| 1 | /* |
| 2 | * This file is part of DisOrder |
| 3 | * Copyright (C) 2008 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 2 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, but |
| 11 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | * 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, write to the Free Software |
| 17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 |
| 18 | * USA |
| 19 | */ |
| 20 | /** @file lib/trackdb-playlists.c |
| 21 | * @brief Track database playlist support |
| 22 | * |
| 23 | * This file implements reading and modification of playlists, including access |
| 24 | * control, but not locking or event logging (at least yet). |
| 25 | */ |
| 26 | #include "common.h" |
| 27 | |
| 28 | #include <errno.h> |
| 29 | |
| 30 | #include "trackdb-int.h" |
| 31 | #include "mem.h" |
| 32 | #include "log.h" |
| 33 | #include "configuration.h" |
| 34 | #include "vector.h" |
| 35 | #include "eventlog.h" |
| 36 | |
| 37 | static int trackdb_playlist_get_tid(const char *name, |
| 38 | const char *who, |
| 39 | char ***tracksp, |
| 40 | int *ntracksp, |
| 41 | char **sharep, |
| 42 | DB_TXN *tid); |
| 43 | static int trackdb_playlist_set_tid(const char *name, |
| 44 | const char *who, |
| 45 | char **tracks, |
| 46 | int ntracks, |
| 47 | const char *share, |
| 48 | DB_TXN *tid); |
| 49 | static int trackdb_playlist_list_tid(const char *who, |
| 50 | char ***playlistsp, |
| 51 | int *nplaylistsp, |
| 52 | DB_TXN *tid); |
| 53 | static int trackdb_playlist_delete_tid(const char *name, |
| 54 | const char *who, |
| 55 | DB_TXN *tid); |
| 56 | |
| 57 | /** @brief Parse a playlist name |
| 58 | * @param name Playlist name |
| 59 | * @param ownerp Where to put owner, or NULL |
| 60 | * @param sharep Where to put default sharing, or NULL |
| 61 | * @return 0 on success, -1 on error |
| 62 | * |
| 63 | * Playlists take the form USER.PLAYLIST or just PLAYLIST. The PLAYLIST part |
| 64 | * is alphanumeric and nonempty. USER is a username (see valid_username()). |
| 65 | */ |
| 66 | int playlist_parse_name(const char *name, |
| 67 | char **ownerp, |
| 68 | char **sharep) { |
| 69 | const char *dot = strchr(name, '.'), *share; |
| 70 | char *owner; |
| 71 | |
| 72 | if(dot) { |
| 73 | /* Owned playlist */ |
| 74 | owner = xstrndup(name, dot - name); |
| 75 | if(!valid_username(owner)) |
| 76 | return -1; |
| 77 | if(!valid_username(dot + 1)) |
| 78 | return -1; |
| 79 | share = "private"; |
| 80 | } else { |
| 81 | /* Shared playlist */ |
| 82 | if(!valid_username(name)) |
| 83 | return -1; |
| 84 | owner = 0; |
| 85 | share = "shared"; |
| 86 | } |
| 87 | if(ownerp) |
| 88 | *ownerp = owner; |
| 89 | if(sharep) |
| 90 | *sharep = xstrdup(share); |
| 91 | return 0; |
| 92 | } |
| 93 | |
| 94 | /** @brief Check read access rights |
| 95 | * @param name Playlist name |
| 96 | * @param who Who wants to read |
| 97 | * @param share Playlist share status |
| 98 | */ |
| 99 | static int playlist_may_read(const char *name, |
| 100 | const char *who, |
| 101 | const char *share) { |
| 102 | char *owner; |
| 103 | |
| 104 | if(playlist_parse_name(name, &owner, 0)) |
| 105 | return 0; |
| 106 | /* Anyone can read shared playlists */ |
| 107 | if(!owner) |
| 108 | return 1; |
