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ospf_sr.c
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/*
* This is an implementation of Segment Routing
* as per RFC 8665 - OSPF Extensions for Segment Routing
* and RFC 8476 - Signaling Maximum SID Depth (MSD) Using OSPF
*
* Module name: Segment Routing
*
* Author: Olivier Dugeon <olivier.dugeon@orange.com>
* Author: Anselme Sawadogo <anselmesawadogo@gmail.com>
*
* Copyright (C) 2016 - 2020 Orange Labs http://www.orange.com
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; see the file COPYING; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <zebra.h>
#include "printfrr.h"
#include "command.h"
#include "hash.h"
#include "if.h"
#include "if.h"
#include "jhash.h"
#include "libospf.h" /* for ospf interface types */
#include "linklist.h"
#include "log.h"
#include "memory.h"
#include "monotime.h"
#include "network.h"
#include "prefix.h"
#include "sockunion.h" /* for inet_aton() */
#include "stream.h"
#include "table.h"
#include "thread.h"
#include "vty.h"
#include "zclient.h"
#include "sbuf.h"
#include <lib/json.h>
#include "ospf_errors.h"
#include "ospfd/ospfd.h"
#include "ospfd/ospf_interface.h"
#include "ospfd/ospf_ism.h"
#include "ospfd/ospf_asbr.h"
#include "ospfd/ospf_lsa.h"
#include "ospfd/ospf_lsdb.h"
#include "ospfd/ospf_neighbor.h"
#include "ospfd/ospf_nsm.h"
#include "ospfd/ospf_flood.h"
#include "ospfd/ospf_packet.h"
#include "ospfd/ospf_spf.h"
#include "ospfd/ospf_dump.h"
#include "ospfd/ospf_route.h"
#include "ospfd/ospf_ase.h"
#include "ospfd/ospf_sr.h"
#include "ospfd/ospf_ri.h"
#include "ospfd/ospf_ext.h"
#include "ospfd/ospf_zebra.h"
/*
* Global variable to manage Segment Routing on this node.
* Note that all parameter values are stored in network byte order.
*/
static struct ospf_sr_db OspfSR;
static void ospf_sr_register_vty(void);
static inline void del_adj_sid(struct sr_nhlfe nhlfe);
static int ospf_sr_start(struct ospf *ospf);
/*
* Segment Routing Data Base functions
*/
/* Hash function for Segment Routing entry */
static unsigned int sr_hash(const void *p)
{
const struct in_addr *rid = p;
return jhash_1word(rid->s_addr, 0);
}
/* Compare 2 Router ID hash entries based on SR Node */
static bool sr_cmp(const void *p1, const void *p2)
{
const struct sr_node *srn = p1;
const struct in_addr *rid = p2;
return IPV4_ADDR_SAME(&srn->adv_router, rid);
}
/* Functions to remove an SR Link */
static void del_sr_link(void *val)
{
struct sr_link *srl = (struct sr_link *)val;
del_adj_sid(srl->nhlfe[0]);
del_adj_sid(srl->nhlfe[1]);
XFREE(MTYPE_OSPF_SR_PARAMS, val);
}
/* Functions to remove an SR Prefix */
static void del_sr_pref(void *val)
{
struct sr_prefix *srp = (struct sr_prefix *)val;
ospf_zebra_delete_prefix_sid(srp);
XFREE(MTYPE_OSPF_SR_PARAMS, val);
}
/* Allocate new Segment Routine node */
static struct sr_node *sr_node_new(struct in_addr *rid)
{
if (rid == NULL)
return NULL;
struct sr_node *new;
/* Allocate Segment Routing node memory */
new = XCALLOC(MTYPE_OSPF_SR_PARAMS, sizeof(struct sr_node));
/* Default Algorithm, SRGB and MSD */
for (int i = 0; i < ALGORITHM_COUNT; i++)
new->algo[i] = SR_ALGORITHM_UNSET;
new->srgb.range_size = 0;
new->srgb.lower_bound = 0;
new->msd = 0;
/* Create Link, Prefix and Range TLVs list */
new->ext_link = list_new();
new->ext_prefix = list_new();
new->ext_link->del = del_sr_link;
new->ext_prefix->del = del_sr_pref;
