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         const char realm[] = "airplay";
 127         raop_conn_t *conn = ptr;
 128         raop_t *raop = conn->raop;
 129
 130         http_response_t *res;
 131         const char *method;
 132         const char *cseq;
 133         const char *challenge;
 134         int require_auth = 0;
 135
 136         method = http_request_get_method(request);
 137         cseq = http_request_get_header(request, "CSeq");
 138         if (!method || !cseq) {
 139                 return;
 140         }
 141
 142         res = http_response_init("RTSP/1.0", 200, "OK");
 143
 144         /* We need authorization for everything else than OPTIONS request */
 145         if (strcmp(method, "OPTIONS") != 0 && strlen(raop->password)) {
 146                 const char *authorization;
 147
 148                 authorization = http_request_get_header(request, "Authorization");
 149                 if (authorization) {
 150                         logger_log(conn->raop->logger, LOGGER_DEBUG, "Our nonce: %s", conn->nonce);
 151                         logger_log(conn->raop->logger, LOGGER_DEBUG, "Authorization: %s", authorization);
 152                 }
 153                 if (!digest_is_valid(realm, raop->password, conn->nonce, method, http_request_get_url(request), authorization)) {
 154                         char *authstr;
 155                         int authstrlen;
 156
 157                         /* Allocate the authenticate string */
 158                         authstrlen = sizeof("Digest realm=\"\", nonce=\"\"") + sizeof(realm) + sizeof(conn->nonce) + 1;
 159                         authstr = malloc(authstrlen);
 160
 161                         /* Concatenate the authenticate string */
 162                         memset(authstr, 0, authstrlen);
 163                         strcat(authstr, "Digest realm=\"");
 164                         strcat(authstr, realm);
 165                         strcat(authstr, "\", nonce=\"");
 166                         strcat(authstr, conn->nonce);
 167                         strcat(authstr, "\"");
 168
 169                         /* Construct a new response */
 170                         require_auth = 1;
 171                         http_response_destroy(res);
 172                         res = http_response_init("RTSP/1.0", 401, "Unauthorized");
 173                         http_response_add_header(res, "WWW-Authenticate", authstr);
 174                         free(authstr);
 175                         logger_log(conn->raop->logger, LOGGER_DEBUG, "Authentication unsuccessful, sending Unauthorized");
 176                 } else {
 177                         logger_log(conn->raop->logger, LOGGER_DEBUG, "Authentication successful!");
 178                 }
 179         }
 180
 181         http_response_add_header(res, "CSeq", cseq);
 182         http_response_add_header(res, "Apple-Jack-Status", "connected; type=analog");
 183
 184         challenge = http_request_get_header(request, "Apple-Challenge");
 185         if (!require_auth && challenge) {
 186                 char signature[MAX_SIGNATURE_LEN];
 187
 188                 memset(signature, 0, sizeof(signature));
 189                 rsakey_sign(raop->rsakey, signature, sizeof(signature), challenge,
 190                             conn->local, conn->locallen, raop->hwaddr, raop->hwaddrlen);
 191                 http_response_add_header(res, "Apple-Response", signature);
 192
 193                 logger_log(conn->raop->logger, LOGGER_DEBUG, "Got challenge: %s", challenge);
 194                 logger_log(conn->raop->logger, LOGGER_DEBUG, "Got response: %s", signature);
 195         }
 196
 197         if (require_auth) {
 198                 /* Do nothing in case of authentication request */
 199         } else if (!strcmp(method, "OPTIONS")) {
 200                 http_response_add_header(res, "Public", "ANNOUNCE, SETUP, RECORD, PAUSE, FLUSH, TEARDOWN, OPTIONS, GET_PARAMETER, SET_PARAMETER");
 201         } else if (!strcmp(method, "ANNOUNCE")) {
 202                 const char *data;
 203                 int datalen;
 204
 205                 unsigned char aeskey[16];
 206                 unsigned char aesiv[16];
 207                 int aeskeylen, aesivlen;
 208
 209                 data = http_request_get_data(request, &datalen);
 210                 if (data) {
 211                         sdp_t *sdp;
 212                         const char *remotestr, *rtpmapstr, *fmtpstr, *aeskeystr, *aesivstr;
 213
 214                         sdp = sdp_init(data, datalen);
 215                         remotestr = sdp_get_connection(sdp);
