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/*
Unix SMB/Netbios implementation.
Version 1.9.
Locking functions
Copyright (C) Andrew Tridgell 1992-1997
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:
12 aug 96: Erik.Devriendt@te6.siemens.be
added support for shared memory implementation of share mode locking
May 1997. Jeremy Allison (jallison@whistle.com). Modified share mode
locking to deal with multiple share modes per open file.
*/
#include "includes.h"
extern int DEBUGLEVEL;
extern connection_struct Connections[];
extern files_struct Files[];
/****************************************************************************
utility function called to see if a file region is locked
****************************************************************************/
BOOL is_locked(int fnum,int cnum,uint32 count,uint32 offset)
{
int snum = SNUM(cnum);
if (count == 0)
return(False);
if (!lp_locking(snum) || !lp_strict_locking(snum))
return(False);
return(fcntl_lock(Files[fnum].fd_ptr->fd,F_GETLK,offset,count,
(Files[fnum].can_write?F_WRLCK:F_RDLCK)));
}
/****************************************************************************
utility function called by locking requests
****************************************************************************/
BOOL do_lock(int fnum,int cnum,uint32 count,uint32 offset,int *eclass,uint32 *ecode)
{
BOOL ok = False;
if (!lp_locking(SNUM(cnum)))
return(True);
if (count == 0) {
*eclass = ERRDOS;
*ecode = ERRnoaccess;
return False;
}
if (Files[fnum].can_lock && OPEN_FNUM(fnum) && (Files[fnum].cnum == cnum))
ok = fcntl_lock(Files[fnum].fd_ptr->fd,F_SETLK,offset,count,
(Files[fnum].can_write?F_WRLCK:F_RDLCK));
if (!ok) {
*eclass = ERRDOS;
*ecode = ERRlock;
return False;
}
return True; /* Got lock */
}
/****************************************************************************
utility function called by unlocking requests
****************************************************************************/
BOOL do_unlock(int fnum,int cnum,uint32 count,uint32 offset,int *eclass,uint32 *ecode)
{
BOOL ok = False;
if (!lp_locking(SNUM(cnum)))
return(True);
if (Files[fnum].can_lock && OPEN_FNUM(fnum) && (Files[fnum].cnum == cnum))
ok = fcntl_lock(Files[fnum].fd_ptr->fd,F_SETLK,offset,count,F_UNLCK);
if (!ok) {
*eclass = ERRDOS;
*ecode = ERRlock;
return False;
}
return True; /* Did unlock */
}
#ifdef FAST_SHARE_MODES
/*******************************************************************
initialize the shared memory for share_mode management
******************************************************************/
BOOL start_share_mode_mgmt(void)
{
pstring shmem_file_name;
pstrcpy(shmem_file_name,lp_lockdir());
if (!directory_exist(shmem_file_name,NULL))
mkdir(shmem_file_name,0755);
trim_string(shmem_file_name,"","/");
if (!*shmem_file_name) return(False);
strcat(shmem_file_name, "/SHARE_MEM_FILE");
return smb_shm_open(shmem_file_name, lp_shmem_size());
}
/*******************************************************************
deinitialize the shared memory for share_mode management
******************************************************************/
BOOL stop_share_mode_mgmt(void)
{
return smb_shm_close();
}
/*******************************************************************
lock a hash bucket entry in shared memory for share_mode management
******************************************************************/
BOOL lock_share_entry(int cnum, uint32 dev, uint32 inode, share_lock_token *ptok)
{
return smb_shm_lock_hash_entry(HASH_ENTRY(dev, inode));
}
/*******************************************************************
unlock a hash bucket entry in shared memory for share_mode management
******************************************************************/
BOOL unlock_share_entry(int cnum, uint32 dev, uint32 inode, share_lock_token token)
{
return smb_shm_unlock_hash_entry(HASH_ENTRY(dev, inode));
}
/*******************************************************************
get all share mode entries in shared memory for a dev/inode pair.
