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samba-mirror/source3/smbd/files.c
2007-10-10 15:34:30 -05:00

567 lines
14 KiB
C

/*
Unix SMB/CIFS implementation.
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 3 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, see <http://www.gnu.org/licenses/>.
*/
#include "includes.h"
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;
static int files_used;
/* A singleton cache to speed up searching by dev/inode. */
static struct fsp_singleton_cache {
files_struct *fsp;
struct file_id id;
} fsp_fi_cache;
/****************************************************************************
Return a unique number identifying this fsp over the life of this pid.
****************************************************************************/
static unsigned long get_gen_count(void)
{
static unsigned long file_gen_counter;
if ((++file_gen_counter) == 0)
return ++file_gen_counter;
return file_gen_counter;
}
/****************************************************************************
Find first available file slot.
****************************************************************************/
NTSTATUS file_new(connection_struct *conn, files_struct **result)
{
int i;
static int first_file;
files_struct *fsp;
/* 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 = (sys_getpid() ^ (int)time(NULL)) % real_max_open_files;
}
/* TODO: Port the id-tree implementation from Samba4 */
i = bitmap_find(file_bmap, first_file);
if (i == -1) {
DEBUG(0,("ERROR! Out of file structures\n"));
/* TODO: We have to unconditionally return a DOS error here,
* W2k3 even returns ERRDOS/ERRnofids for ntcreate&x with
* NTSTATUS negotiated */
return NT_STATUS_TOO_MANY_OPENED_FILES;
}
fsp = SMB_MALLOC_P(files_struct);
if (!fsp) {
return NT_STATUS_NO_MEMORY;
}
ZERO_STRUCTP(fsp);
fsp->fh = SMB_MALLOC_P(struct fd_handle);
if (!fsp->fh) {
SAFE_FREE(fsp);
return NT_STATUS_NO_MEMORY;
}
ZERO_STRUCTP(fsp->fh);
fsp->fh->ref_count = 1;
fsp->fh->fd = -1;
fsp->conn = conn;
fsp->fh->gen_id = get_gen_count();
GetTimeOfDay(&fsp->open_time);
first_file = (i+1) % real_max_open_files;
bitmap_set(file_bmap, i);
files_used++;
fsp->fnum = i + FILE_HANDLE_OFFSET;
SMB_ASSERT(fsp->fnum < 65536);
string_set(&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;
/* A new fsp invalidates a negative fsp_fi_cache. */
if (fsp_fi_cache.fsp == NULL) {
ZERO_STRUCT(fsp_fi_cache);
}
*result = fsp;
return NT_STATUS_OK;
}
/****************************************************************************
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) {
close_file(fsp,SHUTDOWN_CLOSE);
}
}
}
/****************************************************************************
Close all open files for a pid and a vuid.
****************************************************************************/
void file_close_pid(uint16 smbpid, int vuid)
{
files_struct *fsp, *next;
for (fsp=Files;fsp;fsp=next) {
next = fsp->next;
if ((fsp->file_pid == smbpid) && (fsp->vuid == vuid)) {
close_file(fsp,SHUTDOWN_CLOSE);
}
}
}
/****************************************************************************
Initialise file structures.
****************************************************************************/
#define MAX_OPEN_FUDGEFACTOR 20
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 + FILE_HANDLE_OFFSET + MAX_OPEN_PIPES > 65536)
real_max_open_files = 65536 - FILE_HANDLE_OFFSET - MAX_OPEN_PIPES;
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));
}
SMB_ASSERT(real_max_open_files > 100);
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) {
close_file(fsp,SHUTDOWN_CLOSE);
}
}
}
/****************************************************************************
Debug to enumerate all open files in the smbd.
