ospfd: OSPFv2 support for draft-ietf-lsr-flex-algo

.clang-format

@@ -110,6 +110,8 @@ ForEachMacros:
   - 'FOREACH_CMT_REC'
   - 'FOREACH_MGMTD_BE_CLIENT_ID'
   - 'FOREACH_MGMTD_DS_ID'
+  - 'FOREACH_ADMIN_GROUP_BITS'
+  - 'FOREACH_FLEX_ALGO_DEFN'
   - 'FOREACH_SAFI'
   - 'FOREACH_SESSION_IN_LIST'
   - 'FOREACH_TXN_CFG_BATCH_IN_LIST'

doc/user/ospfd.rst

@@ -1174,6 +1174,214 @@ TI-LFA requires a proper Segment Routing configuration.
 
    Note that so far only P2P interfaces are supported.
 
+Flexible Algorithms (Flex-Algo)
+===============================
+
+This is a bare-minimum implementation of : :t:`draft-ietf-lsr-flex-algo`. Currently
+`Shortest Path First` is the only algorithm supported, with `IGP-Metric` and
+`Shortest-Path-First` are the only values supported for `metric-type` and
+`calculation-type` respectively. In future support for more algorithms,
+metric-types and calculation-types shall be added.
+
+Please note, since Flexible Algorithm Definitions (also referred to as FAD)
+are advertised in Opaque LSAs (one ore more), capability to carry Opaque
+Linkstate Information (in the form of Opaque LSAs) should be turned on using
+``capability opaque`` and ``router-info area`` configration commands under
+`router ospf` level.
+
+.. clicmd:: [no] flexible-algorithm (128-255)
+
+   Add a new or remove an existing Flexible Algorithm Definition for the
+   current router to support.
+
+   The add will result in the router advertsing the new flexible-algorithm
+   definition (with the specified algorithm-id) in all relevant types of
+   self-originated LSAs. By default, `calculation-type` and `metric-type`
+   for the new flexible-algorithm shall be set to `Shortest-Path-First` and
+   `IGP-Metric` respectively.
+
+   Removing an existing Flexible Algorithm Definition will result in the
+   router removing all advertisements for the specified algorithm-id from all
+   the relevant types of self-originated LSAs.
+
+.. clicmd:: [no] flexible-algorithm (128-255) calculation-type (spf)
+
+   Set (or reset) the `calculation-type` for the Flexible Algorithm Definition
+   specified by the algorithm-id. Currently `spf` (i.e. Shortest-Path-First)
+   only allowed value. Support for more metric-types shall be added in future.
+
+   Resetting the `calculation-type` for the Flexible Algorithm Definition will
+   reset it to the default value of `spf`.
+
+.. clicmd:: [no] flexible-algorithm (128-255) metric-type (igp)
+
+   Set the (or reset) `metric-type` for the Flexible Algorithm Definition
+   specified by the algorithm-id. Currently `igp-metric` is the only allowed
+   value. Support for more metric-types shall be added in future.
+
+   Resetting the `metric-type` for the Flexible Algorithm Definition will
+   reset it to efault value of `igp-metric`.
+
+.. clicmd:: [no] flexible-algorithm (128-255) priority (0-4294967295)
+
+   Set the (or reset) `priority` for the Flexible Algorithm Definition
+   specified by the algorithm-id. Default value of priority is 0.
+
+   Resetting the `priority` for the Flexible Algorithm Definition will reset
+   it to default value 0.
+
+.. clicmd:: [no] flexible-algorithm (128-255) exclude-admin-group (0-4294967295)
+
+   Add (or remove) the specified `admin-group` value to (or from) the list of
+   Exclude-Admin-Groups for the Flexible Algorithm Definition specified by the
+   algorithm-id.
+
+   This will add (or remove) the admin-group to (or from) the list of
+   admin-groups advertised in the Exclude-Admin-Group Sub-TLV included in the
+   corresponding Flexible Algorithm Definition TLV (carried inside the
+   Router-Info external LSA).
+
+.. clicmd:: [no] flexible-algorithm (128-255) include-any-admin-group (0-4294967295)
+
+   Add (or remove) the specified `admin-group` value to (or from) the list of
+   Include-Any-Admin-Groups for the Flexible Algorithm Definition specified by
+   the algorithm-id.
+
+   This will add (or remove) the admin-group to (or from) the list of
+   admin-groups advertised in the Include-Any-Admin-Group Sub-TLV included in
+   the corresponding Flexible Algorithm Definition TLV (carried inside the
+   Router-Info external LSA).
+
+.. clicmd:: [no] flexible-algorithm (128-255) include-all-admin-group (0-4294967295)
+
+   Add (or remove) the specified `admin-group` value to (or from) the list of
+   Include-All-Admin-Groups for the Flexible Algorithm Definition specified by
