4.4BSD/usr/src/usr.sbin/amd/amd/wire.c
/*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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.
*
* @(#)wire.c 8.1 (Berkeley) 6/6/93
*
* $Id: wire.c,v 5.2.2.1 1992/02/09 15:09:15 jsp beta $
*
*/
/*
* 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)
*/
#include "am.h"
#include <sys/ioctl.h>
#define NO_SUBNET "notknown"
/*
* List of locally connected networks
*/
typedef struct addrlist addrlist;
struct addrlist {
addrlist *ip_next;
unsigned long ip_addr;
unsigned long ip_mask;
};
static addrlist *localnets = 0;
#ifdef SIOCGIFFLAGS
#ifdef STELLIX
#include <sys/sema.h>
#endif /* STELLIX */
#include <net/if.h>
#include <netdb.h>
#if defined(IFF_LOCAL_LOOPBACK) && !defined(IFF_LOOPBACK)
#define IFF_LOOPBACK IFF_LOCAL_LOOPBACK
#endif
#define GFBUFLEN 1024
#define clist (ifc.ifc_ifcu.ifcu_req)
#define count (ifc.ifc_len/sizeof(struct ifreq))
char *getwire P((void));
char *getwire()
{
struct hostent *hp;
struct netent *np;
struct ifconf ifc;
struct ifreq *ifr;
caddr_t cp, cplim;
unsigned long address, netmask, subnet;
char buf[GFBUFLEN], *s;
int sk = -1;
char *netname = 0;
/*
* Get suitable socket
*/
if ((sk = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
goto out;
/*
* Fill in ifconf details
*/
ifc.ifc_len = sizeof buf;
ifc.ifc_buf = buf;
/*
* Get network interface configurations
*/
if (ioctl(sk, SIOCGIFCONF, (caddr_t) &ifc) < 0)
goto out;
/*
* Upper bound on array
*/
cplim = buf + ifc.ifc_len;
/*
* This is some magic to cope with both "traditional" and the
* new 4.4BSD-style struct sockaddrs. The new structure has
* variable length and a size field to support longer addresses.
* AF_LINK is a new definition for 4.4BSD.
*/
#ifdef AF_LINK
#define max(a, b) ((a) > (b) ? (a) : (b))
#define size(ifr) (max((ifr)->ifr_addr.sa_len, sizeof((ifr)->ifr_addr)) + sizeof(ifr->ifr_name))
#else
#define size(ifr) sizeof(*ifr)
#endif
/*
* Scan the list looking for a suitable interface
*/
for (cp = buf; cp < cplim; cp += size(ifr)) {
addrlist *al;
ifr = (struct ifreq *) cp;
if (ifr->ifr_addr.sa_family != AF_INET)
continue;
else
address = ((struct sockaddr_in *) &ifr->ifr_addr)->sin_addr.s_addr;
/*
* Get interface flags
*/
if (ioctl(sk, SIOCGIFFLAGS, (caddr_t) ifr) < 0)
continue;
/*
* If the interface is a loopback, or its not running
* then ignore it.
*/
if ((ifr->ifr_flags & IFF_LOOPBACK) != 0)
continue;
if ((ifr->ifr_flags & IFF_RUNNING) == 0)
continue;
/*
* Get the netmask of this interface
*/
if (ioctl(sk, SIOCGIFNETMASK, (caddr_t) ifr) < 0)
continue;
netmask = ((struct sockaddr_in *) &ifr->ifr_addr)->sin_addr.s_addr;
/*
* Add interface to local network list
*/
al = ALLOC(addrlist);
al->ip_addr = address;
al->ip_mask = netmask;
al->ip_next = localnets;
localnets = al;
if (netname == 0) {
unsigned long net;
unsigned long mask;
unsigned long subnetshift;
/*
* Figure out the subnet's network address
*/
subnet = address & netmask;
#ifdef IN_CLASSA
subnet = ntohl(subnet);
if (IN_CLASSA(subnet)) {
mask = IN_CLASSA_NET;
subnetshift = 8;
} else if (IN_CLASSB(subnet)) {
mask = IN_CLASSB_NET;
subnetshift = 8;
} else {
mask = IN_CLASSC_NET;
subnetshift = 4;
}
/*
* If there are more bits than the standard mask
* would suggest, subnets must be in use.
* Guess at the subnet mask, assuming reasonable
* width subnet fields.
* XXX: Or-in at least 1 byte's worth of 1s to make
* sure the top bits remain set.
*/
while (subnet &~ mask)
mask = (mask >> subnetshift) | 0xff000000;
net = subnet & mask;
while ((mask & 1) == 0)
mask >>= 1, net >>= 1;
/*
* Now get a usable name.
* First use the network database,
* then the host database,
* and finally just make a dotted quad.
*/
np = getnetbyaddr(net, AF_INET);
#else
/* This is probably very wrong. */
np = getnetbyaddr(subnet, AF_INET);
#endif /* IN_CLASSA */
if (np)
s = np->n_name;
else {
subnet = address & netmask;
hp = gethostbyaddr((char *) &subnet, 4, AF_INET);
if (hp)
s = hp->h_name;
else
s = inet_dquad(buf, subnet);
}
netname = strdup(s);
}
}
out:
if (sk >= 0)
(void) close(sk);
if (netname)
return netname;
return strdup(NO_SUBNET);
}
#else
char *getwire P((void));
char *getwire()
{
return strdup(NO_SUBNET);
}
#endif /* SIOCGIFFLAGS */
/*
* Determine whether a network is on a local network
* (addr) is in network byte order.
*/
int islocalnet P((unsigned long addr));
int islocalnet(addr)
unsigned long 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, addr));
}
#endif
return FALSE;
}