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Diffstat (limited to 'source3/nameelect.c')
| -rw-r--r-- | source3/nameelect.c | 371 |
1 files changed, 371 insertions, 0 deletions
diff --git a/source3/nameelect.c b/source3/nameelect.c new file mode 100644 index 0000000000..30c3c3795e --- /dev/null +++ b/source3/nameelect.c @@ -0,0 +1,371 @@ +/* + Unix SMB/Netbios implementation. + Version 1.9. + NBT netbios routines and daemon - version 2 + Copyright (C) Andrew Tridgell 1994-1995 + + 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. + + Revision History: + + 14 jan 96: lkcl@pires.co.uk + added multiple workgroup domain master support + +*/ + +#include "includes.h" +#include "loadparm.h" +#include "localnet.h" + +extern int DEBUGLEVEL; +extern pstring scope; + +extern pstring myname; + +/* machine comment for host announcements */ +extern pstring ServerComment; + +/* here are my election parameters */ + +/* NTAS uses 2, NT uses 1, WfWg uses 0 */ +#define MAINTAIN_LIST 2 +#define ELECTION_VERSION 2 + +extern time_t StartupTime; + +#define AM_MASTER(work) (work->ServerType & SV_TYPE_MASTER_BROWSER) + +#define MSBROWSE "\001\002__MSBROWSE__\002" +#define BROWSE_MAILSLOT "\\MAILSLOT\\BROWSE" + +extern struct domain_record *domainlist; + + +/******************************************************************* + occasionally check to see if the master browser is around + ******************************************************************/ +void check_master_browser(void) +{ + static time_t lastrun=0; + time_t t = time(NULL); + struct domain_record *d; + + if (!lastrun) lastrun = t; + if (t < lastrun + 2*60) return; + lastrun = t; + + for (d = domainlist; d; d = d->next) + { + struct work_record *work; + + for (work = d->workgrouplist; work; work = work->next) + { + /* if we are not the browse master of a workgroup, and we can't + find a browser on the subnet, do something about it. */ + + if (!AM_MASTER(work)) + { + queue_netbios_packet(ClientNMB,NMB_QUERY,CHECK_MASTER, + work->work_group,0x1d,0, + True,False,d->bcast_ip); + } + } + } +} + + +/******************************************************************* + what to do if a master browser DOESN't exist + ******************************************************************/ +void browser_gone(char *work_name, struct in_addr ip) +{ + struct domain_record *d = find_domain(ip); + struct work_record *work = find_workgroupstruct(d, work_name, False); + + if (!work || !d) return; + + DEBUG(2,("Forcing election on %s\n",work->work_group)); + + if (strequal(work->work_group, lp_workgroup()) && + ip_equal(bcast_ip, d->bcast_ip)) + { + /* we can attempt to become master browser */ + work->needelection = True; + } + else + { + DEBUG(2,("no master browser for persistent entry %s %s\n", + work->work_group, inet_ntoa(d->bcast_ip))); + + /* XXXX oh dear. we are going to have problems here. the + entry is a persistent one, there isn't anyone responsible + for this workgroup up and running, yet we can't find it + and we are going to continually have name_queries until + a master browser is found for this workgroup on the + remote subnet. + */ + } +} +/**************************************************************************** + send an election packet + **************************************************************************/ +void send_election(struct domain_record *d, char *group,uint32 criterion, + int timeup,char *name) +{ + pstring outbuf; + char *p; + + if (!d) return; + + DEBUG(2,("Sending election to %s for workgroup %s\n", + inet_ntoa(d->bcast_ip),group)); + + bzero(outbuf,sizeof(outbuf)); + p = outbuf; + CVAL(p,0) = 8; /* election */ + p++; + + CVAL(p,0) = (criterion == 0 && timeup == 0) ? 0 : ELECTION_VERSION; + SIVAL(p,1,criterion); + SIVAL(p,5,timeup*1000); /* ms - despite the spec */ + p += 13; + strcpy(p,name); + strupper(p); + p = skip_string(p,1); + + send_mailslot_reply(BROWSE_MAILSLOT,ClientDGRAM,outbuf,PTR_DIFF(p,outbuf), + name,group,0,0x1e,d->bcast_ip,myip); +} + + +/******************************************************************* + become the master browser + ******************************************************************/ +static void become_master(struct domain_record *d, struct work_record *work) +{ + uint32 domain_type = SV_TYPE_DOMAIN_ENUM | SV_TYPE_SERVER_UNIX | 0x00400000; + + if (!work) return; + + DEBUG(2,("Becoming master for %s\n",work->work_group)); + + work->ServerType |= SV_TYPE_MASTER_BROWSER; + work->ServerType &= ~SV_TYPE_POTENTIAL_BROWSER; + work->ElectionCriterion |= 0x5; + + /* add browse, master and general names to database or register with WINS */ + add_name_entry(MSBROWSE ,0x01,NB_ACTIVE|NB_GROUP); + add_name_entry(work->work_group,0x1d,NB_ACTIVE ); + + if (lp_domain_master()) + { + DEBUG(4,("Domain master: adding names...