gbproxy: Only patch what has been configured

Currently when patching is basically enabled P-TMSI and TLLI gets
patched even when P-TMSI patching is not enabled. Albeit the result
is correct in this case (the same value is re-written), the counter
shows unexpected results.

This patch adds configuration checks for P-TMSI and TLLI patching. It
also reorders the code of gbproxy_patch_raid to return early if there
is nothing to patch.

Sponsored-by: On-Waves ehf

2 files changed, 22 insertions, 25 deletions

diff --git a/openbsc/src/gprs/gb_proxy_patch.c b/openbsc/src/gprs/gb_proxy_patch.c
index caedf8965..bf0f22e08 100644
--- a/openbsc/src/gprs/gb_proxy_patch.c
+++ b/openbsc/src/gprs/gb_proxy_patch.c
@@ -37,6 +37,13 @@ static void gbproxy_patch_raid(uint8_t *raid_enc, struct gbproxy_peer *peer,
 	int old_mcc;
 	int old_mnc;
 	struct gprs_ra_id raid;
+	enum gbproxy_peer_ctr counter =
+		to_bss ?
+		GBPROX_PEER_CTR_RAID_PATCHED_SGSN :
+		GBPROX_PEER_CTR_RAID_PATCHED_BSS;
+
+	if (!state->local_mcc || !state->local_mnc)
+		return;
 
 	gsm48_parse_ra(&raid, raid_enc);
 
@@ -59,23 +66,16 @@ static void gbproxy_patch_raid(uint8_t *raid_enc, struct gbproxy_peer *peer,
 			raid.mnc = state->local_mnc;
 	}
 
-	if (state->local_mcc || state->local_mnc) {
-		enum gbproxy_peer_ctr counter =
-			to_bss ?
-			GBPROX_PEER_CTR_RAID_PATCHED_SGSN :
-			GBPROX_PEER_CTR_RAID_PATCHED_BSS;
-
-		LOGP(DGPRS, LOGL_DEBUG,
-		       "Patching %s to %s: "
-		       "%d-%d-%d-%d -> %d-%d-%d-%d\n",
-		       log_text,
-		       to_bss ? "BSS" : "SGSN",
-		       old_mcc, old_mnc, raid.lac, raid.rac,
-		       raid.mcc, raid.mnc, raid.lac, raid.rac);
-
-		gsm48_construct_ra(raid_enc, &raid);
-		rate_ctr_inc(&peer->ctrg->ctr[counter]);
-	}
+	LOGP(DGPRS, LOGL_DEBUG,
+	     "Patching %s to %s: "
+	     "%d-%d-%d-%d -> %d-%d-%d-%d\n",
+	     log_text,
+	     to_bss ? "BSS" : "SGSN",
+	     old_mcc, old_mnc, raid.lac, raid.rac,
+	     raid.mcc, raid.mnc, raid.lac, raid.rac);
+
+	gsm48_construct_ra(raid_enc, &raid);
+	rate_ctr_inc(&peer->ctrg->ctr[counter]);
 }
 
 static void gbproxy_patch_apn_ie(struct msgb *msg,
@@ -200,7 +200,7 @@ int gbproxy_patch_llc(struct msgb *msg, uint8_t *llc, size_t llc_len,
 	int fcs;
 
 	if (parse_ctx->ptmsi_enc && tlli_info &&
-	    !parse_ctx->old_raid_is_foreign) {
+	    !parse_ctx->old_raid_is_foreign && peer->cfg->patch_ptmsi) {
 		uint32_t ptmsi;
 		if (parse_ctx->to_bss)
 			ptmsi = tlli_info->tlli.ptmsi;
@@ -216,7 +216,7 @@ int gbproxy_patch_llc(struct msgb *msg, uint8_t *llc, size_t llc_len,
 		}
 	}
 
