bgpd/bgp_label.h

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* BGP carrying Label information
   3  * Copyright (C) 2013 Cumulus Networks, Inc.
   4  */
   5
   6 #ifndef _BGP_LABEL_H
   7 #define _BGP_LABEL_H
   8
   9 #define BGP_LABEL_BYTES 3
  10 #define BGP_LABEL_BITS 24
  11 #define BGP_WITHDRAW_LABEL 0x800000
  12 #define BGP_PREVENT_VRF_2_VRF_LEAK 0xFFFFFFFE
  13
  14 struct bgp_dest;
  15 struct bgp_path_info;
  16 struct peer;
  17
  18 extern int bgp_reg_for_label_callback(mpls_label_t new_label, void *labelid,
  19                                     bool allocated);
  20 extern void bgp_reg_dereg_for_label(struct bgp_dest *dest,
  21                                     struct bgp_path_info *pi, bool reg);
  22 extern int bgp_parse_fec_update(void);
  23 extern mpls_label_t bgp_adv_label(struct bgp_dest *dest,
  24                                   struct bgp_path_info *pi, struct peer *to,
  25                                   afi_t afi, safi_t safi);
  26
  27 extern int bgp_nlri_parse_label(struct peer *peer, struct attr *attr,
  28                                 struct bgp_nlri *packet);
  29
  30 static inline int bgp_labeled_safi(safi_t safi)
  31 {
  32         /* NOTE: This API really says a label (tag) MAY be present. Not all EVPN
  33          * routes will have a label.
  34          */
  35         if ((safi == SAFI_LABELED_UNICAST) || (safi == SAFI_MPLS_VPN)
  36             || (safi == SAFI_EVPN))
  37                 return 1;
  38         return 0;
  39 }
  40
  41 static inline int bgp_is_withdraw_label(mpls_label_t *label)
  42 {
  43         uint8_t *pkt = (uint8_t *)label;
  44
  45         /* The check on pkt[2] for 0x00 or 0x02 is in case bgp_set_valid_label()
  46          * was called on the withdraw label */
  47         if (((pkt[0] == 0x80) || (pkt[0] == 0x00)) && (pkt[1] == 0x00)
  48             && ((pkt[2] == 0x00) || (pkt[2] == 0x02)))
  49                 return 1;
  50         return 0;
  51 }
  52
  53 static inline int bgp_is_valid_label(const mpls_label_t *label)
  54 {
  55         uint8_t *t = (uint8_t *)label;
  56         if (!t)
  57                 return 0;
  58         return (t[2] & 0x02);
  59 }
  60
  61 static inline void bgp_set_valid_label(mpls_label_t *label)
  62 {
  63         uint8_t *t = (uint8_t *)label;
  64         if (t)
  65                 t[2] |= 0x02;
  66 }
  67
  68 static inline void bgp_unset_valid_label(mpls_label_t *label)
  69 {
  70         uint8_t *t = (uint8_t *)label;
  71         if (t)
  72                 t[2] &= ~0x02;
  73 }
  74
  75 static inline void bgp_register_for_label(struct bgp_dest *dest,
  76                                           struct bgp_path_info *pi)
  77 {
  78         bgp_reg_dereg_for_label(dest, pi, true);
  79 }
  80
  81 static inline void bgp_unregister_for_label(struct bgp_dest *dest)
  82 {
  83         bgp_reg_dereg_for_label(dest, NULL, false);
  84 }
  85
  86 /* Return BOS value of label stream */
  87 static inline uint8_t label_bos(mpls_label_t *label)
  88 {
  89         uint8_t *t = (uint8_t *)label;
  90         return (t[2] & 0x01);
  91 };
  92
  93 #endif /* _BGP_LABEL_H */