If someone has updated a network to change its bridge name, but the
network is still active (so that bridge name hasn't taken effect yet),
we still want to disallow another network from taking that new name.

We already check that any auto-assigned bridge device name for a
virtual network (e.g. "virbr1") doesn't conflict with the bridge name
for any existing libvirt network (via virNetworkSetBridgeName() in
conf/network_conf.c).

We also want to check that the name doesn't conflict with any bridge
device created on the host system outside the control of libvirt
(history: possibly due to the ploriferation of references to libvirt's
bridge devices in HOWTO documents all around the web, it is not
uncommon for an admin to manually create a bridge in their host's
system network config and name it "virbrX"). To add such a check to
virNetworkBridgeInUse() (which is called by virNetworkSetBridgeName())
we would have to call virNetDevExists() (from util/virnetdev.c); this
function calls ioctl(SIOCGIFFLAGS), which everyone on the mailing list
agreed should not be done from an XML parsing function in the conf
directory.

To remedy that problem, this patch removes virNetworkSetBridgeName()
from conf/network_conf.c and puts an identically functioning
networkBridgeNameValidate() in network/bridge_driver.c (because it's
reasonable for the bridge driver to call virNetDevExists(), although
we don't do that yet because I wanted this patch to have as close to 0
effect on function as possible).

There are a couple of inevitable changes though:

1) We no longer check the bridge name during
   virNetworkLoadConfig(). Close examination of the code shows that
   this wasn't necessary anyway - the only *correct* way to get XML
   into the config files is via networkDefine(), and networkDefine()
   will always call networkValidate(), which previously called
   virNetworkSetBridgeName() (and now calls
   networkBridgeNameValidate()). This means that the only way the
   bridge name can be unset during virNetworkLoadConfig() is if
   someone edited the config file on disk by hand (which we explicitly
   prohibit).

2) Just on the off chance that somebody *has* edited the file by hand,
   rather than crashing when they try to start their malformed
   network, a check for non-NULL bridge name has been added to
   networkStartNetworkVirtual().

   (For those wondering why I don't instead call
   networkValidateBridgeName() there to set a bridge name if one
   wasn't present - the problem is that during
   networkStartNetworkVirtual(), the lock for the network being
   started has already been acquired, but the lock for the network
   list itself *has not* (because we aren't adding/removing a
   network). But virNetworkBridgeInuse() iterates through *all*
   networks (including this one) and locks each network as it is
   checked for a duplicate entry; it is necessary to lock each network
   even before checking if it is the designated "skip" network because
   otherwise some other thread might acquire the list lock and delete
   the very entry we're examining. In the end, permitting a setting of
   the bridge name during network start would require that we lock the
   entire network list during any networkStartNetwork(), which
   eliminates a *lot* of parallelism that we've worked so hard to
   achieve (it can make a huge difference during libvirtd startup). So
   rather than try to adjust for someone playing against the rules, I
   choose to instead give them the error they deserve.)

3) virNetworkAllocateBridge() (now removed) would leak any "template"
   string set as the bridge name. Its replacement
   networkFindUnusedBridgeName() doesn't leak the template string - it
   is properly freed.

In the order of appearance:

* MAX_LISTEN - never used
  added by 23ad665c (qemud) and addec57 (lock daemon)

* NEXT_FREE_CLASS_ID - never used, added by 07d1b6b5

* virLockError - never used, added by eb8268a4

* OPENVZ_MAX_ARG, CMDBUF_LEN, CMDOP_LEN
  unused since the removal of ADD_ARG_LIT in d8b31306

* QEMU_NB_PER_CPU_STAT_PARAM - unused since 897808e7

* QEMU_CMD_PROMPT, QEMU_PASSWD_PROMPT - unused since 1dc10a7b

* TEST_MODEL_WORDSIZE - unused since c25c18f7

* TEMPDIR - never used, added by 714bef5b

* NSIG - workaround around old headers
  added by commit 60ed1d2a
  unused since virExec was moved by commit 02e86910

* DO_TEST_PARSE - never used, added by 9afa0060

* DIFF_MSEC, GETTIMEOFDAY - unused since eee6eb66

This function does not make any sense now, that network driver is
(almost) dropped. I mean, previously, when threads were
serialized, this function was there to check, if no other network
with the same name or UUID exists. However, nowadays that threads
can run more in parallel, this function is useless, in fact it
gives misleading return values. Consider the following scenario.
Two threads, both trying to define networks with same name but
different UUID (e.g. because it was generated during XML parsing
phase, whatever). Lets assume that both threads are about to call
networkValidate() which immediately calls
virNetworkObjIsDuplicate().