-	if (parse_ctx->new_ptmsi_enc && tlli_info) {
+	if (parse_ctx->new_ptmsi_enc && tlli_info && peer->cfg->patch_ptmsi) {
 		uint32_t ptmsi;
 		if (parse_ctx->to_bss)
 			ptmsi = tlli_info->tlli.ptmsi;
@@ -245,7 +245,7 @@ int gbproxy_patch_llc(struct msgb *msg, uint8_t *llc, size_t llc_len,
 	if (parse_ctx->apn_ie &&
 	    peer->cfg->core_apn &&
 	    !parse_ctx->to_bss &&
-	    gbproxy_check_tlli(peer, tlli_info)) {
+	    gbproxy_check_tlli(peer, tlli_info) && peer->cfg->core_apn) {
 		size_t new_len;
 		gbproxy_patch_apn_ie(msg,
 				     parse_ctx->apn_ie, parse_ctx->apn_ie_len,
@@ -308,7 +308,7 @@ void gbproxy_patch_bssgp(struct msgb *msg, uint8_t *bssgp, size_t bssgp_len,
 	if (!tlli_info)
 		return;
 
-	if (parse_ctx->tlli_enc) {
+	if (parse_ctx->tlli_enc && peer->cfg->patch_ptmsi) {
 		uint32_t tlli = gbproxy_map_tlli(parse_ctx->tlli,
 						 tlli_info, parse_ctx->to_bss);
 
diff --git a/openbsc/tests/gbproxy/gbproxy_test.ok b/openbsc/tests/gbproxy/gbproxy_test.ok
index ffa6b57f0..80a691e93 100644
--- a/openbsc/tests/gbproxy/gbproxy_test.ok
+++ b/openbsc/tests/gbproxy/gbproxy_test.ok
@@ -4663,7 +4663,7 @@ CALLBACK, event 0, msg length 31, bvci 0x1002
 
 NS UNITDATA MESSAGE to SGSN, BVCI 0x1002, msg length 75 (gprs_ns_sendmsg)
 MESSAGE to SGSN at 0x05060708:32000, msg length 79
-00 00 10 02 01 af e2 b7 00 00 00 04 08 88 11 22 33 40 50 60 12 34 00 80 0e 00 34 01 c0 39 08 01 02 f5 e0 21 08 02 05 f4 ef e2 b7 00 11 22 33 40 50 60 19 18 b3 43 2b 25 96 62 00 60 80 9a c2 c6 62 00 60 80 ba c8 c6 62 00 60 80 00 e4 85 12 
+00 00 10 02 01 af e2 b7 00 00 00 04 08 88 11 22 33 40 50 60 12 34 00 80 0e 00 34 01 c0 39 08 01 02 f5 e0 21 08 02 05 f4 fb c5 46 79 11 22 33 40 50 60 19 18 b3 43 2b 25 96 62 00 60 80 9a c2 c6 62 00 60 80 ba c8 c6 62 00 60 80 00 e4 e8 65 
 
 NS UNITDATA MESSAGE to SGSN, BVCI 0x1002, msg length 31 (gprs_ns_sendmsg)
 MESSAGE to SGSN at 0x05060708:32000, msg length 35
@@ -4673,7 +4673,6 @@ result (ATTACH COMPLETE) = 35
 
 Peers:
   NSEI 4096, BVCI 4098, not blocked, RAI 112-332-16464-96
-    P-TMSI patched            (BSS ): 1
     Attach Request count            : 5
     TLLI cache size                 : 2
     TLLI-Cache: 2
@@ -4693,7 +4692,6 @@ result (DETACH REQ) = 73
 
 Peers:
   NSEI 4096, BVCI 4098, not blocked, RAI 112-332-16464-96
-    P-TMSI patched            (BSS ): 1
     Attach Request count            : 5
     TLLI cache size                 : 2
     TLLI-Cache: 2
@@ -4713,7 +4711,6 @@ result (DETACH ACC) = 35
 
 Peers:
   NSEI 4096, BVCI 4098, not blocked, RAI 112-332-16464-96
-    P-TMSI patched            (BSS ): 1
     Attach Request count            : 5
     TLLI cache size                 : 1
     TLLI-Cache: 1