/* * 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_or(struct ebitmap *dst, struct ebitmap *e1, struct ebitmap *e2){	struct ebitmap_node *n1, *n2, *new, *prev;	ebitmap_init(dst);	n1 = e1->node;	n2 = e2->node;	prev = NULL;	while (n1 || n2) {		new = kmalloc(sizeof(*new), GFP_ATOMIC);		if (!new) {			ebitmap_destroy(dst);			return -ENOMEM;		}		memset(new, 0, sizeof(*new));		if (n1 && n2 && n1->startbit == n2->startbit) {			new->startbit = n1->startbit;			new->map = n1->map | n2->map;			n1 = n1->next;			n2 = n2->next;		} else if (!n2 || (n1 && n1->startbit < n2->startbit)) {			new->startbit = n1->startbit;			new->map = n1->map;			n1 = n1->next;		} else {			new->startbit = n2->startbit;			new->map = n2->map;			n2 = n2->next;		}		new->next = NULL;		if (prev)			prev->next = new;		else			dst->node = new;		prev = new;	}	dst->highbit = (e1->highbit > e2->highbit) ? e1->highbit : e2->highbit;	return 0;}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 = -EINVAL;	struct ebitmap_node *n, *l;	u32 *buf, mapsize, count, i;	u64 map;	ebitmap_init(e);	buf = next_entry(fp, sizeof(u32)*3);	if (!buf)		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 out;	}	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++) {		buf = next_entry(fp, sizeof(u32));		if (!buf) {			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;		}		buf = next_entry(fp, sizeof(u64));		if (!buf) {			printk(KERN_ERR "security: ebitmap: truncated map\n");			goto bad_free;		}		memcpy(&map, buf, sizeof(u64));		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:	ebitmap_destroy(e);	goto out;}