1 files changed, 335 insertions, 0 deletions
diff --git a/source4/lib/socket/interface.c b/source4/lib/socket/interface.c
new file mode 100644
index 0000000000..c327f02bbd
--- /dev/null
+++ b/source4/lib/socket/interface.c
@@ -0,0 +1,335 @@
+/* 
+   Unix SMB/CIFS implementation.
+
+   multiple interface handling
+
+   Copyright (C) Andrew Tridgell 1992-2005
+   
+   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 3 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, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "includes.h"
+#include "system/network.h"
+#include "lib/socket/netif.h"
+#include "lib/util/dlinklist.h"
+#include "param/param.h"
+
+/** used for network interfaces */
+struct interface {
+	struct interface *next, *prev;
+	struct in_addr ip;
+	struct in_addr nmask;
+	const char *ip_s;
+	const char *bcast_s;
+	const char *nmask_s;
+};
+
+#define ALLONES  ((uint32_t)0xFFFFFFFF)
+/*
+  address construction based on a patch from fred@datalync.com
+*/
+#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 interface *interfaces, 
+				    struct in_addr ip, bool CheckMask)
+{
+	struct interface *i;
+	if (is_zero_ip(ip)) return interfaces;
+
+	for (i=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(TALLOC_CTX *mem_ctx, struct in_addr ip, struct in_addr nmask, struct interface **interfaces)
+{
+	struct interface *iface;
+	struct in_addr bcast;
+
+	if (iface_find(*interfaces, ip, false)) {
+		DEBUG(3,("not adding duplicate interface %s\n",inet_ntoa(ip)));
+		return;
+	}
+
+	iface = talloc(*interfaces == NULL ? mem_ctx : *interfaces, struct interface);
+	if (iface == NULL) 
+		return;
+	
+	ZERO_STRUCTPN(iface);
+
+	iface->ip = ip;
+	iface->nmask = nmask;
+	bcast.s_addr = MKBCADDR(iface->ip.s_addr, iface->nmask.s_addr);
+
+	/* keep string versions too, to avoid people tripping over the implied
+	   static in inet_ntoa() */
+	iface->ip_s = talloc_strdup(iface, inet_ntoa(iface->ip));
+	iface->nmask_s = talloc_strdup(iface, inet_ntoa(iface->nmask));
+	
+	if (nmask.s_addr != ~0) {
+		iface->bcast_s = talloc_strdup(iface, inet_ntoa(bcast));
+	}
+
+	DLIST_ADD_END(*interfaces, iface, struct interface *);
+
+	DEBUG(2,("added interface ip=%s nmask=%s\n", iface->ip_s, iface->nmask_s));
+}
+
+
+
+/**
+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 iface_struct *probed_ifaces, 
+				int total_probed,
+				struct interface **local_interfaces)
+{
+	struct in_addr ip, nmask;
+	char *p;
+	char *address;
+	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(mem_ctx, probed_ifaces[i].ip,
+				      probed_ifaces[i].netmask,
+				      local_interfaces);
+			added = 1;
+		}
+	}
+	if (added) return;
+
+	/* maybe it is a DNS name */
+	p = strchr_m(token,'/');
+	if (!p) {
+		/* don't try to do dns lookups on wildcard names */
+		if (strpbrk(token, "*?") != NULL) {
+			return;
+		}
+		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) {
+				add_interface(mem_ctx, probed_ifaces[i].ip,
+					      probed_ifaces[i].netmask,
+					      local_interfaces);
+				return;
+			}
+		}
+		DEBUG(2,("can't determine netmask for %s\n", token));
+		return;
+	}
+
+	address = talloc_strdup(mem_ctx, token);
+	p = strchr_m(address,'/');
+
+	/* parse it into an IP address/netmasklength pair */
+	*p++ = 0;
+
