/*
* 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 header definitions
*
* 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
*/
#ifndef _FRR_OSPF_SR_H
#define _FRR_OSPF_SR_H
/* macros and constants for segment routing */
#define SET_RANGE_SIZE_MASK 0xffffff00
#define GET_RANGE_SIZE_MASK 0x00ffffff
#define SET_LABEL_MASK 0xffffff00
#define GET_LABEL_MASK 0x00ffffff
#define SET_RANGE_SIZE(range_size) ((range_size << 8) & SET_RANGE_SIZE_MASK)
#define GET_RANGE_SIZE(range_size) ((range_size >> 8) & GET_RANGE_SIZE_MASK)
#define SET_LABEL(label) ((label << 8) & SET_LABEL_MASK)
#define GET_LABEL(label) ((label >> 8) & GET_LABEL_MASK)
#define OSPF_SR_DEFAULT_METRIC 1
/* Segment Routing TLVs as per RFC 8665 */
/* Segment ID could be a Label (3 bytes) or an Index (4 bytes) */
#define SID_LABEL 3
#define SID_LABEL_SIZE(U) (U - 1)
#define SID_INDEX 4
#define SID_INDEX_SIZE(U) (U)
/* Macro to log debug message */
#define osr_debug(...) \
do { \
if (IS_DEBUG_OSPF_SR) \
zlog_debug(__VA_ARGS__); \
} while (0)
/* Macro to check if SR Prefix has no valid route */
#define IS_NO_ROUTE(srp) ((srp->route == NULL) || (srp->route->paths == NULL) \
|| list_isempty(srp->route->paths))
/* SID/Label Sub TLV - section 2.1 */
#define SUBTLV_SID_LABEL 1
#define SUBTLV_SID_LABEL_SIZE 8
struct subtlv_sid_label {
/* Length is 3 (20 rightmost bits MPLS label) or 4 (32 bits SID) */
struct tlv_header header;
uint32_t value;
};
/*
* Following section defines Segment Routing TLV (tag, length, value)
* structures, used in Router Information Opaque LSA.
*/
/* RI SR-Algorithm TLV - section 3.1 */
#define RI_SR_TLV_SR_ALGORITHM 8
struct ri_sr_tlv_sr_algorithm {
struct tlv_header header;
#define SR_ALGORITHM_SPF 0
#define SR_ALGORITHM_STRICT_SPF 1
#define SR_ALGORITHM_UNSET 255
#define ALGORITHM_COUNT 4
/* Only 4 algorithms supported in this code */
uint8_t value[ALGORITHM_COUNT];
};
/* RI SID/Label Range TLV used for SRGB & SRLB - section 3.2 & 3.3 */
#define RI_SR_TLV_SRGB_LABEL_RANGE 9
#define RI_SR_TLV_SRLB_LABEL_RANGE 14
struct ri_sr_tlv_sid_label_range {
struct tlv_header header;
/* Only 24 upper most bits are significant */
#define SID_RANGE_LABEL_LENGTH 3
uint32_t size;
/* A SID/Label sub-TLV will follow. */
struct subtlv_sid_label lower;
};
/* RI Node/MSD TLV as per RFC 8476 */
#define RI_SR_TLV_NODE_MSD 12
struct ri_sr_tlv_node_msd {
struct tlv_header header;
uint8_t subtype; /* always = 1 */
uint8_t value;
uint16_t padding;
};
/*
* Following section defines Segment Routing TLV (tag, length, value)
* structures, used in Extended Prefix/Link Opaque LSA.
