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 /* Default Route priority for OSPF Segment Routing */
  31 #define OSPF_SR_PRIORITY_DEFAULT        10
  32
  33 /* macros and constants for segment routing */
  34 #define SET_RANGE_SIZE_MASK             0xffffff00
  35 #define GET_RANGE_SIZE_MASK             0x00ffffff
  36 #define SET_LABEL_MASK                  0xffffff00
  37 #define GET_LABEL_MASK                  0x00ffffff
  38 #define SET_RANGE_SIZE(range_size) ((range_size << 8) & SET_RANGE_SIZE_MASK)
  39 #define GET_RANGE_SIZE(range_size) ((range_size >> 8) & GET_RANGE_SIZE_MASK)
  40 #define SET_LABEL(label) ((label << 8) & SET_LABEL_MASK)
  41 #define GET_LABEL(label) ((label >> 8) & GET_LABEL_MASK)
  42
  43 /* Label range for Adj-SID attribution purpose. Start just right after SRGB */
  44 #define ADJ_SID_MIN                     MPLS_DEFAULT_MAX_SRGB_LABEL
  45 #define ADJ_SID_MAX                     (MPLS_DEFAULT_MAX_SRGB_LABEL + 1000)
  46
  47 #define OSPF_SR_DEFAULT_METRIC          1
  48
  49 /* Segment Routing TLVs as per draft-ietf-ospf-segment-routing-extensions-19 */
  50
  51 /* Segment ID could be a Label (3 bytes) or an Index (4 bytes) */
  52 #define SID_BASE_SIZE   4
  53 #define SID_LABEL       3
  54 #define SID_LABEL_SIZE  (SID_BASE_SIZE + SID_LABEL)
  55 #define SID_INDEX       4
  56 #define SID_INDEX_SIZE  (SID_BASE_SIZE + SID_INDEX)
  57
  58 /* SID/Label Sub TLV - section 2.1 */
  59 #define SUBTLV_SID_LABEL                1
  60 #define SUBTLV_SID_LABEL_SIZE           8
  61 struct subtlv_sid_label {
  62         /* Length is 3 (20 rightmost bits MPLS label) or 4 (32 bits SID) */
  63         struct tlv_header header;
  64         uint32_t value;
  65 };
  66
  67 /*
  68  * Following section defines Segment Routing TLV (tag, length, value)
  69  * structures, used in Router Information Opaque LSA.
  70  */
  71
  72 /* RI SR-Algorithm TLV - section 3.1 */
  73 #define RI_SR_TLV_SR_ALGORITHM          8
  74 struct ri_sr_tlv_sr_algorithm {
  75         struct tlv_header header;
  76 #define SR_ALGORITHM_SPF         0
  77 #define SR_ALGORITHM_STRICT_SPF  1
  78 #define SR_ALGORITHM_UNSET       255
  79 #define ALGORITHM_COUNT          4
  80         /* Only 4 algorithms supported in this code */
  81         uint8_t value[ALGORITHM_COUNT];
  82 };
  83
  84 /* RI SID/Label Range TLV - section 3.2 */
  85 #define RI_SR_TLV_SID_LABEL_RANGE       9
  86 struct ri_sr_tlv_sid_label_range {
  87         struct tlv_header header;
  88 /* Only 24 upper most bits are significant */
  89 #define SID_RANGE_LABEL_LENGTH  3
  90         uint32_t size;
  91         /* A SID/Label sub-TLV will follow. */
  92         struct subtlv_sid_label lower;
  93 };
  94
  95 /* RI Node/MSD TLV as per draft-ietf-ospf-segment-routing-msd-05 */
  96 #define RI_SR_TLV_NODE_MSD              12
  97 struct ri_sr_tlv_node_msd {
  98         struct tlv_header header;
  99         uint8_t subtype; /* always = 1 */
 100         uint8_t value;
 101         uint16_t padding;
 102 };
 103
 104 /*
 105  * Following section defines Segment Routing TLV (tag, length, value)
 106  * structures, used in Extended Prefix/Link Opaque LSA.
