From patchwork Tue Oct 13 08:11:22 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 529623 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.sourceforge.net (lists.sourceforge.net [216.34.181.88]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 898F61402C4 for ; Tue, 13 Oct 2015 19:11:50 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=sfs-ml-2.v29.ch3.sourceforge.com) by sfs-ml-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1ZlugU-0001mj-EC; Tue, 13 Oct 2015 08:11:46 +0000 Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1ZlugT-0001mb-UL for tpmdd-devel@lists.sourceforge.net; Tue, 13 Oct 2015 08:11:45 +0000 X-ACL-Warn: Received: from mga09.intel.com ([134.134.136.24]) by sog-mx-1.v43.ch3.sourceforge.com with esmtp (Exim 4.76) id 1ZlugT-0008HF-2Q for tpmdd-devel@lists.sourceforge.net; Tue, 13 Oct 2015 08:11:45 +0000 Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga102.jf.intel.com with ESMTP; 13 Oct 2015 01:11:41 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.17,677,1437462000"; d="scan'208";a="825650165" Received: from jsakkine-mobl1.tm.intel.com (HELO localhost) ([10.237.48.26]) by fmsmga002.fm.intel.com with ESMTP; 13 Oct 2015 01:11:39 -0700 From: Jarkko Sakkinen To: tpmdd-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org Date: Tue, 13 Oct 2015 11:11:22 +0300 Message-Id: <1444723889-11650-2-git-send-email-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1444723889-11650-1-git-send-email-jarkko.sakkinen@linux.intel.com> References: <1444723889-11650-1-git-send-email-jarkko.sakkinen@linux.intel.com> X-Spam-Score: -0.0 (/) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain X-Headers-End: 1ZlugT-0008HF-2Q Cc: gregkh@linuxfoundation.org Subject: [tpmdd-devel] [PATCH v2 1/4] tpm: introduce tpm_buf X-BeenThere: tpmdd-devel@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: Tpm Device Driver maintainance List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: tpmdd-devel-bounces@lists.sourceforge.net This patch introduces struct tpm_buf that provides a string buffer for constructing TPM commands. This allows to construct variable sized TPM commands. For the buffer a page is allocated and mapped, which limits maximum size to PAGE_SIZE. Variable sized TPM commands are needed in order to add algorithmic agility. Signed-off-by: Jarkko Sakkinen --- drivers/char/tpm/tpm.h | 97 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 97 insertions(+) diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index f8319a0..df43979 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -1,5 +1,6 @@ /* * Copyright (C) 2004 IBM Corporation + * Copyright (C) 2015 Intel Corporation * * Authors: * Leendert van Doorn @@ -28,6 +29,7 @@ #include #include #include +#include enum tpm_const { TPM_MINOR = 224, /* officially assigned */ @@ -382,6 +384,101 @@ struct tpm_cmd_t { tpm_cmd_params params; } __packed; +/* A string buffer type for constructing TPM commands. This is based on the + * ideas of string buffer code in security/keys/trusted.h but is heap based + * in order to keep the stack usage minimal. + */ + +enum tpm_buf_flags { + TPM_BUF_OVERFLOW = BIT(0), +}; + +struct tpm_buf { + struct page *data_page; + unsigned int flags; + u8 *data; +}; + +static inline void tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal) +{ + struct tpm_input_header *head; + + buf->data_page = alloc_page(GFP_HIGHUSER); + if (!buf->data_page) + return -ENOMEM; + + buf->flags = 0; + buf->data = kmap(buf->data_page); + + head = (struct tpm_input_header *) buf->data; + + head->tag = cpu_to_be16(tag); + head->length = cpu_to_be32(sizeof(*head)); + head->ordinal = cpu_to_be32(ordinal); + + return 0; +} + +static inline void tpm_buf_destroy(struct tpm_buf *buf) +{ + kunmap(buf->data_page); + __free_page(buf->data_page); +} + +static inline u32 tpm_buf_length(struct tpm_buf *buf) +{ + struct tpm_input_header *head = (struct tpm_input_header *) buf->data; + + return be32_to_cpu(head->length); +} + +static inline u16 tpm_buf_tag(struct tpm_buf *buf) +{ + struct tpm_input_header *head = (struct tpm_input_header *) buf->data; + + return be16_to_cpu(head->tag); +} + +static inline void tpm_buf_append(struct tpm_buf *buf, + const unsigned char *new_data, + unsigned int new_len) +{ + struct tpm_input_header *head = (struct tpm_input_header *) buf->data; + u32 len = tpm_buf_length(buf); + + /* Return silently if overflow has already happened. */ + if (buf->flags & TPM_BUF_OVERFLOW) + return; + + if ((len + new_len) > PAGE_SIZE) { + WARN(1, "tpm_buf: overflow\n"); + buf->flags |= TPM_BUF_OVERFLOW; + return; + } + + memcpy(&buf->data[len], new_data, new_len); + head->length = cpu_to_be32(len + new_len); +} + +static inline void tpm_buf_append_u8(struct tpm_buf *buf, const u8 value) +{ + tpm_buf_append(buf, &value, 1); +} + +static inline void tpm_buf_append_u16(struct tpm_buf *buf, const u16 value) +{ + __be16 value2 = cpu_to_be16(value); + + tpm_buf_append(buf, (u8 *) &value2, 2); +} + +static inline void tpm_buf_append_u32(struct tpm_buf *buf, const u32 value) +{ + __be32 value2 = cpu_to_be32(value); + + tpm_buf_append(buf, (u8 *) &value2, 4); +} + extern struct class *tpm_class; extern dev_t tpm_devt; extern const struct file_operations tpm_fops;