1. 17 Jan, 2012 1 commit
  2. 13 Dec, 2011 1 commit
  3. 16 Aug, 2011 1 commit
  4. 21 Jul, 2011 1 commit
  5. 15 Apr, 2011 1 commit
  6. 03 Apr, 2011 1 commit
  7. 25 Mar, 2011 1 commit
  8. 17 Mar, 2011 1 commit
  9. 07 Dec, 2010 1 commit
  10. 16 Nov, 2010 1 commit
    • Kevin Atkinson's avatar
      Add support for all node "tb-set-tarfiles". · a0d0c95e
      Kevin Atkinson authored
      "tb-set-tarfiles" is like "tb-set-node-tarfiles" except that it
      distributes the tarfile to all nodes rather than just one and that it
      uses frisbee to distribute the file.
      
      These changes involved 1) refactoring frisbee info from images table
      into a new table, frisbee_blobs, 2) a new experiment_blobs table, and
      3) a new tmcd command so the node knows how to get the files from the
      server.
      
      The changes where designed to be general purpose enough to eventually
      support:
        1) Distributing arbitrary files (not just tarfiles) to nodes
        2) Perform arbitrary actions on those files
        3) Use arbitrary methods to get the files
      
      As such the tmcd line is as follows:
        URL=* ACTION=*
      
      where URL is currently:
        frisbee.mcast://<ADDR>/<FILE>
      for example
        frisbee.mcast://234.16.184.192:18092/users/kevina/home-dir.tar.gz
      and when we get around to using a master Frisbee server it could be
        frisbee://*
      or it could be a file://, http://, etc.
      
      and ACTION is currently:
        unpack:<LOCATION>
      for example
        unpackt:/users
      with future syntax to be determined.
      a0d0c95e
  11. 29 Sep, 2010 1 commit
  12. 15 Apr, 2010 1 commit
    • Ryan Jackson's avatar
      Various subboss-related bits · 3d95a752
      Ryan Jackson authored
      - Add support for new tmcd dhcpdconf command to watchdog
      - Fix dhcpd.conf template so that ddns-update-style is set to none
      - Pull some utility functions from boss's libtestbed.pm into the client
        libtestbed.pm for use by subboss_dhcpd_makeconf and daemon_wrapper.
      - Add stuff to simplify getting control interface IP address.
      3d95a752
  13. 07 Mar, 2010 2 commits
  14. 03 Mar, 2010 1 commit
  15. 23 Feb, 2010 1 commit
  16. 01 Dec, 2009 1 commit
  17. 05 Nov, 2009 1 commit
  18. 12 Oct, 2009 1 commit
    • David Johnson's avatar
      Add the ability to load images on virtnodes. For now, we just overload · c6c57bc9
      David Johnson authored
      the tb-set-node-os command with a second optional argument; if that is
      present, the first arg is the child OS and the second is the parent OS.
      We add some new features in ptopgen (OS-parentOSname-childOSname) based
      off a new table that maps which child OSes can run on which parents, and
      the right desires get added to match.  We setup the reloads in os_setup
      along with the parents.  Also needed a new opmode, RELOAD-PCVM, to handle
      all this.
      
      For now, users only have to specify that their images can run on pcvms, a
      special hack for which type the images can run on.  This makes sense in
      general since there is no point conditionalizing childOS loading on
      hardware type at the moment, but rather on parentOS.  Hopefully this stuff
      wiill mostly work on shared nodes too, although we'll have to be more
      aggressive on the client side garbage collecting old frisbee'd images for
      long-lived shared hosts.
      
      I only made these changes in libvtop, so assign_wrapper folks are left in
      the dark.
      
