From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Berger Subject: Re: [PATCH v6 2/3] tpm: vtpm_proxy: Implement request_locality function. Date: Wed, 24 May 2017 19:03:27 -0400 Message-ID: References: <1495661981-27249-1-git-send-email-stefanb@linux.vnet.ibm.com> <1495661981-27249-3-git-send-email-stefanb@linux.vnet.ibm.com> <20170524222130.cqnt433dbrr3t43i@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20170524222130.cqnt433dbrr3t43i@intel.com> Sender: owner-linux-security-module@vger.kernel.org To: Jarkko Sakkinen Cc: tpmdd-devel@lists.sourceforge.net, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, jgunthorpe@obsidianresearch.com List-Id: tpmdd-devel@lists.sourceforge.net On 05/24/2017 06:21 PM, Jarkko Sakkinen wrote: > On Wed, May 24, 2017 at 05:39:40PM -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_TRANSMIT_RAW flag when calling tpm_transmit_cmd. To avoid recursing >> into TPM 2 space related commands, we set the space parameter to NULL. >> >> Signed-off-by: Stefan Berger >> --- >> 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); > I would always go with this branch. > >> + 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 */ >> -- >> 2.4.3 > What practical benefit you get from these two constants? I understand > the value range but not so much the redundant code. If you want to change this, please go ahead and give it a sinle name. For the code branches above I think that we should at least send a TPM 1.2 formatted command in case of TPM 1.2 and a TPM 2 formatted one in case of TPM 2. It seems just 'proper.' Stefan