audiod_command.c

   1 /* Copyright (C) 2005 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
   2
   3 /** \file audiod_command.c Commands for para_audiod. */
   4
   5 #include <netinet/in.h>
   6 #include <sys/socket.h>
   7 #include <regex.h>
   8 #include <sys/types.h>
   9 #include <arpa/inet.h>
  10 #include <sys/un.h>
  11 #include <netdb.h>
  12 #include <lopsub.h>
  13
  14 #include "audiod.lsg.h"
  15 #include "para.h"
  16 #include "lsu.h"
  17 #include "audiod_cmd.lsg.h"
  18 #include "list.h"
  19 #include "sched.h"
  20 #include "buffer_tree.h"
  21 #include "filter.h"
  22 #include "grab_client.h"
  23 #include "error.h"
  24 #include "audiod.h"
  25 #include "net.h"
  26 #include "daemon.h"
  27 #include "string.h"
  28 #include "write.h"
  29 #include "fd.h"
  30 #include "version.h"
  31
  32 extern struct sched sched;
  33 extern char *stat_item_values[NUM_STAT_ITEMS];
  34
  35 /** The maximal number of simultaneous connections. */
  36 #define MAX_STAT_CLIENTS 50
  37
  38 /** Pointer to a command handler function. */
  39 typedef int (*audiod_cmd_handler_t)(int, struct lls_parse_result *);
  40
  41 /** The lopsub user_data pointer. Only the command handler at the moment. */
  42 struct audiod_command_info {
  43         audiod_cmd_handler_t handler; /**< Implementation of the command. */
  44 };
  45
  46 /** Define the user_data pointer as expected by lopsub. */
  47 #define EXPORT_AUDIOD_CMD_HANDLER(_cmd) \
  48         /** Implementation of _cmd. */ \
  49         const struct audiod_command_info lsg_audiod_cmd_com_ ## _cmd ## _user_data = { \
  50                 .handler = com_ ## _cmd \
  51         };
  52
  53 /** Flags used for the stat command of para_audiod. */
  54 enum stat_client_flags {
  55         /** Enable parser-friendly output. */
  56         SCF_PARSER_FRIENDLY = 1,
  57 };
  58
  59 /**
  60  * Describes a status client of para_audiod.
  61  *
  62  * There's one such structure per audiod client that sent the 'stat' command.
  63  *
  64  * A status client is identified by its file descriptor.  para_audiod
  65  * keeps a list of connected status clients.
  66  */
  67 struct stat_client {
  68         /** The stat client's file descriptor. */
  69         int fd;
  70         /** Bitmask of those status items the client is interested in. */
  71         uint64_t item_mask;
  72         /** See \ref stat_client flags. */
  73         unsigned flags;
  74         /** Its entry in the list of stat clients. */
  75         struct list_head node;
  76 };
  77
  78 static INITIALIZED_LIST_HEAD(client_list);
  79 static int num_clients;
  80
  81 /** The list of all status items used by para_{server,audiod,gui}. */
  82 const char *status_item_list[] = {STATUS_ITEMS};
  83
  84 static void dump_stat_client_list(void)
  85 {
  86         struct stat_client *sc;
  87
  88         list_for_each_entry(sc, &client_list, node)
  89                 PARA_INFO_LOG("stat client on fd %d\n", sc->fd);
  90 }
  91 /**
  92  * Add a status client to the list.
  93  *
  94  * \param fd The file descriptor of the client.
  95  * \param mask Bitfield of status items for this client.
  96  * \param parser_friendly Enable parser-friendly output mode.
  97  *
  98  * Only those status items having the bit set in \a mask will be
  99  * sent to the client.
 100  *
 101  * \return Positive value on success, or -E_TOO_MANY_CLIENTS if
 102  * the number of connected clients exceeds #MAX_STAT_CLIENTS.
 103  */
 104 static int stat_client_add(int fd, uint64_t mask, int parser_friendly)
 105 {
 106         struct stat_client *new_client;
 107         int ret;
 108
 109         if (num_clients >= MAX_STAT_CLIENTS) {
 110                 PARA_ERROR_LOG("maximal number of stat clients (%d) exceeded\n",
 111                         MAX_STAT_CLIENTS);
 112                 return -E_TOO_MANY_CLIENTS;
 113         }
 114         ret = dup(fd);
 115         if (ret < 0)
 116                 return -ERRNO_TO_PARA_ERROR(errno);
 117         new_client = para_calloc(sizeof(*new_client));
 118         new_client->fd = ret;
 119         PARA_INFO_LOG("adding client on fd %d\n", new_client->fd);
 120         new_client->item_mask = mask;
 121         if (parser_friendly)
 122                 new_client->flags = SCF_PARSER_FRIENDLY;
 123         para_list_add(&new_client->node, &client_list);
 124         dump_stat_client_list();
 125         num_clients++;
 126         return 1;
 127 }
 128
 129 static void close_stat_client(struct stat_client *sc)
 130 {
 131         PARA_INFO_LOG("closing client fd %d\n", sc->fd);
 132         close(sc->fd);
 133         list_del(&sc->node);
 134         free(sc);
 135         num_clients--;
 136 }
 137
 138 /**
 139  * Empty the status clients list.
