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 /* smallest configurable SRGB / SRLB sizes */
  42 #define MIN_SRLB_SIZE 16
  43 #define MIN_SRGB_SIZE 16
  44
  45 /* Segment Routing TLVs as per RFC 8665 */
  46
  47 /* Segment ID could be a Label (3 bytes) or an Index (4 bytes) */
  48 #define SID_LABEL       3
  49 #define SID_LABEL_SIZE(U) (U - 1)
  50 #define SID_INDEX       4
  51 #define SID_INDEX_SIZE(U) (U)
  52
  53 /* Macro to log debug message */
  54 #define osr_debug(...)                                                         \
  55         do {                                                                   \
  56                 if (IS_DEBUG_OSPF_SR)                                          \
  57                         zlog_debug(__VA_ARGS__);                               \
  58         } while (0)
  59
  60 /* Macro to check if SR Prefix has no valid route */
  61 #define IS_NO_ROUTE(srp) ((srp->route == NULL) || (srp->route->paths == NULL)  \
  62                            || list_isempty(srp->route->paths))
  63
  64 /* SID/Label Sub TLV - section 2.1 */
  65 #define SUBTLV_SID_LABEL                1
  66 #define SUBTLV_SID_LABEL_SIZE           4
  67 struct subtlv_sid_label {
  68         /* Length is 3 (20 rightmost bits MPLS label) or 4 (32 bits SID) */
  69         struct tlv_header header;
  70         uint32_t value;
  71 };
  72
  73 /*
  74  * Following section defines Segment Routing TLV (tag, length, value)
  75  * structures, used in Router Information Opaque LSA.
  76  */
  77
  78 /* RI SR-Algorithm TLV - section 3.1 */
  79 #define RI_SR_TLV_SR_ALGORITHM          8
  80 struct ri_sr_tlv_sr_algorithm {
  81         struct tlv_header header;
  82 #define SR_ALGORITHM_SPF         0
  83 #define SR_ALGORITHM_STRICT_SPF  1
  84 #define SR_ALGORITHM_UNSET       255
  85 #define ALGORITHM_COUNT          4
  86         /* Only 4 algorithms supported in this code */
  87         uint8_t value[ALGORITHM_COUNT];
  88 };
  89
  90 /* RI SID/Label Range TLV used for SRGB & SRLB - section 3.2 & 3.3 */
  91 #define RI_SR_TLV_SRGB_LABEL_RANGE      9
  92 #define RI_SR_TLV_SRLB_LABEL_RANGE      14
  93 #define RI_SR_TLV_LABEL_RANGE_SIZE      12
  94 struct ri_sr_tlv_sid_label_range {
  95         struct tlv_header header;
  96 /* Only 24 upper most bits are significant */
  97 #define SID_RANGE_LABEL_LENGTH  3
  98         uint32_t size;
  99         /* A SID/Label sub-TLV will follow. */
 100         struct subtlv_sid_label lower;
 101 };
 102
 103 /* RI Node/MSD TLV as per RFC 8476 */
 104 #define RI_SR_TLV_NODE_MSD              12
 105 #define RI_SR_TLV_NODE_MSD_SIZE         4
 106 struct ri_sr_tlv_node_msd {
 107         struct tlv_header header;
 108         uint8_t subtype; /* always = 1 */
 109         uint8_t value;
 110         uint16_t padding;
 111 };
 112
 113 /*
 114  * Following section defines Segment Routing TLV (tag, length, value)
 115  * structures, used in Extended Prefix/Link Opaque LSA.
