diff options
Diffstat (limited to 'source4/nmbd/nmbd_become_lmb.c')
| -rw-r--r-- | source4/nmbd/nmbd_become_lmb.c | 605 |
1 files changed, 605 insertions, 0 deletions
diff --git a/source4/nmbd/nmbd_become_lmb.c b/source4/nmbd/nmbd_become_lmb.c new file mode 100644 index 0000000000..8b87ca7444 --- /dev/null +++ b/source4/nmbd/nmbd_become_lmb.c @@ -0,0 +1,605 @@ +/* + 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 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" + +extern uint16 samba_nb_type; /* Samba's NetBIOS name type. */ + +/******************************************************************* + Utility function to add a name to the unicast subnet, or add in + our IP address if it already exists. +******************************************************************/ + +void insert_permanent_name_into_unicast( struct subnet_record *subrec, + struct nmb_name *nmbname, uint16 nb_type ) +{ + struct name_record *namerec; + + if((namerec = find_name_on_subnet(unicast_subnet, nmbname, FIND_SELF_NAME)) == NULL) + { + /* The name needs to be created on the unicast subnet. */ + (void)add_name_to_subnet( unicast_subnet, nmbname->name, + nmbname->name_type, nb_type, + PERMANENT_TTL, PERMANENT_NAME, 1, &subrec->myip); + } + else + { + /* The name already exists on the unicast subnet. Add our local + IP for the given broadcast subnet to the name. */ + add_ip_to_name_record( namerec, subrec->myip); + } +} + +/******************************************************************* + Utility function to remove a name from the unicast subnet. +******************************************************************/ + +static void remove_permanent_name_from_unicast( struct subnet_record *subrec, + struct nmb_name *nmbname ) +{ + struct name_record *namerec; + + if((namerec = find_name_on_subnet(unicast_subnet, nmbname, FIND_SELF_NAME)) != NULL) + { + /* Remove this broadcast subnet IP address from the name. */ + remove_ip_from_name_record( namerec, subrec->myip); + if(namerec->data.num_ips == 0) + remove_name_from_namelist( unicast_subnet, namerec); + } +} + +/******************************************************************* + Utility function always called to set our workgroup and server + state back to potential browser, or none. +******************************************************************/ + +static void reset_workgroup_state( struct subnet_record *subrec, char *workgroup_name, + BOOL force_new_election ) +{ + struct work_record *work; + struct server_record *servrec; + struct nmb_name nmbname; + + if((work = find_workgroup_on_subnet( subrec, workgroup_name)) == NULL) + { + DEBUG(0,("reset_workgroup_state: Error - cannot find workgroup %s on \ +subnet %s.\n", workgroup_name, subrec->subnet_name )); + return; + } + + if((servrec = find_server_in_workgroup( work, lp_netbios_name())) == NULL) + { + DEBUG(0,("reset_workgroup_state: Error - cannot find server %s \ +in workgroup %s on subnet %s\n", + lp_netbios_name(), work->work_group, subrec->subnet_name)); + work->mst_state = lp_local_master() ? MST_POTENTIAL : MST_NONE; + return; + } + + /* Update our server status - remove any master flag and replace + it with the potential browser flag. */ + servrec->serv.type &= ~SV_TYPE_MASTER_BROWSER; + servrec->serv.type |= (lp_local_master() ? SV_TYPE_POTENTIAL_BROWSER : 0); + + /* Tell the namelist writer to write out a change. */ + subrec->work_changed = True; + + /* Reset our election flags. */ + work->ElectionCriterion &= ~0x4; + + work->mst_state = lp_local_master() ? MST_POTENTIAL : MST_NONE; + + /* Forget who the local master browser was for + this workgroup. */ + + set_workgroup_local_master_browser_name( work, ""); + + /* + * Ensure the IP address of this subnet is not registered as one + * of the IP addresses of the WORKGROUP<1d> name on the unicast + * subnet. This undoes what we did below when we became a local + * master browser. + */ + + make_nmb_name(&nmbname, work->work_group, 0x1d); + + remove_permanent_name_from_unicast( subrec, &nmbname); + + if(force_new_election) + work->needelection = True; +} + +/******************************************************************* + Unbecome the local master browser name release success function. +******************************************************************/ + +static void unbecome_local_master_success(struct subnet_record *subrec, + struct userdata_struct *userdata, + struct nmb_name *released_name, + struct in_addr released_ip) +{ + BOOL force_new_election = False; + + memcpy((char *)&force_new_election, userdata->data, sizeof(BOOL)); + + DEBUG(3,("unbecome_local_master_success: released name %s.