src/lib/raop.c

   1 /**
   2  *  Copyright (C) 2011-2012  Juho Vähä-Herttua
   3  *
   4  *  This library is free software; you can redistribute it and/or
   5  *  modify it under the terms of the GNU Lesser General Public
   6  *  License as published by the Free Software Foundation; either
   7  *  version 2.1 of the License, or (at your option) any later version.
   8  *
   9  *  This library is distributed in the hope that it will be useful,
  10  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  *  Lesser General Public License for more details.
  13  */
  14
  15 #include <stdlib.h>
  16 #include <stdio.h>
  17 #include <string.h>
  18 #include <assert.h>
  19
  20 #include "raop.h"
  21 #include "raop_rtp.h"
  22 #include "rsakey.h"
  23 #include "digest.h"
  24 #include "httpd.h"
  25 #include "sdp.h"
  26
  27 #include "global.h"
  28 #include "utils.h"
  29 #include "netutils.h"
  30 #include "logger.h"
  31 #include "compat.h"
  32
  33 /* Actually 345 bytes for 2048-bit key */
  34 #define MAX_SIGNATURE_LEN 512
  35
  36 /* Let's just decide on some length */
  37 #define MAX_PASSWORD_LEN 64
  38
  39 /* MD5 as hex fits here */
  40 #define MAX_NONCE_LEN 32
  41
  42 struct raop_s {
  43         /* Callbacks for audio */
  44         raop_callbacks_t callbacks;
  45
  46         /* Logger instance */
  47         logger_t *logger;
  48
  49         /* HTTP daemon and RSA key */
  50         httpd_t *httpd;
  51         rsakey_t *rsakey;
  52
  53         /* Hardware address information */
  54         unsigned char hwaddr[MAX_HWADDR_LEN];
  55         int hwaddrlen;
  56
  57         /* Password information */
  58         char password[MAX_PASSWORD_LEN+1];
  59 };
  60
  61 struct raop_conn_s {
  62         raop_t *raop;
  63         raop_rtp_t *raop_rtp;
  64
  65         unsigned char *local;
  66         int locallen;
  67
  68         unsigned char *remote;
  69         int remotelen;
  70
  71         char nonce[MAX_NONCE_LEN+1];
  72 };
  73 typedef struct raop_conn_s raop_conn_t;
  74
  75 static void *
  76 conn_init(void *opaque, unsigned char *local, int locallen, unsigned char *remote, int remotelen)
  77 {
  78         raop_conn_t *conn;
  79
  80         conn = calloc(1, sizeof(raop_conn_t));
  81         if (!conn) {
  82                 return NULL;
  83         }
  84         conn->raop = opaque;
  85         conn->raop_rtp = NULL;
  86
  87         if (locallen == 4) {
  88                 logger_log(conn->raop->logger, LOGGER_INFO,
  89                            "Local: %d.%d.%d.%d",
  90                            local[0], local[1], local[2], local[3]);
  91         } else if (locallen == 16) {
  92                 logger_log(conn->raop->logger, LOGGER_INFO,
  93                            "Local: %02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x",
  94                            local[0], local[1], local[2], local[3], local[4], local[5], local[6], local[7],
  95                            local[8], local[9], local[10], local[11], local[12], local[13], local[14], local[15]);
  96         }
  97         if (remotelen == 4) {
  98                 logger_log(conn->raop->logger, LOGGER_INFO,
  99                            "Remote: %d.%d.%d.%d",
 100                            remote[0], remote[1], remote[2], remote[3]);
 101         } else if (remotelen == 16) {
 102                 logger_log(conn->raop->logger, LOGGER_INFO,
 103                            "Remote: %02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x",
 104                            remote[0], remote[1], remote[2], remote[3], remote[4], remote[5], remote[6], remote[7],
 105                            remote[8], remote[9], remote[10], remote[11], remote[12], remote[13], remote[14], remote[15]);
 106         }
 107
 108         conn->local = malloc(locallen);
 109         assert(conn->local);
 110         memcpy(conn->local, local, locallen);
 111
 112         conn->remote = malloc(remotelen);
 113         assert(conn->remote);
 114         memcpy(conn->remote, remote, remotelen);
 115
 116         conn->locallen = locallen;
 117         conn->remotelen = remotelen;
 118
 119         digest_generate_nonce(conn->nonce, sizeof(conn->nonce));
 120         return conn;
 121 }
 122
 123 static void
 124 conn_request(void *ptr, http_request_t *request, http_response_t **response)
 125 {
 126         raop_conn_t *conn = ptr;
 127         raop_t *raop = conn->raop;
 128
 129         http_response_t *res;
 130         const char *method;
 131         const char *cseq;
