[tpmdd-devel,v5,2/2] tpm: vtpm_proxy: Implement request_locality function.

Submitted by Stefan Berger on May 15, 2017, 4:51 p.m.

Details

Message ID 1494867105-30722-3-git-send-email-stefanb@linux.vnet.ibm.com
State New
Headers show

Commit Message

Stefan Berger May 15, 2017, 4:51 p.m.
Implement the request_locality function. To set the locality on the
backend we define vendor-specific TPM 1.2 and TPM 2 ordinals and send
a command to the backend to set the locality for the next commands.

To avoid recursing into requesting the locality, we set the
TPM_TRASNMIT_RAW flag when calling tpm_trasnmit_cmd. To avoid recursing
into TPM 2 space related commands, we set the space parameter to NULL.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
---
 drivers/char/tpm/tpm-interface.c  |  1 +
 drivers/char/tpm/tpm_vtpm_proxy.c | 36 ++++++++++++++++++++++++++++++++++++
 include/uapi/linux/vtpm_proxy.h   |  4 ++++
 3 files changed, 41 insertions(+)

Comments

Jarkko Sakkinen May 20, 2017, 12:40 p.m.
On Mon, May 15, 2017 at 12:51:45PM -0400, Stefan Berger wrote:
> Implement the request_locality function. To set the locality on the
> backend we define vendor-specific TPM 1.2 and TPM 2 ordinals and send
> a command to the backend to set the locality for the next commands.
> 
> To avoid recursing into requesting the locality, we set the
> TPM_TRASNMIT_RAW flag when calling tpm_trasnmit_cmd. To avoid recursing
> into TPM 2 space related commands, we set the space parameter to NULL.
> 
> Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
> ---
>  drivers/char/tpm/tpm-interface.c  |  1 +
>  drivers/char/tpm/tpm_vtpm_proxy.c | 36 ++++++++++++++++++++++++++++++++++++
>  include/uapi/linux/vtpm_proxy.h   |  4 ++++
>  3 files changed, 41 insertions(+)
> 
> diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
> index 2eacda2..876d45f 100644
> --- a/drivers/char/tpm/tpm-interface.c
> +++ b/drivers/char/tpm/tpm-interface.c
> @@ -537,6 +537,7 @@ ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_space *space,
>  
>  	return 0;
>  }
> +EXPORT_SYMBOL_GPL(tpm_transmit_cmd);
>  
>  #define TPM_DIGEST_SIZE 20
>  #define TPM_RET_CODE_IDX 6
> diff --git a/drivers/char/tpm/tpm_vtpm_proxy.c b/drivers/char/tpm/tpm_vtpm_proxy.c
> index 751059d..66024bf 100644
> --- a/drivers/char/tpm/tpm_vtpm_proxy.c
> +++ b/drivers/char/tpm/tpm_vtpm_proxy.c
> @@ -371,6 +371,41 @@ static bool vtpm_proxy_tpm_req_canceled(struct tpm_chip  *chip, u8 status)
>  	return ret;
>  }
>  
> +static int vtpm_proxy_request_locality(struct tpm_chip *chip, int locality)
> +{
> +	struct tpm_buf buf;
> +	int rc;
> +	const struct tpm_output_header *header;
> +
> +	if (chip->flags & TPM_CHIP_FLAG_TPM2)
> +		rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS,
> +				  TPM2_CC_SET_LOCALITY);
> +	else
> +		rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND,
> +				  TPM_ORD_SET_LOCALITY);
> +	if (rc)
> +		return rc;
> +	tpm_buf_append_u8(&buf, locality);
> +
> +	rc = tpm_transmit_cmd(chip, NULL, buf.data, tpm_buf_length(&buf), 0,
> +			      TPM_TRANSMIT_UNLOCKED | TPM_TRANSMIT_RAW,
> +			      "attempting to set locality");
> +	if (rc < 0) {
> +		locality = rc;
> +		goto out;
> +	}
> +
> +	header = (const struct tpm_output_header *)buf.data;
> +	rc = be32_to_cpu(header->return_code);
> +	if (rc)
> +		locality = -1;
> +
> +out:
> +	tpm_buf_destroy(&buf);
> +
> +	return locality;
> +}
> +

This looks good.