IPV4_ADDR_COPY(&new->adv_router, rid);
new->neighbor = NULL;
new->instance = 0;
osr_debug(" |- Created new SR node for %pI4", &new->adv_router);
return new;
}
/* Supposed to be used for testing */
struct sr_node *ospf_sr_node_create(struct in_addr *rid)
{
struct sr_node *srn;
srn = hash_get(OspfSR.neighbors, (void *)rid, (void *)sr_node_new);
return srn;
}
/* Delete Segment Routing node */
static void sr_node_del(struct sr_node *srn)
{
/* Sanity Check */
if (srn == NULL)
return;
osr_debug(" |- Delete SR node for %pI4", &srn->adv_router);
/* Clean Extended Link */
list_delete(&srn->ext_link);
/* Clean Prefix List */
list_delete(&srn->ext_prefix);
XFREE(MTYPE_OSPF_SR_PARAMS, srn);
}
/* Get SR Node for a given nexthop */
static struct sr_node *get_sr_node_by_nexthop(struct ospf *ospf,
struct in_addr nexthop)
{
struct ospf_interface *oi = NULL;
struct ospf_neighbor *nbr = NULL;
struct listnode *node;
struct route_node *rn;
struct sr_node *srn;
bool found;
/* Sanity check */
if (OspfSR.neighbors == NULL)
return NULL;
osr_debug(" |- Search SR-Node for nexthop %pI4", &nexthop);
/* First, search neighbor Router ID for this nexthop */
found = false;
for (ALL_LIST_ELEMENTS_RO(ospf->oiflist, node, oi)) {
for (rn = route_top(oi->nbrs); rn; rn = route_next(rn)) {
nbr = rn->info;
if ((nbr) && (IPV4_ADDR_SAME(&nexthop, &nbr->src))) {
found = true;
break;
}
}
if (found)
break;
}
if (!found)
return NULL;
osr_debug(" |- Found nexthop Router ID %pI4", &nbr->router_id);
/* Then, search SR Node */
srn = (struct sr_node *)hash_lookup(OspfSR.neighbors, &nbr->router_id);
return srn;
}
/*
* Segment Routing Local Block management functions
*/
/**
* It is necessary to known which label is already allocated to manage the range
* of SRLB. This is particular useful when an interface flap (goes up / down
* frequently). Here, SR will release and then allocate label for the Adjacency
* for each concerned interface. If we don't care, there is a risk to run out of
* label.
*
* For that purpose, a similar principle as already provided to manage chunk of
* label is proposed. But, here, the label chunk has not a fix range of 64
* labels that could be easily manage with a single variable of 64 bits size.
* So, used_mark is used as a bit wise to mark label reserved (bit set) or not
* (bit unset). Its size is equal to the number of label of the SRLB range round
* up to 64 bits.
*
* - sr__local_block_init() computes the number of 64 bits variables that are
* needed to manage the SRLB range and allocates this number.
* - ospf_sr_local_block_request_label() pick up the first available label and
* set corresponding bit
* - ospf_sr_local_block_release_label() release label by reseting the
* corresponding bit and set the next label to the first free position
*/
/**
* Initialize Segment Routing Local Block from SRDB configuration and reserve
* block of bits to manage label allocation.
*
* @param lower_bound The lower bound of the SRLB range
* @param upper_bound The upper bound of the SRLB range
*
* @return 0 on success, -1 otherwise
*/
static int sr_local_block_init(uint32_t lower_bound, uint32_t upper_bound)
{
struct sr_local_block *srlb = &OspfSR.srlb;
uint32_t size;
/* Check if SRLB is not already configured */
if (srlb->reserved)
return 0;
/*
* Request SRLB to the label manager. If the allocation fails, return
* an error to disable SR until a new SRLB is successfully allocated.
