ospfd/ospf_sr.h

   1 /*
   2  * This is an implementation of Segment Routing
   3  * as per RFC 8665 - OSPF Extensions for Segment Routing
   4  * and RFC 8476 - Signaling Maximum SID Depth (MSD) Using OSPF
   5  *
   6  * Module name: Segment Routing header definitions
   7  *
   8  * Author: Olivier Dugeon <olivier.dugeon@orange.com>
   9  * Author: Anselme Sawadogo <anselmesawadogo@gmail.com>
  10  *
  11  * Copyright (C) 2016 - 2020 Orange Labs http://www.orange.com
  12  *
  13  * This program is free software; you can redistribute it and/or modify it
  14  * under the terms of the GNU General Public License as published by the Free
  15  * Software Foundation; either version 2 of the License, or (at your option)
  16  * any later version.
  17  *
  18  * This program is distributed in the hope that it will be useful, but WITHOUT
  19  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  20  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  21  * more details.
  22  *
  23  * You should have received a copy of the GNU General Public License along
  24  * with this program; see the file COPYING; if not, write to the Free Software
  25  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  26  */
  27
  28 #ifndef _FRR_OSPF_SR_H
  29 #define _FRR_OSPF_SR_H
  30
  31 /* macros and constants for segment routing */
  32 #define SET_RANGE_SIZE_MASK             0xffffff00
  33 #define GET_RANGE_SIZE_MASK             0x00ffffff
  34 #define SET_LABEL_MASK                  0xffffff00
  35 #define GET_LABEL_MASK                  0x00ffffff
  36 #define SET_RANGE_SIZE(range_size) ((range_size << 8) & SET_RANGE_SIZE_MASK)
  37 #define GET_RANGE_SIZE(range_size) ((range_size >> 8) & GET_RANGE_SIZE_MASK)
  38 #define SET_LABEL(label) ((label << 8) & SET_LABEL_MASK)
  39 #define GET_LABEL(label) ((label >> 8) & GET_LABEL_MASK)
  40
  41 #define OSPF_SR_DEFAULT_METRIC          1
  42
  43 /* Segment Routing TLVs as per RFC 8665 */
  44
  45 /* Segment ID could be a Label (3 bytes) or an Index (4 bytes) */
  46 #define SID_LABEL       3
  47 #define SID_LABEL_SIZE(U) (U - 1)
  48 #define SID_INDEX       4
  49 #define SID_INDEX_SIZE(U) (U)
  50
  51 /* Macro to log debug message */
  52 #define osr_debug(...)                                                         \
  53         do {                                                                   \
  54                 if (IS_DEBUG_OSPF_SR)                                          \
  55                         zlog_debug(__VA_ARGS__);                               \
  56         } while (0)
  57
  58 /* Macro to check if SR Prefix has no valid route */
  59 #define IS_NO_ROUTE(srp) ((srp->route == NULL) || (srp->route->paths == NULL)  \
  60                            || list_isempty(srp->route->paths))
  61
  62 /* SID/Label Sub TLV - section 2.1 */
  63 #define SUBTLV_SID_LABEL                1
  64 #define SUBTLV_SID_LABEL_SIZE           4
  65 struct subtlv_sid_label {
  66         /* Length is 3 (20 rightmost bits MPLS label) or 4 (32 bits SID) */
  67         struct tlv_header header;
  68         uint32_t value;
  69 };
  70
  71 /*
  72  * Following section defines Segment Routing TLV (tag, length, value)
  73  * structures, used in Router Information Opaque LSA.
