bin/named/interfacemgr.c

	interfacemgr.c revision a55d0a9080c8ef4117d2fc27f63220a56afb2434
/*
 * Copyright (C) 1999  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.
 */

#include <config.h>

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>

#include <isc/assertions.h>
#include <isc/error.h>
#include <isc/mem.h>
#include <isc/result.h>
#include <isc/socket.h>
#include <isc/types.h>
#include <isc/net.h>
#include <isc/interfaceiter.h>
#include <isc/util.h>

#include <dns/dispatch.h>

#include <named/client.h>
#include <named/globals.h>
#include <named/listenlist.h>
#include <named/log.h>
#include <named/interfacemgr.h>

#define IFMGR_MAGIC     0x49464D47U /* IFMG. */
#define NS_INTERFACEMGR_VALID(t) ((t) != NULL && (t)->magic == IFMGR_MAGIC)

struct ns_interfacemgr {
    unsigned int        magic;      /* Magic number. */
    int         references;
    isc_mutex_t     lock;
    isc_mem_t *     mctx;       /* Memory context. */
    isc_taskmgr_t *     taskmgr;    /* Task manager. */
    isc_socketmgr_t *   socketmgr;  /* Socket manager. */
    ns_clientmgr_t *    clientmgr;  /* Client manager. */
    unsigned int        generation; /* Current generation no. */
    ns_listenlist_t *   listenon;
    ISC_LIST(ns_interface_t) interfaces;    /* List of interfaces. */
};

static void purge_old_interfaces(ns_interfacemgr_t *mgr);

isc_result_t
ns_interfacemgr_create(isc_mem_t *mctx, isc_taskmgr_t *taskmgr,
               isc_socketmgr_t *socketmgr, ns_clientmgr_t *clientmgr,
               ns_interfacemgr_t **mgrp)
{
    isc_result_t result;
    ns_interfacemgr_t *mgr;

    REQUIRE(mctx != NULL);
    REQUIRE(mgrp != NULL);
    REQUIRE(*mgrp == NULL);

    mgr = isc_mem_get(mctx, sizeof(*mgr));
    if (mgr == NULL)
        return (DNS_R_NOMEMORY);

    result = isc_mutex_init(&mgr->lock);
    if (result != ISC_R_SUCCESS)
        goto cleanup;

    mgr->mctx = mctx;
    mgr->taskmgr = taskmgr;
    mgr->socketmgr = socketmgr;
    mgr->clientmgr = clientmgr;
    mgr->generation = 1;
    mgr->listenon = NULL;
    ISC_LIST_INIT(mgr->interfaces);

    result = ns_listenlist_default(mctx, ns_g_port,
                       &mgr->listenon);
    if (result != DNS_R_SUCCESS)
        goto cleanup;

    mgr->references = 1;
    mgr->magic = IFMGR_MAGIC;
    *mgrp = mgr;
    return (DNS_R_SUCCESS);

 cleanup:
    isc_mem_put(mctx, mgr, sizeof(*mgr));
    return (result);
}

static void
ns_interfacemgr_destroy(ns_interfacemgr_t *mgr)
{
    REQUIRE(NS_INTERFACEMGR_VALID(mgr));
    ns_listenlist_detach(&mgr->listenon);
    isc_mutex_destroy(&mgr->lock);
    mgr->magic = 0;
    isc_mem_put(mgr->mctx, mgr, sizeof *mgr);
}

void
ns_interfacemgr_attach(ns_interfacemgr_t *source,
               ns_interfacemgr_t **target)
{
    REQUIRE(NS_INTERFACEMGR_VALID(source));
    LOCK(&source->lock);
    INSIST(source->references > 0);
    source->references++;
    UNLOCK(&source->lock);
    *target = source;
}

void
ns_interfacemgr_detach(ns_interfacemgr_t **targetp)
{
    isc_result_t need_destroy = ISC_FALSE;
    ns_interfacemgr_t *target = *targetp;
    REQUIRE(target != NULL);
    REQUIRE(NS_INTERFACEMGR_VALID(target));
    LOCK(&target->lock);
    REQUIRE(target->references > 0);
    target->references--;
    if (target->references == 0)
        need_destroy = ISC_TRUE;
    UNLOCK(&target->lock);
    if (need_destroy)
        ns_interfacemgr_destroy(target);
    *targetp = NULL;
}

void
ns_interfacemgr_shutdown(ns_interfacemgr_t *mgr)
{
    REQUIRE(NS_INTERFACEMGR_VALID(mgr));