*/
size = upper_bound - lower_bound + 1;
if (ospf_zebra_request_label_range(lower_bound, size)) {
srlb->reserved = false;
return -1;
}
osr_debug("SR (%s): Got new SRLB [%u/%u]", __func__, lower_bound,
upper_bound);
/* Initialize the SRLB */
srlb->start = lower_bound;
srlb->end = upper_bound;
srlb->current = 0;
/* Compute the needed Used Mark number and allocate them */
srlb->max_block = size / SRLB_BLOCK_SIZE;
if ((size % SRLB_BLOCK_SIZE) != 0)
srlb->max_block++;
srlb->used_mark = XCALLOC(MTYPE_OSPF_SR_PARAMS,
srlb->max_block * SRLB_BLOCK_SIZE);
srlb->reserved = true;
return 0;
}
/**
* Remove Segment Routing Local Block.
*
*/
static void sr_local_block_delete(void)
{
struct sr_local_block *srlb = &OspfSR.srlb;
/* Check if SRLB is not already delete */
if (!srlb->reserved)
return;
osr_debug("SR (%s): Remove SRLB [%u/%u]", __func__, srlb->start,
srlb->end);
/* First release the label block */
ospf_zebra_release_label_range(srlb->start, srlb->end);
/* Then reset SRLB structure */
if (srlb->used_mark != NULL)
XFREE(MTYPE_OSPF_SR_PARAMS, srlb->used_mark);
srlb->reserved = false;
}
/**
* Request a label from the Segment Routing Local Block.
*
* @return First available label on success or MPLS_INVALID_LABEL if the
* block of labels is full
*/
mpls_label_t ospf_sr_local_block_request_label(void)
{
struct sr_local_block *srlb = &OspfSR.srlb;
mpls_label_t label;
uint32_t index;
uint32_t pos;
/* Check if we ran out of available labels */
if (srlb->current >= srlb->end)
return MPLS_INVALID_LABEL;
/* Get first available label and mark it used */
label = srlb->current + srlb->start;
index = srlb->current / SRLB_BLOCK_SIZE;
pos = 1ULL << (srlb->current % SRLB_BLOCK_SIZE);
srlb->used_mark[index] |= pos;
/* Jump to the next free position */
srlb->current++;
pos = srlb->current % SRLB_BLOCK_SIZE;
while (srlb->current < srlb->end) {
if (pos == 0)
index++;
if (!((1ULL << pos) & srlb->used_mark[index]))
break;
else {
srlb->current++;
pos = srlb->current % SRLB_BLOCK_SIZE;
}
}
return label;
}
/**
* Release label in the Segment Routing Local Block.
*
* @param label Label to be release
*
* @return 0 on success or -1 if label falls outside SRLB
*/
int ospf_sr_local_block_release_label(mpls_label_t label)
{
struct sr_local_block *srlb = &OspfSR.srlb;
uint32_t index;
uint32_t pos;
/* Check that label falls inside the SRLB */
if ((label < srlb->start) || (label > srlb->end)) {
flog_warn(EC_OSPF_SR_SID_OVERFLOW,
"%s: Returning label %u is outside SRLB [%u/%u]",
__func__, label, srlb->start, srlb->end);
return -1;
}
index = (label - srlb->start) / SRLB_BLOCK_SIZE;
pos = 1ULL << ((label - srlb->start) % SRLB_BLOCK_SIZE);
srlb->used_mark[index] &= ~pos;
/* Reset current to the first available position */
for (index = 0; index < srlb->max_block; index++) {
if (srlb->used_mark[index] != 0xFFFFFFFFFFFFFFFF) {
for (pos = 0; pos < SRLB_BLOCK_SIZE; pos++)
if (!((1ULL << pos) & srlb->used_mark[index])) {
srlb->current =
index * SRLB_BLOCK_SIZE + pos;
break;
}
break;
}
}
return 0;
}
/*
* Segment Routing Initialization functions
*/
/**
* Thread function to re-attempt connection to the Label Manager and thus be
* able to start Segment Routing.