  74  */
  75
  76 /* RI SR-Algorithm TLV - section 3.1 */
  77 #define RI_SR_TLV_SR_ALGORITHM          8
  78 struct ri_sr_tlv_sr_algorithm {
  79         struct tlv_header header;
  80 #define SR_ALGORITHM_SPF         0
  81 #define SR_ALGORITHM_STRICT_SPF  1
  82 #define SR_ALGORITHM_UNSET       255
  83 #define ALGORITHM_COUNT          4
  84         /* Only 4 algorithms supported in this code */
  85         uint8_t value[ALGORITHM_COUNT];
  86 };
  87
  88 /* RI SID/Label Range TLV used for SRGB & SRLB - section 3.2 & 3.3 */
  89 #define RI_SR_TLV_SRGB_LABEL_RANGE      9
  90 #define RI_SR_TLV_SRLB_LABEL_RANGE      14
  91 #define RI_SR_TLV_LABEL_RANGE_SIZE      12
  92 struct ri_sr_tlv_sid_label_range {
  93         struct tlv_header header;
  94 /* Only 24 upper most bits are significant */
  95 #define SID_RANGE_LABEL_LENGTH  3
  96         uint32_t size;
  97         /* A SID/Label sub-TLV will follow. */
  98         struct subtlv_sid_label lower;
  99 };
 100
 101 /* RI Node/MSD TLV as per RFC 8476 */
 102 #define RI_SR_TLV_NODE_MSD              12
 103 #define RI_SR_TLV_NODE_MSD_SIZE         4
 104 struct ri_sr_tlv_node_msd {
 105         struct tlv_header header;
 106         uint8_t subtype; /* always = 1 */
 107         uint8_t value;
 108         uint16_t padding;
 109 };
 110
 111 /*
 112  * Following section defines Segment Routing TLV (tag, length, value)
 113  * structures, used in Extended Prefix/Link Opaque LSA.
 114  */
 115
 116 /* Adj-SID and LAN-Ajd-SID subtlvs' flags */
 117 #define EXT_SUBTLV_LINK_ADJ_SID_BFLG    0x80
 118 #define EXT_SUBTLV_LINK_ADJ_SID_VFLG    0x40
 119 #define EXT_SUBTLV_LINK_ADJ_SID_LFLG    0x20
 120 #define EXT_SUBTLV_LINK_ADJ_SID_SFLG    0x10
 121
 122 /* Prefix SID subtlv Flags */
 123 #define EXT_SUBTLV_PREFIX_SID_NPFLG     0x40
 124 #define EXT_SUBTLV_PREFIX_SID_MFLG      0x20
 125 #define EXT_SUBTLV_PREFIX_SID_EFLG      0x10
 126 #define EXT_SUBTLV_PREFIX_SID_VFLG      0x08
 127 #define EXT_SUBTLV_PREFIX_SID_LFLG      0x04
 128
 129 /* SID/Label Binding subtlv Flags */
 130 #define EXT_SUBTLV_SID_BINDING_MFLG     0x80
 131
 132 /* Extended Prefix Range TLV - section 4 */
 133 #define EXT_TLV_PREF_RANGE              2
 134 #define EXT_SUBTLV_PREFIX_RANGE_SIZE    12
 135 struct ext_tlv_prefix_range {
 136         struct tlv_header header;
 137         uint8_t pref_length;
 138         uint8_t af;
 139         uint16_t range_size;
 140         uint8_t flags;
 141         uint8_t reserved[3];
 142         struct in_addr address;
 143 };
 144
 145 /* Prefix SID Sub-TLV - section 5 */
 146 #define EXT_SUBTLV_PREFIX_SID           2
 147 #define EXT_SUBTLV_PREFIX_SID_SIZE      8
 148 struct ext_subtlv_prefix_sid {
 149         struct tlv_header header;
 150         uint8_t flags;
 151         uint8_t reserved;
 152         uint8_t mtid;
 153         uint8_t algorithm;
 154         uint32_t value;
 155 };
 156
 157 /* Adj-SID Sub-TLV - section 6.1 */
 158 #define EXT_SUBTLV_ADJ_SID              2
 159 #define EXT_SUBTLV_ADJ_SID_SIZE         8
 160 struct ext_subtlv_adj_sid {
 161         struct tlv_header header;
 162         uint8_t flags;
 163         uint8_t reserved;
 164         uint8_t mtid;
 165         uint8_t weight;
 166         uint32_t value;
 167 };
 168
 169 /* LAN Adj-SID Sub-TLV - section 6.2 */
 170 #define EXT_SUBTLV_LAN_ADJ_SID          3
 171 #define EXT_SUBTLV_LAN_ADJ_SID_SIZE     12
 172 struct ext_subtlv_lan_adj_sid {
 173         struct tlv_header header;
 174         uint8_t flags;
 175         uint8_t reserved;
 176         uint8_t mtid;
 177         uint8_t weight;
 178         struct in_addr neighbor_id;
 179         uint32_t value;
