/*
 * virnetserverservice.c: generic network RPC server service
 *
 * Copyright (C) 2006-2012, 2014 Red Hat, Inc.
 * Copyright (C) 2006 Daniel P. Berrange
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library.  If not, see
 * <http://www.gnu.org/licenses/>.
 *
 * Author: Daniel P. Berrange <berrange@redhat.com>
 */

#include <config.h>

#include "virnetserverservice.h"

#include <unistd.h>

#include "viralloc.h"
#include "virerror.h"
#include "virthread.h"

#define VIR_FROM_THIS VIR_FROM_RPC

struct _virNetServerService {
    virObject parent;

    size_t nsocks;
    virNetSocketPtr *socks;

    int auth;
    bool readonly;
    size_t nrequests_client_max;

#if WITH_GNUTLS
    virNetTLSContextPtr tls;
#endif

    virNetServerServiceDispatchFunc dispatchFunc;
    void *dispatchOpaque;
};


static virClassPtr virNetServerServiceClass;
static void virNetServerServiceDispose(void *obj);

static int virNetServerServiceOnceInit(void)
{
    if (!VIR_CLASS_NEW(virNetServerService, virClassForObject()))
        return -1;

    return 0;
}

VIR_ONCE_GLOBAL_INIT(virNetServerService)


static void virNetServerServiceAccept(virNetSocketPtr sock,
                                      int events ATTRIBUTE_UNUSED,
                                      void *opaque)
{
    virNetServerServicePtr svc = opaque;
    virNetSocketPtr clientsock = NULL;

    if (virNetSocketAccept(sock, &clientsock) < 0)
        goto cleanup;

    if (!clientsock) /* Connection already went away */
        goto cleanup;

    if (!svc->dispatchFunc)
        goto cleanup;

    svc->dispatchFunc(svc, clientsock, svc->dispatchOpaque);

 cleanup:
    virObjectUnref(clientsock);
}


virNetServerServicePtr
virNetServerServiceNewFDOrUNIX(const char *path,
                               mode_t mask,
                               gid_t grp,
                               int auth,
#if WITH_GNUTLS
                               virNetTLSContextPtr tls,
#endif
                               bool readonly,
                               size_t max_queued_clients,
                               size_t nrequests_client_max,
                               unsigned int nfds,
                               unsigned int *cur_fd)
{
    if (*cur_fd - STDERR_FILENO > nfds) {
        /*
         * There are no more file descriptors to use, so we have to
         * fallback to UNIX socket.
         */
        return virNetServerServiceNewUNIX(path,
                                          mask,
                                          grp,
                                          auth,
#if WITH_GNUTLS
                                          tls,
#endif
                                          readonly,
                                          max_queued_clients,
                                          nrequests_client_max);

    } else {
        /*
         * There's still enough file descriptors.  In this case we'll
         * use the current one and increment it afterwards. Take care
         * with order of operation for pointer arithmetic and auto
         * increment on cur_fd - the parentheses are necessary.
         */
        return virNetServerServiceNewFD((*cur_fd)++,
                                        auth,
#if WITH_GNUTLS
                                        tls,
#endif
                                        readonly,
                                        max_queued_clients,
                                        nrequests_client_max);
    }
}


virNetServerServicePtr virNetServerServiceNewTCP(const char *nodename,
                                                 const char *service,
                                                 int family,
                                                 int auth,
#if WITH_GNUTLS
                                                 virNetTLSContextPtr tls,
#endif
                                                 bool readonly,
                                                 size_t max_queued_clients,
                                                 size_t nrequests_client_max)
{
    virNetServerServicePtr svc;
    size_t i;

    if (virNetServerServiceInitialize() < 0)
        return NULL;

    if (!(svc = virObjectNew(virNetServerServiceClass)))
        return NULL;

    svc->auth = auth;
    svc->readonly = readonly;
    svc->nrequests_client_max = nrequests_client_max;
#if WITH_GNUTLS
    svc->tls = virObjectRef(tls);
#endif

    if (virNetSocketNewListenTCP(nodename,
                                 service,
                                 family,
                                 &svc->socks,
                                 &svc->nsocks) < 0)
        goto error;

    for (i = 0; i < svc->nsocks; i++) {
        if (virNetSocketListen(svc->socks[i], max_queued_clients) < 0)
            goto error;

