/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1985, 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.
 */

#ifndef _NETINET_IN_VAR_H_
#define _NETINET_IN_VAR_H_

/*
 * Argument structure for SIOCAIFADDR.
 */
struct  in_aliasreq {
        char    ifra_name[IFNAMSIZ];            /* if name, e.g. "en0" */
        struct  sockaddr_in ifra_addr;
        struct  sockaddr_in ifra_broadaddr;
#define ifra_dstaddr ifra_broadaddr
        struct  sockaddr_in ifra_mask;
        int     ifra_vhid;
};

#ifdef _KERNEL
#include <sys/queue.h>
#include <sys/fnv_hash.h>
#include <sys/tree.h>

struct igmp_ifsoftc;
struct in_multi;
struct lltable;
SLIST_HEAD(in_multi_head, in_multi);

/*
 * IPv4 per-interface state.
 */
struct in_ifinfo {
        struct lltable          *ii_llt;        /* ARP state */
        struct igmp_ifsoftc     *ii_igmp;       /* IGMP state */
        struct in_multi         *ii_allhosts;   /* 224.0.0.1 membership */
};

/*
 * Interface address, Internet version.  One of these structures
 * is allocated for each Internet address on an interface.
 * The ifaddr structure contains the protocol-independent part
 * of the structure and is assumed to be first.
 */
struct in_ifaddr {
        struct  ifaddr ia_ifa;          /* protocol-independent info */
#define ia_ifp          ia_ifa.ifa_ifp
#define ia_flags        ia_ifa.ifa_flags
                                        /* ia_subnet{,mask} in host order */
        u_long  ia_subnet;              /* subnet address */
        u_long  ia_subnetmask;          /* mask of subnet */
        CK_LIST_ENTRY(in_ifaddr) ia_hash;       /* hash of internet addresses */
        CK_STAILQ_ENTRY(in_ifaddr) ia_link;     /* list of internet addresses */
        struct  sockaddr_in ia_addr;    /* reserve space for interface name */
        struct  sockaddr_in ia_dstaddr; /* reserve space for broadcast addr */
#define ia_broadaddr    ia_dstaddr
        struct  sockaddr_in ia_sockmask; /* reserve space for general netmask */
        struct  callout ia_garp_timer;  /* timer for retransmitting GARPs */
        int     ia_garp_count;          /* count of retransmitted GARPs */
};

/*
 * Given a pointer to an in_ifaddr (ifaddr),
 * return a pointer to the addr as a sockaddr_in.
 */
#define IA_SIN(ia)    (&(((struct in_ifaddr *)(ia))->ia_addr))
#define IA_DSTSIN(ia) (&(((struct in_ifaddr *)(ia))->ia_dstaddr))
#define IA_MASKSIN(ia) (&(((struct in_ifaddr *)(ia))->ia_sockmask))

#define IN_LNAOF(in, ifa) \
        ((ntohl((in).s_addr) & ~((struct in_ifaddr *)(ifa)->ia_subnetmask))

#ifdef _KERNEL
#define IN_ARE_MASKED_ADDR_EQUAL(d, a, m)       (               \
        ((((d).s_addr ^ (a).s_addr) & (m).s_addr)) == 0 )
#endif

#define LLTABLE(ifp)    ((struct in_ifinfo *)(ifp)->if_inet)->ii_llt
/*
 * Hash table for IP addresses.
 */
CK_STAILQ_HEAD(in_ifaddrhead, in_ifaddr);
CK_LIST_HEAD(in_ifaddrhashhead, in_ifaddr);

VNET_DECLARE(struct in_ifaddrhashhead *, in_ifaddrhashtbl);
VNET_DECLARE(struct in_ifaddrhead, in_ifaddrhead);
VNET_DECLARE(u_long, in_ifaddrhmask);           /* mask for hash table */

#define V_in_ifaddrhashtbl      VNET(in_ifaddrhashtbl)
#define V_in_ifaddrhead         VNET(in_ifaddrhead)
#define V_in_ifaddrhmask        VNET(in_ifaddrhmask)

#define INADDR_NHASH_LOG2       9
#define INADDR_NHASH            (1 << INADDR_NHASH_LOG2)
#define INADDR_HASHVAL(x)       fnv_32_buf((&(x)), sizeof(x), FNV1_32_INIT)
#define INADDR_HASH(x) \
        (&V_in_ifaddrhashtbl[INADDR_HASHVAL(x) & V_in_ifaddrhmask])

