bgpd: fix labels static-analyser

Fix static-analyser warnings with BGP labels:

> $ scan-build make -j12
> bgpd/bgp_updgrp_packet.c:819:10: warning: Access to field 'extra' results in a dereference of a null pointer (loaded from variable 'path') [core.NullDereference]
>                                                 ? &path->extra->labels->label[0]
>                                                    ^~~~~~~~~

Signed-off-by: Louis Scalbert <louis.scalbert@6wind.com>

16 files changed, 40 insertions, 50 deletions

diff --git a/bgpd/bgp_bmp.c b/bgpd/bgp_bmp.c
index 43f8006e2..675e4765e 100644
--- a/bgpd/bgp_bmp.c
+++ b/bgpd/bgp_bmp.c
@@ -1221,7 +1221,7 @@ afibreak:
 	    (safi == SAFI_MPLS_VPN))
 		prd = (struct prefix_rd *)bgp_dest_get_prefix(bmp->syncrdpos);
 
-	bpi_num_labels = bgp_path_info_num_labels(bpi);
+	bpi_num_labels = BGP_PATH_INFO_NUM_LABELS(bpi);
 
 	if (bpi && CHECK_FLAG(bpi->flags, BGP_PATH_SELECTED) &&
 	    CHECK_FLAG(bmp->targets->afimon[afi][safi], BMP_MON_LOC_RIB)) {
@@ -1356,7 +1356,7 @@ static bool bmp_wrqueue_locrib(struct bmp *bmp, struct pullwr *pullwr)
 			break;
 	}
 
-	bpi_num_labels = bgp_path_info_num_labels(bpi);
+	bpi_num_labels = BGP_PATH_INFO_NUM_LABELS(bpi);
 
 	bmp_monitor(bmp, peer, 0, BMP_PEER_TYPE_LOC_RIB_INSTANCE, &bqe->p, prd,
 		    bpi ? bpi->attr : NULL, afi, safi,
@@ -1434,7 +1434,7 @@ static bool bmp_wrqueue(struct bmp *bmp, struct pullwr *pullwr)
 				break;
 		}
 
-		bpi_num_labels = bgp_path_info_num_labels(bpi);
+		bpi_num_labels = BGP_PATH_INFO_NUM_LABELS(bpi);
 
 		bmp_monitor(bmp, peer, BMP_PEER_FLAG_L,
 			    BMP_PEER_TYPE_GLOBAL_INSTANCE, &bqe->p, prd,
diff --git a/bgpd/bgp_evpn.c b/bgpd/bgp_evpn.c
index ef7b13f32..cb5c89831 100644
--- a/bgpd/bgp_evpn.c
+++ b/bgpd/bgp_evpn.c
@@ -3013,7 +3013,7 @@ bgp_create_evpn_bgp_path_info(struct bgp_path_info *parent_pi,
 	if (parent_pi->extra)
 		pi->extra->igpmetric = parent_pi->extra->igpmetric;
 
-	if (bgp_path_info_num_labels(parent_pi))
+	if (BGP_PATH_INFO_NUM_LABELS(parent_pi))
 		pi->extra->labels = bgp_labels_intern(parent_pi->extra->labels);
 
 	bgp_path_info_add(dest, pi);
diff --git a/bgpd/bgp_label.c b/bgpd/bgp_label.c
index ad40fef62..af1011160 100644
--- a/bgpd/bgp_label.c
+++ b/bgpd/bgp_label.c
@@ -208,7 +208,7 @@ mpls_label_t bgp_adv_label(struct bgp_dest *dest, struct bgp_path_info *pi,
 	if (!dest || !pi || !to)
 		return MPLS_INVALID_LABEL;
 
