/*
- * This is an implementation of Segment Routing for IS-IS
- * as per draft draft-ietf-isis-segment-routing-extensions-25
+ * This is an implementation of Segment Routing for IS-IS as per RFC 8667
*
- * Copyright (C) 2019 Orange Labs http://www.orange.com
+ * Copyright (C) 2019 Orange http://www.orange.com
*
* Author: Olivier Dugeon <olivier.dugeon@orange.com>
* Contributor: Renato Westphal <renato@opensourcerouting.org> for NetDEF
#include "isisd/isis_zebra.h"
#include "isisd/isis_errors.h"
+/* Local variables and functions */
DEFINE_MTYPE_STATIC(ISISD, ISIS_SR_INFO, "ISIS segment routing information")
static void sr_prefix_uninstall(struct sr_prefix *srp);
static void sr_prefix_reinstall(struct sr_prefix *srp, bool make_before_break);
-/*----------------------------------------------------------------------------*/
+/* --- RB-Tree Management functions ----------------------------------------- */
+/**
+ * SR Prefix comparison for RB-Tree.
+ *
+ * @param a First SR prefix
+ * @param b Second SR prefix
+ *
+ * @return -1 (a < b), 0 (a == b) or +1 (a > b)
+ */
static inline int sr_prefix_sid_compare(const struct sr_prefix *a,
const struct sr_prefix *b)
{
DECLARE_RBTREE_UNIQ(srdb_area_prefix, struct sr_prefix, area_entry,
sr_prefix_sid_compare)
+/**
+ * Configured SR Prefix comparison for RB-Tree.
+ *
+ * @param a First SR prefix
+ * @param b Second SR prefix
+ *
+ * @return -1 (a < b), 0 (a == b) or +1 (a > b)
+ */
static inline int sr_prefix_sid_cfg_compare(const struct sr_prefix_cfg *a,
const struct sr_prefix_cfg *b)
{
DECLARE_RBTREE_UNIQ(srdb_prefix_cfg, struct sr_prefix_cfg, entry,
sr_prefix_sid_cfg_compare)
+/**
+ * SR Node comparison for RB-Tree.
+ *
+ * @param a First SR node
+ * @param b Second SR node
+ *
+ * @return -1 (a < b), 0 (a == b) or +1 (a > b)
+ */
static inline int sr_node_compare(const struct sr_node *a,
const struct sr_node *b)
{
}
DECLARE_RBTREE_UNIQ(srdb_node, struct sr_node, entry, sr_node_compare)
-/*----------------------------------------------------------------------------*/
+/* --- Functions used for Yang model and CLI to configure Segment Routing --- */
-/* Returns true if the interface/address pair corresponds to a Node-SID. */
+/**
+ * Check if prefix correspond to a Node SID.
+ *
+ * @param ifp Interface
+ * @param prefix Prefix to be checked
+ *
+ * @return True if the interface/address pair corresponds to a Node-SID
+ */
static bool sr_prefix_is_node_sid(const struct interface *ifp,
const struct prefix *prefix)
{
return (if_is_loopback(ifp) && is_host_route(prefix));
}
-/* Handle changes in the local SRGB configuration. */
+/**
+ * Update local SRGB configuration. SRGB is reserved though Label Manager.
+ * This function trigger the update of local Prefix-SID installation.
+ *
+ * @param area IS-IS area
+ * @param lower_bound Lower bound of SRGB
+ * @param upper_bound Upper bound of SRGB
+ *
+ * @return 0 on success, -1 otherwise
+ */
int isis_sr_cfg_srgb_update(struct isis_area *area, uint32_t lower_bound,
uint32_t upper_bound)
{
return 0;
}
-/* Handle new Prefix-SID configuration. */
+/**
+ * Add new Prefix-SID configuration to the SRDB.
+ *
+ * @param area IS-IS area
+ * @param prefix Prefix to be added
+ *
+ * @return Newly added Prefix-SID configuration structure
+ */
struct sr_prefix_cfg *isis_sr_cfg_prefix_add(struct isis_area *area,
const struct prefix *prefix)
{
return pcfg;
}
-/* Handle removal of locally configured Prefix-SID. */
+/**
+ * Removal of locally configured Prefix-SID.
+ *
+ * @param pcfg Configured Prefix-SID
+ */
void isis_sr_cfg_prefix_del(struct sr_prefix_cfg *pcfg)
{
struct isis_area *area = pcfg->area;
XFREE(MTYPE_ISIS_SR_INFO, pcfg);
}
-/* Lookup Prefix-SID in the local configuration. */
+/**
+ * Lookup for Prefix-SID in the local configuration.