\n")); + + /* add domain master and domain member names or register with WINS */ + add_name_entry(work->work_group,0x1b,NB_ACTIVE ); + add_name_entry(work->work_group,0x1c,NB_ACTIVE|NB_GROUP); + + work->ServerType |= SV_TYPE_DOMAIN_MASTER; + + if (lp_domain_logons()) + { + work->ServerType |= SV_TYPE_DOMAIN_CTRL; + work->ServerType |= SV_TYPE_DOMAIN_MEMBER; + } + } + + /* update our server status */ + add_server_entry(d,work,work->work_group,domain_type,0,myname,True); + add_server_entry(d,work,myname,work->ServerType,0,ServerComment,True); + + if (ip_equal(bcast_ip, d->bcast_ip)) + { + /* ask all servers on our local net to announce to us */ + announce_request(work, d->bcast_ip); + } +} + + +/******************************************************************* + unbecome the master browser + ******************************************************************/ +void become_nonmaster(struct domain_record *d, struct work_record *work) +{ + DEBUG(2,("Becoming non-master for %s\n",work->work_group)); + + work->ServerType &= ~SV_TYPE_MASTER_BROWSER; + work->ServerType &= ~SV_TYPE_DOMAIN_MASTER; + work->ServerType |= SV_TYPE_POTENTIAL_BROWSER; + + work->ElectionCriterion &= ~0x4; + + remove_name_entry(work->work_group,0x1b); + remove_name_entry(work->work_group,0x1c); + remove_name_entry(work->work_group,0x1d); + remove_name_entry(MSBROWSE ,0x01); +} + + +/******************************************************************* + run the election + ******************************************************************/ +void run_elections(void) +{ + time_t t = time(NULL); + static time_t lastime = 0; + + struct domain_record *d; + + /* send election packets once a second */ + if (lastime && t-lastime <= 0) return; + + lastime = t; + + for (d = domainlist; d; d = d->next) + { + struct work_record *work; + for (work = d->workgrouplist; work; work = work->next) + { + if (work->RunningElection) + { + send_election(d,work->work_group, work->ElectionCriterion, + t-StartupTime,myname); + + if (work->ElectionCount++ >= 4) + { + /* I won! now what :-) */ + DEBUG(2,(">>> Won election on %s <<<\n",work->work_group)); + + work->RunningElection = False; + become_master(d, work); + } + } + } + } +} + + +/******************************************************************* + work out if I win an election + ******************************************************************/ +static BOOL win_election(struct work_record *work,int version,uint32 criterion, + int timeup,char *name) +{ + time_t t = time(NULL); + uint32 mycriterion; + if (version > ELECTION_VERSION) return(False); + if (version < ELECTION_VERSION) return(True); + + mycriterion = work->ElectionCriterion; + + if (criterion > mycriterion) return(False); + if (criterion < mycriterion) return(True); + + if (timeup > (t - StartupTime)) return(False); + if (timeup < (t - StartupTime)) return(True); + + if (strcasecmp(myname,name) > 0) return(False); + + return(True); +} + + +/******************************************************************* + process a election packet + + An election dynamically decides who will be the master. + ******************************************************************/ +void process_election(struct packet_struct *p,char *buf) +{ + struct dgram_packet *dgram = &p->packet.dgram; + struct in_addr ip = dgram->header.source_ip; + struct domain_record *d = find_domain(ip); + int version = CVAL(buf,0); + uint32 criterion = IVAL(buf,1); + int timeup = IVAL(buf,5)/1000; + char *name = buf+13; + struct work_record *work; + + if (!d) return; + + name[15] = 0; + + DEBUG(3,("Election request from %s vers=%d criterion=%08x timeup=%d\n", + name,version,criterion,timeup)); + + if (same_context(dgram)) return; + + for (work = d->workgrouplist; work; work = work->next) + { + if (listening_name(work, &dgram->dest_name) && + strequal(work->work_group, lp_workgroup()) && + ip_equal(d->bcast_ip, bcast_ip)) + { + if (win_election(work, version,criterion,timeup,name)) + { + if (!work->RunningElection) + { + work->needelection = True; + work->ElectionCount=0; + } + } + else + { + work->needelection = False; + + if (work->RunningElection) + { + work->RunningElection = False; + DEBUG(3,(">>> Lost election on %s <<<\n",work->work_group)); + + /* if we are the master then remove our masterly names */ + if (AM_MASTER(work)) + { + become_nonmaster(d, work); + } + } + } + } + } +} + + +/**************************************************************************** + checks whether a browser election is to be run on any workgroup + ***************************************************************************/ +BOOL check_elections(void) +{ + struct domain_record *d; + BOOL run_any_election = False; + + for (d = domainlist; d; d = d->next) + { + struct work_record *work; + for (work = d->workgrouplist; work; work = work->next) + { + run_any_election |= work->RunningElection; + + if (work->needelection && !work->RunningElection) + { + DEBUG(3,(">>> Starting election on %s <<<\n",work->work_group)); + work->ElectionCount = 0; + work->RunningElection = True; + work->needelection = False; + } + } + } + return run_any_election; +} + |