 216                         rtpmapstr = sdp_get_rtpmap(sdp);
 217                         fmtpstr = sdp_get_fmtp(sdp);
 218                         aeskeystr = sdp_get_rsaaeskey(sdp);
 219                         aesivstr = sdp_get_aesiv(sdp);
 220
 221                         logger_log(conn->raop->logger, LOGGER_DEBUG, "connection: %s", remotestr);
 222                         logger_log(conn->raop->logger, LOGGER_DEBUG, "rtpmap: %s", rtpmapstr);
 223                         logger_log(conn->raop->logger, LOGGER_DEBUG, "fmtp: %s", fmtpstr);
 224                         logger_log(conn->raop->logger, LOGGER_DEBUG, "rsaaeskey: %s", aeskeystr);
 225                         logger_log(conn->raop->logger, LOGGER_DEBUG, "aesiv: %s", aesivstr);
 226
 227                         aeskeylen = rsakey_decrypt(raop->rsakey, aeskey, sizeof(aeskey), aeskeystr);
 228                         aesivlen = rsakey_parseiv(raop->rsakey, aesiv, sizeof(aesiv), aesivstr);
 229                         logger_log(conn->raop->logger, LOGGER_DEBUG, "aeskeylen: %d", aeskeylen);
 230                         logger_log(conn->raop->logger, LOGGER_DEBUG, "aesivlen: %d", aesivlen);
 231
 232                         if (conn->raop_rtp) {
 233                                 /* This should never happen */
 234                                 raop_rtp_destroy(conn->raop_rtp);
 235                                 conn->raop_rtp = NULL;
 236                         }
 237                         conn->raop_rtp = raop_rtp_init(raop->logger, &raop->callbacks, remotestr, rtpmapstr, fmtpstr, aeskey, aesiv);
 238                         if (!conn->raop_rtp) {
 239                                 logger_log(conn->raop->logger, LOGGER_ERR, "Error initializing the audio decoder");
 240                                 http_response_set_disconnect(res, 1);
 241                         }
 242                         sdp_destroy(sdp);
 243                 }
 244         } else if (!strcmp(method, "SETUP")) {
 245                 unsigned short remote_cport=0, remote_tport=0;
 246                 unsigned short cport=0, tport=0, dport=0;
 247                 const char *transport;
 248                 char buffer[1024];
 249                 int use_udp;
 250
 251                 transport = http_request_get_header(request, "Transport");
 252                 assert(transport);
 253
 254                 logger_log(conn->raop->logger, LOGGER_INFO, "Transport: %s", transport);
 255                 use_udp = strncmp(transport, "RTP/AVP/TCP", 11);
 256                 if (use_udp) {
 257                         char *original, *current, *tmpstr;
 258
 259                         current = original = strdup(transport);
 260                         if (original) {
 261                                 while ((tmpstr = utils_strsep(&current, ";")) != NULL) {
 262                                         unsigned short value;
 263                                         int ret;
 264
 265                                         ret = sscanf(tmpstr, "control_port=%hu", &value);
 266                                         if (ret == 1) {
 267                                                 logger_log(conn->raop->logger, LOGGER_DEBUG, "Found remote control port: %hu", value);
 268                                                 remote_cport = value;
 269                                         }
 270                                         ret = sscanf(tmpstr, "timing_port=%hu", &value);
 271                                         if (ret == 1) {
 272                                                 logger_log(conn->raop->logger, LOGGER_DEBUG, "Found remote timing port: %hu", value);
 273                                                 remote_tport = value;
 274                                         }
 275                                 }
 276                         }
 277                         free(original);
 278                 }
 279                 if (conn->raop_rtp) {
 280                         raop_rtp_start(conn->raop_rtp, use_udp, remote_cport, remote_tport, &cport, &tport, &dport);
 281                 } else {
 282                         logger_log(conn->raop->logger, LOGGER_ERR, "RAOP not initialized at SETUP, playing will fail!");
 283                         http_response_set_disconnect(res, 1);
 284                 }
 285
 286                 memset(buffer, 0, sizeof(buffer));
 287                 if (use_udp) {
 288                         snprintf(buffer, sizeof(buffer)-1,
 289                                  "RTP/AVP/UDP;unicast;mode=record;timing_port=%hu;events;control_port=%hu;server_port=%hu",