+ *
+ * @param area IS-IS area
+ * @param prefix Prefix to lookup
+ *
+ * @return Configured Prefix-SID structure if found, NULL otherwise
+ */
struct sr_prefix_cfg *isis_sr_cfg_prefix_find(struct isis_area *area,
union prefixconstptr prefix)
{
return srdb_prefix_cfg_find(&area->srdb.config.prefix_sids, &pcfg);
}
-/* Fill in Prefix-SID Sub-TLV according to the corresponding configuration. */
+/**
+ * Fill in Prefix-SID Sub-TLV according to the corresponding configuration.
+ *
+ * @param pcfg Prefix-SID configuration
+ * @param external False if prefix is locally configured, true otherwise
+ * @param psid Prefix-SID sub-TLV to be updated
+ */
void isis_sr_prefix_cfg2subtlv(const struct sr_prefix_cfg *pcfg, bool external,
struct isis_prefix_sid *psid)
{
}
}
-/*----------------------------------------------------------------------------*/
+/* --- Segment Routing Prefix Management functions -------------------------- */
+/**
+ * Add Segment Routing Prefix to a given Segment Routing Node.
+ *
+ * @param area IS-IS area
+ * @param srn Segment Routing Node
+ * @param prefix Prefix to be added
+ * @param local True if prefix is locally configured, false otherwise
+ * @param psid Prefix-SID sub-TLVs
+ *
+ * @return New Segment Routing Prefix structure
+ */
static struct sr_prefix *sr_prefix_add(struct isis_area *area,
struct sr_node *srn,
union prefixconstptr prefix, bool local,
return srp;
}
+/**
+ * Remove given Segment Prefix from given Segment Routing Node.
+ * Prefix-SID is un-installed first.
+ *
+ * @param area IS-IS area
+ * @param srn Segment Routing Node
+ * @param srp Segment Routing Prefix
+ */
static void sr_prefix_del(struct isis_area *area, struct sr_node *srn,
struct sr_prefix *srp)
{
XFREE(MTYPE_ISIS_SR_INFO, srp);
}
+/**
+ * Find Segment Routing Prefix by Area.
+ *
+ * @param area IS-IS area
+ * @param level IS-IS level
+ * @param prefix Prefix to lookup
+ *
+ * @return Segment Routing Prefix structure if found, NULL otherwise
+ */
static struct sr_prefix *sr_prefix_find_by_area(struct isis_area *area,
int level,
union prefixconstptr prefix)
struct sr_prefix srp = {};
prefix_copy(&srp.prefix, prefix.p);
- return srdb_area_prefix_find(&area->srdb.prefix_sids[level - 1],
- &srp);
+ return srdb_area_prefix_find(&area->srdb.prefix_sids[level - 1], &srp);
}
+/**
+ * Find Segment Routing Prefix by Segment Routing Node.
+ *
+ * @param srn Segment Routing Node
+ * @param prefix Prefix to lookup
+ *
+ * @return Segment Routing Prefix structure if found, NULL otherwise
+ */
static struct sr_prefix *sr_prefix_find_by_node(struct sr_node *srn,
union prefixconstptr prefix)
{
return srdb_node_prefix_find(&srn->prefix_sids, &srp);
}
+/* --- Segment Routing Node Management functions ---------------------------- */
+
+/**
+ * Add Segment Routing Node to the Segment Routing Data Base.
+ *
+ * @param area IS-IS area
+ * @param level IS-IS level
+ * @param sysid Node System ID
+ * @param cap Segment Routing Capability sub-TLVs
+ *
+ * @return New Segment Routing Node structure
+ */
static struct sr_node *sr_node_add(struct isis_area *area, int level,
const uint8_t *sysid,
const struct isis_router_cap *cap)
}
static void sr_node_del(struct isis_area *area, int level, struct sr_node *srn)
+/**
+ * Remove Segment Routing Node from the Segment Routing Data Base.
+ * All Prefix-SID attached to this Segment Routing Node are removed first.
+ *
+ * @param area IS-IS area
+ * @param level IS-IS level
+ * @param srn Segment Routing Node to be deleted
+ */
{
sr_debug(" |- Delete SR Node %s", sysid_print(srn->sysid));
XFREE(MTYPE_ISIS_SR_INFO, srn);
}
+/**
+ * Find Segment Routing Node in the Segment Routing Data Base per system ID.
+ *
+ * @param area IS-IS area
+ * @param level IS-IS level
+ * @param sysid Node System ID to lookup
+ *
+ * @return Segment Routing Node structure if found, NULL otherwise
+ */
static struct sr_node *sr_node_find(struct isis_area *area, int level,
const uint8_t *sysid)
{
return srdb_node_find(&area->srdb.sr_nodes[level - 1], &srn);
}
+/**
+ * Update Segment Routing Node following an SRGB update. This function
+ * is called when a neighbor SR Node has updated its SRGB.
