mdw@git.distorted.org.uk Git - disorder/blob - lib/client.c

   1 /*
   2  * This file is part of DisOrder.
   3  * Copyright (C) 2004-2009 Richard Kettlewell
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18 /** @file lib/client.c
  19  * @brief Simple C client
  20  *
  21  * See @ref lib/eclient.c for an asynchronous-capable client
  22  * implementation.
  23  */
  24
  25 #include "common.h"
  26
  27 #include <sys/types.h>
  28 #include <sys/socket.h>
  29 #include <netinet/in.h>
  30 #include <sys/un.h>
  31 #include <unistd.h>
  32 #include <errno.h>
  33 #include <netdb.h>
  34 #include <pcre.h>
  35
  36 #include "log.h"
  37 #include "mem.h"
  38 #include "queue.h"
  39 #include "client.h"
  40 #include "charset.h"
  41 #include "hex.h"
  42 #include "split.h"
  43 #include "vector.h"
  44 #include "inputline.h"
  45 #include "kvp.h"
  46 #include "syscalls.h"
  47 #include "printf.h"
  48 #include "sink.h"
  49 #include "addr.h"
  50 #include "authhash.h"
  51 #include "client-common.h"
  52 #include "rights.h"
  53 #include "trackdb.h"
  54 #include "kvp.h"
  55
  56 /** @brief Client handle contents */
  57 struct disorder_client {
  58   /** @brief Stream to read from */
  59   FILE *fpin;
  60   /** @brief Stream to write to */
  61   FILE *fpout;
  62   /** @brief Peer description */
  63   char *ident;
  64   /** @brief Username */
  65   char *user;
  66   /** @brief Report errors to @c stderr */
  67   int verbose;
  68   /** @brief Last error string */
  69   const char *last;
  70 };
  71
  72 /** @brief Create a new client
  73  * @param verbose If nonzero, write extra junk to stderr
  74  * @return Pointer to new client
  75  *
  76  * You must call disorder_connect(), disorder_connect_user() or
  77  * disorder_connect_cookie() to connect it.  Use disorder_close() to
  78  * dispose of the client when finished with it.
  79  */
  80 disorder_client *disorder_new(int verbose) {
  81   disorder_client *c = xmalloc(sizeof (struct disorder_client));
  82
  83   c->verbose = verbose;
  84   return c;
  85 }
  86
  87 /** @brief Read a response line
  88  * @param c Client
  89  * @param rp Where to store response, or NULL (UTF-8)
  90  * @return Response code 0-999 or -1 on error
  91  */
  92 static int response(disorder_client *c, char **rp) {
  93   char *r;
  94
  95   if(inputline(c->ident, c->fpin, &r, '\n')) {
  96     byte_xasprintf((char **)&c->last, "input error: %s", strerror(errno));
  97     return -1;
  98   }
  99   D(("response: %s", r));
 100   if(rp)
 101     *rp = r;
 102   if(r[0] >= '0' && r[0] <= '9'
 103      && r[1] >= '0' && r[1] <= '9'
 104      && r[2] >= '0' && r[2] <= '9'
 105      && r[3] == ' ') {
 106     c->last = r + 4;
 107     return (r[0] * 10 + r[1]) * 10 + r[2] - 111 * '0';
 108   } else {
 109     c->last = "invalid reply format";
 110     disorder_error(0, "invalid reply format from %s", c->ident);
 111     return -1;
 112   }
 113 }
 114
 115 /** @brief Return last response string
 116  * @param c Client
 117  * @return Last response string (UTF-8, English) or NULL
 118  */
 119 const char *disorder_last(disorder_client *c) {
 120   return c->last;
 121 }
 122
 123 /** @brief Read and partially parse a response
 124  * @param c Client
 125  * @param rp Where to store response text (or NULL) (UTF-8)
 126  * @return 0 on success, non-0 on error
 127  *
 128  * 5xx responses count as errors.
 129  *
 130  * @p rp will NOT be filled in for xx9 responses (where it is just
 131  * commentary for a command where it would normally be meaningful).
 132  *
 133  * NB that the response will NOT be converted to the local encoding.