      Currently, the client side supports frisbee.  Only in openvz for now, and
      this probably breaks libvnode_xen.pm.  Also in here are some openvz
      improvements, like ability to sniff out which network is the public
      control net, and which is the fake virtual control net.
      c6c57bc9
  19. 13 Aug, 2008 1 commit
  20. 16 Apr, 2008 1 commit
    • Leigh B. Stoller's avatar
      A set of changes to implement dynamic root passwords on local nodes · bac0172e
      Leigh B. Stoller authored
      (and vnodes). Each time a node is allocated to an experiment it gets a
      new root password (using the node_attributes table). The watchdog has
      a new section that resets the root password (defaults to hourly).  We
      still using a common password in the image to avoid totally bricking
      ourselves, but once a node boots into an experiment it gets a new root
      password.
      
      This prevents hundreds of nodes with the same password, and all of the
      problems associated with that.
      bac0172e
  21. 17 Aug, 2007 1 commit
  22. 25 Aug, 2006 1 commit
    • Leigh B. Stoller's avatar
      Add support for dynamic registration of ports on experimental nodes so · 73102ef8
      Leigh B. Stoller authored
      that clients and servers can avoid using hardwired ports on those
      experimental nodes. I have added the following tmcd operation:
      
      	tmcc portregister <service> [<port>]
      
      where we assume its the control network IP (from the DB), and the pid/eid
      of the node the experiment belongs to. The given port is entered into
      the port_registration table for the experiment, using the service as the
      tag. Supplying port=0 clears the registration from the table.
      
      When called like:
      
      	tmcc portregister <service>
      
      we return the registered port, or nothing.
      
      I hacked up a little C library module in libtb so that there is something
      that looks like a C interface to this:
      
       	int
       	PortRegister(char *service, int port);
      
       	int
       	PortLookup(char *service, char *hostname, int namelen, int *port);
      
      The above routines call out to tmcc of course.
      
      Lastly, I changed the sync server and client to use the new port
      registration, via the library calls above.
      
      There are other emulab services that need to be changed as well, but
      they can be done on an as needed basis.
      73102ef8
  23. 04 Apr, 2006 1 commit
  24. 23 Mar, 2006 1 commit
    • Kirk Webb's avatar
      · 89e7491a
      Kirk Webb authored
      Add "plabeventkeys" tmcc command to libtmcc.pm
      89e7491a
  25. 25 Jan, 2006 1 commit
    • Kirk Webb's avatar
      · c6b8cf83
      Kirk Webb authored
      Changes to support reporting back the port elvind bound to in the
      management slice, and also sending this back to non-MS slivers.
      c6b8cf83
  26. 17 Aug, 2005 2 commits
    • Mike Hibler's avatar
      Don't set the permissions 600 on the accounts cache file. · eaa14c02
      Mike Hibler authored
      It breaks the windows port and also doesn't accomplish anything.
      (a non-root user can always just make the tmcc call to boss to
      get the info).
      eaa14c02
    • Mike Hibler's avatar
      Reduce number of boottime TMCD calls: · 273f0f2c
      Mike Hibler authored
       * ipodinfo and watchdoginfo are now fullconfig commands
       * ipod setup moved later in startup to take advantage of fullconfig
       * watchdog changed to use cached info on the first call
       * move firewall setup later to take advantage of fullconfig
      Other stuff:
       * accounts/ipodinfo cache files protected 600
      
      Along with Tim's changes, this should eliminate 4 more boot time calls!
      273f0f2c
  27. 22 Jun, 2005 1 commit
    • Leigh B. Stoller's avatar
      Added my simplistic link tracing and monitoring. Example usage and · 7942119e
      Leigh B. Stoller authored
      some details can be found in the advanced tutorial that I wrote up.
      See this link:
      
      http://www.emulab.net/tutorial/docwrapper.php3?docname=advanced.html#Tracing
      
      The basic idea is that each virt_lan entry gets a couple of new slots
      describing the type of tracing that is desired.
      
        traced tinyint(1) default '0',
        trace_type enum('header','packet','monitor') NOT NULL default 'header',
        trace_expr tinytext,
        trace_snaplen int(11) NOT NULL default '0',
        trace_endnode tinyint(1) NOT NULL default '0',
      
      There is a new physical table called "traces" that is a little bit
      like the current delays table. A new tmcd command returns the trace
      configuration to the client nodes (tmcd/common/config/rc.trace).
      
