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 - 2017 Orange Labs http://www.orange.com
  11  *
  12  * This file is part of FRR.
  13  *
  14  * FRR is free software; you can redistribute it and/or modify it
  15  * under the terms of the GNU General Public License as published by the
  16  * Free Software Foundation; either version 2, or (at your option) any
  17  * later version.
  18  *
  19  * FRR is distributed in the hope that it will be useful, but
  20  * WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  22  * General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with FRR; see the file COPYING.  If not, write to the Free
  26  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  27  * 02111-1307, USA.
  28  */
  29
  30 #ifndef _FRR_OSPF_SR_H
  31 #define _FRR_OSPF_SR_H
  32
  33 /* Default Route priority for OSPF Segment Routing */
  34 #define OSPF_SR_PRIORITY_DEFAULT        10
  35
  36 /* macros and constants for segment routing */
  37 #define SET_RANGE_SIZE_MASK             0xffffff00
  38 #define GET_RANGE_SIZE_MASK             0x00ffffff
  39 #define SET_LABEL_MASK                  0xffffff00
  40 #define GET_LABEL_MASK                  0x00ffffff
  41 #define SET_RANGE_SIZE(range_size) ((range_size << 8) & SET_RANGE_SIZE_MASK)
  42 #define GET_RANGE_SIZE(range_size) ((range_size >> 8) & GET_RANGE_SIZE_MASK)
  43 #define SET_LABEL(label) ((label << 8) & SET_LABEL_MASK)
  44 #define GET_LABEL(label) ((label >> 8) & GET_LABEL_MASK)
  45
  46 /* Label range for Adj-SID attribution purpose. See ospf_ext.c */
  47 #define ADJ_SID_MIN                     50000
  48 #define ADJ_SID_MAX                     51000
  49
  50 #define OSPF_SR_DEFAULT_METRIC          1
  51
  52 /* Segment Routing TLVs as per draft-ietf-ospf-segment-routing-extensions-19 */
  53
  54 /* Segment ID could be a Label (3 bytes) or an Index (4 bytes) */
  55 #define SID_BASE_SIZE   4
  56 #define SID_LABEL       3
  57 #define SID_LABEL_SIZE  (SID_BASE_SIZE + SID_LABEL)
  58 #define SID_INDEX       4
  59 #define SID_INDEX_SIZE  (SID_BASE_SIZE + SID_INDEX)
  60
  61 /* SID/Label Sub TLV - section 2.1 */
  62 #define SUBTLV_SID_LABEL                1
  63 #define SUBTLV_SID_LABEL_SIZE           8
  64 struct subtlv_sid_label {
  65         /* Length is 3 (20 rightmost bits MPLS label) or 4 (32 bits SID) */
  66         struct tlv_header header;
  67         u_int32_t value;
  68 };
  69
  70 /*
  71  * Following section defines Segment Routing TLV (tag, length, value)
  72  * structures, used in Router Information Opaque LSA.
  73  */
  74
  75 /* RI SR-Algorithm TLV - section 3.1 */
  76 #define RI_SR_TLV_SR_ALGORITHM          8
  77 struct ri_sr_tlv_sr_algorithm {
  78         struct tlv_header header;
  79 #define SR_ALGORITHM_SPF         0
  80 #define SR_ALGORITHM_STRICT_SPF  1
  81 #define SR_ALGORITHM_UNSET       255
  82 #define ALGORITHM_COUNT          4
  83         /* Only 4 algorithms supported in this code */
  84         u_int8_t value[ALGORITHM_COUNT];
  85 };
  86
  87 /* RI SID/Label Range TLV - section 3.2 */
  88 #define RI_SR_TLV_SID_LABEL_RANGE       9
  89 struct ri_sr_tlv_sid_label_range {
  90         struct tlv_header header;
  91 /* Only 24 upper most bits are significant */
  92 #define SID_RANGE_LABEL_LENGTH  3
  93         u_int32_t size;
  94         /* A SID/Label sub-TLV will follow. */
  95         struct subtlv_sid_label lower;
  96 };
  97
  98 /* RI Node/MSD TLV as per draft-ietf-ospf-segment-routing-msd-05 */
  99 #define RI_SR_TLV_NODE_MSD              12
 100 struct ri_sr_tlv_node_msd {
 101         struct tlv_header header;
 102         u_int8_t subtype; /* always = 1 */
 103         u_int8_t value;
 104         u_int16_t padding;
 105 };
 106
 107 /*
 108  * Following section defines Segment Routing TLV (tag, length, value)
 109  * structures, used in Extended Prefix/Link Opaque LSA.