/*
 * Macro for finding the internet address structure (in_ifaddr)
 * corresponding to one of our IP addresses (in_addr).
 */
#define INADDR_TO_IFADDR(addr, ia) \
        /* struct in_addr addr; */ \
        /* struct in_ifaddr *ia; */ \
do {                                                                    \
        NET_EPOCH_ASSERT();                                             \
        CK_LIST_FOREACH(ia, INADDR_HASH((addr).s_addr), ia_hash)        \
                if (IA_SIN(ia)->sin_addr.s_addr == (addr).s_addr)       \
                        break;                                          \
} while (0)

/*
 * Macro for finding the interface (ifnet structure) corresponding to one
 * of our IP addresses.
 */
#define INADDR_TO_IFP(addr, ifp) \
        /* struct in_addr addr; */ \
        /* struct ifnet *ifp; */ \
{ \
        struct in_ifaddr *ia; \
\
        INADDR_TO_IFADDR(addr, ia); \
        (ifp) = (ia == NULL) ? NULL : ia->ia_ifp; \
}

/*
 * Legacy IPv4 IGMP per-link structure.
 */
struct router_info {
        struct ifnet *rti_ifp;
        int    rti_type; /* type of router which is querier on this interface */
        int    rti_time; /* # of slow timeouts since last old query */
        SLIST_ENTRY(router_info) rti_list;
};

/*
 * IPv4 multicast IGMP-layer source entry.
 */
struct ip_msource {
        RB_ENTRY(ip_msource)    ims_link;       /* RB tree links */
        in_addr_t               ims_haddr;      /* host byte order */
        struct ims_st {
                uint16_t        ex;             /* # of exclusive members */
                uint16_t        in;             /* # of inclusive members */
        }                       ims_st[2];      /* state at t0, t1 */
        uint8_t                 ims_stp;        /* pending query */
};

/*
 * IPv4 multicast PCB-layer source entry.
 */
struct in_msource {
        RB_ENTRY(ip_msource)    ims_link;       /* RB tree links */
        in_addr_t               ims_haddr;      /* host byte order */
        uint8_t                 imsl_st[2];     /* state before/at commit */
};

RB_HEAD(ip_msource_tree, ip_msource);   /* define struct ip_msource_tree */

static __inline int
ip_msource_cmp(const struct ip_msource *a, const struct ip_msource *b)
{

        if (a->ims_haddr < b->ims_haddr)
                return (-1);
        if (a->ims_haddr == b->ims_haddr)
                return (0);
        return (1);
}
RB_PROTOTYPE(ip_msource_tree, ip_msource, ims_link, ip_msource_cmp);

/*
 * IPv4 multicast PCB-layer group filter descriptor.
 */
struct in_mfilter {
        struct ip_msource_tree  imf_sources; /* source list for (S,G) */
        u_long                  imf_nsrc;    /* # of source entries */
        uint8_t                 imf_st[2];   /* state before/at commit */
        struct in_multi        *imf_inm;     /* associated multicast address */
        STAILQ_ENTRY(in_mfilter) imf_entry;  /* list entry */
};

/*
 * Helper types and functions for IPv4 multicast filters.
 */
STAILQ_HEAD(ip_mfilter_head, in_mfilter);

struct in_mfilter *ip_mfilter_alloc(int mflags, int st0, int st1);
void ip_mfilter_free(struct in_mfilter *);

static inline void
ip_mfilter_init(struct ip_mfilter_head *head)
{

        STAILQ_INIT(head);
}

static inline struct in_mfilter *
ip_mfilter_first(const struct ip_mfilter_head *head)
{

        return (STAILQ_FIRST(head));
}

static inline void
ip_mfilter_insert(struct ip_mfilter_head *head, struct in_mfilter *imf)
{

        STAILQ_INSERT_TAIL(head, imf, imf_entry);
}

static inline void
ip_mfilter_remove(struct ip_mfilter_head *head, struct in_mfilter *imf)
{

        STAILQ_REMOVE(head, imf, in_mfilter, imf_entry);
}

#define IP_MFILTER_FOREACH(imf, head) \
        STAILQ_FOREACH(imf, head, imf_entry)

static inline size_t
ip_mfilter_count(struct ip_mfilter_head *head)
{
        struct in_mfilter *imf;
        size_t num = 0;

        STAILQ_FOREACH(imf, head, imf_entry)
                num++;
        return (num);
}

