vfs.c

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/*
   Unix SMB/Netbios implementation.
   Version 1.9.
   VFS initialisation and support functions
   Copyright (C) Tim Potter 1999
   Copyright (C) Alexander Bokovoy 2002

   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.

   This work was sponsored by Optifacio Software Services, Inc.
*/

#include "includes.h"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_VFS

struct vfs_init_function_entry {
	char *name;
 	vfs_op_tuple *vfs_op_tuples;
	struct vfs_init_function_entry *prev, *next;
};

static struct vfs_init_function_entry *backends = NULL;

/* Some structures to help us initialise the vfs operations table */

struct vfs_syminfo {
	char *name;
	void *fptr;
};

/* Default vfs hooks.  WARNING: The order of these initialisers is
   very important.  They must be in the same order as defined in
   vfs.h.  Change at your own peril. */

static struct vfs_ops default_vfs = {

	{
		/* Disk operations */
	
		vfswrap_dummy_connect,
		vfswrap_dummy_disconnect,
		vfswrap_disk_free,
		vfswrap_get_quota,
		vfswrap_set_quota,
		vfswrap_get_shadow_copy_data,
		vfswrap_statvfs,
	
		/* Directory operations */
	
		vfswrap_opendir,
		vfswrap_readdir,
		vfswrap_seekdir,
		vfswrap_telldir,
		vfswrap_rewinddir,
		vfswrap_mkdir,
		vfswrap_rmdir,
		vfswrap_closedir,
	
		/* File operations */
	
		vfswrap_open,
		vfswrap_close,
		vfswrap_read,
		vfswrap_pread,
		vfswrap_write,
		vfswrap_pwrite,
		vfswrap_lseek,
		vfswrap_sendfile,
		vfswrap_rename,
		vfswrap_fsync,
		vfswrap_stat,
		vfswrap_fstat,
		vfswrap_lstat,
		vfswrap_unlink,
		vfswrap_chmod,
		vfswrap_fchmod,
		vfswrap_chown,
		vfswrap_fchown,
		vfswrap_chdir,
		vfswrap_getwd,
		vfswrap_utime,
		vfswrap_ftruncate,
		vfswrap_lock,
		vfswrap_symlink,
		vfswrap_readlink,
		vfswrap_link,
		vfswrap_mknod,
		vfswrap_realpath,
	
		/* Windows ACL operations. */
		vfswrap_fget_nt_acl,
		vfswrap_get_nt_acl,
		vfswrap_fset_nt_acl,
		vfswrap_set_nt_acl,
	
		/* POSIX ACL operations. */
		vfswrap_chmod_acl,
		vfswrap_fchmod_acl,

		vfswrap_sys_acl_get_entry,
		vfswrap_sys_acl_get_tag_type,
		vfswrap_sys_acl_get_permset,
		vfswrap_sys_acl_get_qualifier,
		vfswrap_sys_acl_get_file,
		vfswrap_sys_acl_get_fd,
		vfswrap_sys_acl_clear_perms,
		vfswrap_sys_acl_add_perm,
		vfswrap_sys_acl_to_text,
		vfswrap_sys_acl_init,
		vfswrap_sys_acl_create_entry,
		vfswrap_sys_acl_set_tag_type,
		vfswrap_sys_acl_set_qualifier,
		vfswrap_sys_acl_set_permset,
		vfswrap_sys_acl_valid,
		vfswrap_sys_acl_set_file,
		vfswrap_sys_acl_set_fd,
		vfswrap_sys_acl_delete_def_file,
		vfswrap_sys_acl_get_perm,
		vfswrap_sys_acl_free_text,
		vfswrap_sys_acl_free_acl,
		vfswrap_sys_acl_free_qualifier,

