/* 
   Unix SMB/Netbios implementation.
   Version 1.9.
   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

   SMB Version handling
   Copyright (C) John H Terpstra 1995-1998
   
   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;
extern char **my_netbios_names;
extern int  updatecount;
extern BOOL found_lm_clients;

/****************************************************************************
 Send a browser reset packet.
**************************************************************************/

void send_browser_reset(int reset_type, const char *to_name, int to_type, struct in_addr to_ip)
{
  pstring outbuf;
  char *p;

  DEBUG(3,("send_browser_reset: sending reset request type %d to %s<%02x> IP %s.\n",
       reset_type, to_name, to_type, inet_ntoa(to_ip) ));

  memset(outbuf,'\0',sizeof(outbuf));
  p = outbuf;
  SCVAL(p,0,ANN_ResetBrowserState);
  p++;
  SCVAL(p,0,reset_type);
  p++;

  send_mailslot(True, BROWSE_MAILSLOT, outbuf,PTR_DIFF(p,outbuf),
                global_myname, 0x0, to_name, to_type, to_ip, 
		FIRST_SUBNET->myip, DGRAM_PORT);
}

/****************************************************************************
  Broadcast a packet to the local net requesting that all servers in this
  workgroup announce themselves to us.
  **************************************************************************/

void broadcast_announce_request(struct subnet_record *subrec, struct work_record *work)
{
  pstring outbuf;
  char *p;

  work->needannounce = True;

  DEBUG(3,("broadcast_announce_request: sending announce request for workgroup %s \
to subnet %s\n", work->work_group, subrec->subnet_name));

  memset(outbuf,'\0',sizeof(outbuf));
  p = outbuf;
  SCVAL(p,0,ANN_AnnouncementRequest);
  p++;

  SCVAL(p,0,work->token); /* (local) Unique workgroup token id. */
  p++;
  StrnCpy(p,global_myname,15);
  strupper(p);
  p = skip_string(p,1);
  
  send_mailslot(False, BROWSE_MAILSLOT, outbuf,PTR_DIFF(p,outbuf),
                global_myname, 0x0, work->work_group,0x1e, subrec->bcast_ip, 
		subrec->myip, DGRAM_PORT);
}

/****************************************************************************
  Broadcast an announcement.
  **************************************************************************/

static void send_announcement(struct subnet_record *subrec, int announce_type,
                              const char *from_name, const char *to_name, int to_type, struct in_addr to_ip,
                              time_t announce_interval,
                              const char *server_name, int server_type, const char *server_comment)
{
  pstring outbuf;
  char *p;

  memset(outbuf,'\0',sizeof(outbuf));
  p = outbuf+1;

  SCVAL(outbuf,0,announce_type);

  /* Announcement parameters. */
  SCVAL(p,0,updatecount);
  SIVAL(p,1,announce_interval*1000); /* Milliseconds - despite the spec. */

  StrnCpy(p+5,server_name,15);
  strupper(p+5);

  SCVAL(p,21,lp_major_announce_version()); /* Major version. */
  SCVAL(p,22,lp_minor_announce_version()); /* Minor version. */

  SIVAL(p,23,server_type & ~SV_TYPE_LOCAL_LIST_ONLY);
  /* Browse version: got from NT/AS 4.00  - Value defined in smb.h (JHT). */
  SSVAL(p,27,BROWSER_ELECTION_VERSION);
  SSVAL(p,29,BROWSER_CONSTANT); /* Browse signature. */

  pstrcpy(p+31,server_comment);
  p += 31;
  p = skip_string(p,1);

  send_mailslot(False,BROWSE_MAILSLOT, outbuf, PTR_DIFF(p,outbuf),
                from_name, 0x0, to_name, to_type, to_ip, subrec->myip,
		DGRAM_PORT);
}

