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                 } else {
 171                         logger_log(&conn->raop->logger, LOGGER_DEBUG, "AUTHENTICATION SUCCESS!");
 172                 }
 173         }
 174
 175         http_response_add_header(res, "CSeq", cseq);
 176         http_response_add_header(res, "Apple-Jack-Status", "connected; type=analog");
 177
 178         challenge = http_request_get_header(request, "Apple-Challenge");
 179         if (!require_auth && challenge) {
 180                 char signature[MAX_SIGNATURE_LEN];
 181
 182                 memset(signature, 0, sizeof(signature));
 183                 rsakey_sign(raop->rsakey, signature, sizeof(signature), challenge,
 184                             conn->local, conn->locallen, raop->hwaddr, raop->hwaddrlen);
 185                 http_response_add_header(res, "Apple-Response", signature);
 186
 187                 logger_log(&conn->raop->logger, LOGGER_DEBUG, "Got challenge: %s", challenge);
 188                 logger_log(&conn->raop->logger, LOGGER_DEBUG, "Got response: %s", signature);
 189         }
 190
 191         if (require_auth) {
 192                 /* Do nothing in case of authentication request */
 193         } else if (!strcmp(method, "OPTIONS")) {
 194                 http_response_add_header(res, "Public", "ANNOUNCE, SETUP, RECORD, PAUSE, FLUSH, TEARDOWN, OPTIONS, GET_PARAMETER, SET_PARAMETER");
 195         } else if (!strcmp(method, "ANNOUNCE")) {
 196                 const char *data;
 197                 int datalen;
 198
 199                 unsigned char aeskey[16];
 200                 unsigned char aesiv[16];
 201                 int aeskeylen, aesivlen;
 202
 203                 data = http_request_get_data(request, &datalen);
 204                 if (data) {
 205                         sdp_t *sdp;
 206                         const char *remotestr, *fmtpstr, *aeskeystr, *aesivstr;
 207
 208                         sdp = sdp_init(data, datalen);
 209                         remotestr = sdp_get_connection(sdp);
 210                         fmtpstr = sdp_get_fmtp(sdp);
 211                         aeskeystr = sdp_get_rsaaeskey(sdp);
 212                         aesivstr = sdp_get_aesiv(sdp);
 213
 214                         logger_log(&conn->raop->logger, LOGGER_DEBUG, "connection: %s", remotestr);
 215                         logger_log(&conn->raop->logger, LOGGER_DEBUG, "fmtp: %s", fmtpstr);
 216                         logger_log(&conn->raop->logger, LOGGER_DEBUG, "rsaaeskey: %s", aeskeystr);
 217                         logger_log(&conn->raop->logger, LOGGER_DEBUG, "aesiv: %s", aesivstr);
 218
 219                         aeskeylen = rsakey_decrypt(raop->rsakey, aeskey, sizeof(aeskey), aeskeystr);
 220                         aesivlen = rsakey_parseiv(raop->rsakey, aesiv, sizeof(aesiv), aesivstr);
 221                         logger_log(&conn->raop->logger, LOGGER_DEBUG, "aeskeylen: %d", aeskeylen);
 222                         logger_log(&conn->raop->logger, LOGGER_DEBUG, "aesivlen: %d", aesivlen);
 223
 224                         if (conn->raop_rtp) {
 225                                 /* This should never happen */
 226                                 raop_rtp_destroy(conn->raop_rtp);
 227                                 conn->raop_rtp = NULL;
 228                         }
 229                         conn->raop_rtp = raop_rtp_init(&raop->logger, &raop->callbacks, remotestr, fmtpstr, aeskey, aesiv);
 230                         sdp_destroy(sdp);
 231                 }
 232         } else if (!strcmp(method, "SETUP")) {
 233                 unsigned short remote_cport=0, remote_tport=0;
 234                 unsigned short cport=0, tport=0, dport=0;
 235                 const char *transport;
 236                 char buffer[1024];
 237                 int use_udp;
 238
 239                 transport = http_request_get_header(request, "Transport");
 240                 assert(transport);
 241
 242                 logger_log(&conn->raop->logger, LOGGER_INFO, "Transport: %s", transport);
 243                 use_udp = strncmp(transport, "RTP/AVP/TCP", 11);
 244                 if (use_udp) {
 245                         char *original, *current, *tmpstr;
 246
 247                         current = original = strdup(transport);
 248                         if (original) {