+ *
+ * @param area IS-IS area
+ * @param level IS-IS level
+ * @param sysid Segment Routing Node system ID
+ */
static void sr_node_srgb_update(struct isis_area *area, int level,
uint8_t *sysid)
{
}
}
+/* --- Segment Routing Nexthop information Management functions ------------- */
+
+/**
+ * Update Segment Routing Nexthop.
+ *
+ * @param srnh Segment Routing next hop
+ * @param label Output MPLS label
+ */
void isis_sr_nexthop_update(struct sr_nexthop_info *srnh, mpls_label_t label)
{
srnh->label = label;
srnh->uptime = time(NULL);
}
+/**
+ * Reset Segment Routing Nexthop.
+ *
+ * @param srnh Segment Routing Nexthop
+ */
void isis_sr_nexthop_reset(struct sr_nexthop_info *srnh)
{
srnh->label = MPLS_INVALID_LABEL;
srnh->uptime = 0;
}
-/*----------------------------------------------------------------------------*/
+/* --- Segment Routing Prefix-SID Management functions to configure LFIB ---- */
-/* Lookup IS-IS route in the SPT. */
+/**
+ * Lookup IS-IS route in the Shortest Path Tree.
+ *
+ * @param area IS-IS area
+ * @param tree_id Shortest Path Tree identifier
+ * @param srp Segment Routing Prefix to lookup
+ *
+ * @return Route Information for this prefix if found, NULL otherwise
+ */
static struct isis_route_info *sr_prefix_lookup_route(struct isis_area *area,
enum spf_tree_id tree_id,
struct sr_prefix *srp)
return NULL;
}
-/* Calculate Prefix-SID input label. */
+/**
+ * Compute input label for the given Prefix-SID.
+ *
+ * @param srp Segment Routing Prefix
+ *
+ * @return MPLS label or MPLS_INVALID_LABEL in case of SRGB overflow
+ */
static mpls_label_t sr_prefix_in_label(const struct sr_prefix *srp)
{
const struct sr_node *srn = srp->srn;
struct isis_area *area = srn->area;
- /* Absolute SID value. */
+ /* Return SID value as MPLS label if it is an Absolute SID */
if (CHECK_FLAG(srp->sid.flags,
ISIS_PREFIX_SID_VALUE | ISIS_PREFIX_SID_LOCAL))
return srp->sid.value;
- /* Index SID value. */
+ /* Check that SID index falls inside the SRGB */
if (srp->sid.value >= (area->srdb.config.srgb_upper_bound
- area->srdb.config.srgb_lower_bound + 1)) {
flog_warn(EC_ISIS_SID_OVERFLOW,
return MPLS_INVALID_LABEL;
}
+ /* Return MPLS label as SID index + SRGB_lower_bound as per RFC 8667 */
return (area->srdb.config.srgb_lower_bound + srp->sid.value);
}
-/* Calculate Prefix-SID output label. */
+/**
+ * Compute output label for the given Prefix-SID.
+ *
+ * @param srp Segment Routing Prefix
+ * @param srn_nexthop Segment Routing nexthop node
+ * @param sysid System ID of the SR node which advertised the Prefix-SID
+ *
+ * @return MPLS label or MPLS_INVALID_LABEL in case of error
+ */
static mpls_label_t sr_prefix_out_label(const struct sr_prefix *srp,
const struct sr_node *srn_nexthop,
const uint8_t *sysid)
{
const struct sr_node *srn = srp->srn;
- /* Is the adjacency the last hop? */
+ /* Check if the nexthop SR Node is the last hop? */
if (memcmp(sysid, srn->sysid, ISIS_SYS_ID_LEN) == 0) {
+ /* SR-Node doesn't request NO-PHP. Return Implicit NULL label */
if (!CHECK_FLAG(srp->sid.flags, ISIS_PREFIX_SID_NO_PHP))
return MPLS_LABEL_IMPLICIT_NULL;
+ /* SR-Node requests Implicit NULL Label */
if (CHECK_FLAG(srp->sid.flags, ISIS_PREFIX_SID_EXPLICIT_NULL)) {
if (srp->prefix.family == AF_INET)
return MPLS_LABEL_IPV4_EXPLICIT_NULL;
/* Fallthrough */
}
- /* Absolute SID value. */
+ /* Return SID value as MPLS label if it is an Absolute SID */
if (CHECK_FLAG(srp->sid.flags,
ISIS_PREFIX_SID_VALUE | ISIS_PREFIX_SID_LOCAL)) {
/*
* V/L SIDs have local significance, so only adjacent routers
- * can use them.
