[PATCH v3 16/40] misc/mei/hdcp: Verify M_prime

Ramalingam C ramalingam.c at intel.com
Wed May 16 16:32:05 UTC 2018



On Wednesday 09 May 2018 07:20 PM, Shankar, Uma wrote:
>
>> -----Original Message-----
>> From: dri-devel [mailto:dri-devel-bounces at lists.freedesktop.org] On Behalf Of
>> Ramalingam C
>> Sent: Tuesday, April 3, 2018 7:27 PM
>> To: intel-gfx at lists.freedesktop.org; dri-devel at lists.freedesktop.org;
>> seanpaul at chromium.org; daniel at ffwll.ch; chris at chris-wilson.co.uk;
>> jani.nikula at linux.intel.com; Winkler, Tomas <tomas.winkler at intel.com>;
>> Usyskin, Alexander <alexander.usyskin at intel.com>
>> Cc: Vivi, Rodrigo <rodrigo.vivi at intel.com>
>> Subject: [PATCH v3 16/40] misc/mei/hdcp: Verify M_prime
>>
>> Request to ME to verify the M_Prime received from the HDCP sink.
>>
>> ME FW will calculate the M and compare with M_prime received as part of
>> RepeaterAuth_Stream_Ready, which is HDCP2.2 protocol msg.
>>
>> On successful completion of this stage, downstream propagation of the stream
>> management info is completed.
>>
>> v2:
>>   Rebased.
>> v3:
>>   cldev is passed as first parameter [Tomas]
>>   Redundant comments and cast are removed [Tomas]
>>
>> Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
>> ---
>> drivers/misc/mei/hdcp/mei_hdcp.c | 79
>> ++++++++++++++++++++++++++++++++++++++++
>> include/linux/mei_hdcp.h         |  8 ++++
>> 2 files changed, 87 insertions(+)
>>
>> diff --git a/drivers/misc/mei/hdcp/mei_hdcp.c
>> b/drivers/misc/mei/hdcp/mei_hdcp.c
>> index 64fcecfa5b10..68eb5267a8e7 100644
>> --- a/drivers/misc/mei/hdcp/mei_hdcp.c
>> +++ b/drivers/misc/mei/hdcp/mei_hdcp.c
>> @@ -553,6 +553,85 @@ mei_repeater_check_flow_prepare_ack(struct
>> mei_cl_device *cldev,  }
>> EXPORT_SYMBOL(mei_repeater_check_flow_prepare_ack);
>>
>> +static inline void reverse_endianness(u8 *dest, size_t dst_sz, u8 *src)
> Function with loop ideally should not be inline.
Thanks for catching it.
>
>> +{
>> +	u32 index;
>> +
>> +	if (dest != NULL && dst_sz != 0) {
> Good to check for src as well. Also this function will not do anything if these
> check fails with caller not even been aware of the failure. Atleast return an
> error or make sure no parameter validation happens here and its done by calling
> function.
bit rewriting this function. Thanks

