libreoffice/sd/source/ui/remotecontrol/AvahiNetworkService.cxx

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <time.h>
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>

#include <avahi-client/client.h>
#include <avahi-client/publish.h>

#include <avahi-common/alternative.h>
#include <avahi-common/malloc.h>
#include <avahi-common/error.h>
#include <avahi-common/timeval.h>
#include <avahi-common/thread-watch.h>

#include "AvahiNetworkService.hxx"

static AvahiClient *client = NULL;
static AvahiThreadedPoll *threaded_poll = NULL;
static AvahiEntryGroup *group = NULL;
static char *name = NULL;

static void create_services(AvahiClient *c);
static void client_callback(AvahiClient *c, AvahiClientState state, AVAHI_GCC_UNUSED void * userdata);

static void entry_group_callback(AvahiEntryGroup *g, AvahiEntryGroupState state, AVAHI_GCC_UNUSED void *userdata) {
    assert(g == group || group == NULL);
    group = g;

    /* Called whenever the entry group state changes */

    switch (state) {
        case AVAHI_ENTRY_GROUP_ESTABLISHED :
            /* The entry group has been established successfully */
            fprintf(stderr, "Service '%s' successfully established.\n", name);
            break;

        case AVAHI_ENTRY_GROUP_COLLISION : {
            char *n;

            /* A service name collision with a remote service
             * happened. Let's pick a new name */
            n = avahi_alternative_service_name(name);
            avahi_free(name);
            name = n;

            fprintf(stderr, "Service name collision, renaming service to '%s'\n", name);

            /* And recreate the services */
            create_services(avahi_entry_group_get_client(g));
            break;
        }

        case AVAHI_ENTRY_GROUP_FAILURE :

            fprintf(stderr, "Entry group failure: %s\n", avahi_strerror(avahi_client_errno(avahi_entry_group_get_client(g))));

            /* Some kind of failure happened while we were registering our services */
            avahi_threaded_poll_quit(threaded_poll);
            break;

        case AVAHI_ENTRY_GROUP_UNCOMMITED:
        case AVAHI_ENTRY_GROUP_REGISTERING:
            ;
    }
}

static void create_services(AvahiClient *c) {
    char *n, r[128];
    int ret;
    assert(c);

    /* If this is the first time we're called, let's create a new
     * entry group if necessary */

    if (!group)
        if (!(group = avahi_entry_group_new(c, entry_group_callback, NULL))) {
            fprintf(stderr, "avahi_entry_group_new() failed: %s\n", avahi_strerror(avahi_client_errno(c)));
            goto fail;
        }

    /* If the group is empty (either because it was just created, or
     * because it was reset previously, add our entries.  */

    if (avahi_entry_group_is_empty(group)) {
        fprintf(stderr, "Adding service '%s'\n", name);

        /* Create some random TXT data */
        snprintf(r, sizeof(r), "random=%i", rand());

        /* We will now add two services and one subtype to the entry
         * group. The two services have the same name, but differ in
         * the service type (IPP vs. BSD LPR). Only services with the
         * same name should be put in the same entry group. */

        /* Add the service for IPP */
        if ((ret = avahi_entry_group_add_service(group, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, static_cast<AvahiPublishFlags>(0), name, "_impressremote._libreoffice._tcp", NULL, NULL, 1599, "local", r, NULL)) < 0) {

            if (ret == AVAHI_ERR_COLLISION)
                goto collision;

            fprintf(stderr, "Failed to add _impressremote._libreoffice._tcp service: %s\n", avahi_strerror(ret));
            goto fail;
        }

        /* Tell the server to register the service */
        if ((ret = avahi_entry_group_commit(group)) < 0) {
            fprintf(stderr, "Failed to commit entry group: %s\n", avahi_strerror(ret));
            goto fail;
        }
    }

    return;

collision:

    /* A service name collision with a local service happened. Let's
     * pick a new name */
    n = avahi_alternative_service_name(name);
    avahi_free(name);
    name = n;

    fprintf(stderr, "Service name collision, renaming service to '%s'\n", name);

    avahi_entry_group_reset(group);

    create_services(c);
    return;

fail:
    avahi_shutdown();
}

static void client_callback(AvahiClient *c, AvahiClientState state, AVAHI_GCC_UNUSED void * userdata) {
    assert(c);

    /* Called whenever the client or server state changes */

    switch (state) {
        case AVAHI_CLIENT_S_RUNNING:

            /* The server has startup successfully and registered its host
             * name on the network, so it's time to create our services */
            create_services(c);
            break;

        case AVAHI_CLIENT_FAILURE:

            fprintf(stderr, "Client failure: %s\n", avahi_strerror(avahi_client_errno(c)));
            avahi_shutdown();

            break;

        case AVAHI_CLIENT_S_COLLISION:

            /* Let's drop our registered services. When the server is back
             * in AVAHI_SERVER_RUNNING state we will register them
             * again with the new host name. */

        case AVAHI_CLIENT_S_REGISTERING:

            /* The server records are now being established. This
             * might be caused by a host name change. We need to wait
             * for our own records to register until the host name is
             * properly esatblished. */

            if (group)
                avahi_entry_group_reset(group);

            break;

        case AVAHI_CLIENT_CONNECTING:
            ;
    }
}




void avahi_setup(const char * sname) {
   /* Call this when the application starts up. */
   int error = 0;
   name = avahi_strdup( sname );
   if (!(threaded_poll = avahi_threaded_poll_new())) {
     fprintf(stderr, "avahi_threaded_poll_new '%s' failed.\n", name);
     return;
   }

   if (!(client = avahi_client_new(avahi_threaded_poll_get(threaded_poll), static_cast<AvahiClientFlags>(0), client_callback, NULL, &error))) {
     fprintf(stderr, "avahi_client_new failed.\n");
     return;
   }

   create_services(client);

   /* Finally, start the event loop thread */
   if (avahi_threaded_poll_start(threaded_poll) < 0) {
     fprintf(stderr, "avahi_threaded_poll_start failed.\n");
     return;
   }

   fprintf(stderr, "setup done.\n");
}

void avahi_shutdown(void) {
  /* Call this when the app shuts down */

  avahi_threaded_poll_stop(threaded_poll);
  avahi_client_free(client);
  avahi_threaded_poll_free(threaded_poll);
}