summaryrefslogtreecommitdiffstats
path: root/src/modules/raop/raop_client.c
blob: 68ddabea903da4c642d9466202cb82bb041dc329 (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
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
/***
  This file is part of PulseAudio.

  Copyright 2008 Colin Guthrie

  PulseAudio is free software; you can redistribute it and/or modify
  it under the terms of the GNU Lesser General Public License as published
  by the Free Software Foundation; either version 2.1 of the License,
  or (at your option) any later version.

  PulseAudio is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with PulseAudio; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  USA.
***/

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

#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <sys/ioctl.h>

#ifdef HAVE_SYS_FILIO_H
#include <sys/filio.h>
#endif

/* TODO: Replace OpenSSL with NSS */
#include <openssl/err.h>
#include <openssl/rand.h>
#include <openssl/aes.h>
#include <openssl/rsa.h>
#include <openssl/engine.h>

#include <pulse/xmalloc.h>

#include <pulsecore/core-error.h>
#include <pulsecore/core-util.h>
#include <pulsecore/socket-util.h>
#include <pulsecore/log.h>
#include <pulsecore/macro.h>
#include <pulsecore/strbuf.h>
#include <pulsecore/random.h>
#include <pulsecore/poll.h>

#include "raop_client.h"
#include "rtsp_client.h"
#include "base64.h"

#define AES_CHUNKSIZE 16

#define JACK_STATUS_DISCONNECTED 0
#define JACK_STATUS_CONNECTED 1

#define JACK_TYPE_ANALOG 0
#define JACK_TYPE_DIGITAL 1

#define VOLUME_DEF -30
#define VOLUME_MIN -144
#define VOLUME_MAX 0


struct pa_raop_client {
    pa_core *core;
    char *host;
    char *sid;
    pa_rtsp_client *rtsp;

    uint8_t jack_type;
    uint8_t jack_status;

    /* Encryption Related bits */
    AES_KEY aes;
    uint8_t aes_iv[AES_CHUNKSIZE]; /* initialization vector for aes-cbc */
    uint8_t aes_nv[AES_CHUNKSIZE]; /* next vector for aes-cbc */
    uint8_t aes_key[AES_CHUNKSIZE]; /* key for aes-cbc */

    pa_socket_client *sc;
    int fd;

    uint16_t seq;
    uint32_t rtptime;

    pa_raop_client_cb_t callback;
    void* userdata;
    pa_raop_client_closed_cb_t closed_callback;
    void* closed_userdata;
};

/**
 * Function to write bits into a buffer.
 * @param buffer Handle to the buffer. It will be incremented if new data requires it.
 * @param bit_pos A pointer to a position buffer to keep track the current write location (0 for MSB, 7 for LSB)
 * @param size A pointer to the byte size currently written. This allows the calling function to do simple buffer overflow checks
 * @param data The data to write
 * @param data_bit_len The number of bits from data to write
 */
static inline void bit_writer(uint8_t **buffer, uint8_t *bit_pos, int *size, uint8_t data, uint8_t data_bit_len) {
    int bits_left, bit_overflow;
    uint8_t bit_data;

    if (!data_bit_len)
        return;

    /* If bit pos is zero, we will definatly use at least one bit from the current byte so size increments. */
    if (!*bit_pos)
        *size += 1;

    /* Calc the number of bits left in the current byte of buffer */
    bits_left = 7 - *bit_pos  + 1;
    /* Calc the overflow of bits in relation to how much space we have left... */
    bit_overflow = bits_left - data_bit_len;
    if (bit_overflow >= 0) {
        /* We can fit the new data in our current byte */
        /* As we write from MSB->LSB we need to left shift by the overflow amount */
        bit_data = data << bit_overflow;
        if (*bit_pos)
            **buffer |= bit_data;
        else
            **buffer = bit_data;
        /* If our data fits exactly into the current byte, we need to increment our pointer */
        if (0 == bit_overflow) {
            /* Do not increment size as it will be incremeneted on next call as bit_pos is zero */
            *buffer += 1;
            *bit_pos = 0;
        } else {
            *bit_pos += data_bit_len;
        }
    } else {
        /* bit_overflow is negative, there for we will need a new byte from our buffer */
        /* Firstly fill up what's left in the current byte */
        bit_data = data >> -bit_overflow;
        **buffer |= bit_data;
        /* Increment our buffer pointer and size counter*/
        *buffer += 1;
        *size += 1;
        **buffer = data << (8 + bit_overflow);
        *bit_pos = -bit_overflow;
    }
}

