first public release of samba4 code

(This used to be commit b0510b5428b3461aeb9bbe3cc95f62fc73e2b97f)

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);
+}