google. These student projects included security research, improved installation tools, new utilities, and more. Many of the students have continued working on their FreeBSD projects even after the official close of the program.

We are happy to report that all students made some progress towards their goals for the summer, and the 22 students listed below completed the program successfully.

Information about the student projects is available from our Summer of Code wiki and all of the code is checked into Perforce. The summaries below were submitted by the individual students and their mentors with minor editing for consistency.

2007 Student Projects

  • Project: GNOME front-end to freebsd-update(8)
    Student: Andrew Turner
    Mentor: Joe Marcus Clarke

    The FreeBSD update front-end is a GTK+ interface to freebsd-update. It is split into a GUI to allow system administrators to select the binary patches to update or rollback and a back-end that communicates with freebsd-update. Development of both parts has moved to Berlios at

    Ready to enter CVS: The back-end is not yet ready to enter CVS, but a port is being made for the front-end

  • Project: Multicast DNS responder (BSD-licensed)
    Student: Fredrik Lindberg
    Mentor: Bruce M. Simpson

    Multicast DNS (mDNS) is a part of Zero Configuration Networking (Zeroconf) and provides the ability to address hosts using DNS-like names without the need of an existing (unicast), managed DNS server.

    The Multicast DNS responder (mdnsd), is more or less feature complete and is currently in a bug fixing and testing phase. A few more features are planned, most notably mdns proxy support. The daemon performs multicast dns queries on behalf of clients and acts as a unified cache to all clients. Provides the ability to announce its own mdns records onto the network.

    The daemons abilities are exposed to clients through libmdns, it provides an API to do mDNS queries and to add/remove/list records and view/flush cache. Two consumers exists, one console based basic debugging and administrative utility (mdns) which simply provides whatever libmdns provides and a NSS module (nss_mdns) which integrates mDNS lookups with the systems name lookup routines.

    Ready to enter CVS: after testing and reviewing

  • Project: Unified ports / package system database backend
    Student: Garrett Cooper
    Mentor: Kirill Ponomarew

    This project revised FreeBSD's package tools (/usr/src/usr.sbin/pkg_install) to use Berkeley DB files for storing information held in /var/db/pkg/*, and use Hash table structures. It also aims to devise a frontend for dealing with package and ports installation and management and insert virtuals into ports infrastructure to support modular components functionality, for dealing with ports installed components vs base installed components (OpenSSL, OpenSSH, Kerberos).

    Ready to enter CVS: not determined yet

  • Project: Super Tunnel Daemon
    Student: Matus Harvan
    Mentor: Max Laier

    The project implements the Super Tunnel Daemon, a tunneling daemon using plugins for different encapsulations and automagically selecting the best encapsulation in each environment. When the environment changes, the user should not notice the transition to a different encapsulation except for a small delay. Connections established within the tunnel shall seamlessly migrate to a different encapsulation. In this way, mobility is supported as well, even to the extent of changing between different physical network interfaces, e.g. disabling the wireless interface and plugging in an ethernet cable. New encapsulations can easily be added in the future using the plugin interface.

    The daemon and several plugins have been written. The daemon now has multi-user support, i.e., one server supports multiple clients. Plugins implemented so far are UDP, TCP, ICMP, DNS. There are also sys patches allowing it to listen on all unused UDP and TCP ports as well as processing ICMP echo requests in the user space.

    Missing features:

    • more plugins (HTTP, SSH,...)
    • config file format and parsing
    • and some more...

    More details are available at

    Ready to enter CVS: after some additional features as part of the Ports Collection

  • Project: Rewriting lockmgr(9)
    Student: Attilio Rao
    Mentor: Jeff Roberson

    This project involved rewriting the lockmgr synchronization primitive since recent efforts (in particular sun4v porting) evicted that this is a strong bottleneck for fs workloads (due to its spreadness in VFS land). One of the main goals of the rewriting was offering a more customized interface, trimming all unused (and possibly bugged) features of lockmgr and offering a more intelligent interface (that would help a lot in debugging and lock assertions).

