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// SPDX-License-Identifier: GPL-2.0-only
/******************************************************************************
*******************************************************************************
**
** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
** Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
**
**
*******************************************************************************
******************************************************************************/
/*
* 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 <asm/unaligned.h>
#include "dlm_internal.h"
#include "lowcomms.h"
#include "config.h"
#include "lock.h"
#include "midcomms.h"
/*
* Called from the low-level comms layer to process a buffer of
* commands.
*/
int dlm_process_incoming_buffer(int nodeid, unsigned char *buf, int len)
{
const unsigned char *ptr = buf;
const struct dlm_header *hd;
uint16_t msglen;
int ret = 0;
while (len >= sizeof(struct dlm_header)) {
hd = (struct dlm_header *)ptr;
/* no message should be more than this otherwise we
* cannot deliver this message to upper layers
*/
msglen = get_unaligned_le16(&hd->h_length);
if (msglen > DEFAULT_BUFFER_SIZE ||
msglen < sizeof(struct dlm_header)) {
log_print("received invalid length header: %u from node %d, will abort message parsing",
msglen, nodeid);
return -EBADMSG;
}
/* caller will take care that leftover
* will be parsed next call with more data
*/
if (msglen > len)
break;
switch (hd->h_cmd) {
case DLM_MSG:
if (msglen < sizeof(struct dlm_message)) {
log_print("dlm msg too small: %u, will skip this message",
msglen);
goto skip;
}
break;
case DLM_RCOM:
if (msglen < sizeof(struct dlm_rcom)) {
log_print("dlm rcom msg too small: %u, will skip this message",
msglen);
goto skip;
}
break;
default:
log_print("unsupported h_cmd received: %u, will skip this message",
hd->h_cmd);
goto skip;
}
/* for aligned memory access, we just copy current message
* to begin of the buffer which contains already parsed buffer
* data and should provide align access for upper layers
* because the start address of the buffer has a aligned
* address. This memmove can be removed when the upperlayer
* is capable of unaligned memory access.
*/
memmove(buf, ptr, msglen);
dlm_receive_buffer((union dlm_packet *)buf, nodeid);
skip:
ret += msglen;
len -= msglen;
ptr += msglen;
}
return ret;
}
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