********************************************************************/
int get_share_modes(int cnum, share_lock_token token, uint32 dev, uint32 inode,
min_share_mode_entry **old_shares)
{
smb_shm_offset_t *mode_array;
unsigned int hash_entry = HASH_ENTRY(dev, inode);
share_mode_record *file_scanner_p;
share_mode_record *file_prev_p;
share_mode_entry *entry_scanner_p;
share_mode_entry *entry_prev_p;
int num_entries;
int num_entries_copied;
BOOL found = False;
min_share_mode_entry *share_array = (min_share_mode_entry *)0;
*old_shares = 0;
if(hash_entry > lp_shmem_hash_size() )
{
DEBUG(0,
("PANIC ERROR : get_share_modes (FAST_SHARE_MODES): hash_entry %d too large \
(max = %d)\n",
hash_entry, lp_shmem_hash_size() ));
return 0;
}
mode_array = (smb_shm_offset_t *)smb_shm_offset2addr(smb_shm_get_userdef_off());
if(mode_array[hash_entry] == NULL_OFFSET)
{
DEBUG(5,("get_share_modes (FAST_SHARE_MODES): hash bucket %d empty\n", hash_entry));
return 0;
}
file_scanner_p = (share_mode_record *)smb_shm_offset2addr(mode_array[hash_entry]);
file_prev_p = file_scanner_p;
while(file_scanner_p)
{
if( (file_scanner_p->st_dev == dev) && (file_scanner_p->st_ino == inode) )
{
found = True;
break;
}
else
{
file_prev_p = file_scanner_p ;
file_scanner_p = (share_mode_record *)smb_shm_offset2addr(
file_scanner_p->next_offset);
}
}
if(!found)
{
DEBUG(5,("get_share_modes (FAST_SHARE_MODES): no entry for \
file dev = %d, ino = %d in hash_bucket %d\n", dev, inode, hash_entry));
return (0);
}
if(file_scanner_p->locking_version != LOCKING_VERSION)
{
DEBUG(0,("ERROR:get_share_modes (FAST_SHARE_MODES): Deleting old share mode \
record due to old locking version %d for file dev = %d, inode = %d in hash \
bucket %d\n",file_scanner_p->locking_version, dev, inode, hash_entry));
if(file_prev_p == file_scanner_p)
mode_array[hash_entry] = file_scanner_p->next_offset;
else
file_prev_p->next_offset = file_scanner_p->next_offset;
smb_shm_free(smb_shm_addr2offset(file_scanner_p));
return (0);
}
/* Allocate the old_shares array */
num_entries = file_scanner_p->num_share_mode_entries;
if(num_entries)
{
*old_shares = share_array = (min_share_mode_entry *)
malloc(num_entries * sizeof(min_share_mode_entry));
if(*old_shares == 0)
{
DEBUG(0,("get_share_modes (FAST_SHARE_MODES): malloc fail !\n"));
return 0;
}
}
num_entries_copied = 0;
entry_scanner_p = (share_mode_entry*)smb_shm_offset2addr(
file_scanner_p->share_mode_entries);
entry_prev_p = entry_scanner_p;
while(entry_scanner_p)
{
int pid = entry_scanner_p->pid;
if (pid && !process_exists(pid))
{
/* Delete this share mode entry */
share_mode_entry *delete_entry_p = entry_scanner_p;
int share_mode = entry_scanner_p->share_mode;
if(entry_prev_p == entry_scanner_p)
{
/* We are at start of list */
file_scanner_p->share_mode_entries = entry_scanner_p->next_share_mode_entry;
entry_scanner_p = (share_mode_entry*)smb_shm_offset2addr(
file_scanner_p->share_mode_entries);
entry_prev_p = entry_scanner_p;
}
else
{
entry_prev_p->next_share_mode_entry = entry_scanner_p->next_share_mode_entry;
entry_scanner_p = (share_mode_entry*)
smb_shm_offset2addr(entry_scanner_p->next_share_mode_entry);
}
/* Decrement the number of share mode entries on this share mode record */
file_scanner_p->num_share_mode_entries -= 1;
/* PARANOIA TEST */
if(file_scanner_p->num_share_mode_entries < 0)
{
DEBUG(0,("PANIC ERROR:get_share_mode (FAST_SHARE_MODES): num_share_mode_entries < 0 (%d) \
for dev = %d, ino = %d, hashbucket %d\n", file_scanner_p->num_share_mode_entries,
dev, inode, hash_entry));
return 0;
}
DEBUG(0,("get_share_modes (FAST_SHARE_MODES): process %d no longer exists and \
it left a share mode entry with mode 0x%X for file dev = %d, ino = %d in hash \
bucket %d (number of entries now = %d)\n",
pid, share_mode, dev, inode, hash_entry,
file_scanner_p->num_share_mode_entries));
smb_shm_free(smb_shm_addr2offset(delete_entry_p));
}
else
{
/* This is a valid share mode entry and the process that
created it still exists. Copy it into the output array.
*/
share_array[num_entries_copied].pid = entry_scanner_p->pid;
share_array[num_entries_copied].share_mode = entry_scanner_p->share_mode;
memcpy(&share_array[num_entries_copied].time, &entry_scanner_p->time,
sizeof(struct timeval));
num_entries_copied++;
DEBUG(5,("get_share_modes (FAST_SHARE_MODES): Read share mode \
record mode 0x%X pid=%d\n", entry_scanner_p->share_mode, entry_scanner_p->pid));
entry_prev_p = entry_scanner_p;
entry_scanner_p = (share_mode_entry *)
smb_shm_offset2addr(entry_scanner_p->next_share_mode_entry);
}
}
/* If no valid share mode entries were found then this record shouldn't exist ! */
if(num_entries_copied == 0)
{
DEBUG(0,("get_share_modes (FAST_SHARE_MODES): file with dev %d, inode %d in \
hash bucket %d has a share mode record but no entries - deleting\n",
dev, inode, hash_entry));
if(*old_shares)
free((char *)*old_shares);
*old_shares = 0;
if(file_prev_p == file_scanner_p)
mode_array[hash_entry] = file_scanner_p->next_offset;
else
file_prev_p->next_offset = file_scanner_p->next_offset;
smb_shm_free(smb_shm_addr2offset(file_scanner_p));
}
DEBUG(5,("get_share_modes (FAST_SHARE_MODES): file with dev %d, inode %d in \
hash bucket %d returning %d entries\n", dev, inode, hash_entry,
num_entries_copied));
return(num_entries_copied);
}
/*******************************************************************
del the share mode of a file.
