/* Unix SMB/CIFS implementation. multiple interface handling Copyright (C) Andrew Tridgell 1992-1998 Copyright (C) Jeremy Allison 2007 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 3 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, see <http://www.gnu.org/licenses/>. */ #include "includes.h" static struct iface_struct *probed_ifaces; static int total_probed; static struct interface *local_interfaces; /**************************************************************************** Check if an IP is one of mine. **************************************************************************/ bool ismyaddr(const struct sockaddr_storage *ip) { struct interface *i; for (i=local_interfaces;i;i=i->next) { if (addr_equal(&i->ip,ip)) { return true; } } return false; } bool ismyip_v4(struct in_addr ip) { struct sockaddr_storage ss; in_addr_to_sockaddr_storage(&ss, ip); return ismyaddr(&ss); } /**************************************************************************** Try and find an interface that matches an ip. If we cannot, return NULL. **************************************************************************/ static struct interface *iface_find(const struct sockaddr_storage *ip, bool check_mask) { struct interface *i; if (is_address_any(ip)) { return local_interfaces; } for (i=local_interfaces;i;i=i->next) { if (check_mask) { if (same_net(ip, &i->ip, &i->netmask)) { return i; } } else if (addr_equal(&i->ip, ip)) { return i; } } return NULL; } /**************************************************************************** Check if a packet is from a local (known) net. **************************************************************************/ bool is_local_net(const struct sockaddr_storage *from) { struct interface *i; for (i=local_interfaces;i;i=i->next) { if (same_net(from, &i->ip, &i->netmask)) { return true; } } return false; } #if defined(HAVE_IPV6) void setup_linklocal_scope_id(struct sockaddr_storage *pss) { struct interface *i; for (i=local_interfaces;i;i=i->next) { if (addr_equal(&i->ip,pss)) { struct sockaddr_in6 *psa6 = (struct sockaddr_in6 *)pss; psa6->sin6_scope_id = if_nametoindex(i->name); return; } } } #endif /**************************************************************************** Check if a packet is from a local (known) net. **************************************************************************/ bool is_local_net_v4(struct in_addr from) { struct sockaddr_storage ss; in_addr_to_sockaddr_storage(&ss, from); return is_local_net(&ss); } /**************************************************************************** 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; } /**************************************************************************** How many interfaces do we have (v4 only) ? **************************************************************************/ int iface_count_v4(void) { int ret = 0; struct interface *i; for (i=local_interfaces;i;i=i->next) { if (i->ip.ss_family == AF_INET) { ret++; } } return ret; } /**************************************************************************** Return a pointer to the in_addr of the first IPv4 interface. **************************************************************************/ const struct in_addr *first_ipv4_iface(void) { struct interface *i; for (i=local_interfaces;i ;i=i->next) { if (i->ip.ss_family == AF_INET) { break; } } if (!i) { return NULL; } return &((const struct sockaddr_in *)&i->ip)->sin_addr; } /**************************************************************************** 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 sockaddr_storage of the Nth interface. **************************************************************************/ const struct sockaddr_storage *iface_n_sockaddr_storage(int n) { struct interface *i; for (i=local_interfaces;i && n;i=i->next) { n--; } if (i) { return &i->ip; } return NULL; } /**************************************************************************** Return IPv4 of the Nth interface (if a v4 address). NULL otherwise. **************************************************************************/ const struct in_addr *iface_n_ip_v4(int n) { struct interface *i; for (i=local_interfaces;i && n;i=i->next) { n--; } if (i && i->ip.ss_family == AF_INET) { return &((const struct sockaddr_in *)&i->ip)->sin_addr; } return NULL; } /**************************************************************************** Return IPv4 bcast of the Nth interface (if a v4 address). NULL otherwise. **************************************************************************/ const struct in_addr *iface_n_bcast_v4(int n) { struct interface *i; for (i=local_interfaces;i && n;i=i->next) { n--; } if (i && i->ip.ss_family == AF_INET) { return &((const struct sockaddr_in *)&i->bcast)->sin_addr; } return NULL; } /**************************************************************************** Return bcast of the Nth interface. **************************************************************************/ const struct sockaddr_storage *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. */ const struct sockaddr_storage *iface_ip(const