+   the algorithm-id.
+
+   This will add (or remove) the admin-group to (or from) the list of
+   admin-groups advertised in the Include-All-Admin-Group Sub-TLV included in
+   the corresponding Flexible Algorithm Definition TLV (carried inside the
+   Router-Info external LSA).
+
+.. clicmd:: [no] flexible-algorithm (128-255) exclude-srlg (0-4294967295)
+
+   Add (or remove) the specified `srlg` value to (or from) the list of
+   Exclude-SRLGs for the Flexible Algorithm Definition specified by the
+   algorithm-id.
+
+   This will add (or remove) the admin-group to (or from) the list of
+   SRLGs advertised in the Exclude-SRLG Sub-TLV included in the
+   corresponding Flexible Algorithm Definition TLV (carried inside the
+   Router-Info external LSA).
+
+.. clicmd:: [no] flexible-algorithm (128-255) advertise-prefix-metric (0-4294967295)
+
+   Set (or reset) the `advertise-prefix-metric` for the Flexible Algorithm
+   Definition specified by the algorithm-id.
+
+   Setting the `advertise-prefix-metric` for the Flexible Algorithm
+   Definition will results in the router advertising the configured value
+   inside a Flexible-Algorithm Prefix-Metric(FAPM) Sub-TLV (carried inside
+   Extended Prefix TLV within a Extended Prefix Opaque LSA), as well as
+   inside a Flexible-Algorithm ASBR Metric(FAAM) Sub-TLV (to be carried in
+   the Extended Inter-Area ASBR TLV within a new Extended Inter-Area LSA).
+   By default no prefix metric is advertised.
+
+   Resetting the `advertise-prefix-metric` for the Flexible Algorithm Definition
+   specified by the algorithm-id will remove advertisement of the previously
+   configured value from all the relevant Sub-TLVs, TLVs and LSAs.
+
+.. clicmd:: show ip ospf [vrf (vrf-name)] database opaque-area
+
+   This existing command's output has been enhanced to display the new
+   Flexible-Algorithm definition LSAs, TLVs and Sub-TLVs.
+
+   Following show command output shows the new Flexible Algoritms Definition
+   LSAs, TLVs and Sub-TLVs advertised.
+
+   .. code-block:: frr
+
+      frr# show ip ospf database opaque-area
+
+            OSPF Router with ID (1.1.1.1)
+
+
+                     Area-Local Opaque-LSA (Area 0.0.0.0)
+
+      LS age: 524
+      Options: 0x42 : *|O|-|-|-|-|E|-
+      LS Flags: 0x1
+      LS Type: Area-Local Opaque-LSA
+      Link State ID: 4.0.0.0 (Area-Local Opaque-Type/ID)
+      Advertising Router: 1.1.1.1
+      LS Seq Number: 8000000b
+      Checksum: 0x9b60
+      Length: 80
+
+      Opaque-Type 4 (Router Information LSA)
+      Opaque-ID   0x0
+      Opaque-Info: 60 octets of data
+      Router Capabilities: 0x10000000
+      Flexible Algorithm Defintion TLV: Length: 48
+         Algorithm-Identifier = 128
+         Priority = 10
+         Metric-Type = Invalid-Metric-Type
+         Calculation-Type = spf
+         FAD Exclude Admin Groups:
+            [ 30 ]
+         FAD Include Any Admin Groups:
+            [ 60, 70 ]
+         FAD Include All Admin Groups:
+            [ 20 ]
+         FAD Flags:
+            [ 10 ]
+         FAD Exclude SRLGs:
+            [ 10 ]
+
+      LS age: 771
+      Options: 0x42 : *|O|-|-|-|-|E|-
+      LS Flags: 0x6
+      LS Type: Area-Local Opaque-LSA
+      Link State ID: 4.0.0.0 (Area-Local Opaque-Type/ID)
+      Advertising Router: 2.2.2.2
+      LS Seq Number: 8000000b
+      Checksum: 0x4d9d
+      Length: 28
+
+      Opaque-Type 7 (Extended Prefix Opaque LSA)
+      Opaque-ID   0x1
+      Opaque-Info: 24 octets of data
+      Extended Prefix TLV: Length 20
+         Route Type: 1
+         Address Family: 0x0
+         Flags: 0x40
+         Address: 1.1.1.1/32
+      Prefix FAPM Sub-TLV: Length 8
+         Algorithm: 128
+         Flags: 0x0
+         Metric: 100
+
+      LS age: 1383
+      Options: 0x42 : *|O|-|-|-|-|E|-
+      LS Flags: 0x1
+      LS Type: Area-Local Opaque-LSA
+      Link State ID: 11.0.0.0 (Area-Local Opaque-Type/ID)
+      Advertising Router: 1.1.1.1
+      LS Seq Number: 8000000a
+      Checksum: 0xc826
+      Length: 40
+
+      Opaque-Type 11 (Extended Inter-Area ASBR Opaque LSA)
+      Opaque-ID   0x0
+      Opaque-Info: 20 octets of data
+      Extended Inter-Area ASBR TLV: Length 16
+         ASBR-Router-Id: 1.1.1.1
+      Flex-Algo ASBR Metric Sub-TLV: Length 8
+         Algorithm: 128
+         Metric:100
+
+      frr#
+
 .. _debugging-ospf:
 
