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path: root/drivers/char/tpm/tpm2-cmd.c
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Diffstat (limited to 'drivers/char/tpm/tpm2-cmd.c')
-rw-r--r--drivers/char/tpm/tpm2-cmd.c258
1 files changed, 106 insertions, 152 deletions
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index d31b09099216..c31b490bd41d 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -27,46 +27,6 @@ enum tpm2_session_attributes {
TPM2_SA_CONTINUE_SESSION = BIT(0),
};
-struct tpm2_startup_in {
- __be16 startup_type;
-} __packed;
-
-struct tpm2_get_tpm_pt_in {
- __be32 cap_id;
- __be32 property_id;
- __be32 property_cnt;
-} __packed;
-
-struct tpm2_get_tpm_pt_out {
- u8 more_data;
- __be32 subcap_id;
- __be32 property_cnt;
- __be32 property_id;
- __be32 value;
-} __packed;
-
-struct tpm2_get_random_in {
- __be16 size;
-} __packed;
-
-struct tpm2_get_random_out {
- __be16 size;
- u8 buffer[TPM_MAX_RNG_DATA];
-} __packed;
-
-union tpm2_cmd_params {
- struct tpm2_startup_in startup_in;
- struct tpm2_get_tpm_pt_in get_tpm_pt_in;
- struct tpm2_get_tpm_pt_out get_tpm_pt_out;
- struct tpm2_get_random_in getrandom_in;
- struct tpm2_get_random_out getrandom_out;
-};
-
-struct tpm2_cmd {
- tpm_cmd_header header;
- union tpm2_cmd_params params;
-} __packed;
-
struct tpm2_hash {
unsigned int crypto_id;
unsigned int tpm_id;
@@ -321,82 +281,72 @@ int tpm2_pcr_extend(struct tpm_chip *chip, int pcr_idx, u32 count,
}
-#define TPM2_GETRANDOM_IN_SIZE \
- (sizeof(struct tpm_input_header) + \
- sizeof(struct tpm2_get_random_in))
-
-static const struct tpm_input_header tpm2_getrandom_header = {
- .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
- .length = cpu_to_be32(TPM2_GETRANDOM_IN_SIZE),
- .ordinal = cpu_to_be32(TPM2_CC_GET_RANDOM)
-};
+struct tpm2_get_random_out {
+ __be16 size;
+ u8 buffer[TPM_MAX_RNG_DATA];
+} __packed;
/**
* tpm2_get_random() - get random bytes from the TPM RNG
*
- * @chip: TPM chip to use
- * @out: destination buffer for the random bytes
- * @max: the max number of bytes to write to @out
+ * @chip: a &tpm_chip instance
+ * @dest: destination buffer
+ * @max: the max number of random bytes to pull
*
* Return:
- * Size of the output buffer, or -EIO on error.
+ * size of the buffer on success,
+ * -errno otherwise
*/
-int tpm2_get_random(struct tpm_chip *chip, u8 *out, size_t max)
+int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max)
{
- struct tpm2_cmd cmd;
- u32 recd, rlength;
- u32 num_bytes;
+ struct tpm2_get_random_out *out;
+ struct tpm_buf buf;
+ u32 recd;
+ u32 num_bytes = max;
int err;
int total = 0;
int retries = 5;
- u8 *dest = out;
+ u8 *dest_ptr = dest;
- num_bytes = min_t(u32, max, sizeof(cmd.params.getrandom_out.buffer));
-
- if (!out || !num_bytes ||
- max > sizeof(cmd.params.getrandom_out.buffer))
+ if (!num_bytes || max > TPM_MAX_RNG_DATA)
return -EINVAL;
- do {
- cmd.header.in = tpm2_getrandom_header;
- cmd.params.getrandom_in.size = cpu_to_be16(num_bytes);
+ err = tpm_buf_init(&buf, 0, 0);
+ if (err)
+ return err;
- err = tpm_transmit_cmd(chip, NULL, &cmd, sizeof(cmd),
+ do {
+ tpm_buf_reset(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_RANDOM);
+ tpm_buf_append_u16(&buf, num_bytes);
+ err = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,
offsetof(struct tpm2_get_random_out,
buffer),
0, "attempting get random");
if (err)
- break;
+ goto out;
- recd = min_t(u32, be16_to_cpu(cmd.params.getrandom_out.size),
- num_bytes);
- rlength = be32_to_cpu(cmd.header.out.length);
- if (rlength < offsetof(struct tpm2_get_random_out, buffer) +
- recd)
- return -EFAULT;
- memcpy(dest, cmd.params.getrandom_out.buffer, recd);
+ out = (struct tpm2_get_random_out *)
+ &buf.data[TPM_HEADER_SIZE];