/****************************************************************************
  Broadcast a LanMan announcement.
**************************************************************************/

static void send_lm_announcement(struct subnet_record *subrec, int announce_type,
                              char *from_name, char *to_name, int to_type, struct in_addr to_ip,
                              time_t announce_interval,
                              char *server_name, int server_type, char *server_comment)
{
  pstring outbuf;
  char *p=outbuf;

  memset(outbuf,'\0',sizeof(outbuf));

  SSVAL(p,0,announce_type);
  SIVAL(p,2,server_type & ~SV_TYPE_LOCAL_LIST_ONLY);
  SCVAL(p,6,lp_major_announce_version()); /* Major version. */
  SCVAL(p,7,lp_minor_announce_version()); /* Minor version. */
  SSVAL(p,8,announce_interval);            /* In seconds - according to spec. */

  p += 10;
  StrnCpy(p,server_name,15);
  strupper(p);
  p = skip_string(p,1);
  pstrcpy(p,server_comment);
  p = skip_string(p,1);

  send_mailslot(False,LANMAN_MAILSLOT, outbuf, PTR_DIFF(p,outbuf),
                from_name, 0x0, to_name, to_type, to_ip, subrec->myip,
		DGRAM_PORT);
}

/****************************************************************************
 We are a local master browser. Announce this to WORKGROUP<1e>.
****************************************************************************/

static void send_local_master_announcement(struct subnet_record *subrec, struct work_record *work,
                                           struct server_record *servrec)
{
  /* Ensure we don't have the prohibited bit set. */
  uint32 type = servrec->serv.type & ~SV_TYPE_LOCAL_LIST_ONLY;

  DEBUG(3,("send_local_master_announcement: type %x for name %s on subnet %s for workgroup %s\n",
            type, global_myname, subrec->subnet_name, work->work_group));

  send_announcement(subrec, ANN_LocalMasterAnnouncement,
                    global_myname,                   /* From nbt name. */
                    work->work_group, 0x1e,          /* To nbt name. */
                    subrec->bcast_ip,                /* To ip. */
                    work->announce_interval,         /* Time until next announce. */
                    global_myname,                   /* Name to announce. */
                    type,                            /* Type field. */
                    servrec->serv.comment);
}

/****************************************************************************
 Announce the workgroup WORKGROUP to MSBROWSE<01>.
****************************************************************************/

static void send_workgroup_announcement(struct subnet_record *subrec, struct work_record *work)
{
  DEBUG(3,("send_workgroup_announcement: on subnet %s for workgroup %s\n",
            subrec->subnet_name, work->work_group));

  send_announcement(subrec, ANN_DomainAnnouncement,
                    global_myname,                   /* From nbt name. */
                    MSBROWSE, 0x1,                   /* To nbt name. */
                    subrec->bcast_ip,                /* To ip. */
                    work->announce_interval,         /* Time until next announce. */
                    work->work_group,                /* Name to announce. */
                    SV_TYPE_DOMAIN_ENUM|SV_TYPE_NT,  /* workgroup announce flags. */
                    global_myname);                  /* From name as comment. */
}

/****************************************************************************
 Announce the given host to WORKGROUP<1d>.
****************************************************************************/

static void send_host_announcement(struct subnet_record *subrec, struct work_record *work,
                                   struct server_record *servrec)
{
  /* Ensure we don't have the prohibited bits set. */
  uint32 type = servrec->serv.type & ~SV_TYPE_LOCAL_LIST_ONLY;

  DEBUG(3,("send_host_announcement: type %x for host %s on subnet %s for workgroup %s\n",
            type, servrec->serv.name, subrec->subnet_name, work->work_group));

  send_announcement(subrec, ANN_HostAnnouncement,
                    servrec->serv.name,              /* From nbt name. */
                    work->work_group, 0x1d,          /* To nbt name. */
                    subrec->bcast_ip,                /* To ip. */
                    work->announce_interval,         /* Time until next announce. */
                    servrec->serv.name,              /* Name to announce. */
                    type,                            /* Type field. */
                    servrec->serv.comment);
}

