open.c

samba-3.0.22.tar.gz 编译smb服务器的源码

		DEBUG(0,("validate_my_share_entries: PANIC : %s\n",
			 share_mode_str(num, share_entry) ));
		slprintf(str, sizeof(str)-1, "validate_my_share_entries: "
			 "file %s, oplock_type = 0x%x, op_type = 0x%x\n",
			 fsp->fsp_name, (unsigned int)fsp->oplock_type,
			 (unsigned int)share_entry->op_type );
		smb_panic(str);
	}
}
#endif

static BOOL is_stat_open(uint32 access_mask)
{
	return (access_mask &&
		((access_mask & ~(SYNCHRONIZE_ACCESS| FILE_READ_ATTRIBUTES|
				  FILE_WRITE_ATTRIBUTES))==0) &&
		((access_mask & (SYNCHRONIZE_ACCESS|FILE_READ_ATTRIBUTES|
				 FILE_WRITE_ATTRIBUTES)) != 0));
}

/****************************************************************************
 Deal with share modes
 Invarient: Share mode must be locked on entry and exit.
 Returns -1 on error, or number of share modes on success (may be zero).
****************************************************************************/

static NTSTATUS open_mode_check(connection_struct *conn,
				const char *fname,
				struct share_mode_lock *lck,
				uint32 access_mask,
				uint32 share_access,
				uint32 create_options,
				BOOL *file_existed)
{
	int i;

	if(lck->num_share_modes == 0) {
		return NT_STATUS_OK;
	}

	*file_existed = True;
	
	if (is_stat_open(access_mask)) {
		/* Stat open that doesn't trigger oplock breaks or share mode
		 * checks... ! JRA. */
		return NT_STATUS_OK;
	}

	/* A delete on close prohibits everything */

	if (lck->delete_on_close) {
		return NT_STATUS_DELETE_PENDING;
	}

	/*
	 * Check if the share modes will give us access.
	 */
	
#if defined(DEVELOPER)
	for(i = 0; i < lck->num_share_modes; i++) {
		validate_my_share_entries(i, &lck->share_modes[i]);
	}
#endif

	if (!lp_share_modes(SNUM(conn))) {
		return NT_STATUS_OK;
	}

	/* Now we check the share modes, after any oplock breaks. */
	for(i = 0; i < lck->num_share_modes; i++) {

		if (!is_valid_share_mode_entry(&lck->share_modes[i])) {
			continue;
		}

		/* someone else has a share lock on it, check to see if we can
		 * too */
		if (share_conflict(&lck->share_modes[i],
				   access_mask, share_access)) {
			return NT_STATUS_SHARING_VIOLATION;
		}
	}
	
	return NT_STATUS_OK;
}

static BOOL is_delete_request(files_struct *fsp) {
	return ((fsp->access_mask == DELETE_ACCESS) &&
		(fsp->oplock_type == NO_OPLOCK));
}

/*
 * 1) No files open at all: Grant whatever the client wants.
 *
 * 2) Exclusive (or batch) oplock around: If the requested access is a delete
 *    request, break if the oplock around is a batch oplock. If it's another
 *    requested access type, break.
 * 
 * 3) Only level2 around: Grant level2 and do nothing else.
 */

static BOOL delay_for_oplocks(struct share_mode_lock *lck, files_struct *fsp)
{
	int i;
	struct share_mode_entry *exclusive = NULL;
	BOOL delay_it = False;
	BOOL have_level2 = False;

	if (is_stat_open(fsp->access_mask)) {
		fsp->oplock_type = NO_OPLOCK;
		return False;
	}

	if (lck->num_share_modes == 0) {
		/* No files open at all: Directly grant whatever the client
		 * wants. */

		if (fsp->oplock_type == NO_OPLOCK) {
			/* Store a level2 oplock, but don't tell the client */
			fsp->oplock_type = FAKE_LEVEL_II_OPLOCK;
		}
		return False;
	}

	for (i=0; i<lck->num_share_modes; i++) {

		if (!is_valid_share_mode_entry(&lck->share_modes[i])) {
			continue;
		}

		if (EXCLUSIVE_OPLOCK_TYPE(lck->share_modes[i].op_type)) {
			SMB_ASSERT(exclusive == NULL);			
			exclusive = &lck->share_modes[i];
		}

		if (lck->share_modes[i].op_type == LEVEL_II_OPLOCK) {
			have_level2 = True;
		}
	}

