Commit 2c8f981d authored by Jeff Layton's avatar Jeff Layton Committed by Steve French
Browse files

cifs: consolidate SendReceive response checks 



Further consolidate the SendReceive code by moving the checks run over
the packet into a separate function that all the SendReceive variants
can call.

We can also eliminate the check for a receive_len that's too big or too
small. cifs_demultiplex_thread already checks that and disconnects the
socket if that occurs, while setting the midStatus to MALFORMED. It'll
never call this code if that's the case.

Finally do a little cleanup. Use "goto out" on errors so that the flow
of code in the normal case is more evident. Also switch the logErr
variable in map_smb_to_linux_error to a bool.

Reviewed-by: default avatarPavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: default avatarJeff Layton <jlayton@redhat.com>
Signed-off-by: default avatarSteve French <sfrench@us.ibm.com>
parent 71a86384

fs/cifs/cifsproto.h

+3 −1
Original line number Diff line number Diff line
@@ -76,6 +76,8 @@ extern int SendReceive(const unsigned int /* xid */ , struct cifsSesInfo *, 
			int * /* bytes returned */ , const int long_op);

extern int SendReceiveNoRsp(const unsigned int xid, struct cifsSesInfo *ses,

			struct smb_hdr *in_buf, int flags);

extern int cifs_check_receive(struct mid_q_entry *mid,

			struct TCP_Server_Info *server, bool log_error);

extern int SendReceive2(const unsigned int /* xid */ , struct cifsSesInfo *,

			struct kvec *, int /* nvec to send */,

			int * /* type of buf returned */ , const int flags);
@@ -99,7 +101,7 @@ extern int cifs_convert_address(struct sockaddr *dst, const char *src, int len); 
extern int cifs_set_port(struct sockaddr *addr, const unsigned short int port);

extern int cifs_fill_sockaddr(struct sockaddr *dst, const char *src, int len,

				const unsigned short int port);

extern int map_smb_to_linux_error(struct smb_hdr *smb, int logErr);

extern int map_smb_to_linux_error(struct smb_hdr *smb, bool logErr);

extern void header_assemble(struct smb_hdr *, char /* command */ ,

			    const struct cifsTconInfo *, int /* length of

			    fixed section (word count) in two byte units */);

fs/cifs/netmisc.c

+1 −1
Original line number Diff line number Diff line
@@ -836,7 +836,7 @@ ntstatus_to_dos(__u32 ntstatus, __u8 *eclass, __u16 *ecode) 
}



int

map_smb_to_linux_error(struct smb_hdr *smb, int logErr)

map_smb_to_linux_error(struct smb_hdr *smb, bool logErr)

{

	unsigned int i;

	int rc = -EIO;	/* if transport error smb error may not be set */

fs/cifs/transport.c

+41 −116
Original line number Diff line number Diff line
@@ -501,6 +501,25 @@ send_nt_cancel(struct TCP_Server_Info *server, struct smb_hdr *in_buf, 
	return rc;

}



int

cifs_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,

		   bool log_error)

{

	dump_smb(mid->resp_buf,

		 min_t(u32, 92, be32_to_cpu(mid->resp_buf->smb_buf_length)));



	/* convert the length into a more usable form */

	if (server->secMode & (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED)) {

		/* FIXME: add code to kill session */

		if (cifs_verify_signature(mid->resp_buf, server,

					  mid->sequence_number + 1) != 0)

			cERROR(1, "Unexpected SMB signature");

	}



	/* BB special case reconnect tid and uid here? */

	return map_smb_to_linux_error(mid->resp_buf, log_error);

}



int

SendReceive2(const unsigned int xid, struct cifsSesInfo *ses,

	     struct kvec *iov, int n_vec, int *pRespBufType /* ret */,
@@ -508,7 +527,6 @@ SendReceive2(const unsigned int xid, struct cifsSesInfo *ses, 
{

	int rc = 0;

	int long_op;

	unsigned int receive_len;

	struct mid_q_entry *midQ;

	struct smb_hdr *in_buf = iov[0].iov_base;
@@ -605,54 +623,24 @@ SendReceive2(const unsigned int xid, struct cifsSesInfo *ses, 
		return rc;

	}



	receive_len = be32_to_cpu(midQ->resp_buf->smb_buf_length);



	if (receive_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) {

		cERROR(1, "Frame too large received.  Length: %d  Xid: %d",

			receive_len, xid);

	if (!midQ->resp_buf || midQ->midState != MID_RESPONSE_RECEIVED) {

		rc = -EIO;

		cFYI(1, "Bad MID state?");

		goto out;

	}



	/* rcvd frame is ok */



	if (midQ->resp_buf &&

	    (midQ->midState == MID_RESPONSE_RECEIVED)) {



	iov[0].iov_base = (char *)midQ->resp_buf;

	iov[0].iov_len = be32_to_cpu(midQ->resp_buf->smb_buf_length) + 4;

	if (midQ->largeBuf)

		*pRespBufType = CIFS_LARGE_BUFFER;

	else

		*pRespBufType = CIFS_SMALL_BUFFER;

		iov[0].iov_len = receive_len + 4;



		dump_smb(midQ->resp_buf, 80);

