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 Marker for a command body */
 155 static const char disorder_body[1];
 156
 157 /** @brief Issue a command and parse a simple response
 158  * @param c Client
 159  * @param rp Where to store result, or NULL
 160  * @param cmd Command
 161  * @param ap Arguments (UTF-8), terminated by (char *)0
 162  * @return 0 on success, non-0 on error
 163  *
 164  * 5xx responses count as errors.
 165  *
 166  * @p rp will NOT be filled in for xx9 responses (where it is just
 167  * commentary for a command where it would normally be meaningful).
 168  *
 169  * NB that the response will NOT be converted to the local encoding
 170  * nor will quotes be stripped.  See dequote().
 171  *
 172  * Put @ref disorder_body in the argument list followed by a char **
 173  * and int giving the body to follow the command.  If the int is @c -1
 174  * then the list is assumed to be NULL-terminated.
 175  *
 176  * Usually you would call this via one of the following interfaces:
 177  * - disorder_simple()
 178  * - disorder_simple_list()
 179  */
 180 static int disorder_simple_v(disorder_client *c,
 181                              char **rp,
 182                              const char *cmd,
 183                              va_list ap) {
 184   const char *arg;
 185   struct dynstr d;
 186   char **body = NULL;
 187   int nbody = 0;
 188   int has_body = 0;
 189
 190   if(!c->fpout) {
 191     c->last = "not connected";
 192     disorder_error(0, "not connected to server");
 193     return -1;
 194   }
 195   if(cmd) {
 196     dynstr_init(&d);
 197     dynstr_append_string(&d, cmd);
 198     while((arg = va_arg(ap, const char *))) {
 199       if(arg == disorder_body) {
 200         body = va_arg(ap, char **);
 201         nbody = va_arg(ap, int);
 202         has_body = 1;
 203       } else {
 204         dynstr_append(&d, ' ');
 205         dynstr_append_string(&d, quoteutf8(arg));
 206       }
 207     }
 208     dynstr_append(&d, '\n');
 209     dynstr_terminate(&d);
 210     D(("command: %s", d.vec));
 211     if(fputs(d.vec, c->fpout) < 0)
 212       goto write_error;
 213     xfree(d.vec);
 214     if(has_body) {
 215       if(nbody < 0)
 216         for(nbody = 0; body[nbody]; ++nbody)
 217           ;
 218       for(int n = 0; n < nbody; ++n) {
 219         if(body[n][0] == '.')
 220           if(fputc('.', c->fpout) < 0)
 221             goto write_error;
 222         if(fputs(body[n], c->fpout) < 0)
 223           goto write_error;
 224         if(fputc('\n', c->fpout) < 0)
 225           goto write_error;
 226       }
 227       if(fputs(".\n", c->fpout) < 0)
 228         goto write_error;
 229     }
 230     if(fflush(c->fpout))
 231       goto write_error;
 232   }
 233   return check_response(c, rp);
 234 write_error:
 235   byte_xasprintf((char **)&c->last, "write error: %s", strerror(errno));
 236   disorder_error(errno, "error writing to %s", c->ident);
 237   return -1;
 238 }
 239
 240 /** @brief Issue a command and parse a simple response
 241  * @param c Client
 242  * @param rp Where to store result, or NULL (UTF-8)
 243  * @param cmd Command
 244  * @return 0 on success, non-0 on error
 245  *
 246  * The remaining arguments are command arguments, terminated by (char
 247  * *)0.  They should be in UTF-8.
 248  *
 249  * 5xx responses count as errors.
 250  *
 251  * @p rp will NOT be filled in for xx9 responses (where it is just
 252  * commentary for a command where it would normally be meaningful).
 253  *
 254  * NB that the response will NOT be converted to the local encoding
 255  * nor will quotes be stripped.  See dequote().
 256  */
 257 static int disorder_simple(disorder_client *c,
 258                            char **rp,
 259                            const char *cmd, ...) {
 260   va_list ap;
 261   int ret;
 262
 263   va_start(ap, cmd);
 264   ret = disorder_simple_v(c, rp, cmd, ap);
 265   va_end(ap);
 266   return ret;
 267 }
 268
 269 /** @brief Dequote a result string
 270  * @param rc 0 on success, non-0 on error
 271  * @param rp Where result string is stored (UTF-8)
 272  * @return @p rc
 273  *
 274  * This is used as a wrapper around disorder_simple() to dequote
 275  * results in place.