		/* EA operations. */
		vfswrap_getxattr,
		vfswrap_lgetxattr,
		vfswrap_fgetxattr,
		vfswrap_listxattr,
		vfswrap_llistxattr,
		vfswrap_flistxattr,
		vfswrap_removexattr,
		vfswrap_lremovexattr,
		vfswrap_fremovexattr,
		vfswrap_setxattr,
		vfswrap_lsetxattr,
		vfswrap_fsetxattr,

		/* AIO operations. */
		vfswrap_aio_read,
		vfswrap_aio_write,
		vfswrap_aio_return,
		vfswrap_aio_cancel,
		vfswrap_aio_error,
		vfswrap_aio_fsync,
		vfswrap_aio_suspend
	}
};

/****************************************************************************
    maintain the list of available backends
****************************************************************************/

static struct vfs_init_function_entry *vfs_find_backend_entry(const char *name)
{
	struct vfs_init_function_entry *entry = backends;
 
	while(entry) {
		if (strcmp(entry->name, name)==0) return entry;
		entry = entry->next;
	}

	return NULL;
}

NTSTATUS smb_register_vfs(int version, const char *name, vfs_op_tuple *vfs_op_tuples)
{
	struct vfs_init_function_entry *entry = backends;

 	if ((version != SMB_VFS_INTERFACE_VERSION)) {
		DEBUG(0, ("Failed to register vfs module.\n"
		          "The module was compiled against SMB_VFS_INTERFACE_VERSION %d,\n"
		          "current SMB_VFS_INTERFACE_VERSION is %d.\n"
		          "Please recompile against the current Samba Version!\n",  
			  version, SMB_VFS_INTERFACE_VERSION));
		return NT_STATUS_OBJECT_TYPE_MISMATCH;
  	}

	if (!name || !name[0] || !vfs_op_tuples) {
		DEBUG(0,("smb_register_vfs() called with NULL pointer or empty name!\n"));
		return NT_STATUS_INVALID_PARAMETER;
	}

	if (vfs_find_backend_entry(name)) {
		DEBUG(0,("VFS module %s already loaded!\n", name));
		return NT_STATUS_OBJECT_NAME_COLLISION;
	}

	entry = SMB_XMALLOC_P(struct vfs_init_function_entry);
	entry->name = smb_xstrdup(name);
	entry->vfs_op_tuples = vfs_op_tuples;

	DLIST_ADD(backends, entry);
	DEBUG(5, ("Successfully added vfs backend '%s'\n", name));
	return NT_STATUS_OK;
}

/****************************************************************************
  initialise default vfs hooks
****************************************************************************/

static void vfs_init_default(connection_struct *conn)
{
	DEBUG(3, ("Initialising default vfs hooks\n"));

	memcpy(&conn->vfs.ops, &default_vfs.ops, sizeof(default_vfs.ops));
	memcpy(&conn->vfs_opaque.ops, &default_vfs.ops, sizeof(default_vfs.ops));
}

/****************************************************************************
  initialise custom vfs hooks
 ****************************************************************************/

BOOL vfs_init_custom(connection_struct *conn, const char *vfs_object)
{
	vfs_op_tuple *ops;
	char *module_name = NULL;
	char *module_param = NULL, *p;
	int i;
	vfs_handle_struct *handle;
	struct vfs_init_function_entry *entry;
	
	if (!conn||!vfs_object||!vfs_object[0]) {
		DEBUG(0,("vfs_init_custon() called with NULL pointer or emtpy vfs_object!\n"));
		return False;
	}

	if(!backends) {
		static_init_vfs;
	}

	DEBUG(3, ("Initialising custom vfs hooks from [%s]\n", vfs_object));

	module_name = smb_xstrdup(vfs_object);

	p = strchr_m(module_name, ':');

	if (p) {
		*p = 0;
		module_param = p+1;
		trim_char(module_param, ' ', ' ');
	}

	trim_char(module_name, ' ', ' ');

	/* First, try to load the module with the new module system */
	if((entry = vfs_find_backend_entry(module_name)) || 
	   (NT_STATUS_IS_OK(smb_probe_module("vfs", module_name)) && 
		(entry = vfs_find_backend_entry(module_name)))) {