********************************************************************/
void del_share_mode(share_lock_token token, int fnum)
{
uint32 dev, inode;
smb_shm_offset_t *mode_array;
unsigned int hash_entry;
share_mode_record *file_scanner_p;
share_mode_record *file_prev_p;
share_mode_entry *entry_scanner_p;
share_mode_entry *entry_prev_p;
BOOL found = False;
int pid = getpid();
dev = Files[fnum].fd_ptr->dev;
inode = Files[fnum].fd_ptr->inode;
hash_entry = HASH_ENTRY(dev, inode);
if(hash_entry > lp_shmem_hash_size() )
{
DEBUG(0,
("PANIC ERROR:del_share_mode (FAST_SHARE_MODES): hash_entry %d too large \
(max = %d)\n",
hash_entry, lp_shmem_hash_size() ));
return;
}
mode_array = (smb_shm_offset_t *)smb_shm_offset2addr(smb_shm_get_userdef_off());
if(mode_array[hash_entry] == NULL_OFFSET)
{
DEBUG(0,("PANIC ERROR:del_share_mode (FAST_SHARE_MODES): hash bucket %d empty\n",
hash_entry));
return;
}
file_scanner_p = (share_mode_record *)smb_shm_offset2addr(mode_array[hash_entry]);
file_prev_p = file_scanner_p;
while(file_scanner_p)
{
if( (file_scanner_p->st_dev == dev) && (file_scanner_p->st_ino == inode) )
{
found = True;
break;
}
else
{
file_prev_p = file_scanner_p ;
file_scanner_p = (share_mode_record *)
smb_shm_offset2addr(file_scanner_p->next_offset);
}
}
if(!found)
{
DEBUG(0,("ERROR:del_share_mode (FAST_SHARE_MODES): no entry found for dev %d, \
inode %d in hash bucket %d\n", dev, inode, hash_entry));
return;
}
if(file_scanner_p->locking_version != LOCKING_VERSION)
{
DEBUG(0,("ERROR: del_share_modes (FAST_SHARE_MODES): Deleting old share mode \
record due to old locking version %d for file dev %d, inode %d hash bucket %d\n",
file_scanner_p->locking_version, dev, inode, hash_entry ));
if(file_prev_p == file_scanner_p)
mode_array[hash_entry] = file_scanner_p->next_offset;
else
file_prev_p->next_offset = file_scanner_p->next_offset;
smb_shm_free(smb_shm_addr2offset(file_scanner_p));
return;
}
found = False;
entry_scanner_p = (share_mode_entry*)smb_shm_offset2addr(
file_scanner_p->share_mode_entries);
entry_prev_p = entry_scanner_p;
while(entry_scanner_p)
{
if( (pid == entry_scanner_p->pid) &&
(memcmp(&entry_scanner_p->time,
&Files[fnum].open_time,sizeof(struct timeval)) == 0) )
{
found = True;
break;
}
else
{
entry_prev_p = entry_scanner_p;
entry_scanner_p = (share_mode_entry *)
smb_shm_offset2addr(entry_scanner_p->next_share_mode_entry);
}
}
if (found)
{
/* Decrement the number of entries in the record. */
file_scanner_p->num_share_mode_entries -= 1;
DEBUG(2,("del_share_modes (FAST_SHARE_MODES): \
Deleting share mode entry dev = %d, inode = %d in hash bucket %d (num entries now = %d)\n",
dev, inode, hash_entry, file_scanner_p->num_share_mode_entries));
if(entry_prev_p == entry_scanner_p)
/* We are at start of list */
file_scanner_p->share_mode_entries = entry_scanner_p->next_share_mode_entry;
else
entry_prev_p->next_share_mode_entry = entry_scanner_p->next_share_mode_entry;
smb_shm_free(smb_shm_addr2offset(entry_scanner_p));
/* PARANOIA TEST */
if(file_scanner_p->num_share_mode_entries < 0)
{
DEBUG(0,("PANIC ERROR:del_share_mode (FAST_SHARE_MODES): num_share_mode_entries < 0 (%d) \
for dev = %d, ino = %d, hashbucket %d\n", file_scanner_p->num_share_mode_entries,
dev, inode, hash_entry));
return;
}
/* If we deleted the last share mode entry then remove the share mode record. */
if(file_scanner_p->num_share_mode_entries == 0)
{
DEBUG(2,("del_share_modes (FAST_SHARE_MODES): num entries = 0, deleting share_mode \
record dev = %d, inode = %d in hash bucket %d\n", dev, inode, hash_entry));
if(file_prev_p == file_scanner_p)
mode_array[hash_entry] = file_scanner_p->next_offset;
else
file_prev_p->next_offset = file_scanner_p->next_offset;
smb_shm_free(smb_shm_addr2offset(file_scanner_p));
}
}
else
{
DEBUG(0,("ERROR: del_share_modes (FAST_SHARE_MODES): No share mode record found \
dev = %d, inode = %d in hash bucket %d\n", dev, inode, hash_entry));
}
}
/*******************************************************************
set the share mode of a file. Return False on fail, True on success.
