/*      $OpenBSD: ospf6.h,v 1.22 2023/06/21 09:47:03 sthen Exp $ */

/*
 * Copyright (c) 2004, 2005, 2007 Esben Norby <norby@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/* OSPF protocol definitions */

#ifndef _OSPF_H_
#define _OSPF_H_

#include <netinet/in.h>
#include <stddef.h>

/* misc */
#define OSPF6_VERSION           3
#define IPPROTO_OSPF            89
#define AllSPFRouters           "ff02::5"
#define AllDRouters             "ff02::6"

#define PACKET_HDR              100 /* XXX used to calculate the IP payload */

#define DEFAULT_METRIC          10
#define DEFAULT_REDIST_METRIC   100
#define MIN_METRIC              1
#define MAX_METRIC              65535   /* sum & as-ext lsa use 24bit metrics */

#define DEFAULT_PRIORITY        1
#define MIN_PRIORITY            0
#define MAX_PRIORITY            255

#define DEFAULT_HELLO_INTERVAL  10
#define MIN_HELLO_INTERVAL      1
#define MAX_HELLO_INTERVAL      65535

#define DEFAULT_RTR_DEAD_TIME   40
#define MIN_RTR_DEAD_TIME       2
#define MAX_RTR_DEAD_TIME       65535

#define DEFAULT_RXMT_INTERVAL   5
#define MIN_RXMT_INTERVAL       5
#define MAX_RXMT_INTERVAL       3600

#define DEFAULT_TRANSMIT_DELAY  1
#define MIN_TRANSMIT_DELAY      1
#define MAX_TRANSMIT_DELAY      3600

#define DEFAULT_ADJ_TMOUT       120

#define DEFAULT_NBR_TMOUT       86400   /* 24 hours */

#define DEFAULT_SPF_DELAY       1
#define MIN_SPF_DELAY           1
#define MAX_SPF_DELAY           10

#define DEFAULT_SPF_HOLDTIME    5
#define MIN_SPF_HOLDTIME        1
#define MAX_SPF_HOLDTIME        5

/* msec */
#define KR_RELOAD_TIMER         250
#define KR_RELOAD_HOLD_TIMER    5000

#define MIN_MD_ID               0
#define MAX_MD_ID               255

#define DEFAULT_INSTANCE_ID     0
#define MIN_INSTANCE_ID 0
#define MAX_INSTANCE_ID 0

/* OSPF compatibility flags */
#define OSPF_OPTION_V6          0x01
#define OSPF_OPTION_E           0x02
#define OSPF_OPTION_x           0x04    /* ignored, should be 0 */
#define OSPF_OPTION_N           0x08
#define OSPF_OPTION_R           0x10
#define OSPF_OPTION_DC          0x20

/* OSPF packet types */
#define PACKET_TYPE_HELLO       1
#define PACKET_TYPE_DD          2
#define PACKET_TYPE_LS_REQUEST  3
#define PACKET_TYPE_LS_UPDATE   4
#define PACKET_TYPE_LS_ACK      5

/* LSA */
#define LS_REFRESH_TIME         1800
#define MIN_LS_INTERVAL         5
#define MIN_LS_ARRIVAL          1
#define DEFAULT_AGE             0
#define MAX_AGE                 3600
#define CHECK_AGE               300
#define MAX_AGE_DIFF            900
#define LS_INFINITY             0xffffff
#define RESV_SEQ_NUM            0x80000000U     /* reserved and "unused" */
#define INIT_SEQ_NUM            0x80000001U
#define MAX_SEQ_NUM             0x7fffffffU

/* OSPF header */
struct ospf_hdr {
        u_int8_t                version;
        u_int8_t                type;
        u_int16_t               len;
        u_int32_t               rtr_id;
        u_int32_t               area_id;
        u_int16_t               chksum;
        u_int8_t                instance;
        u_int8_t                zero;           /* must be zero */
};

/* Hello header (type 1) */
struct hello_hdr {
        u_int32_t               iface_id;
        u_int32_t               opts;   /* 8bit rtr_priority + 24bits options */
        u_int16_t               hello_interval;
        u_int16_t               rtr_dead_interval;
        u_int32_t               d_rtr;
        u_int32_t               bd_rtr;
};

/* Database Description header (type 2) */
struct db_dscrp_hdr {
        u_int32_t               opts;
        u_int16_t               iface_mtu;
        u_int8_t                zero;           /* must be zero */
        u_int8_t                bits;
        u_int32_t               dd_seq_num;
};

#define OSPF_DBD_MS             0x01
#define OSPF_DBD_M              0x02
#define OSPF_DBD_I              0x04

/*  Link State Request header (type 3) */
struct ls_req_hdr {
        u_int16_t               zero;
        u_int16_t               type;
        u_int32_t               ls_id;
        u_int32_t               adv_rtr;
};

/* Link State Update header (type 4) */
struct ls_upd_hdr {
        u_int32_t               num_lsa;
};

#define LSA_TYPE_LINK           0x0008
#define LSA_TYPE_ROUTER         0x2001
#define LSA_TYPE_NETWORK        0x2002
#define LSA_TYPE_INTER_A_PREFIX 0x2003
#define LSA_TYPE_INTER_A_ROUTER 0x2004
#define LSA_TYPE_INTRA_A_PREFIX 0x2009
#define LSA_TYPE_EXTERNAL       0x4005

