/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1983, 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.
 *
 * $FreeBSD: head/sbin/ifconfig/ifclone.c 326025 2017-11-20 19:49:47Z pfg $
 */

#include <sys/param.h>
#include <sys/queue.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <net/if.h>
#include <net/if_clone.h>

#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "ifconfig.h"

static void
list_cloners(void)
{
        struct if_clonereq ifcr;
        char *cp, *buf;
        int idx;
        int s;

        s = socket(AF_LOCAL, SOCK_DGRAM, 0);
        if (s == -1)
                err(1, "socket(AF_LOCAL,SOCK_DGRAM)");

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

        if (ioctl(s, SIOCIFGCLONERS, &ifcr) < 0)
                err(1, "SIOCIFGCLONERS for count");

        buf = malloc(ifcr.ifcr_total * IFNAMSIZ);
        if (buf == NULL)
                err(1, "unable to allocate cloner name buffer");

        ifcr.ifcr_count = ifcr.ifcr_total;
        ifcr.ifcr_buffer = buf;

        if (ioctl(s, SIOCIFGCLONERS, &ifcr) < 0)
                err(1, "SIOCIFGCLONERS for names");

        /*
         * In case some disappeared in the mean time, clamp it down.
         */
        if (ifcr.ifcr_count > ifcr.ifcr_total)
                ifcr.ifcr_count = ifcr.ifcr_total;

        for (cp = buf, idx = 0; idx < ifcr.ifcr_count; idx++, cp += IFNAMSIZ) {
                if (idx > 0)
                        putchar(' ');
                printf("%s", cp);
        }

        putchar('\n');
        free(buf);
        close(s);
}

struct clone_defcb {
        char ifprefix[IFNAMSIZ];
        clone_callback_func *clone_cb;
        SLIST_ENTRY(clone_defcb) next;
};

static SLIST_HEAD(, clone_defcb) clone_defcbh =
   SLIST_HEAD_INITIALIZER(clone_defcbh);

void
clone_setdefcallback(const char *ifprefix, clone_callback_func *p)
{
        struct clone_defcb *dcp;

        dcp = malloc(sizeof(*dcp));
        strlcpy(dcp->ifprefix, ifprefix, IFNAMSIZ-1);
        dcp->clone_cb = p;
        SLIST_INSERT_HEAD(&clone_defcbh, dcp, next);
}

/*
 * Do the actual clone operation.  Any parameters must have been
 * setup by now.  If a callback has been setup to do the work
 * then defer to it; otherwise do a simple create operation with
 * no parameters.
 */
static void
ifclonecreate(int s, void *arg __unused)
{
        struct ifreq ifr;
        struct clone_defcb *dcp;
        clone_callback_func *clone_cb = NULL;

        memset(&ifr, 0, sizeof(ifr));
        strlcpy(ifr.ifr_name, IfName, sizeof(ifr.ifr_name));

        if (clone_cb == NULL) {
                /* Try to find a default callback */
                SLIST_FOREACH(dcp, &clone_defcbh, next) {
                        if (strncmp(dcp->ifprefix, ifr.ifr_name,
                                    strlen(dcp->ifprefix)) == 0) {
                                clone_cb = dcp->clone_cb;
                                break;
                        }
                }
        }
        if (clone_cb == NULL) {
                /* NB: no parameters */
                if (ioctl(s, SIOCIFCREATE2, &ifr) < 0)
                        err(1, "SIOCIFCREATE2");
        } else {
                clone_cb(s, &ifr);
        }

        /*
         * If we get a different name back than we put in, update record and
         * indicate it should be printed later.
         */
        if (strncmp(IfName, ifr.ifr_name, sizeof(IfName)) != 0) {
                strlcpy(IfName, ifr.ifr_name, sizeof(IfName));
                printifname = true;
        }
}

static void
clone_create(const char *x __unused, int arg __unused, int s __unused,
             const struct afswtch *afp __unused)
{
        callback_register(ifclonecreate, NULL);
}

static void
clone_destroy(const char *x __unused, int arg __unused, int s __unused,
              const struct afswtch *afp __unused)
{
        struct ifreq ifr;

        memset(&ifr, 0, sizeof(ifr));
        strlcpy(ifr.ifr_name, IfName, sizeof(ifr.ifr_name));

        if (ioctl(s, SIOCIFDESTROY, &ifr) < 0)
                err(1, "SIOCIFDESTROY");
}

static struct cmd clone_cmds[] = {
        DEF_CLONE_CMD("create", 0,      clone_create),
        DEF_CMD("destroy",      0,      clone_destroy),
        DEF_CLONE_CMD("plumb",  0,      clone_create),
        DEF_CMD("unplumb",      0,      clone_destroy),
};

static void
clone_Copt_cb(const char *arg __unused)
{
        list_cloners();
        exit(exit_code);
}

static struct option clone_Copt = {
        .opt = "C",
        .opt_usage = "[-C]",
        .cb = clone_Copt_cb,
};

__constructor(121)
static void
clone_ctor(void)
{
        size_t i;

        for (i = 0; i < nitems(clone_cmds); i++)
                cmd_register(&clone_cmds[i]);

        opt_register(&clone_Copt);
}