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Diffstat (limited to '')
| -rw-r--r-- | source3/nmbd/nmbd_subnetdb.c | 436 |
1 files changed, 436 insertions, 0 deletions
diff --git a/source3/nmbd/nmbd_subnetdb.c b/source3/nmbd/nmbd_subnetdb.c new file mode 100644 index 0000000..b2bcedd --- /dev/null +++ b/source3/nmbd/nmbd_subnetdb.c @@ -0,0 +1,436 @@ +/* + Unix SMB/CIFS implementation. + NBT netbios routines and daemon - version 2 + Copyright (C) Andrew Tridgell 1994-1998 + Copyright (C) Luke Kenneth Casson Leighton 1994-1998 + Copyright (C) Jeremy Allison 1994-1998 + + 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 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/>. + + Revision History: + +*/ + +#include "includes.h" +#include "nmbd/nmbd.h" + +extern int global_nmb_port; + +/* This is the broadcast subnets database. */ +struct subnet_record *subnetlist = NULL; + +/* Extra subnets - keep these separate so enumeration code doesn't + run onto it by mistake. */ + +struct subnet_record *unicast_subnet = NULL; +struct subnet_record *remote_broadcast_subnet = NULL; +struct subnet_record *wins_server_subnet = NULL; + +extern uint16_t samba_nb_type; /* Samba's NetBIOS name type. */ + +/**************************************************************************** + Add a subnet into the list. + **************************************************************************/ + +static void add_subnet(struct subnet_record *subrec) +{ + DLIST_ADD(subnetlist, subrec); +} + +/**************************************************************************** +stop listening on a subnet +we don't free the record as we don't have proper reference counting for it +yet and it may be in use by a response record + ****************************************************************************/ + +void close_subnet(struct subnet_record *subrec) +{ + if (subrec->nmb_sock != -1) { + close(subrec->nmb_sock); + subrec->nmb_sock = -1; + } + if (subrec->nmb_bcast != -1) { + close(subrec->nmb_bcast); + subrec->nmb_bcast = -1; + } + if (subrec->dgram_sock != -1) { + close(subrec->dgram_sock); + subrec->dgram_sock = -1; + } + if (subrec->dgram_bcast != -1) { + close(subrec->dgram_bcast); + subrec->dgram_bcast = -1; + } + + DLIST_REMOVE(subnetlist, subrec); +} + +/**************************************************************************** + Create a subnet entry. + ****************************************************************************/ + +static struct subnet_record *make_subnet(const char *name, enum subnet_type type, + struct in_addr myip, struct in_addr bcast_ip, + struct in_addr mask_ip) +{ + struct subnet_record *subrec = NULL; + int nmb_sock = -1; + int dgram_sock = -1; + int nmb_bcast = -1; + int dgram_bcast = -1; + bool bind_bcast = lp_nmbd_bind_explicit_broadcast(); + + /* Check if we are creating a non broadcast subnet - if so don't create + sockets. */ + + if (type == NORMAL_SUBNET) { + struct sockaddr_storage ss; + struct sockaddr_storage ss_bcast; + + in_addr_to_sockaddr_storage(&ss, myip); + in_addr_to_sockaddr_storage(&ss_bcast, bcast_ip); + + /* + * Attempt to open the sockets on port 137/138 for this interface + * and bind them. + * Fail the subnet creation if this fails. + */ + + nmb_sock = open_socket_in( + SOCK_DGRAM, &ss, global_nmb_port, true); + if (nmb_sock < 0) { + DBG_ERR("Failed to open nmb socket on interface %s " + "for port %d: %s\n", + inet_ntoa(myip), + global_nmb_port, + strerror(-nmb_sock)); + goto failed; + } + set_socket_options(nmb_sock,"SO_BROADCAST"); + set_blocking(nmb_sock, false); + + if (bind_bcast) { + nmb_bcast = open_socket_in( + SOCK_DGRAM, &ss_bcast, global_nmb_port, true); + if (nmb_bcast < 0) { + DBG_ERR("Failed to open nmb bcast socket on " + "interface %s for port %d: %s\n", + inet_ntoa(myip), + global_nmb_port, + strerror(-nmb_bcast)); + goto failed; + } + set_socket_options(nmb_bcast, "SO_BROADCAST"); + set_blocking(nmb_bcast, false); + } + + dgram_sock = open_socket_in(SOCK_DGRAM, &ss, DGRAM_PORT, true); + if (dgram_sock < 0) { + DBG_ERR("Failed to open dgram socket on " + "interface %s for port %d: %s\n", + inet_ntoa(myip), + DGRAM_PORT, + strerror(-dgram_sock)); + goto failed; + } + set_socket_options(dgram_sock, "SO_BROADCAST"); + set_blocking(dgram_sock, false); + + if (bind_bcast) { + dgram_bcast = open_socket_in( + SOCK_DGRAM, &ss_bcast, DGRAM_PORT, true); + if (dgram_bcast < 0) { + DBG_ERR("Failed to open dgram bcast socket on " + "interface %s for port %d: %s\n", + inet_ntoa(myip), + DGRAM_PORT, + strerror(-dgram_bcast)); + goto failed; + } + set_socket_options(dgram_bcast, "SO_BROADCAST"); + set_blocking(dgram_bcast, false); + } + } + + subrec = SMB_MALLOC_P(struct subnet_record); + if (!subrec) { + DEBUG(0,("make_subnet: malloc fail !\n")); + goto failed; + } + + ZERO_STRUCTP(subrec); + + if((subrec->subnet_name = SMB_STRDUP(name)) == NULL) { + DEBUG(0,("make_subnet: malloc fail for subnet name !\n")); + goto failed; + } + + DEBUG(2, ("making subnet name:%s ", name )); + DEBUG(2, ("Broadcast address:%s ", inet_ntoa(bcast_ip))); + DEBUG(2, ("Subnet mask:%s\n", inet_ntoa(mask_ip))); + + subrec->namelist_changed = False; + subrec->work_changed = False; + + subrec->bcast_ip = bcast_ip; + subrec->mask_ip = mask_ip; + subrec->myip = myip; + subrec->type = type; + subrec->nmb_sock = nmb_sock; + subrec->nmb_bcast = nmb_bcast; + subrec->dgram_sock = dgram_sock; + subrec->dgram_bcast = dgram_bcast; + + return subrec; + +failed: + SAFE_FREE(subrec); + if (nmb_sock >= 0) { + close(nmb_sock); + } + if (nmb_bcast >= 0) { + close(nmb_bcast); + } + if (dgram_sock >= 0) { + close(dgram_sock); + } + if (dgram_bcast >= 0) { + close(dgram_bcast); + } + return NULL; +} + +/**************************************************************************** + Create a normal subnet +**************************************************************************/ + +struct subnet_record *make_normal_subnet(const struct interface *iface) +{ + + struct subnet_record *subrec; + const struct in_addr *pip = &((const struct sockaddr_in *)&iface->ip)->sin_addr; + const struct in_addr *pbcast = &((const struct sockaddr_in *)&iface->bcast)->sin_addr; + const struct in_addr *pnmask = &((const struct sockaddr_in *)&iface->netmask)->sin_addr; + + subrec = make_subnet(inet_ntoa(*pip), NORMAL_SUBNET, + *pip, *pbcast, *pnmask); + if (subrec) { + add_subnet(subrec); + } + return subrec; +} + +/**************************************************************************** + Create subnet entries. +**************************************************************************/ + +bool create_subnets(void) +{ + /* We only count IPv4 interfaces whilst we're waiting. */ + int num_interfaces; + int i; + struct in_addr unicast_ip, ipzero; + + try_interfaces_again: + + /* Only count IPv4, non-loopback interfaces. */ + if (iface_count_v4_nl() == 0) { + daemon_status("nmbd", + "No local IPv4 non-loopback interfaces " + "available, waiting for interface ..."); + DEBUG(0,("NOTE: NetBIOS name resolution is not supported for " + "Internet Protocol Version 6 (IPv6).\n")); + } + + /* We only count IPv4, non-loopback interfaces here. */ + while (iface_count_v4_nl() == 0) { + void (*saved_handler)(int); + + /* + * Whilst we're waiting for an interface, allow SIGTERM to + * cause us to exit. + */ + + saved_handler = CatchSignal(SIGTERM, SIG_DFL); + + usleep(NMBD_WAIT_INTERFACES_TIME_USEC); + load_interfaces(); + + /* + * We got an interface, restore our normal term handler. + */ + + CatchSignal(SIGTERM, saved_handler); + } + + /* + * Here we count v4 and v6 - we know there's at least one + * IPv4 interface and we filter on it below. + */ + num_interfaces = iface_count(); + + /* + * Create subnets from all the local interfaces and thread them onto + * the linked list. + */ + + for (i = 0 ; i < num_interfaces; i++) { + const struct interface *iface = get_interface(i); + + if (!iface) { + DEBUG(2,("create_subnets: can't get interface %d.