********************************************************************/
BOOL set_share_mode(share_lock_token token, int fnum)
{
files_struct *fs_p = &Files[fnum];
int32 dev, inode;
smb_shm_offset_t *mode_array;
unsigned int hash_entry;
share_mode_record *file_scanner_p;
share_mode_record *file_prev_p;
share_mode_entry *new_entry_p;
smb_shm_offset_t new_entry_offset;
BOOL found = False;
dev = fs_p->fd_ptr->dev;
inode = fs_p->fd_ptr->inode;
hash_entry = HASH_ENTRY(dev, inode);
if(hash_entry > lp_shmem_hash_size() )
{
DEBUG(0,
("PANIC ERROR:set_share_mode (FAST_SHARE_MODES): hash_entry %d too large \
(max = %d)\n",
hash_entry, lp_shmem_hash_size() ));
return False;
}
mode_array = (smb_shm_offset_t *)smb_shm_offset2addr(smb_shm_get_userdef_off());
file_scanner_p = (share_mode_record *)smb_shm_offset2addr(mode_array[hash_entry]);
file_prev_p = file_scanner_p;
while(file_scanner_p)
{
if( (file_scanner_p->st_dev == dev) && (file_scanner_p->st_ino == inode) )
{
found = True;
break;
}
else
{
file_prev_p = file_scanner_p ;
file_scanner_p = (share_mode_record *)
smb_shm_offset2addr(file_scanner_p->next_offset);
}
}
if(!found)
{
/* We must create a share_mode_record */
share_mode_record *new_mode_p = NULL;
smb_shm_offset_t new_offset = smb_shm_alloc( sizeof(share_mode_record) +
strlen(fs_p->name) + 1);
if(new_offset == NULL_OFFSET)
{
DEBUG(0,("ERROR:set_share_mode (FAST_SHARE_MODES): smb_shm_alloc fail !\n"));
return False;
}
new_mode_p = smb_shm_offset2addr(new_offset);
new_mode_p->locking_version = LOCKING_VERSION;
new_mode_p->st_dev = dev;
new_mode_p->st_ino = inode;
new_mode_p->num_share_mode_entries = 0;
new_mode_p->share_mode_entries = NULL_OFFSET;
strcpy(new_mode_p->file_name, fs_p->name);
/* Chain onto the start of the hash chain (in the hope we will be used first). */
new_mode_p->next_offset = mode_array[hash_entry];
mode_array[hash_entry] = new_offset;
file_scanner_p = new_mode_p;
DEBUG(3,("set_share_mode (FAST_SHARE_MODES): Created share record for %s (dev %d \
inode %d in hash bucket %d\n", fs_p->name, dev, inode, hash_entry));
}
/* Now create the share mode entry */
new_entry_offset = smb_shm_alloc( sizeof(share_mode_entry));
if(new_entry_offset == NULL_OFFSET)
{
smb_shm_offset_t delete_offset = mode_array[hash_entry];
DEBUG(0,("ERROR:set_share_mode (FAST_SHARE_MODES): smb_shm_alloc fail 1!\n"));
/* Unlink the damaged record */
mode_array[hash_entry] = file_scanner_p->next_offset;
/* And delete it */
smb_shm_free( delete_offset );
return False;
}
new_entry_p = smb_shm_offset2addr(new_entry_offset);
new_entry_p->pid = getpid();
new_entry_p->share_mode = fs_p->share_mode;
memcpy( (char *)&new_entry_p->time, (char *)&fs_p->open_time, sizeof(struct timeval));
/* Chain onto the share_mode_record */
new_entry_p->next_share_mode_entry = file_scanner_p->share_mode_entries;
file_scanner_p->share_mode_entries = new_entry_offset;
/* PARANOIA TEST */
if(file_scanner_p->num_share_mode_entries < 0)
{
DEBUG(0,("PANIC ERROR:set_share_mode (FAST_SHARE_MODES): num_share_mode_entries < 0 (%d) \
for dev = %d, ino = %d, hashbucket %d\n", file_scanner_p->num_share_mode_entries,
dev, inode, hash_entry));
return False;
}
/* Increment the share_mode_entries counter */
file_scanner_p->num_share_mode_entries += 1;
DEBUG(3,("set_share_mode (FAST_SHARE_MODES): Created share entry for %s with mode \
0x%X pid=%d (num_entries now = %d)\n",fs_p->name, fs_p->share_mode, new_entry_p->pid,
file_scanner_p->num_share_mode_entries));
return(True);
}
#else /* FAST_SHARE_MODES */
/* SHARE MODE LOCKS USING SLOW DESCRIPTION FILES */
/*******************************************************************
name a share file
******************************************************************/
static BOOL share_name(int cnum, uint32 dev, uint32 inode, char *name)
{
strcpy(name,lp_lockdir());
standard_sub(cnum,name);
trim_string(name,"","/");
if (!*name) return(False);
name += strlen(name);
sprintf(name,"/share.%u.%u",dev,inode);
return(True);
}
/*******************************************************************
Force a share file to be deleted.
