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-rw-r--r--source4/lib/interface.c333
1 files changed, 333 insertions, 0 deletions
diff --git a/source4/lib/interface.c b/source4/lib/interface.c
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index 0000000000..2540c898ff
--- /dev/null
+++ b/source4/lib/interface.c
@@ -0,0 +1,333 @@
+/*
+ Unix SMB/CIFS implementation.
+ 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"
+
+static struct iface_struct *probed_ifaces;
+static int total_probed;
+
+static struct in_addr allones_ip;
+struct in_addr loopback_ip;
+
+static struct interface *local_interfaces;
+
+#define ALLONES ((uint32)0xFFFFFFFF)
+#define MKBCADDR(_IP, _NM) ((_IP & _NM) | (_NM ^ ALLONES))
+#define MKNETADDR(_IP, _NM) (_IP & _NM)
+
+/****************************************************************************
+Try and find an interface that matches an ip. If we cannot, return NULL
+ **************************************************************************/
+static struct interface *iface_find(struct in_addr ip, BOOL CheckMask)
+{
+ struct interface *i;
+ if (is_zero_ip(ip)) return local_interfaces;
+
+ for (i=local_interfaces;i;i=i->next)
+ if (CheckMask) {
+ if (same_net(i->ip,ip,i->nmask)) return i;
+ } else if ((i->ip).s_addr == ip.s_addr) return i;
+
+ return NULL;
+}
+
+
+/****************************************************************************
+add an interface to the linked list of interfaces
+****************************************************************************/
+static void add_interface(struct in_addr ip, struct in_addr nmask)
+{
+ struct interface *iface;
+ if (iface_find(ip, False)) {
+ DEBUG(3,("not adding duplicate interface %s\n",inet_ntoa(ip)));
+ return;
+ }
+
+ if (ip_equal(nmask, allones_ip)) {
+ DEBUG(3,("not adding non-broadcast interface %s\n",inet_ntoa(ip)));
+ return;
+ }
+
+ iface = (struct interface *)malloc(sizeof(*iface));
+ if (!iface) return;
+
+ ZERO_STRUCTPN(iface);
+
+ iface->ip = ip;
+ iface->nmask = nmask;
+ iface->bcast.s_addr = MKBCADDR(iface->ip.s_addr, iface->nmask.s_addr);
+
+ DLIST_ADD(local_interfaces, 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)));
+}
+
+
+
+/****************************************************************************
+interpret a single element from a interfaces= config line
+
+This handles the following different forms:
+
+1) wildcard interface name
+2) DNS name
+3) IP/masklen
+4) ip/mask
+5) bcast/mask
+****************************************************************************/
+static void interpret_interface(TALLOC_CTX *mem_ctx, const char *token)
+{
+ struct in_addr ip, nmask;
+ char *p;
+ int i, added=0;
+
+ zero_ip(&ip);
+ zero_ip(&nmask);
+
+ /* first check if it is an interface name */
+ for (i=0;i<total_probed;i++) {
+ if (gen_fnmatch(token, probed_ifaces[i].name) == 0) {
+ add_interface(probed_ifaces[i].ip,
+ probed_ifaces[i].netmask);
+ added = 1;
+ }
+ }
+ if (added) return;
+
+ /* maybe it is a DNS name */
+ p = strchr_m(token,'/');
+ if (!p) {
+ ip = *interpret_addr2(mem_ctx, token);
+ for (i=0;i<total_probed;i++) {
+ if (ip.s_addr == probed_ifaces[i].ip.s_addr &&
+ !ip_equal(allones_ip, probed_ifaces[i].netmask)) {
+ add_interface(probed_ifaces[i].ip,
+ probed_ifaces[i].netmask);
+ return;
+ }
+ }
+ DEBUG(2,("can't determine netmask for %s\n", token));
+ return;
+ }
+
+ /* parse it into an IP address/netmasklength pair */
+ *p++ = 0;
+
+ ip = *interpret_addr2(mem_ctx, token);
+
+ if (strlen(p) > 2) {
+ nmask = *interpret_addr2(mem_ctx, p);
+ } else {
+ nmask.s_addr = htonl(((ALLONES >> atoi(p)) ^ ALLONES));
+ }
+
+ /* maybe the first component was a broadcast address */