 134  */
 135 static int check_response(disorder_client *c, char **rp) {
 136   int rc;
 137   char *r;
 138
 139   if((rc = response(c, &r)) == -1)
 140     return -1;
 141   else if(rc / 100 == 2) {
 142     if(rp)
 143       *rp = (rc % 10 == 9) ? 0 : xstrdup(r + 4);
 144     xfree(r);
 145     return 0;
 146   } else {
 147     if(c->verbose)
 148       disorder_error(0, "from %s: %s", c->ident, utf82mb(r));
 149     xfree(r);
 150     return rc;
 151   }
 152 }
 153
 154 /** @brief Issue a command and parse a simple response
 155  * @param c Client
 156  * @param rp Where to store result, or NULL
 157  * @param cmd Command
 158  * @param body Body or NULL
 159  * @param nbody Length of body or -1
 160  * @param ap Arguments (UTF-8), terminated by (char *)0
 161  * @return 0 on success, non-0 on error
 162  *
 163  * 5xx responses count as errors.
 164  *
 165  * @p rp will NOT be filled in for xx9 responses (where it is just
 166  * commentary for a command where it would normally be meaningful).
 167  *
 168  * NB that the response will NOT be converted to the local encoding
 169  * nor will quotes be stripped.  See dequote().
 170  *
 171  * If @p body is not NULL then the body is sent immediately after the
 172  * command.  @p nbody should be the number of lines or @c -1 to count
 173  * them if @p body is NULL-terminated.
 174  *
 175  * Usually you would call this via one of the following interfaces:
 176  * - disorder_simple()
 177  * - disorder_simple_body()
 178  * - disorder_simple_list()
 179  */
 180 static int disorder_simple_v(disorder_client *c,
 181                              char **rp,
 182                              const char *cmd,
 183                              char **body, int nbody,
 184                              va_list ap) {
 185   const char *arg;
 186   struct dynstr d;
 187
 188   if(!c->fpout) {
 189     c->last = "not connected";
 190     disorder_error(0, "not connected to server");
 191     return -1;
 192   }
 193   if(cmd) {
 194     dynstr_init(&d);
 195     dynstr_append_string(&d, cmd);
 196     while((arg = va_arg(ap, const char *))) {
 197       dynstr_append(&d, ' ');
 198       dynstr_append_string(&d, quoteutf8(arg));
 199     }
 200     dynstr_append(&d, '\n');
 201     dynstr_terminate(&d);
 202     D(("command: %s", d.vec));
 203     if(fputs(d.vec, c->fpout) < 0)
 204       goto write_error;
 205     xfree(d.vec);
 206     if(body) {
 207       if(nbody < 0)
 208         for(nbody = 0; body[nbody]; ++nbody)
 209           ;
 210       for(int n = 0; n < nbody; ++n) {
 211         if(body[n][0] == '.')
 212           if(fputc('.', c->fpout) < 0)
 213             goto write_error;
 214         if(fputs(body[n], c->fpout) < 0)
 215           goto write_error;
 216         if(fputc('\n', c->fpout) < 0)
 217           goto write_error;
 218       }
 219       if(fputs(".\n", c->fpout) < 0)
 220         goto write_error;
 221     }
 222     if(fflush(c->fpout))
 223       goto write_error;
 224   }
 225   return check_response(c, rp);
 226 write_error:
 227   byte_xasprintf((char **)&c->last, "write error: %s", strerror(errno));
 228   disorder_error(errno, "error writing to %s", c->ident);
 229   return -1;
 230 }
 231
 232 /** @brief Issue a command and parse a simple response
 233  * @param c Client
 234  * @param rp Where to store result, or NULL (UTF-8)
 235  * @param cmd Command
 236  * @return 0 on success, non-0 on error
 237  *
 238  * The remaining arguments are command arguments, terminated by (char
 239  * *)0.  They should be in UTF-8.
 240  *
 241  * 5xx responses count as errors.
 242  *
 243  * @p rp will NOT be filled in for xx9 responses (where it is just
 244  * commentary for a command where it would normally be meaningful).
 245  *
 246  * NB that the response will NOT be converted to the local encoding
 247  * nor will quotes be stripped.  See dequote().
