The previous commit created new chains to hold the firewall rules. This
commit changes the code that creates rules to place them in the new
private chains instead of the builtin top level chains.

With two networks running, the rules in the filter table now look like

  -N LIBVIRT_FWI
  -N LIBVIRT_FWO
  -N LIBVIRT_FWX
  -N LIBVIRT_INP
  -N LIBVIRT_OUT
  -A INPUT -j LIBVIRT_INP
  -A FORWARD -j LIBVIRT_FWX
  -A FORWARD -j LIBVIRT_FWI
  -A FORWARD -j LIBVIRT_FWO
  -A OUTPUT -j LIBVIRT_OUT
  -A LIBVIRT_FWI -d 192.168.0.0/24 -o virbr0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
  -A LIBVIRT_FWI -o virbr0 -j REJECT --reject-with icmp-port-unreachable
  -A LIBVIRT_FWI -d 192.168.1.0/24 -o virbr1 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
  -A LIBVIRT_FWI -o virbr1 -j REJECT --reject-with icmp-port-unreachable
  -A LIBVIRT_FWO -s 192.168.0.0/24 -i virbr0 -j ACCEPT
  -A LIBVIRT_FWO -i virbr0 -j REJECT --reject-with icmp-port-unreachable
  -A LIBVIRT_FWO -s 192.168.1.0/24 -i virbr1 -j ACCEPT
  -A LIBVIRT_FWO -i virbr1 -j REJECT --reject-with icmp-port-unreachable
  -A LIBVIRT_FWX -i virbr0 -o virbr0 -j ACCEPT
  -A LIBVIRT_FWX -i virbr1 -o virbr1 -j ACCEPT
  -A LIBVIRT_INP -i virbr0 -p udp -m udp --dport 53 -j ACCEPT
  -A LIBVIRT_INP -i virbr0 -p tcp -m tcp --dport 53 -j ACCEPT
  -A LIBVIRT_INP -i virbr0 -p udp -m udp --dport 67 -j ACCEPT
  -A LIBVIRT_INP -i virbr0 -p tcp -m tcp --dport 67 -j ACCEPT
  -A LIBVIRT_INP -i virbr1 -p udp -m udp --dport 53 -j ACCEPT
  -A LIBVIRT_INP -i virbr1 -p tcp -m tcp --dport 53 -j ACCEPT
  -A LIBVIRT_INP -i virbr1 -p udp -m udp --dport 67 -j ACCEPT
  -A LIBVIRT_INP -i virbr1 -p tcp -m tcp --dport 67 -j ACCEPT
  -A LIBVIRT_OUT -o virbr0 -p udp -m udp --dport 68 -j ACCEPT
  -A LIBVIRT_OUT -o virbr1 -p udp -m udp --dport 68 -j ACCEPT

While in the nat table:

  -N LIBVIRT_PRT
  -A POSTROUTING -j LIBVIRT_PRT
  -A LIBVIRT_PRT -s 192.168.0.0/24 -d 224.0.0.0/24 -j RETURN
  -A LIBVIRT_PRT -s 192.168.0.0/24 -d 255.255.255.255/32 -j RETURN
  -A LIBVIRT_PRT -s 192.168.0.0/24 ! -d 192.168.0.0/24 -p tcp -j MASQUERADE --to-ports 1024-65535
  -A LIBVIRT_PRT -s 192.168.0.0/24 ! -d 192.168.0.0/24 -p udp -j MASQUERADE --to-ports 1024-65535
  -A LIBVIRT_PRT -s 192.168.0.0/24 ! -d 192.168.0.0/24 -j MASQUERADE
  -A LIBVIRT_PRT -s 192.168.1.0/24 -d 224.0.0.0/24 -j RETURN
  -A LIBVIRT_PRT -s 192.168.1.0/24 -d 255.255.255.255/32 -j RETURN
  -A LIBVIRT_PRT -s 192.168.1.0/24 ! -d 192.168.1.0/24 -p tcp -j MASQUERADE --to-ports 1024-65535
  -A LIBVIRT_PRT -s 192.168.1.0/24 ! -d 192.168.1.0/24 -p udp -j MASQUERADE --to-ports 1024-65535
  -A LIBVIRT_PRT -s 192.168.1.0/24 ! -d 192.168.1.0/24 -j MASQUERADE