 276  */
 277 static int dequote(int rc, char **rp) {
 278   char **rr;
 279
 280   if(!rc) {
 281     if((rr = split(*rp, 0, SPLIT_QUOTES, 0, 0)) && *rr) {
 282       xfree(*rp);
 283       *rp = *rr;
 284       xfree(rr);
 285       return 0;
 286     }
 287     disorder_error(0, "invalid reply: %s", *rp);
 288   }
 289   return rc;
 290 }
 291
 292 /** @brief Generic connection routine
 293  * @param conf Configuration to follow
 294  * @param c Client
 295  * @param username Username to log in with or NULL
 296  * @param password Password to log in with or NULL
 297  * @param cookie Cookie to log in with or NULL
 298  * @return 0 on success, non-0 on error
 299  *
 300  * @p cookie is tried first if not NULL.  If it is NULL then @p
 301  * username must not be.  If @p username is not NULL then nor may @p
 302  * password be.
 303  */
 304 int disorder_connect_generic(struct config *conf,
 305                              disorder_client *c,
 306                              const char *username,
 307                              const char *password,
 308                              const char *cookie) {
 309   int fd = -1, fd2 = -1, nrvec = 0, rc;
 310   unsigned char *nonce = NULL;
 311   size_t nl;
 312   char *res = NULL;
 313   char *r = NULL, **rvec = NULL;
 314   const char *protocol, *algorithm, *challenge;
 315   struct sockaddr *sa = NULL;
 316   socklen_t salen;
 317
 318   if((salen = find_server(conf, &sa, &c->ident)) == (socklen_t)-1)
 319     return -1;
 320   c->fpin = c->fpout = 0;
 321   if((fd = socket(sa->sa_family, SOCK_STREAM, 0)) < 0) {
 322     byte_xasprintf((char **)&c->last, "socket: %s", strerror(errno));
 323     disorder_error(errno, "error calling socket");
 324     return -1;
 325   }
 326   if(connect(fd, sa, salen) < 0) {
 327     byte_xasprintf((char **)&c->last, "connect: %s", strerror(errno));
 328     disorder_error(errno, "error calling connect");
 329     goto error;
 330   }
 331   if((fd2 = dup(fd)) < 0) {
 332     byte_xasprintf((char **)&c->last, "dup: %s", strerror(errno));
 333     disorder_error(errno, "error calling dup");
 334     goto error;
 335   }
 336   if(!(c->fpin = fdopen(fd, "rb"))) {
 337     byte_xasprintf((char **)&c->last, "fdopen: %s", strerror(errno));
 338     disorder_error(errno, "error calling fdopen");
 339     goto error;
 340   }
 341   fd = -1;
 342   if(!(c->fpout = fdopen(fd2, "wb"))) {
 343     byte_xasprintf((char **)&c->last, "fdopen: %s", strerror(errno));
 344     disorder_error(errno, "error calling fdopen");
 345     goto error;
 346   }
 347   fd2 = -1;
 348   if((rc = disorder_simple(c, &r, 0, (const char *)0)))
 349     goto error_rc;
 350   if(!(rvec = split(r, &nrvec, SPLIT_QUOTES, 0, 0)))
 351     goto error;
 352   if(nrvec != 3) {
 353     c->last = "cannot parse server greeting";
 354     disorder_error(0, "cannot parse server greeting %s", r);
 355     goto error;
 356   }
 357   protocol = rvec[0];
 358   if(strcmp(protocol, "2")) {
 359     c->last = "unknown protocol version";
 360     disorder_error(0, "unknown protocol version: %s", protocol);
 361     goto error;
 362   }
 363   algorithm = rvec[1];
 364   challenge = rvec[2];
 365   if(!(nonce = unhex(challenge, &nl)))
 366     goto error;
 367   if(cookie) {
 368     if(!dequote(disorder_simple(c, &c->user, "cookie", cookie, (char *)0),
 369                 &c->user))
 370       return 0;                         /* success */
 371     if(!username) {
 372       c->last = "cookie failed and no username";
 373       disorder_error(0, "cookie did not work and no username available");
 374       goto error;
 375     }
 376   }
 377   if(!(res = authhash(nonce, nl, password, algorithm))) {
 378     c->last = "error computing authorization hash";
 379     goto error;
 380   }
 381   if((rc = disorder_simple(c, 0, "user", username, res, (char *)0)))
 382     goto error_rc;
 383   c->user = xstrdup(username);
 384   xfree(res);
 385   free_strings(nrvec, rvec);
 386   xfree(nonce);
 387   xfree(sa);
 388   xfree(r);
 389   return 0;
 390 error:
 391   rc = -1;
 392 error_rc:
 393   if(c->fpin) {
 394     fclose(c->fpin);
 395     c->fpin = 0;
 396   }
 397   if(c->fpout) {
 398     fclose(c->fpout);
 399     c->fpout = 0;
 400   }
 401   if(fd2 != -1) close(fd2);
 402   if(fd != -1) close(fd);
 403   return rc;
 404 }
 405
 406 /** @brief Connect a client with a specified username and password
