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"
27 /** used for network interfaces */
29 struct interface *next, *prev;
37 #define ALLONES ((uint32_t)0xFFFFFFFF)
39 address construction based on a patch from fred@datalync.com
41 #define MKBCADDR(_IP, _NM) ((_IP & _NM) | (_NM ^ ALLONES))
42 #define MKNETADDR(_IP, _NM) (_IP & _NM)
44 /****************************************************************************
45 Try and find an interface that matches an ip. If we cannot, return NULL
46 **************************************************************************/
47 static struct interface *iface_find(struct interface *interfaces,
48 struct in_addr ip, bool CheckMask)
51 if (is_zero_ip_v4(ip)) return interfaces;
53 for (i=interfaces;i;i=i->next)
55 if (same_net_v4(i->ip,ip,i->nmask)) return i;
56 } else if (i->ip.s_addr == ip.s_addr) return i;
62 /****************************************************************************
63 add an interface to the linked list of interfaces
64 ****************************************************************************/
65 static void add_interface(TALLOC_CTX *mem_ctx, struct in_addr ip, struct in_addr nmask, struct interface **interfaces)
67 struct interface *iface;
70 if (iface_find(*interfaces, ip, false)) {
71 DEBUG(3,("not adding duplicate interface %s\n",inet_ntoa(ip)));
75 iface = talloc(*interfaces == NULL ? mem_ctx : *interfaces, struct interface);
83 bcast.s_addr = MKBCADDR(iface->ip.s_addr, iface->nmask.s_addr);
85 /* keep string versions too, to avoid people tripping over the implied
86 static in inet_ntoa() */
87 iface->ip_s = talloc_strdup(iface, inet_ntoa(iface->ip));
88 iface->nmask_s = talloc_strdup(iface, inet_ntoa(iface->nmask));
90 if (nmask.s_addr != ~0) {
91 iface->bcast_s = talloc_strdup(iface, inet_ntoa(bcast));
94 DLIST_ADD_END(*interfaces, iface, struct interface *);
96 DEBUG(2,("added interface ip=%s nmask=%s\n", iface->ip_s, iface->nmask_s));
102 interpret a single element from a interfaces= config line
104 This handles the following different forms:
106 1) wildcard interface name
112 static void interpret_interface(TALLOC_CTX *mem_ctx,
114 struct iface_struct *probed_ifaces,
116 struct interface **local_interfaces)
118 struct in_addr ip, nmask;
126 /* first check if it is an interface name */
127 for (i=0;i<total_probed;i++) {
128 if (gen_fnmatch(token, probed_ifaces[i].name) == 0) {
129 add_interface(mem_ctx, probed_ifaces[i].ip,
130 probed_ifaces[i].netmask,
137 /* maybe it is a DNS name */
138 p = strchr_m(token,'/');
140 /* don't try to do dns lookups on wildcard names */
141 if (strpbrk(token, "*?") != NULL) {
144 ip.s_addr = interpret_addr2(token).s_addr;
145 for (i=0;i<total_probed;i++) {
146 if (ip.s_addr == probed_ifaces[i].ip.s_addr) {
147 add_interface(mem_ctx, probed_ifaces[i].ip,
148 probed_ifaces[i].netmask,
153 DEBUG(2,("can't determine netmask for %s\n", token));
157 address = talloc_strdup(mem_ctx, token);
158 p = strchr_m(address,'/');
160 /* parse it into an IP address/netmasklength pair */
163 ip.s_addr = interpret_addr2(address).s_addr;
166 nmask.s_addr = interpret_addr2(p).s_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_v4(ip, probed_ifaces[i].ip, nmask)) {
176 add_interface(mem_ctx, probed_ifaces[i].ip, nmask,
178 talloc_free(address);
182 DEBUG(2,("Can't determine ip for broadcast address %s\n", address));
183 talloc_free(address);
187 add_interface(mem_ctx, ip, nmask, local_interfaces);
188 talloc_free(address);
193 load the list of network interfaces
195 void load_interfaces(TALLOC_CTX *mem_ctx, const char **interfaces, struct interface **local_interfaces)
197 const char **ptr = interfaces;
199 struct iface_struct ifaces[MAX_INTERFACES];
200 struct in_addr loopback_ip;
203 *local_interfaces = NULL;
205 loopback_ip = interpret_addr2("127.0.0.1");
207 /* probe the kernel for interfaces */
208 total_probed = get_interfaces(ifaces, MAX_INTERFACES);
210 /* if we don't have a interfaces line then use all interfaces
212 if (!ptr || !*ptr || !**ptr) {
213 if (total_probed <= 0) {
214 DEBUG(0,("ERROR: Could not determine network interfaces, you must use a interfaces config line\n"));
216 for (i=0;i<total_probed;i++) {
217 if (ifaces[i].ip.s_addr != loopback_ip.s_addr) {
218 add_interface(mem_ctx, ifaces[i].ip,
219 ifaces[i].netmask, local_interfaces);
224 while (ptr && *ptr) {
225 interpret_interface(mem_ctx, *ptr, ifaces, total_probed, local_interfaces);
229 if (!*local_interfaces) {
230 DEBUG(0,("WARNING: no network interfaces found\n"));
235 how many interfaces do we have
237 int iface_count(struct interface *ifaces)
242 for (i=ifaces;i;i=i->next)
248 return IP of the Nth interface
250 const char *iface_n_ip(struct interface *ifaces, int n)
254 for (i=ifaces;i && n;i=i->next)
264 return bcast of the Nth interface
266 const char *iface_n_bcast(struct interface *ifaces, int n)
270 for (i=ifaces;i && n;i=i->next)
280 return netmask of the Nth interface
282 const char *iface_n_netmask(struct interface *ifaces, int n)
286 for (i=ifaces;i && n;i=i->next)
296 return the local IP address that best matches a destination IP, or
297 our first interface if none match
299 const char *iface_best_ip(struct interface *ifaces, const char *dest)
301 struct interface *iface;
304 ip.s_addr = interpret_addr(dest);
305 iface = iface_find(ifaces, ip, true);
309 return iface_n_ip(ifaces, 0);
313 return true if an IP is one one of our local networks
315 bool iface_is_local(struct interface *ifaces, const char *dest)
319 ip.s_addr = interpret_addr(dest);
320 if (iface_find(ifaces, ip, true)) {
327 return true if a IP matches a IP/netmask pair
329 bool iface_same_net(const char *ip1, const char *ip2, const char *netmask)
331 return same_net_v4(interpret_addr2(ip1),
332 interpret_addr2(ip2),
333 interpret_addr2(netmask));