\n", + nmb_namestr(released_name))); + + /* Now reset the workgroup and server state. */ + reset_workgroup_state( subrec, released_name->name, force_new_election ); + + if( DEBUGLVL( 0 ) ) + { + dbgtext( "*****\n\n" ); + dbgtext( "Samba name server %s ", lp_netbios_name() ); + dbgtext( "has stopped being a local master browser " ); + dbgtext( "for workgroup %s ", released_name->name ); + dbgtext( "on subnet %s\n\n*****\n", subrec->subnet_name ); + } + +} + +/******************************************************************* + Unbecome the local master browser name release fail function. +******************************************************************/ + +static void unbecome_local_master_fail(struct subnet_record *subrec, struct response_record *rrec, + struct nmb_name *fail_name) +{ + struct name_record *namerec; + struct userdata_struct *userdata = rrec->userdata; + BOOL force_new_election = False; + + memcpy((char *)&force_new_election, userdata->data, sizeof(BOOL)); + + DEBUG(0,("unbecome_local_master_fail: failed to release name %s. \ +Removing from namelist anyway.\n", nmb_namestr(fail_name))); + + /* Do it anyway. */ + namerec = find_name_on_subnet(subrec, fail_name, FIND_SELF_NAME); + if(namerec) + remove_name_from_namelist(subrec, namerec); + + /* Now reset the workgroup and server state. */ + reset_workgroup_state( subrec, fail_name->name, force_new_election ); + + if( DEBUGLVL( 0 ) ) + { + dbgtext( "*****\n\n" ); + dbgtext( "Samba name server %s ", lp_netbios_name() ); + dbgtext( "has stopped being a local master browser " ); + dbgtext( "for workgroup %s ", fail_name->name ); + dbgtext( "on subnet %s\n\n*****\n", subrec->subnet_name ); + } +} + +/******************************************************************* + Utility function to remove the WORKGROUP<1d> name. +******************************************************************/ + +static void release_1d_name( struct subnet_record *subrec, char *workgroup_name, + BOOL force_new_election) +{ + struct nmb_name nmbname; + struct name_record *namerec; + + make_nmb_name(&nmbname, workgroup_name, 0x1d); + if((namerec = find_name_on_subnet( subrec, &nmbname, FIND_SELF_NAME))!=NULL) + { + struct userdata_struct *userdata; + int size = sizeof(struct userdata_struct) + sizeof(BOOL); + + if((userdata = (struct userdata_struct *)malloc(size)) == NULL) + { + DEBUG(0,("release_1d_name: malloc fail.\n")); + return; + } + + userdata->copy_fn = NULL; + userdata->free_fn = NULL; + userdata->userdata_len = sizeof(BOOL); + memcpy((char *)userdata->data, &force_new_election, sizeof(BOOL)); + + release_name(subrec, namerec, + unbecome_local_master_success, + unbecome_local_master_fail, + userdata); + + zero_free(userdata, size); + } +} + +/******************************************************************* + Unbecome the local master browser MSBROWSE name release success function. +******************************************************************/ + +static void release_msbrowse_name_success(struct subnet_record *subrec, + struct userdata_struct *userdata, + struct nmb_name *released_name, + struct in_addr released_ip) +{ + DEBUG(4,("release_msbrowse_name_success: Released name %s on subnet %s\n.", + nmb_namestr(released_name), subrec->subnet_name )); + + /* Remove the permanent MSBROWSE name added into the unicast subnet. */ + remove_permanent_name_from_unicast( subrec, released_name); +} + +/******************************************************************* + Unbecome the local master browser MSBROWSE name release fail