From 89482a56a079f01c2f4c709f8e23fbf7eeda1b43 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Wed, 19 Oct 2011 15:28:57 -0400 Subject: [PATCH] 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 Signed-off-by: Jeff Layton --- fs/cifs/connect.c | 31 ++++++++++++++++++++++++------- 1 file changed, 24 insertions(+), 7 deletions(-) diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index ee70075c5fb1..5308bc6e1248 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -746,11 +746,25 @@ cifs_demultiplex_thread(void *p) 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 @@ cifs_demultiplex_thread(void *p) /* 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;