[paraslash.git] / audiod.c

/*
 * Copyright (C) 2005-2006 Andre Noll <noll@mathematik.tu-darmstadt.de>
 *
 *     This program is free software; you can redistribute it and/or modify
 *     it under the terms of the GNU General Public License as published by
 *     the Free Software Foundation; either version 2 of the License, or
 *     (at your option) any later version.
 *
 *     This program is distributed in the hope that it will be useful,
 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *     GNU General Public License for more details.
 *
 *     You should have received a copy of the GNU General Public License
 *     along with this program; if not, write to the Free Software
 *     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
 */

/** \file audiod.c the paraslash's audio daemon */

#include "para.h"

#include "audiod.cmdline.h"
#include "list.h"
#include "close_on_fork.h"
#include "sched.h"
#include "recv.h"
#include "filter.h"
#include "grab_client.cmdline.h"
#include "grab_client.h"

#include "error.h"
#include "audiod.h"
#include "net.h"
#include "daemon.h"
#include "string.h"
#include "fd.h"
#include "write.h"
#include "write_common.h"

/** define the array of error lists needed by para_audiod */
INIT_AUDIOD_ERRLISTS;
/** define the array containing all supported audio formats */
DEFINE_AUDIO_FORMAT_ARRAY;

/**
 * the possible modes of operation
 *
 * - off: disconnect from para_server
 * - on: receive status information from para_server and play the audio stream
 * - sb: only receive status information but not the audio stream
*/
enum {AUDIOD_OFF, AUDIOD_ON, AUDIOD_STANDBY};

/** defines how to handle one supported audio format */
struct audio_format_info {
        /** pointer to the receiver for this audio format */
        struct receiver *receiver;
        /** the receiver configuration */
        void *receiver_conf;
        /** the number of filters that should be activated for this audio format */
        unsigned int num_filters;
        /** pointer to the array of filters to be activated */
        struct filter **filters;
        /** pointer to the array of filter configurations */
        void **filter_conf;
        /** the number of filters that should be activated for this audio format */
        unsigned int num_writers;
        /** pointer to the array of writers to be activated */
        struct writer **writers;
        /** pointer to the array of writer configurations */
        void **writer_conf;
        /** do not start receiver/filters/writer before this time */
        struct timeval restart_barrier;
};

/**
 * describes one instance of a receiver-filter-writer chain
 *
 * \sa receier_node, receiver, filter, filter_node, filter_chain, writer,
 * writer_node, writer_node_group.
  */
struct slot_info {
        /** number of the audio format in this slot */
        int format;
        /** writer start time */
        struct timeval wstime;
        /** the receiver info associated with this slot */
        struct receiver_node *receiver_node;
        /** the active filter chain */
        struct filter_chain *fc;
        /** the active writer node group */
        struct writer_node_group *wng;
};
static struct slot_info slot[MAX_STREAM_SLOTS];

extern const char *status_item_list[NUM_STAT_ITEMS];

static struct gengetopt_args_info conf;
static struct timeval server_stream_start, sa_time_diff;
static int playing, current_decoder = -1,
        audiod_status = AUDIOD_ON, offset_seconds, length_seconds,
        sa_time_diff_sign = 1;
static char *af_status, /* the audio format announced in server status */
        *socket_name, *hostname;
static char *stat_item_values[NUM_STAT_ITEMS];
static FILE *logfile;
static const struct timeval restart_delay = {0, 300 * 1000};
static struct audio_format_info afi[NUM_AUDIO_FORMATS];
static struct timeval *now;

static struct signal_task signal_task_struct, *sig_task = &signal_task_struct;

/**
 * the task for handling audiod commands
 *
 * \sa struct task, struct sched
 */
struct command_task {
        /** the local listening socket */
        int fd;
        /** the associated task structure */
        struct task task;
};

/**
 * the task for audiod's child (para_client stat)
 *
 * \sa struct task, struct sched
 */
struct status_task {
        /** the output of the stat command is read from this fd */
        int fd;
        /** stat data is stored here */
        char buf[STRINGSIZE];
        /** number of bytes loaded in \a buf */
        unsigned loaded;
        /** the associated task structure */
        struct task task;
};
static struct status_task status_task_struct, *stat_task = &status_task_struct;

struct signal_task {
        int fd;
        int signum;
        struct task task;
};

/** defines one command of para_audiod */
struct audiod_command {
        /** the name of the command */
        const char *name;
        /** pointer to the function that handles the command */
        int (*handler)(int, int, char**);
        /**
         * if the command prefers to handle the full line (rather than the usual
         * argv[] array), it stores a pointer to the corresponding line handling
         * function here. In this case, the above \a handler pointer must be NULL.
         */
        int (*line_handler)(int, char*);
        /** one-line description of the command */
        const char *description;
        /** summary of the command line options */
        const char *synopsis;
        /** the long help text */
        const char *help;
};
static int com_grab(int, char *);
static int com_cycle(int, int, char **);
static int com_help(int, int, char **);
static int com_off(int, int, char **);
static int com_on(int, int, char **);
static int com_sb(int, int, char **);
static int com_stat(int, int, char **);
static int com_term(int, int, char **);
static struct audiod_command cmds[] = {
{
.name = "cycle",
.handler = com_cycle,
.description = "switch to next mode",
.synopsis = "cycle",
.help =

"on -> standby -> off -> on\n"

},
{
.name = "grab",
.line_handler = com_grab,
.description = "grab the audio stream",
.synopsis = "-- grab [grab_options]",
.help =

"grab ('splice') the audio stream at any position in the filter      \n"
"chain and send that data back to the client. Try\n"
"\t para_audioc -- grab -h\n"
"for the list of available options.\n"
},

{
.name = "help",
.handler = com_help,
.description = "display command list or help for given command",
.synopsis = "help [command]",
.help =

"When I was younger, so much younger than today, I never needed\n"
"anybody's help in any way. But now these days are gone, I'm not so\n"
"self assured. Now I find I've changed my mind and opened up the doors.\n"
"\n"
"                               -- Beatles: Help\n"

},
{
.name = "off",
.handler = com_off,
.description = "deactivate para_audiod",
.synopsis = "off",
.help =

"Close connection to para_server and stop all decoders.\n"

},
{
.name = "on",
.handler = com_on,
.description = "activate para_audiod",
.synopsis = "on",
.help =

