dvb_demux.c

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/*
 * dvb_demux.c - DVB kernel demux API
 *
 * Copyright (C) 2000-2001 Ralph  Metzler <[email protected]>
 *             & Marcus Metzler <[email protected]>
 *           for convergence integrated media GmbH
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation; either version 2.1
 * 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 Lesser General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 */

#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/module.h>
#include <linux/poll.h>
#include <linux/string.h>
#include <linux/crc32.h>
#include <asm/uaccess.h>
#include <asm/div64.h>

#include "dvb_demux.h"

#define NOBUFS
/*
** #define DVB_DEMUX_SECTION_LOSS_LOG to monitor payload loss in the syslog
*/
// #define DVB_DEMUX_SECTION_LOSS_LOG

static int dvb_demux_tscheck;
module_param(dvb_demux_tscheck, int, 0644);
MODULE_PARM_DESC(dvb_demux_tscheck,
        "enable transport stream continuity and TEI check");

static int dvb_demux_speedcheck;
module_param(dvb_demux_speedcheck, int, 0644);
MODULE_PARM_DESC(dvb_demux_speedcheck,
        "enable transport stream speed check");

static int dvb_demux_feed_err_pkts = 1;
module_param(dvb_demux_feed_err_pkts, int, 0644);
MODULE_PARM_DESC(dvb_demux_feed_err_pkts,
         "when set to 0, drop packets with the TEI bit set (1 by default)");

#define dprintk_tscheck(x...) do {                              \
        if (dvb_demux_tscheck && printk_ratelimit())    \
            printk(x);                              \
    } while (0)

/******************************************************************************
 * static inlined helper functions
 ******************************************************************************/

static inline u16 section_length(const u8 *buf)
{
    return 3 + ((buf[1] & 0x0f) << 8) + buf[2];
}

static inline u16 ts_pid(const u8 *buf)
{
    return ((buf[1] & 0x1f) << 8) + buf[2];
}

static inline u8 payload(const u8 *tsp)
{
    if (!(tsp[3] & 0x10))   // no payload?
        return 0;

    if (tsp[3] & 0x20) {    // adaptation field?
        if (tsp[4] > 183)   // corrupted data?
            return 0;
        else
            return 184 - 1 - tsp[4];
    }

    return 184;
}

static u32 dvb_dmx_crc32(struct dvb_demux_feed *f, const u8 *src, size_t len)
{
    return (f->feed.sec.crc_val = crc32_be(f->feed.sec.crc_val, src, len));
}

static void dvb_dmx_memcopy(struct dvb_demux_feed *f, u8 *d, const u8 *s,
                size_t len)
{
    memcpy(d, s, len);
}

/******************************************************************************
 * Software filter functions
 ******************************************************************************/

static inline int dvb_dmx_swfilter_payload(struct dvb_demux_feed *feed,
                       const u8 *buf)
{
    int count = payload(buf);
    int p;
    //int ccok;
    //u8 cc;

    if (count == 0)
        return -1;

    p = 188 - count;

    /*
    cc = buf[3] & 0x0f;
    ccok = ((feed->cc + 1) & 0x0f) == cc;
    feed->cc = cc;
    if (!ccok)
        printk("missed packet!\n");
    */

    if (buf[1] & 0x40)  // PUSI ?
        feed->peslen = 0xfffa;

    feed->peslen += count;

    return feed->cb.ts(&buf[p], count, NULL, 0, &feed->feed.ts, DMX_OK);
}

static int dvb_dmx_swfilter_sectionfilter(struct dvb_demux_feed *feed,
                      struct dvb_demux_filter *f)
{
    u8 neq = 0;
    int i;

    for (i = 0; i < DVB_DEMUX_MASK_MAX; i++) {
        u8 xor = f->filter.filter_value[i] ^ feed->feed.sec.secbuf[i];

        if (f->maskandmode[i] & xor)
            return 0;

        neq |= f->maskandnotmode[i] & xor;
    }

    if (f->doneq && !neq)
        return 0;

    return feed->cb.sec(feed->feed.sec.secbuf, feed->feed.sec.seclen,
                NULL, 0, &f->filter, DMX_OK);
}

static inline int dvb_dmx_swfilter_section_feed(struct dvb_demux_feed *feed)
{
    struct dvb_demux *demux = feed->demux;
    struct dvb_demux_filter *f = feed->filter;
    struct dmx_section_feed *sec = &feed->feed.sec;
    int section_syntax_indicator;

    if (!sec->is_filtering)
        return 0;

    if (!f)
        return 0;

    if (sec->check_crc) {
        section_syntax_indicator = ((sec->secbuf[1] & 0x80) != 0);
        if (section_syntax_indicator &&
            demux->check_crc32(feed, sec->secbuf, sec->seclen))
            return -1;
    }

    do {
        if (dvb_dmx_swfilter_sectionfilter(feed, f) < 0)
            return -1;
    } while ((f = f->next) && sec->is_filtering);

    sec->seclen = 0;

    return 0;
}

static void dvb_dmx_swfilter_section_new(struct dvb_demux_feed *feed)
{
    struct dmx_section_feed *sec = &feed->feed.sec;

#ifdef DVB_DEMUX_SECTION_LOSS_LOG
    if (sec->secbufp < sec->tsfeedp) {
        int i, n = sec->tsfeedp - sec->secbufp;