-	remote_label = bgp_path_info_num_labels(pi)
+	remote_label = BGP_PATH_INFO_NUM_LABELS(pi)
 			       ? pi->extra->labels->label[0]
 			       : MPLS_INVALID_LABEL;
 	from = pi->peer;
diff --git a/bgpd/bgp_mac.c b/bgpd/bgp_mac.c
index bc44a212c..86d6281ed 100644
--- a/bgpd/bgp_mac.c
+++ b/bgpd/bgp_mac.c
@@ -169,7 +169,7 @@ static void bgp_process_mac_rescan_table(struct bgp *bgp, struct peer *peer,
 			    && !dest_affected)
 				continue;
 
-			num_labels = bgp_path_info_num_labels(pi);
+			num_labels = BGP_PATH_INFO_NUM_LABELS(pi);
 			label_pnt = num_labels ? &pi->extra->labels->label[0]
 					       : NULL;
 
diff --git a/bgpd/bgp_mplsvpn.c b/bgpd/bgp_mplsvpn.c
index 9de1c5f4c..f7ca51e14 100644
--- a/bgpd/bgp_mplsvpn.c
+++ b/bgpd/bgp_mplsvpn.c
@@ -2322,7 +2322,7 @@ static void vpn_leak_to_vrf_update_onevrf(struct bgp *to_bgp,   /* to */
 		}
 
 		num_labels = origin_local ? 0
-					  : bgp_path_info_num_labels(path_vpn);
+					  : BGP_PATH_INFO_NUM_LABELS(path_vpn);
 		label_pnt = num_labels ? path_vpn->extra->labels->label : NULL;
 	}
 
@@ -4212,7 +4212,7 @@ void bgp_mplsvpn_nh_label_bind_register_local_label(struct bgp *bgp,
 	struct bgp_mplsvpn_nh_label_bind_cache_head *tree;
 	mpls_label_t label;
 
-	label = bgp_path_info_num_labels(pi)
+	label = BGP_PATH_INFO_NUM_LABELS(pi)
 			? decode_label(&pi->extra->labels->label[0])
 			: MPLS_INVALID_LABEL;
 
diff --git a/bgpd/bgp_nht.c b/bgpd/bgp_nht.c
index f75df1e12..0259da06d 100644
--- a/bgpd/bgp_nht.c
+++ b/bgpd/bgp_nht.c
@@ -505,7 +505,7 @@ int bgp_find_or_add_nexthop(struct bgp *bgp_route, struct bgp *bgp_nexthop,
 		return 1;
 	else if (safi == SAFI_UNICAST && pi &&
 		 pi->sub_type == BGP_ROUTE_IMPORTED &&
-		 bgp_path_info_num_labels(pi) && !bnc->is_evpn_gwip_nexthop)
+		 BGP_PATH_INFO_NUM_LABELS(pi) && !bnc->is_evpn_gwip_nexthop)
 		return bgp_isvalid_nexthop_for_l3vpn(bnc, pi);
 	else if (safi == SAFI_MPLS_VPN && pi &&
 		 pi->sub_type != BGP_ROUTE_IMPORTED)
@@ -1310,7 +1310,7 @@ void evaluate_paths(struct bgp_nexthop_cache *bnc)
 
 		if (safi == SAFI_UNICAST &&
 		    path->sub_type == BGP_ROUTE_IMPORTED &&
-		    bgp_path_info_num_labels(path) &&
+		    BGP_PATH_INFO_NUM_LABELS(path) &&
 		    !(bre && bre->type == OVERLAY_INDEX_GATEWAY_IP)) {
 			bnc_is_valid_nexthop =
 				bgp_isvalid_nexthop_for_l3vpn(bnc, path)
diff --git a/bgpd/bgp_route.c b/bgpd/bgp_route.c
index e76329fca..49f3c77ad 100644
--- a/bgpd/bgp_route.c
+++ b/bgpd/bgp_route.c
@@ -327,7 +327,7 @@ struct bgp_path_info_extra *bgp_path_info_extra_get(struct bgp_path_info *pi)
 
 bool bgp_path_info_has_valid_label(const struct bgp_path_info *path)
 {
-	if (!bgp_path_info_num_labels(path))
+	if (!BGP_PATH_INFO_NUM_LABELS(path))
 		return false;
 
 	return bgp_is_valid_label(&path->extra->labels->label[0]);
@@ -339,27 +339,13 @@ bool bgp_path_info_labels_same(const struct bgp_path_info *bpi,
 	uint8_t bpi_num_labels;
 	const mpls_label_t *bpi_label;
 
