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