/*-
 * Copyright (c) 2015-2016
 *      Alexander V. Chernikov <melifaro@FreeBSD.org>
 *
 * 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 _NET_ROUTE_VAR_H_
#define _NET_ROUTE_VAR_H_

#ifndef RNF_NORMAL
#include <net/radix.h>
#endif
#include <sys/ck.h>
#include <sys/epoch.h>
#include <netinet/in.h>         /* struct sockaddr_in */
#include <sys/counter.h>
#include <net/route/nhop.h>

struct nh_control;
/* Sets prefix-specific nexthop flags (NHF_DEFAULT, RTF/NHF_HOST, RTF_BROADCAST,..) */
typedef int rnh_set_nh_pfxflags_f_t(u_int fibnum, const struct sockaddr *addr,
        const struct sockaddr *mask, struct nhop_object *nh);
/* Fills in family-specific details that are not yet set up (mtu, nhop type, ..) */
typedef int rnh_augment_nh_f_t(u_int fibnum, struct nhop_object *nh);

struct rib_head {
        struct radix_head       head;
        rn_matchaddr_f_t        *rnh_matchaddr; /* longest match for sockaddr */
        rn_addaddr_f_t          *rnh_addaddr;   /* add based on sockaddr*/
        rn_deladdr_f_t          *rnh_deladdr;   /* remove based on sockaddr */
        rn_lookup_f_t           *rnh_lookup;    /* exact match for sockaddr */
        rn_walktree_t           *rnh_walktree;  /* traverse tree */
        rn_walktree_from_t      *rnh_walktree_from; /* traverse tree below a */
        rnh_set_nh_pfxflags_f_t *rnh_set_nh_pfxflags;   /* hook to alter record prior to insertion */
        rt_gen_t                rnh_gen;        /* datapath generation counter */
        int                     rnh_multipath;  /* multipath capable ? */
        struct radix_node       rnh_nodes[3];   /* empty tree for common case */
        struct rmlock           rib_lock;       /* config/data path lock */
        struct radix_mask_head  rmhead;         /* masks radix head */
        struct vnet             *rib_vnet;      /* vnet pointer */
        int                     rib_family;     /* AF of the rtable */
        u_int                   rib_fibnum;     /* fib number */
        struct callout          expire_callout; /* Callout for expiring dynamic routes */
        time_t                  next_expire;    /* Next expire run ts */
        uint32_t                rnh_prefixes;   /* Number of prefixes */
        rt_gen_t                rnh_gen_rib;    /* fib algo: rib generation counter */
        uint32_t                rib_dying:1;    /* rib is detaching */
        uint32_t                rib_algo_fixed:1;/* fixed algorithm */
        uint32_t                rib_algo_init:1;/* algo init done */
        struct nh_control       *nh_control;    /* nexthop subsystem data */
        rnh_augment_nh_f_t      *rnh_augment_nh;/* hook to alter nexthop prior to insertion */
        CK_STAILQ_HEAD(, rib_subscription)      rnh_subscribers;/* notification subscribers */
};

#define RIB_RLOCK_TRACKER       struct rm_priotracker _rib_tracker
#define RIB_LOCK_INIT(rh)       rm_init_flags(&(rh)->rib_lock, "rib head lock", RM_DUPOK)
#define RIB_LOCK_DESTROY(rh)    rm_destroy(&(rh)->rib_lock)
#define RIB_RLOCK(rh)           rm_rlock(&(rh)->rib_lock, &_rib_tracker)
#define RIB_RUNLOCK(rh)         rm_runlock(&(rh)->rib_lock, &_rib_tracker)
#define RIB_WLOCK(rh)           rm_wlock(&(rh)->rib_lock)
#define RIB_WUNLOCK(rh)         rm_wunlock(&(rh)->rib_lock)
#define RIB_LOCK_ASSERT(rh)     rm_assert(&(rh)->rib_lock, RA_LOCKED)
#define RIB_WLOCK_ASSERT(rh)    rm_assert(&(rh)->rib_lock, RA_WLOCKED)