 290                                  tport, cport, dport);
 291                 } else {
 292                         snprintf(buffer, sizeof(buffer)-1,
 293                                  "RTP/AVP/TCP;unicast;interleaved=0-1;mode=record;server_port=%u",
 294                                  dport);
 295                 }
 296                 logger_log(conn->raop->logger, LOGGER_INFO, "Responding with %s", buffer);
 297                 http_response_add_header(res, "Transport", buffer);
 298                 http_response_add_header(res, "Session", "DEADBEEF");
 299         } else if (!strcmp(method, "SET_PARAMETER")) {
 300                 const char *content_type;
 301                 const char *data;
 302                 int datalen;
 303
 304                 content_type = http_request_get_header(request, "Content-Type");
 305                 data = http_request_get_data(request, &datalen);
 306                 if (!strcmp(content_type, "text/parameters")) {
 307                         char *datastr;
 308                         datastr = calloc(1, datalen+1);
 309                         if (data && datastr && conn->raop_rtp) {
 310                                 memcpy(datastr, data, datalen);
 311                                 if (!strncmp(datastr, "volume: ", 8)) {
 312                                         float vol = 0.0;
 313                                         sscanf(datastr+8, "%f", &vol);
 314                                         raop_rtp_set_volume(conn->raop_rtp, vol);
 315                                 }
 316                         } else if (!conn->raop_rtp) {
 317                                 logger_log(conn->raop->logger, LOGGER_WARNING, "RAOP not initialized at SET_PARAMETER volume");
 318                         }
 319                         free(datastr);
 320                 } else if (!strcmp(content_type, "image/jpeg")) {
 321                         logger_log(conn->raop->logger, LOGGER_INFO, "Got image data of %d bytes", datalen);
 322                         if (conn->raop_rtp) {
 323                                 raop_rtp_set_coverart(conn->raop_rtp, data, datalen);
 324                         } else {
 325                                 logger_log(conn->raop->logger, LOGGER_WARNING, "RAOP not initialized at SET_PARAMETER coverart");
 326                         }
 327                 } else if (!strcmp(content_type, "application/x-dmap-tagged")) {
 328                         logger_log(conn->raop->logger, LOGGER_INFO, "Got metadata of %d bytes", datalen);
 329                         if (conn->raop_rtp) {
 330                                 raop_rtp_set_metadata(conn->raop_rtp, data, datalen);
 331                         } else {
 332                                 logger_log(conn->raop->logger, LOGGER_WARNING, "RAOP not initialized at SET_PARAMETER metadata");
 333                         }
 334                 }
 335         } else if (!strcmp(method, "FLUSH")) {
 336                 const char *rtpinfo;
 337                 int next_seq = -1;
 338
 339                 rtpinfo = http_request_get_header(request, "RTP-Info");
 340                 if (rtpinfo) {
 341                         logger_log(conn->raop->logger, LOGGER_INFO, "Flush with RTP-Info: %s", rtpinfo);
 342                         if (!strncmp(rtpinfo, "seq=", 4)) {
 343                                 next_seq = strtol(rtpinfo+4, NULL, 10);
 344                         }
 345                 }
 346                 if (conn->raop_rtp) {
 347                         raop_rtp_flush(conn->raop_rtp, next_seq);
 348                 } else {
 349                         logger_log(conn->raop->logger, LOGGER_WARNING, "RAOP not initialized at FLUSH");
 350                 }
 351         } else if (!strcmp(method, "TEARDOWN")) {
 352                 http_response_add_header(res, "Connection", "close");
 353                 if (conn->raop_rtp) {
 354                         /* Destroy our RTP session */
 355                         raop_rtp_stop(conn->raop_rtp);
 356                         raop_rtp_destroy(conn->raop_rtp);
 357                         conn->raop_rtp = NULL;
 358                 }
 359         }
 360         http_response_finish(res, NULL, 0);
 361
 362         logger_log(conn->raop->logger, LOGGER_DEBUG, "Handled request %s with URL %s", method, http_request_get_url(request));
 363         *response = res;
 364 }
 365
 366 static void
 367 conn_destroy(void *ptr)
 368 {
 369         raop_conn_t *conn = ptr;
 370
 371         if (conn->raop_rtp) {
 372                 /* This is done in case TEARDOWN was not called */
 373                 raop_rtp_destroy(conn->raop_rtp);
