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/*
Unix SMB/Netbios implementation.
Version 1.9.
connection claim routines
Copyright (C) Andrew Tridgell 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 fstring remote_machine;
extern int DEBUGLEVEL;
/****************************************************************************
simple routines to do connection counting
****************************************************************************/
BOOL yield_connection(connection_struct *conn,char *name,int max_connections)
{
struct connect_record crec;
pstring fname;
int fd;
int mypid = getpid();
int i;
DEBUG(3,("Yielding connection to %s\n",name));
if (max_connections <= 0)
return(True);
bzero(&crec,sizeof(crec));
pstrcpy(fname,lp_lockdir());
trim_string(fname,"","/");
pstrcat(fname,"/");
pstrcat(fname,name);
pstrcat(fname,".LCK");
fd = open(fname,O_RDWR);
if (fd == -1) {
DEBUG(2,("Couldn't open lock file %s (%s)\n",fname,strerror(errno)));
return(False);
}
if (fcntl_lock(fd,F_SETLKW,0,1,F_WRLCK)==False) {
DEBUG(0,("ERROR: can't get lock on %s\n", fname));
return False;
}
/* find the right spot */
for (i=0;i<max_connections;i++) {
if (read(fd, &crec,sizeof(crec)) != sizeof(crec)) {
DEBUG(2,("Entry not found in lock file %s\n",fname));
if (fcntl_lock(fd,F_SETLKW,0,1,F_UNLCK)==False) {
DEBUG(0,("ERROR: can't release lock on %s\n", fname));
}
close(fd);
return(False);
}
if (crec.pid == mypid && crec.cnum == conn->cnum)
break;
}
if (crec.pid != mypid || crec.cnum != conn->cnum) {
if (fcntl_lock(fd,F_SETLKW,0,1,F_UNLCK)==False) {
DEBUG(0,("ERROR: can't release lock on %s\n", fname));
}
close(fd);
DEBUG(2,("Entry not found in lock file %s\n",fname));
return(False);
}
bzero((void *)&crec,sizeof(crec));
/* remove our mark */
if (lseek(fd,i*sizeof(crec),SEEK_SET) != i*sizeof(crec) ||
write(fd, &crec,sizeof(crec)) != sizeof(crec)) {
DEBUG(2,("Couldn't update lock file %s (%s)\n",fname,strerror(errno)));
if (fcntl_lock(fd,F_SETLKW,0,1,F_UNLCK)==False) {
DEBUG(0,("ERROR: can't release lock on %s\n", fname));
}
close(fd);
return(False);
}
if (fcntl_lock(fd,F_SETLKW,0,1,F_UNLCK)==False) {
DEBUG(0,("ERROR: can't release lock on %s\n", fname));
}
DEBUG(3,("Yield successful\n"));
close(fd);
return(True);
}
/****************************************************************************
simple routines to do connection counting
****************************************************************************/
BOOL claim_connection(connection_struct *conn,char *name,int max_connections,BOOL Clear)
{
extern int Client;
struct connect_record crec;
pstring fname;
int fd=-1;
int i,foundi= -1;
int total_recs;
if (max_connections <= 0)
return(True);
DEBUG(5,("trying claim %s %s %d\n",lp_lockdir(),name,max_connections));
pstrcpy(fname,lp_lockdir());
trim_string(fname,"","/");
if (!directory_exist(fname,NULL))
mkdir(fname,0755);
pstrcat(fname,"/");
pstrcat(fname,name);
pstrcat(fname,".LCK");
if (!file_exist(fname,NULL)) {
fd = open(fname,O_RDWR|O_CREAT|O_EXCL, 0644);
}
if (fd == -1) {
fd = open(fname,O_RDWR);
}
if (fd == -1) {
DEBUG(1,("couldn't open lock file %s\n",fname));
return(False);
}
if (fcntl_lock(fd,F_SETLKW,0,1,F_WRLCK)==False) {
DEBUG(0,("ERROR: can't get lock on %s\n", fname));
return False;
}
total_recs = file_size(fname) / sizeof(crec);
/* find a free spot */
for (i=0;i<max_connections;i++) {
if (i>=total_recs ||
lseek(fd,i*sizeof(crec),SEEK_SET) != i*sizeof(crec) ||
read(fd,&crec,sizeof(crec)) != sizeof(crec)) {
if (foundi < 0) foundi = i;
break;
}
if (Clear && crec.pid && !process_exists(crec.pid)) {
lseek(fd,i*sizeof(crec),SEEK_SET);
bzero((void *)&crec,sizeof(crec));
write(fd, &crec,sizeof(crec));
if (foundi < 0) foundi = i;
continue;
}
if (foundi < 0 && (!crec.pid || !process_exists(crec.pid))) {
foundi=i;
if (!Clear) break;
}
}
if (foundi < 0) {
DEBUG(3,("no free locks in %s\n",fname));
if (fcntl_lock(fd,F_SETLKW,0,1,F_UNLCK)==False) {
DEBUG(0,("ERROR: can't release lock on %s\n", fname));
}
close(fd);
return(False);
}
/* fill in the crec */
bzero((void *)&crec,sizeof(crec));
crec.magic = 0x280267;
crec.pid = getpid();
if (conn) {
crec.cnum = conn->cnum;
crec.uid = conn->uid;
crec.gid = conn->gid;
StrnCpy(crec.name,
lp_servicename(SNUM(conn)),sizeof(crec.name)-1);
} else {
crec.cnum = -1;
}
crec.start = time(NULL);
StrnCpy(crec.machine,remote_machine,sizeof(crec.machine)-1);
StrnCpy(crec.addr,client_addr(Client),sizeof(crec.addr)-1);
/* make our mark */
if (lseek(fd,foundi*sizeof(crec),SEEK_SET) != foundi*sizeof(crec) ||
write(fd, &crec,sizeof(crec)) != sizeof(crec)) {
if (fcntl_lock(fd,F_SETLKW,0,1,F_UNLCK)==False) {
DEBUG(0,("ERROR: can't release lock on %s\n", fname));
}
close(fd);
return(False);
}
if (fcntl_lock(fd,F_SETLKW,0,1,F_UNLCK)==False) {
DEBUG(0,("ERROR: can't release lock on %s\n", fname));
}
close(fd);
return(True);
}
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