OSCL-LXR linux-6.0.1/​drivers/​char/​tpm/​tpm_vtpm_proxy.c	Source navigation Diff markup Identifier search General search
	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2015, 2016 IBM Corporation
  * Copyright (C) 2016 Intel Corporation
  *
  * Author: Stefan Berger <stefanb@us.ibm.com>
  *
  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
  *
  * Device driver for vTPM (vTPM proxy driver)
  */
 
 #include <linux/types.h>
 #include <linux/spinlock.h>
 #include <linux/uaccess.h>
 #include <linux/wait.h>
 #include <linux/miscdevice.h>
 #include <linux/vtpm_proxy.h>
 #include <linux/file.h>
 #include <linux/anon_inodes.h>
 #include <linux/poll.h>
 #include <linux/compat.h>
 
 #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 */
 #define STATE_REGISTERED_FLAG    BIT(2)
 #define STATE_DRIVER_COMMAND     BIT(3)  /* sending a driver specific command */
 
     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 */
 
     struct work_struct work;     /* task that retrieves TPM timeouts */
 };
 
 /* all supported flags */
 #define VTPM_PROXY_FLAGS_ALL  (VTPM_PROXY_FLAG_TPM2)
 
 static struct workqueue_struct *workqueue;
 
 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'
  *
  * @filp: file pointer
  * @buf: read buffer
  * @count: number of bytes to read
  * @off: offset
  *
  * Return:
  *  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 ||
         !(proxy_dev->state & STATE_OPENED_FLAG));
     if (sig)
         return -EINTR;
 
     mutex_lock(&proxy_dev->buf_lock);
 
     if (!(proxy_dev->state & STATE_OPENED_FLAG)) {
         mutex_unlock(&proxy_dev->buf_lock);
         return -EPIPE;
     }
 
     len = proxy_dev->req_len;
 
     if (count < len || len > sizeof(proxy_dev->buffer)) {
         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'
  *
  * @filp: file pointer
  * @buf: write buffer
  * @count: number of bytes to write
  * @off: offset
  *
  * Return:
  *  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 (!(proxy_dev->state & STATE_OPENED_FLAG)) {
         mutex_unlock(&proxy_dev->buf_lock);
         return -EPIPE;
     }
 
     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'
  *
  * @filp: file pointer
  * @wait: poll table
  *
  * Return: Poll flags
  */
 static __poll_t vtpm_proxy_fops_poll(struct file *filp, poll_table *wait)
 {
     struct proxy_dev *proxy_dev = filp->private_data;
     __poll_t ret;
 
     poll_wait(filp, &proxy_dev->wq, wait);
 
     ret = EPOLLOUT;
 
     mutex_lock(&proxy_dev->buf_lock);
 
     if (proxy_dev->req_len)
         ret |= EPOLLIN | EPOLLRDNORM;
 
     if (!(proxy_dev->state & STATE_OPENED_FLAG))
         ret |= EPOLLHUP;
 
     mutex_unlock(&proxy_dev->buf_lock);
 
     return ret;
 }
 
 /*
  * vtpm_proxy_fops_open - Open vTPM device on 'server side'
  *
  * @filp: file pointer
  *
  * 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
  *
  *@proxy_dev: tpm proxy device
  */
 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'
  *
  * @inode: inode
  * @filp: file pointer
  * Return:
  *      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'
  *
  * @chip: tpm chip to use
  * @buf: receive buffer
  * @count: bytes to read
  * Return:
  *      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 = dev_get_drvdata(&chip->dev);
     size_t len;
 
     /* 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;
 }
 
 static int vtpm_proxy_is_driver_command(struct tpm_chip *chip,
                     u8 *buf, size_t count)
 {
     struct tpm_header *hdr = (struct tpm_header *)buf;
 
     if (count < sizeof(struct tpm_header))
         return 0;
 
     if (chip->flags & TPM_CHIP_FLAG_TPM2) {
         switch (be32_to_cpu(hdr->ordinal)) {
         case TPM2_CC_SET_LOCALITY:
             return 1;
         }
     } else {
         switch (be32_to_cpu(hdr->ordinal)) {
         case TPM_ORD_SET_LOCALITY:
             return 1;
         }
     }
     return 0;
 }
 
 /*
  * Called when core TPM driver forwards TPM requests to 'server side'.
  *
  * @chip: tpm chip to use
  * @buf: send buffer
  * @count: bytes to send
  *
  * Return:
  *      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 = dev_get_drvdata(&chip->dev);
 
     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;
     }
 
     if (!(proxy_dev->state & STATE_DRIVER_COMMAND) &&
         vtpm_proxy_is_driver_command(chip, buf, count))
         return -EFAULT;
 
     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 0;
 }
 
 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 = dev_get_drvdata(&chip->dev);
 