 116  */
 117
 118 /* Adj-SID and LAN-Ajd-SID subtlvs' flags */
 119 #define EXT_SUBTLV_LINK_ADJ_SID_BFLG    0x80
 120 #define EXT_SUBTLV_LINK_ADJ_SID_VFLG    0x40
 121 #define EXT_SUBTLV_LINK_ADJ_SID_LFLG    0x20
 122 #define EXT_SUBTLV_LINK_ADJ_SID_SFLG    0x10
 123
 124 /* Prefix SID subtlv Flags */
 125 #define EXT_SUBTLV_PREFIX_SID_NPFLG     0x40
 126 #define EXT_SUBTLV_PREFIX_SID_MFLG      0x20
 127 #define EXT_SUBTLV_PREFIX_SID_EFLG      0x10
 128 #define EXT_SUBTLV_PREFIX_SID_VFLG      0x08
 129 #define EXT_SUBTLV_PREFIX_SID_LFLG      0x04
 130
 131 /* SID/Label Binding subtlv Flags */
 132 #define EXT_SUBTLV_SID_BINDING_MFLG     0x80
 133
 134 /* Extended Prefix Range TLV - section 4 */
 135 #define EXT_TLV_PREF_RANGE              2
 136 #define EXT_SUBTLV_PREFIX_RANGE_SIZE    12
 137 struct ext_tlv_prefix_range {
 138         struct tlv_header header;
 139         uint8_t pref_length;
 140         uint8_t af;
 141         uint16_t range_size;
 142         uint8_t flags;
 143         uint8_t reserved[3];
 144         struct in_addr address;
 145 };
 146
 147 /* Prefix SID Sub-TLV - section 5 */
 148 #define EXT_SUBTLV_PREFIX_SID           2
 149 #define EXT_SUBTLV_PREFIX_SID_SIZE      8
 150 struct ext_subtlv_prefix_sid {
 151         struct tlv_header header;
 152         uint8_t flags;
 153         uint8_t reserved;
 154         uint8_t mtid;
 155         uint8_t algorithm;
 156         uint32_t value;
 157 };
 158
 159 /* Adj-SID Sub-TLV - section 6.1 */
 160 #define EXT_SUBTLV_ADJ_SID              2
 161 #define EXT_SUBTLV_ADJ_SID_SIZE         8
 162 struct ext_subtlv_adj_sid {
 163         struct tlv_header header;
 164         uint8_t flags;
 165         uint8_t reserved;
 166         uint8_t mtid;
 167         uint8_t weight;
 168         uint32_t value;
 169 };
 170
 171 /* LAN Adj-SID Sub-TLV - section 6.2 */
 172 #define EXT_SUBTLV_LAN_ADJ_SID          3
 173 #define EXT_SUBTLV_LAN_ADJ_SID_SIZE     12
 174 struct ext_subtlv_lan_adj_sid {
 175         struct tlv_header header;
 176         uint8_t flags;
 177         uint8_t reserved;
 178         uint8_t mtid;
 179         uint8_t weight;
 180         struct in_addr neighbor_id;
 181         uint32_t value;
 182 };
 183
 184 /*
 185  * Following section define structure used to manage Segment Routing
 186  * information and TLVs / SubTLVs
 187  */
 188 /* Default min and size of SR Global Block label range */
 189 #define DEFAULT_SRGB_LABEL        16000
 190 #define DEFAULT_SRGB_SIZE         8000
 191 #define DEFAULT_SRGB_END (DEFAULT_SRGB_LABEL + DEFAULT_SRGB_SIZE - 1)
 192
 193 /* Default min and size of SR Local Block label range */
 194 #define DEFAULT_SRLB_LABEL        15000
 195 #define DEFAULT_SRLB_SIZE         1000
 196 #define DEFAULT_SRLB_END (DEFAULT_SRLB_LABEL + DEFAULT_SRLB_SIZE - 1)
 197
 198 /* Structure aggregating SR Range Block info retrieved from an lsa */
 199 struct sr_block {
 200         uint32_t range_size;
 201         uint32_t lower_bound;
 202 };
 203
 204 /* Segment Routing Global Block allocation */
 205 struct sr_global_block {
 206         bool reserved;
 207         uint32_t start;
 208         uint32_t size;
 209 };
 210
 211 /* Segment Routing Local Block allocation */
 212 struct sr_local_block {
 213         bool reserved;
 214         uint32_t start;
 215         uint32_t end;
 216         uint32_t current;
 217         uint32_t max_block;
 218         uint64_t *used_mark;
 219 };
 220 #define SRLB_BLOCK_SIZE 64
 221
 222 /* SID type to make difference between loopback interfaces and others */
 223 enum sid_type { PREF_SID, LOCAL_SID, ADJ_SID, LAN_ADJ_SID };
 224
 225 /* Status of Segment Routing: Off (Disable), On (Enable), (Up) Started */
 226 enum sr_status { SR_OFF, SR_ON, SR_UP };
 227
 228 /* Structure aggregating all OSPF Segment Routing information for the node */
 229 struct ospf_sr_db {
 230         /* Status of Segment Routing */
 231         enum sr_status status;
 232
 233         /* Flooding Scope: Area = 10 or AS = 11 */
 234         uint8_t scope;
 235
 236         /* FRR SR node */
 237         struct sr_node *self;
 238
 239         /* List of neighbour SR nodes */
 240         struct hash *neighbors;
 241
 242         /* Local SR info announced in Router Info LSA */
 243
 244         /* Algorithms supported by the node */
 245         uint8_t algo[ALGORITHM_COUNT];
 246         /*
 247          * Segment Routing Global Block i.e. label range
 248          * Only one range supported in this code
 249          */
 250         struct sr_global_block srgb;
 251
 252         /* Segment Routing Local Block */
 253         struct sr_local_block srlb;
 254
 255         /* Maximum SID Depth supported by the node */
 256         uint8_t msd;
 257
 258         /* Thread timer to start Label Manager */
 259         struct thread *t_start_lm;
