Handle IPv6 (and IPv4v6) PDU sessions by correctly instructing
nas_config() to set up the interface with provided IP addresses.
Note that as of now, IPv6 PDU sessions have not been fully tested.
Remove a useless assert at the gNB; to my understanding the gNB does not
care about the IP session type (at least for IP), as it just
transparently tunnels the IP packets from/to GTP.
I added a comment in the code where to change to request a PDU session
different from IPv4. Currently it is hardcoded to IPv4, and it seems
that a default OAI 5GC config would reject a PDU session type different
from IPv4.
- Read interface flags before setting status to not inadvertently
overwrite existing flags
- Set interface flag point-to-point, remove multicast (I think a UE is
not supposed to send anywhere else than to the UPF, so it seems to not
make sense to declare the interface as multicast)
These rules & route are necessary to properly send packets on oaitun_ue1
interface:
1. This forces the packets coming from a subnet different than the UE's
subnet to go back through oaitun_ue1 rather than via what the default
route defined on the system (e.g., important if ping from the
internet arrives).
2. On machines setting net.ipv4.conf.oaitun_ue1.rp_filter=1 (e.g.
RHEL), this prevents that source filtering for packets coming back is
applied and those packets be dropped. By default, many hosts have
rp_filter=2, so no strict source filtering is applied, and it would
work; on others, this rule prevents source filter dropping.
Prior to this commit, there was a global variable baseNetAddress that
could be set independently through a setter and also through the
configuration module. This baseNetAddress (16 bits IPv4) would then be
complemented with two more bytes in nas_config().
However, this is counter-productive, as not only we have a global
variable that is avoidable (we can give the entire address to
nas_config() directly), but it also would not work with IPv6. Hence,
modify to give nas_config() the entire address. A follow-up commit will
add IPv6 support.
- refactor functions to make them shorter
- provide doxygen strings
- open socket for operation once instead of in each function
- use named constant (from enum) to differentiate interface UP/DOWN
- Linux kernel defines name length as IFNAM_SIZE, so use that for
interface name length. Also, it seems no null-byte is needed.
I initially planned to entirely remove the netmask configuration.
However, in specific configurations, e.g. in 4G Rfsim with feMBMS,
routing does not seem to work anymore using these commands:
iperf -B 10.0.2.2 -s -u -i1
iperf -c 10.0.2.2 -B 10.0.2.1 -u -t 30 -b 2.00M -i1
Therefore, we simplify by hardcoding the netmask to /24, which allows
the above to work.
Remove the broadcast address from the UE, as logically, a UE has nothing
to broadcast: it can only directly talk to the core. Additionally, at
least as of now, the UE interface is shown as "POINTOPOINT", so
broadcasting is not possible.
Does the same change in the _mbms() functions as in the previous commit.
Also, simplify logic in netlink_init_mbms_tun(): directly use the id in
the interface. This requires a slight ID change in the users, which is
also done in this commit.
Instead of implicitly using a hardcoded prefix "oaitun_" interface
name, move that out to the callers of these functions to make it clear.
The ID still remains outside.
The "sister functions" nas_config_mbms()/netlink_init_tun_mbms() will do
the same change in the next commit.
Comparing both functions, it seems that nas_config_mbms_s1() sets the
same parameters, assuming that in nas_config_mbms(), we set
- (UE_NAS_USE_TUN || ENB_NAS_USE_TUN) yielding true -> should yield the
same interface name
- netmask is hardcoded to 255.255.255.0
- baseNetAddress is hardcoded 10.0
So replace the call with nas_config_mbms() by setting parameters
accordingly.
- Remove unused NAS_config(): It does most of what the highly similar
nas_config() does.
- Remove unused set_gateway()
- Remove unused blocking_NAS_config()
- Remove unused functions getNetMask()
- Remove unused broadcast functionality: functions setBroadcastAddress()
and getBroadcastAddress(), as well as global variable broadcastAddr
are not used in consumers. Remove it.
- Make functions static
This assert and assumption is incorrect, according to 38.101-1 UE channel is defined only by the BWP size
and BWP size can be any value supported by the RRC parameters defining the BWP.
To determine the UE channel the smallest bandwidth supporting the BWP is selected. This is an assumption based
on references in the same document to UE channel bandwidth being equal to one of the values in set
{5, 10, 15, 20, 25, 30, 35, 40, 50, 60, 70, 80, 90, 100}.
Also:
- calculated P_CMIN during BWP setup since the parameter doesn't depend on DCI.
