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 along
  18  * with this program; see the file COPYING; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #ifndef _QUAGGA_MPLS_H
  23 #define _QUAGGA_MPLS_H
  24
  25 #include <zebra.h>
  26 #include <arpa/inet.h>
  27
  28 #ifdef __cplusplus
  29 extern "C" {
  30 #endif
  31
  32 #ifdef MPLS_LABEL_MAX
  33 #undef MPLS_LABEL_MAX
  34 #endif
  35
  36 #define MPLS_LABEL_HELPSTR                                                     \
  37         "Specify label(s) for this route\nOne or more "                        \
  38         "labels in the range (16-1048575) separated by '/'\n"
  39
  40 /* Well-known MPLS label values (RFC 3032 etc). */
  41 #define MPLS_LABEL_IPV4_EXPLICIT_NULL  0       /* [RFC3032] */
  42 #define MPLS_LABEL_ROUTER_ALERT        1       /* [RFC3032] */
  43 #define MPLS_LABEL_IPV6_EXPLICIT_NULL  2       /* [RFC3032] */
  44 #define MPLS_LABEL_IMPLICIT_NULL       3       /* [RFC3032] */
  45 #define MPLS_LABEL_ELI                 7       /* [RFC6790] */
  46 #define MPLS_LABEL_GAL                 13      /* [RFC5586] */
  47 #define MPLS_LABEL_OAM_ALERT           14      /* [RFC3429] */
  48 #define MPLS_LABEL_EXTENSION           15      /* [RFC7274] */
  49 #define MPLS_LABEL_MAX                 1048575
  50 #define MPLS_LABEL_VALUE_MASK          0x000FFFFF
  51 #define MPLS_LABEL_NONE                0xFFFFFFFF /* for internal use only */
  52
  53 /* Minimum and maximum label values */
  54 #define MPLS_LABEL_RESERVED_MIN            0
  55 #define MPLS_LABEL_RESERVED_MAX            15
  56 #define MPLS_LABEL_UNRESERVED_MIN          16
  57 #define MPLS_LABEL_UNRESERVED_MAX          1048575
  58 #define MPLS_LABEL_BASE_ANY                0
  59
  60 /* Default min and max SRGB label range */
  61 /* Even if the SRGB allows to manage different Label space between routers,
  62  * if an operator want to use the same SRGB for all its router, we must fix
  63  * a common range. However, Cisco start its SRGB at 16000 and Juniper ends
  64  * its SRGB at 16384 for OSPF. Thus, by fixing the minimum SRGB label to
  65  * 8000 we could deal with both Cisco and Juniper.
  66  */
  67 #define MPLS_DEFAULT_MIN_SRGB_LABEL        8000
  68 #define MPLS_DEFAULT_MAX_SRGB_LABEL        50000
  69 #define MPLS_DEFAULT_MIN_SRGB_SIZE         5000
  70 #define MPLS_DEFAULT_MAX_SRGB_SIZE         20000
  71
  72 /* Maximum # labels that can be pushed. */
  73 #define MPLS_MAX_LABELS                    16
  74
  75 #define IS_MPLS_RESERVED_LABEL(label) (label <= MPLS_LABEL_RESERVED_MAX)
  76
  77 #define IS_MPLS_UNRESERVED_LABEL(label)                                        \
  78         (label >= MPLS_LABEL_UNRESERVED_MIN                                    \
  79          && label <= MPLS_LABEL_UNRESERVED_MAX)
  80
  81 /* Definitions for a MPLS label stack entry (RFC 3032). This encodes the
  82  * label, EXP, BOS and TTL fields.
  83  */
  84 typedef unsigned int mpls_lse_t;
  85
  86 #define MPLS_LS_LABEL_MASK             0xFFFFF000
  87 #define MPLS_LS_LABEL_SHIFT            12
  88 #define MPLS_LS_EXP_MASK               0x00000E00
  89 #define MPLS_LS_EXP_SHIFT              9
  90 #define MPLS_LS_S_MASK                 0x00000100
  91 #define MPLS_LS_S_SHIFT                8
  92 #define MPLS_LS_TTL_MASK               0x000000FF
  93 #define MPLS_LS_TTL_SHIFT              0
  94
  95 #define MPLS_LABEL_VALUE(lse)                                                  \
  96         ((lse & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT)
  97 #define MPLS_LABEL_EXP(lse) ((lse & MPLS_LS_EXP_MASK) >> MPLS_LS_EXP_SHIFT)
  98 #define MPLS_LABEL_BOS(lse) ((lse & MPLS_LS_S_MASK) >> MPLS_LS_S_SHIFT)
  99 #define MPLS_LABEL_TTL(lse) ((lse & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT)
 100
 101 #define IS_MPLS_LABEL_BOS(ls)          (MPLS_LABEL_BOS(ls) == 1)
 102
 103 #define MPLS_LABEL_LEN_BITS            20
 104
 105 /* MPLS label value as a 32-bit (mostly we only care about the label value). */
 106 typedef unsigned int mpls_label_t;
 107
 108 struct mpls_label_stack {
 109         uint8_t num_labels;
 110         uint8_t reserved[3];
 111         mpls_label_t label[0]; /* 1 or more labels */
 112 };
 113
 114 /* The MPLS explicit-null label is 0 which means when you memset a mpls_label_t
 115  * to zero you have set that variable to explicit-null which was probably not
 116  * your intent. The work-around is to use one bit to indicate if the
 117  * mpls_label_t has been set by the user. MPLS_INVALID_LABEL has this bit clear
 118  * so that we can use MPLS_INVALID_LABEL to initialize mpls_label_t variables.
