rsl: Introduce new osmocom extension IE RSL_IE_OSMO_ABS_FRAME_NUMBER

This will be used in RSLms to provide Absolute Frame Number information
of the primitive indications being sent to upper layers, so that it's
possible to track GSM time in the upper layers.
The existing RSL_IE_FRAME_NUMBER and RSL_IE_STARTNG_TIME cannot be used
there, since those are 16bit fields containing Relative FN values.

Related: OS#3626
Change-Id: Ia28caa24dd141b1162b6e11500d753353fe6500d
---
M include/osmocom/gsm/protocol/gsm_08_58.h
M src/gsm/rsl.c
2 files changed, 18 insertions(+), 0 deletions(-)

diff --git a/include/osmocom/gsm/protocol/gsm_08_58.h b/include/osmocom/gsm/protocol/gsm_08_58.h
index 0a44db9..ec9ebe7 100644
--- a/include/osmocom/gsm/protocol/gsm_08_58.h
+++ b/include/osmocom/gsm/protocol/gsm_08_58.h
@@ -369,6 +369,7 @@
 	RSL_IE_OSMO_TRAINING_SEQUENCE	= 0x61,
 	RSL_IE_OSMO_TEMP_OVP_ACCH_CAP	= 0x62,
 	RSL_IE_OSMO_OSMUX_CID		= 0x63,
+	RSL_IE_OSMO_ABS_FRAME_NUMBER	= 0x64, /* uint32_t fn in network byte order */
 
 	/* ip.access */
 	RSL_IE_IPAC_SRTP_CONFIG	= 0xe0,
diff --git a/src/gsm/rsl.c b/src/gsm/rsl.c
index fbba982..53eb983 100644
--- a/src/gsm/rsl.c
+++ b/src/gsm/rsl.c
@@ -126,6 +126,7 @@
 		[RSL_IE_OSMO_TRAINING_SEQUENCE]	= { TLV_TYPE_TLV },
 		[RSL_IE_OSMO_TEMP_OVP_ACCH_CAP]	= { TLV_TYPE_TLV },
 		[RSL_IE_OSMO_OSMUX_CID]		= { TLV_TYPE_TLV },
+		[RSL_IE_OSMO_ABS_FRAME_NUMBER]	= { TLV_TYPE_TLV }, /* uint32_t fn in network byte order */
 		[RSL_IE_IPAC_SRTP_CONFIG]	= { TLV_TYPE_TLV },
 		[RSL_IE_IPAC_PROXY_UDP]		= { TLV_TYPE_FIXED, 2 },
 		[RSL_IE_IPAC_BSCMPL_TOUT]	= { TLV_TYPE_TV },