 407  * @param c Client
 408  * @param username Username to log in with
 409  * @param password Password to log in with
 410  * @return 0 on success, non-0 on error
 411  */
 412 int disorder_connect_user(disorder_client *c,
 413                           const char *username,
 414                           const char *password) {
 415   return disorder_connect_generic(config,
 416                                   c,
 417                                   username,
 418                                   password,
 419                                   0);
 420 }
 421
 422 /** @brief Connect a client
 423  * @param c Client
 424  * @return 0 on success, non-0 on error
 425  *
 426  * The connection will use the username and password found in @ref
 427  * config, or directly from the database if no password is found and
 428  * the database is readable (usually only for root).
 429  */
 430 int disorder_connect(disorder_client *c) {
 431   const char *username, *password;
 432
 433   if(!(username = config->username)) {
 434     c->last = "no username";
 435     disorder_error(0, "no username configured");
 436     return -1;
 437   }
 438   password = config->password;
 439   /* Maybe we can read the database */
 440   if(!password && trackdb_readable()) {
 441     trackdb_init(TRACKDB_NO_RECOVER|TRACKDB_NO_UPGRADE);
 442     trackdb_open(TRACKDB_READ_ONLY);
 443     password = trackdb_get_password(username);
 444     trackdb_close();
 445   }
 446   if(!password) {
 447     /* Oh well */
 448     c->last = "no password";
 449     disorder_error(0, "no password configured for user '%s'", username);
 450     return -1;
 451   }
 452   return disorder_connect_generic(config,
 453                                   c,
 454                                   username,
 455                                   password,
 456                                   0);
 457 }
 458
 459 /** @brief Connect a client
 460  * @param c Client
 461  * @param cookie Cookie to log in with, or NULL
 462  * @return 0 on success, non-0 on error
 463  *
 464  * If @p cookie is NULL or does not work then we attempt to log in as
 465  * guest instead (so when the cookie expires only an extra round trip
 466  * is needed rathre than a complete new login).
 467  */
 468 int disorder_connect_cookie(disorder_client *c,
 469                             const char *cookie) {
 470   return disorder_connect_generic(config,
 471                                   c,
 472                                   "guest",
 473                                   "",
 474                                   cookie);
 475 }
 476
 477 /** @brief Close a client
 478  * @param c Client
 479  * @return 0 on succcess, non-0 on errior
 480  *
 481  * The client is still closed even on error.  It might well be
 482  * appropriate to ignore the return value.
 483  */
 484 int disorder_close(disorder_client *c) {
 485   int ret = 0;
 486
 487   if(c->fpin) {
 488     if(fclose(c->fpin) < 0) {
 489       byte_xasprintf((char **)&c->last, "fclose: %s", strerror(errno));
 490       disorder_error(errno, "error calling fclose");
 491       ret = -1;
 492     }
 493     c->fpin = 0;
 494   }
 495   if(c->fpout) {
 496     if(fclose(c->fpout) < 0) {
 497       byte_xasprintf((char **)&c->last, "fclose: %s", strerror(errno));
 498       disorder_error(errno, "error calling fclose");
 499       ret = -1;
 500     }
 501     c->fpout = 0;
 502   }
 503   xfree(c->ident);
 504   c->ident = 0;
 505   xfree(c->user);
 506   c->user = 0;
 507   return ret;
 508 }
 509
 510 /** @brief Move a track
 511  * @param c Client
 512  * @param track Track to move (UTF-8)
 513  * @param delta Distance to move by
 514  * @return 0 on success, non-0 on error
 515  */
 516 int disorder_move(disorder_client *c, const char *track, int delta) {
 517   char d[16];
 518
 519   byte_snprintf(d, sizeof d, "%d", delta);
 520   return disorder_simple(c, 0, "move", track, d, (char *)0);
 521 }
 522
 523 static void client_error(const char *msg,
 524                          void attribute((unused)) *u) {
 525   disorder_error(0, "error parsing reply: %s", msg);
 526 }
 527
 528 /** @brief Get currently playing track
 529  * @param c Client
 530  * @param qp Where to store track information
 531  * @return 0 on success, non-0 on error
 532  *
 533  * @p qp gets NULL if no track is playing.