*/
/* Adj-SID and LAN-Ajd-SID subtlvs' flags */
#define EXT_SUBTLV_LINK_ADJ_SID_BFLG 0x80
#define EXT_SUBTLV_LINK_ADJ_SID_VFLG 0x40
#define EXT_SUBTLV_LINK_ADJ_SID_LFLG 0x20
#define EXT_SUBTLV_LINK_ADJ_SID_SFLG 0x10
/* Prefix SID subtlv Flags */
#define EXT_SUBTLV_PREFIX_SID_NPFLG 0x40
#define EXT_SUBTLV_PREFIX_SID_MFLG 0x20
#define EXT_SUBTLV_PREFIX_SID_EFLG 0x10
#define EXT_SUBTLV_PREFIX_SID_VFLG 0x08
#define EXT_SUBTLV_PREFIX_SID_LFLG 0x04
/* SID/Label Binding subtlv Flags */
#define EXT_SUBTLV_SID_BINDING_MFLG 0x80
/* Extended Prefix Range TLV - section 4 */
#define EXT_TLV_PREF_RANGE 2
#define EXT_SUBTLV_PREFIX_RANGE_SIZE 12
struct ext_tlv_prefix_range {
struct tlv_header header;
uint8_t pref_length;
uint8_t af;
uint16_t range_size;
uint8_t flags;
uint8_t reserved[3];
struct in_addr address;
};
/* Prefix SID Sub-TLV - section 5 */
#define EXT_SUBTLV_PREFIX_SID 2
#define EXT_SUBTLV_PREFIX_SID_SIZE 8
struct ext_subtlv_prefix_sid {
struct tlv_header header;
uint8_t flags;
uint8_t reserved;
uint8_t mtid;
uint8_t algorithm;
uint32_t value;
};
/* Adj-SID Sub-TLV - section 6.1 */
#define EXT_SUBTLV_ADJ_SID 2
#define EXT_SUBTLV_ADJ_SID_SIZE 8
struct ext_subtlv_adj_sid {
struct tlv_header header;
uint8_t flags;
uint8_t reserved;
uint8_t mtid;
uint8_t weight;
uint32_t value;
};
/* LAN Adj-SID Sub-TLV - section 6.2 */
#define EXT_SUBTLV_LAN_ADJ_SID 3
#define EXT_SUBTLV_LAN_ADJ_SID_SIZE 12
struct ext_subtlv_lan_adj_sid {
struct tlv_header header;
uint8_t flags;
uint8_t reserved;
uint8_t mtid;
uint8_t weight;
struct in_addr neighbor_id;
uint32_t value;
};
/*
* Following section define structure used to manage Segment Routing
* information and TLVs / SubTLVs
*/
/* Default min and size of SR Global Block label range */
#define DEFAULT_SRGB_LABEL 16000
#define DEFAULT_SRGB_SIZE 8000
/* Default min and size of SR Local Block label range */
#define DEFAULT_SRLB_LABEL 15000
#define DEFAULT_SRLB_SIZE 1000
/* Structure aggregating SR Range Block info retrieved from an lsa */
struct sr_block {
uint32_t range_size;
uint32_t lower_bound;
};
/* Segment Routing Global Block allocation */
struct sr_global_block {
bool reserved;
uint32_t start;
uint32_t size;
};
/* Segment Routing Local Block allocation */
struct sr_local_block {
bool reserved;
uint32_t start;
uint32_t end;
uint32_t current;
uint32_t max_block;
uint64_t *used_mark;
};
#define SRLB_BLOCK_SIZE 64
/* SID type to make difference between loopback interfaces and others */
enum sid_type { PREF_SID, LOCAL_SID, ADJ_SID, LAN_ADJ_SID };
/* Status of Segment Routing: Off (Disable), On (Enable), (Up) Started */
enum sr_status { SR_OFF, SR_ON, SR_UP, SR_DOWN };
/* Structure aggregating all OSPF Segment Routing information for the node */
struct ospf_sr_db {
/* Status of Segment Routing */
enum sr_status status;
/* Flooding Scope: Area = 10 or AS = 11 */
uint8_t scope;
/* FRR SR node */
struct sr_node *self;
/* List of neighbour SR nodes */
struct hash *neighbors;
/* List of SR prefix */
struct route_table *prefix;
/* Local SR info announced in Router Info LSA */
/* Algorithms supported by the node */
uint8_t algo[ALGORITHM_COUNT];
/*
* Segment Routing Global Block i.e. label range
* Only one range supported in this code
*/
struct sr_global_block srgb;
/* Segment Routing Local Block */
struct sr_local_block srlb;
/* Maximum SID Depth supported by the node */
uint8_t msd;
/* Thread timer to start Label Manager */
struct thread *t_start_lm;
