Merge pull request #17231 from guoguojia2021/guozhongfeng_alibaba

bgpd:support of color extended community color-only types

bgpd/bgp_ecommunity.c

@@ -361,16 +361,22 @@ static void ecommunity_color_str(char *buf, size_t bufsz, uint8_t *ptr)
 {
 	/*
 	 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-	 *  | 0x03         | Sub-Type(0x0b) |    Flags                      |
+	 *  | 0x03         | Sub-Type(0x0b) | CO|    Flags                  |
 	 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 	 *  |                          Color Value                          |
 	 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	 *  https://datatracker.ietf.org/doc/rfc9256/, Section 8.8.1
+	 *  The CO bits can have 4 different values: 00 01 10 11
 	 */
 	uint32_t colorid;
+	uint8_t color_type;
+	/* get the color type */
+	ptr++;
+	color_type = (*ptr) >> 6;
 
-	memcpy(&colorid, ptr + 3, 4);
+	memcpy(&colorid, ptr + 2, 4);
 	colorid = ntohl(colorid);
-	snprintf(buf, bufsz, "Color:%d", colorid);
+	snprintf(buf, bufsz, "Color:%d%d:%d", (color_type & 0x2) >> 1, color_type & 0x1, colorid);
 }
 
 /* Initialize Extended Comminities related hash. */
@@ -531,7 +537,7 @@ static int ecommunity_encode_internal(uint8_t type, uint8_t sub_type,
 		eval6->val[19] = val & 0xff;
 	} else if (type == ECOMMUNITY_ENCODE_OPAQUE &&
 		   sub_type == ECOMMUNITY_COLOR) {
-		encode_color(val, eval);
+		encode_color(val, as, eval);
 	} else {
 		encode_route_target_as4(as, val, eval, trans);
 	}
@@ -739,6 +745,13 @@ static const char *ecommunity_gettoken(const char *str, void *eval_ptr,
 				 */
 				if (!asn_str2asn(buf, &as))
 					goto error;
+			} else if (type == ECOMMUNITY_COLOR) {
+				/* If extcommunity is color, only support 00/01/10/11, max value is 3 */
+				/* color value */
+				as = strtoul(buf, &endptr, 2);
+				if (*endptr != '\0' || as > 3)
+					goto error;
+				val_color = 0;
 			} else {
 				/* Parsing A AS number in A:MN */
 				errno = 0;
@@ -753,6 +766,8 @@ static const char *ecommunity_gettoken(const char *str, void *eval_ptr,
 				if (*endptr != '\0' || tmp_as > BGP_AS4_MAX ||
 				    errno)
 					goto error;
+				if (*token == ecommunity_token_color && as > 3)
+					goto error;
 				as = (as_t)tmp_as;
 			}
 		} else if (*p == '.') {
@@ -791,13 +806,15 @@ static const char *ecommunity_gettoken(const char *str, void *eval_ptr,
 		/* Encode result into extended community for AS format or color.  */
 		if (as > BGP_AS_MAX)
 			ecomm_type = ECOMMUNITY_ENCODE_AS4;
-		else if (as > 0)
+		else if (type == ECOMMUNITY_COLOR) {
-			ecomm_type = ECOMMUNITY_ENCODE_AS;
-		else if (val_color) {
 			ecomm_type = ECOMMUNITY_ENCODE_OPAQUE;
 			sub_type = ECOMMUNITY_COLOR;
-			val = val_color;
+			if (val_color) {
-		}
+				val = val_color;
+				as = 1;
+			}
+		} else if (as > 0)
+			ecomm_type = ECOMMUNITY_ENCODE_AS;
 	}
 	if (ecommunity_encode(ecomm_type, sub_type, 1, as, ip, val, eval))
 		goto error;
@@ -1419,7 +1436,15 @@ char *ecommunity_ecom2str(struct ecommunity *ecom, int format, int filter)
 			else if (sub_type == ECOMMUNITY_EXTENDED_LINK_BANDWIDTH)
 				ipv6_ecommunity_lb_str(encbuf, sizeof(encbuf),
 						       pnt, len);
-			else
+			else if (sub_type == ECOMMUNITY_OPAQUE_SUBTYPE_COLOR) {
+				uint32_t color;
+				/* get the color type */
+				uint8_t color_type = (*pnt) >> 6;
+				memcpy(&color, pnt + 2, 4);
+				color = ntohl(color);
+				snprintf(encbuf, sizeof(encbuf), "Color:%d%d:%u",
+					 (color_type & 0x2) >> 1, color_type & 0x1, color);
+			} else
 				unk_ecom = true;
 		} else if (CHECK_FLAG(type, ECOMMUNITY_ENCODE_IP_NON_TRANS)) {
 			sub_type = *pnt++;
@@ -1439,6 +1464,7 @@ unknown:
 				 sub_type);
 
 		int r = strlcat(str_buf, encbuf, str_size);
+
 		assert(r < str_size);
 	}
 

bgpd/bgp_ecommunity.h

@@ -85,6 +85,7 @@
 
 /* Low-order octet of the Extended Communities type field for OPAQUE types */
 #define ECOMMUNITY_OPAQUE_SUBTYPE_ENCAP     0x0c
+#define ECOMMUNITY_OPAQUE_SUBTYPE_COLOR	    0x0b
 
