bgpd/bgp_label.h

   1 /* BGP carrying Label information
   2  * Copyright (C) 2013 Cumulus Networks, Inc.
   3  *
   4  * This file is part of GNU Zebra.
   5  *
   6  * GNU Zebra is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the
   8  * Free Software Foundation; either version 2, or (at your option) any
   9  * later version.
  10  *
  11  * GNU Zebra is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; see the file COPYING; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #ifndef _BGP_LABEL_H
  22 #define _BGP_LABEL_H
  23
  24 #define BGP_LABEL_BYTES 3
  25 #define BGP_LABEL_BITS 24
  26 #define BGP_WITHDRAW_LABEL 0x800000
  27 #define BGP_PREVENT_VRF_2_VRF_LEAK 0xFFFFFFFE
  28
  29 struct bgp_node;
  30 struct bgp_path_info;
  31 struct peer;
  32
  33 extern void bgp_reg_dereg_for_label(struct bgp_node *rn,
  34                                     struct bgp_path_info *pi, int reg);
  35 extern int bgp_parse_fec_update(void);
  36 extern mpls_label_t bgp_adv_label(struct bgp_node *rn, struct bgp_path_info *pi,
  37                                   struct peer *to, afi_t afi, safi_t safi);
  38
  39 extern int bgp_nlri_parse_label(struct peer *peer, struct attr *attr,
  40                                 struct bgp_nlri *packet);
  41
  42 static inline int bgp_labeled_safi(safi_t safi)
  43 {
  44         /* NOTE: This API really says a label (tag) MAY be present. Not all EVPN
  45          * routes will have a label.
  46          */
  47         if ((safi == SAFI_LABELED_UNICAST) || (safi == SAFI_MPLS_VPN)
  48             || (safi == SAFI_EVPN))
  49                 return 1;
  50         return 0;
  51 }
  52
  53 static inline int bgp_is_withdraw_label(mpls_label_t *label)
  54 {
  55         uint8_t *pkt = (uint8_t *)label;
  56
  57         /* The check on pkt[2] for 0x00 or 0x02 is in case bgp_set_valid_label()
  58          * was called on the withdraw label */
  59         if ((pkt[0] == 0x80) && (pkt[1] == 0x00)
  60             && ((pkt[2] == 0x00) || (pkt[2] == 0x02)))
  61                 return 1;
  62         return 0;
  63 }
  64
  65 static inline int bgp_is_valid_label(mpls_label_t *label)
  66 {
  67         uint8_t *t = (uint8_t *)label;
  68         if (!t)
  69                 return 0;
  70         return (t[2] & 0x02);
  71 }
  72
  73 static inline void bgp_set_valid_label(mpls_label_t *label)
  74 {
  75         uint8_t *t = (uint8_t *)label;
  76         if (t)
  77                 t[2] |= 0x02;
  78 }
  79
  80 static inline void bgp_unset_valid_label(mpls_label_t *label)
  81 {
  82         uint8_t *t = (uint8_t *)label;
  83         if (t)
  84                 t[2] &= ~0x02;
  85 }
  86
  87 static inline void bgp_register_for_label(struct bgp_node *rn,
  88                                           struct bgp_path_info *pi)
  89 {
  90         bgp_reg_dereg_for_label(rn, pi, 1);
  91 }
  92
  93 static inline void bgp_unregister_for_label(struct bgp_node *rn)
  94 {
  95         bgp_reg_dereg_for_label(rn, NULL, 0);
  96 }
  97
  98 /* Label stream to value */
  99 static inline uint32_t label_pton(mpls_label_t *label)
 100 {
 101         uint8_t *t = (uint8_t *)label;
 102         return ((((unsigned int)t[0]) << 12) | (((unsigned int)t[1]) << 4)
 103                 | ((unsigned int)((t[2] & 0xF0) >> 4)));
 104 }
 105
 106 /* Encode label values */
 107 static inline void label_ntop(uint32_t l, int bos, mpls_label_t *label)
 108 {
 109         uint8_t *t = (uint8_t *)label;
 110         t[0] = ((l & 0x000FF000) >> 12);
 111         t[1] = ((l & 0x00000FF0) >> 4);
 112         t[2] = ((l & 0x0000000F) << 4);
 113         if (bos)
 114                 t[2] |= 0x01;
 115 }
 116
 117 /* Return BOS value of label stream */
 118 static inline uint8_t label_bos(mpls_label_t *label)
 119 {
 120         uint8_t *t = (uint8_t *)label;
 121         return (t[2] & 0x01);
 122 };
 123
 124 #endif /* _BGP_LABEL_H */