	if (exclusive != NULL) { /* Found an exclusive oplock */
		SMB_ASSERT(!have_level2);
		delay_it = is_delete_request(fsp) ?
			BATCH_OPLOCK_TYPE(exclusive->op_type) :	True;
	}

	if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
		/* We can at most grant level2 */
		fsp->oplock_type = LEVEL_II_OPLOCK;
	}

	if ((fsp->oplock_type == NO_OPLOCK) && have_level2) {
		/* Store a level2 oplock, but don't tell the client */
		fsp->oplock_type = FAKE_LEVEL_II_OPLOCK;
	}

	if (delay_it) {
		BOOL ret;
		char msg[MSG_SMB_SHARE_MODE_ENTRY_SIZE];

		DEBUG(10, ("Sending break request to PID %s\n",
			   procid_str_static(&exclusive->pid)));
		exclusive->op_mid = get_current_mid();

		share_mode_entry_to_message(msg, exclusive);

		become_root();
		ret = message_send_pid(exclusive->pid, MSG_SMB_BREAK_REQUEST,
				       msg, MSG_SMB_SHARE_MODE_ENTRY_SIZE, True);
		unbecome_root();
		if (!ret) {
			DEBUG(3, ("Could not send oplock break message\n"));
		}
		file_free(fsp);
	}

	return delay_it;
}

static BOOL request_timed_out(struct timeval request_time,
			      struct timeval timeout)
{
	struct timeval now, end_time;
	GetTimeOfDay(&now);
	end_time = timeval_sum(&request_time, &timeout);
	return (timeval_compare(&end_time, &now) < 0);
}

/****************************************************************************
 Handle the 1 second delay in returning a SHARING_VIOLATION error.
****************************************************************************/

static void defer_open(struct share_mode_lock *lck,
		       struct timeval request_time,
		       struct timeval timeout,
		       struct deferred_open_record *state)
{
	uint16 mid = get_current_mid();
	int i;

	/* Paranoia check */

	for (i=0; i<lck->num_share_modes; i++) {
		struct share_mode_entry *e = &lck->share_modes[i];

		if (!is_deferred_open_entry(e)) {
			continue;
		}

		if (procid_is_me(&e->pid) && (e->op_mid == mid)) {
			DEBUG(0, ("Trying to defer an already deferred "
				  "request: mid=%d, exiting\n", mid));
			exit_server("exiting");
		}
	}

	/* End paranoia check */

	DEBUG(10,("defer_open_sharing_error: time [%u.%06u] adding deferred "
		  "open entry for mid %u\n",
		  (unsigned int)request_time.tv_sec,
		  (unsigned int)request_time.tv_usec,
		  (unsigned int)mid));

	if (!push_deferred_smb_message(mid, request_time, timeout,
				       (char *)state, sizeof(*state))) {
		exit_server("push_deferred_smb_message failed\n");
	}
	add_deferred_open(lck, mid, request_time, state->dev, state->inode);

	/*
	 * Push the MID of this packet on the signing queue.
	 * We only do this once, the first time we push the packet
	 * onto the deferred open queue, as this has a side effect
	 * of incrementing the response sequence number.
	 */

	srv_defer_sign_response(mid);
}

/****************************************************************************
 Set a kernel flock on a file for NFS interoperability.
 This requires a patch to Linux.
****************************************************************************/

static void kernel_flock(files_struct *fsp, uint32 share_mode)
{
#if HAVE_KERNEL_SHARE_MODES
	int kernel_mode = 0;
	if (share_mode == FILE_SHARE_WRITE) {
		kernel_mode = LOCK_MAND|LOCK_WRITE;
	} else if (share_mode == FILE_SHARE_READ) {
		kernel_mode = LOCK_MAND|LOCK_READ;
	} else if (share_mode == FILE_SHARE_NONE) {
		kernel_mode = LOCK_MAND;
	}
	if (kernel_mode) {
		flock(fsp->fh->fd, kernel_mode);
	}
#endif
	;
}