+ recd = min_t(u32, be16_to_cpu(out->size), num_bytes);
+ if (tpm_buf_length(&buf) <
+ offsetof(struct tpm2_get_random_out, buffer) + recd) {
+ err = -EFAULT;
+ goto out;
+ }
+ memcpy(dest_ptr, out->buffer, recd);
- dest += recd;
+ dest_ptr += recd;
total += recd;
num_bytes -= recd;
} while (retries-- && total < max);
+ tpm_buf_destroy(&buf);
return total ? total : -EIO;
+out:
+ tpm_buf_destroy(&buf);
+ return err;
}
-#define TPM2_GET_TPM_PT_IN_SIZE \
- (sizeof(struct tpm_input_header) + \
- sizeof(struct tpm2_get_tpm_pt_in))
-
-#define TPM2_GET_TPM_PT_OUT_BODY_SIZE \
- sizeof(struct tpm2_get_tpm_pt_out)
-
-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)
-};
-
/**
* tpm2_flush_context_cmd() - execute a TPM2_FlushContext command
* @chip: TPM chip to use
@@ -471,7 +421,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
{
unsigned int blob_len;
struct tpm_buf buf;
- u32 hash, rlength;
+ u32 hash;
int i;
int rc;
@@ -546,8 +496,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
rc = -E2BIG;
goto out;
}
- rlength = be32_to_cpu(((struct tpm2_cmd *)&buf)->header.out.length);
- if (rlength < TPM_HEADER_SIZE + 4 + blob_len) {
+ if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 4 + blob_len) {
rc = -EFAULT;
goto out;
}
@@ -657,7 +606,6 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip,
u16 data_len;
u8 *data;
int rc;
- u32 rlength;
rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_UNSEAL);
if (rc)
@@ -685,9 +633,7 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip,
goto out;
}
- rlength = be32_to_cpu(((struct tpm2_cmd *)&buf)
- ->header.out.length);
- if (rlength < TPM_HEADER_SIZE + 6 + data_len) {
+ if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 6 + data_len) {
rc = -EFAULT;
goto out;
}
@@ -733,69 +679,71 @@ out:
return rc;
}
+struct tpm2_get_cap_out {
+ u8 more_data;
+ __be32 subcap_id;
+ __be32 property_cnt;
+ __be32 property_id;
+ __be32 value;
+} __packed;
+
/**
* tpm2_get_tpm_pt() - get value of a TPM_CAP_TPM_PROPERTIES type property
- * @chip: TPM chip to use.
+ * @chip: a &tpm_chip instance
* @property_id: property ID.
* @value: output variable.
* @desc: passed to tpm_transmit_cmd()
*
- * Return: Same as with tpm_transmit_cmd.
+ * Return:
+ * 0 on success,
+ * -errno or a TPM return code otherwise
*/
ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id, u32 *value,
const char *desc)
{
- struct tpm2_cmd cmd;
+ struct tpm2_get_cap_out *out;
+ struct tpm_buf buf;
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);
-
- rc = tpm_transmit_cmd(chip, NULL, &cmd, sizeof(cmd),
- TPM2_GET_TPM_PT_OUT_BODY_SIZE, 0, desc);
- if (!rc)
- *value = be32_to_cpu(cmd.params.get_tpm_pt_out.value);
-
+ rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
+ if (rc)
+ return rc;
+ tpm_buf_append_u32(&buf, TPM2_CAP_TPM_PROPERTIES);
+ tpm_buf_append_u32(&buf, property_id);
+ tpm_buf_append_u32(&buf, 1);
+ rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0, NULL);
+ if (!rc) {
+ out = (struct tpm2_get_cap_out *)
+ &buf.data[TPM_HEADER_SIZE];
+ *value = be32_to_cpu(out->value);
+ }
+ tpm_buf_destroy(&buf);
return rc;
}
EXPORT_SYMBOL_GPL(tpm2_get_tpm_pt);
-#define TPM2_SHUTDOWN_IN_SIZE \
- (sizeof(struct tpm_input_header) + \
- sizeof(struct tpm2_startup_in))
-
-static const struct tpm_input_header tpm2_shutdown_header = {
- .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
- .length = cpu_to_be32(TPM2_SHUTDOWN_IN_SIZE),
- .ordinal = cpu_to_be32(TPM2_CC_SHUTDOWN)
-};
-
/**
- * tpm2_shutdown() - send shutdown command to the TPM chip
+ * tpm2_shutdown() - send a TPM shutdown command
+ *
+ * Sends a TPM shutdown command. The shutdown command is used in call
+ * sites where the system is going down. If it fails, there is not much
+ * that can be done except print an error message.