And finally the mangle table:

  -N LIBVIRT_PRT
  -A POSTROUTING -j LIBVIRT_PRT
  -A LIBVIRT_PRT -o virbr0 -p udp -m udp --dport 68 -j CHECKSUM --checksum-fill
  -A LIBVIRT_PRT -o virbr1 -p udp -m udp --dport 68 -j CHECKSUM --checksum-fill
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

Historically firewall rules for virtual networks were added straight
into the base chains. This works but has a number of bugs and design
limitations:

  - It is inflexible for admins wanting to add extra rules ahead
    of libvirt's rules, via hook scripts.

  - It is not clear to the admin that the rules were created by
    libvirt

  - Each rule must be deleted by libvirt individually since they
    are all directly in the builtin chains

  - The ordering of rules in the forward chain is incorrect
    when multiple networks are created, allowing traffic to
    mistakenly flow between networks in one direction.

To address all of these problems, libvirt needs to move to creating
rules in its own private chains. In the top level builtin chains,
libvirt will add links to its own private top level chains.

Addressing the traffic ordering bug requires some extra steps. With
everything going into the FORWARD chain there was interleaving of rules
for outbound traffic and inbound traffic for each network:

  -A FORWARD -d 192.168.3.0/24 -o virbr1 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
  -A FORWARD -s 192.168.3.0/24 -i virbr1 -j ACCEPT
  -A FORWARD -i virbr1 -o virbr1 -j ACCEPT
  -A FORWARD -o virbr1 -j REJECT --reject-with icmp-port-unreachable
  -A FORWARD -i virbr1 -j REJECT --reject-with icmp-port-unreachable
  -A FORWARD -d 192.168.2.0/24 -o virbr0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
  -A FORWARD -s 192.168.2.0/24 -i virbr0 -j ACCEPT
  -A FORWARD -i virbr0 -o virbr0 -j ACCEPT
  -A FORWARD -o virbr0 -j REJECT --reject-with icmp-port-unreachable
  -A FORWARD -i virbr0 -j REJECT --reject-with icmp-port-unreachable

The rule allowing outbound traffic from virbr1 would mistakenly
allow packets from virbr1 to virbr0, before the rule denying input
to virbr0 gets a chance to run.

What we really need todo is group the forwarding rules into three
distinct sets:

 * Cross rules - LIBVIRT_FWX

  -A FORWARD -i virbr1 -o virbr1 -j ACCEPT
  -A FORWARD -i virbr0 -o virbr0 -j ACCEPT

 * Incoming rules - LIBVIRT_FWI

  -A FORWARD -d 192.168.3.0/24 -o virbr1 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
  -A FORWARD -o virbr1 -j REJECT --reject-with icmp-port-unreachable
  -A FORWARD -d 192.168.2.0/24 -o virbr0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
  -A FORWARD -o virbr0 -j REJECT --reject-with icmp-port-unreachable

 * Outgoing rules - LIBVIRT_FWO

  -A FORWARD -s 192.168.3.0/24 -i virbr1 -j ACCEPT
  -A FORWARD -i virbr1 -j REJECT --reject-with icmp-port-unreachable
  -A FORWARD -s 192.168.2.0/24 -i virbr0 -j ACCEPT
  -A FORWARD -i virbr0 -j REJECT --reject-with icmp-port-unreachable

There is thus no risk of outgoing rules for one network mistakenly
allowing incoming traffic for another network, as all incoming rules
are evalated first.

