lib/mpls.h

   1 /*
   2  * MPLS definitions
   3  * Copyright 2015 Cumulus Networks, Inc.
   4  *
   5  * This file is part of GNU Zebra.
   6  *
   7  * GNU Zebra is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published
   9  * by the Free Software Foundation; either version 2, or (at your
  10  * option) any later version.
  11  *
  12  * GNU Zebra is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with GNU Zebra; see the file COPYING.  If not, write to the
  19  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  20  * Boston, MA 02111-1307, USA.
  21  */
  22
  23 #ifndef _QUAGGA_MPLS_H
  24 #define _QUAGGA_MPLS_H
  25
  26 #include <arpa/inet.h>
  27
  28 /* Well-known MPLS label values (RFC 3032 etc). */
  29 #define MPLS_V4_EXP_NULL_LABEL             0
  30 #define MPLS_RA_LABEL                      1
  31 #define MPLS_V6_EXP_NULL_LABEL             2
  32 #define MPLS_IMP_NULL_LABEL                3
  33 #define MPLS_ENTROPY_LABEL_INDICATOR       7
  34 #define MPLS_GAL_LABEL                     13
  35 #define MPLS_OAM_ALERT_LABEL               14
  36 #define MPLS_EXTENSION_LABEL               15
  37
  38 /* Minimum and maximum label values */
  39 #define MPLS_MIN_RESERVED_LABEL            0
  40 #define MPLS_MAX_RESERVED_LABEL            15
  41 #define MPLS_MIN_UNRESERVED_LABEL          16
  42 #define MPLS_MAX_UNRESERVED_LABEL          1048575
  43
  44 #define IS_MPLS_RESERVED_LABEL(label) \
  45         (label >= MPLS_MIN_RESERVED_LABEL && label <= MPLS_MAX_RESERVED_LABEL)
  46
  47 #define IS_MPLS_UNRESERVED_LABEL(label) \
  48         (label >= MPLS_MIN_UNRESERVED_LABEL && label <= MPLS_MAX_UNRESERVED_LABEL)
  49
  50 /* Definitions for a MPLS label stack entry (RFC 3032). This encodes the
  51  * label, EXP, BOS and TTL fields.
  52  */
  53 typedef unsigned int mpls_lse_t;
  54
  55 #define MPLS_LS_LABEL_MASK             0xFFFFF000
  56 #define MPLS_LS_LABEL_SHIFT            12
  57 #define MPLS_LS_EXP_MASK               0x00000E00
  58 #define MPLS_LS_EXP_SHIFT              9
  59 #define MPLS_LS_S_MASK                 0x00000100
  60 #define MPLS_LS_S_SHIFT                8
  61 #define MPLS_LS_TTL_MASK               0x000000FF
  62 #define MPLS_LS_TTL_SHIFT              0
  63
  64 #define MPLS_LABEL_VALUE(lse) \
  65         ((lse & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT)
  66 #define MPLS_LABEL_EXP(lse) \
  67         ((lse & MPLS_LS_EXP_MASK) >> MPLS_LS_EXP_SHIFT)
  68 #define MPLS_LABEL_BOS(lse) \
  69         ((lse & MPLS_LS_S_MASK) >> MPLS_LS_S_SHIFT)
  70 #define MPLS_LABEL_TTL(lse) \
  71         ((lse & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT)
  72
  73 #define IS_MPLS_LABEL_BOS(ls)          (MPLS_LABEL_BOS(ls) == 1)
  74
  75 #define MPLS_LABEL_LEN_BITS            20
  76
  77 /* MPLS label value as a 32-bit (mostly we only care about the label value). */
  78 typedef unsigned int mpls_label_t;
  79
  80 #define MPLS_NO_LABEL                      0xFFFFFFFF
  81 #define MPLS_INVALID_LABEL                 0xFFFFFFFF
  82
  83 /* LSP types. */
  84 enum lsp_types_t
  85 {
  86   ZEBRA_LSP_NONE = 0,        /* No LSP. */
  87   ZEBRA_LSP_STATIC = 1,      /* Static LSP. */
  88   ZEBRA_LSP_LDP = 2,         /* LDP LSP. */
  89   ZEBRA_LSP_BGP = 3          /* BGP LSP. */
  90 };
  91
  92 /* Functions for basic label operations. */
  93
  94 /* Encode a label stack entry from fields; convert to network byte-order as
  95  * the Netlink interface expects MPLS labels to be in this format.
