V4L/DVB (11930): TS continuity check: show error message when discontinuity detected or TEI flag detected in header

Signed-off-by: Abylay Ospan <aospan@netup.ru>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

2 files changed, 46 insertions, 0 deletions

diff --git a/drivers/media/dvb/dvb-core/dvb_demux.c b/drivers/media/dvb/dvb-core/dvb_demux.c
index e2eca0b1fe7c..cfe2768d24af 100644
--- a/drivers/media/dvb/dvb-core/dvb_demux.c
+++ b/drivers/media/dvb/dvb-core/dvb_demux.c
@@ -38,6 +38,16 @@
 */
 // #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");
+
+#define dprintk_tscheck(x...) do {                              \
+                if (dvb_demux_tscheck && printk_ratelimit())    \
+                        printk(x);                              \
+        } while (0)
+
 /******************************************************************************
  * static inlined helper functions
  ******************************************************************************/
@@ -376,6 +386,36 @@ static void dvb_dmx_swfilter_packet(struct dvb_demux *demux, const u8 *buf)
         u16 pid = ts_pid(buf);
         int dvr_done = 0;
 
+        if (dvb_demux_tscheck) {
+                if (!demux->cnt_storage)
+                        demux->cnt_storage = vmalloc(MAX_PID + 1);
+
+                if (!demux->cnt_storage) {
+                        printk(KERN_WARNING "Couldn't allocate memory for TS/TEI check. Disabling it\n");
+                        dvb_demux_tscheck = 0;
+                        goto no_dvb_demux_tscheck;
+                }
+
+                /* check pkt counter */
+                if (pid < MAX_PID) {
+                        if (buf[1] & 0x80)
+                                dprintk_tscheck("TEI detected. "
+                                                "PID=0x%x data1=0x%x\n",
+                                                pid, buf[1]);
+
+                        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 */
+        };
+no_dvb_demux_tscheck:
+
         list_for_each_entry(feed, &demux->feed_list, list_head) {
                 if ((feed->pid != pid) && (feed->pid != 0x2000))
                         continue;
@@ -1160,6 +1200,7 @@ 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));
 
@@ -1226,6 +1267,7 @@ EXPORT_SYMBOL(dvb_dmx_init);
 
 void dvb_dmx_release(struct dvb_demux *dvbdemux)
 {
+        vfree(dvbdemux->cnt_storage);
         vfree(dvbdemux->filter);
         vfree(dvbdemux->feed);
 }
diff --git a/drivers/media/dvb/dvb-core/dvb_demux.h b/drivers/media/dvb/dvb-core/dvb_demux.h
index 2c5f915329ca..2fe05d03240d 100644
--- a/drivers/media/dvb/dvb-core/dvb_demux.h
+++ b/drivers/media/dvb/dvb-core/dvb_demux.h
@@ -42,6 +42,8 @@
 
 #define DVB_DEMUX_MASK_MAX 18
 
+#define MAX_PID 0x1fff
+
 struct dvb_demux_filter {
         struct dmx_section_filter filter;
         u8 maskandmode[DMX_MAX_FILTER_SIZE];
@@ -127,6 +129,8 @@ struct dvb_demux {
 
         struct mutex mutex;
         spinlock_t lock;
+
+        uint8_t *cnt_storage; /* for TS continuity check */
 };
 
 int dvb_dmx_init(struct dvb_demux *dvbdemux);