bind/lib/isccc/ccmsg.c

/*
 * Portions Copyright (C) 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/.
 *
 * See the COPYRIGHT file distributed with this work for additional
 * information regarding copyright ownership.
 *
 * 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.
 */

/*! \file */

#include <inttypes.h>

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

#include <isccc/ccmsg.h>
#include <isccc/events.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 = NULL;
	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 = NULL;
	isccc_ccmsg_t *ccmsg = ev_in->ev_arg;

	UNUSED(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 = (isccc_ccmsg_t){
		.magic = CCMSG_MAGIC,
		.maxsize = 0xffffffffU, /* Largest message possible. */
		.mctx = mctx,
		.sock = sock,
		.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; /* 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);
}

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;
	}
}