 180 };
 181
 182 /*
 183  * Following section define structure used to manage Segment Routing
 184  * information and TLVs / SubTLVs
 185  */
 186 /* Default min and size of SR Global Block label range */
 187 #define DEFAULT_SRGB_LABEL        16000
 188 #define DEFAULT_SRGB_SIZE         8000
 189
 190 /* Default min and size of SR Local Block label range */
 191 #define DEFAULT_SRLB_LABEL        15000
 192 #define DEFAULT_SRLB_SIZE         1000
 193
 194 /* Structure aggregating SR Range Block info retrieved from an lsa */
 195 struct sr_block {
 196         uint32_t range_size;
 197         uint32_t lower_bound;
 198 };
 199
 200 /* Segment Routing Global Block allocation */
 201 struct sr_global_block {
 202         bool reserved;
 203         uint32_t start;
 204         uint32_t size;
 205 };
 206
 207 /* Segment Routing Local Block allocation */
 208 struct sr_local_block {
 209         bool reserved;
 210         uint32_t start;
 211         uint32_t end;
 212         uint32_t current;
 213         uint32_t max_block;
 214         uint64_t *used_mark;
 215 };
 216 #define SRLB_BLOCK_SIZE 64
 217
 218 /* SID type to make difference between loopback interfaces and others */
 219 enum sid_type { PREF_SID, LOCAL_SID, ADJ_SID, LAN_ADJ_SID };
 220
 221 /* Status of Segment Routing: Off (Disable), On (Enable), (Up) Started */
 222 enum sr_status { SR_OFF, SR_ON, SR_UP, SR_DOWN };
 223
 224 /* Structure aggregating all OSPF Segment Routing information for the node */
 225 struct ospf_sr_db {
 226         /* Status of Segment Routing */
 227         enum sr_status status;
 228
 229         /* Flooding Scope: Area = 10 or AS = 11 */
 230         uint8_t scope;
 231
 232         /* FRR SR node */
 233         struct sr_node *self;
 234
 235         /* List of neighbour SR nodes */
 236         struct hash *neighbors;
 237
 238         /* Local SR info announced in Router Info LSA */
 239
 240         /* Algorithms supported by the node */
 241         uint8_t algo[ALGORITHM_COUNT];
 242         /*
 243          * Segment Routing Global Block i.e. label range
 244          * Only one range supported in this code
 245          */
 246         struct sr_global_block srgb;
 247
 248         /* Segment Routing Local Block */
 249         struct sr_local_block srlb;
 250
 251         /* Maximum SID Depth supported by the node */
 252         uint8_t msd;
 253
 254         /* Thread timer to start Label Manager */
 255         struct thread *t_start_lm;
 256 };
 257
 258 /* Structure aggregating all received SR info from LSAs by node */
 259 struct sr_node {
 260         struct in_addr adv_router; /* used to identify sender of LSA */
 261         /* 24-bit Opaque-ID field value according to RFC 7684 specification */
 262         uint32_t instance;
 263
 264         uint8_t algo[ALGORITHM_COUNT]; /* Algorithms supported by the node */
 265         struct sr_block srgb;          /* Segment Routing Global Block */
 266         struct sr_block srlb;          /* Segment Routing Local Block */
 267         uint8_t msd;                   /* Maximum SID Depth */
 268
 269         /* List of Prefix & Link advertise by this node */
 270         struct list *ext_prefix; /* For Node SID */
 271         struct list *ext_link;   /* For Adjacency SID */
 272
 273         /* Pointer to FRR SR-Node or NULL if it is not a neighbor */
 274         struct sr_node *neighbor;
 275 };
 276
 277 /* Segment Routing - NHLFE info: support IPv4 Only */
 278 struct sr_nhlfe {
 279         struct in_addr nexthop;
 280         ifindex_t ifindex;
 281         mpls_label_t label_in;
 282         mpls_label_t label_out;
 283 };
 284