 Debugging OSPF

lib/admin_group.h

@@ -34,6 +34,10 @@ struct admin_group {
 	bitfield_t bitmap;
 };
 
+#define FOREACH_ADMIN_GROUP_BITS(admngrp, bitpos)			\
+	bf_for_each_set_bit((admngrp)->bitmap, (bitpos), 		\
+			    EXT_ADMIN_GROUP_MAX_POSITIONS)
+
 char *admin_group_string(char *out, size_t sz, int indent,
 			 const struct admin_group *ag);
 char *admin_group_standard_print(char *out, int indent, uint32_t bitmap);

lib/affinitymap.h

@@ -81,7 +81,7 @@ void cli_show_affinity_map(struct vty *vty, const struct lyd_node *dnode,
 			   bool show_defaults);
 
 void affinity_map_init(void);
-
+void affinity_map_set_nb_bypass(bool bypass);
 
 #ifdef __cplusplus
 }

lib/affinitymap_cli.c

@@ -39,6 +39,37 @@ static struct cmd_node affinitymap_node = {
 	.config_write = affinity_map_config_write,
 };
 
+static bool bypass_nb;
+
+static int affinity_map_update(struct vty *vty, const char *name,
+			       const int position, bool delete)
+{
+	char *old = NULL;
+	struct affinity_map *map;
+
+	if (position >= 0)
+		old = affinity_map_name_get(position);
+	map = affinity_map_get(name);
+	if (!delete) {
+		if (old && strncmp(old, name, AFFINITY_NAME_SIZE)) {
+			vty_out(vty, "Bit '%d' already mapped to name '%s'\n",
+				position, old);
+			return CMD_WARNING_CONFIG_FAILED;
+		}
+
+		if (!old)
+			affinity_map_set(name, position);
+	} else {
+		if (map)
+			affinity_map_unset(name);
+	}
+
+	zlog_err("%s: %sd affinity-map '%s', bit %d",
+		 __func__, delete ? "Delete" : "Update", name, position);
+
+	return CMD_SUCCESS;
+}
+
 /* max value is EXT_ADMIN_GROUP_MAX_POSITIONS - 1 */
 DEFPY_YANG_NOSH(affinity_map, affinity_map_cmd,
 		"affinity-map NAME$name bit-position (0-1023)$position",
@@ -49,6 +80,9 @@ DEFPY_YANG_NOSH(affinity_map, affinity_map_cmd,
 {
 	char xpathr[XPATH_MAXLEN];
 
