/*-
 * 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 <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"
#include "nl_defs.h"

/*
 * Definitions for showing gateway flags.
 */
struct bits rt_bits[] = {
        { RTF_UP,       'U', "up" },
        { RTF_GATEWAY,  'G', "gateway" },
        { RTF_HOST,     'H', "host" },
        { RTF_REJECT,   'R', "reject" },
        { RTF_DYNAMIC,  'D', "dynamic" },
        { RTF_MODIFIED, 'M', "modified" },
        { RTF_DONE,     'd', "done" }, /* Completed -- for routing msgs only */
        { RTF_XRESOLVE, 'X', "xresolve" },
        { RTF_STATIC,   'S', "static" },
        { RTF_PROTO1,   '1', "proto1" },
        { RTF_PROTO2,   '2', "proto2" },
        { RTF_PROTO3,   '3', "proto3" },
        { RTF_BLACKHOLE,'B', "blackhole" },
        { RTF_BROADCAST,'b', "broadcast" },
#ifdef RTF_LLINFO
        { RTF_LLINFO,   'L', "llinfo" },
#endif
        { 0 , 0, NULL }
};

#ifdef WITHOUT_NETLINK
static struct ifmap_entry *ifmap;
static size_t ifmap_size;
#endif
static struct timespec uptime;

static const char *netname4(in_addr_t, in_addr_t);
#ifdef INET6
static const char *netname6(struct sockaddr_in6 *, struct sockaddr_in6 *);
#endif
#ifdef WITHOUT_NETLINK
static void p_rtable_sysctl(int, int);
static void p_rtentry_sysctl(const char *name, struct rt_msghdr *);
#endif
static void domask(char *, size_t, u_long);

const uint32_t rt_default_weight = RT_DEFAULT_WEIGHT;

/*
 * Print routing tables.
 */
void
routepr(int fibnum, int af)
{
        size_t intsize;
        int numfibs;

        if (live == 0)
                return;

        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);
        /*
         * Since kernel & userland use different timebase
         * (time_uptime vs time_second) and we are reading kernel memory
         * directly we should do rt_expire --> expire_time conversion.
         */
        if (clock_gettime(CLOCK_UPTIME, &uptime) < 0)
                xo_err(EX_OSERR, "clock_gettime() failed");

        xo_open_container("route-information");
        xo_emit("{T:Routing tables}");
        if (fibnum)
                xo_emit(" ({L:fib}: {:fib/%d})", fibnum);
        xo_emit("\n");
#ifdef WITHOUT_NETLINK
        p_rtable_sysctl(fibnum, af);
#else
        p_rtable_netlink(fibnum, af);
#endif
        xo_close_container("route-information");
}


/*
 * Print address family header before a section of the routing table.
 */
void
pr_family(int af1)
{
        const char *afname;

        switch (af1) {
        case AF_INET:
                afname = "Internet";
                break;
#ifdef INET6
        case AF_INET6:
                afname = "Internet6";
                break;
#endif /*INET6*/
        case AF_ISO:
                afname = "ISO";
                break;
        case AF_CCITT:
                afname = "X.25";
                break;
        case AF_NETGRAPH:
                afname = "Netgraph";
                break;
        default:
                afname = NULL;
                break;
        }
        if (afname)
                xo_emit("\n{k:address-family/%s}:\n", afname);
        else
                xo_emit("\n{L:Protocol Family} {k:address-family/%d}:\n", af1);
}

/* 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*/

struct _wid wid;

