aboutsummaryrefslogtreecommitdiff
path: root/src/adbd-client.cpp
blob: 47914cb7c52bf3afbc4d03f464271ae01107e63d (plain)
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
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
/*
 * Copyright 2016 Canonical Ltd.
 *
 * This program is free software: you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 3, as published
 * by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranties of
 * MERCHANTABILITY, SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR
 * PURPOSE.  See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Authors:
 *   Charles Kerr <charles.kerr@canonical.com>
 */

#include <src/adbd-client.h>

#include <gio/gio.h>
#include <gio/gunixsocketaddress.h>

#include <algorithm>
#include <atomic>
#include <cctype>
#include <cstring>
#include <chrono>
#include <condition_variable>
#include <mutex>
#include <thread>

class GAdbdClient::Impl
{
public:

    explicit Impl(const std::string& socket_path):
        m_socket_path{socket_path},
        m_cancellable{g_cancellable_new()},
        m_worker_thread{&Impl::worker_func, this}
    {
    }

    ~Impl()
    {
        // tell the worker thread to stop whatever it's doing and exit.
        g_debug("%s Client::Impl dtor, cancelling m_cancellable", G_STRLOC);
        g_cancellable_cancel(m_cancellable);
        m_pkresponse_cv.notify_one();
        m_sleep_cv.notify_one();
        if (m_worker_thread.joinable()) {
            m_worker_thread.join();
        }
        g_clear_object(&m_cancellable);
    }

    core::Signal<const PKRequest&>& on_pk_request()
    {
        return m_on_pk_request;
    }

private:

    // struct to carry request info from the worker thread to the GMainContext thread
    struct PKIdleData
    {
        Impl* self = nullptr;
        GCancellable* cancellable = nullptr;
        const std::string public_key;

        PKIdleData(Impl* self_, GCancellable* cancellable_, const std::string& public_key_):
            self(self_),
            cancellable(G_CANCELLABLE(g_object_ref(cancellable_))),
            public_key(public_key_) {}

        ~PKIdleData() {g_clear_object(&cancellable);}
        
    };

    void pass_public_key_to_main_thread(const std::string& public_key)
    {
        g_idle_add_full(G_PRIORITY_DEFAULT_IDLE,
                        on_public_key_request_static,
                        new PKIdleData{this, m_cancellable, public_key},
                        [](gpointer id){delete static_cast<PKIdleData*>(id);});
    }

    static gboolean on_public_key_request_static (gpointer gdata) // runs in main thread
    {
        /* NB: It's possible (though unlikely) that data.self was destroyed
           while this callback was pending, so we must check is-cancelled FIRST */
        auto data = static_cast<PKIdleData*>(gdata);
        if (!g_cancellable_is_cancelled(data->cancellable))
        {
            // notify our listeners of the request
            auto self = data->self;
            struct PKRequest req;
            req.public_key = data->public_key;
            req.fingerprint = get_fingerprint(req.public_key);
            req.respond = [self](PKResponse response){self->on_public_key_response(response);};
            self->m_on_pk_request(req);
        }

        return G_SOURCE_REMOVE;
    }

    void on_public_key_response(PKResponse response)
    {
        g_debug("%s thread %p got response %d", G_STRLOC, g_thread_self(), int(response));

        // set m_pkresponse and wake up the waiting worker thread
        m_pkresponse = response;
        m_pkresponse_ready = true;
        m_pkresponse_cv.notify_one();
    }

    /***
    ****
    ***/

    void worker_func() // runs in worker thread
    {
        const std::string socket_path {m_socket_path};

        while (!g_cancellable_is_cancelled(m_cancellable))
        {
            g_debug("%s thread %p creating a client socket to '%s'", G_STRLOC, g_thread_self(), socket_path.c_str());
            auto socket = create_client_socket(socket_path);
            bool got_valid_req = false;

            g_debug("%s thread %p calling read_request", g_thread_self(), G_STRLOC);
            std::string reqstr;
            if (socket != nullptr)
                reqstr = read_request(socket);
            if (!reqstr.empty())
                g_debug("%s got request [%s]", G_STRLOC, reqstr.c_str());

            if (reqstr.substr(0,2) == "PK") {
                PKResponse response = PKResponse::DENY;
                const auto public_key = reqstr.substr(2);
                g_debug("%s thread %p got pk [%s]", G_STRLOC, g_thread_self(), public_key.c_str());
                if (!public_key.empty()) {
                    got_valid_req = true;
                    std::unique_lock<std::mutex> lk(m_pkresponse_mutex);
                    m_pkresponse_ready = false;
                    m_pkresponse = AdbdClient::PKResponse::DENY;
                    pass_public_key_to_main_thread(public_key);
                    m_pkresponse_cv.wait(lk, [this](){
                        return m_pkresponse_ready || g_cancellable_is_cancelled(m_cancellable);
                    });
                    response = m_pkresponse;
                    g_debug("%s thread %p got response '%d', is-cancelled %d", G_STRLOC,
                            g_thread_self(),
                            int(response),
                            int(g_cancellable_is_cancelled(m_cancellable)));
                }
                if (!g_cancellable_is_cancelled(m_cancellable)) {
                    send_pk_response(socket, response);
                }
            } else if (!reqstr.empty()) {
                g_warning("Invalid ADB request: [%s]", reqstr.c_str());
            }

            g_clear_object(&socket);