| 109 | /* You can always read playlists you own */ |
| 110 | if(!strcmp(owner, who)) |
| 111 | return 1; |
| 112 | /* You can read public playlists */ |
| 113 | if(!strcmp(share, "public")) |
| 114 | return 1; |
| 115 | /* Anything else is prohibited */ |
| 116 | return 0; |
| 117 | } |
| 118 | |
| 119 | /** @brief Check modify access rights |
| 120 | * @param name Playlist name |
| 121 | * @param who Who wants to modify |
| 122 | * @param share Playlist share status |
| 123 | */ |
| 124 | static int playlist_may_write(const char *name, |
| 125 | const char *who, |
| 126 | const char attribute((unused)) *share) { |
| 127 | char *owner; |
| 128 | |
| 129 | if(playlist_parse_name(name, &owner, 0)) |
| 130 | return 0; |
| 131 | /* Anyone can modify shared playlists */ |
| 132 | if(!owner) |
| 133 | return 1; |
| 134 | /* You can always modify playlists you own */ |
| 135 | if(!strcmp(owner, who)) |
| 136 | return 1; |
| 137 | /* Anything else is prohibited */ |
| 138 | return 0; |
| 139 | } |
| 140 | |
| 141 | /** @brief Get playlist data |
| 142 | * @param name Name of playlist |
| 143 | * @param who Who wants to know |
| 144 | * @param tracksp Where to put list of tracks, or NULL |
| 145 | * @param ntracksp Where to put count of tracks, or NULL |
| 146 | * @param sharep Where to put sharing type, or NULL |
| 147 | * @return 0 on success, non-0 on error |
| 148 | * |
| 149 | * Possible return values: |
| 150 | * - @c 0 on success |
| 151 | * - @c ENOENT if the playlist doesn't exist |
| 152 | * - @c EINVAL if the playlist name is invalid |
| 153 | * - @c EACCES if the playlist cannot be read by @p who |
| 154 | */ |
| 155 | int trackdb_playlist_get(const char *name, |
| 156 | const char *who, |
| 157 | char ***tracksp, |
| 158 | int *ntracksp, |
| 159 | char **sharep) { |
| 160 | int e; |
| 161 | |
| 162 | if(playlist_parse_name(name, 0, 0)) { |
| 163 | error(0, "invalid playlist name '%s'", name); |
| 164 | return EINVAL; |
| 165 | } |
| 166 | WITH_TRANSACTION(trackdb_playlist_get_tid(name, who, |
| 167 | tracksp, ntracksp, sharep, |
| 168 | tid)); |
| 169 | /* Don't expose libdb error codes too much */ |
| 170 | if(e == DB_NOTFOUND) |
| 171 | e = ENOENT; |
| 172 | return e; |
| 173 | } |
| 174 | |
| 175 | static int trackdb_playlist_get_tid(const char *name, |
| 176 | const char *who, |
| 177 | char ***tracksp, |
| 178 | int *ntracksp, |
| 179 | char **sharep, |
| 180 | DB_TXN *tid) { |
| 181 | struct kvp *k; |
| 182 | int e, ntracks; |
| 183 | const char *s; |
| 184 | |
| 185 | if((e = trackdb_getdata(trackdb_playlistsdb, name, &k, tid))) |
| 186 | return e; |
| 187 | /* Get sharability */ |
| 188 | if(!(s = kvp_get(k, "sharing"))) { |
| 189 | error(0, "playlist '%s' has no 'sharing' key", name); |
| 190 | s = "private"; |
| 191 | } |
| 192 | /* Check the read is allowed */ |
| 193 | if(!playlist_may_read(name, who, s)) |
| 194 | return EACCES; |
| 195 | /* Return sharability */ |
| 196 | if(sharep) |
| 197 | *sharep = xstrdup(s); |
| 198 | /* Get track count */ |
| 199 | if(!(s = kvp_get(k, "count"))) { |
| 200 | error(0, "playlist '%s' has no 'count' key", name); |
| 201 | s = "0"; |
| 202 | } |
| 203 | ntracks = atoi(s); |
| 204 | if(ntracks < 0) { |
| 205 | error(0, "playlist '%s' has negative count", name); |