 248  */
 249 static int disorder_simple(disorder_client *c,
 250                            char **rp,
 251                            const char *cmd, ...) {
 252   va_list ap;
 253   int ret;
 254
 255   va_start(ap, cmd);
 256   ret = disorder_simple_v(c, rp, cmd, 0, 0, ap);
 257   va_end(ap);
 258   return ret;
 259 }
 260
 261 /** @brief Issue a command with a body and parse a simple response
 262  * @param c Client
 263  * @param rp Where to store result, or NULL (UTF-8)
 264  * @param body Pointer to body
 265  * @param nbody Size of body
 266  * @param cmd Command
 267  * @return 0 on success, non-0 on error
 268  *
 269  * See disorder_simple().
 270  */
 271 static int disorder_simple_body(disorder_client *c,
 272                                 char **rp,
 273                                 char **body, int nbody,
 274                                 const char *cmd, ...) {
 275   va_list ap;
 276   int ret;
 277
 278   va_start(ap, cmd);
 279   ret = disorder_simple_v(c, rp, cmd, body, nbody, ap);
 280   va_end(ap);
 281   return ret;
 282 }
 283
 284 /** @brief Dequote a result string
 285  * @param rc 0 on success, non-0 on error
 286  * @param rp Where result string is stored (UTF-8)
 287  * @return @p rc
 288  *
 289  * This is used as a wrapper around disorder_simple() to dequote
 290  * results in place.
 291  */
 292 static int dequote(int rc, char **rp) {
 293   char **rr;
 294
 295   if(!rc) {
 296     if((rr = split(*rp, 0, SPLIT_QUOTES, 0, 0)) && *rr) {
 297       xfree(*rp);
 298       *rp = *rr;
 299       xfree(rr);
 300       return 0;
 301     }
 302     disorder_error(0, "invalid reply: %s", *rp);
 303   }
 304   return rc;
 305 }
 306
 307 /** @brief Generic connection routine
 308  * @param conf Configuration to follow
 309  * @param c Client
 310  * @param username Username to log in with or NULL
 311  * @param password Password to log in with or NULL
 312  * @param cookie Cookie to log in with or NULL
 313  * @return 0 on success, non-0 on error
 314  *
 315  * @p cookie is tried first if not NULL.  If it is NULL then @p
 316  * username must not be.  If @p username is not NULL then nor may @p
 317  * password be.
 318  */
 319 int disorder_connect_generic(struct config *conf,
 320                              disorder_client *c,
 321                              const char *username,
 322                              const char *password,
 323                              const char *cookie) {
 324   int fd = -1, fd2 = -1, nrvec = 0, rc;
 325   unsigned char *nonce = NULL;
 326   size_t nl;
 327   char *res = NULL;
 328   char *r = NULL, **rvec = NULL;
 329   const char *protocol, *algorithm, *challenge;
 330   struct sockaddr *sa = NULL;
 331   socklen_t salen;
 332
 333   if((salen = find_server(conf, &sa, &c->ident)) == (socklen_t)-1)
 334     return -1;
 335   c->fpin = c->fpout = 0;
 336   if((fd = socket(sa->sa_family, SOCK_STREAM, 0)) < 0) {
 337     byte_xasprintf((char **)&c->last, "socket: %s", strerror(errno));
 338     disorder_error(errno, "error calling socket");
 339     return -1;
 340   }
 341   if(connect(fd, sa, salen) < 0) {
 342     byte_xasprintf((char **)&c->last, "connect: %s", strerror(errno));
 343     disorder_error(errno, "error calling connect");
 344     goto error;
 345   }
 346   if((fd2 = dup(fd)) < 0) {
 347     byte_xasprintf((char **)&c->last, "dup: %s", strerror(errno));
 348     disorder_error(errno, "error calling dup");
 349     goto error;
 350   }
 351   if(!(c->fpin = fdopen(fd, "rb"))) {
 352     byte_xasprintf((char **)&c->last, "fdopen: %s", strerror(errno));
 353     disorder_error(errno, "error calling fdopen");
 354     goto error;
 355   }
 356   fd = -1;
 357   if(!(c->fpout = fdopen(fd2, "wb"))) {
 358     byte_xasprintf((char **)&c->last, "fdopen: %s", strerror(errno));
 359     disorder_error(errno, "error calling fdopen");
 360     goto error;
 361   }
 362   fd2 = -1;
 363   if((rc = disorder_simple(c, &r, 0, (const char *)0)))
 364     goto error_rc;
