[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 <sys/time.h> /* gettimeofday */
#include "para.h"

#include "audiod.cmdline.h"
#include "list.h"
#include "close_on_fork.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"

/** 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;
/** output of the last filter is written to stdin of this command */
        char *write_cmd;
/** 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_info
  */
struct slot_info {
/** number of the audio format in this slot */
        int format;
/** the file descriptor of the writer */
        int write_fd;
/** the process id of the writer */
        pid_t wpid;
/** time of the last successful read from the receiver */
        struct timeval rtime;
/** time the last write to the write fd happend */
        struct timeval wtime;
/** writer start time */
        struct timeval wstime;
/** did we include \a write_fd in the fdset */
        int  wcheck;
/** set to one if we have sent the TERM signal to \a wpid */
        int wkilled;
/** the receiver info associated with this slot */
        struct receiver_node *receiver_node;
/** the active filter chain */
        struct filter_chain_info *fci;
};

static struct slot_info slot[MAX_STREAM_SLOTS];

/** 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**);
/** 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;
};

extern const char *status_item_list[NUM_STAT_ITEMS];

static int com_grab(int, 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 int stat_pipe = -1, signal_pipe;

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, audiod_socket = -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 audiod_command cmds[] = {
{
.name = "cycle",
.handler = com_cycle,
.description = "switch to next mode",
.synopsis = "cycle",
.help =

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

},
{
.name = "grab",
.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. \n"
"Available options:\n\n"
GRAB_HELP_TXT
},
{
.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",
.help =

"Add para_audiod status information to para_server's status information\n"
"and dump everything 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;
        if (!logfile && conf.logfile_given)
                logfile = open_log(conf.logfile_arg);
        if (!logfile && conf.daemon_given)
                return;
        if (!logfile) {
                if (ll < WARNING)
                        outfd = stdout;
                else
                        outfd = stderr;
        } else
                outfd = logfile;
        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 now, diff, adj_stream_start, tmp;
        int total = 0, use_server_time = 1;

        if (!playing) {
                if (length_seconds)
                        return NULL;
                return make_message("%s:", 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;
                }
        }
        gettimeofday(&now, NULL);
        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)",
                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
        );
}

static char *audiod_status_string(void)
{
        int i;
        struct timeval *newest_stime = NULL;
        char *ret, *time_string, *uptime_string, *decoder_flags =
                para_malloc((MAX_STREAM_SLOTS + 1) * sizeof(char));

        FOR_EACH_SLOT(i) {
                struct slot_info *s = &slot[i];
                char flag = '0';
                if (s->receiver_node)
                        flag += 1;
                if (s->wpid > 0)
                        flag += 2;
                if (flag != '0')
                        flag += s->format * 4;
                decoder_flags[i] = flag;
                if (s->wpid <= 0)
                        continue;
                if (newest_stime && tv_diff(&s->wstime, newest_stime, NULL) <= 0)
                        continue;
                newest_stime = &s->wstime;
        }
        decoder_flags[MAX_STREAM_SLOTS] = '\0';
        time_string = get_time_string(newest_stime);
        uptime_string = uptime_str();
        ret = make_message("%s:%s\n%s:%s\n%s:%s",
                status_item_list[SI_AUDIOD_UPTIME], uptime_string,
                status_item_list[SI_DECODER_FLAGS], decoder_flags,
                status_item_list[SI_AUDIOD_STATUS], audiod_status == AUDIOD_ON?
                        "on" : (audiod_status == AUDIOD_OFF? "off": "sb"));
        if (time_string)
                ret = make_message("%s\n%s", ret, time_string);
        free(uptime_string);
        free(decoder_flags);
        free(time_string);
        return ret;
}

