Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754546AbcCMW4A (ORCPT ); Sun, 13 Mar 2016 18:56:00 -0400 Received: from e33.co.us.ibm.com ([32.97.110.151]:43866 "EHLO e33.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754379AbcCMWyt (ORCPT ); Sun, 13 Mar 2016 18:54:49 -0400 X-IBM-Helo: d03dlp02.boulder.ibm.com X-IBM-MailFrom: stefanb@linux.vnet.ibm.com X-IBM-RcptTo: linux-api@vger.kernel.org;linux-doc@vger.kernel.org;linux-kernel@vger.kernel.org;linux-security-module@vger.kernel.org From: Stefan Berger To: tpmdd-devel@lists.sourceforge.net Cc: jarkko.sakkinen@linux.intel.com, jgunthorpe@obsidianresearch.com, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, Stefan Berger , linux-doc@vger.kernel.org, linux-api@vger.kernel.org Subject: [PATCH v8 08/10] tpm: Proxy driver for supporting multiple emulated TPMs Date: Sun, 13 Mar 2016 18:54:38 -0400 Message-Id: <1457909680-14085-9-git-send-email-stefanb@linux.vnet.ibm.com> X-Mailer: git-send-email 2.4.3 In-Reply-To: <1457909680-14085-1-git-send-email-stefanb@linux.vnet.ibm.com> References: <1457909680-14085-1-git-send-email-stefanb@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16031322-0009-0000-0000-00001396CD7E Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 17207 Lines: 694 This patch implements a proxy driver for supporting multiple emulated TPMs in a system. The driver implements a device /dev/vtpmx that is used to created a client device pair /dev/tpmX (e.g., /dev/tpm10) and a server side that is accessed using a file descriptor returned by an ioctl. The device /dev/tpmX is the usual TPM device created by the core TPM driver. Applications or kernel subsystems can send TPM commands to it and the corresponding server-side file descriptor receives these commands and delivers them to an emulated TPM. Signed-off-by: Stefan Berger CC: linux-kernel@vger.kernel.org CC: linux-doc@vger.kernel.org CC: linux-api@vger.kernel.org --- drivers/char/tpm/Kconfig | 10 + drivers/char/tpm/Makefile | 1 + drivers/char/tpm/tpm_vtpm_proxy.c | 572 ++++++++++++++++++++++++++++++++++++++ include/uapi/linux/Kbuild | 1 + include/uapi/linux/vtpm_proxy.h | 42 +++ 5 files changed, 626 insertions(+) create mode 100644 drivers/char/tpm/tpm_vtpm_proxy.c create mode 100644 include/uapi/linux/vtpm_proxy.h diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig index 3b84a8b..0eac596 100644 --- a/drivers/char/tpm/Kconfig +++ b/drivers/char/tpm/Kconfig @@ -122,5 +122,15 @@ config TCG_CRB from within Linux. To compile this driver as a module, choose M here; the module will be called tpm_crb. +config TCG_VTPM_PROXY + tristate "VTPM Proxy Interface" + depends on TCG_TPM + ---help--- + This driver proxies for an emulated TPM (vTPM) running in userspace. + A device /dev/vtpmx is provided that creates a device pair + /dev/vtpmX and a server-side file descriptor on which the vTPM + can receive commands. + + source "drivers/char/tpm/st33zp24/Kconfig" endif # TCG_TPM diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile index 56e8f1f..98de5e6 100644 --- a/drivers/char/tpm/Makefile +++ b/drivers/char/tpm/Makefile @@ -23,3 +23,4 @@ obj-$(CONFIG_TCG_IBMVTPM) += tpm_ibmvtpm.o obj-$(CONFIG_TCG_TIS_ST33ZP24) += st33zp24/ obj-$(CONFIG_TCG_XEN) += xen-tpmfront.o obj-$(CONFIG_TCG_CRB) += tpm_crb.o +obj-$(CONFIG_TCG_VTPM_PROXY) += tpm_vtpm_proxy.o diff --git a/drivers/char/tpm/tpm_vtpm_proxy.c b/drivers/char/tpm/tpm_vtpm_proxy.c new file mode 100644 index 