"Establish connection to para_server, retrieve para_server's current\n"
"status. If playing, start corresponding decoder. Otherwise stop\n"
"all decoders.\n"

},
{
.name = "sb",
.handler = com_sb,
.description = "enter standby mode",
.synopsis = "sb",
.help =

"Stop all decoders but leave connection to para_server open.\n"

},
{
.name = "stat",
.handler = com_stat,
.description = "print status information",
.synopsis = "stat [item1 ...]",
.help =

"Dump given status items (all if none given) to stdout.\n"

},
{
.name = "term",
.handler = com_term,
.description = "terminate audiod",
.synopsis = "term",
.help =

"Stop all decoders, shut down connection to para_server and exit.\n"

},
{
.name = NULL,
}
};

/** iterate over all slots */
#define FOR_EACH_SLOT(_slot) for (_slot = 0; _slot < MAX_STREAM_SLOTS; _slot++)
/** iterate over all supported audio formats */
#define FOR_EACH_AUDIO_FORMAT(af) for (af = 0; af < NUM_AUDIO_FORMATS; af++)
/** iterate over the array of all audiod commands */
#define FOR_EACH_COMMAND(c) for (c = 0; cmds[c].name; c++)

/**
 * get the audio format number
 * \param name the name of the audio format
 *
 * \return The audio format number on success, -E_UNSUPPORTED_AUDIO_FORMAT if
 * \a name is not a supported audio format.
 */
int get_audio_format_num(char *name)
{
        int i;
        FOR_EACH_AUDIO_FORMAT(i)
                if (!strcmp(name, audio_formats[i]))
                        return i;
        return -E_UNSUPPORTED_AUDIO_FORMAT;
}

/*
 * log function. first argument is loglevel.
 */
void para_log(int ll, const char* fmt,...)
{
        va_list argp;
        FILE *outfd;
        struct tm *tm;
        time_t t1;
        char str[MAXLINE] = "";

        if (ll < conf.loglevel_arg)
                return;
        outfd = logfile? logfile : stderr;
        time(&t1);
        tm = localtime(&t1);
        strftime(str, MAXLINE, "%b %d %H:%M:%S", tm);
        fprintf(outfd, "%s %s ", str, hostname);
        if (conf.loglevel_arg <= INFO)
                fprintf(outfd, "%i ", ll);
        va_start(argp, fmt);
        vfprintf(outfd, fmt, argp);
        va_end(argp);
}

static int client_write(int fd, const char *buf)
{
        size_t len = strlen(buf);
        return write(fd, buf, len) != len? -E_CLIENT_WRITE: 1;
}

static char *get_time_string(struct timeval *newest_stime)
{
        struct timeval diff, adj_stream_start, tmp;
        int total = 0, use_server_time = 1;

        if (!playing) {
                if (length_seconds)
                        return NULL;
                return make_message("%s:\n", status_item_list[SI_PLAY_TIME]);
        }
        if (audiod_status == AUDIOD_OFF)
                goto out;
        if (sa_time_diff_sign > 0)
                tv_diff(&server_stream_start, &sa_time_diff,
                        &adj_stream_start);
        else
                tv_add(&server_stream_start, &sa_time_diff,
                        &adj_stream_start);
        tmp = adj_stream_start;
        if (newest_stime && audiod_status == AUDIOD_ON) {
                tv_diff(newest_stime, &adj_stream_start, &diff);
                if (tv2ms(&diff) < 5000) {
                        tmp = *newest_stime;
                        use_server_time = 0;
                }
        }
        tv_diff(now, &tmp, &diff);
        total = diff.tv_sec + offset_seconds;
        if (total > length_seconds)
                total = length_seconds;
        if (total < 0)
                total = 0;
out:
        return make_message(
                "%s:%s%d:%02d [%d:%02d] (%d%%/%d:%02d)\n",
                status_item_list[SI_PLAY_TIME],
                use_server_time? "~" : "",
                total / 60,
                total % 60,
                (length_seconds - total) / 60,
                (length_seconds - total) % 60,
                length_seconds? (total * 100 + length_seconds / 2) /
                        length_seconds : 0,
                length_seconds / 60,
                length_seconds % 60
        );
}

__malloc static char *audiod_status_string(void)
{
        const char *status = (audiod_status == AUDIOD_ON)?
                "on" : (audiod_status == AUDIOD_OFF)? "off": "sb";
        return make_message("%s:%s\n", status_item_list[SI_AUDIOD_STATUS], status);
}

static struct timeval *wstime(void)
{
        int i;
        struct timeval *max = NULL;
        FOR_EACH_SLOT(i) {
                struct slot_info *s = &slot[i];
                if (!s->wng)
                        continue;
                if (max && tv_diff(&s->wstime, max, NULL) <= 0)
                        continue;
                max = &s->wstime;
        }
        return max;
}
__malloc static char *decoder_flags(void)
{
        int i;
        char decoder_flags[MAX_STREAM_SLOTS + 1];

        FOR_EACH_SLOT(i) {
                struct slot_info *s = &slot[i];
                char flag = '0';
                if (s->receiver_node)
                        flag += 1;
                if (s->wng)
                        flag += 2;
                decoder_flags[i] = flag;
        }
        decoder_flags[MAX_STREAM_SLOTS] = '\0';
        return make_message("%s:%s\n", status_item_list[SI_DECODER_FLAGS],
                decoder_flags);
}

static char *configfile_exists(void)
{
        static char *config_file;

        if (!config_file) {
                char *home = para_homedir();
                config_file = make_message("%s/.paraslash/audiod.conf", home);
                free(home);
        }
        return file_exists(config_file)? config_file : NULL;
}

static void setup_signal_handling(void)
{
        sig_task->fd = para_signal_init();
        PARA_INFO_LOG("signal pipe: fd %d\n", sig_task->fd);
        para_install_sighandler(SIGINT);
        para_install_sighandler(SIGTERM);
        para_install_sighandler(SIGCHLD);
        para_install_sighandler(SIGHUP);
        signal(SIGPIPE, SIG_IGN);
}

static void audiod_status_dump(void)
{
        static char *p_ts, *p_us, *p_as, *p_df;
        struct timeval *t = wstime();
        char *us, *tmp = get_time_string(t);