 534  */
 535 int disorder_playing(disorder_client *c, struct queue_entry **qp) {
 536   char *r;
 537   struct queue_entry *q;
 538   int rc;
 539
 540   if((rc = disorder_simple(c, &r, "playing", (char *)0)))
 541     return rc;
 542   if(r) {
 543     q = xmalloc(sizeof *q);
 544     if(queue_unmarshall(q, r, client_error, 0))
 545       return -1;
 546     *qp = q;
 547   } else
 548     *qp = 0;
 549   return 0;
 550 }
 551
 552 /** @brief Fetch the queue, recent list, etc */
 553 static int disorder_somequeue(disorder_client *c,
 554                               const char *cmd, struct queue_entry **qp) {
 555   struct queue_entry *qh, **qt = &qh, *q;
 556   char *l;
 557   int rc;
 558
 559   if((rc = disorder_simple(c, 0, cmd, (char *)0)))
 560     return rc;
 561   while(inputline(c->ident, c->fpin, &l, '\n') >= 0) {
 562     if(!strcmp(l, ".")) {
 563       *qt = 0;
 564       *qp = qh;
 565       xfree(l);
 566       return 0;
 567     }
 568     q = xmalloc(sizeof *q);
 569     if(!queue_unmarshall(q, l, client_error, 0)) {
 570       *qt = q;
 571       qt = &q->next;
 572     }
 573     xfree(l);
 574   }
 575   if(ferror(c->fpin)) {
 576     byte_xasprintf((char **)&c->last, "input error: %s", strerror(errno));
 577     disorder_error(errno, "error reading %s", c->ident);
 578   } else {
 579     c->last = "input error: unexpxected EOF";
 580     disorder_error(0, "error reading %s: unexpected EOF", c->ident);
 581   }
 582   return -1;
 583 }
 584
 585 /** @brief Read a dot-stuffed list
 586  * @param c Client
 587  * @param vecp Where to store list (UTF-8)
 588  * @param nvecp Where to store number of items, or NULL
 589  * @return 0 on success, non-0 on error
 590  *
 591  * The list will have a final NULL not counted in @p nvecp.
 592  */
 593 static int readlist(disorder_client *c, char ***vecp, int *nvecp) {
 594   char *l;
 595   struct vector v;
 596
 597   vector_init(&v);
 598   while(inputline(c->ident, c->fpin, &l, '\n') >= 0) {
 599     if(!strcmp(l, ".")) {
 600       vector_terminate(&v);
 601       if(nvecp)
 602         *nvecp = v.nvec;
 603       *vecp = v.vec;
 604       xfree(l);
 605       return 0;
 606     }
 607     vector_append(&v, xstrdup(l + (*l == '.')));
 608     xfree(l);
 609   }
 610   if(ferror(c->fpin)) {
 611     byte_xasprintf((char **)&c->last, "input error: %s", strerror(errno));
 612     disorder_error(errno, "error reading %s", c->ident);
 613   } else {
 614     c->last = "input error: unexpxected EOF";
 615     disorder_error(0, "error reading %s: unexpected EOF", c->ident);
 616   }
 617   return -1;
 618 }
 619
 620 /** @brief Issue a comamnd and get a list response
 621  * @param c Client
 622  * @param vecp Where to store list (UTF-8)
 623  * @param nvecp Where to store number of items, or NULL
 624  * @param cmd Command
 625  * @return 0 on success, non-0 on error
 626  *
 627  * The remaining arguments are command arguments, terminated by (char
 628  * *)0.  They should be in UTF-8.
 629  *
 630  * 5xx responses count as errors.
 631  *
 632  * See disorder_simple().