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)
{
        signal_pipe = para_signal_init();
        PARA_INFO_LOG("signal pipe: fd %d\n", signal_pipe);
        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 *prev_status;
        char *tmp = audiod_status_string();

        if (!prev_status || strcmp(tmp, prev_status))
                stat_client_write(tmp);
        free(prev_status);
        prev_status = 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 kill_stream_writer(int slot_num)
{
        struct slot_info *s = &slot[slot_num];

        if (s->format < 0 || s->wkilled || s->wpid <= 0)
                return;
        PARA_DEBUG_LOG("kill -TERM %d (%s stream writer in slot %d)\n",
                s->wpid, audio_formats[s->format], slot_num);
        kill(s->wpid, SIGTERM);
        s->wkilled = 1;
        s->fci->error = 1;
}

static void set_restart_barrier(int format, struct timeval *now)
{
        struct timeval tmp;

        if (now)
                tmp = *now;
        else
                gettimeofday(&tmp, NULL);
        tv_add(&tmp, &restart_delay, &afi[format].restart_barrier);
}

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 recevier in slot %d\n",
                audio_formats[s->format] , slot_num);
        a->receiver->close(s->receiver_node);
        free(s->receiver_node);
        s->receiver_node = NULL;
        set_restart_barrier(s->format, NULL);
}

static void kill_all_decoders(void)
{
        int i;

        FOR_EACH_SLOT(i)
                if (slot[i].format >= 0) {
                        PARA_INFO_LOG("stopping decoder in slot %d\n", i);
                        kill_stream_writer(i);
                }
}

static void check_sigchld(void)
{
        pid_t pid;
        int i;
        struct timeval now;
        gettimeofday(&now, NULL);

reap_next_child:
        pid = para_reap_child();
        if (pid <= 0)
                return;
        FOR_EACH_SLOT(i) {
                struct slot_info *s = &slot[i];
                long lifetime;
                if (s->format < 0)
                        continue;
                if (pid == s->wpid) {
                        s->wpid = -1;
                        lifetime = now.tv_sec - s->wstime.tv_sec;
                        PARA_INFO_LOG("%s stream writer in slot %d died "
                                "after %li secs\n",
                                audio_formats[s->format], i, lifetime);
                        set_restart_barrier(s->format, &now);
                        goto reap_next_child;
                }
        }
        PARA_CRIT_LOG("para_client died (pid %d)\n", pid);
        goto reap_next_child;
}

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->write_fd > 0 || s->wpid > 0)
                        continue;
                if (s->receiver_node)
                        continue;
                if (s->fci)
                        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->wpid > 0)
                        ret |= 2;
        }
        return ret;
}

static void close_stat_pipe(void)
{
        int i;

        if (stat_pipe < 0)
                return;
        PARA_NOTICE_LOG("%s", "closing status pipe\n");
        close(stat_pipe);
        del_close_on_fork_list(stat_pipe);
        stat_pipe = -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]);
}

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

__malloc static char *glob_cmd(char *cmd)
{
        char *ret, *replacement;
        struct timeval tmp, delay, rss; /* real stream start */

        delay.tv_sec = conf.stream_delay_arg / 1000;
        delay.tv_usec = (conf.stream_delay_arg % 1000) * 1000;
//      PARA_INFO_LOG("delay: %lu:%lu\n", delay.tv_sec, delay.tv_usec);
        if (sa_time_diff_sign < 0)
                tv_add(&server_stream_start, &sa_time_diff, &rss);
        else
                tv_diff(&server_stream_start, &sa_time_diff, &rss);
        tv_add(&rss, &delay, &tmp);
        replacement = make_message("%lu:%lu", tmp.tv_sec, tmp.tv_usec);
        ret = s_a_r(cmd, "STREAM_START", replacement);
        free(replacement);
        if (!ret)
                goto out;
        PARA_INFO_LOG("cmd: %s, repl: %s\n", cmd, ret);
        {
        struct timeval now;
        gettimeofday(&now, NULL);
        PARA_INFO_LOG("now: %lu:%lu\n", now.tv_sec, now.tv_usec);
        }
out:
        return ret;
}