 365   if(!(rvec = split(r, &nrvec, SPLIT_QUOTES, 0, 0)))
 366     goto error;
 367   if(nrvec != 3) {
 368     c->last = "cannot parse server greeting";
 369     disorder_error(0, "cannot parse server greeting %s", r);
 370     goto error;
 371   }
 372   protocol = rvec[0];
 373   if(strcmp(protocol, "2")) {
 374     c->last = "unknown protocol version";
 375     disorder_error(0, "unknown protocol version: %s", protocol);
 376     goto error;
 377   }
 378   algorithm = rvec[1];
 379   challenge = rvec[2];
 380   if(!(nonce = unhex(challenge, &nl)))
 381     goto error;
 382   if(cookie) {
 383     if(!dequote(disorder_simple(c, &c->user, "cookie", cookie, (char *)0),
 384                 &c->user))
 385       return 0;                         /* success */
 386     if(!username) {
 387       c->last = "cookie failed and no username";
 388       disorder_error(0, "cookie did not work and no username available");
 389       goto error;
 390     }
 391   }
 392   if(!(res = authhash(nonce, nl, password, algorithm))) {
 393     c->last = "error computing authorization hash";
 394     goto error;
 395   }
 396   if((rc = disorder_simple(c, 0, "user", username, res, (char *)0)))
 397     goto error_rc;
 398   c->user = xstrdup(username);
 399   xfree(res);
 400   free_strings(nrvec, rvec);
 401   xfree(nonce);
 402   xfree(sa);
 403   xfree(r);
 404   return 0;
 405 error:
 406   rc = -1;
 407 error_rc:
 408   if(c->fpin) {
 409     fclose(c->fpin);
 410     c->fpin = 0;
 411   }
 412   if(c->fpout) {
 413     fclose(c->fpout);
 414     c->fpout = 0;
 415   }
 416   if(fd2 != -1) close(fd2);
 417   if(fd != -1) close(fd);
 418   return rc;
 419 }
 420
 421 /** @brief Connect a client with a specified username and password
 422  * @param c Client
 423  * @param username Username to log in with
 424  * @param password Password to log in with
 425  * @return 0 on success, non-0 on error
 426  */
 427 int disorder_connect_user(disorder_client *c,
 428                           const char *username,
 429                           const char *password) {
 430   return disorder_connect_generic(config,
 431                                   c,
 432                                   username,
 433                                   password,
 434                                   0);
 435 }
 436
 437 /** @brief Connect a client
 438  * @param c Client
 439  * @return 0 on success, non-0 on error
 440  *
 441  * The connection will use the username and password found in @ref
 442  * config, or directly from the database if no password is found and
 443  * the database is readable (usually only for root).
 444  */
 445 int disorder_connect(disorder_client *c) {
 446   const char *username, *password;
 447
 448   if(!(username = config->username)) {
 449     c->last = "no username";
 450     disorder_error(0, "no username configured");
 451     return -1;
 452   }
 453   password = config->password;
 454   /* Maybe we can read the database */
 455   if(!password && trackdb_readable()) {
 456     trackdb_init(TRACKDB_NO_RECOVER|TRACKDB_NO_UPGRADE);
 457     trackdb_open(TRACKDB_READ_ONLY);
 458     password = trackdb_get_password(username);
 459     trackdb_close();
 460   }
 461   if(!password) {
 462     /* Oh well */
 463     c->last = "no password";
 464     disorder_error(0, "no password configured for user '%s'", username);
 465     return -1;
 466   }
 467   return disorder_connect_generic(config,
 468                                   c,
 469                                   username,
 470                                   password,
 471                                   0);
 472 }
 473
 474 /** @brief Connect a client
 475  * @param c Client
 476  * @param cookie Cookie to log in with, or NULL
 477  * @return 0 on success, non-0 on error
 478  *
 479  * If @p cookie is NULL or does not work then we attempt to log in as
 480  * guest instead (so when the cookie expires only an extra round trip
 481  * is needed rathre than a complete new login).