/****************************************************************************
 Announce the given LanMan host
****************************************************************************/

static void send_lm_host_announcement(struct subnet_record *subrec, struct work_record *work,
                                   struct server_record *servrec, int lm_interval)
{
  /* Ensure we don't have the prohibited bits set. */
  uint32 type = servrec->serv.type & ~SV_TYPE_LOCAL_LIST_ONLY;

  DEBUG(3,("send_lm_host_announcement: type %x for host %s on subnet %s for workgroup %s, ttl: %d\n",
            type, servrec->serv.name, subrec->subnet_name, work->work_group, lm_interval));

  send_lm_announcement(subrec, ANN_HostAnnouncement,
                    servrec->serv.name,              /* From nbt name. */
                    work->work_group, 0x00,          /* To nbt name. */
                    subrec->bcast_ip,                /* To ip. */
                    lm_interval,                     /* Time until next announce. */
                    servrec->serv.name,              /* Name to announce. */
                    type,                            /* Type field. */
                    servrec->serv.comment);
}

/****************************************************************************
  Announce a server record.
  ****************************************************************************/

static void announce_server(struct subnet_record *subrec, struct work_record *work,
                     struct server_record *servrec)
{
  /* Only do domain announcements if we are a master and it's
     our primary name we're being asked to announce. */

  if (AM_LOCAL_MASTER_BROWSER(work) && strequal(global_myname,servrec->serv.name))
  {
    send_local_master_announcement(subrec, work, servrec);
    send_workgroup_announcement(subrec, work);
  }
  else
  {
    send_host_announcement(subrec, work, servrec);
  }
}

/****************************************************************************
  Go through all my registered names on all broadcast subnets and announce
  them if the timeout requires it.
  **************************************************************************/

void announce_my_server_names(time_t t)
{
  struct subnet_record *subrec;

  for (subrec = FIRST_SUBNET; subrec; subrec = NEXT_SUBNET_EXCLUDING_UNICAST(subrec))
  {
    struct work_record *work = find_workgroup_on_subnet(subrec, global_myworkgroup);

    if(work)
    {
      struct server_record *servrec;

      if (work->needannounce)
      {
        /* Drop back to a max 3 minute announce. This is to prevent a
           single lost packet from breaking things for too long. */

        work->announce_interval = MIN(work->announce_interval,
                                    CHECK_TIME_MIN_HOST_ANNCE*60);
        work->lastannounce_time = t - (work->announce_interval+1);
        work->needannounce = False;
      }

      /* Announce every minute at first then progress to every 12 mins */
      if ((t - work->lastannounce_time) < work->announce_interval)
        continue;

      if (work->announce_interval < (CHECK_TIME_MAX_HOST_ANNCE * 60))
        work->announce_interval += 60;

      work->lastannounce_time = t;

      for (servrec = work->serverlist; servrec; servrec = servrec->next)
      {
        if (is_myname(servrec->serv.name))
          announce_server(subrec, work, servrec);
      }
    } /* if work */
  } /* for subrec */
}

/****************************************************************************
  Go through all my registered names on all broadcast subnets and announce
  them as a LanMan server if the timeout requires it.
**************************************************************************/

void announce_my_lm_server_names(time_t t)
{
  struct subnet_record *subrec;
  static time_t last_lm_announce_time=0;
  int announce_interval = lp_lm_interval();
  int lm_announce = lp_lm_announce();

  if ((announce_interval <= 0) || (lm_announce <= 0))
  {
    /* user absolutely does not want LM announcements to be sent. */
    return;
  }

  if ((lm_announce >= 2) && (!found_lm_clients))
  {
    /* has been set to 2 (Auto) but no LM clients detected (yet). */
    return;
  }