            // If nothing interesting's happening, sleep a bit.
            // (Interval copied from UsbDebuggingManager.java)
            static constexpr std::chrono::seconds sleep_interval {std::chrono::seconds(1)};
            if (!got_valid_req && !g_cancellable_is_cancelled(m_cancellable)) {
                std::unique_lock<std::mutex> lk(m_sleep_mutex);
                m_sleep_cv.wait_for(lk, sleep_interval);
            }
        }
    }

    // connect to a local domain socket
    GSocket* create_client_socket(const std::string& socket_path)
    {
        GError* error {};
        auto socket = g_socket_new(G_SOCKET_FAMILY_UNIX,
                                   G_SOCKET_TYPE_STREAM,
                                   G_SOCKET_PROTOCOL_DEFAULT,
                                   &error);
        if (error != nullptr) {
            g_warning("Error creating adbd client socket: %s", error->message);
            g_clear_error(&error);
            g_clear_object(&socket);
            return nullptr;
        }

        auto address = g_unix_socket_address_new(socket_path.c_str());
        const auto connected = g_socket_connect(socket, address, m_cancellable, &error);
        g_clear_object(&address);
        if (!connected) {
            g_debug("unable to connect to '%s': %s", socket_path.c_str(), error->message);
            g_clear_error(&error);
            g_clear_object(&socket);
            return nullptr;
        }

        return socket;
    }

    std::string read_request(GSocket* socket)
    {
        char buf[4096] = {};
        g_debug("%s calling g_socket_receive()", G_STRLOC);
        const auto n_bytes = g_socket_receive (socket, buf, sizeof(buf), m_cancellable, nullptr);
        std::string ret;
        if (n_bytes > 0)
            ret.append(buf, std::string::size_type(n_bytes));
        g_debug("%s g_socket_receive got %d bytes: [%s]", G_STRLOC, int(n_bytes), ret.c_str());
        return ret;
    }

    void send_pk_response(GSocket* socket, PKResponse response)
    {
        std::string response_str;
        switch(response) {
            case PKResponse::ALLOW: response_str = "OK"; break;
            case PKResponse::DENY:  response_str = "NO"; break;
        }
        g_debug("%s sending reply: [%s]", G_STRLOC, response_str.c_str());

        GError* error {};
        g_socket_send(socket,
                      response_str.c_str(),
                      response_str.size(),
                      m_cancellable,
                      &error);
        if (error != nullptr) {
            if (!g_error_matches(error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
                g_warning("GAdbdServer: Error accepting socket connection: %s", error->message);
            g_clear_error(&error);
        }
    }

    static std::string get_fingerprint(const std::string& public_key)
    {
        // The first token is base64-encoded data, so cut on the first whitespace
        const std::string base64 (
            public_key.begin(),
            std::find_if(
                public_key.begin(), public_key.end(),
                [](const std::string::value_type& ch){return std::isspace(ch);}
            )
        );

        gsize digest_len {};
        auto digest = g_base64_decode(base64.c_str(), &digest_len);

        auto checksum = g_compute_checksum_for_data(G_CHECKSUM_MD5, digest, digest_len);
        const gsize checksum_len = checksum ? strlen(checksum) : 0;

        // insert ':' between character pairs; eg "ff27b5f3" --> "ff:27:b5:f3"
        std::string fingerprint;
        for (gsize i=0; i<checksum_len; ) {
            fingerprint.append(checksum+i, checksum+i+2);
            if (i < checksum_len-2)
                fingerprint.append(":");
            i += 2;
        }

        g_clear_pointer(&digest, g_free);
        g_clear_pointer(&checksum, g_free);
        return fingerprint;
    }

    const std::string m_socket_path;
    GCancellable* m_cancellable = nullptr;
    std::thread m_worker_thread;
    core::Signal<const PKRequest&> m_on_pk_request;

    std::mutex m_sleep_mutex;
    std::condition_variable m_sleep_cv;

    std::mutex m_pkresponse_mutex;
    std::condition_variable m_pkresponse_cv;
    std::atomic<bool> m_pkresponse_ready {false};
    PKResponse m_pkresponse = PKResponse::DENY;
};

/***
****
***/

AdbdClient::~AdbdClient()
{
}

/***
****
***/

GAdbdClient::GAdbdClient(const std::string& socket_path):
    impl{new Impl{socket_path}}
{
}

GAdbdClient::~GAdbdClient()
{
}

core::Signal<const AdbdClient::PKRequest&>&
GAdbdClient::on_pk_request()
{
    return impl->on_pk_request();
}