| 206 | ntracks = 0; |
| 207 | } |
| 208 | /* Return track count */ |
| 209 | if(ntracksp) |
| 210 | *ntracksp = ntracks; |
| 211 | if(tracksp) { |
| 212 | /* Get track list */ |
| 213 | char **tracks = xcalloc(ntracks + 1, sizeof (char *)); |
| 214 | char b[16]; |
| 215 | |
| 216 | for(int n = 0; n < ntracks; ++n) { |
| 217 | snprintf(b, sizeof b, "%d", n); |
| 218 | if(!(s = kvp_get(k, b))) { |
| 219 | error(0, "playlist '%s' lacks track %d", name, n); |
| 220 | s = "unknown"; |
| 221 | } |
| 222 | tracks[n] = xstrdup(s); |
| 223 | } |
| 224 | tracks[ntracks] = 0; |
| 225 | /* Return track list */ |
| 226 | *tracksp = tracks; |
| 227 | } |
| 228 | return 0; |
| 229 | } |
| 230 | |
| 231 | /** @brief Modify or create a playlist |
| 232 | * @param name Playlist name |
| 233 | * @param who User modifying playlist |
| 234 | * @param tracks List of tracks to set, or NULL to leave alone |
| 235 | * @param ntracks Length of @p tracks |
| 236 | * @param share Sharing status, or NULL to leave alone |
| 237 | * @return 0 on success, non-0 on error |
| 238 | * |
| 239 | * If the playlist exists it is just modified. |
| 240 | * |
| 241 | * If the playlist does not exist it is created. The default set of tracks is |
| 242 | * none, and the default sharing is private (if it is an owned one) or shared |
| 243 | * (otherwise). |
| 244 | * |
| 245 | * If neither @c tracks nor @c share are set then we only do an access check. |
| 246 | * The database is never modified (even to create the playlist) in this |
| 247 | * situation. |
| 248 | * |
| 249 | * Possible return values: |
| 250 | * - @c 0 on success |
| 251 | * - @c EINVAL if the playlist name is invalid |
| 252 | * - @c EACCES if the playlist cannot be modified by @p who |
| 253 | */ |
| 254 | int trackdb_playlist_set(const char *name, |
| 255 | const char *who, |
| 256 | char **tracks, |
| 257 | int ntracks, |
| 258 | const char *share) { |
| 259 | int e; |
| 260 | char *owner; |
| 261 | |
| 262 | if(playlist_parse_name(name, &owner, 0)) { |
| 263 | error(0, "invalid playlist name '%s'", name); |
| 264 | return EINVAL; |
| 265 | } |
| 266 | /* Check valid share types */ |
| 267 | if(share) { |
| 268 | if(owner) { |
| 269 | /* Playlists with an owner must be public or private */ |
| 270 | if(strcmp(share, "public") |
| 271 | && strcmp(share, "private")) { |
| 272 | error(0, "playlist '%s' must be public or private", name); |
| 273 | return EINVAL; |
| 274 | } |
| 275 | } else { |
| 276 | /* Playlists with no owner must be shared */ |
| 277 | if(strcmp(share, "shared")) { |
| 278 | error(0, "playlist '%s' must be shared", name); |
| 279 | return EINVAL; |
| 280 | } |
| 281 | } |
| 282 | } |
| 283 | /* We've checked as much as we can for now, now go and attempt the change */ |
| 284 | WITH_TRANSACTION(trackdb_playlist_set_tid(name, who, tracks, ntracks, share, |
| 285 | tid)); |
| 286 | return e; |
| 287 | } |
| 288 | |
| 289 | static int trackdb_playlist_set_tid(const char *name, |
| 290 | const char *who, |
| 291 | char **tracks, |
| 292 | int ntracks, |
| 293 | const char *share, |
| 294 | DB_TXN *tid) { |
| 295 | struct kvp *k; |
| 296 | int e; |
| 297 | const char *s; |
| 298 | const char *event = "playlist_modified"; |
| 299 | |