/****************************************************************************
 On overwrite open ensure that the attributes match.
****************************************************************************/

static BOOL open_match_attributes(connection_struct *conn,
				const char *path,
				uint32 old_dos_attr,
				uint32 new_dos_attr,
				mode_t existing_unx_mode,
				mode_t new_unx_mode,
				mode_t *returned_unx_mode)
{
	uint32 noarch_old_dos_attr, noarch_new_dos_attr;

	noarch_old_dos_attr = (old_dos_attr & ~FILE_ATTRIBUTE_ARCHIVE);
	noarch_new_dos_attr = (new_dos_attr & ~FILE_ATTRIBUTE_ARCHIVE);

	if((noarch_old_dos_attr == 0 && noarch_new_dos_attr != 0) || 
	   (noarch_old_dos_attr != 0 && ((noarch_old_dos_attr & noarch_new_dos_attr) == noarch_old_dos_attr))) {
		*returned_unx_mode = new_unx_mode;
	} else {
		*returned_unx_mode = (mode_t)0;
	}

	DEBUG(10,("open_match_attributes: file %s old_dos_attr = 0x%x, "
		  "existing_unx_mode = 0%o, new_dos_attr = 0x%x "
		  "returned_unx_mode = 0%o\n",
		  path,
		  (unsigned int)old_dos_attr,
		  (unsigned int)existing_unx_mode,
		  (unsigned int)new_dos_attr,
		  (unsigned int)*returned_unx_mode ));

	/* If we're mapping SYSTEM and HIDDEN ensure they match. */
	if (lp_map_system(SNUM(conn)) || lp_store_dos_attributes(SNUM(conn))) {
		if ((old_dos_attr & FILE_ATTRIBUTE_SYSTEM) &&
		    !(new_dos_attr & FILE_ATTRIBUTE_SYSTEM)) {
			return False;
		}
	}
	if (lp_map_hidden(SNUM(conn)) || lp_store_dos_attributes(SNUM(conn))) {
		if ((old_dos_attr & FILE_ATTRIBUTE_HIDDEN) &&
		    !(new_dos_attr & FILE_ATTRIBUTE_HIDDEN)) {
			return False;
		}
	}
	return True;
}

/****************************************************************************
 Special FCB or DOS processing in the case of a sharing violation.
 Try and find a duplicated file handle.
****************************************************************************/

static files_struct *fcb_or_dos_open(connection_struct *conn,
				     const char *fname, SMB_DEV_T dev,
				     SMB_INO_T inode,
				     uint32 access_mask,
				     uint32 share_access,
				     uint32 create_options)
{
	files_struct *fsp;
	files_struct *dup_fsp;

	DEBUG(5,("fcb_or_dos_open: attempting old open semantics for "
		 "file %s.\n", fname ));

	for(fsp = file_find_di_first(dev, inode); fsp;
	    fsp = file_find_di_next(fsp)) {

		DEBUG(10,("fcb_or_dos_open: checking file %s, fd = %d, "
			  "vuid = %u, file_pid = %u, private_options = 0x%x "
			  "access_mask = 0x%x\n", fsp->fsp_name,
			  fsp->fh->fd, (unsigned int)fsp->vuid,
			  (unsigned int)fsp->file_pid,
			  (unsigned int)fsp->fh->private_options,
			  (unsigned int)fsp->access_mask ));

		if (fsp->fh->fd != -1 &&
		    fsp->vuid == current_user.vuid &&
		    fsp->file_pid == global_smbpid &&
		    (fsp->fh->private_options & (NTCREATEX_OPTIONS_PRIVATE_DENY_DOS |
						 NTCREATEX_OPTIONS_PRIVATE_DENY_FCB)) &&
		    (fsp->access_mask & FILE_WRITE_DATA) &&
		    strequal(fsp->fsp_name, fname)) {
			DEBUG(10,("fcb_or_dos_open: file match\n"));
			break;
		}
	}

	if (!fsp) {
		return NULL;
	}

	/* quite an insane set of semantics ... */
	if (is_executable(fname) &&
	    (fsp->fh->private_options & NTCREATEX_OPTIONS_PRIVATE_DENY_DOS)) {
		DEBUG(10,("fcb_or_dos_open: file fail due to is_executable.\n"));
		return NULL;
	}

	/* We need to duplicate this fsp. */
	dup_fsp = dup_file_fsp(fsp, access_mask, share_access, create_options);
	if (!dup_fsp) {
		return NULL;
	}

	return dup_fsp;
}

/****************************************************************************
 Open a file with a share mode - old openX method - map into NTCreate.
****************************************************************************/

BOOL map_open_params_to_ntcreate(const char *fname, int deny_mode, int open_func,
				uint32 *paccess_mask,
				uint32 *pshare_mode,
				uint32 *pcreate_disposition,
				uint32 *pcreate_options)
{
	uint32 access_mask;
	uint32 share_mode;
	uint32 create_disposition;
	uint32 create_options = 0;

