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-rw-r--r--security/selinux/ss/ebitmap.c530
1 files changed, 530 insertions, 0 deletions
diff --git a/security/selinux/ss/ebitmap.c b/security/selinux/ss/ebitmap.c
new file mode 100644
index 000000000..8f624f800
--- /dev/null
+++ b/security/selinux/ss/ebitmap.c
@@ -0,0 +1,530 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Implementation of the extensible bitmap type.
+ *
+ * Author : Stephen Smalley, <sds@tycho.nsa.gov>
+ */
+/*
+ * Updated: Hewlett-Packard <paul@paul-moore.com>
+ *
+ * Added support to import/export the NetLabel category bitmap
+ *
+ * (c) Copyright Hewlett-Packard Development Company, L.P., 2006
+ */
+/*
+ * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
+ * Applied standard bit operations to improve bitmap scanning.
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <net/netlabel.h>
+#include "ebitmap.h"
+#include "policydb.h"
+
+#define BITS_PER_U64 (sizeof(u64) * 8)
+
+static struct kmem_cache *ebitmap_node_cachep;
+
+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) &&
+ !memcmp(n1->maps, n2->maps, EBITMAP_SIZE / 8)) {
+ 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 = kmem_cache_zalloc(ebitmap_node_cachep, GFP_ATOMIC);
+ if (!new) {
+ ebitmap_destroy(dst);
+ return -ENOMEM;
+ }
+ new->startbit = n->startbit;
+ memcpy(new->maps, n->maps, EBITMAP_SIZE / 8);
+ new->next = NULL;
+ if (prev)
+ prev->next = new;
+ else
+ dst->node = new;
+ prev = new;
+ n = n->next;
+ }
+
+ dst->highbit = src->highbit;
+ return 0;
+}
+
+#ifdef CONFIG_NETLABEL
+/**
+ * ebitmap_netlbl_export - Export an ebitmap into a NetLabel category bitmap
+ * @ebmap: the ebitmap to export
+ * @catmap: the NetLabel category bitmap
+ *
+ * Description:
+ * Export a SELinux extensibile bitmap into a NetLabel category bitmap.
+ * Returns zero on success, negative values on error.
+ *
+ */
+int ebitmap_netlbl_export(struct ebitmap *ebmap,
+ struct netlbl_lsm_catmap **catmap)
+{
+ struct ebitmap_node *e_iter = ebmap->node;
+ unsigned long e_map;
+ u32 offset;
+ unsigned int iter;
+ int rc;
+
+ if (e_iter == NULL) {
+ *catmap = NULL;
+ return 0;
+ }
+
+ if (*catmap != NULL)
+ netlbl_catmap_free(*catmap);
+ *catmap = NULL;
+
+ while (e_iter) {
+ offset = e_iter->startbit;
+ for (iter = 0; iter < EBITMAP_UNIT_NUMS; iter++) {
+ e_map = e_iter->maps[iter];
+ if (e_map != 0) {
+ rc = netlbl_catmap_setlong(catmap,
+ offset,
+ e_map,
+ GFP_ATOMIC);
+ if (rc != 0)
+ goto netlbl_export_failure;
+ }
+ offset += EBITMAP_UNIT_SIZE;
+ }
+ e_iter = e_iter->next;
+ }
+
+ return 0;
+
+netlbl_export_failure:
+ netlbl_catmap_free(*catmap);
+ return -ENOMEM;
+}
+
+/**
+ * ebitmap_netlbl_import - Import a NetLabel category bitmap into an ebitmap
+ * @ebmap: the ebitmap to import
+ * @catmap: the NetLabel category bitmap
+ *
+ * Description:
+ * Import a NetLabel category bitmap into a SELinux extensibile bitmap.
+ * Returns zero on success, negative values on error.
+ *
+ */
+int ebitmap_netlbl_import(struct ebitmap *ebmap,
+ struct netlbl_lsm_catmap *catmap)
+{
+ int rc;
+ struct ebitmap_node *e_iter = NULL;
+ struct ebitmap_node *e_prev = NULL;
+ u32 offset = 0, idx;
+ unsigned long bitmap;
+
+ for (;;) {
+ rc = netlbl_catmap_getlong(catmap, &offset, &bitmap);
+ if (rc < 0)
+ goto netlbl_import_failure;
+ if (offset == (u32)-1)
+ return 0;
+
+ /* don't waste ebitmap space if the netlabel bitmap is empty */
+ if (bitmap == 0) {
+ offset += EBITMAP_UNIT_SIZE;
+ continue;
+ }
+
+ if (e_iter == NULL ||
+ offset >= e_iter->startbit + EBITMAP_SIZE) {
+ e_prev = e_iter;
+ e_iter = kmem_cache_zalloc(ebitmap_node_cachep, GFP_ATOMIC);
+ if (e_iter == NULL)
+ goto netlbl_import_failure;
+ e_iter->startbit = offset - (offset % EBITMAP_SIZE);
+ if (e_prev == NULL)
+ ebmap->node = e_iter;
+ else
+ e_prev->next = e_iter;
+ ebmap->highbit = e_iter->startbit + EBITMAP_SIZE;
+ }
+
+ /* offset will always be aligned to an unsigned long */
+ idx = EBITMAP_NODE_INDEX(e_iter, offset);
+ e_iter->maps[idx] = bitmap;
+
+ /* next */
+ offset += EBITMAP_UNIT_SIZE;
+ }
+
+ /* NOTE: we should never reach this return */
+ return 0;
+
+netlbl_import_failure:
+ ebitmap_destroy(ebmap);
+ return -ENOMEM;
+}
+#endif /* CONFIG_NETLABEL */
+
+/*
+ * Check to see if all the bits set in e2 are also set in e1. Optionally,
+ * if last_e2bit is non-zero, the highest set bit in e2 cannot exceed
+ * last_e2bit.
