When it is starting up, firewalld will delete all existing iptables
rules and chains before adding its own rules. If libvirtd were to try
to directly add iptables rules during the time before firewalld has
finished initializing, firewalld would end up deleting the rules that
libvirtd has just added.
Currently this isn't a problem, since libvirtd only adds iptables
rules via the firewalld "passthrough command" API, and so firewalld is
able to properly serialize everything. However, we will soon be
changing libvirtd to add its iptables and ebtables rules by directly
calling iptables/ebtables rather than via firewalld, thus removing the
serialization of libvirtd adding rules vs. firewalld deleting rules.
This will especially apparent (if we don't fix it in advance, as this
patch does) when libvirtd is responding to the dbus NameOwnerChanged
event, which is used to learn when firewalld has been restarted. In
that case, dbus sends the event before firewalld has been able to
complete its initialization, so when libvirt responds to the event by
adding back its iptables rules (with direct calls to
/usr/bin/iptables), some of those rules are added before firewalld has
a chance to do its "remove everything" startup protocol. The usual
result of this is that libvirt will successfully add its private
chains (e.g. LIBVIRT_INP, etc), but then fail when it tries to add a
rule jumping to one of those chains (because in the interim, firewalld
has deleted the new chains).
The solution is for libvirt to preface it's direct calling to iptables
with a iptables command sent via firewalld's passthrough command
API. Since commands sent to firewalld are completed synchronously, and
since firewalld won't service them until it has completed its own
initialization, this will assure that by the time libvirt starts
calling iptables to add rules, that firewalld will not be following up
by deleting any of those rules.
To minimize the amount of extra overhead, we request the simplest
iptables command possible: "iptables -V" (and aside from logging a
debug message, we ignore the result, for good measure).
(This patch is being done *before* the patch that switches to calling
iptables directly, so that everything will function properly with any
fractional part of the series applied).
Signed-off-by: Laine Stump <laine@redhat.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Don't hide our use of GHashTable behind our typedef. This will also
promote the use of glibs hash function directly.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Matt Coleman <matt@datto.com>
It doesn't make much sense to configure the bucket count in the hash
table for each case specifically. Replace all calls of virHashCreate
with virHashNew which has a pre-set size and remove virHashCreate
completely.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
IPv6 does support masquerade since Linux 3.9.0 / ip6tables 1.4.18,
which is Fedora 18 / RHEL-7 vintage, which covers all our supported
Linux versions.
Reviewed-by: Laine Stump <laine@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Most code now uses the virProcess / virCommand APIs, so
the need for sys/wait.h is quite limited. Removing this
include removes the dependency on GNULIB providing a
dummy sys/wait.h for Windows.
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Glib implementation follows the ISO C99 standard so it's safe to replace
the gnulib implementation.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
While the default iptables setup used by Fedora/RHEL distros
only restricts traffic on the INPUT and/or FORWARD rules,
some users might have custom firewalls that restrict the
OUTPUT rules too.
These can prevent DHCP/DNS/TFTP responses from dnsmasq
from reaching the guest VMs. We should thus whitelist
these protocols in the OUTPUT chain, as well as the
INPUT chain.
Signed-off-by: Malina Salina <malina.salina@protonmail.com>
Initial patch then modified to add unit tests and IPv6
support
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Since commit 44e7f02915
util: rewrite auto cleanup macros to use glib's equivalent
VIR_AUTOFREE is just an alias for g_autofree. Use the GLib macros
directly instead of our custom aliases.
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
During startup libvirtd creates top level chains for both ipv4
and ipv6 protocols. If this fails for any reason then startup
of virtual networks is blocked.
The default virtual network, however, only requires use of ipv4
and some servers have ipv6 disabled so it is expected that ipv6
chain creation will fail. There could equally be servers with
no ipv4, only ipv6.
This patch thus makes error reporting a little more fine grained
so that it works more sensibly when either ipv4 or ipv6 is
disabled on the server. Only the protocols that are actually
used by the virtual network have errors reported.
Reviewed-by: Andrea Bolognani <abologna@redhat.com>
Signed-off-by: Daniel 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: Daniel 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: Erik Skultety <eskultet@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Most of the iptables APIs share code for the add/delete paths, but a
couple were separated. Merge the remaining APIs to facilitate future
changes.
Reviewed-by: Laine Stump <laine@laine.org>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
All of the ones being removed are pulled in by internal.h. The only
exception is sanlock which expects the application to include <stdint.h>
before sanlock's headers, because sanlock prototypes use fixed width
int, but they don't include stdint.h themselves, so we have to leave
that one in place.
Signed-off-by: Erik Skultety <eskultet@redhat.com>
Acked-by: Michal Privoznik <mprivozn@redhat.com>
It doesn't really make sense for us to have stdlib.h and string.h but
not stdio.h in the internal.h header.
Signed-off-by: Erik Skultety <eskultet@redhat.com>
Acked-by: Michal Privoznik <mprivozn@redhat.com>
By making use of GNU C's cleanup attribute handled by the
VIR_AUTOFREE macro for declaring scalar variables, majority
of the VIR_FREE calls can be dropped, which in turn leads to
getting rid of most of our cleanup sections.