 374         }
 375         free(conn->local);
 376         free(conn->remote);
 377         free(conn);
 378 }
 379
 380 raop_t *
 381 raop_init(int max_clients, raop_callbacks_t *callbacks, const char *pemkey, int *error)
 382 {
 383         raop_t *raop;
 384         httpd_t *httpd;
 385         rsakey_t *rsakey;
 386         httpd_callbacks_t httpd_cbs;
 387
 388         assert(callbacks);
 389         assert(max_clients > 0);
 390         assert(max_clients < 100);
 391         assert(pemkey);
 392
 393         /* Initialize the network */
 394         if (netutils_init() < 0) {
 395                 return NULL;
 396         }
 397
 398         /* Validate the callbacks structure */
 399         if (!callbacks->audio_init ||
 400             !callbacks->audio_process ||
 401             !callbacks->audio_destroy) {
 402                 return NULL;
 403         }
 404
 405         /* Allocate the raop_t structure */
 406         raop = calloc(1, sizeof(raop_t));
 407         if (!raop) {
 408                 return NULL;
 409         }
 410
 411         /* Initialize the logger */
 412         raop->logger = logger_init();
 413
 414         /* Set HTTP callbacks to our handlers */
 415         memset(&httpd_cbs, 0, sizeof(httpd_cbs));
 416         httpd_cbs.opaque = raop;
 417         httpd_cbs.conn_init = &conn_init;
 418         httpd_cbs.conn_request = &conn_request;
 419         httpd_cbs.conn_destroy = &conn_destroy;
 420
 421         /* Initialize the http daemon */
 422         httpd = httpd_init(raop->logger, &httpd_cbs, max_clients);
 423         if (!httpd) {
 424                 free(raop);
 425                 return NULL;
 426         }
 427
 428         /* Copy callbacks structure */
 429         memcpy(&raop->callbacks, callbacks, sizeof(raop_callbacks_t));
 430
 431         /* Initialize RSA key handler */
 432         rsakey = rsakey_init_pem(pemkey);
 433         if (!rsakey) {
 434                 free(httpd);
 435                 free(raop);
 436                 return NULL;
 437         }
 438
 439         raop->httpd = httpd;
 440         raop->rsakey = rsakey;
 441
 442         return raop;
 443 }
 444
 445 raop_t *
 446 raop_init_from_keyfile(int max_clients, raop_callbacks_t *callbacks, const char *keyfile, int *error)
 447 {
 448         raop_t *raop;
 449         char *pemstr;
 450
 451         if (utils_read_file(&pemstr, keyfile) < 0) {
 452                 return NULL;
 453         }
 454         raop = raop_init(max_clients, callbacks, pemstr, error);
 455         free(pemstr);
 456         return raop;
 457 }
 458
 459 void
 460 raop_destroy(raop_t *raop)
 461 {
 462         if (raop) {
 463                 raop_stop(raop);
 464
 465                 httpd_destroy(raop->httpd);
 466                 rsakey_destroy(raop->rsakey);
 467                 logger_destroy(raop->logger);
 468                 free(raop);
 469
 470                 /* Cleanup the network */
 471                 netutils_cleanup();
 472         }
 473 }
 474
 475 int
 476 raop_is_running(raop_t *raop)
 477 {
 478         assert(raop);
 479
 480         return httpd_is_running(raop->httpd);
 481 }
 482
 483 void
 484 raop_set_log_level(raop_t *raop, int level)
 485 {
 486         assert(raop);
 487
 488         logger_set_level(raop->logger, level);
 489 }
 490
 491 void
 492 raop_set_log_callback(raop_t *raop, raop_log_callback_t callback, void *cls)
 493 {
 494         assert(raop);
 495
 496         logger_set_callback(raop->logger, callback, cls);
 497 }
 498
 499 int
 500 raop_start(raop_t *raop, unsigned short *port, const char *hwaddr, int hwaddrlen, const char *password)
 501 {
 502         assert(raop);
 503         assert(port);
 504         assert(hwaddr);
 505
 506         /* Validate hardware address */
 507         if (hwaddrlen > MAX_HWADDR_LEN) {
 508                 return -1;
 509         }
 510
 511         memset(raop->password, 0, sizeof(raop->password));
 512         if (password) {
 513                 /* Validate password */
 514                 if (strlen(password) > MAX_PASSWORD_LEN) {
 515                         return -1;
 516                 }
 517
 518                 /* Copy password to the raop structure */
 519                 strncpy(raop->password, password, MAX_PASSWORD_LEN);
 520         }
 521
 522         /* Copy hwaddr to the raop structure */
 523         memcpy(raop->hwaddr, hwaddr, hwaddrlen);
 524         raop->hwaddrlen = hwaddrlen;
 525
 526         return httpd_start(raop->httpd, port);
 527 }
 528
 529 void
 530 raop_stop(raop_t *raop)
 531 {
 532         assert(raop);
 533
 534         httpd_stop(raop->httpd);
 535 }
 536