*
* @param start Thread structure that contains area as argument
*
* @return 1 on success
*/
static int sr_start_label_manager(struct thread *start)
{
struct ospf *ospf;
ospf = THREAD_ARG(start);
/* re-attempt to start SR & Label Manager connection */
ospf_sr_start(ospf);
return 1;
}
/* Segment Routing starter function */
static int ospf_sr_start(struct ospf *ospf)
{
struct route_node *rn;
struct ospf_lsa *lsa;
struct sr_node *srn;
int rc = 0;
osr_debug("SR (%s): Start Segment Routing", __func__);
/* Initialize self SR Node if not already done */
if (OspfSR.self == NULL) {
srn = hash_get(OspfSR.neighbors, (void *)&(ospf->router_id),
(void *)sr_node_new);
/* Complete & Store self SR Node */
srn->srgb.range_size = OspfSR.srgb.size;
srn->srgb.lower_bound = OspfSR.srgb.start;
srn->srlb.lower_bound = OspfSR.srlb.start;
srn->srlb.range_size = OspfSR.srlb.end - OspfSR.srlb.start + 1;
srn->algo[0] = OspfSR.algo[0];
srn->msd = OspfSR.msd;
OspfSR.self = srn;
}
/* Then, start Label Manager if not ready */
if (!ospf_zebra_label_manager_ready())
if (ospf_zebra_label_manager_connect() < 0) {
/* Re-attempt to connect to Label Manager in 1 sec. */
thread_add_timer(master, sr_start_label_manager, ospf,
1, &OspfSR.t_start_lm);
osr_debug(" |- Failed to start the Label Manager");
return -1;
}
/*
* Request SRLB & SGRB to the label manager if not already reserved.
* If the allocation fails, return an error to disable SR until a new
* SRLB and/or SRGB are successfully allocated.
*/
sr_local_block_init(OspfSR.srlb.start, OspfSR.srlb.end);
if (!OspfSR.srgb.reserved) {
if (ospf_zebra_request_label_range(OspfSR.srgb.start,
OspfSR.srgb.size)
< 0) {
OspfSR.srgb.reserved = false;
return -1;
} else
OspfSR.srgb.reserved = true;
}
/* SR is UP and ready to flood LSA */
OspfSR.status = SR_UP;
/* Set Router Information SR parameters */
osr_debug("SR: Activate SR for Router Information LSA");
ospf_router_info_update_sr(true, OspfSR.self);
/* Update Ext LSA */
osr_debug("SR: Activate SR for Extended Link/Prefix LSA");
ospf_ext_update_sr(true);
osr_debug("SR (%s): Update SR-DB from LSDB", __func__);
/* Start by looking to Router Info & Extended LSA in lsdb */
if ((ospf != NULL) && (ospf->backbone != NULL)) {
LSDB_LOOP (OPAQUE_AREA_LSDB(ospf->backbone), rn, lsa) {
if (IS_LSA_MAXAGE(lsa) || IS_LSA_SELF(lsa))
continue;
int lsa_id =
GET_OPAQUE_TYPE(ntohl(lsa->data->id.s_addr));
switch (lsa_id) {
case OPAQUE_TYPE_ROUTER_INFORMATION_LSA:
ospf_sr_ri_lsa_update(lsa);
break;
case OPAQUE_TYPE_EXTENDED_PREFIX_LSA:
ospf_sr_ext_prefix_lsa_update(lsa);
break;
case OPAQUE_TYPE_EXTENDED_LINK_LSA:
ospf_sr_ext_link_lsa_update(lsa);
break;
default:
break;
}
}
}
rc = 1;
return rc;
}
/* Stop Segment Routing */
static void ospf_sr_stop(void)
{
if (OspfSR.status == SR_OFF)
return;
osr_debug("SR (%s): Stop Segment Routing", __func__);
