bin/named/lwdclient.c

	lwdclient.c revision 40f53fa8d9c6a4fc38c0014495e7a42b08f52481
/*
 * Copyright (C) 2000  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and 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 INTERNET SOFTWARE CONSORTIUM
 * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
 * INTERNET SOFTWARE CONSORTIUM 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: lwdclient.c,v 1.6 2000/08/01 01:11:45 tale Exp $ */

#include <config.h>

#include <isc/socket.h>
#include <isc/string.h>
#include <isc/task.h>
#include <isc/util.h>

#include <dns/view.h>
#include <dns/log.h>

#include <named/types.h>
#include <named/lwdclient.h>

void
ns_lwdclient_log(int level, const char *format, ...) {
    va_list args;

    va_start(args, format);
    isc_log_vwrite(dns_lctx,
               DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_ADB,
               ISC_LOG_DEBUG(level), format, args);
    va_end(args);
}

static void
clientmgr_can_die(ns_lwdclientmgr_t *cm) {
    if ((cm->flags & NS_LWDCLIENTMGR_FLAGSHUTTINGDOWN) == 0)
        return;

    if (ISC_LIST_HEAD(cm->running) != NULL)
        return;

    lwres_context_destroy(&cm->lwctx);
    isc_socket_detach(&cm->sock);
    dns_view_detach(&cm->view);
    isc_task_detach(&cm->task);
}

static void
process_request(ns_lwdclient_t *client) {
    lwres_buffer_t b;
    isc_result_t result;

    lwres_buffer_init(&b, client->buffer, client->recvlength);
    lwres_buffer_add(&b, client->recvlength);

    result = lwres_lwpacket_parseheader(&b, &client->pkt);
    if (result != ISC_R_SUCCESS) {
        ns_lwdclient_log(50, "invalid packet header received");
        goto restart;
    }

    ns_lwdclient_log(50, "opcode %08x", client->pkt.opcode);

    switch (client->pkt.opcode) {
    case LWRES_OPCODE_GETADDRSBYNAME:
        ns_lwdclient_processgabn(client, &b);
        return;
    case LWRES_OPCODE_GETNAMEBYADDR:
        ns_lwdclient_processgnba(client, &b);
        return;
    case LWRES_OPCODE_NOOP:
        ns_lwdclient_processnoop(client, &b);
        return;
    default:
        ns_lwdclient_log(50, "unknown opcode %08x", client->pkt.opcode);
        goto restart;
    }

    /*
     * Drop the packet.
     */
 restart:
    ns_lwdclient_log(50, "restarting client %p...", client);
    ns_lwdclient_stateidle(client);
}

void
ns_lwdclient_recv(isc_task_t *task, isc_event_t *ev) {
    ns_lwdclient_t *client = ev->ev_arg;
    ns_lwdclientmgr_t *cm = client->clientmgr;
    isc_socketevent_t *dev = (isc_socketevent_t *)ev;

    INSIST(dev->region.base == client->buffer);
    INSIST(NS_LWDCLIENT_ISRECV(client));

    NS_LWDCLIENT_SETRECVDONE(client);

    INSIST((cm->flags & NS_LWDCLIENTMGR_FLAGRECVPENDING) != 0);
    cm->flags &= ~NS_LWDCLIENTMGR_FLAGRECVPENDING;

    ns_lwdclient_log(50,
             "event received: task %p, length %u, result %u (%s)",
             task, dev->n, dev->result,
             isc_result_totext(dev->result));

    if (dev->result != ISC_R_SUCCESS) {
        isc_event_free(&ev);
        dev = NULL;

        /*
         * Go idle.
         */
        ns_lwdclient_stateidle(client);

        return;
    }

    /*
     * XXXMLG If we wanted to run on ipv6 as well, we'd need the pktinfo
     * bits.  Right now we don't, so don't remember them.
     */
    client->recvlength = dev->n;
    client->address = dev->address;
    isc_event_free(&ev);
    dev = NULL;

    ns_lwdclient_startrecv(cm);

    process_request(client);
}

/*
 * This function will start a new recv() on a socket for this client manager.
 */
isc_result_t
ns_lwdclient_startrecv(ns_lwdclientmgr_t *cm) {
    ns_lwdclient_t *client;
    isc_result_t result;
    isc_region_t r;

    if ((cm->flags & NS_LWDCLIENTMGR_FLAGSHUTTINGDOWN) != 0)
        return (ISC_R_SUCCESS);

