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 #define DEFAULT_SRGB_END (DEFAULT_SRGB_LABEL + DEFAULT_SRGB_SIZE - 1)
 190
 191 /* Default min and size of SR Local Block label range */
 192 #define DEFAULT_SRLB_LABEL        15000
 193 #define DEFAULT_SRLB_SIZE         1000
 194 #define DEFAULT_SRLB_END (DEFAULT_SRLB_LABEL + DEFAULT_SRLB_SIZE - 1)
 195
 196 /* Structure aggregating SR Range Block info retrieved from an lsa */
 197 struct sr_block {
 198         uint32_t range_size;
 199         uint32_t lower_bound;
 200 };
 201
 202 /* Segment Routing Global Block allocation */
 203 struct sr_global_block {
 204         bool reserved;
 205         uint32_t start;
 206         uint32_t size;
 207 };
 208
 209 /* Segment Routing Local Block allocation */
 210 struct sr_local_block {
 211         bool reserved;
 212         uint32_t start;
 213         uint32_t end;
 214         uint32_t current;
 215         uint32_t max_block;
 216         uint64_t *used_mark;
 217 };
 218 #define SRLB_BLOCK_SIZE 64
 219
 220 /* SID type to make difference between loopback interfaces and others */
 221 enum sid_type { PREF_SID, LOCAL_SID, ADJ_SID, LAN_ADJ_SID };
 222
 223 /* Status of Segment Routing: Off (Disable), On (Enable), (Up) Started */
 224 enum sr_status { SR_OFF, SR_ON, SR_UP, SR_DOWN };
 225
 226 /* Structure aggregating all OSPF Segment Routing information for the node */
 227 struct ospf_sr_db {
 228         /* Status of Segment Routing */
 229         enum sr_status status;
 230
 231         /* Flooding Scope: Area = 10 or AS = 11 */
 232         uint8_t scope;
 233
 234         /* FRR SR node */
 235         struct sr_node *self;
 236
 237         /* List of neighbour SR nodes */
 238         struct hash *neighbors;
 239
 240         /* Local SR info announced in Router Info LSA */
 241
 242         /* Algorithms supported by the node */
 243         uint8_t algo[ALGORITHM_COUNT];
 244         /*
 245          * Segment Routing Global Block i.e. label range
 246          * Only one range supported in this code
 247          */
 248         struct sr_global_block srgb;
 249
 250         /* Segment Routing Local Block */
 251         struct sr_local_block srlb;
 252
 253         /* Maximum SID Depth supported by the node */
 254         uint8_t msd;
 255
 256         /* Thread timer to start Label Manager */
 257         struct thread *t_start_lm;
 258 };
 259
 260 /* Structure aggregating all received SR info from LSAs by node */
 261 struct sr_node {
 262         struct in_addr adv_router; /* used to identify sender of LSA */
 263         /* 24-bit Opaque-ID field value according to RFC 7684 specification */
 264         uint32_t instance;
 265
 266         uint8_t algo[ALGORITHM_COUNT]; /* Algorithms supported by the node */
 267         struct sr_block srgb;          /* Segment Routing Global Block */
 268         struct sr_block srlb;          /* Segment Routing Local Block */
 269         uint8_t msd;                   /* Maximum SID Depth */
 270
 271         /* List of Prefix & Link advertise by this node */
 272         struct list *ext_prefix; /* For Node SID */
 273         struct list *ext_link;   /* For Adjacency SID */
 274
 275         /* Pointer to FRR SR-Node or NULL if it is not a neighbor */
 276         struct sr_node *neighbor;
 277 };
 278
 279 /* Segment Routing - NHLFE info: support IPv4 Only */
 280 struct sr_nhlfe {
 281         struct in_addr nexthop;
 282         ifindex_t ifindex;
 283         mpls_label_t label_in;
 284         mpls_label_t label_out;
 285 };
 286
 287 /* Structure aggregating all Segment Routing Link information */