+	if (bypass_nb)
+		return affinity_map_update(vty, name, position, false);
+
 	snprintf(
 		xpathr, sizeof(xpathr),
 		"/frr-affinity-map:lib/affinity-maps/affinity-map[name='%s']/value",
@@ -68,6 +102,10 @@ DEFPY_YANG_NOSH(no_affinity_map, no_affinity_map_cmd,
 {
 	char xpathr[XPATH_MAXLEN];
 
+	if (bypass_nb)
+		return affinity_map_update(
+			vty, name, argc > 3 ? (int) position : -1, true);
+
 	snprintf(xpathr, sizeof(xpathr),
 		 "/frr-affinity-map:lib/affinity-maps/affinity-map[name='%s']",
 		 name);
@@ -105,3 +143,8 @@ void affinity_map_init(void)
 	install_element(CONFIG_NODE, &affinity_map_cmd);
 	install_element(CONFIG_NODE, &no_affinity_map_cmd);
 }
+
+void affinity_map_set_nb_bypass(bool bypass)
+{
+	bypass_nb = bypass;
+}

lib/bitfield.h

@@ -95,6 +95,15 @@ DECLARE_MTYPE(BITFIELD);
 /* compare two bitmaps of the same length */
 #define bf_cmp(v1, v2) (memcmp((v1).data, (v2).data, ((v1).m * sizeof(word_t))))
 
+/* return number bits in the allocated bitmap data so far */
+#define bf_bit_size(v) ((v).m * WORD_SIZE)
+
+/* return number of bytes in the allocated bitmap data so far */
+#define bf_byte_size(v) ((v).m * sizeof(word_t))
+
+/* return number of words in the allocated bitmap data so far */
+#define bf_word_size(v) (v).m
+
 /*
  * return 0th index back to bitfield
  */
@@ -268,6 +277,61 @@ static inline bitfield_t bf_copy(bitfield_t src)
 	return dst;
 }
 
+/*
+ * Encode a bitmap to a word-stream. Returns the number of bytes encoded
+ * instead of words.
+ */
+static inline void bf_encode_to_buf(bitfield_t *v, u_int8_t *buf,
+				    u_int16_t *buflen)
+{
+	u_int16_t bm_len, len;
+	int indx;
+	word_t *w;
+
+	if (!bf_is_inited(*v) || !buflen)
+		return;
+
+	bm_len = (u_int16_t)bf_byte_size(*v);
+	len = (u_int16_t)bf_word_size(*v);
+	if (*buflen < bm_len) {
+		*buflen = 0;
+		return;
+	}
+
+	w = (word_t *)buf;
+	*buflen = 0;
+	for (indx = 0; indx < len; indx++) {
+		w[indx] = htonl(v->data[indx]);
+
+		/* Avoid encoding trailing zeroes */
+		if (w[indx])
+			*buflen = indx + 1;
+	}
+	(*buflen) *= sizeof(word_t);
+}
+
+/*
+ * Decode a bitmap from a word-stream.
+ */
+static inline void bf_decode_from_buf(bitfield_t *v, u_int8_t *buf,
+				      u_int16_t buflen)
+{
+	size_t indx;
+	word_t *w;
+
+	assert(buflen);
+	v->n = 0;
+	v->m = buflen / sizeof(word_t);
+	v->data = (word_t *)XCALLOC(MTYPE_BITFIELD, v->m * sizeof(word_t));
+
+	w = (word_t *)buf;
+	for (indx = 0; indx < v->m; indx++) {
+		v->data[indx] = ntohl(w[indx]);
+		if (v->data[indx])
+			v->n = indx + 1;
+	}
+}
+
 
 #ifdef __cplusplus
 }