Commit d926ee92 authored by Jarkko Sakkinen's avatar Jarkko Sakkinen
Browse files

tpm: TPM2B formatted buffers 



Declare tpm_buf_init_sized() and tpm_buf_reset_sized() for creating TPM2B
formatted buffers. These buffers are also known as sized buffers in the
specifications and literature.

Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
Reviewed-by: default avatarStefan Berger <stefanb@linux.ibm.com>
Reviewed-by: default avatarJarkko Sakkinen <jarkko@kernel.org>
Tested-by: default avatarJarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: default avatarJarkko Sakkinen <jarkko@kernel.org>
parent e1b72e1b

drivers/char/tpm/tpm-buf.c

+35 −3
Original line number Diff line number Diff line
@@ -47,6 +47,36 @@ void tpm_buf_reset(struct tpm_buf *buf, u16 tag, u32 ordinal) 
}

EXPORT_SYMBOL_GPL(tpm_buf_reset);



/**

 * tpm_buf_init_sized() - Allocate and initialize a sized (TPM2B) buffer

 * @buf:	A @tpm_buf

 *

 * Return: 0 or -ENOMEM

 */

int tpm_buf_init_sized(struct tpm_buf *buf)

{

	buf->data = (u8 *)__get_free_page(GFP_KERNEL);

	if (!buf->data)

		return -ENOMEM;



	tpm_buf_reset_sized(buf);

	return 0;

}

EXPORT_SYMBOL_GPL(tpm_buf_init_sized);



/**

 * tpm_buf_reset_sized() - Initialize a sized buffer

 * @buf:	A &tpm_buf

 */

void tpm_buf_reset_sized(struct tpm_buf *buf)

{

	buf->flags = TPM_BUF_TPM2B;

	buf->length = 2;

	buf->data[0] = 0;

	buf->data[1] = 0;

}

EXPORT_SYMBOL_GPL(tpm_buf_reset_sized);



void tpm_buf_destroy(struct tpm_buf *buf)

{

	free_page((unsigned long)buf->data);
@@ -73,8 +103,6 @@ EXPORT_SYMBOL_GPL(tpm_buf_length); 
 */

void tpm_buf_append(struct tpm_buf *buf, const u8 *new_data, u16 new_length)

{

	struct tpm_header *head = (struct tpm_header *)buf->data;



	/* Return silently if overflow has already happened. */

	if (buf->flags & TPM_BUF_OVERFLOW)

		return;
@@ -87,7 +115,11 @@ void tpm_buf_append(struct tpm_buf *buf, const u8 *new_data, u16 new_length) 


	memcpy(&buf->data[buf->length], new_data, new_length);

	buf->length += new_length;

	head->length = cpu_to_be32(buf->length);



	if (buf->flags & TPM_BUF_TPM2B)

		((__be16 *)buf->data)[0] = cpu_to_be16(buf->length - 2);

	else

		((struct tpm_header *)buf->data)->length = cpu_to_be32(buf->length);

}

EXPORT_SYMBOL_GPL(tpm_buf_append);

include/linux/tpm.h

+4 −0
Original line number Diff line number Diff line
@@ -300,6 +300,8 @@ struct tpm_header { 
enum tpm_buf_flags {

	/* the capacity exceeded: */

	TPM_BUF_OVERFLOW	= BIT(0),

	/* TPM2B format: */

	TPM_BUF_TPM2B		= BIT(1),

};



/*
@@ -328,6 +330,8 @@ struct tpm2_hash { 


int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal);

void tpm_buf_reset(struct tpm_buf *buf, u16 tag, u32 ordinal);

int tpm_buf_init_sized(struct tpm_buf *buf);

void tpm_buf_reset_sized(struct tpm_buf *buf);

void tpm_buf_destroy(struct tpm_buf *buf);

u32 tpm_buf_length(struct tpm_buf *buf);

void tpm_buf_append(struct tpm_buf *buf, const u8 *new_data, u16 new_length);