        /*
         * Section padding is done with 0xff bytes entirely.
         * Due to speed reasons, we won't check all of them
         * but just first and last.
         */
        if (sec->secbuf[0] != 0xff || sec->secbuf[n - 1] != 0xff) {
            printk("dvb_demux.c section ts padding loss: %d/%d\n",
                   n, sec->tsfeedp);
            printk("dvb_demux.c pad data:");
            for (i = 0; i < n; i++)
                printk(" %02x", sec->secbuf[i]);
            printk("\n");
        }
    }
#endif

    sec->tsfeedp = sec->secbufp = sec->seclen = 0;
    sec->secbuf = sec->secbuf_base;
}

/*
 * Losless Section Demux 1.4.1 by Emard
 * Valsecchi Patrick:
 *  - middle of section A  (no PUSI)
 *  - end of section A and start of section B
 *    (with PUSI pointing to the start of the second section)
 *
 *  In this case, without feed->pusi_seen you'll receive a garbage section
 *  consisting of the end of section A. Basically because tsfeedp
 *  is incemented and the use=0 condition is not raised
 *  when the second packet arrives.
 *
 * Fix:
 * when demux is started, let feed->pusi_seen = 0 to
 * prevent initial feeding of garbage from the end of
 * previous section. When you for the first time see PUSI=1
 * then set feed->pusi_seen = 1
 */
static int dvb_dmx_swfilter_section_copy_dump(struct dvb_demux_feed *feed,
                          const u8 *buf, u8 len)
{
    struct dvb_demux *demux = feed->demux;
    struct dmx_section_feed *sec = &feed->feed.sec;
    u16 limit, seclen, n;

    if (sec->tsfeedp >= DMX_MAX_SECFEED_SIZE)
        return 0;

    if (sec->tsfeedp + len > DMX_MAX_SECFEED_SIZE) {
#ifdef DVB_DEMUX_SECTION_LOSS_LOG
        printk("dvb_demux.c section buffer full loss: %d/%d\n",
               sec->tsfeedp + len - DMX_MAX_SECFEED_SIZE,
               DMX_MAX_SECFEED_SIZE);
#endif
        len = DMX_MAX_SECFEED_SIZE - sec->tsfeedp;
    }

    if (len <= 0)
        return 0;

    demux->memcopy(feed, sec->secbuf_base + sec->tsfeedp, buf, len);
    sec->tsfeedp += len;

    /*
     * Dump all the sections we can find in the data (Emard)
     */
    limit = sec->tsfeedp;
    if (limit > DMX_MAX_SECFEED_SIZE)
        return -1;  /* internal error should never happen */

    /* to be sure always set secbuf */
    sec->secbuf = sec->secbuf_base + sec->secbufp;

    for (n = 0; sec->secbufp + 2 < limit; n++) {
        seclen = section_length(sec->secbuf);
        if (seclen <= 0 || seclen > DMX_MAX_SECTION_SIZE
            || seclen + sec->secbufp > limit)
            return 0;
        sec->seclen = seclen;
        sec->crc_val = ~0;
        /* dump [secbuf .. secbuf+seclen) */
        if (feed->pusi_seen)
            dvb_dmx_swfilter_section_feed(feed);
#ifdef DVB_DEMUX_SECTION_LOSS_LOG
        else
            printk("dvb_demux.c pusi not seen, discarding section data\n");
#endif
        sec->secbufp += seclen; /* secbufp and secbuf moving together is */
        sec->secbuf += seclen;  /* redundant but saves pointer arithmetic */
    }

    return 0;
}

static int dvb_dmx_swfilter_section_packet(struct dvb_demux_feed *feed,
                       const u8 *buf)
{
    u8 p, count;
    int ccok, dc_i = 0;
    u8 cc;

    count = payload(buf);

    if (count == 0)     /* count == 0 if no payload or out of range */
        return -1;

    p = 188 - count;    /* payload start */

    cc = buf[3] & 0x0f;
    ccok = ((feed->cc + 1) & 0x0f) == cc;
    feed->cc = cc;

    if (buf[3] & 0x20) {
        /* adaption field present, check for discontinuity_indicator */
        if ((buf[4] > 0) && (buf[5] & 0x80))
            dc_i = 1;
    }

    if (!ccok || dc_i) {
#ifdef DVB_DEMUX_SECTION_LOSS_LOG
        printk("dvb_demux.c discontinuity detected %d bytes lost\n",
               count);
        /*
         * those bytes under sume circumstances will again be reported
         * in the following dvb_dmx_swfilter_section_new
         */
#endif
        /*
         * Discontinuity detected. Reset pusi_seen = 0 to
         * stop feeding of suspicious data until next PUSI=1 arrives
         */
        feed->pusi_seen = 0;
        dvb_dmx_swfilter_section_new(feed);
    }

    if (buf[1] & 0x40) {
        /* PUSI=1 (is set), section boundary is here */
        if (count > 1 && buf[p] < count) {
            const u8 *before = &buf[p + 1];
            u8 before_len = buf[p];
            const u8 *after = &before[before_len];
            u8 after_len = count - 1 - before_len;

            dvb_dmx_swfilter_section_copy_dump(feed, before,
                               before_len);
            /* before start of new section, set pusi_seen = 1 */
            feed->pusi_seen = 1;
            dvb_dmx_swfilter_section_new(feed);
            dvb_dmx_swfilter_section_copy_dump(feed, after,
                               after_len);
        }
#ifdef DVB_DEMUX_SECTION_LOSS_LOG
        else if (count > 0)
            printk("dvb_demux.c PUSI=1 but %d bytes lost\n", count);
#endif
    } else {
        /* PUSI=0 (is not set), no section boundary */
        dvb_dmx_swfilter_section_copy_dump(feed, &buf[p], count);
    }