		DEBUGADD(5,("Successfully loaded vfs module [%s] with the new modules system\n", vfs_object));
		
	 	if ((ops = entry->vfs_op_tuples) == NULL) {
	 		DEBUG(0, ("entry->vfs_op_tuples==NULL for [%s] failed\n", vfs_object));
	 		SAFE_FREE(module_name);
	 		return False;
	 	}
	} else {
		DEBUG(0,("Can't find a vfs module [%s]\n",vfs_object));
		SAFE_FREE(module_name);
		return False;
	}

	handle = TALLOC_ZERO_P(conn->mem_ctx,vfs_handle_struct);
	if (!handle) {
		DEBUG(0,("talloc_zero() failed!\n"));
		SAFE_FREE(module_name);
		return False;
	}
	memcpy(&handle->vfs_next, &conn->vfs, sizeof(struct vfs_ops));
	handle->conn = conn;
	if (module_param) {
		handle->param = talloc_strdup(conn->mem_ctx, module_param);
	}
	DLIST_ADD(conn->vfs_handles, handle);

 	for(i=0; ops[i].op != NULL; i++) {
		DEBUG(5, ("Checking operation #%d (type %d, layer %d)\n", i, ops[i].type, ops[i].layer));
		if(ops[i].layer == SMB_VFS_LAYER_OPAQUE) {
			/* Check whether this operation was already made opaque by different module */
			if(((void**)&conn->vfs_opaque.ops)[ops[i].type] == ((void**)&default_vfs.ops)[ops[i].type]) {
				/* No, it isn't overloaded yet. Overload. */
				DEBUGADD(5, ("Making operation type %d opaque [module %s]\n", ops[i].type, vfs_object));
				((void**)&conn->vfs_opaque.ops)[ops[i].type] = ops[i].op;
				((vfs_handle_struct **)&conn->vfs_opaque.handles)[ops[i].type] = handle;
			}
		}
		/* Change current VFS disposition*/
		DEBUGADD(5, ("Accepting operation type %d from module %s\n", ops[i].type, vfs_object));
		((void**)&conn->vfs.ops)[ops[i].type] = ops[i].op;
		((vfs_handle_struct **)&conn->vfs.handles)[ops[i].type] = handle;
	}

	SAFE_FREE(module_name);
	return True;
}

/*****************************************************************
 Generic VFS init.
******************************************************************/

BOOL smbd_vfs_init(connection_struct *conn)
{
	const char **vfs_objects;
	unsigned int i = 0;
	int j = 0;
	
	/* Normal share - initialise with disk access functions */
	vfs_init_default(conn);
	vfs_objects = lp_vfs_objects(SNUM(conn));

	/* Override VFS functions if 'vfs object' was not specified*/
	if (!vfs_objects || !vfs_objects[0])
		return True;
	
	for (i=0; vfs_objects[i] ;) {
		i++;
	}

	for (j=i-1; j >= 0; j--) {
		if (!vfs_init_custom(conn, vfs_objects[j])) {
			DEBUG(0, ("smbd_vfs_init: vfs_init_custom failed for %s\n", vfs_objects[j]));
			return False;
		}
	}
	return True;
}

/*******************************************************************
 Check if directory exists.
********************************************************************/

BOOL vfs_directory_exist(connection_struct *conn, const char *dname, SMB_STRUCT_STAT *st)
{
	SMB_STRUCT_STAT st2;
	BOOL ret;

	if (!st)
		st = &st2;

	if (SMB_VFS_STAT(conn,dname,st) != 0)
		return(False);

	ret = S_ISDIR(st->st_mode);
	if(!ret)
		errno = ENOTDIR;

	return ret;
}

/*******************************************************************
 vfs mkdir wrapper 
********************************************************************/

int vfs_MkDir(connection_struct *conn, const char *name, mode_t mode)
{
	int ret;
	SMB_STRUCT_STAT sbuf;

	if(!(ret=SMB_VFS_MKDIR(conn, name, mode))) {

		inherit_access_acl(conn, name, mode);