********************************************************************/
static int delete_share_file( int cnum, char *fname )
{
/* the share file could be owned by anyone, so do this as root */
become_root(0);
if(unlink(fname) != 0) {
DEBUG(0,("delete_share_file: Can't delete share file %s (%s)\n",
fname, strerror(errno)));
} else {
DEBUG(5,("delete_share_file: Deleted share file %s\n", fname));
}
unbecome_root(0);
return 0;
}
/*******************************************************************
lock a share mode file.
******************************************************************/
BOOL lock_share_entry(int cnum, uint32 dev, uint32 inode, share_lock_token *ptok)
{
pstring fname;
int fd;
int ret = True;
*ptok = (share_lock_token)-1;
if(!share_name(cnum, dev, inode, fname))
return False;
/* we need to do this as root */
become_root(0);
{
int old_umask;
BOOL gotlock = False;
old_umask = umask(0);
/*
* There was a race condition in the original slow share mode code.
* A smbd could open a share mode file, and before getting
* the lock, another smbd could delete the last entry for
* the share mode file and delete the file entry from the
* directory. Thus this smbd would be left with a locked
* share mode fd attached to a file that no longer had a
* directory entry. Thus another smbd would think that
* there were no outstanding opens on the file. To fix
* this we now check we can do a stat() call on the filename
* before allowing the lock to proceed, and back out completely
* and try the open again if we cannot.
* Jeremy Allison (jallison@whistle.com).
*/
do
{
struct stat dummy_stat;
#ifdef SECURE_SHARE_MODES
fd = (share_lock_token)open(fname,O_RDWR|O_CREAT,0600);
#else /* SECURE_SHARE_MODES */
fd = (share_lock_token)open(fname,O_RDWR|O_CREAT,0666);
#endif /* SECURE_SHARE_MODES */
if(fd < 0)
{
DEBUG(0,("ERROR lock_share_entry: failed to open share file %s. Error was %s\n",
fname, strerror(errno)));
ret = False;
break;
}
/* At this point we have an open fd to the share mode file.
Lock the first byte exclusively to signify a lock. */
if(fcntl_lock(fd, F_SETLKW, 0, 1, F_WRLCK) == False)
{
DEBUG(0,("ERROR lock_share_entry: fcntl_lock failed with %s\n",
strerror(errno)));
close(fd);
ret = False;
break;
}
/*
* If we cannot stat the filename, the file was deleted between
* the open and the lock call. Back out and try again.
*/
if(stat(fname, &dummy_stat)!=0)
{
DEBUG(2,("lock_share_entry: Re-issuing open on %s to fix race. Error was %s\n",
fname, strerror(errno)));
close(fd);
}
else
gotlock = True;
} while(!gotlock);
umask(old_umask);
}
*ptok = (share_lock_token)fd;
/* return to our previous privilage level */
unbecome_root(0);
return ret;
}
/*******************************************************************
unlock a share mode file.
******************************************************************/
BOOL unlock_share_entry(int cnum, uint32 dev, uint32 inode, share_lock_token token)
{
int fd = (int)token;
int ret = True;
struct stat sb;
pstring fname;
/* Fix for zero length share files from
Gerald Werner <wernerg@mfldclin.edu> */
share_name(cnum, dev, inode, fname);
/* get the share mode file size */
if(fstat((int)token, &sb) != 0)
{
DEBUG(0,("ERROR: unlock_share_entry: Failed to do stat on share file %s (%s)\n",
fname, strerror(errno)));
sb.st_size = 1;
ret = False;
}
/* If the file was zero length, we must delete before
doing the unlock to avoid a race condition (see
the code in lock_share_mode_entry for details.
*/
/* remove the share file if zero length */
if(sb.st_size == 0)
delete_share_file(cnum, fname);
/* token is the fd of the open share mode file. */
/* Unlock the first byte. */
if(fcntl_lock(fd, F_SETLKW, 0, 1, F_UNLCK) == False)
{
DEBUG(0,("ERROR unlock_share_entry: fcntl_lock failed with %s\n",
strerror(errno)));
ret = False;
}
close((int)token);
return ret;
}
/*******************************************************************
Read a share file into a buffer.