/* Constants */
#define RIB_MAX_RETRIES 3
#define RT_MAXFIBS      UINT16_MAX
#define RIB_MAX_MPATH_WIDTH     64

/* Macro for verifying fields in af-specific 'struct route' structures */
#define CHK_STRUCT_FIELD_GENERIC(_s1, _f1, _s2, _f2)                    \
_Static_assert(sizeof(((_s1 *)0)->_f1) == sizeof(((_s2 *)0)->_f2),      \
                "Fields " #_f1 " and " #_f2 " size differs");           \
_Static_assert(__offsetof(_s1, _f1) == __offsetof(_s2, _f2),            \
                "Fields " #_f1 " and " #_f2 " offset differs");

#define _CHK_ROUTE_FIELD(_route_new, _field) \
        CHK_STRUCT_FIELD_GENERIC(struct route, _field, _route_new, _field)

#define CHK_STRUCT_ROUTE_FIELDS(_route_new)     \
        _CHK_ROUTE_FIELD(_route_new, ro_nh)     \
        _CHK_ROUTE_FIELD(_route_new, ro_lle)    \
        _CHK_ROUTE_FIELD(_route_new, ro_prepend)\
        _CHK_ROUTE_FIELD(_route_new, ro_plen)   \
        _CHK_ROUTE_FIELD(_route_new, ro_flags)  \
        _CHK_ROUTE_FIELD(_route_new, ro_mtu)    \
        _CHK_ROUTE_FIELD(_route_new, spare)

#define CHK_STRUCT_ROUTE_COMPAT(_ro_new, _dst_new)                              \
CHK_STRUCT_ROUTE_FIELDS(_ro_new);                                               \
_Static_assert(__offsetof(struct route, ro_dst) == __offsetof(_ro_new, _dst_new),\
                "ro_dst and " #_dst_new " are at different offset")

static inline void
rib_bump_gen(struct rib_head *rnh)
{
#ifdef FIB_ALGO
        rnh->rnh_gen_rib++;
#else
        rnh->rnh_gen++;
#endif
}

struct rib_head *rt_tables_get_rnh(uint32_t table, sa_family_t family);
int rt_getifa_fib(struct rt_addrinfo *info, u_int fibnum);
struct rib_cmd_info;

VNET_PCPUSTAT_DECLARE(struct rtstat, rtstat);
#define RTSTAT_ADD(name, val)   \
        VNET_PCPUSTAT_ADD(struct rtstat, rtstat, name, (val))
#define RTSTAT_INC(name)        RTSTAT_ADD(name, 1)

/*
 * Convert a 'struct radix_node *' to a 'struct rtentry *'.
 * The operation can be done safely (in this code) because a
 * 'struct rtentry' starts with two 'struct radix_node''s, the first
 * one representing leaf nodes in the routing tree, which is
 * what the code in radix.c passes us as a 'struct radix_node'.
 *
 * But because there are a lot of assumptions in this conversion,
 * do not cast explicitly, but always use the macro below.
 */
#define RNTORT(p)       ((struct rtentry *)(p))

struct rtentry {
        struct  radix_node rt_nodes[2]; /* tree glue, and other values */
        /*
         * XXX struct rtentry must begin with a struct radix_node (or two!)
         * because the code does some casts of a 'struct radix_node *'
         * to a 'struct rtentry *'
         */
#define rt_key(r)       (*((struct sockaddr **)(&(r)->rt_nodes->rn_key)))
#define rt_mask(r)      (*((struct sockaddr **)(&(r)->rt_nodes->rn_mask)))
#define rt_key_const(r)         (*((const struct sockaddr * const *)(&(r)->rt_nodes->rn_key)))
#define rt_mask_const(r)        (*((const struct sockaddr * const *)(&(r)->rt_nodes->rn_mask)))

