/*      $NetBSD: util.c,v 1.20 2020/10/11 21:32:37 roy Exp $    */

/*-
 * Copyright (c) 2008 David Young.  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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: util.c,v 1.20 2020/10/11 21:32:37 roy Exp $");
#endif /* not lint */

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <netdb.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <util.h>

#include <sys/param.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <ifaddrs.h>

#include <sys/ioctl.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <netinet/in.h>         /* XXX */

#include "env.h"
#include "extern.h"
#include "util.h"
#include "prog_ops.h"

int
getsock(int naf)
{
        static int oaf = -1, s;

        if (oaf == naf || (oaf != -1 && naf == AF_UNSPEC))
                return s;

        if (oaf != -1)
                prog_close(s);

        if (naf == AF_UNSPEC)
                naf = AF_INET;

        s = prog_socket(naf, SOCK_DGRAM, 0);
        if (s == -1)
                oaf = -1;
        else
                oaf = naf;
        return s;
}

const char *
get_string(const char *val, const char *sep, u_int8_t *buf, int *lenp,
    bool hexok)
{
        int len;
        bool hexstr;
        u_int8_t *p;

        len = *lenp;
        p = buf;
        hexstr = hexok && val[0] == '0' && tolower((u_char)val[1]) == 'x';
        if (hexstr)
                val += 2;
        for (;;) {
                if (*val == '\0')
                        break;
                if (sep != NULL && strchr(sep, *val) != NULL) {
                        val++;
                        break;
                }
                if (hexstr) {
                        if (!isxdigit((u_char)val[0]) ||
                            !isxdigit((u_char)val[1])) {
                                warnx("bad hexadecimal digits");
                                return NULL;
                        }
                }
                if (p >= buf + len) {
                        if (hexstr)
                                warnx("hexadecimal digits too long");
                        else
                                warnx("strings too long");
                        return NULL;
                }
                if (hexstr) {
#define tohex(x)        (isdigit(x) ? (x) - '0' : tolower(x) - 'a' + 10)
                        *p++ = (tohex((u_char)val[0]) << 4) |
                            tohex((u_char)val[1]);
#undef tohex
                        val += 2;
                } else
                        *p++ = *val++;
        }
        len = p - buf;
        if (len < *lenp)
                memset(p, 0, *lenp - len);
        *lenp = len;
        return val;
}

void
print_string(const u_int8_t *buf, int len)
{
        int i;
        bool hasspc;

        i = 0;
        hasspc = false;
        if (len < 2 || buf[0] != '0' || tolower(buf[1]) != 'x') {
                for (; i < len; i++) {
                        if (!isprint(buf[i]))
                                break;
                        if (isspace(buf[i]))
                                hasspc = true;
                }
        }
        if (i == len) {
                if (hasspc || len == 0)
                        printf("\"%.*s\"", len, buf);
                else
                        printf("%.*s", len, buf);
        } else {
                printf("0x");
                for (i = 0; i < len; i++)
                        printf("%02x", buf[i]);
        }
}

struct paddr_prefix *
prefixlen_to_mask(int af, int plen)
{
        union {
                struct sockaddr sa;
                struct sockaddr_in sin;
                struct sockaddr_in6 sin6;
        } u;
        struct paddr_prefix *pfx;
        size_t addrlen;
        uint8_t *addr;
        int nbit;

        memset(&u, 0, sizeof(u));

        switch (af) {
        case AF_INET:
                addrlen = sizeof(u.sin.sin_addr);
                addr = (uint8_t *)&u.sin.sin_addr;
                u.sa.sa_len = sizeof(u.sin);
                break;
        case AF_INET6:
                addrlen = sizeof(u.sin6.sin6_addr);
                addr = (uint8_t *)&u.sin6.sin6_addr;
                u.sa.sa_len = sizeof(u.sin6);
                break;
        default:
                errno = EINVAL;
                return NULL;
        }
        u.sa.sa_family = af;

        if (plen < 0 || (size_t)plen > addrlen * NBBY) {
                errno = EINVAL;
                return NULL;
        }

        if (plen == 0)
                plen = addrlen * NBBY;

        memset(addr, 0xff, (plen + NBBY - 1) / NBBY);

        nbit = plen % NBBY;
        if (nbit != 0)
                addr[plen / NBBY] &= ~((uint8_t)0xff >> nbit);
        pfx = malloc(offsetof(struct paddr_prefix, pfx_addr) + u.sa.sa_len);
        if (pfx == NULL)
                return NULL;
        pfx->pfx_len = plen;
        memcpy(&pfx->pfx_addr, &u.sa, u.sa.sa_len);