 482  */
 483 int disorder_connect_cookie(disorder_client *c,
 484                             const char *cookie) {
 485   return disorder_connect_generic(config,
 486                                   c,
 487                                   "guest",
 488                                   "",
 489                                   cookie);
 490 }
 491
 492 /** @brief Close a client
 493  * @param c Client
 494  * @return 0 on succcess, non-0 on errior
 495  *
 496  * The client is still closed even on error.  It might well be
 497  * appropriate to ignore the return value.
 498  */
 499 int disorder_close(disorder_client *c) {
 500   int ret = 0;
 501
 502   if(c->fpin) {
 503     if(fclose(c->fpin) < 0) {
 504       byte_xasprintf((char **)&c->last, "fclose: %s", strerror(errno));
 505       disorder_error(errno, "error calling fclose");
 506       ret = -1;
 507     }
 508     c->fpin = 0;
 509   }
 510   if(c->fpout) {
 511     if(fclose(c->fpout) < 0) {
 512       byte_xasprintf((char **)&c->last, "fclose: %s", strerror(errno));
 513       disorder_error(errno, "error calling fclose");
 514       ret = -1;
 515     }
 516     c->fpout = 0;
 517   }
 518   xfree(c->ident);
 519   c->ident = 0;
 520   xfree(c->user);
 521   c->user = 0;
 522   return ret;
 523 }
 524
 525 /** @brief Play a track
 526  * @param c Client
 527  * @param track Track to play (UTF-8)
 528  * @return 0 on success, non-0 on error
 529  */
 530 int disorder_play(disorder_client *c, const char *track) {
 531   return disorder_simple(c, 0, "play", track, (char *)0);
 532 }
 533
 534 /** @brief Move a track
 535  * @param c Client
 536  * @param track Track to move (UTF-8)
 537  * @param delta Distance to move by
 538  * @return 0 on success, non-0 on error
 539  */
 540 int disorder_move(disorder_client *c, const char *track, int delta) {
 541   char d[16];
 542
 543   byte_snprintf(d, sizeof d, "%d", delta);
 544   return disorder_simple(c, 0, "move", track, d, (char *)0);
 545 }
 546
 547 static void client_error(const char *msg,
 548                          void attribute((unused)) *u) {
 549   disorder_error(0, "error parsing reply: %s", msg);
 550 }
 551
 552 /** @brief Get currently playing track
 553  * @param c Client
 554  * @param qp Where to store track information
 555  * @return 0 on success, non-0 on error
 556  *
 557  * @p qp gets NULL if no track is playing.
 558  */
 559 int disorder_playing(disorder_client *c, struct queue_entry **qp) {
 560   char *r;
 561   struct queue_entry *q;
 562   int rc;
 563
 564   if((rc = disorder_simple(c, &r, "playing", (char *)0)))
 565     return rc;
 566   if(r) {
 567     q = xmalloc(sizeof *q);
 568     if(queue_unmarshall(q, r, client_error, 0))
 569       return -1;
 570     *qp = q;
 571   } else
 572     *qp = 0;
 573   return 0;
 574 }
 575
 576 /** @brief Fetch the queue, recent list, etc */
 577 static int disorder_somequeue(disorder_client *c,
 578                               const char *cmd, struct queue_entry **qp) {
 579   struct queue_entry *qh, **qt = &qh, *q;
 580   char *l;
 581   int rc;
 582
 583   if((rc = disorder_simple(c, 0, cmd, (char *)0)))
 584     return rc;
 585   while(inputline(c->ident, c->fpin, &l, '\n') >= 0) {
 586     if(!strcmp(l, ".")) {
 587       *qt = 0;
 588       *qp = qh;
 589       xfree(l);
 590       return 0;
 591     }
 592     q = xmalloc(sizeof *q);
 593     if(!queue_unmarshall(q, l, client_error, 0)) {
 594       *qt = q;
 595       qt = &q->next;
 596     }
 597     xfree(l);
 598   }
 599   if(ferror(c->fpin)) {
 600     byte_xasprintf((char **)&c->last, "input error: %s", strerror(errno));
 601     disorder_error(errno, "error reading %s", c->ident);
 602   } else {
 603     c->last = "input error: unexpxected EOF";
 604     disorder_error(0, "error reading %s: unexpected EOF", c->ident);
 605   }
 606   return -1;
 607 }
 608
 609 /** @brief Get recently played tracks
 610  * @param c Client
 611  * @param qp Where to store track information
 612  * @return 0 on success, non-0 on error
 613  *
 614  * The last entry in the list is the most recently played track.
