linux-imx

/******************************************************************************

*******************************************************************************

**

**  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.

**  Copyright (C) 2004-2008 Red Hat, Inc.  All rights reserved.

**

**  This copyrighted material is made available to anyone wishing to use,

**  modify, copy, or redistribute it subject to the terms and conditions

**  of the GNU General Public License v.2.

**

*******************************************************************************

******************************************************************************/

​

/*

 * midcomms.c

 *

 * This is the appallingly named "mid-level" comms layer.

 *

 * Its purpose is to take packets from the "real" comms layer,

 * split them up into packets and pass them to the interested

 * part of the locking mechanism.

 *

 * It also takes messages from the locking layer, formats them

 * into packets and sends them to the comms layer.

 */

​

#include "dlm_internal.h"

#include "lowcomms.h"

#include "config.h"

#include "lock.h"

#include "midcomms.h"

​

​

static void copy_from_cb(void *dst, const void *base, unsigned offset,

             unsigned len, unsigned limit)

{

    unsigned copy = len;

​

    if ((copy + offset) > limit)

        copy = limit - offset;

    memcpy(dst, base + offset, copy);

    len -= copy;

    if (len)

        memcpy(dst + copy, base, len);

}

​

/*

 * Called from the low-level comms layer to process a buffer of

 * commands.

 *

 * Only complete messages are processed here, any "spare" bytes from

 * the end of a buffer are saved and tacked onto the front of the next

 * message that comes in. I doubt this will happen very often but we

 * need to be able to cope with it and I don't want the task to be waiting

 * for packets to come in when there is useful work to be done.

 */

​

int dlm_process_incoming_buffer(int nodeid, const void *base,

                unsigned offset, unsigned len, unsigned limit)

{

    union {

        unsigned char __buf[DLM_INBUF_LEN];

        /* this is to force proper alignment on some arches */