-	bpi_num_labels = bgp_path_info_num_labels(bpi);
+	bpi_num_labels = BGP_PATH_INFO_NUM_LABELS(bpi);
 	bpi_label = bpi_num_labels ? bpi->extra->labels->label : NULL;
 
 	return bgp_labels_same(bpi_label, bpi_num_labels,
 			       (const mpls_label_t *)label, n);
 }
 
-uint8_t bgp_path_info_num_labels(const struct bgp_path_info *pi)
-{
-	if (!pi)
-		return 0;
-
-	if (!pi->extra)
-		return 0;
-
-	if (!pi->extra->labels)
-		return 0;
-
-	return pi->extra->labels->num_labels;
-}
-
 /* Free bgp route information. */
 void bgp_path_info_free_with_caller(const char *name,
 				    struct bgp_path_info *path)
@@ -2252,7 +2238,7 @@ bool subgroup_announce_check(struct bgp_dest *dest, struct bgp_path_info *pi,
 	 * off box as that the RT and RD created are localy
 	 * significant and globaly useless.
 	 */
-	if (safi == SAFI_MPLS_VPN && bgp_path_info_num_labels(pi) &&
+	if (safi == SAFI_MPLS_VPN && BGP_PATH_INFO_NUM_LABELS(pi) &&
 	    pi->extra->labels->label[0] == BGP_PREVENT_VRF_2_VRF_LEAK)
 		return false;
 
@@ -6861,7 +6847,7 @@ void bgp_static_update(struct bgp *bgp, const struct prefix *p,
 						bgp, p, pi);
 				}
 			} else {
-				if (bgp_path_info_num_labels(pi))
+				if (BGP_PATH_INFO_NUM_LABELS(pi))
 					label = decode_label(
 						&pi->extra->labels->label[0]);
 			}
@@ -10540,7 +10526,7 @@ void route_vty_out_detail(struct vty *vty, struct bgp *bgp, struct bgp_dest *bn,
 		json_nexthop_global = json_object_new_object();
 	}
 
-	if (bgp_path_info_num_labels(path)) {
+	if (BGP_PATH_INFO_NUM_LABELS(path)) {
 		bgp_evpn_label2str(path->extra->labels->label,
 				   path->extra->labels->num_labels, vni_buf,
 				   sizeof(vni_buf));
diff --git a/bgpd/bgp_route.h b/bgpd/bgp_route.h
index 5b433b555..b1c835630 100644
--- a/bgpd/bgp_route.h
+++ b/bgpd/bgp_route.h
@@ -561,6 +561,11 @@ struct bgp_aggregate {
 /* path PREFIX (addpath rxid NUMBER) */
 #define PATH_ADDPATH_STR_BUFFER PREFIX2STR_BUFFER + 32
 
+#define BGP_PATH_INFO_NUM_LABELS(pi)                                           \
+	((pi) && (pi)->extra && (pi)->extra->labels                            \
+		 ? (pi)->extra->labels->num_labels                             \
+		 : 0)
+
 enum bgp_path_type {
 	BGP_PATH_SHOW_ALL,
 	BGP_PATH_SHOW_BESTPATH,
@@ -748,7 +753,6 @@ extern void bgp_path_info_delete(struct bgp_dest *dest,
 extern struct bgp_path_info_extra *
 bgp_path_info_extra_get(struct bgp_path_info *path);
 extern bool bgp_path_info_has_valid_label(const struct bgp_path_info *path);
-extern uint8_t bgp_path_info_num_labels(const struct bgp_path_info *pi);
 extern void bgp_path_info_set_flag(struct bgp_dest *dest,
 				   struct bgp_path_info *path, uint32_t flag);
 extern void bgp_path_info_unset_flag(struct bgp_dest *dest,
diff --git a/bgpd/bgp_routemap.c b/bgpd/bgp_routemap.c
index 79c61e2ee..d0b65a742 100644
--- a/bgpd/bgp_routemap.c
+++ b/bgpd/bgp_routemap.c
@@ -1081,7 +1081,7 @@ route_match_vni(void *rule, const struct prefix *prefix, void *object)
 		return RMAP_NOOP;
 