+ */
+int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2, u32 last_e2bit)
+{
+ struct ebitmap_node *n1, *n2;
+ int i;
+
+ 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;
+ }
+ for (i = EBITMAP_UNIT_NUMS - 1; (i >= 0) && !n2->maps[i]; )
+ i--; /* Skip trailing NULL map entries */
+ if (last_e2bit && (i >= 0)) {
+ u32 lastsetbit = n2->startbit + i * EBITMAP_UNIT_SIZE +
+ __fls(n2->maps[i]);
+ if (lastsetbit > last_e2bit)
+ return 0;
+ }
+
+ while (i >= 0) {
+ if ((n1->maps[i] & n2->maps[i]) != n2->maps[i])
+ return 0;
+ i--;
+ }
+
+ 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 + EBITMAP_SIZE) > bit)
+ return ebitmap_node_get_bit(n, bit);
+ 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 + EBITMAP_SIZE) > bit) {
+ if (value) {
+ ebitmap_node_set_bit(n, bit);
+ } else {
+ unsigned int s;
+
+ ebitmap_node_clr_bit(n, bit);
+
+ s = find_first_bit(n->maps, EBITMAP_SIZE);
+ if (s < EBITMAP_SIZE)
+ return 0;
+
+ /* drop this node from the bitmap */
+ if (!n->next) {
+ /*
+ * this was the highest map
+ * within the bitmap
+ */
+ if (prev)
+ e->highbit = prev->startbit
+ + EBITMAP_SIZE;
+ else
+ e->highbit = 0;
+ }
+ if (prev)
+ prev->next = n->next;
+ else
+ e->node = n->next;
+ kmem_cache_free(ebitmap_node_cachep, n);
+ }
+ return 0;
+ }
+ prev = n;
+ n = n->next;
+ }
+
+ if (!value)
+ return 0;
+
+ new = kmem_cache_zalloc(ebitmap_node_cachep, GFP_ATOMIC);
+ if (!new)
+ return -ENOMEM;
+
+ new->startbit = bit - (bit % EBITMAP_SIZE);
+ ebitmap_node_set_bit(new, bit);
+
+ if (!n)
+ /* this node will be the highest map within the bitmap */
+ e->highbit = new->startbit + EBITMAP_SIZE;
+
+ 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;
+ kmem_cache_free(ebitmap_node_cachep, temp);
+ }
+
+ e->highbit = 0;
+ e->node = NULL;
+ return;
+}
+
+int ebitmap_read(struct ebitmap *e, void *fp)
+{
+ struct ebitmap_node *n = NULL;
+ u32 mapunit, count, startbit, index;
+ u64 map;
+ __le32 buf[3];
+ int rc, i;
+
+ ebitmap_init(e);
+
+ rc = next_entry(buf, fp, sizeof buf);
+ if (rc < 0)
+ goto out;
+
+ mapunit = le32_to_cpu(buf[0]);
+ e->highbit = le32_to_cpu(buf[1]);
+ count = le32_to_cpu(buf[2]);
+
+ if (mapunit != BITS_PER_U64) {
+ pr_err("SELinux: ebitmap: map size %u does not "
+ "match my size %zd (high bit was %d)\n",
+ mapunit, BITS_PER_U64, e->highbit);
+ goto bad;
+ }
+
+ /* round up e->highbit */
+ e->highbit += EBITMAP_SIZE - 1;
+ e->highbit -= (e->highbit % EBITMAP_SIZE);
+
+ if (!e->highbit) {
+ e->node = NULL;
+ goto ok;
+ }
+
+ if (e->highbit && !count)
+ goto bad;
+
+ for (i = 0; i < count; i++) {
+ rc = next_entry(&startbit, fp, sizeof(u32));
+ if (rc < 0) {
+ pr_err("SELinux: ebitmap: truncated map\n");
+ goto bad;
+ }
+ startbit = le32_to_cpu(startbit);
+
+ if (startbit & (mapunit - 1)) {
+ pr_err("SELinux: ebitmap start bit (%d) is "
+ "not a multiple of the map unit size (%u)\n",
+ startbit, mapunit);
+ goto bad;
+ }
+ if (startbit > e->highbit - mapunit) {