With this in mind, we'll thus need three distinct chains linked from
the FORWARD chain, so we end up with:

        INPUT --> LIBVIRT_INP   (filter)

       OUTPUT --> LIBVIRT_OUT   (filter)

      FORWARD +-> LIBVIRT_FWX   (filter)
              +-> LIBVIRT_FWO
              \-> LIBVIRT_FWI

  POSTROUTING --> LIBVIRT_PRT   (nat & mangle)
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

Require that all headers are guarded by a symbol named

  LIBVIRT_$FILENAME

where $FILENAME is the uppercased filename, with all characters
outside a-z changed into '_'.

Note we do not use a leading __ because that is technically a
namespace reserved for the toolchain.
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

In many files there are header comments that contain an Author:
statement, supposedly reflecting who originally wrote the code.
In a large collaborative project like libvirt, any non-trivial
file will have been modified by a large number of different
contributors. IOW, the Author: comments are quickly out of date,
omitting people who have made significant contribitions.

In some places Author: lines have been added despite the person
merely being responsible for creating the file by moving existing
code out of another file. IOW, the Author: lines give an incorrect
record of authorship.

With this all in mind, the comments are useless as a means to identify
who to talk to about code in a particular file. Contributors will always
be better off using 'git log' and 'git blame' if they need to  find the
author of a particular bit of code.

This commit thus deletes all Author: comments from the source and adds
a rule to prevent them reappearing.

The Copyright headers are similarly misleading and inaccurate, however,
we cannot delete these as they have legal meaning, despite being largely
inaccurate. In addition only the copyright holder is permitted to change
their respective copyright statement.
Reviewed-by: NErik Skultety <eskultet@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

Update the iptablesXXXX methods so that instead of directly
executing iptables commands, they populate rules in an
instance of virFirewallPtr. The bridge driver can thus
construct the ruleset and then invoke it in one operation
having rollback handled automatically.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

When the host is configured with very restrictive firewall (default policy
is DROP for all chains, including OUTPUT), the bridge driver for Linux
adds netfilter entries to allow DHCP and DNS requests to go from the VM
to the dnsmasq of the host.

The issue that this commit fixes is the fact that a DROP policy on the OUTPUT
chain blocks the DHCP replies from the host’s dnsmasq to the VM.
As DHCP replies are sent in UDP, they are not caught by any --ctstate ESTABLISHED
rule and so, need to be explicitly allowed.
Signed-off-by: NLénaïc Huard <lenaic@lhuard.fr.eu.org>

The functions
- iptablesAddForwardDontMasquerade(),
- iptablesRemoveForwardDontMasquerade
handle exceptions in the masquerading implemented in the POSTROUTING chain
of the "nat" table. Such exceptions should be added as chronologically
latest, logically top-most rules.

The bridge driver will call these functions beginning with the next patch:
some special destination IP addresses always refer to the local
subnetwork, even though they don't match any practical subnetwork's
netmask. Packets from virbrN targeting such IP addresses are never routed
outwards, but the current rules treat them as non-virbrN-destined packets
and masquerade them. This causes problems for some receivers on virbrN.
Signed-off-by: NLaszlo Ersek <lersek@redhat.com>

iptablesContext holds only 4 pairs of iptables
(table, chain) and there's no need to pass
it around.

This is a first step towards separating bridge_driver.c
in platform-specific parts.

We pass over the address/port start/end values many times so we put
them in structs.
Signed-off-by: NNatanael Copa <ncopa@alpinelinux.org>
Signed-off-by: NLaine Stump <laine@laine.org>

Let users set the port range to be used for forward mode NAT:

...
  <forward mode='nat'>
    <nat>
      <port start='1024' end='65535'/>
    </nat>
  </forward>
...
Signed-off-by: NNatanael Copa <ncopa@alpinelinux.org>
Signed-off-by: NLaine Stump <laine@laine.org>

Support setting which public ip to use for NAT via attribute
address in subelement <nat> in <forward>:

...
  <forward mode='nat'>
      <address start='1.2.3.4' end='1.2.3.10'/>
  </forward>
...

This will construct an iptables line using:

  '-j SNAT --to-source <start>-<end>'

instead of:

  '-j MASQUERADE'
Signed-off-by: NNatanael Copa <ncopa@alpinelinux.org>
Signed-off-by: NLaine Stump <laine@laine.org>

https://www.gnu.org/licenses/gpl-howto.html recommends that
the 'If not, see <url>.' phrase be a separate sentence.