0000000..2bb2c8c --- /dev/null +++ b/drivers/char/tpm/tpm_vtpm_proxy.c @@ -0,0 +1,572 @@ +/* + * Copyright (C) 2015, 2016 IBM Corporation + * + * Author: Stefan Berger + * + * Maintained by: + * + * Device driver for vTPM (vTPM proxy driver) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation, version 2 of the + * License. + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "tpm.h" + +#define VTPM_PROXY_REQ_COMPLETE_FLAG BIT(0) + +struct proxy_dev { + struct tpm_chip *chip; + + u32 flags; /* public API flags */ + + wait_queue_head_t wq; + + struct mutex buf_lock; /* protect buffer and flags */ + + long state; /* internal state */ +#define STATE_OPENED_FLAG BIT(0) +#define STATE_WAIT_RESPONSE_FLAG BIT(1) /* waiting for emulator response */ + + size_t req_len; /* length of queued TPM request */ + size_t resp_len; /* length of queued TPM response */ + u8 buffer[TPM_BUFSIZE]; /* request/response buffer */ +}; + + +static void vtpm_proxy_delete_device(struct proxy_dev *proxy_dev); + +/* + * Functions related to 'server side' + */ + +/** + * vtpm_proxy_fops_read - Read TPM commands on 'server side' + * + * Return value: + * Number of bytes read or negative error code + */ +static ssize_t vtpm_proxy_fops_read(struct file *filp, char __user *buf, + size_t count, loff_t *off) +{ + struct proxy_dev *proxy_dev = filp->private_data; + size_t len; + int sig, rc; + + sig = wait_event_interruptible(proxy_dev->wq, proxy_dev->req_len != 0); + if (sig) + return -EINTR; + + mutex_lock(&proxy_dev->buf_lock); + + len = proxy_dev->req_len; + + if (count < len) { + mutex_unlock(&proxy_dev->buf_lock); + pr_debug("Invalid size in recv: count=%zd, req_len=%zd\n", + count, len); + return -EIO; + } + + rc = copy_to_user(buf, proxy_dev->buffer, len); + memset(proxy_dev->buffer, 0, len); + proxy_dev->req_len = 0; + + if (!rc) + proxy_dev->state |= STATE_WAIT_RESPONSE_FLAG; + + mutex_unlock(&proxy_dev->buf_lock); + + if (rc) + return -EFAULT; + + return len; +} + +/** + * vtpm_proxy_fops_write - Write TPM responses on 'server side' + * + * Return value: + * Number of bytes read or negative error value + */ +static ssize_t vtpm_proxy_fops_write(struct file *filp, const char __user *buf, + size_t count, loff_t *off) +{ + struct proxy_dev *proxy_dev = filp->private_data; + + mutex_lock(&proxy_dev->buf_lock); + + if (count > sizeof(proxy_dev->buffer) || + !(proxy_dev->state & STATE_WAIT_RESPONSE_FLAG)) { + mutex_unlock(&proxy_dev->buf_lock); + return -EIO; + } + + proxy_dev->state &= ~STATE_WAIT_RESPONSE_FLAG; + + proxy_dev->req_len = 0; + + if (copy_from_user(proxy_dev->buffer, buf, count)) { + mutex_unlock(&proxy_dev->buf_lock); + return -EFAULT; + } + + proxy_dev->resp_len = count; + + mutex_unlock(&proxy_dev->buf_lock); + + wake_up_interruptible(&proxy_dev->wq); + + return count; +} + +/* + * vtpm_proxy_fops_poll: Poll status on 'server side' + * + * Return value: + * Poll flags + */ +static unsigned int vtpm_proxy_fops_poll(struct file *filp, poll_table *wait) +{ + struct proxy_dev *proxy_dev = filp->private_data; + unsigned ret; + + poll_wait(filp, &proxy_dev->wq, wait); + + ret = POLLOUT; + + mutex_lock(&proxy_dev->buf_lock); + + if (proxy_dev->req_len) + ret |= POLLIN | POLLRDNORM; + + mutex_unlock(&proxy_dev->buf_lock); + + return ret; +} + +/* + * vtpm_proxy_fops_open - Open vTPM device on 'server side' + * + * Called when setting up the anonymous file descriptor + */ +static void