 107  */
 108
 109 /* Adj-SID and LAN-Ajd-SID subtlvs' flags */
 110 #define EXT_SUBTLV_LINK_ADJ_SID_BFLG    0x80
 111 #define EXT_SUBTLV_LINK_ADJ_SID_VFLG    0x40
 112 #define EXT_SUBTLV_LINK_ADJ_SID_LFLG    0x20
 113 #define EXT_SUBTLV_LINK_ADJ_SID_SFLG    0x10
 114
 115 /* Prefix SID subtlv Flags */
 116 #define EXT_SUBTLV_PREFIX_SID_NPFLG     0x40
 117 #define EXT_SUBTLV_PREFIX_SID_MFLG      0x20
 118 #define EXT_SUBTLV_PREFIX_SID_EFLG      0x10
 119 #define EXT_SUBTLV_PREFIX_SID_VFLG      0x08
 120 #define EXT_SUBTLV_PREFIX_SID_LFLG      0x04
 121
 122 /* SID/Label Binding subtlv Flags */
 123 #define EXT_SUBTLV_SID_BINDING_MFLG     0x80
 124
 125 /* Extended Prefix Range TLV - section 4 */
 126 #define EXT_TLV_PREF_RANGE              2
 127 #define EXT_SUBTLV_PREFIX_RANGE_SIZE    12
 128 struct ext_tlv_prefix_range {
 129         struct tlv_header header;
 130         uint8_t pref_length;
 131         uint8_t af;
 132         uint16_t range_size;
 133         uint8_t flags;
 134         uint8_t reserved[3];
 135         struct in_addr address;
 136 };
 137
 138 /* Prefix SID Sub-TLV - section 5 */
 139 #define EXT_SUBTLV_PREFIX_SID           2
 140 #define EXT_SUBTLV_PREFIX_SID_SIZE      8
 141 struct ext_subtlv_prefix_sid {
 142         struct tlv_header header;
 143         uint8_t flags;
 144         uint8_t reserved;
 145         uint8_t mtid;
 146         uint8_t algorithm;
 147         uint32_t value;
 148 };
 149
 150 /* Adj-SID Sub-TLV - section 6.1 */
 151 #define EXT_SUBTLV_ADJ_SID              2
 152 #define EXT_SUBTLV_ADJ_SID_SIZE         8
 153 struct ext_subtlv_adj_sid {
 154         struct tlv_header header;
 155         uint8_t flags;
 156         uint8_t reserved;
 157         uint8_t mtid;
 158         uint8_t weight;
 159         uint32_t value;
 160 };
 161
 162 /* LAN Adj-SID Sub-TLV - section 6.2 */
 163 #define EXT_SUBTLV_LAN_ADJ_SID          3
 164 #define EXT_SUBTLV_LAN_ADJ_SID_SIZE     12
 165 struct ext_subtlv_lan_adj_sid {
 166         struct tlv_header header;
 167         uint8_t flags;
 168         uint8_t reserved;
 169         uint8_t mtid;
 170         uint8_t weight;
 171         struct in_addr neighbor_id;
 172         uint32_t value;
 173 };
 174
 175 /*
 176  * Following section define structure used to manage Segment Routing
 177  * information and TLVs / SubTLVs
 178  */
 179
 180 /* Structure aggregating SRGB info retrieved from an lsa */
 181 struct sr_srgb {
 182         uint32_t range_size;
 183         uint32_t lower_bound;
 184 };
 185
 186 /* SID type to make difference between loopback interfaces and others */
 187 enum sid_type { PREF_SID, ADJ_SID, LAN_ADJ_SID };
 188
 189 /* Structure aggregating all OSPF Segment Routing information for the node */
 190 struct ospf_sr_db {
 191         /* Status of Segment Routing: enable or disable */
 192         bool enabled;
 193
 194         /* Ongoing Update following an OSPF SPF */
 195         bool update;
 196
 197         /* Flooding Scope: Area = 10 or AS = 11 */
 198         uint8_t scope;
 199
 200         /* FRR SR node */
 201         struct sr_node *self;
 202
 203         /* List of neighbour SR nodes */
 204         struct hash *neighbors;
 205
 206         /* List of SR prefix */
 207         struct route_table *prefix;
 208
 209         /* Local SR info announced in Router Info LSA */
 210
 211         /* Algorithms supported by the node */
 212         uint8_t algo[ALGORITHM_COUNT];
 213         /*
 214          * Segment Routing Global Block i.e. label range
 215          * Only one range supported in this code
 216          */
 217         struct sr_srgb srgb;
 218         /* Maximum SID Depth supported by the node */
 219         uint8_t msd;
 220 };
 221