>  static const struct tpm_class_ops vtpm_proxy_tpm_ops = {
>  	.flags = TPM_OPS_AUTO_STARTUP,
>  	.recv = vtpm_proxy_tpm_op_recv,
> @@ -380,6 +415,7 @@ static const struct tpm_class_ops vtpm_proxy_tpm_ops = {
>  	.req_complete_mask = VTPM_PROXY_REQ_COMPLETE_FLAG,
>  	.req_complete_val = VTPM_PROXY_REQ_COMPLETE_FLAG,
>  	.req_canceled = vtpm_proxy_tpm_req_canceled,
> +	.request_locality = vtpm_proxy_request_locality,
>  };
>  
>  /*
> diff --git a/include/uapi/linux/vtpm_proxy.h b/include/uapi/linux/vtpm_proxy.h
> index a69e991..58ac73c 100644
> --- a/include/uapi/linux/vtpm_proxy.h
> +++ b/include/uapi/linux/vtpm_proxy.h
> @@ -46,4 +46,8 @@ struct vtpm_proxy_new_dev {
>  
>  #define VTPM_PROXY_IOC_NEW_DEV	_IOWR(0xa1, 0x00, struct vtpm_proxy_new_dev)
>  
> +/* vendor specific commands to set locality */
> +#define TPM2_CC_SET_LOCALITY	0x20001000
> +#define TPM_ORD_SET_LOCALITY	0x20001000
> +

Maybe we should just have VTPM_CC_SET_LOCALITY? No reason to have TPM
version specific constant names. I wonder what would be the best range
for these CCs.  Maybe 0xF0xxxxxxxx would be better?

These are not changes that require a new patch set version but we they
need to be discussed before merging these changes.

>  #endif /* _UAPI_LINUX_VTPM_PROXY_H */
> -- 
> 2.4.3
> 

/Jarkko

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diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 2eacda2..876d45f 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -537,6 +537,7 @@  ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_space *space,
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(tpm_transmit_cmd);
 
 #define TPM_DIGEST_SIZE 20
 #define TPM_RET_CODE_IDX 6
diff --git a/drivers/char/tpm/tpm_vtpm_proxy.c b/drivers/char/tpm/tpm_vtpm_proxy.c
index 751059d..66024bf 100644
--- a/drivers/char/tpm/tpm_vtpm_proxy.c
+++ b/drivers/char/tpm/tpm_vtpm_proxy.c
@@ -371,6 +371,41 @@  static bool vtpm_proxy_tpm_req_canceled(struct tpm_chip  *chip, u8 status)
 	return ret;
 }
 
+static int vtpm_proxy_request_locality(struct tpm_chip *chip, int locality)
+{
+	struct tpm_buf buf;
+	int rc;
+	const struct tpm_output_header *header;
+
+	if (chip->flags & TPM_CHIP_FLAG_TPM2)
+		rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS,
+				  TPM2_CC_SET_LOCALITY);
+	else
+		rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND,
+				  TPM_ORD_SET_LOCALITY);
+	if (rc)
+		return rc;
+	tpm_buf_append_u8(&buf, locality);
+
+	rc = tpm_transmit_cmd(chip, NULL, buf.data, tpm_buf_length(&buf), 0,
+			      TPM_TRANSMIT_UNLOCKED | TPM_TRANSMIT_RAW,
+			      "attempting to set locality");
+	if (rc < 0) {
+		locality = rc;
+		goto out;
+	}
+
+	header = (const struct tpm_output_header *)buf.data;
+	rc = be32_to_cpu(header->return_code);
+	if (rc)
+		locality = -1;
+
+out:
+	tpm_buf_destroy(&buf);
+
+	return locality;
+}
+
 static const struct tpm_class_ops vtpm_proxy_tpm_ops = {
 	.flags = TPM_OPS_AUTO_STARTUP,
 	.recv = vtpm_proxy_tpm_op_recv,
@@ -380,6 +415,7 @@  static const struct tpm_class_ops vtpm_proxy_tpm_ops = {
 	.req_complete_mask = VTPM_PROXY_REQ_COMPLETE_FLAG,
 	.req_complete_val = VTPM_PROXY_REQ_COMPLETE_FLAG,
 	.req_canceled = vtpm_proxy_tpm_req_canceled,
+	.request_locality = vtpm_proxy_request_locality,
 };
 
 /*
diff --git a/include/uapi/linux/vtpm_proxy.h b/include/uapi/linux/vtpm_proxy.h
index a69e991..58ac73c 100644
--- a/include/uapi/linux/vtpm_proxy.h
+++ b/include/uapi/linux/vtpm_proxy.h
@@ -46,4 +46,8 @@  struct vtpm_proxy_new_dev {
 
 #define VTPM_PROXY_IOC_NEW_DEV	_IOWR(0xa1, 0x00, struct vtpm_proxy_new_dev)
 
+/* vendor specific commands to set locality */
+#define TPM2_CC_SET_LOCALITY	0x20001000
+#define TPM_ORD_SET_LOCALITY	0x20001000
+
 #endif /* _UAPI_LINUX_VTPM_PROXY_H */