    /*
     * If a recv is already running, don't bother.
     */
    if ((cm->flags & NS_LWDCLIENTMGR_FLAGRECVPENDING) != 0)
        return (ISC_R_SUCCESS);

    /*
     * If we have no idle slots, just return success.
     */
    client = ISC_LIST_HEAD(cm->idle);
    if (client == NULL)
        return (ISC_R_SUCCESS);
    INSIST(NS_LWDCLIENT_ISIDLE(client));

    /*
     * Issue the recv.  If it fails, return that it did.
     */
    r.base = client->buffer;
    r.length = LWRES_RECVLENGTH;
    result = isc_socket_recv(cm->sock, &r, 0, cm->task, ns_lwdclient_recv,
                 client);
    if (result != ISC_R_SUCCESS)
        return (result);

    /*
     * Set the flag to say we've issued a recv() call.
     */
    cm->flags |= NS_LWDCLIENTMGR_FLAGRECVPENDING;

    /*
     * Remove the client from the idle list, and put it on the running
     * list.
     */
    NS_LWDCLIENT_SETRECV(client);
    ISC_LIST_UNLINK(cm->idle, client, link);
    ISC_LIST_APPEND(cm->running, client, link);

    return (ISC_R_SUCCESS);
}

void
ns_lwdclient_shutdown(isc_task_t *task, isc_event_t *ev) {
    ns_lwdclientmgr_t *cm = ev->ev_arg;

    REQUIRE((cm->flags & NS_LWDCLIENTMGR_FLAGSHUTTINGDOWN) == 0);

    ns_lwdclient_log(50, "got shutdown event, task %p", task);

    /*
     * Cancel any pending I/O.
     */
    if ((cm->flags & NS_LWDCLIENTMGR_FLAGRECVPENDING) != 0)
        isc_socket_cancel(cm->sock, task, ISC_SOCKCANCEL_ALL);

    /*
     * Run through the running client list and kill off any finds
     * in progress.
     */
    /* XXXMLG */

    cm->flags |= NS_LWDCLIENTMGR_FLAGSHUTTINGDOWN;

    isc_event_free(&ev);
}

/*
 * Do all the crap needed to move a client from the run queue to the idle
 * queue.
 */
void
ns_lwdclient_stateidle(ns_lwdclient_t *client) {
    ns_lwdclientmgr_t *cm;

    cm = client->clientmgr;

    INSIST(client->sendbuf == NULL);
    INSIST(client->sendlength == 0);
    INSIST(client->arg == NULL);
    INSIST(client->v4find == NULL);
    INSIST(client->v6find == NULL);

    ISC_LIST_UNLINK(cm->running, client, link);
    ISC_LIST_PREPEND(cm->idle, client, link);

    NS_LWDCLIENT_SETIDLE(client);

    clientmgr_can_die(cm);

    ns_lwdclient_startrecv(cm);
}

void
ns_lwdclient_send(isc_task_t *task, isc_event_t *ev) {
    ns_lwdclient_t *client = ev->ev_arg;
    ns_lwdclientmgr_t *cm = client->clientmgr;
    isc_socketevent_t *dev = (isc_socketevent_t *)ev;

    UNUSED(task);
    UNUSED(dev);

    INSIST(NS_LWDCLIENT_ISSEND(client));
    INSIST(client->sendbuf == dev->region.base);

    ns_lwdclient_log(50, "task %p for client %p got send-done event",
             task, client);

    if (client->sendbuf != client->buffer)
        lwres_context_freemem(cm->lwctx, client->sendbuf,
                      client->sendlength);
    client->sendbuf = NULL;
    client->sendlength = 0;

    ns_lwdclient_stateidle(client);

    isc_event_free(&ev);
}

void
ns_lwdclient_initialize(ns_lwdclient_t *client, ns_lwdclientmgr_t *cmgr) {
    client->clientmgr = cmgr;
    ISC_LINK_INIT(client, link);
    NS_LWDCLIENT_SETIDLE(client);
    client->arg = NULL;

    client->recvlength = 0;

    client->sendbuf = NULL;
    client->sendlength = 0;

    client->find = NULL;
    client->v4find = NULL;
    client->v6find = NULL;
    client->find_wanted = 0;

    client->options = 0;
    client->byaddr = NULL;
    client->addrinfo = NULL;

    ISC_LIST_APPEND(cmgr->idle, client, link);
}