		/* convert the length into a more usable form */

		if ((receive_len > 24) &&

		    (ses->server->secMode & (SECMODE_SIGN_REQUIRED |

					     SECMODE_SIGN_ENABLED))) {

			rc = cifs_verify_signature(midQ->resp_buf,

						ses->server,

						midQ->sequence_number+1);

			if (rc) {

				cERROR(1, "Unexpected SMB signature");

				/* BB FIXME add code to kill session */

			}

		}



		/* BB special case reconnect tid and uid here? */

		rc = map_smb_to_linux_error(midQ->resp_buf,

					    flags & CIFS_LOG_ERROR);

	rc = cifs_check_receive(midQ, ses->server, flags & CIFS_LOG_ERROR);



	/* mark it so buf will not be freed by delete_mid */

	if ((flags & CIFS_NO_RESP) == 0)

			midQ->resp_buf = NULL;  /* mark it so buf will

						   not be freed by

						   delete_mid */

	} else {

		rc = -EIO;

		cFYI(1, "Bad MID state?");

	}



		midQ->resp_buf = NULL;

out:

	delete_mid(midQ);

	atomic_dec(&ses->server->inFlight);
@@ -667,7 +655,6 @@ SendReceive(const unsigned int xid, struct cifsSesInfo *ses, 
	    int *pbytes_returned, const int long_op)

{

	int rc = 0;

	unsigned int receive_len;

	struct mid_q_entry *midQ;



	if (ses == NULL) {
@@ -757,47 +744,16 @@ SendReceive(const unsigned int xid, struct cifsSesInfo *ses, 
		return rc;

	}



	receive_len = be32_to_cpu(midQ->resp_buf->smb_buf_length);



	if (receive_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) {

		cERROR(1, "Frame too large received.  Length: %d  Xid: %d",

			receive_len, xid);

		rc = -EIO;

		goto out;

	}



	/* rcvd frame is ok */



	if (midQ->resp_buf && out_buf

	    && (midQ->midState == MID_RESPONSE_RECEIVED)) {

		out_buf->smb_buf_length = cpu_to_be32(receive_len);

		memcpy((char *)out_buf + 4,

		       (char *)midQ->resp_buf + 4,

		       receive_len);



		dump_smb(out_buf, 92);

		/* convert the length into a more usable form */

		if ((receive_len > 24) &&

		    (ses->server->secMode & (SECMODE_SIGN_REQUIRED |

					     SECMODE_SIGN_ENABLED))) {

			rc = cifs_verify_signature(out_buf,

						ses->server,

						midQ->sequence_number+1);

			if (rc) {

				cERROR(1, "Unexpected SMB signature");

				/* BB FIXME add code to kill session */

			}

		}



		*pbytes_returned = be32_to_cpu(out_buf->smb_buf_length);



		/* BB special case reconnect tid and uid here? */

		rc = map_smb_to_linux_error(out_buf, 0 /* no log */ );

	} else {

	if (!midQ->resp_buf || !out_buf ||

	    midQ->midState != MID_RESPONSE_RECEIVED) {

		rc = -EIO;

		cERROR(1, "Bad MID state?");

		goto out;

	}



	*pbytes_returned = be32_to_cpu(midQ->resp_buf->smb_buf_length);

	memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);

	rc = cifs_check_receive(midQ, ses->server, 0);

out:

	delete_mid(midQ);

	atomic_dec(&ses->server->inFlight);
@@ -838,7 +794,6 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifsTconInfo *tcon, 
{

	int rc = 0;

	int rstart = 0;

	unsigned int receive_len;

	struct mid_q_entry *midQ;

	struct cifsSesInfo *ses;
@@ -961,46 +916,16 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifsTconInfo *tcon, 
	if (rc != 0)

		return rc;



	receive_len = be32_to_cpu(midQ->resp_buf->smb_buf_length);

	if (receive_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) {

		cERROR(1, "Frame too large received.  Length: %d  Xid: %d",

			receive_len, xid);

		rc = -EIO;

		goto out;

	}



	/* rcvd frame is ok */



	if ((out_buf == NULL) || (midQ->midState != MID_RESPONSE_RECEIVED)) {

	if (out_buf == NULL || midQ->midState != MID_RESPONSE_RECEIVED) {

		rc = -EIO;

		cERROR(1, "Bad MID state?");

		goto out;

	}



	out_buf->smb_buf_length = cpu_to_be32(receive_len);

	memcpy((char *)out_buf + 4,

	       (char *)midQ->resp_buf + 4,

	       receive_len);



	dump_smb(out_buf, 92);

	/* convert the length into a more usable form */

	if ((receive_len > 24) &&

	    (ses->server->secMode & (SECMODE_SIGN_REQUIRED |

				     SECMODE_SIGN_ENABLED))) {

		rc = cifs_verify_signature(out_buf,

					   ses->server,

					   midQ->sequence_number+1);

		if (rc) {

			cERROR(1, "Unexpected SMB signature");

			/* BB FIXME add code to kill session */

		}

	}



	*pbytes_returned = be32_to_cpu(out_buf->smb_buf_length);



	/* BB special case reconnect tid and uid here? */

	rc = map_smb_to_linux_error(out_buf, 0 /* no log */ );



	*pbytes_returned = be32_to_cpu(midQ->resp_buf->smb_buf_length);

	memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);

	rc = cifs_check_receive(midQ, ses->server, 0);

out:

	delete_mid(midQ);

	if (rstart && rc == -EACCES)

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