==================== ipv4: icmp: Fix source IP derivation in presence of VRFs
Align IPv4 with IPv6 and in the presence of VRFs generate ICMP error messages with a source IP that is derived from the receiving interface and not from its VRF master. This is especially important when the error messages are "Time Exceeded" messages as it means that utilities like traceroute will show an incorrect packet path.
Patches #1-#2 are preparations.
Patch #3 is the actual change.
Patches #4-#7 make small improvements in the existing traceroute test.
Patch #8 extends the traceroute test with VRF test cases for both IPv4 and IPv6.