 	for (label_cnt = 0; label_cnt < BGP_MAX_LABELS &&
-			    label_cnt < bgp_path_info_num_labels(path);
+			    label_cnt < BGP_PATH_INFO_NUM_LABELS(path);
 	     label_cnt++) {
 		if (vni == label2vni(&path->extra->labels->label[label_cnt]))
 			return RMAP_MATCH;
diff --git a/bgpd/bgp_rpki.c b/bgpd/bgp_rpki.c
index 9db7b1529..f9cbf2403 100644
--- a/bgpd/bgp_rpki.c
+++ b/bgpd/bgp_rpki.c
@@ -666,7 +666,7 @@ static void revalidate_bgp_node(struct bgp_dest *bgp_dest, afi_t afi,
 		struct bgp_path_info *path =
 			bgp_dest_get_bgp_path_info(bgp_dest);
 
-		num_labels = bgp_path_info_num_labels(path);
+		num_labels = BGP_PATH_INFO_NUM_LABELS(path);
 		label = num_labels ? path->extra->labels->label : NULL;
 
 		(void)bgp_update(ain->peer, bgp_dest_get_prefix(bgp_dest),
diff --git a/bgpd/bgp_updgrp_packet.c b/bgpd/bgp_updgrp_packet.c
index 8cd851b9a..bed00a664 100644
--- a/bgpd/bgp_updgrp_packet.c
+++ b/bgpd/bgp_updgrp_packet.c
@@ -813,7 +813,7 @@ struct bpacket *subgroup_update_packet(struct update_subgroup *subgrp)
 				label_pnt = &label;
 				num_labels = 1;
 			} else {
-				num_labels = bgp_path_info_num_labels(path);
+				num_labels = BGP_PATH_INFO_NUM_LABELS(path);
 				label_pnt =
 					num_labels
 						? &path->extra->labels->label[0]
diff --git a/bgpd/bgp_zebra.c b/bgpd/bgp_zebra.c
index 2d9100b89..6e2efabf8 100644
--- a/bgpd/bgp_zebra.c
+++ b/bgpd/bgp_zebra.c
@@ -1311,7 +1311,7 @@ static void bgp_zebra_announce_parse_nexthop(
 		api_nh->srte_color = bgp_attr_get_color(info->attr);
 
 		if (bgp_debug_zebra(&api->prefix)) {
-			if (bgp_path_info_num_labels(mpinfo)) {
+			if (BGP_PATH_INFO_NUM_LABELS(mpinfo)) {
 				zlog_debug("%s: p=%pFX, bgp_is_valid_label: %d",
 					   __func__, p,
 					   bgp_is_valid_label(
@@ -1385,7 +1385,7 @@ static void bgp_zebra_announce_parse_nexthop(
 		     mpinfo->peer->sort == BGP_PEER_CONFED))
 			*allow_recursion = true;
 
-		num_labels = bgp_path_info_num_labels(mpinfo);
+		num_labels = BGP_PATH_INFO_NUM_LABELS(mpinfo);
 		labels = num_labels ? mpinfo->extra->labels->label : NULL;
 
 		if (num_labels && (is_evpn || bgp_is_valid_label(&labels[0]))) {
diff --git a/bgpd/rfapi/rfapi_import.c b/bgpd/rfapi/rfapi_import.c
index 2afcb2f45..44dfc88cf 100644
--- a/bgpd/rfapi/rfapi_import.c
+++ b/bgpd/rfapi/rfapi_import.c
@@ -1272,7 +1272,7 @@ rfapiRouteInfo2NextHopEntry(struct rfapi_ip_prefix *rprefix,
 
