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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /security/selinux/ss/ebitmap.c
downloadlinux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
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!
Diffstat (limited to 'security/selinux/ss/ebitmap.c')
-rw-r--r--security/selinux/ss/ebitmap.c293
1 files changed, 293 insertions, 0 deletions
diff --git a/security/selinux/ss/ebitmap.c b/security/selinux/ss/ebitmap.c
new file mode 100644
index 000000000000..d8ce9cc0b9f1
--- /dev/null
+++ b/security/selinux/ss/ebitmap.c
@@ -0,0 +1,293 @@
+/*
+ * Implementation of the extensible bitmap type.
+ *
+ * Author : Stephen Smalley, <sds@epoch.ncsc.mil>
+ */
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include "ebitmap.h"
+#include "policydb.h"
+
+int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2)
+{
+	struct ebitmap_node *n1, *n2;
+
+	if (e1->highbit != e2->highbit)
+		return 0;
+
+	n1 = e1->node;
+	n2 = e2->node;
+	while (n1 && n2 &&
+	       (n1->startbit == n2->startbit) &&
+	       (n1->map == n2->map)) {
+		n1 = n1->next;
+		n2 = n2->next;
+	}
+
+	if (n1 || n2)
+		return 0;
+
+	return 1;
+}
+
+int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src)
+{
+	struct ebitmap_node *n, *new, *prev;
+
+	ebitmap_init(dst);
+	n = src->node;
+	prev = NULL;
+	while (n) {
+		new = kmalloc(sizeof(*new), GFP_ATOMIC);
+		if (!new) {
+			ebitmap_destroy(dst);
+			return -ENOMEM;
+		}
+		memset(new, 0, sizeof(*new));
+		new->startbit = n->startbit;
+		new->map = n->map;
+		new->next = NULL;
+		if (prev)
+			prev->next = new;
+		else
+			dst->node = new;
+		prev = new;
+		n = n->next;
+	}
+
+	dst->highbit = src->highbit;
+	return 0;
+}
+
+int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2)
+{
+	struct ebitmap_node *n1, *n2;
+
+	if (e1->highbit < e2->highbit)
+		return 0;
+
+	n1 = e1->node;
+	n2 = e2->node;
+	while (n1 && n2 && (n1->startbit <= n2->startbit)) {
+		if (n1->startbit < n2->startbit) {
+			n1 = n1->next;
+			continue;
+		}
+		if ((n1->map & n2->map) != n2->map)
+			return 0;
+
+		n1 = n1->next;
+		n2 = n2->next;
+	}
+
+	if (n2)
+		return 0;
+
+	return 1;
+}
+
+int ebitmap_get_bit(struct ebitmap *e, unsigned long bit)
+{
+	struct ebitmap_node *n;
+
+	if (e->highbit < bit)
+		return 0;
+
+	n = e->node;
+	while (n && (n->startbit <= bit)) {
+		if ((n->startbit + MAPSIZE) > bit) {
+			if (n->map & (MAPBIT << (bit - n->startbit)))
+				return 1;
+			else
+				return 0;
+		}
+		n = n->next;
+	}
+
+	return 0;
+}
+
+int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value)
+{
+	struct ebitmap_node *n, *prev, *new;
+
+	prev = NULL;
+	n = e->node;
+	while (n && n->startbit <= bit) {
+		if ((n->startbit + MAPSIZE) > bit) {
+			if (value) {
+				n->map |= (MAPBIT << (bit - n->startbit));
+			} else {
+				n->map &= ~(MAPBIT << (bit - n->startbit));
+				if (!n->map) {
+					/* drop this node from the bitmap */
+
+					if (!n->next) {
+						/*
+						 * this was the highest map
+						 * within the bitmap
+						 */
+						if (prev)
+							e->highbit = prev->startbit + MAPSIZE;
+						else
+							e->highbit = 0;
+					}
+					if (prev)
+						prev->next = n->next;
