pimd/pim_bsm.h

   1 /*
   2  * pim_bsm.h: PIM BSM handling related
   3  *
   4  * Copyright (C) 2018-19 Vmware, Inc.
   5  * Saravanan K
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program 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 this program; see the file COPYING; if not, write to the
  19  * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
  20  * MA 02110-1301 USA
  21  */
  22
  23 #ifndef __PIM_BSM_H__
  24 #define __PIM_BSM_H__
  25
  26 #include "if.h"
  27 #include "vty.h"
  28 #include "typesafe.h"
  29 #include "table.h"
  30 #include "pim_rp.h"
  31 #include "pim_msg.h"
  32
  33 /* Defines */
  34 #define PIM_GBL_SZ_ID 0             /* global scope zone id set to 0 */
  35 #define PIM_BS_TIME 60              /* RFC 5059 - Sec 5 */
  36 #define PIM_BSR_DEFAULT_TIMEOUT 130 /* RFC 5059 - Sec 5 */
  37
  38 /* These structures are only encoded IPv4 specific */
  39 #define PIM_BSM_HDR_LEN sizeof(struct bsm_hdr)
  40 #define PIM_BSM_GRP_LEN sizeof(struct bsmmsg_grpinfo)
  41 #define PIM_BSM_RP_LEN sizeof(struct bsmmsg_rpinfo)
  42
  43 #define PIM_MIN_BSM_LEN \
  44         (PIM_HDR_LEN + PIM_BSM_HDR_LEN + PIM_BSM_GRP_LEN + PIM_BSM_RP_LEN)
  45
  46 /* Datastructures
  47  * ==============
  48  */
  49
  50 /* Non candidate BSR states */
  51 enum ncbsr_state {
  52         NO_INFO = 0,
  53         ACCEPT_ANY,
  54         ACCEPT_PREFERRED
  55 };
  56
  57 PREDECL_DLIST(bsm_frags);
  58
  59 /* BSM scope - bsm processing is per scope */
  60 struct bsm_scope {
  61         int sz_id;                      /* scope zone id */
  62         enum ncbsr_state state;         /* non candidate BSR state */
  63         bool accept_nofwd_bsm;          /* no fwd bsm accepted for scope */
  64         pim_addr current_bsr;           /* current elected BSR for the sz */
  65         uint32_t current_bsr_prio;      /* current BSR priority */
  66         int64_t current_bsr_first_ts;   /* current BSR elected time */
  67         int64_t current_bsr_last_ts;    /* Last BSM received from E-BSR */
  68         uint16_t bsm_frag_tag;          /* Last received frag tag from E-BSR */
  69         uint8_t hashMasklen;            /* Mask in hash calc RFC 7761 4.7.2 */
  70         struct pim_instance *pim;       /* Back pointer to pim instance */
  71
  72         /* current set of fragments for forwarding */
  73         struct bsm_frags_head bsm_frags[1];
  74
  75         struct route_table *bsrp_table; /* group2rp mapping rcvd from BSR */
  76         struct thread *bs_timer;        /* Boot strap timer */
  77 };
  78
  79 /* BSM packet (= fragment) - this is stored as list in bsm_frags inside scope
  80  * This is used for forwarding to new neighbors or restarting mcast routers
  81  */
  82 struct bsm_frag {
  83         struct bsm_frags_item item;
  84
  85         uint32_t size;   /* size of the packet */
  86         uint8_t data[0]; /* Actual packet (dyn size) */
  87 };
  88
  89 DECLARE_DLIST(bsm_frags, struct bsm_frag, item);
  90
  91 PREDECL_SORTLIST_UNIQ(bsm_rpinfos);
  92
  93 /* This is the group node of the bsrp table in scope.
  94  * this node maintains the list of rp for the group.
  95  */
  96 struct bsgrp_node {
  97         struct prefix group;            /* Group range */
  98         struct bsm_scope *scope;        /* Back ptr to scope */
  99
 100         /* RPs advertised by BSR, and temporary list while receiving new set */
 101         struct bsm_rpinfos_head bsrp_list[1];
 102         struct bsm_rpinfos_head partial_bsrp_list[1];
 103
 104         int pend_rp_cnt;                /* Total RP - Received RP */
 105         uint16_t frag_tag;              /* frag tag to identify the fragment */
 106 };
 107
 108 /* Items on [partial_]bsrp_list above.
 109  * Holds info of each candidate RP received for the bsgrp_node's prefix.