        if (tmp && (!p_ts || strcmp(tmp, p_ts)))
                stat_client_write(tmp, SI_PLAY_TIME);
        free(p_ts);
        p_ts = tmp;

        us = uptime_str();
        tmp = make_message("%s:%s\n", status_item_list[SI_AUDIOD_UPTIME], us);
        free(us);
        if (!p_us || strcmp(p_us, tmp))
                stat_client_write(tmp, SI_AUDIOD_UPTIME);
        free(p_us);
        p_us = tmp;

        tmp = audiod_status_string();
        if (!p_as || strcmp(p_as, tmp))
                stat_client_write(tmp, SI_AUDIOD_STATUS);
        free(p_as);
        p_as = tmp;

        tmp = decoder_flags();
        if (!p_df || strcmp(p_df, tmp))
                stat_client_write(tmp, SI_DECODER_FLAGS);
        free(p_df);
        p_df = tmp;
}

static void clear_slot(int slot_num)
{
        struct slot_info *s = &slot[slot_num];

        PARA_INFO_LOG("clearing slot %d\n", slot_num);
        memset(s, 0, sizeof(struct slot_info));
        s->format = -1;
}

static void close_receiver(int slot_num)
{
        struct slot_info *s = &slot[slot_num];
        struct audio_format_info *a;

        if (s->format < 0 || !s->receiver_node)
                return;
        a = &afi[s->format];
        PARA_NOTICE_LOG("closing %s receiver in slot %d (eof = %d)\n",
                audio_formats[s->format] , slot_num, s->receiver_node->eof);
        if (!s->receiver_node->eof)
                unregister_task(&s->receiver_node->task);
        a->receiver->close(s->receiver_node);
        free(s->receiver_node);
        s->receiver_node = NULL;
        /* set restart barrier */
        tv_add(now, &restart_delay, &afi[s->format].restart_barrier);
}

static void kill_all_decoders(void)
{
        int i;

        FOR_EACH_SLOT(i) {
                struct slot_info *s = &slot[i];
                if (s->wng && !s->wng->eof) {
                        PARA_INFO_LOG("unregistering writer node group in slot %d\n",
                                i);
                        wng_unregister(s->wng);
                        s->wng->eof = 1;
                }
                if (s->fc && !s->fc->eof) {
                        PARA_INFO_LOG("unregistering filter chain in slot %d\n", i);
                        unregister_task(&s->fc->task);
                        s->fc->eof = 1;
                }
                if (s->receiver_node && !s->receiver_node->eof) {
                        PARA_INFO_LOG("unregistering receiver_node in slot %d\n", i);
                        unregister_task(&s->receiver_node->task);
                        s->receiver_node->eof = 1;
                }
        }
}

static int get_empty_slot(void)
{
        int i;
        struct slot_info *s;

        FOR_EACH_SLOT(i) {
                s = &slot[i];
                if (s->format < 0) {
                        clear_slot(i);
                        return i;
                }
                if (s->wng || s->receiver_node || s->fc)
                        continue;
                clear_slot(i);
                return i;
        }
        return -E_NO_MORE_SLOTS;
}

static int decoder_running(int format)
{
        int i, ret = 0;
        struct slot_info *s;

        FOR_EACH_SLOT(i) {
                s = &slot[i];
                if (s->format == format && s->receiver_node)
                        ret |= 1;
                if (s->format == format && s->wng)
                        ret |= 2;
        }
        return ret;
}

static void close_stat_pipe(void)
{
        int i;

        if (stat_task->fd < 0)
                return;
        PARA_NOTICE_LOG("%s", "closing status pipe\n");
        close(stat_task->fd);
        del_close_on_fork_list(stat_task->fd);
        stat_task->fd = -1;
        kill_all_decoders();
        for (i = 0; i < NUM_STAT_ITEMS; i++) {
                free(stat_item_values[i]);
                stat_item_values[i] = NULL;
        }
        dump_empty_status();
        length_seconds = 0;
        offset_seconds = 0;
        audiod_status_dump();
        playing = 0;
        stat_item_values[SI_STATUS_BAR] = make_message(
                "%s:no connection to para_server\n",
                status_item_list[SI_STATUS_BAR]);
        stat_client_write(stat_item_values[SI_STATUS_BAR], SI_STATUS_BAR);
}

static void __noreturn clean_exit(int status, const char *msg)
{
        PARA_EMERG_LOG("%s\n", msg);
        if (socket_name)
                unlink(socket_name);
        if (stat_task->fd >= 0)
                close_stat_pipe();
        exit(status);
}

/**
 * get the number of filters
 *
 * \param audio_format_num the number identifying the audio format
 *
 * \return the number of filters for the given audio format
 *
 * \sa struct filter;
 */
int num_filters(int audio_format_num)
{
        return afi[audio_format_num].num_filters;
}

static void filter_event_handler(struct task *t)
{
        PARA_NOTICE_LOG("%s\n", PARA_STRERROR(-t->ret));
        unregister_task(t);
}

static void open_filters(int slot_num)
{
        struct slot_info *s = &slot[slot_num];
        struct audio_format_info *a = &afi[s->format];
        int nf = a->num_filters;
        int i;

        s->fc = NULL;
        if (!nf)
                return;
        PARA_INFO_LOG("opening %s filters\n", audio_formats[s->format]);
        s->fc = para_calloc(sizeof(struct filter_chain));
        INIT_LIST_HEAD(&s->fc->filters);
        s->fc->inbuf = s->receiver_node->buf;
        s->fc->in_loaded = &s->receiver_node->loaded;
        s->fc->input_eof = &s->receiver_node->eof;
        s->fc->task.pre_select = filter_pre_select;
        s->fc->task.event_handler = filter_event_handler;
        s->fc->task.private_data = s->fc;
        s->fc->task.flags = 0;
        s->fc->eof = 0;

        s->receiver_node->output_eof = &s->fc->eof;
        sprintf(s->fc->task.status, "filter chain");
        for (i = 0; i < nf; i++) {
                struct filter_node *fn = para_calloc(sizeof(struct filter_node));
                fn->conf = a->filter_conf[i];
                fn->fc = s->fc;
                fn->filter = a->filters[i];
                INIT_LIST_HEAD(&fn->callbacks);
                list_add_tail(&fn->node, &s->fc->filters);
                fn->filter->open(fn);
                PARA_NOTICE_LOG("%s filter %d/%d (%s) started in slot %d\n",
                        audio_formats[s->format], i + 1,  nf,
                        fn->filter->name, slot_num);
                s->fc->outbuf = fn->buf;
                s->fc->out_loaded = &fn->loaded;
        }
        register_task(&s->fc->task);
}

static struct filter_node *find_filter_node(int slot_num, int format, int filternum)
{
        struct filter_node *fn;
        int i, j;