vtpm_proxy_fops_open(struct file *filp) +{ + struct proxy_dev *proxy_dev = filp->private_data; + + proxy_dev->state |= STATE_OPENED_FLAG; +} + +/** + * vtpm_proxy_fops_undo_open - counter-part to vtpm_fops_open + * + * Call to undo vtpm_proxy_fops_open + */ +static void vtpm_proxy_fops_undo_open(struct proxy_dev *proxy_dev) +{ + mutex_lock(&proxy_dev->buf_lock); + + proxy_dev->state &= ~STATE_OPENED_FLAG; + + mutex_unlock(&proxy_dev->buf_lock); + + /* no more TPM responses -- wake up anyone waiting for them */ + wake_up_interruptible(&proxy_dev->wq); +} + +/* + * vtpm_proxy_fops_release: Close 'server side' + * + * Return value: + * Always returns 0. + */ +static int vtpm_proxy_fops_release(struct inode *inode, struct file *filp) +{ + struct proxy_dev *proxy_dev = filp->private_data; + + filp->private_data = NULL; + + vtpm_proxy_delete_device(proxy_dev); + + return 0; +} + +static const struct file_operations vtpm_proxy_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .read = vtpm_proxy_fops_read, + .write = vtpm_proxy_fops_write, + .poll = vtpm_proxy_fops_poll, + .release = vtpm_proxy_fops_release, +}; + +/* + * Functions invoked by the core TPM driver to send TPM commands to + * 'server side' and receive responses from there. + */ + +/* + * Called when core TPM driver reads TPM responses from 'server side' + * + * Return value: + * Number of TPM response bytes read, negative error value otherwise + */ +static int vtpm_proxy_tpm_op_recv(struct tpm_chip *chip, u8 *buf, size_t count) +{ + struct proxy_dev *proxy_dev = chip->vendor.priv; + size_t len; + + if (!proxy_dev) + return -EIO; + + /* process gone ? */ + mutex_lock(&proxy_dev->buf_lock); + + if (!(proxy_dev->state & STATE_OPENED_FLAG)) { + mutex_unlock(&proxy_dev->buf_lock); + return -EPIPE; + } + + len = proxy_dev->resp_len; + if (count < len) { + dev_err(&chip->dev, + "Invalid size in recv: count=%zd, resp_len=%zd\n", + count, len); + len = -EIO; + goto out; + } + + memcpy(buf, proxy_dev->buffer, len); + proxy_dev->resp_len = 0; + +out: + mutex_unlock(&proxy_dev->buf_lock); + + return len; +} + +/* + * Called when core TPM driver forwards TPM requests to 'server side'. + * + * Return value: + * 0 in case of success, negative error value otherwise. + */ +static int vtpm_proxy_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t count) +{ + struct proxy_dev *proxy_dev = chip->vendor.priv; + int rc = 0; + + if (!proxy_dev) + return -EIO; + + if (count > sizeof(proxy_dev->buffer)) { + dev_err(&chip->dev, + "Invalid size in send: count=%zd, buffer size=%zd\n", + count, sizeof(proxy_dev->buffer)); + return -EIO; + } + + mutex_lock(&proxy_dev->buf_lock); + + if (!(proxy_dev->state & STATE_OPENED_FLAG)) { + mutex_unlock(&proxy_dev->buf_lock); + return -EPIPE; + } + + proxy_dev->resp_len = 0; + + proxy_dev->req_len = count; + memcpy(proxy_dev->buffer, buf, count); + + proxy_dev->state &= ~STATE_WAIT_RESPONSE_FLAG; + + mutex_unlock(&proxy_dev->buf_lock); + + wake_up_interruptible(&proxy_dev->wq); + + return rc; +} + +static void vtpm_proxy_tpm_op_cancel(struct tpm_chip *chip) +{ + /* not supported */ +} + +static u8 vtpm_proxy_tpm_op_status(struct tpm_chip *chip) +{ + struct proxy_dev *proxy_dev = chip->vendor.priv; + + if (proxy_dev->resp_len) + return VTPM_PROXY_REQ_COMPLETE_FLAG; + + return 0; +} + +static bool vtpm_proxy_tpm_req_canceled(struct tpm_chip *chip, u8 status) +{ + struct proxy_dev *proxy_dev = chip->vendor.priv; + bool ret; + + mutex_lock(&proxy_dev->buf_lock); + + ret = !