/* Disable any re-attempt to connect to Label Manager */
THREAD_OFF(OspfSR.t_start_lm);
/* Release SRGB & SRLB if active. */
if (OspfSR.srgb.reserved) {
ospf_zebra_release_label_range(
OspfSR.srgb.start,
OspfSR.srgb.start + OspfSR.srgb.size - 1);
OspfSR.srgb.reserved = false;
}
sr_local_block_delete();
/*
* Remove all SR Nodes from the Hash table. Prefix and Link SID will
* be remove though list_delete() call. See sr_node_del()
*/
hash_clean(OspfSR.neighbors, (void *)sr_node_del);
OspfSR.self = NULL;
OspfSR.status = SR_OFF;
}
/*
* Segment Routing initialize function
*
* @param - nothing
*
* @return 0 if OK, -1 otherwise
*/
int ospf_sr_init(void)
{
int rc = -1;
osr_debug("SR (%s): Initialize SR Data Base", __func__);
memset(&OspfSR, 0, sizeof(struct ospf_sr_db));
OspfSR.status = SR_OFF;
/* Only AREA flooding is supported in this release */
OspfSR.scope = OSPF_OPAQUE_AREA_LSA;
/* Initialize Algorithms, SRGB, SRLB and MSD TLVs */
/* Only Algorithm SPF is supported */
OspfSR.algo[0] = SR_ALGORITHM_SPF;
for (int i = 1; i < ALGORITHM_COUNT; i++)
OspfSR.algo[i] = SR_ALGORITHM_UNSET;
OspfSR.srgb.size = DEFAULT_SRGB_SIZE;
OspfSR.srgb.start = DEFAULT_SRGB_LABEL;
OspfSR.srgb.reserved = false;
OspfSR.srlb.start = DEFAULT_SRLB_LABEL;
OspfSR.srlb.end = DEFAULT_SRLB_LABEL + DEFAULT_SRLB_SIZE - 1;
OspfSR.srlb.reserved = false;
OspfSR.msd = 0;
/* Initialize Hash table for neighbor SR nodes */
OspfSR.neighbors = hash_create(sr_hash, sr_cmp, "OSPF_SR");
if (OspfSR.neighbors == NULL)
return rc;
/* Register Segment Routing VTY command */
ospf_sr_register_vty();
rc = 0;
return rc;
}
/*
* Segment Routing termination function
*
* @param - nothing
* @return - nothing
*/
void ospf_sr_term(void)
{
/* Stop Segment Routing */
ospf_sr_stop();
/* Clear SR Node Table */
if (OspfSR.neighbors)
hash_free(OspfSR.neighbors);
}
/*
* Segment Routing finish function
*
* @param - nothing
* @return - nothing
*/
void ospf_sr_finish(void)
{
/* Stop Segment Routing */
ospf_sr_stop();
}
/*
* Following functions are used to manipulate the
* Next Hop Label Forwarding entry (NHLFE)
*/
/* Compute label from index */
static mpls_label_t index2label(uint32_t index, struct sr_block srgb)
{
mpls_label_t label;
label = srgb.lower_bound + index;
if (label > (srgb.lower_bound + srgb.range_size)) {
flog_warn(EC_OSPF_SR_SID_OVERFLOW,
"%s: SID index %u falls outside SRGB range",
__func__, index);
return MPLS_INVALID_LABEL;
} else
return label;
}
/* Get the prefix sid for a specific router id */
mpls_label_t ospf_sr_get_prefix_sid_by_id(struct in_addr *id)
{
struct sr_node *srn;
struct sr_prefix *srp;
mpls_label_t label;
srn = (struct sr_node *)hash_lookup(OspfSR.neighbors, id);
if (srn) {
/*
* TODO: Here we assume that the SRGBs are the same,
* and that the node's prefix SID is at the head of
* the list, probably needs tweaking.