    Ready to enter CVS: not determined yet

  • Project: Apple's MacBook on FreeBSD
    Student: Rui Paulo
    Mentor: Andre Oppermann

    Apple's MacBook computers are nicely designed and have neat features that other laptops don't. While Mac OS X is a nice operating system, UNIX folks (like me) would prefer to run other operating systems like FreeBSD. This project brings bug fixes and new drivers to FreeBSD that help running this OS on this platform.

    Ready to enter CVS: some parts committed already

  • Project: Security regression tests
    Student: Zhouyi ZHOU
    Mentor: Robert Watson

    This project involved testing the correctness of FreeBSD Mandatory Access Control Framework including correctly passing the security label from userland to kernel and non-bypassibility of Mandatory Access Control Hooks. Specific contributions include:

    1. A pair of pseudo ethernet drivers used for testing network related hooks. To avoid the packet go through the lo interface, the IP address in the packet is twisted in the driver.
    2. A framework for logging Mandatory Access Control hooks which is called during a period of time.
      • In kernel, every non-null label is got externalized into human readable string and recorded in a tail queue together with the name of hook that got called and possible flags or modes (etc. VREAD/VWRITE for mac_check_vnode_open hook). There is a thread much like audit subsystem's audit_worker logging the queue into a userspace file. The userland program use open, ioctl and close the /dev/mactest node to trigger and stop the logging. The logging file is truncated to zero every time the logging mechanism is triggered.
      • In userland, a bison based parsing tool is used to parse the logged file and reconstruct the record chain which will be compared with testsuite supplied configuration file to examine if expected hooks is got called and the label/flags/modes are correct. The testsuite mainly follows src/tools/regression/fstest, modified to adapt to test Mandatory Access Control Framework and include tests for signals
    3. The test cases about mandatory access control hooks for fifo, link, mdconfig, netinet, open, pipe, rename, rmdir, signal, symlink, sysvshm and truncate are written. Two security vulnerabilities where found during the test case writing.
    Ready to enter CVS: not determined yet

  • Project: GVinum Enhancements
    Student: Ulf Lilleengen
    Mentor: Lukas Ertl

    The project schedule was a bit changed in the start, because there were some rewriting of some internal parts of gvinum. Much of the time went to adapt the rest of gvinum to this new event-based system. This rewrite made gvinum less vulnerable to race bugs, and made it much easier for a developer to reason about the code.

    Improvements were made to the rebuild and syncing process of volumes, so that one could still use the volume (e.g. have it mounted) while rebuilding or syncing gvinum plexes.

    The growing of striped volumes (includes RAID-5) in the background was also implemented. Perhaps most important, is that most important gvinum features were implemented, and many bugs were fixed. A lot of testing has been done to make gvinum more robust.

    Ready to enter CVS: yes

  • Project: TCP/IP regression test suite
    Student: Nanjun Li
    Mentor: George V. Neville-Neil

    The project was about a testing suite for any host's perform-ability in TCP/IP networks. N. Li implemented it on a FreeBSD machine using libpcap (a library of BSD Packet Filter) to sniff frames on MAC layer, decode them into human-readable format, and send crafted ones to examinate if the target host follows RFC793's requirements.

    Ready to enter CVS: no

  • Project: Avoiding syscall overhead
    Student: Jesper Brix Rosenkilde
    Mentor: Scott Long

    In FreeBSD the setproctitle call is implemented with a sysctl, this has the unfortunate side effect that this simple call locks the Giant-lock. As this call is a simple matter of setting a value, it could be better implemented with shared memory between the kernel and user-space.

    This project proposes a scheme to securely share process specific data between the kernel and a user-space process. This is done by having each process allocate a special memory page, in which the kernel and user-space process can share data. This will give the security needed, as the VM-system will make sure that no outside processes can fiddle with a process' data. As everything is going on in user-space, there is no concern about a rogue process could write inside the kernel memory. There is still a locking concern, which will be addressed either by locking the entire page, or micro-locking each data field on the page.