    return 0;
}

static inline void dvb_dmx_swfilter_packet_type(struct dvb_demux_feed *feed,
                        const u8 *buf)
{
    switch (feed->type) {
    case DMX_TYPE_TS:
        if (!feed->feed.ts.is_filtering)
            break;
        if (feed->ts_type & TS_PACKET) {
            if (feed->ts_type & TS_PAYLOAD_ONLY)
                dvb_dmx_swfilter_payload(feed, buf);
            else
                feed->cb.ts(buf, 188, NULL, 0, &feed->feed.ts,
                        DMX_OK);
        }
        if (feed->ts_type & TS_DECODER)
            if (feed->demux->write_to_decoder)
                feed->demux->write_to_decoder(feed, buf, 188);
        break;

    case DMX_TYPE_SEC:
        if (!feed->feed.sec.is_filtering)
            break;
        if (dvb_dmx_swfilter_section_packet(feed, buf) < 0)
            feed->feed.sec.seclen = feed->feed.sec.secbufp = 0;
        break;

    default:
        break;
    }
}

#define DVR_FEED(f)                         \
    (((f)->type == DMX_TYPE_TS) &&                  \
    ((f)->feed.ts.is_filtering) &&                  \
    (((f)->ts_type & (TS_PACKET | TS_DEMUX)) == TS_PACKET))

static void dvb_dmx_swfilter_packet(struct dvb_demux *demux, const u8 *buf)
{
    struct dvb_demux_feed *feed;
    u16 pid = ts_pid(buf);
    int dvr_done = 0;

    if (dvb_demux_speedcheck) {
        struct timespec cur_time, delta_time;
        u64 speed_bytes, speed_timedelta;

        demux->speed_pkts_cnt++;

        /* show speed every SPEED_PKTS_INTERVAL packets */
        if (!(demux->speed_pkts_cnt % SPEED_PKTS_INTERVAL)) {
            cur_time = current_kernel_time();

            if (demux->speed_last_time.tv_sec != 0 &&
                    demux->speed_last_time.tv_nsec != 0) {
                delta_time = timespec_sub(cur_time,
                        demux->speed_last_time);
                speed_bytes = (u64)demux->speed_pkts_cnt
                    * 188 * 8;
                /* convert to 1024 basis */
                speed_bytes = 1000 * div64_u64(speed_bytes,
                        1024);
                speed_timedelta =
                    (u64)timespec_to_ns(&delta_time);
                speed_timedelta = div64_u64(speed_timedelta,
                        1000000); /* nsec -> usec */
                printk(KERN_INFO "TS speed %llu Kbits/sec \n",
                        div64_u64(speed_bytes,
                            speed_timedelta));
            }

            demux->speed_last_time = cur_time;
            demux->speed_pkts_cnt = 0;
        }
    }

    if (buf[1] & 0x80) {
        dprintk_tscheck("TEI detected. "
                "PID=0x%x data1=0x%x\n",
                pid, buf[1]);
        /* data in this packet cant be trusted - drop it unless
         * module option dvb_demux_feed_err_pkts is set */
        if (!dvb_demux_feed_err_pkts)
            return;
    } else /* if TEI bit is set, pid may be wrong- skip pkt counter */
    if (demux->cnt_storage && dvb_demux_tscheck) {
        /* check pkt counter */
        if (pid < MAX_PID) {
            if ((buf[3] & 0xf) != demux->cnt_storage[pid])
                dprintk_tscheck("TS packet counter mismatch. "
                        "PID=0x%x expected 0x%x "
                        "got 0x%x\n",
                        pid, demux->cnt_storage[pid],
                        buf[3] & 0xf);

            demux->cnt_storage[pid] = ((buf[3] & 0xf) + 1)&0xf;
        }
        /* end check */
    }

    list_for_each_entry(feed, &demux->feed_list, list_head) {
        if ((feed->pid != pid) && (feed->pid != 0x2000))
            continue;

        /* copy each packet only once to the dvr device, even
         * if a PID is in multiple filters (e.g. video + PCR) */
        if ((DVR_FEED(feed)) && (dvr_done++))
            continue;

        if (feed->pid == pid)
            dvb_dmx_swfilter_packet_type(feed, buf);
        else if (feed->pid == 0x2000)
            feed->cb.ts(buf, 188, NULL, 0, &feed->feed.ts, DMX_OK);
    }
}

void dvb_dmx_swfilter_packets(struct dvb_demux *demux, const u8 *buf,
                  size_t count)
{
    spin_lock(&demux->lock);

    while (count--) {
        if (buf[0] == 0x47)
            dvb_dmx_swfilter_packet(demux, buf);
        buf += 188;
    }

    spin_unlock(&demux->lock);
}

EXPORT_SYMBOL(dvb_dmx_swfilter_packets);

static inline int find_next_packet(const u8 *buf, int pos, size_t count,
                   const int pktsize)
{
    int start = pos, lost;

    while (pos < count) {
        if (buf[pos] == 0x47 ||
            (pktsize == 204 && buf[pos] == 0xB8))
            break;
        pos++;
    }

    lost = pos - start;
    if (lost) {
        /* This garbage is part of a valid packet? */
        int backtrack = pos - pktsize;
        if (backtrack >= 0 && (buf[backtrack] == 0x47 ||
            (pktsize == 204 && buf[backtrack] == 0xB8)))
            return backtrack;
    }

