Comparing Labels

The blequal(), bldominates(), and blstrictdom() routines are used to compare labels. The blinrange() routine is used to determine whether a label is within a specified label range. In these routines, a level refers to a classification and a set of compartments in a sensitivity label or in a clearance label.

int blequal(const blevel_t *level1, const blevel_t *level2);

The blequal() routine compares two labels to determine whether level1 equals level2.

int bldominates(const m_label_t *level1, const m_label_t *level2);

The bldominates() routine compares two labels to determine whether level1 dominates level2.

int blstrictdom(const m_label_t *level1, const m_label_t *level2);

The blstrictdom() routine compares two labels to determine whether level1 strictly dominates level2.

int blinrange(const m_label_t *level, const brange_t *range);

The blinrange() routine determines whether the label, level, is within the specified range, range.

These routines return a nonzero value when the comparison is true and a value of 0 when the comparison is false. For more information about these routines, see the blcompare(3TSOL) man page.

For more information about label relationships, see Label Relationships.

The blmaximum() and blminimum() routines are used to determine the upper and lower bounds of the specified label range.

void blmaximum(m_label_t *maximum_label, const m_label_t *bounding_label);

The blmaximum() routine compares two labels to find the least upper bound of the range. The least upper bound is the lower of two clearances, which is used to determine whether you have access to a system of a particular clearance.

For instance, use this routine to determine the label to use when creating a new labeled object that combines information from two other labeled objects. The label of the new object will dominate both of the original labeled objects.

See the blminmax(3TSOL) man page.

void blminimum(m_label_t *minimum_label, const m_label_t *bounding_label);

The blminimum() routine compares two labels to find the label that represents the greatest lower bound of the range that is bounded by the two levels. The greatest lower bound is the higher of two labels, which is also used to determine whether you have access to a system of a particular clearance.

See the blminmax(3TSOL) man page.