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c2ac923c6a
Rather than have safe_string.h #include string_wrappers.h, make users of string_wrappers.h include it explicitly. includes.h now no longer includes string_wrappers.h transitively. Still allow includes.h to #include safe_string.h for now so that as many modules as possible get the safety checks in it. Signed-off-by: Matthew DeVore <matvore@google.com> Reviewed-by: David Mulder <dmulder@samba.org> Reviewed-by: Jeremy Allison <jra@samba.org>
396 lines
13 KiB
C
396 lines
13 KiB
C
/*
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Unix SMB/CIFS implementation.
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NBT netbios routines and daemon - version 2
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Copyright (C) Andrew Tridgell 1994-1998
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Copyright (C) Luke Kenneth Casson Leighton 1994-1998
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Copyright (C) Jeremy Allison 1994-2003
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include "includes.h"
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#include "nmbd/nmbd.h"
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#include "lib/util/string_wrappers.h"
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/* Election parameters. */
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extern time_t StartupTime;
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/****************************************************************************
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Send an election datagram packet.
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**************************************************************************/
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static void send_election_dgram(struct subnet_record *subrec, const char *workgroup_name,
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uint32_t criterion, int timeup,const char *server_name)
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{
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char outbuf[1024];
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unstring srv_name;
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char *p;
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DEBUG(2,("send_election_dgram: Sending election packet for workgroup %s on subnet %s\n",
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workgroup_name, subrec->subnet_name ));
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memset(outbuf,'\0',sizeof(outbuf));
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p = outbuf;
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SCVAL(p,0,ANN_Election); /* Election opcode. */
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p++;
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SCVAL(p,0,((criterion == 0 && timeup == 0) ? 0 : ELECTION_VERSION));
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SIVAL(p,1,criterion);
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SIVAL(p,5,timeup*1000); /* ms - Despite what the spec says. */
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p += 13;
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unstrcpy(srv_name, server_name);
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if (!strupper_m(srv_name)) {
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DEBUG(2,("strupper_m failed for %s\n", srv_name));
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return;
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}
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/* The following call does UNIX -> DOS charset conversion. */
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push_ascii(p, srv_name, sizeof(outbuf)-PTR_DIFF(p,outbuf)-1, STR_TERMINATE);
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p = skip_string(outbuf,sizeof(outbuf),p);
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send_mailslot(False, BROWSE_MAILSLOT, outbuf, PTR_DIFF(p,outbuf),
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lp_netbios_name(), 0,
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workgroup_name, 0x1e,
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subrec->bcast_ip, subrec->myip, DGRAM_PORT);
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}
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/*******************************************************************
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We found a current master browser on one of our broadcast interfaces.
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******************************************************************/
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static void check_for_master_browser_success(struct subnet_record *subrec,
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struct userdata_struct *userdata,
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struct nmb_name *answer_name,
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struct in_addr answer_ip, struct res_rec *rrec)
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{
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unstring aname;
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pull_ascii_nstring(aname, sizeof(aname), answer_name->name);
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DEBUG(3,("check_for_master_browser_success: Local master browser for workgroup %s exists at \
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IP %s (just checking).\n", aname, inet_ntoa(answer_ip) ));
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}
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/*******************************************************************
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We failed to find a current master browser on one of our broadcast interfaces.
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******************************************************************/
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static void check_for_master_browser_fail( struct subnet_record *subrec,
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struct response_record *rrec,
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struct nmb_name *question_name,
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int fail_code)
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{
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unstring workgroup_name;
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struct work_record *work;
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pull_ascii_nstring(workgroup_name,sizeof(workgroup_name),question_name->name);
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work = find_workgroup_on_subnet(subrec, workgroup_name);
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if(work == NULL) {
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DEBUG(0,("check_for_master_browser_fail: Unable to find workgroup %s on subnet %s.=\n",
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workgroup_name, subrec->subnet_name ));
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return;
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}
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if (strequal(work->work_group, lp_workgroup())) {
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if (lp_local_master()) {
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/* We have discovered that there is no local master
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browser, and we are configured to initiate
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an election that we will participate in.
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*/
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DEBUG(2,("check_for_master_browser_fail: Forcing election on workgroup %s subnet %s\n",
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work->work_group, subrec->subnet_name ));
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/* Setting this means we will participate when the
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election is run in run_elections(). */
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work->needelection = True;
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} else {
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/* We need to force an election, because we are configured
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not to become the local master, but we still need one,
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having detected that one doesn't exist.