+	ip.s_addr = interpret_addr2(address).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(ip, probed_ifaces[i].ip, nmask)) {
+				add_interface(mem_ctx, probed_ifaces[i].ip, nmask,
+					      local_interfaces);
+				talloc_free(address);
+				return;
+			}
+		}
+		DEBUG(2,("Can't determine ip for broadcast address %s\n", address));
+		talloc_free(address);
+		return;
+	}
+
+	add_interface(mem_ctx, ip, nmask, local_interfaces);
+	talloc_free(address);
+}
+
+
+/**
+load the list of network interfaces
+**/
+void load_interfaces(TALLOC_CTX *mem_ctx, const char **interfaces, struct interface **local_interfaces)
+{
+	const char **ptr = interfaces;
+	int i;
+	struct iface_struct ifaces[MAX_INTERFACES];
+	struct in_addr loopback_ip;
+	int total_probed;
+
+	*local_interfaces = NULL;
+
+	loopback_ip = interpret_addr2("127.0.0.1");
+
+	/* probe the kernel for interfaces */
+	total_probed = get_interfaces(ifaces, MAX_INTERFACES);
+
+	/* if we don't have a interfaces line then use all 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"));
+		}
+		for (i=0;i<total_probed;i++) {
+			if (ifaces[i].ip.s_addr != loopback_ip.s_addr) {
+				add_interface(mem_ctx, ifaces[i].ip, 
+					      ifaces[i].netmask, local_interfaces);
+			}
+		}
+	}
+
+	while (ptr && *ptr) {
+		interpret_interface(mem_ctx, *ptr, ifaces, total_probed, local_interfaces);
+		ptr++;
+	}
+
+	if (!*local_interfaces) {
+		DEBUG(0,("WARNING: no network interfaces found\n"));
+	}
+}
+
+/**
+  how many interfaces do we have
+  **/
+int iface_count(struct interface *ifaces)
+{
+	int ret = 0;
+	struct interface *i;
+
+	for (i=ifaces;i;i=i->next)
+		ret++;
+	return ret;
+}
+
+/**
+  return IP of the Nth interface
+  **/
+const char *iface_n_ip(struct interface *ifaces, int n)
+{
+	struct interface *i;
+  
+	for (i=ifaces;i && n;i=i->next)
+		n--;
+
+	if (i) {
+		return i->ip_s;
+	}
+	return NULL;
+}
+
+/**
+  return bcast of the Nth interface
+  **/
+const char *iface_n_bcast(struct interface *ifaces, int n)
+{
+	struct interface *i;
+  
+	for (i=ifaces;i && n;i=i->next)
+		n--;
+
+	if (i) {
+		return i->bcast_s;
+	}
+	return NULL;
+}
+
+/**
+  return netmask of the Nth interface
+  **/
+const char *iface_n_netmask(struct interface *ifaces, int n)
+{
+	struct interface *i;
+  
+	for (i=ifaces;i && n;i=i->next)
+		n--;
+
+	if (i) {
+		return i->nmask_s;
+	}
+	return NULL;
+}
+
+/**
+  return the local IP address that best matches a destination IP, or
+  our first interface if none match
+*/
+const char *iface_best_ip(struct interface *ifaces, const char *dest)
+{
+	struct interface *iface;
+	struct in_addr ip;
+
+	ip.s_addr = interpret_addr(dest);
+	iface = iface_find(ifaces, ip, true);
+	if (iface) {
+		return iface->ip_s;
+	}
+	return iface_n_ip(ifaces, 0);
+}
+
+/**
+  return true if an IP is one one of our local networks
+*/
+bool iface_is_local(struct interface *ifaces, const char *dest)
+{
+	struct in_addr ip;
+
+	ip.s_addr = interpret_addr(dest);
+	if (iface_find(ifaces, ip, true)) {
+		return true;
+	}
+	return false;
+}
+
+/**
+  return true if a IP matches a IP/netmask pair
+*/
+bool iface_same_net(const char *ip1, const char *ip2, const char *netmask)
+{
+	return same_net(interpret_addr2(ip1),
+			interpret_addr2(ip2),
+			interpret_addr2(netmask));
+}