This commit resolves undefined behaviour runtime errors related
to misaligned memory access. E.g.
> openair3/NAS/COMMON/IES/FGSMobileIdentity.c:193:3:
> runtime error: store to misaligned address 0x608000021e2b for type 'uint16_t',
> which requires 2 byte alignment 0x608000021e2b: note: pointer points here 00 f1 ...
* ENCODE_U24: safely encode 24-bit values into a buffer
by using memcpy to copy 3 bytes in network byte order (big-endian).
* ENCODE_U16: safely encodes a 16-bit value into a buffer, handling
misalignment by memcpy 2 bytes to buffer in network byte order (big-endian).
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.
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.
The main work of this commit is to rewrite cipher_aes_128_cbc_cmac()
which was too slow and created issues when running the 4G eNB on some
machines (LLL when using a b210).
Instead of creating the security context, use it, and delete it, all in
cipher_aes_128_cbc_cmac(), we introduce the function init_aes_128_cbc_cmac()
to create it, and we change cipher_aes_128_cbc_cmac() to just use it,
and we also adapt free_aes_128_cbc_cmac(). The function aes_128_cbc_cmac()
is removed, it does not follow the new init/use/free API.
Doing so, on the primary test machine used to do this work (a powerful
and fast machine where it is possible to set the CPUs' frequencies)
it was possible to limit the CPUs' frequencies to 500 MHz (it was not
possible to go lower) without any LLL (using a b210, quectel UE in
idle, no data traffic, only periodic measurement reports). Before this
commit, it was necessary to set a frequency of at least 1.8 GHz
otherwise some LLL would appear.
Then we need to adapt the rest of the code to take into account those
changes.
A notion of security container (stream_security_container_t) containing
ciphering and integrity contexts is introduced.
And the code is harmonized for, hopefully, better readability.
The (opaque) type stream_security_context_t is introduced, used by
both integrity and ciphering contexts. The idea is to use a
init()/use()/free() API for all the security procedures, identical for
all the ciphering and integrity procedures.
remove several unused files
remove mem_block_t that is never used in a different way than a simple heap buffer
move up IP address type and remove duplications of the same struct declaration
Before this commit each time the message was captured, it entered the
default switch statement, which is meant to show that we received an
uknown IEI.
Now after the DNN IEI, we set offset=msg_length, to exit the
switch.
Guido Casati