    return pos;
}

/* Filter all pktsize= 188 or 204 sized packets and skip garbage. */
static inline void _dvb_dmx_swfilter(struct dvb_demux *demux, const u8 *buf,
        size_t count, const int pktsize)
{
    int p = 0, i, j;
    const u8 *q;

    spin_lock(&demux->lock);

    if (demux->tsbufp) { /* tsbuf[0] is now 0x47. */
        i = demux->tsbufp;
        j = pktsize - i;
        if (count < j) {
            memcpy(&demux->tsbuf[i], buf, count);
            demux->tsbufp += count;
            goto bailout;
        }
        memcpy(&demux->tsbuf[i], buf, j);
        if (demux->tsbuf[0] == 0x47) /* double check */
            dvb_dmx_swfilter_packet(demux, demux->tsbuf);
        demux->tsbufp = 0;
        p += j;
    }

    while (1) {
        p = find_next_packet(buf, p, count, pktsize);
        if (p >= count)
            break;
        if (count - p < pktsize)
            break;

        q = &buf[p];

        if (pktsize == 204 && (*q == 0xB8)) {
            memcpy(demux->tsbuf, q, 188);
            demux->tsbuf[0] = 0x47;
            q = demux->tsbuf;
        }
        dvb_dmx_swfilter_packet(demux, q);
        p += pktsize;
    }

    i = count - p;
    if (i) {
        memcpy(demux->tsbuf, &buf[p], i);
        demux->tsbufp = i;
        if (pktsize == 204 && demux->tsbuf[0] == 0xB8)
            demux->tsbuf[0] = 0x47;
    }

bailout:
    spin_unlock(&demux->lock);
}

void dvb_dmx_swfilter(struct dvb_demux *demux, const u8 *buf, size_t count)
{
    _dvb_dmx_swfilter(demux, buf, count, 188);
}
EXPORT_SYMBOL(dvb_dmx_swfilter);

void dvb_dmx_swfilter_204(struct dvb_demux *demux, const u8 *buf, size_t count)
{
    _dvb_dmx_swfilter(demux, buf, count, 204);
}
EXPORT_SYMBOL(dvb_dmx_swfilter_204);

void dvb_dmx_swfilter_raw(struct dvb_demux *demux, const u8 *buf, size_t count)
{
    spin_lock(&demux->lock);

    demux->feed->cb.ts(buf, count, NULL, 0, &demux->feed->feed.ts, DMX_OK);

    spin_unlock(&demux->lock);
}
EXPORT_SYMBOL(dvb_dmx_swfilter_raw);

static struct dvb_demux_filter *dvb_dmx_filter_alloc(struct dvb_demux *demux)
{
    int i;

    for (i = 0; i < demux->filternum; i++)
        if (demux->filter[i].state == DMX_STATE_FREE)
            break;

    if (i == demux->filternum)
        return NULL;

    demux->filter[i].state = DMX_STATE_ALLOCATED;

    return &demux->filter[i];
}

static struct dvb_demux_feed *dvb_dmx_feed_alloc(struct dvb_demux *demux)
{
    int i;

    for (i = 0; i < demux->feednum; i++)
        if (demux->feed[i].state == DMX_STATE_FREE)
            break;

    if (i == demux->feednum)
        return NULL;

    demux->feed[i].state = DMX_STATE_ALLOCATED;

    return &demux->feed[i];
}

static int dvb_demux_feed_find(struct dvb_demux_feed *feed)
{
    struct dvb_demux_feed *entry;

    list_for_each_entry(entry, &feed->demux->feed_list, list_head)
        if (entry == feed)
            return 1;

    return 0;
}

static void dvb_demux_feed_add(struct dvb_demux_feed *feed)
{
    spin_lock_irq(&feed->demux->lock);
    if (dvb_demux_feed_find(feed)) {
        printk(KERN_ERR "%s: feed already in list (type=%x state=%x pid=%x)\n",
               __func__, feed->type, feed->state, feed->pid);
        goto out;
    }

    list_add(&feed->list_head, &feed->demux->feed_list);
out:
    spin_unlock_irq(&feed->demux->lock);
}

static void dvb_demux_feed_del(struct dvb_demux_feed *feed)
{
    spin_lock_irq(&feed->demux->lock);
    if (!(dvb_demux_feed_find(feed))) {
        printk(KERN_ERR "%s: feed not in list (type=%x state=%x pid=%x)\n",
               __func__, feed->type, feed->state, feed->pid);
        goto out;
    }

    list_del(&feed->list_head);
out:
    spin_unlock_irq(&feed->demux->lock);
}

static int dmx_ts_feed_set(struct dmx_ts_feed *ts_feed, u16 pid, int ts_type,
               enum dmx_ts_pes pes_type,
               size_t circular_buffer_size, struct timespec timeout)
{
    struct dvb_demux_feed *feed = (struct dvb_demux_feed *)ts_feed;
    struct dvb_demux *demux = feed->demux;

    if (pid > DMX_MAX_PID)
        return -EINVAL;

    if (mutex_lock_interruptible(&demux->mutex))
        return -ERESTARTSYS;

    if (ts_type & TS_DECODER) {
        if (pes_type >= DMX_TS_PES_OTHER) {
            mutex_unlock(&demux->mutex);
            return -EINVAL;
        }

        if (demux->pesfilter[pes_type] &&
            demux->pesfilter[pes_type] != feed) {
            mutex_unlock(&demux->mutex);
            return -EINVAL;
        }

