cifs: add a third receive phase to cifs_demultiplex_thread
Have the demultiplex thread receive just enough to get to the MID, and
then find it before receiving the rest. Later, we'll use this to swap
in a preallocated receive buffer for some calls.
Reviewed-and-Tested-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index ee70075..5308bc6 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -746,11 +746,25 @@
if (!is_smb_response(server, buf[0]))
continue;
- /* check the length */
- if ((pdu_length > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) ||
- (pdu_length < sizeof(struct smb_hdr) - 1 - 4)) {
- cERROR(1, "Invalid size SMB length %d pdu_length %d",
- 4, pdu_length + 4);
+ /* make sure we have enough to get to the MID */
+ if (pdu_length < sizeof(struct smb_hdr) - 1 - 4) {
+ cERROR(1, "SMB response too short (%u bytes)",
+ pdu_length);
+ cifs_reconnect(server);
+ wake_up(&server->response_q);
+ continue;
+ }
+
+ /* read down to the MID */
+ length = read_from_socket(server, buf + 4,
+ sizeof(struct smb_hdr) - 1 - 4);
+ if (length < 0)
+ continue;
+ total_read += length;
+
+ if (pdu_length > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
+ cERROR(1, "SMB response too long (%u bytes)",
+ pdu_length);
cifs_reconnect(server);
wake_up(&server->response_q);
continue;
@@ -759,12 +773,15 @@
/* else length ok */
if (pdu_length > MAX_CIFS_SMALL_BUFFER_SIZE - 4) {
isLargeBuf = true;
- memcpy(bigbuf, smallbuf, 4);
+ memcpy(bigbuf, smallbuf, total_read);
smb_buffer = (struct smb_hdr *)bigbuf;
buf = bigbuf;
}
- length = read_from_socket(server, buf + 4, pdu_length);
+ /* now read the rest */
+ length = read_from_socket(server,
+ buf + sizeof(struct smb_hdr) - 1,
+ pdu_length - sizeof(struct smb_hdr) + 1 + 4);
if (length < 0)
continue;
total_read += length;