/uClinux-dist/user/samba/source/lib/interface.c
C | 363 lines | 226 code | 62 blank | 75 comment | 58 complexity | b0a76ff56b92a8d7c5787110403109b9 MD5 | raw file
Possible License(s): AGPL-3.0, GPL-2.0, LGPL-2.0, MPL-2.0, ISC, BSD-3-Clause, LGPL-2.1, MPL-2.0-no-copyleft-exception, 0BSD, CC-BY-SA-3.0, GPL-3.0, LGPL-3.0, AGPL-1.0, Unlicense
- /*
- Unix SMB/CIFS implementation.
- multiple interface handling
- Copyright (C) Andrew Tridgell 1992-1998
-
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
- (at your option) any later version.
-
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- */
- #include "includes.h"
- static struct iface_struct *probed_ifaces;
- static int total_probed;
- struct in_addr allones_ip;
- struct in_addr loopback_ip;
- static struct interface *local_interfaces;
- #define ALLONES ((uint32)0xFFFFFFFF)
- #define MKBCADDR(_IP, _NM) ((_IP & _NM) | (_NM ^ ALLONES))
- #define MKNETADDR(_IP, _NM) (_IP & _NM)
- /****************************************************************************
- Try and find an interface that matches an ip. If we cannot, return NULL
- **************************************************************************/
- static struct interface *iface_find(struct in_addr ip, BOOL CheckMask)
- {
- struct interface *i;
- if (is_zero_ip(ip)) return local_interfaces;
- for (i=local_interfaces;i;i=i->next)
- if (CheckMask) {
- if (same_net(i->ip,ip,i->nmask)) return i;
- } else if ((i->ip).s_addr == ip.s_addr) return i;
- return NULL;
- }
- /****************************************************************************
- add an interface to the linked list of interfaces
- ****************************************************************************/
- static void add_interface(struct in_addr ip, struct in_addr nmask)
- {
- struct interface *iface;
- if (iface_find(ip, False)) {
- DEBUG(3,("not adding duplicate interface %s\n",inet_ntoa(ip)));
- return;
- }
- #if !defined(__s390__)
- if (ip_equal(nmask, allones_ip)) {
- DEBUG(3,("not adding non-broadcast interface %s\n",inet_ntoa(ip)));
- return;
- }
- #endif
- iface = SMB_MALLOC_P(struct interface);
- if (!iface) return;
-
- ZERO_STRUCTPN(iface);
- iface->ip = ip;
- iface->nmask = nmask;
- iface->bcast.s_addr = MKBCADDR(iface->ip.s_addr, iface->nmask.s_addr);
- DLIST_ADD(local_interfaces, iface);
- DEBUG(2,("added interface ip=%s ",inet_ntoa(iface->ip)));
- DEBUG(2,("bcast=%s ",inet_ntoa(iface->bcast)));
- DEBUG(2,("nmask=%s\n",inet_ntoa(iface->nmask)));
- }
- /****************************************************************************
- interpret a single element from a interfaces= config line
- This handles the following different forms:
- 1) wildcard interface name
- 2) DNS name
- 3) IP/masklen
- 4) ip/mask
- 5) bcast/mask
- ****************************************************************************/
- static void interpret_interface(char *token)
- {
- struct in_addr ip, nmask;
- char *p;
- int i, added=0;
- zero_ip(&ip);
- zero_ip(&nmask);
-
- /* first check if it is an interface name */
- for (i=0;i<total_probed;i++) {
- if (gen_fnmatch(token, probed_ifaces[i].name) == 0) {
- add_interface(probed_ifaces[i].ip,
- probed_ifaces[i].netmask);
- added = 1;
- }
- }
- if (added) return;
- /* maybe it is a DNS name */
- p = strchr_m(token,'/');
- if (!p) {
- ip = *interpret_addr2(token);
- for (i=0;i<total_probed;i++) {
- if (ip.s_addr == probed_ifaces[i].ip.s_addr &&
- !ip_equal(allones_ip, probed_ifaces[i].netmask)) {
- add_interface(probed_ifaces[i].ip,
- probed_ifaces[i].netmask);
- return;
- }
- }
- DEBUG(2,("can't determine netmask for %s\n", token));
- return;
- }
- /* parse it into an IP address/netmasklength pair */
- *p = 0;
- ip = *interpret_addr2(token);
- *p++ = '/';
- if (strlen(p) > 2) {
- nmask = *interpret_addr2(p);
- } else {
- nmask.s_addr = htonl(((ALLONES >> atoi(p)) ^ ALLONES));
- }
- /* maybe the first component was a broadcast address */
- if (ip.s_addr == MKBCADDR(ip.s_addr, nmask.s_addr) ||
- ip.s_addr == MKNETADDR(ip.s_addr, nmask.s_addr)) {
- for (i=0;i<total_probed;i++) {
- if (same_net(ip, probed_ifaces[i].ip, nmask)) {
- add_interface(probed_ifaces[i].ip, nmask);
- return;
- }
- }
- DEBUG(2,("Can't determine ip for broadcast address %s\n", token));
- return;
- }
- add_interface(ip, nmask);
- }
- /****************************************************************************
- load the list of network interfaces
- ****************************************************************************/
- void load_interfaces(void)
- {
- const char **ptr;
- int i;
- struct iface_struct ifaces[MAX_INTERFACES];
- ptr = lp_interfaces();
- allones_ip = *interpret_addr2("255.255.255.255");
- loopback_ip = *interpret_addr2("127.0.0.1");
- SAFE_FREE(probed_ifaces);