#define LSA_TYPE_FLAG_U         0x8000
#define LSA_TYPE_FLAG_S2        0x4000
#define LSA_TYPE_FLAG_S1        0x2000
#define LSA_TYPE_SCOPE_MASK     0x6000

#define LSA_IS_SCOPE_LLOCAL(x)  \
    (((x) & LSA_TYPE_SCOPE_MASK) == 0)
#define LSA_IS_SCOPE_AREA(x)    \
    (((x) & LSA_TYPE_SCOPE_MASK) == LSA_TYPE_FLAG_S1)
#define LSA_IS_SCOPE_AS(x)      \
    (((x) & LSA_TYPE_SCOPE_MASK) == LSA_TYPE_FLAG_S2)

#define LINK_TYPE_POINTTOPOINT  1
#define LINK_TYPE_TRANSIT_NET   2
#define LINK_TYPE_RESERVED      3
#define LINK_TYPE_VIRTUAL       4

/* for some reason they thought 24bit types are fun, make them less a hazard */
#define LSA_24_MASK 0xffffff
#define LSA_24_GETHI(x)         \
        ((x) >> 24)
#define LSA_24_GETLO(x)         \
        ((x) & LSA_24_MASK)
#define LSA_24_SETHI(x, y)      \
        ((x) = ((x) & LSA_24_MASK) | (((y) & 0xff) << 24))
#define LSA_24_SETLO(x, y)      \
        ((x) = ((y) & LSA_24_MASK) | ((x) & ~LSA_24_MASK))

/* LSA headers */
#define LSA_METRIC_MASK         0x00ffffff      /* only for sum & as-ext */
#define LSA_ASEXT_E_FLAG        0x04000000
#define LSA_ASEXT_F_FLAG        0x02000000
#define LSA_ASEXT_T_FLAG        0x01000000

#define OSPF_RTR_B              0x01
#define OSPF_RTR_E              0x02
#define OSPF_RTR_V              0x04
#define OSPF_RTR_x              0x08    /* ignored, should be 0 */
#define OSPF_RTR_Nt             0x10

#define OSPF_PREFIX_NU          0x01
#define OSPF_PREFIX_LA          0x02
#define OSPF_PREFIX_x           0x04    /* ignored, should be 0 */
#define OSPF_PREFIX_P           0x08
#define OSPF_PREFIX_DN          0x10

/* return encoded IPv6 prefix size in bytes depending on the prefixlen */
#define LSA_PREFIXSIZE(x)       (((x) + 31)/32 * 4)

struct lsa_prefix {
        u_int8_t                prefixlen;
        u_int8_t                options;
        u_int16_t               metric; /* Ref. LS type in AS-Ext-LSA */
        /* + an IPv6 prefix encoded in (prefixlen + 31)/32 words */
};

struct lsa_rtr {
        u_int32_t               opts;   /* 8bit flags + 24bits options */
};

struct lsa_rtr_link {
        u_int8_t                type;
        u_int8_t                dummy;
        u_int16_t               metric;
        u_int32_t               iface_id;
        u_int32_t               nbr_iface_id;
        u_int32_t               nbr_rtr_id;
};

struct lsa_net {
        u_int32_t               opts;   /* 24bits options */
};

struct lsa_net_link {
        u_int32_t               att_rtr;
};

struct lsa_prefix_sum {
        u_int32_t               metric;         /* only lower 24 bit */
        /* + one prefix */
};

struct lsa_rtr_sum {
        u_int32_t               opts;           /* lower 24bit options */
        u_int32_t               metric;         /* only lower 24 bit */
        u_int32_t               dest_rtr_id;
};

struct lsa_asext {
        u_int32_t               metric;         /* lower 24 bit plus EFT bits */
        struct lsa_prefix       prefix;
        /* + if F bit is set, an optional forwarding address (128bit) */
        /* + if T bit is set, an optional external route tag (32bit) */
        /* + if referenced LS type (i.e. prefix.metric) is non-zero, an
         *   optional referenced LS ID (32bit) -- not used by OSPF itself */
};

struct lsa_link {
        u_int32_t               opts;           /* rtr pri & 24bit options */
        struct in6_addr         lladdr;
        u_int32_t               numprefix;
        /* + numprefix * lsa_prefix */
};

struct lsa_intra_prefix {
        u_int16_t               numprefix;
        u_int16_t               ref_type;
        u_int32_t               ref_ls_id;
        u_int32_t               ref_adv_rtr;
        /* + numprefix * lsa_prefix */
};

struct lsa_hdr {
        u_int16_t               age;
        u_int16_t               type;
        u_int32_t               ls_id;
        u_int32_t               adv_rtr;
        u_int32_t               seq_num;
        u_int16_t               ls_chksum;
        u_int16_t               len;
};

#define LS_CKSUM_OFFSET offsetof(struct lsa_hdr, ls_chksum)

struct lsa {
        struct lsa_hdr          hdr;
        union {
                struct lsa_rtr          rtr;
                struct lsa_net          net;
                struct lsa_prefix_sum   pref_sum;
                struct lsa_rtr_sum      rtr_sum;
                struct lsa_asext        asext;
                struct lsa_link         link;
                struct lsa_intra_prefix pref_intra;
        }                       data;
};

#endif /* !_OSPF_H_ */