summaryrefslogtreecommitdiffstats
path: root/security/selinux/ss/ebitmap.c
diff options
context:
space:
mode:
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;
+}
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-06-04 09:15:12 +0200