     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 = dev_get_drvdata(&chip->dev);
     bool ret;
 
     mutex_lock(&proxy_dev->buf_lock);
 
     ret = !(proxy_dev->state & STATE_OPENED_FLAG);
 
     mutex_unlock(&proxy_dev->buf_lock);
 
     return ret;
 }
 
 static int vtpm_proxy_request_locality(struct tpm_chip *chip, int locality)
 {
     struct tpm_buf buf;
     int rc;
     const struct tpm_header *header;
     struct proxy_dev *proxy_dev = dev_get_drvdata(&chip->dev);
 
     if (chip->flags & TPM_CHIP_FLAG_TPM2)
         rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS,
                   TPM2_CC_SET_LOCALITY);
     else
         rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND,
                   TPM_ORD_SET_LOCALITY);
     if (rc)
         return rc;
     tpm_buf_append_u8(&buf, locality);
 
     proxy_dev->state |= STATE_DRIVER_COMMAND;
 
     rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to set locality");
 
     proxy_dev->state &= ~STATE_DRIVER_COMMAND;
 
     if (rc < 0) {
         locality = rc;
         goto out;
     }
 
     header = (const struct tpm_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,
     .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,
     .request_locality = vtpm_proxy_request_locality,
 };
 
 /*
  * Code related to the startup of the TPM 2 and startup of TPM 1.2 +
  * retrieval of timeouts and durations.
  */
 
 static void vtpm_proxy_work(struct work_struct *work)
 {
     struct proxy_dev *proxy_dev = container_of(work, struct proxy_dev,
                            work);
     int rc;
 
     rc = tpm_chip_register(proxy_dev->chip);
     if (rc)
         vtpm_proxy_fops_undo_open(proxy_dev);
     else
         proxy_dev->state |= STATE_REGISTERED_FLAG;
 }
 
 /*
  * vtpm_proxy_work_stop: make sure the work has finished
  *
  * This function is useful when user space closed the fd
  * while the driver still determines timeouts.
  */
 static void vtpm_proxy_work_stop(struct proxy_dev *proxy_dev)
 {
     vtpm_proxy_fops_undo_open(proxy_dev);
     flush_work(&proxy_dev->work);
 }
 
 /*
  * vtpm_proxy_work_start: Schedule the work for TPM 1.2 & 2 initialization
  */
 static inline void vtpm_proxy_work_start(struct proxy_dev *proxy_dev)
 {
     queue_work(workqueue, &proxy_dev->work);
 }
 
 /*
  * 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);
     INIT_WORK(&proxy_dev->work, vtpm_proxy_work);
 
     chip = tpm_chip_alloc(NULL, &vtpm_proxy_tpm_ops);
     if (IS_ERR(chip)) {
         err = PTR_ERR(chip);
         goto err_proxy_dev_free;
     }
     dev_set_drvdata(&chip->dev, 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:
  *      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;
 
     vtpm_proxy_work_start(proxy_dev);
 
     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_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)
 {
     vtpm_proxy_work_stop(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);
 
     if (proxy_dev->state & STATE_REGISTERED_FLAG)
         tpm_chip_unregister(proxy_dev->chip);
 
     vtpm_proxy_delete_proxy_dev(proxy_dev);
 }
 
 /*
  * Code related to the control device /dev/vtpmx
  */
 
 /**
  * vtpmx_ioc_new_dev - handler for the %VTPM_PROXY_IOC_NEW_DEV ioctl
  * @file:   /dev/vtpmx
  * @ioctl:  the ioctl number
  * @arg:    pointer to the struct vtpmx_proxy_new_dev
  *
  * Creates an anonymous file that is used by the process acting as a TPM to
  * communicate with the client processes. The function will also add a new TPM
  * device through which data is proxied to this TPM acting process. The caller
  * will be provided with a file descriptor to communicate with the clients and
  * major and minor numbers for the TPM device.
  */
 static long vtpmx_ioc_new_dev(struct file *file, unsigned int ioctl,
                   unsigned long arg)
 {
     void __user *argp = (void __user *)arg;
     struct vtpm_proxy_new_dev __user *vtpm_new_dev_p;
     struct vtpm_proxy_new_dev vtpm_new_dev;
     struct file *vtpm_file;
 
     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;
 
     vtpm_file = vtpm_proxy_create_device(&vtpm_new_dev);
     if (IS_ERR(vtpm_file))
         return PTR_ERR(vtpm_file);
 
     if (copy_to_user(vtpm_new_dev_p, &vtpm_new_dev,
              sizeof(vtpm_new_dev))) {
         put_unused_fd(vtpm_new_dev.fd);
         fput(vtpm_file);
         return -EFAULT;
     }
 
     fd_install(vtpm_new_dev.fd, vtpm_file);
     return 0;
 }
 
 /*
  * vtpmx_fops_ioctl: ioctl on /dev/vtpmx
  *
  * Return:
  *      Returns 0 on success, a negative error code otherwise.
  */
 static long vtpmx_fops_ioctl(struct file *f, unsigned int ioctl,
                  unsigned long arg)
 {
     switch (ioctl) {
     case VTPM_PROXY_IOC_NEW_DEV:
         return vtpmx_ioc_new_dev(f, ioctl, arg);
     default:
         return -ENOIOCTLCMD;
     }
 }
 
 static const struct file_operations vtpmx_fops = {
     .owner = THIS_MODULE,
     .unlocked_ioctl = vtpmx_fops_ioctl,
     .compat_ioctl = compat_ptr_ioctl,
     .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;
     }
 
     workqueue = create_workqueue("tpm-vtpm");
     if (!workqueue) {
         pr_err("couldn't create workqueue\n");
         rc = -ENOMEM;
         goto err_vtpmx_cleanup;
     }
 
     return 0;
 
 err_vtpmx_cleanup:
     vtpmx_cleanup();
 
     return rc;
 }
 
 static void __exit vtpm_module_exit(void)
 {
     destroy_workqueue(workqueue);
     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");

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