static void
parse_field(const struct mf_field *mf, const char *s, struct match *match)
{
union mf_value value, mask;
char *error;
error = mf_parse(mf, s, &value, &mask);
if (error) {
ovs_fatal(0, "%s", error);
}
mf_set(mf, &value, &mask, match);
}
/* Parses 's' as the (possibly masked) value of field 'mf', and updates
* 'match' appropriately. Restricts the set of usable protocols to ones
* supporting the parsed field.
*
* Returns NULL if successful, otherwise a malloc()'d string describing the
* error. The caller is responsible for freeing the returned string. */
char * OVS_WARN_UNUSED_RESULT
ofp_parse_field(const struct mf_field *mf, const char *s,
const struct ofputil_port_map *port_map, struct match *match,
enum ofputil_protocol *usable_protocols)
{
union mf_value value, mask;
char *error;
if (!*s) {
/* If there's no string, we're just trying to match on the
* existence of the field, so use a no-op value. */
s = "0/0";
}
error = mf_parse(mf, s, port_map, &value, &mask);
if (!error) {
*usable_protocols &= mf_set(mf, &value, &mask, match, &error);
match_add_ethernet_prereq(match, mf);
}
return error;
}
