5G NR F1AP RRC_Version.iE_Extensions encoding/decoding error

[ruffyontheweb]

Hi everyone. I've run across a strange condition that seems to be an encoding/decoding error when attempting to encode or decode the F1_Setup_Request message. The message works fine unless the optional RRC_Version.iE_Extensions is included. A bitstream of what is generated vs what is expected is below

expected: 00010080be000005004e00020000002a0003200258002d400d050054657261564d2d44552d31002c00808a0000002b0080834800021700000004001000010000010802170000000083400400000020410009bf8800004d0027000c1030000001000081ec0002000003020328489200000c240f10000000101000004001a4213401800009a59c32cd7e646e080400030010000820c04200000134b9c32cc89940001c29afbc0090b854070e8041603b0091b3da30a000ab000af0000000c740030f0600

generated: 00010080dd000005004e00020000002a0003200258002d400d050054657261564d2d44552d31002c0080a80000002b0080a14800021700000004001000010000010802170000000083400400000020410009bf8800004d0027000c1030000001000081ec0002000003020328669200000c240f10000000101000004001a4213401800009a59c32cd7e646e080400030010000820c04200000134b9c32cc89940001c29afbc0090b854070e8041603b0091b3da30a048000000000000000000000000000000000000000000000000000000050000ab000bf0000000c74004030f0600

The IE in question is c740030f0600 (correct) vs c74004030f0600 (incorrect). More critically is that the asn1 decoder fails on the expected bitstream, though it does pass on the generated bit stream.

If you put the generated through any online free decoded it will give you an error about the construction f the F1AP-PDU.initiatingMessage.value.F1SetupRequest.protocolIEs.SEQUENCE#5.value.RRC-Version.iE-Extensions.SEQUENCE#1.extensionValue

I've tried master, the latest from oai and @brchiu repo, and have even merged master of vlm/asn1c into latest from the oai fork. Tagging @brchiu who has done some 5G specific work, so tagging in hopes he sees this.