2 Unix SMB/CIFS implementation.
4 multiple interface handling
6 Copyright (C) Andrew Tridgell 1992-2005
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 #include "system/network.h"
25 #include "lib/netif/netif.h"
26 #include "dlinklist.h"
28 /* used for network interfaces */
30 struct interface *next, *prev;
32 struct ipv4_addr bcast;
33 struct ipv4_addr nmask;
39 static struct interface *local_interfaces;
41 #define ALLONES ((uint32_t)0xFFFFFFFF)
43 address construction based on a patch from fred@datalync.com
45 #define MKBCADDR(_IP, _NM) ((_IP & _NM) | (_NM ^ ALLONES))
46 #define MKNETADDR(_IP, _NM) (_IP & _NM)
48 static struct ipv4_addr tov4(struct in_addr in)
55 /****************************************************************************
56 Try and find an interface that matches an ip. If we cannot, return NULL
57 **************************************************************************/
58 static struct interface *iface_find(struct in_addr ip, BOOL CheckMask)
61 if (is_zero_ip(tov4(ip))) return local_interfaces;
63 for (i=local_interfaces;i;i=i->next)
65 if (same_net(i->ip,tov4(ip),i->nmask)) return i;
66 } else if (i->ip.addr == ip.s_addr) return i;
72 /****************************************************************************
73 add an interface to the linked list of interfaces
74 ****************************************************************************/
75 static void add_interface(struct in_addr ip, struct in_addr nmask)
77 struct interface *iface;
78 if (iface_find(ip, False)) {
79 DEBUG(3,("not adding duplicate interface %s\n",inet_ntoa(ip)));
83 if (nmask.s_addr == ~0) {
84 DEBUG(3,("not adding non-broadcast interface %s\n",inet_ntoa(ip)));
88 iface = talloc(local_interfaces, struct interface);
94 iface->nmask = tov4(nmask);
95 iface->bcast.addr = MKBCADDR(iface->ip.addr, iface->nmask.addr);
97 /* keep string versions too, to avoid people tripping over the implied
98 static in sys_inet_ntoa() */
99 iface->ip_s = talloc_strdup(iface, sys_inet_ntoa(iface->ip));
100 iface->bcast_s = talloc_strdup(iface, sys_inet_ntoa(iface->bcast));
101 iface->nmask_s = talloc_strdup(iface, sys_inet_ntoa(iface->nmask));
103 DLIST_ADD_END(local_interfaces, iface, struct interface *);
105 DEBUG(2,("added interface ip=%s bcast=%s nmask=%s\n",
106 iface->ip_s, iface->bcast_s, iface->nmask_s));
111 /****************************************************************************
112 interpret a single element from a interfaces= config line
114 This handles the following different forms:
116 1) wildcard interface name
121 ****************************************************************************/
122 static void interpret_interface(const char *token,
123 struct iface_struct *probed_ifaces,
126 struct in_addr ip, nmask;
133 /* first check if it is an interface name */
134 for (i=0;i<total_probed;i++) {
135 if (gen_fnmatch(token, probed_ifaces[i].name) == 0) {
136 add_interface(probed_ifaces[i].ip,
137 probed_ifaces[i].netmask);
143 /* maybe it is a DNS name */
144 p = strchr_m(token,'/');
146 /* don't try to do dns lookups on wildcard names */
147 if (strpbrk(token, "*?") != NULL) {
150 ip.s_addr = interpret_addr2(token).addr;
151 for (i=0;i<total_probed;i++) {
152 if (ip.s_addr == probed_ifaces[i].ip.s_addr &&
153 probed_ifaces[i].netmask.s_addr != ~0) {
154 add_interface(probed_ifaces[i].ip,
155 probed_ifaces[i].netmask);
159 DEBUG(2,("can't determine netmask for %s\n", token));
163 /* parse it into an IP address/netmasklength pair */
166 ip.s_addr = interpret_addr2(token).addr;
169 nmask.s_addr = interpret_addr2(p).addr;
171 nmask.s_addr = htonl(((ALLONES >> atoi(p)) ^ ALLONES));
174 /* maybe the first component was a broadcast address */
175 if (ip.s_addr == MKBCADDR(ip.s_addr, nmask.s_addr) ||
176 ip.s_addr == MKNETADDR(ip.s_addr, nmask.s_addr)) {
177 for (i=0;i<total_probed;i++) {
178 if (same_net(tov4(ip), tov4(probed_ifaces[i].ip), tov4(nmask))) {
179 add_interface(probed_ifaces[i].ip, nmask);
183 DEBUG(2,("Can't determine ip for broadcast address %s\n", token));
187 add_interface(ip, nmask);
191 /****************************************************************************
192 load the list of network interfaces
193 ****************************************************************************/
194 static void load_interfaces(void)
198 struct iface_struct ifaces[MAX_INTERFACES];
199 struct ipv4_addr loopback_ip;
202 if (local_interfaces != NULL) {
206 ptr = lp_interfaces();
207 loopback_ip = interpret_addr2("127.0.0.1");
209 /* probe the kernel for interfaces */
210 total_probed = get_interfaces(ifaces, MAX_INTERFACES);
212 /* if we don't have a interfaces line then use all broadcast capable
213 interfaces except loopback */
214 if (!ptr || !*ptr || !**ptr) {
215 if (total_probed <= 0) {
216 DEBUG(0,("ERROR: Could not determine network interfaces, you must use a interfaces config line\n"));
218 for (i=0;i<total_probed;i++) {
219 if (ifaces[i].netmask.s_addr != ~0 &&
220 ifaces[i].ip.s_addr != loopback_ip.addr) {
221 add_interface(ifaces[i].ip,
227 while (ptr && *ptr) {
228 interpret_interface(*ptr, ifaces, total_probed);
232 if (!local_interfaces) {
233 DEBUG(0,("WARNING: no network interfaces found\n"));
239 unload the interfaces list, so it can be reloaded when needed
241 void unload_interfaces(void)
243 talloc_free(local_interfaces);
244 local_interfaces = NULL;
247 /****************************************************************************
248 how many interfaces do we have
249 **************************************************************************/
250 int iface_count(void)
257 for (i=local_interfaces;i;i=i->next)
262 /****************************************************************************
263 return IP of the Nth interface
264 **************************************************************************/
265 const char *iface_n_ip(int n)
271 for (i=local_interfaces;i && n;i=i->next)
280 /****************************************************************************
281 return bcast of the Nth interface
282 **************************************************************************/
283 const char *iface_n_bcast(int n)
289 for (i=local_interfaces;i && n;i=i->next)
298 /****************************************************************************
299 return netmask of the Nth interface
300 **************************************************************************/
301 const char *iface_n_netmask(int n)
307 for (i=local_interfaces;i && n;i=i->next)
317 return the local IP address that best matches a destination IP, or
318 our first interface if none match
320 const char *iface_best_ip(const char *dest)
322 struct interface *iface;
327 ip.s_addr = interpret_addr(dest);
328 iface = iface_find(ip, True);
332 return iface_n_ip(0);
336 return True if an IP is one one of our local networks
338 BOOL iface_is_local(const char *dest)
344 ip.s_addr = interpret_addr(dest);
345 if (iface_find(ip, True)) {
352 return True if a IP matches a IP/netmask pair
354 BOOL iface_same_net(const char *ip1, const char *ip2, const char *netmask)
356 return same_net(interpret_addr2(ip1),
357 interpret_addr2(ip2),
358 interpret_addr2(netmask));