 615  */
 616 int disorder_recent(disorder_client *c, struct queue_entry **qp) {
 617   return disorder_somequeue(c, "recent", qp);
 618 }
 619
 620 /** @brief Get queue
 621  * @param c Client
 622  * @param qp Where to store track information
 623  * @return 0 on success, non-0 on error
 624  *
 625  * The first entry in the list will be played next.
 626  */
 627 int disorder_queue(disorder_client *c, struct queue_entry **qp) {
 628   return disorder_somequeue(c, "queue", qp);
 629 }
 630
 631 /** @brief Read a dot-stuffed list
 632  * @param c Client
 633  * @param vecp Where to store list (UTF-8)
 634  * @param nvecp Where to store number of items, or NULL
 635  * @return 0 on success, non-0 on error
 636  *
 637  * The list will have a final NULL not counted in @p nvecp.
 638  */
 639 static int readlist(disorder_client *c, char ***vecp, int *nvecp) {
 640   char *l;
 641   struct vector v;
 642
 643   vector_init(&v);
 644   while(inputline(c->ident, c->fpin, &l, '\n') >= 0) {
 645     if(!strcmp(l, ".")) {
 646       vector_terminate(&v);
 647       if(nvecp)
 648         *nvecp = v.nvec;
 649       *vecp = v.vec;
 650       xfree(l);
 651       return 0;
 652     }
 653     vector_append(&v, xstrdup(l + (*l == '.')));
 654     xfree(l);
 655   }
 656   if(ferror(c->fpin)) {
 657     byte_xasprintf((char **)&c->last, "input error: %s", strerror(errno));
 658     disorder_error(errno, "error reading %s", c->ident);
 659   } else {
 660     c->last = "input error: unexpxected EOF";
 661     disorder_error(0, "error reading %s: unexpected EOF", c->ident);
 662   }
 663   return -1;
 664 }
 665
 666 /** @brief Issue a comamnd and get a list response
 667  * @param c Client
 668  * @param vecp Where to store list (UTF-8)
 669  * @param nvecp Where to store number of items, or NULL
 670  * @param cmd Command
 671  * @return 0 on success, non-0 on error
 672  *
 673  * The remaining arguments are command arguments, terminated by (char
 674  * *)0.  They should be in UTF-8.
 675  *
 676  * 5xx responses count as errors.
 677  *
 678  * See disorder_simple().
 679  */
 680 static int disorder_simple_list(disorder_client *c,
 681                                 char ***vecp, int *nvecp,
 682                                 const char *cmd, ...) {
 683   va_list ap;
 684   int ret;
 685
 686   va_start(ap, cmd);
 687   ret = disorder_simple_v(c, 0, cmd, 0, 0, ap);
 688   va_end(ap);
 689   if(ret) return ret;
 690   return readlist(c, vecp, nvecp);
 691 }
 692
 693 /** @brief Return the user we logged in with
 694  * @param c Client
 695  * @return User name (owned by @p c, don't modify)
 696  */
 697 char *disorder_user(disorder_client *c) {
 698   return c->user;
 699 }
 700
 701 static void pref_error_handler(const char *msg,
 702                                void attribute((unused)) *u) {
 703   disorder_error(0, "error handling 'prefs' reply: %s", msg);
 704 }
 705
 706 /** @brief Get all preferences for a trcak
 707  * @param c Client
 708  * @param track Track name
 709  * @param kp Where to store linked list of preferences
 710  * @return 0 on success, non-0 on error
 711  */
 712 int disorder_prefs(disorder_client *c, const char *track, struct kvp **kp) {
 713   char **vec, **pvec;
 714   int nvec, npvec, n, rc;
 715   struct kvp *k;
 716
 717   if((rc = disorder_simple_list(c, &vec, &nvec, "prefs", track, (char *)0)))
 718     return rc;
 719   for(n = 0; n < nvec; ++n) {
 720     if(!(pvec = split(vec[n], &npvec, SPLIT_QUOTES, pref_error_handler, 0)))
 721       return -1;
 722     if(npvec != 2) {
 723       pref_error_handler("malformed response", 0);
 724       return -1;
 725     }
 726     *kp = k = xmalloc(sizeof *k);
 727     k->name = pvec[0];
 728     k->value = pvec[1];
 729     kp = &k->next;
 730     xfree(pvec);
 731   }
 732   free_strings(nvec, vec);
 733   *kp = 0;
 734   return 0;
 735 }
 736
 737 /** @brief Parse a boolean response
 738  * @param cmd Command for use in error messsage
 739  * @param value Result from server
 740  * @param flagp Where to store result
 741  * @return 0 on success, non-0 on error
 742  */
 743 static int boolean(const char *cmd, const char *value,
 744                    int *flagp) {
 745   if(!strcmp(value, "yes")) *flagp = 1;
 746   else if(!strcmp(value, "no")) *flagp = 0;
 747   else {
 748     disorder_error(0, "malformed response to '%s'", cmd);
 749     return -1;
 750   }
 751   return 0;
 752 }
 753
 754 /** @brief Get the length of a track
 755  * @param c Client
 756  * @param track Track name (UTF-8)
 757  * @param valuep Where to store length in seconds
 758  * @return 0 on success, non-0 on error
 759  *
 760  * If the length is unknown 0 is returned.
