mirror of
https://github.com/samba-team/samba.git
synced 2024-12-23 17:34:34 +03:00
cd68afe312
Changed "SMB/Netbios" to "SMB/CIFS" in file header.
(This used to be commit 6a58c9bd06
)
407 lines
13 KiB
C
407 lines
13 KiB
C
/*
|
|
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 pstring global_myname;
|
|
extern fstring global_myworkgroup;
|
|
|
|
/* Election parameters. */
|
|
extern time_t StartupTime;
|
|
|
|
/****************************************************************************
|
|
Send an election datagram packet.
|
|
**************************************************************************/
|
|
static void send_election_dgram(struct subnet_record *subrec, char *workgroup_name,
|
|
uint32 criterion, int timeup,char *server_name)
|
|
{
|
|
pstring outbuf;
|
|
char *p;
|
|
|
|
DEBUG(2,("send_election_dgram: Sending election packet for workgroup %s on subnet %s\n",
|
|
workgroup_name, subrec->subnet_name ));
|
|
|
|
memset(outbuf,'\0',sizeof(outbuf));
|
|
p = outbuf;
|
|
SCVAL(p,0,ANN_Election); /* Election opcode. */
|
|
p++;
|
|
|
|
SCVAL(p,0,((criterion == 0 && timeup == 0) ? 0 : ELECTION_VERSION));
|
|
SIVAL(p,1,criterion);
|
|
SIVAL(p,5,timeup*1000); /* ms - Despite what the spec says. */
|
|
p += 13;
|
|
pstrcpy(p,server_name);
|
|
strupper(p);
|
|
p = skip_string(p,1);
|
|
|
|
send_mailslot(False, BROWSE_MAILSLOT, outbuf, PTR_DIFF(p,outbuf),
|
|
global_myname, 0,
|
|
workgroup_name, 0x1e,
|
|
subrec->bcast_ip, subrec->myip, DGRAM_PORT);
|
|
}
|
|
|
|
/*******************************************************************
|
|
We found a current master browser on one of our broadcast interfaces.
|
|
******************************************************************/
|
|
|
|
static void check_for_master_browser_success(struct subnet_record *subrec,
|
|
struct userdata_struct *userdata,
|
|
struct nmb_name *answer_name,
|
|
struct in_addr answer_ip, struct res_rec *rrec)
|
|
{
|
|
DEBUG(3,("check_for_master_browser_success: Local master browser for workgroup %s exists at \
|
|
IP %s (just checking).\n", answer_name->name, inet_ntoa(answer_ip) ));
|
|
}
|
|
|
|
/*******************************************************************
|
|
We failed to find a current master browser on one of our broadcast interfaces.
|
|
******************************************************************/
|
|
|
|
static void check_for_master_browser_fail( struct subnet_record *subrec,
|
|
struct response_record *rrec,
|
|
struct nmb_name *question_name,
|
|
int fail_code)
|
|
{
|
|
char *workgroup_name = question_name->name;
|
|
struct work_record *work = find_workgroup_on_subnet(subrec, workgroup_name);
|
|
|
|
if(work == NULL)
|
|
{
|
|
DEBUG(0,("check_for_master_browser_fail: Unable to find workgroup %s on subnet %s.=\n",
|
|
workgroup_name, subrec->subnet_name ));
|
|
return;
|
|
}
|
|
|
|
if (strequal(work->work_group, global_myworkgroup))
|
|
{
|
|
|
|
if (lp_local_master())
|
|
{
|
|
/* We have discovered that there is no local master
|
|
browser, and we are configured to initiate
|
|
an election that we will participate in.
|
|
*/
|
|
DEBUG(2,("check_for_master_browser_fail: Forcing election on workgroup %s subnet %s\n",
|
|
work->work_group, subrec->subnet_name ));
|
|
|
|
/* Setting this means we will participate when the
|
|
election is run in run_elections(). */
|
|
work->needelection = True;
|
|
}
|
|
else
|
|
{
|
|
/* We need to force an election, because we are configured
|
|
not to become the local master, but we still need one,
|
|
having detected that one doesn't exist.
|
|
*/
|
|
send_election_dgram(subrec, work->work_group, 0, 0, "");
|
|
}
|
|
}
|
|
}
|
|
|
|
/*******************************************************************
|
|
Ensure there is a local master browser for a workgroup on our
|
|
broadcast interfaces.
|
|
******************************************************************/
|
|
|
|
void check_master_browser_exists(time_t t)
|
|
{
|
|
static time_t lastrun=0;
|
|
struct subnet_record *subrec;
|
|
char *workgroup_name = global_myworkgroup;
|
|
|
|
if (!lastrun)
|
|
lastrun = t;
|
|
|
|
if (t < (lastrun + (CHECK_TIME_MST_BROWSE * 60)))
|
|
return;
|
|
|
|
lastrun = t;
|
|
|
|
dump_workgroups(False);
|
|
|
|
for (subrec = FIRST_SUBNET; subrec; subrec = NEXT_SUBNET_EXCLUDING_UNICAST(subrec))
|
|
{
|
|
struct work_record *work;
|
|
|
|
for (work = subrec->workgrouplist; work; work = work->next)
|
|
{
|
|
if (strequal(work->work_group, workgroup_name) && !AM_LOCAL_MASTER_BROWSER(work))
|
|
{
|
|
/* Do a name query for the local master browser on this net. */
|
|
query_name( subrec, work->work_group, 0x1d,
|
|
check_for_master_browser_success,
|
|
check_for_master_browser_fail,
|
|
NULL);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/*******************************************************************
|
|
Run an election.