********************************************************************/
static int read_share_file(int cnum, int fd, char *fname, char **out, BOOL *p_new_file)
{
struct stat sb;
char *buf;
int size;
*out = 0;
*p_new_file = False;
if(fstat(fd, &sb) != 0)
{
DEBUG(0,("ERROR: read_share_file: Failed to do stat on share file %s (%s)\n",
fname, strerror(errno)));
return -1;
}
if(sb.st_size == 0)
{
*p_new_file = True;
return 0;
}
/* Allocate space for the file */
if((buf = (char *)malloc(sb.st_size)) == NULL)
{
DEBUG(0,("read_share_file: malloc for file size %d fail !\n", sb.st_size));
return -1;
}
if(lseek(fd, 0, SEEK_SET) != 0)
{
DEBUG(0,("ERROR: read_share_file: Failed to reset position to 0 \
for share file %s (%s)\n", fname, strerror(errno)));
if(buf)
free(buf);
return -1;
}
if (read(fd,buf,sb.st_size) != sb.st_size)
{
DEBUG(0,("ERROR: read_share_file: Failed to read share file %s (%s)\n",
fname, strerror(errno)));
if(buf)
free(buf);
return -1;
}
if (IVAL(buf,0) != LOCKING_VERSION) {
DEBUG(0,("ERROR: read_share_file: share file %s has incorrect \
locking version (was %d, should be %d).\n",fname, IVAL(buf,0), LOCKING_VERSION));
if(buf)
free(buf);
delete_share_file(cnum, fname);
return -1;
}
/* Sanity check for file contents */
size = sb.st_size;
size -= 10; /* Remove the header */
/* Remove the filename component. */
size -= SVAL(buf, 8);
/* The remaining size must be a multiple of 16 - error if not. */
if((size % 16) != 0)
{
DEBUG(0,("ERROR: read_share_file: share file %s is an incorrect length - \
deleting it.\n", fname));
if(buf)
free(buf);
delete_share_file(cnum, fname);
return -1;
}
*out = buf;
return 0;
}
/*******************************************************************
get all share mode entries in a share file for a dev/inode pair.
********************************************************************/
int get_share_modes(int cnum, share_lock_token token, uint32 dev, uint32 inode,
min_share_mode_entry **old_shares)
{
int fd = (int)token;
pstring fname;
int i;
int num_entries;
int num_entries_copied;
int newsize;
min_share_mode_entry *share_array;
char *buf = 0;
char *base = 0;
BOOL new_file;
*old_shares = 0;
/* Read the share file header - this is of the form:
0 - locking version.
4 - number of share mode entries.
8 - 2 byte name length
[n bytes] file name (zero terminated).
Followed by <n> share mode entries of the form :
0 - tv_sec
4 - tv_usec
8 - share_mode
12 - pid
*/
share_name(cnum, dev, inode, fname);
if(read_share_file( cnum, fd, fname, &buf, &new_file) != 0)
{
DEBUG(0,("ERROR: get_share_modes: Failed to read share file %s\n",
fname));
return 0;
}
if(new_file == True)
return 0;
num_entries = IVAL(buf,4);
DEBUG(5,("get_share_modes: share file %s has %d share mode entries.\n",
fname, num_entries));
/* PARANOIA TEST */
if(num_entries < 0)
{
DEBUG(0,("PANIC ERROR:get_share_mode: num_share_mode_entries < 0 (%d) \
for share file %d\n", num_entries, fname));
return 0;
}
if(num_entries)
{
*old_shares = share_array = (min_share_mode_entry *)
malloc(num_entries * sizeof(min_share_mode_entry));
if(*old_shares == 0)
{
DEBUG(0,("get_share_modes: malloc fail !\n"));
return 0;
}
}
else
{
/* No entries - just delete the file. */
DEBUG(0,("get_share_modes: share file %s has no share mode entries - deleting.\n",
fname));
if(buf)
free(buf);
delete_share_file(cnum, fname);
return 0;
}
num_entries_copied = 0;
base = buf + 10 + SVAL(buf,8);
for( i = 0; i < num_entries; i++)
{
int pid;
char *p = base + (i*16);
pid = IVAL(p,12);
if(!process_exists(pid))
