fasferraz/enb

eNB s1 Emulator - S1AP and S1-U interfaces.

Hi there 👋

• 🔭 I’m currently working on almost everything ...
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Next project: gNB application similar to my eNB application, but for 5G.

enb's Issues

User plane not working (GTP-U)

Dear @fasferraz

Everything works great up until the point I try to send some IP data across the GTP-U tunnel (towards the SGW).

S1 setup succeeds
Attach succeeds

2022-12-27 18:56:03.207215: S1AP: sending S1SetupRequest                                                    |
2022-12-27 18:56:03.217254: S1AP: S1SetupResponse received                                                  |
2022-12-27 18:56:04.751138: S1AP: sending InitialUEMessage                                                  |
2022-12-27 18:56:04.857392: S1AP: DownlinkNASTransport received                                             |
2022-12-27 18:56:04.860707: NAS: AuthenticatonRequest received                                              |
2022-12-27 18:56:04.865603: S1AP: sending UplinkNASTransport                                                |
2022-12-27 18:56:04.875660: S1AP: DownlinkNASTransport received                                             |
2022-12-27 18:56:04.878713: NAS: SecurityMode received                                                      |
2022-12-27 18:56:04.928814: NAS: sending SecurityModeComplete                                               |
2022-12-27 18:56:04.931396: S1AP: sending UplinkNASTransport                                                |
2022-12-27 18:56:05.039040: S1AP: InitialContextSetupRequest received                                       |
2022-12-27 18:56:05.041977: S1AP: sending InitialContextSetupResponse                                       |
2022-12-27 18:56:05.044763: NAS: AttachAccept received                                                      |
2022-12-27 18:56:05.047482: [('apn', 'dyn.delta')]                                                          |
2022-12-27 18:56:05.050234: [('pdn type value', 1), ('ipv4', '10.45.0.4')]                                  |
2022-12-27 18:56:05.057832: [('type of identity', 6), ('mcc', 101), ('mnc', 10), ('mme group id', 100), ('m |
2022-12-27 18:56:05.057832: me code', 101), ('m-tmsi', 69), ('s-tmsi', b'e\x00\x00\x00E')]                  |
2022-12-27 18:56:05.060878: NAS: sending AttachComplete                                                     |
2022-12-27 18:56:05.101081: S1AP: sending UplinkNASTransport     

After this, a tun1 named interface is already present with IP 10.45.0.4 set.

I add the proper route back: ip route add 10.45.0.0/24 dev tun1

When I try to ping 10.45.0.1 (the SGW side) no response is coming back, tshark records ICMP requests outside of the tunnel:

Capturing on 'tun1'
    1 0.000000000    10.45.0.4 → 10.45.0.1    ICMP 84 Echo (ping) request  id=0x0004, seq=122/31232, ttl=64
    2 1.023971084    10.45.0.4 → 10.45.0.1    ICMP 84 Echo (ping) request  id=0x0004, seq=123/31488, ttl=64
    3 2.047980988    10.45.0.4 → 10.45.0.1    ICMP 84 Echo (ping) request  id=0x0004, seq=124/31744, ttl=64
    4 3.071968997    10.45.0.4 → 10.45.0.1    ICMP 84 Echo (ping) request  id=0x0004, seq=125/32000, ttl=64
    5 4.095967761    10.45.0.4 → 10.45.0.1    ICMP 84 Echo (ping) request  id=0x0004, seq=126/32256, ttl=64

When I try to ping 10.45.0.4 from the SGW, the GTP-U encapsulated packets are arriving correctly, but no response:

Capturing on 'ens18'
    1 0.000000000 10.253.250.51 → 10.253.250.221 GTP 54 Echo request
    2 0.000388885 10.253.250.221 → 10.253.250.51 GTP 56 Echo response
    3 0.577967074    10.45.0.1 → 10.45.0.4    GTP <ICMP> 134 Echo (ping) request  id=0x1a28, seq=1/256, ttl=64
    4 1.579006583    10.45.0.1 → 10.45.0.4    GTP <ICMP> 134 Echo (ping) request  id=0x1a28, seq=2/512, ttl=64
    5 2.579048708    10.45.0.1 → 10.45.0.4    GTP <ICMP> 134 Echo (ping) request  id=0x1a28, seq=3/768, ttl=64
    6 3.580070569    10.45.0.1 → 10.45.0.4    GTP <ICMP> 134 Echo (ping) request  id=0x1a28, seq=4/1024, ttl=64
    7 4.580065463    10.45.0.1 → 10.45.0.4    GTP <ICMP> 134 Echo (ping) request  id=0x1a28, seq=5/1280, ttl=64

Seemingly every works a it should, the routes are correct, IPs are correct, yet the userplane part is not passing.

Firewall is disabled on both sides, IP_forwarding is enabled on both sides.

erroring out with plmn 001001 or 00101

when using with plmn 001001 or with plmn 00101 i get following error:

Returning PLMN from: 001001
Traceback (most recent call last):
  File "/home/admin/eNB/eNB_LOCAL.py", line 2704, in <module>
    main()
  File "/home/admin/eNB/eNB_LOCAL.py", line 2630, in main
    session_dict = session_dict_initialization(session_dict)
  File "/home/admin/eNB/eNB_LOCAL.py", line 188, in session_dict_initialization
    session_dict['ENCODED-GUTI'] = eNAS.encode_guti(int(session_dict['PLMN']),32769,1,12345678)
  File "/home/admin/eNB/eNAS.py", line 1156, in encode_guti
    guti += unhexlify(mcc_mnc[1] + mcc_mnc[0] + mcc_mnc[5] +mcc_mnc[2]+ mcc_mnc[4]+ mcc_mnc[3])
IndexError: string index out of range

to resolve it i added before line 1155:
if len(mcc_mnc) == 3: mcc_mnc += 'f'
if len(mcc_mnc) == 4: mcc_mnc += 'f'

diff:

index 05fe379..221742d 100644
--- a/eNAS.py
+++ b/eNAS.py
@@ -1152,6 +1152,8 @@ def encode_guti(mcc_mnc, mme_group_id, mme_code, m_tmsi):
     guti = b'\xf6'
     mcc_mnc = str(mcc_mnc)

+    if len(mcc_mnc) == 3: mcc_mnc += 'f'
+    if len(mcc_mnc) == 4: mcc_mnc += 'f'
     if len(mcc_mnc) == 5: mcc_mnc += 'f'
     guti += unhexlify(mcc_mnc[1] + mcc_mnc[0] + mcc_mnc[5] +mcc_mnc[2]+ mcc_mnc[4]+ mcc_mnc[3])
     guti += struct.pack("!H", mme_group_id)

PS thank you for your awesome code

PLMN Encoding Fix

Hey @fasferraz ,

Here is what the code was before:
return bcd(mccmnc[0] + mccmnc[1] + mccmnc[2] + mccmnc[3] + mccmnc[4] + mccmnc[5])

With that when I input 315123 (MCC 315 MNC 123) the pLMNidentity: comes back as 133521 which is MCC 315 / MNC 312

With the change I made yesterday, when I input 315123 (MCC 315 MNC 123) I get back 313532 which is MCC 315 MNC 123.

And here's the change:
return bcd(mccmnc[0] + mccmnc[1] + mccmnc[2] + mccmnc[3] + mccmnc[4] + mccmnc[5])

Let me know if I've missed something or if you think the encoding I've got is invalid,

YAML config file support

YAML file with default values and include support for multiple:
IMSI

• IMEI
• OPc / OP / Ki

eNodeB

• TAC List
• eNB ID
• PCI

With the view of having support for multiple eNodeBs and UEs, so you can test connecting multiple UEs to an eNodeB, and handing over between eNodeBs in a future release.

Will start working on this.

Handle multiple users

scope of this ticket to create multiple users to attach and run traffic