        FOR_EACH_SLOT(i) {
                struct slot_info *s = &slot[i];
                if (s->format < 0 || !s->fc)
                        continue;
                if (slot_num >= 0 && slot_num != i)
                        continue;
                if (format >= 0 && s->format != format)
                        continue;
                if (num_filters(i) < filternum)
                        continue;
                /* success */
                j = 1;
                list_for_each_entry(fn, &s->fc->filters, node)
                        if (filternum <= 0 || j++ == filternum)
                                break;
                return fn;
        }
        return NULL;
}

static void wng_event_handler(struct task *t)
{
        struct writer_node_group *wng = t->private_data;
        int i;

        wng_unregister(wng);
        FOR_EACH_SLOT(i) {
                struct slot_info *s = &slot[i];
                if (s->wng != wng)
                        continue;
                PARA_INFO_LOG("slot %d: %s\n", i, PARA_STRERROR(-t->ret));
        }
}

static void open_writers(int slot_num)
{
        int ret, i;
        struct slot_info *s = &slot[slot_num];
        struct audio_format_info *a = &afi[s->format];

        PARA_INFO_LOG("opening %s writers\n", audio_formats[s->format]);
        if (!a->num_writers)
                s->wng = setup_default_wng();
        else
                s->wng = wng_new(a->num_writers);
        if (s->fc) {
                s->wng->buf = s->fc->outbuf;
                s->wng->loaded = s->fc->out_loaded;
                s->wng->input_eof = &s->fc->eof;
                s->wng->channels = &s->fc->channels;
                s->wng->samplerate = &s->fc->samplerate;
                s->fc->output_eof = &s->wng->eof;
                PARA_INFO_LOG("samplerate: %d\n", *s->wng->samplerate);
        } else {
                s->wng->buf = s->receiver_node->buf;
                s->wng->loaded = &s->receiver_node->loaded;
                s->wng->input_eof = &s->receiver_node->eof;
        }
        s->wng->task.event_handler = wng_event_handler;
        for (i = 0; i < a->num_writers; i++) {
                s->wng->writer_nodes[i].conf = a->writer_conf[i];
                s->wng->writer_nodes[i].writer = a->writers[i];
                sprintf(s->wng->writer_nodes[i].task.status, "writer_node");
        }
        ret = wng_open(s->wng); /* FIXME */
        s->wstime = *now;
        current_decoder = slot_num;
        activate_inactive_grab_clients(slot_num, s->format, &s->fc->filters);
}

static void rn_event_handler(struct task *t)
{
//      struct receiver_node *rn = t->private_data;
        PARA_NOTICE_LOG("%s\n", PARA_STRERROR(-t->ret));
        unregister_task(t);
}

static void open_receiver(int format)
{
        struct audio_format_info *a = &afi[format];
        struct slot_info *s;
        int ret, slot_num;
        struct receiver_node *rn;

        slot_num = get_empty_slot();
        if (slot_num < 0)
                clean_exit(EXIT_FAILURE, PARA_STRERROR(-slot_num));
        s = &slot[slot_num];
        s->format = format;
        s->receiver_node = para_calloc(sizeof(struct receiver_node));
        rn = s->receiver_node;
        rn->receiver = a->receiver;
        rn->conf = a->receiver_conf;
        ret = a->receiver->open(s->receiver_node);
        if (ret < 0) {
                PARA_ERROR_LOG("failed to open receiver (%s)\n",
                        PARA_STRERROR(-ret));
                free(s->receiver_node);
                s->receiver_node = NULL;
                return;
        }
        PARA_NOTICE_LOG("started %s: %s receiver in slot %d\n",
                audio_formats[s->format], a->receiver->name, slot_num);
        rn->task.private_data = s->receiver_node;
        rn->task.pre_select = a->receiver->pre_select;
        rn->task.post_select = a->receiver->post_select;
        rn->task.event_handler = rn_event_handler;
        rn->task.flags = 0;
        sprintf(rn->task.status, "receiver node");
        register_task(&rn->task);
}

static int is_frozen(int format)
{
        struct audio_format_info *a = &afi[format];

        return (tv_diff(now, &a->restart_barrier, NULL) > 0)? 0 : 1;
}

static void open_current_receiver(void)
{
        int i;

        if (!af_status)
                return;
        i = get_audio_format_num(af_status);
        if (i < 0)
                return;
        if (decoder_running(i) || is_frozen(i))
                return;
        open_receiver(i);
}

static void compute_time_diff(const struct timeval *status_time)
{
        struct timeval tmp, diff;
        static int count;
        int sign;
        const struct timeval max_deviation = {0, 500 * 1000};
        const int time_smooth = 5;

        sign = tv_diff(status_time, now, &diff);
//              PARA_NOTICE_LOG("%s: sign = %i, sa_time_diff_sign = %i\n", __func__,
//                      sign, sa_time_diff_sign);
        if (!count) {
                sa_time_diff_sign = sign;
                sa_time_diff = diff;
                count++;
                return;
        }
        if (count > 5) {
                int s = tv_diff(&diff, &sa_time_diff, &tmp);
                if (tv_diff(&max_deviation, &tmp, NULL) < 0)
                        PARA_WARNING_LOG("time diff jump: %lims\n",
                                s * tv2ms(&tmp));
        }
        count++;
        sa_time_diff_sign = tv_convex_combination(
                sa_time_diff_sign * time_smooth, &sa_time_diff,
                count > 10? sign : sign * time_smooth, &diff,
                &tmp);
        sa_time_diff = tmp;
        PARA_INFO_LOG("time diff (cur/avg): %s%lums/%s%lums\n",
                sign > 0? "+" : "-",
                tv2ms(&diff),
                sa_time_diff_sign ? "+" : "-",
                tv2ms(&sa_time_diff)
        );
}

static void check_stat_line(char *line)
{
        int itemnum;
        size_t ilen = 0;
        long unsigned sec, usec;
        char *tmp;