+ * can use them (RFC8667 section #2.1.1.1)
*/
if (srp->srn != srn_nexthop)
return MPLS_INVALID_LABEL;
return srp->sid.value;
}
- /* Index SID value. */
+ /* Check that SID index falls inside the SRGB */
if (srp->sid.value >= srn_nexthop->cap.srgb.range_size) {
flog_warn(EC_ISIS_SID_OVERFLOW,
"%s: SID index %u falls outside remote SRGB range",
return MPLS_INVALID_LABEL;
}
+ /* Return MPLS label as SID index + SRGB_lower_bound as per RFC 8667 */
return (srn_nexthop->cap.srgb.lower_bound + srp->sid.value);
}
-/* Process local Prefix-SID and install it if possible. */
+/**
+ * Process local Prefix-SID and install it if possible. Input label is
+ * computed before installing it in LFIB.
+ *
+ * @param srp Segment Routing Prefix
+ *
+ * @return 0 on success, -1 otherwise
+ */
static int sr_prefix_install_local(struct sr_prefix *srp)
{
mpls_label_t input_label;
const struct sr_node *srn = srp->srn;
/*
- * No need to install LSP to local Prefix-SID unless the
+ * No need to install Label for local Prefix-SID unless the
* no-PHP option is configured.
*/
if (!CHECK_FLAG(srp->sid.flags, ISIS_PREFIX_SID_NO_PHP)
&srp->prefix, IS_SID_VALUE(srp->sid.flags) ? "label" : "index",
srp->sid.value, circuit_t2string(srn->level));
- /* Calculate local label. */
+ /* Compute input label and check that is valid. */
input_label = sr_prefix_in_label(srp);
if (input_label == MPLS_INVALID_LABEL)
return -1;
return 0;
}
-/* Process remote Prefix-SID and install it if possible. */
+/**
+ * Process remote Prefix-SID and install it if possible. Input and Output
+ * labels are computed before installing them in LFIB.
+ *
+ * @param srp Segment Routing Prefix
+ *
+ * @return 0 on success, -1 otherwise
+ */
static int sr_prefix_install_remote(struct sr_prefix *srp)
{
const struct sr_node *srn = srp->srn;
mpls_label_t input_label;
size_t nexthop_num = 0;
- /* Lookup associated IS-IS route. */
+ /* Lookup to associated IS-IS route. */
tree_id = (srp->prefix.family == AF_INET) ? SPFTREE_IPV4 : SPFTREE_IPV6;
srp->u.remote.rinfo = sr_prefix_lookup_route(area, tree_id, srp);
if (!srp->u.remote.rinfo)
/* SPF hasn't converged for this route yet. */
return -1;
- /* Calculate local label. */
+ /* Compute input label and check that is valid. */
input_label = sr_prefix_in_label(srp);
if (input_label == MPLS_INVALID_LABEL)
return -1;
IS_SID_VALUE(srp->sid.flags) ? "label" : "index",
srp->sid.value, circuit_t2string(srn->level));
+ /* Process all SPF nexthops */
for (ALL_LIST_ELEMENTS_RO(srp->u.remote.rinfo->nexthops, node,
nexthop)) {
struct sr_node *srn_nexthop;
&& !IS_SR_IPV6(srn_nexthop->cap.srgb)))
goto next;
+ /* Compute output label and check if it is valid */
output_label =
sr_prefix_out_label(srp, srn_nexthop, nexthop->sysid);
if (output_label == MPLS_INVALID_LABEL)
next:
isis_sr_nexthop_reset(&nexthop->sr);
}
+
+ /* Check that we found at least one valid nexthop */
if (nexthop_num == 0) {
sr_debug(" |- no valid nexthops");
return -1;
return 0;
}
-/* Process local or remote Prefix-SID and install it if possible. */
+/**
+ * Process local or remote Prefix-SID and install it if possible.
+ *
+ * @param srp Segment Routing Prefix
+ */
static void sr_prefix_install(struct sr_prefix *srp)
{
const struct sr_node *srn = srp->srn;
}
}
+ /* Install corresponding LFIB entry */
if (srp->type == ISIS_SR_PREFIX_LOCAL)
ret = sr_prefix_install_local(srp);
else
sr_prefix_uninstall(srp);
}
-/* Uninstall local or remote Prefix-SID. */
+/**
+ * Uninstall local or remote Prefix-SID.
