-/*
- * Copyright (C) 2007 Andre Noll <maan@tuebingen.mpg.de>
- *
- * Licensed under the GPL v2. For licencing details see COPYING.
- */
+/* Copyright (C) 2007 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
/** \file afs.c Paraslash's audio file selector. */
#include "string.h"
#include "afh.h"
#include "afs.h"
-#include "server.h"
#include "net.h"
+#include "server.h"
#include "ipc.h"
#include "list.h"
#include "sched.h"
TBLNUM_AUDIO_FILES,
/** The table for the paraslash attributes. See \ref attribute.c. */
TBLNUM_ATTRIBUTES,
- /**
- * Paraslash's scoring system is based on Gaussian normal
- * distributions, and the relevant data is stored in the rbtrees of an
- * osl table containing only volatile columns. See \ref score.c for
- * details.
+ /*
+ * Moods and playlists organize the current set of admissible files in
+ * an osl table which contains only volatile columns. Each row consists
+ * of a pointer to an audio file and the score value of this file.
*/
TBLNUM_SCORES,
/**
struct command_task {
/** The file descriptor for the local socket. */
int fd;
- /**
- * Value sent by the command handlers to identify themselves as
- * children of the running para_server.
- */
- uint32_t cookie;
/** The associated task structure. */
struct task *task;
};
static enum play_mode current_play_mode;
static char *current_mop; /* mode or playlist specifier. NULL means dummy mood */
-/**
- * A random number used to "authenticate" the connection.
- *
- * para_server picks this number by random before it forks the afs process. The
- * command handlers know this number as well and write it to the afs socket,
- * together with the id of the shared memory area which contains the payload of
- * the afs command. A local process has to know this number to abuse the afs
- * service provided by the local socket.
- */
extern uint32_t afs_socket_cookie;
/**
- * Struct to let command handlers execute a callback in afs context.
+ * Passed from command handlers to afs.
*
- * Commands that need to change the state of afs can't change the relevant data
- * structures directly because commands are executed in a child process, i.e.
- * they get their own virtual address space.
+ * Command handlers cannot change the afs database directly because they run in
+ * a separate process. The callback query structure circumvents this
+ * restriction as follows. To instruct the afs process to execute a particular
+ * function, the command hander writes an instance of this structure to a
+ * shared memory area, along with the arguments to the callback function. The
+ * identifier of the shared memory area is transferred to the afs process via
+ * the command socket.
*
- * This structure is used by \p send_callback_request() (executed from handler
- * context) in order to let the afs process call the specified function. An
- * instance of that structure is written to a shared memory area together with
- * the arguments to the callback function. The identifier of the shared memory
- * area is written to the command socket.
+ * The afs process reads the shared memory id from the command socket, attaches
+ * the corresponding area, and calls the callback function whose address is
+ * stored in the area.
*
- * The afs process accepts connections on the command socket and reads the
- * shared memory id, attaches the corresponding area, calls the given handler to
- * perform the desired action and to optionally compute a result.
- *
- * The result and a \p callback_result structure is then written to another
- * shared memory area. The identifier for that area is written to the handler's
- * command socket, so that the handler process can read the id, attach the
- * shared memory area and use the result.
+ * The command output, if any, is transferred back to the command handler in
+ * the same way: The afs process writes the output to a second shared memory
+ * area together with a fixed size metadata header whose format corresponds to
+ * the \ref callback_result structure. The identifier of this area is sent back
+ * to the command handler which attaches the area and forwards the output to
+ * the remote client.
*
* \sa \ref struct callback_result.
