int pccard_validate_cis()

in cistpl.c [1376:1468]

• 71 lines of code
• 34 McCabe index (conditional complexity)

int pccard_validate_cis(struct pcmcia_socket *s, unsigned int *info)
{
	tuple_t *tuple;
	cisparse_t *p;
	unsigned int count = 0;
	int ret, reserved, dev_ok = 0, ident_ok = 0;

	if (!s)
		return -EINVAL;

	if (s->functions || !(s->state & SOCKET_PRESENT)) {
		WARN_ON(1);
		return -EINVAL;
	}

	/* We do not want to validate the CIS cache... */
	mutex_lock(&s->ops_mutex);
	destroy_cis_cache(s);
	mutex_unlock(&s->ops_mutex);

	tuple = kmalloc(sizeof(*tuple), GFP_KERNEL);
	if (tuple == NULL) {
		dev_warn(&s->dev, "no memory to validate CIS\n");
		return -ENOMEM;
	}
	p = kmalloc(sizeof(*p), GFP_KERNEL);
	if (p == NULL) {
		kfree(tuple);
		dev_warn(&s->dev, "no memory to validate CIS\n");
		return -ENOMEM;
	}

	count = reserved = 0;
	tuple->DesiredTuple = RETURN_FIRST_TUPLE;
	tuple->Attributes = TUPLE_RETURN_COMMON;
	ret = pccard_get_first_tuple(s, BIND_FN_ALL, tuple);
	if (ret != 0)
		goto done;

	/* First tuple should be DEVICE; we should really have either that
	   or a CFTABLE_ENTRY of some sort */
	if ((tuple->TupleCode == CISTPL_DEVICE) ||
	    (!pccard_read_tuple(s, BIND_FN_ALL, CISTPL_CFTABLE_ENTRY, p)) ||
	    (!pccard_read_tuple(s, BIND_FN_ALL, CISTPL_CFTABLE_ENTRY_CB, p)))
		dev_ok++;

	/* All cards should have a MANFID tuple, and/or a VERS_1 or VERS_2
	   tuple, for card identification.  Certain old D-Link and Linksys
	   cards have only a broken VERS_2 tuple; hence the bogus test. */
	if ((pccard_read_tuple(s, BIND_FN_ALL, CISTPL_MANFID, p) == 0) ||
	    (pccard_read_tuple(s, BIND_FN_ALL, CISTPL_VERS_1, p) == 0) ||
	    (pccard_read_tuple(s, BIND_FN_ALL, CISTPL_VERS_2, p) != -ENOSPC))
		ident_ok++;

	if (!dev_ok && !ident_ok)
		goto done;

	for (count = 1; count < MAX_TUPLES; count++) {
		ret = pccard_get_next_tuple(s, BIND_FN_ALL, tuple);
		if (ret != 0)
			break;
		if (((tuple->TupleCode > 0x23) && (tuple->TupleCode < 0x40)) ||
		    ((tuple->TupleCode > 0x47) && (tuple->TupleCode < 0x80)) ||
		    ((tuple->TupleCode > 0x90) && (tuple->TupleCode < 0xff)))
			reserved++;
	}
	if ((count == MAX_TUPLES) || (reserved > 5) ||
		((!dev_ok || !ident_ok) && (count > 10)))
		count = 0;

	ret = 0;

done:
	/* invalidate CIS cache on failure */
	if (!dev_ok || !ident_ok || !count) {
		mutex_lock(&s->ops_mutex);
		destroy_cis_cache(s);
		mutex_unlock(&s->ops_mutex);
		/* We differentiate between dev_ok, ident_ok and count
		   failures to allow for an override for anonymous cards
		   in ds.c */
		if (!dev_ok || !ident_ok)
			ret = -EIO;
		else
			ret = -EFAULT;
	}

	if (info)
		*info = count;
	kfree(tuple);
	kfree(p);
	return ret;
}