static int rsa_encrypt(uint8_t *text, int len, uint8_t *res) {
    const char n[] =
        "59dE8qLieItsH1WgjrcFRKj6eUWqi+bGLOX1HL3U3GhC/j0Qg90u3sG/1CUtwC"
        "5vOYvfDmFI6oSFXi5ELabWJmT2dKHzBJKa3k9ok+8t9ucRqMd6DZHJ2YCCLlDR"
        "KSKv6kDqnw4UwPdpOMXziC/AMj3Z/lUVX1G7WSHCAWKf1zNS1eLvqr+boEjXuB"
        "OitnZ/bDzPHrTOZz0Dew0uowxf/+sG+NCK3eQJVxqcaJ/vEHKIVd2M+5qL71yJ"
        "Q+87X6oV3eaYvt3zWZYD6z5vYTcrtij2VZ9Zmni/UAaHqn9JdsBWLUEpVviYnh"
        "imNVvYFZeCXg/IdTQ+x4IRdiXNv5hEew==";
    const char e[] = "AQAB";
    uint8_t modules[256];
    uint8_t exponent[8];
    int size;
    RSA *rsa;

    rsa = RSA_new();
    size = pa_base64_decode(n, modules);
    rsa->n = BN_bin2bn(modules, size, NULL);
    size = pa_base64_decode(e, exponent);
    rsa->e = BN_bin2bn(exponent, size, NULL);

    size = RSA_public_encrypt(len, text, res, rsa, RSA_PKCS1_OAEP_PADDING);
    RSA_free(rsa);
    return size;
}

static int aes_encrypt(pa_raop_client* c, uint8_t *data, int size) {
    uint8_t *buf;
    int i=0, j;

    pa_assert(c);

    memcpy(c->aes_nv, c->aes_iv, AES_CHUNKSIZE);
    while (i+AES_CHUNKSIZE <= size) {
        buf = data + i;
        for (j=0; j<AES_CHUNKSIZE; ++j)
            buf[j] ^= c->aes_nv[j];

        AES_encrypt(buf, buf, &c->aes);
        memcpy(c->aes_nv, buf, AES_CHUNKSIZE);
        i += AES_CHUNKSIZE;
    }
    return i;
}

static inline void rtrimchar(char *str, char rc) {
    char *sp = str + strlen(str) - 1;
    while (sp >= str && *sp == rc) {
        *sp = '\0';
        sp -= 1;
    }
}

static void on_connection(pa_socket_client *sc, pa_iochannel *io, void *userdata) {
    pa_raop_client *c = userdata;

    pa_assert(sc);
    pa_assert(c);
    pa_assert(c->sc == sc);
    pa_assert(c->fd < 0);
    pa_assert(c->callback);

    pa_socket_client_unref(c->sc);
    c->sc = NULL;

    if (!io) {
        pa_log("Connection failed: %s", pa_cstrerror(errno));
        return;
    }

    c->fd = pa_iochannel_get_send_fd(io);

    pa_iochannel_set_noclose(io, TRUE);
    pa_iochannel_socket_set_sndbuf(io, 1024);
    pa_iochannel_free(io);

    pa_make_tcp_socket_low_delay(c->fd);

    pa_log_debug("Connection established");
    c->callback(c->fd, c->userdata);
}

static void rtsp_cb(pa_rtsp_client *rtsp, pa_rtsp_state state, pa_headerlist* headers, void *userdata) {
    pa_raop_client* c = userdata;
    pa_assert(c);
    pa_assert(rtsp);
    pa_assert(rtsp == c->rtsp);

    switch (state) {
        case STATE_CONNECT: {
            int i;
            uint8_t rsakey[512];
            char *key, *iv, *sac, *sdp;
            uint16_t rand_data;
            const char *ip;
            char *url;

            pa_log_debug("RAOP: CONNECTED");
            ip = pa_rtsp_localip(c->rtsp);
            /* First of all set the url properly */
            url = pa_sprintf_malloc("rtsp://%s/%s", ip, c->sid);
            pa_rtsp_set_url(c->rtsp, url);
            pa_xfree(url);

            /* Now encrypt our aes_public key to send to the device */
            i = rsa_encrypt(c->aes_key, AES_CHUNKSIZE, rsakey);
            pa_base64_encode(rsakey, i, &key);
            rtrimchar(key, '=');
            pa_base64_encode(c->aes_iv, AES_CHUNKSIZE, &iv);
            rtrimchar(iv, '=');

            pa_random(&rand_data, sizeof(rand_data));
            pa_base64_encode(&rand_data, AES_CHUNKSIZE, &sac);
            rtrimchar(sac, '=');
            pa_rtsp_add_header(c->rtsp, "Apple-Challenge", sac);
            sdp = pa_sprintf_malloc(
                "v=0\r\n"
                "o=iTunes %s 0 IN IP4 %s\r\n"
                "s=iTunes\r\n"
                "c=IN IP4 %s\r\n"
                "t=0 0\r\n"
                "m=audio 0 RTP/AVP 96\r\n"
                "a=rtpmap:96 AppleLossless\r\n"
                "a=fmtp:96 4096 0 16 40 10 14 2 255 0 0 44100\r\n"
                "a=rsaaeskey:%s\r\n"
                "a=aesiv:%s\r\n",
                c->sid, ip, c->host, key, iv);
            pa_rtsp_announce(c->rtsp, sdp);
            pa_xfree(key);
            pa_xfree(iv);
            pa_xfree(sac);
            pa_xfree(sdp);
            break;
        }