 110  */
 111
 112 /* Adj-SID and LAN-Ajd-SID subtlvs' flags */
 113 #define EXT_SUBTLV_LINK_ADJ_SID_BFLG    0x80
 114 #define EXT_SUBTLV_LINK_ADJ_SID_VFLG    0x40
 115 #define EXT_SUBTLV_LINK_ADJ_SID_LFLG    0x20
 116 #define EXT_SUBTLV_LINK_ADJ_SID_SFLG    0x10
 117
 118 /* Prefix SID subtlv Flags */
 119 #define EXT_SUBTLV_PREFIX_SID_NPFLG     0x40
 120 #define EXT_SUBTLV_PREFIX_SID_MFLG      0x20
 121 #define EXT_SUBTLV_PREFIX_SID_EFLG      0x10
 122 #define EXT_SUBTLV_PREFIX_SID_VFLG      0x08
 123 #define EXT_SUBTLV_PREFIX_SID_LFLG      0x04
 124
 125 /* SID/Label Binding subtlv Flags */
 126 #define EXT_SUBTLV_SID_BINDING_MFLG     0x80
 127
 128 /* Extended Prefix Range TLV - section 4 */
 129 #define EXT_TLV_PREF_RANGE              2
 130 #define EXT_SUBTLV_PREFIX_RANGE_SIZE    12
 131 struct ext_tlv_prefix_range {
 132         struct tlv_header header;
 133         u_int8_t pref_length;
 134         u_int8_t af;
 135         u_int16_t range_size;
 136         u_int8_t flags;
 137         u_int8_t reserved[3];
 138         struct in_addr address;
 139 };
 140
 141 /* Prefix SID Sub-TLV - section 5 */
 142 #define EXT_SUBTLV_PREFIX_SID           2
 143 #define EXT_SUBTLV_PREFIX_SID_SIZE      8
 144 struct ext_subtlv_prefix_sid {
 145         struct tlv_header header;
 146         u_int8_t flags;
 147         u_int8_t reserved;
 148         u_int8_t mtid;
 149         u_int8_t algorithm;
 150         u_int32_t value;
 151 };
 152
 153 /* Adj-SID Sub-TLV - section 6.1 */
 154 #define EXT_SUBTLV_ADJ_SID              2
 155 #define EXT_SUBTLV_ADJ_SID_SIZE         8
 156 struct ext_subtlv_adj_sid {
 157         struct tlv_header header;
 158         u_int8_t flags;
 159         u_int8_t reserved;
 160         u_int8_t mtid;
 161         u_int8_t weight;
 162         u_int32_t value;
 163 };
 164
 165 /* LAN Adj-SID Sub-TLV - section 6.2 */
 166 #define EXT_SUBTLV_LAN_ADJ_SID          3
 167 #define EXT_SUBTLV_LAN_ADJ_SID_SIZE     12
 168 struct ext_subtlv_lan_adj_sid {
 169         struct tlv_header header;
 170         u_int8_t flags;
 171         u_int8_t reserved;
 172         u_int8_t mtid;
 173         u_int8_t weight;
 174         struct in_addr neighbor_id;
 175         u_int32_t value;
 176 };
 177
 178 /*
 179  * Following section define structure used to manage Segment Routing
 180  * information and TLVs / SubTLVs
 181  */
 182
 183 /* Structure aggregating SRGB info retrieved from an lsa */
 184 struct sr_srgb {
 185         u_int32_t range_size;
 186         u_int32_t lower_bound;
 187 };
 188
 189 /* SID type to make difference between loopback interfaces and others */
 190 enum sid_type { PREF_SID, ADJ_SID, LAN_ADJ_SID };
 191
 192 /* Structure aggregating all OSPF Segment Routing information for the node */
 193 struct ospf_sr_db {
 194         /* Status of Segment Routing: enable or disable */
 195         bool enabled;
 196
 197         /* Ongoing Update following an OSPF SPF */
 198         bool update;
 199
 200         /* Flooding Scope: Area = 10 or AS = 11 */
 201         u_int8_t scope;
 202
 203         /* FRR SR node */
 204         struct sr_node *self;
 205
 206         /* List of neighbour SR nodes */
 207         struct hash *neighbors;
 208
 209         /* List of SR prefix */
 210         struct route_table *prefix;
 211
 212         /* Local SR info announced in Router Info LSA */
 213
 214         /* Algorithms supported by the node */
 215         u_int8_t algo[ALGORITHM_COUNT];
 216         /*
