Replace hardcoded protocol discriminator and message type bitmasks with
function calls recently introduced in libosmocore.
Note that the release 98 bitmasks slightly differ from the release 99 bitmasks.
This patch uses the "default" gsm48_hdr_msg_type invocation, thus it depends on
libosmocore whether 98 or 99 bitmasks are used.
In some places, use of the bitmask was erratic. Fix these implicitly by
employing the bitmask functions:
* silent_call.c: silent_call_reroute(): add missing bitmask for MM.
* bsc_msg_filter.c: bsc_msg_filter_initial(): RR vs. MM messages.
* osmo_bsc_filter.c: bsc_find_msc() and bsc_scan_bts_msg(): RR vs. MM
messages.
* bsc_nat_rewrite.c: bsc_nat_rewrite_msg(): SMS vs. CC messages.
* bsc_ussd.c: no bitmask is applicable for the message types used here.
* gb_proxy.c: gbproxy_imsi_acquisition(): missing bit mask for pdisc.
In gprs_gb_parse.c: gprs_gb_parse_dtap(), add a log notice for unexpected
message types.
In the libfilter source code, which is built regardless of --enable-nat,
headers from libosmo-sccp were used, thus causing a build failure (see
below) when building without --enable-nat, and libosmo-sccp not being
installed (or being installed in a prefix not otherwise included in the
build).
The build fails like this:
In file included from ../../../src/libfilter/bsc_msg_filter.c:27:0:
../../../include/openbsc/bsc_nat_sccp.h:27:37: fatal error: osmocom/sccp/sccp_types.h: No such file or directory
As the includes seem not to be actually needed, this change fixes the
issue by just omitting them.
For the BSC we will have the gsm48_hdr and don't need to
find data within SCCP. For legacy reasons we need to
initialize con_type, imsi, reject causes early on and
need to do the same in the filter method.
This means we need to require a talloc context and
simply operate on the list. I had considered creating
a structure to hold the list head but I didn't find
any other members so omitted it for now.
Move the filter methods to the filter module. This is
still only usable for the NAT and the _dt/_cr filter
routines need to move back to the bsc_nat in the long
run.
For customer requirements we want to be able to do
filtering on the BSC as well. The same messages need
to be scanned and the same access-lists will be looked
at. In the future we might even split traffic based
on the IMSI. Begin with moving the code to a new top
level directory and then renaming and removing the
nat dependency.
Alexander Huemer
Neels Hofmeyr
Jacob Erlbeck