    LOCK(&mgr->lock);
    /*
     * Shut down and detach all interfaces.
     * By incrementing the generation count, we make purge_old_interfaces()
     * consider all interfaces "old".
     */
    mgr->generation++;
    purge_old_interfaces(mgr);
    INSIST(ISC_LIST_EMPTY(mgr->interfaces));
    UNLOCK(&mgr->lock);
}


static isc_result_t
ns_interface_create(ns_interfacemgr_t *mgr, isc_sockaddr_t *addr,
            ns_interface_t **ifpret)
{
        ns_interface_t *ifp;
    isc_result_t result;

    REQUIRE(NS_INTERFACEMGR_VALID(mgr));
    ifp = isc_mem_get(mgr->mctx, sizeof(*ifp));
    if (ifp == NULL)
        return (DNS_R_NOMEMORY);
    ifp->mgr = NULL;
    ifp->generation = mgr->generation;
    ifp->addr = *addr;

    result = isc_mutex_init(&ifp->lock);
    if (result != ISC_R_SUCCESS)
        goto lock_create_failure;

    /*
     * Create a task.
     */
    ifp->task = NULL;
    result = isc_task_create(mgr->taskmgr, mgr->mctx, 0, &ifp->task);
    if (result != ISC_R_SUCCESS) {
        UNEXPECTED_ERROR(__FILE__, __LINE__,
                 "isc_task_create() failed: %s",
                 isc_result_totext(result));
        goto task_create_failure;
    }

    ifp->udpsocket = NULL;
    ifp->udpdispatch = NULL;

    ifp->tcpsocket = NULL;
    ifp->ntcptarget = ns_g_cpus;
    ifp->ntcpcurrent = 0;

    ns_interfacemgr_attach(mgr, &ifp->mgr);
    ISC_LIST_APPEND(mgr->interfaces, ifp, link);

    ifp->references = 1;
    ifp->magic = IFACE_MAGIC;
    *ifpret = ifp;

    return (DNS_R_SUCCESS);


    isc_task_detach(&ifp->task);
 task_create_failure:
    isc_mutex_destroy(&ifp->lock);
 lock_create_failure:
    ifp->magic = 0;
    isc_mem_put(mgr->mctx, ifp, sizeof(*ifp));

    return (DNS_R_UNEXPECTED);
}

static isc_result_t
ns_interface_listenudp(ns_interface_t *ifp) {
    isc_result_t result;

    /*
     * Open a UDP socket.
     */
    result = isc_socket_create(ifp->mgr->socketmgr,
                   isc_sockaddr_pf(&ifp->addr),
                   isc_sockettype_udp,
                   &ifp->udpsocket);
    if (result != ISC_R_SUCCESS) {
        UNEXPECTED_ERROR(__FILE__, __LINE__,
                 "creating UDP socket: %s",
                 isc_result_totext(result));
        goto udp_socket_failure;
    }
    result = isc_socket_bind(ifp->udpsocket, &ifp->addr);
    if (result != ISC_R_SUCCESS) {
        UNEXPECTED_ERROR(__FILE__, __LINE__,
                 "binding UDP socket: %s",
                 isc_result_totext(result));
        goto udp_bind_failure;
    }
    /*
     * XXXRTH hardwired constants.  We're going to need to determine if
     * this UDP socket will be shared with the resolver, and if so, we
     * need to set the hashsize to be be something bigger than 17.
     */
    result = dns_dispatch_create(ifp->mgr->mctx, ifp->udpsocket, ifp->task,
                     4096, 50, 50, 17, 19, NULL,
                     &ifp->udpdispatch);
    if (result != ISC_R_SUCCESS) {
        UNEXPECTED_ERROR(__FILE__, __LINE__,
                 "UDP dns_dispatch_create(): %s",
                 isc_result_totext(result));
        goto udp_dispatch_failure;
    }

