Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 381 insertions, 0 deletions

diff --git a/fs/posix_acl.c b/fs/posix_acl.c
new file mode 100644
index 000000000000..296480e96dd5
--- /dev/null
+++ b/fs/posix_acl.c
@@ -0,0 +1,381 @@
+/*
+ * linux/fs/posix_acl.c
+ *
+ *  Copyright (C) 2002 by Andreas Gruenbacher <a.gruenbacher@computer.org>
+ *
+ *  Fixes from William Schumacher incorporated on 15 March 2001.
+ *     (Reported by Charles Bertsch, <CBertsch@microtest.com>).
+ */
+
+/*
+ *  This file contains generic functions for manipulating
+ *  POSIX 1003.1e draft standard 17 ACLs.
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <asm/atomic.h>
+#include <linux/fs.h>
+#include <linux/sched.h>
+#include <linux/posix_acl.h>
+#include <linux/module.h>
+
+#include <linux/errno.h>
+
+EXPORT_SYMBOL(posix_acl_alloc);
+EXPORT_SYMBOL(posix_acl_clone);
+EXPORT_SYMBOL(posix_acl_valid);
+EXPORT_SYMBOL(posix_acl_equiv_mode);
+EXPORT_SYMBOL(posix_acl_from_mode);
+EXPORT_SYMBOL(posix_acl_create_masq);
+EXPORT_SYMBOL(posix_acl_chmod_masq);
+EXPORT_SYMBOL(posix_acl_permission);
+
+/*
+ * Allocate a new ACL with the specified number of entries.
+ */
+struct posix_acl *
+posix_acl_alloc(int count, unsigned int __nocast flags)
+{
+	const size_t size = sizeof(struct posix_acl) +
+	                    count * sizeof(struct posix_acl_entry);
+	struct posix_acl *acl = kmalloc(size, flags);
+	if (acl) {
+		atomic_set(&acl->a_refcount, 1);
+		acl->a_count = count;
+	}
+	return acl;
+}
+
+/*
+ * Clone an ACL.
+ */
+struct posix_acl *
+posix_acl_clone(const struct posix_acl *acl, unsigned int __nocast flags)
+{
+	struct posix_acl *clone = NULL;
+
+	if (acl) {
+		int size = sizeof(struct posix_acl) + acl->a_count *
+		           sizeof(struct posix_acl_entry);
+		clone = kmalloc(size, flags);
+		if (clone) {
+			memcpy(clone, acl, size);
+			atomic_set(&clone->a_refcount, 1);
+		}
+	}
+	return clone;
+}
+
+/*
+ * Check if an acl is valid. Returns 0 if it is, or -E... otherwise.
+ */
+int
+posix_acl_valid(const struct posix_acl *acl)
+{
+	const struct posix_acl_entry *pa, *pe;
+	int state = ACL_USER_OBJ;
+	unsigned int id = 0;  /* keep gcc happy */
+	int needs_mask = 0;
+
+	FOREACH_ACL_ENTRY(pa, acl, pe) {
+		if (pa->e_perm & ~(ACL_READ|ACL_WRITE|ACL_EXECUTE))
+			return -EINVAL;
+		switch (pa->e_tag) {
+			case ACL_USER_OBJ:
+				if (state == ACL_USER_OBJ) {
+					id = 0;
+					state = ACL_USER;
+					break;
+				}
+				return -EINVAL;
+
+			case ACL_USER:
+				if (state != ACL_USER)
+					return -EINVAL;
+				if (pa->e_id == ACL_UNDEFINED_ID ||
+				    pa->e_id < id)
+					return -EINVAL;
+				id = pa->e_id + 1;
+				needs_mask = 1;
+				break;
+
+			case ACL_GROUP_OBJ:
+				if (state == ACL_USER) {
+					id = 0;
+					state = ACL_GROUP;
+					break;
+				}
+				return -EINVAL;
+
+			case ACL_GROUP:
+				if (state != ACL_GROUP)
+					return -EINVAL;
+				if (pa->e_id == ACL_UNDEFINED_ID ||
+				    pa->e_id < id)
+					return -EINVAL;
+				id = pa->e_id + 1;
+				needs_mask = 1;
+				break;
+
+			case ACL_MASK:
+				if (state != ACL_GROUP)
+					return -EINVAL;
+				state = ACL_OTHER;
+				break;
+
+			case ACL_OTHER:
+				if (state == ACL_OTHER ||
+				    (state == ACL_GROUP && !needs_mask)) {
+					state = 0;
+					break;
+				}
+				return -EINVAL;
+
+			default:
+				return -EINVAL;
+		}
+	}
+	if (state == 0)
+		return 0;
+	return -EINVAL;
+}
+
+/*
+ * Returns 0 if the acl can be exactly represented in the traditional
+ * file mode permission bits, or else 1. Returns -E... on error.