*/
*/
int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
{
- const char *str1 = (const char *)obj1->data;
- const char *str2 = (const char *)obj2->data;
+ const char *str1 = obj1->data;
+ const char *str2 = obj2->data;
return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
}
*/
static int open_next_audio_file(void)
{
- struct audio_file_data afd;
- int ret, shmid;
+ int ret, shmid, fd;
char buf[8];
- ret = open_and_update_audio_file(&afd);
+ ret = open_and_update_audio_file(&fd);
if (ret < 0) {
- PARA_ERROR_LOG("%s\n", para_strerror(-ret));
+ if (ret != -OSL_ERRNO_TO_PARA_ERROR(E_OSL_RB_KEY_NOT_FOUND))
+ PARA_ERROR_LOG("%s\n", para_strerror(-ret));
goto no_admissible_files;
}
shmid = ret;
}
*(uint32_t *)buf = NEXT_AUDIO_FILE;
*(uint32_t *)(buf + 4) = (uint32_t)shmid;
- ret = pass_afd(afd.fd, buf, 8);
- close(afd.fd);
+ ret = pass_afd(fd, buf, 8);
+ close(fd);
if (ret >= 0)
return ret;
destroy:
return write_all(server_socket, buf, 8);
}
-/* Never fails if arg == NULL */
-static int activate_mood_or_playlist(const char *arg, int *num_admissible)
+static int activate_mood_or_playlist(const char *arg, int *num_admissible,
+ char **errmsg)
{
enum play_mode mode;
int ret;
if (!arg) {
- ret = change_current_mood(NULL); /* always successful */
mode = PLAY_MODE_MOOD;
+ ret = change_current_mood(NULL, errmsg);
+ if (ret < 0) {
+ if (num_admissible)
+ *num_admissible = 0;
+ return ret;
+ }
} else {
if (!strncmp(arg, "p/", 2)) {
ret = playlist_open(arg + 2);
+ if (ret < 0 && errmsg)
+ *errmsg = make_message( "could not open %s",
+ arg);
mode = PLAY_MODE_PLAYLIST;
} else if (!strncmp(arg, "m/", 2)) {
- ret = change_current_mood(arg + 2);
+ ret = change_current_mood(arg + 2, errmsg);
mode = PLAY_MODE_MOOD;
- } else
+ } else {
+ if (errmsg)
+ *errmsg = make_message("%s: parse error", arg);
return -ERRNO_TO_PARA_ERROR(EINVAL);
+ }
if (ret < 0)
return ret;
}
if (num_admissible)
*num_admissible = ret;
current_play_mode = mode;
+ /*
+ * We get called with arg == current_mop from the signal dispatcher
+ * after SIGHUP and from the error path of the select command to
+ * re-select the current mood or playlist. In this case the assignment
+ * to current_mop below would result in a use-after-free condition.
+ */
if (arg != current_mop) {
free(current_mop);
if (arg) {
const struct lls_command *cmd = SERVER_CMD_CMD_PTR(SELECT);
const char *arg;
int num_admissible, ret;
+ char *errmsg;
ret = lls_deserialize_parse_result(aca->query.data, cmd, &aca->lpr);
assert(ret >= 0);
close_current_mood();
else
playlist_close();
- ret = activate_mood_or_playlist(arg, &num_admissible);
+ ret = activate_mood_or_playlist(arg, &num_admissible, &errmsg);
if (ret >= 0)
goto out;
/* ignore subsequent errors (but log them) */
+ para_printf(&aca->pbout, "%s\n", errmsg);
+ free(errmsg);
para_printf(&aca->pbout, "could not activate %s\n", arg);
if (current_mop && strcmp(current_mop, arg) != 0) {
int ret2;
para_printf(&aca->pbout, "switching back to %s\n", current_mop);
- ret2 = activate_mood_or_playlist(current_mop, &num_admissible);
+ ret2 = activate_mood_or_playlist(current_mop, &num_admissible,
+ &errmsg);
if (ret2 >= 0)
goto out;
+ para_printf(&aca->pbout, "%s\n", errmsg);
+ free(errmsg);
para_printf(&aca->pbout, "could not reactivate %s: %s\n",
current_mop, para_strerror(-ret2));
}
para_printf(&aca->pbout, "activating dummy mood\n");
- activate_mood_or_playlist(NULL, &num_admissible);
+ activate_mood_or_playlist(NULL, &num_admissible, NULL);
out:
- para_printf(&aca->pbout, "activated %s (%d admissible files)\n",
- current_mop? current_mop : "dummy mood", num_admissible);
+ para_printf(&aca->pbout, "activated %s (%d admissible file%s)\n",
+ current_mop? current_mop : "dummy mood", num_admissible,
+ num_admissible == 1? "" : "s");
free_lpr:
lls_free_parse_result(aca->lpr, cmd);
return ret;
static void init_admissible_files(const char *arg)
{
- int ret = activate_mood_or_playlist(arg, NULL);
+ int ret = activate_mood_or_playlist(arg, NULL, NULL);
if (ret < 0) {
- assert(arg);
PARA_WARNING_LOG("could not activate %s: %s\n", arg,
para_strerror(-ret));
- activate_mood_or_playlist(NULL, NULL); /* always successful */
+ if (arg)
+ activate_mood_or_playlist(NULL, NULL, NULL);
}
}
return socket_fd;
}
+static char *database_dir;
+
static void close_afs_tables(void)
{
int i;
- PARA_NOTICE_LOG("closing afs_tables\n");
