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-rw-r--r--source/lib/interface.c382
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diff --git a/source/lib/interface.c b/source/lib/interface.c
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+++ b/source/lib/interface.c
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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)
+{
+ uint32 nm;
+ short onbc;
+ short offbc;
+
+ /* get a default netmask and broadcast */
+ default_netmask(if_nmask, if_ipaddr);
+
+ get_netmask(if_ipaddr, if_nmask);
+
+ /* sanity check on the netmask */
+ 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)));
+}
+
+
+
+/****************************************************************************
+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,sizeof(token))) {
+ /* 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 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;
+}
+
+
+/****************************************************************************
+this function provides a simple hash of the configured interfaces. It is
+used to detect a change in interfaces to tell us whether to discard
+the current wins.dat file.
+Note that the result is independent of the order of the interfaces
+ **************************************************************************/
+unsigned iface_hash(void)
+{
+ unsigned ret = 0;
+ struct interface *i;
+
+ for (i=local_interfaces;i;i=i->next) {
+ unsigned x1 = (unsigned)str_checksum(inet_ntoa(i->ip));
+ unsigned x2 = (unsigned)str_checksum(inet_ntoa(i->nmask));
+ ret ^= (x1 ^ x2);
+ }
+
+ return ret;
+}
+
+
+/* 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_ip(struct in_addr ip)
+{
+ struct interface *i = iface_find(ip);
+ return(i ? &i->ip : &local_interfaces->ip);
+}
+
+
+
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