static int tpm_passthrough_test_tpmdev(int fd) { struct tpm_req_hdr req = { .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND), .len = cpu_to_be32(sizeof(req)), .ordinal = cpu_to_be32(TPM_ORD_GetTicks), }; struct tpm_resp_hdr *resp; fd_set readfds; int n; struct timeval tv = { .tv_sec = 1, .tv_usec = 0, }; unsigned char buf[1024]; n = write(fd, &req, sizeof(req)); if (n < 0) { return errno; } if (n != sizeof(req)) { return EFAULT; } FD_ZERO(&readfds); FD_SET(fd, &readfds); /* wait for a second */ n = select(fd + 1, &readfds, NULL, NULL, &tv); if (n != 1) { return errno; } n = read(fd, &buf, sizeof(buf)); if (n < sizeof(struct tpm_resp_hdr)) { return EFAULT; } resp = (struct tpm_resp_hdr *)buf; /* check the header */ if (be16_to_cpu(resp->tag) != TPM_TAG_RSP_COMMAND || be32_to_cpu(resp->len) != n) { return EBADMSG; } return 0; }
static int tpm_passthrough_test_tpmdev(int fd) { struct tpm_req_hdr req = { .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND), .len = cpu_to_be32(sizeof(req)), .ordinal = cpu_to_be32(TPM_ORD_GetTicks), }; struct tpm_resp_hdr *resp; fd_set readfds; int n; struct timeval tv = { .tv_sec = 1, .tv_usec = 0, }; unsigned char buf[1024]; n = write(fd, &req, sizeof(req)); if (n < 0) { return errno; } if (n != sizeof(req)) { return EFAULT; } FD_ZERO(&readfds); FD_SET(fd, &readfds);   n = select(fd + 1, &readfds, NULL, NULL, &tv); if (n != 1) { return errno; } n = read(fd, &buf, sizeof(buf)); if (n < sizeof(struct tpm_resp_hdr)) { return EFAULT; } resp = (struct tpm_resp_hdr *)buf;   if (be16_to_cpu(resp->tag) != TPM_TAG_RSP_COMMAND || be32_to_cpu(resp->len) != n) { return EBADMSG; } return 0; }