Fixed MTP to work with TWRP

security/selinux/ss/ebitmap.c

@@ -0,0 +1,512 @@
+/*
+ * Implementation of the extensible bitmap type.
+ *
+ * Author : Stephen Smalley, <sds@epoch.ncsc.mil>
+ */
+/*
+ * 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)
+
+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 = kzalloc(sizeof(*new), 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;
+
+		if (e_iter == NULL ||
+		    offset >= e_iter->startbit + EBITMAP_SIZE) {
+			e_prev = e_iter;
+			e_iter = kzalloc(sizeof(*e_iter), GFP_ATOMIC);
+			if (e_iter == NULL)
+				goto netlbl_import_failure;
+			e_iter->startbit = offset & ~(EBITMAP_SIZE - 1);
+			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;
+				kfree(n);
+			}
+			return 0;
+		}
+		prev = n;
+		n = n->next;
+	}
+
+	if (!value)
+		return 0;
+
+	new = kzalloc(sizeof(*new), 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;
+		kfree(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) {
+		printk(KERN_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;
+	}
+
+	for (i = 0; i < count; i++) {
+		rc = next_entry(&startbit, fp, sizeof(u32));
+		if (rc < 0) {
+			printk(KERN_ERR "SELinux: ebitmap: truncated map\n");
+			goto bad;
+		}
+		startbit = le32_to_cpu(startbit);
+
+		if (startbit & (mapunit - 1)) {
+			printk(KERN_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) {
+			printk(KERN_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 = kzalloc(sizeof(*tmp), GFP_KERNEL);
+			if (!tmp) {
+				printk(KERN_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) {
+			printk(KERN_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) {
+			printk(KERN_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;
+}