****************************************************************************/
void file_dump_open_table(void)
{
int count=0;
files_struct *fsp;
for (fsp=Files;fsp;fsp=fsp->next,count++) {
DEBUG(10,("Files[%d], fnum = %d, name %s, fd = %d, gen = %lu, fileid=%s\n",
count, fsp->fnum, fsp->fsp_name, fsp->fh->fd, (unsigned long)fsp->fh->gen_id,
file_id_string_tos(&fsp->file_id)));
}
}
/****************************************************************************
Find a fsp given a file descriptor.
****************************************************************************/
files_struct *file_find_fd(int fd)
{
int count=0;
files_struct *fsp;
for (fsp=Files;fsp;fsp=fsp->next,count++) {
if (fsp->fh->fd == fd) {
if (count > 10) {
DLIST_PROMOTE(Files, fsp);
}
return fsp;
}
}
return NULL;
}
/****************************************************************************
Find a fsp given a device, inode and file_id.
****************************************************************************/
files_struct *file_find_dif(struct file_id id, unsigned long gen_id)
{
int count=0;
files_struct *fsp;
for (fsp=Files;fsp;fsp=fsp->next,count++) {
/* We can have a fsp->fh->fd == -1 here as it could be a stat open. */
if (file_id_equal(&fsp->file_id, &id) &&
fsp->fh->gen_id == gen_id ) {
if (count > 10) {
DLIST_PROMOTE(Files, fsp);
}
/* Paranoia check. */
if ((fsp->fh->fd == -1) &&
(fsp->oplock_type != NO_OPLOCK) &&
(fsp->oplock_type != FAKE_LEVEL_II_OPLOCK)) {
DEBUG(0,("file_find_dif: file %s file_id = %s, gen = %u \
oplock_type = %u is a stat open with oplock type !\n", fsp->fsp_name,
file_id_string_tos(&fsp->file_id),
(unsigned int)fsp->fh->gen_id,
(unsigned int)fsp->oplock_type ));
smb_panic("file_find_dif");
}
return fsp;
}
}
return NULL;
}
/****************************************************************************
Check if an fsp still exists.
****************************************************************************/
files_struct *file_find_fsp(files_struct *orig_fsp)
{
files_struct *fsp;
for (fsp=Files;fsp;fsp=fsp->next) {
if (fsp == orig_fsp)
return fsp;
}
return NULL;
}
/****************************************************************************
Find the first fsp given a device and inode.
We use a singleton cache here to speed up searching from getfilepathinfo
calls.
****************************************************************************/
files_struct *file_find_di_first(struct file_id id)
{
files_struct *fsp;
if (file_id_equal(&fsp_fi_cache.id, &id)) {
/* Positive or negative cache hit. */
return fsp_fi_cache.fsp;
}
fsp_fi_cache.id = id;
for (fsp=Files;fsp;fsp=fsp->next) {
if ( fsp->fh->fd != -1 &&
file_id_equal(&fsp->file_id, &id)) {
/* Setup positive cache. */
fsp_fi_cache.fsp = fsp;
return fsp;
}
}
/* Setup negative cache. */
fsp_fi_cache.fsp = NULL;
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->fh->fd != -1 &&
file_id_equal(&fsp->file_id, &start_fsp->file_id)) {
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->print_file) {
return fsp;
}
}
return NULL;
}
/****************************************************************************
Set a pending modtime across all files with a given dev/ino pair.
Record the owner of that modtime.
****************************************************************************/
void fsp_set_pending_modtime(files_struct *tfsp, const struct timespec mod)
{
files_struct *fsp;
if (null_timespec(mod)) {
return;
}
for (fsp = Files;fsp;fsp=fsp->next) {
if ( fsp->fh->fd != -1 && file_id_equal(&fsp->file_id, &tfsp->file_id)) {
fsp->pending_modtime = mod;
fsp->pending_modtime_owner = False;
}
}
tfsp->pending_modtime_owner = True;
}
/****************************************************************************
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 ((conn == fsp->conn) && (fsp->fh->fd != -1)) {
sync_file(conn, fsp, True /* write through */);
}
}
}
/****************************************************************************
Free up a fsp.