};
/* Structure aggregating all received SR info from LSAs by node */
struct sr_node {
struct in_addr adv_router; /* used to identify sender of LSA */
/* 24-bit Opaque-ID field value according to RFC 7684 specification */
uint32_t instance;
uint8_t algo[ALGORITHM_COUNT]; /* Algorithms supported by the node */
struct sr_block srgb; /* Segment Routing Global Block */
struct sr_block srlb; /* Segment Routing Local Block */
uint8_t msd; /* Maximum SID Depth */
/* List of Prefix & Link advertise by this node */
struct list *ext_prefix; /* For Node SID */
struct list *ext_link; /* For Adj and LAN SID */
/* Pointer to FRR SR-Node or NULL if it is not a neighbor */
struct sr_node *neighbor;
};
/* Segment Routing - NHLFE info: support IPv4 Only */
struct sr_nhlfe {
struct in_addr nexthop;
ifindex_t ifindex;
mpls_label_t label_in;
mpls_label_t label_out;
};
/* Structure aggregating all Segment Routing Link information */
/* Link are generally advertised by pair: primary + backup */
struct sr_link {
struct in_addr adv_router; /* used to identify sender of LSA */
/* 24-bit Opaque-ID field value according to RFC 7684 specification */
uint32_t instance;
/* Interface address */
struct in_addr itf_addr;
/* Flags to manage this link parameters. */
uint8_t flags[2];
/* Segment Routing ID */
uint32_t sid[2];
enum sid_type type;
/* SR NHLFE (Primary + Backup) for this link */
struct sr_nhlfe nhlfe[2];
/* Back pointer to SR Node which advertise this Link */
struct sr_node *srn;
};
/* Structure aggregating all Segment Routing Prefix information */
struct sr_prefix {
struct in_addr adv_router; /* used to identify sender of LSA */
/* 24-bit Opaque-ID field value according to RFC 7684 specification */
uint32_t instance;
/* Prefix itself */
struct prefix_ipv4 prefv4;
/* Flags to manage this prefix parameters. */
uint8_t flags;
/* Segment Routing ID */
uint32_t sid;
enum sid_type type;
/* Incoming label for this prefix */
mpls_label_t label_in;
/* Back pointer to OSPF Route for remote prefix */
struct ospf_route *route;
/* NHLFE for local prefix */
struct sr_nhlfe nhlfe;
/* Back pointer to SR Node which advertise this Prefix */
struct sr_node *srn;
};
/* Prototypes definition */
/* Segment Routing initialisation functions */
extern int ospf_sr_init(void);
extern void ospf_sr_term(void);
extern void ospf_sr_finish(void);
/* Segment Routing label allocation functions */
extern mpls_label_t ospf_sr_local_block_request_label(void);
extern int ospf_sr_local_block_release_label(mpls_label_t label);
/* Segment Routing LSA update & delete functions */
extern void ospf_sr_ri_lsa_update(struct ospf_lsa *lsa);
extern void ospf_sr_ri_lsa_delete(struct ospf_lsa *lsa);
extern void ospf_sr_ext_link_lsa_update(struct ospf_lsa *lsa);
extern void ospf_sr_ext_link_lsa_delete(struct ospf_lsa *lsa);
extern void ospf_sr_ext_prefix_lsa_update(struct ospf_lsa *lsa);
extern void ospf_sr_ext_prefix_lsa_delete(struct ospf_lsa *lsa);
/* Segment Routing Extending Link management */
struct ext_itf;
extern void ospf_sr_ext_itf_add(struct ext_itf *exti);
extern void ospf_sr_ext_itf_delete(struct ext_itf *exti);
/* Segment Routing configuration functions */
extern void ospf_sr_config_write_router(struct vty *vty);
extern void ospf_sr_update_local_prefix(struct interface *ifp,
struct prefix *p);
/* Segment Routing re-routing function */
extern void ospf_sr_update_task(struct ospf *ospf);
#endif /* _FRR_OSPF_SR_H */