Staging: p9auth: remove driver from tree

No one seems to be maintaining this anymore, and it is not on any
track to be merged to mainline.

Cc: Ashwin Ganti <ashwin.ganti@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/staging/Kconfig

@@ -91,8 +91,6 @@ source "drivers/staging/pohmelfs/Kconfig"
 
 source "drivers/staging/phison/Kconfig"
 
-source "drivers/staging/p9auth/Kconfig"
-
 source "drivers/staging/line6/Kconfig"
 
 source "drivers/gpu/drm/vmwgfx/Kconfig"

drivers/staging/Makefile

@@ -28,7 +28,6 @@ obj-$(CONFIG_TRANZPORT)		+= frontier/
 obj-$(CONFIG_DREAM)		+= dream/
 obj-$(CONFIG_POHMELFS)		+= pohmelfs/
 obj-$(CONFIG_IDE_PHISON)	+= phison/
-obj-$(CONFIG_PLAN9AUTH)		+= p9auth/
 obj-$(CONFIG_LINE6_USB)		+= line6/
 obj-$(CONFIG_USB_SERIAL_QUATECH2)	+= serqt_usb2/
 obj-$(CONFIG_USB_SERIAL_QUATECH_USB2)	+= quatech_usb2/

drivers/staging/p9auth/Kconfig

-config PLAN9AUTH
-	tristate "Plan 9 style capability device implementation"
-	default n
-	depends on CRYPTO
-	help
-	  This module implements the Plan 9 style capability device.
-
-	  To compile this driver as a module, choose
-	  M here: the module will be called p9auth.