 761  */
 762 int disorder_length(disorder_client *c, const char *track,
 763                     long *valuep) {
 764   char *value;
 765   int rc;
 766
 767   if((rc = disorder_simple(c, &value, "length", track, (char *)0)))
 768     return rc;
 769   *valuep = atol(value);
 770   return 0;
 771 }
 772
 773 /** @brief Set volume
 774  * @param c Client
 775  * @param left New left channel value
 776  * @param right New right channel value
 777  * @return 0 on success, non-0 on error
 778  */
 779 int disorder_set_volume(disorder_client *c, int left, int right) {
 780   char *ls, *rs;
 781
 782   if(byte_asprintf(&ls, "%d", left) < 0
 783      || byte_asprintf(&rs, "%d", right) < 0)
 784     return -1;
 785   return disorder_simple(c, 0, "volume", ls, rs, (char *)0);
 786 }
 787
 788 /** @brief Get volume
 789  * @param c Client
 790  * @param left Where to store left channel value
 791  * @param right Where to store right channel value
 792  * @return 0 on success, non-0 on error
 793  */
 794 int disorder_get_volume(disorder_client *c, int *left, int *right) {
 795   char *r;
 796   int rc;
 797
 798   if((rc = disorder_simple(c, &r, "volume", (char *)0)))
 799     return rc;
 800   if(sscanf(r, "%d %d", left, right) != 2) {
 801     c->last = "malformed volume response";
 802     disorder_error(0, "error parsing response to 'volume': '%s'", r);
 803     return -1;
 804   }
 805   return 0;
 806 }
 807
 808 /** @brief Log to a sink
 809  * @param c Client
 810  * @param s Sink to write log lines to
 811  * @return 0 on success, non-0 on error
 812  */
 813 int disorder_log(disorder_client *c, struct sink *s) {
 814   char *l;
 815   int rc;
 816
 817   if((rc = disorder_simple(c, 0, "log", (char *)0)))
 818     return rc;
 819   while(inputline(c->ident, c->fpin, &l, '\n') >= 0 && strcmp(l, "."))