* tests/securityselinuxhelper.c: Remove doubled line.
* tests/securityselinuxtest.c: Likewise.
* globally: s/;  If/.  If/

Per the FSF address could be changed from time to time, and GNU
recommends the following now: (http://www.gnu.org/licenses/gpl-howto.html)

  You should have received a copy of the GNU General Public License
  along with Foobar.  If not, see <http://www.gnu.org/licenses/>.

This patch removes the explicit FSF address, and uses above instead
(of course, with inserting 'Lesser' before 'General').

Except a bunch of files for security driver, all others are changed
automatically, the copyright for securify files are not complete,
that's why to do it manually:

  src/security/security_selinux.h
  src/security/security_driver.h
  src/security/security_selinux.c
  src/security/security_apparmor.h
  src/security/security_apparmor.c
  src/security/security_driver.c

The src/util/network.c file is a dumping ground for many different
APIs. Split it up into 5 pieces, along functional lines

 - src/util/virnetdevbandwidth.c: virNetDevBandwidth type & helper APIs
 - src/util/virnetdevvportprofile.c: virNetDevVPortProfile type & helper APIs
 - src/util/virsocketaddr.c: virSocketAddr and APIs
 - src/conf/netdev_bandwidth_conf.c: XML parsing / formatting
   for virNetDevBandwidth
 - src/conf/netdev_vport_profile_conf.c: XML parsing / formatting
   for virNetDevVPortProfile

* src/util/network.c, src/util/network.h: Split into 5 pieces
* src/conf/netdev_bandwidth_conf.c, src/conf/netdev_bandwidth_conf.h,
  src/conf/netdev_vport_profile_conf.c, src/conf/netdev_vport_profile_conf.h,
  src/util/virnetdevbandwidth.c, src/util/virnetdevbandwidth.h,
  src/util/virnetdevvportprofile.c, src/util/virnetdevvportprofile.h,
  src/util/virsocketaddr.c, src/util/virsocketaddr.h: New pieces
* daemon/libvirtd.h, daemon/remote.c, src/conf/domain_conf.c,
  src/conf/domain_conf.h, src/conf/network_conf.c,
  src/conf/network_conf.h, src/conf/nwfilter_conf.h,
  src/esx/esx_util.h, src/network/bridge_driver.c,
  src/qemu/qemu_conf.c, src/rpc/virnetsocket.c,
  src/rpc/virnetsocket.h, src/util/dnsmasq.h, src/util/interface.h,
  src/util/iptables.h, src/util/macvtap.c, src/util/macvtap.h,
  src/util/virnetdev.h, src/util/virnetdevtap.c,
  tools/virsh.c: Update include files

All of the iptables functions eventually call down to a single
bottom-level function, and fortunately, ip6tables syntax (for all the
args that we use) is identical to iptables format (except the
addresses), so all we need to do is:

1) Get an address family down to the lowest level function in each
   case, either implied through an address, or explicitly when no
   address is in the parameter list, and

2) At the lowest level, just decide whether to call "iptables" or
   "ip6tables" based on the family.

The location of the ip6tables binary is determined at build time by
autoconf. If a particular target system happens to not have ip6tables
installed, any attempts to run it will generate an error, but that
won't happen unless someone tries to define an IPv6 address for a
network. This is identical behavior to IPv4 addresses and iptables.

IPv6 will use prefix exclusively, and IPv4 will also optionally be
able to use it, and the iptables functions really need a prefix
anyway, so use the new virNetworkDefPrefix() function to send prefixes
into iptables functions instead of netmasks.

Also, in a couple places where a netmask is actually needed, use the
new private API function for it rather than getting it directly. This
will allow for cases where no netmask or prefix is specified (it
returns the default for the current class of network.)