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*/
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send_election_dgram(subrec, work->work_group, 0, 0, "");
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}
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}
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}
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/*******************************************************************
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Ensure there is a local master browser for a workgroup on our
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broadcast interfaces.
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******************************************************************/
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void check_master_browser_exists(time_t t)
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{
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static time_t lastrun=0;
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struct subnet_record *subrec;
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const char *workgroup_name = lp_workgroup();
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if (t < (lastrun + (CHECK_TIME_MST_BROWSE * 60)))
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return;
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lastrun = t;
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dump_workgroups(False);
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for (subrec = FIRST_SUBNET; subrec; subrec = NEXT_SUBNET_EXCLUDING_UNICAST(subrec)) {
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struct work_record *work;
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for (work = subrec->workgrouplist; work; work = work->next) {
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if (strequal(work->work_group, workgroup_name) && !AM_LOCAL_MASTER_BROWSER(work)) {
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/* Do a name query for the local master browser on this net. */
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query_name( subrec, work->work_group, 0x1d,
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check_for_master_browser_success,
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check_for_master_browser_fail,
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NULL);
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}
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}
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}
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}
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/*******************************************************************
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Run an election.
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******************************************************************/
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void run_elections(time_t t)
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{
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static time_t lastime = 0;
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struct subnet_record *subrec;
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/* Send election packets once every 2 seconds - note */
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if (lastime && (t - lastime < 2)) {
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return;
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}
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lastime = t;
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for (subrec = FIRST_SUBNET; subrec; subrec = NEXT_SUBNET_EXCLUDING_UNICAST(subrec)) {
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struct work_record *work;
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for (work = subrec->workgrouplist; work; work = work->next) {
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if (work->RunningElection) {
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/*
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* We can only run an election for a workgroup if we have
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* registered the WORKGROUP<1e> name, as that's the name
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* we must listen to.
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*/
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struct nmb_name nmbname;
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make_nmb_name(&nmbname, work->work_group, 0x1e);
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if(find_name_on_subnet( subrec, &nmbname, FIND_SELF_NAME)==NULL) {
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DEBUG(8,("run_elections: Cannot send election packet yet as name %s not \
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yet registered on subnet %s\n", nmb_namestr(&nmbname), subrec->subnet_name ));
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continue;
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}
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send_election_dgram(subrec, work->work_group, work->ElectionCriterion,
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t - StartupTime, lp_netbios_name());
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if (work->ElectionCount++ >= 4) {
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/* Won election (4 packets were sent out uncontested. */
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DEBUG(2,("run_elections: >>> Won election for workgroup %s on subnet %s <<<\n",
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work->work_group, subrec->subnet_name ));
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work->RunningElection = False;
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become_local_master_browser(subrec, work);
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}
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}
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}
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}
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}
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/*******************************************************************
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Determine if I win an election.
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******************************************************************/
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static bool win_election(struct work_record *work, int version,
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uint32_t criterion, int timeup, const char *server_name)
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{
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int mytimeup = time(NULL) - StartupTime;
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uint32_t mycriterion = work->ElectionCriterion;
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/* If local master is false then never win in election broadcasts. */
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if(!lp_local_master()) {
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DEBUG(3,("win_election: Losing election as local master == False\n"));
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return False;
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}
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DEBUG(4,("win_election: election comparison: %x:%x %x:%x %d:%d %s:%s\n",
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version, ELECTION_VERSION,
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criterion, mycriterion,
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timeup, mytimeup,
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server_name, lp_netbios_name()));
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if (version > ELECTION_VERSION)
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return(False);
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if (version < ELECTION_VERSION)
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return(True);
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if (criterion > mycriterion)
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return(False);
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if (criterion < mycriterion)
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return(True);
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if (timeup > mytimeup)
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return(False);
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if (timeup < mytimeup)
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return(True);
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if (strcasecmp_m(lp_netbios_name(), server_name) > 0)
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return(False);
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return(True);
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}
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/*******************************************************************
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Process an incoming election datagram packet.