/*
 * Print header for routing table columns.
 */
void
pr_rthdr(int af1 __unused)
{

        if (Wflag) {
                xo_emit("{T:/%-*.*s} {T:/%-*.*s} {T:/%-*.*s} {T:/%*.*s} "
                    "{T:/%*.*s} {T:/%*.*s} {T:/%*s}\n",
                        wid.dst,        wid.dst,        "Destination",
                        wid.gw,         wid.gw,         "Gateway",
                        wid.flags,      wid.flags,      "Flags",
                        wid.mtu,        wid.mtu,        "Nhop#",
                        wid.mtu,        wid.mtu,        "Mtu",
                        wid.iface,      wid.iface,      "Netif",
                        wid.expire,                     "Expire");
        } else {
                xo_emit("{T:/%-*.*s} {T:/%-*.*s} {T:/%-*.*s} {T:/%*.*s} "
                    "{T:/%*s}\n",
                        wid.dst,        wid.dst,        "Destination",
                        wid.gw,         wid.gw,         "Gateway",
                        wid.flags,      wid.flags,      "Flags",
                        wid.iface,      wid.iface,      "Netif",
                        wid.expire,                     "Expire");
        }
}

void
set_wid(int fam)
{
        wid.dst = WID_DST_DEFAULT(fam);
        wid.gw = WID_GW_DEFAULT(fam);
        wid.flags = 6;
        wid.pksent = 8;
        wid.mtu = 6;
        wid.iface = WID_IF_DEFAULT;
        wid.expire = 6;
}

#ifdef WITHOUT_NETLINK
static void
p_rtable_sysctl(int fibnum, int af)
{
        size_t needed;
        int mib[7];
        char *buf, *next, *lim;
        struct rt_msghdr *rtm;
        struct sockaddr *sa;
        int fam = AF_UNSPEC;
        int need_table_close = false;

        ifmap = prepare_ifmap(&ifmap_size);

        mib[0] = CTL_NET;
        mib[1] = PF_ROUTE;
        mib[2] = 0;
        mib[3] = af;
        mib[4] = NET_RT_DUMP;
        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.dump.%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.dump.%d", af, fibnum);
        lim  = buf + needed;
        xo_open_container("route-table");
        xo_open_list("rt-family");
        for (next = buf; next < lim; next += rtm->rtm_msglen) {
                rtm = (struct rt_msghdr *)next;
                if (rtm->rtm_version != RTM_VERSION)
                        continue;
                /*
                 * Peek inside header to determine AF
                 */
                sa = (struct sockaddr *)(rtm + 1);
                /* Only print family first time. */
                if (fam != sa->sa_family) {
                        if (need_table_close) {
                                xo_close_list("rt-entry");
                                xo_close_instance("rt-family");
                        }
                        need_table_close = true;
                        fam = sa->sa_family;
                        set_wid(fam);
                        xo_open_instance("rt-family");
                        pr_family(fam);
                        xo_open_list("rt-entry");

                        pr_rthdr(fam);
                }
                p_rtentry_sysctl("rt-entry", rtm);
        }
        if (need_table_close) {
                xo_close_list("rt-entry");
                xo_close_instance("rt-family");
        }
        xo_close_list("rt-family");
        xo_close_container("route-table");
        free(buf);
}

static void
p_rtentry_sysctl(const char *name, struct rt_msghdr *rtm)
{
        struct sockaddr *sa, *addr[RTAX_MAX];
        char buffer[128];
        char prettyname[128];
        int i, protrusion;

        xo_open_instance(name);
        sa = (struct sockaddr *)(rtm + 1);
        for (i = 0; i < RTAX_MAX; i++) {
                if (rtm->rtm_addrs & (1 << i)) {
                        addr[i] = sa;
                        sa = (struct sockaddr *)((char *)sa + SA_SIZE(sa));
                }
        }

        protrusion = p_sockaddr("destination", addr[RTAX_DST],
            addr[RTAX_NETMASK],
            rtm->rtm_flags, wid.dst);
        protrusion = p_sockaddr("gateway", addr[RTAX_GATEWAY], NULL, RTF_HOST,
            wid.gw - protrusion);
        snprintf(buffer, sizeof(buffer), "{[:-%d}{:flags/%%s}{]:} ",
            wid.flags - protrusion);
        p_flags(rtm->rtm_flags, buffer);
        /* Output path weight as non-visual property */
        xo_emit("{e:weight/%u}", rtm->rtm_rmx.rmx_weight);
        if (Wflag) {
                /* XXX: use=0? */
                xo_emit("{t:nhop/%*lu} ", wid.mtu, rtm->rtm_rmx.rmx_nhidx);