+ *
+ * @param srp Segment Routing Prefix
+ */
static void sr_prefix_uninstall(struct sr_prefix *srp)
{
struct listnode *node;
struct isis_nexthop *nexthop;
+ /* Check that Input Label is valid */
if (srp->input_label == MPLS_INVALID_LABEL)
return;
}
}
-/* Reinstall local or remote Prefix-SID. */
+/**
+ * Reinstall local or remote Prefix-SID.
+ *
+ * @param srp Segment Routing Prefix
+ */
static inline void sr_prefix_reinstall(struct sr_prefix *srp,
bool make_before_break)
{
if (!make_before_break)
sr_prefix_uninstall(srp);
+ /* New input label is computed in sr_prefix_install() function */
sr_prefix_install(srp);
}
-/*----------------------------------------------------------------------------*/
+/* --- IS-IS LSP Parse functions -------------------------------------------- */
-/* Parse all SR-related information from the given Router Capabilities TLV. */
+/**
+ * Parse all SR-related information from the given Router Capabilities TLV.
+ *
+ * @param area IS-IS area
+ * @param level IS-IS level
+ * @param sysid System ID of the LSP
+ * @param router_cap Router Capability subTLVs
+ *
+ * @return Segment Routing Node structure for this System ID
+ */
static struct sr_node *
parse_router_cap_tlv(struct isis_area *area, int level, const uint8_t *sysid,
const struct isis_router_cap *router_cap)
return srn;
}
-/* Parse list of Prefix-SID Sub-TLVs. */
+/**
+ * Parse list of Prefix-SID Sub-TLVs.
+ *
+ * @param srn Segment Routing Node
+ * @param prefix Prefix to be parsed
+ * @param local True if prefix comes from own LSP, false otherwise
+ * @param prefix_sids Prefix SID subTLVs
+ */
static void parse_prefix_sid_subtlvs(struct sr_node *srn,
union prefixconstptr prefix, bool local,
struct isis_item_list *prefix_sids)
sr_debug("ISIS-Sr (%s): Parse Prefix SID TLV", area->area_tag);
+ /* Parse list of Prefix SID subTLVs */
for (i = prefix_sids->head; i; i = i->next) {
struct isis_prefix_sid *psid = (struct isis_prefix_sid *)i;
struct sr_prefix *srp;
+ /* Only SPF algorithm is supported right now */
if (psid->algorithm != SR_ALGORITHM_SPF)
continue;
+ /* Compute corresponding Segment Routing Prefix */
srp = sr_prefix_find_by_node(srn, prefix);
if (srp) {
if (srp->sid.flags != psid->flags
}
}
-/* Parse all SR-related information from the given LSP. */
+/**
+ * Parse all SR-related information from the given LSP.
+ *
+ * @param area IS-IS area
+ * @param level IS-IS level
+ * @param srn Segment Routing Node
+ * @param lsp IS-IS LSP
+ */
static void parse_lsp(struct isis_area *area, int level, struct sr_node **srn,
struct isis_lsp *lsp)
{
struct isis_item *i;
bool local = lsp->own_lsp;
+ /* Check LSP sequence number */
if (lsp->hdr.seqno == 0) {
zlog_warn("%s: lsp with 0 seq_num - ignore", __func__);
return;
}
}
-/* Parse all SR-related information from the entire LSPDB. */
+/**
+ * Parse all SR-related information from the entire LSPDB.
+ *
+ * @param area IS-IS area
+ */
static void parse_lspdb(struct isis_area *area)
{
struct isis_lsp *lsp;
sr_debug("ISIS-Sr (%s): Parse LSP Data Base", area->area_tag);
+ /* Process all LSP from Level 1 & 2 */
for (int level = ISIS_LEVEL1; level <= ISIS_LEVELS; level++) {
frr_each (lspdb, &area->lspdb[level - 1], lsp) {
struct isis_lsp *frag;
struct listnode *node;
struct sr_node *srn = NULL;
+ /* Skip Pseudo ID LSP and LSP without TLVs */
if (LSP_PSEUDO_ID(lsp->hdr.lsp_id))
continue;
if (!lsp->tlvs)
continue;
+ /* Parse LSP, then fragment */
parse_lsp(area, level, &srn, lsp);
for (ALL_LIST_ELEMENTS_RO(lsp->lspu.frags, node, frag))
parse_lsp(area, level, &srn, frag);
}
}
-/* Process any new/deleted/modified Prefix-SID in the LSPDB. */
+/**
+ * Process any new/deleted/modified Prefix-SID in the LSPDB.
+ *
+ * @param srn Segment Routing Node
+ * @param srp Segment Routing Prefix
+ */
static void process_prefix_changes(struct sr_node *srn, struct sr_prefix *srp)
{
struct isis_area *area = srn->area;
return;
}
+ /* Validate SRDB State for next LSPDB parsing */
srp->state = SRDB_STATE_VALIDATED;
}
-/* Process any new/deleted/modified SRGB in the LSPDB. */
+/**
+ * Process any new/deleted/modified SRGB in the LSPDB.