//      PARA_INFO_LOG("line: %s\n", line);
        if (!line)
                return;
        itemnum = stat_line_valid(line);
        if (itemnum < 0) {
                PARA_WARNING_LOG("invalid status line: %s\n", line);
                return;
        }
        tmp = make_message("%s\n", line);
        stat_client_write(tmp, itemnum);
        free(tmp);
        free(stat_item_values[itemnum]);
        stat_item_values[itemnum] = para_strdup(line);
        ilen = strlen(status_item_list[itemnum]);
        switch (itemnum) {
        case SI_STATUS:
                playing = strstr(line, "playing")? 1 : 0;
                break;
        case SI_FORMAT:
                free(af_status);
                af_status = para_strdup(line + ilen + 1);
                break;
        case SI_OFFSET:
                offset_seconds = atoi(line + ilen + 1);
                break;
        case SI_LENGTH:
                length_seconds = atoi(line + ilen + 1);
                break;
        case SI_STREAM_START:
                if (sscanf(line + ilen + 1, "%lu.%lu", &sec, &usec) == 2) {
                        server_stream_start.tv_sec = sec;
                        server_stream_start.tv_usec = usec;
                }
                break;
        case SI_CURRENT_TIME:
                if (sscanf(line + ilen + 1, "%lu.%lu", &sec, &usec) == 2) {
                        struct timeval tv = {sec, usec};
                        compute_time_diff(&tv);
                }
                break;
        }
}

static void handle_signal(int sig)
{
        switch (sig) {
        case SIGCHLD:
                for (;;) {
                        pid_t pid = para_reap_child();
                        if (pid <= 0)
                                return;
                        PARA_CRIT_LOG("para_client died (pid %d)\n", pid);
                }
        case SIGINT:
        case SIGTERM:
        case SIGHUP:
                PARA_EMERG_LOG("terminating on signal %d\n", sig);
                clean_exit(EXIT_FAILURE, "caught deadly signal");
                return;
        }
}

static void try_to_close_slot(int slot_num)
{
        struct slot_info *s = &slot[slot_num];

        if (s->format < 0)
                return;
        if (s->receiver_node && !s->receiver_node->eof)
                return;
        if (s->fc && !s->fc->eof)
                return;
        if (s->wng && !s->wng->eof)
                return;
        PARA_INFO_LOG("closing slot %d \n", slot_num);
        wng_close(s->wng);
        close_filters(s->fc);
        free(s->fc);
        close_receiver(slot_num);
        clear_slot(slot_num);
}

static void audiod_pre_select(struct sched *s, __a_unused struct task *t)
{
        int i;

        t->ret = 1;
        now = &s->now;
        if (audiod_status != AUDIOD_ON)
                kill_all_decoders();
        else if (playing)
                open_current_receiver();
        FOR_EACH_SLOT(i) {
                struct slot_info *s = &slot[i];
                struct audio_format_info *a;

                try_to_close_slot(i);
                if (s->format < 0)
                        continue;
                a = &afi[s->format];
                if (!s->receiver_node)
                        continue;
                if (!a->num_filters) {
                        if (s->receiver_node->loaded && !s->wng)
                                open_writers(i);
                        continue;
                }
                if (s->receiver_node->loaded && !s->fc) {
                        open_filters(i);
                        continue;
                }
                if (s->fc && *s->fc->out_loaded && !s->wng)
                        open_writers(i);
        }
}

static void audiod_post_select(struct sched *s, __a_unused struct task *t)
{
        /* only save away the current time for other users */
        now = &s->now;
        t->ret = 1;
}

static void init_audiod_task(struct task *t)
{
        t->pre_select = audiod_pre_select;
        t->post_select = audiod_post_select;
        t->event_handler = NULL;
        t->private_data = t;
        t->flags = 0;
        sprintf(t->status, "audiod task");
}

static int parse_stream_command(const char *txt, char **cmd)
{
        char *p = strchr(txt, ':');
        int i;

        if (!p)
                return -E_MISSING_COLON;
        p++;
        FOR_EACH_AUDIO_FORMAT(i) {
                if (strncmp(txt, audio_formats[i], strlen(audio_formats[i])))
                        continue;
                *cmd = p;
                return i;
        }
        return -E_UNSUPPORTED_AUDIO_FORMAT;
}

static int add_filter(int format, char *cmdline)
{
        struct audio_format_info *a = &afi[format];
        int filter_num, nf = a->num_filters;

        filter_num = check_filter_arg(cmdline, &a->filter_conf[nf]);
        if (filter_num < 0)
                return filter_num;
        a->filters[nf] = &filters[filter_num];
        a->num_filters++;
        PARA_INFO_LOG("%s filter %d: %s\n", audio_formats[format], nf + 1,
                a->filters[nf]->name);
        return filter_num;
}

static int init_writers(void)
{
        int i, ret, nw;
        char *cmd;
        struct audio_format_info *a;

        init_supported_writers();
        nw = PARA_MAX(1, conf.writer_given);
        PARA_INFO_LOG("maximal number of writers: %d\n", nw);
        FOR_EACH_AUDIO_FORMAT(i) {
                a = &afi[i];
                a->writer_conf = para_malloc(nw * sizeof(void *));
                a->writers = para_malloc(nw * sizeof(struct writer *));
                a->num_writers = 0;
        }
        for (i = 0; i < conf.writer_given; i++) {
                void *wconf;
                int writer_num;
                ret = parse_stream_command(conf.writer_arg[i], &cmd);
                if (ret < 0)
                        goto out;
                a = &afi[ret];
                nw = a->num_writers;
                wconf = check_writer_arg(cmd, &writer_num);
                if (!wconf) {
                        ret = writer_num;
                        goto out;
                }
                a->writers[nw] = &writers[writer_num];
                a->writer_conf[nw] = wconf;
                PARA_INFO_LOG("%s writer #%d: %s\n", audio_formats[ret],
                        nw, writer_names[writer_num]);
                a->num_writers++;
        }
        ret = 1;
out:
        return ret;
}

static int init_receivers(void)
{
        int i, ret, receiver_num;
        char *cmd = NULL;
        struct audio_format_info *a;