      The delays table got a new boolean called "noshaping" that tells the
      delay node to bridge, but not set up any pipes. This allows us to
      capture traffic at the delay node, but without much less overhead on
      the packets.
      
      The pcapper got bloated up to do packet capture and more event stuff.
      I also had to add some mutex locking around calls into the pcap
      library and around malloc, since the current setup used linuxthreads,
      which is not compatable with the standard libc_r library. I was
      getting all kinds of memory corruption, and I am sure that if someone
      breathes on the pcapper again, it will break in some new way.
      7942119e
  28. 04 Apr, 2005 1 commit
    • Timothy Stack's avatar
      · 463ee6b1
      Timothy Stack authored
      Mote and robot related stuff.  The main thing is the addition of relay
      capabilities to capture and related things.
      
      	* GNUmakefile.in: Add the capture and tip subdirectories to the
      	client and client-install targets.
      
      	* configure, configure.in, config.h.in: Detect srandomdev() for
      	capture and add "mote/newmote" script.
      
      	* capture/GNUmakefile.in, capture/capture.c: Add "relay"
      	capabilities to capture.
      
      	* capture/capquery.c: Query the capserver for the relay receiver's
      	port number.
      
      	* capture/capserver.c: Small hack to return the port number
              for a node.
      
      	* db/libdb.pm.in, db/xmlconvert.in: Add virt_tiptunnels table.
      
      	* event/program-agent/program-agent.c: Change log file names to
      	something a little more user-friendly.  Add a "MODIFY" event
      	handler that lets the user set agent attributes (command, tag,
      	timeout) without having to run a program.
      
      	* event/sched/GNUmakefile.in, event/sched/console-agent.cc,
      	event/sched/console-agent.h, event/sched/event-sched.c: Add
      	console agents that can be used to snapshot a section of the
      	capture log file.
      
      	* event/sched/node-agent.cc: Some minor cleanup.
      
      	* event/sched/simulator-agent.cc, event/sched/simulator-agent.h:
      	Add the config data to the report mail.  Add a "RESET" event
      	handler that runs "loghole clean".  Save the report mail in a file
      	so it gets archived with the rest of the logs.
      
      	* lib/libtb/tbdefs.h: Add CONSOLE object type.
      
      	* mote/GNUmakefile.in, mote/newmote: Add newmote script, just a
      	quick hack to add motes to the DB.
      
      	* mote/tbuisp.in: Add another backend for loading motes through
      	their relay capture server.
      
      	* robots/mtp/mtp_dump.c: Dump the min/max values for x and y,
      	handy for figuring out the bounds of the camera.
      
      	* sql/database-fill.sql: Change the RELOAD-MOTE/SHUTDOWN ->
      	ALWAYSUP/SHUTDOWN mode transition to ALWAYSUP/ISUP since stated
      	doesn't seem to run triggers after a state change by a mode
      	transition.
      
      	* tbsetup/tbreport.in: Change the ordering of the eventlist so it
      	displays event-sequences appropriately.
      
      	* tbsetup/ns2ir/GNUmakefile.in, tbsetup/ns2ir/console.tcl,
      	tbsetup/ns2ir/node.tcl, tbsetup/ns2ir/parse.tcl.in,
      	tbsetup/ns2ir/sim.tcl.in: Add a "console" agent that represents
      	the serial console for a node.
      
      	* tbsetup/ns2ir/sequence.tcl: Add an "append" method so it is
      	easier to build sequences dynamically.
      
      	* tbsetup/ns2ir/topography.tcl: Make checkdest available to
      	regular users.
      
