[Xen-devel] [PATCH 5/7] vtpm: passthru requests to manager

[Daniel De Graaf <dgdegra@xxxxxxxxxxxxx>]

When sending commands to a vTPM, commands with the VTPM_TAG_REQ2 tag are
passed directly to the TPM Manager since they are used in the management
interface to the TPM Manager. The VTPM_TAG_REQ tag is translated to
TPM_TAG_RQU_COMMAND to allow access to the physical TPM for certain
ordinals (PCRRead, Extend, and GetRandom).

Signed-off-by: Daniel De Graaf <dgdegra@xxxxxxxxxxxxx>
Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
---
 stubdom/vtpm/vtpm.c | 40 +++++++++++++++++++++++++++++++++++++++-
 1 file changed, 39 insertions(+), 1 deletion(-)

diff --git a/stubdom/vtpm/vtpm.c b/stubdom/vtpm/vtpm.c
index f67de18..61982c2 100644
--- a/stubdom/vtpm/vtpm.c
+++ b/stubdom/vtpm/vtpm.c
@@ -33,6 +33,7 @@
 #include "vtpm_cmd.h"
 #include "vtpm_pcrs.h"
 #include "vtpmblk.h"
+#include "vtpm_manager.h"
 
 #define TPM_LOG_INFO LOG_INFO
 #define TPM_LOG_ERROR LOG_ERR
@@ -117,6 +118,40 @@ int init_random(void) {
    return 0;
 }
 
+int check_passthru(tpmcmd_t* tpmcmd) {
+   TPM_TAG tag;
+   UINT32 len = 10;
+   BYTE* ptr;
+   size_t size;
+
+   if(tpmcmd->req_len < 10) {
+      return false;
+   }
+
+   ptr = tpmcmd->req;
+   tpm_unmarshal_UINT16(&ptr, &len, &tag);
+
+   if (tag == VTPM_TAG_REQ2) {
+      info("VTPM passthru: %d bytes", (int)tpmcmd->req_len);
+      tpmfront_cmd(tpmfront_dev, tpmcmd->req, tpmcmd->req_len, &tpmcmd->resp, 
&size);
+      tpmcmd->resp_len = size;
+      info("VTPM passthru return: %d bytes", (int)size);
+      return true;
+   }
+
+   if (tag == VTPM_TAG_REQ) {
+      info("VTPM pTPM-cmd: %d bytes", (int)tpmcmd->req_len);
+      ptr = tpmcmd->req;
+      tpm_marshal_UINT16(&ptr, &len, TPM_TAG_RQU_COMMAND);
+      tpmfront_cmd(tpmfront_dev, tpmcmd->req, tpmcmd->req_len, &tpmcmd->resp, 
&size);
+      tpmcmd->resp_len = size;
+      info("VTPM pTPM-cmd return: %d bytes", (int)size);
+      return true;
+   }
+
+   return false;
+}
+
 int check_ordinal(tpmcmd_t* tpmcmd) {
    TPM_COMMAND_CODE ord;
    UINT32 len = 4;
@@ -209,6 +244,9 @@ static void main_loop(void) {
             error("Invalid locality (%d) for client in tpm_handle_command", 
tpmcmd->locality);
             create_error_response(tpmcmd, TPM_FAIL);
         }
+         /* Check for TPM Manager passthrough command */
+         else if(check_passthru(tpmcmd)) {
+        }
          /* Check for disabled ordinals */
          else if(!check_ordinal(tpmcmd)) {
             create_error_response(tpmcmd, TPM_BAD_ORDINAL);
@@ -231,7 +269,7 @@ static void main_loop(void) {
    }
 
 abort_postpcrs:
-   info("VTPM Shutting down\n");
+   info("VTPM Shutting down");
 
    tpm_emulator_shutdown();
 }
-- 
1.8.5.3


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