This is a *big* checkin that may break some things, but implements the

new open mechanism Andrew & I discussed.

config.sub:
configure: Included the QNX patch.

include/vfs.h:
smbd/vfs-wrap.c:
smbd/vfs.c: Added ftruncate vfs call (needed).

Note that we will also need locking calls in the vfs (to be added).

lib/util_unistr.c:
nmbd/nmbd_processlogon.c: Fix for NT domain logons causing nmbd to core dump.
                          Also fix for sidsize DOS bug.

locking/locking.c: Check value of ret before using it for memdup.

printing/printing.c: Convert print_fsp_open to return an allocated fsp.

rpc_server/srv_lsa.c: Fix for NT domain logons.

I have removed all use of lp_share_modes() from the code (although I
left the parameter in the table for backwards compatibility). It no longer makes
sense for this to exist.

smbd/close.c: Removed lp_share_modes().
smbd/fileio.c: Fixed parameters to unlock_share_entry call in panic code.
smbd/files.c: Correctly set the unix_ERR_code to ERRnofids on fsp allocation fail.

smbd/nttrans.c:
smbd/reply.c:
smbd/trans2.c: Changed all occurrences of open_file_shared/open_directory/
               open_file_stat to return an fsp from the call.

smbd/open.c: Changed all occurrences of open_file_shared/open_directory/
             open_file_stat to return an fsp from the call.

In addition I have fixed a long standing race condition in the deny mode
processing w.r.t. two smbd's creating a file. Andrew, please note that
your original idea of using open with O_EXCL in this case would not work
(I went over the races very carefully) and so we must re-check deny modes
*after* the open() call returns. This is because there is a race between
the open with O_EXCL and the lock of the share mode entry. Imagine the
case where the first smbd does the open with O_EXCL and a deny mode of DENY_ALL,
but is pre-empted before it locks the share modes and creates the deny
mode entry for DENY_ALL. A second smbd could then come in with O_RDONLY
and a deny mode of DENY_NONE and the two opens would be allowed.

The *only* way to fix this race is to lock the share modes after the
open and then do the deny mode checks *after* this lock in the case
where the file did not originally exist.

This code will need extensive testing but seems to initially work.

Jeremy.
(This used to be commit ab0ecc39d688f16b9692fe90b991f0b89287070a)

1 files changed, 2 insertions, 1 deletions

diff --git a/source3/locking/locking.c b/source3/locking/locking.c
index bde1ffb567e..affda89f08c 100644
--- a/source3/locking/locking.c
+++ b/source3/locking/locking.c
@@ -662,7 +662,8 @@ int get_share_modes(connection_struct *conn,
 
 	data = (struct locking_data *)dbuf.dptr;
 	ret = data->num_share_mode_entries;
-	*shares = (share_mode_entry *)memdup(dbuf.dptr + sizeof(*data), ret * sizeof(**shares));
+	if(ret)
+		*shares = (share_mode_entry *)memdup(dbuf.dptr + sizeof(*data), ret * sizeof(**shares));
 	free(dbuf.dptr);
 
 	if (! *shares) return 0;