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 3 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, see <http://www.gnu.org/licenses/>.
23 #include "system/network.h"
24 #include "lib/socket/netif.h"
25 #include "lib/util/dlinklist.h"
26 #include "param/param.h"
28 /** used for network interfaces */
30 struct interface *next, *prev;
38 static struct interface *local_interfaces;
40 #define ALLONES ((uint32_t)0xFFFFFFFF)
42 address construction based on a patch from fred@datalync.com
44 #define MKBCADDR(_IP, _NM) ((_IP & _NM) | (_NM ^ ALLONES))
45 #define MKNETADDR(_IP, _NM) (_IP & _NM)
47 /****************************************************************************
48 Try and find an interface that matches an ip. If we cannot, return NULL
49 **************************************************************************/
50 static struct interface *iface_find(struct in_addr ip, bool CheckMask)
53 if (is_zero_ip(ip)) return local_interfaces;
55 for (i=local_interfaces;i;i=i->next)
57 if (same_net(i->ip,ip,i->nmask)) return i;
58 } else if (i->ip.s_addr == ip.s_addr) return i;
64 /****************************************************************************
65 add an interface to the linked list of interfaces
66 ****************************************************************************/
67 static void add_interface(struct in_addr ip, struct in_addr nmask)
69 struct interface *iface;
72 if (iface_find(ip, false)) {
73 DEBUG(3,("not adding duplicate interface %s\n",inet_ntoa(ip)));
77 iface = talloc(local_interfaces == NULL ? talloc_autofree_context() : local_interfaces, struct interface);
84 bcast.s_addr = MKBCADDR(iface->ip.s_addr, iface->nmask.s_addr);
86 /* keep string versions too, to avoid people tripping over the implied
87 static in inet_ntoa() */
88 iface->ip_s = talloc_strdup(iface, inet_ntoa(iface->ip));
89 iface->nmask_s = talloc_strdup(iface, inet_ntoa(iface->nmask));
91 if (nmask.s_addr != ~0) {
92 iface->bcast_s = talloc_strdup(iface, inet_ntoa(bcast));
95 DLIST_ADD_END(local_interfaces, iface, struct interface *);
97 DEBUG(2,("added interface ip=%s nmask=%s\n", iface->ip_s, iface->nmask_s));
103 interpret a single element from a interfaces= config line
105 This handles the following different forms:
107 1) wildcard interface name
113 static void interpret_interface(const char *token,
114 struct iface_struct *probed_ifaces,
117 struct in_addr ip, nmask;
124 /* first check if it is an interface name */
125 for (i=0;i<total_probed;i++) {
126 if (gen_fnmatch(token, probed_ifaces[i].name) == 0) {
127 add_interface(probed_ifaces[i].ip,
128 probed_ifaces[i].netmask);
134 /* maybe it is a DNS name */
135 p = strchr_m(token,'/');
137 /* don't try to do dns lookups on wildcard names */
138 if (strpbrk(token, "*?") != NULL) {
141 ip.s_addr = interpret_addr2(token).s_addr;
142 for (i=0;i<total_probed;i++) {
143 if (ip.s_addr == probed_ifaces[i].ip.s_addr) {
144 add_interface(probed_ifaces[i].ip,
145 probed_ifaces[i].netmask);
149 DEBUG(2,("can't determine netmask for %s\n", token));
153 /* parse it into an IP address/netmasklength pair */
156 ip.s_addr = interpret_addr2(token).s_addr;
159 nmask.s_addr = interpret_addr2(p).s_addr;
161 nmask.s_addr = htonl(((ALLONES >> atoi(p)) ^ ALLONES));
164 /* maybe the first component was a broadcast address */
165 if (ip.s_addr == MKBCADDR(ip.s_addr, nmask.s_addr) ||
166 ip.s_addr == MKNETADDR(ip.s_addr, nmask.s_addr)) {
167 for (i=0;i<total_probed;i++) {
168 if (same_net(ip, probed_ifaces[i].ip, nmask)) {
169 add_interface(probed_ifaces[i].ip, nmask);
173 DEBUG(2,("Can't determine ip for broadcast address %s\n", token));
177 add_interface(ip, nmask);
182 load the list of network interfaces
184 static void load_interfaces(const char **interfaces)
186 const char **ptr = interfaces;
188 struct iface_struct ifaces[MAX_INTERFACES];
189 struct in_addr loopback_ip;
192 if (local_interfaces != NULL) {
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 interfaces
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].ip.s_addr != loopback_ip.s_addr) {
209 add_interface(ifaces[i].ip,
215 while (ptr && *ptr) {
216 interpret_interface(*ptr, ifaces, total_probed);
220 if (!local_interfaces) {
221 DEBUG(0,("WARNING: no network interfaces found\n"));
227 unload the interfaces list, so it can be reloaded when needed
229 void unload_interfaces(void)
231 talloc_free(local_interfaces);
232 local_interfaces = NULL;
236 how many interfaces do we have
238 int iface_count(void)
243 load_interfaces(lp_interfaces(global_loadparm));
245 for (i=local_interfaces;i;i=i->next)
251 return IP of the Nth interface
253 const char *iface_n_ip(int n)
257 load_interfaces(lp_interfaces(global_loadparm));
259 for (i=local_interfaces;i && n;i=i->next)
269 return bcast of the Nth interface
271 const char *iface_n_bcast(int n)
275 load_interfaces(lp_interfaces(global_loadparm));
277 for (i=local_interfaces;i && n;i=i->next)
287 return netmask of the Nth interface
289 const char *iface_n_netmask(int n)
293 load_interfaces(lp_interfaces(global_loadparm));
295 for (i=local_interfaces;i && n;i=i->next)
305 return the local IP address that best matches a destination IP, or
306 our first interface if none match
308 const char *iface_best_ip(const char *dest)
310 struct interface *iface;
313 load_interfaces(lp_interfaces(global_loadparm));
315 ip.s_addr = interpret_addr(dest);
316 iface = iface_find(ip, true);
320 return iface_n_ip(0);
324 return true if an IP is one one of our local networks
326 bool iface_is_local(const char *dest)
330 load_interfaces(lp_interfaces(global_loadparm));
332 ip.s_addr = interpret_addr(dest);
333 if (iface_find(ip, true)) {
340 return true if a IP matches a IP/netmask pair
342 bool iface_same_net(const char *ip1, const char *ip2, const char *netmask)
344 return same_net(interpret_addr2(ip1),
345 interpret_addr2(ip2),
346 interpret_addr2(netmask));