In GCC 7 there is a new warning triggered when a switch
case has a conditional statement (eg if ... else...) and
some of the code paths fallthrough to the next switch
statement. e.g.

conf/domain_conf.c: In function 'virDomainChrEquals':
conf/domain_conf.c:14926:12: error: this statement may fall through [-Werror=implicit-fallthrough=]
         if (src->targetTypeAttr != tgt->targetTypeAttr)
            ^
conf/domain_conf.c:14928:5: note: here
     case VIR_DOMAIN_CHR_DEVICE_TYPE_CONSOLE:
     ^~~~
conf/domain_conf.c: In function 'virDomainChrDefFormat':
conf/domain_conf.c:22143:12: error: this statement may fall through [-Werror=implicit-fallthrough=]
         if (def->targetTypeAttr) {
            ^
conf/domain_conf.c:22151:5: note: here
     default:
     ^~~~~~~

GCC introduced a __attribute__((fallthrough)) to let you
indicate that this is intentionale behaviour rather than
a bug.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

This resolves: https://bugzilla.redhat.com/1224348

virNetDevTapCreateInBridgePort() has always set the new tap device to
the current MTU of the bridge it's being attached to. There is one
case where we will want to set the new tap device to a different
(usually larger) MTU - if that's done with the very first device added
to the bridge, the bridge's MTU will be set to the device's MTU. This
patch allows for that possibility by adding "int mtu" to the arg list
for virNetDevTapCreateInBridgePort(), but all callers are sending -1,
so it doesn't yet have any effect.

Since the requested MTU isn't necessarily what is used in the end (for
example, if there is no MTU requested, the tap device will be set to
the current MTU of the bridge), and the hypervisor may want to know
the actual MTU used, we also return the actual MTU to the caller (if
actualMTU is non-NULL).

After 478ddedc a bug is fixed where we wrongly presumed loopack
device name on non-Linux systems. It's lo0. However, the fix is
not reflected in the tests which are failing now.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Similarly to localOnly DNS domain, localPtr attribute can be used to
tell the DNS server not to forward reverse lookups for unknown IPs which
belong to the virtual network.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Now that we have a module that's able to track
<domain, mac addres list> pairs, hook it up into
our network driver.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

In dd7bfb2c I've removed locking of the network driver upon
it's allocation. However, I forgot to remove one location of the
driver unlock.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

 On BSD family OSes (Free/Net/Open/DragonFlyBSD, Mac OS) and
 Solaris loopback interface is called 'lo0' instead of just 'lo'.

commit 9065cfaa added the ability to disable DNS services for a
libvirt virtual network. If neither DNS nor DHCP is needed for a
network, then we don't need to start dnsmasq, so code was added to
check for this.

Unfortunately, it was written with a great lack of attention to detail
(I can say that, because I was the author), and the loop that checked
if DHCP is needed for the network would never end if the network had
multiple IP addresses and the first <ip> had no <dhcp> subelement
(which would have contained a <range> or <host> subelement, thus
requiring DHCP services).

This patch rewrites the check to be more compact and (more
importantly) finite.

This bug was present in release 2.2.0 and 2.3.0, so will need to be
backported to any relevant maintainence branches.

Reported here:
  https://www.redhat.com/archives/libvirt-users/2016-October/msg00032.html
  https://www.redhat.com/archives/libvirt-users/2016-October/msg00045.html

New line character in name of network is now forbidden because it
mess virsh output and can be confusing for users.  Validation of
name is done in network driver, after parsing XML to avoid
problems with disappeared network which was already created with
new-line char in name.

Closes-Bug: https://bugzilla.redhat.com/show_bug.cgi?id=818064Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

This way we get reference counting and we can get rid of locking
function.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

The dnsmasq man page recommends that dhcp-authoritative "should be
set when dnsmasq is definitely the only DHCP server on a network".
This is the case for libvirt-managed virtual networks.

The effect of this is that VMs that fail to renew their DHCP lease
in time (e.g. if the VM or host is suspended) will be able to
re-acquire the lease even if it's expired, unless the IP address has
been taken by some other host. This avoids various annoyances caused
by changing VM IP addresses.

Commit id '0b6336c2' formatted the 'addr', but didn't VIR_FREE it.

Found by Coverity.