      	* tip/GNUmakefile.in, tip/tiptunnel.c: Add support for uploading a
      	file to a relay version of capture and exporting the end
      	connection as a pty.
      
      	* tmcd/decls.h, tmcd/common/libsetup.pm: Bump version number since
      	the dosubnodelist change is not backwards compatible.
      
      	* tmcd/tmcd.c: Make dosubnodelist and dosubconfig callable even
      	when a node isn't allocated.  Add dotiptunnels command that
      	returns which serial consoles are to be mounted on a node.  Add
      	mote version of subconfig that returns information needed to
      	startup the relay version of capture.
      
      	* tmcd/common/bootsubnodes: For motes, startup the relay version
      	of capture (XXX stargate specific).
      
      	* tmcd/common/libsetup.pm, tmcd/common/libtmcc.pm,
      	tmcd/common/config/rc.config, tmcd/common/config/rc.tiptunnels:
      	Client side changes for mounting another nodes serial line.
      
      	* tmcd/common/rc.bootsetup: Always boot the subnodes, even when
      	free.  This is used for motes since their capture needs to be up
      	for reloading at the time.
      
      	* tmcd/linux/ixpboot: Shuffle some code around so the script
      	doesn't fail if the ixp isn't allocated.
      
      	* utils/loghole.in: Add "digest.out" and "report.mail" as global
      	logs to be saved in archives and display the "report.mail" file
      	when showing a loghole archive.
      
      	* xmlrpc/emulabserver.py.in: Scrub more of the return values to
      	get rid of "None"s.
      463ee6b1
  29. 07 Mar, 2005 1 commit
    • Timothy Stack's avatar
      · 898cf9a2
      Timothy Stack authored
      Checkin some changes related to experiment automation and vnode feedback:
      
      	* configure, configure.in: Add sensors/canaryd/feedbacklogs
      	template.
      
      	* db/libdb.pm.in, db/xmlconvert.in: Add "virt_user_environment"
      	table that holds environment variable names and values.
      
      	* event/lib/event.c: Allocate memory of the right size for
      	event_notifications.
      
      	* event/program-agent/GNUmakefile.in: Add version.c file and
      	add install targets for the man page.
      
      	* event/program-agent/program-agent.8: Man page describing the
      	program-agent daemon.
      
      	* event/program-agent/program-agent.c: Add a bunch of convenience
      	features: let the user specify the working directory for commands;
      	save output to separate files on every invocation of an agent; let
      	the user specify a timeout for a command; make the set of
      	environment variables sane and add vars given in the NS file in
      	the opt array; a "status" file containing process information is
      	written out when children are collected.  Internal changes: child
      	processes are collected immediately, instead of waiting for the
      	next START event, so we can send back COMPLETE events; the daemon
      	now runs with a real-time priority, to increase the chances of
      	receiving events.
      
      	* event/proxy/evproxy.c: Made it bidirectional so the
      	program-agent's COMPLETE events make it back to the scheduler.
      
      	* event/sched/error-record.c: Change the default log directory.
      
      	* event/sched/event-sched.h, event/sched/event-sched.c: Setup an
      	environment similar to a program-agent to run the user's log
      	digester.
      
      	* event/sched/node-agent.cc: Add a handler for the SNAPSHOT event
      	that runs create_image for the node.
      
      	* event/sched/simulator-agent.h, event/sched/simulator-agent.cc:
      	Let the user specify a "DIGESTER" script that digests the log
      	files into a summary of the results.  Add event handler for
      	remapping a vnode experiment.
      
      	* event/sched/timeline-agent.c: Accept the RUN event as well as
      	the START event.
      
      	* os/GNUmakefile.in: Install the install-tarfile.1 man page.
      
      	* os/install-tarfile: Automatically chown/chgrp any files that do
      	not have valid user or group IDs, the new owner will be the user
      	that swapped in the experiment.  Include the install directory in
      	the DB file.  Add a "list" mode that just dumps what files have
      	been installed and where.  Add a "force" option so the user can
      	forcefully install the file, even though the DB says its already
      	there.
      
