2 Unix SMB/Netbios implementation.
4 multiple interface handling
5 Copyright (C) Andrew Tridgell 1992-1997
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 extern int DEBUGLEVEL;
26 struct in_addr ipzero;
27 struct in_addr wins_ip;
28 struct in_addr loopback_ip;
29 static struct in_addr default_ip;
30 static struct in_addr default_bcast;
31 static struct in_addr default_nmask;
32 static BOOL got_ip=False;
33 static BOOL got_bcast=False;
34 static BOOL got_nmask=False;
36 struct interface *local_interfaces = NULL;
38 struct interface *last_iface;
40 /****************************************************************************
41 calculate the default netmask for an address
42 ****************************************************************************/
43 static void default_netmask(struct in_addr *inm, struct in_addr *iad)
45 uint32 ad = ntohl(iad->s_addr);
48 ** Guess a netmask based on the class of the IP address given.
50 if ( (ad & 0x80000000) == 0 ) {
53 } else if ( (ad & 0xC0000000) == 0x80000000 ) {
56 } else if ( (ad & 0xE0000000) == 0xC0000000 ) {
60 /* class D or E; netmask doesn't make much sense - guess 4 bits */
63 inm->s_addr = htonl(nm);
67 /****************************************************************************
68 get the broadcast address for our address
69 (troyer@saifr00.ateng.az.honeywell.com)
70 ****************************************************************************/
71 static void get_broadcast(struct in_addr *if_ipaddr,
72 struct in_addr *if_bcast,
73 struct in_addr *if_nmask)
76 #ifndef NO_GET_BROADCAST
77 int sock = -1; /* AF_INET raw socket desc */
79 struct ifreq *ifr=NULL;
86 #elif defined(USE_IFREQ)
88 struct strioctl strioctl;
95 /* get a default netmask and broadcast */
96 default_netmask(if_nmask, if_ipaddr);
98 #ifndef NO_GET_BROADCAST
99 /* Create a socket to the INET kernel. */
101 if ((sock = socket(AF_INET, SOCK_RAW, PF_INET )) < 0)
103 if ((sock = socket(AF_INET, SOCK_DGRAM, 0 )) < 0)
106 DEBUG(0,( "Unable to open socket to get broadcast address\n"));
110 /* Get a list of the configured interfaces */
112 /* This is part of SCO Openserver 5: The ioctls are no longer part
113 if the lower level STREAMS interface glue. They are now real
116 if (ioctl(sock, SIOCGIFANUM, &n_interfaces) < 0) {
117 DEBUG(0,( "SIOCGIFANUM: %s\n", strerror(errno)));
119 DEBUG(0,( "number of interfaces returned is: %d\n", n_interfaces));
121 ifc.ifc_len = sizeof(struct ifreq) * n_interfaces;
122 ifc.ifc_buf = (caddr_t) alloca(ifc.ifc_len);
124 if (ioctl(sock, SIOCGIFCONF, &ifc) < 0)
125 DEBUG(0, ( "SIOCGIFCONF: %s\n", strerror(errno)));
129 for (i = 0; i < n_interfaces; ++i) {
130 if (if_ipaddr->s_addr ==
131 ((struct sockaddr_in *) &ifr[i].ifr_addr)->sin_addr.s_addr) {
138 #elif defined(USE_IFREQ)
139 ifc = (struct ifconf *)buff;
140 ifc->ifc_len = BUFSIZ - sizeof(struct ifconf);
141 strioctl.ic_cmd = SIOCGIFCONF;
142 strioctl.ic_dp = (char *)ifc;
143 strioctl.ic_len = sizeof(buff);
144 if (ioctl(sock, I_STR, &strioctl) < 0) {
145 DEBUG(0,( "I_STR/SIOCGIFCONF: %s\n", strerror(errno)));
147 ifr = (struct ifreq *)ifc->ifc_req;
149 /* Loop through interfaces, looking for given IP address */
150 for (i = ifc->ifc_len / sizeof(struct ifreq); --i >= 0; ifr++) {
151 if (if_ipaddr->s_addr ==
152 (*(struct sockaddr_in *) &ifr->ifr_addr).sin_addr.s_addr) {
158 #elif defined(__FreeBSD__) || defined(NETBSD) || defined(AMIGA) || defined(_AIX41)
159 ifc.ifc_len = sizeof(buff);
161 if (ioctl(sock, SIOCGIFCONF, &ifc) < 0) {
162 DEBUG(0,("SIOCGIFCONF: %s\n", strerror(errno)));
165 /* Loop through interfaces, looking for given IP address */
