lib/isccc/ccmsg.c

/*
 * Portions Copyright (C) 2001, 2004, 2005, 2007, 2016  Internet Systems Consortium, Inc. ("ISC")
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * Portions Copyright (C) 2001  Nominum, Inc.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC AND NOMINUM DISCLAIMS ALL
 * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY
 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/* $Id: ccmsg.c,v 1.10 2007/08/28 07:20:43 tbox Exp $ */

/*! \file */

#include <config.h>

#include <isc/mem.h>
#include <isc/result.h>
#include <isc/task.h>
#include <isc/util.h>

#include <isccc/events.h>
#include <isccc/ccmsg.h>

#define CCMSG_MAGIC     ISC_MAGIC('C', 'C', 'm', 's')
#define VALID_CCMSG(foo)    ISC_MAGIC_VALID(foo, CCMSG_MAGIC)

static void recv_length(isc_task_t *, isc_event_t *);
static void recv_message(isc_task_t *, isc_event_t *);


static void
recv_length(isc_task_t *task, isc_event_t *ev_in) {
    isc_socketevent_t *ev = (isc_socketevent_t *)ev_in;
    isc_event_t *dev;
    isccc_ccmsg_t *ccmsg = ev_in->ev_arg;
    isc_region_t region;
    isc_result_t result;

    INSIST(VALID_CCMSG(ccmsg));

    dev = &ccmsg->event;

    if (ev->result != ISC_R_SUCCESS) {
        ccmsg->result = ev->result;
        goto send_and_free;
    }

    /*
     * Success.
     */
    ccmsg->size = ntohl(ccmsg->size);
    if (ccmsg->size == 0) {
        ccmsg->result = ISC_R_UNEXPECTEDEND;
        goto send_and_free;
    }
    if (ccmsg->size > ccmsg->maxsize) {
        ccmsg->result = ISC_R_RANGE;
        goto send_and_free;
    }

    region.base = isc_mem_get(ccmsg->mctx, ccmsg->size);
    region.length = ccmsg->size;
    if (region.base == NULL) {
        ccmsg->result = ISC_R_NOMEMORY;
        goto send_and_free;
    }

    isc_buffer_init(&ccmsg->buffer, region.base, region.length);
    result = isc_socket_recv(ccmsg->sock, &region, 0,
                 task, recv_message, ccmsg);
    if (result != ISC_R_SUCCESS) {
        ccmsg->result = result;
        goto send_and_free;
    }

    isc_event_free(&ev_in);
    return;

 send_and_free:
    isc_task_send(ccmsg->task, &dev);
    ccmsg->task = NULL;
    isc_event_free(&ev_in);
    return;
}

static void
recv_message(isc_task_t *task, isc_event_t *ev_in) {
    isc_socketevent_t *ev = (isc_socketevent_t *)ev_in;
    isc_event_t *dev;
    isccc_ccmsg_t *ccmsg = ev_in->ev_arg;

    (void)task;

    INSIST(VALID_CCMSG(ccmsg));

    dev = &ccmsg->event;

    if (ev->result != ISC_R_SUCCESS) {
        ccmsg->result = ev->result;
        goto send_and_free;
    }

    ccmsg->result = ISC_R_SUCCESS;
    isc_buffer_add(&ccmsg->buffer, ev->n);
    ccmsg->address = ev->address;

 send_and_free:
    isc_task_send(ccmsg->task, &dev);
    ccmsg->task = NULL;
    isc_event_free(&ev_in);
}

void
isccc_ccmsg_init(isc_mem_t *mctx, isc_socket_t *sock, isccc_ccmsg_t *ccmsg) {
    REQUIRE(mctx != NULL);
    REQUIRE(sock != NULL);
    REQUIRE(ccmsg != NULL);

    ccmsg->magic = CCMSG_MAGIC;
    ccmsg->size = 0;
    ccmsg->buffer.base = NULL;
    ccmsg->buffer.length = 0;
    ccmsg->maxsize = 4294967295U;   /* Largest message possible. */
    ccmsg->mctx = mctx;
    ccmsg->sock = sock;
    ccmsg->task = NULL;         /* None yet. */
    ccmsg->result = ISC_R_UNEXPECTED;   /* None yet. */
    /*
     * Should probably initialize the event here, but it can wait.
     */
}


void
isccc_ccmsg_setmaxsize(isccc_ccmsg_t *ccmsg, unsigned int maxsize) {
    REQUIRE(VALID_CCMSG(ccmsg));

    ccmsg->maxsize = maxsize;
}


isc_result_t
isccc_ccmsg_readmessage(isccc_ccmsg_t *ccmsg,
               isc_task_t *task, isc_taskaction_t action, void *arg)
{
    isc_result_t result;
    isc_region_t region;

    REQUIRE(VALID_CCMSG(ccmsg));
    REQUIRE(task != NULL);
    REQUIRE(ccmsg->task == NULL);  /* not currently in use */

    if (ccmsg->buffer.base != NULL) {
        isc_mem_put(ccmsg->mctx, ccmsg->buffer.base,
                ccmsg->buffer.length);
        ccmsg->buffer.base = NULL;
        ccmsg->buffer.length = 0;
    }

    ccmsg->task = task;
    ccmsg->action = action;
    ccmsg->arg = arg;
    ccmsg->result = ISC_R_UNEXPECTED;  /* unknown right now */

    ISC_EVENT_INIT(&ccmsg->event, sizeof(isc_event_t), 0, 0,
               ISCCC_EVENT_CCMSG, action, arg, ccmsg,
               NULL, NULL);

    region.base = (unsigned char *)&ccmsg->size;
    region.length = 4;  /* isc_uint32_t */
    result = isc_socket_recv(ccmsg->sock, &region, 0,
                 ccmsg->task, recv_length, ccmsg);

    if (result != ISC_R_SUCCESS)
        ccmsg->task = NULL;

    return (result);
}

void
isccc_ccmsg_cancelread(isccc_ccmsg_t *ccmsg) {
    REQUIRE(VALID_CCMSG(ccmsg));

    isc_socket_cancel(ccmsg->sock, NULL, ISC_SOCKCANCEL_RECV);
}

#if 0
void
isccc_ccmsg_freebuffer(isccc_ccmsg_t *ccmsg) {
    REQUIRE(VALID_CCMSG(ccmsg));

    if (ccmsg->buffer.base == NULL)
        return;

    isc_mem_put(ccmsg->mctx, ccmsg->buffer.base, ccmsg->buffer.length);
    ccmsg->buffer.base = NULL;
    ccmsg->buffer.length = 0;
}
#endif

void
isccc_ccmsg_invalidate(isccc_ccmsg_t *ccmsg) {
    REQUIRE(VALID_CCMSG(ccmsg));

    ccmsg->magic = 0;

    if (ccmsg->buffer.base != NULL) {
        isc_mem_put(ccmsg->mctx, ccmsg->buffer.base,
                ccmsg->buffer.length);
        ccmsg->buffer.base = NULL;
        ccmsg->buffer.length = 0;
    }
}