(proxy_dev->state & STATE_OPENED_FLAG); + + mutex_unlock(&proxy_dev->buf_lock); + + return ret; +} + +static const struct tpm_class_ops vtpm_proxy_tpm_ops = { + .recv = vtpm_proxy_tpm_op_recv, + .send = vtpm_proxy_tpm_op_send, + .cancel = vtpm_proxy_tpm_op_cancel, + .status = vtpm_proxy_tpm_op_status, + .req_complete_mask = VTPM_PROXY_REQ_COMPLETE_FLAG, + .req_complete_val = VTPM_PROXY_REQ_COMPLETE_FLAG, + .req_canceled = vtpm_proxy_tpm_req_canceled, +}; + +/* + * Code related to creation and deletion of device pairs + */ +static struct proxy_dev *vtpm_proxy_create_proxy_dev(void) +{ + struct proxy_dev *proxy_dev; + struct tpm_chip *chip; + int err; + + proxy_dev = kzalloc(sizeof(*proxy_dev), GFP_KERNEL); + if (proxy_dev == NULL) + return ERR_PTR(-ENOMEM); + + init_waitqueue_head(&proxy_dev->wq); + mutex_init(&proxy_dev->buf_lock); + + chip = tpm_chip_alloc(NULL, &vtpm_proxy_tpm_ops); + if (IS_ERR(chip)) { + err = PTR_ERR(chip); + goto err_proxy_dev_free; + } + chip->vendor.priv = proxy_dev; + + proxy_dev->chip = chip; + + return proxy_dev; + +err_proxy_dev_free: + kfree(proxy_dev); + + return ERR_PTR(err); +} + +/* + * Undo what has been done in vtpm_create_proxy_dev + */ +static inline void vtpm_proxy_delete_proxy_dev(struct proxy_dev *proxy_dev) +{ + put_device(&proxy_dev->chip->dev); /* frees chip */ + kfree(proxy_dev); +} + +/* + * Create a /dev/tpm%d and 'server side' file descriptor pair + * + * Return value: + * Returns file pointer on success, an error value otherwise + */ +static struct file *vtpm_proxy_create_device( + struct vtpm_proxy_new_dev *vtpm_new_dev) +{ + struct proxy_dev *proxy_dev; + int rc, fd; + struct file *file; + + if (vtpm_new_dev->flags & ~VTPM_PROXY_FLAGS_ALL) + return ERR_PTR(-EOPNOTSUPP); + + proxy_dev = vtpm_proxy_create_proxy_dev(); + if (IS_ERR(proxy_dev)) + return ERR_CAST(proxy_dev); + + proxy_dev->flags = vtpm_new_dev->flags; + + /* setup an anonymous file for the server-side */ + fd = get_unused_fd_flags(O_RDWR); + if (fd < 0) { + rc = fd; + goto err_delete_proxy_dev; + } + + file = anon_inode_getfile("[vtpms]", &vtpm_proxy_fops, proxy_dev, + O_RDWR); + if (IS_ERR(file)) { + rc = PTR_ERR(file); + goto err_put_unused_fd; + } + + /* from now on we can unwind with put_unused_fd() + fput() */ + /* simulate an open() on the server side */ + vtpm_proxy_fops_open(file); + + if (proxy_dev->flags & VTPM_PROXY_FLAG_TPM2) + proxy_dev->chip->flags |= TPM_CHIP_FLAG_TPM2; + + rc = tpm_chip_register(proxy_dev->chip); + if (rc) + goto err_vtpm_fput; + + vtpm_new_dev->fd = fd; + vtpm_new_dev->major = MAJOR(proxy_dev->chip->dev.devt); + vtpm_new_dev->minor = MINOR(proxy_dev->chip->dev.devt); + vtpm_new_dev->tpm_num = proxy_dev->chip->dev_num; + + return file; + +err_vtpm_fput: + put_unused_fd(fd); + fput(file); + + return ERR_PTR(rc); + +err_put_unused_fd: + put_unused_fd(fd); + +err_delete_proxy_dev: + vtpm_proxy_delete_proxy_dev(proxy_dev); + + return ERR_PTR(rc); +} + +/* + * Counter part to vtpm_create_device. + */ +static void vtpm_proxy_delete_device(struct proxy_dev *proxy_dev) +{ + /* + * A client may hold the 'ops' lock, so let it know that the server + * side shuts down before we try to grab the 'ops' lock when + * unregistering the chip. + */ + vtpm_proxy_fops_undo_open(proxy_dev); + + tpm_chip_unregister(proxy_dev->chip); + + vtpm_proxy_delete_proxy_dev(proxy_dev); +} + +/* + * Code related to the