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;
36 static struct interface *local_interfaces;
38 #define ALLONES ((uint32_t)0xFFFFFFFF)
39 #define MKBCADDR(_IP, _NM) ((_IP & _NM) | (_NM ^ ALLONES))
40 #define MKNETADDR(_IP, _NM) (_IP & _NM)
42 static struct ipv4_addr tov4(struct in_addr in)
49 /****************************************************************************
50 Try and find an interface that matches an ip. If we cannot, return NULL
51 **************************************************************************/
52 static struct interface *iface_find(struct in_addr ip, BOOL CheckMask)
55 if (is_zero_ip(tov4(ip))) return local_interfaces;
57 for (i=local_interfaces;i;i=i->next)
59 if (same_net(i->ip,tov4(ip),i->nmask)) return i;
60 } else if (i->ip.addr == ip.s_addr) return i;
66 /****************************************************************************
67 add an interface to the linked list of interfaces
68 ****************************************************************************/
69 static void add_interface(struct in_addr ip, struct in_addr nmask)
71 struct interface *iface;
72 if (iface_find(ip, False)) {
73 DEBUG(3,("not adding duplicate interface %s\n",inet_ntoa(ip)));
77 if (nmask.s_addr == ~0) {
78 DEBUG(3,("not adding non-broadcast interface %s\n",inet_ntoa(ip)));
82 iface = talloc(local_interfaces, struct interface);
88 iface->nmask = tov4(nmask);
89 iface->bcast.addr = MKBCADDR(iface->ip.addr, iface->nmask.addr);
91 DLIST_ADD_END(local_interfaces, iface, struct interface *);
93 DEBUG(2,("added interface ip=%s ",sys_inet_ntoa(iface->ip)));
94 DEBUG(2,("bcast=%s ",sys_inet_ntoa(iface->bcast)));
95 DEBUG(2,("nmask=%s\n",sys_inet_ntoa(iface->nmask)));
100 /****************************************************************************
101 interpret a single element from a interfaces= config line
103 This handles the following different forms:
105 1) wildcard interface name
110 ****************************************************************************/
111 static void interpret_interface(const char *token,
112 struct iface_struct *probed_ifaces,
115 struct in_addr ip, nmask;
122 /* first check if it is an interface name */
123 for (i=0;i<total_probed;i++) {
124 if (gen_fnmatch(token, probed_ifaces[i].name) == 0) {
125 add_interface(probed_ifaces[i].ip,
126 probed_ifaces[i].netmask);
132 /* maybe it is a DNS name */
133 p = strchr_m(token,'/');
135 /* don't try to do dns lookups on wildcard names */
136 if (strpbrk(token, "*?") != NULL) {
139 ip.s_addr = interpret_addr2(token).addr;
140 for (i=0;i<total_probed;i++) {
141 if (ip.s_addr == probed_ifaces[i].ip.s_addr &&
142 probed_ifaces[i].netmask.s_addr != ~0) {
143 add_interface(probed_ifaces[i].ip,
144 probed_ifaces[i].netmask);
148 DEBUG(2,("can't determine netmask for %s\n", token));
152 /* parse it into an IP address/netmasklength pair */
155 ip.s_addr = interpret_addr2(token).addr;
158 nmask.s_addr = interpret_addr2(p).addr;
160 nmask.s_addr = htonl(((ALLONES >> atoi(p)) ^ ALLONES));
163 /* maybe the first component was a broadcast address */
164 if (ip.s_addr == MKBCADDR(ip.s_addr, nmask.s_addr) ||
165 ip.s_addr == MKNETADDR(ip.s_addr, nmask.s_addr)) {
166 for (i=0;i<total_probed;i++) {
167 if (same_net(tov4(ip), tov4(probed_ifaces[i].ip), tov4(nmask))) {
168 add_interface(probed_ifaces[i].ip, nmask);
172 DEBUG(2,("Can't determine ip for broadcast address %s\n", token));
176 add_interface(ip, nmask);
180 /****************************************************************************
181 load the list of network interfaces
182 ****************************************************************************/
183 static void load_interfaces(void)
187 struct iface_struct ifaces[MAX_INTERFACES];
188 struct ipv4_addr loopback_ip;
191 if (local_interfaces != NULL) {
195 ptr = lp_interfaces();
196 loopback_ip = interpret_addr2("127.0.0.1");
198 /* probe the kernel for interfaces */
199 total_probed = get_interfaces(ifaces, MAX_INTERFACES);
201 /* if we don't have a interfaces line then use all broadcast capable
202 interfaces except loopback */
203 if (!ptr || !*ptr || !**ptr) {
204 if (total_probed <= 0) {
205 DEBUG(0,("ERROR: Could not determine network interfaces, you must use a interfaces config line\n"));
207 for (i=0;i<total_probed;i++) {
208 if (ifaces[i].netmask.s_addr != ~0 &&
209 ifaces[i].ip.s_addr != loopback_ip.addr) {
210 add_interface(ifaces[i].ip,
216 while (ptr && *ptr) {
217 interpret_interface(*ptr, ifaces, total_probed);
221 if (!local_interfaces) {
222 DEBUG(0,("WARNING: no network interfaces found\n"));
228 unload the interfaces list, so it can be reloaded when needed
230 void unload_interfaces(void)
232 talloc_free(local_interfaces);
233 local_interfaces = NULL;
236 /****************************************************************************
237 how many interfaces do we have
238 **************************************************************************/
239 int iface_count(void)
246 for (i=local_interfaces;i;i=i->next)
251 /****************************************************************************
252 return IP of the Nth interface
253 **************************************************************************/
254 const char *iface_n_ip(int n)
260 for (i=local_interfaces;i && n;i=i->next)
264 return sys_inet_ntoa(i->ip);
269 /****************************************************************************
270 return bcast of the Nth interface
271 **************************************************************************/
272 const char *iface_n_bcast(int n)
278 for (i=local_interfaces;i && n;i=i->next)
282 return sys_inet_ntoa(i->bcast);
287 /****************************************************************************
288 return netmask of the Nth interface
289 **************************************************************************/
290 const char *iface_n_netmask(int n)
296 for (i=local_interfaces;i && n;i=i->next)
300 return sys_inet_ntoa(i->nmask);
306 return the local IP address that best matches a destination IP, or
307 our first interface if none match
309 const char *iface_best_ip(const char *dest)
311 struct interface *iface;
316 ip.s_addr = interpret_addr(dest);
317 iface = iface_find(ip, True);
319 return sys_inet_ntoa(iface->ip);
321 return iface_n_ip(0);
325 return True if an IP is one one of our local networks
327 BOOL iface_is_local(const char *dest)
333 ip.s_addr = interpret_addr(dest);
334 if (iface_find(ip, True)) {
341 return True if a IP matches a IP/netmask pair
343 BOOL iface_same_net(const char *ip1, const char *ip2, const char *netmask)
345 return same_net(interpret_addr2(ip1),
346 interpret_addr2(ip2),
347 interpret_addr2(netmask));