1 // Copyright 2015 The Weave Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "examples/provider/avahi_client.h"
6
7 #include <cstdlib>
8 #include <vector>
9
10 #include <avahi-common/error.h>
11
12 namespace weave {
13 namespace examples {
14
15 namespace {
16
GroupCallback(AvahiEntryGroup * g,AvahiEntryGroupState state,AVAHI_GCC_UNUSED void * userdata)17 void GroupCallback(AvahiEntryGroup* g,
18 AvahiEntryGroupState state,
19 AVAHI_GCC_UNUSED void* userdata) {
20 CHECK_NE(state, AVAHI_ENTRY_GROUP_COLLISION);
21 CHECK_NE(state, AVAHI_ENTRY_GROUP_FAILURE);
22 }
23
GetId()24 std::string GetId() {
25 return "WEAVE" + std::to_string(gethostid());
26 }
27
28 } // namespace
29
AvahiClient()30 AvahiClient::AvahiClient() {
31 thread_pool_.reset(avahi_threaded_poll_new());
32 CHECK(thread_pool_);
33
34 LOG(INFO) << "connecting to avahi-daemon";
35 int ret = 0;
36 client_.reset(avahi_client_new(avahi_threaded_poll_get(thread_pool_.get()),
37 {}, nullptr, this, &ret));
38 CHECK(client_) << "failed to connect to avahi-daemon: "
39 << avahi_strerror(ret);
40
41 avahi_threaded_poll_start(thread_pool_.get());
42
43 group_.reset(avahi_entry_group_new(client_.get(), GroupCallback, nullptr));
44 CHECK(group_) << avahi_strerror(avahi_client_errno(client_.get()))
45 << ". Check avahi-daemon configuration";
46 }
47
~AvahiClient()48 AvahiClient::~AvahiClient() {
49 if (thread_pool_)
50 avahi_threaded_poll_stop(thread_pool_.get());
51 }
52
PublishService(const std::string & service_type,uint16_t port,const std::vector<std::string> & txt)53 void AvahiClient::PublishService(const std::string& service_type,
54 uint16_t port,
55 const std::vector<std::string>& txt) {
56 LOG(INFO) << "Publishing service";
57 CHECK(group_);
58
59 // Create txt record.
60 std::unique_ptr<AvahiStringList, decltype(&avahi_string_list_free)> txt_list{
61 nullptr, &avahi_string_list_free};
62 if (!txt.empty()) {
63 std::vector<const char*> txt_vector_ptr;
64 for (const auto& i : txt)
65 txt_vector_ptr.push_back(i.c_str());
66 txt_list.reset(avahi_string_list_new_from_array(txt_vector_ptr.data(),
67 txt_vector_ptr.size()));
68 CHECK(txt_list);
69 }
70
71 int ret = 0;
72 if (prev_port_ == port && prev_type_ == service_type) {
73 ret = avahi_entry_group_update_service_txt_strlst(
74 group_.get(), AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, {}, GetId().c_str(),
75 service_type.c_str(), nullptr, txt_list.get());
76 CHECK_GE(ret, 0) << avahi_strerror(ret);
77 } else {
78 prev_port_ = port;
79 prev_type_ = service_type;
80
81 avahi_entry_group_reset(group_.get());
82 CHECK(avahi_entry_group_is_empty(group_.get()));
83
84 ret = avahi_entry_group_add_service_strlst(
85 group_.get(), AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, {}, GetId().c_str(),
86 service_type.c_str(), nullptr, nullptr, port, txt_list.get());
87 CHECK_GE(ret, 0) << avahi_strerror(ret);
88 ret = avahi_entry_group_commit(group_.get());
89 CHECK_GE(ret, 0) << avahi_strerror(ret);
90 }
91 }
92
StopPublishing(const std::string & service_name)93 void AvahiClient::StopPublishing(const std::string& service_name) {
94 CHECK(group_);
95 avahi_entry_group_reset(group_.get());
96 }
97
98 } // namespace examples
99 } // namespace weave
100