sd/source/ui/remotecontrol/AvahiNetworkService.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  */
   9 #include <time.h>
  10 #include <iostream>
  11 #include <limits>
  12 #include <new>
  13 #include <stdlib.h>
  14 #include <assert.h>
  15
  16 #include <avahi-client/client.h>
  17 #include <avahi-client/publish.h>
  18
  19 #include <avahi-common/alternative.h>
  20 #include <avahi-common/malloc.h>
  21 #include <avahi-common/error.h>
  22 #include <avahi-common/timeval.h>
  23 #include <avahi-common/thread-watch.h>
  24 #include <comphelper/random.hxx>
  25 #include <dbus/dbus.h>
  26
  27 #include <sal/log.hxx>
  28
  29 #include "AvahiNetworkService.hxx"
  30 #include "ZeroconfService.hxx"
  31
  32 using namespace sd;
  33
  34 static AvahiClient *client = NULL;
  35 static AvahiThreadedPoll *threaded_poll = NULL;
  36 static AvahiEntryGroup *group = NULL;
  37 static AvahiNetworkService *avahiService = NULL;
  38
  39 static bool create_services(AvahiClient *c);
  40
  41 static void entry_group_callback(AvahiEntryGroup *g, AvahiEntryGroupState state, AVAHI_GCC_UNUSED void *userdata) {
  42     assert(g == group || group == NULL);
  43     group = g;
  44
  45     /* Called whenever the entry group state changes */
  46
  47     switch (state) {
  48         case AVAHI_ENTRY_GROUP_ESTABLISHED :
  49             /* The entry group has been established successfully */
  50             SAL_INFO( "sdremote.wifi", "Service '" << avahiService->getName() << "' successfully established." );
  51             break;
  52
  53         case AVAHI_ENTRY_GROUP_COLLISION : {
  54             char *n;
  55
  56             /* A service name collision with a remote service
  57              * happened. Let's pick a new name */
  58             n = avahi_alternative_service_name(avahiService->getName().c_str());
  59             avahiService->setName(n);
  60
  61             SAL_INFO( "sdremote.wifi", "Service name collision, renaming service to '" << avahiService->getName() << "'");
  62
  63             /* And recreate the services */
  64             create_services(avahi_entry_group_get_client(g));
  65             break;
  66         }
  67
  68         case AVAHI_ENTRY_GROUP_FAILURE :
  69
  70             SAL_WARN("sdremote.wifi", "Entry group failure: " << avahi_strerror(avahi_client_errno(avahi_entry_group_get_client(g))));
  71
  72             /* Some kind of failure happened while we were registering our services */
  73             avahi_threaded_poll_quit(threaded_poll);
  74             break;
  75
  76         case AVAHI_ENTRY_GROUP_UNCOMMITED:
  77         case AVAHI_ENTRY_GROUP_REGISTERING:
  78             ;
  79     }
  80 }
  81
  82 static bool create_services(AvahiClient *c) {
  83     assert(c);
  84
  85     /* If this is the first time we're called, let's create a new
  86      * entry group if necessary */
  87     if(!client)
  88         return false;
  89
  90     if (!group)
  91         if (!(group = avahi_entry_group_new(c, entry_group_callback, NULL))) {
  92             SAL_WARN("sdremote.wifi", "avahi_entry_group_new() failed: " << avahi_strerror(avahi_client_errno(c)));
  93             avahiService->clear();
  94             return false;
  95         }
  96
  97     /* If the group is empty (either because it was just created, or
  98      * because it was reset previously, add our entries.  */
  99
 100     if (avahi_entry_group_is_empty(group)) {
 101         SAL_INFO("sdremote.wifi", "Adding service '" << avahiService->getName() << "'");
 102         char r[128];
 103         int nRandom = comphelper::rng::uniform_int_distribution(0, std::numeric_limits<int>::max());
 104         snprintf(r, sizeof(r), "random=%i", nRandom);
 105         int ret = avahi_entry_group_add_service(