For some unknown reason the original implementation of the <forwarder>
element only took advantage of part of the functionality in the
dnsmasq feature it exposes - it allowed specifying the ip address of a
DNS server which *all* DNS requests would be forwarded to, like this:

   <forwarder addr='192.168.123.25'/>

This is a frontend for dnsmasq's "server" option, which also allows
you to specify a domain that must be matched in order for a request to
be forwarded to a particular server. This patch adds support for
specifying the domain. For example:

   <forwarder domain='example.com' addr='192.168.1.1'/>
   <forwarder domain='www.example.com'/>
   <forwarder domain='travesty.org' addr='10.0.0.1'/>

would forward requests for bob.example.com, ftp.example.com and
joe.corp.example.com all to the DNS server at 192.168.1.1, but would
forward requests for travesty.org and www.travesty.org to
10.0.0.1. And due to the second line, requests for www.example.com,
and odd.www.example.com would be resolved by the libvirt network's own
DNS server (i.e. thery wouldn't be immediately forwarded) even though
they also match 'example.com' - the match is given to the entry with
the longest matching domain. DNS requests not matching any of the
entries would be resolved by the libvirt network's own DNS server.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1331796

If you define a libvirt virtual network with one or more IP addresses,
it starts up an instance of dnsmasq. It's always been possible to
avoid dnsmasq's dhcp server (simply don't include a <dhcp> element),
but until now it wasn't possible to avoid having the DNS server
listening; even if the network has no <dns> element, it is started
using default settings.

This patch adds a new attribute to <dns>: enable='yes|no'. For
backward compatibility, it defaults to 'yes', but if you don't want a
DNS server created for the network, you can simply add:

   <dns enable='no'/>

to the network configuration, and next time the network is started
there will be no dns server created (if there is dhcp configuration,
dnsmasq will be started with "port=0" which disables the DNS server;
if there is no dhcp configuration, dnsmasq won't be started at all).

The new forward mode 'open' is just like mode='route', except that no
firewall rules are added to assure that any traffic does or doesn't
pass. It is assumed that either they aren't necessary, or they will be
setup outside the scope of libvirt.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=846810

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1181539

IPv6 RA always contains an implicit default route via
the link-local address of the source of RA. This forces
the guest to install a route via isolated network, which
may disturb the guest's networking in case of multiple interfaces.
More info in 013427e6.

The validity of this route is controlled by "default [route] lifetime"
field of RA. If the lifetime is set to 0 seconds, then no route
is installed by receiver.

dnsmasq 2.67+ supports "ra-param=<interface>,<RA interval>,<default
lifetime>" option. We pass "ra-param=*,0,0"
(here, RA_interval=0 means default) to disable default gateway in RA
for isolated networks.

These functions all need to be called from a utility function that
must be located in the util directory, so we move them all into
util/virnetdevip.[ch] now that it exists.

Function and struct names were appropriately changed for the new
location, but all code is unchanged aside from motion and renaming.

This patch splits virnetdev.[ch] into multiple files, with the new
virnetdevip.[ch] containing all the functions related to setting and
retrieving IP-related info for a device (both addresses and routes).

I'm tired of mistyping this all the time, so let's do it the same all
the time (similar to how we changed all "Pci" to "PCI" awhile back).

(NB: I've left alone some things in the esx and vbox drivers because
I'm unable to compile them and they weren't obviously *not* a part of
some API. I also didn't change a couple of variables named,
e.g. "somethingIptables", because they were derived from the name of
the "iptables" command)

Use it instead of opendir everywhere we need to check for ENOENT.

It skips those directory entries.

Introduce a helper that only calls closedir if DIR* is non-NULL
and sets it to NULL afterwards.

Although dns host records are stored in a separate configuration file
that is reread by dnsmasq when it receives a SIGHUP, the txt and srv
records are directly in the dnsmasq .conf file which can't be reread
after initial dnsmasq startup. This means that if an srv or txt record
is modified in a network config, libvirt needs to restart the dnsmasq
process rather than just sending a SIGHUP.

This was pointed out in a question in
https://bugzilla.redhat.com/show_bug.cgi?id=988718 , but no separate
BZ was filed.

This would previously be silently ignored.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1319044

SRIOV VFs used in macvtap passthrough mode can take advantage of the
SRIOV card's transparent vlan tagging. All the code was there to set
the vlan tag, and it has been used for SRIOV VFs used for hostdev
interfaces for several years, but for some reason, the vlan tag for
macvtap passthrough devices was stubbed out with a -1.

This patch moves a bit of common validation down to a lower level
(virNetDevReplaceNetConfig()) so it is shared by hostdev and macvtap
modes, and updates the macvtap caller to actually send the vlan config
instead of -1.