+ */
+int
+posix_acl_equiv_mode(const struct posix_acl *acl, mode_t *mode_p)
+{
+	const struct posix_acl_entry *pa, *pe;
+	mode_t mode = 0;
+	int not_equiv = 0;
+
+	FOREACH_ACL_ENTRY(pa, acl, pe) {
+		switch (pa->e_tag) {
+			case ACL_USER_OBJ:
+				mode |= (pa->e_perm & S_IRWXO) << 6;
+				break;
+			case ACL_GROUP_OBJ:
+				mode |= (pa->e_perm & S_IRWXO) << 3;
+				break;
+			case ACL_OTHER:
+				mode |= pa->e_perm & S_IRWXO;
+				break;
+			case ACL_MASK:
+				mode = (mode & ~S_IRWXG) |
+				       ((pa->e_perm & S_IRWXO) << 3);
+				not_equiv = 1;
+				break;
+			case ACL_USER:
+			case ACL_GROUP:
+				not_equiv = 1;
+				break;
+			default:
+				return -EINVAL;
+		}
+	}
+        if (mode_p)
+                *mode_p = (*mode_p & ~S_IRWXUGO) | mode;
+        return not_equiv;
+}
+
+/*
+ * Create an ACL representing the file mode permission bits of an inode.
+ */
+struct posix_acl *
+posix_acl_from_mode(mode_t mode, unsigned int __nocast flags)
+{
+	struct posix_acl *acl = posix_acl_alloc(3, flags);
+	if (!acl)
+		return ERR_PTR(-ENOMEM);
+
+	acl->a_entries[0].e_tag  = ACL_USER_OBJ;
+	acl->a_entries[0].e_id   = ACL_UNDEFINED_ID;
+	acl->a_entries[0].e_perm = (mode & S_IRWXU) >> 6;
+
+	acl->a_entries[1].e_tag  = ACL_GROUP_OBJ;
+	acl->a_entries[1].e_id   = ACL_UNDEFINED_ID;
+	acl->a_entries[1].e_perm = (mode & S_IRWXG) >> 3;
+
+	acl->a_entries[2].e_tag  = ACL_OTHER;
+	acl->a_entries[2].e_id   = ACL_UNDEFINED_ID;
+	acl->a_entries[2].e_perm = (mode & S_IRWXO);
+	return acl;
+}
+
+/*
+ * Return 0 if current is granted want access to the inode
+ * by the acl. Returns -E... otherwise.