	DEBUG(10,("map_open_params_to_ntcreate: fname = %s, deny_mode = 0x%x, "
		  "open_func = 0x%x\n",
		  fname, (unsigned int)deny_mode, (unsigned int)open_func ));

	/* Create the NT compatible access_mask. */
	switch (GET_OPENX_MODE(deny_mode)) {
		case DOS_OPEN_EXEC: /* Implies read-only - used to be FILE_READ_DATA */
		case DOS_OPEN_RDONLY:
			access_mask = FILE_GENERIC_READ;
			break;
		case DOS_OPEN_WRONLY:
			access_mask = FILE_GENERIC_WRITE;
			break;
		case DOS_OPEN_RDWR:
		case DOS_OPEN_FCB:
			access_mask = FILE_GENERIC_READ|FILE_GENERIC_WRITE;
			break;
		default:
			DEBUG(10,("map_open_params_to_ntcreate: bad open mode = 0x%x\n",
				  (unsigned int)GET_OPENX_MODE(deny_mode)));
			return False;
	}

	/* Create the NT compatible create_disposition. */
	switch (open_func) {
		case OPENX_FILE_EXISTS_FAIL|OPENX_FILE_CREATE_IF_NOT_EXIST:
			create_disposition = FILE_CREATE;
			break;

		case OPENX_FILE_EXISTS_OPEN:
			create_disposition = FILE_OPEN;
			break;

		case OPENX_FILE_EXISTS_OPEN|OPENX_FILE_CREATE_IF_NOT_EXIST:
			create_disposition = FILE_OPEN_IF;
			break;
       
		case OPENX_FILE_EXISTS_TRUNCATE:
			create_disposition = FILE_OVERWRITE;
			break;

		case OPENX_FILE_EXISTS_TRUNCATE|OPENX_FILE_CREATE_IF_NOT_EXIST:
			create_disposition = FILE_OVERWRITE_IF;
			break;

		default:
			/* From samba4 - to be confirmed. */
			if (GET_OPENX_MODE(deny_mode) == DOS_OPEN_EXEC) {
				create_disposition = FILE_CREATE;
				break;
			}
			DEBUG(10,("map_open_params_to_ntcreate: bad "
				  "open_func 0x%x\n", (unsigned int)open_func));
			return False;
	}
 
	/* Create the NT compatible share modes. */
	switch (GET_DENY_MODE(deny_mode)) {
		case DENY_ALL:
			share_mode = FILE_SHARE_NONE;
			break;

		case DENY_WRITE:
			share_mode = FILE_SHARE_READ;
			break;

		case DENY_READ:
			share_mode = FILE_SHARE_WRITE;
			break;

		case DENY_NONE:
			share_mode = FILE_SHARE_READ|FILE_SHARE_WRITE;
			break;

		case DENY_DOS:
			create_options |= NTCREATEX_OPTIONS_PRIVATE_DENY_DOS;
	                if (is_executable(fname)) {
				share_mode = FILE_SHARE_READ|FILE_SHARE_WRITE;
			} else {
				if (GET_OPENX_MODE(deny_mode) == DOS_OPEN_RDONLY) {
					share_mode = FILE_SHARE_READ;
				} else {
					share_mode = FILE_SHARE_NONE;
				}
			}
			break;

		case DENY_FCB:
			create_options |= NTCREATEX_OPTIONS_PRIVATE_DENY_FCB;
			share_mode = FILE_SHARE_NONE;
			break;

		default:
			DEBUG(10,("map_open_params_to_ntcreate: bad deny_mode 0x%x\n",
				(unsigned int)GET_DENY_MODE(deny_mode) ));
			return False;
	}

	DEBUG(10,("map_open_params_to_ntcreate: file %s, access_mask = 0x%x, "
		  "share_mode = 0x%x, create_disposition = 0x%x, "
		  "create_options = 0x%x\n",
		  fname,
		  (unsigned int)access_mask,
		  (unsigned int)share_mode,
		  (unsigned int)create_disposition,
		  (unsigned int)create_options ));

	if (paccess_mask) {
		*paccess_mask = access_mask;
	}
	if (pshare_mode) {
		*pshare_mode = share_mode;
	}
	if (pcreate_disposition) {
		*pcreate_disposition = create_disposition;
	}
	if (pcreate_options) {
		*pcreate_options = create_options;
	}