*/
srp = listnode_head(srn->ext_prefix);
label = index2label(srp->sid, srn->srgb);
} else {
label = MPLS_INVALID_LABEL;
}
return label;
}
/* Get the adjacency sid for a specific 'root' id and 'neighbor' id */
mpls_label_t ospf_sr_get_adj_sid_by_id(struct in_addr *root_id,
struct in_addr *neighbor_id)
{
struct sr_node *srn;
struct sr_link *srl;
mpls_label_t label;
struct listnode *node;
srn = (struct sr_node *)hash_lookup(OspfSR.neighbors, root_id);
label = MPLS_INVALID_LABEL;
if (srn) {
for (ALL_LIST_ELEMENTS_RO(srn->ext_link, node, srl)) {
if (srl->type == ADJ_SID
&& srl->remote_id.s_addr == neighbor_id->s_addr) {
label = srl->sid[0];
break;
}
}
}
return label;
}
/* Get neighbor full structure from address */
static struct ospf_neighbor *get_neighbor_by_addr(struct ospf *top,
struct in_addr addr)
{
struct ospf_neighbor *nbr;
struct ospf_interface *oi;
struct listnode *node;
struct route_node *rn;
/* Sanity Check */
if (top == NULL)
return NULL;
for (ALL_LIST_ELEMENTS_RO(top->oiflist, node, oi))
for (rn = route_top(oi->nbrs); rn; rn = route_next(rn)) {
nbr = rn->info;
if (nbr)
if (IPV4_ADDR_SAME(&nbr->address.u.prefix4,
&addr)
|| IPV4_ADDR_SAME(&nbr->router_id, &addr)) {
route_unlock_node(rn);
return nbr;
}
}
return NULL;
}
/* Get OSPF Path from address */
static struct ospf_route *get_nexthop_by_addr(struct ospf *top,
struct prefix_ipv4 p)
{
struct route_node *rn;
/* Sanity Check */
if (top == NULL)
return NULL;
osr_debug(" |- Search Nexthop for prefix %pFX",
(struct prefix *)&p);
rn = route_node_lookup(top->new_table, (struct prefix *)&p);
/*
* Check if we found an OSPF route. May be NULL if SPF has not
* yet populate routing table for this prefix.
*/
if (rn == NULL)
return NULL;
route_unlock_node(rn);
return rn->info;
}
/* Compute NHLFE entry for Extended Link */
static int compute_link_nhlfe(struct sr_link *srl)
{
struct ospf *top = ospf_lookup_by_vrf_id(VRF_DEFAULT);
struct ospf_neighbor *nh;
int rc = 0;
osr_debug(" |- Compute NHLFE for link %pI4", &srl->itf_addr);
/* First determine the OSPF Neighbor */
nh = get_neighbor_by_addr(top, srl->nhlfe[0].nexthop);
/* Neighbor could be not found when OSPF Adjacency just fire up
* because SPF don't yet populate routing table. This NHLFE will
* be fixed later when SR SPF schedule will be called.
*/
if (nh == NULL)
return rc;
osr_debug(" |- Found nexthop %pI4", &nh->router_id);
/* Set ifindex for this neighbor */
srl->nhlfe[0].ifindex = nh->oi->ifp->ifindex;
srl->nhlfe[1].ifindex = nh->oi->ifp->ifindex;
/* Update neighbor address for LAN_ADJ_SID */
if (srl->type == LAN_ADJ_SID) {
IPV4_ADDR_COPY(&srl->nhlfe[0].nexthop, &nh->src);
IPV4_ADDR_COPY(&srl->nhlfe[1].nexthop, &nh->src);
}
/* Set Input & Output Label */
if (CHECK_FLAG(srl->flags[0], EXT_SUBTLV_LINK_ADJ_SID_VFLG))
srl->nhlfe[0].label_in = srl->sid[0];
else
srl->nhlfe[0].label_in =
index2label(srl->sid[0], srl->srn->srgb);
if (CHECK_FLAG(srl->flags[1], EXT_SUBTLV_LINK_ADJ_SID_VFLG))
srl->nhlfe[1].label_in = srl->sid[1];
else
srl->nhlfe[1].label_in =
index2label(srl->sid[1], srl->srn->srgb);
srl->nhlfe[0].label_out = MPLS_LABEL_IMPLICIT_NULL;
srl->nhlfe[1].label_out = MPLS_LABEL_IMPLICIT_NULL;
rc = 1;
return rc;
}
/**
* Compute output label for the given Prefix-SID.