\n", i )); + continue; + } + + /* Ensure we're only dealing with IPv4 here. */ + if (iface->ip.ss_family != AF_INET) { + DEBUG(2,("create_subnets: " + "ignoring non IPv4 interface.\n")); + continue; + } + + /* + * We don't want to add a loopback interface, in case + * someone has added 127.0.0.1 for smbd, nmbd needs to + * ignore it here. JRA. + */ + + if (is_loopback_addr((const struct sockaddr *)&iface->ip)) { + DEBUG(2,("create_subnets: Ignoring loopback interface.\n" )); + continue; + } + + if (!make_normal_subnet(iface)) + return False; + } + + /* We must have at least one subnet. */ + if (subnetlist == NULL) { + void (*saved_handler)(int); + + DEBUG(0,("create_subnets: Unable to create any subnet from " + "given interfaces. Is your interface line in " + "smb.conf correct ?\n")); + + saved_handler = CatchSignal(SIGTERM, SIG_DFL); + + usleep(NMBD_WAIT_INTERFACES_TIME_USEC); + load_interfaces(); + + CatchSignal(SIGTERM, saved_handler); + goto try_interfaces_again; + } + + if (lp_we_are_a_wins_server()) { + /* Pick the first interface IPv4 address as the WINS server + * ip. */ + const struct in_addr *nip = first_ipv4_iface(); + + if (!nip) { + return False; + } + + unicast_ip = *nip; + } else { + /* note that we do not set the wins server IP here. We just + set it at zero and let the wins registration code cope + with getting the IPs right for each packet */ + zero_ip_v4(&unicast_ip); + } + + /* + * Create the unicast and remote broadcast subnets. + * Don't put these onto the linked list. + * The ip address of the unicast subnet is set to be + * the WINS server address, if it exists, or ipzero if not. + */ + + unicast_subnet = make_subnet( "UNICAST_SUBNET", UNICAST_SUBNET, + unicast_ip, unicast_ip, unicast_ip); + + zero_ip_v4(&ipzero); + + remote_broadcast_subnet = make_subnet( "REMOTE_BROADCAST_SUBNET", + REMOTE_BROADCAST_SUBNET, + ipzero, ipzero, ipzero); + + if((unicast_subnet == NULL) || (remote_broadcast_subnet == NULL)) + return False; + + /* + * If we are WINS server, create the WINS_SERVER_SUBNET - don't put on + * the linked list. + */ + + if (lp_we_are_a_wins_server()) { + if( (wins_server_subnet = make_subnet( "WINS_SERVER_SUBNET", + WINS_SERVER_SUBNET, + ipzero, ipzero, ipzero )) == NULL ) + return False; + } + + return True; +} + +/******************************************************************* +Function to tell us if we can use the unicast subnet. +******************************************************************/ + +bool we_are_a_wins_client(void) +{ + if (wins_srv_count() > 0) { + return True; + } + + return False; +} + +/******************************************************************* +Access function used by NEXT_SUBNET_INCLUDING_UNICAST +******************************************************************/ + +struct subnet_record *get_next_subnet_maybe_unicast(struct subnet_record *subrec) +{ + if(subrec == unicast_subnet) + return NULL; + else if((subrec->next == NULL) && we_are_a_wins_client()) + return unicast_subnet; + else + return subrec->next; +} + +/******************************************************************* + Access function used by retransmit_or_expire_response_records() in + nmbd_packets.c. Patch from Andrey Alekseyev <fetch@muffin.arcadia.spb.ru> + Needed when we need to enumerate all the broadcast, unicast and + WINS subnets. +******************************************************************/ + +struct subnet_record *get_next_subnet_maybe_unicast_or_wins_server(struct subnet_record *subrec) +{ + if(subrec == unicast_subnet) { + if(wins_server_subnet) + return wins_server_subnet; + else + return NULL; + } + + if(wins_server_subnet && subrec == wins_server_subnet) + return NULL; + + if((subrec->next == NULL) && we_are_a_wins_client()) + return unicast_subnet; + else + return subrec->next; +} |