        demux->pesfilter[pes_type] = feed;
        demux->pids[pes_type] = pid;
    }

    dvb_demux_feed_add(feed);

    feed->pid = pid;
    feed->buffer_size = circular_buffer_size;
    feed->timeout = timeout;
    feed->ts_type = ts_type;
    feed->pes_type = pes_type;

    if (feed->buffer_size) {
#ifdef NOBUFS
        feed->buffer = NULL;
#else
        feed->buffer = vmalloc(feed->buffer_size);
        if (!feed->buffer) {
            mutex_unlock(&demux->mutex);
            return -ENOMEM;
        }
#endif
    }

    feed->state = DMX_STATE_READY;
    mutex_unlock(&demux->mutex);

    return 0;
}

static int dmx_ts_feed_start_filtering(struct dmx_ts_feed *ts_feed)
{
    struct dvb_demux_feed *feed = (struct dvb_demux_feed *)ts_feed;
    struct dvb_demux *demux = feed->demux;
    int ret;

    if (mutex_lock_interruptible(&demux->mutex))
        return -ERESTARTSYS;

    if (feed->state != DMX_STATE_READY || feed->type != DMX_TYPE_TS) {
        mutex_unlock(&demux->mutex);
        return -EINVAL;
    }

    if (!demux->start_feed) {
        mutex_unlock(&demux->mutex);
        return -ENODEV;
    }

    if ((ret = demux->start_feed(feed)) < 0) {
        mutex_unlock(&demux->mutex);
        return ret;
    }

    spin_lock_irq(&demux->lock);
    ts_feed->is_filtering = 1;
    feed->state = DMX_STATE_GO;
    spin_unlock_irq(&demux->lock);
    mutex_unlock(&demux->mutex);

    return 0;
}

static int dmx_ts_feed_stop_filtering(struct dmx_ts_feed *ts_feed)
{
    struct dvb_demux_feed *feed = (struct dvb_demux_feed *)ts_feed;
    struct dvb_demux *demux = feed->demux;
    int ret;

    mutex_lock(&demux->mutex);

    if (feed->state < DMX_STATE_GO) {
        mutex_unlock(&demux->mutex);
        return -EINVAL;
    }

    if (!demux->stop_feed) {
        mutex_unlock(&demux->mutex);
        return -ENODEV;
    }

    ret = demux->stop_feed(feed);

    spin_lock_irq(&demux->lock);
    ts_feed->is_filtering = 0;
    feed->state = DMX_STATE_ALLOCATED;
    spin_unlock_irq(&demux->lock);
    mutex_unlock(&demux->mutex);

    return ret;
}

static int dvbdmx_allocate_ts_feed(struct dmx_demux *dmx,
                   struct dmx_ts_feed **ts_feed,
                   dmx_ts_cb callback)
{
    struct dvb_demux *demux = (struct dvb_demux *)dmx;
    struct dvb_demux_feed *feed;

    if (mutex_lock_interruptible(&demux->mutex))
        return -ERESTARTSYS;

    if (!(feed = dvb_dmx_feed_alloc(demux))) {
        mutex_unlock(&demux->mutex);
        return -EBUSY;
    }

    feed->type = DMX_TYPE_TS;
    feed->cb.ts = callback;
    feed->demux = demux;
    feed->pid = 0xffff;
    feed->peslen = 0xfffa;
    feed->buffer = NULL;

    (*ts_feed) = &feed->feed.ts;
    (*ts_feed)->parent = dmx;
    (*ts_feed)->priv = NULL;
    (*ts_feed)->is_filtering = 0;
    (*ts_feed)->start_filtering = dmx_ts_feed_start_filtering;
    (*ts_feed)->stop_filtering = dmx_ts_feed_stop_filtering;
    (*ts_feed)->set = dmx_ts_feed_set;

    if (!(feed->filter = dvb_dmx_filter_alloc(demux))) {
        feed->state = DMX_STATE_FREE;
        mutex_unlock(&demux->mutex);
        return -EBUSY;
    }

    feed->filter->type = DMX_TYPE_TS;
    feed->filter->feed = feed;
    feed->filter->state = DMX_STATE_READY;

    mutex_unlock(&demux->mutex);

    return 0;
}

static int dvbdmx_release_ts_feed(struct dmx_demux *dmx,
                  struct dmx_ts_feed *ts_feed)
{
    struct dvb_demux *demux = (struct dvb_demux *)dmx;
    struct dvb_demux_feed *feed = (struct dvb_demux_feed *)ts_feed;

    mutex_lock(&demux->mutex);

    if (feed->state == DMX_STATE_FREE) {
        mutex_unlock(&demux->mutex);
        return -EINVAL;
    }
#ifndef NOBUFS
    vfree(feed->buffer);
    feed->buffer = NULL;
#endif

    feed->state = DMX_STATE_FREE;
    feed->filter->state = DMX_STATE_FREE;

    dvb_demux_feed_del(feed);

    feed->pid = 0xffff;

    if (feed->ts_type & TS_DECODER && feed->pes_type < DMX_TS_PES_OTHER)
        demux->pesfilter[feed->pes_type] = NULL;

    mutex_unlock(&demux->mutex);
    return 0;
}

/******************************************************************************
 * dmx_section_feed API calls
 ******************************************************************************/