  96  */
  97 static inline mpls_lse_t
  98 mpls_lse_encode (mpls_label_t label, u_int32_t ttl,
  99                  u_int32_t exp, u_int32_t bos)
 100 {
 101   mpls_lse_t lse;
 102   lse = htonl ((label << MPLS_LS_LABEL_SHIFT) |
 103                (exp << MPLS_LS_EXP_SHIFT) |
 104                (bos ? (1 << MPLS_LS_S_SHIFT) : 0) |
 105                (ttl << MPLS_LS_TTL_SHIFT));
 106   return lse;
 107 }
 108
 109 /* Extract the fields from a label stack entry after converting to host-byte
 110  * order. This is expected to be called only for messages received over the
 111  * Netlink interface.
 112  */
 113 static inline void
 114 mpls_lse_decode (mpls_lse_t lse, mpls_label_t *label,
 115                  u_int32_t *ttl, u_int32_t *exp, u_int32_t *bos)
 116 {
 117   mpls_lse_t local_lse;
 118
 119   local_lse = ntohl (lse);
 120   *label = MPLS_LABEL_VALUE(local_lse);
 121   *exp = MPLS_LABEL_EXP(local_lse);
 122   *bos = MPLS_LABEL_BOS(local_lse);
 123   *ttl = MPLS_LABEL_TTL(local_lse);
 124 }
 125
 126 /* Invalid label index value (when used with BGP Prefix-SID). Should
 127  * match the BGP definition.
 128  */
 129 #define MPLS_INVALID_LABEL_INDEX   0xFFFFFFFF
 130
 131
 132 /* Printable string for labels (with consideration for reserved values). */
 133 static inline char *
 134 label2str (mpls_label_t label, char *buf, size_t len)
 135 {
 136   switch(label) {
 137   case MPLS_V4_EXP_NULL_LABEL:
 138     strlcpy(buf, "IPv4 Explicit Null", len);
 139     return(buf);
 140   case MPLS_RA_LABEL:
 141     strlcpy(buf, "Router Alert", len);
 142     return(buf);
 143   case MPLS_V6_EXP_NULL_LABEL:
 144     strlcpy(buf, "IPv6 Explict Null", len);
 145     return(buf);
 146   case MPLS_IMP_NULL_LABEL:
 147     strlcpy(buf, "implicit-null", len);
 148     return(buf);
 149   case MPLS_ENTROPY_LABEL_INDICATOR:
 150     strlcpy(buf, "Entropy Label Indicator", len);
 151     return(buf);
 152   case MPLS_GAL_LABEL:
 153     strlcpy(buf, "Generic Associated Channel", len);
 154     return(buf);
 155   case MPLS_OAM_ALERT_LABEL:
 156     strlcpy(buf, "OAM Alert", len);
 157     return(buf);
 158   case MPLS_EXTENSION_LABEL:
 159     strlcpy(buf, "Extension", len);
 160     return(buf);
 161   default:
 162     if (label < 16)
 163       snprintf(buf, len, "Reserved (%u)", label);
 164     else
 165       snprintf(buf, len, "%u", label);
 166     return(buf);
 167   }
 168 }
 169
 170 /* constants used by ldpd */
 171 #define MPLS_LABEL_IPV4NULL     0               /* IPv4 Explicit NULL Label */
 172 #define MPLS_LABEL_RTALERT      1               /* Router Alert Label       */
 173 #define MPLS_LABEL_IPV6NULL     2               /* IPv6 Explicit NULL Label */
 174 #define MPLS_LABEL_IMPLNULL     3               /* Implicit NULL Label      */
 175 /*      MPLS_LABEL_RESERVED     4-15 */         /* Values 4-15 are reserved */
 176 #define MPLS_LABEL_RESERVED_MAX 15
 177 #define MPLS_LABEL_MAX          ((1 << 20) - 1)
 178
 179 #endif