|
|
******************************************************************/
|
|
|
|
void run_elections(time_t t)
|
|
{
|
|
static time_t lastime = 0;
|
|
|
|
struct subnet_record *subrec;
|
|
|
|
/* Send election packets once every 2 seconds - note */
|
|
if (lastime && (t - lastime < 2))
|
|
return;
|
|
|
|
lastime = t;
|
|
|
|
START_PROFILE(run_elections);
|
|
for (subrec = FIRST_SUBNET; subrec; subrec = NEXT_SUBNET_EXCLUDING_UNICAST(subrec))
|
|
{
|
|
struct work_record *work;
|
|
|
|
for (work = subrec->workgrouplist; work; work = work->next)
|
|
{
|
|
if (work->RunningElection)
|
|
{
|
|
/*
|
|
* We can only run an election for a workgroup if we have
|
|
* registered the WORKGROUP<1e> name, as that's the name
|
|
* we must listen to.
|
|
*/
|
|
struct nmb_name nmbname;
|
|
|
|
make_nmb_name(&nmbname, work->work_group, 0x1e);
|
|
if(find_name_on_subnet( subrec, &nmbname, FIND_SELF_NAME)==NULL) {
|
|
DEBUG(8,("run_elections: Cannot send election packet yet as name %s not \
|
|
yet registered on subnet %s\n", nmb_namestr(&nmbname), subrec->subnet_name ));
|
|
continue;
|
|
}
|
|
|
|
send_election_dgram(subrec, work->work_group, work->ElectionCriterion,
|
|
t - StartupTime, global_myname);
|
|
|
|
if (work->ElectionCount++ >= 4)
|
|
{
|
|
/* Won election (4 packets were sent out uncontested. */
|
|
DEBUG(2,("run_elections: >>> Won election for workgroup %s on subnet %s <<<\n",
|
|
work->work_group, subrec->subnet_name ));
|
|
|
|
work->RunningElection = False;
|
|
|
|
become_local_master_browser(subrec, work);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
END_PROFILE(run_elections);
|
|
}
|
|
|
|
/*******************************************************************
|
|
Determine if I win an election.
|
|
******************************************************************/
|
|
|
|
static BOOL win_election(struct work_record *work, int version,
|
|
uint32 criterion, int timeup, char *server_name)
|
|
{
|
|
int mytimeup = time(NULL) - StartupTime;
|
|
uint32 mycriterion = work->ElectionCriterion;
|
|
|
|
/* If local master is false then never win
|
|
in election broadcasts. */
|
|
if(!lp_local_master())
|
|
{
|
|
DEBUG(3,("win_election: Losing election as local master == False\n"));
|
|
return False;
|
|
}
|
|
|
|
DEBUG(4,("win_election: election comparison: %x:%x %x:%x %d:%d %s:%s\n",
|
|
version, ELECTION_VERSION,
|
|
criterion, mycriterion,
|
|
timeup, mytimeup,
|
|
server_name, global_myname));
|
|
|
|
if (version > ELECTION_VERSION)
|
|
return(False);
|
|
if (version < ELECTION_VERSION)
|
|
return(True);
|
|
|
|
if (criterion > mycriterion)
|
|
return(False);
|
|
if (criterion < mycriterion)
|
|
return(True);
|
|
|
|
if (timeup > mytimeup)
|
|
return(False);
|
|
if (timeup < mytimeup)
|
|
return(True);
|
|
|
|
if (strcasecmp(global_myname, server_name) > 0)
|
|
return(False);
|
|
|
|
return(True);
|
|
}
|
|
|
|
/*******************************************************************
|
|
Process an incoming election datagram packet.
