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SubjectRe: [tpmdd-devel] [PATCH RFC 2/2] tpm: refactor tpm2_get_tpm_pt to tpm2_getcap_cmd
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On 10/09/2016 03:44 PM, Jarkko Sakkinen wrote:
> Refactored tpm2_get_tpm_pt to tpm2_getcap_cmd, which means that it also
> takes capability ID as input. This is required to access
> TPM_CAP_HANDLES, which contains metadata needed for swapping transient
> data.
>
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> ---
> drivers/char/tpm/tpm.h | 6 +++-
> drivers/char/tpm/tpm2-cmd.c | 64 ++++++++++++++++++++---------------------
> drivers/char/tpm/tpm_tis_core.c | 3 +-
> 3 files changed, 38 insertions(+), 35 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
> index 0fab6d5..8176f42 100644
> --- a/drivers/char/tpm/tpm.h
> +++ b/drivers/char/tpm/tpm.h
> @@ -85,6 +85,10 @@ enum tpm2_capabilities {
> TPM2_CAP_TPM_PROPERTIES = 6,
> };
>
> +enum tpm2_properties {
> + TPM2_PT_FAMILY_INDICATOR = 0x100,
> +};
> +
> enum tpm2_startup_types {
> TPM2_SU_CLEAR = 0x0000,
> TPM2_SU_STATE = 0x0001,
> @@ -485,7 +489,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
> int tpm2_unseal_trusted(struct tpm_chip *chip,
> struct trusted_key_payload *payload,
> struct trusted_key_options *options);
> -ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id,
> +ssize_t tpm2_getcap_cmd(struct tpm_chip *chip, u32 cap_id, u32 property_id,
> u32 *value, const char *desc);
>
> int tpm2_auto_startup(struct tpm_chip *chip);
> diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
> index 2900e18..fcf3d86 100644
> --- a/drivers/char/tpm/tpm2-cmd.c
> +++ b/drivers/char/tpm/tpm2-cmd.c
> @@ -111,13 +111,13 @@ struct tpm2_pcr_extend_in {
> u8 digest[TPM_DIGEST_SIZE];
> } __packed;
>
> -struct tpm2_get_tpm_pt_in {
> +struct tpm2_getcap_in {
> __be32 cap_id;
> __be32 property_id;
> __be32 property_cnt;
> } __packed;
>
> -struct tpm2_get_tpm_pt_out {
> +struct tpm2_getcap_out {
> u8 more_data;
> __be32 subcap_id;
> __be32 property_cnt;
> @@ -140,8 +140,8 @@ union tpm2_cmd_params {
> struct tpm2_pcr_read_in pcrread_in;
> struct tpm2_pcr_read_out pcrread_out;
> struct tpm2_pcr_extend_in pcrextend_in;
> - struct tpm2_get_tpm_pt_in get_tpm_pt_in;
> - struct tpm2_get_tpm_pt_out get_tpm_pt_out;
> + struct tpm2_getcap_in getcap_in;
> + struct tpm2_getcap_out getcap_out;
> struct tpm2_get_random_in getrandom_in;
> struct tpm2_get_random_out getrandom_out;
> };
> @@ -435,16 +435,6 @@ int tpm2_get_random(struct tpm_chip *chip, u8 *out, size_t max)
> return total ? total : -EIO;
> }
>
> -#define TPM2_GET_TPM_PT_IN_SIZE \
> - (sizeof(struct tpm_input_header) + \
> - sizeof(struct tpm2_get_tpm_pt_in))
> -
> -static const struct tpm_input_header tpm2_get_tpm_pt_header = {
> - .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
> - .length = cpu_to_be32(TPM2_GET_TPM_PT_IN_SIZE),
> - .ordinal = cpu_to_be32(TPM2_CC_GET_CAPABILITY)
> -};
> -
> /**
> * Append TPMS_AUTH_COMMAND to the buffer. The buffer must be allocated with
> * tpm_buf_alloc().
> @@ -750,35 +740,43 @@ out:
> return rc;
> }
>
> +#define TPM2_GETCAP_IN_SIZE \
> + (sizeof(struct tpm_input_header) + sizeof(struct tpm2_getcap_in))
> +
> +static const struct tpm_input_header tpm2_getcap_header = {
> + .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
> + .length = cpu_to_be32(TPM2_GETCAP_IN_SIZE),
> + .ordinal = cpu_to_be32(TPM2_CC_GET_CAPABILITY)
> +};
> +
> /**
> - * tpm2_get_tpm_pt() - get value of a TPM_CAP_TPM_PROPERTIES type property
> - * @chip: TPM chip to use.
> - * @property_id: property ID.
> - * @value: output variable.
> + * tpm2_getcap_cmd() - execute a TPM2_GetCapability command
> + * @chip: TPM chip to use
> + * @cap_id: capability ID
> + * @property_id: property ID
> + * @value: value of the property
> * @desc: passed to tpm_transmit_cmd()
> *
> - * 0 is returned when the operation is successful. If a negative number is
> - * returned it remarks a POSIX error code. If a positive number is returned
> - * it remarks a TPM error.
> + * Return: same as with tpm_transmit_cmd
> */
> -ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id, u32 *value,
> - const char *desc)
> +ssize_t tpm2_getcap_cmd(struct tpm_chip *chip, u32 cap_id, u32 property_id,
> + u32 *value, const char *desc)

