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 int bgp_reg_for_label_callback(mpls_label_t new_label, void *labelid,
  34                                     bool allocated);
  35 extern void bgp_reg_dereg_for_label(struct bgp_node *rn,
  36                                     struct bgp_path_info *pi, bool reg);
  37 extern int bgp_parse_fec_update(void);
  38 extern mpls_label_t bgp_adv_label(struct bgp_node *rn, struct bgp_path_info *pi,
  39                                   struct peer *to, afi_t afi, safi_t safi);
  40
  41 extern int bgp_nlri_parse_label(struct peer *peer, struct attr *attr,
  42                                 struct bgp_nlri *packet);
  43
  44 static inline int bgp_labeled_safi(safi_t safi)
  45 {
  46         /* NOTE: This API really says a label (tag) MAY be present. Not all EVPN
  47          * routes will have a label.
  48          */
  49         if ((safi == SAFI_LABELED_UNICAST) || (safi == SAFI_MPLS_VPN)
  50             || (safi == SAFI_EVPN))
  51                 return 1;
  52         return 0;
  53 }
  54
  55 static inline int bgp_is_withdraw_label(mpls_label_t *label)
  56 {
  57         uint8_t *pkt = (uint8_t *)label;
  58
  59         /* The check on pkt[2] for 0x00 or 0x02 is in case bgp_set_valid_label()
  60          * was called on the withdraw label */
  61         if (((pkt[0] == 0x80) || (pkt[0] == 0x00)) && (pkt[1] == 0x00)
  62             && ((pkt[2] == 0x00) || (pkt[2] == 0x02)))
  63                 return 1;
  64         return 0;
  65 }
  66
  67 static inline int bgp_is_valid_label(mpls_label_t *label)
  68 {
  69         uint8_t *t = (uint8_t *)label;
  70         if (!t)
  71                 return 0;
  72         return (t[2] & 0x02);
  73 }
  74
  75 static inline void bgp_set_valid_label(mpls_label_t *label)
  76 {
  77         uint8_t *t = (uint8_t *)label;
  78         if (t)
  79                 t[2] |= 0x02;
  80 }
  81
  82 static inline void bgp_unset_valid_label(mpls_label_t *label)
  83 {
  84         uint8_t *t = (uint8_t *)label;
  85         if (t)
  86                 t[2] &= ~0x02;
  87 }
  88
  89 static inline void bgp_register_for_label(struct bgp_node *rn,
  90                                           struct bgp_path_info *pi)
  91 {
  92         bgp_reg_dereg_for_label(rn, pi, true);
  93 }
  94
  95 static inline void bgp_unregister_for_label(struct bgp_node *rn)
  96 {
  97         bgp_reg_dereg_for_label(rn, NULL, false);
  98 }
  99
 100 /* Label stream to value */
 101 static inline uint32_t label_pton(mpls_label_t *label)
 102 {
 103         uint8_t *t = (uint8_t *)label;
 104         return ((((unsigned int)t[0]) << 12) | (((unsigned int)t[1]) << 4)
 105                 | ((unsigned int)((t[2] & 0xF0) >> 4)));
 106 }
 107
 108 /* Encode label values */
 109 static inline void label_ntop(uint32_t l, int bos, mpls_label_t *label)
 110 {
 111         uint8_t *t = (uint8_t *)label;
 112         t[0] = ((l & 0x000FF000) >> 12);
 113         t[1] = ((l & 0x00000FF0) >> 4);
 114         t[2] = ((l & 0x0000000F) << 4);
 115         if (bos)
 116                 t[2] |= 0x01;
 117 }
 118
 119 /* Return BOS value of label stream */
 120 static inline uint8_t label_bos(mpls_label_t *label)
 121 {
 122         uint8_t *t = (uint8_t *)label;
 123         return (t[2] & 0x01);
 124 };
 125
 126 #endif /* _BGP_LABEL_H */