lib/irs/context.c

	context.c revision b454c0319685041db3f3e8fd7671e1b364fd20c5
/*
 * Copyright (C) 2009  Internet Systems Consortium, Inc. ("ISC")
 *
 * 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 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: context.c,v 1.3 2009/09/02 23:48:02 tbox Exp $ */

#include <config.h>

#include <isc/app.h>
#include <isc/lib.h>
#include <isc/magic.h>
#include <isc/mem.h>
#include <isc/once.h>
#include <isc/socket.h>
#include <isc/task.h>
#include <isc/thread.h>
#include <isc/timer.h>
#include <isc/util.h>

#include <dns/client.h>
#include <dns/lib.h>

#include <irs/context.h>
#include <irs/dnsconf.h>
#include <irs/resconf.h>

#define IRS_CONTEXT_MAGIC       ISC_MAGIC('I', 'R', 'S', 'c')
#define IRS_CONTEXT_VALID(c)        ISC_MAGIC_VALID(c, IRS_CONTEXT_MAGIC)

#ifndef RESOLV_CONF
/*% location of resolve.conf */
#define RESOLV_CONF "/etc/resolv.conf"
#endif

#ifndef DNS_CONF
/*% location of dns.conf */
#define DNS_CONF "/etc/dns.conf"
#endif

#ifndef ISC_PLATFORM_USETHREADS
irs_context_t *irs_g_context = NULL;
#else
static isc_boolean_t thread_key_initialized = ISC_FALSE;
static isc_mutex_t thread_key_mutex;
static isc_thread_key_t irs_context_key;
static isc_once_t once = ISC_ONCE_INIT;
#endif


struct irs_context {
    /*
     * An IRS context is a thread-specific object, and does not need to
     * be locked.
     */
    unsigned int            magic;
    isc_mem_t           *mctx;
    isc_appctx_t            *actx;
    isc_taskmgr_t           *taskmgr;
    isc_task_t          *task;
    isc_socketmgr_t         *socketmgr;
    isc_timermgr_t          *timermgr;
    dns_client_t            *dnsclient;
    irs_resconf_t           *resconf;
    irs_dnsconf_t           *dnsconf;
};

static void
ctxs_destroy(isc_mem_t **mctxp, isc_appctx_t **actxp,
         isc_taskmgr_t **taskmgrp, isc_socketmgr_t **socketmgrp,
         isc_timermgr_t **timermgrp)
{
    if (taskmgrp != NULL)
        isc_taskmgr_destroy(taskmgrp);

    if (timermgrp != NULL)
        isc_timermgr_destroy(timermgrp);

    if (socketmgrp != NULL)
        isc_socketmgr_destroy(socketmgrp);

    if (actxp != NULL)
        isc_appctx_destroy(actxp);

    if (mctxp != NULL)
        isc_mem_destroy(mctxp);
}

static isc_result_t
ctxs_init(isc_mem_t **mctxp, isc_appctx_t **actxp,
      isc_taskmgr_t **taskmgrp, isc_socketmgr_t **socketmgrp,
      isc_timermgr_t **timermgrp)
{
    isc_result_t result;

    result = isc_mem_create(0, 0, mctxp);
    if (result != ISC_R_SUCCESS)
        goto fail;

    result = isc_appctx_create(*mctxp, actxp);
    if (result != ISC_R_SUCCESS)
        goto fail;

    result = isc_taskmgr_createinctx(*mctxp, *actxp, 1, 0, taskmgrp);
    if (result != ISC_R_SUCCESS)
        goto fail;

    result = isc_socketmgr_createinctx(*mctxp, *actxp, socketmgrp);
    if (result != ISC_R_SUCCESS)
        goto fail;

    result = isc_timermgr_createinctx(*mctxp, *actxp, timermgrp);
    if (result != ISC_R_SUCCESS)
        goto fail;

    return (ISC_R_SUCCESS);

 fail:
    ctxs_destroy(mctxp, actxp, taskmgrp, socketmgrp, timermgrp);

