/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1983, 1988, 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.
 */

#include <sys/param.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <sys/time.h>

#include <net/ethernet.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <net/route.h>
#include <net/route/nhop.h>

#include <netinet/in.h>
#include <netgraph/ng_socket.h>

#include <arpa/inet.h>
#include <ifaddrs.h>
#include <libutil.h>
#include <netdb.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <sysexits.h>
#include <unistd.h>
#include <libxo/xo.h>
#include "netstat.h"
#include "common.h"

/* column widths; each followed by one space */
#define WID_IF_DEFAULT          (Wflag ? IFNAMSIZ : 12) /* width of netif column */
#ifndef INET6
#define WID_DST_DEFAULT(af)     18      /* width of destination column */
#define WID_GW_DEFAULT(af)      18      /* width of gateway column */
#else
#define WID_DST_DEFAULT(af) \
        ((af) == AF_INET6 ? (numeric_addr ? 33: 18) : 18)
#define WID_GW_DEFAULT(af) \
        ((af) == AF_INET6 ? (numeric_addr ? 29 : 18) : 18)
#endif /*INET6*/
static int wid_dst;
static int wid_gw;
static int wid_flags;
static int wid_pksent;
static int wid_mtu;
static int wid_if;
static int wid_nhidx;
static int wid_nhtype;
static int wid_refcnt;
static int wid_prepend;

static struct bits nh_bits[] = {
        { NHF_REJECT,   'R', "reject" },
        { NHF_BLACKHOLE,'B', "blackhole" },
        { NHF_REDIRECT, 'r', "redirect" },
        { NHF_GATEWAY,  'G', "gateway" },
        { NHF_DEFAULT,  'd', "default" },
        { NHF_BROADCAST,'b', "broadcast" },
        { 0 , 0, NULL }
};

static char *nh_types[] = {
        "empty", /* 0 */
        "v4/resolve", /* 1 */
        "v4/gw",
        "v6/resolve",
        "v6/gw"
};

struct nhop_entry {
        char    gw[64];
        char    ifname[IFNAMSIZ];
};

struct nhop_map {
        struct nhop_entry       *ptr;
        size_t                  size;
};
static struct nhop_map global_nhop_map;

static struct nhop_entry *nhop_get(struct nhop_map *map, uint32_t idx);


static struct ifmap_entry *ifmap;
static size_t ifmap_size;

static void
print_sockaddr_buf(char *buf, size_t bufsize, const struct sockaddr *sa)
{

        switch (sa->sa_family) {
        case AF_INET:
                inet_ntop(AF_INET, &((struct sockaddr_in *)sa)->sin_addr,
                    buf, bufsize);
                break;
        case AF_INET6:
                inet_ntop(AF_INET6, &((struct sockaddr_in6 *)sa)->sin6_addr,
                    buf, bufsize);
                break;
        default:
                snprintf(buf, bufsize, "unknown:%d", sa->sa_family);
                break;
        }
}

static int
print_addr(const char *name, const char *addr, int width)
{
        char buf[128];
        int protrusion;

        if (width < 0) {
                snprintf(buf, sizeof(buf), "{:%s/%%s} ", name);
                xo_emit(buf, addr);
                protrusion = 0;
        } else {
                if (Wflag != 0 || numeric_addr) {
                        snprintf(buf, sizeof(buf), "{[:%d}{:%s/%%s}{]:} ",
                            -width, name);
                        xo_emit(buf, addr);
                        protrusion = strlen(addr) - width;
                        if (protrusion < 0)
                                protrusion = 0;
                } else {
                        snprintf(buf, sizeof(buf), "{[:%d}{:%s/%%-.*s}{]:} ",
                            -width, name);
                        xo_emit(buf, width, addr);
                        protrusion = 0;
                }
        }
        return (protrusion);
}


