/*      $NetBSD: route.h,v 1.135 2025/09/21 15:11:52 christos Exp $     */

/*
 * Copyright (c) 1980, 1986, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)route.h     8.5 (Berkeley) 2/8/95
 */

#ifndef _NET_ROUTE_H_
#define _NET_ROUTE_H_

#include <sys/queue.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <net/if.h>
#ifdef _KERNEL
#include <sys/rwlock.h>
#include <sys/condvar.h>
#include <sys/pserialize.h>
#include <sys/percpu.h>
#endif
#include <sys/psref.h>

#if !(defined(_KERNEL) || defined(_STANDALONE))
#include <stdbool.h>
#endif

/*
 * Kernel resident routing tables.
 *
 * The routing tables are initialized when interface addresses
 * are set by making entries for all directly connected interfaces.
 */

/*
 * A route consists of a destination address and a reference
 * to a routing entry.  These are often held by protocols
 * in their control blocks, e.g. inpcb.
 */
struct route {
        struct  rtentry         *_ro_rt;
        struct  sockaddr        *ro_sa;
        uint64_t                ro_rtcache_generation;
        struct  psref           ro_psref;
        int                     ro_bound;
};

/*
 * These numbers are used by reliable protocols for determining
 * retransmission behavior and are included in the routing structure.
 */
struct rt_metrics {
        uint64_t rmx_locks;     /* Kernel must leave these values alone */
        uint64_t rmx_mtu;       /* MTU for this path */
        uint64_t rmx_hopcount;  /* max hops expected */
        uint64_t rmx_recvpipe;  /* inbound delay-bandwidth product */
        uint64_t rmx_sendpipe;  /* outbound delay-bandwidth product */
        uint64_t rmx_ssthresh;  /* outbound gateway buffer limit */
        uint64_t rmx_rtt;       /* estimated round trip time */
        uint64_t rmx_rttvar;    /* estimated rtt variance */
        time_t  rmx_expire;     /* lifetime for route, e.g. redirect */
        time_t  rmx_pksent;     /* packets sent using this route */
};

/*
 * rmx_rtt and rmx_rttvar are stored as microseconds;
 * RTTTOPRHZ(rtt) converts to a value suitable for use
 * by a protocol slowtimo counter.
 */
#define RTM_RTTUNIT     1000000 /* units for rtt, rttvar, as units per sec */
#define RTTTOPRHZ(r)    ((r) / (RTM_RTTUNIT / PR_SLOWHZ))

/*
 * We distinguish between routes to hosts and routes to networks,
 * preferring the former if available.  For each route we infer
 * the interface to use from the gateway address supplied when
 * the route was entered.  Routes that forward packets through
 * gateways are marked so that the output routines know to address the
 * gateway rather than the ultimate destination.
 */
#ifndef RNF_NORMAL
#include <net/radix.h>
#endif
struct rtentry {
        struct  radix_node rt_nodes[2]; /* tree glue, and other values */
#define rt_mask(r)      ((const struct sockaddr *)((r)->rt_nodes->rn_mask))
        struct  sockaddr *rt_gateway;   /* value */
        int     rt_flags;               /* up/down?, host/net */
        int     rt_refcnt;              /* # held references */
        uint64_t rt_use;                        /* raw # packets forwarded */
        struct  ifnet *rt_ifp;          /* the answer: interface to use */
        struct  ifaddr *rt_ifa;         /* the answer: interface to use */
        uint32_t rt_ifa_seqno;
        void *  rt_llinfo;              /* pointer to link level info cache */
        struct  rt_metrics rt_rmx;      /* metrics used by rx'ing protocols */
        struct  rtentry *rt_gwroute;    /* implied entry for gatewayed routes */
        LIST_HEAD(, rttimer) rt_timer;  /* queue of timeouts for misc funcs */
        struct  rtentry *rt_parent;     /* parent of cloned route */
        struct  sockaddr *_rt_key;
        struct  sockaddr *rt_tag;       /* route tagging info */
#ifdef _KERNEL
        kcondvar_t rt_cv;
        struct psref_target rt_psref;
        SLIST_ENTRY(rtentry) rt_free;   /* queue of deferred frees */
#endif
};

static __inline const struct sockaddr *
rt_getkey(const struct rtentry *rt)
{
        return rt->_rt_key;
}