The network address was being set to 192.168.122.0 instead
of 192.168.122.0/24. Fix this by removing the unneccessary
'network' field from virNetworkDef and just pass the
network address and netmask into the iptables APIs directly.

* src/conf/network_conf.h, src/conf/network_conf.c: Remove
  the 'network' field from virNEtworkDef.
* src/network/bridge_driver.c: Update for iptables API changes
* src/util/iptables.c, src/util/iptables.h: Require the
  network address + netmask pair to be passed in

Instead of storing the IP address string in virNetwork related
structs, store the parsed virSocketAddr. This will make it
easier to add IPv6 support in the future, by letting driver
code directly check what address family is present

* src/conf/network_conf.c, src/conf/network_conf.h,
  src/network/bridge_driver.c: Convert to use virSocketAddr
  in virNetwork, instead of char *.
* src/util/bridge.c, src/util/bridge.h,
  src/util/dnsmasq.c, src/util/dnsmasq.h,
  src/util/iptables.c, src/util/iptables.h: Convert to
  take a virSocketAddr instead of char * for any IP
  address parameters
* src/util/network.h: Add macros to determine if an address
  is set, and what address family is set.

This patch attempts to take advantage of a newly added netfilter
module to correct for a problem with some guest DHCP client
implementations when used in conjunction with a DHCP server run on the
host systems with packet checksum offloading enabled.

The problem is that, when the guest uses a RAW socket to read the DHCP
response packets, the checksum hasn't yet been fixed by the IP stack,
so it is incorrect.

The fix implemented here is to add a rule to the POSTROUTING chain of
the mangle table in iptables that fixes up the checksum for packets on
the virtual network's bridge that are destined for the bootpc port (ie
"dhcpc", ie port 68) port on the guest.

Only very new versions of iptables will have this support (it will be
in the next upstream release), so a failure to add this rule only
results in a warning message. The iptables patch is here:

  http://patchwork.ozlabs.org/patch/58525/

A corresponding kernel module patch is also required (the backend of
the iptables patch) and that will be in the next release of the
kernel.

IPtables will seek to preserve the source port unchanged when
doing masquerading, if possible. NFS has a pseudo-security
option where it checks for the source port <= 1023 before
allowing a mount request. If an admin has used this to make the
host OS trusted for mounts, the default iptables behaviour will
potentially allow NAT'd guests access too. This needs to be
stopped.

With this change, the iptables -t nat -L -n -v rules for the
default network will be

Chain POSTROUTING (policy ACCEPT 95 packets, 9163 bytes)
 pkts bytes target     prot opt in     out     source               destination
   14   840 MASQUERADE  tcp  --  *      *       192.168.122.0/24    !192.168.122.0/24    masq ports: 1024-65535
   75  5752 MASQUERADE  udp  --  *      *       192.168.122.0/24    !192.168.122.0/24    masq ports: 1024-65535
    0     0 MASQUERADE  all  --  *      *       192.168.122.0/24    !192.168.122.0/24

* src/network/bridge_driver.c: Add masquerade rules for TCP
  and UDP protocols
* src/util/iptables.c, src/util/iptables.c: Add source port
  mappings for TCP & UDP protocols when masquerading.

* global: patch created by running:
for f in $(git ls-files '*.[ch]') ; do
    cppi $f > $f.t && mv $f.t $f
done

We don't use this method of reloading rules anymore, so we can just
kill the code.

This simplifies things a lot because we no longer need to keep a
table of the rules we've added.

* src/util/iptables.c: kill iptablesReloadRules()

Long ago we tried to use Fedora's lokkit utility in order to register
our iptables rules so that 'service iptables restart' would
automatically load our rules.

There was one fatal flaw - if the user had configured iptables without
lokkit, then we would clobber that configuration by running lokkit.

We quickly disabled lokkit support, but never removed it. Let's do
that now.

