aboutsummaryrefslogtreecommitdiff
path: root/shard/lib/app/identity.ex
blob: 42d1bf8cd53954730fe5198b43ffa12ee43df604 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
defmodule SApp.Identity do
  @moduledoc"""
  Shard application for keeping state associated with a user's identity.

  Current functionality:

  - nickname
  - peer info: ip, port to connect to if we want a secure connection with this person
    (used for private chat)

  Future functionnality:

  - friend list
  - notifications & invites
  """

  use GenServer

  require Logger

  defmodule Manifest do
    @moduledoc"""
    Manifest for a user identity shard, defined by the public key of the user.
    """

    defstruct [:pk]
  end

  defimpl Shard.Manifest, for: Manifest do
    def start(m) do
      DynamicSupervisor.start_child(Shard.DynamicSupervisor, {SApp.Identity, m.pk})
    end
  end

  defmodule State do
    defstruct [:info, :rev, :signed]
  end

  def start_link(pk) do
    GenServer.start_link(__MODULE__, pk)
  end

  def init(pk) do
    manifest = %Manifest{pk: pk}
    id = SData.term_hash manifest

    case Shard.Manager.register(id, manifest, self()) do
      :ok ->
        Shard.Manager.dispatch_to(id, nil, self())
        state = case Shard.Manager.load_state(id) do
          nil ->
            info = %{nick: default_nick(pk)}
            SData.SignRev.new info
          st ->
            st
        end
        netgroup = %SNet.PubShardGroup{id: id}
        SNet.Group.init_lookup(netgroup, self())
        if Shard.Keys.have_sk? pk do
          GenServer.cast(self(), :update_peer_info)
        end
        {:ok, %{pk: pk, id: id, state: state, netgroup: netgroup}}
      :redundant ->
        exit(:redundant)
    end
  end

  def handle_call(:manifest, _from, state) do
    {:reply, state.manifest, state}
  end

  def handle_call(:get_info, _from, state) do
    {:reply, SData.SignRev.get(state.state), state}
  end

  def handle_call({:set_info, new_info}, _from, state) do
    if Shard.Keys.have_sk?(state.pk) do
      {:ok, st2} = SData.SignRev.set(state.state, new_info, state.pk)
      Shard.Manager.save_state(state.id, st2)
      state = put_in(state.state, st2)
      bcast_state(state)
      {:reply, :ok, state}
    else
      {:reply, :impossible, state}
    end
  end

  def handle_cast({:peer_connected, peer_pid}, state) do
    GenServer.cast(peer_pid, {:send_msg, {:interested, [state.id]}})
    {:noreply, state}
  end

  def handle_cast({:interested, peer_pid, _auth}, state) do
    SNet.Manager.send_pid(peer_pid, {state.id, nil, {:update, SData.SignRev.signed(state.state), true}})
    {:noreply, state}
  end

  def handle_cast({:msg, conn_pid, _auth, _shard_id, nil, msg}, state) do
    state = case msg do
      {:update, signed, ask_reply} when signed != nil ->
        state = case SData.SignRev.merge(state.state, signed, state.pk) do
          {true, st2} ->
            Shard.Manager.save_state(state.id, st2)
            state = put_in(state.state, st2)
            bcast_state(state, [conn_pid])
            state
          {false, _} ->
            state
        end
        if ask_reply do
          SNet.Manager.send_pid(conn_pid, {state.id, nil, {:update, SData.SignRev.signed(state.state), false}})
        end
        state
      _ -> state
    end
    {:noreply, state}
  end

  def handle_cast(:update_peer_info, state) do
    peer_info = SNet.Addr.get_all_inet4()
                |> Enum.map(&({:inet, &1, Application.get_env(:shard, :port)}))

    prev_info = SData.SignRev.get(state.state)
    # TODO multi peer info
    new_info = Map.put(prev_info, :peer_info, peer_info)
    {:ok, st2} = SData.SignRev.set(state.state, new_info, state.pk)

    Shard.Manager.save_state(state.id, st2)
    state = put_in(state.state, st2)
    bcast_state(state)
    {:noreply, state}
  end

  defp bcast_state(state, exclude \\ []) do
    msg = {state.id, nil, {:update, SData.SignRev.signed(state.state), false}}
    SNet.Group.broadcast(state.netgroup, msg, exclude_pid: exclude)
  end

  # ================
  # PUBLIC INTERFACE
  # ================

  @doc"""
  Return the default nickname associated to a pk,
  in the form "Anonxxxxxxxx" with some bytes of the pk in hex.
  """
  def default_nick(pk) do
    nick_suffix = Shard.Keys.pk_display pk
    "Anon" <> nick_suffix
  end

  @doc"""
  Find the shard process for an identity. Launches such a process
  if necessary.
  """
  def find_proc(pk) do
    Shard.Manager.find_or_start %Manifest{pk: pk}
  end

  @doc"""
  Get the info dict of an identity shard. The pid of the shard must be given as an argument.
  """
  def get_info(pid) do
    GenServer.call(pid, :get_info)
  end

  @doc"""
  Set the info dict of an identity shard.
  """
  def set_info(pid, new_info) do
    GenServer.call(pid, {:set_info, new_info})
  end

  @doc"""
  Get a user's nickname from his pk
  """
  def get_nick(pk) do
    get_info(find_proc pk).nick
  end
end