 249                                 while ((tmpstr = utils_strsep(&current, ";")) != NULL) {
 250                                         unsigned short value;
 251                                         int ret;
 252
 253                                         ret = sscanf(tmpstr, "control_port=%hu", &value);
 254                                         if (ret == 1) {
 255                                                 logger_log(&conn->raop->logger, LOGGER_DEBUG, "Found remote control port: %hu", value);
 256                                                 remote_cport = value;
 257                                         }
 258                                         ret = sscanf(tmpstr, "timing_port=%hu", &value);
 259                                         if (ret == 1) {
 260                                                 logger_log(&conn->raop->logger, LOGGER_DEBUG, "Found remote timing port: %hu", value);
 261                                                 remote_tport = value;
 262                                         }
 263                                 }
 264                         }
 265                         free(original);
 266                 }
 267                 raop_rtp_start(conn->raop_rtp, use_udp, remote_cport, remote_tport, &cport, &tport, &dport);
 268
 269                 memset(buffer, 0, sizeof(buffer));
 270                 if (use_udp) {
 271                         snprintf(buffer, sizeof(buffer)-1,
 272                                  "RTP/AVP/UDP;unicast;mode=record;timing_port=%hu;events;control_port=%hu;server_port=%hu",
 273                                  tport, cport, dport);
 274                 } else {
 275                         snprintf(buffer, sizeof(buffer)-1,
 276                                  "RTP/AVP/TCP;unicast;interleaved=0-1;mode=record;server_port=%u",
 277                                  dport);
 278                 }
 279                 logger_log(&conn->raop->logger, LOGGER_INFO, "Responding with %s", buffer);
 280                 http_response_add_header(res, "Transport", buffer);
 281                 http_response_add_header(res, "Session", "DEADBEEF");
 282         } else if (!strcmp(method, "SET_PARAMETER")) {
 283                 const char *data;
 284                 int datalen;
 285                 char *datastr;
 286
 287                 data = http_request_get_data(request, &datalen);
 288                 datastr = calloc(1, datalen+1);
 289                 if (data && datastr && conn->raop_rtp) {
 290                         memcpy(datastr, data, datalen);
 291                         if (!strncmp(datastr, "volume: ", 8)) {
 292                                 float vol = 0.0;
 293                                 sscanf(datastr+8, "%f", &vol);
 294                                 raop_rtp_set_volume(conn->raop_rtp, vol);
 295                         }
 296                 }
 297                 free(datastr);
 298         } else if (!strcmp(method, "FLUSH")) {
 299                 const char *rtpinfo;
 300                 int next_seq = -1;
 301
 302                 rtpinfo = http_request_get_header(request, "RTP-Info");
 303                 if (rtpinfo) {
 304                         logger_log(&conn->raop->logger, LOGGER_INFO, "Flush with RTP-Info: %s", rtpinfo);
 305                         if (!strncmp(rtpinfo, "seq=", 4)) {
 306                                 next_seq = strtol(rtpinfo+4, NULL, 10);
 307                         }
 308                 }
 309                 if (conn->raop_rtp) {
 310                         raop_rtp_flush(conn->raop_rtp, next_seq);
 311                 }
 312         } else if (!strcmp(method, "TEARDOWN")) {
 313                 http_response_add_header(res, "Connection", "close");
 314                 if (conn->raop_rtp) {
 315                         /* Destroy our RTP session */
 316                         raop_rtp_stop(conn->raop_rtp);
 317                         raop_rtp_destroy(conn->raop_rtp);
 318                         conn->raop_rtp = NULL;
 319                 }
 320         }
 321         http_response_finish(res, NULL, 0);
 322
 323         logger_log(&conn->raop->logger, LOGGER_DEBUG, "Got request %s with URL %s", method, http_request_get_url(request));
 324         *response = res;
 325 }
 326
 327 static void
 328 conn_destroy(void *ptr)
