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 /* SID/Label Sub TLV - section 2.1 */
  55 #define SUBTLV_SID_LABEL                1
  56 #define SUBTLV_SID_LABEL_SIZE           8
  57 struct subtlv_sid_label {
  58         /* Length is 3 (20 rightmost bits MPLS label) or 4 (32 bits SID) */
  59         struct tlv_header header;
  60         uint32_t value;
  61 };
  62
  63 /*
  64  * Following section defines Segment Routing TLV (tag, length, value)
  65  * structures, used in Router Information Opaque LSA.
  66  */
  67
  68 /* RI SR-Algorithm TLV - section 3.1 */
  69 #define RI_SR_TLV_SR_ALGORITHM          8
  70 struct ri_sr_tlv_sr_algorithm {
  71         struct tlv_header header;
  72 #define SR_ALGORITHM_SPF         0
  73 #define SR_ALGORITHM_STRICT_SPF  1
  74 #define SR_ALGORITHM_UNSET       255
  75 #define ALGORITHM_COUNT          4
  76         /* Only 4 algorithms supported in this code */
  77         uint8_t value[ALGORITHM_COUNT];
  78 };
  79
  80 /* RI SID/Label Range TLV - section 3.2 */
  81 #define RI_SR_TLV_SID_LABEL_RANGE       9
  82 struct ri_sr_tlv_sid_label_range {
  83         struct tlv_header header;
  84 /* Only 24 upper most bits are significant */
  85 #define SID_RANGE_LABEL_LENGTH  3
  86         uint32_t size;
  87         /* A SID/Label sub-TLV will follow. */
  88         struct subtlv_sid_label lower;
  89 };
  90
  91 /* RI Node/MSD TLV as per draft-ietf-ospf-segment-routing-msd-05 */
  92 #define RI_SR_TLV_NODE_MSD              12
  93 struct ri_sr_tlv_node_msd {
  94         struct tlv_header header;
  95         uint8_t subtype; /* always = 1 */
  96         uint8_t value;
  97         uint16_t padding;
  98 };
  99
 100 /*
 101  * Following section defines Segment Routing TLV (tag, length, value)
 102  * structures, used in Extended Prefix/Link Opaque LSA.
 103  */
 104
 105 /* Adj-SID and LAN-Ajd-SID subtlvs' flags */
 106 #define EXT_SUBTLV_LINK_ADJ_SID_BFLG    0x80
 107 #define EXT_SUBTLV_LINK_ADJ_SID_VFLG    0x40
 108 #define EXT_SUBTLV_LINK_ADJ_SID_LFLG    0x20
 109 #define EXT_SUBTLV_LINK_ADJ_SID_SFLG    0x10
 110
 111 /* Prefix SID subtlv Flags */
 112 #define EXT_SUBTLV_PREFIX_SID_NPFLG     0x40
 113 #define EXT_SUBTLV_PREFIX_SID_MFLG      0x20
 114 #define EXT_SUBTLV_PREFIX_SID_EFLG      0x10
 115 #define EXT_SUBTLV_PREFIX_SID_VFLG      0x08
 116 #define EXT_SUBTLV_PREFIX_SID_LFLG      0x04
 117
 118 /* SID/Label Binding subtlv Flags */
 119 #define EXT_SUBTLV_SID_BINDING_MFLG     0x80
 120
 121 /* Extended Prefix Range TLV - section 4 */
 122 #define EXT_TLV_PREF_RANGE              2
 123 #define EXT_SUBTLV_PREFIX_RANGE_SIZE    12
 124 struct ext_tlv_prefix_range {
 125         struct tlv_header header;
 126         uint8_t pref_length;
 127         uint8_t af;
 128         uint16_t range_size;
 129         uint8_t flags;
 130         uint8_t reserved[3];
 131         struct in_addr address;
 132 };
 133
 134 /* Prefix SID Sub-TLV - section 5 */
 135 #define EXT_SUBTLV_PREFIX_SID           2
 136 #define EXT_SUBTLV_PREFIX_SID_SIZE      8
 137 struct ext_subtlv_prefix_sid {
 138         struct tlv_header header;
 139         uint8_t flags;
 140         uint8_t reserved;
 141         uint8_t mtid;
 142         uint8_t algorithm;
 143         uint32_t value;
 144 };
 145
 146 /* Adj-SID Sub-TLV - section 6.1 */
 147 #define EXT_SUBTLV_ADJ_SID              2
 148 #define EXT_SUBTLV_ADJ_SID_SIZE         8
 149 struct ext_subtlv_adj_sid {
 150         struct tlv_header header;
 151         uint8_t flags;
 152         uint8_t reserved;
 153         uint8_t mtid;
 154         uint8_t weight;
 155         uint32_t value;
 156 };
 157
 158 /* LAN Adj-SID Sub-TLV - section 6.2 */
 159 #define EXT_SUBTLV_LAN_ADJ_SID          3
 160 #define EXT_SUBTLV_LAN_ADJ_SID_SIZE     12
 161 struct ext_subtlv_lan_adj_sid {
 162         struct tlv_header header;
 163         uint8_t flags;
 164         uint8_t reserved;
 165         uint8_t mtid;
 166         uint8_t weight;
 167         struct in_addr neighbor_id;
 168         uint32_t value;
 169 };
 170
 171 /*
 172  * Following section define structure used to manage Segment Routing
 173  * information and TLVs / SubTLVs
 174  */
 175
 176 /* Structure aggregating SRGB info retrieved from an lsa */
 177 struct sr_srgb {
 178         uint32_t range_size;
 179         uint32_t lower_bound;
 180 };
 181
 182 /* SID type to make difference between loopback interfaces and others */
 183 enum sid_type { PREF_SID, ADJ_SID, LAN_ADJ_SID };
 184
 185 /* Structure aggregating all OSPF Segment Routing information for the node */
 186 struct ospf_sr_db {
 187         /* Status of Segment Routing: enable or disable */
 188         bool enabled;
