csu3_am335x/EVSE/GPL/open-plc-utils-0.3/mme

/*====================================================================*
*
* Copyright (c) 2013 Qualcomm Atheros, Inc.
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted (subject to the limitations
* in the disclaimer below) provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* * Neither the name of Qualcomm Atheros nor the names of
* its contributors may be used to endorse or promote products
* derived from this software without specific prior written
* permission.
*
* NO EXPRESS OR IMPLIED LICENSES TO ANY PARTY'S PATENT RIGHTS ARE
* GRANTED BY THIS LICENSE. THIS SOFTWARE IS PROVIDED BY THE
* COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*--------------------------------------------------------------------*/

/*====================================================================*
*
* ssize_t readmessage (struct channel const * channel, struct message * message, uint8_t MMV, uint16_t MMTYPE);
*
* plc.h
*
* wait for a QCA vendor specific message of given MMV and MMTYPE;
* discard unwanted messages until the desired message arrives or
* the channel timeout expires; return packet length on success,
* 0 on timeout or -1 on error;
*
* see sendmessage for the send counterpart to this function;
*
* a well designed UnwantedMessage function is critical here;
*
* Contributor(s):
* Charles Maier
* Nathaniel Houghton
*
*--------------------------------------------------------------------*/

#ifndef READMESSAGE_SOURCE
#define READMESSAGE_SOURCE

#include
#include
#include

#include "../tools/error.h"
#include "../tools/timer.h"
#include "../plc/plc.h"

ssize_t readmessage (struct channel const * channel, struct message * message, uint8_t MMV, uint16_t MMTYPE)

{
struct timeval ts;
struct timeval tc;
ssize_t length;
if (gettimeofday (& ts, NULL) == - 1)
{
error (1, errno, CANT_START_TIMER);
}
while ((length = readpacket (channel, message, sizeof (* message))) >= 0)
{
if (! UnwantedMessage (message, length, MMV, MMTYPE))
{
return (length);
}
if (gettimeofday (& tc, NULL) == - 1)
{
error (1, errno, CANT_RESET_TIMER);
}
if (channel->timeout < 0)
{
continue;
}
if (channel->timeout > MILLISECONDS (ts, tc))
{
continue;
}
return (0);
}
return (- 1);
}

#endif