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

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->fci = para_calloc(sizeof(struct filter_chain_info));
        INIT_LIST_HEAD(&s->fci->filters);
        if (!nf)
                return;
        s->fci->inbuf = s->receiver_node->buf;
        s->fci->in_loaded = &s->receiver_node->loaded;
        s->fci->outbuf = s->receiver_node->buf;
        s->fci->out_loaded = &s->receiver_node->loaded;
        s->fci->eof = &s->receiver_node->eof;
        for (i = 0; i < nf; i++) {
                struct filter_node *fn = para_calloc(sizeof(struct filter_node));
                fn->conf = a->filter_conf[i];
                fn->fci = s->fci;
                fn->filter = a->filters[i];
                INIT_LIST_HEAD(&fn->callbacks);
                list_add_tail(&fn->node, &s->fci->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->fci->outbuf = fn->buf;
                s->fci->out_loaded = &fn->loaded;
        }
        PARA_DEBUG_LOG("output buffer for filter chain %p: %p\n", s->fci,
                s->fci->outbuf);
}

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->fci)
                        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->fci->filters, node)
                        if (filternum <= 0 || j++ == filternum)
                                break;
                return fn;
        }
        return NULL;
}

static void start_stream_writer(int slot_num)
{
        int ret, fds[3] = {1, -1, -1};
        struct slot_info *s = &slot[slot_num];
        struct audio_format_info *a = &afi[s->format];
        char *glob = NULL;

        if (a->write_cmd)
                glob = glob_cmd(a->write_cmd);
        if (!glob)
                glob = para_strdup("para_play");
        PARA_INFO_LOG("starting stream writer: %s\n", glob);
        open_filters(slot_num);
        ret = para_exec_cmdline_pid(&s->wpid, glob, fds);
        free(glob);
        if (ret < 0) {
                PARA_ERROR_LOG("exec failed (%d)\n", ret);
                return;
        }
        s->write_fd = fds[0];
        add_close_on_fork_list(s->write_fd);
        /* we write to this fd in do_select, so we need non-blocking */
        fcntl(s->write_fd, F_SETFL, O_NONBLOCK);
        gettimeofday(&s->wstime, NULL);
        current_decoder = slot_num;
        activate_inactive_grab_clients(slot_num, s->format, &s->fci->filters);
}

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

        slot_num = get_empty_slot();
        if (slot_num < 0)
                clean_exit(EXIT_FAILURE, PARA_STRERROR(-slot_num));
        s = &slot[slot_num];
        s->format = format;
        gettimeofday(&s->rtime, NULL);
        s->wtime = s->rtime;
        s->receiver_node = para_calloc(sizeof(struct receiver_node));
        s->receiver_node->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);
}

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

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

static void start_current_receiver(void)
{
        int i;

        if (!af_status)
                return;
        i = get_audio_format_num(af_status);
        if (i < 0)
                return;
        if ((decoder_running(i) & 1) || is_frozen(i))
                return;
        open_receiver(i);
}

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

        gettimeofday(&now, NULL);
        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): "
                "%li:%lu/%li:%lu\n",
                sign * diff.tv_sec, (diff.tv_usec + 500) / 1000,
                sa_time_diff_sign * sa_time_diff.tv_sec,
                (sa_time_diff.tv_usec + 500)/ 1000);
}

static void check_stat_line(char *line)
{
        int itemnum;
        size_t ilen = 0;
        struct timeval tv;

        if (!line)
                return;
        itemnum = stat_line_valid(line);
        if (itemnum < 0) {
                PARA_WARNING_LOG("invalid status line: %s\n", line);
                return;
        }
        stat_client_write(line);
        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",
                                &tv.tv_sec, &tv.tv_usec) == 2)
                        server_stream_start = tv;
                break;
        case SI_CURRENT_TIME:
                if (sscanf(line + ilen + 1, "%lu.%lu", &tv.tv_sec,
                                &tv.tv_usec) == 2)
                        compute_time_diff(&tv);
                break;
        }
}

static void handle_signal(int sig)
{
        switch (sig) {
        case SIGCHLD:
                return check_sigchld();
        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 check_timeouts(void)
{
        struct timeval now;
        int slot_num, timeout = conf.stream_timeout_arg;