 132         const char *challenge;
 133         int require_auth = 0;
 134
 135         method = http_request_get_method(request);
 136         cseq = http_request_get_header(request, "CSeq");
 137         if (!method || !cseq) {
 138                 return;
 139         }
 140
 141         res = http_response_init("RTSP/1.0", 200, "OK");
 142         if (strlen(raop->password)) {
 143                 const char *authorization;
 144
 145                 authorization = http_request_get_header(request, "Authorization");
 146                 if (authorization) {
 147                         logger_log(conn->raop->logger, LOGGER_DEBUG, "Our nonce: %s", conn->nonce);
 148                         logger_log(conn->raop->logger, LOGGER_DEBUG, "Authorization: %s", authorization);
 149                 }
 150                 if (!digest_is_valid("AppleTV", raop->password, conn->nonce, method, http_request_get_url(request), authorization)) {
 151                         char *authstr;
 152                         int authstrlen;
 153
 154                         /* Allocate the authenticate string */
 155                         authstrlen = sizeof("Digest realm=\"AppleTV\", nonce=\"\"") + sizeof(conn->nonce) + 1;
 156                         authstr = malloc(authstrlen);
 157
 158                         /* Concatenate the authenticate string */
 159                         memset(authstr, 0, authstrlen);
 160                         strcat(authstr, "Digest realm=\"AppleTV\", nonce=\"");
 161                         strcat(authstr, conn->nonce);
 162                         strcat(authstr, "\"");
 163
 164                         /* Construct a new response */
 165                         require_auth = 1;
 166                         http_response_destroy(res);
 167                         res = http_response_init("RTSP/1.0", 401, "Unauthorized");
 168                         http_response_add_header(res, "WWW-Authenticate", authstr);
 169                         free(authstr);
 170                         logger_log(conn->raop->logger, LOGGER_DEBUG, "Authentication unsuccessful, sending Unauthorized");
 171                 } else {
 172                         logger_log(conn->raop->logger, LOGGER_DEBUG, "Authentication successful!");
 173                 }
 174         }
 175
 176         http_response_add_header(res, "CSeq", cseq);
 177         http_response_add_header(res, "Apple-Jack-Status", "connected; type=analog");
 178
 179         challenge = http_request_get_header(request, "Apple-Challenge");
 180         if (!require_auth && challenge) {
 181                 char signature[MAX_SIGNATURE_LEN];
 182
 183                 memset(signature, 0, sizeof(signature));
 184                 rsakey_sign(raop->rsakey, signature, sizeof(signature), challenge,
 185                             conn->local, conn->locallen, raop->hwaddr, raop->hwaddrlen);
 186                 http_response_add_header(res, "Apple-Response", signature);
 187
 188                 logger_log(conn->raop->logger, LOGGER_DEBUG, "Got challenge: %s", challenge);
 189                 logger_log(conn->raop->logger, LOGGER_DEBUG, "Got response: %s", signature);
 190         }
 191
 192         if (require_auth) {
 193                 /* Do nothing in case of authentication request */
 194         } else if (!strcmp(method, "OPTIONS")) {
 195                 http_response_add_header(res, "Public", "ANNOUNCE, SETUP, RECORD, PAUSE, FLUSH, TEARDOWN, OPTIONS, GET_PARAMETER, SET_PARAMETER");
 196         } else if (!strcmp(method, "ANNOUNCE")) {
 197                 const char *data;
 198                 int datalen;
 199
 200                 unsigned char aeskey[16];
 201                 unsigned char aesiv[16];
 202                 int aeskeylen, aesivlen;
 203
 204                 data = http_request_get_data(request, &datalen);
 205                 if (data) {
 206                         sdp_t *sdp;
 207                         const char *remotestr, *rtpmapstr, *fmtpstr, *aeskeystr, *aesivstr;
 208
 209                         sdp = sdp_init(data, datalen);
 210                         remotestr = sdp_get_connection(sdp);
 211                         rtpmapstr = sdp_get_rtpmap(sdp);
 212                         fmtpstr = sdp_get_fmtp(sdp);
 213                         aeskeystr = sdp_get_rsaaeskey(sdp);
 214                         aesivstr = sdp_get_aesiv(sdp);
 215
 216                         logger_log(conn->raop->logger, LOGGER_DEBUG, "connection: %s", remotestr);