    return (result);
}

#ifdef ISC_PLATFORM_USETHREADS
static void
free_specific_context(void *arg) {
    irs_context_t *context = arg;

    irs_context_destroy(&context);

    isc_thread_key_setspecific(irs_context_key, NULL);
}

static void
thread_key_mutex_init(void) {
    RUNTIME_CHECK(isc_mutex_init(&thread_key_mutex) == ISC_R_SUCCESS);
}

static isc_result_t
thread_key_init(void) {
    isc_result_t result;

    result = isc_once_do(&once, thread_key_mutex_init);
    if (result != ISC_R_SUCCESS)
        return (result);

    if (!thread_key_initialized) {
        LOCK(&thread_key_mutex);

        if (!thread_key_initialized &&
            isc_thread_key_create(&irs_context_key,
                      free_specific_context) != 0) {
            result = ISC_R_FAILURE;
        } else
            thread_key_initialized = ISC_TRUE;

        UNLOCK(&thread_key_mutex);
    }

    return (result);
}
#endif /* ISC_PLATFORM_USETHREADS */

isc_result_t
irs_context_get(irs_context_t **contextp) {
    irs_context_t *context;
    isc_result_t result;

    REQUIRE(contextp != NULL && *contextp == NULL);

#ifndef ISC_PLATFORM_USETHREADS
    if (irs_g_context == NULL) {
        result = irs_context_create(&irs_g_context);
        if (result != ISC_R_SUCCESS)
            return (result);
    }

    context = irs_g_context;
#else
    result = thread_key_init();
    if (result != ISC_R_SUCCESS)
        return (result);

    context = isc_thread_key_getspecific(irs_context_key);
    if (context == NULL) {
        result = irs_context_create(&context);
        if (result != ISC_R_SUCCESS)
            return (result);
        result = isc_thread_key_setspecific(irs_context_key, context);
        if (result != ISC_R_SUCCESS) {
            irs_context_destroy(&context);
            return (result);
        }
    }
#endif /* ISC_PLATFORM_USETHREADS */

    *contextp = context;

    return (ISC_R_SUCCESS);
}

isc_result_t
irs_context_create(irs_context_t **contextp) {
    isc_result_t result;
    irs_context_t *context;
    isc_appctx_t *actx = NULL;
    isc_mem_t *mctx = NULL;
    isc_taskmgr_t *taskmgr = NULL;
    isc_socketmgr_t *socketmgr = NULL;
    isc_timermgr_t *timermgr = NULL;
    dns_client_t *client = NULL;
    isc_sockaddrlist_t *nameservers;
    irs_dnsconf_dnskeylist_t *trustedkeys;
    irs_dnsconf_dnskey_t *trustedkey;

    isc_lib_register();
    result = dns_lib_init();
    if (result != ISC_R_SUCCESS)
        return (result);

    result = ctxs_init(&mctx, &actx, &taskmgr, &socketmgr, &timermgr);
    if (result != ISC_R_SUCCESS)
        return (result);

    result = isc_app_ctxstart(actx);
    if (result != ISC_R_SUCCESS) {
        ctxs_destroy(&mctx, &actx, &taskmgr, &socketmgr, &timermgr);
        return (result);
    }

    context = isc_mem_get(mctx, sizeof(*context));
    if (context == NULL) {
        ctxs_destroy(&mctx, &actx, &taskmgr, &socketmgr, &timermgr);
        return (ISC_R_NOMEMORY);
    }

    context->mctx = mctx;
    context->actx = actx;
    context->taskmgr = taskmgr;
    context->socketmgr = socketmgr;
    context->timermgr = timermgr;
    context->resconf = NULL;
    context->dnsconf = NULL;
    context->task = NULL;
    result = isc_task_create(taskmgr, 0, &context->task);
    if (result != ISC_R_SUCCESS)
        goto fail;

    /* Create a DNS client object */
    result = dns_client_createx(mctx, actx, taskmgr, socketmgr, timermgr,
                    0, &client);
    if (result != ISC_R_SUCCESS)
        goto fail;
    context->dnsclient = client;