 217          * Segment Routing Global Block i.e. label range
 218          * Only one range supported in this code
 219          */
 220         struct sr_srgb srgb;
 221         /* Maximum SID Depth supported by the node */
 222         u_int8_t msd;
 223 };
 224
 225 /* Structure aggregating all received SR info from LSAs by node */
 226 struct sr_node {
 227         struct in_addr adv_router; /* used to identify sender of LSA */
 228         /* 24-bit Opaque-ID field value according to RFC 7684 specification */
 229         u_int32_t instance;
 230
 231         u_int8_t algo[ALGORITHM_COUNT]; /* Algorithms supported by the node */
 232         /* Segment Routing Global Block i.e. label range */
 233         struct sr_srgb srgb;
 234         u_int8_t msd; /* Maximum SID Depth */
 235
 236         /* List of Prefix & Link advertise by this node */
 237         struct list *ext_prefix; /* For Node SID */
 238         struct list *ext_link;   /* For Adj and LAN SID */
 239
 240         /* Pointer to FRR SR-Node or NULL if it is not a neighbor */
 241         struct sr_node *neighbor;
 242 };
 243
 244
 245 /* Segment Routing - NHLFE info: support IPv4 Only */
 246 struct sr_nhlfe {
 247         struct prefix_ipv4 prefv4;
 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         u_int32_t instance;
 260
 261         /* Flags to manage this link parameters. */
 262         u_int32_t flags[2];
 263
 264         /* Segment Routing ID */
 265         u_int32_t sid[2];
 266         enum sid_type type;
 267
 268         /* SR NHLFE for this link */
 269         struct sr_nhlfe nhlfe[2];
 270
 271         /* Back pointer to SR Node which advertise this Link */
 272         struct sr_node *srn;
 273 };
 274
 275 /* Structure aggregating all Segment Routing Prefix information */
 276 struct sr_prefix {
 277         struct in_addr adv_router; /* used to identify sender of LSA */
 278         /* 24-bit Opaque-ID field value according to RFC 7684 specification */
 279         u_int32_t instance;
 280
 281         /* Flags to manage this prefix parameters. */
 282         u_int32_t flags;
 283
 284         /* Segment Routing ID */
 285         u_int32_t sid;
 286         enum sid_type type;
 287
 288         /* SR NHLFE for this prefix */
 289         struct sr_nhlfe nhlfe;
 290
 291         /* Back pointer to SR Node which advertise this Prefix */
 292         struct sr_node *srn;
 293
 294         /* Pointer to SR Node which is the next hop for this Prefix
 295          * or NULL if next hop is the destination of the prefix */
 296         struct sr_node *nexthop;
 297 };
 298
 299 /* Prototypes definition */
 300 /* Segment Routing initialisation functions */
 301 extern int ospf_sr_init(void);
 302 extern void ospf_sr_term(void);
 303 /* Segment Routing LSA update & delete functions */
 304 extern void ospf_sr_ri_lsa_update(struct ospf_lsa *lsa);
 305 extern void ospf_sr_ri_lsa_delete(struct ospf_lsa *lsa);
 306 extern void ospf_sr_ext_link_lsa_update(struct ospf_lsa *);
 307 extern void ospf_sr_ext_link_lsa_delete(struct ospf_lsa *);
 308 extern void ospf_sr_ext_prefix_lsa_update(struct ospf_lsa *);
 309 extern void ospf_sr_ext_prefix_lsa_delete(struct ospf_lsa *);
 310 /* Segment Routing configuration functions */
 311 extern u_int32_t get_ext_link_label_value(void);
 312 extern void ospf_sr_config_write_router(struct vty *);
 313 /* Segment Routing re-routing function */
 314 extern void ospf_sr_update_timer_add(struct ospf *);
 315 #endif /* _FRR_OSPF_SR_H */