/*
 * IPv4 group descriptor.
 *
 * For every entry on an ifnet's if_multiaddrs list which represents
 * an IP multicast group, there is one of these structures.
 *
 * If any source filters are present, then a node will exist in the RB-tree
 * to permit fast lookup by source whenever an operation takes place.
 * This permits pre-order traversal when we issue reports.
 * Source filter trees are kept separately from the socket layer to
 * greatly simplify locking.
 *
 * When IGMPv3 is active, inm_timer is the response to group query timer.
 * The state-change timer inm_sctimer is separate; whenever state changes
 * for the group the state change record is generated and transmitted,
 * and kept if retransmissions are necessary.
 *
 * FUTURE: inm_link is now only used when groups are being purged
 * on a detaching ifnet. It could be demoted to a SLIST_ENTRY.
 */
struct in_multi {
        LIST_ENTRY(in_multi) inm_link;  /* to-be-released by in_ifdetach */
        struct  in_addr inm_addr;       /* IP multicast address, convenience */
        struct  ifnet *inm_ifp;         /* back pointer to ifnet */
        struct  ifmultiaddr *inm_ifma;  /* back pointer to ifmultiaddr */
        u_int   inm_timer;              /* IGMPv1/v2 group / v3 query timer */
        u_int   inm_state;              /* state of the membership */
        void    *inm_rti;               /* unused, legacy field */
        u_int   inm_refcount;           /* reference count */

        /* New fields for IGMPv3 follow. */
        struct igmp_ifsoftc     *inm_igi;       /* IGMP info */
        SLIST_ENTRY(in_multi)    inm_nrele;     /* to-be-released by IGMP */
        struct ip_msource_tree   inm_srcs;      /* tree of sources */
        u_long                   inm_nsrc;      /* # of tree entries */

        struct mbufq             inm_scq;       /* queue of pending
                                                 * state-change packets */
        struct timeval           inm_lastgsrtv; /* Time of last G-S-R query */
        uint16_t                 inm_sctimer;   /* state-change timer */
        uint16_t                 inm_scrv;      /* state-change rexmit count */

        /*
         * SSM state counters which track state at T0 (the time the last
         * state-change report's RV timer went to zero) and T1
         * (time of pending report, i.e. now).
         * Used for computing IGMPv3 state-change reports. Several refcounts
         * are maintained here to optimize for common use-cases.
         */
        struct inm_st {
                uint16_t        iss_fmode;      /* IGMP filter mode */
                uint16_t        iss_asm;        /* # of ASM listeners */
                uint16_t        iss_ex;         /* # of exclusive members */
                uint16_t        iss_in;         /* # of inclusive members */
                uint16_t        iss_rec;        /* # of recorded sources */
        }                       inm_st[2];      /* state at t0, t1 */
};

/*
 * Helper function to derive the filter mode on a source entry
 * from its internal counters. Predicates are:
 *  A source is only excluded if all listeners exclude it.
 *  A source is only included if no listeners exclude it,
 *  and at least one listener includes it.
 */
static __inline uint8_t
ims_get_mode(const struct in_multi *inm, const struct ip_msource *ims,
    uint8_t t)
{

        t = !!t;
        if (inm->inm_st[t].iss_ex > 0 &&
            inm->inm_st[t].iss_ex == ims->ims_st[t].ex)
                return (MCAST_EXCLUDE);
        else if (ims->ims_st[t].in > 0 && ims->ims_st[t].ex == 0)
                return (MCAST_INCLUDE);
        return (MCAST_UNDEFINED);
}

#ifdef SYSCTL_DECL
SYSCTL_DECL(_net_inet);
SYSCTL_DECL(_net_inet_ip);
SYSCTL_DECL(_net_inet_raw);
#endif

/*
 * Lock macros for IPv4 layer multicast address lists.  IPv4 lock goes
 * before link layer multicast locks in the lock order.  In most cases,
 * consumers of IN_*_MULTI() macros should acquire the locks before
 * calling them; users of the in_{add,del}multi() functions should not.
 */
extern struct mtx in_multi_list_mtx;
extern struct sx in_multi_sx;

#define IN_MULTI_LIST_LOCK()            mtx_lock(&in_multi_list_mtx)
#define IN_MULTI_LIST_UNLOCK()  mtx_unlock(&in_multi_list_mtx)
#define IN_MULTI_LIST_LOCK_ASSERT()     mtx_assert(&in_multi_list_mtx, MA_OWNED)
#define IN_MULTI_LIST_UNLOCK_ASSERT() mtx_assert(&in_multi_list_mtx, MA_NOTOWNED)

