policydb.c

linux 内核源代码

	}

	rc = next_entry(buf, fp, sizeof buf);
	if (rc < 0)
		goto bad;

	len = le32_to_cpu(buf[0]);
	usrdatum->value = le32_to_cpu(buf[1]);

	key = kmalloc(len + 1,GFP_KERNEL);
	if (!key) {
		rc = -ENOMEM;
		goto bad;
	}
	rc = next_entry(key, fp, len);
	if (rc < 0)
		goto bad;
	key[len] = 0;

	rc = ebitmap_read(&usrdatum->roles, fp);
	if (rc)
		goto bad;

	if (p->policyvers >= POLICYDB_VERSION_MLS) {
		rc = mls_read_range_helper(&usrdatum->range, fp);
		if (rc)
			goto bad;
		rc = mls_read_level(&usrdatum->dfltlevel, fp);
		if (rc)
			goto bad;
	}

	rc = hashtab_insert(h, key, usrdatum);
	if (rc)
		goto bad;
out:
	return rc;
bad:
	user_destroy(key, usrdatum, NULL);
	goto out;
}

static int sens_read(struct policydb *p, struct hashtab *h, void *fp)
{
	char *key = NULL;
	struct level_datum *levdatum;
	int rc;
	__le32 buf[2];
	u32 len;

	levdatum = kzalloc(sizeof(*levdatum), GFP_ATOMIC);
	if (!levdatum) {
		rc = -ENOMEM;
		goto out;
	}

	rc = next_entry(buf, fp, sizeof buf);
	if (rc < 0)
		goto bad;

	len = le32_to_cpu(buf[0]);
	levdatum->isalias = le32_to_cpu(buf[1]);

	key = kmalloc(len + 1,GFP_ATOMIC);
	if (!key) {
		rc = -ENOMEM;
		goto bad;
	}
	rc = next_entry(key, fp, len);
	if (rc < 0)
		goto bad;
	key[len] = 0;

	levdatum->level = kmalloc(sizeof(struct mls_level), GFP_ATOMIC);
	if (!levdatum->level) {
		rc = -ENOMEM;
		goto bad;
	}
	if (mls_read_level(levdatum->level, fp)) {
		rc = -EINVAL;
		goto bad;
	}

	rc = hashtab_insert(h, key, levdatum);
	if (rc)
		goto bad;
out:
	return rc;
bad:
	sens_destroy(key, levdatum, NULL);
	goto out;
}

static int cat_read(struct policydb *p, struct hashtab *h, void *fp)
{
	char *key = NULL;
	struct cat_datum *catdatum;
	int rc;
	__le32 buf[3];
	u32 len;

	catdatum = kzalloc(sizeof(*catdatum), GFP_ATOMIC);
	if (!catdatum) {
		rc = -ENOMEM;
		goto out;
	}

	rc = next_entry(buf, fp, sizeof buf);
	if (rc < 0)
		goto bad;

	len = le32_to_cpu(buf[0]);
	catdatum->value = le32_to_cpu(buf[1]);
	catdatum->isalias = le32_to_cpu(buf[2]);

	key = kmalloc(len + 1,GFP_ATOMIC);
	if (!key) {
		rc = -ENOMEM;
		goto bad;
	}
	rc = next_entry(key, fp, len);
	if (rc < 0)
		goto bad;
	key[len] = 0;

	rc = hashtab_insert(h, key, catdatum);
	if (rc)
		goto bad;
out:
	return rc;

bad:
	cat_destroy(key, catdatum, NULL);
	goto out;
}

static int (*read_f[SYM_NUM]) (struct policydb *p, struct hashtab *h, void *fp) =
{
	common_read,
	class_read,
	role_read,
	type_read,
	user_read,
	cond_read_bool,
	sens_read,
	cat_read,
};

extern int ss_initialized;

/*
 * Read the configuration data from a policy database binary
 * representation file into a policy database structure.
 */
int policydb_read(struct policydb *p, void *fp)
{
	struct role_allow *ra, *lra;
	struct role_trans *tr, *ltr;
	struct ocontext *l, *c, *newc;
	struct genfs *genfs_p, *genfs, *newgenfs;
	int i, j, rc;
	__le32 buf[8];
	u32 len, len2, config, nprim, nel, nel2;
	char *policydb_str;
	struct policydb_compat_info *info;
	struct range_trans *rt, *lrt;

	config = 0;

	rc = policydb_init(p);
	if (rc)
		goto out;