struct sockaddr_storage *ip) { struct interface *i = iface_find(ip, true); if (i) { return &i->ip; } /* Search for the first interface with * matching address family. */ for (i=local_interfaces;i;i=i->next) { if (i->ip.ss_family == ip->ss_family) { return &i->ip; } } return NULL; } /* return True if a IP is directly reachable on one of our interfaces */ bool iface_local(const struct sockaddr_storage *ip) { return iface_find(ip, True) ? true : false; } /**************************************************************************** Add an interface to the linked list of interfaces. ****************************************************************************/ static void add_interface(const struct iface_struct *ifs) { char addr[INET6_ADDRSTRLEN]; struct interface *iface; if (iface_find(&ifs->ip, False)) { DEBUG(3,("add_interface: not adding duplicate interface %s\n", print_sockaddr(addr, sizeof(addr), &ifs->ip) )); return; } if (!(ifs->flags & (IFF_BROADCAST|IFF_LOOPBACK))) { DEBUG(3,("not adding non-broadcast interface %s\n", ifs->name )); return; } iface = SMB_MALLOC_P(struct interface); if (!iface) { return; } ZERO_STRUCTPN(iface); iface->name = SMB_STRDUP(ifs->name); if (!iface->name) { SAFE_FREE(iface); return; } iface->flags = ifs->flags; iface->ip = ifs->ip; iface->netmask = ifs->netmask; iface->bcast = ifs->bcast; DLIST_ADD(local_interfaces, iface); DEBUG(2,("added interface %s ip=%s ", iface->name, print_sockaddr(addr, sizeof(addr), &iface->ip) )); DEBUG(2,("bcast=%s ", print_sockaddr(addr, sizeof(addr), &iface->bcast) )); DEBUG(2,("netmask=%s\n", print_sockaddr(addr, sizeof(addr), &iface->netmask) )); } /**************************************************************************** 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 sockaddr_storage ss; struct sockaddr_storage ss_mask; struct sockaddr_storage ss_net; struct sockaddr_storage ss_bcast; struct iface_struct ifs; char *p; int i; bool added=false; bool goodaddr = false; /* 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]); added = true; } } if (added) { return; } /* maybe it is a DNS name */ p = strchr_m(token,'/'); if (p == NULL) { if (!interpret_string_addr(&ss, token, 0)) { DEBUG(2, ("interpret_interface: Can't find address " "for %s\n", token)); return; } for (i=0;i<total_probed;i++) { if (addr_equal(&ss, &probed_ifaces[i].ip)) { add_interface(&probed_ifaces[i]); return; } } DEBUG(2,("interpret_interface: " "can't determine interface for %s\n", token)); return; } /* parse it into an IP address/netmasklength pair */ *p = 0; goodaddr = interpret_string_addr(&ss, token, 0); *p++ = '/'; if (!goodaddr) { DEBUG(2,("interpret_interface: " "can't determine interface for %s\n", token)); return; } if (strlen(p) > 2) { goodaddr = interpret_string_addr(&ss_mask, p, 0); if (!goodaddr) { DEBUG(2,("interpret_interface: " "can't determine netmask from %s\n", p)); return; } } else { char *endp = NULL; unsigned long val = strtoul(p, &endp, 0); if (p == endp || (endp && *endp != '\0')) { DEBUG(2,("interpret_interface: " "can't determine netmask value from %s\n", p)); return; } if (!make_netmask(&ss_mask, &ss, val)) { DEBUG(2,("interpret_interface: " "can't apply netmask value %lu from %s\n", val, p)); return; } } make_bcast(&ss_bcast, &ss, &ss_mask); make_net(&ss_net, &ss, &ss_mask); /* Maybe the first component was a broadcast address. */ if (addr_equal(&ss_bcast, &ss) || addr_equal(&ss_net, &ss)) { for (i=0;i<total_probed;i++) { if (same_net(&ss, &probed_ifaces[i].ip, &ss_mask)) { /* Temporarily replace netmask on * the detected interface - user knows * best.... */ struct sockaddr_storage saved_mask = probed_ifaces[i].netmask; probed_ifaces[i].netmask = ss_mask; DEBUG(2,("interpret_interface: " "using netmask value %s from " "config file on interface %s\n", p, probed_ifaces[i].name)); add_interface(&probed_ifaces[i]); probed_ifaces[i].netmask = saved_mask; return; } } DEBUG(2,("interpret_interface: Can't determine ip for " "broadcast address %s\n", token)); return; } /* Just fake up the interface definition. User knows best. */ DEBUG(2,("interpret_interface: Adding interface %s\n", token)); ZERO_STRUCT(ifs); (void)strlcpy(ifs.name, token, sizeof(ifs.name)); ifs.flags = IFF_BROADCAST; ifs.ip = ss; ifs.netmask = ss_mask; ifs.bcast = ss_bcast; add_interface(&ifs); } /**************************************************************************** Load the list of network interfaces. ****************************************************************************/ void load_interfaces(void) { struct iface_struct ifaces[MAX_INTERFACES]; const char **ptr = lp_interfaces(); int i; SAFE_FREE(probed_ifaces); /* dump the current interfaces if any */ while (local_interfaces) { struct interface *iface = local_interfaces; DLIST_REMOVE(local_interfaces, local_interfaces); SAFE_FREE(iface->name); 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 (probed_ifaces[i].flags & IFF_BROADCAST) { add_interface(&probed_ifaces[i]); } } 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); SAFE_FREE(iface->name); 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; }