    /* Read resolver configuration file */
    result = irs_resconf_load(mctx, RESOLV_CONF, &context->resconf);
    if (result != ISC_R_SUCCESS)
        goto fail;
    /* Set nameservers */
    nameservers = irs_resconf_getnameservers(context->resconf);
    result = dns_client_setservers(client, dns_rdataclass_in, NULL,
                       nameservers);
    if (result != ISC_R_SUCCESS)
        goto fail;

    /* Read advanced DNS configuration (if any) */
    result = irs_dnsconf_load(mctx, DNS_CONF, &context->dnsconf);
    if (result != ISC_R_SUCCESS)
        goto fail;
    trustedkeys = irs_dnsconf_gettrustedkeys(context->dnsconf);
    for (trustedkey = ISC_LIST_HEAD(*trustedkeys);
         trustedkey != NULL;
         trustedkey = ISC_LIST_NEXT(trustedkey, link)) {
        result = dns_client_addtrustedkey(client, dns_rdataclass_in,
                          trustedkey->keyname,
                          trustedkey->keydatabuf);
        if (result != ISC_R_SUCCESS)
            goto fail;
    }

    context->magic = IRS_CONTEXT_MAGIC;
    *contextp = context;

    return (ISC_R_SUCCESS);

  fail:
    if (context->task != NULL)
        isc_task_detach(&context->task);
    if (context->resconf != NULL)
        irs_resconf_destroy(&context->resconf);
    if (context->dnsconf != NULL)
        irs_dnsconf_destroy(&context->dnsconf);
    if (client != NULL)
        dns_client_destroy(&client);
    ctxs_destroy(NULL, &actx, &taskmgr, &socketmgr, &timermgr);
    isc_mem_putanddetach(&mctx, context, sizeof(*context));

    return (result);
}

void
irs_context_destroy(irs_context_t **contextp) {
    irs_context_t *context;

    REQUIRE(contextp != NULL);
    context = *contextp;
    REQUIRE(IRS_CONTEXT_VALID(context));

    isc_task_detach(&context->task);
    irs_dnsconf_destroy(&context->dnsconf);
    irs_resconf_destroy(&context->resconf);
    dns_client_destroy(&context->dnsclient);

    ctxs_destroy(NULL, &context->actx, &context->taskmgr,
             &context->socketmgr, &context->timermgr);

    context->magic = 0;

    isc_mem_putanddetach(&context->mctx, context, sizeof(*context));

    *contextp = NULL;

#ifndef ISC_PLATFORM_USETHREADS
    irs_g_context = NULL;
#else
    (void)isc_thread_key_setspecific(irs_context_key, NULL);
#endif
}

isc_mem_t *
irs_context_getmctx(irs_context_t *context) {
    REQUIRE(IRS_CONTEXT_VALID(context));

    return (context->mctx);
}

isc_appctx_t *
irs_context_getappctx(irs_context_t *context) {
    REQUIRE(IRS_CONTEXT_VALID(context));

    return (context->actx);
}

isc_taskmgr_t *
irs_context_gettaskmgr(irs_context_t *context) {
    REQUIRE(IRS_CONTEXT_VALID(context));

    return (context->taskmgr);
}

isc_timermgr_t *
irs_context_gettimermgr(irs_context_t *context) {
    REQUIRE(IRS_CONTEXT_VALID(context));

    return (context->timermgr);
}

isc_task_t *
irs_context_gettask(irs_context_t *context) {
    REQUIRE(IRS_CONTEXT_VALID(context));

    return (context->task);
}

dns_client_t *
irs_context_getdnsclient(irs_context_t *context) {
    REQUIRE(IRS_CONTEXT_VALID(context));

    return (context->dnsclient);
}

irs_resconf_t *
irs_context_getresconf(irs_context_t *context) {
    REQUIRE(IRS_CONTEXT_VALID(context));

    return (context->resconf);
}

irs_dnsconf_t *
irs_context_getdnsconf(irs_context_t *context) {
    REQUIRE(IRS_CONTEXT_VALID(context));

    return (context->dnsconf);
}