 329 {
 330         raop_conn_t *conn = ptr;
 331
 332         if (conn->raop_rtp) {
 333                 /* This is done in case TEARDOWN was not called */
 334                 raop_rtp_destroy(conn->raop_rtp);
 335         }
 336         free(conn->local);
 337         free(conn->remote);
 338         free(conn);
 339 }
 340
 341 raop_t *
 342 raop_init(raop_callbacks_t *callbacks, const char *pemkey)
 343 {
 344         raop_t *raop;
 345         httpd_t *httpd;
 346         rsakey_t *rsakey;
 347         httpd_callbacks_t httpd_cbs;
 348
 349         assert(callbacks);
 350         assert(pemkey);
 351
 352         /* Initialize the network */
 353         if (netutils_init() < 0) {
 354                 return NULL;
 355         }
 356
 357         /* Validate the callbacks structure */
 358         if (!callbacks->audio_init || !callbacks->audio_set_volume ||
 359             !callbacks->audio_process || !callbacks->audio_flush ||
 360             !callbacks->audio_destroy) {
 361                 return NULL;
 362         }
 363
 364         /* Allocate the raop_t structure */
 365         raop = calloc(1, sizeof(raop_t));
 366         if (!raop) {
 367                 return NULL;
 368         }
 369
 370         /* Initialize the logger */
 371         logger_init(&raop->logger);
 372
 373         /* Set HTTP callbacks to our handlers */
 374         memset(&httpd_cbs, 0, sizeof(httpd_cbs));
 375         httpd_cbs.opaque = raop;
 376         httpd_cbs.conn_init = &conn_init;
 377         httpd_cbs.conn_request = &conn_request;
 378         httpd_cbs.conn_destroy = &conn_destroy;
 379
 380         /* Initialize the http daemon */
 381         httpd = httpd_init(&raop->logger, &httpd_cbs, 10, 1);
 382         if (!httpd) {
 383                 free(raop);
 384                 return NULL;
 385         }
 386
 387         /* Copy callbacks structure */
 388         memcpy(&raop->callbacks, callbacks, sizeof(raop_callbacks_t));
 389
 390         /* Initialize RSA key handler */
 391         rsakey = rsakey_init_pem(pemkey);
 392         if (!rsakey) {
 393                 free(httpd);
 394                 free(raop);
 395                 return NULL;
 396         }
 397
 398         raop->httpd = httpd;
 399         raop->rsakey = rsakey;
 400
 401         return raop;
 402 }
 403
 404 raop_t *
 405 raop_init_from_keyfile(raop_callbacks_t *callbacks, const char *keyfile)
 406 {
 407         raop_t *raop;
 408         char *pemstr;
 409
 410         if (utils_read_file(&pemstr, keyfile) < 0) {
 411                 return NULL;
 412         }
 413         raop = raop_init(callbacks, pemstr);
 414         free(pemstr);
 415         return raop;
 416 }
 417
 418 void
 419 raop_destroy(raop_t *raop)
 420 {
 421         if (raop) {
 422                 raop_stop(raop);
 423
 424                 httpd_destroy(raop->httpd);
 425                 rsakey_destroy(raop->rsakey);
 426                 free(raop);
 427
 428                 /* Cleanup the network */
 429                 netutils_cleanup();
 430         }
 431 }
 432
 433 int
 434 raop_is_running(raop_t *raop)
 435 {
 436         assert(raop);
 437
 438         return httpd_is_running(raop->httpd);
 439 }
 440
 441 int
 442 raop_start(raop_t *raop, unsigned short *port, const char *hwaddr, int hwaddrlen, const char *password)
 443 {
 444         assert(raop);
 445         assert(port);
 446         assert(hwaddr);
 447
 448         /* Validate hardware address */
 449         if (hwaddrlen > MAX_HWADDR_LEN) {
 450                 return -1;
 451         }
 452
 453         memset(raop->password, 0, sizeof(raop->password));
 454         if (password) {
 455                 /* Validate password */
 456                 if (strlen(password) > MAX_PASSWORD_LEN) {
 457                         return -1;
 458                 }
 459
 460                 /* Copy password to the raop structure */
 461                 strncpy(raop->password, password, MAX_PASSWORD_LEN);
 462         }
 463
 464         /* Copy hwaddr to the raop structure */
 465         memcpy(raop->hwaddr, hwaddr, hwaddrlen);
 466         raop->hwaddrlen = hwaddrlen;
 467
 468         return httpd_start(raop->httpd, port);
 469 }
 470
 471 void
 472 raop_stop(raop_t *raop)
 473 {
 474         assert(raop);
 475
 476         httpd_stop(raop->httpd);
 477 }
 478