/*
 * Following structure necessary for 4.3 compatibility;
 * We should eventually move it to a compat file.
 */
struct ortentry {
        uint32_t rt_hash;               /* to speed lookups */
        struct  sockaddr rt_dst;        /* key */
        struct  sockaddr rt_gateway;    /* value */
        int16_t rt_flags;               /* up/down?, host/net */
        int16_t rt_refcnt;              /* # held references */
        uint32_t rt_use;                /* raw # packets forwarded */
        struct  ifnet *rt_ifp;          /* the answer: interface to use */
};

#define RTF_UP          0x1             /* route usable */
#define RTF_GATEWAY     0x2             /* destination is a gateway */
#define RTF_HOST        0x4             /* host entry (net otherwise) */
#define RTF_REJECT      0x8             /* host or net unreachable */
#define RTF_DYNAMIC     0x10            /* created dynamically (by redirect) */
#define RTF_MODIFIED    0x20            /* modified dynamically (by redirect) */
#define RTF_DONE        0x40            /* message confirmed */
#define RTF_MASK        0x80            /* subnet mask present */
// #define RTF_CLONING  0x100           /* generate new routes on use */
#define RTF_CONNECTED   0x100           /* hosts on this route are neighbours */
// #define RTF_XRESOLVE 0x200           /* external daemon resolves name */
// #define RTF_LLINFO   0x400           /* generated by ARP or NDP */
#define RTF_LLDATA      0x400           /* used by apps to add/del L2 entries */
#define RTF_STATIC      0x800           /* manually added */
#define RTF_BLACKHOLE   0x1000          /* just discard pkts (during updates) */
// #define RTF_CLONED   0x2000          /* this is a cloned route */
#define RTF_PROTO2      0x4000          /* protocol specific routing flag */
#define RTF_PROTO1      0x8000          /* protocol specific routing flag */
#define RTF_SRC         0x10000         /* route has fixed source address */
#define RTF_ANNOUNCE    0x20000         /* announce new ARP or NDP entry */
#define RTF_LOCAL       0x40000         /* route represents a local address */
#define RTF_BROADCAST   0x80000         /* route represents a bcast address */
#define RTF_UPDATING    0x100000        /* route is updating */
/*
 * The flag is nevert set to rt_flags.  It just tells rtrequest1 to set a passed
 * ifa to rt_ifa (via rti_ifa) and not replace rt_ifa in ifa_rtrequest.
 */
#define RTF_DONTCHANGEIFA       0x200000        /* suppress rt_ifa replacement */

/*
 * 0x400 is exposed to userland just for backward compatibility. For that
 * purpose, it should be shown as LLINFO.
 */
#define RTFBITS "\020\1UP\2GATEWAY\3HOST\4REJECT\5DYNAMIC\6MODIFIED\7DONE" \
    "\010MASK_PRESENT\011CONNECTED\012XRESOLVE\013LLINFO\014STATIC" \
    "\015BLACKHOLE\016CLONED\017PROTO2\020PROTO1\021SRC\022ANNOUNCE" \
    "\023LOCAL\024BROADCAST\025UPDATING"


/*
 * Routing statistics.
 */
struct  rtstat {
        uint64_t rts_badredirect;       /* bogus redirect calls */
        uint64_t rts_dynamic;           /* routes created by redirects */
        uint64_t rts_newgateway;        /* routes modified by redirects */
        uint64_t rts_unreach;           /* lookups which failed */
        uint64_t rts_wildcard;          /* lookups satisfied by a wildcard */
};

