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-rw-r--r--source3/nmbd/nmbd_become_lmb.c596
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diff --git a/source3/nmbd/nmbd_become_lmb.c b/source3/nmbd/nmbd_become_lmb.c
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+++ b/source3/nmbd/nmbd_become_lmb.c
@@ -0,0 +1,596 @@
+/*
+ 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 1994-2003
+
+ 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"
+#include "nmbd/nmbd.h"
+#include "../librpc/gen_ndr/svcctl.h"
+#include "lib/util/string_wrappers.h"
+
+extern uint16_t 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_t nb_type )
+{
+ unstring name;
+ struct name_record *namerec;
+
+ if((namerec = find_name_on_subnet(unicast_subnet, nmbname, FIND_SELF_NAME)) == NULL) {
+ pull_ascii_nstring(name, sizeof(name), nmbname->name);
+ /* The name needs to be created on the unicast subnet. */
+ (void)add_name_to_subnet( unicast_subnet, 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, const 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;
+ unstring relname;
+
+ 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. */
+ pull_ascii_nstring(relname, sizeof(relname), released_name->name);
+ reset_workgroup_state( subrec, relname, 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 ", relname );
+ 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;
+ unstring failname;
+
+ 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. */
+ pull_ascii_nstring(failname, sizeof(failname), fail_name->name);
+ reset_workgroup_state( subrec, failname, 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 ", failname );
+ 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, const 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;
+ size_t size = sizeof(struct userdata_struct) + sizeof(bool);
+
+ if((userdata = (struct userdata_struct *)SMB_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_t nb_flags,
+ int ttl, struct in_addr registered_ip)
+{
+ int i = 0;
+ struct server_record *sl;
+ struct work_record *work;
+ struct server_record *servrec;
+ unstring regname;
+
+ pull_ascii_nstring(regname, sizeof(regname), registered_name->name);
+ work = find_workgroup_on_subnet( subrec, regname);
+
+ if(!work) {
+ DEBUG(0,("become_local_master_stage2: Error - cannot find \
+workgroup %s on subnet %s\n", regname, 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(), regname, 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)
+{
+ unstring failname;
+ struct work_record *work;
+
+ 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));
+
+ pull_ascii_nstring(failname, sizeof(failname), fail_name->name);
+ work = find_workgroup_on_subnet( subrec, failname);
+
+ if(!work) {
+ DEBUG(0,("become_local_master_fail2: Error - cannot find \
+workgroup %s on subnet %s\n", failname, 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_t 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 \
+ %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;
+ size_t 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 *)SMB_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;
+ strlcpy(userdata->data, work->work_group, size - sizeof(*userdata));
+
+ /* 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
+
+ unstrcpy(work->local_master_browser_name, newname);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-30 20:38:26 +0000