virPortAllocatorSetUsed permits to set a port as already used and
prevent the port allocator to use it without any attempt to bind it.
Signed-off-by: NGiuseppe Scrivano <gscrivan@redhat.com>
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

SO_REUSEADDR on Windows is actually akin to SO_REUSEPORT
on Linux/BSD. ie it allows 2 apps to listen to the same
port at once. Thus we must not set it on Win32 platforms

See http://msdn.microsoft.com/en-us/library/windows/desktop/ms740621.aspxSigned-off-by: NDaniel P. Berrange <berrange@redhat.com>

IN6ADDR_ANY_INIT does not seem to be working as expected on MinGW:
error: missing braces around initializer [-Werror=missing-braces]
         .sin6_addr = IN6ADDR_ANY_INIT,

Use the in6addr_any variable instead.

Reported by Daniel P. Berrange.

Also try to bind on IPv6 to check if the port is occupied.

Change the mocked bind in the test to return EADDRINUSE
for some ports only for the IPv4/IPv6 socket if we're testing
on a host with IPv6 compiled in.

Also mock socket() to make it fail with EAFNOTSUPPORTED
if LIBVIRT_TEST_IPV4ONLY is set in the environment, to
simulate a host without IPv6 support in the kernel. The
tests are repeated again with this variable set.

https://bugzilla.redhat.com/show_bug.cgi?id=1025407

Report the error in virPortAllocatorAcquire instead
of doing it in every caller.

The error contains the port range name instead of the intended
use for the port, e.g.:
Unable to find an unused port in range 'display' (65534-65535)
instead of:
Unable to find an unused port for SPICE

This also adds error reporting when the QEMU driver could not
find an unused port for VNC, VNC WebSockets or NBD migration.

This allows its error messages to be more specific.

Convert the type of loop iterators named 'i', 'j', k',
'ii', 'jj', 'kk', to be 'size_t' instead of 'int' or
'unsigned int', also santizing 'ii', 'jj', 'kk' to use
the normal 'i', 'j', 'k' naming
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Whenever virPortAllocatorRelease is called with port == 0, it complains
that the port is not in an allowed range, which is expectable as the
port was never allocated. Let's make virPortAllocatorRelease ignore 0
ports in a similar way free() ignores NULL pointers.

A build on FreeBSD failed with:
util/virportallocator.c:108: error: storage size of 'addr' isn't known
util/virportallocator.c:123: error: 'INADDR_ANY' undeclared (first use in this function)

It turns out that while POSIX allows sockaddr_in to leak in through
<arpa/inet.h> (the way Linux does it), it is not mandatory, and
conforming applications are required to get it through <netinet/in.h>.

* src/util/virportallocator.c: Include header for struct
sockaddr_in.
* tests/virportallocatortest.c: Likewise.

Change iterator variable datatype to int

The QEMU driver default max port is 65535, but it then increments
this by 1 to 65536. This maps to 0 in an unsigned short :-( This
was apparently done so that for() loops could use "< max" instead
of "<= max". Remove this insanity and just make the loop do the
right thing.

Introduce a virPortAllocator for managing TCP port allocations.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>