+ *
+ * @param area IS-IS area
+ * @param level IS-IS level
+ * @param srn Segment Routing Node
+ */
static void process_node_changes(struct isis_area *area, int level,
struct sr_node *srn)
{
memcpy(sysid, srn->sysid, sizeof(sysid));
/*
- * If an adjacent router's SRGB was changed or created, then reinstall
- * all Prefix-SIDs from all nodes.
+ * If an neighbor router's SRGB was changed or created, then reinstall
+ * all Prefix-SIDs from all nodes that use this neighbor as nexthop.
*/
adjacent = isis_adj_exists(area, level, sysid);
switch (srn->state) {
case SRDB_STATE_UNCHANGED:
break;
default:
+ /* SR capabilities have been removed. Delete SR-Node */
sr_debug("ISIS-Sr (%s): Remove SR node %s", area->area_tag,
sysid_print(srn->sysid));
- sr_node_del(area, level, srn);
+ sr_node_del(area, level, srn);
+ /* and Update remaining Prefix-SID from all remaining SR Node */
if (adjacent)
sr_node_srgb_update(area, level, sysid);
return;
}
+ /* Validate SRDB State for next LSPDB parsing */
srn->state = SRDB_STATE_VALIDATED;
+ /* Finally, process all Prefix-SID of this SR Node */
frr_each_safe (srdb_node_prefix, &srn->prefix_sids, srp)
process_prefix_changes(srn, srp);
}
-/* Parse and process all SR-related Sub-TLVs after running the SPF algorithm. */
+/**
+ * Parse and process all SR-related Sub-TLVs after running the SPF algorithm.
+ *
+ * @param area IS-IS area
+ */
void isis_area_verify_sr(struct isis_area *area)
{
struct sr_node *srn;
}
}
-/*
+/**
* Once a route is updated in the SPT, reinstall or uninstall its corresponding
* Prefix-SID (if any).
+ *
+ * @param area IS-IS area
+ * @param prefix Prefix to be updated
+ * @param route_info New Route Information
+ *
+ * @return 0
*/
static int sr_route_update(struct isis_area *area, struct prefix *prefix,
struct isis_route_info *route_info)
sr_debug("ISIS-Sr (%s): Update route for prefix %pFX", area->area_tag,
prefix);
+ /* Lookup to Segment Routing Prefix for this prefix */
switch (area->is_type) {
case IS_LEVEL_1:
srp = sr_prefix_find_by_area(area, ISIS_LEVEL1, prefix);
exit(1);
}
+ /* Skip NULL or local Segment Routing Prefix */
if (!srp || srp->type == ISIS_SR_PREFIX_LOCAL)
return 0;
+ /* Install or unintall Prefix-SID if route is Active or not */
if (CHECK_FLAG(route_info->flag, ISIS_ROUTE_FLAG_ACTIVE)) {
/*
* The Prefix-SID input label hasn't changed. We could use the
return 0;
}
-/*----------------------------------------------------------------------------*/
+/* --- Segment Routing Adjacency-SID management functions ------------------- */
-/* Add new local Adj-SID. */
+/**
+ * Add new local Adjacency-SID.
+ *
+ * @param adj IS-IS Adjacency
+ * @param family Inet Family (IPv4 or IPv6)
+ * @param backup True to initialize backup Adjacency SID
+ */
static void sr_adj_sid_add_single(struct isis_adjacency *adj, int family,
bool backup)
{
sr_debug("ISIS-Sr (%s): Add %s Adjacency SID", area->area_tag,
backup ? "Backup" : "Primary");
+ /* Determine nexthop IP address */
switch (family) {
case AF_INET:
if (!circuit->ip_router)
exit(1);
}
+ /* Prepare Segment Routing Adjacency as per RFC8667 section #2.2 */
flags = EXT_SUBTLV_LINK_ADJ_SID_VFLG | EXT_SUBTLV_LINK_ADJ_SID_LFLG;
if (family == AF_INET6)
SET_FLAG(flags, EXT_SUBTLV_LINK_ADJ_SID_FFLG);
sra->nexthop.address = nexthop;
sra->nexthop.label = input_label;
switch (circuit->circ_type) {
+ /* LAN Adjacency-SID for Broadcast interface section #2.2.2 */
case CIRCUIT_T_BROADCAST:
ladj_sid = XCALLOC(MTYPE_ISIS_SUBTLV, sizeof(*ladj_sid));
ladj_sid->family = family;
isis_tlvs_add_lan_adj_sid(circuit->ext, ladj_sid);
sra->u.ladj_sid = ladj_sid;
break;
+ /* Adjacency-SID for Point to Point interface section #2.2.1 */
case CIRCUIT_T_P2P:
adj_sid = XCALLOC(MTYPE_ISIS_SUBTLV, sizeof(*adj_sid));
adj_sid->family = family;
__func__, circuit->circ_type);
exit(1);
}
+
+ /* Add Adjacency-SID in SRDB */
sra->adj = adj;
listnode_add(area->srdb.adj_sids, sra);
listnode_add(adj->adj_sids, sra);
isis_zebra_send_adjacency_sid(ZEBRA_MPLS_LABELS_ADD, sra);
}
+/**
+ * Add Primary and Backup local Adjacency SID.