	/* Read the magic number and string length. */
	rc = next_entry(buf, fp, sizeof(u32)* 2);
	if (rc < 0)
		goto bad;

	if (le32_to_cpu(buf[0]) != POLICYDB_MAGIC) {
		printk(KERN_ERR "security:  policydb magic number 0x%x does "
		       "not match expected magic number 0x%x\n",
		       le32_to_cpu(buf[0]), POLICYDB_MAGIC);
		goto bad;
	}

	len = le32_to_cpu(buf[1]);
	if (len != strlen(POLICYDB_STRING)) {
		printk(KERN_ERR "security:  policydb string length %d does not "
		       "match expected length %Zu\n",
		       len, strlen(POLICYDB_STRING));
		goto bad;
	}
	policydb_str = kmalloc(len + 1,GFP_KERNEL);
	if (!policydb_str) {
		printk(KERN_ERR "security:  unable to allocate memory for policydb "
		       "string of length %d\n", len);
		rc = -ENOMEM;
		goto bad;
	}
	rc = next_entry(policydb_str, fp, len);
	if (rc < 0) {
		printk(KERN_ERR "security:  truncated policydb string identifier\n");
		kfree(policydb_str);
		goto bad;
	}
	policydb_str[len] = 0;
	if (strcmp(policydb_str, POLICYDB_STRING)) {
		printk(KERN_ERR "security:  policydb string %s does not match "
		       "my string %s\n", policydb_str, POLICYDB_STRING);
		kfree(policydb_str);
		goto bad;
	}
	/* Done with policydb_str. */
	kfree(policydb_str);
	policydb_str = NULL;

	/* Read the version, config, and table sizes. */
	rc = next_entry(buf, fp, sizeof(u32)*4);
	if (rc < 0)
		goto bad;

	p->policyvers = le32_to_cpu(buf[0]);
	if (p->policyvers < POLICYDB_VERSION_MIN ||
	    p->policyvers > POLICYDB_VERSION_MAX) {
	    	printk(KERN_ERR "security:  policydb version %d does not match "
	    	       "my version range %d-%d\n",
	    	       le32_to_cpu(buf[0]), POLICYDB_VERSION_MIN, POLICYDB_VERSION_MAX);
	    	goto bad;
	}

	if ((le32_to_cpu(buf[1]) & POLICYDB_CONFIG_MLS)) {
		if (ss_initialized && !selinux_mls_enabled) {
			printk(KERN_ERR "Cannot switch between non-MLS and MLS "
			       "policies\n");
			goto bad;
		}
		selinux_mls_enabled = 1;
		config |= POLICYDB_CONFIG_MLS;

		if (p->policyvers < POLICYDB_VERSION_MLS) {
			printk(KERN_ERR "security policydb version %d (MLS) "
			       "not backwards compatible\n", p->policyvers);
			goto bad;
		}
	} else {
		if (ss_initialized && selinux_mls_enabled) {
			printk(KERN_ERR "Cannot switch between MLS and non-MLS "
			       "policies\n");
			goto bad;
		}
	}
	p->reject_unknown = !!(le32_to_cpu(buf[1]) & REJECT_UNKNOWN);
	p->allow_unknown = !!(le32_to_cpu(buf[1]) & ALLOW_UNKNOWN);

	info = policydb_lookup_compat(p->policyvers);
	if (!info) {
		printk(KERN_ERR "security:  unable to find policy compat info "
		       "for version %d\n", p->policyvers);
		goto bad;
	}

	if (le32_to_cpu(buf[2]) != info->sym_num ||
		le32_to_cpu(buf[3]) != info->ocon_num) {
		printk(KERN_ERR "security:  policydb table sizes (%d,%d) do "
		       "not match mine (%d,%d)\n", le32_to_cpu(buf[2]),
			le32_to_cpu(buf[3]),
		       info->sym_num, info->ocon_num);
		goto bad;
	}