/*
 * Structures for routing messages.  By forcing the first member to be aligned
 * at a 64-bit boundary, we also force the size to be a multiple of 64-bits.
 */

#if !defined(_KERNEL) || !defined(COMPAT_RTSOCK)
/*
 * If we aren't being compiled for backwards compatibility, enforce 64-bit
 * alignment so any routing message is the same regardless if the kernel
 * is an ILP32 or LP64 kernel.
 */
#define __align64       __aligned(sizeof(uint64_t))
#else
#define __align64
#endif

struct rt_msghdr {
        u_short rtm_msglen __align64;
                                /* to skip over non-understood messages */
        u_char  rtm_version;    /* future binary compatibility */
        u_char  rtm_type;       /* message type */
        u_short rtm_index;      /* index for associated ifp */
        int     rtm_flags;      /* flags, incl. kern & message, e.g. DONE */
        int     rtm_addrs;      /* bitmask identifying sockaddrs in msg */
        pid_t   rtm_pid;        /* identify sender */
        int     rtm_seq;        /* for sender to identify action */
        int     rtm_errno;      /* why failed */
        int     rtm_use;        /* from rtentry */
        int     rtm_inits;      /* which metrics we are initializing */
        struct  rt_metrics rtm_rmx __align64;
                                /* metrics themselves */
};

#undef __align64

#define RTM_VERSION     4       /* Up the ante and ignore older versions */

#define RTM_ADD         0x1     /* Add Route */
#define RTM_DELETE      0x2     /* Delete Route */
#define RTM_CHANGE      0x3     /* Change Metrics or flags */
#define RTM_GET         0x4     /* Report Metrics */
#define RTM_LOSING      0x5     /* Kernel Suspects Partitioning */
#define RTM_REDIRECT    0x6     /* Told to use different route */
#define RTM_MISS        0x7     /* Lookup failed on this address */
#define RTM_LOCK        0x8     /* fix specified metrics */
#define RTM_OLDADD      0x9     /* caused by SIOCADDRT */
#define RTM_OLDDEL      0xa     /* caused by SIOCDELRT */
// #define RTM_RESOLVE  0xb     /* req to resolve dst to LL addr */
#define RTM_ONEWADDR    0xc     /* Old (pre-8.0) RTM_NEWADDR message */
#define RTM_ODELADDR    0xd     /* Old (pre-8.0) RTM_DELADDR message */
#define RTM_OOIFINFO    0xe     /* Old (pre-1.5) RTM_IFINFO message */
#define RTM_OIFINFO     0xf     /* Old (pre-64bit time) RTM_IFINFO message */
#define RTM_IFANNOUNCE  0x10    /* iface arrival/departure */
#define RTM_IEEE80211   0x11    /* IEEE80211 wireless event */
#define RTM_SETGATE     0x12    /* set prototype gateway for clones
                                 * (see example in arp_rtrequest).
                                 */
#define RTM_LLINFO_UPD  0x13    /* indication to ARP/NDP/etc. that link-layer
                                 * address has changed
                                 */
#define RTM_IFINFO      0x14    /* iface/link going up/down etc. */
#define RTM_OCHGADDR    0x15    /* Old (pre-8.0) RTM_CHGADDR message */
#define RTM_NEWADDR     0x16    /* address being added to iface */
#define RTM_DELADDR     0x17    /* address being removed from iface */
#define RTM_CHGADDR     0x18    /* address properties changed */

#ifdef RTM_NAMES
static const char *rtm_names[] = {
    "*none*", "add", "delete", "change", "get",
    "losing", "redirect", "miss", "lock", "oldadd",
    "olddel", "*resolve*", "onewaddr", "odeladdr", "ooifinfo",
    "oifinfo", "ifannounce", "ieee80211", "setgate", "llinfo_upd",
    "ifinfo", "ochgaddr",  "newaddr", "deladdr", "chgaddr",
};
#endif

