msc_cipher_mode_compl: Handle CIPH MOD COMPL without L3 message
According to TS 44.008 Section 3.2.1.31, the "Layer 3 Message Contents"
IE of the BSSMAP Cipher Mode Complete is optional. The BSC may hence
inlcude that IE or not include it.
Without this patch, OsmoMSC is crashing if that IE was missing:
<000a> a_iface_bssap.c:699 Rx BSC DT: 00 03 55 2c 02
<000a> a_iface_bssap.c:629 Rx MSC DT1 BSSMAP CIPHER MODE COMPLETE
<001f> a_iface_bssap.c:91 Found A subscriber for conn_id 1
<000a> a_iface_bssap.c:415 BSC sends cipher mode complete (conn_id=1)
==5611== Invalid read of size 8
==5611== at 0x128D0F: msc_cipher_mode_compl (osmo_msc.c:159)
==5611== by 0x114F62: bssmap_rx_ciph_compl.isra.8 (a_iface_bssap.c:432)
==5611== by 0x113267: sccp_sap_up (a_iface.c:520)
Change-Id: I722f9b468b157b3736918f090daaa9489a6028ee
Closes: OS#2871
1 file changed