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, the log level is always LOGL_DEBUG. In case of errors it
would be helpful to use a higher log level.
This patch adds a log_level parameter to gprs_gb_log_parse_context to
let the caller decide about the level.
Ticket: OW#1307
Sponsored-by: On-Waves ehf
This function tries to get an accurate name for the message even if
the parsing has been aborted due to message errors.
The patch also moves the settings of the BSSGP related fields in
parse_ctx from behind to the front of bssgp_tlv_parse, to get more
information in the case of failure. This is now consistent with the
handling of the llc and g48_hdr fields.
Id addition, gprs_gb_log_parse_context now uses the new function to
derive a more accurate message name.
Ticket: OW#1307
Sponsored-by: On-Waves ehf
Currently the SGSN side message's TLLI are searched without checking
the originating SGSN. This leads to collisions if both SGSN use the
same P-TMSI for different MS.
With this patch, the SGSN NSEI is stored within the tlli_info and is
used in comparisons to separate the namespaces.
Note that this type of collision cannot happen with BSS numbers,
since the tlli_info are already separated and stored per (BSS) peer.
Sponsored-by: On-Waves ehf
Currently a tlli_info entry is deleted when the TLLI gets invalidated
by a Detach message.
This patch introduces the possibility to keep tlli_info entries in
the list. Those entries then have cleared TLLI fields, are marked as
de-registered, and can only be retrieved by a message containing an
IMSI or a P-TMSI.
The following VTY configuration commands are added to the gbproxy
node:
- tlli-list keep-mode never : Don't keep the entries (default)
- tlli-list keep-mode re-attach : Only keep them, when a Detach
message with re-attach required has been received
- tlli-list keep-mode identified : Only keep entries which are
associated with an IMSI
- tlli-list keep-mode always : Keep all entries
Note that at least one of max-length or max-age should be set when
this feature is used to limit the number of entries.
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
Currently when patching is enabled and an error happens when
receiving a message from the SGSN, the patched message is sent back
with the PDU_IN_ERROR IE.
This patch modifies gbprox_rx_sig_from_sgsn() to copy the message
before it is patched, so that the original message can be used with
the STATUS message. gbprox_rx_ptp_from_sgsn() does all checks before
the message is patched, so copying is not necessary.
Since gbprox_rx_sig_from_sgsn() is not called for BSSGP UNITDATA
messages and the msgb is already been copied in the gbprox_relay2peer
function, the relative performance impact is expected to be low.
Note that the PDU IE of STATUS messages received from an MS and
forwarded to the SGSN will not be patched. STATUS messages from the
SGSN are only logged and not forwarded to the MS.
Sponsored-by: On-Waves ehf
The compiler also uses this attribute for code elimination. If the
nonnull attribute has been given erroneously for an parameter, that
is later been checked against NULL, this check is removed silently
by the gcc if optimization is enabled. This can lead to hard-to-find
segmentation violation faults.
To be on the safe side, this patch removes all uses of the nonnull
attribute in openbsc.
Compiler:
- gcc 4.8.2 (Ubuntu 4.8.2-19ubuntu1): no warning, segfault
- clang 3.4 (3.4-1ubuntu3): no warning, no segfault, asm ok
Example:
/* foo.c */
int f(int* p) __attribute((nonnull));
int f(int *p) {
if (!p)
return 0;
return *p;
}
/* main.c */
int f(int* p) __attribute((nonnull));
int g () {
return f(arg);
}
int main() {
return g(NULL);
}
When these files are compiled into an executable, no warnungs are
issued but it will fail with a segfault when -O2 is used (unless LTO
is active).
Compiler output (gcc -O2):
int f(int *p) {
0: 8b 44 24 04 mov 0x4(%esp),%eax
4: 8b 00 mov (%eax),%eax
6: c3 ret
}
Sponsored-by: On-Waves ehf
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
Jacob Erlbeck