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tpm-passthrough: move reusable code to utils
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Signed-off-by: Amarnath Valluri <amarnath.valluri@intel.com>
Reviewed-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
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avalluri authored and stefanberger committed Oct 13, 2017
1 parent d0c519b commit 4a3d809
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Showing 3 changed files with 34 additions and 59 deletions.
64 changes: 5 additions & 59 deletions hw/tpm/tpm_passthrough.c
Expand Up @@ -68,27 +68,6 @@ typedef struct TPMPassthruState TPMPassthruState;

static void tpm_passthrough_cancel_cmd(TPMBackend *tb);

static int tpm_passthrough_unix_write(int fd, const uint8_t *buf, uint32_t len)
{
int ret, remain;

remain = len;
while (remain > 0) {
ret = write(fd, buf, remain);
if (ret < 0) {
if (errno != EINTR && errno != EAGAIN) {
return -1;
}
} else if (ret == 0) {
break;
} else {
buf += ret;
remain -= ret;
}
}
return len - remain;
}

static int tpm_passthrough_unix_read(int fd, uint8_t *buf, uint32_t len)
{
int ret;
Expand All @@ -102,55 +81,22 @@ static int tpm_passthrough_unix_read(int fd, uint8_t *buf, uint32_t len)
}
return ret;
}

static uint32_t tpm_passthrough_get_size_from_buffer(const uint8_t *buf)
{
struct tpm_resp_hdr *resp = (struct tpm_resp_hdr *)buf;

return be32_to_cpu(resp->len);
}

/*
* Write an error message in the given output buffer.
*/
static void tpm_write_fatal_error_response(uint8_t *out, uint32_t out_len)
{
if (out_len >= sizeof(struct tpm_resp_hdr)) {
struct tpm_resp_hdr *resp = (struct tpm_resp_hdr *)out;

resp->tag = cpu_to_be16(TPM_TAG_RSP_COMMAND);
resp->len = cpu_to_be32(sizeof(struct tpm_resp_hdr));
resp->errcode = cpu_to_be32(TPM_FAIL);
}
}

static bool tpm_passthrough_is_selftest(const uint8_t *in, uint32_t in_len)
{
struct tpm_req_hdr *hdr = (struct tpm_req_hdr *)in;

if (in_len >= sizeof(*hdr)) {
return (be32_to_cpu(hdr->ordinal) == TPM_ORD_ContinueSelfTest);
}

return false;
}

static int tpm_passthrough_unix_tx_bufs(TPMPassthruState *tpm_pt,
const uint8_t *in, uint32_t in_len,
uint8_t *out, uint32_t out_len,
bool *selftest_done)
{
int ret;
ssize_t ret;
bool is_selftest;
const struct tpm_resp_hdr *hdr;

tpm_pt->tpm_op_canceled = false;
tpm_pt->tpm_executing = true;
*selftest_done = false;

is_selftest = tpm_passthrough_is_selftest(in, in_len);
is_selftest = tpm_util_is_selftest(in, in_len);

ret = tpm_passthrough_unix_write(tpm_pt->tpm_fd, in, in_len);
ret = qemu_write_full(tpm_pt->tpm_fd, (const void *)in, (size_t)in_len);
if (ret != in_len) {
if (!tpm_pt->tpm_op_canceled || errno != ECANCELED) {
error_report("tpm_passthrough: error while transmitting data "
Expand All @@ -170,7 +116,7 @@ static int tpm_passthrough_unix_tx_bufs(TPMPassthruState *tpm_pt,
strerror(errno), errno);
}
} else if (ret < sizeof(struct tpm_resp_hdr) ||
tpm_passthrough_get_size_from_buffer(out) != ret) {
be32_to_cpu(((struct tpm_resp_hdr *)out)->len) != ret) {
ret = -1;
error_report("tpm_passthrough: received invalid response "
"packet from TPM");
Expand All @@ -183,7 +129,7 @@ static int tpm_passthrough_unix_tx_bufs(TPMPassthruState *tpm_pt,

err_exit:
if (ret < 0) {
tpm_write_fatal_error_response(out, out_len);
tpm_util_write_fatal_error_response(out, out_len);
}

tpm_pt->tpm_executing = false;
Expand Down
25 changes: 25 additions & 0 deletions hw/tpm/tpm_util.c
Expand Up @@ -23,6 +23,31 @@
#include "tpm_util.h"
#include "tpm_int.h"

/*
* Write an error message in the given output buffer.
*/
void tpm_util_write_fatal_error_response(uint8_t *out, uint32_t out_len)
{
if (out_len >= sizeof(struct tpm_resp_hdr)) {
struct tpm_resp_hdr *resp = (struct tpm_resp_hdr *)out;

resp->tag = cpu_to_be16(TPM_TAG_RSP_COMMAND);
resp->len = cpu_to_be32(sizeof(struct tpm_resp_hdr));
resp->errcode = cpu_to_be32(TPM_FAIL);
}
}

bool tpm_util_is_selftest(const uint8_t *in, uint32_t in_len)
{
struct tpm_req_hdr *hdr = (struct tpm_req_hdr *)in;

if (in_len >= sizeof(*hdr)) {
return (be32_to_cpu(hdr->ordinal) == TPM_ORD_ContinueSelfTest);
}

return false;
}

/*
* A basic test of a TPM device. We expect a well formatted response header
* (error response is fine) within one second.
Expand Down
4 changes: 4 additions & 0 deletions hw/tpm/tpm_util.h
Expand Up @@ -24,6 +24,10 @@

#include "sysemu/tpm_backend.h"

void tpm_util_write_fatal_error_response(uint8_t *out, uint32_t out_len);

bool tpm_util_is_selftest(const uint8_t *in, uint32_t in_len);

int tpm_util_test_tpmdev(int tpm_fd, TPMVersion *tpm_version);

#endif /* TPM_TPM_UTIL_H */

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