| 300 | if((e = trackdb_getdata(trackdb_playlistsdb, name, &k, tid)) |
| 301 | && e != DB_NOTFOUND) |
| 302 | return e; |
| 303 | /* If the playlist doesn't exist set some defaults */ |
| 304 | if(e == DB_NOTFOUND) { |
| 305 | char *defshare, *owner; |
| 306 | |
| 307 | if(playlist_parse_name(name, &owner, &defshare)) |
| 308 | return EINVAL; |
| 309 | /* Can't create a non-shared playlist belonging to someone else. In fact |
| 310 | * this should be picked up by playlist_may_write() below but it's clearer |
| 311 | * to do it here. */ |
| 312 | if(owner && strcmp(owner, who)) |
| 313 | return EACCES; |
| 314 | k = 0; |
| 315 | kvp_set(&k, "count", 0); |
| 316 | kvp_set(&k, "sharing", defshare); |
| 317 | event = "playlist_created"; |
| 318 | } |
| 319 | /* Check that the modification is allowed */ |
| 320 | if(!(s = kvp_get(k, "sharing"))) { |
| 321 | error(0, "playlist '%s' has no 'sharing' key", name); |
| 322 | s = "private"; |
| 323 | } |
| 324 | if(!playlist_may_write(name, who, s)) |
| 325 | return EACCES; |
| 326 | /* If no change was requested then don't even create */ |
| 327 | if(!share && !tracks) |
| 328 | return 0; |
| 329 | /* Set the new values */ |
| 330 | if(share) |
| 331 | kvp_set(&k, "sharing", share); |
| 332 | if(tracks) { |
| 333 | char b[16]; |
| 334 | int oldcount, n; |
| 335 | |
| 336 | /* Sanity check track count */ |
| 337 | if(ntracks < 0 || ntracks > config->playlist_max) { |
| 338 | error(0, "invalid track count %d", ntracks); |
| 339 | return EINVAL; |
| 340 | } |
| 341 | /* Set the tracks */ |
| 342 | for(n = 0; n < ntracks; ++n) { |
| 343 | snprintf(b, sizeof b, "%d", n); |
| 344 | kvp_set(&k, b, tracks[n]); |
| 345 | } |
| 346 | /* Get the old track count */ |
| 347 | if((s = kvp_get(k, "count"))) |
| 348 | oldcount = atoi(s); |
| 349 | else |
| 350 | oldcount = 0; |
| 351 | /* Delete old slots */ |
| 352 | for(; n < oldcount; ++n) { |
| 353 | snprintf(b, sizeof b, "%d", n); |
| 354 | kvp_set(&k, b, NULL); |
| 355 | } |
| 356 | /* Set the new count */ |
| 357 | snprintf(b, sizeof b, "%d", ntracks); |
| 358 | kvp_set(&k, "count", b); |
| 359 | } |
| 360 | /* Store the resulting record */ |
| 361 | e = trackdb_putdata(trackdb_playlistsdb, name, k, tid, 0); |
| 362 | /* Log the event */ |
| 363 | if(!e) |
| 364 | eventlog(event, name, kvp_get(k, "sharing"), (char *)0); |
| 365 | return e; |
| 366 | } |
| 367 | |
| 368 | /** @brief Get a list of playlists |
| 369 | * @param who Who wants to know |
| 370 | * @param playlistsp Where to put list of playlists |
| 371 | * @param nplaylistsp Where to put count of playlists, or NULL |
| 372 | */ |
| 373 | void trackdb_playlist_list(const char *who, |
| 374 | char ***playlistsp, |
| 375 | int *nplaylistsp) { |
| 376 | int e; |
| 377 | |
| 378 | WITH_TRANSACTION(trackdb_playlist_list_tid(who, playlistsp, nplaylistsp, |
| 379 | tid)); |
| 380 | } |
| 381 | |
| 382 | static int trackdb_playlist_list_tid(const char *who, |
| 383 | char ***playlistsp, |
| 384 | int *nplaylistsp, |
| 385 | DB_TXN *tid) { |
| 386 | struct vector v[1]; |
| 387 | DBC *c; |
| 388 | DBT k[1], d[1]; |
| 389 | int e; |
| 390 | |
| 391 | vector_init(v); |
| 392 | c = trackdb_opencursor(trackdb_playlistsdb, tid); |
| 393 | memset(k, 0, sizeof k); |