    A suggestion by Howard Su is a multi page scheme, where a read/write page is used for things like get/setproctitle and a read-only page for things like getpid. And maybe a system wide read-only page for things like getdomain, gethostname etc.

    Ready to enter CVS: not determined yet

  • Project: Port OpenBSD's sysctl Hardware Sensors framework
    Student: Constantine A. Murenin
    Mentor: Shteryana Shopova

    The GSoC2007/cnst-sensors project was about porting the sysctl hw.sensors framework from OpenBSD to FreeBSD. The project was successfully completed, and is pending final review and integration into the CVS tree.

    The sensors framework provides a unified interface for storing, registering and accessing information about hardware monitoring sensors. Sensor types include, but are not limited to, temperature, voltage, fan RPM, time offset and logical drive status. In the OpenBSD base system, the framework spans sensor_attach(9), sysctl(3), sysctl(8), systat(1), sensorsd(8), ntpd(8), and more than 50 drivers, ranging from I2C temperature sensors and Super I/O hardware monitors to ipmi(4) and RAID controllers. Several third-party tools are also available, for example, a plug-in for Nagios and ports/sysutils/symon.

    As a part of this project, all major parts of the framework were ported, including sysctl, systat and sensorsd. Some drivers for most popular Super I/O Hardware Monitors were ported, too: it(4), supporting most contemporary ITE Tech Super I/O, and lm(4), supporting most contemporary Winbond Super I/O. Moreover, some existing FreeBSD drivers were modified to use the new framework, for example, coretemp(4).

    Ready to enter CVS: after more testing and review

  • Project: Distributed audit daemon
    Student: Alexey Mikhailov
    Mentor: Bjoern A. Zeeb

    The basic idea of this project was to implement secure and reliable log file shipping to remote hosts. While the implementation focuses on audit logs, the goal was to build tools that will make it possible to perform distributed logging for any application by using a simple API and linking with a shared library. The audit logs served as a testbed, other logs can be adopted.

    Ready to enter CVS: not yet, needs further work

  • Project: Generic input device layer
    Student: Maxim Zhuravlev
    Mentor: Philip Paeps

    Originally selected to design and implement a common way to retrieve and process data from input devices, the project resulted in a code base of a bigger and more generic project -- Enhanced NewBus. The following features are introduced by now: basic functional devices support, filter drivers and NewBus input/output subsystem. Functional devices (ex. demuxing, muxing, terminals) are supposed to coordinate real devices. Each device is handled by a stack of drivers (low-level and filters). Filter drivers are to simplify code reuse. The NewBus input/output subsystem is designed to push io requests through the NewBus graph.

    Ready to enter CVS: not determined yet

  • Project: bus_alloc_resources() Code Update
    Student: Christopher Davis
    Mentor: Warner Losh

    Currently, many devices in FreeBSD's source tree use the excessively verbose methods of resource allocation and deallocation. Numerous calls to bus_alloc_resource() or bus_alloc_resource_any() are used to allocate resources, and subsequently, multiple calls to bus_release_resource() are used to free the resources after an error in allocation or when the device is detached.

    Recently, however, the bus_alloc_resources() and bus_release_resources() functions have been added. These simple wrappers around bus_alloc_resource_any() and bus_release_resource() both operate on the same resource description, so that much of the repetition once needed to allocate and free resources can be mitigated.

    This project updated driver source code where necessary using the new functions to make the code related to allocation and deallocation simpler and clearer, while making other refinements as needed. Approximately 40 drivers were updated during SoC, although testing is still needed. There are likely 25 or more other drivers that could be updated as well, and these are listed on the wiki.

    Ready to enter CVS: not determined yet

  • Project: BSD bintools project (Part I)
    Student: Kai Wang
    Mentor: Joseph Koshy

    This project re-implemented part of the GNU binutils based on the libelf and libarchive libraries. It will bring FreeBSD a BSD Licensed toolchain for processing ELF binary files. The project mainly concentrated on re-implementing the tools ar(1), ranlib(1), objcopy(1), strip(1) and composing corresponding manual pages.

