/*      $KAME: ip6addrctl.c,v 1.3 2003/12/16 08:14:28 suz Exp $ */

/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (C) 2001 WIDE Project.
 * 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 project 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 PROJECT 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 PROJECT 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/types.h>
#include <sys/socket.h>
#include <sys/queue.h>
#include <sys/param.h>
#include <sys/ioctl.h>
#ifdef JAIL
#include <sys/jail.h>
#endif
#include <sys/sysctl.h>

#include <net/if.h>

#include <netinet/in.h>
#include <netinet6/in6_var.h>

#include <stdlib.h>
#include <netdb.h>
#ifdef JAIL
#include <jail.h>
#endif
#include <stdio.h>
#include <unistd.h>
#include <limits.h>
#include <string.h>
#include <err.h>

#ifdef JAIL
static char *jailname;
#endif
static char *configfile;

struct policyqueue {
        TAILQ_ENTRY(policyqueue) pc_entry;
        struct in6_addrpolicy pc_policy;
};
TAILQ_HEAD(policyhead, policyqueue);
static struct policyhead policyhead = TAILQ_HEAD_INITIALIZER(policyhead);

static void usage(void) __dead2;
static void attach_jail(void);
static void get_policy(void);
static void dump_policy(void);
static int mask2plen(struct sockaddr_in6 *);
static int parse_prefix(const char *, struct in6_addrpolicy *);
static void make_policy_fromfile(char *);
static void plen2mask(struct sockaddr_in6 *, int);
static void set_policy(void);
static void add_policy(char *, char *, char *);
static void delete_policy(char *);
static void flush_policy(void);

int
main(int argc, char *argv[])
{
        int ch;

        while ((ch = getopt(argc, argv, "j:")) != -1) {
                switch (ch) {
                case 'j':
#ifdef JAIL
                        if ((jailname = optarg) == NULL)
                                usage();
#else
                        errx(1, "not built with jail support");
#endif
                        break;
                default:
                        usage();
                }
        }
        argc -= optind;
        argv += optind;

        if (argc == 0 || (argc == 1 && strcasecmp(argv[0], "show") == 0)) {
                attach_jail();
                get_policy();
                dump_policy();
        } else if (strcasecmp(argv[0], "add") == 0) {
                if (argc != 4)
                        usage();
                attach_jail();
                add_policy(argv[1], argv[2], argv[3]);
        } else if (strcasecmp(argv[0], "delete") == 0) {
                if (argc != 2)
                        usage();
                attach_jail();
                delete_policy(argv[1]);
        } else if (strcasecmp(argv[0], "flush") == 0) {
                if (argc != 1)
                        usage();
                attach_jail();
                get_policy();
                flush_policy();
        } else if (strcasecmp(argv[0], "install") == 0) {
                if (argc != 2)
                        usage();
                configfile = argv[1];
                make_policy_fromfile(configfile);
                attach_jail();
                set_policy();
        } else
                usage();

        exit(0);
}

static void
attach_jail(void)
{
#ifdef JAIL
        int jid;

        if (jailname == NULL)
                return;

        jid = jail_getid(jailname);
        if (jid == -1)
                errx(1, "jail not found");
        if (jail_attach(jid) != 0)
                errx(1, "cannot attach to jail");
#endif
}

static void
get_policy(void)
{
        int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_ADDRCTLPOLICY };
        size_t l;
        struct in6_addrpolicy *buf;
        struct in6_addrpolicy *pol, *ep;

        if (sysctl(mib, nitems(mib), NULL, &l, NULL, 0) < 0) {
                err(1, "sysctl(IPV6CTL_ADDRCTLPOLICY)");
                /* NOTREACHED */
        }
        if (l == 0) {
                printf("no source-address-selection policy is installed\n");
                return;
        }
        if ((buf = malloc(l)) == NULL) {
                errx(1, "malloc failed");
                /* NOTREACHED */
        }
        if (sysctl(mib, nitems(mib), buf, &l, NULL, 0) < 0) {
                err(1, "sysctl(IPV6CTL_ADDRCTLPOLICY)");
                /* NOTREACHED */
        }

        ep = buf + l/sizeof(*buf);
        for (pol = buf; pol + 1 <= ep; pol++) {
                struct policyqueue *new;

                if ((new = malloc(sizeof(*new))) == NULL)
                        errx(1, "malloc failed\n");
                new->pc_policy = *pol;
                TAILQ_INSERT_TAIL(&policyhead, new, pc_entry);
        }