static int dmx_section_feed_allocate_filter(struct dmx_section_feed *feed,
                        struct dmx_section_filter **filter)
{
    struct dvb_demux_feed *dvbdmxfeed = (struct dvb_demux_feed *)feed;
    struct dvb_demux *dvbdemux = dvbdmxfeed->demux;
    struct dvb_demux_filter *dvbdmxfilter;

    if (mutex_lock_interruptible(&dvbdemux->mutex))
        return -ERESTARTSYS;

    dvbdmxfilter = dvb_dmx_filter_alloc(dvbdemux);
    if (!dvbdmxfilter) {
        mutex_unlock(&dvbdemux->mutex);
        return -EBUSY;
    }

    spin_lock_irq(&dvbdemux->lock);
    *filter = &dvbdmxfilter->filter;
    (*filter)->parent = feed;
    (*filter)->priv = NULL;
    dvbdmxfilter->feed = dvbdmxfeed;
    dvbdmxfilter->type = DMX_TYPE_SEC;
    dvbdmxfilter->state = DMX_STATE_READY;
    dvbdmxfilter->next = dvbdmxfeed->filter;
    dvbdmxfeed->filter = dvbdmxfilter;
    spin_unlock_irq(&dvbdemux->lock);

    mutex_unlock(&dvbdemux->mutex);
    return 0;
}

static int dmx_section_feed_set(struct dmx_section_feed *feed,
                u16 pid, size_t circular_buffer_size,
                int check_crc)
{
    struct dvb_demux_feed *dvbdmxfeed = (struct dvb_demux_feed *)feed;
    struct dvb_demux *dvbdmx = dvbdmxfeed->demux;

    if (pid > 0x1fff)
        return -EINVAL;

    if (mutex_lock_interruptible(&dvbdmx->mutex))
        return -ERESTARTSYS;

    dvb_demux_feed_add(dvbdmxfeed);

    dvbdmxfeed->pid = pid;
    dvbdmxfeed->buffer_size = circular_buffer_size;
    dvbdmxfeed->feed.sec.check_crc = check_crc;

#ifdef NOBUFS
    dvbdmxfeed->buffer = NULL;
#else
    dvbdmxfeed->buffer = vmalloc(dvbdmxfeed->buffer_size);
    if (!dvbdmxfeed->buffer) {
        mutex_unlock(&dvbdmx->mutex);
        return -ENOMEM;
    }
#endif

    dvbdmxfeed->state = DMX_STATE_READY;
    mutex_unlock(&dvbdmx->mutex);
    return 0;
}

static void prepare_secfilters(struct dvb_demux_feed *dvbdmxfeed)
{
    int i;
    struct dvb_demux_filter *f;
    struct dmx_section_filter *sf;
    u8 mask, mode, doneq;

    if (!(f = dvbdmxfeed->filter))
        return;
    do {
        sf = &f->filter;
        doneq = 0;
        for (i = 0; i < DVB_DEMUX_MASK_MAX; i++) {
            mode = sf->filter_mode[i];
            mask = sf->filter_mask[i];
            f->maskandmode[i] = mask & mode;
            doneq |= f->maskandnotmode[i] = mask & ~mode;
        }
        f->doneq = doneq ? 1 : 0;
    } while ((f = f->next));
}

static int dmx_section_feed_start_filtering(struct dmx_section_feed *feed)
{
    struct dvb_demux_feed *dvbdmxfeed = (struct dvb_demux_feed *)feed;
    struct dvb_demux *dvbdmx = dvbdmxfeed->demux;
    int ret;

    if (mutex_lock_interruptible(&dvbdmx->mutex))
        return -ERESTARTSYS;

    if (feed->is_filtering) {
        mutex_unlock(&dvbdmx->mutex);
        return -EBUSY;
    }

    if (!dvbdmxfeed->filter) {
        mutex_unlock(&dvbdmx->mutex);
        return -EINVAL;
    }

    dvbdmxfeed->feed.sec.tsfeedp = 0;
    dvbdmxfeed->feed.sec.secbuf = dvbdmxfeed->feed.sec.secbuf_base;
    dvbdmxfeed->feed.sec.secbufp = 0;
    dvbdmxfeed->feed.sec.seclen = 0;

    if (!dvbdmx->start_feed) {
        mutex_unlock(&dvbdmx->mutex);
        return -ENODEV;
    }

    prepare_secfilters(dvbdmxfeed);

    if ((ret = dvbdmx->start_feed(dvbdmxfeed)) < 0) {
        mutex_unlock(&dvbdmx->mutex);
        return ret;
    }

    spin_lock_irq(&dvbdmx->lock);
    feed->is_filtering = 1;
    dvbdmxfeed->state = DMX_STATE_GO;
    spin_unlock_irq(&dvbdmx->lock);

    mutex_unlock(&dvbdmx->mutex);
    return 0;
}

static int dmx_section_feed_stop_filtering(struct dmx_section_feed *feed)
{
    struct dvb_demux_feed *dvbdmxfeed = (struct dvb_demux_feed *)feed;
    struct dvb_demux *dvbdmx = dvbdmxfeed->demux;
    int ret;

    mutex_lock(&dvbdmx->mutex);

    if (!dvbdmx->stop_feed) {
        mutex_unlock(&dvbdmx->mutex);
        return -ENODEV;
    }

    ret = dvbdmx->stop_feed(dvbdmxfeed);

    spin_lock_irq(&dvbdmx->lock);
    dvbdmxfeed->state = DMX_STATE_READY;
    feed->is_filtering = 0;
    spin_unlock_irq(&dvbdmx->lock);