T1: calls virNetworkObjIsDuplicate() and since no network with
given name or UUID exist, success is returned.
T2: calls virNetworkObjIsDuplicate() and since no network with
given name or UUID exist, success is returned.

T1: calls virNetworkAssignDef() and successfully places its
network into the virNetworkObjList.
T2: calls virNetworkAssignDef() and since network with the same
name exists, the network definition is replaced.

Okay, this is mainly because virNetworkAssignDef() does not check
whether name and UUID matches. Well, lets make it so! And drop
useless function too.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

This patch turns both virNetworkObjFindByUUID() and
virNetworkObjFindByName() to return an referenced object so that
even if caller unlocks it, it's for sure that object won't
disappear meanwhile. Especially if the object (in general) is
locked and unlocked during the caller run.
Moreover, this commit is nicely small, since the object unrefing
can be done in virNetworkObjEndAPI().
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Every API that touches internal structure of the object must lock
the object first. Not every API that has the object as an
argument needs to do that though. Some APIs just pass the object
to lower layers which, however, must lock the object then. Look
at the code, you'll get my meaning soon.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

This is going to be needed later, when some functions already
have the virNetworkObjList object already locked and need to
lookup a object to work on. As an example of such function is
virNetworkAssignDef(). The other use case might be in
virNetworkObjListForEach() callback.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Later we can turn APIs to lock the object if needed instead of
relying on caller to mutually exclude itself (probably done by
locking a big lock anyway).
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

This is practically copy of qemuDomObjEndAPI. The reason why is
it so widely available is to avoid code duplication, since the
function is going to be called from our bridge driver, test
driver and parallels driver too.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

So far it's just a structure which happens to have 'Obj' in its
name, but otherwise it not related to virObject at all. No
reference counting, not virObjectLock(), nothing.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Undefining a running, autostarted domain removes the autostart link, but
dom->autostart is not cleared. If the domain is subsequently redefined,
libvirt thinks it is already autostarted and will not create the link
even if requested:

  # virsh dominfo example | grep Autostart
  Autostart:      enable

  # ls /etc/libvirt/qemu/autostart/example.xml
  /etc/libvirt/qemu/autostart/example.xml

  # virsh undefine example
  Domain example has been undefined

  # virsh define example.xml
  Domain example defined from example.xml

  # virsh dominfo example | grep Autostart
  Autostart:      enable

  # virsh autostart example
  Domain example marked as autostarted

  # ls /etc/libvirt/qemu/autostart/example.xml
  ls: cannot access /etc/libvirt/qemu/autostart/example.xml: No such file or directory

This commit ensures dom->autostart is cleared whenever the config and
autostart link (if present) are removed.

The bridge network driver cleared this flag itself in networkUndefine.
This commit moves this into virNetworkDeleteConfig for symmetry with
virDomainDeleteConfig, and to ensure it is not missed in future network
drivers.
Signed-off-by: NMichael Chapman <mike@very.puzzling.org>

Now that all the code uses accessors, don't expose the structure
anyway.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Well, one day this will be self-locking object, but not today.
But lets prepare the code for that! Moreover,
virNetworkObjListFree() is no longer needed, so turn it into
virNetworkObjListDispose().
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

The API will iterate over the list of network object and remove
desired ones from it.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

An accessor following pattern laid out by virDomainObjList* APIs.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

An accessor following pattern laid out by virDomainObjList* APIs.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

This API will be used in the future to call passed callback over
each network object in the list. It's slightly different to its
virDomainObjListForEach counterpart, because virDomainObjList
uses a hash table to store domain object, while virNetworkObjList
uses an array.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

It's returning virNetworkObjPtr after all. And it matches the
pattern laid out by domain_conf.h.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

It's returning virNetworkObjPtr after all. And it matches the
pattern laid out by domain_conf.h.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Instead of copying the whole object onto stack when calling the
function, just pass the pointer to the object and save up some
space on the stack. Moreover, this prepares the code to hide the
virNetworkObjList structure into network_conf.c and use accessors
only.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

All of our vir*Free() functions should accept NULL, even though
that there's no way of actually passing NULL with current code.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

This is probably a copy-paste error from virDomainObj*
counterpart.  But when speaking of virNetworkObj we should use
variable @nets for an array of networks, rather than @doms. It's
just confusing.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

In virNetworkDHCPHostDefParseXML an error is reported
when partialOkay == true, and none of ip, mac, name
were supplied.

