source: branches/samba-3.2.x/source/lib/interface.c

/*
   Unix SMB/CIFS implementation.
   multiple interface handling
   Copyright (C) Andrew Tridgell 1992-1998
   Copyright (C) Jeremy Allison 2007

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"

static struct iface_struct *probed_ifaces;
static int total_probed;

static struct interface *local_interfaces;

/****************************************************************************
 Check if an IP is one of mine.
**************************************************************************/

bool ismyaddr(const struct sockaddr_storage *ip)
{
        struct interface *i;
        for (i=local_interfaces;i;i=i->next) {
                if (sockaddr_equal(&i->ip,ip)) {
                        return true;
                }
        }
        return false;
}

bool ismyip_v4(struct in_addr ip)
{
        struct sockaddr_storage ss;
        in_addr_to_sockaddr_storage(&ss, ip);
        return ismyaddr(&ss);
}

/****************************************************************************
 Try and find an interface that matches an ip. If we cannot, return NULL.
**************************************************************************/

static struct interface *iface_find(const struct sockaddr_storage *ip,
                                bool check_mask)
{
        struct interface *i;

        if (is_address_any(ip)) {
                return local_interfaces;
        }

        for (i=local_interfaces;i;i=i->next) {
                if (check_mask) {
                        if (same_net(ip, &i->ip, &i->netmask)) {
                                return i;
                        }
                } else if (sockaddr_equal(&i->ip, ip)) {
                        return i;
                }
        }

        return NULL;
}

/****************************************************************************
 Check if a packet is from a local (known) net.
**************************************************************************/

bool is_local_net(const struct sockaddr_storage *from)
{
        struct interface *i;
        for (i=local_interfaces;i;i=i->next) {
                if (same_net(from, &i->ip, &i->netmask)) {
                        return true;
                }
        }
        return false;
}

#if defined(HAVE_IPV6)
void setup_linklocal_scope_id(struct sockaddr_storage *pss)
{
        struct interface *i;
        for (i=local_interfaces;i;i=i->next) {
                if (sockaddr_equal(&i->ip,pss)) {
                        struct sockaddr_in6 *psa6 =
                                (struct sockaddr_in6 *)pss;
                        psa6->sin6_scope_id = if_nametoindex(i->name);
                        return;
                }
        }
}
#endif

/****************************************************************************
 Check if a packet is from a local (known) net.
**************************************************************************/

bool is_local_net_v4(struct in_addr from)
{
        struct sockaddr_storage ss;

        in_addr_to_sockaddr_storage(&ss, from);
        return is_local_net(&ss);
}

/****************************************************************************
 How many interfaces do we have ?
**************************************************************************/

int iface_count(void)
{
        int ret = 0;
        struct interface *i;

        for (i=local_interfaces;i;i=i->next) {
                ret++;
        }
        return ret;
}

/****************************************************************************
 How many non-loopback IPv4 interfaces do we have ?
**************************************************************************/

int iface_count_v4_nl(void)
{
        int ret = 0;
        struct interface *i;

        for (i=local_interfaces;i;i=i->next) {
                if (is_loopback_addr(&i->ip)) {
                        continue;
                }
                if (i->ip.ss_family == AF_INET) {
                        ret++;
                }
        }
        return ret;
}

/****************************************************************************
 Return a pointer to the in_addr of the first IPv4 interface that's
 not 0.0.0.0.
**************************************************************************/

const struct in_addr *first_ipv4_iface(void)
{
        struct interface *i;

        for (i=local_interfaces;i ;i=i->next) {
                if ((i->ip.ss_family == AF_INET) &&
                    (!is_zero_ip_v4(((struct sockaddr_in *)&i->ip)->sin_addr)))
                {
                        break;
                }
        }

        if (!i) {
                return NULL;
        }
        return &((const struct sockaddr_in *)&i->ip)->sin_addr;
}