        for (i = 0; receivers[i].name; i++) {
                PARA_INFO_LOG("initializing %s receiver\n", receivers[i].name);
                receivers[i].init(&receivers[i]);
        }
        for (i = 0; i < conf.receiver_given; i++) {
                char *arg = conf.receiver_arg[i];
                char *recv = strchr(arg, ':');
                ret = -E_MISSING_COLON;
                if (!recv)
                        goto out;
                *recv = '\0';
                recv++;
                ret = get_audio_format_num(arg);
                if (ret < 0)
                        goto out;
                afi[ret].receiver_conf = check_receiver_arg(recv, &receiver_num);
                if (!afi[ret].receiver_conf) {
                        ret = -E_RECV_SYNTAX;
                        goto out;
                }
                afi[ret].receiver = &receivers[receiver_num];
        }
        /* use the first available receiver with no arguments
         * for those audio formats for which no receiver
         * was specified
         */
        cmd = para_strdup(receivers[0].name);
        FOR_EACH_AUDIO_FORMAT(i) {
                a = &afi[i];
                if (a->receiver_conf)
                        continue;
                a->receiver_conf = check_receiver_arg(cmd, &receiver_num);
                if (!a->receiver_conf)
                        return -E_RECV_SYNTAX;
                a->receiver = &receivers[receiver_num];
        }
        ret = 1;
out:
        free(cmd);
        return ret;
}

static int init_default_filters(void)
{
        int i, ret = 1;

        FOR_EACH_AUDIO_FORMAT(i) {
                struct audio_format_info *a = &afi[i];
                char *tmp;
                int j;

                if (a->num_filters)
                        continue; /* no default -- nothing to to */
                /* add "dec" to audio format name */
                tmp = make_message("%sdec", audio_formats[i]);
                for (j = 0; filters[j].name; j++)
                        if (!strcmp(tmp, filters[j].name))
                                break;
                free(tmp);
                ret = -E_UNSUPPORTED_FILTER;
                if (!filters[j].name)
                        goto out;
                tmp = para_strdup(filters[j].name);
                ret = add_filter(i, tmp);
                free(tmp);
                if (ret < 0)
                        goto out;
                PARA_INFO_LOG("%s -> default filter: %s\n", audio_formats[i],
                        filters[j].name);
        }
out:
        return ret;
}

static int init_filters(void)
{
        int i, ret, nf;

        filter_init(filters);
        nf = PARA_MAX(1,  conf.filter_given);
        PARA_INFO_LOG("maximal number of filters: %d\n", nf);
        FOR_EACH_AUDIO_FORMAT(i) {
                afi[i].filter_conf = para_malloc(nf * sizeof(void *));
                afi[i].filters = para_malloc(nf * sizeof(struct filter *));
        }
        if (!conf.no_default_filters_given)
                return init_default_filters();
        for (i = 0; i < conf.filter_given; i++) {
                char *arg = conf.filter_arg[i];
                char *filter_name = strchr(arg, ':');
                ret = -E_MISSING_COLON;
                if (!filter_name)
                        goto out;
                *filter_name = '\0';
                filter_name++;
                ret = get_audio_format_num(arg);
                if (ret < 0)
                        goto out;
                ret = add_filter(ret, filter_name);
                if (ret < 0)
                        goto out;
        }
        ret = init_default_filters(); /* use default values for the rest */
out:
        return ret;
}

static int init_stream_io(void)
{
        int ret;

        ret = init_writers();
        if (ret < 0)
                return ret;
        ret = init_receivers();
        if (ret < 0)
                return ret;
        ret = init_filters();
        if (ret < 0)
                return ret;
        return 1;
}

static int dump_commands(int fd)
{
        char *buf = para_strdup(""), *tmp = NULL;
        int i;
        ssize_t ret;

        FOR_EACH_COMMAND(i) {
                tmp = make_message("%s%s\t%s\n", buf, cmds[i].name,
                        cmds[i].description);
                free(buf);
                buf = tmp;
        }
        ret = client_write(fd, buf);
        free(buf);
        return ret;
}

/*
 * command handlers don't close their fd on errors (ret < 0) so that
 * its caller can send an error message. Otherwise (ret >= 0) it's up
 * to each individual command to close the fd if necessary.
 */

static int com_help(int fd, int argc, char **argv)
{
        int i, ret;
        char *buf;
        const char *dflt = "No such command. Available commands:\n";

        if (argc < 2) {
                ret = dump_commands(fd);
                goto out;
        }
        FOR_EACH_COMMAND(i) {
                if (strcmp(cmds[i].name, argv[1]))
                        continue;
                buf = make_message(
                        "NAME\n\t%s -- %s\n"
                        "SYNOPSIS\n\tpara_audioc %s\n"
                        "DESCRIPTION\n%s\n",
                        argv[1],
                        cmds[i].description,
                        cmds[i].synopsis,
                        cmds[i].help
                );
                ret = client_write(fd, buf);
                free(buf);
                goto out;
        }
        ret = client_write(fd, dflt);
        if (ret > 0)
                ret = dump_commands(fd);
out:
        if (ret >= 0)
                close(fd);
        return ret;
}

static int com_stat(int fd, __a_unused int argc, __a_unused char **argv)
{
        int i, ret;
        char *buf = NULL;
        long unsigned mask = ~0LU;

        if (argc > 1) {
                mask = 0;
                for (i = 1; i < argc; i++) {
                        ret = stat_item_valid(argv[i]);
                        if (ret < 0)
                                return ret;
                        mask |= (1 << ret);
                }
        }
        PARA_INFO_LOG("mask: 0x%lx\n", mask);
        if (mask & (1 << SI_PLAY_TIME)) {
                struct timeval *t = wstime();
                char *ts = get_time_string(t);
                if (ts) {
                        ret = client_write(fd, ts);
                        if (ret < 0)
                                goto out;
                        free(ts);
                }
        }
        if (mask & (1 << SI_AUDIOD_UPTIME)) {
                char *tmp, *us = uptime_str();
                tmp = make_message("%s:%s\n",
                        status_item_list[SI_AUDIOD_UPTIME], us);
                free(us);
                ret = client_write(fd, tmp);
                if (ret < 0)
                        goto out;
                free(tmp);
        }
        if (mask & (1 << SI_AUDIOD_STATUS)) {
                char *s = audiod_status_string();
                ret = client_write(fd, s);
                if (ret < 0)
                        goto out;
                free(s);
        }
        if (mask & (1 << SI_DECODER_FLAGS)) {
                char *df =decoder_flags();
                ret = client_write(fd, df);
                if (ret < 0)
                        goto out;
                free(df);
        }