 189
 190         /* Ongoing Update following an OSPF SPF */
 191         bool update;
 192
 193         /* Flooding Scope: Area = 10 or AS = 11 */
 194         uint8_t scope;
 195
 196         /* FRR SR node */
 197         struct sr_node *self;
 198
 199         /* List of neighbour SR nodes */
 200         struct hash *neighbors;
 201
 202         /* List of SR prefix */
 203         struct route_table *prefix;
 204
 205         /* Local SR info announced in Router Info LSA */
 206
 207         /* Algorithms supported by the node */
 208         uint8_t algo[ALGORITHM_COUNT];
 209         /*
 210          * Segment Routing Global Block i.e. label range
 211          * Only one range supported in this code
 212          */
 213         struct sr_srgb srgb;
 214         /* Maximum SID Depth supported by the node */
 215         uint8_t msd;
 216 };
 217
 218 /* Structure aggregating all received SR info from LSAs by node */
 219 struct sr_node {
 220         struct in_addr adv_router; /* used to identify sender of LSA */
 221         /* 24-bit Opaque-ID field value according to RFC 7684 specification */
 222         uint32_t instance;
 223
 224         uint8_t algo[ALGORITHM_COUNT]; /* Algorithms supported by the node */
 225         /* Segment Routing Global Block i.e. label range */
 226         struct sr_srgb srgb;
 227         uint8_t msd; /* Maximum SID Depth */
 228
 229         /* List of Prefix & Link advertise by this node */
 230         struct list *ext_prefix; /* For Node SID */
 231         struct list *ext_link;   /* For Adj and LAN SID */
 232
 233         /* Pointer to FRR SR-Node or NULL if it is not a neighbor */
 234         struct sr_node *neighbor;
 235 };
 236
 237
 238 /* Segment Routing - NHLFE info: support IPv4 Only */
 239 struct sr_nhlfe {
 240         struct prefix_ipv4 prefv4;
 241         struct in_addr nexthop;
 242         ifindex_t ifindex;
 243         mpls_label_t label_in;
 244         mpls_label_t label_out;
 245 };
 246
 247 /* Structure aggregating all Segment Routing Link information */
 248 /* Link are generally advertised by pair: primary + backup */
 249 struct sr_link {
 250         struct in_addr adv_router; /* used to identify sender of LSA */
 251         /* 24-bit Opaque-ID field value according to RFC 7684 specification */
 252         uint32_t instance;
 253
 254         /* Flags to manage this link parameters. */
 255         uint8_t flags[2];
 256
 257         /* Segment Routing ID */
 258         uint32_t sid[2];
 259         enum sid_type type;
 260
 261         /* SR NHLFE for this link */
 262         struct sr_nhlfe nhlfe[2];
 263
 264         /* Back pointer to SR Node which advertise this Link */
 265         struct sr_node *srn;
 266 };
 267
 268 /* Structure aggregating all Segment Routing Prefix information */
 269 struct sr_prefix {
 270         struct in_addr adv_router; /* used to identify sender of LSA */
 271         /* 24-bit Opaque-ID field value according to RFC 7684 specification */
 272         uint32_t instance;
 273
 274         /* Flags to manage this prefix parameters. */
 275         uint8_t flags;
 276
 277         /* Segment Routing ID */
 278         uint32_t sid;
 279         enum sid_type type;
 280
 281         /* SR NHLFE for this prefix */
 282         struct sr_nhlfe nhlfe;
 283
 284         /* Back pointer to SR Node which advertise this Prefix */
 285         struct sr_node *srn;
 286
 287         /*
 288          * Pointer to SR Node which is the next hop for this Prefix
 289          * or NULL if next hop is the destination of the prefix
 290          */
 291         struct sr_node *nexthop;
 292 };
 293
 294 /* Prototypes definition */
 295 /* Segment Routing initialisation functions */
 296 extern int ospf_sr_init(void);
 297 extern void ospf_sr_term(void);
 298 extern void ospf_sr_finish(void);
 299 /* Segment Routing LSA update & delete functions */
 300 extern void ospf_sr_ri_lsa_update(struct ospf_lsa *lsa);
 301 extern void ospf_sr_ri_lsa_delete(struct ospf_lsa *lsa);
 302 extern void ospf_sr_ext_link_lsa_update(struct ospf_lsa *lsa);
 303 extern void ospf_sr_ext_link_lsa_delete(struct ospf_lsa *lsa);
 304 extern void ospf_sr_ext_prefix_lsa_update(struct ospf_lsa *lsa);
 305 extern void ospf_sr_ext_prefix_lsa_delete(struct ospf_lsa *lsa);
 306 /* Segment Routing configuration functions */
 307 extern uint32_t get_ext_link_label_value(void);
 308 extern void ospf_sr_config_write_router(struct vty *vty);
 309 extern void ospf_sr_update_prefix(struct interface *ifp, struct prefix *p);
 310 /* Segment Routing re-routing function */
 311 extern void ospf_sr_update_timer_add(struct ospf *ospf);
 312 #endif /* _FRR_OSPF_SR_H */