                if (rtm->rtm_rmx.rmx_mtu != 0)
                        xo_emit("{t:mtu/%*lu} ", wid.mtu, rtm->rtm_rmx.rmx_mtu);
                else
                        xo_emit("{P:/%*s} ", wid.mtu, "");
        }

        memset(prettyname, 0, sizeof(prettyname));
        if (rtm->rtm_index < ifmap_size) {
                strlcpy(prettyname, ifmap[rtm->rtm_index].ifname,
                    sizeof(prettyname));
                if (*prettyname == '\0')
                        strlcpy(prettyname, "---", sizeof(prettyname));
        }

        if (Wflag)
                xo_emit("{t:interface-name/%*s}", wid.iface, prettyname);
        else
                xo_emit("{t:interface-name/%*.*s}", wid.iface, wid.iface,
                    prettyname);
        if (rtm->rtm_rmx.rmx_expire) {
                time_t expire_time;

                if ((expire_time = rtm->rtm_rmx.rmx_expire - uptime.tv_sec) > 0)
                        xo_emit(" {:expire-time/%*d}", wid.expire,
                            (int)expire_time);
        }

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

int
p_sockaddr(const char *name, struct sockaddr *sa, struct sockaddr *mask,
    int flags, int width)
{
        const char *cp;
        char buf[128];
        int protrusion;

        cp = fmt_sockaddr(sa, mask, flags);

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

const char *
fmt_sockaddr(struct sockaddr *sa, struct sockaddr *mask, int flags)
{
        static char buf[128];
        const char *cp;

        if (sa == NULL)
                return ("null");

        switch(sa->sa_family) {
#ifdef INET6
        case AF_INET6:
                /*
                 * The sa6->sin6_scope_id must be filled here because
                 * this sockaddr is extracted from kmem(4) directly
                 * and has KAME-specific embedded scope id in
                 * sa6->sin6_addr.s6_addr[2].
                 */
                in6_fillscopeid(satosin6(sa));
                /* FALLTHROUGH */
#endif /*INET6*/
        case AF_INET:
                if (flags & RTF_HOST)
                        cp = routename(sa, numeric_addr);
                else if (mask)
                        cp = netname(sa, mask);
                else
                        cp = netname(sa, NULL);
                break;
        case AF_NETGRAPH:
            {
                strlcpy(buf, ((struct sockaddr_ng *)sa)->sg_data,
                    sizeof(buf));
                cp = buf;
                break;
            }
        case AF_LINK:
            {
#if 0
                struct sockaddr_dl *sdl = (struct sockaddr_dl *)sa;

                /* Interface route. */
                if (sdl->sdl_nlen)
                        cp = sdl->sdl_data;
                else
#endif
                        cp = routename(sa, 1);
                break;
            }
        default:
            {
                u_char *s = (u_char *)sa->sa_data, *slim;
                char *cq, *cqlim;

                cq = buf;
                slim =  sa->sa_len + (u_char *) sa;
                cqlim = cq + sizeof(buf) - sizeof(" ffff");
                snprintf(cq, sizeof(buf), "(%d)", sa->sa_family);
                cq += strlen(cq);
                while (s < slim && cq < cqlim) {
                        snprintf(cq, sizeof(" ff"), " %02x", *s++);
                        cq += strlen(cq);
                        if (s < slim) {
                            snprintf(cq, sizeof("ff"), "%02x", *s++);
                            cq += strlen(cq);
                        }
                }
                cp = buf;
            }
        }