#define IN_MULTI_LOCK()         sx_xlock(&in_multi_sx)
#define IN_MULTI_UNLOCK()       sx_xunlock(&in_multi_sx)
#define IN_MULTI_LOCK_ASSERT()  sx_assert(&in_multi_sx, SA_XLOCKED)
#define IN_MULTI_UNLOCK_ASSERT() sx_assert(&in_multi_sx, SA_XUNLOCKED)

void inm_disconnect(struct in_multi *inm);

/*
 * Get the in_multi pointer from a ifmultiaddr.
 * Returns NULL if ifmultiaddr is no longer valid.
 */
static __inline struct in_multi *
inm_ifmultiaddr_get_inm(struct ifmultiaddr *ifma)
{

        NET_EPOCH_ASSERT();

        return ((ifma->ifma_addr->sa_family != AF_INET ||
            (ifma->ifma_flags & IFMA_F_ENQUEUED) == 0) ? NULL :
            ifma->ifma_protospec);
}

/* Acquire an in_multi record. */
static __inline void
inm_acquire_locked(struct in_multi *inm)
{

        IN_MULTI_LIST_LOCK_ASSERT();
        ++inm->inm_refcount;
}

static __inline void
inm_acquire(struct in_multi *inm)
{
        IN_MULTI_LIST_LOCK();
        inm_acquire_locked(inm);
        IN_MULTI_LIST_UNLOCK();
}

static __inline void
inm_rele_locked(struct in_multi_head *inmh, struct in_multi *inm)
{
        MPASS(inm->inm_refcount > 0);
        IN_MULTI_LIST_LOCK_ASSERT();

        if (--inm->inm_refcount == 0) {
                MPASS(inmh != NULL);
                inm_disconnect(inm);
                inm->inm_ifma->ifma_protospec = NULL;
                SLIST_INSERT_HEAD(inmh, inm, inm_nrele);
        }
}

/*
 * Return values for imo_multi_filter().
 */
#define MCAST_PASS              0       /* Pass */
#define MCAST_NOTGMEMBER        1       /* This host not a member of group */
#define MCAST_NOTSMEMBER        2       /* This host excluded source */
#define MCAST_MUTED             3       /* [deprecated] */

struct rib_head;
struct  ip_moptions;
struct ucred;

struct in_multi *inm_lookup_locked(struct ifnet *, const struct in_addr);
struct in_multi *inm_lookup(struct ifnet *, const struct in_addr);
int     imo_multi_filter(const struct ip_moptions *, const struct ifnet *,
            const struct sockaddr *, const struct sockaddr *);
void    inm_commit(struct in_multi *);
void    inm_clear_recorded(struct in_multi *);
void    inm_print(const struct in_multi *);
int     inm_record_source(struct in_multi *inm, const in_addr_t);
void    inm_release_deferred(struct in_multi *);
void    inm_release_list_deferred(struct in_multi_head *);
void    inm_release_wait(void *);
int     in_joingroup(struct ifnet *, const struct in_addr *,
            /*const*/ struct in_mfilter *, struct in_multi **);
int     in_joingroup_locked(struct ifnet *, const struct in_addr *,
            /*const*/ struct in_mfilter *, struct in_multi **);
int     in_leavegroup(struct in_multi *, /*const*/ struct in_mfilter *);
int     in_leavegroup_locked(struct in_multi *,
            /*const*/ struct in_mfilter *);
int     in_mask2len(struct in_addr *);
int     in_control(struct socket *, u_long, void *, struct ifnet *,
            struct thread *);
int     in_control_ioctl(u_long, void *, struct ifnet *,
            struct ucred *);
int     in_addprefix(struct in_ifaddr *);
int     in_scrubprefix(struct in_ifaddr *, u_int);
void    in_ifscrub_all(void);
void    ip_input(struct mbuf *);
void    ip_direct_input(struct mbuf *);
void    in_ifadown(struct ifaddr *ifa, int);
struct  mbuf    *ip_tryforward(struct mbuf *);
struct rib_head *in_inithead(uint32_t fibnum);
void    in_ifattach(void *, struct ifnet *);

#ifdef VIMAGE
void    in_detachhead(struct rib_head *rh);
#endif

#endif /* _KERNEL */

/* INET6 stuff */
#include <netinet6/in6_var.h>

#endif /* _NETINET_IN_VAR_H_ */