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;
32 struct ipv4_addr nmask;
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 static struct ipv4_addr tov4(struct in_addr in)
54 /****************************************************************************
55 Try and find an interface that matches an ip. If we cannot, return NULL
56 **************************************************************************/
57 static struct interface *iface_find(struct in_addr ip, BOOL CheckMask)
60 if (is_zero_ip(tov4(ip))) return local_interfaces;
62 for (i=local_interfaces;i;i=i->next)
64 if (same_net(i->ip,tov4(ip),i->nmask)) return i;
65 } else if (i->ip.addr == ip.s_addr) return i;
71 /****************************************************************************
72 add an interface to the linked list of interfaces
73 ****************************************************************************/
74 static void add_interface(struct in_addr ip, struct in_addr nmask)
76 struct interface *iface;
77 struct ipv4_addr bcast;
79 if (iface_find(ip, false)) {
80 DEBUG(3,("not adding duplicate interface %s\n",inet_ntoa(ip)));
84 iface = talloc(local_interfaces == NULL ? talloc_autofree_context() : local_interfaces, struct interface);
90 iface->nmask = tov4(nmask);
91 bcast.addr = MKBCADDR(iface->ip.addr, iface->nmask.addr);
93 /* keep string versions too, to avoid people tripping over the implied
94 static in sys_inet_ntoa() */
95 iface->ip_s = talloc_strdup(iface, sys_inet_ntoa(iface->ip));
96 iface->nmask_s = talloc_strdup(iface, sys_inet_ntoa(iface->nmask));
98 if (nmask.s_addr != ~0) {
99 iface->bcast_s = talloc_strdup(iface, sys_inet_ntoa(bcast));
102 DLIST_ADD_END(local_interfaces, iface, struct interface *);
104 DEBUG(2,("added interface ip=%s nmask=%s\n", iface->ip_s, iface->nmask_s));
110 interpret a single element from a interfaces= config line
112 This handles the following different forms:
114 1) wildcard interface name
120 static void interpret_interface(const char *token,
121 struct iface_struct *probed_ifaces,
124 struct in_addr ip, nmask;
131 /* first check if it is an interface name */
132 for (i=0;i<total_probed;i++) {
133 if (gen_fnmatch(token, probed_ifaces[i].name) == 0) {
134 add_interface(probed_ifaces[i].ip,
135 probed_ifaces[i].netmask);
141 /* maybe it is a DNS name */
142 p = strchr_m(token,'/');
144 /* don't try to do dns lookups on wildcard names */
145 if (strpbrk(token, "*?") != NULL) {
148 ip.s_addr = interpret_addr2(token).addr;
149 for (i=0;i<total_probed;i++) {
150 if (ip.s_addr == probed_ifaces[i].ip.s_addr) {
151 add_interface(probed_ifaces[i].ip,
152 probed_ifaces[i].netmask);
156 DEBUG(2,("can't determine netmask for %s\n", token));
160 /* parse it into an IP address/netmasklength pair */
163 ip.s_addr = interpret_addr2(token).addr;
166 nmask.s_addr = interpret_addr2(p).addr;
168 nmask.s_addr = htonl(((ALLONES >> atoi(p)) ^ ALLONES));
171 /* maybe the first component was a broadcast address */
172 if (ip.s_addr == MKBCADDR(ip.s_addr, nmask.s_addr) ||
173 ip.s_addr == MKNETADDR(ip.s_addr, nmask.s_addr)) {
174 for (i=0;i<total_probed;i++) {
175 if (same_net(tov4(ip), tov4(probed_ifaces[i].ip), tov4(nmask))) {
176 add_interface(probed_ifaces[i].ip, nmask);
180 DEBUG(2,("Can't determine ip for broadcast address %s\n", token));
184 add_interface(ip, nmask);
189 load the list of network interfaces
191 static void load_interfaces(void)
195 struct iface_struct ifaces[MAX_INTERFACES];
196 struct ipv4_addr loopback_ip;
199 if (local_interfaces != NULL) {
203 ptr = lp_interfaces(global_loadparm);
204 loopback_ip = interpret_addr2("127.0.0.1");
206 /* probe the kernel for interfaces */
207 total_probed = get_interfaces(ifaces, MAX_INTERFACES);
209 /* if we don't have a interfaces line then use all interfaces
211 if (!ptr || !*ptr || !**ptr) {
212 if (total_probed <= 0) {
213 DEBUG(0,("ERROR: Could not determine network interfaces, you must use a interfaces config line\n"));
215 for (i=0;i<total_probed;i++) {
216 if (ifaces[i].ip.s_addr != loopback_ip.addr) {
217 add_interface(ifaces[i].ip,
223 while (ptr && *ptr) {
224 interpret_interface(*ptr, ifaces, total_probed);
228 if (!local_interfaces) {
229 DEBUG(0,("WARNING: no network interfaces found\n"));
235 unload the interfaces list, so it can be reloaded when needed
237 void unload_interfaces(void)
239 talloc_free(local_interfaces);
240 local_interfaces = NULL;
244 how many interfaces do we have
246 int iface_count(void)
253 for (i=local_interfaces;i;i=i->next)
259 return IP of the Nth interface
261 const char *iface_n_ip(int n)
267 for (i=local_interfaces;i && n;i=i->next)
277 return bcast of the Nth interface
279 const char *iface_n_bcast(int n)
285 for (i=local_interfaces;i && n;i=i->next)
295 return netmask of the Nth interface
297 const char *iface_n_netmask(int n)
303 for (i=local_interfaces;i && n;i=i->next)
313 return the local IP address that best matches a destination IP, or
314 our first interface if none match
316 const char *iface_best_ip(const char *dest)
318 struct interface *iface;
323 ip.s_addr = interpret_addr(dest);
324 iface = iface_find(ip, True);
328 return iface_n_ip(0);
332 return True if an IP is one one of our local networks
334 BOOL iface_is_local(const char *dest)
340 ip.s_addr = interpret_addr(dest);
341 if (iface_find(ip, True)) {
348 return True if a IP matches a IP/netmask pair
350 BOOL iface_same_net(const char *ip1, const char *ip2, const char *netmask)
352 return same_net(interpret_addr2(ip1),
353 interpret_addr2(ip2),
354 interpret_addr2(netmask));