| 394 | while(!(e = c->c_get(c, k, prepare_data(d), DB_NEXT))) { |
| 395 | char *name = xstrndup(k->data, k->size), *owner; |
| 396 | const char *share = kvp_get(kvp_urldecode(d->data, d->size), |
| 397 | "sharing"); |
| 398 | |
| 399 | /* Extract owner; malformed names are skipped */ |
| 400 | if(playlist_parse_name(name, &owner, 0)) { |
| 401 | error(0, "invalid playlist name '%s' found in database", name); |
| 402 | continue; |
| 403 | } |
| 404 | if(!share) { |
| 405 | error(0, "playlist '%s' has no 'sharing' key", name); |
| 406 | continue; |
| 407 | } |
| 408 | /* Always list public and shared playlists |
| 409 | * Only list private ones to their owner |
| 410 | * Don't list anything else |
| 411 | */ |
| 412 | if(!strcmp(share, "public") |
| 413 | || !strcmp(share, "shared") |
| 414 | || (!strcmp(share, "private") |
| 415 | && owner && !strcmp(owner, who))) |
| 416 | vector_append(v, name); |
| 417 | } |
| 418 | trackdb_closecursor(c); |
| 419 | switch(e) { |
| 420 | case DB_NOTFOUND: |
| 421 | break; |
| 422 | case DB_LOCK_DEADLOCK: |
| 423 | return e; |
| 424 | default: |
| 425 | fatal(0, "c->c_get: %s", db_strerror(e)); |
| 426 | } |
| 427 | vector_terminate(v); |
| 428 | if(playlistsp) |
| 429 | *playlistsp = v->vec; |
| 430 | if(nplaylistsp) |
| 431 | *nplaylistsp = v->nvec; |
| 432 | return 0; |
| 433 | } |
| 434 | |
| 435 | /** @brief Delete a playlist |
| 436 | * @param name Playlist name |
| 437 | * @param who Who is deleting it |
| 438 | * @return 0 on success, non-0 on error |
| 439 | * |
| 440 | * Possible return values: |
| 441 | * - @c 0 on success |
| 442 | * - @c EINVAL if the playlist name is invalid |
| 443 | * - @c EACCES if the playlist cannot be modified by @p who |
| 444 | * - @c ENOENT if the playlist doesn't exist |
| 445 | */ |
| 446 | int trackdb_playlist_delete(const char *name, |
| 447 | const char *who) { |
| 448 | int e; |
| 449 | char *owner; |
| 450 | |
| 451 | if(playlist_parse_name(name, &owner, 0)) { |
| 452 | error(0, "invalid playlist name '%s'", name); |
| 453 | return EINVAL; |
| 454 | } |
| 455 | /* We've checked as much as we can for now, now go and attempt the change */ |
| 456 | WITH_TRANSACTION(trackdb_playlist_delete_tid(name, who, tid)); |
| 457 | if(e == DB_NOTFOUND) |
| 458 | e = ENOENT; |
| 459 | return e; |
| 460 | } |
| 461 | |
| 462 | static int trackdb_playlist_delete_tid(const char *name, |
| 463 | const char *who, |
| 464 | DB_TXN *tid) { |
| 465 | struct kvp *k; |
| 466 | int e; |
| 467 | const char *s; |
| 468 | |
| 469 | if((e = trackdb_getdata(trackdb_playlistsdb, name, &k, tid))) |
| 470 | return e; |
| 471 | /* Check that modification is allowed */ |
| 472 | if(!(s = kvp_get(k, "sharing"))) { |
| 473 | error(0, "playlist '%s' has no 'sharing' key", name); |
| 474 | s = "private"; |
| 475 | } |
| 476 | if(!playlist_may_write(name, who, s)) |
| 477 | return EACCES; |
| 478 | /* Delete the playlist */ |
| 479 | e = trackdb_delkey(trackdb_playlistsdb, name, tid); |
| 480 | if(!e) |
| 481 | eventlog("playlist_deleted", name, 0); |
| 482 | return e; |
| 483 | } |
| 484 | |
| 485 | /* |
| 486 | Local Variables: |
| 487 | c-basic-offset:2 |
| 488 | comment-column:40 |
| 489 | fill-column:79 |
| 490 | indent-tabs-mode:nil |
| 491 | End: |
| 492 | */ |