1 files changed, 355 insertions, 0 deletions
diff --git a/source4/lib/netif/interface.c b/source4/lib/netif/interface.c
new file mode 100644
index 0000000000..75fdf8c976
--- /dev/null
+++ b/source4/lib/netif/interface.c
@@ -0,0 +1,355 @@
+/* 
+   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"
+#include "system/network.h"
+#include "lib/netif/netif.h"
+
+static struct iface_struct *probed_ifaces;
+static int total_probed;
+
+static struct ipv4_addr allones_ip;
+struct ipv4_addr loopback_ip;
+
+/* used for network interfaces */
+struct interface {
+	struct interface *next, *prev;
+	struct ipv4_addr ip;
+	struct ipv4_addr bcast;
+	struct ipv4_addr nmask;
+};
+
+static struct interface *local_interfaces;
+
+#define ALLONES  ((uint32_t)0xFFFFFFFF)
+#define MKBCADDR(_IP, _NM) ((_IP & _NM) | (_NM ^ ALLONES))
+#define MKNETADDR(_IP, _NM) (_IP & _NM)
+
+static struct ipv4_addr tov4(struct in_addr in)
+{
+	struct ipv4_addr in2;
+	in2.s_addr = in.s_addr;
+	return in2;
+}
+
+/****************************************************************************
+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(tov4(ip))) return local_interfaces;
+
+	for (i=local_interfaces;i;i=i->next)
+		if (CheckMask) {
+			if (same_net(i->ip,tov4(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 = tov4(ip);
+	iface->nmask = tov4(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 ",sys_inet_ntoa(iface->ip)));
+	DEBUG(2,("bcast=%s ",sys_inet_ntoa(iface->bcast)));
+	DEBUG(2,("nmask=%s\n",sys_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;
+
+	ip.s_addr = 0;
+	nmask.s_addr = 0;
+	
+	/* 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.s_addr = interpret_addr2(token).s_addr;
+		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.s_addr = interpret_addr2(token).s_addr;
+
+	if (strlen(p) > 2) {
+		nmask.s_addr = interpret_addr2(p).s_addr;
+	} 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(tov4(ip), tov4(probed_ifaces[i].ip), tov4(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("255.255.255.255");
+	loopback_ip = interpret_addr2("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 ipv4_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 ipv4_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 ipv4_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 ipv4_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 ipv4_addr *iface_ip(struct ipv4_addr ip)
+{
+	struct in_addr in;
+	struct interface *i;
+	in.s_addr = ip.s_addr;
+	i = iface_find(in, 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 ipv4_addr ip)
+{
+	struct in_addr in;
+	in.s_addr = ip.s_addr;
+	return iface_find(in, True) ? True : False;
+}