Commit c94115ff authored by Henrik Kurelid's avatar Henrik Kurelid Committed by Mauro Carvalho Chehab
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V4L/DVB (13237): firedtv: length field corrupt in ca2host if length>127 



This solves a problem in firedtv that has become major for Swedish DVB-T
users the last month or so.  It will most likely solve issues seen by
other users as well.

If the length of an AVC message is greater than 127, the length field
should be encoded in LV mode instead of V mode. V mode can only be used
if the length is 127 or less. This patch ensures that the CA_PMT
message is always encoded in LV mode so PMT message of greater lengths
can be supported.

Signed-off-by: default avatarHenrik Kurelid <henrik@kurelid.se>
Signed-off-by: default avatarStefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent 1f957257

drivers/media/dvb/firewire/firedtv-avc.c

+20 −18
Original line number Diff line number Diff line
@@ -1050,28 +1050,28 @@ int avc_ca_pmt(struct firedtv *fdtv, char *msg, int length) 
	c->operand[4] = 0; /* slot */

	c->operand[5] = SFE_VENDOR_TAG_CA_PMT; /* ca tag */

	c->operand[6] = 0; /* more/last */

	/* c->operand[7] = XXXprogram_info_length + 17; */ /* length */

	c->operand[8] = list_management;

	c->operand[9] = 0x01; /* pmt_cmd=OK_descramble */

	/* Use three bytes for length field in case length > 127 */

	c->operand[10] = list_management;

	c->operand[11] = 0x01; /* pmt_cmd=OK_descramble */



	/* TS program map table */



	c->operand[10] = 0x02; /* Table id=2 */

	c->operand[11] = 0x80; /* Section syntax + length */

	/* c->operand[12] = XXXprogram_info_length + 12; */

	c->operand[13] = msg[1]; /* Program number */

	c->operand[14] = msg[2];

	c->operand[15] = 0x01; /* Version number=0 + current/next=1 */

	c->operand[16] = 0x00; /* Section number=0 */

	c->operand[17] = 0x00; /* Last section number=0 */

	c->operand[18] = 0x1f; /* PCR_PID=1FFF */

	c->operand[19] = 0xff;

	c->operand[20] = (program_info_length >> 8); /* Program info length */

	c->operand[21] = (program_info_length & 0xff);

	c->operand[12] = 0x02; /* Table id=2 */

	c->operand[13] = 0x80; /* Section syntax + length */

	/* c->operand[14] = XXXprogram_info_length + 12; */

	c->operand[15] = msg[1]; /* Program number */

	c->operand[16] = msg[2];

	c->operand[17] = 0x01; /* Version number=0 + current/next=1 */

	c->operand[18] = 0x00; /* Section number=0 */

	c->operand[19] = 0x00; /* Last section number=0 */

	c->operand[20] = 0x1f; /* PCR_PID=1FFF */

	c->operand[21] = 0xff;

	c->operand[22] = (program_info_length >> 8); /* Program info length */

	c->operand[23] = (program_info_length & 0xff);



	/* CA descriptors at programme level */

	read_pos = 6;

	write_pos = 22;

	write_pos = 24;

	if (program_info_length > 0) {

		pmt_cmd_id = msg[read_pos++];

		if (pmt_cmd_id != 1 && pmt_cmd_id != 4)
@@ -1113,8 +1113,10 @@ int avc_ca_pmt(struct firedtv *fdtv, char *msg, int length) 
	c->operand[write_pos++] = 0x00;

	c->operand[write_pos++] = 0x00;



	c->operand[7] = write_pos - 8;

	c->operand[12] = write_pos - 13;

	c->operand[7] = 0x82;

	c->operand[8] = (write_pos - 10) >> 8;

	c->operand[9] = (write_pos - 10) & 0xff;

	c->operand[14] = write_pos - 15;



	crc32_csum = crc32_be(0, &c->operand[10], c->operand[12] - 1);

	c->operand[write_pos - 4] = (crc32_csum >> 24) & 0xff;

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