    result = ns_clientmgr_addtodispatch(ifp->mgr->clientmgr, ns_g_cpus, ifp);
    if (result != ISC_R_SUCCESS) {
        UNEXPECTED_ERROR(__FILE__, __LINE__,
                 "UDP ns_clientmgr_addtodispatch(): %s",
                 isc_result_totext(result));
        goto addtodispatch_failure;
    }
    return (ISC_R_SUCCESS);

 addtodispatch_failure:
    dns_dispatch_detach(&ifp->udpdispatch);
 udp_dispatch_failure:
 udp_bind_failure:
    isc_socket_detach(&ifp->udpsocket);
 udp_socket_failure:
    return (result);
}

static isc_result_t
ns_interface_accepttcp(ns_interface_t *ifp) {
    isc_result_t result;

    /*
     * Open a TCP socket.
     */
    result = isc_socket_create(ifp->mgr->socketmgr,
                   isc_sockaddr_pf(&ifp->addr),
                   isc_sockettype_tcp,
                   &ifp->tcpsocket);
    if (result != ISC_R_SUCCESS) {
        UNEXPECTED_ERROR(__FILE__, __LINE__,
                 "creating TCP socket: %s",
                 isc_result_totext(result));
        goto tcp_socket_failure;
    }
    result = isc_socket_bind(ifp->tcpsocket, &ifp->addr);
    if (result != ISC_R_SUCCESS) {
        UNEXPECTED_ERROR(__FILE__, __LINE__,
                 "binding TCP socket: %s",
                 isc_result_totext(result));
        goto tcp_bind_failure;
    }
    result = isc_socket_listen(ifp->tcpsocket, 0);
    if (result != ISC_R_SUCCESS) {
        UNEXPECTED_ERROR(__FILE__, __LINE__,
                 "listen TCP socket: %s",
                 isc_result_totext(result));
        goto tcp_listen_failure;
    }
    result = ns_clientmgr_accepttcp(ifp->mgr->clientmgr,
                    ifp->ntcptarget, ifp);
    if (result != ISC_R_SUCCESS) {
        UNEXPECTED_ERROR(__FILE__, __LINE__,
                 "TCP ns_clientmgr_accepttcp(): %s",
                 isc_result_totext(result));
        goto accepttcp_failure;
    }
    return (ISC_R_SUCCESS);

 accepttcp_failure:
 tcp_listen_failure:
 tcp_bind_failure:
    isc_socket_detach(&ifp->tcpsocket);
 tcp_socket_failure:
    return (DNS_R_SUCCESS);
}

static isc_result_t
ns_interface_setup(ns_interfacemgr_t *mgr, isc_sockaddr_t *addr,
           ns_interface_t **ifpret)
{
    isc_result_t result;
    ns_interface_t *ifp = NULL;
    REQUIRE(ifpret != NULL && *ifpret == NULL);

    result = ns_interface_create(mgr, addr, &ifp);
    if (result != DNS_R_SUCCESS)
        return (result);

    result = ns_interface_listenudp(ifp);
    if (result != DNS_R_SUCCESS)
        goto cleanup_interface;

    result = ns_interface_accepttcp(ifp);
    if (result != DNS_R_SUCCESS) {
        /*
         * XXXRTH  We don't currently have a way to easily stop dispatch
         * service, so we return currently return DNS_R_SUCCESS (the UDP
         * stuff will work even if TCP creation failed).  This will be fixed
         * later.
         */
        result = ISC_R_SUCCESS;
    }
    *ifpret = ifp;
    return (ISC_R_SUCCESS);

 cleanup_interface:
    ISC_LIST_UNLINK(ifp->mgr->interfaces, ifp, link);
    ns_interface_detach(&ifp);
    return (result);
}

static void
ns_interface_destroy(ns_interface_t *ifp) {
    isc_mem_t *mctx = ifp->mgr->mctx;
    REQUIRE(NS_INTERFACE_VALID(ifp));