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******************************************************************/
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void process_election(struct subnet_record *subrec, struct packet_struct *p, const char *buf)
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{
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struct dgram_packet *dgram = &p->packet.dgram;
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int version = CVAL(buf,0);
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uint32_t criterion = IVAL(buf,1);
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int timeup = IVAL(buf,5)/1000;
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unstring server_name;
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struct work_record *work;
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unstring workgroup_name;
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pull_ascii_nstring(server_name, sizeof(server_name), buf+13);
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pull_ascii_nstring(workgroup_name, sizeof(workgroup_name), dgram->dest_name.name);
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server_name[15] = 0;
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DEBUG(3,("process_election: Election request from %s at IP %s on subnet %s for workgroup %s.\n",
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server_name,inet_ntoa(p->ip), subrec->subnet_name, workgroup_name ));
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DEBUG(5,("process_election: vers=%d criterion=%08x timeup=%d\n", version,criterion,timeup));
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if(( work = find_workgroup_on_subnet(subrec, workgroup_name)) == NULL) {
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DEBUG(0,("process_election: Cannot find workgroup %s on subnet %s.\n",
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workgroup_name, subrec->subnet_name ));
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goto done;
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}
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if (!strequal(work->work_group, lp_workgroup())) {
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DEBUG(3,("process_election: ignoring election request for workgroup %s on subnet %s as this \
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is not my workgroup.\n", work->work_group, subrec->subnet_name ));
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goto done;
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}
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if (win_election(work, version,criterion,timeup,server_name)) {
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/* We take precedence over the requesting server. */
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if (!work->RunningElection) {
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/* We weren't running an election - start running one. */
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work->needelection = True;
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work->ElectionCount=0;
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}
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/* Note that if we were running an election for this workgroup on this
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subnet already, we just ignore the server we take precedence over. */
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} else {
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/* We lost. Stop participating. */
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work->needelection = False;
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if (work->RunningElection || AM_LOCAL_MASTER_BROWSER(work)) {
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work->RunningElection = False;
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DEBUG(3,("process_election: >>> Lost election for workgroup %s on subnet %s <<<\n",
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work->work_group, subrec->subnet_name ));
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if (AM_LOCAL_MASTER_BROWSER(work))
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unbecome_local_master_browser(subrec, work, False);
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}
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}
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done:
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return;
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}
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/****************************************************************************
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This function looks over all the workgroups known on all the broadcast
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subnets and decides if a browser election is to be run on that workgroup.
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It returns True if any election packets need to be sent (this will then
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be done by run_elections().
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***************************************************************************/
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bool check_elections(void)
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{
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struct subnet_record *subrec;
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bool run_any_election = False;
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for (subrec = FIRST_SUBNET; subrec; subrec = NEXT_SUBNET_EXCLUDING_UNICAST(subrec)) {
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struct work_record *work;
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for (work = subrec->workgrouplist; work; work = work->next) {
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if (work->RunningElection) {
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run_any_election = work->RunningElection;
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}
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/*
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* Start an election if we have any chance of winning.
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* Note this is a change to the previous code, that would
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* only run an election if nmbd was in the potential browser
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* state. We need to run elections in any state if we're told
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* to. JRA.
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*/
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if (work->needelection && !work->RunningElection && lp_local_master()) {
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/*
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* We can only run an election for a workgroup if we have
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* registered the WORKGROUP<1e> name, as that's the name
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* we must listen to.
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*/
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struct nmb_name nmbname;
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make_nmb_name(&nmbname, work->work_group, 0x1e);
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if(find_name_on_subnet( subrec, &nmbname, FIND_SELF_NAME)==NULL) {
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DEBUG(8,("check_elections: Cannot send election packet yet as name %s not \
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yet registered on subnet %s\n", nmb_namestr(&nmbname), subrec->subnet_name ));
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continue;
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}
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DEBUG(3,("check_elections: >>> Starting election for workgroup %s on subnet %s <<<\n",
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work->work_group, subrec->subnet_name ));
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work->ElectionCount = 0;
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work->RunningElection = True;
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work->needelection = False;
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}
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}
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}
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return run_any_election;
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}
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/****************************************************************************
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Process a internal Samba message forcing an election.
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***************************************************************************/
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void nmbd_message_election(struct messaging_context *msg,
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void *private_data,
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uint32_t msg_type,
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struct server_id server_id,
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DATA_BLOB *data)
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{
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struct subnet_record *subrec;
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for (subrec = FIRST_SUBNET; subrec; subrec = NEXT_SUBNET_EXCLUDING_UNICAST(subrec)) {
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struct work_record *work;
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for (work = subrec->workgrouplist; work; work = work->next) {
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if (strequal(work->work_group, lp_workgroup())) {
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work->needelection = True;
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work->ElectionCount=0;
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work->mst_state = lp_local_master() ? MST_POTENTIAL : MST_NONE;
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}
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}
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}
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}
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