        gettimeofday(&now, NULL);
        FOR_EACH_SLOT(slot_num) {
                struct slot_info *s = &slot[slot_num];
                if (s->format < 0)
                        continue;
                /* check read time */
                if (s->receiver_node &&
                        now.tv_sec > s->rtime.tv_sec + timeout) {
                        PARA_INFO_LOG("%s input buffer (slot %d) not ready\n",
                                audio_formats[s->format], slot_num);
                        if (s->fci)
                                s->fci->error = 42;
                        else
                                close_receiver(slot_num);
                }
                /* check write time */
                if (s->wpid > 0 && !s->wkilled &&
                        now.tv_sec > s->wtime.tv_sec + timeout) {
                        PARA_INFO_LOG("%s output buffer (slot %d) not ready\n",
                                audio_formats[s->format], slot_num);
                        if (s->fci)
                                s->fci->error = 42;
                }
        }
}

static size_t get_loaded_bytes(int slot_num)
{
        size_t loaded = 0;
        struct slot_info *s = &slot[slot_num];
        struct receiver_node *rn = s->receiver_node;

        if (s->format < 0)
                goto out;

        if (afi[s->format].num_filters) {
                if (s->fci)
                        loaded = *s->fci->out_loaded;
        } else {
                if (rn)
                        loaded = rn->loaded;
        }
out:
        return loaded;
}


static void close_decoder_if_idle(int slot_num)
{
        struct slot_info *s = &slot[slot_num];
        struct receiver_node *rn = s->receiver_node;

        if (s->format < 0)
                return;
        if (!s->fci)
                return;
        if (!rn->eof && !s->fci->error && s->wpid > 0)
                return;
        if (!s->fci->error && s->wpid > 0) { /* eof */
                if (filter_io(s->fci) > 0)
                        return;
                if (get_loaded_bytes(slot_num))
                        return;
        }
        if (s->write_fd > 0) {
                PARA_INFO_LOG("slot %d: closing write fd %d\n", slot_num,
                        s->write_fd);
                close(s->write_fd);
                del_close_on_fork_list(s->write_fd);
                s->write_fd = -1;
        }
        if (s->wpid > 0)
                return; /* wait until writer dies before closing filters */
        PARA_INFO_LOG("closing all filters in slot %d (filter_chain %p)\n",
                slot_num, s->fci);
        close_filters(s->fci);
        free(s->fci);
        close_receiver(slot_num);
        clear_slot(slot_num);
}

static int set_stream_fds(fd_set *wfds)
{
        int i, max_fileno = -1;

        check_timeouts();
        FOR_EACH_SLOT(i) {
                struct slot_info *s = &slot[i];
                struct audio_format_info *a;
                struct receiver_node *rn;

                close_decoder_if_idle(i);
                s->wcheck = 0;
                if (s->format < 0)
                        continue;
                a = &afi[s->format];
                rn = s->receiver_node;
                if (rn && rn->loaded && !s->wpid) {
                        PARA_INFO_LOG("no writer in slot %d\n", i);
                        start_stream_writer(i);
                }
                if (s->write_fd <= 0)
                        continue;
                if (!get_loaded_bytes(i))
                        continue;
                FD_SET(s->write_fd, wfds);
                s->wcheck = 1;
                max_fileno = MAX(s->write_fd, max_fileno);
        }
//      PARA_INFO_LOG("return %d\n", max_fileno);
        return max_fileno;
}

static int write_audio_data(int slot_num)
{
        struct slot_info *s = &slot[slot_num];
        struct audio_format_info *a = &afi[s->format];
        struct receiver_node *rn = s->receiver_node;
        int rv;
        char **buf;
        size_t *len;

