bgpd: fixing strict aliasing warning in bmp_get_peer_distinguisher

bmp_get_peer_distinguisher warning fix
bmp_get_peer_distinguisher use of flag check for prefix_rd

Signed-off-by: Maxence Younsi <[email protected]>

bgpd/bgp_bmp.c

@@ -262,25 +262,35 @@ static inline uint64_t bmp_get_peer_distinguisher(struct bmp *bmp, afi_t afi,
 						  uint8_t peer_type)
 {
 
-	// remove this check when the other peer types get correct peer dist.
-	// (RFC7854) impl.
+	/* remove this check when the other peer types get correct peer dist.
+	 *(RFC7854) impl.
+	 */
 	if (peer_type != BMP_PEER_TYPE_LOC_RIB_INSTANCE)
 		return 0;
 
 	// sending vrf_id or rd could be turned into an option at some point
 	struct bgp *bgp = bmp->targets->bgp;
-	struct prefix_rd *prd = &bgp->vpn_policy[afi].tovpn_rd;
-	/*
-	 * default vrf => can't have RD => 0
+
+	/*  default vrf => can't have RD => 0
 	 * vrf => has RD?
-	 * 		if yes => use RD value
-	 * 		else => use vrf_id and convert it so that
+	 *		if yes => use RD value
+	 *		else => use vrf_id and convert it so that
 	 * peer_distinguisher is 0::vrf_id
 	 */
-	return bgp->inst_type == VRF_DEFAULT
-		       ? 0
-		       : prd ? *(uint64_t *)prd->val
-			     : (((uint64_t)htonl(bgp->vrf_id)) << 32);
+	if (bgp->inst_type == VRF_DEFAULT)
+		return 0;
+
+	struct prefix_rd *prd = &bgp->vpn_policy[afi].tovpn_rd;
+
+	if (CHECK_FLAG(bgp->vpn_policy[afi].flags,
+		       BGP_VPN_POLICY_TOVPN_RD_SET)) {
+		uint64_t peerd = 0;
+
+		memcpy(&peerd, prd->val, sizeof(prd->val));
+		return peerd;
+	}
+
+	return ((uint64_t)htonl(bgp->vrf_id)) << 32;
 }
 
 static void bmp_common_hdr(struct stream *s, uint8_t ver, uint8_t type)
@@ -317,7 +327,8 @@ static void bmp_per_peer_hdr(struct stream *s, struct bgp *bgp,
 
 	/* Peer Address */
 	/* Set to 0 if it's a LOC-RIB INSTANCE (RFC 9069) or if it's not an
-	 * IPv4/6 address */
+	 * IPv4/6 address
+	 */
 	if (is_locrib || (peer->su.sa.sa_family != AF_INET6 &&
 			  peer->su.sa.sa_family != AF_INET)) {
 		stream_putl(s, 0);
@@ -335,15 +346,19 @@ static void bmp_per_peer_hdr(struct stream *s, struct bgp *bgp,
 
 	/* Peer AS */
 	/* set peer ASN but for LOC-RIB INSTANCE (RFC 9069) put the local bgp
-	 * ASN if available or 0 */
+	 * ASN if available or 0
+	 */
 	as_t asn = !is_locrib ? peer->as : bgp ? bgp->as : 0L;
+
 	stream_putl(s, asn);
 
 	/* Peer BGP ID */
 	/* set router-id but for LOC-RIB INSTANCE (RFC 9069) put the instance
-	 * router-id if available or 0 */
+	 * router-id if available or 0
+	 */
 	struct in_addr *bgp_id =
 		!is_locrib ? &peer->remote_id : bgp ? &bgp->router_id : NULL;
+
 	stream_put_in_addr(s, bgp_id);
 
 	/* Timestamp */
@@ -1243,8 +1258,9 @@ static inline struct bmp_queue_entry *bmp_pull_locrib(struct bmp *bmp)
 				   &bmp->locrib_queuepos);
 }
 
-// TODO BMP_MON_LOCRIB find a way to merge properly this function with
-// bmp_wrqueue or abstract it if possible
+/* TODO BMP_MON_LOCRIB find a way to merge properly this function with
+ * bmp_wrqueue or abstract it if possible
+ */
 static bool bmp_wrqueue_locrib(struct bmp *bmp, struct pullwr *pullwr)
 {
 
@@ -1260,9 +1276,8 @@ static bool bmp_wrqueue_locrib(struct bmp *bmp, struct pullwr *pullwr)
 	afi_t afi = bqe->afi;
 	safi_t safi = bqe->safi;
 