--Ram
>
>> +		for (index = 0; index < dst_sz && index < sizeof(u32);
>> +		     index++) {
>> +			dest[dst_sz - index - 1] = src[index];
>> +		}
>> +	}
>> +}
>> +
>> +/**
>> + * mei_verify_mprime:
>> + *	Function to verify mprime.
>> + *
>> + * @cldev		: Pointer for mei client device
>> + * @data		: Intel HW specific Data
>> + * @stream_ready	: pointer for RepeaterAuth_Stream_Ready message.
>> + *
>> + * Returns 0 on Success, <0 on Failure
>> + */
>> +int mei_verify_mprime(struct mei_cl_device *cldev, struct mei_hdcp_data
>> *data,
>> +		      struct hdcp2_rep_stream_ready *stream_ready) {
>> +	struct wired_cmd_repeater_auth_stream_req_in
>> +					verify_mprime_in = { { 0 } };
>> +	struct wired_cmd_repeater_auth_stream_req_out
>> +					verify_mprime_out = { { 0 } };
>> +	struct device *dev;
>> +	ssize_t byte;
>> +
>> +	if (!stream_ready || !data)
>> +		return -EINVAL;
>> +
>> +	dev = &cldev->dev;
>> +
>> +	verify_mprime_in.header.api_version = HDCP_API_VERSION;
>> +	verify_mprime_in.header.command_id =
>> WIRED_REPEATER_AUTH_STREAM_REQ;
>> +	verify_mprime_in.header.status = ME_HDCP_STATUS_SUCCESS;
>> +	verify_mprime_in.header.buffer_len =
>> +
>> 	WIRED_CMD_BUF_LEN_REPEATER_AUTH_STREAM_REQ_MIN_IN;
>> +
>> +	verify_mprime_in.port.integrated_port_type = data->port_type;
>> +	verify_mprime_in.port.physical_port = data->port;
>> +
>> +	memcpy(verify_mprime_in.m_prime, stream_ready->m_prime,
> Validate stream_ready->m_prime.
>
>> +	       HDCP_2_2_MPRIME_LEN);
>> +	reverse_endianness((u8 *)&verify_mprime_in.seq_num_m,
>> +			   HDCP_2_2_SEQ_NUM_LEN, (u8 *)&data-
>>> seq_num_m);
>> +	memcpy(verify_mprime_in.streams, data->streams,
> Validate data->streams.
>
>> +	       (data->k * sizeof(struct hdcp2_streamid_type)));
>> +
>> +	verify_mprime_in.k = __swab16(data->k);
>> +
>> +	byte = mei_cldev_send(cldev, (u8 *)&verify_mprime_in,
>> +			      sizeof(verify_mprime_in));
>> +	if (byte < 0) {
>> +		dev_dbg(dev, "mei_cldev_send failed. %d\n", (int)byte);
>> +		return byte;
>> +	}
>> +
>> +	byte = mei_cldev_recv(cldev, (u8 *)&verify_mprime_out,
>> +			      sizeof(verify_mprime_out));
>> +	if (byte < 0) {
>> +		dev_dbg(dev, "mei_cldev_recv failed. %d\n", (int)byte);
>> +		return byte;
>> +	}
>> +
>> +	if (verify_mprime_out.header.status != ME_HDCP_STATUS_SUCCESS) {
>> +		dev_dbg(dev, "ME cmd 0x%08X failed. status: 0x%X\n",
>> +			WIRED_REPEATER_AUTH_STREAM_REQ,
>> +			verify_mprime_out.header.status);
>> +		return -1;
>> +	}
> Leave a blank line here.
>
>> +	return 0;
>> +}
>> +EXPORT_SYMBOL(mei_verify_mprime);
>> +
>> void mei_cldev_state_notify_clients(struct mei_cl_device *cldev, bool enabled)  {
>> 	if (enabled)
>> diff --git a/include/linux/mei_hdcp.h b/include/linux/mei_hdcp.h index
>> 46e2dc295d03..dbc216e13f97 100644
>> --- a/include/linux/mei_hdcp.h
>> +++ b/include/linux/mei_hdcp.h
>> @@ -134,6 +134,8 @@ mei_repeater_check_flow_prepare_ack(struct
>> mei_cl_device *cldev,
>> 				    struct hdcp2_rep_send_receiverid_list
>> 							*rep_topology,
>> 				    struct hdcp2_rep_send_ack *rep_send_ack);
>> +int mei_verify_mprime(struct mei_cl_device *cldev, struct mei_hdcp_data
>> *data,
>> +		      struct hdcp2_rep_stream_ready *stream_ready);
>> #else
>> static int mei_cldev_register_notify(struct notifier_block *nb)  { @@ -201,5
>> +203,11 @@ mei_repeater_check_flow_prepare_ack(struct mei_cl_device
>> *cldev,  {
>> 	return -ENODEV;
>> }
>> +static inline
>> +int mei_verify_mprime(struct mei_cl_device *cldev, struct mei_hdcp_data
>> *data,
>> +		      struct hdcp2_rep_stream_ready *stream_ready) {
>> +	return -ENODEV;
>> +}
>> #endif /* defined (CONFIG_INTEL_MEI_HDCP) */  #endif /* defined
>> (_LINUX_MEI_HDCP_H) */
>> --
>> 2.7.4
>>
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>> dri-devel at lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/dri-devel



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