The 'my virtual network stops working when I restart iptables' still
remains. For all the background on this saga, see:

  https://bugzilla.redhat.com/227011

* src/util/iptables.c: remove lokkit support

* configure.in: remove --enable-lokkit

* libvirt.spec.in: remove the dirs used only for saving rules for lokkit

* src/Makefile.am: ditto

* src/libvirt_private.syms, src/network/bridge_driver.c,
  src/util/iptables.h: remove references to iptablesSaveRules

* src/bridge.c, src/bridge.h, src/buf.c, src/buf.h, src/cgroup.c,
  src/cgroup.h, src/conf.c, src/conf.h, src/event.c, src/event.h,
  src/hash.c, src/hash.h, src/hostusb.c, src/hostusb.h,
  src/iptables.c, src/iptables.h, src/logging.c, src/logging.h,
  src/memory.c, src/memory.h, src/pci.c, src/pci.h, src/qparams.c,
  src/qparams.h, src/stats_linux.c, src/stats_linux.h,
  src/threads-pthread.c, src/threads-pthread.h, src/threads-win32.c,
  src/threads-win32.h, src/threads.c, src/threads.h, src/util.c,
  src/util.h, src/uuid.c, src/uuid.h, src/virterror.c,
  src/virterror_internal.h, src/xml.c, src/xml.h: Move all files
  into src/util/
* daemon/Makefile.am: Add -Isrc/util/ to build flags
* src/Makefile.am: Add -Isrc/util/ to build flags and update for
  moved files
* src/libvirt_private.syms: Export cgroup APIs since they're now
  in util rather than linking directly to drivers
* src/xen/xs_internal.c: Disable bogus virEventRemoveHandle call
  when built under PROXY
* proxy/Makefile.am: Update for changed file locations. Remove
  bogus build of event.c
* tools/Makefile.am, tests/Makefile.am: Add -Isrc/util/ to build flags

Avoid a build error when configuring --without-xen --without-qemu.
* src/iptables.c [WITH_QEMU]: Don't #ifdef-out.
* src/iptables.h [WITH_QEMU]: Don't #ifdef-out.
* src/util.c (virRun) [__MINGW32__]: Define a stub that always fails.

Done with these commands:
git grep -l Local.variab|xargs \
  perl -0x3b -pi -e 's,\n+/\*\n \* vim:(.|\n)*,\n,'

git grep -l Local.variab|xargs \
  perl -0x3b -pi -e 's,\n+/\*\n \* Local variables:\n(.|\n)*,\n,'

and run lokkit each time a new rule is added.

	* src/.cvsignore: Ignore *.loT files (generated under Windows).
	* proxy/libvirt_proxy.c: Bail out earlier --without-xen.
	* src/proxy_internal.c: Don't build proxy client side if
	  configured --without-xen.
	* src/iptables.c, src/iptables.h: Disable this code if
	  configured --without-qemu.
	* src/nodeinfo.c: If no 'uname' function, set model name to
	  empty string (for Windows).
	* src/xen_unified.h, src/util.c, src/test.c: Include <winsock2.h>
	  on Windows.
	* src/util.c: Disable virExec* and virFileLinkPointsTo on
	  MinGW.

        * qemud/iptables.c: As suggested by danpb, make libvirt_qemud
        handle SIGHUP by re-loading the iptables rules.

        * qemud/iptables.c: Remove the target interface parameter
        from iptablesPhysdevForward(). This rule is intended to
        allow frames to be forwarded across the bridge from the
        supplied bridge port. In this context, the --out parameter
        would match the outgoing bridge port, which will never
        be network->def->forwardDev.

        * qemud/iptables.[ch]: add code for managing iptables
        rules.

        * qemud/Makefile.am: add iptables.[ch].

        * qemud/qemud.c: add and remove iptables rules as
        appropriate.

        * qemud/conf.c: when starting a guess, add a rule
        allowing it to forward packets across the networks
        bridge.

        * qemud/internal.h: add iptables context ptr

        * configure.in: add --with-iptables-dir and
        --with-iptables-prefix to allow us to put our rules
        in a chain with the given prefix and save the rules
        in files in the given dir so as to integrate with
        the proposed "service iptables restart" solution
        in:

           https://bugzilla.redhat.com/227011