        return (cp);
}

void
p_flags(int f, const char *format)
{

        print_flags_generic(f, rt_bits, format, "flags_pretty");
}


char *
routename(struct sockaddr *sa, int flags)
{
        static char line[NI_MAXHOST];
        int error, f;

        f = (flags) ? NI_NUMERICHOST : 0;
        error = getnameinfo(sa, sa->sa_len, line, sizeof(line),
            NULL, 0, f);
        if (error) {
                const void *src;
                switch (sa->sa_family) {
#ifdef INET
                case AF_INET:
                        src = &satosin(sa)->sin_addr;
                        break;
#endif /* INET */
#ifdef INET6
                case AF_INET6:
                        src = &satosin6(sa)->sin6_addr;
                        break;
#endif /* INET6 */
                default:
                        return(line);
                }
                inet_ntop(sa->sa_family, src, line, sizeof(line) - 1);
                return (line);
        }
        trimdomain(line, strlen(line));

        return (line);
}

#define NSHIFT(m) (                                                     \
        (m) == IN_CLASSA_NET ? IN_CLASSA_NSHIFT :                       \
        (m) == IN_CLASSB_NET ? IN_CLASSB_NSHIFT :                       \
        (m) == IN_CLASSC_NET ? IN_CLASSC_NSHIFT :                       \
        0)

static void
domask(char *dst, size_t buflen, u_long mask)
{
        int b, i;

        if (mask == 0) {
                *dst = '\0';
                return;
        }
        i = 0;
        for (b = 0; b < 32; b++)
                if (mask & (1 << b)) {
                        int bb;

                        i = b;
                        for (bb = b+1; bb < 32; bb++)
                                if (!(mask & (1 << bb))) {
                                        i = -1; /* noncontig */
                                        break;
                                }
                        break;
                }
        if (i == -1)
                snprintf(dst, buflen, "&0x%lx", mask);
        else
                snprintf(dst, buflen, "/%d", 32-i);
}

/*
 * Return the name of the network whose address is given.
 */
const char *
netname(struct sockaddr *sa, struct sockaddr *mask)
{
        switch (sa->sa_family) {
        case AF_INET:
                if (mask != NULL)
                        return (netname4(satosin(sa)->sin_addr.s_addr,
                            satosin(mask)->sin_addr.s_addr));
                else
                        return (netname4(satosin(sa)->sin_addr.s_addr,
                            INADDR_ANY));
                break;
#ifdef INET6
        case AF_INET6:
                return (netname6(satosin6(sa), satosin6(mask)));
#endif /* INET6 */
        default:
                return (NULL);
        }
}

static const char *
netname4(in_addr_t in, in_addr_t mask)
{
        char *cp = 0;
        static char line[MAXHOSTNAMELEN + sizeof("&0xffffffff")];
        char nline[INET_ADDRSTRLEN];
        struct netent *np = 0;
        in_addr_t i;

        if (numeric_addr < 2 && in == INADDR_ANY && mask == 0) {
                strlcpy(line, "default", sizeof(line));
                return (line);
        }

        /* It is ok to supply host address. */
        in &= mask;

        i = ntohl(in);
        if (!numeric_addr && i) {
                np = getnetbyaddr(i >> NSHIFT(ntohl(mask)), AF_INET);
                if (np != NULL) {
                        cp = np->n_name;
                        trimdomain(cp, strlen(cp));
                }
        }
        if (cp != NULL)
                strlcpy(line, cp, sizeof(line));
        else {
                inet_ntop(AF_INET, &in, nline, sizeof(nline));
                strlcpy(line, nline, sizeof(line));
                domask(line + strlen(line), sizeof(line) - strlen(line), ntohl(mask));
        }

        return (line);
}

#undef NSHIFT

#ifdef INET6
void
in6_fillscopeid(struct sockaddr_in6 *sa6)
{
#if defined(__KAME__)
        /*
         * XXX: This is a special workaround for KAME kernels.
         * sin6_scope_id field of SA should be set in the future.
         */
        if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr) ||
            IN6_IS_ADDR_MC_NODELOCAL(&sa6->sin6_addr) ||
            IN6_IS_ADDR_MC_LINKLOCAL(&sa6->sin6_addr)) {
                if (sa6->sin6_scope_id == 0)
                        sa6->sin6_scope_id =
                            ntohs(*(u_int16_t *)&sa6->sin6_addr.s6_addr[2]);
                sa6->sin6_addr.s6_addr[2] = sa6->sin6_addr.s6_addr[3] = 0;
        }
#endif
}