+ pr_err("SELinux: ebitmap start bit (%d) is "
+ "beyond the end of the bitmap (%u)\n",
+ startbit, (e->highbit - mapunit));
+ goto bad;
+ }
+
+ if (!n || startbit >= n->startbit + EBITMAP_SIZE) {
+ struct ebitmap_node *tmp;
+ tmp = kmem_cache_zalloc(ebitmap_node_cachep, GFP_KERNEL);
+ if (!tmp) {
+ pr_err("SELinux: ebitmap: out of memory\n");
+ rc = -ENOMEM;
+ goto bad;
+ }
+ /* round down */
+ tmp->startbit = startbit - (startbit % EBITMAP_SIZE);
+ if (n)
+ n->next = tmp;
+ else
+ e->node = tmp;
+ n = tmp;
+ } else if (startbit <= n->startbit) {
+ pr_err("SELinux: ebitmap: start bit %d"
+ " comes after start bit %d\n",
+ startbit, n->startbit);
+ goto bad;
+ }
+
+ rc = next_entry(&map, fp, sizeof(u64));
+ if (rc < 0) {
+ pr_err("SELinux: ebitmap: truncated map\n");
+ goto bad;
+ }
+ map = le64_to_cpu(map);
+
+ index = (startbit - n->startbit) / EBITMAP_UNIT_SIZE;
+ while (map) {
+ n->maps[index++] = map & (-1UL);
+ map = EBITMAP_SHIFT_UNIT_SIZE(map);
+ }
+ }
+ok:
+ rc = 0;
+out:
+ return rc;
+bad:
+ if (!rc)
+ rc = -EINVAL;
+ ebitmap_destroy(e);
+ goto out;
+}
+
+int ebitmap_write(struct ebitmap *e, void *fp)
+{
+ struct ebitmap_node *n;
+ u32 count;
+ __le32 buf[3];
+ u64 map;
+ int bit, last_bit, last_startbit, rc;
+
+ buf[0] = cpu_to_le32(BITS_PER_U64);
+
+ count = 0;
+ last_bit = 0;
+ last_startbit = -1;
+ ebitmap_for_each_positive_bit(e, n, bit) {
+ if (rounddown(bit, (int)BITS_PER_U64) > last_startbit) {
+ count++;
+ last_startbit = rounddown(bit, BITS_PER_U64);
+ }
+ last_bit = roundup(bit + 1, BITS_PER_U64);
+ }
+ buf[1] = cpu_to_le32(last_bit);
+ buf[2] = cpu_to_le32(count);
+
+ rc = put_entry(buf, sizeof(u32), 3, fp);
+ if (rc)
+ return rc;
+
+ map = 0;
+ last_startbit = INT_MIN;
+ ebitmap_for_each_positive_bit(e, n, bit) {
+ if (rounddown(bit, (int)BITS_PER_U64) > last_startbit) {
+ __le64 buf64[1];
+
+ /* this is the very first bit */
+ if (!map) {
+ last_startbit = rounddown(bit, BITS_PER_U64);
+ map = (u64)1 << (bit - last_startbit);
+ continue;
+ }
+
+ /* write the last node */
+ buf[0] = cpu_to_le32(last_startbit);
+ rc = put_entry(buf, sizeof(u32), 1, fp);
+ if (rc)
+ return rc;
+
+ buf64[0] = cpu_to_le64(map);
+ rc = put_entry(buf64, sizeof(u64), 1, fp);
+ if (rc)
+ return rc;
+
+ /* set up for the next node */
+ map = 0;
+ last_startbit = rounddown(bit, BITS_PER_U64);
+ }
+ map |= (u64)1 << (bit - last_startbit);
+ }
+ /* write the last node */
+ if (map) {
+ __le64 buf64[1];
+
+ /* write the last node */
+ buf[0] = cpu_to_le32(last_startbit);
+ rc = put_entry(buf, sizeof(u32), 1, fp);
+ if (rc)
+ return rc;
+
+ buf64[0] = cpu_to_le64(map);
+ rc = put_entry(buf64, sizeof(u64), 1, fp);
+ if (rc)
+ return rc;
+ }
+ return 0;
+}
+
+void __init ebitmap_cache_init(void)
+{
+ ebitmap_node_cachep = kmem_cache_create("ebitmap_node",
+ sizeof(struct ebitmap_node),
+ 0, SLAB_PANIC, NULL);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-22 16:44:18 +0000