s3:smbd: use smb1srv_open_lookup() in is_valid_writeX_buffer()

It's more logical to check the fnum instead of tid here.
This will make it easier to reuse the logic for SMB2 and
allows per fsp recvfile detection.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>

diff --git a/source3/smbd/reply.c b/source3/smbd/reply.c
index e58735ed93e474c4ffa7c7786276da849b5d1c3a..da59ca75ae1bb2c1f50a06e7b4a99728d78fd010 100644 (file)
--- a/source3/smbd/reply.c
+++ b/source3/smbd/reply.c
@@ -4598,12 +4598,12 @@ bool is_valid_writeX_buffer(struct smbd_server_connection *sconn,
                            const uint8_t *inbuf)
 {
        size_t numtowrite;
-       connection_struct *conn = NULL;
        unsigned int doff = 0;
        size_t len = smb_len_large(inbuf);
-       struct smbXsrv_tcon *tcon;
+       uint16_t fnum;
+       struct smbXsrv_open *op = NULL;
+       struct files_struct *fsp = NULL;
        NTSTATUS status;
-       NTTIME now = 0;
 
        if (is_encrypted_packet(sconn, inbuf)) {
                /* Can't do this on encrypted
@@ -4622,19 +4622,30 @@ bool is_valid_writeX_buffer(struct smbd_server_connection *sconn,
                return false;
        }
 
-       status = smb1srv_tcon_lookup(sconn->conn, SVAL(inbuf, smb_tid),
-                                    now, &tcon);
+       fnum = SVAL(inbuf, smb_vwv2);
+       status = smb1srv_open_lookup(sconn->conn,
+                                    fnum,
+                                    0, /* now */
+                                    &op);
        if (!NT_STATUS_IS_OK(status)) {
-               DEBUG(10,("is_valid_writeX_buffer: bad tid\n"));
+               DEBUG(10,("is_valid_writeX_buffer: bad fnum\n"));
+               return false;
+       }
+       fsp = op->compat;
+       if (fsp == NULL) {
+               DEBUG(10,("is_valid_writeX_buffer: bad fsp\n"));
+               return false;
+       }
+       if (fsp->conn == NULL) {
+               DEBUG(10,("is_valid_writeX_buffer: bad fsp->conn\n"));
                return false;
        }
-       conn = tcon->compat;
 
-       if (IS_IPC(conn)) {
+       if (IS_IPC(fsp->conn)) {
                DEBUG(10,("is_valid_writeX_buffer: IPC$ tid\n"));
                return false;
        }
-       if (IS_PRINT(conn)) {
+       if (IS_PRINT(fsp->conn)) {
                DEBUG(10,("is_valid_writeX_buffer: printing tid\n"));
                return false;
        }