Commit 98bac62c authored by Pavel Shilovsky's avatar Pavel Shilovsky Committed by Steve French
Browse files

CIFS: Move RFC1002 check to a separate function 



Reviewed-and-Tested-by: default avatarJeff Layton <jlayton@redhat.com>
Signed-off-by: default avatarPavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: default avatarSteve French <sfrench@us.ibm.com>
parent e7015fb1

fs/cifs/connect.c

+67 −49
Original line number Diff line number Diff line
@@ -416,6 +416,63 @@ read_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg, 
	return rc;

}



static bool

check_rfc1002_header(struct TCP_Server_Info *server, char *buf)

{

	char temp = *buf;

	unsigned int pdu_length = be32_to_cpu(

				((struct smb_hdr *)buf)->smb_buf_length);



	/*

	 * The first byte big endian of the length field,

	 * is actually not part of the length but the type

	 * with the most common, zero, as regular data.

	 */

	if (temp == (char) RFC1002_SESSION_KEEP_ALIVE) {

		return false;

	} else if (temp == (char)RFC1002_POSITIVE_SESSION_RESPONSE) {

		cFYI(1, "Good RFC 1002 session rsp");

		return false;

	} else if (temp == (char)RFC1002_NEGATIVE_SESSION_RESPONSE) {

		/*

		 * We get this from Windows 98 instead of an error on

		 * SMB negprot response.

		 */

		cFYI(1, "Negative RFC1002 Session Response Error 0x%x)",

			pdu_length);

		/* give server a second to clean up */

		msleep(1000);

		/*

		 * Always try 445 first on reconnect since we get NACK

		 * on some if we ever connected to port 139 (the NACK

		 * is since we do not begin with RFC1001 session

		 * initialize frame).

		 */

		cifs_set_port((struct sockaddr *)

				&server->dstaddr, CIFS_PORT);

		cifs_reconnect(server);

		wake_up(&server->response_q);

		return false;

	} else if (temp != (char) 0) {

		cERROR(1, "Unknown RFC 1002 frame");

		cifs_dump_mem(" Received Data: ", buf, 4);

		cifs_reconnect(server);

		return false;

	}



	/* else we have an SMB response */

	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);

		cifs_reconnect(server);

		wake_up(&server->response_q);

		return false;

	}



	return true;

}



static int

cifs_demultiplex_thread(void *p)

{
@@ -429,7 +486,6 @@ cifs_demultiplex_thread(void *p) 
	struct list_head *tmp, *tmp2;

	struct task_struct *task_to_wake = NULL;

	struct mid_q_entry *mid_entry;

	char temp;

	bool isLargeBuf = false;

	bool isMultiRsp;

	int rc;
@@ -482,59 +538,21 @@ cifs_demultiplex_thread(void *p) 
		else if (rc == 1)

			continue;



		/* The right amount was read from socket - 4 bytes */

		/* so we can now interpret the length field */



		/* the first byte big endian of the length field,

		is actually not part of the length but the type

		with the most common, zero, as regular data */

		temp = *buf;

		/*

		 * The right amount was read from socket - 4 bytes,

		 * so we can now interpret the length field.

		 */



		/* Note that FC 1001 length is big endian on the wire,

		but we convert it here so it is always manipulated

		as host byte order */

		/*

		 * Note that RFC 1001 length is big endian on the wire,

		 * but we convert it here so it is always manipulated

		 * as host byte order.

		 */

		pdu_length = be32_to_cpu(smb_buffer->smb_buf_length);



		cFYI(1, "rfc1002 length 0x%x", pdu_length+4);



		if (temp == (char) RFC1002_SESSION_KEEP_ALIVE) {

			continue;

		} else if (temp == (char)RFC1002_POSITIVE_SESSION_RESPONSE) {

			cFYI(1, "Good RFC 1002 session rsp");

			continue;

		} else if (temp == (char)RFC1002_NEGATIVE_SESSION_RESPONSE) {

			/* we get this from Windows 98 instead of

			   an error on SMB negprot response */

			cFYI(1, "Negative RFC1002 Session Response Error 0x%x)",

				pdu_length);

			/* give server a second to clean up  */

			msleep(1000);

			/* always try 445 first on reconnect since we get NACK

			 * on some if we ever connected to port 139 (the NACK

			 * is since we do not begin with RFC1001 session

			 * initialize frame)

			 */

			cifs_set_port((struct sockaddr *)

					&server->dstaddr, CIFS_PORT);

			cifs_reconnect(server);

			wake_up(&server->response_q);

			continue;

		} else if (temp != (char) 0) {

			cERROR(1, "Unknown RFC 1002 frame");

			cifs_dump_mem(" Received Data: ", buf, length);

			cifs_reconnect(server);

		if (!check_rfc1002_header(server, buf))

			continue;

		}



		/* else we have an SMB response */

		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",

					length, pdu_length+4);

			cifs_reconnect(server);

			wake_up(&server->response_q);

			continue;

		}



		/* else length ok */

		if (pdu_length > MAX_CIFS_SMALL_BUFFER_SIZE - 4) {