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-rw-r--r--source3/smbd/files.c400
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diff --git a/source3/smbd/files.c b/source3/smbd/files.c
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+/*
+ 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 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"
+
+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;
+
+static int files_used;
+
+/****************************************************************************
+ 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.
+****************************************************************************/
+
+files_struct *file_new(connection_struct *conn)
+{
+ 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 = (sys_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(conn);
+ }
+ }
+
+ DEBUG(0,("ERROR! Out of file structures\n"));
+ unix_ERR_class = ERRSRV;
+ unix_ERR_code = ERRnofids;
+ return NULL;
+ }
+
+ fsp = (files_struct *)malloc(sizeof(*fsp));
+ if (!fsp) {
+ unix_ERR_class = ERRSRV;
+ unix_ERR_code = ERRnofids;
+ return NULL;
+ }
+
+ ZERO_STRUCTP(fsp);
+ fsp->fd = -1;
+ fsp->conn = conn;
+ fsp->file_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;
+ 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;
+
+ return fsp;
+}
+
+/****************************************************************************
+ 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,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) {
+ close_file(fsp,False);
+ }
+ }
+}
+
+/****************************************************************************
+ 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->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(SMB_DEV_T dev, SMB_INO_T inode, unsigned long file_id)
+{
+ int count=0;
+ files_struct *fsp;
+
+ for (fsp=Files;fsp;fsp=fsp->next,count++) {
+ if (fsp->fd != -1 &&
+ fsp->dev == dev &&
+ fsp->inode == inode &&
+ fsp->file_id == file_id ) {
+ if (count > 10) {
+ DLIST_PROMOTE(Files, fsp);
+ }
+ 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.
+****************************************************************************/
+
+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->fd != -1 &&
+ fsp->dev == dev &&
+ fsp->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->fd != -1 &&
+ fsp->dev == start_fsp->dev &&
+ fsp->inode == start_fsp->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->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 ((conn == fsp->conn) && (fsp->fd != -1)) {
+ sync_file(conn,fsp);
+ }
+ }
+}
+
+/****************************************************************************
+ Free up a fsp.
+****************************************************************************/
+
+void file_free(files_struct *fsp)
+{
+ DLIST_REMOVE(Files, fsp);
+
+ string_free(&fsp->fsp_name);
+
+ 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;
+
+ SAFE_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;
+}
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