 217                         logger_log(conn->raop->logger, LOGGER_DEBUG, "rtpmap: %s", rtpmapstr);
 218                         logger_log(conn->raop->logger, LOGGER_DEBUG, "fmtp: %s", fmtpstr);
 219                         logger_log(conn->raop->logger, LOGGER_DEBUG, "rsaaeskey: %s", aeskeystr);
 220                         logger_log(conn->raop->logger, LOGGER_DEBUG, "aesiv: %s", aesivstr);
 221
 222                         aeskeylen = rsakey_decrypt(raop->rsakey, aeskey, sizeof(aeskey), aeskeystr);
 223                         aesivlen = rsakey_parseiv(raop->rsakey, aesiv, sizeof(aesiv), aesivstr);
 224                         logger_log(conn->raop->logger, LOGGER_DEBUG, "aeskeylen: %d", aeskeylen);
 225                         logger_log(conn->raop->logger, LOGGER_DEBUG, "aesivlen: %d", aesivlen);
 226
 227                         if (conn->raop_rtp) {
 228                                 /* This should never happen */
 229                                 raop_rtp_destroy(conn->raop_rtp);
 230                                 conn->raop_rtp = NULL;
 231                         }
 232                         conn->raop_rtp = raop_rtp_init(raop->logger, &raop->callbacks, remotestr, rtpmapstr, fmtpstr, aeskey, aesiv);
 233                         if (!conn->raop_rtp) {
 234                                 logger_log(conn->raop->logger, LOGGER_ERR, "Error initializing the audio decoder");
 235                                 http_response_set_disconnect(res, 1);
 236                         }
 237                         sdp_destroy(sdp);
 238                 }
 239         } else if (!strcmp(method, "SETUP")) {
 240                 unsigned short remote_cport=0, remote_tport=0;
 241                 unsigned short cport=0, tport=0, dport=0;
 242                 const char *transport;
 243                 char buffer[1024];
 244                 int use_udp;
 245
 246                 transport = http_request_get_header(request, "Transport");
 247                 assert(transport);
 248
 249                 logger_log(conn->raop->logger, LOGGER_INFO, "Transport: %s", transport);
 250                 use_udp = strncmp(transport, "RTP/AVP/TCP", 11);
 251                 if (use_udp) {
 252                         char *original, *current, *tmpstr;
 253
 254                         current = original = strdup(transport);
 255                         if (original) {
 256                                 while ((tmpstr = utils_strsep(&current, ";")) != NULL) {
 257                                         unsigned short value;
 258                                         int ret;
 259
 260                                         ret = sscanf(tmpstr, "control_port=%hu", &value);
 261                                         if (ret == 1) {
 262                                                 logger_log(conn->raop->logger, LOGGER_DEBUG, "Found remote control port: %hu", value);
 263                                                 remote_cport = value;
 264                                         }
 265                                         ret = sscanf(tmpstr, "timing_port=%hu", &value);
 266                                         if (ret == 1) {
 267                                                 logger_log(conn->raop->logger, LOGGER_DEBUG, "Found remote timing port: %hu", value);
 268                                                 remote_tport = value;
 269                                         }
 270                                 }
 271                         }
 272                         free(original);
 273                 }
 274                 if (conn->raop_rtp) {
 275                         raop_rtp_start(conn->raop_rtp, use_udp, remote_cport, remote_tport, &cport, &tport, &dport);
 276                 } else {
 277                         logger_log(conn->raop->logger, LOGGER_ERR, "RAOP not initialized at SETUP, playing will fail!");
 278                         http_response_set_disconnect(res, 1);
 279                 }
 280
 281                 memset(buffer, 0, sizeof(buffer));
 282                 if (use_udp) {
 283                         snprintf(buffer, sizeof(buffer)-1,
 284                                  "RTP/AVP/UDP;unicast;mode=record;timing_port=%hu;events;control_port=%hu;server_port=%hu",
 285                                  tport, cport, dport);
 286                 } else {
 287                         snprintf(buffer, sizeof(buffer)-1,
 288                                  "RTP/AVP/TCP;unicast;interleaved=0-1;mode=record;server_port=%u",
