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df9e06b800
This patch removes unaligned memory access handling for receiving midcomms messages. This handling will not fix the unaligned memory access in general. All messages should be length aligned to 8 bytes, there exists cases where this isn't the case. It's part of the sending handling to not send such messages. As the sending handling itself, with the internal allocator of page buffers, can occur in unaligned memory access of dlm message fields we just ignore that problem for now as it seems this code is used by architecture which can handle it. This patch adds a comment to take care about that problem in a major bump of dlm protocol. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
104 lines
2.8 KiB
C
104 lines
2.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/******************************************************************************
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*******************************************************************************
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**
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** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
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** Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
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**
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**
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*******************************************************************************
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******************************************************************************/
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/*
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* midcomms.c
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*
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* This is the appallingly named "mid-level" comms layer.
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*
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* Its purpose is to take packets from the "real" comms layer,
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* split them up into packets and pass them to the interested
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* part of the locking mechanism.
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*
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* It also takes messages from the locking layer, formats them
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* into packets and sends them to the comms layer.
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*/
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#include "dlm_internal.h"
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#include "lowcomms.h"
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#include "config.h"
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#include "lock.h"
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#include "midcomms.h"
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/*
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* Called from the low-level comms layer to process a buffer of
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* commands.
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*/
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int dlm_process_incoming_buffer(int nodeid, unsigned char *buf, int len)
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{
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const unsigned char *ptr = buf;
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const struct dlm_header *hd;
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uint16_t msglen;
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int ret = 0;
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while (len >= sizeof(struct dlm_header)) {
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hd = (struct dlm_header *)ptr;
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/* no message should be more than DEFAULT_BUFFER_SIZE or
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* less than dlm_header size.
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*
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* Some messages does not have a 8 byte length boundary yet
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* which can occur in a unaligned memory access of some dlm
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* messages. However this problem need to be fixed at the
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* sending side, for now it seems nobody run into architecture
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* related issues yet but it slows down some processing.
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* Fixing this issue should be scheduled in future by doing
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* the next major version bump.
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*/
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msglen = le16_to_cpu(hd->h_length);
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if (msglen > DEFAULT_BUFFER_SIZE ||
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msglen < sizeof(struct dlm_header)) {
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log_print("received invalid length header: %u from node %d, will abort message parsing",
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msglen, nodeid);
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return -EBADMSG;
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}
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/* caller will take care that leftover
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* will be parsed next call with more data
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*/
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if (msglen > len)
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break;
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switch (hd->h_cmd) {
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case DLM_MSG:
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if (msglen < sizeof(struct dlm_message)) {
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log_print("dlm msg too small: %u, will skip this message",
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msglen);
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goto skip;
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}
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break;
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case DLM_RCOM:
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if (msglen < sizeof(struct dlm_rcom)) {
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log_print("dlm rcom msg too small: %u, will skip this message",
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msglen);
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goto skip;
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}
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break;
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default:
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log_print("unsupported h_cmd received: %u, will skip this message",
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hd->h_cmd);
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goto skip;
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}
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dlm_receive_buffer((union dlm_packet *)ptr, nodeid);
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skip:
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ret += msglen;
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len -= msglen;
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ptr += msglen;
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}
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return ret;
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}
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