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 "linklist.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 /* BSM scope - bsm processing is per scope */
  58 struct bsm_scope {
  59         int sz_id;                      /* scope zone id */
  60         enum ncbsr_state state;         /* non candidate BSR state */
  61         bool accept_nofwd_bsm;          /* no fwd bsm accepted for scope */
  62         struct in_addr current_bsr;     /* current elected BSR for the sz */
  63         uint32_t current_bsr_prio;      /* current BSR priority */
  64         int64_t current_bsr_first_ts;   /* current BSR elected time */
  65         int64_t current_bsr_last_ts;    /* Last BSM received from E-BSR */
  66         uint16_t bsm_frag_tag;          /* Last received frag tag from E-BSR */
  67         uint8_t hashMasklen;            /* Mask in hash calc RFC 7761 4.7.2 */
  68         struct pim_instance *pim;       /* Back pointer to pim instance */
  69         struct list *bsm_list;          /* list of bsm frag for frowarding */
  70         struct route_table *bsrp_table; /* group2rp mapping rcvd from BSR */
  71         struct thread *bs_timer;        /* Boot strap timer */
  72         struct thread *sz_timer;
  73 };
  74
  75 /* BSM packet - this is stored as list in bsm_list inside scope
  76  * This is used for forwarding to new neighbors or restarting mcast routers
  77  */
  78 struct bsm_info {
  79         uint32_t size;      /* size of the packet */
  80         unsigned char *bsm; /* Actual packet */
  81 };
  82
  83 /* This is the group node of the bsrp table in scope.
  84  * this node maintains the list of rp for the group.
  85  */
  86 struct bsgrp_node {
  87         struct prefix group;            /* Group range */
  88         struct bsm_scope *scope;        /* Back ptr to scope */
  89         struct list *bsrp_list;         /* list of RPs adv by BSR */
  90         struct list *partial_bsrp_list; /* maintained until all RPs received */
  91         int pend_rp_cnt;                /* Total RP - Received RP */
  92         uint16_t frag_tag;              /* frag tag to identify the fragment */
  93 };
  94
  95 /* This is the list node of bsrp_list and partial bsrp list in
  96  * bsgrp_node. Hold info of each RP received for the group
  97  */
  98 struct bsm_rpinfo {
  99         uint32_t hash;                  /* Hash Value as per RFC 7761 4.7.2 */
 100         uint32_t elapse_time;           /* upd at expiry of elected RP node */
 101         uint16_t rp_prio;               /* RP priority */
 102         uint16_t rp_holdtime;           /* RP holdtime - g2rp timer value */
 103         struct in_addr rp_address;      /* RP Address */
 104         struct bsgrp_node *bsgrp_node;  /* Back ptr to bsgrp_node */
 105         struct thread *g2rp_timer;      /* Run only for elected RP node */
 106 };
 107
 108 /*  Structures to extract Bootstrap Message header and Grp to RP Mappings
 109  *  =====================================================================
 110  *  BSM Format:
 111  *
 112  *   0                   1                   2                   3
 113  *   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
 114  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 115  *  |PIM Ver| Type  |N|  Reserved   |           Checksum            | PIM HDR
 116  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 117  *  |         Fragment Tag          | Hash Mask Len | BSR Priority  | BS HDR(1)
 118  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 119  *  |             BSR Address (Encoded-Unicast format)              | BS HDR(2)
 120  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 121  *  |            Group Address 1 (Encoded-Group format)             |
 122  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 123  *  | RP Count 1    | Frag RP Cnt 1 |         Reserved              |
 124  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 125  *  |             RP Address 1 (Encoded-Unicast format)             |
 126  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 127  *  |          RP1 Holdtime         | RP1 Priority  |   Reserved    |
 128  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 129  *  |             RP Address 2 (Encoded-Unicast format)             |
 130  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 131  *  |          RP2 Holdtime         | RP2 Priority  |   Reserved    |
 132  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 133  *  |                               .                               |
 134  *  |                               .                               |
 135  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 136  *  |             RP Address m (Encoded-Unicast format)             |
 137  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 138  *  |          RPm Holdtime         | RPm Priority  |   Reserved    |
 139  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 140  *  |            Group Address 2 (Encoded-Group format)             |
 141  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 142  *  |                               .                               |
 143  *  |                               .                               |
 144  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 145  *  |            Group Address n (Encoded-Group format)             |
 146  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 147  *  | RP Count n    | Frag RP Cnt n |          Reserved             |
 148  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 149  *  |             RP Address 1 (Encoded-Unicast format)             |
 150  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 151  *  |          RP1 Holdtime         | RP1 Priority  |   Reserved    |
 152  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 153  *  |             RP Address 2 (Encoded-Unicast format)             |
 154  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 155  *  |          RP2 Holdtime         | RP2 Priority  |   Reserved    |
 156  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 157  *  |                               .                               |
 158  *  |                               .                               |
 159  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 160  *  |             RP Address m (Encoded-Unicast format)             |
 161  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 162  *  |          RPm Holdtime         | RPm Priority  |   Reserved    |
 163  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 164  */
 165 struct bsm_hdr {
 166         uint16_t frag_tag;
 167         uint8_t hm_len;
 168         uint8_t bsr_prio;
 169         struct pim_encoded_ipv4_unicast bsr_addr;
 170 } __attribute__((packed));
 171
 172 struct bsmmsg_grpinfo {
 173         struct pim_encoded_group_ipv4 group;
 174         uint8_t rp_count;
 175         uint8_t frag_rp_count;
 176         uint16_t reserved;
 177 } __attribute__((packed));
 178
 179 struct bsmmsg_rpinfo {
 180         struct pim_encoded_ipv4_unicast rpaddr;
 181         uint16_t rp_holdtime;
 182         uint8_t rp_pri;
 183         uint8_t reserved;
 184 } __attribute__((packed));
 185
 186 /* API */
 187 void pim_bsm_proc_init(struct pim_instance *pim);
 188 void pim_bsm_proc_free(struct pim_instance *pim);
 189 void pim_bsm_write_config(struct vty *vty, struct interface *ifp);
 190 int  pim_bsm_process(struct interface *ifp,
 191                      struct ip *ip_hdr,
 192                      uint8_t *buf,
 193                      uint32_t buf_size,
 194                      bool no_fwd);
 195 bool pim_bsm_new_nbr_fwd(struct pim_neighbor *neigh, struct interface *ifp);
 196 struct bsgrp_node *pim_bsm_get_bsgrp_node(struct bsm_scope *scope,
 197                                           struct prefix *grp);
 198 #endif