        return pfx;
}

int
direct_ioctl(prop_dictionary_t env, unsigned long cmd, void *data)
{
        const char *ifname;
        int s;

        if ((s = getsock(AF_UNSPEC)) == -1)
                err(EXIT_FAILURE, "getsock");

        if ((ifname = getifname(env)) == NULL)
                err(EXIT_FAILURE, "getifname");

        estrlcpy(data, ifname, IFNAMSIZ);

        return prog_ioctl(s, cmd, data);
}

int
indirect_ioctl(prop_dictionary_t env, unsigned long cmd, void *data)
{
        struct ifreq ifr;

        memset(&ifr, 0, sizeof(ifr));

        ifr.ifr_data = data;

        return direct_ioctl(env, cmd, &ifr);
}

void
print_link_addresses(prop_dictionary_t env, bool print_active_only)
{
        char hbuf[NI_MAXHOST];
        const char *ifname;
        int s;
        struct ifaddrs *ifa, *ifap;
        const struct sockaddr_dl *sdl;
        struct if_laddrreq iflr;

        if ((ifname = getifname(env)) == NULL)
                err(EXIT_FAILURE, "%s: getifname", __func__);

        if ((s = getsock(AF_LINK)) == -1)
                err(EXIT_FAILURE, "%s: getsock", __func__);

        if (getifaddrs(&ifap) == -1)
                err(EXIT_FAILURE, "%s: getifaddrs", __func__);

        memset(&iflr, 0, sizeof(iflr));

        strlcpy(iflr.iflr_name, ifname, sizeof(iflr.iflr_name));

        for (ifa = ifap; ifa != NULL; ifa = ifa->ifa_next) {
                if (strcmp(ifname, ifa->ifa_name) != 0)
                        continue;
                if (ifa->ifa_addr->sa_family != AF_LINK)
                        continue;

                sdl = satocsdl(ifa->ifa_addr);

                memcpy(&iflr.addr, ifa->ifa_addr, MIN(ifa->ifa_addr->sa_len,
                    sizeof(iflr.addr)));
                iflr.flags = IFLR_PREFIX;
                iflr.prefixlen = sdl->sdl_alen * NBBY;

                if (prog_ioctl(s, SIOCGLIFADDR, &iflr) == -1) {
                        warn("%s: ioctl SIOCGLIFADDR", __func__);
                        continue;
                }

                if (((iflr.flags & IFLR_ACTIVE) != 0) != print_active_only)
                        continue;

                if (getnameinfo(ifa->ifa_addr, ifa->ifa_addr->sa_len,
                        hbuf, sizeof(hbuf), NULL, 0,
                        Nflag ? 0 : NI_NUMERICHOST) == 0 &&
                    hbuf[0] != '\0') {
                        printf("\t%s %s\n",
                            print_active_only ? "address:" : "link", hbuf);
                }
        }
        freeifaddrs(ifap);
}

int16_t
ifa_get_preference(const char *ifname, const struct sockaddr *sa)
{
        struct if_addrprefreq ifap;
        int s;

        if ((s = getsock(sa->sa_family)) == -1) {
                if (errno == EPROTONOSUPPORT)
                        return 0;
                err(EXIT_FAILURE, "socket");
        }
        memset(&ifap, 0, sizeof(ifap));
        estrlcpy(ifap.ifap_name, ifname, sizeof(ifap.ifap_name));
        memcpy(&ifap.ifap_addr, sa, MIN(sizeof(ifap.ifap_addr), sa->sa_len));
        if (prog_ioctl(s, SIOCGIFADDRPREF, &ifap) == -1) {
                if (errno == EADDRNOTAVAIL || errno == EAFNOSUPPORT)
                        return 0;
                warn("SIOCGIFADDRPREF");
        }
        return ifap.ifap_preference;
}

void
ifa_print_preference(const char *ifname, const struct sockaddr *sa)
{
        int16_t preference;

        if (lflag)
                return;

        preference = ifa_get_preference(ifname, sa);
        printf(" preference %" PRId16, preference);
}

bool
ifa_any_preferences(const char *ifname, struct ifaddrs *ifap, int family)
{
        struct ifaddrs *ifa;

        /* Print address preference numbers if any address has a non-zero
         * preference assigned.
         */
        for (ifa = ifap; ifa != NULL; ifa = ifa->ifa_next) {
                if (strcmp(ifname, ifa->ifa_name) != 0)
                        continue;
                if (ifa->ifa_addr->sa_family != family)
                        continue;
                if (ifa_get_preference(ifa->ifa_name, ifa->ifa_addr) != 0)
                        return true;
        }
        return false;
}