[CLATJ#4] libclat: move selectIpv4Address() and isIpv4AddressFree() from netd to apex
isIpv4AddressFree() is moved from ClatdController without behavior
change.
selectIpv4Address() and its test are moved from ClatdController as well.
They have been refactored slightly for testing because function pointer
of isIpv4AddressFreeFunc is not a global variable anymore. We can't set
global function pointer to change selectIpv4Address() behavior for
testing. Instead isIpv4AddressFree is sent as an argument of function
pointer. For public caller, selectIpv4Address() has no behavior change.
For test caller, they can call an internal selectIpv4AddressInternal
(.., fn) to change isIpv4AddrFreeFn function pointer for testing.
Bug: 212345928
Test: build and boot
atest libclat_test
Change-Id: Iab5e6fd5ebbccf10e7b3be2251b45949cf3f3464
3 files changed