 /* Extended communities attribute string format.  */
 #define ECOMMUNITY_FORMAT_ROUTE_MAP            0
@@ -328,26 +329,25 @@ static inline void encode_node_target(struct in_addr *node_id,
 
 /*
  * Encode BGP Color extended community
- * is's a transitive opaque Extended community (RFC 9012 4.3)
+ * is's a transitive opaque Extended community (RFC 9256  8.8.1)
  * flag is set to 0
- * RFC 9012 14.10: No values have currently been registered.
- *            4.3: this field MUST be set to zero by the originator
- *                 and ignored by the receiver;
  *
  */
-static inline void encode_color(uint32_t color_id, struct ecommunity_val *eval)
+static inline void encode_color(uint32_t color_id, uint32_t flags, struct ecommunity_val *eval)
 {
 	/*
 	 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-	 *  | 0x03         | Sub-Type(0x0b) |    Flags                      |
+	 *  | 0x03         | Sub-Type(0x0b) |CO |         Flags             |
 	 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 	 *  |                          Color Value                          |
 	 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	 *  https://datatracker.ietf.org/doc/rfc9256/, Section 8.8.1
+	 *  The CO bits can have 4 different values: 00 01 10 11
 	 */
 	memset(eval, 0, sizeof(*eval));
 	eval->val[0] = ECOMMUNITY_ENCODE_OPAQUE;
 	eval->val[1] = ECOMMUNITY_COLOR;
-	eval->val[2] = 0x00;
+	eval->val[2] = (flags << 6) & 0xff;
 	eval->val[3] = 0x00;
 	eval->val[4] = (color_id >> 24) & 0xff;
 	eval->val[5] = (color_id >> 16) & 0xff;

doc/user/bgp.rst

@@ -2928,6 +2928,23 @@ BGP Extended Communities in Route Map
 
    This command sets colors values.
 
+:rfc:`9256`.
+
+``CO:COLOR``
+   This is a format to define colors value. ``CO`` part is always 00 (default),
+   it can be used to support the requirements of Color-Only steering when using 
+   a Null Endpoint in the SR-TE Policy as specified in Section 8.8 of [RFC9256].
+   The below shows in detail what the different combinations of ``CO`` bits can
+   match on to for the purpose of determining what type of SR-TE Policy Tunnel
+   a BGP route can resolve over, and it also shows the order for resolving the
+   BGP route if there are different tunnels.
+   - ``00`` Can match on a specific endpoint only which should be the nexthop
+     of the route(Default Setting).
+   - ``01`` Can match on a specific endpoint or a null endpoint.
+   - ``10`` Can match on a specific endpoint, null endpoint or any endpoint.
+   - ``11`` Reserved for future use and shuould not be used.
+
+
 .. clicmd:: set extcommunity bandwidth <(1-25600) | cumulative | num-multipaths> [non-transitive]
 
    This command sets the BGP link-bandwidth extended community for the prefix

tests/topotests/bgp_color_extcommunities/r1/bgpd.conf

@@ -11,7 +11,7 @@ router bgp 65001
  exit-address-family
 !
 route-map rmap permit 10
- set extcommunity color 1
+ set extcommunity color 01:1
  set extcommunity rt 80:987
- set extcommunity color 100 55555 200
+ set extcommunity color 01:100 01:55555 01:200
 exit

tests/topotests/bgp_color_extcommunities/test_bgp_color_extcommunities.py

@@ -105,7 +105,7 @@ def test_bgp_color_extended_communities():
                     {
                         "valid": True,
                         "extendedCommunity": {
-                            "string": "RT:80:987 Color:100 Color:200 Color:55555"
+                            "string": "RT:80:987 Color:01:100 Color:01:200 Color:01:55555"
                         },
                     }
                 ],

yang/frr-bgp-route-map.yang

@@ -532,7 +532,7 @@ identity set-extcommunity-color {
 
   typedef color-list {
     type string {
-      pattern '((429496729[0-5]|42949672[0-8][0-9]|'
+      pattern '((00|01|10|11):(429496729[0-5]|42949672[0-8][0-9]|'
       +	    '4294967[0-1][0-9]{2}|429496[0-6][0-9]{3}|'
       +	    '42949[0-5][0-9]{4}|4294[0-8][0-9]{5}|'
       +	    '429[0-3][0-9]{6}|42[0-8][0-9]{7}|'
@@ -540,10 +540,11 @@ identity set-extcommunity-color {
       +	    '[1-9][0-9]{0,8})(\s*))+';
     }
     description
-      "The color-list type represent a set of colors of value (1..4294967295)
+      "The color-list type represent a set of colors of value (examples 00:200 01:200 10:200)
        values are separated by white spaces";
     reference
-      "RFC 9012 - The BGP Tunnel Encapsulation Attribute";
+      "RFC 9012 - The BGP Tunnel Encapsulation Attribute.
+       RFC 9256 - Segment Routing Policy Architecture.";
   }
 
   augment "/frr-route-map:lib/frr-route-map:route-map/frr-route-map:entry/frr-route-map:match-condition/frr-route-map:rmap-match-condition/frr-route-map:match-condition" {