        if (a->num_filters) {
                buf = &s->fci->outbuf;
                len = s->fci->out_loaded;
        } else {
                buf = &rn->buf;
                len = &rn->loaded;
        }
        PARA_DEBUG_LOG("writing %p (%zd bytes)\n", *buf, *len);
        rv = write(s->write_fd, *buf, *len);
        PARA_DEBUG_LOG("wrote %d/%zd\n", rv, *len);
        if (rv < 0) {
                PARA_WARNING_LOG("write error in slot %d (fd %d): %s\n",
                        slot_num, s->write_fd, strerror(errno));
                *len = 0;
                s->fci->error = E_WRITE_AUDIO_DATA;
        } else if (rv != *len) {
                PARA_DEBUG_LOG("partial %s write (%i/%zd) for slot %d\n",
                        audio_formats[s->format], rv, *len, slot_num);
                *len -= rv;
                memmove(*buf, *buf + rv, *len);
        } else
                *len = 0;
        if (rv > 0)
                gettimeofday(&s->wtime, NULL);
        return rv;
}

static void slot_io(fd_set *wfds)
{
        int ret, i;

        FOR_EACH_SLOT(i) {
                struct slot_info *s = &slot[i];
                struct receiver_node *rn = s->receiver_node;

                if (rn && rn->loaded)
                        gettimeofday(&s->rtime, NULL);
                if (s->format >= 0 && s->write_fd > 0 && s->fci) {
                        ret = filter_io(s->fci);
                        if (ret < 0)
                                s->fci->error = -ret;
//                      PARA_DEBUG_LOG("slot %d, filter io %d bytes, check write: %d, loaded: %d/%d, eof: %d\n",
//                               i, ret, s->wcheck, rn->loaded, *s->fci->out_loaded, rn->eof);
                }
                if (s->write_fd <= 0 || !s->wcheck || !FD_ISSET(s->write_fd, wfds))
                        continue;
                write_audio_data(i);
        }
}

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 setup_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;
                /* 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);
                ret = add_filter(i, para_strdup("wav"));
                if (ret < 0)
                        goto out;
                PARA_INFO_LOG("%s -> default filter: wav\n", audio_formats[i]);
        }
out:
        return ret;
}

static int init_stream_io(void)
{
        int i, ret, receiver_num;
        char *cmd;

        for (i = 0; i < conf.stream_write_cmd_given; i++) {
                ret = parse_stream_command(conf.stream_write_cmd_arg[i], &cmd);
                if (ret < 0)
                        goto out;
                afi[ret].write_cmd = para_strdup(cmd);
                PARA_INFO_LOG("%s write command: %s\n", audio_formats[ret], afi[ret].write_cmd);
        }
        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) {
                struct audio_format_info *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];
        }
        free(cmd);
        /* filters */
        filter_init(filters);
        FOR_EACH_AUDIO_FORMAT(i) {
                afi[i].filter_conf = para_malloc((conf.filter_given + 1) * sizeof(char *));
                afi[i].filters = para_malloc((conf.filter_given + 1) * sizeof(struct filter *));
        }
        if (!conf.no_default_filters_given)
                return setup_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 = 1;
out:
        return ret;
}

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, __unused int argc, __unused char **argv)
{
        int i, ret;
        char *buf = make_message("%s\n", audiod_status_string());

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

#if 0
static char *list_filters(void)
{
        int i, j;
        char *tmp, *msg = make_message("format\tnum\tcmd\n");

        FOR_EACH_AUDIO_FORMAT(i) {
                for (j = 0; j < afi[i].num_filters; j++) {
                        tmp = make_message("%s\t%i\t%s\n",
                                afi[i].name, j, afi[i].filter_cmds[j]);
                        msg = para_strcat(msg, tmp);
                        free(tmp);
                }
                tmp = make_message("%s\t%i\t%s\n", afi[i].name,
                        j, afi[i].write_cmd);
                msg = para_strcat(msg, tmp);
                free(tmp);
        }
        return msg;
}
#endif

static int com_grab(int fd, int argc, char **argv)
{
        struct grab_client *gc;
        struct filter_node *fn;
        int err;