168 if (if_ipaddr->s_addr ==
169 (*(struct sockaddr_in *) &ifr->ifr_addr).sin_addr.s_addr) {
173 i -= ifr->ifr_addr.sa_len + IFNAMSIZ;
174 ifr = (struct ifreq*) ((char*) ifr + ifr->ifr_addr.sa_len + IFNAMSIZ);
178 ifc.ifc_len = sizeof(buff);
180 if (ioctl(sock, SIOCGIFCONF, &ifc) < 0) {
181 DEBUG(0,("SIOCGIFCONF: %s\n", strerror(errno)));
185 /* Loop through interfaces, looking for given IP address */
186 for (i = ifc.ifc_len / sizeof(struct ifreq); --i >= 0; ifr++) {
188 if (ioctl(sock, SIOCGIFADDR, ifr) < 0) break;
190 if (if_ipaddr->s_addr ==
191 (*(struct sockaddr_in *) &ifr->ifr_addr).sin_addr.s_addr) {
200 DEBUG(0,("No interface found for address %s\n", inet_ntoa(*if_ipaddr)));
202 /* Get the netmask address from the kernel */
206 strioctl.ic_cmd = SIOCGIFNETMASK;
207 strioctl.ic_dp = (char *)&ifreq;
208 strioctl.ic_len = sizeof(struct ifreq);
209 if (ioctl(sock, I_STR, &strioctl) < 0)
210 DEBUG(0,("Failed I_STR/SIOCGIFNETMASK: %s\n", strerror(errno)));
212 *if_nmask = ((struct sockaddr_in *)&ifreq.ifr_addr)->sin_addr;
214 if (ioctl(sock, SIOCGIFNETMASK, ifr) < 0)
215 DEBUG(0,("SIOCGIFNETMASK failed\n"));
217 *if_nmask = ((struct sockaddr_in *)&ifr->ifr_addr)->sin_addr;
220 DEBUG(4,("Netmask for %s = %s\n", ifr->ifr_name,
221 inet_ntoa(*if_nmask)));
229 /* sanity check on the netmask */
231 uint32 nm = ntohl(if_nmask->s_addr);
232 if ((nm >> 24) != 0xFF) {
233 DEBUG(0,("Impossible netmask %s - using defaults\n",inet_ntoa(*if_nmask)));
234 default_netmask(if_nmask, if_ipaddr);
238 /* derive the broadcast assuming a 1's broadcast, as this is what
239 all MS operating systems do, we have to comply even if the unix
240 box is setup differently */
242 uint32 ad = ntohl(if_ipaddr->s_addr);
243 uint32 nm = ntohl(if_nmask->s_addr);
244 uint32 bc = (ad & nm) | (0xffffffff & ~nm);
245 if_bcast->s_addr = htonl(bc);
248 DEBUG(4,("Derived broadcast address %s\n", inet_ntoa(*if_bcast)));
249 } /* get_broadcast */
253 /****************************************************************************
254 load a list of network interfaces
255 ****************************************************************************/
256 static void interpret_interfaces(char *s, struct interface **interfaces,
261 struct interface *iface;
264 ipzero = *interpret_addr2("0.0.0.0");
265 wins_ip = *interpret_addr2("255.255.255.255");
266 loopback_ip = *interpret_addr2("127.0.0.1");
268 while (next_token(&ptr,token,NULL)) {
269 /* parse it into an IP address/netmasklength pair */
270 char *p = strchr(token,'/');
273 ip = *interpret_addr2(token);
275 /* maybe we already have it listed */
278 for (i=(*interfaces);i;i=i->next)
279 if (ip_equal(ip,i->ip)) break;
283 iface = (struct interface *)malloc(sizeof(*iface));
290 iface->nmask = *interpret_addr2(p+1);
292 iface->nmask.s_addr = htonl(~((1<<(32-atoi(p+1)))-1));
294 default_netmask(&iface->nmask,&iface->ip);
296 iface->bcast.s_addr = iface->ip.s_addr | ~iface->nmask.s_addr;
299 if (!(*interfaces)) {
300 (*interfaces) = iface;
302 last_iface->next = iface;
305 DEBUG(2,("Added %s ip=%s ",description,inet_ntoa(iface->ip)));
306 DEBUG(2,("bcast=%s ",inet_ntoa(iface->bcast)));
307 DEBUG(2,("nmask=%s\n",inet_ntoa(iface->nmask)));
310 if (*interfaces) return;
312 /* setup a default interface */
313 iface = (struct interface *)malloc(sizeof(*iface));
319 iface->ip = default_ip;
321 get_myname(NULL,&iface->ip);
325 iface->bcast = default_bcast;
327 get_broadcast(&iface->ip,&iface->bcast,&iface->nmask);
331 iface->nmask = default_nmask;
332 iface->bcast.s_addr = iface->ip.s_addr | ~iface->nmask.s_addr;
335 if (iface->bcast.s_addr != (iface->ip.s_addr | ~iface->nmask.s_addr)) {
