ospfd/ospf_sr.h

   1 /*
   2  * This is an implementation of Segment Routing
   3  * as per draft draft-ietf-ospf-segment-routing-extensions-24
   4  *
   5  * Module name: Segment Routing header definitions
   6  *
   7  * Author: Olivier Dugeon <olivier.dugeon@orange.com>
   8  * Author: Anselme Sawadogo <anselmesawadogo@gmail.com>
   9  *
  10  * Copyright (C) 2016 - 2018 Orange Labs http://www.orange.com
  11  *
  12  * This program is free software; you can redistribute it and/or modify it
  13  * under the terms of the GNU General Public License as published by the Free
  14  * Software Foundation; either version 2 of the License, or (at your option)
  15  * any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful, but WITHOUT
  18  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  19  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  20  * more details.
  21  *
  22  * You should have received a copy of the GNU General Public License along
  23  * with this program; see the file COPYING; if not, write to the Free Software
  24  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  25  */
  26
  27 #ifndef _FRR_OSPF_SR_H
  28 #define _FRR_OSPF_SR_H
  29
  30 /* macros and constants for segment routing */
  31 #define SET_RANGE_SIZE_MASK             0xffffff00
  32 #define GET_RANGE_SIZE_MASK             0x00ffffff
  33 #define SET_LABEL_MASK                  0xffffff00
  34 #define GET_LABEL_MASK                  0x00ffffff
  35 #define SET_RANGE_SIZE(range_size) ((range_size << 8) & SET_RANGE_SIZE_MASK)
  36 #define GET_RANGE_SIZE(range_size) ((range_size >> 8) & GET_RANGE_SIZE_MASK)
  37 #define SET_LABEL(label) ((label << 8) & SET_LABEL_MASK)
  38 #define GET_LABEL(label) ((label >> 8) & GET_LABEL_MASK)
  39
  40 /* Label range for Adj-SID attribution purpose. Start just right after SRGB */
  41 #define ADJ_SID_MIN                     MPLS_DEFAULT_MAX_SRGB_LABEL
  42 #define ADJ_SID_MAX                     (MPLS_DEFAULT_MAX_SRGB_LABEL + 1000)
  43
  44 #define OSPF_SR_DEFAULT_METRIC          1
  45
  46 /* Segment Routing TLVs as per draft-ietf-ospf-segment-routing-extensions-19 */
  47
  48 /* Segment ID could be a Label (3 bytes) or an Index (4 bytes) */
  49 #define SID_LABEL       3
  50 #define SID_LABEL_SIZE(U) (U - 1)
  51 #define SID_INDEX       4
  52 #define SID_INDEX_SIZE(U) (U)
  53
  54 /* Macro to log debug message */
  55 #define osr_debug(...)                                                         \
  56         do {                                                                   \
  57                 if (IS_DEBUG_OSPF_SR)                                          \
  58                         zlog_debug(__VA_ARGS__);                               \
  59         } while (0)
  60
  61 /* Macro to check if SR Prefix has no valid route */
  62 #define IS_NO_ROUTE(srp) ((srp->route == NULL) || (srp->route->paths == NULL)  \
  63                            || list_isempty(srp->route->paths))
  64
  65 /* SID/Label Sub TLV - section 2.1 */
  66 #define SUBTLV_SID_LABEL                1
  67 #define SUBTLV_SID_LABEL_SIZE           8
  68 struct subtlv_sid_label {
  69         /* Length is 3 (20 rightmost bits MPLS label) or 4 (32 bits SID) */
  70         struct tlv_header header;
  71         uint32_t value;
  72 };
  73
  74 /*
  75  * Following section defines Segment Routing TLV (tag, length, value)
  76  * structures, used in Router Information Opaque LSA.
  77  */
  78
  79 /* RI SR-Algorithm TLV - section 3.1 */
  80 #define RI_SR_TLV_SR_ALGORITHM          8
  81 struct ri_sr_tlv_sr_algorithm {
  82         struct tlv_header header;
  83 #define SR_ALGORITHM_SPF         0
  84 #define SR_ALGORITHM_STRICT_SPF  1
  85 #define SR_ALGORITHM_UNSET       255
  86 #define ALGORITHM_COUNT          4
  87         /* Only 4 algorithms supported in this code */
  88         uint8_t value[ALGORITHM_COUNT];
  89 };
  90
  91 /* RI SID/Label Range TLV - section 3.2 */
  92 #define RI_SR_TLV_SID_LABEL_RANGE       9
  93 struct ri_sr_tlv_sid_label_range {
  94         struct tlv_header header;
  95 /* Only 24 upper most bits are significant */
  96 #define SID_RANGE_LABEL_LENGTH  3
  97         uint32_t size;
  98         /* A SID/Label sub-TLV will follow. */
  99         struct subtlv_sid_label lower;
 100 };
 101
 102 /* RI Node/MSD TLV as per draft-ietf-ospf-segment-routing-msd-05 */
 103 #define RI_SR_TLV_NODE_MSD              12
 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
 187 /* Structure aggregating SRGB info retrieved from an lsa */
 188 struct sr_srgb {
 189         uint32_t range_size;
 190         uint32_t lower_bound;
 191 };
 192
 193 /* SID type to make difference between loopback interfaces and others */
 194 enum sid_type { PREF_SID, LOCAL_SID, ADJ_SID, LAN_ADJ_SID };
 195
 196 /* Structure aggregating all OSPF Segment Routing information for the node */
 197 struct ospf_sr_db {
 198         /* Status of Segment Routing: enable or disable */