function. +******************************************************************/ + +static void release_msbrowse_name_fail( struct subnet_record *subrec, + struct response_record *rrec, + struct nmb_name *fail_name) +{ + struct name_record *namerec; + + DEBUG(4,("release_msbrowse_name_fail: Failed to release name %s on subnet %s\n.", + nmb_namestr(fail_name), subrec->subnet_name )); + + /* Release the name anyway. */ + namerec = find_name_on_subnet(subrec, fail_name, FIND_SELF_NAME); + if(namerec) + remove_name_from_namelist(subrec, namerec); + + /* Remove the permanent MSBROWSE name added into the unicast subnet. */ + remove_permanent_name_from_unicast( subrec, fail_name); +} + +/******************************************************************* + Unbecome the local master browser. If force_new_election is true, restart + the election process after we've unbecome the local master. +******************************************************************/ + +void unbecome_local_master_browser(struct subnet_record *subrec, struct work_record *work, + BOOL force_new_election) +{ + struct name_record *namerec; + struct nmb_name nmbname; + + /* Sanity check. */ + + DEBUG(2,("unbecome_local_master_browser: unbecoming local master for workgroup %s \ +on subnet %s\n",work->work_group, subrec->subnet_name)); + + if(find_server_in_workgroup( work, lp_netbios_name()) == NULL) + { + DEBUG(0,("unbecome_local_master_browser: Error - cannot find server %s \ +in workgroup %s on subnet %s\n", + lp_netbios_name(), work->work_group, subrec->subnet_name)); + work->mst_state = lp_local_master() ? MST_POTENTIAL : MST_NONE; + return; + } + + /* Set the state to unbecoming. */ + work->mst_state = MST_UNBECOMING_MASTER; + + /* + * Release the WORKGROUP<1d> name asap to allow another machine to + * claim it. + */ + + release_1d_name( subrec, work->work_group, force_new_election); + + /* Deregister any browser names we may have. */ + make_nmb_name(&nmbname, MSBROWSE, 0x1); + if((namerec = find_name_on_subnet( subrec, &nmbname, FIND_SELF_NAME))!=NULL) + { + release_name(subrec, namerec, + release_msbrowse_name_success, + release_msbrowse_name_fail, + NULL); + } + + /* + * Ensure we have sent and processed these release packets + * before returning - we don't want to process any election + * packets before dealing with the 1d release. + */ + + retransmit_or_expire_response_records(time(NULL)); +} + +/**************************************************************************** + Success in registering the WORKGROUP<1d> name. + We are now *really* a local master browser. + ****************************************************************************/ + +static void become_local_master_stage2(struct subnet_record *subrec, + struct userdata_struct *userdata, + struct nmb_name *registered_name, + uint16 nb_flags, + int ttl, struct in_addr registered_ip) +{ + int i = 0; + struct server_record *sl; + struct work_record *work = find_workgroup_on_subnet( subrec, registered_name->name); + struct server_record *servrec; + + if(!work) + { + DEBUG(0,("become_local_master_stage2: Error - cannot find \ +workgroup %s on subnet %s\n", registered_name->name, subrec->subnet_name)); + return; + } + + if((servrec = find_server_in_workgroup( work, lp_netbios_name())) == NULL) + { + DEBUG(0,("become_local_master_stage2: Error - cannot find server %s \ +in workgroup %s on subnet %s\n", + lp_netbios_name(), registered_name->name, subrec->subnet_name)); + work->mst_state = lp_local_master() ? MST_POTENTIAL : MST_NONE; + return; + } + + DEBUG(3,("become_local_master_stage2: registered as master browser for workgroup %s \ +on subnet %s\n", work->work_group, subrec->subnet_name)); + + work->mst_state = MST_BROWSER; /* registering WORKGROUP(1d) succeeded */ + + /* update our server status */ + servrec->serv.type |= SV_TYPE_MASTER_BROWSER; + servrec->serv.type &= ~SV_TYPE_POTENTIAL_BROWSER; + + /* Tell the namelist writer to write out a change. */ + subrec->work_changed = True; + + /* Add this name to the workgroup as local master browser. */ + set_workgroup_local_master_browser_name( work, lp_netbios_name()); + + /* Count