        free(buf);
}

static void
dump_policy(void)
{
        size_t addrlen;
        char addrbuf[NI_MAXHOST];
        struct in6_addrpolicy *pol;
        struct policyqueue *ent;
        int plen, first = 1;

        for (ent = TAILQ_FIRST(&policyhead); ent;
             ent = TAILQ_NEXT(ent, pc_entry)) {
                pol = &ent->pc_policy;
                if (first) {
                        printf("%-30s %5s %5s %8s\n",
                               "Prefix", "Prec", "Label", "Use");
                        first = 0;
                }

                if ((getnameinfo((struct sockaddr *)&pol->addr,
                                 sizeof(pol->addr), addrbuf, sizeof(addrbuf),
                                 NULL, 0, NI_NUMERICHOST))) {
                        warnx("getnameinfo for prefix address failed");
                        continue;
                }
                if ((plen = mask2plen(&pol->addrmask)) < 0) {
                        warnx("invalid address mask");
                        continue;
                }
                addrlen = strlen(addrbuf);
                if (addrlen + sizeof("/128") < sizeof(addrbuf)) {
                        snprintf(&addrbuf[addrlen],
                                 sizeof(addrbuf) - addrlen - 1,
                                 "/%d", plen);
                        printf("%-30s", addrbuf);
                } else          /* XXX */
                        printf("%s/%d", addrbuf, plen);
                printf(" %5d %5d %8llu\n", pol->preced, pol->label,
                    (unsigned long long)pol->use);
        }
}

#define SKIP_WHITE(p, emptyok) \
        do { \
                while((*(p) == ' ' || *(p) == '\t')) \
                        (p)++; \
                if ((*(p) == '\0' || (*(p) == '\n')) && !(emptyok)) \
                        goto bad; \
        } while (0);
#define SKIP_WORD(p) \
        do { \
                while(*(p) != ' ' && *(p) != '\t') \
                        (p)++; \
                if (*(p) == '\0' || *(p) == '\n') \
                        goto bad; \
        } while (0);

static void
make_policy_fromfile(char *conf)
{
        char line[_POSIX2_LINE_MAX], *cp;
        char *addrstr;
        FILE *fp;
        int count = 0;
        struct in6_addrpolicy pol0;
        struct policyqueue *new;

        if ((fp = fopen(conf, "r")) == NULL)
                err(1, "fopen: %s", conf);

        while(fgets(line, sizeof(line), fp)) {
                count++;
                cp = line;

                memset(&pol0, 0, sizeof(pol0));

                /* get prefix */
                SKIP_WHITE(cp, 1);
                if (*cp == '\n') /* empty line */
                        continue;
                if (*cp == '#')
                        continue;
                addrstr = cp;
                if (parse_prefix((const char *)addrstr, &pol0))
                        goto bad;

                /* get precedence value */
                SKIP_WORD(cp);
                SKIP_WHITE(cp, 0);
                pol0.preced = atoi(cp);

                /* get label */
                SKIP_WORD(cp);
                SKIP_WHITE(cp, 0);
                pol0.label = atoi(cp);

                /* parse succeeded.  make a control buffer entry. */
                if ((new = malloc(sizeof(*new))) == NULL)
                        errx(1, "malloc failed\n");
                memset(new, 0, sizeof(*new));
                new->pc_policy = pol0;
                TAILQ_INSERT_TAIL(&policyhead, new, pc_entry);
        }

        fclose(fp);
        return;

  bad:
        errx(1, "parse failed at line %d", count);
        /* NOTREACHED */
}

static int
parse_prefix(const char *prefix0, struct in6_addrpolicy *pol)
{
        int e = 0, plen;
        char *prefix, *plenstr;
        struct addrinfo hints, *res;

        if ((prefix = strdup(prefix0)) == NULL)
                errx(1, "strdup failed");

        if ((plenstr = strchr(prefix, '/')) == NULL) {
                e = -1;
                goto end;
        }
        *plenstr = '\0';

        memset(&hints, 0, sizeof(hints));
        hints.ai_flags = AI_NUMERICHOST;
        hints.ai_family = AF_INET6;