drivers/staging/p9auth/Makefile

-obj-$(CONFIG_PLAN9AUTH)	+= p9auth.o

drivers/staging/p9auth/p9auth.c

-/*
- * Plan 9 style capability device implementation for the Linux Kernel
- *
- * Copyright 2008, 2009 Ashwin Ganti <ashwin.ganti@gmail.com>
- *
- * Released under the GPLv2
- *
- */
-#include <linux/init.h>
-#include <linux/kernel.h>
-#include <linux/moduleparam.h>
-#include <linux/slab.h>
-#include <linux/fs.h>
-#include <linux/errno.h>
-#include <linux/fcntl.h>
-#include <linux/cdev.h>
-#include <linux/uaccess.h>
-#include <linux/list.h>
-#include <linux/mm.h>
-#include <linux/string.h>
-#include <linux/crypto.h>
-#include <linux/highmem.h>
-#include <linux/scatterlist.h>
-#include <linux/sched.h>
-#include <linux/cred.h>
-
-#ifndef CAP_MAJOR
-#define CAP_MAJOR 0
-#endif
-
-#ifndef CAP_NR_DEVS
-#define CAP_NR_DEVS 2		/* caphash and capuse */
-#endif
-
-#ifndef CAP_NODE_SIZE
-#define CAP_NODE_SIZE 20
-#endif
-
-#define MAX_DIGEST_SIZE  20
-
-struct cap_node {
-	char data[CAP_NODE_SIZE];
-	struct list_head list;
-};
-
-struct cap_dev {
-	struct cap_node *head;
-	int node_size;
-	unsigned long size;
-	struct semaphore sem;
-	struct cdev cdev;
-};
-
-static int cap_major = CAP_MAJOR;
-static int cap_minor;
-static int cap_nr_devs = CAP_NR_DEVS;
-static int cap_node_size = CAP_NODE_SIZE;
-
-module_param(cap_major, int, S_IRUGO);
-module_param(cap_minor, int, S_IRUGO);
-module_param(cap_nr_devs, int, S_IRUGO);
-
-MODULE_AUTHOR("Ashwin Ganti");
-MODULE_LICENSE("GPL");
-
-static struct cap_dev *cap_devices;
-
-static void hexdump(unsigned char *buf, unsigned int len)
-{
-	while (len--)
-		printk("%02x", *buf++);
-	printk("\n");
-}
-
-static char *cap_hash(char *plain_text, unsigned int plain_text_size,
-		      char *key, unsigned int key_size)
-{
-	struct scatterlist sg;
-	char *result;
-	struct crypto_hash *tfm;
-	struct hash_desc desc;
-	int ret;
-
-	tfm = crypto_alloc_hash("hmac(sha1)", 0, CRYPTO_ALG_ASYNC);
-	if (IS_ERR(tfm)) {
-		printk(KERN_ERR
-		       "failed to load transform for hmac(sha1): %ld\n",
-		       PTR_ERR(tfm));
-		return NULL;
-	}
-
-	desc.tfm = tfm;
-	desc.flags = 0;
-
-	result = kzalloc(MAX_DIGEST_SIZE, GFP_KERNEL);
-	if (!result) {
-		printk(KERN_ERR "out of memory!\n");
-		goto out;
-	}
-
-	sg_set_buf(&sg, plain_text, plain_text_size);
-
-	ret = crypto_hash_setkey(tfm, key, key_size);
-	if (ret) {
-		printk(KERN_ERR "setkey() failed ret=%d\n", ret);
-		kfree(result);
-		result = NULL;
-		goto out;
-	}
-
-	ret = crypto_hash_digest(&desc, &sg, plain_text_size, result);
-	if (ret) {
-		printk(KERN_ERR "digest () failed ret=%d\n", ret);
-		kfree(result);
-		result = NULL;
-		goto out;
-	}
-
-	printk(KERN_DEBUG "crypto hash digest size %d\n",
-	       crypto_hash_digestsize(tfm));
-	hexdump(result, MAX_DIGEST_SIZE);
-
-out:
-	crypto_free_hash(tfm);
-	return result;
-}
-
-static int cap_trim(struct cap_dev *dev)
-{
-	struct cap_node *tmp;
-	struct list_head *pos, *q;
-	if (dev->head != NULL) {
-		list_for_each_safe(pos, q, &(dev->head->list)) {
-			tmp = list_entry(pos, struct cap_node, list);
-			list_del(pos);
-			kfree(tmp);
-		}
-	}
-	return 0;
-}
-
-static int cap_open(struct inode *inode, struct file *filp)
-{
-	struct cap_dev *dev;
-	dev = container_of(inode->i_cdev, struct cap_dev, cdev);
-	filp->private_data = dev;
-
-	/* trim to 0 the length of the device if open was write-only */
-	if ((filp->f_flags & O_ACCMODE) == O_WRONLY) {
-		if (down_interruptible(&dev->sem))
-			return -ERESTARTSYS;
-		cap_trim(dev);
-		up(&dev->sem);
-	}
-	/* initialise the head if it is NULL */
-	if (dev->head == NULL) {
-		dev->head = kmalloc(sizeof(struct cap_node), GFP_KERNEL);
-		INIT_LIST_HEAD(&(dev->head->list));
-	}
-	return 0;
-}
-
-static int cap_release(struct inode *inode, struct file *filp)
-{
-	return 0;
-}
-
-static ssize_t cap_write(struct file *filp, const char __user *buf,
-			 size_t count, loff_t *f_pos)
-{
-	struct cap_node *node_ptr, *tmp;
-	struct list_head *pos;
-	struct cap_dev *dev = filp->private_data;
-	ssize_t retval = -ENOMEM;
-	struct cred *new;
-	int len, target_int, source_int, flag = 0;
-	char *user_buf, *user_buf_running, *source_user, *target_user,
-	    *rand_str, *hash_str, *result;
-
-	if (down_interruptible(&dev->sem))
-		return -ERESTARTSYS;
-
-	user_buf_running = NULL;
-	hash_str = NULL;
-	node_ptr = kmalloc(sizeof(struct cap_node), GFP_KERNEL);
-	user_buf = kzalloc(count+1, GFP_KERNEL);
-	if (!node_ptr || !user_buf)
-		goto out;
-
-	if (copy_from_user(user_buf, buf, count)) {
-		retval = -EFAULT;
-		goto out;
-	}
-
-	/*
-	 * If the minor number is 0 ( /dev/caphash ) then simply add the
-	 * hashed capability supplied by the user to the list of hashes
-	 */
-	if (0 == iminor(filp->f_dentry->d_inode)) {
-		if (count > CAP_NODE_SIZE) {
-			retval = -EINVAL;
-			goto out;
-		}
-		printk(KERN_INFO "Capability being written to /dev/caphash : \n");
-		hexdump(user_buf, count);
-		memcpy(node_ptr->data, user_buf, count);
-		list_add(&(node_ptr->list), &(dev->head->list));