 288 /* Link are generally advertised by pair: primary + backup */
 289 struct sr_link {
 290         struct in_addr adv_router; /* used to identify sender of LSA */
 291         /* 24-bit Opaque-ID field value according to RFC 7684 specification */
 292         uint32_t instance;
 293
 294         /* Addressed (remote) router id */
 295         struct in_addr remote_id;
 296
 297         /* Interface address */
 298         struct in_addr itf_addr;
 299
 300         /* Flags to manage this link parameters. */
 301         uint8_t flags[2];
 302
 303         /* Segment Routing ID */
 304         uint32_t sid[2];
 305         enum sid_type type;
 306
 307         /* SR NHLFE (Primary + Backup) for this link */
 308         struct sr_nhlfe nhlfe[2];
 309
 310         /* Back pointer to SR Node which advertise this Link */
 311         struct sr_node *srn;
 312 };
 313
 314 /* Structure aggregating all Segment Routing Prefix information */
 315 struct sr_prefix {
 316         struct in_addr adv_router; /* used to identify sender of LSA */
 317         /* 24-bit Opaque-ID field value according to RFC 7684 specification */
 318         uint32_t instance;
 319
 320         /* Prefix itself */
 321         struct prefix_ipv4 prefv4;
 322
 323         /* Flags to manage this prefix parameters. */
 324         uint8_t flags;
 325
 326         /* Segment Routing ID */
 327         uint32_t sid;
 328         enum sid_type type;
 329
 330         /* Incoming label for this prefix */
 331         mpls_label_t label_in;
 332
 333         /* Back pointer to OSPF Route for remote prefix */
 334         struct ospf_route *route;
 335
 336         /* NHLFE for local prefix */
 337         struct sr_nhlfe nhlfe;
 338
 339         /* Back pointer to SR Node which advertise this Prefix */
 340         struct sr_node *srn;
 341 };
 342
 343 /* Prototypes definition */
 344 /* Segment Routing initialisation functions */
 345 extern int ospf_sr_init(void);
 346 extern void ospf_sr_term(void);
 347 extern void ospf_sr_finish(void);
 348 /* Segment Routing label allocation functions */
 349 extern mpls_label_t ospf_sr_local_block_request_label(void);
 350 extern int ospf_sr_local_block_release_label(mpls_label_t label);
 351 /* Segment Routing LSA update & delete functions */
 352 extern void ospf_sr_ri_lsa_update(struct ospf_lsa *lsa);
 353 extern void ospf_sr_ri_lsa_delete(struct ospf_lsa *lsa);
 354 extern void ospf_sr_ext_link_lsa_update(struct ospf_lsa *lsa);
 355 extern void ospf_sr_ext_link_lsa_delete(struct ospf_lsa *lsa);
 356 extern void ospf_sr_ext_prefix_lsa_update(struct ospf_lsa *lsa);
 357 extern void ospf_sr_ext_prefix_lsa_delete(struct ospf_lsa *lsa);
 358 /* Segment Routing Extending Link management */
 359 struct ext_itf;
 360 extern void ospf_sr_ext_itf_add(struct ext_itf *exti);
 361 extern void ospf_sr_ext_itf_delete(struct ext_itf *exti);
 362 /* Segment Routing configuration functions */
 363 extern void ospf_sr_config_write_router(struct vty *vty);
 364 extern void ospf_sr_update_local_prefix(struct interface *ifp,
 365                                         struct prefix *p);
 366 /* Segment Routing re-routing function */
 367 extern void ospf_sr_update_task(struct ospf *ospf);
 368
 369 /* Support for TI-LFA */
 370 extern mpls_label_t ospf_sr_get_prefix_sid_by_id(struct in_addr *id);
 371 extern mpls_label_t ospf_sr_get_adj_sid_by_id(struct in_addr *root_id,
 372                                               struct in_addr *neighbor_id);
 373 extern struct sr_node *ospf_sr_node_create(struct in_addr *rid);
 374
 375 #endif /* _FRR_OSPF_SR_H */