1
0
mirror of https://github.com/samba-team/samba.git synced 2024-12-24 21:34:56 +03:00
samba-mirror/source3/smbd/files.c
1999-12-13 13:27:58 +00:00

440 lines
12 KiB
C

/*
Unix SMB/Netbios implementation.
Version 1.9.
Files[] structure handling
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 int DEBUGLEVEL;
static int real_max_open_files;
#define VALID_FNUM(fnum) (((fnum) >= 0) && ((fnum) < real_max_open_files))
#define FILE_HANDLE_OFFSET 0x1000
static struct bitmap *file_bmap;
static files_struct *Files;
/* a fsp to use when chaining */
static files_struct *chain_fsp = NULL;
/* a fsp to use to save when breaking an oplock. */
static files_struct *oplock_save_chain_fsp = NULL;
/*
* Indirection for file fd's. Needed as POSIX locking
* is based on file/process, not fd/process.
*/
static file_fd_struct *FileFd;
static int files_used, fd_ptr_used;
/****************************************************************************
find first available file slot
****************************************************************************/
files_struct *file_new(void )
{
int i;
static int first_file;
files_struct *fsp, *next;
/* we want to give out file handles differently on each new
connection because of a common bug in MS clients where they try to
reuse a file descriptor from an earlier smb connection. This code
increases the chance that the errant client will get an error rather
than causing corruption */
if (first_file == 0) {
first_file = (getpid() ^ (int)time(NULL)) % real_max_open_files;
}
i = bitmap_find(file_bmap, first_file);
if (i == -1) {
/*
* Before we give up, go through the open files
* and see if there are any files opened with a
* batch oplock. If so break the oplock and then
* re-use that entry (if it becomes closed).
* This may help as NT/95 clients tend to keep
* files batch oplocked for quite a long time
* after they have finished with them.
*/
for (fsp=Files;fsp;fsp=next) {
next=fsp->next;
if (attempt_close_oplocked_file(fsp)) {
return file_new();
}
}
DEBUG(0,("ERROR! Out of file structures\n"));
return NULL;
}
fsp = (files_struct *)malloc(sizeof(*fsp));
if (!fsp) return NULL;
ZERO_STRUCTP(fsp);
first_file = (i+1) % real_max_open_files;
bitmap_set(file_bmap, i);
files_used++;
fsp->fnum = i + FILE_HANDLE_OFFSET;
string_init(&fsp->fsp_name,"");
DLIST_ADD(Files, fsp);
DEBUG(5,("allocated file structure %d, fnum = %d (%d used)\n",
i, fsp->fnum, files_used));
chain_fsp = fsp;
return fsp;
}
/****************************************************************************
fd support routines - attempt to find an already open file by dev
and inode - increments the ref_count of the returned file_fd_struct *.
****************************************************************************/
file_fd_struct *fd_get_already_open(SMB_STRUCT_STAT *sbuf)
{
file_fd_struct *fd_ptr;
if(!sbuf) return NULL;
for (fd_ptr=FileFd;fd_ptr;fd_ptr=fd_ptr->next) {
if ((fd_ptr->ref_count > 0) &&
(sbuf->st_dev == fd_ptr->dev) &&
(sbuf->st_ino == fd_ptr->inode)) {
fd_ptr->ref_count++;
DEBUG(3,("Re-used file_fd_struct dev = %x, inode = %.0f, ref_count = %d\n",
(unsigned int)fd_ptr->dev, (double)fd_ptr->inode,
fd_ptr->ref_count));
return fd_ptr;
}
}
return NULL;
}
/****************************************************************************
fd support routines - attempt to find a empty slot in the FileFd array.
Increments the ref_count of the returned entry.
****************************************************************************/
file_fd_struct *fd_get_new(void)
{
extern struct current_user current_user;
file_fd_struct *fd_ptr;
fd_ptr = (file_fd_struct *)malloc(sizeof(*fd_ptr));
if (!fd_ptr) {
DEBUG(0,("ERROR! malloc fail for file_fd struct.\n"));
return NULL;
}
ZERO_STRUCTP(fd_ptr);
fd_ptr->dev = (SMB_DEV_T)-1;
fd_ptr->inode = (SMB_INO_T)-1;
fd_ptr->fd = -1;
fd_ptr->fd_readonly = -1;
fd_ptr->fd_writeonly = -1;
fd_ptr->real_open_flags = -1;
fd_add_to_uid_cache(fd_ptr, (uid_t)current_user.uid);
fd_ptr->ref_count++;
fd_ptr_used++;
DLIST_ADD(FileFd, fd_ptr);
DEBUG(5,("allocated fd_ptr structure (%d used)\n", fd_ptr_used));
return fd_ptr;
}
/****************************************************************************
close all open files for a connection
****************************************************************************/
void file_close_conn(connection_struct *conn)
{
files_struct *fsp, *next;
for (fsp=Files;fsp;fsp=next) {
next = fsp->next;
if (fsp->conn == conn && fsp->open) {
close_file(fsp,False);
}
}
}
/****************************************************************************
initialise file structures
****************************************************************************/
#define MAX_OPEN_FUDGEFACTOR 10
void file_init(void)
{
int request_max_open_files = lp_max_open_files();
int real_lim;
/*
* Set the max_open files to be the requested
* max plus a fudgefactor to allow for the extra
* fd's we need such as log files etc...