*
- * @chip: TPM chip to use.
- * @shutdown_type: shutdown type. The value is either
- * TPM_SU_CLEAR or TPM_SU_STATE.
+ * @chip: a &tpm_chip instance
+ * @shutdown_type: TPM_SU_CLEAR or TPM_SU_STATE.
*/
void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type)
{
- struct tpm2_cmd cmd;
+ struct tpm_buf buf;
int rc;
- cmd.header.in = tpm2_shutdown_header;
- cmd.params.startup_in.startup_type = cpu_to_be16(shutdown_type);
-
- rc = tpm_transmit_cmd(chip, NULL, &cmd, sizeof(cmd), 0, 0,
- "stopping the TPM");
-
- /* In places where shutdown command is sent there's no much we can do
- * except print the error code on a system failure.
- */
- if (rc < 0 && rc != -EPIPE)
- dev_warn(&chip->dev, "transmit returned %d while stopping the TPM",
- rc);
+ rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_SHUTDOWN);
+ if (rc)
+ return;
+ tpm_buf_append_u16(&buf, shutdown_type);
+ tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
+ "stopping the TPM");
+ tpm_buf_destroy(&buf);
}
/*
@@ -863,31 +811,37 @@ static int tpm2_do_selftest(struct tpm_chip *chip)
}
/**
- * tpm2_probe() - probe TPM 2.0
- * @chip: TPM chip to use
+ * tpm2_probe() - probe for the TPM 2.0 protocol
+ * @chip: a &tpm_chip instance
*
- * Return: < 0 error and 0 on success.
+ * Send an idempotent TPM 2.0 command and see whether there is TPM2 chip in the
+ * other end based on the response tag. The flag TPM_CHIP_FLAG_TPM2 is set by
+ * this function if this is the case.
*
- * Send idempotent TPM 2.0 command and see whether TPM 2.0 chip replied based on
- * the reply tag.
+ * Return:
+ * 0 on success,
+ * -errno otherwise
*/
int tpm2_probe(struct tpm_chip *chip)
{
- struct tpm2_cmd cmd;
+ struct tpm_output_header *out;
+ struct tpm_buf buf;
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);
-
- rc = tpm_transmit_cmd(chip, NULL, &cmd, sizeof(cmd), 0, 0, NULL);
- if (rc < 0)
+ rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
+ if (rc)
return rc;
-
- if (be16_to_cpu(cmd.header.out.tag) == TPM2_ST_NO_SESSIONS)
- chip->flags |= TPM_CHIP_FLAG_TPM2;
-
+ tpm_buf_append_u32(&buf, TPM2_CAP_TPM_PROPERTIES);
+ tpm_buf_append_u32(&buf, TPM_PT_TOTAL_COMMANDS);
+ tpm_buf_append_u32(&buf, 1);
+ rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0, NULL);
+ /* We ignore TPM return codes on purpose. */
+ if (rc >= 0) {
+ out = (struct tpm_output_header *)buf.data;
+ if (be16_to_cpu(out->tag) == TPM2_ST_NO_SESSIONS)
+ chip->flags |= TPM_CHIP_FLAG_TPM2;
+ }
+ tpm_buf_destroy(&buf);
return 0;
}
EXPORT_SYMBOL_GPL(tpm2_probe);