 140  *
 141  * This iterates over the list of connected status clients, closes each client
 142  * file descriptor and frees the resources.
 143  */
 144 void close_stat_clients(void)
 145 {
 146         struct stat_client *sc, *tmp;
 147
 148         list_for_each_entry_safe(sc, tmp, &client_list, node)
 149                 close_stat_client(sc);
 150         assert(num_clients == 0);
 151 }
 152
 153 /**
 154  * Write a message to all connected status clients.
 155  *
 156  * \param item_num The number of the status item of \a msg.
 157  *
 158  * On write errors, remove the status client from the client list and close its
 159  * file descriptor.
 160  */
 161 void stat_client_write_item(int item_num)
 162 {
 163         struct stat_client *sc, *tmp;
 164         struct para_buffer pb = {.flags = 0};
 165         struct para_buffer pfpb = {.flags = PBF_SIZE_PREFIX};
 166         const uint64_t one = 1;
 167         char *msg = stat_item_values[item_num];
 168         struct para_buffer *b;
 169
 170         list_for_each_entry_safe(sc, tmp, &client_list, node) {
 171                 int ret;
 172
 173                 if (!((one << item_num) & sc->item_mask))
 174                         continue;
 175                 b = (sc->flags & SCF_PARSER_FRIENDLY)? &pfpb : &pb;
 176                 if (!b->buf)
 177                         WRITE_STATUS_ITEM(b, item_num, "%s\n", msg? msg : "");
 178                 ret = write(sc->fd, b->buf, b->offset);
 179                 if (ret == b->offset)
 180                         continue;
 181                 /* write error or short write */
 182                 close_stat_client(sc);
 183                 dump_stat_client_list();
 184         }
 185         free(pb.buf);
 186         free(pfpb.buf);
 187 }
 188
 189 /**
 190  * Check if string is a known status item.
 191  *
 192  * \param item Buffer containing the text to check.
 193  *
 194  * \return If \a item is a valid status item, the number of that status item is
 195  * returned. Otherwise, this function returns \p -E_UNKNOWN_STAT_ITEM.
 196  */
 197 static int stat_item_valid(const char *item)
 198 {
 199         int i;
 200         if (!item || !*item) {
 201                 PARA_ERROR_LOG("%s\n", "no item");
 202                 return -E_UNKNOWN_STAT_ITEM;
 203         }
 204         FOR_EACH_STATUS_ITEM(i)
 205                 if (!strcmp(status_item_list[i], item))
 206                         return i;
 207         PARA_ERROR_LOG("invalid stat item: %s\n", item);
 208         return -E_UNKNOWN_STAT_ITEM;
 209 }
 210
 211 static int client_write(int fd, const char *buf)
 212 {
 213         size_t len;
 214
 215         if (!buf)
 216                 return 0;
 217         len = strlen(buf);
 218         return write(fd, buf, len) != len? -E_CLIENT_WRITE: 1;
 219 }
 220
 221 __malloc static char *audiod_status_string(void)
 222 {
 223         const char *status = (audiod_status == AUDIOD_ON)?