This function currently returns single value "u32 *value" as output data.

Some calling function expect list of values from capabilities output.
For eg., get_active_banks() use TPM_CAP_PCRS capability to retrieve list
of active banks. And this capability returns array of pcr
selections(which is a struct representing each active PCR bank)

I was thinking, can we define output parameter as struct of cap_id and
union of expected cap_data ?

struct cap_out {
u32 cap_id;
union cap_data {
struct tpml_pcr_selection assignedPCR;
struct tpml_tagged_tpm_property tpmProperties;
struct tpml_handle handles;
}
}

And then the calling function, map union to the cap_data expected as per
id, and parse it.

Thanks & Regards,
- Nayna


> {
> struct tpm2_cmd cmd;
> int rc;
>
> - cmd.header.in = tpm2_get_tpm_pt_header;
> - cmd.params.get_tpm_pt_in.cap_id = cpu_to_be32(TPM2_CAP_TPM_PROPERTIES);
> - cmd.params.get_tpm_pt_in.property_id = cpu_to_be32(property_id);
> - cmd.params.get_tpm_pt_in.property_cnt = cpu_to_be32(1);
> + cmd.header.in = tpm2_getcap_header;
> + cmd.params.getcap_in.cap_id = cpu_to_be32(cap_id);
> + cmd.params.getcap_in.property_id = cpu_to_be32(property_id);
> + cmd.params.getcap_in.property_cnt = cpu_to_be32(1);
>
> rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, desc);
> if (!rc)
> - *value = be32_to_cpu(cmd.params.get_tpm_pt_out.value);
> + *value = be32_to_cpu(cmd.params.getcap_out.value);
>
> return rc;
> }
> -EXPORT_SYMBOL_GPL(tpm2_get_tpm_pt);
> +EXPORT_SYMBOL_GPL(tpm2_getcap_cmd);
>
> #define TPM2_STARTUP_IN_SIZE \
> (sizeof(struct tpm_input_header) + \
> @@ -978,10 +976,10 @@ int tpm2_probe(struct tpm_chip *chip)
> struct tpm2_cmd cmd;
> int rc;
>
> - cmd.header.in = tpm2_get_tpm_pt_header;
> - cmd.params.get_tpm_pt_in.cap_id = cpu_to_be32(TPM2_CAP_TPM_PROPERTIES);
> - cmd.params.get_tpm_pt_in.property_id = cpu_to_be32(0x100);
> - cmd.params.get_tpm_pt_in.property_cnt = cpu_to_be32(1);
> + cmd.header.in = tpm2_getcap_header;
> + cmd.params.getcap_in.cap_id = cpu_to_be32(TPM2_CAP_TPM_PROPERTIES);
> + cmd.params.getcap_in.property_id = cpu_to_be32(TPM2_PT_FAMILY_INDICATOR);
> + cmd.params.getcap_in.property_cnt = cpu_to_be32(1);
>
> rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, NULL);
> if (rc < 0)
> diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
> index e3bf31b..792ccd1 100644
> --- a/drivers/char/tpm/tpm_tis_core.c
> +++ b/drivers/char/tpm/tpm_tis_core.c
> @@ -528,7 +528,8 @@ static int tpm_tis_gen_interrupt(struct tpm_chip *chip)
> cap_t cap;
>
> if (chip->flags & TPM_CHIP_FLAG_TPM2)
> - return tpm2_get_tpm_pt(chip, 0x100, &cap2, desc);
> + return tpm2_getcap_cmd(chip, TPM2_CAP_TPM_PROPERTIES,
> + TPM2_PT_FAMILY_INDICATOR, &cap2, desc);
> else
> return tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, desc);
> }
>

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