*
* @param srp Segment Routing Prefix
* @param srnext Segment Routing nexthop node
*
* @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 *srnext)
{
/* Check if the nexthop SR Node is the last hop? */
if (srnext == srp->srn) {
/* SR-Node doesn't request NO-PHP. Return Implicit NULL label */
if (!CHECK_FLAG(srp->flags, EXT_SUBTLV_PREFIX_SID_NPFLG))
return MPLS_LABEL_IMPLICIT_NULL;
/* SR-Node requests Explicit NULL Label */
if (CHECK_FLAG(srp->flags, EXT_SUBTLV_PREFIX_SID_EFLG))
return MPLS_LABEL_IPV4_EXPLICIT_NULL;
/* Fallthrough */
}
/* Return SID value as MPLS label if it is an Absolute SID */
if (CHECK_FLAG(srp->flags, EXT_SUBTLV_PREFIX_SID_VFLG
| EXT_SUBTLV_PREFIX_SID_LFLG)) {
/*
* V/L SIDs have local significance, so only adjacent routers
* can use them (RFC8665 section #5)
*/
if (srp->srn != srnext)
return MPLS_INVALID_LABEL;
return srp->sid;
}
/* Return MPLS label as SRGB lower bound + SID index as per RFC 8665 */
return (index2label(srp->sid, srnext->srgb));
}
/*
* Compute NHLFE entry for Extended Prefix
*
* @param srp - Segment Routing Prefix
*
* @return -1 if no route is found, 0 if there is no SR route ready
* and 1 if success or update
*/
static int compute_prefix_nhlfe(struct sr_prefix *srp)
{
struct ospf *top = ospf_lookup_by_vrf_id(VRF_DEFAULT);
struct ospf_path *path;
struct listnode *node;
struct sr_node *srnext;
int rc = -1;
osr_debug(" |- Compute NHLFE for prefix %pFX",
(struct prefix *)&srp->prefv4);
/* First determine the nexthop */
srp->route = get_nexthop_by_addr(top, srp->prefv4);
/* Nexthop could be not found when OSPF Adjacency just fire up
* because SPF don't yet populate routing table. This NHLFE will
* be fixed later when SR SPF schedule will be called.
*/
if (srp->route == NULL)
return rc;
/* Compute Input Label with self SRGB */
srp->label_in = index2label(srp->sid, OspfSR.self->srgb);
rc = 0;
for (ALL_LIST_ELEMENTS_RO(srp->route->paths, node, path)) {
osr_debug(" |- Process new route via %pI4 for this prefix",
&path->nexthop);
/*
* Get SR-Node for this nexthop. Could be not yet available
* as Extended Link / Prefix and Router Information are flooded
* after LSA Type 1 & 2 which populate the OSPF Route Table
*/
srnext = get_sr_node_by_nexthop(top, path->nexthop);
if (srnext == NULL)
continue;
/* And store this information for later update */
srnext->neighbor = OspfSR.self;
path->srni.nexthop = srnext;
/*
* SR Node could be known, but SRGB could be not initialize
* This is due to the fact that Extended Link / Prefix could
* be received before corresponding Router Information LSA
*/
if (srnext == NULL || srnext->srgb.lower_bound == 0
|| srnext->srgb.range_size == 0) {