	for (i = 0; i < info->sym_num; i++) {
		rc = next_entry(buf, fp, sizeof(u32)*2);
		if (rc < 0)
			goto bad;
		nprim = le32_to_cpu(buf[0]);
		nel = le32_to_cpu(buf[1]);
		for (j = 0; j < nel; j++) {
			rc = read_f[i](p, p->symtab[i].table, fp);
			if (rc)
				goto bad;
		}

		p->symtab[i].nprim = nprim;
	}

	rc = avtab_read(&p->te_avtab, fp, p);
	if (rc)
		goto bad;

	if (p->policyvers >= POLICYDB_VERSION_BOOL) {
		rc = cond_read_list(p, fp);
		if (rc)
			goto bad;
	}

	rc = next_entry(buf, fp, sizeof(u32));
	if (rc < 0)
		goto bad;
	nel = le32_to_cpu(buf[0]);
	ltr = NULL;
	for (i = 0; i < nel; i++) {
		tr = kzalloc(sizeof(*tr), GFP_KERNEL);
		if (!tr) {
			rc = -ENOMEM;
			goto bad;
		}
		if (ltr) {
			ltr->next = tr;
		} else {
			p->role_tr = tr;
		}
		rc = next_entry(buf, fp, sizeof(u32)*3);
		if (rc < 0)
			goto bad;
		tr->role = le32_to_cpu(buf[0]);
		tr->type = le32_to_cpu(buf[1]);
		tr->new_role = le32_to_cpu(buf[2]);
		if (!policydb_role_isvalid(p, tr->role) ||
		    !policydb_type_isvalid(p, tr->type) ||
		    !policydb_role_isvalid(p, tr->new_role)) {
			rc = -EINVAL;
			goto bad;
		}
		ltr = tr;
	}

	rc = next_entry(buf, fp, sizeof(u32));
	if (rc < 0)
		goto bad;
	nel = le32_to_cpu(buf[0]);
	lra = NULL;
	for (i = 0; i < nel; i++) {
		ra = kzalloc(sizeof(*ra), GFP_KERNEL);
		if (!ra) {
			rc = -ENOMEM;
			goto bad;
		}
		if (lra) {
			lra->next = ra;
		} else {
			p->role_allow = ra;
		}
		rc = next_entry(buf, fp, sizeof(u32)*2);
		if (rc < 0)
			goto bad;
		ra->role = le32_to_cpu(buf[0]);
		ra->new_role = le32_to_cpu(buf[1]);
		if (!policydb_role_isvalid(p, ra->role) ||
		    !policydb_role_isvalid(p, ra->new_role)) {
			rc = -EINVAL;
			goto bad;
		}
		lra = ra;
	}

	rc = policydb_index_classes(p);
	if (rc)
		goto bad;

	rc = policydb_index_others(p);
	if (rc)
		goto bad;