/*
 * setsockopt defines used for the filtering.
 */
#define RO_MSGFILTER    1       /* array of which rtm_type to send to client */
#define RO_MISSFILTER   2       /* array of sockaddrs to match miss dst */

#define RO_FILTSA_MAX   30      /* maximum number of sockaddrs per filter */

#define RTV_MTU         0x1     /* init or lock _mtu */
#define RTV_HOPCOUNT    0x2     /* init or lock _hopcount */
#define RTV_EXPIRE      0x4     /* init or lock _expire */
#define RTV_RPIPE       0x8     /* init or lock _recvpipe */
#define RTV_SPIPE       0x10    /* init or lock _sendpipe */
#define RTV_SSTHRESH    0x20    /* init or lock _ssthresh */
#define RTV_RTT         0x40    /* init or lock _rtt */
#define RTV_RTTVAR      0x80    /* init or lock _rttvar */

#define RTVBITS "\020\1MTU\2HOPCOUNT\3EXPIRE\4RECVPIPE\5SENDPIPE" \
    "\6SSTHRESH\7RTT\010RTTVAR"

/*
 * Bitmask values for rtm_addr.
 */
#define RTA_DST         0x1     /* destination sockaddr present */
#define RTA_GATEWAY     0x2     /* gateway sockaddr present */
#define RTA_NETMASK     0x4     /* netmask sockaddr present */
#define RTA_GENMASK     0x8     /* cloning mask sockaddr present */
#define RTA_IFP         0x10    /* interface name sockaddr present */
#define RTA_IFA         0x20    /* interface addr sockaddr present */
#define RTA_AUTHOR      0x40    /* sockaddr for author of redirect */
#define RTA_BRD         0x80    /* for NEWADDR, broadcast or p-p dest addr */
#define RTA_TAG         0x100   /* route tag */

#define RTABITS "\020\1DST\2GATEWAY\3NETMASK\4GENMASK\5IFP\6IFA\7AUTHOR" \
    "\010BRD\011TAG"

/*
 * Index offsets for sockaddr array for alternate internal encoding.
 */
#define RTAX_DST        0       /* destination sockaddr present */
#define RTAX_GATEWAY    1       /* gateway sockaddr present */
#define RTAX_NETMASK    2       /* netmask sockaddr present */
#define RTAX_GENMASK    3       /* cloning mask sockaddr present */
#define RTAX_IFP        4       /* interface name sockaddr present */
#define RTAX_IFA        5       /* interface addr sockaddr present */
#define RTAX_AUTHOR     6       /* sockaddr for author of redirect */
#define RTAX_BRD        7       /* for NEWADDR, broadcast or p-p dest addr */
#define RTAX_TAG        8       /* route tag */
#define RTAX_MAX        9       /* size of array to allocate */

#define RT_ROUNDUP2(a, n)       ((a) > 0 ? (1 + (((a) - 1U) | ((n) - 1))) : (n))
#define RT_ROUNDUP(a)           RT_ROUNDUP2((a), sizeof(uint64_t))
#define RT_ADVANCE(x, n)        (x += RT_ROUNDUP((n)->sa_len))

struct rt_addrinfo {
        int     rti_addrs;
        const struct    sockaddr *rti_info[RTAX_MAX];
        int     rti_flags;
        struct  ifaddr *rti_ifa;
        struct  ifnet *rti_ifp;
};

struct route_cb {
        int     ip_count;
        int     ip6_count;
        int     unused1;
        int     mpls_count;
        int     any_count;
};

