From f11087a9bc483424a5853b40b5932a2cbd5aa5c9 Mon Sep 17 00:00:00 2001
From: Harald Welte <laforge@gnumonks.org>
Date: Mon, 25 Jan 2016 15:43:03 +0100
Subject: fix migration of check_for_ciph_cmd() from sysmobts to l1sap

During the L1SAP related changes, somehow an old version of
check_for_ciph_cmd() was re-introduced, which didn't store the N(s) as
part of the lchan.  To make things worse, the old code was still present
in the sysmobts specific part, but never executed.
---
 src/common/l1sap.c         | 12 ++++++++++++
 src/osmo-bts-sysmo/l1_if.c | 45 ---------------------------------------------
 2 files changed, 12 insertions(+), 45 deletions(-)

diff --git a/src/common/l1sap.c b/src/common/l1sap.c
index 9d048e0a..3f77f05d 100644
--- a/src/common/l1sap.c
+++ b/src/common/l1sap.c
@@ -113,6 +113,7 @@ static int l1sap_tx_ciph_req(struct gsm_bts_trx *trx, uint8_t chan_nr,
 static int check_for_ciph_cmd(struct msgb *msg, struct gsm_lchan *lchan,
 	uint8_t chan_nr)
 {
+	uint8_t n_s;
 
 	/* only do this if we are in the right state */
 	switch (lchan->ciph_state) {
@@ -133,11 +134,22 @@ static int check_for_ciph_cmd(struct msgb *msg, struct gsm_lchan *lchan,
 	if ((msg->data[4] & 0x3F) != GSM48_MT_RR_CIPH_M_CMD)
 		return 0;
 
+	/* Remember N(S) + 1 to find the first ciphered frame */
+	n_s = (msg->data[1] >> 1) & 0x7;
+	lchan->ciph_ns = (n_s + 1) % 8;
+
 	l1sap_tx_ciph_req(lchan->ts->trx, chan_nr, 0, 1);
 
 	return 1;
 }
 
+/* public helpers for the test */
+int bts_check_for_ciph_cmd(struct msgb *msg, struct gsm_lchan *lchan,
+			   uint8_t chan_nr)
+{
+	return check_for_ciph_cmd(msg, lchan, chan_nr);
+}
+
 struct gsmtap_inst *gsmtap = NULL;
 uint32_t gsmtap_sapi_mask = 0;
 uint8_t gsmtap_sapi_acch = 0;
diff --git a/src/osmo-bts-sysmo/l1_if.c b/src/osmo-bts-sysmo/l1_if.c
index 8457a748..ce393a4d 100644
--- a/src/osmo-bts-sysmo/l1_if.c
+++ b/src/osmo-bts-sysmo/l1_if.c
@@ -232,51 +232,6 @@ empty_req_from_rts_ind(GsmL1_Prim_t *l1p,
 	return empty_req;
 }
 
-/* check if the message is a GSM48_MT_RR_CIPH_M_CMD, and if yes, enable
- * uni-directional de-cryption on the uplink. We need this ugly layering
- * violation as we have no way of passing down L3 metadata (RSL CIPHERING CMD)
- * to this point in L1 */
-static int check_for_ciph_cmd(struct femtol1_hdl *fl1h,
-			      struct msgb *msg, struct gsm_lchan *lchan)
-{
-	uint8_t n_s;
-
-	/* only do this if we are in the right state */
-	switch (lchan->ciph_state) {
-	case LCHAN_CIPH_NONE:
-	case LCHAN_CIPH_RX_REQ:
-		break;
-	default:
-		return 0;
-	}
-
-	/* First byte (Address Field) of LAPDm header) */
-	if (msg->data[0] != 0x03)
-		return 0;
-	/* First byte (protocol discriminator) of RR */
-	if ((msg->data[3] & 0xF) != GSM48_PDISC_RR)
-		return 0;
-	/* 2nd byte (msg type) of RR */
-	if ((msg->data[4] & 0x3F) != GSM48_MT_RR_CIPH_M_CMD)
-		return 0;
-
-	/* Remember N(S) + 1 to find the first ciphered frame */
-	n_s = (msg->data[1] >> 1) & 0x7;
-	lchan->ciph_ns = (n_s + 1) % 8;
-
-	lchan->ciph_state = LCHAN_CIPH_RX_REQ;
-	l1if_set_ciphering(fl1h, lchan, 0);
-
-	return 1;
-}
-
-/* public helpers for the test */
-int bts_check_for_ciph_cmd(struct femtol1_hdl *fl1h,
-			      struct msgb *msg, struct gsm_lchan *lchan)
-{
-	return check_for_ciph_cmd(fl1h, msg, lchan);
-}
-
 static const uint8_t fill_frame[GSM_MACBLOCK_LEN] = {
 	0x03, 0x03, 0x01, 0x2B, 0x2B, 0x2B, 0x2B, 0x2B, 0x2B, 0x2B,
 	0x2B, 0x2B, 0x2B, 0x2B, 0x2B, 0x2B, 0x2B, 0x2B, 0x2B, 0x2B,
-- 
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