 289                                  dport);
 290                 }
 291                 logger_log(conn->raop->logger, LOGGER_INFO, "Responding with %s", buffer);
 292                 http_response_add_header(res, "Transport", buffer);
 293                 http_response_add_header(res, "Session", "DEADBEEF");
 294         } else if (!strcmp(method, "SET_PARAMETER")) {
 295                 const char *content_type;
 296                 const char *data;
 297                 int datalen;
 298
 299                 content_type = http_request_get_header(request, "Content-Type");
 300                 data = http_request_get_data(request, &datalen);
 301                 if (!strcmp(content_type, "text/parameters")) {
 302                         char *datastr;
 303                         datastr = calloc(1, datalen+1);
 304                         if (data && datastr && conn->raop_rtp) {
 305                                 memcpy(datastr, data, datalen);
 306                                 if (!strncmp(datastr, "volume: ", 8)) {
 307                                         float vol = 0.0;
 308                                         sscanf(datastr+8, "%f", &vol);
 309                                         raop_rtp_set_volume(conn->raop_rtp, vol);
 310                                 }
 311                         } else if (!conn->raop_rtp) {
 312                                 logger_log(conn->raop->logger, LOGGER_WARNING, "RAOP not initialized at SET_PARAMETER volume");
 313                         }
 314                         free(datastr);
 315                 } else if (!strcmp(content_type, "image/jpeg")) {
 316                         logger_log(conn->raop->logger, LOGGER_INFO, "Got image data of %d bytes", datalen);
 317                         if (conn->raop_rtp) {
 318                                 raop_rtp_set_coverart(conn->raop_rtp, data, datalen);
 319                         } else {
 320                                 logger_log(conn->raop->logger, LOGGER_WARNING, "RAOP not initialized at SET_PARAMETER coverart");
 321                         }
 322                 } else if (!strcmp(content_type, "application/x-dmap-tagged")) {
 323                         logger_log(conn->raop->logger, LOGGER_INFO, "Got metadata of %d bytes", datalen);
 324                         if (conn->raop_rtp) {
 325                                 raop_rtp_set_metadata(conn->raop_rtp, data, datalen);
 326                         } else {
 327                                 logger_log(conn->raop->logger, LOGGER_WARNING, "RAOP not initialized at SET_PARAMETER metadata");
 328                         }
 329                 }
 330         } else if (!strcmp(method, "FLUSH")) {
 331                 const char *rtpinfo;
 332                 int next_seq = -1;
 333
 334                 rtpinfo = http_request_get_header(request, "RTP-Info");
 335                 if (rtpinfo) {
 336                         logger_log(conn->raop->logger, LOGGER_INFO, "Flush with RTP-Info: %s", rtpinfo);
 337                         if (!strncmp(rtpinfo, "seq=", 4)) {
 338                                 next_seq = strtol(rtpinfo+4, NULL, 10);
 339                         }
 340                 }
 341                 if (conn->raop_rtp) {
 342                         raop_rtp_flush(conn->raop_rtp, next_seq);
 343                 } else {
 344                         logger_log(conn->raop->logger, LOGGER_WARNING, "RAOP not initialized at FLUSH");
 345                 }
 346         } else if (!strcmp(method, "TEARDOWN")) {
 347                 http_response_add_header(res, "Connection", "close");
 348                 if (conn->raop_rtp) {
 349                         /* Destroy our RTP session */
 350                         raop_rtp_stop(conn->raop_rtp);
 351                         raop_rtp_destroy(conn->raop_rtp);
 352                         conn->raop_rtp = NULL;
 353                 }
 354         }
 355         http_response_finish(res, NULL, 0);
 356
 357         logger_log(conn->raop->logger, LOGGER_DEBUG, "Handled request %s with URL %s", method, http_request_get_url(request));
 358         *response = res;
 359 }
 360
 361 static void
 362 conn_destroy(void *ptr)
 363 {
 364         raop_conn_t *conn = ptr;
 365
 366         if (conn->raop_rtp) {
 367                 /* This is done in case TEARDOWN was not called */
 368                 raop_rtp_destroy(conn->raop_rtp);
 369         }
 370         free(conn->local);
 371         free(conn->remote);
 372         free(conn);
 373 }
 374