    Ready to enter CVS: soon

  • Project: Update of Linuxulator for Linux 2.6
    Student: Roman Divacky
    Mentor: Konstantin Belousov

    This is a continuation of the same project of the last GSoC. While the last year the focus was to bring basic 2.6 compatibility to FreeBSD, this year was focused on bug fixing and implementing epoll() and *at().

    Ready to enter CVS: after a final review

  • Project: FreeBSD 'safety net' IO logging utility
    Student: Sonja Milicic
    Mentor: Lukas Ertl

    Some administrative operations like filesystem or partition table debugging/repair would benefit from an "Undo" function, so they can be performed without putting vital data at risk. This project's goal was to implement a module which plugs into the GEOM framework and allows copy-on-write style logging of I/O requests to one or more snapshot files, including the possibility to rollback, replay or analyze their effects.

    The core functionality of this module and a userland tool was finished, but will need more testing/bug fixing.

    Ready to enter CVS: not determined yet

  • Project: Provide an audit log analysis tool
    Student: Liu Dongmei
    Mentor: Robert Watson

    A GUI audit log analysis tool which can display audit log in tree view and list view and analyze audit log lively. It is important to provide a intuitionistic and visualize audit log to administrator. This program's intention is to provide a totally GUI audit log display, filter and statistic, in addition provide expandability when a new type of token added. The Glib library is used as a basic platform abstraction library and GTK are used to build AuditAnalyzer's GUI.

    Ready to enter CVS: not determined yet

  • Project: Improve the FreeBSD Ports Collection Infrastructure
    Student: Gábor Kövesdán
    Mentor: Andrew Pantyukhin

    This project reimplemented the DESTDIR support from the last GSoC by the same student in a technically better way. Additionally, the PERL support was refactored from into its own file and enhanced to provide more features.

    Ready to enter CVS: already committed

  • Project: http support for PXE
    Student: Alexey Tarasov
    Mentor: Ed Maste

    The goal of this project was to write extendable code wrappers (as much as possible in C) to provided by PXE and UNDI APIs to support downloading of files via TCP-based protocols in the preboot environment. This allows to download and prepare the booting of a FreeBSD kernel from a remote server via a direct connection or a http proxy.

    Ready to enter CVS: not determined yet

  • Project: Graphical installer for FreeBSD (finstall)
    Student: Ivan Voras
    Mentor: Murray Stokely

    This project aims to create a user-friendly graphical installer for FreeBSD & FreeBSD-derived systems. The project should yield something usable for 7.x-RELEASE, but the intention is to keep it as a "second" installer system during 7.x, alongside sysinstall. In any case, sysinstall will be kept for architectures not supported by finstall (e.g. currently all except i386 and amd64).

    Ready to enter CVS: ready to enter the Ports Collection after some src patches

  • Project: Porting Linux KVM to FreeBSD
    Student: Fabio Checconi
    Mentor: Luigi Rizzo

    Linux KVM is a Virtual Machine Monitor, part of the Linux kernel, that uses Intel VT-x or AMD-V extensions for x86 processors to create a full virtualization environment. This project consists in porting Linux KVM to the FreeBSD kernel.

    Since Linux KVM has a structure similar to that of a device driver (actually, it is a device driver, from many points of view) core kernel changes are not required to support it, so it is an external loadable kernel module, exporting an interface based on ioctl() calls to a device descriptor. Part of the project was also the porting of the userspace client for that interface, a modified qemu that uses KVM to execute its guests.

    A project snapshot at the end of the Summer of Code is available. It supports only AMD-V (SVM) on amd64, as this was the hardware used during the development (adding support for other platforms is in progress); it is still highly experimental code, but it can boot FreeBSD guests.

    For code, further details, and future developments, please refer to:

    Ready to enter CVS: no

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