control device /dev/vtpmx + */ + +/* + * vtpmx_fops_ioctl: ioctl on /dev/vtpmx + * + * Return value: + * Returns 0 on success, a negative error code otherwise. + */ +static long vtpmx_fops_ioctl(struct file *f, unsigned int ioctl, + unsigned long arg) +{ + void __user *argp = (void __user *)arg; + struct vtpm_proxy_new_dev *vtpm_new_dev_p; + struct vtpm_proxy_new_dev vtpm_new_dev; + struct file *file; + + switch (ioctl) { + case VTPM_PROXY_IOC_NEW_DEV: + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + vtpm_new_dev_p = argp; + if (copy_from_user(&vtpm_new_dev, vtpm_new_dev_p, + sizeof(vtpm_new_dev))) + return -EFAULT; + file = vtpm_proxy_create_device(&vtpm_new_dev); + if (IS_ERR(file)) + return PTR_ERR(file); + if (copy_to_user(vtpm_new_dev_p, &vtpm_new_dev, + sizeof(vtpm_new_dev))) { + put_unused_fd(vtpm_new_dev.fd); + fput(file); + return -EFAULT; + } + + fd_install(vtpm_new_dev.fd, file); + return 0; + + default: + return -ENOIOCTLCMD; + } +} + +#ifdef CONFIG_COMPAT +static long vtpmx_fops_compat_ioctl(struct file *f, unsigned int ioctl, + unsigned long arg) +{ + return vtpmx_fops_ioctl(f, ioctl, (unsigned long)compat_ptr(arg)); +} +#endif + +static const struct file_operations vtpmx_fops = { + .owner = THIS_MODULE, + .unlocked_ioctl = vtpmx_fops_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = vtpmx_fops_compat_ioctl, +#endif + .llseek = noop_llseek, +}; + +static struct miscdevice vtpmx_miscdev = { + .minor = MISC_DYNAMIC_MINOR, + .name = "vtpmx", + .fops = &vtpmx_fops, +}; + +static int vtpmx_init(void) +{ + return misc_register(&vtpmx_miscdev); +} + +static void vtpmx_cleanup(void) +{ + misc_deregister(&vtpmx_miscdev); +} + +static int __init vtpm_module_init(void) +{ + int rc; + + rc = vtpmx_init(); + if (rc) { + pr_err("couldn't create vtpmx device\n"); + return rc; + } + + return 0; +} + +static void __exit vtpm_module_exit(void) +{ + vtpmx_cleanup(); +} + +module_init(vtpm_module_init); +module_exit(vtpm_module_exit); + +MODULE_AUTHOR("Stefan Berger (stefanb@us.ibm.com)"); +MODULE_DESCRIPTION("vTPM Driver"); +MODULE_VERSION("0.1"); +MODULE_LICENSE("GPL"); diff --git a/include/uapi/linux/Kbuild b/include/uapi/linux/Kbuild index ebd10e6..ac767ce 100644 --- a/include/uapi/linux/Kbuild +++ b/include/uapi/linux/Kbuild @@ -449,6 +449,7 @@ header-y += virtio_scsi.h header-y += virtio_types.h header-y += vm_sockets.h header-y += vt.h +header-y += vtpm_proxy.h header-y += wait.h header-y += wanrouter.h header-y += watchdog.h diff --git a/include/uapi/linux/vtpm_proxy.h b/include/uapi/linux/vtpm_proxy.h new file mode 100644 index 0000000..dc73f00 --- /dev/null +++ b/include/uapi/linux/vtpm_proxy.h @@ -0,0 +1,42 @@ +/* + * Definitions for the VTPM proxy driver + * Copyright (c) 2015, 2016, IBM Corporation + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + */ + +#ifndef _UAPI_LINUX_VTPM_PROXY_H +#define _UAPI_LINUX_VTPM_PROXY_H + +#include +#include + +/* ioctls */ + +struct vtpm_proxy_new_dev { + __u32 flags; /* input */ + __u32 tpm_num; /* output */ + __u32 fd; /* output */ + __u32 major; /* output */ + __u32 minor; /* output */ +}; + +/* above flags */ +#define VTPM_PROXY_FLAG_TPM2 1 /* emulator is TPM 2 */ + +/* all supported flags */ +#define VTPM_PROXY_FLAGS_ALL (VTPM_PROXY_FLAG_TPM2) + +#define VTPM_PROXY_MAGIC 0xa1 + +#define VTPM_PROXY_IOC_NEW_DEV _IOW(VTPM_PROXY_MAGIC, 0x00, \ + struct vtpm_proxy_new_dev) + +#endif /* _UAPI_LINUX_VTPM_PROXY_H */ -- 2.4.3