    mutex_unlock(&dvbdmx->mutex);
    return ret;
}

static int dmx_section_feed_release_filter(struct dmx_section_feed *feed,
                       struct dmx_section_filter *filter)
{
    struct dvb_demux_filter *dvbdmxfilter = (struct dvb_demux_filter *)filter, *f;
    struct dvb_demux_feed *dvbdmxfeed = (struct dvb_demux_feed *)feed;
    struct dvb_demux *dvbdmx = dvbdmxfeed->demux;

    mutex_lock(&dvbdmx->mutex);

    if (dvbdmxfilter->feed != dvbdmxfeed) {
        mutex_unlock(&dvbdmx->mutex);
        return -EINVAL;
    }

    if (feed->is_filtering)
        feed->stop_filtering(feed);

    spin_lock_irq(&dvbdmx->lock);
    f = dvbdmxfeed->filter;

    if (f == dvbdmxfilter) {
        dvbdmxfeed->filter = dvbdmxfilter->next;
    } else {
        while (f->next != dvbdmxfilter)
            f = f->next;
        f->next = f->next->next;
    }

    dvbdmxfilter->state = DMX_STATE_FREE;
    spin_unlock_irq(&dvbdmx->lock);
    mutex_unlock(&dvbdmx->mutex);
    return 0;
}

static int dvbdmx_allocate_section_feed(struct dmx_demux *demux,
                    struct dmx_section_feed **feed,
                    dmx_section_cb callback)
{
    struct dvb_demux *dvbdmx = (struct dvb_demux *)demux;
    struct dvb_demux_feed *dvbdmxfeed;

    if (mutex_lock_interruptible(&dvbdmx->mutex))
        return -ERESTARTSYS;

    if (!(dvbdmxfeed = dvb_dmx_feed_alloc(dvbdmx))) {
        mutex_unlock(&dvbdmx->mutex);
        return -EBUSY;
    }

    dvbdmxfeed->type = DMX_TYPE_SEC;
    dvbdmxfeed->cb.sec = callback;
    dvbdmxfeed->demux = dvbdmx;
    dvbdmxfeed->pid = 0xffff;
    dvbdmxfeed->feed.sec.secbuf = dvbdmxfeed->feed.sec.secbuf_base;
    dvbdmxfeed->feed.sec.secbufp = dvbdmxfeed->feed.sec.seclen = 0;
    dvbdmxfeed->feed.sec.tsfeedp = 0;
    dvbdmxfeed->filter = NULL;
    dvbdmxfeed->buffer = NULL;

    (*feed) = &dvbdmxfeed->feed.sec;
    (*feed)->is_filtering = 0;
    (*feed)->parent = demux;
    (*feed)->priv = NULL;

    (*feed)->set = dmx_section_feed_set;
    (*feed)->allocate_filter = dmx_section_feed_allocate_filter;
    (*feed)->start_filtering = dmx_section_feed_start_filtering;
    (*feed)->stop_filtering = dmx_section_feed_stop_filtering;
    (*feed)->release_filter = dmx_section_feed_release_filter;

    mutex_unlock(&dvbdmx->mutex);
    return 0;
}

static int dvbdmx_release_section_feed(struct dmx_demux *demux,
                       struct dmx_section_feed *feed)
{
    struct dvb_demux_feed *dvbdmxfeed = (struct dvb_demux_feed *)feed;
    struct dvb_demux *dvbdmx = (struct dvb_demux *)demux;

    mutex_lock(&dvbdmx->mutex);

    if (dvbdmxfeed->state == DMX_STATE_FREE) {
        mutex_unlock(&dvbdmx->mutex);
        return -EINVAL;
    }
#ifndef NOBUFS
    vfree(dvbdmxfeed->buffer);
    dvbdmxfeed->buffer = NULL;
#endif
    dvbdmxfeed->state = DMX_STATE_FREE;

    dvb_demux_feed_del(dvbdmxfeed);

    dvbdmxfeed->pid = 0xffff;

    mutex_unlock(&dvbdmx->mutex);
    return 0;
}

/******************************************************************************
 * dvb_demux kernel data API calls
 ******************************************************************************/

static int dvbdmx_open(struct dmx_demux *demux)
{
    struct dvb_demux *dvbdemux = (struct dvb_demux *)demux;

    if (dvbdemux->users >= MAX_DVB_DEMUX_USERS)
        return -EUSERS;

    dvbdemux->users++;
    return 0;
}

static int dvbdmx_close(struct dmx_demux *demux)
{
    struct dvb_demux *dvbdemux = (struct dvb_demux *)demux;

    if (dvbdemux->users == 0)
        return -ENODEV;

    dvbdemux->users--;
    //FIXME: release any unneeded resources if users==0
    return 0;
}

static int dvbdmx_write(struct dmx_demux *demux, const char __user *buf, size_t count)
{
    struct dvb_demux *dvbdemux = (struct dvb_demux *)demux;
    void *p;

    if ((!demux->frontend) || (demux->frontend->source != DMX_MEMORY_FE))
        return -EINVAL;

    p = memdup_user(buf, count);
    if (IS_ERR(p))
        return PTR_ERR(p);
    if (mutex_lock_interruptible(&dvbdemux->mutex)) {
        kfree(p);
        return -ERESTARTSYS;
    }
    dvb_dmx_swfilter(dvbdemux, p, count);
    kfree(p);
    mutex_unlock(&dvbdemux->mutex);