 		/* label comes from MP_REACH_NLRI label */
 		vo->v.l2addr.label =
-			bgp_path_info_num_labels(bpi)
+			BGP_PATH_INFO_NUM_LABELS(bpi)
 				? decode_label(&bpi->extra->labels->label[0])
 				: MPLS_INVALID_LABEL;
 
@@ -4167,7 +4167,7 @@ static void rfapiBgpTableFilteredImport(struct bgp *bgp,
 						       BGP_PATH_REMOVED))
 						continue;
 
-					if (bgp_path_info_num_labels(bpi))
+					if (BGP_PATH_INFO_NUM_LABELS(bpi))
 						label = decode_label(
 							&bpi->extra->labels
 								 ->label[0]);
diff --git a/bgpd/rfapi/rfapi_rib.c b/bgpd/rfapi/rfapi_rib.c
index a0bdf4961..53e416b2e 100644
--- a/bgpd/rfapi/rfapi_rib.c
+++ b/bgpd/rfapi/rfapi_rib.c
@@ -692,7 +692,7 @@ static void rfapiRibBi2Ri(struct bgp_path_info *bpi, struct rfapi_info *ri,
 
 		/* label comes from MP_REACH_NLRI label */
 		vo->v.l2addr.label =
-			bgp_path_info_num_labels(bpi)
+			BGP_PATH_INFO_NUM_LABELS(bpi)
 				? decode_label(&bpi->extra->labels->label[0])
 				: MPLS_INVALID_LABEL;
 
diff --git a/bgpd/rfapi/rfapi_vty.c b/bgpd/rfapi/rfapi_vty.c
index 9bfb6c4b4..8f1f509bb 100644
--- a/bgpd/rfapi/rfapi_vty.c
+++ b/bgpd/rfapi/rfapi_vty.c
@@ -413,7 +413,7 @@ void rfapi_vty_out_vncinfo(struct vty *vty, const struct prefix *p,
 		XFREE(MTYPE_ECOMMUNITY_STR, s);
 	}
 
-	if (bgp_path_info_num_labels(bpi)) {
+	if (BGP_PATH_INFO_NUM_LABELS(bpi)) {
 		if (bpi->extra->labels->label[0] == BGP_PREVENT_VRF_2_VRF_LEAK)
 			vty_out(vty, " label=VRF2VRF");
 		else
@@ -1052,7 +1052,7 @@ static int rfapiPrintRemoteRegBi(struct bgp *bgp, void *stream,
 		snprintf(buf_un, sizeof(buf_un), "%s",
 			 inet_ntop(pfx_vn.family, &pfx_vn.u.prefix, buf_ntop,
 				   sizeof(buf_ntop)));
-		if (bgp_path_info_num_labels(bpi)) {
+		if (BGP_PATH_INFO_NUM_LABELS(bpi)) {
 			uint32_t l = decode_label(&bpi->extra->labels->label[0]);
 			snprintf(buf_vn, sizeof(buf_vn), "Label: %d", l);
 		} else /* should never happen */
@@ -1161,7 +1161,7 @@ static int rfapiPrintRemoteRegBi(struct bgp *bgp, void *stream,
 			}
 		}
 	}
-	if (tun_type != BGP_ENCAP_TYPE_MPLS && bgp_path_info_num_labels(bpi)) {
+	if (tun_type != BGP_ENCAP_TYPE_MPLS && BGP_PATH_INFO_NUM_LABELS(bpi)) {
 		uint32_t l = decode_label(&bpi->extra->labels->label[0]);
 