 106             group, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, static_cast<AvahiPublishFlags>(0),
 107             avahiService->getName().c_str(), kREG_TYPE, NULL, NULL, 1599, "local", r, NULL
 108         );
 109         if (ret < 0) {
 110
 111             if (ret == AVAHI_ERR_COLLISION){
 112                 /* A service name collision with a local service happened. Let's
 113                  * pick a new name */
 114                 char *n = avahi_alternative_service_name(avahiService->getName().c_str());
 115                 avahiService->setName(n);
 116
 117                 SAL_WARN("sdremote.wifi", "Service name collision, renaming service to '" << avahiService->getName() << "'");
 118
 119                 avahi_entry_group_reset(group);
 120
 121                 return create_services(c);
 122             }
 123
 124             SAL_WARN("sdremote.wifi", "Failed to add _impressremote._tcp service: " << avahi_strerror(ret));
 125             avahiService->clear();
 126             return false;
 127         }
 128
 129         /* Tell the server to register the service */
 130         if ((ret = avahi_entry_group_commit(group)) < 0) {
 131             SAL_WARN("sdremote.wifi", "Failed to commit entry group: " << avahi_strerror(ret));
 132             avahiService->clear();
 133             return false;
 134         }
 135     }
 136
 137     return true; //Services we're already created
 138 }
 139
 140 static void client_callback(AvahiClient *c, AvahiClientState state, AVAHI_GCC_UNUSED void * userdata) {
 141     assert(c);
 142
 143     /* Called whenever the client or server state changes */
 144
 145     switch (state) {
 146         case AVAHI_CLIENT_S_RUNNING:
 147             create_services(c);
 148             break;
 149         case AVAHI_CLIENT_FAILURE:
 150             SAL_WARN("sdremote.wifi", "Client failure: " << avahi_strerror(avahi_client_errno(c)));
 151             avahiService->clear();
 152             break;
 153         case AVAHI_CLIENT_S_COLLISION:
 154         case AVAHI_CLIENT_S_REGISTERING:
 155             if (group)
 156                 avahi_entry_group_reset(group);
 157             break;
 158         case AVAHI_CLIENT_CONNECTING:
 159             ;
 160     }
 161 }
 162
 163 void AvahiNetworkService::setup() {
 164     // Avahi internally uses D-Bus, which requires the following in order to be
 165     // thread-safe (and we potentially access D-Bus from different threads in
 166     // different places of the code base):
 167     if (!dbus_threads_init_default()) {
 168         throw std::bad_alloc();
 169     }
 170
 171    int error = 0;
 172    avahiService = this;
 173    if (!(threaded_poll = avahi_threaded_poll_new())) {
 174        SAL_WARN("sdremote.wifi", "avahi_threaded_poll_new '" << avahiService->getName() << "' failed");
 175        return;
 176    }
 177
 178    if (!(client = avahi_client_new(avahi_threaded_poll_get(threaded_poll), static_cast<AvahiClientFlags>(0), client_callback, NULL, &error))) {
 179        SAL_WARN("sdremote.wifi", "avahi_client_new failed");
 180        return;
 181    }
 182
 183    if(!create_services(client))
 184         return;
 185
 186    /* Finally, start the event loop thread */
 187    if (avahi_threaded_poll_start(threaded_poll) < 0) {
 188        SAL_WARN("sdremote.wifi", "avahi_threaded_poll_start failed");
 189        return;
 190    }
 191 }
 192
 193 void AvahiNetworkService::clear() {
 194     /* Call this when the app shuts down */
 195         if(threaded_poll)
 196             avahi_threaded_poll_stop(threaded_poll);
 197         if(client)
 198             avahi_client_free(client);
 199         if(threaded_poll)
 200             avahi_threaded_poll_free(threaded_poll);
 201 }