 285 /* Structure aggregating all Segment Routing Link information */
 286 /* Link are generally advertised by pair: primary + backup */
 287 struct sr_link {
 288         struct in_addr adv_router; /* used to identify sender of LSA */
 289         /* 24-bit Opaque-ID field value according to RFC 7684 specification */
 290         uint32_t instance;
 291
 292         /* Addressed (remote) router id */
 293         struct in_addr remote_id;
 294
 295         /* Interface address */
 296         struct in_addr itf_addr;
 297
 298         /* Flags to manage this link parameters. */
 299         uint8_t flags[2];
 300
 301         /* Segment Routing ID */
 302         uint32_t sid[2];
 303         enum sid_type type;
 304
 305         /* SR NHLFE (Primary + Backup) for this link */
 306         struct sr_nhlfe nhlfe[2];
 307
 308         /* Back pointer to SR Node which advertise this Link */
 309         struct sr_node *srn;
 310 };
 311
 312 /* Structure aggregating all Segment Routing Prefix information */
 313 struct sr_prefix {
 314         struct in_addr adv_router; /* used to identify sender of LSA */
 315         /* 24-bit Opaque-ID field value according to RFC 7684 specification */
 316         uint32_t instance;
 317
 318         /* Prefix itself */
 319         struct prefix_ipv4 prefv4;
 320
 321         /* Flags to manage this prefix parameters. */
 322         uint8_t flags;
 323
 324         /* Segment Routing ID */
 325         uint32_t sid;
 326         enum sid_type type;
 327
 328         /* Incoming label for this prefix */
 329         mpls_label_t label_in;
 330
 331         /* Back pointer to OSPF Route for remote prefix */
 332         struct ospf_route *route;
 333
 334         /* NHLFE for local prefix */
 335         struct sr_nhlfe nhlfe;
 336
 337         /* Back pointer to SR Node which advertise this Prefix */
 338         struct sr_node *srn;
 339 };
 340
 341 /* Prototypes definition */
 342 /* Segment Routing initialisation functions */
 343 extern int ospf_sr_init(void);
 344 extern void ospf_sr_term(void);
 345 extern void ospf_sr_finish(void);
 346 /* Segment Routing label allocation functions */
 347 extern mpls_label_t ospf_sr_local_block_request_label(void);
 348 extern int ospf_sr_local_block_release_label(mpls_label_t label);
 349 /* Segment Routing LSA update & delete functions */
 350 extern void ospf_sr_ri_lsa_update(struct ospf_lsa *lsa);
 351 extern void ospf_sr_ri_lsa_delete(struct ospf_lsa *lsa);
 352 extern void ospf_sr_ext_link_lsa_update(struct ospf_lsa *lsa);
 353 extern void ospf_sr_ext_link_lsa_delete(struct ospf_lsa *lsa);
 354 extern void ospf_sr_ext_prefix_lsa_update(struct ospf_lsa *lsa);
 355 extern void ospf_sr_ext_prefix_lsa_delete(struct ospf_lsa *lsa);
 356 /* Segment Routing Extending Link management */
 357 struct ext_itf;
 358 extern void ospf_sr_ext_itf_add(struct ext_itf *exti);
 359 extern void ospf_sr_ext_itf_delete(struct ext_itf *exti);
 360 /* Segment Routing configuration functions */
 361 extern void ospf_sr_config_write_router(struct vty *vty);
 362 extern void ospf_sr_update_local_prefix(struct interface *ifp,
 363                                         struct prefix *p);
 364 /* Segment Routing re-routing function */
 365 extern void ospf_sr_update_task(struct ospf *ospf);
 366
 367 /* Support for TI-LFA */
 368 extern mpls_label_t ospf_sr_get_prefix_sid_by_id(struct in_addr *id);
 369 extern mpls_label_t ospf_sr_get_adj_sid_by_id(struct in_addr *root_id,
 370                                               struct in_addr *neighbor_id);
 371 extern struct sr_node *ospf_sr_node_create(struct in_addr *rid);
 372
 373 #endif /* _FRR_OSPF_SR_H */