 260 };
 261
 262 /* Structure aggregating all received SR info from LSAs by node */
 263 struct sr_node {
 264         struct in_addr adv_router; /* used to identify sender of LSA */
 265         /* 24-bit Opaque-ID field value according to RFC 7684 specification */
 266         uint32_t instance;
 267
 268         uint8_t algo[ALGORITHM_COUNT]; /* Algorithms supported by the node */
 269         struct sr_block srgb;          /* Segment Routing Global Block */
 270         struct sr_block srlb;          /* Segment Routing Local Block */
 271         uint8_t msd;                   /* Maximum SID Depth */
 272
 273         /* List of Prefix & Link advertise by this node */
 274         struct list *ext_prefix; /* For Node SID */
 275         struct list *ext_link;   /* For Adjacency SID */
 276
 277         /* Pointer to FRR SR-Node or NULL if it is not a neighbor */
 278         struct sr_node *neighbor;
 279 };
 280
 281 /* Segment Routing - NHLFE info: support IPv4 Only */
 282 struct sr_nhlfe {
 283         struct in_addr nexthop;
 284         ifindex_t ifindex;
 285         mpls_label_t label_in;
 286         mpls_label_t label_out;
 287 };
 288
 289 /* Structure aggregating all Segment Routing Link information */
 290 /* Link are generally advertised by pair: primary + backup */
 291 struct sr_link {
 292         struct in_addr adv_router; /* used to identify sender of LSA */
 293         /* 24-bit Opaque-ID field value according to RFC 7684 specification */
 294         uint32_t instance;
 295
 296         /* Addressed (remote) router id */
 297         struct in_addr remote_id;
 298
 299         /* Interface address */
 300         struct in_addr itf_addr;
 301
 302         /* Flags to manage this link parameters. */
 303         uint8_t flags[2];
 304
 305         /* Segment Routing ID */
 306         uint32_t sid[2];
 307         enum sid_type type;
 308
 309         /* SR NHLFE (Primary + Backup) for this link */
 310         struct sr_nhlfe nhlfe[2];
 311
 312         /* Back pointer to SR Node which advertise this Link */
 313         struct sr_node *srn;
 314 };
 315
 316 /* Structure aggregating all Segment Routing Prefix information */
 317 struct sr_prefix {
 318         struct in_addr adv_router; /* used to identify sender of LSA */
 319         /* 24-bit Opaque-ID field value according to RFC 7684 specification */
 320         uint32_t instance;
 321
 322         /* Prefix itself */
 323         struct prefix_ipv4 prefv4;
 324
 325         /* Flags to manage this prefix parameters. */
 326         uint8_t flags;
 327
 328         /* Segment Routing ID */
 329         uint32_t sid;
 330         enum sid_type type;
 331
 332         /* Incoming label for this prefix */
 333         mpls_label_t label_in;
 334
 335         /* Back pointer to OSPF Route for remote prefix */
 336         struct ospf_route *route;
 337
 338         /* NHLFE for local prefix */
 339         struct sr_nhlfe nhlfe;
 340
 341         /* Back pointer to SR Node which advertise this Prefix */
 342         struct sr_node *srn;
 343 };
 344
 345 /* Prototypes definition */
 346 /* Segment Routing initialisation functions */
 347 extern int ospf_sr_init(void);
 348 extern void ospf_sr_term(void);
 349 extern void ospf_sr_finish(void);
 350 /* Segment Routing label allocation functions */
 351 extern mpls_label_t ospf_sr_local_block_request_label(void);
 352 extern int ospf_sr_local_block_release_label(mpls_label_t label);
 353 /* Segment Routing LSA update & delete functions */
 354 extern void ospf_sr_ri_lsa_update(struct ospf_lsa *lsa);
 355 extern void ospf_sr_ri_lsa_delete(struct ospf_lsa *lsa);
 356 extern void ospf_sr_ext_link_lsa_update(struct ospf_lsa *lsa);
 357 extern void ospf_sr_ext_link_lsa_delete(struct ospf_lsa *lsa);
 358 extern void ospf_sr_ext_prefix_lsa_update(struct ospf_lsa *lsa);
 359 extern void ospf_sr_ext_prefix_lsa_delete(struct ospf_lsa *lsa);
 360 /* Segment Routing Extending Link management */
 361 struct ext_itf;
 362 extern void ospf_sr_ext_itf_add(struct ext_itf *exti);
 363 extern void ospf_sr_ext_itf_delete(struct ext_itf *exti);
 364 /* Segment Routing configuration functions */
 365 extern void ospf_sr_config_write_router(struct vty *vty);
 366 extern void ospf_sr_update_local_prefix(struct interface *ifp,
 367                                         struct prefix *p);
 368 /* Segment Routing re-routing function */
 369 extern void ospf_sr_update_task(struct ospf *ospf);
 370
 371 /* Support for TI-LFA */
 372 extern mpls_label_t ospf_sr_get_prefix_sid_by_id(struct in_addr *id);
 373 extern mpls_label_t ospf_sr_get_adj_sid_by_id(struct in_addr *root_id,
 374                                               struct in_addr *neighbor_id);
 375 extern struct sr_node *ospf_sr_node_create(struct in_addr *rid);
 376
 377 #endif /* _FRR_OSPF_SR_H */