Add the missing goto and error out in this case.

https://bugzilla.redhat.com/show_bug.cgi?id=1196503

We already check whether the host id is valid or not, add a jump
to forbid invalid host id.
Signed-off-by: NLuyao Huang <lhuang@redhat.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

https://bugzilla.redhat.com/show_bug.cgi?id=1151942

While the restriction doesn't have origin in any RFC, it matters
to us while constructing the dnsmasq config file (or command line
previously). For better picture, this is how the corresponding
part of network XML look like:

  <dns>
    <forwarder addr='8.8.4.4'/>
    <txt name='example' value='example value'/>
  </dns>

And this is how the config file looks like then:

  server=8.8.4.4
  txt-record=example,example value

Now we can see why there can't be any commas in the TXT name.
They are used by dnsmasq to separate @name and @value.

Funny, we have it in the documentation, but the code (which was
pushed back in 2011) didn't reflect that.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

The function that parses the <forward> subelement of a network used to
fail/log an error if the network definition contained both a <pf>
element as well as at least one <interface> or <address> element. That
check was present because the configuration of a network should have
either one <pf>, one or more <interface>, or one or more <address>,
but never combinations of multiple kinds.

This caused a problem when libvirtd was restarted with a network
already active - when a network with a <pf> element is started, the
referenced PF (Physical Function of an SRIOV-capable network card) is
checked for VFs (Virtual Functions), and the <forward> is filled in
with a list of all VFs for that PF either in the form of their PCI
addresses (a list of <address>) or their netdev names (a list of
<interface>); the <pf> element is not removed though. When libvirtd is
restarted, it parses the network status and finds both the original
<pf> from the config, as well as the list of either <address> or
<interface>, fails the parse, and the network is not added to the
active list. This failure is often obscured because the network is
marked as autostart so libvirt immediately restarts it.

It seems odd to me that <interface> and <address> are stored in the
same array rather than keeping two separate arrays, and having
separate arrays would have made the check much simpler. However,
changing to use two separate arrays would have required changes in
more places, potentially creating more conflicts and (more
importantly) more possible regressions in the event of a backport, so
I chose to keep the existing data structure in order to localize the
change.

It appears that this problem has been in the code ever since support
for <pf> was added (0.9.10), but until commit
34cc3b2f (first in libvirt 1.2.4)
networks with interface pools were not properly marked as active on
restart anyway, so there is no point in backporting this patch any
further than that.

This adds a new "localOnly" attribute on the domain element of the
network xml.  With this set to "yes", DNS requests under that domain
will only be resolved by libvirt's dnsmasq, never forwarded upstream.

This was how it worked before commit f69a6b98, and I found that
functionality useful.  For example, I have my host's NetworkManager
dnsmasq configured to forward that domain to libvirt's dnsmasq, so I can
easily resolve guest names from outside.  But if libvirt's dnsmasq
doesn't know a name and forwards it to the host, I'd get an endless
forwarding loop.  Now I can set localOnly="yes" to prevent the loop.
Signed-off-by: NJosh Stone <jistone@redhat.com>

Moving code for parsing and formatting network routes to
networkcommon_conf helps reusing those routes for domains. The route
definition has been hidden to help reducing the number of unnecessary
checks in the format function.

https://bugzilla.redhat.com/show_bug.cgi?id=1182486

When updating a network and adding new ip-dhcp-host entry, the deamon
may crash. The problem is, we iterate over existing <host/> entries
trying to compare MAC addresses to see if there's already an existing
rule. However, not all entries are required to have MAC address. For
instance, the following is perfectly valid entry:

<host id='00:04:58:fd:e4:15:1b:09:4c:0e:09:af:e4:d3:8c:b8:ca:1e'
name='redhatipv6.redhat.com' ip='2001:db8:ca2:2::119'/>

When the checking loop iterates over this, the entry's MAC address is
accessed directly. Well, the fix is obvious - check if the address is
defined before trying to compare it.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

There's this function virNetDevBandwidthParse which parses the
bandwidth XML snippet. But it's not clever much. For the
following XML it allocates the virNetDevBandwidth structure even
though it's completely empty:

    <bandwidth>
    </bandwidth>

Later in the code there are some places where we check if
bandwidth was set or not. And since we obtained pointer from the
parsing function we think that it is when in fact it isn't.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

This resolves: https://bugzilla.redhat.com/show_bug.cgi?id=907779

A <dhcp> element can exist in only one IPv4 address and one IPv6
address per network.  This patch enforces that in virNetworkUpdate.