        for (i = 0; i < NUM_STAT_ITEMS; i++) {
                char *tmp, *v;
                if (!((1 << i) & mask))
                        continue;
                v = stat_item_values[i];
                tmp = make_message("%s%s%s", buf? buf: "",
                        v? v : "", v? "\n" : "");
                free(buf);
                buf = tmp;
        }
        ret = client_write(fd, buf);
out:
        if (ret > 0)
                ret = stat_client_add(fd, mask);
        free(buf);
        return ret;
}

static int com_grab(int fd, char *cmdline)
{
        struct grab_client *gc;
        struct filter_node *fn;
        int i, err;
        char *msg;

        gc = grab_client_new(fd, cmdline, &err);
        if (!gc)
                goto err_out;
        fn = find_filter_node(gc->conf->slot_arg, gc->audio_format_num, gc->conf->filter_num_arg);
        if (fn)
                activate_grab_client(gc, fn);
        return 1;
err_out:
        if (err != -E_GC_HELP_GIVEN && err != -E_GC_VERSION_GIVEN)
                return err;
        if (err == -E_GC_HELP_GIVEN) {
                msg = make_message("%s\n\n", grab_client_args_info_usage);
                for (i = 0; grab_client_args_info_help[i]; i++) {
                        char *tmp = make_message("%s%s\n", msg,
                                grab_client_args_info_help[i]);
                        free(msg);
                        msg = tmp;
                }
        } else
                msg = make_message("%s %s\n",
                        GRAB_CLIENT_CMDLINE_PARSER_PACKAGE,
                        GRAB_CLIENT_CMDLINE_PARSER_VERSION);
        err = client_write(fd, msg);
        free(msg);
        if (err < 0)
                return err;
        close(fd);
        return 1;
}

static int __noreturn com_term(int fd, __a_unused int argc, __a_unused char **argv)
{
        close(fd);
        clean_exit(EXIT_SUCCESS, "terminating on user request");
}

static int com_on(int fd, __a_unused int argc, __a_unused char **argv)
{
        audiod_status = AUDIOD_ON;
        close(fd);
        return 1;
}

static int com_off(int fd, __a_unused int argc, __a_unused char **argv)
{
        audiod_status = AUDIOD_OFF;
        close(fd);
        return 1;
}

static int com_sb(int fd, __a_unused int argc, __a_unused char **argv)
{
        audiod_status = AUDIOD_STANDBY;
        close(fd);
        return 1;
}

static int com_cycle(int fd, int argc, char **argv)
{
        switch (audiod_status) {
                case  AUDIOD_ON:
                        return com_sb(fd, argc, argv);
                        break;
                case  AUDIOD_OFF:
                        return com_on(fd, argc, argv);
                        break;
                case  AUDIOD_STANDBY:
                        return com_off(fd, argc, argv);
                        break;
        }
        close(fd);
        return 1;
}

static int check_perms(uid_t uid)
{
        int i;

        if (!conf.user_allow_given)
                return 1;
        for (i = 0; i < conf.user_allow_given; i++)
                if (uid == conf.user_allow_arg[i])
                        return 1;
        return -E_UCRED_PERM;
}

static int handle_connect(int accept_fd)
{
        int i, argc, ret, clifd = -1;
        char *cmd = NULL, *p, *buf = para_calloc(MAXLINE), **argv = NULL;
        struct sockaddr_un unix_addr;

        ret = para_accept(accept_fd, &unix_addr, sizeof(struct sockaddr_un));
        if (ret < 0)
                goto out;
        clifd = ret;
        ret = recv_cred_buffer(clifd, buf, MAXLINE - 1);
        if (ret < 0)
                goto out;
        PARA_INFO_LOG("connection from user %i, buf: %s\n",  ret, buf);
        ret = check_perms(ret);
        if (ret < 0)
                goto out;
        ret = -E_INVALID_AUDIOD_CMD;
        cmd = para_strdup(buf);
        p = strchr(cmd, '\n');
        if (!p)
                p = "";
        else {
                *p = '\0';
                p++;
        }
        for (i = 0; cmds[i].name; i++) {
                int j;
                if (strcmp(cmds[i].name, cmd))
                        continue;
                if (cmds[i].handler) {
                        argc = split_args(buf, &argv, "\n");
                        PARA_INFO_LOG("argv[0]: %s, argc= %d\n", argv[0], argc);
                        ret = cmds[i].handler(clifd, argc, argv);
                        goto out;
                }
                for (j = 0; p[j]; j++)
                        if (p[j] == '\n')
                                p[j] = ' ';
                PARA_INFO_LOG("cmd: %s, options: %s\n", cmd, p);
                ret = cmds[i].line_handler(clifd, p);
                goto out;
        }
        ret = -E_INVALID_AUDIOD_CMD; /* cmd not found */
out:
        free(cmd);
        free(buf);
        free(argv);
        if (clifd > 0 && ret < 0 && ret != -E_CLIENT_WRITE) {
                char *tmp = make_message("%s\n", PARA_STRERROR(-ret));
                client_write(clifd, tmp);
                free(tmp);
                close(clifd);
        }
        return ret;
}

static int audiod_get_socket(void)
{
        struct sockaddr_un unix_addr;
        int fd;

        if (conf.socket_given)
                socket_name = para_strdup(conf.socket_arg);
        else {
                char *hn = para_hostname();
                socket_name = make_message("/var/paraslash/audiod_socket.%s",
                        hn);
                free(hn);
        }
        PARA_NOTICE_LOG("local socket: %s\n", socket_name);
        if (conf.force_given)
                unlink(socket_name);
        fd = create_pf_socket(socket_name, &unix_addr,
                        S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
        if (fd < 0) {
                PARA_EMERG_LOG("%s", "can not connect to socket\n");
                exit(EXIT_FAILURE); /* do not unlink socket */
        }
        if (listen(fd , 5) < 0) {
                PARA_EMERG_LOG("%s", "can not listen on socket\n");
                exit(EXIT_FAILURE); /* do not unlink socket */
        }
        add_close_on_fork_list(fd);
        return fd;
}