*/
real_lim = set_maxfiles(request_max_open_files + MAX_OPEN_FUDGEFACTOR);
real_max_open_files = real_lim - MAX_OPEN_FUDGEFACTOR;
if(real_max_open_files != request_max_open_files) {
DEBUG(1,("file_init: Information only: requested %d \
open files, %d are available.\n", request_max_open_files, real_max_open_files));
}
file_bmap = bitmap_allocate(real_max_open_files);
if (!file_bmap) {
exit_server("out of memory in file_init");
}
/*
* Ensure that pipe_handle_oppset is set correctly.
*/
set_pipe_handle_offset(real_max_open_files);
}
/****************************************************************************
close files open by a specified vuid
****************************************************************************/
void file_close_user(int vuid)
{
files_struct *fsp, *next;
for (fsp=Files;fsp;fsp=next) {
next=fsp->next;
if ((fsp->vuid == vuid) && fsp->open) {
close_file(fsp,False);
}
}
}
/****************************************************************************
Find a fsp given a device, inode and timevalue
If this is from a kernel oplock break request then tval may be NULL.
****************************************************************************/
files_struct *file_find_dit(SMB_DEV_T dev, SMB_INO_T inode, struct timeval *tval)
{
int count=0;
files_struct *fsp;
for (fsp=Files;fsp;fsp=fsp->next,count++) {
if (fsp->open &&
fsp->fd_ptr != NULL &&
fsp->fd_ptr->dev == dev &&
fsp->fd_ptr->inode == inode &&
(tval ? (fsp->open_time.tv_sec == tval->tv_sec) : True ) &&
(tval ? (fsp->open_time.tv_usec == tval->tv_usec) : True )) {
if (count > 10) {
DLIST_PROMOTE(Files, fsp);
}
return fsp;
}
}
return NULL;
}
/****************************************************************************
Find the first fsp given a device and inode.
****************************************************************************/
files_struct *file_find_di_first(SMB_DEV_T dev, SMB_INO_T inode)
{
files_struct *fsp;
for (fsp=Files;fsp;fsp=fsp->next) {
if (fsp->open &&
fsp->fd_ptr != NULL &&
fsp->fd_ptr->dev == dev &&
fsp->fd_ptr->inode == inode )
return fsp;
}
return NULL;
}
/****************************************************************************
Find the next fsp having the same device and inode.
****************************************************************************/
files_struct *file_find_di_next(files_struct *start_fsp)
{
files_struct *fsp;
for (fsp = start_fsp->next;fsp;fsp=fsp->next) {
if (fsp->open &&
fsp->fd_ptr != NULL &&
fsp->fd_ptr->dev == start_fsp->fd_ptr->dev &&
fsp->fd_ptr->inode == start_fsp->fd_ptr->inode )
return fsp;
}
return NULL;
}
/****************************************************************************
find a fsp that is open for printing
****************************************************************************/
files_struct *file_find_print(void)
{
files_struct *fsp;
for (fsp=Files;fsp;fsp=fsp->next) {
if (fsp->open && fsp->print_file) return fsp;
}
return NULL;
}
/****************************************************************************
sync open files on a connection
****************************************************************************/
void file_sync_all(connection_struct *conn)
{
files_struct *fsp, *next;
for (fsp=Files;fsp;fsp=next) {
next=fsp->next;
if (fsp->open && (conn == fsp->conn) && (fsp->fd_ptr != NULL)) {
sync_file(conn,fsp);
}
}
}
/****************************************************************************
free up a fd_ptr
****************************************************************************/
void fd_ptr_free(file_fd_struct *fd_ptr)
{
DLIST_REMOVE(FileFd, fd_ptr);
fd_ptr_used--;
DEBUG(5,("freed fd_ptr structure (%d used)\n", fd_ptr_used));
/* paranoia */
ZERO_STRUCTP(fd_ptr);
free(fd_ptr);
}
/****************************************************************************
free up a fsp
****************************************************************************/
void file_free(files_struct *fsp)
{
DLIST_REMOVE(Files, fsp);
string_free(&fsp->fsp_name);
if ((fsp->fd_ptr != NULL) && fsp->fd_ptr->ref_count == 0) {
fd_ptr_free(fsp->fd_ptr);
}
bitmap_clear(file_bmap, fsp->fnum - FILE_HANDLE_OFFSET);
files_used--;
DEBUG(5,("freed files structure %d (%d used)\n",
fsp->fnum, files_used));
/* this is paranoia, just in case someone tries to reuse the
information */
ZERO_STRUCTP(fsp);
if (fsp == chain_fsp) chain_fsp = NULL;
free(fsp);
}
/****************************************************************************
get a fsp from a packet given the offset of a 16 bit fnum
****************************************************************************/
files_struct *file_fsp(char *buf, int where)
{
int fnum, count=0;
files_struct *fsp;
if (chain_fsp) return chain_fsp;
fnum = SVAL(buf, where);
for (fsp=Files;fsp;fsp=fsp->next, count++) {
if (fsp->fnum == fnum) {
chain_fsp = fsp;
if (count > 10) {
DLIST_PROMOTE(Files, fsp);
}
return fsp;
}
}
return NULL;
}
/****************************************************************************
Reset the chained fsp - done at the start of a packet reply
****************************************************************************/
void file_chain_reset(void)
{
chain_fsp = NULL;
}
/****************************************************************************
Save the chained fsp - done when about to do an oplock break.
****************************************************************************/
void file_chain_save(void)
{
oplock_save_chain_fsp = chain_fsp;
}
/****************************************************************************
Restore the chained fsp - done after an oplock break.
****************************************************************************/
void file_chain_restore(void)
{
chain_fsp = oplock_save_chain_fsp;
}