98979cdca4
EBADMSG was only added to OpenBSD very recently. To make QEMU compilable on older OpenBSD versions use EMSGSIZE instead when a mismatch between number of received bytes and message size indicated in the header was found. Return -EMSGSIZE and convert all other errnos in the same functions to return the negative errno. Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
128 lines
3.5 KiB
C
128 lines
3.5 KiB
C
/*
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* TPM utility functions
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*
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* Copyright (c) 2010 - 2015 IBM Corporation
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* Authors:
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* Stefan Berger <stefanb@us.ibm.com>
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, see <http://www.gnu.org/licenses/>
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*/
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#include "qemu/osdep.h"
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#include "tpm_util.h"
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#include "tpm_int.h"
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/*
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* A basic test of a TPM device. We expect a well formatted response header
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* (error response is fine) within one second.
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*/
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static int tpm_util_test(int fd,
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unsigned char *request,
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size_t requestlen,
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uint16_t *return_tag)
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{
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struct tpm_resp_hdr *resp;
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fd_set readfds;
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int n;
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struct timeval tv = {
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.tv_sec = 1,
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.tv_usec = 0,
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};
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unsigned char buf[1024];
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n = write(fd, request, requestlen);
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if (n < 0) {
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return -errno;
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}
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if (n != requestlen) {
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return -EFAULT;
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}
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FD_ZERO(&readfds);
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FD_SET(fd, &readfds);
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/* wait for a second */
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n = select(fd + 1, &readfds, NULL, NULL, &tv);
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if (n != 1) {
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return -errno;
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}
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n = read(fd, &buf, sizeof(buf));
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if (n < sizeof(struct tpm_resp_hdr)) {
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return -EFAULT;
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}
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resp = (struct tpm_resp_hdr *)buf;
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/* check the header */
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if (be32_to_cpu(resp->len) != n) {
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return -EMSGSIZE;
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}
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*return_tag = be16_to_cpu(resp->tag);
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return 0;
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}
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/*
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* Probe for the TPM device in the back
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* Returns 0 on success with the version of the probed TPM set, 1 on failure.
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*/
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int tpm_util_test_tpmdev(int tpm_fd, TPMVersion *tpm_version)
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{
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/*
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* Sending a TPM1.2 command to a TPM2 should return a TPM1.2
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* header (tag = 0xc4) and error code (TPM_BADTAG = 0x1e)
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*
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* Sending a TPM2 command to a TPM 2 will give a TPM 2 tag in the
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* header.
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* Sending a TPM2 command to a TPM 1.2 will give a TPM 1.2 tag
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* in the header and an error code.
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*/
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const struct tpm_req_hdr test_req = {
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.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
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.len = cpu_to_be32(sizeof(test_req)),
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.ordinal = cpu_to_be32(TPM_ORD_GetTicks),
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};
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const struct tpm_req_hdr test_req_tpm2 = {
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.tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
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.len = cpu_to_be32(sizeof(test_req_tpm2)),
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.ordinal = cpu_to_be32(TPM2_CC_ReadClock),
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};
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uint16_t return_tag;
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int ret;
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/* Send TPM 2 command */
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ret = tpm_util_test(tpm_fd, (unsigned char *)&test_req_tpm2,
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sizeof(test_req_tpm2), &return_tag);
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/* TPM 2 would respond with a tag of TPM2_ST_NO_SESSIONS */
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if (!ret && return_tag == TPM2_ST_NO_SESSIONS) {
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*tpm_version = TPM_VERSION_2_0;
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return 0;
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}
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/* Send TPM 1.2 command */
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ret = tpm_util_test(tpm_fd, (unsigned char *)&test_req,
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sizeof(test_req), &return_tag);
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if (!ret && return_tag == TPM_TAG_RSP_COMMAND) {
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*tpm_version = TPM_VERSION_1_2;
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/* this is a TPM 1.2 */
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return 0;
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}
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*tpm_version = TPM_VERSION_UNSPEC;
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return 1;
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}
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