 820     if(sink_printf(s, "%s\n", l) < 0) return -1;
 821   if(ferror(c->fpin) || feof(c->fpin)) {
 822     byte_xasprintf((char **)&c->last, "input error: %s",
 823                    ferror(c->fpin) ? strerror(errno) : "unexpxected EOF");
 824     return -1;
 825   }
 826   return 0;
 827 }
 828
 829 /** @brief Get recently added tracks
 830  * @param c Client
 831  * @param vecp Where to store pointer to list (UTF-8)
 832  * @param nvecp Where to store count
 833  * @param max Maximum tracks to fetch, or 0 for all available
 834  * @return 0 on success, non-0 on error
 835  */
 836 int disorder_new_tracks(disorder_client *c,
 837                         char ***vecp, int *nvecp,
 838                         int max) {
 839   char limit[32];
 840
 841   sprintf(limit, "%d", max);
 842   return disorder_simple_list(c, vecp, nvecp, "new", limit, (char *)0);
 843 }
 844
 845 /** @brief Get server's RTP address information
 846  * @param c Client
 847  * @param addressp Where to store address (UTF-8)
 848  * @param portp Where to store port (UTF-8)
 849  * @return 0 on success, non-0 on error
 850  */
 851 int disorder_rtp_address(disorder_client *c, char **addressp, char **portp) {
 852   char *r;
 853   int rc, n;
 854   char **vec;
 855
 856   if((rc = disorder_simple(c, &r, "rtp-address", (char *)0)))
 857     return rc;
 858   vec = split(r, &n, SPLIT_QUOTES, 0, 0);
 859   if(n != 2) {
 860     c->last = "malformed RTP address";
 861     disorder_error(0, "malformed rtp-address reply");
 862     return -1;
 863   }
 864   *addressp = vec[0];
 865   *portp = vec[1];
 866   return 0;
 867 }
 868
 869 /** @brief Get details of a scheduled event
 870  * @param c Client
 871  * @param id Event ID
 872  * @param actiondatap Where to put details
 873  * @return 0 on success, non-0 on error
 874  */
 875 int disorder_schedule_get(disorder_client *c, const char *id,
 876                           struct kvp **actiondatap) {
 877   char **lines, **bits;
 878   int rc, nbits;
 879
 880   *actiondatap = 0;
 881   if((rc = disorder_simple_list(c, &lines, NULL,
 882                                 "schedule-get", id, (char *)0)))
 883     return rc;
 884   while(*lines) {
 885     if(!(bits = split(*lines++, &nbits, SPLIT_QUOTES, 0, 0))) {
 886       disorder_error(0, "invalid schedule-get reply: cannot split line");
 887       return -1;
 888     }
 889     if(nbits != 2) {
 890       disorder_error(0, "invalid schedule-get reply: wrong number of fields");
 891       return -1;
 892     }
 893     kvp_set(actiondatap, bits[0], bits[1]);
 894   }
 895   return 0;
 896 }
 897
 898 /** @brief Add a scheduled event
 899  * @param c Client
 900  * @param when When to trigger the event
 901  * @param priority Event priority ("normal" or "junk")
 902  * @param action What action to perform
 903  * @param ... Action-specific arguments
 904  * @return 0 on success, non-0 on error
 905  *
 906  * For action @c "play" the next argument is the track.
 907  *
 908  * For action @c "set-global" next argument is the global preference name
 909  * and the final argument the value to set it to, or (char *)0 to unset it.
 910  */
 911 int disorder_schedule_add(disorder_client *c,
 912                           time_t when,
 913                           const char *priority,
 914                           const char *action,
 915                           ...) {
 916   va_list ap;
 917   char when_str[64];
 918   int rc;
 919
 920   snprintf(when_str, sizeof when_str, "%lld", (long long)when);
 921   va_start(ap, action);
 922   if(!strcmp(action, "play"))
 923     rc = disorder_simple(c, 0, "schedule-add", when_str, priority,
 924                          action, va_arg(ap, char *),
 925                          (char *)0);
 926   else if(!strcmp(action, "set-global")) {
 927     const char *key = va_arg(ap, char *);
 928     const char *value = va_arg(ap, char *);
 929     rc = disorder_simple(c, 0,"schedule-add",  when_str, priority,
 930                          action, key, value,
 931                          (char *)0);
 932   } else
 933     disorder_fatal(0, "unknown action '%s'", action);
 934   va_end(ap);
 935   return rc;
 936 }
 937
 938 /** @brief Set the contents of a playlst
 939  * @param c Client
 940  * @param playlist Playlist to modify
 941  * @param tracks List of tracks
 942  * @param ntracks Length of @p tracks (or -1 to count up to the first NULL)
 943  * @return 0 on success, non-0 on error
 944  */
 945 int disorder_playlist_set(disorder_client *c,
 946                           const char *playlist,
 947                           char **tracks,
 948                           int ntracks) {
 949   return disorder_simple_body(c, 0, tracks, ntracks,
 950                               "playlist-set", playlist, (char *)0);
 951 }
 952
 953 #include "client-stubs.c"
 954
 955 /*
 956 Local Variables:
 957 c-basic-offset:2
 958 comment-column:40
 959 End:
 960 */