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