static int open_stat_pipe(void)
{
        int ret, fd[3] = {-1, 1, 0};
        pid_t pid;
        ret = para_exec_cmdline_pid(&pid, BINDIR "/para_client stat", fd);
        if (ret >= 0) {
                ret = fd[1];
                PARA_NOTICE_LOG("stat pipe opened, fd %d\n", ret);
                add_close_on_fork_list(ret);
        } else
                clean_exit(EXIT_FAILURE, "failed to open status pipe");
        return ret;
}

void signal_event_handler(struct task *t)
{
        struct signal_task *st = t->private_data;
        handle_signal(st->signum);
}

void signal_pre_select(struct sched *s, struct task *t)
{
        struct signal_task *st = t->private_data;
        t->ret = 1;
        para_fd_set(st->fd, &s->rfds, &s->max_fileno);
}

void signal_post_select(struct sched *s, struct task *t)
{
        struct signal_task *st = t->private_data;
        t->ret = 1;
        if (!FD_ISSET(st->fd, &s->rfds))
                return;
        t->ret = -E_SIGNAL_CAUGHT;
        st->signum = para_next_signal();
}

void signal_setup_default(struct signal_task *st)
{
        st->task.pre_select = signal_pre_select;
        st->task.post_select = signal_post_select;
        st->task.private_data = st;
        st->task.flags = 0;
        sprintf(st->task.status, "signal task");
}

static void command_pre_select(struct sched *s, struct task *t)
{
        struct command_task *ct = t->private_data;
        t->ret = 1;
        para_fd_set(ct->fd, &s->rfds, &s->max_fileno);

}

static void command_post_select(struct sched *s, struct task *t)
{
        int ret;
        struct command_task *ct = t->private_data;

        t->ret = 1; /* always successful */
        if (audiod_status != AUDIOD_OFF)
                audiod_status_dump();
        if (!FD_ISSET(ct->fd, &s->rfds))
                return;
        ret = handle_connect(ct->fd);
        if (ret < 0)
                PARA_ERROR_LOG("%s\n", PARA_STRERROR(-ret));
}

static void init_command_task(struct command_task *ct)
{
        ct->task.pre_select = command_pre_select;
        ct->task.post_select = command_post_select;
        ct->task.event_handler = NULL;
        ct->task.private_data = ct;
        ct->task.flags = 0;
        ct->fd = audiod_get_socket(); /* doesn't return on errors */
        sprintf(ct->task.status, "command task");
}

static void status_pre_select(struct sched *s, struct task *t)
{
        struct status_task *st = t->private_data;
        t->ret = 1;
        if (st->fd >= 0 && audiod_status == AUDIOD_OFF)
                close_stat_pipe();
        if (st->fd < 0 && audiod_status != AUDIOD_OFF) {
                st->fd = open_stat_pipe();
                st->loaded = 0;
                st->buf[0] = '\0';
        }
        if (st->fd >= 0 && audiod_status != AUDIOD_OFF)
                para_fd_set(st->fd, &s->rfds, &s->max_fileno);
}

static void status_post_select(struct sched *s, struct task *t)
{
        struct status_task *st = t->private_data;
        int ret;

        t->ret = 1;
        if (st->fd < 0 || !FD_ISSET(st->fd, &s->rfds))
                return;
        ret = read(st->fd, st->buf + st->loaded,
                STRINGSIZE - 1 - st->loaded);
        if (ret <= 0) {
                close_stat_pipe();
                /* avoid busy loop if server is down */
                while (sleep(1) > 0) /* FIXME */
                        ; /* try again*/
        } else {
                st->buf[ret + st->loaded] = '\0';
                st->loaded = for_each_line(st->buf, ret + st->loaded,
                        &check_stat_line);
        }
}

static void init_status_task(struct status_task *st)
{
        st->task.pre_select = status_pre_select;
        st->task.post_select = status_post_select;
        st->task.private_data = st;
        st->task.flags = 0;
        st->loaded = 0;
        st->fd = -1;
        st->buf[0] = '\0';
        sprintf(st->task.status, "status task");
}

static void set_initial_status(void)
{
        audiod_status = AUDIOD_ON;
        if (!conf.mode_given)
                return;
        if (!strcmp(conf.mode_arg, "sb")) {
                audiod_status = AUDIOD_STANDBY;
                return;
        }
        if (!strcmp(conf.mode_arg, "off")) {
                audiod_status = AUDIOD_OFF;
                return;
        }
        if (strcmp(conf.mode_arg, "on"))
                PARA_WARNING_LOG("%s", "invalid mode\n");
}

int main(int argc, char *argv[])
{
        char *cf;
        int ret, i;
        struct sched s;
        struct command_task command_task_struct, *cmd_task = &command_task_struct;
        struct task audiod_task_struct, *audiod_task = &audiod_task_struct;

        init_sched();

        valid_fd_012();
        hostname = para_hostname();
        cmdline_parser(argc, argv, &conf);
        para_drop_privileges(conf.user_arg, conf.group_arg);
        cf = configfile_exists();
        if (cf) {
                if (cmdline_parser_configfile(cf, &conf, 0, 0, 0)) {
                        PARA_EMERG_LOG("%s", "parse error in config file\n");
                        exit(EXIT_FAILURE);
                }
        }
        if (conf.logfile_given)
                logfile = open_log(conf.logfile_arg);
        log_welcome("para_audiod", conf.loglevel_arg);
        i = init_stream_io();
        if (i < 0) {
                PARA_EMERG_LOG("init stream io error: %s\n", PARA_STRERROR(-i));
                exit(EXIT_FAILURE);
        }
        server_uptime(UPTIME_SET);
        set_initial_status();
        FOR_EACH_SLOT(i)
                clear_slot(i);
        init_grabbing();
        setup_signal_handling();
        signal_setup_default(sig_task);
        sig_task->task.event_handler = signal_event_handler;

        init_status_task(stat_task);
        init_command_task(cmd_task);
        init_audiod_task(audiod_task);

        if (conf.daemon_given)
                daemon_init();

        register_task(&sig_task->task);
        register_task(&cmd_task->task);
        register_task(&stat_task->task);
        register_task(audiod_task);
        s.default_timeout.tv_sec = 0;
        s.default_timeout.tv_usec = 99 * 1000;
        ret = sched(&s);

        PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));
        return EXIT_FAILURE;
}