The macTableManager attribute of a network's bridge subelement tells
libvirt how the bridge's MAC address table (used to determine the
egress port for packets) is managed. In the default mode, "kernel",
management is left to the kernel, which usually determines entries in
part by turning on promiscuous mode on all ports of the bridge,
flooding packets to all ports when the correct destination is unknown,
and adding/removing entries to the fdb as it sees incoming traffic
from particular MAC addresses.  In "libvirt" mode, libvirt turns off
learning and flooding on all the bridge ports connected to guest
domain interfaces, and adds/removes entries according to the MAC
addresses in the domain interface configurations. A side effect of
turning off learning and unicast_flood on the ports of a bridge is
that (with Linux kernel 3.17 and newer), the kernel can automatically
turn off promiscuous mode on one or more of the bridge's ports
(usually only the one interface that is used to connect the bridge to
the physical network). The result is better performance (because
packets aren't being flooded to all ports, and can be dropped earlier
when they are of no interest) and slightly better security (a guest
can still send out packets with a spoofed source MAC address, but will
only receive traffic intended for the guest interface's configured MAC
address).

The attribute looks like this in the configuration:

  <network>
    <name>test</name>
    <bridge name='br0' macTableManager='libvirt'/>
    ...

This patch only adds the config knob, documentation, and test
cases. The functionality behind this knob is added in later patches.

Partially reverts commit 5754dbd5.

The code in the specfile adds a MAC address to every <bridge>,
even for <forward mode='bridge'> for which we don't support
changing MAC addresses.

Remove it completely. For new networks, we have been adding
MAC addresses on definition/creation since the commit mentioned above.
For existing networks (pre-0.9.0), the MAC is added by this commit.

https://bugzilla.redhat.com/show_bug.cgi?id=1156367

Libvirt's RPMs have been adding it to networks which don't support it.

https://bugzilla.redhat.com/show_bug.cgi?id=1156367

The function virNetworkObjListExport() in network_conf.c had a call to
the public API virNetworkFree() which was causing a link error:

CCLD     libvirt_driver_vbox_network_impl.la
 ./.libs/libvirt_conf.a(libvirt_conf_la-network_conf.o): In function `virNetworkObjListExport':
/home/laine/devel/libvirt/src/conf/network_conf.c:4496: undefined reference to `virNetworkFree'

This would happen when I added

  #include "network_conf.h"

into domain_conf.h, then attempted to call a new function from that
file (and enum converter, similar to virNetworkForwardTypeToString())

In the end, virNetworkFree() ends up just calling virObjectUnref(obj)
anyway (after clearing all pending errors, which we probably *don't*
want to do in the cleanup of a utility function), so this is likely
more correct than the original code as well.

Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

This new attribute will control whether or not libvirt will pay
attention to guest notifications about changes to network device mac
addresses and receive filters. The default for this is 'no' (for
security reasons). If it is set to 'yes' *and* the specified device
model and connection support it (currently only macvtap+virtio) then
libvirt will watch for NIC_RX_FILTER_CHANGED events, and when it
receives one, it will issue a query-rx-filter command, retrieve the
result, and modify the host-side macvtap interface's mac address and
unicast/multicast filters accordingly.

The functionality behind this attribute will be in a later patch. This
patch merely adds the attribute to the top-level of a domain's
<interface> as well as to <network> and <portgroup>, and adds
documentation and schema/xml2xml tests. Rather than adding even more
test files, I've just added the net attribute in various applicable
places of existing test files.

When spanning tree protocol is allowed in bridge settings, forward delay
value is set as well (default is 0 if omitted). Until now, there was no
check for delay value validity. Delay makes sense only as a positive
numerical value.

Note: However, even if you provide positive  numerical value, brctl
utility only uses values from range <2,30>, so the number provided can
be modified (kernel most likely) to fall within this range.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1125764

The code compares def->forwarders when deciding to return 0 at a
couple of points, then uses "def->nfwds" as a way to index into
the def->forwarders array.  That reference results in Coverity
complaining that def->forwarders being NULL was checked as part
of an arithmetic OR operation where failure could be any one 5
conditions, but that is not checked when entering the loop to
dereference the array.  Changing the comparisons to use nfwds
will clear the warnings
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>