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/*
Unix SMB/Netbios implementation.
Version 1.9.
multiple interface handling
Copyright (C) Andrew Tridgell 1992-1998
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 2 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, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "includes.h"
extern int DEBUGLEVEL;
struct in_addr ipzero;
struct in_addr allones_ip;
struct in_addr loopback_ip;
static struct in_addr default_ip;
static struct in_addr default_bcast;
static struct in_addr default_nmask;
static BOOL got_ip=False;
static BOOL got_bcast=False;
static BOOL got_nmask=False;
static struct interface *local_interfaces = NULL;
struct interface *last_iface;
#define ALLONES ((uint32)0xFFFFFFFF)
#define MKBCADDR(_IP, _NM) ((_IP & _NM) | (_NM ^ ALLONES))
/****************************************************************************
calculate the default netmask for an address
****************************************************************************/
static void default_netmask(struct in_addr *inm, struct in_addr *iad)
{
/*
** Guess a netmask based on the class of the IP address given.
*/
switch((ntohl(iad->s_addr) & 0xE0000000)) {
case 0x00000000: /* Class A addr */
case 0x20000000:
case 0x40000000:
case 0x60000000:
inm->s_addr = htonl(0xFF000000);
break;
case 0x80000000: /* Class B addr */
case 0xA0000000:
inm->s_addr = htonl(0xFFFF0000);
break;
case 0xC0000000: /* Class C addr */
inm->s_addr = htonl(0xFFFFFF00);
break;
default: /* ??? */
inm->s_addr = htonl(0xFFFFFFF0);
}
}
/****************************************************************************
get the broadcast address for our address
(troyer@saifr00.ateng.az.honeywell.com)
****************************************************************************/
static void get_broadcast(struct in_addr *if_ipaddr,
struct in_addr *if_bcast,
struct in_addr *if_nmask)
{
BOOL found = False;
#ifndef NO_GET_BROADCAST
int sock = -1; /* AF_INET raw socket desc */
char buff[1024];
struct ifreq *ifr=NULL;
int i;
#if defined(EVEREST)
int n_interfaces;
struct ifconf ifc;
struct ifreq *ifreqs;
#elif defined(USE_IFREQ)
struct ifreq ifreq;
struct strioctl strioctl;
struct ifconf *ifc;
#else
struct ifconf ifc;
#endif
#endif
/* get a default netmask and broadcast */
default_netmask(if_nmask, if_ipaddr);
#ifndef NO_GET_BROADCAST
/* Create a socket to the INET kernel. */
#if USE_SOCKRAW
if ((sock = socket(AF_INET, SOCK_RAW, PF_INET )) < 0)
#else
if ((sock = socket(AF_INET, SOCK_DGRAM, 0 )) < 0)
#endif
{
DEBUG(0,( "Unable to open socket to get broadcast address\n"));
return;
}
/* Get a list of the configured interfaces */
#ifdef EVEREST
/* This is part of SCO Openserver 5: The ioctls are no longer part
if the lower level STREAMS interface glue. They are now real
ioctl calls */
if (ioctl(sock, SIOCGIFANUM, &n_interfaces) < 0) {
DEBUG(0,( "SIOCGIFANUM: %s\n", strerror(errno)));
} else {
DEBUG(0,( "number of interfaces returned is: %d\n", n_interfaces));
ifc.ifc_len = sizeof(struct ifreq) * n_interfaces;
ifc.ifc_buf = (caddr_t) alloca(ifc.ifc_len);
if (ioctl(sock, SIOCGIFCONF, &ifc) < 0)
DEBUG(0, ( "SIOCGIFCONF: %s\n", strerror(errno)));
else {
ifr = ifc.ifc_req;
for (i = 0; i < n_interfaces; ++i) {
if (if_ipaddr->s_addr ==
((struct sockaddr_in *) &ifr[i].ifr_addr)->sin_addr.s_addr) {
found = True;
break;
}
}
}
}
#elif defined(USE_IFREQ)
ifc = (struct ifconf *)buff;
ifc->ifc_len = BUFSIZ - sizeof(struct ifconf);
strioctl.ic_cmd = SIOCGIFCONF;
strioctl.ic_dp = (char *)ifc;
strioctl.ic_len = sizeof(buff);
if (ioctl(sock, I_STR, &strioctl) < 0) {
DEBUG(0,( "I_STR/SIOCGIFCONF: %s\n", strerror(errno)));
} else {
ifr = (struct ifreq *)ifc->ifc_req;
/* Loop through interfaces, looking for given IP address */
for (i = ifc->ifc_len / sizeof(struct ifreq); --i >= 0; ifr++) {
if (if_ipaddr->s_addr ==
(*(struct sockaddr_in *) &ifr->ifr_addr).sin_addr.s_addr) {
found = True;
break;
}
}
}
#elif defined(__FreeBSD__) || defined(NETBSD) || defined(AMIGA) || defined(_AIX41) || defined(__OpenBSD__) || defined(MacOSX) || defined(Rhapsody) || defined(Rhapsody5)
ifc.ifc_len = sizeof(buff);
ifc.ifc_buf = buff;
if (ioctl(sock, SIOCGIFCONF, &ifc) < 0) {
DEBUG(0,("SIOCGIFCONF: %s\n", strerror(errno)));
} else {
ifr = ifc.ifc_req;
/* Loop through interfaces, looking for given IP address */