|
|
******************************************************************/
|
|
|
|
void process_election(struct subnet_record *subrec, struct packet_struct *p, char *buf)
|
|
{
|
|
struct dgram_packet *dgram = &p->packet.dgram;
|
|
int version = CVAL(buf,0);
|
|
uint32 criterion = IVAL(buf,1);
|
|
int timeup = IVAL(buf,5)/1000;
|
|
char *server_name = buf+13;
|
|
struct work_record *work;
|
|
char *workgroup_name = dgram->dest_name.name;
|
|
|
|
START_PROFILE(election);
|
|
server_name[15] = 0;
|
|
|
|
DEBUG(3,("process_election: Election request from %s at IP %s on subnet %s for workgroup %s.\n",
|
|
server_name,inet_ntoa(p->ip), subrec->subnet_name, workgroup_name ));
|
|
|
|
DEBUG(5,("process_election: vers=%d criterion=%08x timeup=%d\n", version,criterion,timeup));
|
|
|
|
if(( work = find_workgroup_on_subnet(subrec, workgroup_name)) == NULL)
|
|
{
|
|
DEBUG(0,("process_election: Cannot find workgroup %s on subnet %s.\n",
|
|
workgroup_name, subrec->subnet_name ));
|
|
goto done;
|
|
}
|
|
|
|
if (!strequal(work->work_group, global_myworkgroup))
|
|
{
|
|
DEBUG(3,("process_election: ignoring election request for workgroup %s on subnet %s as this \
|
|
is not my workgroup.\n", work->work_group, subrec->subnet_name ));
|
|
goto done;
|
|
}
|
|
|
|
if (win_election(work, version,criterion,timeup,server_name))
|
|
{
|
|
/* We take precedence over the requesting server. */
|
|
if (!work->RunningElection)
|
|
{
|
|
/* We weren't running an election - start running one. */
|
|
|
|
work->needelection = True;
|
|
work->ElectionCount=0;
|
|
}
|
|
|
|
/* Note that if we were running an election for this workgroup on this
|
|
subnet already, we just ignore the server we take precedence over. */
|
|
}
|
|
else
|
|
{
|
|
/* We lost. Stop participating. */
|
|
work->needelection = False;
|
|
|
|
if (work->RunningElection || AM_LOCAL_MASTER_BROWSER(work))
|
|
{
|
|
work->RunningElection = False;
|
|
DEBUG(3,("process_election: >>> Lost election for workgroup %s on subnet %s <<<\n",
|
|
work->work_group, subrec->subnet_name ));
|
|
if (AM_LOCAL_MASTER_BROWSER(work))
|
|
unbecome_local_master_browser(subrec, work, False);
|
|
}
|
|
}
|
|
done:
|
|
END_PROFILE(election);
|
|
}
|
|
|
|
/****************************************************************************
|
|
This function looks over all the workgroups known on all the broadcast
|
|
subnets and decides if a browser election is to be run on that workgroup.
|
|
It returns True if any election packets need to be sent (this will then
|
|
be done by run_elections().
|
|
***************************************************************************/
|
|
|
|
BOOL check_elections(void)
|
|
{
|
|
struct subnet_record *subrec;
|
|
BOOL run_any_election = False;
|
|
|
|
for (subrec = FIRST_SUBNET; subrec; subrec = NEXT_SUBNET_EXCLUDING_UNICAST(subrec))
|
|
{
|
|
struct work_record *work;
|
|
for (work = subrec->workgrouplist; work; work = work->next)
|
|
{
|
|
run_any_election |= work->RunningElection;
|
|
|
|
/*
|
|
* Start an election if we have any chance of winning.
|
|
* Note this is a change to the previous code, that would
|
|
* only run an election if nmbd was in the potential browser
|
|
* state. We need to run elections in any state if we're told
|
|
* to. JRA.
|
|
*/
|
|
|
|
if (work->needelection && !work->RunningElection && lp_local_master())
|
|
{
|
|
/*
|
|
* We can only run an election for a workgroup if we have
|
|
* registered the WORKGROUP<1e> name, as that's the name
|
|
* we must listen to.
|
|
*/
|
|
struct nmb_name nmbname;
|
|
|
|
make_nmb_name(&nmbname, work->work_group, 0x1e);
|
|
if(find_name_on_subnet( subrec, &nmbname, FIND_SELF_NAME)==NULL) {
|
|
DEBUG(8,("check_elections: Cannot send election packet yet as name %s not \
|
|
yet registered on subnet %s\n", nmb_namestr(&nmbname), subrec->subnet_name ));
|
|
continue;
|
|
}
|
|
|
|
DEBUG(3,("check_elections: >>> Starting election for workgroup %s on subnet %s <<<\n",
|
|
work->work_group, subrec->subnet_name ));
|
|
|
|
work->ElectionCount = 0;
|
|
work->RunningElection = True;
|
|
work->needelection = False;
|
|
}
|
|
}
|
|
}
|
|
return run_any_election;
|
|
}
|
|
|
|
|
|
|
|
/****************************************************************************
|
|
process a internal Samba message forcing an election
|
|
***************************************************************************/
|
|
void nmbd_message_election(int msg_type, pid_t src, void *buf, size_t len)
|
|
{
|
|
struct subnet_record *subrec;
|
|
|
|
for (subrec = FIRST_SUBNET; subrec; subrec = NEXT_SUBNET_EXCLUDING_UNICAST(subrec)) {
|
|
struct work_record *work;
|
|
for (work = subrec->workgrouplist; work; work = work->next) {
|
|
if (strequal(work->work_group, global_myworkgroup)) {
|
|
work->needelection = True;
|
|
work->ElectionCount=0;
|
|
work->mst_state = lp_local_master() ? MST_POTENTIAL : MST_NONE;
|
|
}
|
|
}
|
|
}
|
|
}
|