symon/symon/symon/symonnet.c

/*
 * Copyright (c) 2001-2007 Willem Dijkstra
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted 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.
 *
 * 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 HOLDERS 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.
 *
 */

#include <sys/types.h>
#include <sys/socket.h>

#include <netdb.h>

#include <string.h>
#include <errno.h>
#include <time.h>

#include "conf.h"
#include "error.h"
#include "data.h"
#include "symon.h"
#include "net.h"

/* Fill a mux structure with inet details */
void
connect2mux(struct mux * mux)
{
    struct sockaddr_storage sockaddr;

    int family;

    bzero((void *) &sockaddr, sizeof(sockaddr));

    get_mux_sockaddr(mux, SOCK_DGRAM);
    family = mux->sockaddr.ss_family;

    get_sockaddr(&sockaddr, family, SOCK_DGRAM, AI_PASSIVE, mux->localaddr, "0");

    if ((mux->symuxsocket = socket(family, SOCK_DGRAM, 0)) == -1)
        fatal("could not obtain socket: %.200s", strerror(errno));

    if (bind(mux->symuxsocket, (struct sockaddr *) & sockaddr, SS_LEN(&sockaddr)) == -1)
        fatal("could not bind socket: %.200s", strerror(errno));

    info("sending packets to udp %.200s", mux->name);
}
/* Send data stored in the mux structure to a mux */
void
send_packet(struct mux * mux)
{
    if (sendto(mux->symuxsocket, mux->packet.data,
               mux->packet.offset, 0, (struct sockaddr *) & mux->sockaddr,
               SS_LEN(&mux->sockaddr))
        != mux->packet.offset) {
        mux->senderr++;
    }

    if (mux->senderr >= SYMON_WARN_SENDERR) {
        warning("%d updates to mux(%.200s) lost due to send errors",
                mux->senderr, mux->name);
        mux->senderr = 0;
    }
}
/* Prepare a packet for data */
void
prepare_packet(struct mux * mux, time_t t)
{
    bzero(mux->packet.data, mux->packet.size);
    mux->packet.header.symon_version = SYMON_PACKET_VER;
    mux->packet.header.timestamp = t;

    /* symonpacketheader is always first stream */
    mux->packet.offset =
        setheader(mux->packet.data,
                  &mux->packet.header);
}
/* Put a stream into the packet for a mux */
void
stream_in_packet(struct stream * stream, struct mux * mux)
{
    mux->packet.offset +=
        (streamfunc[stream->type].get)      /* call getter of stream */
        (mux->packet.data + mux->packet.offset,    /* packet buffer */
         mux->packet.size - mux->packet.offset,    /* maxlen */
         stream);
}
/* Ready a packet for transmission, set length and crc */
void
finish_packet(struct mux * mux)
{
    mux->packet.header.length = mux->packet.offset;
    mux->packet.header.crc = 0;

    /* fill in correct header with crc = 0 */
    setheader(mux->packet.data, &mux->packet.header);

    /* fill in correct header with crc */
    mux->packet.header.crc = crc32(mux->packet.data, mux->packet.offset);
    setheader(mux->packet.data, &mux->packet.header);
}