Both instances use VIR_WARN() to print the error from a failed
virDBusGetSystemBus() call.  Rather than use the virGetLastError
and need to check for valid return err pointer, just use the
virGetLastErrorMessage.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

We will segfault of a daemon reload picks up a new network config
that needs to be autostarted. We shouldn't be passing NULL for
network_driver here. This seems like it was missed in the larger
rework in commit 1009a61e

We had both and the only difference was that the latter also included
information about multifunction setting.  The problem with that was that
we couldn't use functions made for only one of the structs (e.g.
parsing).  To consolidate those two structs, use the one in virpci.h,
include that in domain_conf.h and add the multifunction member in it.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

According to the dnsmasq manpage, the netmask for IPv4 address ranges
will be auto-deteremined from the interface dnsmasq is listening on,
but it can't do this for IPv6 for some reason - it instead assumes a
network prefix of 64 for all IPv6 address ranges. If this is
incorrect, dnsmasq will refuse to give out an address to clients,
instead logging this message:

 dnsmasq-dhcp[2380]: no address range available for DHCPv6 request via virbr0

The solution is for libvirt to add ",$prefix" to all IPv6 dhcp-range
arguments when building the dnsmasq.conf file.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1033739

Signed-off-by: NVasiliy Tolstov <v.tolstov@selfip.ru>

There are times when it's necessary to learn the actual type of a
network connection before any resources have been allocated
(e.g. during qemuProcessPrepareDomain()), but in the past it was
necessary to call networkAllocateActualDevice() in order to have the
actual type filled in.

This new function returns the type of network that *will be* setup
once it actually happens, but without making any changes on the host.

networkStartNetwork() and networkShutdownNetwork() were calling the
wrong type-specific function in the case of networks that were
configured for macvtap ("direct") bridge mode - they were instead
calling the functions for a tap+bridge network. Currently none of
these functions does anything (they just return 0) so it hasn't
created any problems, but that could change in the future.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1316465

An attempt to simplify the code for the VIR_NETWORK_FORWARD_BRIDGE
case of networkUpdateState in commit b61db335 (first in release
1.2.14) resulted in networks based on macvtap bridge mode being
erroneously marked as inactive any time libvirtd was restarted.

The problem is that the original code had differentiated between a
network using tap devices to connect to an existing host-bridge device
(forward mode of VIR_NETWORK_FORWARD_BRIDGE and a non-NULL
def->bridge), and one using macvtap bridge mode to connect to any
ethernet device (still forward mode VIR_NETWORK_FORWARD_BRIDGE, but
null def->bridge), but the changed code assumed that all networks with
VIR_NETWORK_FORWARD_BRIDGE were tap + host-bridge networks, so a null
def->bridge was interpreted as "inactive".

This patch restores the original code in networkUpdateState

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: NMichal Privoznik <mprivozn@redhat.com>

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1315059Signed-off-by: NShanzhi Yu <shyu@redhat.com>

There are three functions that deal with allocating and freeing
devices from a networks netdev/pci device pool:
network(Allocate|Notify|Release)ActualDevice(). These functions also
maintain a counter of the number of domains currently using a network
(regardless of whether or not that network uses a device pool). Each
of these functions had multiple log messages (output using VIR_DEBUG)
that were in slightly different formats and gave varying amounts of
information.

This patch creates a single function to log the pertinent information
in a consistent manner for all three of these functions. Along with
assuring that all the functions produce a consistent form of output
(and making it simpler to change), it adds the MAC address of the
domain interface involved in the operation, making it possible to
verify which interface of which domain the operation is being done for
(assuming that all MAC addresses are unique, of course).

All of these messages are raised from DEBUG to INFO, since they don't
happen that often (once per interface per domain/libvirtd start or
domain stop), and can be very informative and helpful - eliminating
the need to log debug level messages makes it much easier to sort
these out.

networkReleaseActualDevice() and networkNotifyActualDevice() both were
updating the individual devices' connections count in two separate
places (unlike networkAllocateActualDevice() which does it in a single
unified place after success:). The code is correct, but prone to
confusion / later breakage. All of these updates are anyway located at
the end of if/else clauses that are (with the exception of a single
VIR_DEBUG() in each case) immediately followed by the success: label
anyway, so this patch replaces the duplicated ++/-- instructions with
a single ++/-- inside a qualifying "if (dev)" down below success:.
(NB: if dev != NULL, by definition we are using a device (either pci
or netdev, doesn't matter for these purposes) from the network's pool)

The VIR_DEBUG args (which will be replaced in a followup patch anyway)
were all adjusted to account for the connection count being out of
date at the time.

And use the newly added caps->host.netprefix (if it exists) for
interface names that match the autogenerated target names.
Signed-off-by: NJoao Martins <joao.m.martins@oracle.com>