 		if (!MPLS_LABEL_IS_NULL(l)) {
diff --git a/bgpd/rfapi/vnc_import_bgp.c b/bgpd/rfapi/vnc_import_bgp.c
index 2bb7c1b16..e688638ed 100644
--- a/bgpd/rfapi/vnc_import_bgp.c
+++ b/bgpd/rfapi/vnc_import_bgp.c
@@ -470,7 +470,7 @@ static void vnc_import_bgp_add_route_mode_resolve_nve_one_bi(
 	if (bgp_attr_get_ecommunity(bpi->attr))
 		ecommunity_merge(new_ecom, bgp_attr_get_ecommunity(bpi->attr));
 
-	if (bgp_path_info_num_labels(bpi))
+	if (BGP_PATH_INFO_NUM_LABELS(bpi))
 		label = decode_label(&bpi->extra->labels->label[0]);
 	else
 		label = MPLS_INVALID_LABEL;
@@ -1704,7 +1704,7 @@ static void vnc_import_bgp_exterior_add_route_it(
 				else
 					prd = NULL;
 
-				if (bgp_path_info_num_labels(bpi_interior))
+				if (BGP_PATH_INFO_NUM_LABELS(bpi_interior))
 					label = decode_label(
 						&bpi_interior->extra->labels
 							 ->label[0]);
@@ -1878,7 +1878,7 @@ void vnc_import_bgp_exterior_del_route(
 				else
 					prd = NULL;
 
-				if (bgp_path_info_num_labels(bpi_interior))
+				if (BGP_PATH_INFO_NUM_LABELS(bpi_interior))
 					label = decode_label(
 						&bpi_interior->extra->labels
 							 ->label[0]);
@@ -2030,7 +2030,7 @@ void vnc_import_bgp_exterior_add_route_interior(
 			else
 				prd = NULL;
 
-			if (bgp_path_info_num_labels(bpi_interior))
+			if (BGP_PATH_INFO_NUM_LABELS(bpi_interior))
 				label = decode_label(
 					&bpi_interior->extra->labels->label[0]);
 			else
@@ -2147,7 +2147,7 @@ void vnc_import_bgp_exterior_add_route_interior(
 					else
 						prd = NULL;
 
-					if (bgp_path_info_num_labels(bpi))
+					if (BGP_PATH_INFO_NUM_LABELS(bpi))
 						label = decode_label(
 							&bpi->extra->labels
 								 ->label[0]);
@@ -2174,7 +2174,7 @@ void vnc_import_bgp_exterior_add_route_interior(
 				else
 					prd = NULL;
 
-				if (bgp_path_info_num_labels(bpi_interior))
+				if (BGP_PATH_INFO_NUM_LABELS(bpi_interior))
 					label = decode_label(
 						&bpi_interior->extra->labels
 							 ->label[0]);
@@ -2297,7 +2297,7 @@ void vnc_import_bgp_exterior_add_route_interior(
 			else
 				prd = NULL;
 
-			if (bgp_path_info_num_labels(bpi_interior))
+			if (BGP_PATH_INFO_NUM_LABELS(bpi_interior))
 				label = decode_label(
 					&bpi_interior->extra->labels->label[0]);
 			else
@@ -2409,7 +2409,7 @@ void vnc_import_bgp_exterior_del_route_interior(
 		else
 			prd = NULL;
 
-		if (bgp_path_info_num_labels(bpi_interior))
+		if (BGP_PATH_INFO_NUM_LABELS(bpi_interior))
 			label = decode_label(
 				&bpi_interior->extra->labels->label[0]);
 		else
@@ -2491,7 +2491,7 @@ void vnc_import_bgp_exterior_del_route_interior(
 				else
 					prd = NULL;
 
-				if (bgp_path_info_num_labels(bpi))
+				if (BGP_PATH_INFO_NUM_LABELS(bpi))
 					label = decode_label(
 						&bpi->extra->labels->label[0]);
 				else