+ *
+ * @param adj IS-IS Adjacency
+ * @param family Inet Family (IPv4 or IPv6)
+ */
static void sr_adj_sid_add(struct isis_adjacency *adj, int family)
{
sr_adj_sid_add_single(adj, family, false);
sr_adj_sid_add_single(adj, family, true);
}
-/* Delete local Adj-SID. */
+/**
+ * Delete local Adj-SID.
+ *
+ * @param sra Segment Routing Adjacency
+ */
static void sr_adj_sid_del(struct sr_adjacency *sra)
{
struct isis_circuit *circuit = sra->adj->circuit;
isis_zebra_send_adjacency_sid(ZEBRA_MPLS_LABELS_DELETE, sra);
+ /* Release dynamic label and remove subTLVs */
switch (circuit->circ_type) {
case CIRCUIT_T_BROADCAST:
isis_zebra_release_dynamic_label(sra->u.ladj_sid->sid);
exit(1);
}
+ /* Remove Adjacency-SID from the SRDB */
listnode_delete(area->srdb.adj_sids, sra);
listnode_delete(sra->adj->adj_sids, sra);
XFREE(MTYPE_ISIS_SR_INFO, sra);
}
-/* Remove all Adj-SIDs associated to an adjacency that is going down. */
+/**
+ * Remove all Adjacency-SIDs associated to an adjacency that is going down.
+ *
+ * @param adj IS-IS Adjacency
+ *
+ * @return 0
+ */
static int sr_adj_state_change(struct isis_adjacency *adj)
{
struct sr_adjacency *sra;
return 0;
}
-/*
- * Adjacency now has one or more IPv4/IPv6 addresses. Add new IPv4 or IPv6
- * Adj-SID accordingly.
+/**
+ * When IS-IS Adjacency got one or more IPv4/IPv6 addresses, add new IPv4 or
+ * IPv6 address to corresponding Adjacency-SID accordingly.
+ *
+ * @param adj IS-IS Adjacency
+ * @param family Inet Family (IPv4 or IPv6)
+ *
+ * @return 0
*/
static int sr_adj_ip_enabled(struct isis_adjacency *adj, int family)
{
return 0;
}
-/*
- * Adjacency doesn't have any IPv4 or IPv6 addresses anymore. Delete the
- * corresponding Adj-SID(s) accordingly.
+/**
+ * When IS-IS Adjacency doesn't have any IPv4 or IPv6 addresses anymore,
+ * delete the corresponding Adjacency-SID(s) accordingly.
+ *
+ * @param adj IS-IS Adjacency
+ * @param family Inet Family (IPv4 or IPv6)
+ *
+ * @return 0
*/
static int sr_adj_ip_disabled(struct isis_adjacency *adj, int family)
{
return 0;
}
+/**
+ * Activate local Prefix-SID when loopback interface goes up for IS-IS.
+ *
+ * @param ifp Loopback Interface
+ *
+ * @return 0
+ */
static int sr_if_new_hook(struct interface *ifp)
{
struct isis_circuit *circuit;
struct connected *connected;
struct listnode *node;
+ /* Get corresponding circuit */
circuit = circuit_scan_by_ifp(ifp);
if (!circuit)
return 0;
return 0;
}
-/*----------------------------------------------------------------------------*/
+/* --- Segment Routing Show information functions --------------------------- */
+/**
+ * Show Local Prefix-SID.
+ *
+ * @param vty VTY output
+ * @param tt Table format
+ * @param area IS-IS area
+ * @param srp Segment Routing Prefix
+ */
static void show_prefix_sid_local(struct vty *vty, struct ttable *tt,
const struct isis_area *area,
const struct sr_prefix *srp)
srp->sid.value, buf_llabel, buf_rlabel, buf_uptime);
}
+/**
+ * Show Remote Prefix-SID.