-		node_ptr = NULL;
-	} else {
-		char *tmpu;
-		if (!cap_devices[0].head ||
-				list_empty(&(cap_devices[0].head->list))) {
-			retval = -EINVAL;
-			goto out;
-		}
-		/*
-		 * break the supplied string into tokens with @ as the
-		 * delimiter If the string is "user1@user2@randomstring" we
-		 * need to split it and hash 'user1@user2' using 'randomstring'
-		 * as the key.
-		 */
-		tmpu = user_buf_running = kstrdup(user_buf, GFP_KERNEL);
-		source_user = strsep(&tmpu, "@");
-		target_user = strsep(&tmpu, "@");
-		rand_str = tmpu;
-		if (!source_user || !target_user || !rand_str) {
-			retval = -EINVAL;
-			goto out;
-		}
-
-		/* hash the string user1@user2 with rand_str as the key */
-		len = strlen(source_user) + strlen(target_user) + 1;
-		/* src, @, len, \0 */
-		hash_str = kzalloc(len+1, GFP_KERNEL);
-		strcat(hash_str, source_user);
-		strcat(hash_str, "@");
-		strcat(hash_str, target_user);
-
-		printk(KERN_ALERT "the source user is %s \n", source_user);
-		printk(KERN_ALERT "the target user is %s \n", target_user);
-
-		result = cap_hash(hash_str, len, rand_str, strlen(rand_str));
-		if (NULL == result) {
-			retval = -EFAULT;
-			goto out;
-		}
-		memcpy(node_ptr->data, result, CAP_NODE_SIZE);  /* why? */
-		/* Change the process's uid if the hash is present in the
-		 * list of hashes
-		 */
-		list_for_each(pos, &(cap_devices->head->list)) {
-			/*
-			 * Change the user id of the process if the hashes
-			 * match
-			 */
-			if (0 ==
-			    memcmp(result,
-				   list_entry(pos, struct cap_node,
-					      list)->data,
-				   CAP_NODE_SIZE)) {
-				target_int = (unsigned int)
-				    simple_strtol(target_user, NULL, 0);
-				source_int = (unsigned int)
-				    simple_strtol(source_user, NULL, 0);
-				flag = 1;
-
-				/*
-				 * Check whether the process writing to capuse
-				 * is actually owned by the source owner
-				 */
-				if (source_int != current_uid()) {
-					printk(KERN_ALERT
-					       "Process is not owned by the source user of the capability.\n");
-					retval = -EFAULT;
-					goto out;
-				}
-				/*
-				 * What all id's need to be changed here? uid,
-				 * euid, fsid, savedids ??  Currently I am
-				 * changing the effective user id since most of
-				 * the authorisation decisions are based on it
-				 */
-				new = prepare_creds();
-				if (!new) {
-					retval = -ENOMEM;
-					goto out;
-				}
-				new->uid = (uid_t) target_int;
-				new->euid = (uid_t) target_int;
-				retval = commit_creds(new);
-				if (retval)
-					goto out;
-
-				/*
-				 * Remove the capability from the list and
-				 * break
-				 */
-				tmp = list_entry(pos, struct cap_node, list);
-				list_del(pos);
-				kfree(tmp);
-				break;
-			}
-		}
-		if (0 == flag) {
-			/*
-			 * The capability is not present in the list of the
-			 * hashes stored, hence return failure
-			 */
-			printk(KERN_ALERT
-			       "Invalid capabiliy written to /dev/capuse \n");
-			retval = -EFAULT;
-			goto out;
-		}
-	}
-	*f_pos += count;
-	retval = count;
-	/* update the size */
-	if (dev->size < *f_pos)
-		dev->size = *f_pos;
-
-out:
-	kfree(node_ptr);
-	kfree(user_buf);
-	kfree(user_buf_running);
-	kfree(hash_str);
-	up(&dev->sem);
-	return retval;
-}
-
-static const struct file_operations cap_fops = {
-	.owner = THIS_MODULE,
-	.write = cap_write,
-	.open = cap_open,
-	.release = cap_release,
-};
-
-/* no __exit here because it can be called by the init function */
-static void cap_cleanup_module(void)
-{
-	int i;
-	dev_t devno = MKDEV(cap_major, cap_minor);
-	if (cap_devices) {
-		for (i = 0; i < cap_nr_devs; i++) {
-			cap_trim(cap_devices + i);
-			cdev_del(&cap_devices[i].cdev);
-		}
-		kfree(cap_devices);
-	}
-	unregister_chrdev_region(devno, cap_nr_devs);
-
-}
-
-static void cap_setup_cdev(struct cap_dev *dev, int index)
-{
-	int err, devno = MKDEV(cap_major, cap_minor + index);
-	cdev_init(&dev->cdev, &cap_fops);
-	dev->cdev.owner = THIS_MODULE;
-	dev->cdev.ops = &cap_fops;
-	err = cdev_add(&dev->cdev, devno, 1);
-	if (err)
-		printk(KERN_NOTICE "Error %d adding cap%d", err, index);
-}
-
-static int __init cap_init_module(void)
-{
-	int result, i;
-	dev_t dev = 0;
-
-	if (cap_major) {
-		dev = MKDEV(cap_major, cap_minor);
-		result = register_chrdev_region(dev, cap_nr_devs, "cap");
-	} else {
-		result = alloc_chrdev_region(&dev, cap_minor, cap_nr_devs,
-					     "cap");
-		cap_major = MAJOR(dev);
-	}
-
-	if (result < 0) {
-		printk(KERN_WARNING "cap: can't get major %d\n",
-		       cap_major);
-		return result;
-	}
-
-	cap_devices = kzalloc(cap_nr_devs * sizeof(struct cap_dev),
-			      GFP_KERNEL);
-	if (!cap_devices) {
-		result = -ENOMEM;
-		goto fail;
-	}
-
-	/* Initialize each device. */
-	for (i = 0; i < cap_nr_devs; i++) {
-		cap_devices[i].node_size = cap_node_size;
-		init_MUTEX(&cap_devices[i].sem);
-		cap_setup_cdev(&cap_devices[i], i);
-	}
-
-	return 0;
-
-fail:
-	cap_cleanup_module();
-	return result;
-}
-
-module_init(cap_init_module);
-module_exit(cap_cleanup_module);
-
-