/*
 * This structure, and the prototypes for the rt_timer_{init,remove_all,
 * add,timer} functions all used with the kind permission of BSDI.
 * These allow functions to be called for routes at specific times.
 */

struct rttimer {
        TAILQ_ENTRY(rttimer)    rtt_next;  /* entry on timer queue */
        LIST_ENTRY(rttimer)     rtt_link;  /* multiple timers per rtentry */
        struct rttimer_queue   *rtt_queue; /* back pointer to queue */
        struct rtentry         *rtt_rt;    /* Back pointer to the route */
        void                  (*rtt_func)(struct rtentry *, struct rttimer *);
        time_t                  rtt_time;  /* When this timer was registered */
};

struct rttimer_queue {
        long                            rtq_timeout;
        unsigned long                   rtq_count;
        TAILQ_HEAD(, rttimer)           rtq_head;
        LIST_ENTRY(rttimer_queue)       rtq_link;
};


struct rtbl;
typedef struct rtbl rtbl_t;

#ifdef _KERNEL

struct rtbl {
        struct radix_node_head t_rnh;
};

struct rt_walkarg {
        int     w_op;
        int     w_arg;
        int     w_given;
        int     w_needed;
        void *  w_where;
        int     w_tmemsize;
        int     w_tmemneeded;
        void *  w_tmem;
};

#if 0
#define RT_DPRINTF(__fmt, ...)  do { } while (/*CONSTCOND*/0)
#else
#define RT_DPRINTF(__fmt, ...)  /* do nothing */
#endif

struct rtwalk {
        int (*rw_f)(struct rtentry *, void *);
        void *rw_v;
};

/*
 * Global data specific to the routing socket.
 */
struct route_info {
        struct sockaddr ri_dst;
        struct sockaddr ri_src;
        struct route_cb ri_cb;
        int ri_maxqlen;
        struct ifqueue ri_intrq;
        void *ri_sih;
};

extern  struct  route_info route_info;
extern  struct  rtstat  rtstat;

struct socket;

void    rt_init(void);

int     rt_timer_add(struct rtentry *,
            void(*)(struct rtentry *, struct rttimer *),
            struct rttimer_queue *);
unsigned long
        rt_timer_count(struct rttimer_queue *);
void    rt_timer_queue_change(struct rttimer_queue *, long);
struct rttimer_queue *
        rt_timer_queue_create(u_int);
void    rt_timer_queue_destroy(struct rttimer_queue *);

void    rt_free(struct rtentry *);
void    rt_unref(struct rtentry *);

int     rt_update(struct rtentry *, struct rt_addrinfo *, void *);
int     rt_update_prepare(struct rtentry *);
void    rt_update_finish(struct rtentry *);

void    rt_newmsg(const int, const struct rtentry *);
void    rt_newmsg_dynamic(const int, const struct rtentry *);
struct rtentry *
        rtalloc1(const struct sockaddr *, int);
int     rtinit(struct ifaddr *, int, int);
void    rtredirect(const struct sockaddr *, const struct sockaddr *,
            const struct sockaddr *, int, const struct sockaddr *,
            struct rtentry **);
int     rtrequest(int, const struct sockaddr *,
            const struct sockaddr *, const struct sockaddr *, int,
            struct rtentry **);
int     rtrequest1(int, struct rt_addrinfo *, struct rtentry **);

int     rt_ifa_addlocal(struct ifaddr *);
int     rt_ifa_remlocal(struct ifaddr *, struct ifaddr *);
struct ifaddr *
        rt_get_ifa(struct rtentry *);
void    rt_replace_ifa(struct rtentry *, struct ifaddr *);
int     rt_setgate(struct rtentry *, const struct sockaddr *);

const struct sockaddr *
        rt_settag(struct rtentry *, const struct sockaddr *);
struct sockaddr *
        rt_gettag(const struct rtentry *);

int     rt_check_reject_route(const struct rtentry *, const struct ifnet *);
void    rt_delete_matched_entries(sa_family_t,
            int (*)(struct rtentry *, void *), void *, bool);
void    rt_replace_ifa_matched_entries(sa_family_t,
            int (*)(struct rtentry *, void *), void *, struct ifaddr *);
int     rt_walktree(sa_family_t, int (*)(struct rtentry *, void *), void *);