    if (signal_pending(current))
        return -EINTR;
    return count;
}

static int dvbdmx_add_frontend(struct dmx_demux *demux,
                   struct dmx_frontend *frontend)
{
    struct dvb_demux *dvbdemux = (struct dvb_demux *)demux;
    struct list_head *head = &dvbdemux->frontend_list;

    list_add(&(frontend->connectivity_list), head);

    return 0;
}

static int dvbdmx_remove_frontend(struct dmx_demux *demux,
                  struct dmx_frontend *frontend)
{
    struct dvb_demux *dvbdemux = (struct dvb_demux *)demux;
    struct list_head *pos, *n, *head = &dvbdemux->frontend_list;

    list_for_each_safe(pos, n, head) {
        if (DMX_FE_ENTRY(pos) == frontend) {
            list_del(pos);
            return 0;
        }
    }

    return -ENODEV;
}

static struct list_head *dvbdmx_get_frontends(struct dmx_demux *demux)
{
    struct dvb_demux *dvbdemux = (struct dvb_demux *)demux;

    if (list_empty(&dvbdemux->frontend_list))
        return NULL;

    return &dvbdemux->frontend_list;
}

static int dvbdmx_connect_frontend(struct dmx_demux *demux,
                   struct dmx_frontend *frontend)
{
    struct dvb_demux *dvbdemux = (struct dvb_demux *)demux;

    if (demux->frontend)
        return -EINVAL;

    mutex_lock(&dvbdemux->mutex);

    demux->frontend = frontend;
    mutex_unlock(&dvbdemux->mutex);
    return 0;
}

static int dvbdmx_disconnect_frontend(struct dmx_demux *demux)
{
    struct dvb_demux *dvbdemux = (struct dvb_demux *)demux;

    mutex_lock(&dvbdemux->mutex);

    demux->frontend = NULL;
    mutex_unlock(&dvbdemux->mutex);
    return 0;
}

static int dvbdmx_get_pes_pids(struct dmx_demux *demux, u16 * pids)
{
    struct dvb_demux *dvbdemux = (struct dvb_demux *)demux;

    memcpy(pids, dvbdemux->pids, 5 * sizeof(u16));
    return 0;
}

int dvb_dmx_init(struct dvb_demux *dvbdemux)
{
    int i;
    struct dmx_demux *dmx = &dvbdemux->dmx;

    dvbdemux->cnt_storage = NULL;
    dvbdemux->users = 0;
    dvbdemux->filter = vmalloc(dvbdemux->filternum * sizeof(struct dvb_demux_filter));

    if (!dvbdemux->filter)
        return -ENOMEM;

    dvbdemux->feed = vmalloc(dvbdemux->feednum * sizeof(struct dvb_demux_feed));
    if (!dvbdemux->feed) {
        vfree(dvbdemux->filter);
        dvbdemux->filter = NULL;
        return -ENOMEM;
    }
    for (i = 0; i < dvbdemux->filternum; i++) {
        dvbdemux->filter[i].state = DMX_STATE_FREE;
        dvbdemux->filter[i].index = i;
    }
    for (i = 0; i < dvbdemux->feednum; i++) {
        dvbdemux->feed[i].state = DMX_STATE_FREE;
        dvbdemux->feed[i].index = i;
    }

    dvbdemux->cnt_storage = vmalloc(MAX_PID + 1);
    if (!dvbdemux->cnt_storage)
        printk(KERN_WARNING "Couldn't allocate memory for TS/TEI check. Disabling it\n");

    INIT_LIST_HEAD(&dvbdemux->frontend_list);

    for (i = 0; i < DMX_TS_PES_OTHER; i++) {
        dvbdemux->pesfilter[i] = NULL;
        dvbdemux->pids[i] = 0xffff;
    }

    INIT_LIST_HEAD(&dvbdemux->feed_list);

    dvbdemux->playing = 0;
    dvbdemux->recording = 0;
    dvbdemux->tsbufp = 0;

    if (!dvbdemux->check_crc32)
        dvbdemux->check_crc32 = dvb_dmx_crc32;

    if (!dvbdemux->memcopy)
        dvbdemux->memcopy = dvb_dmx_memcopy;

    dmx->frontend = NULL;
    dmx->priv = dvbdemux;
    dmx->open = dvbdmx_open;
    dmx->close = dvbdmx_close;
    dmx->write = dvbdmx_write;
    dmx->allocate_ts_feed = dvbdmx_allocate_ts_feed;
    dmx->release_ts_feed = dvbdmx_release_ts_feed;
    dmx->allocate_section_feed = dvbdmx_allocate_section_feed;
    dmx->release_section_feed = dvbdmx_release_section_feed;

    dmx->add_frontend = dvbdmx_add_frontend;
    dmx->remove_frontend = dvbdmx_remove_frontend;
    dmx->get_frontends = dvbdmx_get_frontends;
    dmx->connect_frontend = dvbdmx_connect_frontend;
    dmx->disconnect_frontend = dvbdmx_disconnect_frontend;
    dmx->get_pes_pids = dvbdmx_get_pes_pids;

    mutex_init(&dvbdemux->mutex);
    spin_lock_init(&dvbdemux->lock);

    return 0;
}

EXPORT_SYMBOL(dvb_dmx_init);

void dvb_dmx_release(struct dvb_demux *dvbdemux)
{
    vfree(dvbdemux->cnt_storage);
    vfree(dvbdemux->filter);
    vfree(dvbdemux->feed);
}

EXPORT_SYMBOL(dvb_dmx_release);