the number of servers we have on our list. If it's + less than 10 (just a heuristic) request the servers + to announce themselves. + */ + for( sl = work->serverlist; sl != NULL; sl = sl->next) + i++; + + if (i < 10) + { + /* Ask all servers on our local net to announce to us. */ + broadcast_announce_request(subrec, work); + } + + /* + * Now we are a local master on a broadcast subnet, we need to add + * the WORKGROUP<1d> name to the unicast subnet so that we can answer + * unicast requests sent to this name. We can create this name directly on + * the unicast subnet as a WINS server always returns true when registering + * this name, and discards the registration. We use the number of IP + * addresses registered to this name as a reference count, as we + * remove this broadcast subnet IP address from it when we stop becoming a local + * master browser for this broadcast subnet. + */ + + insert_permanent_name_into_unicast( subrec, registered_name, nb_flags); + + /* Reset the announce master browser timer so that we try and tell a domain + master browser as soon as possible that we are a local master browser. */ + reset_announce_timer(); + + if( DEBUGLVL( 0 ) ) + { + dbgtext( "*****\n\n" ); + dbgtext( "Samba name server %s ", lp_netbios_name() ); + dbgtext( "is now a local master browser " ); + dbgtext( "for workgroup %s ", work->work_group ); + dbgtext( "on subnet %s\n\n*****\n", subrec->subnet_name ); + } + +} + +/**************************************************************************** + Failed to register the WORKGROUP<1d> name. + ****************************************************************************/ +static void become_local_master_fail2(struct subnet_record *subrec, + struct response_record *rrec, + struct nmb_name *fail_name) +{ + struct work_record *work = find_workgroup_on_subnet( subrec, fail_name->name); + + DEBUG(0,("become_local_master_fail2: failed to register name %s on subnet %s. \ +Failed to become a local master browser.\n", nmb_namestr(fail_name), subrec->subnet_name)); + + if(!work) + { + DEBUG(0,("become_local_master_fail2: Error - cannot find \ +workgroup %s on subnet %s\n", fail_name->name, subrec->subnet_name)); + return; + } + + /* Roll back all the way by calling unbecome_local_master_browser(). */ + unbecome_local_master_browser(subrec, work, False); +} + +/**************************************************************************** + Success in registering the MSBROWSE name. + ****************************************************************************/ + +static void become_local_master_stage1(struct subnet_record *subrec, + struct userdata_struct *userdata, + struct nmb_name *registered_name, + uint16 nb_flags, + int ttl, struct in_addr registered_ip) +{ + char *work_name = userdata->data; + struct work_record *work = find_workgroup_on_subnet( subrec, work_name); + + if(!work) + { + DEBUG(0,("become_local_master_stage1: Error - cannot find \ +workgroup %s on subnet %s\n", work_name, subrec->subnet_name)); + return; + } + + DEBUG(3,("become_local_master_stage1: go to stage 2: register the %s<1d> name.\n", + work->work_group)); + + work->mst_state = MST_MSB; /* Registering MSBROWSE was successful. */ + + /* + * We registered the MSBROWSE name on a broadcast subnet, now need to add + * the MSBROWSE name to the unicast subnet so that we can answer + * unicast requests sent to this name. We create this name directly on + * the unicast subnet. + */ + + insert_permanent_name_into_unicast( subrec, registered_name, nb_flags); + + /* Attempt to register the WORKGROUP<1d> name. */ + register_name(subrec, work->work_group,0x1d,samba_nb_type, + become_local_master_stage2, + become_local_master_fail2, + NULL); +} + +/**************************************************************************** + Failed to register the MSBROWSE name. + ****************************************************************************/ + +static void become_local_master_fail1(struct subnet_record *subrec, + struct response_record *rrec, + struct nmb_name *fail_name) +{ + char *work_name = rrec->userdata->data; + struct