-	if (!CHECK_FLAG(bmp->targets->afimon[afi][safi], BMP_MON_LOC_RIB)) {
+	if (!CHECK_FLAG(bmp->targets->afimon[afi][safi], BMP_MON_LOC_RIB))
 		goto out;
-	}
 
 	switch (bmp->afistate[afi][safi]) {
 	case BMP_AFI_INACTIVE:
@@ -1275,7 +1290,8 @@ static bool bmp_wrqueue_locrib(struct bmp *bmp, struct pullwr *pullwr)
 			break;
 
 		/* currently syncing & haven't reached this prefix yet
-		 * => it'll be sent as part of the table sync, no need here */
+		 * => it'll be sent as part of the table sync, no need here
+		 */
 		zlog_info(
 			"bmp: skipping direct monitor msg bc will be sent with sync :)");
 		goto out;
@@ -1297,10 +1313,12 @@ static bool bmp_wrqueue_locrib(struct bmp *bmp, struct pullwr *pullwr)
 		      (bqe->safi == SAFI_MPLS_VPN);
 
 	struct prefix_rd *prd = is_vpn ? &bqe->rd : NULL;
+
 	bn = bgp_afi_node_lookup(bmp->targets->bgp->rib[afi][safi], afi, safi,
 				 &bqe->p, prd);
 
 	struct bgp_path_info *bpi;
+
 	for (bpi = bn ? bgp_dest_get_bgp_path_info(bn) : NULL; bpi;
 	     bpi = bpi->next) {
 		if (!CHECK_FLAG(bpi->flags, BGP_PATH_SELECTED))
@@ -1489,7 +1507,8 @@ bmp_process_one(struct bmp_targets *bt, struct bmp_qhash_head *updhash,
 	return bqe;
 
 	/* need to update correct queue pos for all sessions of the target after
-	 * a call to this function */
+	 * a call to this function
+	 */
 }
 
 static int bmp_process(struct bgp *bgp, afi_t afi, safi_t safi,
@@ -1512,16 +1531,18 @@ static int bmp_process(struct bgp *bgp, afi_t afi, safi_t safi,
 
 	frr_each(bmp_targets, &bmpbgp->targets, bt) {
 		/* check if any monitoring is enabled (ignoring loc-rib since it
-		 * uses another hook & queue */
+		 * uses another hook & queue
+		 */
 		if (!(bt->afimon[afi][safi] & ~BMP_MON_LOC_RIB))
 			continue;
 
 		struct bmp_queue_entry *last_item =
 			bmp_process_one(bt, &bt->updhash, &bt->updlist, bgp,
 					afi, safi, bn, peer);
 
-		if (!last_item) // if bmp_process_one returns NULL we don't have
-				// anything to do next
+		// if bmp_process_one returns NULL
+		// we don't have anything to do next
+		if (!last_item)
 			continue;
 
 		frr_each(bmp_session, &bt->sessions, bmp) {
@@ -2442,9 +2463,9 @@ DEFPY(bmp_monitor_cfg, bmp_monitor_cmd,
 	argv_find_and_parse_afi(argv, argc, &index, &afi);
 	argv_find_and_parse_safi(argv, argc, &index, &safi);
 
-	if (policy[0] == 'l') {
+	if (policy[0] == 'l')
 		flag = BMP_MON_LOC_RIB;
-	} else if (policy[1] == 'r')
+	else if (policy[1] == 'r')
 		flag = BMP_MON_PREPOLICY;
 	else
 		flag = BMP_MON_POSTPOLICY;
@@ -2793,8 +2814,9 @@ static int bmp_route_update(struct bgp *bgp, afi_t afi, safi_t safi,
 				bt, &bt->locupdhash, &bt->locupdlist, bgp, afi,
 				safi, bn, peer);
 
-			if (!last_item) // if bmp_process_one returns NULL we
-					// don't have anything to do next
+			// if bmp_process_one returns NULL
+			// we don't have anything to do next
+			if (!last_item)
 				continue;
 
 			frr_each (bmp_session, &bt->sessions, bmp) {

bgpd/bgp_bmp.h

@@ -229,15 +229,14 @@ struct bmp_targets {
 	int stat_msec;
 