  /* Otherwise: must have been set to 1 (Yes), or LM clients *have*
     been detected. */

  for (subrec = FIRST_SUBNET; subrec; subrec = NEXT_SUBNET_EXCLUDING_UNICAST(subrec))
  {
    struct work_record *work = find_workgroup_on_subnet(subrec, global_myworkgroup);

    if(work)
    {
      struct server_record *servrec;

      if (last_lm_announce_time && ((t - last_lm_announce_time) < announce_interval ))
        continue;

      last_lm_announce_time = t;

      for (servrec = work->serverlist; servrec; servrec = servrec->next)
      {
        if (is_myname(servrec->serv.name))
          /* skipping equivalent of announce_server() */
          send_lm_host_announcement(subrec, work, servrec, announce_interval);
      }
    } /* if work */
  } /* for subrec */
}

/* Announce timer. Moved into global static so it can be reset
   when a machine becomes a local master browser. */
static time_t announce_timer_last=0;

/****************************************************************************
 Reset the announce_timer so that a local master browser announce will be done
 immediately.
 ****************************************************************************/

void reset_announce_timer(void)
{
  announce_timer_last = time(NULL) - (CHECK_TIME_MST_ANNOUNCE * 60);
}

/****************************************************************************
  Announce myself as a local master browser to a domain master browser.
  **************************************************************************/

void announce_myself_to_domain_master_browser(time_t t)
{
  struct subnet_record *subrec;
  struct work_record *work;

  if(!we_are_a_wins_client())
  {
    DEBUG(10,("announce_myself_to_domain_master_browser: no unicast subnet, ignoring.\n"));
    return;
  }

  if (!announce_timer_last)
    announce_timer_last = t;

  if ((t-announce_timer_last) < (CHECK_TIME_MST_ANNOUNCE * 60))
  {
    DEBUG(10,("announce_myself_to_domain_master_browser: t (%d) - last(%d) < %d\n",
	      (int)t, (int)announce_timer_last, 
	      CHECK_TIME_MST_ANNOUNCE * 60 ));
    return;
  }

  announce_timer_last = t;

  /* Look over all our broadcast subnets to see if any of them
     has the state set as local master browser. */

  for (subrec = FIRST_SUBNET; subrec; subrec = NEXT_SUBNET_EXCLUDING_UNICAST(subrec))
  {
    for (work = subrec->workgrouplist; work; work = work->next)
    {
      if (AM_LOCAL_MASTER_BROWSER(work))
      {
        DEBUG(4,( "announce_myself_to_domain_master_browser: I am a local master browser for \
workgroup %s on subnet %s\n", work->work_group, subrec->subnet_name));

        /* Look in nmbd_browsersync.c for the rest of this code. */
        announce_and_sync_with_domain_master_browser(subrec, work);
      }
    }
  }
}

/****************************************************************************
Announce all samba's server entries as 'gone'.
This must *only* be called on shutdown.
****************************************************************************/

void announce_my_servers_removed(void)
{
  int announce_interval = lp_lm_interval();
  int lm_announce = lp_lm_announce();
  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)
    {
      struct server_record *servrec;

      work->announce_interval = 0;
      for (servrec = work->serverlist; servrec; servrec = servrec->next)
      {
        if (!is_myname(servrec->serv.name))
          continue;
        servrec->serv.type = 0;
        if(AM_LOCAL_MASTER_BROWSER(work))
          send_local_master_announcement(subrec, work, servrec);
        send_host_announcement(subrec, work, servrec);


        if ((announce_interval <= 0) || (lm_announce <= 0))
        {
          /* user absolutely does not want LM announcements to be sent. */
          continue;
        }

        if ((lm_announce >= 2) && (!found_lm_clients))
        {
          /* has been set to 2 (Auto) but no LM clients detected (yet). */
          continue;
        }