 110  */
 111 struct bsm_rpinfo {
 112         struct bsm_rpinfos_item item;
 113
 114         uint32_t hash;                  /* Hash Value as per RFC 7761 4.7.2 */
 115         uint32_t elapse_time;           /* upd at expiry of elected RP node */
 116         uint16_t rp_prio;               /* RP priority */
 117         uint16_t rp_holdtime;           /* RP holdtime - g2rp timer value */
 118         pim_addr rp_address;            /* RP Address */
 119         struct bsgrp_node *bsgrp_node;  /* Back ptr to bsgrp_node */
 120         struct thread *g2rp_timer;      /* Run only for elected RP node */
 121 };
 122
 123 extern int pim_bsm_rpinfo_cmp(const struct bsm_rpinfo *a,
 124                               const struct bsm_rpinfo *b);
 125 DECLARE_SORTLIST_UNIQ(bsm_rpinfos, struct bsm_rpinfo, item, pim_bsm_rpinfo_cmp);
 126
 127 /*  Structures to extract Bootstrap Message header and Grp to RP Mappings
 128  *  =====================================================================
 129  *  BSM Format:
 130  *
 131  *   0                   1                   2                   3
 132  *   0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
 133  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 134  *  |PIM Ver| Type  |N|  Reserved   |           Checksum            | PIM HDR
 135  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 136  *  |         Fragment Tag          | Hash Mask Len | BSR Priority  | BS HDR(1)
 137  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 138  *  |             BSR Address (Encoded-Unicast format)              | BS HDR(2)
 139  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 140  *  |            Group Address 1 (Encoded-Group format)             |
 141  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 142  *  | RP Count 1    | Frag RP Cnt 1 |         Reserved              |
 143  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 144  *  |             RP Address 1 (Encoded-Unicast format)             |
 145  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 146  *  |          RP1 Holdtime         | RP1 Priority  |   Reserved    |
 147  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 148  *  |             RP Address 2 (Encoded-Unicast format)             |
 149  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 150  *  |          RP2 Holdtime         | RP2 Priority  |   Reserved    |
 151  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 152  *  |                               .                               |
 153  *  |                               .                               |
 154  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 155  *  |             RP Address m (Encoded-Unicast format)             |
 156  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 157  *  |          RPm Holdtime         | RPm Priority  |   Reserved    |
 158  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 159  *  |            Group Address 2 (Encoded-Group format)             |
 160  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 161  *  |                               .                               |
 162  *  |                               .                               |
 163  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 164  *  |            Group Address n (Encoded-Group format)             |
 165  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 166  *  | RP Count n    | Frag RP Cnt n |          Reserved             |
 167  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 168  *  |             RP Address 1 (Encoded-Unicast format)             |
 169  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 170  *  |          RP1 Holdtime         | RP1 Priority  |   Reserved    |
 171  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 172  *  |             RP Address 2 (Encoded-Unicast format)             |
 173  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 174  *  |          RP2 Holdtime         | RP2 Priority  |   Reserved    |
 175  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 176  *  |                               .                               |
 177  *  |                               .                               |
 178  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 179  *  |             RP Address m (Encoded-Unicast format)             |
 180  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 181  *  |          RPm Holdtime         | RPm Priority  |   Reserved    |
 182  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 183  */
 184 struct bsm_hdr {
 185         uint16_t frag_tag;
 186         uint8_t hm_len;
 187         uint8_t bsr_prio;
 188 #if PIM_IPV == 4
 189         struct pim_encoded_ipv4_unicast bsr_addr;
 190 #else
 191         struct pim_encoded_ipv6_unicast bsr_addr;
 192 #endif
 193 } __attribute__((packed));
 194
 195 struct bsmmsg_grpinfo {
 196 #if PIM_IPV == 4
 197         struct pim_encoded_group_ipv4 group;
 198 #else
 199         struct pim_encoded_group_ipv6 group;
 200 #endif
 201         uint8_t rp_count;
 202         uint8_t frag_rp_count;
 203         uint16_t reserved;
 204 } __attribute__((packed));
 205
 206 struct bsmmsg_rpinfo {
 207 #if PIM_IPV == 4
 208         struct pim_encoded_ipv4_unicast rpaddr;
 209 #else
 210         struct pim_encoded_ipv6_unicast rpaddr;
 211 #endif
 212         uint16_t rp_holdtime;
 213         uint8_t rp_pri;
 214         uint8_t reserved;
 215 } __attribute__((packed));
 216
 217 /* API */
 218 void pim_bsm_proc_init(struct pim_instance *pim);
 219 void pim_bsm_proc_free(struct pim_instance *pim);
 220 void pim_bsm_clear(struct pim_instance *pim);
 221 void pim_bsm_write_config(struct vty *vty, struct interface *ifp);
 222 int pim_bsm_process(struct interface *ifp, pim_sgaddr *sg, uint8_t *buf,
 223                     uint32_t buf_size, bool no_fwd);
 224 bool pim_bsm_new_nbr_fwd(struct pim_neighbor *neigh, struct interface *ifp);
 225 struct bsgrp_node *pim_bsm_get_bsgrp_node(struct bsm_scope *scope,
 226                                           struct prefix *grp);
 227 #endif