- /* dump the current interfaces if any */
- while (local_interfaces) {
- struct interface *iface = local_interfaces;
- DLIST_REMOVE(local_interfaces, local_interfaces);
- ZERO_STRUCTPN(iface);
- SAFE_FREE(iface);
- }
- /* probe the kernel for interfaces */
- total_probed = get_interfaces(ifaces, MAX_INTERFACES);
- if (total_probed > 0) {
- probed_ifaces = (struct iface_struct *)memdup(ifaces, sizeof(ifaces[0])*total_probed);
- if (!probed_ifaces) {
- DEBUG(0,("ERROR: memdup failed\n"));
- exit(1);
- }
- }
- /* if we don't have a interfaces line then use all broadcast capable
- interfaces except loopback */
- if (!ptr || !*ptr || !**ptr) {
- if (total_probed <= 0) {
- DEBUG(0,("ERROR: Could not determine network interfaces, you must use a interfaces config line\n"));
- exit(1);
- }
- for (i=0;i<total_probed;i++) {
- if (
- #if !defined(__s390__)
- probed_ifaces[i].netmask.s_addr != allones_ip.s_addr &&
- #endif
- probed_ifaces[i].ip.s_addr != loopback_ip.s_addr) {
- add_interface(probed_ifaces[i].ip,
- probed_ifaces[i].netmask);
- }
- }
- return;
- }
- if (ptr) {
- while (*ptr) {
- char *ptr_cpy = SMB_STRDUP(*ptr);
- if (ptr_cpy) {
- interpret_interface(ptr_cpy);
- free(ptr_cpy);
- }
- ptr++;
- }
- }
- if (!local_interfaces) {
- DEBUG(0,("WARNING: no network interfaces found\n"));
- }
- }
- void gfree_interfaces(void)
- {
- while (local_interfaces) {
- struct interface *iface = local_interfaces;
- DLIST_REMOVE(local_interfaces, local_interfaces);
- ZERO_STRUCTPN(iface);
- SAFE_FREE(iface);
- }
- SAFE_FREE(probed_ifaces);
- }
- /****************************************************************************
- return True if the list of probed interfaces has changed
- ****************************************************************************/
- BOOL interfaces_changed(void)
- {
- int n;
- struct iface_struct ifaces[MAX_INTERFACES];
- n = get_interfaces(ifaces, MAX_INTERFACES);
- if ((n > 0 )&& (n != total_probed ||
- memcmp(ifaces, probed_ifaces, sizeof(ifaces[0])*n))) {
- return True;
- }
-
- return False;
- }
- /****************************************************************************
- check if an IP is one of mine
- **************************************************************************/
- BOOL ismyip(struct in_addr ip)
- {
- struct interface *i;
- for (i=local_interfaces;i;i=i->next)
- if (ip_equal(i->ip,ip)) return True;
- return False;
- }
- /****************************************************************************
- check if a packet is from a local (known) net
- **************************************************************************/
- BOOL is_local_net(struct in_addr from)
- {
- struct interface *i;
- for (i=local_interfaces;i;i=i->next) {
- if((from.s_addr & i->nmask.s_addr) ==
- (i->ip.s_addr & i->nmask.s_addr))
- return True;
- }
- return False;
- }
- /****************************************************************************
- how many interfaces do we have
- **************************************************************************/
- int iface_count(void)
- {
- int ret = 0;
- struct interface *i;
- for (i=local_interfaces;i;i=i->next)
- ret++;
- return ret;
- }
- /****************************************************************************
- return the Nth interface
- **************************************************************************/
- struct interface *get_interface(int n)
- {
- struct interface *i;
-
- for (i=local_interfaces;i && n;i=i->next)
- n--;
- if (i) return i;
- return NULL;
- }
- /****************************************************************************
- return IP of the Nth interface
- **************************************************************************/
- struct in_addr *iface_n_ip(int n)
- {
- struct interface *i;
-
- for (i=local_interfaces;i && n;i=i->next)
- n--;
- if (i) return &i->ip;
- return NULL;
- }
- /****************************************************************************
- return bcast of the Nth interface
- **************************************************************************/
- struct in_addr *iface_n_bcast(int n)
- {
- struct interface *i;
-
- for (i=local_interfaces;i && n;i=i->next)
- n--;
- if (i) return &i->bcast;
- return NULL;
- }
- /* these 3 functions return the ip/bcast/nmask for the interface
- most appropriate for the given ip address. If they can't find
- an appropriate interface they return the requested field of the
- first known interface. */
- struct in_addr *iface_ip(struct in_addr ip)
- {
- struct interface *i = iface_find(ip, True);
- return(i ? &i->ip : &local_interfaces->ip);
- }
- /*
- return True if a IP is directly reachable on one of our interfaces
- */
- BOOL iface_local(struct in_addr ip)
- {
- return iface_find(ip, True) ? True : False;
- }