work_record *work = find_workgroup_on_subnet(subrec, work_name); + + if(!work) + { + DEBUG(0,("become_local_master_fail1: Error - cannot find \ +workgroup %s on subnet %s\n", work_name, subrec->subnet_name)); + return; + } + + if(find_server_in_workgroup(work, lp_netbios_name()) == NULL) + { + DEBUG(0,("become_local_master_fail1: Error - cannot find server %s \ +in workgroup %s on subnet %s\n", + lp_netbios_name(), work->work_group, subrec->subnet_name)); + return; + } + + reset_workgroup_state( subrec, work->work_group, False ); + + DEBUG(0,("become_local_master_fail1: Failed to become a local master browser for \ +workgroup %s on subnet %s. Couldn't register name %s.\n", + work->work_group, subrec->subnet_name, nmb_namestr(fail_name))); +} + +/****************************************************************** + Become the local master browser on a subnet. + This gets called if we win an election on this subnet. + + Stage 1: mst_state was MST_POTENTIAL - go to MST_BACK register ^1^2__MSBROWSE__^2^1. + Stage 2: mst_state was MST_BACKUP - go to MST_MSB and register WORKGROUP<1d>. + Stage 3: mst_state was MST_MSB - go to MST_BROWSER. +******************************************************************/ + +void become_local_master_browser(struct subnet_record *subrec, struct work_record *work) +{ + struct userdata_struct *userdata; + int size = sizeof(struct userdata_struct) + sizeof(fstring) + 1; + + /* Sanity check. */ + if (!lp_local_master()) + { + DEBUG(0,("become_local_master_browser: Samba not configured as a local master browser.\n")); + return; + } + + if(!AM_POTENTIAL_MASTER_BROWSER(work)) + { + DEBUG(2,("become_local_master_browser: Awaiting potential browser state. Current state is %d\n", + work->mst_state )); + return; + } + + if(find_server_in_workgroup( work, lp_netbios_name()) == NULL) + { + DEBUG(0,("become_local_master_browser: Error - cannot find server %s \ +in workgroup %s on subnet %s\n", + lp_netbios_name(), work->work_group, subrec->subnet_name)); + return; + } + + DEBUG(2,("become_local_master_browser: Starting to become a master browser for workgroup \ +%s on subnet %s\n", work->work_group, subrec->subnet_name)); + + DEBUG(3,("become_local_master_browser: first stage - attempt to register ^1^2__MSBROWSE__^2^1\n")); + work->mst_state = MST_BACKUP; /* an election win was successful */ + + work->ElectionCriterion |= 0x5; + + /* Tell the namelist writer to write out a change. */ + subrec->work_changed = True; + + /* Setup the userdata_struct. */ + if((userdata = (struct userdata_struct *)malloc(size)) == NULL) + { + DEBUG(0,("become_local_master_browser: malloc fail.\n")); + return; + } + + userdata->copy_fn = NULL; + userdata->free_fn = NULL; + userdata->userdata_len = strlen(work->work_group)+1; + fstrcpy(userdata->data, work->work_group); + + /* Register the special browser group name. */ + register_name(subrec, MSBROWSE, 0x01, samba_nb_type|NB_GROUP, + become_local_master_stage1, + become_local_master_fail1, + userdata); + + zero_free(userdata, size); +} + +/*************************************************************** + Utility function to set the local master browser name. Does + some sanity checking as old versions of Samba seem to sometimes + say that the master browser name for a workgroup is the same + as the workgroup name. +****************************************************************/ + +void set_workgroup_local_master_browser_name( struct work_record *work, const char *newname) +{ + DEBUG(5,("set_workgroup_local_master_browser_name: setting local master name to '%s' \ +for workgroup %s.\n", newname, work->work_group )); + +#if 0 + /* + * Apparently some sites use the workgroup name as the local + * master browser name. Arrrrggghhhhh ! (JRA). + */ + if(strequal( work->work_group, newname)) + { + DEBUG(5, ("set_workgroup_local_master_browser_name: Refusing to set \ +local_master_browser_name for workgroup %s to workgroup name.\n", + work->work_group )); + return; + } +#endif + + StrnCpy(work->local_master_browser_name, newname, + sizeof(work->local_master_browser_name)-1); +} |