{
DEBUG(0,("get_share_modes: process %d no longer exists and \
it left a share mode entry with mode 0x%X in share file %s\n",
pid, IVAL(p,8), fname));
continue;
}
share_array[num_entries_copied].time.tv_sec = IVAL(p,0);
share_array[num_entries_copied].time.tv_usec = IVAL(p,4);
share_array[num_entries_copied].share_mode = IVAL(p,8);
share_array[num_entries_copied].pid = pid;
num_entries_copied++;
}
if(num_entries_copied == 0)
{
/* Delete the whole file. */
DEBUG(0,("get_share_modes: share file %s had no valid entries - deleting it !\n",
fname));
if(*old_shares)
free((char *)*old_shares);
*old_shares = 0;
if(buf)
free(buf);
delete_share_file(cnum, fname);
return 0;
}
/* If we deleted some entries we need to re-write the whole number of
share mode entries back into the file. */
if(num_entries_copied != num_entries)
{
if(lseek(fd, 0, SEEK_SET) != 0)
{
DEBUG(0,("ERROR: get_share_modes: lseek failed to reset to \
position 0 for share mode file %s (%s)\n", fname, strerror(errno)));
if(*old_shares)
free((char *)*old_shares);
*old_shares = 0;
if(buf)
free(buf);
return 0;
}
SIVAL(buf, 4, num_entries_copied);
for( i = 0; i < num_entries_copied; i++)
{
char *p = base + (i*16);
SIVAL(p,12,share_array[i].pid);
SIVAL(p,8,share_array[i].share_mode);
SIVAL(p,0,share_array[i].time.tv_sec);
SIVAL(p,4,share_array[i].time.tv_usec);
}
newsize = (base - buf) + (16*num_entries_copied);
if(write(fd, buf, newsize) != newsize)
{
DEBUG(0,("ERROR: get_share_modes: failed to re-write share \
mode file %s (%s)\n", fname, strerror(errno)));
if(*old_shares)
free((char *)*old_shares);
*old_shares = 0;
if(buf)
free(buf);
return 0;
}
/* Now truncate the file at this point. */
if(ftruncate(fd, newsize)!= 0)
{
DEBUG(0,("ERROR: get_share_modes: failed to ftruncate share \
mode file %s to size %d (%s)\n", fname, newsize, strerror(errno)));
if(*old_shares)
free((char *)*old_shares);
*old_shares = 0;
if(buf)
free(buf);
return 0;
}
}
if(buf)
free(buf);
DEBUG(5,("get_share_modes: Read share file %s returning %d entries\n",fname,
num_entries_copied));
return num_entries_copied;
}
/*******************************************************************
del a share mode from a share mode file.
********************************************************************/
void del_share_mode(share_lock_token token, int fnum)
{
pstring fname;
int fd = (int)token;
char *buf = 0;
char *base = 0;
int num_entries;
int newsize;
int i;
files_struct *fs_p = &Files[fnum];
int pid;
BOOL deleted = False;
BOOL new_file;
share_name(fs_p->cnum, fs_p->fd_ptr->dev,
fs_p->fd_ptr->inode, fname);
if(read_share_file( fs_p->cnum, fd, fname, &buf, &new_file) != 0)
{
DEBUG(0,("ERROR: del_share_mode: Failed to read share file %s\n",
fname));
return;
}
if(new_file == True)
{
DEBUG(0,("ERROR:del_share_mode: share file %s is new (size zero), deleting it.\n",
fname));
delete_share_file(fs_p->cnum, fname);
return;
}
num_entries = IVAL(buf,4);
DEBUG(5,("del_share_mode: share file %s has %d share mode entries.\n",
fname, num_entries));
/* PARANOIA TEST */
if(num_entries < 0)
{
DEBUG(0,("PANIC ERROR:del_share_mode: num_share_mode_entries < 0 (%d) \
for share file %d\n", num_entries, fname));
return;
}
if(num_entries == 0)
{
/* No entries - just delete the file. */
DEBUG(0,("del_share_mode: share file %s has no share mode entries - deleting.\n",
fname));
if(buf)
free(buf);
delete_share_file(fs_p->cnum, fname);
return;
}
pid = getpid();
/* Go through the entries looking for the particular one
we have set - delete it.
