Issue with ASN1 BIT STRING type

[bedrankara]

Hi, first of all thank you for providing this helpful tool.

I currently encounter an issue when looking at the decoded output of elements in S1AP (F1AP, NGAP) that are based on the BIT STRING type.

Here an example snippet of a decoded S1AP PDU:

transport_layer_address: TransportLayerAddress(
                                                        BitVec<u8, bitvec::order::Msb0> {
                                                            addr: 0x00005640288a4050,
                                                            head: 000,
                                                            bits: 32,
                                                            capacity: 64,
                                                        } [

Here is the Hex string of the S1AP message that I try to decode:

00090080c50000060000000200070008000200970042000a1805c81a406002cd29c0001800770000340072450009270f80ac100a650000000763277efa7b4f0207420149062000f1100001003d5201c101090908696e7465726e65740501ac11f1ff5e04fefe9b6927208080211003010010810608080808830608080404000d04080808080010020578500bf600f1100001011a984cf8172164020000006b000518000c0000004900200409ae936c4af5643f94a220c336c6354eb82331071245bb367a3b8fcca4c596

[gabhijit]

@bedrankara : Can you please provide what exactly is the issue? If I understand correctly - it's the display format of the bitvec that is the issue? Or somewhere decoding is broken?

[bedrankara]

I was wondering whether there was some issues in the decoding because the display format was showing me the element as the bitvec . However, if that is just the way it is displayed, then that was a misunderstanding from my side.

[gabhijit]

Actually it's unlikely that an issue with decoding will not result in a CodecError during decode. So per se that's not the problem, I believe. However, as you have pointed out, the displayed information is not very useful if it doesn't actually show the bitvec. I quickly checked, the individual bits in the bitvec are shown. For example here's an output from the NGAP decode in one of the test cases.

 ng_enb_id: MacroNgENB_ID(
                                                NgENB_ID_macroNgENB_ID(
                                                    BitVec<u8, bitvec::order::Msb0> {
                                                        addr: 0x0000564378a3fe40,
                                                        head: 000,
                                                        bits: 20,
                                                        capacity: 64,
                                                    } [
                                                        0,
                                                        0,
                                                        0,
                                                        0,
                                                        0,
                                                        0,
                                                        0,
                                                        0,
                                                        0,
                                                        0,
                                                        0,
                                                        0,
                                                        0,
                                                        0,
                                                        0,
                                                        0,
                                                        0,
                                                        0,
                                                        0,
                                                        0,
                                                    ],
                                                ),
                                            ),

So this is at-least giving useful information. I was also thinking if this could be simplified to simply display a bitstring like 000..1..0b. But right now I guess it's okay. Makes sense?

[bedrankara]

Yes makes sense, thanks for the quick response!