        if ((e = getaddrinfo(prefix, NULL, &hints, &res)) != 0) {
                warnx("getaddrinfo failed for %s: %s", prefix,
                      gai_strerror(e));
                goto end;
        }
        memcpy(&pol->addr, res->ai_addr, res->ai_addrlen);
        freeaddrinfo(res);
        plen = atoi(plenstr + 1);
        if (plen < 0 || plen > 128) {
                warnx("invalid prefix length: %d", plen);
                e = -1;
                goto end;
        }
        plen2mask(&pol->addrmask, plen);

  end:
        free(prefix);
        return(e);
}

static void
plen2mask(struct sockaddr_in6 *mask, int plen)
{
        u_char *cp = (unsigned char *)&mask->sin6_addr;

        memset(mask, 0, sizeof(*mask));
        mask->sin6_family = AF_INET6; /* just in case */
        mask->sin6_len = sizeof(*mask);

        for(; plen >= 8; plen -= 8)
                *cp++ = 0xff;
        if (plen > 0)
                *cp = (0xff << (8 - plen));
}

static void
set_policy(void)
{
        struct policyqueue *ent;
        int s;

        if ((s = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP)) < 0)
                err(1, "socket(UDP)");

        for (ent = TAILQ_FIRST(&policyhead); ent;
             ent = TAILQ_NEXT(ent, pc_entry)) {
                if (ioctl(s, SIOCAADDRCTL_POLICY, &ent->pc_policy))
                        warn("ioctl(SIOCAADDRCTL_POLICY)");
        }

        close(s);
}

static int
mask2plen(struct sockaddr_in6 *mask)
{
        int masklen, final = 0;
        u_char *p, *lim;

        masklen = 0;
        lim = (u_char *)(mask + 1);
        for (p = (u_char *)(&mask->sin6_addr); p < lim; p++) {
                if (final && *p) {
                        goto bad;
                }

                switch (*p & 0xff) {
                case 0xff:
                        masklen += 8;
                        break;
                case 0xfe:
                        masklen += 7;
                        final++;
                        break;
                case 0xfc:
                        masklen += 6;
                        final++;
                        break;
                case 0xf8:
                        masklen += 5;
                        final++;
                        break;
                case 0xf0:
                        masklen += 4;
                        final++;
                        break;
                case 0xe0:
                        masklen += 3;
                        final++;
                        break;
                case 0xc0:
                        masklen += 2;
                        final++;
                        break;
                case 0x80:
                        masklen += 1;
                        final++;
                        break;
                case 0x00:
                        final++;
                        break;
                default:
                        goto bad;
                        break;
                }
        }
        return(masklen);

  bad:
        return(-1);
}

static void
add_policy(char *prefix, char *prec, char *label)
{
        struct in6_addrpolicy p;
        int s;

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

        if (parse_prefix((const char *)prefix, &p))
                errx(1, "bad prefix: %s", prefix);
        p.preced = atoi(prec);
        p.label = atoi(label);

        if ((s = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP)) < 0)
                err(1, "socket(UDP)");
        if (ioctl(s, SIOCAADDRCTL_POLICY, &p))
                err(1, "ioctl(SIOCAADDRCTL_POLICY)");

        close(s);
}

static void
delete_policy(char *prefix)
{
        struct in6_addrpolicy p;
        int s;

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

        if (parse_prefix((const char *)prefix, &p))
                errx(1, "bad prefix: %s", prefix);

        if ((s = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP)) < 0)
                err(1, "socket(UDP)");
        if (ioctl(s, SIOCDADDRCTL_POLICY, &p))
                err(1, "ioctl(SIOCDADDRCTL_POLICY)");

        close(s);
}

static void
flush_policy(void)
{
        struct policyqueue *ent;
        int s;

        if ((s = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP)) < 0)
                err(1, "socket(UDP)");

        for (ent = TAILQ_FIRST(&policyhead); ent;
             ent = TAILQ_NEXT(ent, pc_entry)) {
                if (ioctl(s, SIOCDADDRCTL_POLICY, &ent->pc_policy))
                        warn("ioctl(SIOCDADDRCTL_POLICY)");
        }

        close(s);
}

static void
usage(void)
{
        fprintf(stderr, "usage: ip6addrctl [-j jail] [show]\n");
        fprintf(stderr, "       ip6addrctl [-j jail] add "
                "<prefix> <precedence> <label>\n");
        fprintf(stderr, "       ip6addrctl [-j jail] delete <prefix>\n");
        fprintf(stderr, "       ip6addrctl [-j jail] flush\n");
        fprintf(stderr, "       ip6addrctl [-j jail] install <configfile>\n");

        exit(1);
}