/*-
 * Copyright (c) 2012 maksim yevmenkin <emax@freebsd.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted providing 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 ``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 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.
 */

/* gcc -Wall -ggdb ifpifa.c -lkvm -o ifpifa */

#include <sys/types.h>
#include <sys/callout.h>

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

#include <net/if.h>
#include <net/if_var.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <net/ethernet.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <arpa/inet.h>

#include <err.h>
#include <fcntl.h>
#include <kvm.h>
#include <limits.h>
#include <nlist.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
static struct nlist     nl[] = {
#define N_IFNET         0
        { .n_name = "_ifnet", },
        { .n_name = NULL, },
};

static int
kread(kvm_t *kd, u_long addr, char *buffer, int size)
{
        if (kd == NULL || buffer == NULL)
                return (-1);
 
        if (kvm_read(kd, addr, buffer, size) != size) {
                warnx("kvm_read: %s", kvm_geterr(kd));
                return (-1);
        }
 
        return (0);
}

int
main(void)
{
        kvm_t *kd;
        char errbuf[_POSIX2_LINE_MAX];
        u_long ifnetaddr, ifnetaddr_next;
        u_long ifaddraddr, ifaddraddr_next;
        struct ifnet ifnet;
        struct ifnethead ifnethead;
        union {
                struct ifaddr ifa;
                struct in_ifaddr in;
                struct in6_ifaddr in6;
        } ifaddr;
        union {
                struct sockaddr *sa;
                struct sockaddr_dl *sal;
                struct sockaddr_in *sa4;
                struct sockaddr_in6 *sa6;
        } sa;
        char addr[INET6_ADDRSTRLEN];

        kd = kvm_openfiles(NULL, NULL, NULL, O_RDONLY, errbuf);
        if (kd == NULL) {
                warnx("kvm_openfiles: %s", errbuf);
                exit(0);
        }

        if (kvm_nlist(kd, nl) < 0) {
                warnx("kvm_nlist: %s", kvm_geterr(kd));
                goto out;
        }

        if (nl[N_IFNET].n_type == 0) {
                warnx("kvm_nlist: no namelist");
                goto out;
        }

        if (kread(kd, nl[N_IFNET].n_value,
                  (char *) &ifnethead, sizeof(ifnethead)) != 0)
                goto out;

        for (ifnetaddr = (u_long) TAILQ_FIRST(&ifnethead);
             ifnetaddr != 0;
             ifnetaddr = ifnetaddr_next) {
                if (kread(kd, ifnetaddr, (char *) &ifnet, sizeof(ifnet)) != 0)
                        goto out;
                ifnetaddr_next = (u_long) TAILQ_NEXT(&ifnet, if_link);

                printf("%s\n", ifnet.if_xname);

                for (ifaddraddr = (u_long) TAILQ_FIRST(&ifnet.if_addrhead);
                     ifaddraddr != 0;
                     ifaddraddr = ifaddraddr_next) {
                        if (kread(kd, ifaddraddr,
                                  (char *) &ifaddr, sizeof(ifaddr)) != 0)
                                goto out;

                        ifaddraddr_next = (u_long)
                                TAILQ_NEXT(&ifaddr.ifa, ifa_link);

                        sa.sa = (struct sockaddr *)(
                                (unsigned char *) ifaddr.ifa.ifa_addr -
                                (unsigned char *) ifaddraddr +
                                (unsigned char *) &ifaddr);

                        switch (sa.sa->sa_family) {
                        case AF_LINK:
                                switch (sa.sal->sdl_type) {
                                case IFT_ETHER:
                                case IFT_FDDI:
                                        ether_ntoa_r((struct ether_addr * )
                                                LLADDR(sa.sal), addr);
                                        break;

                                case IFT_LOOP:
                                        strcpy(addr, "loopback");
                                        break;

                                default:
                                        snprintf(addr, sizeof(addr),
                                                 "<Link type %#x>",
                                                sa.sal->sdl_type);
                                        break;
                                }
                                break;

                        case AF_INET:
                                inet_ntop(AF_INET, &sa.sa4->sin_addr,
                                        addr, sizeof(addr)); 
                                break;

                        case AF_INET6:
                                inet_ntop(AF_INET6, &sa.sa6->sin6_addr,
                                        addr, sizeof(addr)); 
                                break;

                        default:
                                snprintf(addr, sizeof(addr), "family=%d",
                                        sa.sa->sa_family);
                                break;
                        }
                
                        printf("\t%s ifa_refcnt=%u\n",
                                addr, ifaddr.ifa.ifa_refcnt);
                }
        }
out:
        kvm_close(kd);

        return (0);
}