 375 raop_t *
 376 raop_init(int max_clients, raop_callbacks_t *callbacks, const char *pemkey, int *error)
 377 {
 378         raop_t *raop;
 379         httpd_t *httpd;
 380         rsakey_t *rsakey;
 381         httpd_callbacks_t httpd_cbs;
 382
 383         assert(callbacks);
 384         assert(max_clients > 0);
 385         assert(max_clients < 100);
 386         assert(pemkey);
 387
 388         /* Initialize the network */
 389         if (netutils_init() < 0) {
 390                 return NULL;
 391         }
 392
 393         /* Validate the callbacks structure */
 394         if (!callbacks->audio_init ||
 395             !callbacks->audio_process ||
 396             !callbacks->audio_destroy) {
 397                 return NULL;
 398         }
 399
 400         /* Allocate the raop_t structure */
 401         raop = calloc(1, sizeof(raop_t));
 402         if (!raop) {
 403                 return NULL;
 404         }
 405
 406         /* Initialize the logger */
 407         raop->logger = logger_init();
 408
 409         /* Set HTTP callbacks to our handlers */
 410         memset(&httpd_cbs, 0, sizeof(httpd_cbs));
 411         httpd_cbs.opaque = raop;
 412         httpd_cbs.conn_init = &conn_init;
 413         httpd_cbs.conn_request = &conn_request;
 414         httpd_cbs.conn_destroy = &conn_destroy;
 415
 416         /* Initialize the http daemon */
 417         httpd = httpd_init(raop->logger, &httpd_cbs, max_clients);
 418         if (!httpd) {
 419                 free(raop);
 420                 return NULL;
 421         }
 422
 423         /* Copy callbacks structure */
 424         memcpy(&raop->callbacks, callbacks, sizeof(raop_callbacks_t));
 425
 426         /* Initialize RSA key handler */
 427         rsakey = rsakey_init_pem(pemkey);
 428         if (!rsakey) {
 429                 free(httpd);
 430                 free(raop);
 431                 return NULL;
 432         }
 433
 434         raop->httpd = httpd;
 435         raop->rsakey = rsakey;
 436
 437         return raop;
 438 }
 439
 440 raop_t *
 441 raop_init_from_keyfile(int max_clients, raop_callbacks_t *callbacks, const char *keyfile, int *error)
 442 {
 443         raop_t *raop;
 444         char *pemstr;
 445
 446         if (utils_read_file(&pemstr, keyfile) < 0) {
 447                 return NULL;
 448         }
 449         raop = raop_init(max_clients, callbacks, pemstr, error);
 450         free(pemstr);
 451         return raop;
 452 }
 453
 454 void
 455 raop_destroy(raop_t *raop)
 456 {
 457         if (raop) {
 458                 raop_stop(raop);
 459
 460                 httpd_destroy(raop->httpd);
 461                 rsakey_destroy(raop->rsakey);
 462                 logger_destroy(raop->logger);
 463                 free(raop);
 464
 465                 /* Cleanup the network */
 466                 netutils_cleanup();
 467         }
 468 }
 469
 470 int
 471 raop_is_running(raop_t *raop)
 472 {
 473         assert(raop);
 474
 475         return httpd_is_running(raop->httpd);
 476 }
 477
 478 void
 479 raop_set_log_level(raop_t *raop, int level)
 480 {
 481         assert(raop);
 482
 483         logger_set_level(raop->logger, level);
 484 }
 485
 486 void
 487 raop_set_log_callback(raop_t *raop, raop_log_callback_t callback, void *cls)
 488 {
 489         assert(raop);
 490
 491         logger_set_callback(raop->logger, callback, cls);
 492 }
 493
 494 int
 495 raop_start(raop_t *raop, unsigned short *port, const char *hwaddr, int hwaddrlen, const char *password)
 496 {
 497         assert(raop);
 498         assert(port);
 499         assert(hwaddr);
 500
 501         /* Validate hardware address */
 502         if (hwaddrlen > MAX_HWADDR_LEN) {
 503                 return -1;
 504         }
 505
 506         memset(raop->password, 0, sizeof(raop->password));
 507         if (password) {
 508                 /* Validate password */
 509                 if (strlen(password) > MAX_PASSWORD_LEN) {
 510                         return -1;
 511                 }
 512
 513                 /* Copy password to the raop structure */
 514                 strncpy(raop->password, password, MAX_PASSWORD_LEN);
 515         }
 516
 517         /* Copy hwaddr to the raop structure */
 518         memcpy(raop->hwaddr, hwaddr, hwaddrlen);
 519         raop->hwaddrlen = hwaddrlen;
 520
 521         return httpd_start(raop->httpd, port);
 522 }
 523
 524 void
 525 raop_stop(raop_t *raop)
 526 {
 527         assert(raop);
 528
 529         httpd_stop(raop->httpd);
 530 }
 531