- initiialize uniqCfg structure in test_nr_ue_power_procedures main function which enables LOG prints during tests
* aper_decode allocates memory for for local pointer `pdusessionTransfer`, in `decodePDUSessionResourceSetup`
* this memory seems not to be freed but its members are by:
`ASN_STRUCT_FREE_CONTENTS_ONLY(asn_DEF_NGAP_PDUSessionResourceSetupRequestTransfer,pdusessionTransfer);`
which btw in its header says: "AVOID using it in the application code; Use a safer ASN_STRUCT_RESET() instead"
* the following mem leak was detected by ASAN:
```
Direct leak of 72 byte(s) in 1 object(s) allocated from:
*0 0x7ffff74b4a57 in __interceptor_calloc /src/libsanitizer/asan/asan_malloc_linux.cpp:154
*1 0x55555cb306df in SEQUENCE_decode_aper /cmake_targets/ran_build/build/openair2/RRC/LTE/MESSAGES/constr_SEQUENCE_aper.c:36
*2 0x55555ca9fa28 in aper_decode /cmake_targets/ran_build/build/openair2/RRC/LTE/MESSAGES/aper_decoder.c:78
*3 0x55555b99bae6 in decodePDUSessionResourceSetup /openair2/RRC/NR/rrc_gNB_NGAP.c:273
*4 0x55555b99fec2 in trigger_bearer_setup /openair2/RRC/NR/rrc_gNB_NGAP.c:357
*5 0x55555b9b54bf in rrc_gNB_process_NGAP_PDUSESSION_SETUP_REQ /openair2/RRC/NR/rrc_gNB_NGAP.c:830
*6 0x55555b936871 in rrc_gnb_task /openair2/RRC/NR/rrc_gNB.c:2428
*7 0x7ffff5e94ac2 in start_thread nptl/pthread_create.c:442
```
* This commit replaces ASN_STRUCT_FREE_CONTENTS_ONLY with ASN_STRUCT_FREE, which will free the memory allocated for the entire struct and its members
OAI 5GC seems to have a bug, and occasionally might send a PDU session
setup request without having sent a UE context setup request, resulting
in no security context activated for a UE. This lead to an assertion in
rrc_gNB_process_e1_bearer_context_setup_resp().
To prevent the gNB from stopping, check if security is active before
triggering PDU sessions. If not, the gNB will reject PDU sessions.
Remove the secondaryCellGroup variable in RRC, as it is not used there.
Note that in the case of F1, the secondaryCellGroup entirely belongs to
the DU, i.e., MAC. Also, we don't do anything with it in RRC.
The RRC UE context has the RRC UE ID. Use that instead of hardcoding
something that might be wrong (because the RRC UE ID can be reused,
whereas the counter just blindly increases).
The next commit will use that RRC UE ID to free the PDCP context for the
UE. It might be wrong on reattach otherwise, because the RRC UE ID could
again be 1.
Variable spCellConfig is only used in function rrc_add_nsa_user(). Make
it local to this function to prevent possible bugs (limit the possible
scope as much as possible).
Variable reconfig is only used in function rrc_add_nsa_user(). Make it
local to this function to prevent possible bugs (limit the possible
scope as much as possible).
Simplify code by returning an allocated object to a CG_Config. It leads
to less code and is easier to reason about, because each call will
return a new CG_Config, which can be freed, irrespective of other calls
to fill_default_reconfig().
Simplify code by returning an allocated object to an RRCReconfiguration.
It leads to less code and is easier to reason about, because each call
will return a new RRCReconfiguration, which can be freed, irrespective
of other calls to fill_default_reconfig().
get_default_secondaryCellGroup() would "sanitize" the servingCellConfig,
i.e., remove BWP that are invalid. However, it is difficult to
understand (we can do sanitization once at the beginning) and reason
(why the servingCellConfig is modified in
get_default_secondaryCellGroup(), because all we want is a new
CellGroupConfig, without modifying other data structures).
Instead, do sanitization once after reading the configuration in
gnb_config.c. Also, modify physical simulators nr_dlsim and nr_ulsim to
apply this sanitization before a call to
get_default_secondaryCellGroup(), as the latter would have done the
sanitization.
Prior to this commit, upon a release of a UE at the gNB in NSA, the gNB
fails with a segv. This is because the servingCellConfigCommon is used
in the reconfigurationWithSync (through a simple pointer). At the
release, the entire secondaryCellGroup is freed, leading to a free of
the servingCellConfigCommon. The gNB then tries to use it (e.g., for
looking up the numerology), and leading to a segv.
To avoid this problem, make a "deep copy" of the ServingCellConfigCommon
so that we can safely free the UEs secondaryCellGroup, without freeing
the initial ServingCellConfigCommon.
- E2SM UE ID requires guami -> therefore RRC_CONNECTED state signaling
to RIC is now done after receiving Initial Context Setup Request
from AMF, which contains the guami info
- r_amf->plmn_Identity was interpreted incorrectly, therefore remove it
- selected_plmn_identity selects one of the list of PLMNs; at the
moment, OAI supports only 1 PLMN ID; print a warning if it is
different, and proceed with index 0
More information in issue #801
Robert Schmidt