1 files changed, 397 insertions, 0 deletions
diff --git a/source/smbd/files.c b/source/smbd/files.c
new file mode 100644
index 00000000000..4030ad4c498
--- /dev/null
+++ b/source/smbd/files.c
@@ -0,0 +1,397 @@
+/* 
+   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) {
+			if (fsp->is_directory)
+				close_directory(fsp); 
+			else                  
+				close_file(fsp,False); 
+		}
+	}
+}
+
+/****************************************************************************
+initialise file structures
+****************************************************************************/
+
+#define MAX_OPEN_FUDGEFACTOR 10
+
+void file_init(void)
+{
+	int lim;
+
+	lim = set_maxfiles();
+	lim = MIN(lim, lp_max_open_files());
+
+	real_max_open_files = lim - MAX_OPEN_FUDGEFACTOR;
+	
+	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) {
+			if(!fsp->is_directory)
+				close_file(fsp,False);
+			else
+				close_directory(fsp);
+		}
+	}
+}
+
+
+/****************************************************************************
+ 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->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 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) {
+			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 && 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;
+}