static void
print_nhop_header(int af1 __unused)
{

        if (Wflag) {
                xo_emit("{T:/%-*.*s} {T:/%-*.*s} {T:/%-*.*s} {T:/%-*.*s} {T:/%*.*s} "
                    "{T:/%*.*s} {T:/%-*.*s} {T:/%*.*s} {T:/%*.*s} {T:/%*.*s} {T:/%*s}\n",
                        wid_nhidx,      wid_nhidx,      "Idx",
                        wid_nhtype,     wid_nhtype,     "Type",
                        wid_dst,        wid_dst,        "IFA",
                        wid_gw,         wid_gw,         "Gateway",
                        wid_flags,      wid_flags,      "Flags",
                        wid_pksent,     wid_pksent,     "Use",
                        wid_mtu,        wid_mtu,        "Mtu",
                        wid_if,         wid_if,         "Netif",
                        wid_if,         wid_if,         "Addrif",
                        wid_refcnt,     wid_refcnt,     "Refcnt",
                        wid_prepend,                    "Prepend");
        } else {
                xo_emit("{T:/%-*.*s} {T:/%-*.*s} {T:/%-*.*s} {T:/%-*.*s} {T:/%*.*s} "
                    " {T:/%*s}\n",
                        wid_nhidx,      wid_nhidx,      "Idx",
                        wid_dst,        wid_dst,        "IFA",
                        wid_gw,         wid_gw,         "Gateway",
                        wid_flags,      wid_flags,      "Flags",
                        wid_if,         wid_if,         "Netif",
                        wid_prepend,                    "Refcnt");
        }
}

void
nhop_map_update(struct nhop_map *map, uint32_t idx, char *gw, char *ifname)
{
        if (idx >= map->size) {
                uint32_t new_size;
                size_t sz;
                if (map->size  == 0)
                        new_size = 32;
                else
                        new_size = map->size * 2;
                if (new_size <= idx)
                        new_size = roundup2(idx + 1, 32);

                sz = new_size * (sizeof(struct nhop_entry));
                if ((map->ptr = realloc(map->ptr, sz)) == NULL)
                        xo_errx(EX_OSERR, "realloc(%zu) failed", sz);

                memset(&map->ptr[map->size], 0, (new_size - map->size) * sizeof(struct nhop_entry));
                map->size = new_size;
        }

        strlcpy(map->ptr[idx].ifname, ifname, sizeof(map->ptr[idx].ifname));
        strlcpy(map->ptr[idx].gw, gw, sizeof(map->ptr[idx].gw));
}

static struct nhop_entry *
nhop_get(struct nhop_map *map, uint32_t idx)
{

        if (idx >= map->size)
                return (NULL);
        if (*map->ptr[idx].ifname == '\0')
                return (NULL);
        return &map->ptr[idx];
}

static void
print_nhop_entry_sysctl(const char *name, struct rt_msghdr *rtm, struct nhop_external *nh)
{
        char buffer[128];
        char iface_name[128];
        int protrusion;
        char gw_addr[64];
        struct nhop_addrs *na;
        struct sockaddr *sa_gw, *sa_ifa;

        xo_open_instance(name);

        snprintf(buffer, sizeof(buffer), "{[:-%d}{:index/%%lu}{]:} ", wid_nhidx);
        //xo_emit("{t:index/%-lu} ", wid_nhidx, nh->nh_idx);
        xo_emit(buffer, nh->nh_idx);

        if (Wflag) {
                char *cp = nh_types[nh->nh_type];
                xo_emit("{t:type_str/%*s} ", wid_nhtype, cp);
        }
        memset(iface_name, 0, sizeof(iface_name));
        if (nh->ifindex < (uint32_t)ifmap_size) {
                strlcpy(iface_name, ifmap[nh->ifindex].ifname,
                    sizeof(iface_name));
                if (*iface_name == '\0')
                        strlcpy(iface_name, "---", sizeof(iface_name));
        }