****************************************************************************/
void file_free(files_struct *fsp)
{
DLIST_REMOVE(Files, fsp);
string_free(&fsp->fsp_name);
if (fsp->fake_file_handle) {
destroy_fake_file_handle(&fsp->fake_file_handle);
}
if (fsp->fh->ref_count == 1) {
SAFE_FREE(fsp->fh);
} else {
fsp->fh->ref_count--;
}
if (fsp->notify) {
notify_remove(fsp->conn->notify_ctx, fsp);
TALLOC_FREE(fsp->notify);
}
/* Ensure this event will never fire. */
TALLOC_FREE(fsp->oplock_timeout);
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;
}
/* Closing a file can invalidate the positive cache. */
if (fsp == fsp_fi_cache.fsp) {
ZERO_STRUCT(fsp_fi_cache);
}
SAFE_FREE(fsp);
}
/****************************************************************************
Get an fsp from a 16 bit fnum.
****************************************************************************/
files_struct *file_fnum(uint16 fnum)
{
files_struct *fsp;
int count=0;
for (fsp=Files;fsp;fsp=fsp->next, count++) {
if (fsp->fnum == fnum) {
if (count > 10) {
DLIST_PROMOTE(Files, fsp);
}
return fsp;
}
}
return NULL;
}
/****************************************************************************
Get an fsp from a packet given the offset of a 16 bit fnum.
****************************************************************************/
files_struct *file_fsp(uint16 fid)
{
files_struct *fsp;
if (chain_fsp) {
return chain_fsp;
}
fsp = file_fnum(fid);
if (fsp) {
chain_fsp = fsp;
}
return fsp;
}
/****************************************************************************
Reset the chained fsp - done at the start of a packet reply.
****************************************************************************/
void file_chain_reset(void)
{
chain_fsp = NULL;
}
/****************************************************************************
Duplicate the file handle part for a DOS or FCB open.
****************************************************************************/
NTSTATUS dup_file_fsp(files_struct *fsp,
uint32 access_mask,
uint32 share_access,
uint32 create_options,
files_struct **result)
{
NTSTATUS status;
files_struct *dup_fsp;
status = file_new(fsp->conn, &dup_fsp);
if (!NT_STATUS_IS_OK(status)) {
return status;
}
SAFE_FREE(dup_fsp->fh);
dup_fsp->fh = fsp->fh;
dup_fsp->fh->ref_count++;
dup_fsp->file_id = fsp->file_id;
dup_fsp->initial_allocation_size = fsp->initial_allocation_size;
dup_fsp->mode = fsp->mode;
dup_fsp->file_pid = fsp->file_pid;
dup_fsp->vuid = fsp->vuid;
dup_fsp->open_time = fsp->open_time;
dup_fsp->access_mask = access_mask;
dup_fsp->share_access = share_access;
dup_fsp->pending_modtime_owner = fsp->pending_modtime_owner;
dup_fsp->pending_modtime = fsp->pending_modtime;
dup_fsp->last_write_time = fsp->last_write_time;
dup_fsp->oplock_type = fsp->oplock_type;
dup_fsp->can_lock = fsp->can_lock;
dup_fsp->can_read = (access_mask & (FILE_READ_DATA)) ? True : False;
if (!CAN_WRITE(fsp->conn)) {
dup_fsp->can_write = False;
} else {
dup_fsp->can_write = (access_mask & (FILE_WRITE_DATA | FILE_APPEND_DATA)) ? True : False;
}
dup_fsp->print_file = fsp->print_file;
dup_fsp->modified = fsp->modified;
dup_fsp->is_directory = fsp->is_directory;
dup_fsp->is_stat = fsp->is_stat;
dup_fsp->aio_write_behind = fsp->aio_write_behind;
string_set(&dup_fsp->fsp_name,fsp->fsp_name);
*result = dup_fsp;
return NT_STATUS_OK;
}