		/*
		 * Check if high bits should have been set,
		 * then (if bits are missing): add them.
		 * Consider bits automagically set by UNIX, i.e. SGID bit from parent dir.
		 */
		if(mode & ~(S_IRWXU|S_IRWXG|S_IRWXO) &&
				!SMB_VFS_STAT(conn,name,&sbuf) && (mode & ~sbuf.st_mode))
			SMB_VFS_CHMOD(conn,name,sbuf.st_mode | (mode & ~sbuf.st_mode));
	}
	return ret;
}

/*******************************************************************
 Check if an object exists in the vfs.
********************************************************************/

BOOL vfs_object_exist(connection_struct *conn,const char *fname,SMB_STRUCT_STAT *sbuf)
{
	SMB_STRUCT_STAT st;

	if (!sbuf)
		sbuf = &st;

	ZERO_STRUCTP(sbuf);

	if (SMB_VFS_STAT(conn,fname,sbuf) == -1)
		return(False);
	return True;
}

/*******************************************************************
 Check if a file exists in the vfs.
********************************************************************/

BOOL vfs_file_exist(connection_struct *conn, const char *fname,SMB_STRUCT_STAT *sbuf)
{
	SMB_STRUCT_STAT st;

	if (!sbuf)
		sbuf = &st;

	ZERO_STRUCTP(sbuf);

	if (SMB_VFS_STAT(conn,fname,sbuf) == -1)
		return False;
	return(S_ISREG(sbuf->st_mode));
}

/****************************************************************************
 Read data from fsp on the vfs. (note: EINTR re-read differs from vfs_write_data)
****************************************************************************/

ssize_t vfs_read_data(files_struct *fsp, char *buf, size_t byte_count)
{
	size_t total=0;

	while (total < byte_count)
	{
		ssize_t ret = SMB_VFS_READ(fsp, fsp->fh->fd, buf + total,
					byte_count - total);

		if (ret == 0) return total;
		if (ret == -1) {
			if (errno == EINTR)
				continue;
			else
				return -1;
		}
		total += ret;
	}
	return (ssize_t)total;
}

ssize_t vfs_pread_data(files_struct *fsp, char *buf,
                size_t byte_count, SMB_OFF_T offset)
{
	size_t total=0;

	while (total < byte_count)
	{
		ssize_t ret = SMB_VFS_PREAD(fsp, fsp->fh->fd, buf + total,
					byte_count - total, offset + total);

		if (ret == 0) return total;
		if (ret == -1) {
			if (errno == EINTR)
				continue;
			else
				return -1;
		}
		total += ret;
	}
	return (ssize_t)total;
}

/****************************************************************************
 Write data to a fd on the vfs.
****************************************************************************/

ssize_t vfs_write_data(files_struct *fsp,const char *buffer,size_t N)
{
	size_t total=0;
	ssize_t ret;

	while (total < N) {
		ret = SMB_VFS_WRITE(fsp,fsp->fh->fd,buffer + total,N - total);

		if (ret == -1)
			return -1;
		if (ret == 0)
			return total;

		total += ret;
	}
	return (ssize_t)total;
}

ssize_t vfs_pwrite_data(files_struct *fsp,const char *buffer,
                size_t N, SMB_OFF_T offset)
{
	size_t total=0;
	ssize_t ret;

	while (total < N) {
		ret = SMB_VFS_PWRITE(fsp, fsp->fh->fd, buffer + total,
                                N - total, offset + total);

		if (ret == -1)
			return -1;
		if (ret == 0)
			return total;

		total += ret;
	}
	return (ssize_t)total;
}
/****************************************************************************
 An allocate file space call using the vfs interface.
 Allocates space for a file from a filedescriptor.
 Returns 0 on success, -1 on failure.
****************************************************************************/