 	/* only supporting:
-	 * - IPv4 / unicast & multicast
-	 * - IPv6 / unicast & multicast
+	 * - IPv4 / unicast & multicast & VPN
+	 * - IPv6 / unicast & multicast & VPN
 	 * - L2VPN / EVPN
 	 */
 #define BMP_MON_PREPOLICY	(1 << 0)
 #define BMP_MON_POSTPOLICY	(1 << 1)
+#define BMP_MON_LOC_RIB		(1 << 2)
 
-// TODO define BMP_MON_LOC_RIB flag
-#define BMP_MON_LOC_RIB (1 << 2)
 	uint8_t afimon[AFI_MAX][SAFI_MAX];
 	bool mirror;
 

bgpd/bgp_route.c

@@ -103,7 +103,7 @@ DEFINE_HOOK(bgp_rpki_prefix_status,
 	    (peer, attr, prefix));
 
 DEFINE_HOOK(bgp_route_update,
-	    (struct bgp * bgp, afi_t afi, safi_t safi, struct bgp_dest *bn,
+	    (struct bgp *bgp, afi_t afi, safi_t safi, struct bgp_dest *bn,
 	     struct bgp_path_info *updated_route, bool withdraw),
 	    (bgp, afi, safi, bn, updated_route, withdraw));
 
@@ -3150,7 +3150,8 @@ static void bgp_process_main_one(struct bgp *bgp, struct bgp_dest *dest,
 	}
 
 	/* call bmp hook for loc-rib route update / withdraw after flags were
-	 * set */
+	 * set
+	 */
 	if (old_select || new_select) {
 
 		if (old_select) /* route is not installed in locrib anymore */
@@ -3159,6 +3160,7 @@ static void bgp_process_main_one(struct bgp *bgp, struct bgp_dest *dest,
 			new_select->rib_uptime = bgp_clock();
 
 		bool is_withdraw = old_select && !new_select;
+
 		hook_call(bgp_route_update, bgp, afi, safi, dest,
 			  is_withdraw ? old_select : new_select, is_withdraw);
 	}

bgpd/bgp_route.h

@@ -630,7 +630,7 @@ DECLARE_HOOK(bgp_process,
 
 /* called when a route is updated in the rib */
 DECLARE_HOOK(bgp_route_update,
-	     (struct bgp * bgp, afi_t afi, safi_t safi, struct bgp_dest *bn,
+	     (struct bgp *bgp, afi_t afi, safi_t safi, struct bgp_dest *bn,
 	      struct bgp_path_info *updated_route, bool withdraw),
 	     (bgp, afi, safi, bn, updated_route, withdraw));
 

doc/user/bmp.rst

@@ -36,7 +36,7 @@ The `BMP` implementation in FRR has the following properties:
   successfully.  OPEN messages for failed sessions cannot currently be
   mirrored.
 
-- **route monitoring** is available for IPv4 and IPv6 AFIs, unicast, multicast 
+- **route monitoring** is available for IPv4 and IPv6 AFIs, unicast, multicast
   EVPN and VPN SAFIs. Other SAFIs (VPN, Labeled-Unicast, Flowspec, etc.) are not
   currently supported.
 
@@ -61,12 +61,12 @@ RFC 7854
 ========
 Unsupported features (non exhaustive):
   - Per-Peer Header
-    
+
     - Peer Type Flag
     - Peer Distingsher
-  
+
   - Peer Up
-  
+
     - Reason codes (according to TODO comments in code)
 
 Peer Type Flag and Peer Distinguisher can be implemented easily using RFC 9069's base code.
@@ -87,7 +87,7 @@ Unsupported features (should be exhaustive):
 - Peer Up/Down
 
   - VRF/Table Name TLV
-  
+
     - code for TLV exists
     - need better RFC understanding
 
@@ -100,8 +100,8 @@ Unsupported features (should be exhaustive):
   - Stat Type = 8: (64-bit Gauge) Number of routes in Loc-RIB.
   - Stat Type = 10: Number of routes in per-AFI/SAFI Loc-RIB. The value is 
     structured as: 2-byte AFI, 1-byte SAFI, followed by a 64-bit Gauge.
- 
-   
+
+
 Starting BMP
 ============
 
@@ -194,7 +194,7 @@ associated with a particular ``bmp targets``:
 .. clicmd:: bmp monitor AFI SAFI <pre-policy|post-policy|loc-rib>
 
    Perform Route Monitoring for the specified AFI and SAFI.  Only IPv4 and
-   IPv6 are currently valid for AFI. SAFI valid values are currently 
+   IPv6 are currently valid for AFI. SAFI valid values are currently
    unicast, multicast, evpn and vpn.
    Other AFI/SAFI combinations may be added in the future.