/* Returns true if the fields in *packet matches the flow entry in *flow_match */
bool
packet_match(struct ofl_match *flow_match, struct ofl_match *packet){
struct ofl_match_tlv *f;
struct ofl_match_tlv *packet_f;
bool has_mask;
int field_len;
int packet_header;
uint8_t *flow_val, *flow_mask= NULL;
uint8_t *packet_val;
//VLOG_WARN_RL(LOG_MODULE, &rl, "Entered to PACKET_MATCH function ...............");
if (flow_match->header.length == 0){
return true;
}
//VLOG_WARN_RL(LOG_MODULE, &rl, "Passed ...............");
/* Loop over the flow entry's match fields */
HMAP_FOR_EACH(f, struct ofl_match_tlv, hmap_node, &flow_match->match_fields)
{
//VLOG_WARN_RL(LOG_MODULE, &rl, "Passed the FOR1 ...............");
/* Check presence of match field in packet */
has_mask = OXM_HASMASK(f->header);
field_len = OXM_LENGTH(f->header);
packet_header = f->header;
flow_val = f->value;
if (has_mask) {
/* Clear the has_mask bit and divide the field_len by two in the packet field header */
field_len /= 2;
packet_header &= 0xfffffe00;
packet_header |= field_len;
flow_mask = f->value + field_len;
}
char *f_str = ofl_structs_oxm_tlv_to_string(f);
free(f_str);
/* Lookup the packet header */
//VLOG_WARN_RL(LOG_MODULE, &rl, "PACKET HEADER is .............. (%"PRIu32")", packet_header);
packet_f = oxm_match_lookup(packet_header, packet);
if (!packet_f) {
if (f->header==OXM_OF_VLAN_VID &&
*((uint16_t *) f->value)==OFPVID_NONE) {
/* There is no VLAN tag, as required */
continue;
}
//VLOG_WARN_RL(LOG_MODULE, &rl, "Passed the FOR2 ...............");
return false;
}
/* Compare the flow and packet field values, considering the mask, if any */
packet_val = packet_f->value;
switch (field_len) {
case 1:
if (has_mask) {
if (!match_mask8(flow_val, flow_mask, packet_val))
return false;
}
else {
if (!match_8(flow_val, packet_val))
return false;
}
break;
case 2:
switch (packet_header) {
case OXM_OF_VLAN_VID: {
/* Special handling for VLAN ID */
uint16_t *flow_vlan_id = (uint16_t*) flow_val;
if (*flow_vlan_id == OFPVID_NONE) {
/* Packet has a VLAN tag when none should be there */
return false;
} else if (*flow_vlan_id == OFPVID_PRESENT) {
/* Any VLAN ID is acceptable. No further checks */
} else {
/* Check the VLAN ID */
*flow_vlan_id &= VLAN_VID_MASK;
if (!match_16(flow_val, packet_val))
return false;
}
break;
}
case OXM_OF_IPV6_EXTHDR: {
/* Special handling for IPv6 Extension header */
uint16_t flow_eh = *((uint16_t *) flow_val);
uint16_t packet_eh = *((uint16_t *) packet_val);
if ((flow_eh & packet_eh) != flow_eh) {
/* The packet doesn't have all extension headers specified in the flow */
return false;
}
break;
}
default:
if (has_mask) {
if (!match_mask16(flow_val, flow_mask, packet_val))
return false;
}
else {
if (!match_16(flow_val, packet_val))
return false;
}
break;
}
break;
case 4:
if (has_mask) {
if (!match_mask32(flow_val, flow_mask, packet_val))
return false;
}
else {
if (!match_32(flow_val, packet_val)){
return false;
}
}
break;
case 6:
if (has_mask) {
if (!match_mask48(flow_val, flow_mask, packet_val))
return false;
}
else {
if (!match_48(flow_val, packet_val))
return false;
}
break;
case 8:
if (has_mask) {
if (!match_mask64(flow_val, flow_mask, packet_val))
return false;
}
else {
if (!match_64(flow_val, packet_val))
return false;
}
break;
case 16:
if (has_mask) {
if (!match_mask128(flow_val, flow_mask, packet_val))
return false;
}
else {
if (!match_128(flow_val, packet_val))
return false;
}
break;
default:
/* Should never happen */
break;
}
}
/* If we get here, all match fields in the flow entry matched the packet */
return true;
}
/* Two matches strictly match if their wildcard fields are the same, and all the
* non-wildcarded fields match on the same exact values.
* NOTE: Handling of bitmasked fields is not specified. In this implementation
* masked fields are checked for equality, and only unmasked bits are compared
* in the field.