        /*
         * 2 radix_node structurs above consists of 2x6 pointers, leaving
         * 4 pointers (32 bytes) of the second cache line on amd64.
         *
         */
        struct nhop_object      *rt_nhop;       /* nexthop data */
        union {
                /*
                 * Destination address storage.
                 * sizeof(struct sockaddr_in6) == 28, however
                 * the dataplane-relevant part (e.g. address) lies
                 * at offset 8..24, making the address not crossing
                 * cacheline boundary.
                 */
                struct sockaddr_in      rt_dst4;
                struct sockaddr_in6     rt_dst6;
                struct sockaddr         rt_dst;
                char                    rt_dstb[28];
        };

        int             rte_flags;      /* up/down?, host/net */
        u_long          rt_weight;      /* absolute weight */ 
        struct rtentry  *rt_chain;      /* pointer to next rtentry to delete */
        struct epoch_context    rt_epoch_ctx;   /* net epoch tracker */
};

/*
 * With the split between the routing entry and the nexthop,
 *  rt_flags has to be split between these 2 entries. As rtentry
 *  mostly contains prefix data and is thought to be generic enough
 *  so one can transparently change the nexthop pointer w/o requiring
 *  any other rtentry changes, most of rt_flags shifts to the particular nexthop.
 * /
 *
 * RTF_UP: rtentry, as an indication that it is linked.
 * RTF_HOST: rtentry, nhop. The latter indication is needed for the datapath
 * RTF_DYNAMIC: nhop, to make rtentry generic.
 * RTF_MODIFIED: nhop, to make rtentry generic. (legacy)
 * -- "native" path (nhop) properties:
 * RTF_GATEWAY, RTF_STATIC, RTF_PROTO1, RTF_PROTO2, RTF_PROTO3, RTF_FIXEDMTU,
 *  RTF_PINNED, RTF_REJECT, RTF_BLACKHOLE, RTF_BROADCAST
 */

/* rtentry rt flag mask */
#define RTE_RT_FLAG_MASK        (RTF_UP | RTF_HOST)

/* route_temporal.c */
void tmproutes_update(struct rib_head *rnh, struct rtentry *rt, struct nhop_object *nh);
void tmproutes_init(struct rib_head *rh);
void tmproutes_destroy(struct rib_head *rh);

/* route_ctl.c */
struct route_nhop_data;
int change_route(struct rib_head *rnh, struct rtentry *rt,
    struct route_nhop_data *rnd, struct rib_cmd_info *rc);
int change_route_conditional(struct rib_head *rnh, struct rtentry *rt,
    struct route_nhop_data *nhd_orig, struct route_nhop_data *nhd_new,
    struct rib_cmd_info *rc);
struct rtentry *lookup_prefix(struct rib_head *rnh,
    const struct rt_addrinfo *info, struct route_nhop_data *rnd);
struct rtentry *lookup_prefix_rt(struct rib_head *rnh, const struct rtentry *rt,
    struct route_nhop_data *rnd);
int rib_copy_route(struct rtentry *rt, const struct route_nhop_data *rnd_src,
    struct rib_head *rh_dst, struct rib_cmd_info *rc);

bool nhop_can_multipath(const struct nhop_object *nh);
bool match_nhop_gw(const struct nhop_object *nh, const struct sockaddr *gw);
int check_info_match_nhop(const struct rt_addrinfo *info,
    const struct rtentry *rt, const struct nhop_object *nh);
bool rib_can_4o6_nhop(void);

/* route_rtentry.c */
void vnet_rtzone_init(void);
void vnet_rtzone_destroy(void);
void rt_free(struct rtentry *rt);
void rt_free_immediate(struct rtentry *rt);
struct rtentry *rt_alloc(struct rib_head *rnh, const struct sockaddr *dst,
    struct sockaddr *netmask);

/* subscriptions */
void rib_init_subscriptions(struct rib_head *rnh);
void rib_destroy_subscriptions(struct rib_head *rnh);

/* route_ifaddrs.c */
void rib_copy_kernel_routes(struct rib_head *rh_src, struct rib_head *rh_dst);