Signed-off-by: Sukrit Bhatnagar <skrtbhtngr@gmail.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>
We include the file in plenty of places. This is mostly due to
historical reasons. The only place that needs something from the
header file is storage_backend_fs which opens _PATH_MOUNTED. But
it gets the file included indirectly via mntent.h. At no other
place in our code we need _PATH_.*. Drop the include and
configure check then.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
A previous commit introduced use of locking with invocation
of iptables in the viriptables.c module
commit ba95426d6f
Author: Serge Hallyn <serge.hallyn@ubuntu.com>
Date: Fri Nov 1 12:36:59 2013 -0500
util: use -w flag when calling iptables
This only ever had effect with the virtual network driver,
as it was not wired up into the nwfilter driver. Unfortunately
in the firewall refactoring the use of the -w flag was
accidentally lost.
This patch introduces it to the virfirewall.c module so that
both the virtual network and nwfilter drivers will be using
it. It also ensures that the equivalent --concurrent flag
to ebtables is used.
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: Daniel P. Berrange <berrange@redhat.com>
Any source file which calls the logging APIs now needs
to have a VIR_LOG_INIT("source.name") declaration at
the start of the file. This provides a static variable
of the virLogSource type.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Commit b9dd878f caused a regression in iptables interaction by
logging non-zero status at a higher level than VIR_INFO. Revert
that portion of the commit, as well as adding a comment explaining
why we check the status ourselves.
Reported by Nehal J Wani.
* src/util/viriptables.c (virIpTablesOnceInit): Undo log regression.
Signed-off-by: Eric Blake <eblake@redhat.com>
Auditing all callers of virCommandRun and virCommandWait that
passed a non-NULL pointer for exit status turned up some
interesting observations. Many callers were merely passing
a pointer to avoid the overall command dying, but without
caring what the exit status was - but these callers would
be better off treating a child death by signal as an abnormal
exit. Other callers were actually acting on the status, but
not all of them remembered to filter by WIFEXITED and convert
with WEXITSTATUS; depending on the platform, this can result
in a status being reported as 256 times too big. And among
those that correctly parse the output, it gets rather verbose.
Finally, there were the callers that explicitly checked that
the status was 0, and gave their own message, but with fewer
details than what virCommand gives for free.
So the best idea is to move the complexity out of callers and
into virCommand - by default, we return the actual exit status
already cleaned through WEXITSTATUS and treat signals as a
failed command; but the few callers that care can ask for raw
status and act on it themselves.
* src/util/vircommand.h (virCommandRawStatus): New prototype.
* src/libvirt_private.syms (util/command.h): Export it.
* docs/internals/command.html.in: Document it.
* src/util/vircommand.c (virCommandRawStatus): New function.
(virCommandWait): Adjust semantics.
* tests/commandtest.c (test1): Test it.
* daemon/remote.c (remoteDispatchAuthPolkit): Adjust callers.
* src/access/viraccessdriverpolkit.c (virAccessDriverPolkitCheck):
Likewise.
* src/fdstream.c (virFDStreamCloseInt): Likewise.
* src/lxc/lxc_process.c (virLXCProcessStart): Likewise.
* src/qemu/qemu_command.c (qemuCreateInBridgePortWithHelper):
Likewise.
* src/xen/xen_driver.c (xenUnifiedXendProbe): Simplify.
* tests/reconnect.c (mymain): Likewise.
* tests/statstest.c (mymain): Likewise.
* src/bhyve/bhyve_process.c (virBhyveProcessStart)
(virBhyveProcessStop): Don't overwrite virCommand error.
* src/libvirt.c (virConnectAuthGainPolkit): Likewise.
* src/openvz/openvz_driver.c (openvzDomainGetBarrierLimit)
(openvzDomainSetBarrierLimit): Likewise.
* src/util/virebtables.c (virEbTablesOnceInit): Likewise.
* src/util/viriptables.c (virIpTablesOnceInit): Likewise.
* src/util/virnetdevveth.c (virNetDevVethCreate): Fix debug
message.
* src/qemu/qemu_capabilities.c (virQEMUCapsInitQMP): Add comment.
* src/storage/storage_backend_iscsi.c
(virStorageBackendISCSINodeUpdate): Likewise.
Signed-off-by: Eric Blake <eblake@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: Lénaïc 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: Laszlo 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.
These all existed before virfile.c was created, and for some reason
weren't moved.
This is mostly straightfoward, although the syntax rule prohibiting
write() had to be changed to have an exception for virfile.c instead
of virutil.c.
This movement pointed out that there is a function called
virBuildPath(), and another almost identical function called
virFileBuildPath(). They really should be a single function, which
I'll take care of as soon as I figure out what the arglist should look
like.
The source code base needs to be adapted as well. Some files
include virutil.h just for the string related functions (here,
the include is substituted to match the new file), some include
virutil.h without any need (here, the include is removed), and
some require both.
iptables-1.4.18 removed the long deprecated "state" match.
Use "conntrack" instead in forwarding rules.
Fixes openSUSE bug https://bugzilla.novell.com/811251#811251.
We pass over the address/port start/end values many times so we put
them in structs.
Signed-off-by: Natanael Copa <ncopa@alpinelinux.org>
Signed-off-by: Laine 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: Natanael Copa <ncopa@alpinelinux.org>
Signed-off-by: Laine 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: Natanael Copa <ncopa@alpinelinux.org>
Signed-off-by: Laine Stump <laine@laine.org>
Instead of creating an iptables command in one shot, do it in steps
so we can add conditional options like physdev and protocol.
This removes code duplication while keeping existing behaviour.
Signed-off-by: Natanael Copa <ncopa@alpinelinux.org>
Signed-off-by: Eric Blake <eblake@redhat.com>