        PARA_INFO_LOG("argc: %d, argv[0]: %s, optind: %d\n", argc, argv[0], optind);
        gc = grab_client_new(fd, argc, argv, &err);
        PARA_INFO_LOG("argc: %d, argv[0]: %s, optind: %d\n", argc, argv[0], optind);
        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)
                return err;
        err = client_write(fd, "Usage: para_audioc [audioc_options] -- "
                "grab [grab_options]\nAvailable options:\n");
        if (err < 0)
                return err;
        err = client_write(fd, GRAB_HELP_TXT);
        if (err < 0)
                return err;
        close(fd);
        return 1;
}

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

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

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

static int com_sb(int fd, __unused int argc, __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(struct ucred *c)
{
        int i;

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

static int handle_connect(void)
{
        int i, argc, ret, clifd = -1;
        struct ucred c;
        char *buf = para_malloc(MAXLINE), **argv = NULL;
        struct sockaddr_un unix_addr;

        ret = para_accept(audiod_socket, &unix_addr, sizeof(struct sockaddr_un));
        if (ret < 0)
                goto out;
        clifd = ret;
        ret = recv_cred_buffer(clifd, buf, MAXLINE - 1, &c);
        if (ret < 0)
                goto out;
        PARA_INFO_LOG("pid: %i, uid: %i, gid: %i, ret: %i, buf: %s\n", c.pid, c.uid, c.gid, ret, buf);
        buf[ret] = '\0';
        ret = check_perms(&c);
        if (ret < 0)
                goto out;
        argc = split_args(buf, &argv, '\n');
        PARA_INFO_LOG("argv[0]: %s\n", argv[0]);
        for (i = 0; cmds[i].name; i++) {
                if (strcmp(cmds[i].name, argv[0]))
                        continue;
                ret = cmds[i].handler(clifd, argc + 1, argv);
                goto out;
        }
        ret = -E_INVALID_AUDIOD_CMD; /* cmd not found */
out:
        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 void audiod_get_socket(void)
{
        struct sockaddr_un unix_addr;

        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("connecting to local socket %s\n", socket_name);
        if (conf.force_given)
                unlink(socket_name);
        audiod_socket = create_pf_socket(socket_name, &unix_addr,
                        S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
        if (audiod_socket < 0) {
                PARA_EMERG_LOG("%s", "can not connect to socket\n");
                exit(EXIT_FAILURE); /* do not unlink socket */
        }
        if (listen(audiod_socket, 5) < 0) {
                PARA_EMERG_LOG("%s", "can not listen on socket\n");
                exit(EXIT_FAILURE); /* do not unlink socket */
        }
        add_close_on_fork_list(audiod_socket);
}

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;
}

static int pre_select(fd_set *rfds, fd_set *wfds, struct timeval *tv)
{
        int i, ret, max = -1;

        FOR_EACH_SLOT(i) {
                struct slot_info *s = &slot[i];
                struct audio_format_info *a;
                struct receiver_node *rn = s->receiver_node;
                if (s->format < 0 || !rn)
                        continue;
                a = &afi[s->format];
                ret = a->receiver->pre_select(rn, rfds, wfds, tv);
//              PARA_NOTICE_LOG("%s preselect: %d\n", a->receiver->name, ret);
                max = MAX(max, ret);
        }
        return max;

}
static void audiod_post_select(int select_ret, fd_set *rfds, fd_set *wfds)
{
        int i, ret;

        FOR_EACH_SLOT(i) {
                struct slot_info *s = &slot[i];
                struct audio_format_info *a;
                struct receiver_node *rn = s->receiver_node;
                if (s->format < 0 || !rn || rn->eof)
                        continue;
                a = &afi[s->format];
                ret = a->receiver->post_select(rn, select_ret, rfds, wfds);
                if (ret <= 0) {
                        if (ret)
                                PARA_ERROR_LOG("%s post select failed: %s (slot %d)\n",
                                a->receiver->name, PARA_STRERROR(-ret), i);
                        else
                                PARA_INFO_LOG("eof in slot %d\n", i);
                        rn->eof = 1;
                }
                if (ret < 0 && s->fci)
                        s->fci->error = ret;
        }
}