 633  */
 634 static int disorder_simple_list(disorder_client *c,
 635                                 char ***vecp, int *nvecp,
 636                                 const char *cmd, ...) {
 637   va_list ap;
 638   int ret;
 639
 640   va_start(ap, cmd);
 641   ret = disorder_simple_v(c, 0, cmd, ap);
 642   va_end(ap);
 643   if(ret) return ret;
 644   return readlist(c, vecp, nvecp);
 645 }
 646
 647 /** @brief Return the user we logged in with
 648  * @param c Client
 649  * @return User name (owned by @p c, don't modify)
 650  */
 651 char *disorder_user(disorder_client *c) {
 652   return c->user;
 653 }
 654
 655 static void pref_error_handler(const char *msg,
 656                                void attribute((unused)) *u) {
 657   disorder_error(0, "error handling 'prefs' reply: %s", msg);
 658 }
 659
 660 /** @brief Get all preferences for a trcak
 661  * @param c Client
 662  * @param track Track name
 663  * @param kp Where to store linked list of preferences
 664  * @return 0 on success, non-0 on error
 665  */
 666 int disorder_prefs(disorder_client *c, const char *track, struct kvp **kp) {
 667   char **vec, **pvec;
 668   int nvec, npvec, n, rc;
 669   struct kvp *k;
 670
 671   if((rc = disorder_simple_list(c, &vec, &nvec, "prefs", track, (char *)0)))
 672     return rc;
 673   for(n = 0; n < nvec; ++n) {
 674     if(!(pvec = split(vec[n], &npvec, SPLIT_QUOTES, pref_error_handler, 0)))
 675       return -1;
 676     if(npvec != 2) {
 677       pref_error_handler("malformed response", 0);
 678       return -1;
 679     }
 680     *kp = k = xmalloc(sizeof *k);
 681     k->name = pvec[0];
 682     k->value = pvec[1];
 683     kp = &k->next;
 684     xfree(pvec);
 685   }
 686   free_strings(nvec, vec);
 687   *kp = 0;
 688   return 0;
 689 }
 690
 691 /** @brief Parse a boolean response
 692  * @param cmd Command for use in error messsage
 693  * @param value Result from server
 694  * @param flagp Where to store result
 695  * @return 0 on success, non-0 on error
 696  */
 697 static int boolean(const char *cmd, const char *value,
 698                    int *flagp) {
 699   if(!strcmp(value, "yes")) *flagp = 1;
 700   else if(!strcmp(value, "no")) *flagp = 0;
 701   else {
 702     disorder_error(0, "malformed response to '%s'", cmd);
 703     return -1;
 704   }
 705   return 0;
 706 }
 707
 708 /** @brief Set volume
 709  * @param c Client
 710  * @param left New left channel value
 711  * @param right New right channel value
 712  * @return 0 on success, non-0 on error
 713  */
 714 int disorder_set_volume(disorder_client *c, int left, int right) {
 715   char *ls, *rs;
 716
 717   if(byte_asprintf(&ls, "%d", left) < 0
 718      || byte_asprintf(&rs, "%d", right) < 0)
 719     return -1;
 720   return disorder_simple(c, 0, "volume", ls, rs, (char *)0);
 721 }
 722
 723 /** @brief Get volume
 724  * @param c Client
 725  * @param left Where to store left channel value
 726  * @param right Where to store right channel value
 727  * @return 0 on success, non-0 on error
 728  */
 729 int disorder_get_volume(disorder_client *c, int *left, int *right) {
 730   char *r;
 731   int rc;
 732
 733   if((rc = disorder_simple(c, &r, "volume", (char *)0)))
 734     return rc;
 735   if(sscanf(r, "%d %d", left, right) != 2) {
 736     c->last = "malformed volume response";
 737     disorder_error(0, "error parsing response to 'volume': '%s'", r);
 738     return -1;
 739   }
 740   return 0;
 741 }
 742
 743 /** @brief Log to a sink
 744  * @param c Client
 745  * @param s Sink to write log lines to
 746  * @return 0 on success, non-0 on error
 747  */
 748 int disorder_log(disorder_client *c, struct sink *s) {
 749   char *l;
 750   int rc;
 751
 752   if((rc = disorder_simple(c, 0, "log", (char *)0)))
 753     return rc;
 754   while(inputline(c->ident, c->fpin, &l, '\n') >= 0 && strcmp(l, "."))
