/* Two flow matches overlap if there exists a packet which both match structures match on.
* Conversely, two flow matches do not overlap if they share at least one match field with
* incompatible value/mask fields that can't match any packet.
*/
bool
match_std_overlap(struct ofl_match *a, struct ofl_match *b, struct ofl_exp *exp)
{
uint64_t all_mask[2] = {~0L, ~0L};
struct ofl_match_tlv *f_a;
struct ofl_match_tlv *f_b;
int header, header_m;
int field_len;
uint8_t *val_a, *mask_a;
uint8_t *val_b, *mask_b;
/* Loop through the match fields in flow entry a */
HMAP_FOR_EACH(f_a, struct ofl_match_tlv, hmap_node, &a->match_fields)
{
val_a = f_a->value;
switch (OXM_VENDOR(f_a->header))
{
case (OFPXMC_OPENFLOW_BASIC):
field_len = OXM_LENGTH(f_a->header);
if (OXM_HASMASK(f_a->header)) {
field_len /= 2;
header = (f_a->header & 0xfffffe00) | field_len;
header_m = f_a->header;
mask_a = f_a->value + field_len;
} else {
header = f_a->header;
header_m = (f_a->header & 0xfffffe00) | 0x100 | (field_len << 1);
/* Set a dummy mask with all bits set to 0 (valid) */
mask_a = (uint8_t *) all_mask;
}
break;
case (OFPXMC_EXPERIMENTER):
if (exp == NULL || exp->field == NULL || exp->field->overlap_a == NULL) {
VLOG_WARN(LOG_MODULE,"Received match is experimental, but no callback was given.");
ofl_error(OFPET_BAD_MATCH, OFPBMC_BAD_TYPE);
}
exp->field->overlap_a(f_a, &field_len, &val_a, &mask_a, &header, &header_m, all_mask);
break;
default:
break;
} /*switch class*/
/* Check presence of corresponding match field in flow entry b
* Need to check for both masked and non-masked field */
f_b = oxm_match_lookup(header, b);
if (!f_b) f_b = oxm_match_lookup(header_m, b);
if (f_b) {
switch (OXM_VENDOR(f_b->header))
{
case (OFPXMC_OPENFLOW_BASIC):
val_b = f_b->value;
if (OXM_HASMASK(f_b->header)) {
mask_b = f_b->value + field_len;
} else {
/* Set a dummy mask with all bits set to 0 (valid) */
mask_b = (uint8_t *) all_mask;
}
break;
case (OFPXMC_EXPERIMENTER):
if (exp == NULL || exp->field == NULL || exp->field->overlap_b == NULL) {
VLOG_WARN(LOG_MODULE,"Received match is experimental, but no callback was given.");
ofl_error(OFPET_BAD_MATCH, OFPBMC_BAD_TYPE);
}
exp->field->overlap_b(f_b, &field_len, &val_b, &mask_b, all_mask);
break;
default:
break;
} /*switch class*/
switch (field_len) {
case 1:
if (incompatible_8(val_a, val_b, mask_a, mask_b)) {
return false;
}
break;
case 2:
if (incompatible_16(val_a, val_b, mask_a, mask_b)) {
return false;
}
break;
case 4:
if (incompatible_32(val_a, val_b, mask_a, mask_b)) {
return false;
}
break;
case 6:
if (incompatible_48(val_a, val_b, mask_a, mask_b)) {
return false;
}
break;
case 8:
if (incompatible_64(val_a, val_b, mask_a, mask_b)) {
return false;
}
break;
case 16:
if (incompatible_128(val_a, val_b, mask_a, mask_b)) {
return false;
}
break;
default:
/* Should never happen */
break;
} /* switch (field_len) */
} /* if (f_b) */
} /* HMAP_FOR_EACH */
/* If we get here, none of the common match fields in a and b were found incompatible.
* The flow entries overlap */
return true;
}
bool
match_std_overlap(struct ofl_match *a, struct ofl_match *b)
{
uint64_t all_mask[2] = {0, 0};
struct ofl_match_tlv *f_a;
struct ofl_match_tlv *f_b;
int header, header_m;
int field_len;
uint8_t *val_a, *mask_a;
uint8_t *val_b, *mask_b;
/* Loop through the match fields in flow entry a */
HMAP_FOR_EACH(f_a, struct ofl_match_tlv, hmap_node, &a->match_fields)
{
field_len = OXM_LENGTH(f_a->header);
val_a = f_a->value;
if (OXM_HASMASK(f_a->header)) {
field_len /= 2;
header = (f_a->header & 0xfffffe00) | field_len;
header_m = f_a->header;
mask_a = f_a->value + field_len;
} else {
header = f_a->header;
header_m = (f_a->header & 0xfffffe00) | 0x100 | (field_len << 1);
/* Set a dummy mask with all bits set to 0 (valid) */
mask_a = (uint8_t *) all_mask;
}
/* Check presence of corresponding match field in flow entry b
* Need to check for both masked and non-masked field */
f_b = oxm_match_lookup(header, b);
if (!f_b) f_b = oxm_match_lookup(header_m, b);
if (f_b) {
val_b = f_b->value;
if (OXM_HASMASK(f_b->header)) {
mask_b = f_b->value + field_len;
} else {
/* Set a dummy mask with all bits set to 0 (valid) */
mask_b = (uint8_t *) all_mask;
}
switch (field_len) {
case 1:
if (incompatible_8(val_a, val_b, mask_a, mask_b)) {
return false;
}
break;
case 2:
if (incompatible_16(val_a, val_b, mask_a, mask_b)) {
return false;
}
break;
case 4:
if (incompatible_32(val_a, val_b, mask_a, mask_b)) {
return false;
}
break;
case 6:
if (incompatible_48(val_a, val_b, mask_a, mask_b)) {
return false;
}
break;
case 8:
if (incompatible_64(val_a, val_b, mask_a, mask_b)) {
return false;
}
break;
case 16:
if (incompatible_128(val_a, val_b, mask_a, mask_b)) {
return false;
}
break;
default:
/* Should never happen */
break;
} /* switch (field_len) */
} /* if (f_b) */
} /* HMAP_FOR_EACH */
/* If we get here, none of the common match fields in a and b were found incompatible.
* The flow entries overlap */
return true;
}