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Diffstat (limited to 'source/lib/interface.c')
| -rw-r--r-- | source/lib/interface.c | 371 |
1 files changed, 371 insertions, 0 deletions
diff --git a/source/lib/interface.c b/source/lib/interface.c new file mode 100644 index 00000000000..08636fa3067 --- /dev/null +++ b/source/lib/interface.c @@ -0,0 +1,371 @@ +/* + Unix SMB/Netbios implementation. + Version 1.9. + 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 (ip_equal(nmask, allones_ip)) { + DEBUG(3,("not adding non-broadcast interface %s\n",inet_ntoa(ip))); + return; + } + + iface = (struct interface *)malloc(sizeof(*iface)); + 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); + + 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) +{ + 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 = memdup(ifaces, sizeof(ifaces[0])*total_probed); + } + + /* 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 (probed_ifaces[i].netmask.s_addr != allones_ip.s_addr && + 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) { + interpret_interface(*ptr); + ptr++; + } + } + + if (!local_interfaces) { + DEBUG(0,("WARNING: no network interfaces found\n")); + } +} + + +/**************************************************************************** +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; +} + +/**************************************************************************** + True if we have two or more interfaces. + **************************************************************************/ +BOOL we_are_multihomed(void) +{ + static int multi = -1; + + if(multi == -1) + multi = (iface_count() > 1 ? True : False); + + return multi; +} + +/**************************************************************************** + 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; +} + + +/**************************************************************************** +this function provides a simple hash of the configured interfaces. It is +used to detect a change in interfaces to tell us whether to discard +the current wins.dat file. +Note that the result is independent of the order of the interfaces + **************************************************************************/ +unsigned iface_hash(void) +{ + unsigned ret = 0; + struct interface *i; + + for (i=local_interfaces;i;i=i->next) { + unsigned x1 = (unsigned)str_checksum(inet_ntoa(i->ip)); + unsigned x2 = (unsigned)str_checksum(inet_ntoa(i->nmask)); + ret ^= (x1 ^ x2); + } + + return ret; +} + + +/* 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_bcast(struct in_addr ip) +{ + struct interface *i = iface_find(ip, True); + return(i ? &i->bcast : &local_interfaces->bcast); +} + +struct in_addr *iface_ip(struct in_addr ip) +{ + struct interface *i = iface_find(ip, True); + return(i ? &i->ip : &local_interfaces->ip); +} |