	for (i = 0; i < info->ocon_num; i++) {
		rc = next_entry(buf, fp, sizeof(u32));
		if (rc < 0)
			goto bad;
		nel = le32_to_cpu(buf[0]);
		l = NULL;
		for (j = 0; j < nel; j++) {
			c = kzalloc(sizeof(*c), GFP_KERNEL);
			if (!c) {
				rc = -ENOMEM;
				goto bad;
			}
			if (l) {
				l->next = c;
			} else {
				p->ocontexts[i] = c;
			}
			l = c;
			rc = -EINVAL;
			switch (i) {
			case OCON_ISID:
				rc = next_entry(buf, fp, sizeof(u32));
				if (rc < 0)
					goto bad;
				c->sid[0] = le32_to_cpu(buf[0]);
				rc = context_read_and_validate(&c->context[0], p, fp);
				if (rc)
					goto bad;
				break;
			case OCON_FS:
			case OCON_NETIF:
				rc = next_entry(buf, fp, sizeof(u32));
				if (rc < 0)
					goto bad;
				len = le32_to_cpu(buf[0]);
				c->u.name = kmalloc(len + 1,GFP_KERNEL);
				if (!c->u.name) {
					rc = -ENOMEM;
					goto bad;
				}
				rc = next_entry(c->u.name, fp, len);
				if (rc < 0)
					goto bad;
				c->u.name[len] = 0;
				rc = context_read_and_validate(&c->context[0], p, fp);
				if (rc)
					goto bad;
				rc = context_read_and_validate(&c->context[1], p, fp);
				if (rc)
					goto bad;
				break;
			case OCON_PORT:
				rc = next_entry(buf, fp, sizeof(u32)*3);
				if (rc < 0)
					goto bad;
				c->u.port.protocol = le32_to_cpu(buf[0]);
				c->u.port.low_port = le32_to_cpu(buf[1]);
				c->u.port.high_port = le32_to_cpu(buf[2]);
				rc = context_read_and_validate(&c->context[0], p, fp);
				if (rc)
					goto bad;
				break;
			case OCON_NODE:
				rc = next_entry(buf, fp, sizeof(u32)* 2);
				if (rc < 0)
					goto bad;
				c->u.node.addr = le32_to_cpu(buf[0]);
				c->u.node.mask = le32_to_cpu(buf[1]);
				rc = context_read_and_validate(&c->context[0], p, fp);
				if (rc)
					goto bad;
				break;
			case OCON_FSUSE:
				rc = next_entry(buf, fp, sizeof(u32)*2);
				if (rc < 0)
					goto bad;
				c->v.behavior = le32_to_cpu(buf[0]);
				if (c->v.behavior > SECURITY_FS_USE_NONE)
					goto bad;
				len = le32_to_cpu(buf[1]);
				c->u.name = kmalloc(len + 1,GFP_KERNEL);
				if (!c->u.name) {
					rc = -ENOMEM;
					goto bad;
				}
				rc = next_entry(c->u.name, fp, len);
				if (rc < 0)
					goto bad;
				c->u.name[len] = 0;
				rc = context_read_and_validate(&c->context[0], p, fp);
				if (rc)
					goto bad;
				break;
			case OCON_NODE6: {
				int k;

				rc = next_entry(buf, fp, sizeof(u32) * 8);
				if (rc < 0)
					goto bad;
				for (k = 0; k < 4; k++)
					c->u.node6.addr[k] = le32_to_cpu(buf[k]);
				for (k = 0; k < 4; k++)
					c->u.node6.mask[k] = le32_to_cpu(buf[k+4]);
				if (context_read_and_validate(&c->context[0], p, fp))
					goto bad;
				break;
			}
			}
		}
	}

	rc = next_entry(buf, fp, sizeof(u32));
	if (rc < 0)
		goto bad;
	nel = le32_to_cpu(buf[0]);
	genfs_p = NULL;
	rc = -EINVAL;
	for (i = 0; i < nel; i++) {
		rc = next_entry(buf, fp, sizeof(u32));
		if (rc < 0)
			goto bad;
		len = le32_to_cpu(buf[0]);
		newgenfs = kzalloc(sizeof(*newgenfs), GFP_KERNEL);
		if (!newgenfs) {
			rc = -ENOMEM;
			goto bad;
		}

		newgenfs->fstype = kmalloc(len + 1,GFP_KERNEL);
		if (!newgenfs->fstype) {
			rc = -ENOMEM;
			kfree(newgenfs);
			goto bad;
		}
		rc = next_entry(newgenfs->fstype, fp, len);
		if (rc < 0) {
			kfree(newgenfs->fstype);
			kfree(newgenfs);
			goto bad;
		}
		newgenfs->fstype[len] = 0;
		for (genfs_p = NULL, genfs = p->genfs; genfs;
		     genfs_p = genfs, genfs = genfs->next) {
			if (strcmp(newgenfs->fstype, genfs->fstype) == 0) {
				printk(KERN_ERR "security:  dup genfs "
				       "fstype %s\n", newgenfs->fstype);
				kfree(newgenfs->fstype);
				kfree(newgenfs);
				goto bad;
			}
			if (strcmp(newgenfs->fstype, genfs->fstype) < 0)
				break;
		}
		newgenfs->next = genfs;
		if (genfs_p)
			genfs_p->next = newgenfs;
		else
			p->genfs = newgenfs;
		rc = next_entry(buf, fp, sizeof(u32));
		if (rc < 0)
			goto bad;
		nel2 = le32_to_cpu(buf[0]);
		for (j = 0; j < nel2; j++) {
			rc = next_entry(buf, fp, sizeof(u32));
			if (rc < 0)
				goto bad;
			len = le32_to_cpu(buf[0]);