static __inline void
rt_assert_referenced(const struct rtentry *rt)
{

        KASSERT(rt->rt_refcnt > 0);
}

void    rtcache_copy(struct route *, struct route *);
void    rtcache_free(struct route *);
struct rtentry *
        rtcache_init(struct route *);
struct rtentry *
        rtcache_init_noclone(struct route *);
struct rtentry *
        rtcache_lookup2(struct route *, const struct sockaddr *, int,
            int *);
int     rtcache_setdst(struct route *, const struct sockaddr *);
struct rtentry *
        rtcache_update(struct route *, int);

static __inline void
rtcache_invariants(const struct route *ro)
{

        KASSERT(ro->ro_sa != NULL || ro->_ro_rt == NULL);
}

static __inline struct rtentry *
rtcache_lookup1(struct route *ro, const struct sockaddr *dst, int clone)
{
        int hit;

        return rtcache_lookup2(ro, dst, clone, &hit);
}

static __inline struct rtentry *
rtcache_lookup(struct route *ro, const struct sockaddr *dst)
{
        return rtcache_lookup1(ro, dst, 1);
}

static __inline const struct sockaddr *
rtcache_getdst(const struct route *ro)
{

        rtcache_invariants(ro);
        return ro->ro_sa;
}

struct rtentry *
        rtcache_validate(struct route *);

void    rtcache_unref(struct rtentry *, struct route *);

percpu_t *
        rtcache_percpu_alloc(void);

static __inline struct route *
rtcache_percpu_getref(percpu_t *pc)
{

        return *(struct route **)percpu_getref(pc);
}

static __inline void
rtcache_percpu_putref(percpu_t *pc)
{

        percpu_putref(pc);
}


/* rtsock */
void    rt_ieee80211msg(struct ifnet *, int, void *, size_t);
void    rt_ifannouncemsg(struct ifnet *, int);
void    rt_ifmsg(struct ifnet *);
void    rt_missmsg(int, const struct rt_addrinfo *, int, int);
struct mbuf *
        rt_msg1(int, struct rt_addrinfo *, void *, int);
int     rt_msg3(int, struct rt_addrinfo *, void *, struct rt_walkarg *, int *);
void    rt_addrmsg(int, struct ifaddr *);
void    rt_addrmsg_src(int, struct ifaddr *, const struct sockaddr *);
void    rt_addrmsg_rt(int, struct ifaddr *, int, struct rtentry *);
void    route_enqueue(struct mbuf *, int);

struct llentry;
void    rt_clonedmsg(int, const struct sockaddr *, const struct sockaddr *,
            const uint8_t *, const struct ifnet *);

void    rt_setmetrics(void *, struct rtentry *);

/* rtbl */
int     rt_addaddr(rtbl_t *, struct rtentry *, const struct sockaddr *);
void    rt_assert_inactive(const struct rtentry *);
struct rtentry *
        rt_deladdr(rtbl_t *, const struct sockaddr *,
            const struct sockaddr *);
rtbl_t *rt_gettable(sa_family_t);
int     rt_inithead(rtbl_t **, int);
struct rtentry *
        rt_lookup(rtbl_t *, const struct sockaddr *,
            const struct sockaddr *);
struct rtentry *
        rt_matchaddr(rtbl_t *, const struct sockaddr *);
int     rt_refines(const struct sockaddr *, const struct sockaddr *);
int     rtbl_walktree(sa_family_t, int (*)(struct rtentry *, void *), void *);
struct rtentry *
        rtbl_search_matched_entry(sa_family_t,
            int (*)(struct rtentry *, void *), void *);
void    rtbl_init(void);

void    sysctl_net_route_setup(struct sysctllog **, int, const char *);

void    rt_unhandled(const char *, const struct ifnet *,
    const struct sockaddr *);

#endif /* _KERNEL */

#endif /* !_NET_ROUTE_H_ */