 199         bool enabled;
 200
 201         /* Flooding Scope: Area = 10 or AS = 11 */
 202         uint8_t scope;
 203
 204         /* FRR SR node */
 205         struct sr_node *self;
 206
 207         /* List of neighbour SR nodes */
 208         struct hash *neighbors;
 209
 210         /* List of SR prefix */
 211         struct route_table *prefix;
 212
 213         /* Local SR info announced in Router Info LSA */
 214
 215         /* Algorithms supported by the node */
 216         uint8_t algo[ALGORITHM_COUNT];
 217         /*
 218          * Segment Routing Global Block i.e. label range
 219          * Only one range supported in this code
 220          */
 221         struct sr_srgb srgb;
 222         /* Maximum SID Depth supported by the node */
 223         uint8_t msd;
 224 };
 225
 226 /* Structure aggregating all received SR info from LSAs by node */
 227 struct sr_node {
 228         struct in_addr adv_router; /* used to identify sender of LSA */
 229         /* 24-bit Opaque-ID field value according to RFC 7684 specification */
 230         uint32_t instance;
 231
 232         uint8_t algo[ALGORITHM_COUNT]; /* Algorithms supported by the node */
 233         /* Segment Routing Global Block i.e. label range */
 234         struct sr_srgb srgb;
 235         uint8_t msd; /* Maximum SID Depth */
 236
 237         /* List of Prefix & Link advertise by this node */
 238         struct list *ext_prefix; /* For Node SID */
 239         struct list *ext_link;   /* For Adj and LAN SID */
 240
 241         /* Pointer to FRR SR-Node or NULL if it is not a neighbor */
 242         struct sr_node *neighbor;
 243 };
 244
 245
 246 /* Segment Routing - NHLFE info: support IPv4 Only */
 247 struct sr_nhlfe {
 248         struct in_addr nexthop;
 249         ifindex_t ifindex;
 250         mpls_label_t label_in;
 251         mpls_label_t label_out;
 252 };
 253
 254 /* Structure aggregating all Segment Routing Link information */
 255 /* Link are generally advertised by pair: primary + backup */
 256 struct sr_link {
 257         struct in_addr adv_router; /* used to identify sender of LSA */
 258         /* 24-bit Opaque-ID field value according to RFC 7684 specification */
 259         uint32_t instance;
 260
 261         /* Interface address */
 262         struct in_addr itf_addr;
 263
 264         /* Flags to manage this link parameters. */
 265         uint8_t flags[2];
 266
 267         /* Segment Routing ID */
 268         uint32_t sid[2];
 269         enum sid_type type;
 270
 271         /* SR NHLFE (Primary + Backup) for this link */
 272         struct sr_nhlfe nhlfe[2];
 273
 274         /* Back pointer to SR Node which advertise this Link */
 275         struct sr_node *srn;
 276 };
 277
 278 /* Structure aggregating all Segment Routing Prefix information */
 279 struct sr_prefix {
 280         struct in_addr adv_router; /* used to identify sender of LSA */
 281         /* 24-bit Opaque-ID field value according to RFC 7684 specification */
 282         uint32_t instance;
 283
 284         /* Prefix itself */
 285         struct prefix_ipv4 prefv4;
 286
 287         /* Flags to manage this prefix parameters. */
 288         uint8_t flags;
 289
 290         /* Segment Routing ID */
 291         uint32_t sid;
 292         enum sid_type type;
 293
 294         /* Incoming label for this prefix */
 295         mpls_label_t label_in;
 296
 297         /* Back pointer to OSPF Route for remote prefix */
 298         struct ospf_route *route;
 299
 300         /* NHLFE for local prefix */
 301         struct sr_nhlfe nhlfe;
 302
 303         /* Back pointer to SR Node which advertise this Prefix */
 304         struct sr_node *srn;
 305 };
 306
 307 /* Prototypes definition */
 308 /* Segment Routing initialisation functions */
 309 extern int ospf_sr_init(void);
 310 extern void ospf_sr_term(void);
 311 extern void ospf_sr_finish(void);
 312 /* Segment Routing LSA update & delete functions */
 313 extern void ospf_sr_ri_lsa_update(struct ospf_lsa *lsa);
 314 extern void ospf_sr_ri_lsa_delete(struct ospf_lsa *lsa);
 315 extern void ospf_sr_ext_link_lsa_update(struct ospf_lsa *lsa);
 316 extern void ospf_sr_ext_link_lsa_delete(struct ospf_lsa *lsa);
 317 extern void ospf_sr_ext_prefix_lsa_update(struct ospf_lsa *lsa);
 318 extern void ospf_sr_ext_prefix_lsa_delete(struct ospf_lsa *lsa);
 319 /* Segment Routing Extending Link management */
 320 struct ext_itf;
 321 extern void ospf_sr_ext_itf_add(struct ext_itf *exti);
 322 extern void ospf_sr_ext_itf_delete(struct ext_itf *exti);
 323 /* Segment Routing configuration functions */
 324 extern uint32_t get_ext_link_label_value(void);
 325 extern void ospf_sr_config_write_router(struct vty *vty);
 326 extern void ospf_sr_update_local_prefix(struct interface *ifp,
 327                                         struct prefix *p);
 328 /* Segment Routing re-routing function */
 329 extern void ospf_sr_update_task(struct ospf *ospf);
 330 #endif /* _FRR_OSPF_SR_H */