*/
base = buf + 10 + SVAL(buf,8);
for(i = 0; i < num_entries; i++)
{
char *p = base + (i*16);
if((IVAL(p,0) != fs_p->open_time.tv_sec) || (IVAL(p,4) != fs_p->open_time.tv_usec) ||
(IVAL(p,8) != fs_p->share_mode) || (IVAL(p,12) != pid))
continue;
DEBUG(5,("del_share_mode: deleting entry number %d (of %d) from the share file %s\n",
i, num_entries, fname));
/* Remove this entry. */
if(i != num_entries - 1)
memcpy(p, p + 16, (num_entries - i - 1)*16);
deleted = True;
break;
}
if(!deleted)
{
DEBUG(0,("del_share_mode: entry not found in share file %s\n", fname));
if(buf)
free(buf);
return;
}
num_entries--;
SIVAL(buf,4, num_entries);
if(num_entries == 0)
{
/* Deleted the last entry - remove the file. */
DEBUG(5,("del_share_mode: removed last entry in share file - deleting share file %s\n",
fname));
if(buf)
free(buf);
delete_share_file(fs_p->cnum,fname);
return;
}
/* Re-write the file - and truncate it at the correct point. */
if(lseek(fd, 0, SEEK_SET) != 0)
{
DEBUG(0,("ERROR: del_share_mode: lseek failed to reset to \
position 0 for share mode file %s (%s)\n", fname, strerror(errno)));
if(buf)
free(buf);
return;
}
newsize = (base - buf) + (16*num_entries);
if(write(fd, buf, newsize) != newsize)
{
DEBUG(0,("ERROR: del_share_mode: failed to re-write share \
mode file %s (%s)\n", fname, strerror(errno)));
if(buf)
free(buf);
return;
}
/* Now truncate the file at this point. */
if(ftruncate(fd, newsize) != 0)
{
DEBUG(0,("ERROR: del_share_mode: failed to ftruncate share \
mode file %s to size %d (%s)\n", fname, newsize, strerror(errno)));
if(buf)
free(buf);
return;
}
}
/*******************************************************************
set the share mode of a file
********************************************************************/
BOOL set_share_mode(share_lock_token token,int fnum)
{
files_struct *fs_p = &Files[fnum];
pstring fname;
int fd = (int)token;
int pid = (int)getpid();
struct stat sb;
char *buf;
int num_entries;
int header_size;
char *p;
share_name(fs_p->cnum, fs_p->fd_ptr->dev,
fs_p->fd_ptr->inode, fname);
if(fstat(fd, &sb) != 0)
{
DEBUG(0,("ERROR: set_share_mode: Failed to do stat on share file %s\n",
fname));
return False;
}
/* Sanity check for file contents (if it's not a new share file). */
if(sb.st_size != 0)
{
int size = sb.st_size;
/* Allocate space for the file plus one extra entry */
if((buf = (char *)malloc(sb.st_size + 16)) == NULL)
{
DEBUG(0,("set_share_mode: malloc for file size %d fail !\n", sb.st_size + 16));
return False;
}
if(lseek(fd, 0, SEEK_SET) != 0)
{
DEBUG(0,("ERROR: set_share_mode: Failed to reset position \
to 0 for share file %s (%s)\n", fname, strerror(errno)));
if(buf)
free(buf);
return False;
}
if (read(fd,buf,sb.st_size) != sb.st_size)
{
DEBUG(0,("ERROR: set_share_mode: Failed to read share file %s (%s)\n",
fname, strerror(errno)));
if(buf)
free(buf);
return False;
}
if (IVAL(buf,0) != LOCKING_VERSION)
{
DEBUG(0,("ERROR: set_share_mode: share file %s has incorrect \
locking version (was %d, should be %d).\n",fname, IVAL(buf,0), LOCKING_VERSION));
if(buf)
free(buf);
delete_share_file(fs_p->cnum, fname);
return False;
}
size -= (10 + SVAL(buf, 8)); /* Remove the header */
/* The remaining size must be a multiple of 16 - error if not. */
if((size % 16) != 0)
{
DEBUG(0,("ERROR: set_share_mode: share file %s is an incorrect length - \
deleting it.\n", fname));
if(buf)
free(buf);
delete_share_file(fs_p->cnum, fname);
return False;
}
}
else
{
/* New file - just use a single_entry. */
if((buf = (char *)malloc(10 + strlen(fs_p->name) + 1 + 16)) == NULL)
{
DEBUG(0,("ERROR: set_share_mode: malloc failed for single entry.\n"));
return False;
}
SIVAL(buf,0,LOCKING_VERSION);
SIVAL(buf,4,0);
SSVAL(buf,8,strlen(fs_p->name) + 1);
strcpy(buf + 10, fs_p->name);
}
num_entries = IVAL(buf,4);
header_size = 10 + SVAL(buf,8);
p = buf + header_size + (num_entries * 16);
SIVAL(p,0,fs_p->open_time.tv_sec);
SIVAL(p,4,fs_p->open_time.tv_usec);
SIVAL(p,8,fs_p->share_mode);
SIVAL(p,12,pid);
num_entries++;
SIVAL(buf,4,num_entries);
if(lseek(fd, 0, SEEK_SET) != 0)
{
DEBUG(0,("ERROR: set_share_mode: (1) Failed to reset position to \
0 for share file %s (%s)\n", fname, strerror(errno)));
if(buf)
free(buf);
return False;
}
if (write(fd,buf,header_size + (num_entries*16)) != (header_size + (num_entries*16)))
{
DEBUG(2,("ERROR: set_share_mode: Failed to write share file %s - \
deleting it (%s).\n",fname, strerror(errno)));
delete_share_file(fs_p->cnum, fname);
if(buf)
free(buf);
return False;
}
/* Now truncate the file at this point - just for safety. */
if(ftruncate(fd, header_size + (16*num_entries))!= 0)
{
DEBUG(0,("ERROR: set_share_mode: failed to ftruncate share \
mode file %s to size %d (%s)\n", fname, header_size + (16*num_entries), strerror(errno)));
if(buf)
free(buf);
return False;
}
if(buf)
free(buf);
DEBUG(3,("set_share_mode: Created share file %s with \
mode 0x%X pid=%d\n",fname,fs_p->share_mode,pid));
return True;
}
#endif /* FAST_SHARE_MODES */
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.