int pccard_get_next_tuple()

in cistpl.c [521:631]

• 100 lines of code
• 31 McCabe index (conditional complexity)

int pccard_get_next_tuple(struct pcmcia_socket *s, unsigned int function,
			tuple_t *tuple)
{
	u_char link[2], tmp;
	int ofs, i, attr;
	int ret;

	if (!s)
		return -EINVAL;
	if (!(s->state & SOCKET_PRESENT) || (s->state & SOCKET_CARDBUS))
		return -ENODEV;

	link[1] = tuple->TupleLink;
	ofs = tuple->CISOffset + tuple->TupleLink;
	attr = SPACE(tuple->Flags);

	for (i = 0; i < MAX_TUPLES; i++) {
		if (link[1] == 0xff)
			link[0] = CISTPL_END;
		else {
			ret = read_cis_cache(s, attr, ofs, 2, link);
			if (ret)
				return -1;
			if (link[0] == CISTPL_NULL) {
				ofs++;
				continue;
			}
		}

		/* End of chain?  Follow long link if possible */
		if (link[0] == CISTPL_END) {
			ofs = follow_link(s, tuple);
			if (ofs < 0)
				return -ENOSPC;
			attr = SPACE(tuple->Flags);
			ret = read_cis_cache(s, attr, ofs, 2, link);
			if (ret)
				return -1;
		}

		/* Is this a link tuple?  Make a note of it */
		if ((link[0] == CISTPL_LONGLINK_A) ||
			(link[0] == CISTPL_LONGLINK_C) ||
			(link[0] == CISTPL_LONGLINK_MFC) ||
			(link[0] == CISTPL_LINKTARGET) ||
			(link[0] == CISTPL_INDIRECT) ||
			(link[0] == CISTPL_NO_LINK)) {
			switch (link[0]) {
			case CISTPL_LONGLINK_A:
				HAS_LINK(tuple->Flags) = 1;
				LINK_SPACE(tuple->Flags) = attr | IS_ATTR;
				ret = read_cis_cache(s, attr, ofs+2, 4,
						&tuple->LinkOffset);
				if (ret)
					return -1;
				break;
			case CISTPL_LONGLINK_C:
				HAS_LINK(tuple->Flags) = 1;
				LINK_SPACE(tuple->Flags) = attr & ~IS_ATTR;
				ret = read_cis_cache(s, attr, ofs+2, 4,
						&tuple->LinkOffset);
				if (ret)
					return -1;
				break;
			case CISTPL_INDIRECT:
				HAS_LINK(tuple->Flags) = 1;
				LINK_SPACE(tuple->Flags) = IS_ATTR |
					IS_INDIRECT;
				tuple->LinkOffset = 0;
				break;
			case CISTPL_LONGLINK_MFC:
				tuple->LinkOffset = ofs + 3;
				LINK_SPACE(tuple->Flags) = attr;
				if (function == BIND_FN_ALL) {
					/* Follow all the MFC links */
					ret = read_cis_cache(s, attr, ofs+2,
							1, &tmp);
					if (ret)
						return -1;
					MFC_FN(tuple->Flags) = tmp;
				} else {
					/* Follow exactly one of the links */
					MFC_FN(tuple->Flags) = 1;
					tuple->LinkOffset += function * 5;
				}
				break;
			case CISTPL_NO_LINK:
				HAS_LINK(tuple->Flags) = 0;
				break;
			}
			if ((tuple->Attributes & TUPLE_RETURN_LINK) &&
				(tuple->DesiredTuple == RETURN_FIRST_TUPLE))
				break;
		} else
			if (tuple->DesiredTuple == RETURN_FIRST_TUPLE)
				break;

		if (link[0] == tuple->DesiredTuple)
			break;
		ofs += link[1] + 2;
	}
	if (i == MAX_TUPLES) {
		dev_dbg(&s->dev, "cs: overrun in pcmcia_get_next_tuple\n");
		return -ENOSPC;
	}

	tuple->TupleCode = link[0];
	tuple->TupleLink = link[1];
	tuple->CISOffset = ofs + 2;
	return 0;
}