        case STATE_ANNOUNCE:
            pa_log_debug("RAOP: ANNOUNCED");
            pa_rtsp_remove_header(c->rtsp, "Apple-Challenge");
            pa_rtsp_setup(c->rtsp);
            break;

        case STATE_SETUP: {
            char *aj = pa_xstrdup(pa_headerlist_gets(headers, "Audio-Jack-Status"));
            pa_log_debug("RAOP: SETUP");
            if (aj) {
                char *token, *pc;
                char delimiters[] = ";";
                const char* token_state = NULL;
                c->jack_type = JACK_TYPE_ANALOG;
                c->jack_status = JACK_STATUS_DISCONNECTED;

                while ((token = pa_split(aj, delimiters, &token_state))) {
                    if ((pc = strstr(token, "="))) {
                      *pc = 0;
                      if (!strcmp(token, "type") && !strcmp(pc+1, "digital")) {
                          c->jack_type = JACK_TYPE_DIGITAL;
                      }
                    } else {
                        if (!strcmp(token,"connected"))
                            c->jack_status = JACK_STATUS_CONNECTED;
                    }
                    pa_xfree(token);
                }
                pa_xfree(aj);
            } else {
                pa_log_warn("Audio Jack Status missing");
            }
            pa_rtsp_record(c->rtsp, &c->seq, &c->rtptime);
            break;
        }

        case STATE_RECORD: {
            uint32_t port = pa_rtsp_serverport(c->rtsp);
            pa_log_debug("RAOP: RECORDED");

            if (!(c->sc = pa_socket_client_new_string(c->core->mainloop, TRUE, c->host, port))) {
                pa_log("failed to connect to server '%s:%d'", c->host, port);
                return;
            }
            pa_socket_client_set_callback(c->sc, on_connection, c);
            break;
        }

        case STATE_FLUSH:
            pa_log_debug("RAOP: FLUSHED");
            break;

        case STATE_TEARDOWN:
            pa_log_debug("RAOP: TEARDOWN");
            break;

        case STATE_SET_PARAMETER:
            pa_log_debug("RAOP: SET_PARAMETER");
            break;

        case STATE_DISCONNECTED:
            pa_assert(c->closed_callback);
            pa_assert(c->rtsp);

            pa_log_debug("RTSP control channel closed");
            pa_rtsp_client_free(c->rtsp);
            c->rtsp = NULL;
            if (c->fd > 0) {
                /* We do not close the fd, we leave it to the closed callback to do that */
                c->fd = -1;
            }
            if (c->sc) {
                pa_socket_client_unref(c->sc);
                c->sc = NULL;
            }
            pa_xfree(c->sid);
            c->sid = NULL;
            c->closed_callback(c->closed_userdata);
            break;
    }
}

pa_raop_client* pa_raop_client_new(pa_core *core, const char* host) {
    pa_raop_client* c = pa_xnew0(pa_raop_client, 1);

    pa_assert(core);
    pa_assert(host);

    c->core = core;
    c->fd = -1;
    c->host = pa_xstrdup(host);

    if (pa_raop_connect(c)) {
        pa_raop_client_free(c);
        return NULL;
    }
    return c;
}


void pa_raop_client_free(pa_raop_client* c) {
    pa_assert(c);

    if (c->rtsp)
        pa_rtsp_client_free(c->rtsp);
    pa_xfree(c->host);
    pa_xfree(c);
}


int pa_raop_connect(pa_raop_client* c) {
    char *sci;
    struct {
        uint32_t a;
        uint32_t b;
        uint32_t c;
    } rand_data;

    pa_assert(c);

    if (c->rtsp) {
        pa_log_debug("Connection already in progress");
        return 0;
    }

    c->rtsp = pa_rtsp_client_new(c->core->mainloop, c->host, 5000, "iTunes/4.6 (Macintosh; U; PPC Mac OS X 10.3)");

    /* Initialise the AES encryption system */
    pa_random(c->aes_iv, sizeof(c->aes_iv));
    pa_random(c->aes_key, sizeof(c->aes_key));
    memcpy(c->aes_nv, c->aes_iv, sizeof(c->aes_nv));
    AES_set_encrypt_key(c->aes_key, 128, &c->aes);