+ PARA_NOTICE_LOG("closing afs tables\n");
for (i = 0; i < NUM_AFS_TABLES; i++)
afs_tables[i].close();
+ free(database_dir);
+ database_dir = NULL;
}
-static char *database_dir;
-
static void get_database_dir(void)
{
if (!database_dir) {
else {
char *home = para_homedir();
database_dir = make_message(
- "%s/.paraslash/afs_database-0.4", home);
+ "%s/.paraslash/afs_database-0.7", home);
free(home);
}
}
ret = afs_tables[i].open(database_dir);
if (ret >= 0)
continue;
- PARA_ERROR_LOG("%s init: %s\n", afs_tables[i].name,
- para_strerror(-ret));
+ PARA_ERROR_LOG("could not open %s\n", afs_tables[i].name);
break;
}
if (ret >= 0)
PARA_EMERG_LOG("para_server died\n");
goto shutdown;
}
- signum = para_next_signal(&s->rfds);
+ signum = para_next_signal();
if (signum == 0)
return 0;
if (signum == SIGHUP) {
return ret;
}
-static int execute_server_command(fd_set *rfds)
+static int execute_server_command(void)
{
char buf[8];
size_t n;
- int ret = read_nonblock(server_socket, buf, sizeof(buf) - 1, rfds, &n);
+ int ret = read_nonblock(server_socket, buf, sizeof(buf) - 1, &n);
if (ret < 0 || n == 0)
return ret;
}
/* returns 0 if no data available, 1 else */
-static int execute_afs_command(int fd, fd_set *rfds, uint32_t expected_cookie)
+static int execute_afs_command(int fd)
{
uint32_t cookie;
int query_shmid;
char buf[sizeof(cookie) + sizeof(query_shmid)];
size_t n;
- int ret = read_nonblock(fd, buf, sizeof(buf), rfds, &n);
+ int ret = read_nonblock(fd, buf, sizeof(buf), &n);
if (ret < 0)
goto err;
return 1;
}
cookie = *(uint32_t *)buf;
- if (cookie != expected_cookie) {
+ if (cookie != afs_socket_cookie) {
PARA_NOTICE_LOG("received invalid cookie (got %u, expected %u)\n",
- (unsigned)cookie, (unsigned)expected_cookie);
+ (unsigned)cookie, (unsigned)afs_socket_cookie);
return 1;
}
query_shmid = *(int *)(buf + sizeof(cookie));
ret = task_get_notification(ct->task);
if (ret < 0)
return ret;
- ret = execute_server_command(&s->rfds);
+ ret = execute_server_command();
if (ret < 0) {
PARA_EMERG_LOG("%s\n", para_strerror(-ret));
task_notify_all(s, -ret);
}
/* Check the list of connected clients. */
list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
- ret = execute_afs_command(client->fd, &s->rfds, ct->cookie);
+ ret = execute_afs_command(client->fd);
if (ret == 0) { /* prevent bogus connection flooding */
struct timeval diff;
tv_diff(now, &client->connect_time, &diff);
return 0;
}
-static void register_command_task(uint32_t cookie, struct sched *s)
+static void register_command_task(struct sched *s)
{
struct command_task *ct = &command_task_struct;
ct->fd = setup_command_socket_or_die();
- ct->cookie = cookie;
ct->task = task_register(&(struct task_info) {
.name = "afs command",
/**
* Initialize the audio file selector process.
*
- * \param cookie The value used for "authentication".
* \param socket_fd File descriptor used for communication with the server.
*/
-__noreturn void afs_init(uint32_t cookie, int socket_fd)
+__noreturn void afs_init(int socket_fd)
{
static struct sched s;
int i, ret;
register_signal_task(&s);
- INIT_LIST_HEAD(&afs_client_list);
+ init_list_head(&afs_client_list);
for (i = 0; i < NUM_AFS_TABLES; i++)
afs_tables[i].init(&afs_tables[i]);
ret = open_afs_tables();
ret = mark_fd_nonblocking(server_socket);
if (ret < 0)
goto out_close;
- PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
- server_socket, (unsigned) cookie);
+ PARA_INFO_LOG("server_socket: %d\n", server_socket);
init_admissible_files(OPT_STRING_VAL(AFS_INITIAL_MODE));
- register_command_task(cookie, &s);
- s.default_timeout.tv_sec = 0;
- s.default_timeout.tv_usec = 999 * 1000;
+ register_command_task(&s);
+ s.default_timeout = 1000;
ret = write(socket_fd, "\0", 1);
if (ret != 1) {
if (ret == 0)
}
ret = schedule(&s);
sched_shutdown(&s);
+ close_current_mood();
out_close:
close_afs_tables();
out:
+ signal_shutdown(signal_task);
+ free_status_items();
+ free(current_mop);
+ free_lpr();
if (ret < 0)
PARA_EMERG_LOG("%s\n", para_strerror(-ret));
exit(EXIT_FAILURE);
int i, ret;
close_afs_tables();
+ get_database_dir();
for (i = 0; i < NUM_AFS_TABLES; i++) {
struct afs_table *t = &afs_tables[i];
}
ret = open_afs_tables();
if (ret < 0)
- para_printf(&aca->pbout, "cannot open afs tables\n");
+ para_printf(&aca->pbout, "cannot open afs tables: %s\n",
+ para_strerror(-ret));
out:
return ret;
}