        /* IO callback is initially disabled, until we're ready
         * to deal with incoming clients */
        virObjectRef(svc);
        if (virNetSocketAddIOCallback(svc->socks[i],
                                      0,
                                      virNetServerServiceAccept,
                                      svc,
                                      virObjectFreeCallback) < 0) {
            virObjectUnref(svc);
            goto error;
        }
    }


    return svc;

 error:
    virObjectUnref(svc);
    return NULL;
}


virNetServerServicePtr virNetServerServiceNewUNIX(const char *path,
                                                  mode_t mask,
                                                  gid_t grp,
                                                  int auth,
#if WITH_GNUTLS
                                                  virNetTLSContextPtr tls,
#endif
                                                  bool readonly,
                                                  size_t max_queued_clients,
                                                  size_t nrequests_client_max)
{
    virNetServerServicePtr svc;
    size_t i;

    if (virNetServerServiceInitialize() < 0)
        return NULL;

    if (!(svc = virObjectNew(virNetServerServiceClass)))
        return NULL;

    svc->auth = auth;
    svc->readonly = readonly;
    svc->nrequests_client_max = nrequests_client_max;
#if WITH_GNUTLS
    svc->tls = virObjectRef(tls);
#endif

    if (VIR_ALLOC_N(svc->socks, 1) < 0)
        goto error;
    svc->nsocks = 1;

    if (virNetSocketNewListenUNIX(path,
                                  mask,
                                  -1,
                                  grp,
                                  &svc->socks[0]) < 0)
        goto error;

    for (i = 0; i < svc->nsocks; i++) {
        if (virNetSocketListen(svc->socks[i], max_queued_clients) < 0)
            goto error;

        /* IO callback is initially disabled, until we're ready
         * to deal with incoming clients */
        virObjectRef(svc);
        if (virNetSocketAddIOCallback(svc->socks[i],
                                      0,
                                      virNetServerServiceAccept,
                                      svc,
                                      virObjectFreeCallback) < 0) {
            virObjectUnref(svc);
            goto error;
        }
    }


    return svc;

 error:
    virObjectUnref(svc);
    return NULL;
}

virNetServerServicePtr virNetServerServiceNewFD(int fd,
                                                int auth,
#if WITH_GNUTLS
                                                virNetTLSContextPtr tls,
#endif
                                                bool readonly,
                                                size_t max_queued_clients,
                                                size_t nrequests_client_max)
{
    virNetServerServicePtr svc;
    size_t i;

    if (virNetServerServiceInitialize() < 0)
        return NULL;

    if (!(svc = virObjectNew(virNetServerServiceClass)))
        return NULL;

    svc->auth = auth;
    svc->readonly = readonly;
    svc->nrequests_client_max = nrequests_client_max;
#if WITH_GNUTLS
    svc->tls = virObjectRef(tls);
#endif

    if (VIR_ALLOC_N(svc->socks, 1) < 0)
        goto error;
    svc->nsocks = 1;

    if (virNetSocketNewListenFD(fd,
                                &svc->socks[0]) < 0)
        goto error;

    for (i = 0; i < svc->nsocks; i++) {
        if (virNetSocketListen(svc->socks[i], max_queued_clients) < 0)
            goto error;

        /* IO callback is initially disabled, until we're ready
         * to deal with incoming clients */
        virObjectRef(svc);
        if (virNetSocketAddIOCallback(svc->socks[i],
                                      0,
                                      virNetServerServiceAccept,
                                      svc,
                                      virObjectFreeCallback) < 0) {
            virObjectUnref(svc);
            goto error;
        }
    }


    return svc;

 error:
    virObjectUnref(svc);
    return NULL;
}


virNetServerServicePtr virNetServerServiceNewPostExecRestart(virJSONValuePtr object)
{
    virNetServerServicePtr svc;
    virJSONValuePtr socks;
    size_t i;
    ssize_t n;
    unsigned int max;

    if (virNetServerServiceInitialize() < 0)
        return NULL;

    if (!(svc = virObjectNew(virNetServerServiceClass)))
        return NULL;

    if (virJSONValueObjectGetNumberInt(object, "auth", &svc->auth) < 0) {
        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                       _("Missing auth field in JSON state document"));
        goto error;
    }
    if (virJSONValueObjectGetBoolean(object, "readonly", &svc->readonly) < 0) {
        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                       _("Missing readonly field in JSON state document"));
        goto error;
    }
    if (virJSONValueObjectGetNumberUint(object, "nrequests_client_max",
                                        &max) < 0) {
        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                       _("Missing nrequests_client_max field in JSON state document"));
        goto error;
    }
    svc->nrequests_client_max = max;