+					else
+						e->node = n->next;
+
+					kfree(n);
+				}
+			}
+			return 0;
+		}
+		prev = n;
+		n = n->next;
+	}
+
+	if (!value)
+		return 0;
+
+	new = kmalloc(sizeof(*new), GFP_ATOMIC);
+	if (!new)
+		return -ENOMEM;
+	memset(new, 0, sizeof(*new));
+
+	new->startbit = bit & ~(MAPSIZE - 1);
+	new->map = (MAPBIT << (bit - new->startbit));
+
+	if (!n)
+		/* this node will be the highest map within the bitmap */
+		e->highbit = new->startbit + MAPSIZE;
+
+	if (prev) {
+		new->next = prev->next;
+		prev->next = new;
+	} else {
+		new->next = e->node;
+		e->node = new;
+	}
+
+	return 0;
+}
+
+void ebitmap_destroy(struct ebitmap *e)
+{
+	struct ebitmap_node *n, *temp;
+
+	if (!e)
+		return;
+
+	n = e->node;
+	while (n) {
+		temp = n;
+		n = n->next;
+		kfree(temp);
+	}
+
+	e->highbit = 0;
+	e->node = NULL;
+	return;
+}
+
+int ebitmap_read(struct ebitmap *e, void *fp)
+{
+	int rc;
+	struct ebitmap_node *n, *l;
+	u32 buf[3], mapsize, count, i;
+	u64 map;
+
+	ebitmap_init(e);
+
+	rc = next_entry(buf, fp, sizeof buf);
+	if (rc < 0)
+		goto out;
+
+	mapsize = le32_to_cpu(buf[0]);
+	e->highbit = le32_to_cpu(buf[1]);
+	count = le32_to_cpu(buf[2]);
+
+	if (mapsize != MAPSIZE) {
+		printk(KERN_ERR "security: ebitmap: map size %u does not "
+		       "match my size %Zd (high bit was %d)\n", mapsize,
+		       MAPSIZE, e->highbit);
+		goto bad;
+	}
+	if (!e->highbit) {
+		e->node = NULL;
+		goto ok;
+	}
+	if (e->highbit & (MAPSIZE - 1)) {
+		printk(KERN_ERR "security: ebitmap: high bit (%d) is not a "
+		       "multiple of the map size (%Zd)\n", e->highbit, MAPSIZE);
+		goto bad;
+	}
+	l = NULL;
+	for (i = 0; i < count; i++) {
+		rc = next_entry(buf, fp, sizeof(u32));
+		if (rc < 0) {
+			printk(KERN_ERR "security: ebitmap: truncated map\n");
+			goto bad;
+		}
+		n = kmalloc(sizeof(*n), GFP_KERNEL);
+		if (!n) {
+			printk(KERN_ERR "security: ebitmap: out of memory\n");
+			rc = -ENOMEM;
+			goto bad;
+		}
+		memset(n, 0, sizeof(*n));
+
+		n->startbit = le32_to_cpu(buf[0]);
+
+		if (n->startbit & (MAPSIZE - 1)) {
+			printk(KERN_ERR "security: ebitmap start bit (%d) is "
+			       "not a multiple of the map size (%Zd)\n",
+			       n->startbit, MAPSIZE);
+			goto bad_free;
+		}
+		if (n->startbit > (e->highbit - MAPSIZE)) {
+			printk(KERN_ERR "security: ebitmap start bit (%d) is "
+			       "beyond the end of the bitmap (%Zd)\n",
+			       n->startbit, (e->highbit - MAPSIZE));
+			goto bad_free;
+		}
+		rc = next_entry(&map, fp, sizeof(u64));
+		if (rc < 0) {
+			printk(KERN_ERR "security: ebitmap: truncated map\n");
+			goto bad_free;
+		}
+		n->map = le64_to_cpu(map);
+
+		if (!n->map) {
+			printk(KERN_ERR "security: ebitmap: null map in "
+			       "ebitmap (startbit %d)\n", n->startbit);
+			goto bad_free;
+		}
+		if (l) {
+			if (n->startbit <= l->startbit) {
+				printk(KERN_ERR "security: ebitmap: start "
+				       "bit %d comes after start bit %d\n",
+				       n->startbit, l->startbit);
+				goto bad_free;
+			}
+			l->next = n;
+		} else
+			e->node = n;
+
+		l = n;
+	}
+
+ok:
+	rc = 0;
+out:
+	return rc;
+bad_free:
+	kfree(n);
+bad:
+	if (!rc)
+		rc = -EINVAL;
+	ebitmap_destroy(e);
+	goto out;
+}