        /* 
         * lm announce was set or we have seen lm announcements, so do
         * a lm announcement of host removed.
         */

        send_lm_host_announcement(subrec, work, servrec, 0);
      }
    }
  }
}

/****************************************************************************
  Do all the "remote" announcements. These are used to put ourselves
  on a remote browse list. They are done blind, no checking is done to
  see if there is actually a local master browser at the other end.
  **************************************************************************/

void announce_remote(time_t t)
{
  char *s;
  const char *ptr;
  static time_t last_time = 0;
  pstring s2;
  struct in_addr addr;
  char *comment;
  int stype = lp_default_server_announce();

  if (last_time && (t < (last_time + REMOTE_ANNOUNCE_INTERVAL)))
    return;

  last_time = t;

  s = lp_remote_announce();
  if (!*s)
    return;

  comment = string_truncate(lp_serverstring(), MAX_SERVER_STRING_LENGTH);

  for (ptr=s; next_token(&ptr,s2,NULL,sizeof(s2)); ) 
  {
    /* The entries are of the form a.b.c.d/WORKGROUP with 
       WORKGROUP being optional */
    char *wgroup;
    int i;

    wgroup = strchr(s2,'/');
    if (wgroup)
      *wgroup++ = 0;
    if (!wgroup || !*wgroup)
      wgroup = global_myworkgroup;

    addr = *interpret_addr2(s2);
    
    /* Announce all our names including aliases */
    /* Give the ip address as the address of our first
       broadcast subnet. */

    for(i=0; my_netbios_names[i]; i++) 
    {
      char *name = my_netbios_names[i];

      DEBUG(5,("announce_remote: Doing remote announce for server %s to IP %s.\n",
                 name, inet_ntoa(addr) ));

      send_announcement(FIRST_SUBNET, ANN_HostAnnouncement,
                    name,                      /* From nbt name. */
                    wgroup, 0x1d,              /* To nbt name. */
                    addr,                      /* To ip. */
                    REMOTE_ANNOUNCE_INTERVAL,  /* Time until next announce. */
                    name,                      /* Name to announce. */
                    stype,                     /* Type field. */
                    comment);
    }
  }
}

/****************************************************************************
  Implement the 'remote browse sync' feature Andrew added.
  These are used to put our browse lists into remote browse lists.
  **************************************************************************/

void browse_sync_remote(time_t t)
{  
  char *s;
  const char *ptr;
  static time_t last_time = 0; 
  pstring s2;
  struct in_addr addr;
  struct work_record *work;
  pstring outbuf;
  char *p;
 
  if (last_time && (t < (last_time + REMOTE_ANNOUNCE_INTERVAL)))
    return;
   
  last_time = t;

  s = lp_remote_browse_sync();
  if (!*s)
    return;

  /*
   * We only do this if we are the local master browser
   * for our workgroup on the firsst subnet.
   */

  if((work = find_workgroup_on_subnet(FIRST_SUBNET, global_myworkgroup)) == NULL)
  {   
    DEBUG(0,("browse_sync_remote: Cannot find workgroup %s on subnet %s\n",
           global_myworkgroup, FIRST_SUBNET->subnet_name ));
    return;
  }   
         
  if(!AM_LOCAL_MASTER_BROWSER(work))
  {
    DEBUG(5,("browse_sync_remote: We can only do this if we are a local master browser \
for workgroup %s on subnet %s.\n", global_myworkgroup, FIRST_SUBNET->subnet_name ));
    return;
  } 

  memset(outbuf,'\0',sizeof(outbuf));
  p = outbuf;
  SCVAL(p,0,ANN_MasterAnnouncement);
  p++;

  StrnCpy(p,global_myname,15);
  strupper(p);
  p = skip_string(p,1);

  for (ptr=s; next_token(&ptr,s2,NULL,sizeof(s2)); ) 
  {
    /* The entries are of the form a.b.c.d */
    addr = *interpret_addr2(s2);

    DEBUG(5,("announce_remote: Doing remote browse sync announce for server %s to IP %s.\n",
                 global_myname, inet_ntoa(addr) ));

    send_mailslot(True, BROWSE_MAILSLOT, outbuf,PTR_DIFF(p,outbuf),
          global_myname, 0x0, "*", 0x0, addr, FIRST_SUBNET->myip, DGRAM_PORT);
  }
}