i = ifc.ifc_len;
while (i > 0) {
if (if_ipaddr->s_addr ==
(*(struct sockaddr_in *) &ifr->ifr_addr).sin_addr.s_addr) {
found = True;
break;
}
i -= ifr->ifr_addr.sa_len + IFNAMSIZ;
ifr = (struct ifreq*) ((char*) ifr + ifr->ifr_addr.sa_len + IFNAMSIZ);
}
}
#else
ifc.ifc_len = sizeof(buff);
ifc.ifc_buf = buff;
if (ioctl(sock, SIOCGIFCONF, &ifc) < 0) {
DEBUG(0,("SIOCGIFCONF: %s\n", strerror(errno)));
} else {
ifr = ifc.ifc_req;
/* Loop through interfaces, looking for given IP address */
for (i = ifc.ifc_len / sizeof(struct ifreq); --i >= 0; ifr++) {
#ifdef BSDI
if (ioctl(sock, SIOCGIFADDR, ifr) < 0) break;
#endif
if (if_ipaddr->s_addr ==
(*(struct sockaddr_in *) &ifr->ifr_addr).sin_addr.s_addr) {
found = True;
break;
}
}
}
#endif
if (!found) {
DEBUG(0,("No interface found for address %s\n", inet_ntoa(*if_ipaddr)));
} else {
/* Get the netmask address from the kernel */
#ifdef USE_IFREQ
ifreq = *ifr;
strioctl.ic_cmd = SIOCGIFNETMASK;
strioctl.ic_dp = (char *)&ifreq;
strioctl.ic_len = sizeof(struct ifreq);
if (ioctl(sock, I_STR, &strioctl) < 0)
DEBUG(0,("Failed I_STR/SIOCGIFNETMASK: %s\n", strerror(errno)));
else
*if_nmask = ((struct sockaddr_in *)&ifreq.ifr_addr)->sin_addr;
#else
if (ioctl(sock, SIOCGIFNETMASK, ifr) < 0)
DEBUG(0,("SIOCGIFNETMASK failed\n"));
else
*if_nmask = ((struct sockaddr_in *)&ifr->ifr_addr)->sin_addr;
#endif
DEBUG(4,("Netmask for %s = %s\n", ifr->ifr_name,
inet_ntoa(*if_nmask)));
}
/* Close up shop */
(void) close(sock);
#endif
/* sanity check on the netmask */
{
uint32 nm;
short onbc;
short offbc;
nm = ntohl(if_nmask->s_addr);
onbc = 0;
offbc = 0;
while( (onbc + offbc) < 32 )
{
if( nm & 0x80000000 )
{
onbc++;
if( offbc ) /* already found an off bit, so mask is wrong */
{
onbc = 34;
}
}
else
{
offbc++;
}
nm <<= 1;
}
if ((onbc < 8)||(onbc == 34)) {
DEBUG(0,("Impossible netmask %s - using defaults\n",inet_ntoa(*if_nmask)));
default_netmask(if_nmask, if_ipaddr);
}
}
/* derive the broadcast assuming a 1's broadcast, as this is what
all MS operating systems do, we have to comply even if the unix
box is setup differently */
{
if_bcast->s_addr = MKBCADDR(if_ipaddr->s_addr, if_nmask->s_addr);
}
DEBUG(4,("Derived broadcast address %s\n", inet_ntoa(*if_bcast)));
} /* get_broadcast */
/****************************************************************************
load a list of network interfaces
****************************************************************************/
static void interpret_interfaces(char *s, struct interface **interfaces,
char *description)
{
char *ptr;
fstring token;
struct interface *iface;
struct in_addr ip;
ptr = s;
ipzero = *interpret_addr2("0.0.0.0");
allones_ip = *interpret_addr2("255.255.255.255");
loopback_ip = *interpret_addr2("127.0.0.1");
while (next_token(&ptr,token,NULL)) {
/* parse it into an IP address/netmasklength pair */
char *p = strchr(token,'/');
if (p) *p++ = 0;
ip = *interpret_addr2(token);
/* maybe we already have it listed */
{
struct interface *i;
for (i=(*interfaces);i;i=i->next)
if (ip_equal(ip,i->ip)) break;
if (i) continue;
}
iface = (struct interface *)malloc(sizeof(*iface));
if (!iface) return;
iface->ip = ip;
if (p) {
if (strlen(p) > 2)
iface->nmask = *interpret_addr2(p);
else
iface->nmask.s_addr = htonl(((ALLONES >> atoi(p)) ^ ALLONES));
} else {
default_netmask(&iface->nmask,&iface->ip);
}
iface->bcast.s_addr = MKBCADDR(iface->ip.s_addr, iface->nmask.s_addr);
iface->next = NULL;
if (!(*interfaces)) {
(*interfaces) = iface;
} else {
last_iface->next = iface;
}
last_iface = iface;
DEBUG(2,("Added %s ip=%s ",description,inet_ntoa(iface->ip)));
DEBUG(2,("bcast=%s ",inet_ntoa(iface->bcast)));
DEBUG(2,("nmask=%s\n",inet_ntoa(iface->nmask)));
}
if (*interfaces) return;
/* setup a default interface */
iface = (struct interface *)malloc(sizeof(*iface));
if (!iface) return;
iface->next = NULL;
if (got_ip) {
iface->ip = default_ip;
} else {
get_myname(NULL,&iface->ip);
}
if (got_bcast) {
iface->bcast = default_bcast;
} else {
get_broadcast(&iface->ip,&iface->bcast,&iface->nmask);
}
if (got_nmask) {
iface->nmask = default_nmask;
iface->bcast.s_addr = MKBCADDR(iface->ip.s_addr, iface->nmask.s_addr);
}
if (iface->bcast.s_addr != MKBCADDR(iface->ip.s_addr, iface->nmask.s_addr)) {
DEBUG(2,("Warning: inconsistant interface %s\n",inet_ntoa(iface->ip)));
}