osr_debug(
" |- SR-Node %pI4 not ready. Stop process",
&srnext->adv_router);
path->srni.label_out = MPLS_INVALID_LABEL;
continue;
}
osr_debug(" |- Found SRGB %u/%u for next hop SR-Node %pI4",
srnext->srgb.range_size, srnext->srgb.lower_bound,
&srnext->adv_router);
/* Compute Output Label with Nexthop SR Node SRGB */
path->srni.label_out = sr_prefix_out_label(srp, srnext);
osr_debug(" |- Computed new labels in: %u out: %u",
srp->label_in, path->srni.label_out);
rc = 1;
}
return rc;
}
/* Add new NHLFE entry for Adjacency SID */
static inline void add_adj_sid(struct sr_nhlfe nhlfe)
{
if (nhlfe.label_in != 0)
ospf_zebra_send_adjacency_sid(ZEBRA_MPLS_LABELS_ADD, nhlfe);
}
/* Remove NHLFE entry for Adjacency SID */
static inline void del_adj_sid(struct sr_nhlfe nhlfe)
{
if (nhlfe.label_in != 0)
ospf_zebra_send_adjacency_sid(ZEBRA_MPLS_LABELS_DELETE, nhlfe);
}
/* Update NHLFE entry for Adjacency SID */
static inline void update_adj_sid(struct sr_nhlfe n1, struct sr_nhlfe n2)
{
del_adj_sid(n1);
add_adj_sid(n2);
}
/*
* Functions to parse and get Extended Link / Prefix
* TLVs and SubTLVs
*/
/* Extended Link SubTLVs Getter */
static struct sr_link *get_ext_link_sid(struct tlv_header *tlvh, size_t size)
{
struct sr_link *srl;
struct ext_tlv_link *link = (struct ext_tlv_link *)tlvh;
struct ext_subtlv_adj_sid *adj_sid;
struct ext_subtlv_lan_adj_sid *lan_sid;
struct ext_subtlv_rmt_itf_addr *rmt_itf;
struct tlv_header *sub_tlvh;
uint16_t length = 0, sum = 0, i = 0;
/* Check TLV size */
if ((ntohs(tlvh->length) > size)
|| ntohs(tlvh->length) < EXT_TLV_LINK_SIZE) {
zlog_warn("Wrong Extended Link TLV size. Abort!");
return NULL;
}
srl = XCALLOC(MTYPE_OSPF_SR_PARAMS, sizeof(struct sr_link));
/* Initialize TLV browsing */
length = ntohs(tlvh->length) - EXT_TLV_LINK_SIZE;
sub_tlvh = (struct tlv_header *)((char *)(tlvh) + TLV_HDR_SIZE
+ EXT_TLV_LINK_SIZE);
for (; sum < length && sub_tlvh; sub_tlvh = TLV_HDR_NEXT(sub_tlvh)) {
switch (ntohs(sub_tlvh->type)) {
case EXT_SUBTLV_ADJ_SID:
adj_sid = (struct ext_subtlv_adj_sid *)sub_tlvh;
srl->type = ADJ_SID;
i = CHECK_FLAG(adj_sid->flags,
EXT_SUBTLV_LINK_ADJ_SID_BFLG)
? 1
: 0;
srl->flags[i] = adj_sid->flags;
if (CHECK_FLAG(adj_sid->flags,
EXT_SUBTLV_LINK_ADJ_SID_VFLG))
srl->sid[i] = GET_LABEL(ntohl(adj_sid->value));
else
srl->sid[i] = ntohl(adj_sid->value);
IPV4_ADDR_COPY(&srl->nhlfe[i].nexthop, &link->link_id);
break;
case EXT_SUBTLV_LAN_ADJ_SID:
lan_sid = (struct ext_subtlv_lan_adj_sid *)sub_tlvh;
srl->type = LAN_ADJ_SID;
i = CHECK_FLAG(lan_sid->flags,
EXT_SUBTLV_LINK_ADJ_SID_BFLG)
? 1
: 0;
srl->flags[i] = lan_sid->flags;
if (CHECK_FLAG(lan_sid->flags,
EXT_SUBTLV_LINK_ADJ_SID_VFLG))