        na = (struct nhop_addrs *)((char *)nh + nh->nh_len);
        //inet_ntop(nh->nh_family, &nh->nh_src, src_addr, sizeof(src_addr));
        //protrusion = p_addr("ifa", src_addr, wid_dst);
        sa_gw = (struct sockaddr *)((char *)na + na->gw_sa_off);
        sa_ifa = (struct sockaddr *)((char *)na + na->src_sa_off);
        protrusion = p_sockaddr("ifa", sa_ifa, NULL, RTF_HOST, wid_dst);

        if (nh->nh_flags & NHF_GATEWAY) {
                const char *cp;
                cp = fmt_sockaddr(sa_gw, NULL, RTF_HOST);
                strlcpy(gw_addr, cp, sizeof(gw_addr));
        } else
                snprintf(gw_addr, sizeof(gw_addr), "%s/resolve", iface_name);
        protrusion = print_addr("gateway", gw_addr, wid_dst - protrusion);

        nhop_map_update(&global_nhop_map, nh->nh_idx, gw_addr, iface_name);

        snprintf(buffer, sizeof(buffer), "{[:-%d}{:flags/%%s}{]:} ",
            wid_flags - protrusion);

        //p_nhflags(nh->nh_flags, buffer);
        print_flags_generic(rtm->rtm_flags, rt_bits, buffer, "rt_flags_pretty");

        if (Wflag) {
                xo_emit("{t:use/%*lu} ", wid_pksent, nh->nh_pksent);
                xo_emit("{t:mtu/%*lu} ", wid_mtu, nh->nh_mtu);
        }
        //printf("IDX: %d IFACE: %s FAMILY: %d TYPE: %d FLAGS: %X GW \n");

        if (Wflag)
                xo_emit("{t:interface-name/%*s}", wid_if, iface_name);
        else
                xo_emit("{t:interface-name/%*.*s}", wid_if, wid_if, iface_name);

        memset(iface_name, 0, sizeof(iface_name));
        if (nh->aifindex < (uint32_t)ifmap_size && nh->ifindex != nh->aifindex) {
                strlcpy(iface_name, ifmap[nh->aifindex].ifname,
                    sizeof(iface_name));
                if (*iface_name == '\0')
                        strlcpy(iface_name, "---", sizeof(iface_name));
        }
        if (Wflag)
                xo_emit("{t:address-interface-name/%*s}", wid_if, iface_name);

        xo_emit("{t:refcount/%*lu} ", wid_refcnt, nh->nh_refcount);
        if (Wflag && nh->prepend_len) {
                int max_bytes = MIN(nh->prepend_len, sizeof(buffer) / 2 - 1);
                for (int i = 0; i < max_bytes; i++)
                        snprintf(&buffer[i * 2], 3, "%02X", nh->nh_prepend[i]);
                xo_emit(" {:nhop-prepend/%*s}", wid_prepend, buffer);
        }

        xo_emit("\n");
        xo_close_instance(name);
}

static int
cmp_nh_idx(const void *_a, const void *_b)
{
        const struct nhops_map *a, *b;

        a = _a;
        b = _b;

        if (a->idx > b->idx)
                return (1);
        else if (a->idx < b->idx)
                return (-1);
        return (0);
}

void
dump_nhops_sysctl(int fibnum, int af, struct nhops_dump *nd)
{
        size_t needed;
        int mib[7];
        char *buf, *next, *lim;
        struct rt_msghdr *rtm;
        struct nhop_external *nh;
        struct nhops_map *nh_map;
        size_t nh_count, nh_size;

        mib[0] = CTL_NET;
        mib[1] = PF_ROUTE;
        mib[2] = 0;
        mib[3] = af;
        mib[4] = NET_RT_NHOP;
        mib[5] = 0;
        mib[6] = fibnum;
        if (sysctl(mib, nitems(mib), NULL, &needed, NULL, 0) < 0)
                xo_err(EX_OSERR, "sysctl: net.route.0.%d.nhdump.%d estimate", af,
                    fibnum);
        if ((buf = malloc(needed)) == NULL)
                xo_errx(EX_OSERR, "malloc(%lu)", (unsigned long)needed);
        if (sysctl(mib, nitems(mib), buf, &needed, NULL, 0) < 0)
                xo_err(EX_OSERR, "sysctl: net.route.0.%d.nhdump.%d", af, fibnum);
        lim  = buf + needed;