iface->next = NULL;
(*interfaces) = last_iface = iface;
DEBUG(2,("Added interface ip=%s ",inet_ntoa(iface->ip)));
DEBUG(2,("bcast=%s ",inet_ntoa(iface->bcast)));
DEBUG(2,("nmask=%s\n",inet_ntoa(iface->nmask)));
}
/****************************************************************************
load the remote and local interfaces
****************************************************************************/
void load_interfaces(void)
{
/* add the machine's interfaces to local interface structure*/
interpret_interfaces(lp_interfaces(), &local_interfaces,"interface");
}
/****************************************************************************
override the defaults
**************************************************************************/
void iface_set_default(char *ip,char *bcast,char *nmask)
{
if (ip) {
got_ip = True;
default_ip = *interpret_addr2(ip);
}
if (bcast) {
got_bcast = True;
default_bcast = *interpret_addr2(bcast);
}
if (nmask) {
got_nmask = True;
default_nmask = *interpret_addr2(nmask);
}
}
/****************************************************************************
check if an IP is one of mine
**************************************************************************/
BOOL ismyip(struct in_addr ip)
{
struct interface *i;
for (i=local_interfaces;i;i=i->next)
if (ip_equal(i->ip,ip)) return True;
return False;
}
/****************************************************************************
check if a bcast is one of mine
**************************************************************************/
BOOL ismybcast(struct in_addr bcast)
{
struct interface *i;
for (i=local_interfaces;i;i=i->next)
if (ip_equal(i->bcast,bcast)) return True;
return False;
}
/****************************************************************************
check if a packet is from a local (known) net
**************************************************************************/
BOOL is_local_net(struct in_addr from)
{
struct interface *i;
for (i=local_interfaces;i;i=i->next)
if((from.s_addr & i->nmask.s_addr) == (i->ip.s_addr & i->nmask.s_addr))
return True;
return False;
}
/****************************************************************************
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;
}
/****************************************************************************
True if we have two or more interfaces.
**************************************************************************/
BOOL we_are_multihomed(void)
{
static int multi = -1;
if(multi == -1)
multi = (iface_count() > 1 ? True : False);
return multi;
}
/****************************************************************************
return the Nth interface
**************************************************************************/
struct interface *get_interface(int n)
{
struct interface *i;
for (i=local_interfaces;i && n;i=i->next)
n--;
if (i) return i;
return NULL;
}
/****************************************************************************
return IP of the Nth interface
**************************************************************************/
struct in_addr *iface_n_ip(int n)
{
struct interface *i;
for (i=local_interfaces;i && n;i=i->next)
n--;
if (i) return &i->ip;
return NULL;
}
/****************************************************************************
Try and find an interface that matches an ip. If we cannot, return NULL
**************************************************************************/
static struct interface *iface_find(struct in_addr ip)
{
struct interface *i;
if (zero_ip(ip)) return local_interfaces;
for (i=local_interfaces;i;i=i->next)
if (same_net(i->ip,ip,i->nmask)) return i;
return NULL;
}
/* these 3 functions return the ip/bcast/nmask for the interface
most appropriate for the given ip address. If they can't find
an appropriate interface they return the requested field of the
first known interface. */
struct in_addr *iface_bcast(struct in_addr ip)
{
struct interface *i = iface_find(ip);
return(i ? &i->bcast : &local_interfaces->bcast);
}
struct in_addr *iface_nmask(struct in_addr ip)
{
struct interface *i = iface_find(ip);
return(i ? &i->nmask : &local_interfaces->nmask);
}
struct in_addr *iface_ip(struct in_addr ip)
{
struct interface *i = iface_find(ip);
return(i ? &i->ip : &local_interfaces->ip);
}
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.