 224                 "on" : (audiod_status == AUDIOD_OFF)? "off": "sb";
 225         return para_strdup(status);
 226 }
 227
 228 static int com_help(int fd, struct lls_parse_result *lpr)
 229 {
 230         char *buf;
 231         int ret;
 232         const struct lls_opt_result *r =
 233                 lls_opt_result(LSG_AUDIOD_CMD_HELP_OPT_LONG, lpr);
 234         bool long_help = lls_opt_given(r);
 235
 236         lsu_com_help(long_help, lpr, audiod_cmd_suite, NULL, &buf, NULL);
 237         ret = client_write(fd, buf);
 238         free(buf);
 239         return ret < 0? ret : 0;
 240 }
 241 EXPORT_AUDIOD_CMD_HANDLER(help)
 242
 243 static int com_tasks(int fd, __a_unused struct lls_parse_result *lpr)
 244 {
 245         int ret;
 246         char *tl = get_task_list(&sched);
 247
 248         if (!tl) /* no tasks registered yet */
 249                 return 0;
 250         ret = client_write(fd, tl);
 251         free(tl);
 252         return ret;
 253 }
 254 EXPORT_AUDIOD_CMD_HANDLER(tasks)
 255
 256 static int com_stat(int fd, struct lls_parse_result *lpr)
 257 {
 258         int i, ret, parser_friendly = 0;
 259         uint64_t mask = 0;
 260         const uint64_t one = 1;
 261         struct para_buffer b = {.flags = 0};
 262         const struct lls_opt_result *r;
 263         unsigned num_inputs;
 264
 265         ret = mark_fd_nonblocking(fd);
 266         if (ret < 0)
 267                 return ret;
 268         r = lls_opt_result(LSG_AUDIOD_CMD_STAT_OPT_PARSER_FRIENDLY, lpr);
 269         if (lls_opt_given(r) > 0) {
 270                 parser_friendly = 1;
 271                 b.flags = PBF_SIZE_PREFIX;
 272         }
 273         num_inputs = lls_num_inputs(lpr);
 274         if (num_inputs == 0)
 275                 mask--; /* set all bits */
 276         for (i = 0; i < num_inputs; i++) {
 277                 ret = stat_item_valid(lls_input(i, lpr));
 278                 if (ret < 0)
 279                         return ret;
 280                 mask |= (one << ret);
 281         }
 282         PARA_INFO_LOG("mask: 0x%llx\n", (long long unsigned)mask);
 283         FOR_EACH_STATUS_ITEM(i) {
 284                 char *item = stat_item_values[i];
 285                 if (!((one << i) & mask))
 286                         continue;
 287                 WRITE_STATUS_ITEM(&b, i, "%s\n", item? item : "");
 288         }
 289         ret = client_write(fd, b.buf);
 290         if (ret >= 0)
 291                 ret = stat_client_add(fd, mask, parser_friendly);
 292         free(b.buf);
 293         return ret < 0? ret : 0;
 294 }
 295 EXPORT_AUDIOD_CMD_HANDLER(stat)
 296
 297 static int com_grab(int fd, struct lls_parse_result *lpr)
 298 {
 299         int ret = grab_client_new(fd, lpr, &sched);
 300         return ret < 0? ret : 0;
 301 }
 302 EXPORT_AUDIOD_CMD_HANDLER(grab)
 303
 304 static int com_term(__a_unused int fd, __a_unused struct lls_parse_result *lpr)
 305 {
 306         return -E_AUDIOD_TERM;
 307 }
 308 EXPORT_AUDIOD_CMD_HANDLER(term)
 309
 310 static int com_on(__a_unused int fd, __a_unused struct lls_parse_result *lpr)
 311 {
 312         audiod_status = AUDIOD_ON;
 313         return 1;
 314 }
 315 EXPORT_AUDIOD_CMD_HANDLER(on)
 316
 317 static int com_off(__a_unused int fd, __a_unused struct lls_parse_result *lpr)
 318 {
 319         audiod_status = AUDIOD_OFF;
 320         return 1;
 321 }
 322 EXPORT_AUDIOD_CMD_HANDLER(off)
 323
 324 static int com_sb(__a_unused int fd, __a_unused struct lls_parse_result *lpr)
 325 {
 326         audiod_status = AUDIOD_STANDBY;
 327         return 1;
 328 }
 329 EXPORT_AUDIOD_CMD_HANDLER(sb)
 330
 331 static int com_cycle(__a_unused int fd, __a_unused struct lls_parse_result *lpr)
 332 {
 333         switch (audiod_status) {
 334                 case  AUDIOD_ON: audiod_status = AUDIOD_STANDBY; break;
 335                 case  AUDIOD_OFF: audiod_status = AUDIOD_ON; break;
 336                 case  AUDIOD_STANDBY: audiod_status = AUDIOD_OFF; break;
 337         }
 338         return 1;
 339 }
 340 EXPORT_AUDIOD_CMD_HANDLER(cycle)
 341
 342 static int com_version(int fd, struct lls_parse_result *lpr)
 343 {
 344         int ret;
 345         char *msg;
 346         const struct lls_opt_result *r_v;
 347
 348         r_v = lls_opt_result(LSG_AUDIOD_CMD_VERSION_OPT_VERBOSE, lpr);
 349         if (lls_opt_given(r_v))
 350                 msg = make_message("%s", version_text("audiod"));
 351         else
 352                 msg = make_message("%s\n", version_single_line("audiod"));
 353         ret = client_write(fd, msg);
 354         free(msg);
 355         return ret < 0? ret : 0;
 356 }
 357 EXPORT_AUDIOD_CMD_HANDLER(version)
 358
 359 /**
 360  * Handle arriving connections on the local socket.
 361  *
 362  * \param accept_fd The fd to accept connections on.
 363  * \param rfds If \a accept_fd is not set in \a rfds, do nothing.