      	* os/install-tarfile.1: Man page describing the install-tarfile
      	tool.
      
      	* os/syncd/GNUmakefile.in: Install man pages on ops.
      
      	* sensors/canaryd/GNUmakefile.in: Link canaryd statically and
      	install "feedbacklogs" tool.
      
      	* sensors/canaryd/canaryd.c: Dump dummynet pipe data.
      
      	* sensors/canaryd/canarydEvents.c: Log errors.
      
      	* sensors/canaryd/feedbacklogs.in: Tool used to generate feedback
      	data from canaryd log files.
      
      	* sensors/slothd/GNUmakefile.in: Install digest-slothd on ops.
      
      	* sensors/slothd/digest-slothd: Fix some bugs and write out an
      	"alert" file with all the nodes/links that were overloaded.
      
      	* tbsetup/os_load.in, tbsetup/libosload.pm.in: Add "waitmode"
      	argument that lets you specify that you want to wait for the disk
      	to finish loading and/or wait for the node to come back up in the
      	new OS.
      
      	* tbsetup/power.in: Remove debugging printf.
      
      	* tbsetup/ns2ir/node.tcl, tbsetup/ns2ir/program.tcl,
      	tbsetup/ns2ir/sequence.tcl, tbsetup/ns2ir/sim.tcl.in: Fix some
      	quoting problems with event-sequences.  Add -expected-exit-code
      	and -tag options to the "$program run" event.  Add -digester to
      	the "$ns report" event that lets the user specify a program to run
      	to digest the log files.
      
      	* tbsetup/ns2ir/tb_compat.tcl.in: Change the initial scaling
      	factor for feedback nodes to 1%, instead of 100%.
      
      	* tmcd/tmcd.c, tmcd/common/libtmcc.pm: Add "userenv" command that
      	returns the values in "virt_user_environment".  Return new program
      	agent fields: dir, timeout, and expected_exit_code.
      
      	* tmcd/common/GNUmakefile.in: Install rc.canaryd.
      
      	* tmcd/common/bootvnodes: Add hack to boost the program-agents to
      	a real-time priority, they can't do it from inside the jail.
      
      	* tmcd/common/rc.canaryd: Rc script for canaryd.
      
      	* tmcd/common/watchdog: Don't fail outright if there is a bad line
      	in the battery.log
      
      	* tmcd/common/rc.progagent: Append "userenv" data to the
      	program-agent config file.
      
      	* utils/GNUmakefile.in: Install loghole and its man page on ops.
      
      	* utils/loghole.1: Document "clean" command and the change in
      	loghole directories.
      
      	* utils/loghole.in: Add "clean" command and parallelization.
      
      	* xmlrpc/emulabserver.py.in: Add "virt_user_environment" table.
      	Order the eventlist by "idx" and time, needed for sequences.  And
      	removed unnecessary nologin checks.
      898cf9a2
  30. 22 Feb, 2005 1 commit
    • Timothy Stack's avatar
      · 48d5c24a
      Timothy Stack authored
      Report battery stats using the watchdog:
      
      	* robots/emc/emcd.c: Don't send events with battery levels
      	anymore.
      
      	* tmcd/tmcd.c: Add 'battery' command that updates the
      	battery_percentage, battery_voltage, and battery_timestamp values
      	in the nodes table.  It's currently only called by the watchdog
      	running on the garcias.
      
      	* tmcd/common/libtmcc.pm: Add TMCCCMD_BATTERY function.
      
      	* tmcd/common/watchdog: Updated to send back battery information
      	obtained from garcia-pilot.
      48d5c24a
  31. 25 Jan, 2005 1 commit
  32. 20 Jan, 2005 1 commit
  33. 06 Jan, 2005 1 commit
    • Leigh B. Stoller's avatar
      A bunch of boot changes. Read carefully. · 94ccc3f4
      Leigh B. Stoller authored
      * Add boot_errno to the nodes table so that nodes can report in a
        subcode to indicate what went wrong. At present, we do not report any
        real error codes; that is going to take some time to work out since it
        will reqiure a bunch of changes to the boot scripts.
      