*/
bool
match_std_strict(struct ofl_match *a, struct ofl_match *b) {
struct ofl_match_tlv *flow_mod_match;
struct ofl_match_tlv *flow_entry_match;
int field_len;
uint8_t *flow_mod_val, *flow_mod_mask=0;
uint8_t *flow_entry_val, *flow_entry_mask=0;
bool has_mask;
/* Both matches all wildcarded */
if(!a->header.length && !b->header.length )
return true;
/* If the matches differ in length, there is no reason to compare */
if (a->header.length != b->header.length)
return false;
/* Loop through the flow_mod match fields */
HMAP_FOR_EACH(flow_mod_match, struct ofl_match_tlv, hmap_node, &a->match_fields)
{
/* Check presence of match field in flow entry */
flow_entry_match = oxm_match_lookup(flow_mod_match->header, b);
if (!flow_entry_match) {
return false;
}
/* At this point match length and has_mask are equal */
has_mask = OXM_HASMASK(flow_mod_match->header);
field_len = OXM_LENGTH(flow_mod_match->header);
flow_mod_val = flow_mod_match->value;
flow_entry_val = flow_entry_match->value;
if (has_mask)
{
field_len /= 2;
flow_mod_mask = flow_mod_match->value + field_len;
flow_entry_mask = flow_entry_match->value + field_len;
}
switch (field_len) {
case 1:
if (has_mask) {
if (!strict_mask8(flow_mod_val, flow_entry_val, flow_mod_mask, flow_entry_mask))
return false;
}
else {
if (!match_8(flow_mod_val, flow_entry_val))
return false;
}
break;
case 2:
if (has_mask) {
if (!strict_mask16(flow_mod_val, flow_entry_val, flow_mod_mask, flow_entry_mask))
return false;
}
else {
if (!match_16(flow_mod_val, flow_entry_val))
return false;
}
break;
case 4:
if (has_mask) {
if (!strict_mask32(flow_mod_val, flow_entry_val, flow_mod_mask, flow_entry_mask))
return false;
}
else {
if (!match_32(flow_mod_val, flow_entry_val))
return false;
}
break;
case 6:
if (has_mask) {
if (!strict_mask48(flow_mod_val, flow_entry_val, flow_mod_mask, flow_entry_mask))
return false;
}
else {
if (!match_48(flow_mod_val, flow_entry_val))
return false;
}
break;
case 8:
if (has_mask) {
if (!strict_mask64(flow_mod_val, flow_entry_val, flow_mod_mask, flow_entry_mask))
return false;
}
else {
if (!match_64(flow_mod_val, flow_entry_val))
return false;
}
break;
case 16:
if (has_mask) {
if (!strict_mask128(flow_mod_val, flow_entry_val, flow_mod_mask, flow_entry_mask))
return false;
}
else {
if (!match_128(flow_mod_val, flow_entry_val))
return false;
}
break;
default:
/* Should never happen */
break;
} /* switch (field_len) */
} /* HMAP_FOR_EACH */
/* If we get here, all match fields in flow_mod were equal to the ones in flow entry */
/* There can't be more fields in the flow entry as the lengths are the same */
return true;
}
/* Flow entry (a) matches flow entry (b) non-strictly if (a) matches whenever (b) matches.
* Thus, flow (a) must not have more match fields than (b) and all match fields in (a) must
* be equal or narrower in (b).
* NOTE: Handling of bitmasked fields is not specified. In this implementation
* a masked field of (a) matches the field of (b) if all masked bits of (b) are
* also masked in (a), and for each unmasked bits of (b) , the bit is either
* masked in (a), or is set to the same value in both matches.
*
*/
bool
match_std_nonstrict(struct ofl_match *a, struct ofl_match *b)
{
struct ofl_match_tlv *flow_mod_match;
struct ofl_match_tlv *flow_entry_match;
int field_len;
uint8_t *flow_mod_val, *flow_mod_mask=0;
uint8_t *flow_entry_val, *flow_entry_mask=0;
bool has_mask;
/* Flow a is fully wildcarded */
if (!a->header.length)
return true;
/* Loop through the match fields in flow entry a */
HMAP_FOR_EACH(flow_mod_match, struct ofl_match_tlv, hmap_node, &a->match_fields)
{
/* Check presence of match field in flow entry */
flow_entry_match = oxm_match_lookup(flow_mod_match->header, b);
if (!flow_entry_match) {
return false;
}
/* At this point match length and has_mask are equal */
has_mask = OXM_HASMASK(flow_mod_match->header);
field_len = OXM_LENGTH(flow_mod_match->header);
flow_mod_val = flow_mod_match->value;
flow_entry_val = flow_entry_match->value;
if (has_mask)
{
field_len /= 2;
flow_mod_mask = flow_mod_match->value + field_len;
flow_entry_mask = flow_entry_match->value + field_len;
}
switch (field_len) {
case 1:
if (has_mask) {
if (!nonstrict_mask8(flow_mod_val, flow_entry_val, flow_mod_mask, flow_entry_mask))
return false;
}
else {
if (!match_8(flow_mod_val, flow_entry_val))
return false;
}
break;
case 2:
if (has_mask) {
if (!nonstrict_mask16(flow_mod_val, flow_entry_val, flow_mod_mask, flow_entry_mask))
return false;
}
else {
if (!match_16(flow_mod_val, flow_entry_val))
return false;
}
break;
case 4:
if (has_mask) {
if (!nonstrict_mask32(flow_mod_val, flow_entry_val, flow_mod_mask, flow_entry_mask))
return false;
}
else {
if (!match_32(flow_mod_val, flow_entry_val))
return false;
}
break;
case 6:
if (has_mask) {
if (!nonstrict_mask48(flow_mod_val, flow_entry_val, flow_mod_mask, flow_entry_mask))
return false;
}
else {
if (!match_48(flow_mod_val, flow_entry_val))
return false;
}
break;
case 8:
if (has_mask) {
if (!nonstrict_mask64(flow_mod_val, flow_entry_val, flow_mod_mask, flow_entry_mask))
return false;
}
else {
if (!match_64(flow_mod_val, flow_entry_val))
return false;
}
break;
case 16:
if (has_mask) {
if (!nonstrict_mask128(flow_mod_val, flow_entry_val, flow_mod_mask, flow_entry_mask))
return false;
}
else {
if (!match_128(flow_mod_val, flow_entry_val))
return false;
}
break;
default:
/* Should never happen */
break;
} /* switch (field_len) */
} /* HMAP_FOR_EACH */
/* If we get here, all match fields in flow a were equal or wider than the ones in b */
/* It doesn't matter if there are further fields in b */
return true;
}