 755     if(sink_printf(s, "%s\n", l) < 0) return -1;
 756   if(ferror(c->fpin) || feof(c->fpin)) {
 757     byte_xasprintf((char **)&c->last, "input error: %s",
 758                    ferror(c->fpin) ? strerror(errno) : "unexpxected EOF");
 759     return -1;
 760   }
 761   return 0;
 762 }
 763
 764 /** @brief Get recently added tracks
 765  * @param c Client
 766  * @param vecp Where to store pointer to list (UTF-8)
 767  * @param nvecp Where to store count
 768  * @param max Maximum tracks to fetch, or 0 for all available
 769  * @return 0 on success, non-0 on error
 770  */
 771 int disorder_new_tracks(disorder_client *c,
 772                         char ***vecp, int *nvecp,
 773                         int max) {
 774   char limit[32];
 775
 776   sprintf(limit, "%d", max);
 777   return disorder_simple_list(c, vecp, nvecp, "new", limit, (char *)0);
 778 }
 779
 780 /** @brief Get server's RTP address information
 781  * @param c Client
 782  * @param addressp Where to store address (UTF-8)
 783  * @param portp Where to store port (UTF-8)
 784  * @return 0 on success, non-0 on error
 785  */
 786 int disorder_rtp_address(disorder_client *c, char **addressp, char **portp) {
 787   char *r;
 788   int rc, n;
 789   char **vec;
 790
 791   if((rc = disorder_simple(c, &r, "rtp-address", (char *)0)))
 792     return rc;
 793   vec = split(r, &n, SPLIT_QUOTES, 0, 0);
 794   if(n != 2) {
 795     c->last = "malformed RTP address";
 796     disorder_error(0, "malformed rtp-address reply");
 797     return -1;
 798   }
 799   *addressp = vec[0];
 800   *portp = vec[1];
 801   return 0;
 802 }
 803
 804 /** @brief Get details of a scheduled event
 805  * @param c Client
 806  * @param id Event ID
 807  * @param actiondatap Where to put details
 808  * @return 0 on success, non-0 on error
 809  */
 810 int disorder_schedule_get(disorder_client *c, const char *id,
 811                           struct kvp **actiondatap) {
 812   char **lines, **bits;
 813   int rc, nbits;
 814
 815   *actiondatap = 0;
 816   if((rc = disorder_simple_list(c, &lines, NULL,
 817                                 "schedule-get", id, (char *)0)))
 818     return rc;
 819   while(*lines) {
 820     if(!(bits = split(*lines++, &nbits, SPLIT_QUOTES, 0, 0))) {
 821       disorder_error(0, "invalid schedule-get reply: cannot split line");
 822       return -1;
 823     }
 824     if(nbits != 2) {
 825       disorder_error(0, "invalid schedule-get reply: wrong number of fields");
 826       return -1;
 827     }
 828     kvp_set(actiondatap, bits[0], bits[1]);
 829   }
 830   return 0;
 831 }
 832
 833 /** @brief Add a scheduled event
 834  * @param c Client
 835  * @param when When to trigger the event
 836  * @param priority Event priority ("normal" or "junk")
 837  * @param action What action to perform
 838  * @param ... Action-specific arguments
 839  * @return 0 on success, non-0 on error
 840  *
 841  * For action @c "play" the next argument is the track.
 842  *
 843  * For action @c "set-global" next argument is the global preference name
 844  * and the final argument the value to set it to, or (char *)0 to unset it.
 845  */
 846 int disorder_schedule_add(disorder_client *c,
 847                           time_t when,
 848                           const char *priority,
 849                           const char *action,
 850                           ...) {
 851   va_list ap;
 852   char when_str[64];
 853   int rc;
 854
 855   snprintf(when_str, sizeof when_str, "%lld", (long long)when);
 856   va_start(ap, action);
 857   if(!strcmp(action, "play"))
 858     rc = disorder_simple(c, 0, "schedule-add", when_str, priority,
 859                          action, va_arg(ap, char *),
 860                          (char *)0);
 861   else if(!strcmp(action, "set-global")) {
 862     const char *key = va_arg(ap, char *);
 863     const char *value = va_arg(ap, char *);
 864     rc = disorder_simple(c, 0,"schedule-add",  when_str, priority,
 865                          action, key, value,
 866                          (char *)0);
 867   } else
 868     disorder_fatal(0, "unknown action '%s'", action);
 869   va_end(ap);
 870   return rc;
 871 }
 872
 873 #include "client-stubs.c"
 874
 875 /*
 876 Local Variables:
 877 c-basic-offset:2
 878 comment-column:40
 879 End:
 880 */