 119  */
 120 #define MPLS_INVALID_LABEL                 0xFFFDFFFF
 121
 122 /* LSP types. */
 123 enum lsp_types_t {
 124         ZEBRA_LSP_NONE = 0,   /* No LSP. */
 125         ZEBRA_LSP_STATIC = 1, /* Static LSP. */
 126         ZEBRA_LSP_LDP = 2,    /* LDP LSP. */
 127         ZEBRA_LSP_BGP = 3,    /* BGP LSP. */
 128         ZEBRA_LSP_OSPF_SR = 4,/* OSPF Segment Routing LSP. */
 129         ZEBRA_LSP_ISIS_SR = 5,/* IS-IS Segment Routing LSP. */
 130         ZEBRA_LSP_SHARP = 6,  /* Identifier for test protocol */
 131         ZEBRA_LSP_SRTE = 7,   /* SR-TE LSP */
 132 };
 133
 134 /* Functions for basic label operations. */
 135
 136 /* Encode a label stack entry from fields; convert to network byte-order as
 137  * the Netlink interface expects MPLS labels to be in this format.
 138  */
 139 static inline mpls_lse_t mpls_lse_encode(mpls_label_t label, uint32_t ttl,
 140                                          uint32_t exp, uint32_t bos)
 141 {
 142         mpls_lse_t lse;
 143         lse = htonl((label << MPLS_LS_LABEL_SHIFT) | (exp << MPLS_LS_EXP_SHIFT)
 144                     | (bos ? (1 << MPLS_LS_S_SHIFT) : 0)
 145                     | (ttl << MPLS_LS_TTL_SHIFT));
 146         return lse;
 147 }
 148
 149 /* Extract the fields from a label stack entry after converting to host-byte
 150  * order. This is expected to be called only for messages received over the
 151  * Netlink interface.
 152  */
 153 static inline void mpls_lse_decode(mpls_lse_t lse, mpls_label_t *label,
 154                                    uint32_t *ttl, uint32_t *exp, uint32_t *bos)
 155 {
 156         mpls_lse_t local_lse;
 157
 158         local_lse = ntohl(lse);
 159         *label = MPLS_LABEL_VALUE(local_lse);
 160         *exp = MPLS_LABEL_EXP(local_lse);
 161         *bos = MPLS_LABEL_BOS(local_lse);
 162         *ttl = MPLS_LABEL_TTL(local_lse);
 163 }
 164
 165 /* Invalid label index value (when used with BGP Prefix-SID). Should
 166  * match the BGP definition.
 167  */
 168 #define MPLS_INVALID_LABEL_INDEX   0xFFFFFFFF
 169
 170 /* Printable string for labels (with consideration for reserved values). */
 171 static inline char *label2str(mpls_label_t label, char *buf, size_t len)
 172 {
 173         switch (label) {
 174         case MPLS_LABEL_IPV4_EXPLICIT_NULL:
 175                 strlcpy(buf, "IPv4 Explicit Null", len);
 176                 return (buf);
 177         case MPLS_LABEL_ROUTER_ALERT:
 178                 strlcpy(buf, "Router Alert", len);
 179                 return (buf);
 180         case MPLS_LABEL_IPV6_EXPLICIT_NULL:
 181                 strlcpy(buf, "IPv6 Explicit Null", len);
 182                 return (buf);
 183         case MPLS_LABEL_IMPLICIT_NULL:
 184                 strlcpy(buf, "implicit-null", len);
 185                 return (buf);
 186         case MPLS_LABEL_ELI:
 187                 strlcpy(buf, "Entropy Label Indicator", len);
 188                 return (buf);
 189         case MPLS_LABEL_GAL:
 190                 strlcpy(buf, "Generic Associated Channel", len);
 191                 return (buf);
 192         case MPLS_LABEL_OAM_ALERT:
 193                 strlcpy(buf, "OAM Alert", len);
 194                 return (buf);
 195         case MPLS_LABEL_EXTENSION:
 196                 strlcpy(buf, "Extension", len);
 197                 return (buf);
 198         default:
 199                 if (label < 16)
 200                         snprintf(buf, len, "Reserved (%u)", label);
 201                 else
 202                         snprintf(buf, len, "%u", label);
 203                 return (buf);
 204         }
 205 }
 206
 207 /*
 208  * String to label conversion, labels separated by '/'.
 209  */
 210 int mpls_str2label(const char *label_str, uint8_t *num_labels,
 211                    mpls_label_t *labels);
 212
 213 /* Generic string buffer for label-stack-to-str */
 214 #define MPLS_LABEL_STRLEN 1024
 215
 216 /*
 217  * Label to string conversion, labels in string separated by '/'.
 218  */
 219 char *mpls_label2str(uint8_t num_labels, const mpls_label_t *labels, char *buf,
 220                      int len, int pretty);
 221
 222 #ifdef __cplusplus
 223 }
 224 #endif
 225
 226 #endif