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/*
* Copyright (c) 1990 Jan-Simon Pendry
* Copyright (c) 1990 Imperial College of Science, Technology & Medicine
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Jan-Simon Pendry at Imperial College, London.
*
* 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.
*
* from: @(#)wire.c 8.1 (Berkeley) 6/6/93
* $Id: wire.c,v 1.13 2014/10/24 10:29:56 schwarze Exp $
*/
/*
* This function returns the subnet (address&netmask) for the primary network
* interface. If the resulting address has an entry in the hosts file, the
* corresponding name is retuned, otherwise the address is returned in
* standard internet format.
* As a side-effect, a list of local IP/net address is recorded for use
* by the islocalnet() function.
*
* Derived from original by Paul Anderson (23/4/90)
* Updates from Dirk Grunwald (11/11/91)
* Modified to use getifaddrs() by Todd C. Miller (6/14/2003)
*/
#include "am.h"
#include <ifaddrs.h>
#include <netdb.h>
#include <net/if.h>
#define NO_SUBNET "notknown"
/*
* List of locally connected networks
*/
typedef struct addrlist addrlist;
struct addrlist {
addrlist *ip_next;
in_addr_t ip_addr;
in_addr_t ip_mask;
};
static addrlist *localnets = 0;
char *
getwire(void)
{
struct ifaddrs *ifa, *ifaddrs;
struct hostent *hp;
addrlist *al;
char *s, *netname = NULL;
if (getifaddrs(&ifaddrs))
return strdup(NO_SUBNET);
for (ifa = ifaddrs; ifa != NULL; ifa = ifa -> ifa_next) {
/*
* Ignore non-AF_INET interfaces as well as any that
* are down or loopback.
*/
if (ifa->ifa_addr == NULL ||
ifa->ifa_addr->sa_family != AF_INET ||
!(ifa->ifa_flags & IFF_UP) ||
(ifa->ifa_flags & IFF_LOOPBACK))
continue;
/*
* Add interface to local network list
*/
al = ALLOC(addrlist);
al->ip_addr =
((struct sockaddr_in *)ifa->ifa_addr)->sin_addr.s_addr;
al->ip_mask =
((struct sockaddr_in *)ifa->ifa_netmask)->sin_addr.s_addr;
al->ip_next = localnets;
localnets = al;
/*
* Look up the host name; fall back to a dotted quad.
*/
if (netname == NULL) {
in_addr_t subnet;
char dq[20];
subnet = al->ip_addr & al->ip_mask;
hp = gethostbyaddr((char *) &subnet, 4, AF_INET);
if (hp)
s = hp->h_name;
else
s = inet_dquad(dq, sizeof(dq), subnet);
netname = strdup(s);
}
}
freeifaddrs(ifaddrs);
return (netname ? netname : strdup(NO_SUBNET));
}
/*
* Determine whether a network is on a local network
* (addr) is in network byte order.
*/
int
islocalnet(in_addr_t addr)
{
addrlist *al;
for (al = localnets; al; al = al->ip_next)
if (((addr ^ al->ip_addr) & al->ip_mask) == 0)
return TRUE;
#ifdef DEBUG
{ char buf[16];
plog(XLOG_INFO, "%s is on a remote network", inet_dquad(buf, sizeof(buf), addr));
}
#endif
return FALSE;
}
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