 364  *
 365  * This is called in each iteration of the select loop. If there is an incoming
 366  * connection on \a accept_fd, this function reads the command sent by the peer,
 367  * checks the connecting user's permissions by using unix socket credentials
 368  * (if supported by the OS) and calls the corresponding command handler if
 369  * permissions are OK.
 370  *
 371  * \return Positive on success, negative on errors, zero if there was no
 372  * connection to accept.
 373  *
 374  * \sa \ref para_accept(), \ref recv_cred_buffer().
 375  * */
 376 int handle_connect(int accept_fd, fd_set *rfds)
 377 {
 378         int argc, ret, clifd;
 379         char buf[MAXLINE], **argv = NULL;
 380         struct sockaddr_un unix_addr;
 381         uid_t uid;
 382         const struct lls_command *cmd;
 383         struct lls_parse_result *lpr;
 384         char *errctx = NULL;
 385         const struct audiod_command_info *aci;
 386
 387         ret = para_accept(accept_fd, rfds, &unix_addr, sizeof(struct sockaddr_un), &clifd);
 388         if (ret <= 0)
 389                 return ret;
 390         ret = recv_cred_buffer(clifd, buf, sizeof(buf) - 1);
 391         if (ret < 0)
 392                 goto out;
 393         uid = ret;
 394         PARA_INFO_LOG("connection from UID %d, buf: %s\n", ret, buf);
 395         ret = -E_UCRED_PERM;
 396         if (!uid_is_whitelisted(uid))
 397                 goto out;
 398         ret = create_argv(buf, "\n", &argv);
 399         if (ret <= 0)
 400                 goto out;
 401         argc = ret;
 402         ret = lls(lls_lookup_subcmd(argv[0], audiod_cmd_suite, &errctx));
 403         if (ret < 0)
 404                 goto out;
 405         cmd = lls_cmd(ret, audiod_cmd_suite);
 406         ret = lls(lls_parse(argc, argv, cmd, &lpr, &errctx));
 407         if (ret < 0)
 408                 goto out;
 409         aci = lls_user_data(cmd);
 410         ret = aci->handler(clifd, lpr);
 411         lls_free_parse_result(lpr, cmd);
 412 out:
 413         free_argv(argv);
 414         if (ret < 0 && ret != -E_CLIENT_WRITE) {
 415                 char *tmp;
 416                 if (errctx) {
 417                         tmp = make_message("%s\n", errctx);
 418                         free(errctx);
 419                         client_write(clifd, tmp);
 420                         free(tmp);
 421                 }
 422                 tmp = make_message("%s\n", para_strerror(-ret));
 423                 client_write(clifd, tmp);
 424                 free(tmp);
 425         }
 426         close(clifd);
 427         return ret;
 428 }
 429
 430 /**
 431  * Send the current audiod status to all connected stat clients.
 432  *
 433  * \param force Whether to write unchanged items.
 434  */
 435 void audiod_status_dump(bool force)
 436 {
 437         char *old, *new;
 438
 439         old = stat_item_values[SI_play_time];
 440         new = get_time_string();
 441         if (new) {
 442                 if (force || !old || strcmp(old, new)) {
 443                         free(old);
 444                         stat_item_values[SI_play_time] = new;
 445                         stat_client_write_item(SI_play_time);
 446                 } else
 447                         free(new);
 448         }
 449
 450         new = daemon_get_uptime_str(now);
 451         old = stat_item_values[SI_audiod_uptime];
 452         if (force || !old || strcmp(old, new)) {
 453                 free(old);
 454                 stat_item_values[SI_audiod_uptime] = new;
 455                 stat_client_write_item(SI_audiod_uptime);
 456         } else
 457                 free(new);
 458
 459         old = stat_item_values[SI_audiod_status];
 460         new = audiod_status_string();
 461         if (force || !old || strcmp(old, new)) {
 462                 free(old);
 463                 stat_item_values[SI_audiod_status] = new;
 464                 stat_client_write_item(SI_audiod_status);
 465         } else
 466                 free(new);
 467
 468         old = stat_item_values[SI_decoder_flags];
 469         new = audiod_get_decoder_flags();
 470         if (force || !old || strcmp(old, new)) {
 471                 free(old);
 472                 stat_item_values[SI_decoder_flags] = new;
 473                 stat_client_write_item(SI_decoder_flags);
 474         } else
 475                 free(new);
 476 }
 477
 478 /**
 479  * Flush and send all status items.
 480  *
 481  * Send to  each connected client the full status item list
 482  * with empty values.
 483  */
 484 void clear_and_dump_items(void)
 485 {
 486         int i;
 487
 488         FOR_EACH_STATUS_ITEM(i) {
 489                 free(stat_item_values[i]);
 490                 stat_item_values[i] = NULL;
 491                 stat_client_write_item(i);
 492         }
 493 }