/* Nexhops */
void nhops_init(void);
int nhops_init_rib(struct rib_head *rh);
void nhops_destroy_rib(struct rib_head *rh);
void nhop_ref_object(struct nhop_object *nh);
int nhop_try_ref_object(struct nhop_object *nh);
void nhop_ref_any(struct nhop_object *nh);
void nhop_free_any(struct nhop_object *nh);
struct nhop_object *nhop_get_nhop_internal(struct rib_head *rnh,
    struct nhop_object *nh, int *perror);

bool nhop_check_gateway(int upper_family, int neigh_family);

int nhop_create_from_info(struct rib_head *rnh, struct rt_addrinfo *info,
    struct nhop_object **nh_ret);
int nhop_create_from_nhop(struct rib_head *rnh, const struct nhop_object *nh_orig,
    struct rt_addrinfo *info, struct nhop_object **pnh_priv);

void nhops_update_ifmtu(struct rib_head *rh, struct ifnet *ifp, uint32_t mtu);
int nhops_dump_sysctl(struct rib_head *rh, struct sysctl_req *w);

/* MULTIPATH */
#define MPF_MULTIPATH   0x08    /* need to be consistent with NHF_MULTIPATH */

struct nhgrp_object {
        uint16_t                nhg_flags;      /* nexthop group flags */
        uint8_t                 nhg_size;       /* dataplain group size */
        uint8_t                 spare;
        struct nhop_object      *nhops[0];      /* nhops */
};

static inline struct nhop_object *
nhop_select(struct nhop_object *nh, uint32_t flowid)
{
        struct nhgrp_object *nhg;

        if (NH_IS_NHGRP(nh)) {
                nhg = (struct nhgrp_object *)nh;
                nh = nhg->nhops[flowid % nhg->nhg_size];
        }
        return (nh);
}


struct weightened_nhop;

/* mpath_ctl.c */
int add_route_mpath(struct rib_head *rnh, struct rt_addrinfo *info,
    struct rtentry *rt, struct route_nhop_data *rnd_add,
    struct route_nhop_data *rnd_orig, struct rib_cmd_info *rc);

/* nhgrp.c */
int nhgrp_ctl_init(struct nh_control *ctl);
void nhgrp_ctl_free(struct nh_control *ctl);
void nhgrp_ctl_unlink_all(struct nh_control *ctl);


/* nhgrp_ctl.c */
int nhgrp_dump_sysctl(struct rib_head *rh, struct sysctl_req *w);

int nhgrp_get_filtered_group(struct rib_head *rh, const struct rtentry *rt,
    const struct nhgrp_object *src, rib_filter_f_t flt_func, void *flt_data,
    struct route_nhop_data *rnd);
int nhgrp_get_addition_group(struct rib_head *rnh,
    struct route_nhop_data *rnd_orig, struct route_nhop_data *rnd_add,
    struct route_nhop_data *rnd_new);

void nhgrp_ref_object(struct nhgrp_object *nhg);
uint32_t nhgrp_get_idx(const struct nhgrp_object *nhg);
void nhgrp_free(struct nhgrp_object *nhg);

/* rtsock */
int rtsock_routemsg(int cmd, struct rtentry *rt, struct nhop_object *nh,
    int fibnum);
int rtsock_routemsg_info(int cmd, struct rt_addrinfo *info, int fibnum);
int rtsock_addrmsg(int cmd, struct ifaddr *ifa, int fibnum);


/* lookup_framework.c */
void fib_grow_rtables(uint32_t new_num_tables);
void fib_setup_family(int family, uint32_t num_tables);
void fib_destroy_rib(struct rib_head *rh);
void vnet_fib_init(void);
void vnet_fib_destroy(void);

/* Entropy data used for outbound hashing */
#define MPATH_ENTROPY_KEY_LEN   40
extern uint8_t mpath_entropy_key[MPATH_ENTROPY_KEY_LEN];

#endif