 222 /* Structure aggregating all received SR info from LSAs by node */
 223 struct sr_node {
 224         struct in_addr adv_router; /* used to identify sender of LSA */
 225         /* 24-bit Opaque-ID field value according to RFC 7684 specification */
 226         uint32_t instance;
 227
 228         uint8_t algo[ALGORITHM_COUNT]; /* Algorithms supported by the node */
 229         /* Segment Routing Global Block i.e. label range */
 230         struct sr_srgb srgb;
 231         uint8_t msd; /* Maximum SID Depth */
 232
 233         /* List of Prefix & Link advertise by this node */
 234         struct list *ext_prefix; /* For Node SID */
 235         struct list *ext_link;   /* For Adj and LAN SID */
 236
 237         /* Pointer to FRR SR-Node or NULL if it is not a neighbor */
 238         struct sr_node *neighbor;
 239 };
 240
 241
 242 /* Segment Routing - NHLFE info: support IPv4 Only */
 243 struct sr_nhlfe {
 244         struct prefix_ipv4 prefv4;
 245         struct in_addr nexthop;
 246         ifindex_t ifindex;
 247         mpls_label_t label_in;
 248         mpls_label_t label_out;
 249 };
 250
 251 /* Structure aggregating all Segment Routing Link information */
 252 /* Link are generally advertised by pair: primary + backup */
 253 struct sr_link {
 254         struct in_addr adv_router; /* used to identify sender of LSA */
 255         /* 24-bit Opaque-ID field value according to RFC 7684 specification */
 256         uint32_t instance;
 257
 258         /* Flags to manage this link parameters. */
 259         uint8_t flags[2];
 260
 261         /* Segment Routing ID */
 262         uint32_t sid[2];
 263         enum sid_type type;
 264
 265         /* SR NHLFE for this link */
 266         struct sr_nhlfe nhlfe[2];
 267
 268         /* Back pointer to SR Node which advertise this Link */
 269         struct sr_node *srn;
 270 };
 271
 272 /* Structure aggregating all Segment Routing Prefix information */
 273 struct sr_prefix {
 274         struct in_addr adv_router; /* used to identify sender of LSA */
 275         /* 24-bit Opaque-ID field value according to RFC 7684 specification */
 276         uint32_t instance;
 277
 278         /* Flags to manage this prefix parameters. */
 279         uint8_t flags;
 280
 281         /* Segment Routing ID */
 282         uint32_t sid;
 283         enum sid_type type;
 284
 285         /* SR NHLFE for this prefix */
 286         struct sr_nhlfe nhlfe;
 287
 288         /* Back pointer to SR Node which advertise this Prefix */
 289         struct sr_node *srn;
 290
 291         /*
 292          * Pointer to SR Node which is the next hop for this Prefix
 293          * or NULL if next hop is the destination of the prefix
 294          */
 295         struct sr_node *nexthop;
 296 };
 297
 298 /* Prototypes definition */
 299 /* Segment Routing initialisation functions */
 300 extern int ospf_sr_init(void);
 301 extern void ospf_sr_term(void);
 302 /* Segment Routing LSA update & delete functions */
 303 extern void ospf_sr_ri_lsa_update(struct ospf_lsa *lsa);
 304 extern void ospf_sr_ri_lsa_delete(struct ospf_lsa *lsa);
 305 extern void ospf_sr_ext_link_lsa_update(struct ospf_lsa *lsa);
 306 extern void ospf_sr_ext_link_lsa_delete(struct ospf_lsa *lsa);
 307 extern void ospf_sr_ext_prefix_lsa_update(struct ospf_lsa *lsa);
 308 extern void ospf_sr_ext_prefix_lsa_delete(struct ospf_lsa *lsa);
 309 /* Segment Routing configuration functions */
 310 extern uint32_t get_ext_link_label_value(void);
 311 extern void ospf_sr_config_write_router(struct vty *vty);
 312 extern void ospf_sr_update_prefix(struct interface *ifp, struct prefix *p);
 313 /* Segment Routing re-routing function */
 314 extern void ospf_sr_update_timer_add(struct ospf *ospf);
 315 #endif /* _FRR_OSPF_SR_H */