+ if (ip.s_addr == MKBCADDR(ip.s_addr, nmask.s_addr) ||
+ ip.s_addr == MKNETADDR(ip.s_addr, nmask.s_addr)) {
+ for (i=0;i<total_probed;i++) {
+ if (same_net(ip, probed_ifaces[i].ip, nmask)) {
+ add_interface(probed_ifaces[i].ip, nmask);
+ return;
+ }
+ }
+ DEBUG(2,("Can't determine ip for broadcast address %s\n", token));
+ return;
+ }
+
+ add_interface(ip, nmask);
+}
+
+
+/****************************************************************************
+load the list of network interfaces
+****************************************************************************/
+void load_interfaces(void)
+{
+ const char **ptr;
+ int i;
+ struct iface_struct ifaces[MAX_INTERFACES];
+ TALLOC_CTX *mem_ctx;
+
+ ptr = lp_interfaces();
+ mem_ctx = talloc_init("load_interfaces");
+ if (!mem_ctx) {
+ DEBUG(2,("no memory to load interfaces \n"));
+ return;
+ }
+
+ allones_ip = *interpret_addr2(mem_ctx, "255.255.255.255");
+ loopback_ip = *interpret_addr2(mem_ctx, "127.0.0.1");
+
+ SAFE_FREE(probed_ifaces);
+
+ /* dump the current interfaces if any */
+ while (local_interfaces) {
+ struct interface *iface = local_interfaces;
+ DLIST_REMOVE(local_interfaces, local_interfaces);
+ ZERO_STRUCTPN(iface);
+ SAFE_FREE(iface);
+ }
+
+ /* probe the kernel for interfaces */
+ total_probed = get_interfaces(ifaces, MAX_INTERFACES);
+
+ if (total_probed > 0) {
+ probed_ifaces = memdup(ifaces, sizeof(ifaces[0])*total_probed);
+ }
+
+ /* if we don't have a interfaces line then use all broadcast capable
+ interfaces except loopback */
+ if (!ptr || !*ptr || !**ptr) {
+ if (total_probed <= 0) {
+ DEBUG(0,("ERROR: Could not determine network interfaces, you must use a interfaces config line\n"));
+ exit(1);
+ }
+ for (i=0;i<total_probed;i++) {
+ if (probed_ifaces[i].netmask.s_addr != allones_ip.s_addr &&
+ probed_ifaces[i].ip.s_addr != loopback_ip.s_addr) {
+ add_interface(probed_ifaces[i].ip,
+ probed_ifaces[i].netmask);
+ }
+ }
+ goto exit;
+ }
+
+ if (ptr) {
+ while (*ptr) {
+ interpret_interface(mem_ctx, *ptr);
+ ptr++;
+ }
+ }
+
+ if (!local_interfaces) {
+ DEBUG(0,("WARNING: no network interfaces found\n"));
+ }
+
+exit:
+ talloc_destroy(mem_ctx);
+}
+
+
+/****************************************************************************
+return True if the list of probed interfaces has changed
+****************************************************************************/
+BOOL interfaces_changed(void)
+{
+ int n;
+ struct iface_struct ifaces[MAX_INTERFACES];
+
+ n = get_interfaces(ifaces, MAX_INTERFACES);
+
+ if ((n > 0 )&& (n != total_probed ||
+ memcmp(ifaces, probed_ifaces, sizeof(ifaces[0])*n))) {
+ return True;
+ }
+
+ return False;
+}
+
+
+/****************************************************************************
+ 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;
+}
+
+/****************************************************************************
+ 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;
+}
+
+/****************************************************************************
+ return bcast of the Nth interface
+ **************************************************************************/
+struct in_addr *iface_n_bcast(int n)
+{
+ struct interface *i;
+
+ for (i=local_interfaces;i && n;i=i->next)
+ n--;
+
+ if (i) return &i->bcast;
+ 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_ip(struct in_addr ip)
+{
+ struct interface *i = iface_find(ip, True);
+ return(i ? &i->ip : &local_interfaces->ip);
+}
+
+/*
+ return True if a IP is directly reachable on one of our interfaces
+*/
+BOOL iface_local(struct in_addr ip)
+{
+ return iface_find(ip, True) ? True : False;
+}