        /*
         * nexhops are received unsorted. Collect everything first, sort and then display
         * sorted.
         */
        nh_count = 0;
        nh_size = 16;
        nh_map = calloc(nh_size, sizeof(struct nhops_map));
        for (next = buf; next < lim; next += rtm->rtm_msglen) {
                rtm = (struct rt_msghdr *)next;
                if (rtm->rtm_version != RTM_VERSION)
                        continue;

                if (nh_count >= nh_size) {
                        nh_size *= 2;
                        nh_map = realloc(nh_map, nh_size * sizeof(struct nhops_map));
                }

                nh = (struct nhop_external *)(rtm + 1); 
                nh_map[nh_count].idx = nh->nh_idx;
                nh_map[nh_count].rtm = rtm;
                nh_count++;
        }

        if (nh_count > 0)
                qsort(nh_map, nh_count, sizeof(struct nhops_map), cmp_nh_idx);
        nd->nh_buf = buf;
        nd->nh_count = nh_count;
        nd->nh_map = nh_map;
}

static void
print_nhops_sysctl(int fibnum, int af)
{
        struct nhops_dump nd;
        struct nhop_external *nh;
        int fam;
        struct rt_msghdr *rtm;

        dump_nhops_sysctl(fibnum, af, &nd);

        xo_open_container("nhop-table");
        xo_open_list("rt-family");
        if (nd.nh_count > 0) {
                nh = (struct nhop_external *)(nd.nh_map[0].rtm + 1);
                fam = nh->nh_family;

                wid_dst = WID_GW_DEFAULT(fam);
                wid_gw = WID_GW_DEFAULT(fam);
                wid_nhidx = 5;
                wid_nhtype = 12;
                wid_refcnt = 6;
                wid_flags = 6;
                wid_pksent = 8;
                wid_mtu = 6;
                wid_if = WID_IF_DEFAULT;
                xo_open_instance("rt-family");
                pr_family(fam);
                xo_open_list("nh-entry");

                print_nhop_header(fam);

                for (size_t i = 0; i < nd.nh_count; i++) {
                        rtm = nd.nh_map[i].rtm;
                        nh = (struct nhop_external *)(rtm + 1);
                        print_nhop_entry_sysctl("nh-entry", rtm, nh);
                }

                xo_close_list("nh-entry");
                xo_close_instance("rt-family");
        }
        xo_close_list("rt-family");
        xo_close_container("nhop-table");
        free(nd.nh_buf);
}

static void
p_nhflags(int f, const char *format)
{
        struct bits *p;
        char *pretty_name = "nh_flags_pretty";

        xo_emit(format, fmt_flags(nh_bits, f));

        xo_open_list(pretty_name);
        for (p = nh_bits; p->b_mask; p++)
                if (p->b_mask & f)
                        xo_emit("{le:nh_flags_pretty/%s}", p->b_name);
        xo_close_list(pretty_name);
}

void
nhops_print(int fibnum, int af)
{
        size_t intsize;
        int numfibs;

        intsize = sizeof(int);
        if (fibnum == -1 &&
            sysctlbyname("net.my_fibnum", &fibnum, &intsize, NULL, 0) == -1)
                fibnum = 0;
        if (sysctlbyname("net.fibs", &numfibs, &intsize, NULL, 0) == -1)
                numfibs = 1;
        if (fibnum < 0 || fibnum > numfibs - 1)
                xo_errx(EX_USAGE, "%d: invalid fib", fibnum);

        ifmap = prepare_ifmap(&ifmap_size);

        xo_open_container("route-nhop-information");
        xo_emit("{T:Nexthop data}");
        if (fibnum)
                xo_emit(" ({L:fib}: {:fib/%d})", fibnum);
        xo_emit("\n");
        print_nhops_sysctl(fibnum, af);
        xo_close_container("route-nhop-information");
}