PCU-originated SNS-CONFIG contains 127.0.0.1 instead of remote IP
When libosmogb sends the PCU-originated SNS-CONFIG message, it constructs the list of local IP endpoints with one entry. However, this entry always indicates 127.0.0.1 as IP address of the PCU, not the real/external/outward IP address used to contact the SGSN.
See attached PCAP file, packet number 3.
- Status changed from New to In Progress
- % Done changed from 0 to 30
The reason for this is that ns_instance.remote_ip is set to '0' and hence we ask the kernel "from which source IP address would you be sending UDP packets if you wanted to reach 0.0.0.0" to which the kernel responds with 127.0.0.1.
A proposed patch is in https://gerrit.osmocom.org/#/c/libosmocore/+/13293
The problem was not found using our PCU_Tests.ttcn suite as the tests apparently fail to validate the IP address in the pcu-originated SNS-Config.
- % Done changed from 30 to 60
Updated test in https://gerrit.osmocom.org/#/c/osmo-ttcn3-hacks/+/13295/
- Status changed from In Progress to Resolved
- % Done changed from 60 to 100
test and patch merged. When the test was merged first around build #7, almost all tests failed as expected. Once the fix to libosmocore.git was applied, builds passed again from build #9. https://jenkins.osmocom.org/jenkins/view/TTCN3/job/ttcn3-pcu-test-sns/