+ *
+ * @param vty VTY output
+ * @param tt Table format
+ * @param area IS-IS area
+ * @param srp Segment Routing Prefix
+ */
static void show_prefix_sid_remote(struct vty *vty, struct ttable *tt,
const struct isis_area *area,
const struct sr_prefix *srp)
}
}
+/**
+ * Show Prefix-SIDs.
+ *
+ * @param vty VTY output
+ * @param area IS-IS area
+ * @param level IS-IS level
+ */
static void show_prefix_sids(struct vty *vty, struct isis_area *area, int level)
{
struct sr_prefix *srp;
ttable_restyle(tt);
ttable_rowseps(tt, 0, BOTTOM, true, '-');
+ /* Process all Prefix-SID from the SRDB */
frr_each (srdb_area_prefix, &area->srdb.prefix_sids[level - 1], srp) {
switch (srp->type) {
case ISIS_SR_PREFIX_LOCAL:
ttable_del(tt);
}
+/**
+ * Declaration of new show command.
+ */
DEFUN(show_sr_prefix_sids, show_sr_prefix_sids_cmd,
"show isis segment-routing prefix-sids",
SHOW_STR PROTO_HELP
return CMD_SUCCESS;
}
-/*----------------------------------------------------------------------------*/
+/* --- IS-IS Segment Routing Management function ---------------------------- */
-/* Try to enable SR on the given IS-IS area. */
+/**
+ * Enable SR on the given IS-IS area.
+ *
+ * @param area IS-IS area
+ *
+ * @return 0 on success, -1 otherwise
+ */
int isis_sr_start(struct isis_area *area)
{
struct isis_sr_db *srdb = &area->srdb;
sr_debug("ISIS-Sr: Starting Segment Routing for area %s",
area->area_tag);
- /* Create Adj-SIDs for existing adjacencies. */
+ /* Create Adjacency-SIDs from existing IS-IS Adjacencies. */
for (ALL_LIST_ELEMENTS_RO(area->circuit_list, node, circuit)) {
struct isis_adjacency *adj;
struct listnode *anode;
}
}
- /* Regenerate LSPs. */
+ /* Regenerate LSPs to advertise Segment Routing capabilities. */
lsp_regenerate_schedule(area, area->is_type, 0);
return 0;
}
-/* Disable SR on the given IS-IS area. */
+/**
+ * Disable SR on the given IS-IS area.
+ *
+ * @param area IS-IS area
+ */
void isis_sr_stop(struct isis_area *area)
{
struct isis_sr_db *srdb = &area->srdb;
sr_debug("ISIS-Sr: Stopping Segment Routing for area %s",
area->area_tag);
- /* Uninstall Adj-SIDs. */
+ /* Uninstall all local Adjacency-SIDs. */
for (ALL_LIST_ELEMENTS(area->srdb.adj_sids, node, nnode, sra))
sr_adj_sid_del(sra);
- /* Uninstall Prefix-SIDs. */
+ /* Uninstall all Prefix-SIDs from all SR Node. */
for (int level = ISIS_LEVEL1; level <= ISIS_LEVELS; level++) {
while (srdb_node_count(&srdb->sr_nodes[level - 1]) > 0) {
struct sr_node *srn;
isis_zebra_release_label_range(srdb->config.srgb_lower_bound,
srdb->config.srgb_upper_bound);
- /* Regenerate LSPs. */
+ /* Regenerate LSPs to advertise that the Node is no more SR enable. */
lsp_regenerate_schedule(area, area->is_type, 0);
}
+/**
+ * IS-IS Segment Routing initialization for given area.
+ *
+ * @param area IS-IS area
+ */
void isis_sr_area_init(struct isis_area *area)
{
struct isis_sr_db *srdb = &area->srdb;
sr_debug("ISIS-Sr (%s): Initialize Segment Routing SRDB",
area->area_tag);
+ /* Initialize Segment Routing Data Base */
memset(srdb, 0, sizeof(*srdb));
srdb->enabled = false;
srdb->adj_sids = list_new();
srdb_prefix_cfg_init(&srdb->config.prefix_sids);
}
+/**
+ * Terminate IS-IS Segment Routing for the given area.
+ *
+ * @param area IS-IS area
+ */
void isis_sr_area_term(struct isis_area *area)
{
struct isis_sr_db *srdb = &area->srdb;
}
}
+/**
+ * IS-IS Segment Routing global initialization.
+ */
void isis_sr_init(void)
{
install_element(VIEW_NODE, &show_sr_prefix_sids_cmd);
hook_register(isis_if_new_hook, sr_if_new_hook);
}
+/**
+ * IS-IS Segment Routing global terminate.
+ */
void isis_sr_term(void)
{
/* Unregister hooks. */
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