/* Mask to length table.  To check an invalid value, (length + 1) is used. */
static const u_char masktolen[256] = {
        [0xff] = 8 + 1,
        [0xfe] = 7 + 1,
        [0xfc] = 6 + 1,
        [0xf8] = 5 + 1,
        [0xf0] = 4 + 1,
        [0xe0] = 3 + 1,
        [0xc0] = 2 + 1,
        [0x80] = 1 + 1,
        [0x00] = 0 + 1,
};

static const char *
netname6(struct sockaddr_in6 *sa6, struct sockaddr_in6 *mask)
{
        static char line[NI_MAXHOST + sizeof("/xxx") - 1];
        struct sockaddr_in6 addr;
        char nline[NI_MAXHOST];
        char maskbuf[sizeof("/xxx")];
        u_char *p, *lim;
        u_char masklen;
        int i;
        bool illegal = false;

        if (mask) {
                p = (u_char *)&mask->sin6_addr;
                for (masklen = 0, lim = p + 16; p < lim; p++) {
                        if (masktolen[*p] > 0) {
                                /* -1 is required. */
                                masklen += (masktolen[*p] - 1);
                        } else
                                illegal = true;
                }
                if (illegal)
                        xo_error("illegal prefixlen\n");

                memcpy(&addr, sa6, sizeof(addr));
                for (i = 0; i < 16; ++i)
                        addr.sin6_addr.s6_addr[i] &=
                            mask->sin6_addr.s6_addr[i];
                sa6 = &addr;
        }
        else
                masklen = 128;

        if (numeric_addr < 2 && masklen == 0 &&
            IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr))
                return("default");

        getnameinfo((struct sockaddr *)sa6, sa6->sin6_len, nline, sizeof(nline),
            NULL, 0, NI_NUMERICHOST);
        if (numeric_addr)
                strlcpy(line, nline, sizeof(line));
        else
                getnameinfo((struct sockaddr *)sa6, sa6->sin6_len, line,
                    sizeof(line), NULL, 0, 0);
        if (numeric_addr || strcmp(line, nline) == 0) {
                snprintf(maskbuf, sizeof(maskbuf), "/%d", masklen);
                strlcat(line, maskbuf, sizeof(line));
        }

        return (line);
}
#endif /*INET6*/

/*
 * Print routing statistics
 */
void
rt_stats(void)
{
        struct rtstat rtstat;

        if (fetch_stats("net.route.stats", nl[N_RTSTAT].n_value, &rtstat,
            sizeof(rtstat), kread_counters) != 0)
                return;

        xo_emit("{T:routing}:\n");

#define p(f, m) if (rtstat.f || sflag <= 1) \
        xo_emit(m, rtstat.f, plural(rtstat.f))

        p(rts_badredirect, "\t{:bad-redirects/%ju} "
            "{N:/bad routing redirect%s}\n");
        p(rts_dynamic, "\t{:dynamically-created/%ju} "
            "{N:/dynamically created route%s}\n");
        p(rts_newgateway, "\t{:new-gateways/%ju} "
            "{N:/new gateway%s due to redirects}\n");
        p(rts_unreach, "\t{:unreachable-destination/%ju} "
            "{N:/destination%s found unreachable}\n");
        p(rts_wildcard, "\t{:wildcard-uses/%ju} "
            "{N:/use%s of a wildcard route}\n");
#undef p
}