336 DEBUG(2,("Warning: inconsistant interface %s\n",inet_ntoa(iface->ip)));
340 (*interfaces) = last_iface = iface;
342 DEBUG(2,("Added interface ip=%s ",inet_ntoa(iface->ip)));
343 DEBUG(2,("bcast=%s ",inet_ntoa(iface->bcast)));
344 DEBUG(2,("nmask=%s\n",inet_ntoa(iface->nmask)));
348 /****************************************************************************
349 load the remote and local interfaces
350 ****************************************************************************/
351 void load_interfaces(void)
353 /* add the machine's interfaces to local interface structure*/
354 interpret_interfaces(lp_interfaces(), &local_interfaces,"interface");
358 /****************************************************************************
359 override the defaults
360 **************************************************************************/
361 void iface_set_default(char *ip,char *bcast,char *nmask)
365 default_ip = *interpret_addr2(ip);
370 default_bcast = *interpret_addr2(bcast);
375 default_nmask = *interpret_addr2(nmask);
380 /****************************************************************************
381 check if an IP is one of mine
382 **************************************************************************/
383 BOOL ismyip(struct in_addr ip)
386 for (i=local_interfaces;i;i=i->next)
387 if (ip_equal(i->ip,ip)) return True;
391 /****************************************************************************
392 check if a bcast is one of mine
393 **************************************************************************/
394 BOOL ismybcast(struct in_addr bcast)
397 for (i=local_interfaces;i;i=i->next)
398 if (ip_equal(i->bcast,bcast)) return True;
402 /****************************************************************************
403 check if a packet is from a local (known) net
404 **************************************************************************/
405 BOOL is_local_net(struct in_addr from)
408 for (i=local_interfaces;i;i=i->next)
409 if((from.s_addr & i->nmask.s_addr) == (i->ip.s_addr & i->nmask.s_addr))
414 /****************************************************************************
415 how many interfaces do we have
416 **************************************************************************/
417 int iface_count(void)
422 for (i=local_interfaces;i;i=i->next)
427 /****************************************************************************
428 return IP of the Nth interface
429 **************************************************************************/
430 struct in_addr *iface_n_ip(int n)
434 for (i=local_interfaces;i && n;i=i->next)
437 if (i) return &i->ip;
441 /****************************************************************************
442 Try and find an interface that matches an ip. If we cannot, return NULL
443 **************************************************************************/
444 static struct interface *iface_find(struct in_addr ip)
447 if (zero_ip(ip)) return local_interfaces;
449 for (i=local_interfaces;i;i=i->next)
450 if (same_net(i->ip,ip,i->nmask)) return i;
455 /* these 3 functions return the ip/bcast/nmask for the interface
456 most appropriate for the given ip address */
458 struct in_addr *iface_bcast(struct in_addr ip)
460 struct interface *i = iface_find(ip);
461 return(i ? &i->bcast : &local_interfaces->bcast);
464 struct in_addr *iface_nmask(struct in_addr ip)
466 struct interface *i = iface_find(ip);
467 return(i ? &i->nmask : &local_interfaces->nmask);
470 struct in_addr *iface_ip(struct in_addr ip)
472 struct interface *i = iface_find(ip);
473 return(i ? &i->ip : &local_interfaces->ip);