      * Add new table node_bootlogs to store logs provided by the nodes. Not
        a full console log, but a log of the tmcd client side part. We can
        make it a full log if we want though; just means mucking about with
        the boot phase a bit.
      
      * Add new state transition to NORMALv2 and PCVM state machines. "TBFAILED"
        is a new state that is sent (after TBSETUP) if a node fails somewhere in
        the tmcd client side.
      
      * Change TBNodeStateWait() to take a list of states (instead of single
        state) and an optional pass by reference parameter to return the actual
        state that the node landed in. Change all calls to TBNodeStateWait() of
        course.
      
      * Change os_setup (and libreboot in wait mode) to look for both TBFAILED
        and ISUP. If a TBFAILED event is seen, we can terminate the wait early
        and not retry os_setup on physical nodes (although still retry virtual
        nodes). The nice thing about this is that the wait should terminate much
        earlier (rather then waiting for timeout), especially for virtual nodes
        which can take a really long time when there are a couple of hundred.
      
      * Add new routines dobooterrno() and dobootlog() to tmcd. Bump version
        number and increase the buffer size to allow for the larger packets that
        a console log wikk generate (added MAXTMCDPACKET variable, set to 0x4000).
      
      * Add new -f option to tmcc to specify a datafile to send along as the last
        argument to tmcd. This is more pleasing then trying to send a console log
        in on the command line. For example: "tmcc -f /tmp/log BOOTLOG" will send
        a BOOTLOG command along with the contents of /tmp/log.
      
        Also close the write side of the pipe so that server sees EOF on
        read. See aside comment below.
      
      * Changes to rc.bootsetup:
           1. Use perl tricks to capture all output, duping to the console and to
              a log file in /var/emulab/logs.
           2. On any error, send a status code (boot_errno) and the bootlog to
              tmcd.
           3. Generate a TBFAILED state transition.
      
      * Changes to rc.injail:
           1. Same as rc.bootsetup, but do not send log files; that would pummel
              boss. Leave them on the physical node.
      
      * Change vnodesetup (which calls mkjail) to watch for any error and send a
        TBFAILED state transition. This should catch almost all errors, and
        dramatically reduce waiting when something fails.
      
      * Changes to rc.cdboot are essentially the same as rc.bootsetup, although a
        bootlog is sent all the time (success or failure), and I do not generate
        a boot_errno yet. Also, instead of TBFAILED, generate a PXEFAILED state
        since the CDROM is actually operating within the PXEFBSD opmode. I have
        yet to work this into the rest of the system though; waiting to get a new
        CD built and actually experiment with it.
      
      * Add new menu option and web page to display the node bootlog. We store
        only the lastest bootlog, but maybe someday store more then one. Display
        boot_errno on node page.
      