+ */
+int
+posix_acl_permission(struct inode *inode, const struct posix_acl *acl, int want)
+{
+	const struct posix_acl_entry *pa, *pe, *mask_obj;
+	int found = 0;
+
+	FOREACH_ACL_ENTRY(pa, acl, pe) {
+                switch(pa->e_tag) {
+                        case ACL_USER_OBJ:
+				/* (May have been checked already) */
+                                if (inode->i_uid == current->fsuid)
+                                        goto check_perm;
+                                break;
+                        case ACL_USER:
+                                if (pa->e_id == current->fsuid)
+                                        goto mask;
+				break;
+                        case ACL_GROUP_OBJ:
+                                if (in_group_p(inode->i_gid)) {
+					found = 1;
+					if ((pa->e_perm & want) == want)
+						goto mask;
+                                }
+				break;
+                        case ACL_GROUP:
+                                if (in_group_p(pa->e_id)) {
+					found = 1;
+					if ((pa->e_perm & want) == want)
+						goto mask;
+                                }
+                                break;
+                        case ACL_MASK:
+                                break;
+                        case ACL_OTHER:
+				if (found)
+					return -EACCES;
+				else
+					goto check_perm;
+			default:
+				return -EIO;
+                }
+        }
+	return -EIO;
+
+mask:
+	for (mask_obj = pa+1; mask_obj != pe; mask_obj++) {
+		if (mask_obj->e_tag == ACL_MASK) {
+			if ((pa->e_perm & mask_obj->e_perm & want) == want)
+				return 0;
+			return -EACCES;
+		}
+	}
+
+check_perm:
+	if ((pa->e_perm & want) == want)
+		return 0;
+	return -EACCES;
+}
+
+/*
+ * Modify acl when creating a new inode. The caller must ensure the acl is
+ * only referenced once.
+ *
+ * mode_p initially must contain the mode parameter to the open() / creat()
+ * system calls. All permissions that are not granted by the acl are removed.
+ * The permissions in the acl are changed to reflect the mode_p parameter.
+ */
+int
+posix_acl_create_masq(struct posix_acl *acl, mode_t *mode_p)
+{
+	struct posix_acl_entry *pa, *pe;
+	struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL;
+	mode_t mode = *mode_p;
+	int not_equiv = 0;
+
+	/* assert(atomic_read(acl->a_refcount) == 1); */
+
+	FOREACH_ACL_ENTRY(pa, acl, pe) {
+                switch(pa->e_tag) {
+                        case ACL_USER_OBJ:
+				pa->e_perm &= (mode >> 6) | ~S_IRWXO;
+				mode &= (pa->e_perm << 6) | ~S_IRWXU;
+				break;
+
+			case ACL_USER:
+			case ACL_GROUP:
+				not_equiv = 1;
+				break;
+
+                        case ACL_GROUP_OBJ:
+				group_obj = pa;
+                                break;
+
+                        case ACL_OTHER:
+				pa->e_perm &= mode | ~S_IRWXO;
+				mode &= pa->e_perm | ~S_IRWXO;
+                                break;
+
+                        case ACL_MASK:
+				mask_obj = pa;
+				not_equiv = 1;
+                                break;
+
+			default:
+				return -EIO;
+                }
+        }
+
+	if (mask_obj) {
+		mask_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
+		mode &= (mask_obj->e_perm << 3) | ~S_IRWXG;
+	} else {
+		if (!group_obj)
+			return -EIO;
+		group_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
+		mode &= (group_obj->e_perm << 3) | ~S_IRWXG;
+	}
+
+	*mode_p = (*mode_p & ~S_IRWXUGO) | mode;
+        return not_equiv;
+}
+
+/*
+ * Modify the ACL for the chmod syscall.
+ */
+int
+posix_acl_chmod_masq(struct posix_acl *acl, mode_t mode)
+{
+	struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL;
+	struct posix_acl_entry *pa, *pe;
+
+	/* assert(atomic_read(acl->a_refcount) == 1); */
+
+	FOREACH_ACL_ENTRY(pa, acl, pe) {
+		switch(pa->e_tag) {
+			case ACL_USER_OBJ:
+				pa->e_perm = (mode & S_IRWXU) >> 6;
+				break;
+
+			case ACL_USER:
+			case ACL_GROUP:
+				break;
+
+			case ACL_GROUP_OBJ:
+				group_obj = pa;
+				break;
+
+			case ACL_MASK:
+				mask_obj = pa;
+				break;
+
+			case ACL_OTHER:
+				pa->e_perm = (mode & S_IRWXO);
+				break;
+
+			default:
+				return -EIO;
+		}
+	}
+
+	if (mask_obj) {
+		mask_obj->e_perm = (mode & S_IRWXG) >> 3;
+	} else {
+		if (!group_obj)
+			return -EIO;
+		group_obj->e_perm = (mode & S_IRWXG) >> 3;
+	}
+
+	return 0;
+}