/* TODO: move everything before the select call to pre_select() */
static void __noreturn audiod_mainloop(void)
{
        fd_set rfds, wfds;
        int ret, max_fileno, sbo = 0;
        char status_buf[STRINGSIZE] = "";
        struct timeval tv;
repeat:
        FD_ZERO(&rfds);
        FD_ZERO(&wfds);
        max_fileno = 0;
        if (audiod_status != AUDIOD_ON)
                kill_all_decoders();
        else if (playing)
                start_current_receiver();
        max_fileno = set_stream_fds(&wfds);
        /* stat pipe (read) */
        if (stat_pipe >= 0 && audiod_status == AUDIOD_OFF)
                close_stat_pipe();
        if (stat_pipe < 0 && audiod_status != AUDIOD_OFF) {
                stat_pipe = open_stat_pipe();
                sbo = 0;
                status_buf[0] = '\0';
        }
        if (stat_pipe >= 0 && audiod_status != AUDIOD_OFF) {
                FD_SET(stat_pipe, &rfds);
                max_fileno = MAX(max_fileno, stat_pipe);
        }
        /* always check signal pipe */
        FD_SET(signal_pipe, &rfds);
        max_fileno = MAX(max_fileno, signal_pipe);
        /* local socket */
        if (audiod_socket < 0)
                audiod_get_socket(); /* doesn't return on errors */
        FD_SET(audiod_socket, &rfds);
        max_fileno = MAX(max_fileno, audiod_socket);
        tv.tv_sec = 0;
        tv.tv_usec = 200 * 1000;
        ret = pre_select(&rfds, &wfds, &tv);
        max_fileno = MAX(max_fileno, ret);
        ret = select(max_fileno + 1, &rfds, &wfds, NULL, &tv);
        if (ret < 0 && errno != EINTR)
                PARA_ERROR_LOG("select returned %d (%s)\n", ret,
                        strerror(errno));
        if (audiod_status != AUDIOD_OFF)
                audiod_status_dump();
        if (ret < 0)
                goto repeat;
        audiod_post_select(ret, &rfds, &wfds);
        /* read status pipe */
        if (stat_pipe >=0 && FD_ISSET(stat_pipe, &rfds)) {
                ret = read(stat_pipe, status_buf + sbo, STRINGSIZE - 1 - sbo);
                if (ret <= 0) {
                        close_stat_pipe();
                        /* avoid busy loop if server is down */
                        while (sleep(1) > 0)
                                ; /* try again*/
                } else {
                        status_buf[ret + sbo] = '\0';
                        sbo = for_each_line(status_buf, ret + sbo,
                                &check_stat_line);
                }
        }
        slot_io(&wfds);
        if (FD_ISSET(audiod_socket, &rfds)) {
                ret = handle_connect();
                if (ret < 0) {
                        PARA_ERROR_LOG("%s\n", PARA_STRERROR(-ret));
                }
        }
        /* signals */
        if (FD_ISSET(signal_pipe, &rfds)) {
                int sig_nr = para_next_signal();
                if (sig_nr > 0)
                        handle_signal(sig_nr);
        }
        goto repeat;
}

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 __noreturn main(int argc, char *argv[])
{
        char *cf;
        int i;

        valid_fd_012();
        hostname = para_hostname();
        cmdline_parser(argc, argv, &conf);
        para_drop_privileges(conf.user_arg);
        cf = configfile_exists();
        if (cf) {
                if (cmdline_parser_configfile(cf, &conf, 0, 0, 0)) {
                        fprintf(stderr, "parse error in config file\n");
                        exit(EXIT_FAILURE);
                }
        }
        log_welcome("para_audiod", conf.loglevel_arg);
        i = init_stream_io();
        if (i < 0) {
                fprintf(stderr, "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();
        if (conf.daemon_given)
                daemon_init();
        audiod_mainloop();
}