    /* Generate random instance id */
    pa_random(&rand_data, sizeof(rand_data));
    c->sid = pa_sprintf_malloc("%u", rand_data.a);
    sci = pa_sprintf_malloc("%08x%08x",rand_data.b, rand_data.c);
    pa_rtsp_add_header(c->rtsp, "Client-Instance", sci);
    pa_xfree(sci);
    pa_rtsp_set_callback(c->rtsp, rtsp_cb, c);
    return pa_rtsp_connect(c->rtsp);
}


int pa_raop_flush(pa_raop_client* c) {
    pa_assert(c);

    pa_rtsp_flush(c->rtsp, c->seq, c->rtptime);
    return 0;
}


int pa_raop_client_set_volume(pa_raop_client* c, pa_volume_t volume) {
    int rv;
    double db;
    char *param;

    pa_assert(c);

    db = pa_sw_volume_to_dB(volume);
    if (db < VOLUME_MIN)
        db = VOLUME_MIN;
    else if (db > VOLUME_MAX)
        db = VOLUME_MAX;

    param = pa_sprintf_malloc("volume: %0.6f\r\n",  db);

    /* We just hit and hope, cannot wait for the callback */
    rv = pa_rtsp_setparameter(c->rtsp, param);
    pa_xfree(param);
    return rv;
}


int pa_raop_client_encode_sample(pa_raop_client* c, pa_memchunk* raw, pa_memchunk* encoded) {
    uint16_t len;
    size_t bufmax;
    uint8_t *bp, bpos;
    uint8_t *ibp, *maxibp;
    int size;
    uint8_t *b, *p;
    uint32_t bsize;
    size_t length;
    static uint8_t header[] = {
        0x24, 0x00, 0x00, 0x00,
        0xF0, 0xFF, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00,
    };
    int header_size = sizeof(header);

    pa_assert(c);
    pa_assert(c->fd > 0);
    pa_assert(raw);
    pa_assert(raw->memblock);
    pa_assert(raw->length > 0);
    pa_assert(encoded);

    /* We have to send 4 byte chunks */
    bsize = (int)(raw->length / 4);
    length = bsize * 4;

    /* Leave 16 bytes extra to allow for the ALAC header which is about 55 bits */
    bufmax = length + header_size + 16;
    pa_memchunk_reset(encoded);
    encoded->memblock = pa_memblock_new(c->core->mempool, bufmax);
    b = pa_memblock_acquire(encoded->memblock);
    memcpy(b, header, header_size);

    /* Now write the actual samples */
    bp = b + header_size;
    size = bpos = 0;
    bit_writer(&bp,&bpos,&size,1,3); /* channel=1, stereo */
    bit_writer(&bp,&bpos,&size,0,4); /* unknown */
    bit_writer(&bp,&bpos,&size,0,8); /* unknown */
    bit_writer(&bp,&bpos,&size,0,4); /* unknown */
    bit_writer(&bp,&bpos,&size,1,1); /* hassize */
    bit_writer(&bp,&bpos,&size,0,2); /* unused */
    bit_writer(&bp,&bpos,&size,1,1); /* is-not-compressed */

    /* size of data, integer, big endian */
    bit_writer(&bp,&bpos,&size,(bsize>>24)&0xff,8);
    bit_writer(&bp,&bpos,&size,(bsize>>16)&0xff,8);
    bit_writer(&bp,&bpos,&size,(bsize>>8)&0xff,8);
    bit_writer(&bp,&bpos,&size,(bsize)&0xff,8);

    ibp = p = pa_memblock_acquire(raw->memblock);
    maxibp = p + raw->length - 4;
    while (ibp <= maxibp) {
        /* Byte swap stereo data */
        bit_writer(&bp,&bpos,&size,*(ibp+1),8);
        bit_writer(&bp,&bpos,&size,*(ibp+0),8);
        bit_writer(&bp,&bpos,&size,*(ibp+3),8);
        bit_writer(&bp,&bpos,&size,*(ibp+2),8);
        ibp += 4;
        raw->index += 4;
        raw->length -= 4;
    }
    pa_memblock_release(raw->memblock);
    encoded->length = header_size + size;

    /* store the lenght (endian swapped: make this better) */
    len = size + header_size - 4;
    *(b + 2) = len >> 8;
    *(b + 3) = len & 0xff;

    /* encrypt our data */
    aes_encrypt(c, (b + header_size), size);

    /* We're done with the chunk */
    pa_memblock_release(encoded->memblock);

    return 0;
}


void pa_raop_client_set_callback(pa_raop_client* c, pa_raop_client_cb_t callback, void *userdata) {
    pa_assert(c);

    c->callback = callback;
    c->userdata = userdata;
}

void pa_raop_client_set_closed_callback(pa_raop_client* c, pa_raop_client_closed_cb_t callback, void *userdata) {
    pa_assert(c);

    c->closed_callback = callback;
    c->closed_userdata = userdata;
}