    if (ifp->udpdispatch != NULL)
        dns_dispatch_detach(&ifp->udpdispatch);
    if (ifp->udpsocket != NULL) {
        isc_socket_cancel(ifp->udpsocket, NULL, ISC_SOCKCANCEL_ALL);
        isc_socket_detach(&ifp->udpsocket);
    }
    if (ifp->tcpsocket != NULL) {
        isc_socket_cancel(ifp->tcpsocket, NULL, ISC_SOCKCANCEL_ALL);
        isc_socket_detach(&ifp->tcpsocket);
    }

    isc_task_detach(&ifp->task);
    isc_mutex_destroy(&ifp->lock);

    ns_interfacemgr_detach(&ifp->mgr);

    ifp->magic = 0;
    isc_mem_put(mctx, ifp, sizeof(*ifp));
}

void
ns_interface_attach(ns_interface_t *source,
            ns_interface_t **target)
{
    REQUIRE(NS_INTERFACE_VALID(source));
    LOCK(&source->lock);
    INSIST(source->references > 0);
    source->references++;
    UNLOCK(&source->lock);
    *target = source;
}

void
ns_interface_detach(ns_interface_t **targetp)
{
    isc_result_t need_destroy = ISC_FALSE;
    ns_interface_t *target = *targetp;
    REQUIRE(target != NULL);
    REQUIRE(NS_INTERFACE_VALID(target));
    LOCK(&target->lock);
    REQUIRE(target->references > 0);
    target->references--;
    if (target->references == 0)
        need_destroy = ISC_TRUE;
    UNLOCK(&target->lock);
    if (need_destroy)
        ns_interface_destroy(target);
    *targetp = NULL;
}

/*
 * Search the interface list for an interface whose address and port
 * both match those of 'addr'.  Return a pointer to it, or NULL if not found.
 */
static ns_interface_t *
find_matching_interface(ns_interfacemgr_t *mgr, isc_sockaddr_t *addr) {
        ns_interface_t *ifp;
        for (ifp = ISC_LIST_HEAD(mgr->interfaces); ifp != NULL;
         ifp = ISC_LIST_NEXT(ifp, link)) {
        if (isc_sockaddr_equal(&ifp->addr, addr))
            break;
    }
        return (ifp);
}

/*
 * Remove any interfaces whose generation number is not the current one.
 */
static void
purge_old_interfaces(ns_interfacemgr_t *mgr) {
        ns_interface_t *ifp, *next;
        for (ifp = ISC_LIST_HEAD(mgr->interfaces); ifp != NULL; ifp = next) {
        INSIST(NS_INTERFACE_VALID(ifp));
        next = ISC_LIST_NEXT(ifp, link);
        if (ifp->generation != mgr->generation) {
            ISC_LIST_UNLINK(ifp->mgr->interfaces, ifp, link);
            ns_interface_detach(&ifp);
        }
    }
}

static void
do_ipv4(ns_interfacemgr_t *mgr) {
    isc_interfaceiter_t *iter = NULL;
    isc_result_t result;

    result = isc_interfaceiter_create(mgr->mctx, &iter);
    if (result != ISC_R_SUCCESS)
        return;

    result = isc_interfaceiter_first(iter);
    while (result == ISC_R_SUCCESS) {
        ns_interface_t *ifp;
        isc_interface_t interface;
        ns_listenelt_t *le;

        /*
         * XXX insert code to match against named.conf
         * "listen-on" statements here.  Also build list of
         * local addresses and local networks.
         */

        result = isc_interfaceiter_current(iter, &interface);
        if (result != ISC_R_SUCCESS)
            break;

        for (le = ISC_LIST_HEAD(mgr->listenon->elts);
             le != NULL;
             le = ISC_LIST_NEXT(le, link))
        {
            int match;
            isc_sockaddr_t listen_addr;
            char buf[128];
            const char *addrstr;

            /*
             * Construct a socket address for this IP/port
             * combination.
             */
            isc_sockaddr_fromin(&listen_addr,
                        &interface.address.type.in,
                        le->port);

            /*
             * Construct a human-readable version of same.
             */
            addrstr = inet_ntop(listen_addr.type.sin.sin_family,
                        &listen_addr.type.sin.sin_addr,
                        buf, sizeof(buf));
            if (addrstr == NULL)
                addrstr = "(bad address)";