			newc = kzalloc(sizeof(*newc), GFP_KERNEL);
			if (!newc) {
				rc = -ENOMEM;
				goto bad;
			}

			newc->u.name = kmalloc(len + 1,GFP_KERNEL);
			if (!newc->u.name) {
				rc = -ENOMEM;
				goto bad_newc;
			}
			rc = next_entry(newc->u.name, fp, len);
			if (rc < 0)
				goto bad_newc;
			newc->u.name[len] = 0;
			rc = next_entry(buf, fp, sizeof(u32));
			if (rc < 0)
				goto bad_newc;
			newc->v.sclass = le32_to_cpu(buf[0]);
			if (context_read_and_validate(&newc->context[0], p, fp))
				goto bad_newc;
			for (l = NULL, c = newgenfs->head; c;
			     l = c, c = c->next) {
				if (!strcmp(newc->u.name, c->u.name) &&
				    (!c->v.sclass || !newc->v.sclass ||
				     newc->v.sclass == c->v.sclass)) {
					printk(KERN_ERR "security:  dup genfs "
					       "entry (%s,%s)\n",
					       newgenfs->fstype, c->u.name);
					goto bad_newc;
				}
				len = strlen(newc->u.name);
				len2 = strlen(c->u.name);
				if (len > len2)
					break;
			}

			newc->next = c;
			if (l)
				l->next = newc;
			else
				newgenfs->head = newc;
		}
	}

	if (p->policyvers >= POLICYDB_VERSION_MLS) {
		int new_rangetr = p->policyvers >= POLICYDB_VERSION_RANGETRANS;
		rc = next_entry(buf, fp, sizeof(u32));
		if (rc < 0)
			goto bad;
		nel = le32_to_cpu(buf[0]);
		lrt = NULL;
		for (i = 0; i < nel; i++) {
			rt = kzalloc(sizeof(*rt), GFP_KERNEL);
			if (!rt) {
				rc = -ENOMEM;
				goto bad;
			}
			if (lrt)
				lrt->next = rt;
			else
				p->range_tr = rt;
			rc = next_entry(buf, fp, (sizeof(u32) * 2));
			if (rc < 0)
				goto bad;
			rt->source_type = le32_to_cpu(buf[0]);
			rt->target_type = le32_to_cpu(buf[1]);
			if (new_rangetr) {
				rc = next_entry(buf, fp, sizeof(u32));
				if (rc < 0)
					goto bad;
				rt->target_class = le32_to_cpu(buf[0]);
			} else
				rt->target_class = SECCLASS_PROCESS;
			if (!policydb_type_isvalid(p, rt->source_type) ||
			    !policydb_type_isvalid(p, rt->target_type) ||
			    !policydb_class_isvalid(p, rt->target_class)) {
				rc = -EINVAL;
				goto bad;
			}
			rc = mls_read_range_helper(&rt->target_range, fp);
			if (rc)
				goto bad;
			if (!mls_range_isvalid(p, &rt->target_range)) {
				printk(KERN_WARNING "security:  rangetrans:  invalid range\n");
				goto bad;
			}
			lrt = rt;
		}
	}

	p->type_attr_map = kmalloc(p->p_types.nprim*sizeof(struct ebitmap), GFP_KERNEL);
	if (!p->type_attr_map)
		goto bad;

	for (i = 0; i < p->p_types.nprim; i++) {
		ebitmap_init(&p->type_attr_map[i]);
		if (p->policyvers >= POLICYDB_VERSION_AVTAB) {
			if (ebitmap_read(&p->type_attr_map[i], fp))
				goto bad;
		}
		/* add the type itself as the degenerate case */
		if (ebitmap_set_bit(&p->type_attr_map[i], i, 1))
				goto bad;
	}

	rc = 0;
out:
	return rc;
bad_newc:
	ocontext_destroy(newc,OCON_FSUSE);
bad:
	if (!rc)
		rc = -EINVAL;
	policydb_destroy(p);
	goto out;
}