    if (!(socks = virJSONValueObjectGet(object, "socks"))) {
        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                       _("Missing socks field in JSON state document"));
        goto error;
    }

    if ((n = virJSONValueArraySize(socks)) < 0) {
        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                       _("socks field in JSON was not an array"));
        goto error;
    }

    if (VIR_ALLOC_N(svc->socks, n) < 0)
        goto error;
    svc->nsocks = n;

    for (i = 0; i < svc->nsocks; i++) {
        virJSONValuePtr child = virJSONValueArrayGet(socks, i);
        virNetSocketPtr sock;

        if (!(sock = virNetSocketNewPostExecRestart(child))) {
            virObjectUnref(sock);
            goto error;
        }

        svc->socks[i] = sock;

        /* IO callback is initially disabled, until we're ready
         * to deal with incoming clients */
        virObjectRef(svc);
        if (virNetSocketAddIOCallback(sock,
                                      0,
                                      virNetServerServiceAccept,
                                      svc,
                                      virObjectFreeCallback) < 0) {
            virObjectUnref(svc);
            goto error;
        }
    }

    return svc;

 error:
    virObjectUnref(svc);
    return NULL;
}


virJSONValuePtr virNetServerServicePreExecRestart(virNetServerServicePtr svc)
{
    virJSONValuePtr object = virJSONValueNewObject();
    virJSONValuePtr socks;
    size_t i;

    if (!object)
        return NULL;

    if (virJSONValueObjectAppendNumberInt(object, "auth", svc->auth) < 0)
        goto error;
    if (virJSONValueObjectAppendBoolean(object, "readonly", svc->readonly) < 0)
        goto error;
    if (virJSONValueObjectAppendNumberUint(object, "nrequests_client_max", svc->nrequests_client_max) < 0)
        goto error;

    if (!(socks = virJSONValueNewArray()))
        goto error;

    if (virJSONValueObjectAppend(object, "socks", socks) < 0) {
        virJSONValueFree(socks);
        goto error;
    }

    for (i = 0; i < svc->nsocks; i++) {
        virJSONValuePtr child;
        if (!(child = virNetSocketPreExecRestart(svc->socks[i])))
            goto error;

        if (virJSONValueArrayAppend(socks, child) < 0) {
            virJSONValueFree(child);
            goto error;
        }
    }

    return object;

 error:
    virJSONValueFree(object);
    return NULL;
}


int virNetServerServiceGetPort(virNetServerServicePtr svc)
{
    /* We're assuming if there are multiple sockets
     * for IPv4 & 6, then they are all on same port */
    return virNetSocketGetPort(svc->socks[0]);
}


int virNetServerServiceGetAuth(virNetServerServicePtr svc)
{
    return svc->auth;
}


bool virNetServerServiceIsReadonly(virNetServerServicePtr svc)
{
    return svc->readonly;
}


size_t virNetServerServiceGetMaxRequests(virNetServerServicePtr svc)
{
    return svc->nrequests_client_max;
}

#if WITH_GNUTLS
virNetTLSContextPtr virNetServerServiceGetTLSContext(virNetServerServicePtr svc)
{
    return svc->tls;
}
#endif

void virNetServerServiceSetDispatcher(virNetServerServicePtr svc,
                                      virNetServerServiceDispatchFunc func,
                                      void *opaque)
{
    svc->dispatchFunc = func;
    svc->dispatchOpaque = opaque;
}


void virNetServerServiceDispose(void *obj)
{
    virNetServerServicePtr svc = obj;
    size_t i;

    for (i = 0; i < svc->nsocks; i++)
       virObjectUnref(svc->socks[i]);
    VIR_FREE(svc->socks);

#if WITH_GNUTLS
    virObjectUnref(svc->tls);
#endif
}

void virNetServerServiceToggle(virNetServerServicePtr svc,
                               bool enabled)
{
    size_t i;

    for (i = 0; i < svc->nsocks; i++)
        virNetSocketUpdateIOCallback(svc->socks[i],
                                     enabled ?
                                     VIR_EVENT_HANDLE_READABLE :
                                     0);
}

void virNetServerServiceClose(virNetServerServicePtr svc)
{
    size_t i;

    if (!svc)
        return;

    for (i = 0; i < svc->nsocks; i++) {
        virNetSocketRemoveIOCallback(svc->socks[i]);
        virNetSocketClose(svc->socks[i]);
        virObjectUnref(svc);
    }
}