            /*
             * See if the address matches the listen-on statement;
             * if not, ignore the interface.
             */
            result = dns_acl_match(&listen_addr, NULL,
                           le->acl, &match, NULL);
            if (match <= 0)
                continue;

            ifp = find_matching_interface(mgr, &listen_addr);
            if (ifp != NULL) {
                ifp->generation = mgr->generation;
            } else {
                isc_log_write(ns_g_lctx, NS_LOGCATEGORY_NETWORK,
                          NS_LOGMODULE_INTERFACEMGR,
                          ISC_LOG_INFO,
                          "listening on IPv4 interface %s, %s port %u",
                          interface.name, addrstr,
                          ntohs(listen_addr.type.sin.sin_port));

                result = ns_interface_setup(mgr, &listen_addr, &ifp);
                if (result != DNS_R_SUCCESS) {
                    UNEXPECTED_ERROR(__FILE__, __LINE__,
                             "creating IPv4 interface %s "
                             "failed; interface ignored",
                             interface.name);
                }
                /* Continue. */
            }

        }
        result = isc_interfaceiter_next(iter);
    }
    if (result != ISC_R_NOMORE)
        UNEXPECTED_ERROR(__FILE__, __LINE__,
                 "IPv4: interface iteration failed: %s",
                 isc_result_totext(result));

    isc_interfaceiter_destroy(&iter);
}

static void
do_ipv6(ns_interfacemgr_t *mgr) {
    isc_result_t result;
    ns_interface_t *ifp;
    isc_sockaddr_t listen_addr;
    struct in6_addr in6a;

    in6a = in6addr_any;
    isc_sockaddr_fromin6(&listen_addr, &in6a, ns_g_port);

    ifp = find_matching_interface(mgr, &listen_addr);
    if (ifp != NULL) {
        ifp->generation = mgr->generation;
    } else {
        isc_log_write(ns_g_lctx, NS_LOGCATEGORY_NETWORK,
                  NS_LOGMODULE_INTERFACEMGR, ISC_LOG_INFO,
                  "listening on IPv6 interfaces, port %u",
                  ns_g_port);
        result = ns_interface_setup(mgr, &listen_addr, &ifp);
        if (result != DNS_R_SUCCESS) {
            UNEXPECTED_ERROR(__FILE__, __LINE__,
                 "listening on IPv6 interfaces failed");
            /* Continue. */
        }
    }
}

void
ns_interfacemgr_scan(ns_interfacemgr_t *mgr) {

    REQUIRE(NS_INTERFACEMGR_VALID(mgr));

    mgr->generation++;  /* Increment the generation count. */

    if (isc_net_probeipv6() == ISC_R_SUCCESS) {
        do_ipv6(mgr);
    } else
        isc_log_write(ns_g_lctx, NS_LOGCATEGORY_NETWORK,
                  NS_LOGMODULE_INTERFACEMGR, ISC_LOG_INFO,
                  "no IPv6 interfaces found");
    if (isc_net_probeipv4() == ISC_R_SUCCESS)
        do_ipv4(mgr);
    else
        isc_log_write(ns_g_lctx, NS_LOGCATEGORY_NETWORK,
                  NS_LOGMODULE_INTERFACEMGR, ISC_LOG_INFO,
                  "no IPv4 interfaces found");

        /*
         * Now go through the interface list and delete anything that
         * does not have the current generation number.  This is
         * how we catch interfaces that go away or change their
         * addresses.
     */
    purge_old_interfaces(mgr);

    if (ISC_LIST_EMPTY(mgr->interfaces)) {
        isc_log_write(ns_g_lctx, NS_LOGCATEGORY_NETWORK,
                  NS_LOGMODULE_INTERFACEMGR, ISC_LOG_WARNING,
                  "not listening on any interfaces");
        /*
         * Continue anyway.
         */
    }
}

void
ns_interfacemgr_setlistenon(ns_interfacemgr_t *mgr,
                ns_listenlist_t *value)
{
    LOCK(&mgr->lock);
    ns_listenlist_detach(&mgr->listenon);
    ns_listenlist_attach(value, &mgr->listenon);
    UNLOCK(&mgr->lock);
}