      Aside: I made a big mistake in the tmcd protocol; I did not envision
      passing more then a small amount of data (one fragment) and so I do not
      include a record terminator (ie: close of the write side on the client
      sends EOF) or a size field at the beginning. No big deal since small
      requests are sent in one fragment and the server sees the entire
      thing. Well, with a large console log, that will end up as multiple
      fragments, and the server will often not get the entire thing on the first
      read, and there are no subsequent reads (with no EOF or known size, it
      would block forever). Well, fixing this in a backwards compatable manner
      (for old images) was way too much pain. Instead, tmcc now closes the write
      side, and the server does subsequent reads *only* in the new dobbootlog()
      routine. Note that it *is* possible to fix this in a backwards compatable
      manner, but I did not want to go down that path just yet.
      94ccc3f4
  34. 27 Oct, 2004 1 commit
  35. 29 Sep, 2004 1 commit
  36. 24 Sep, 2004 1 commit
  37. 20 Sep, 2004 1 commit
    • Leigh B. Stoller's avatar
      More brutal hacks for elab-in-elab, although this one is actually · 3e34ba5f
      Leigh B. Stoller authored
      handy by itself; add -i option to tmcc (C and perl version) to turn
      off SSL mode. So instead of a separate nossl binary, the SSL binary
      can now operate in nossl mode. Like the previous revision, this is
      also controlled by an environment variable so that rc.inelab can make
      sure that all children use the nossl mode. Why? Cause the inner elab
      will have its own set of certificates, and the outer elab tmcd will
      reject the connections. Simpler to just speak nossl to the outer elab,
      rather than try to mess with two sets of certs.
      3e34ba5f
  38. 25 Aug, 2004 1 commit
    • Mike Hibler's avatar
      Firewall support part III: client scripts. · b21e6942
      Mike Hibler authored
      Overview of simply firewall setup.
      
      Experimentor specifies in their ns file:
      
           set fw [new Firewall $ns]
           $fw style <open|closed|basic>
      
      to set up an "open" ("allow any"), "closed" ("deny any"), or "basic"
      (allow ICMP and ssh) firewall.  "basic is the default.  Additional rules
      can be added with:
      
           $fw add-rule <IPFW format rule>
           $fw add-numbered-rule <1-50000> <IPFW format rule>
      
      where the former implicitly numbers rules such that the firewall processes
      them in the order given in the NS file.  The latter allows explicit
      specification of the numbering.  Currently the rules are fixed strings,
      there is no variable substitution.  There is also no syntax checking done
      on the rules at parse time.
      
      We allocate an extra node to the experiment to serve as a firewall.
      Currently that node runs FreeBSD and uses IPFW.  In the initial configuration,
      all other nodes in the experiment will just be setup with a default route
      that points to the firewall node.  So all outbound traffic will pass through
      it.  Inbound traffic will still travel straight to the node.  This should
      prevent nodes from accidentally initiating attacks on the outside world.
      Long term we will of course enforce the firewall on all traffic, that should
      not have any effect on the NS syntax above.
      
      When a node boots, there will be an rc.firewall script that checks to see
      if there is a firewall for the experiment and if so, which node it is.
      This is done with the TMCD "firewallinfo" command which returns:
      
            TYPE=none
      
            TYPE=remote FWIP=N.N.N.N
      
            TYPE=<fwtype> STYLE=<fwstyle> IN_IF=<macaddr> OUT_IF=<macaddr>
            RULENO=<num> RULE="<ipfw command string>"
            RULENO=...
            ...
      
      In the case of no firewall we get back TYPE=none, and we continue as normal.
      Otherwise, there are two types of replies, one for a node that is being
      firewalled (TYPE=remote) and one for a node that is a firewall
      (TYPE=<fwtype> + RULES).
      
      In the TYPE=remote case, the firewall node indicated by FWIP.  This is
      the address we use for the default route.
      
      For TYPE=<fwtype>, we are the firewall, and we get STYLE and IN_IF/OUT_IF
      info.  Here TYPE indicates whether we should use ipfw or whatever.
      For now it is always ipfw.  IN_IF and OUT_IF may someday indicate the
      interfaces to use for the internal and external connections, right now
      both will indicate the control net interface.  So, after ensuring that
      the ipfw modules is loaded, we grab the provided RULE info, which includes
      both per-experiment and default rules, and setup ipfw.
      
      Issues to resolve:
             - synchronization: how to ensure firewall comes up first
             - how to better implement the firewalling
               (i.e., without the cooperation of the nodes)
             - support the equiv of linkdelays (on-node firewalling)?
             - allow firewalls within experiments?
               (ie., on experimental interfaces)
             - dynamic changing of firewall rules via events?
             - how to show firewall state in various web pages
      b21e6942