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Description of problem:
As described in bug 1659269 and bug 1654630 corosync has quite a few problems with reliable resolve of hostname. We used to have a quite good solution which was working most of the time, but it was still not perfect a may require changes in corosync.conf.

Luckily PCS guys were able to come with better solution which will solve both bugs at once without need to edit corosync.conf and forcing ip order.

Steps to Reproduce - problem described in bug 1659269:
1. /etc/hosts contains
1.2.3.4  test-node

2. corosync.conf contains
...
nodelist {
    node {
        ring0_addr: test-node
        name: test-node
        nodeid: 1
    }
...

3. hostname is set to test-node

Actual results:
Corosync will not start as long as:
- ip_version field in corosync.conf is not changed to ipv4
- or ring0_addr: test-node is not replaced by actual ip address
- or "myhostname" is not removed from nsswitch.conf

Problem described in bug 1654630 doesn't happen

Expected results:
1. Corosync will start successfully if conditions for bug 1659269 are configured
2. Problem described in bug 1654630 doesn't reappear

Additional info:

Created attachment 1519878 [details]
2019-01-10-0001-totemip-Use-AF_UNSPEC-for-ipv4-6-and-ipv6-4

totemip: Use AF_UNSPEC for ipv4-6 and ipv6-4

AF_UNSPEC returns different results than AF_INET/AF_INET6, because of
nsswitch.conf search is in order and it stops asking other
modules once current module success.

Example of difference between previous and new code when ipv6-4 is used:
- /etc/hosts contains test_name with an ipv4
- previous code called AF_INET6 where /etc/hosts failed so other methods
were used which may return IPv6 addr -> result was ether fail or IPv6
address.
- new code calls AF_UNSPEC returning IPv4 defined in /etc/hosts ->
result is IPv4 address

New code behavior should solve problems caused by nss-myhostname.

Signed-off-by: Jan Friesse <jfriesse>

Marking verified as this is a dependence of bug 1654630 which is already VERIFIED for this version of corosync-3.0.0-2.el8.