Currently the P-TMSI IE in PAGING_PS is not patched.
This commit adds code to patch BSSGP P-TMSI IE in
gbproxy_patch_bssgp independently from the P-TMSI patching at the LLC
layer. It also extends gbproxy_update_link_state_dl to use the IMSI
to find the link_info if the TLLI is not present in the message.
Note that the spec (GSM 08.18, 7.2) requires to use of the P-TMSI
instead of the IMSI to select the MS if that IE is available.
Nevertheless as long as the IMSI is always present in downlink BSSGP
messages and as long as the optional P-TMSI refers to the same MS
(which is the case currently), this is not an issue.
Sponsored-by: On-Waves ehf
Currently, ptmsi_enc and new_ptmsi_enc point to the beginning of the
mobile identity. Since all P-TMSI in 04.08 (MM) are encoded this way (1
byte header + 4 byte P-TMSI value). This is different to the P-TMSI
encoding in 08.18 (BSSGP), where the P-TMSI is encoded into 4 byte
without MI header.
This patch changes the code to use pointers to the P-TMSI value,
which is encoded in the same way in both specifications.
Sponsored-by: On-Waves ehf
The current implementation makes it difficult to add further match
expressions.
This patch adds a new struct gbproxy_match that contains the fields
needed for each match expression. The matches (config) and the
results (link_info) are stored in arrays. All related functions are
updated to use them. The old fields in the config structure are
removed.
Sponsored-by: On-Waves ehf
Currently in many places where 'tlli' (Temporary Logical Link
Identifier) within identifiers is used, the logical link itself is
meant instead. For instance, the tlli_info contain information about
an LLC logical link including up to four individual TLLI.
To avoid confusion between these concepts, this patch replaces all
'tlli_info' by 'link_info' and a few 'tlli' by 'link'.
Sponsored-by: On-Waves ehf
This patch renames gbproxy_check_tlli() to
gbproxy_imsi_matches() and struct tlli_info's
enable_patching to imsi_matches.
It's meant to be more obvious and consistent this way.
Sponsored-by: On-Waves ehf
Currently when patching is basically enabled P-TMSI and TLLI gets
patched even when P-TMSI patching is not enabled. Albeit the result
is correct in this case (the same value is re-written), the counter
shows unexpected results.
This patch adds configuration checks for P-TMSI and TLLI patching. It
also reorders the code of gbproxy_patch_raid to return early if there
is nothing to patch.
Sponsored-by: On-Waves ehf
Currently the RAI in the LLC part of the message is not updated if
the message has been taken from the list of stored messages. The
reason is, that old_raid_matches is update in
gbprox_process_bssgp_ul() but not in gbproxy_flush_stored_messages().
This patch moves the check to gprs_gb_parse_bssgp() which is called
at both places and where other fields like parse_ctx->tlli are set,
too.
In addition, old_raid_matches is replaced by old_raid_is_foreign
since this is clearer in the case when there is no old RAI at all.
Several RAI patch counter assertions are also added to
test_gbproxy_ra_patching().
Sponsored-by: On-Waves ehf
This patch removes the patch_mode feature including the related VTY
command patch-mode. Where sensible, the other configuration flags are
queried instead.
In addition, this initial checks in gbprox_process_bssgp_dl() and
gbprox_process_bssgp_ul() have been updated.
The patch mode feature has not been used and was increasingly
difficult to maintain.
Sponsored-by: On-Waves ehf
Currently tlli_info are created for SGSN originated messages when
the SGSN TLLI cannot be found and P-TMSI patching is active. This
doesn't make much sense, since the BSS side TLLI is not known in this
case. Given that the SGSN is working properly, that can only happen
if either the tlli_info has expired or the gbproxy has been
restarted.
This patch disables the creation of a tlli_info in this case.
Note that these messages are passed unmodified to the MS so far.
Sponsored-by: On-Waves ehf
Currently the numeric TLLI or tlli_info's enable_patching flag is
used to decide, whether a APN shall be patched or the secondary SGSN
shall be used. Using the numeric TLLI imposes a problem, when
TLLI/P-TMSI patching is used, since gbproxy_check_tlli uses the BSS
side TLLI namespace when trying to get the tlli_info.
This patch modifies the gbproxy_check_tlli() function to accept a
tlli_info pointer instead of a numeric TLLI. The tlli_info is already
available when the function is called. Since this a similar approach
has been used by accessing the enable_patching flag directly, this
commit unifies checking by always using this function instead of the
flag outside of gb_proxy_tlli.c.
This fixes the APN patching that doesn't work currently when P-TMSI
patching is enabled.
Sponsored-by: On-Waves ehf
gbproxy_patch_bssgp: Move a check for tlli_info in front of the first
conditional that depends on it, and return immediately if it is NULL.
gbproxy_register_tlli: Initialize tlli_already_known to 0.
Fixes: Coverity CID 1232691
Fixes: Coverity CID 1232692
Sponsored-by: On-Waves ehf
The gb_proxy shouldn't start to open the box of pandora by including the
gsm_data_shared.h file, particularly not without defining the BSC role.
In any case, as the reserved TMSI is something that's part of the GSM
specs, and not specific to the OpenBSC implementation, it should be part
of libosmocore.
This patch moves several functions and declarations out of gb_proxy.c
to make them reusable by other components and to separate them by
context and task.
Counter enums (prefix is changed to gbproxy_):
enum gbprox_global_ctr -> gprs/gb_proxy.h
enum gbprox_peer_ctr -> gprs/gb_proxy.h
Generic Gb parsing (prefix is changed to gprs_gb_):
struct gbproxy_parse_context -> openbsc/gprs_gb_parse.h
gbprox_parse_dtap() -> gprs/gprs_gb_parse.c
gbprox_parse_llc() -> gprs/gprs_gb_parse.c
gbprox_parse_bssgp() -> gprs/gprs_gb_parse.c
gbprox_log_parse_context() -> gprs/gprs_gb_parse.c
*_shift(), *_match() -> gprs/gprs_gb_parse.c (no prefix)
gbprox_parse_gmm_* -> gprs/gprs_gb_parse.c (static)
gbprox_parse_gsm_* -> gprs/gprs_gb_parse.c (static)
MI testing/parsing (prefix gprs_ added):
is_mi_tmsi() -> gprs/gprs_utils.c
is_mi_imsi() -> gprs/gprs_utils.c
parse_mi_tmsi() -> gprs/gprs_utils.c
TLLI state handling (prefix is changed to gbproxy_):
gbprox_*tlli* -> gprs/gb_proxy_tlli.c
(except gbprox_patch_tlli, gbproxy_make_sgsn_tlli)
Message patching (prefix is changed to gbproxy_):
gbprox_*patch* -> gprs/gb_proxy_patch.c
gbprox_check_imsi -> gprs/gb_proxy_patch.c
Sponsored-by: On-Waves ehf
Harald Welte
Jacob Erlbeck