master-thesis/p4src/nat64.p4
2019-05-06 12:52:29 +02:00

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/* -*- P4_16 -*- */
#include <core.p4>
#include <v1model.p4>
#include "headers.p4"
#include "parsers.p4"
#include "checksums.p4"
#include "settings.p4"
/*************************************************************************
************** I N G R E S S P R O C E S S I N G *******************
*************************************************************************/
control MyIngress(inout headers hdr,
inout metadata meta,
inout standard_metadata_t standard_metadata) {
/********************** GENERAL ACTIONS ***********************************/
action drop() {
mark_to_drop();
}
action set_egress_port (port_t out_port) {
standard_metadata.egress_spec = out_port;
}
action set_egress_port_and_mac (port_t out_port, mac_addr_t mac_addr) {
hdr.ethernet.dst_addr = mac_addr;
standard_metadata.egress_spec = out_port;
}
action controller_reply(task_t task) {
meta.task = task;
meta.ingress_port = standard_metadata.ingress_port;
clone3(CloneType.I2E, 100, meta);
}
action controller_debug_table_id(table_t table_id) {
meta.table_id = table_id;
controller_reply(TASK_DEBUG);
}
action controller_debug() {
controller_reply(TASK_DEBUG);
}
action multicast_pkg(mcast_t mcast_grp) { /* Output PKG on correct ports (plural) */
standard_metadata.mcast_grp = mcast_grp;
}
/********************** NAT64 / NAT46 ACTIONS GENERIC ***********************************/
/* changes for icmp6 -> icmp */
action nat64_icmp6_generic()
{
hdr.icmp.setValid();
hdr.ipv4.protocol = PROTO_ICMP; // overwrite generic same protocol assumption
/* trigger checksumming */
meta.switch_task = TASK_CHECKSUM_ICMP;
meta.chk_icmp = 1;
hdr.icmp6.setInvalid();
/* not needed, as we don't translate them (yet/ever) */
hdr.icmp6_na_ns.setInvalid();
hdr.icmp6_option_link_layer_addr.setInvalid();
}
/* NAT64 protocol unspecific changes */
action nat64_generic(ipv4_addr_t src, ipv4_addr_t dst) {
hdr.ipv4.setValid();
meta.chk_ipv4 = 1; /* need to calculate the hdrchecksum */
/* Stuff that might need to be fixed */
hdr.ipv4.version = (bit<4>)4;
hdr.ipv4.diff_serv = (bit<6>)0; // no ToS
hdr.ipv4.ecn = (bit<2>)0; // unsupported
/* 5 is ok as long as we don't use options / padding /
anything after the destination address */
hdr.ipv4.ihl = (bit<4>) 5; // internet header length: 4*5 = 20
hdr.ipv4.totalLen = (bit<16>) hdr.ipv6.payload_length + 20; // ok under above constraints
hdr.ipv4.identification = (bit<16>) 0; // no support for fragments
hdr.ipv4.flags = (bit<3>) 0; // DF bit and more fragments
hdr.ipv4.fragOffset = (bit<13>) 0; // 0 as there are no fragments
/* Stuff that should be fine */
hdr.ethernet.ethertype = TYPE_IPV4;
hdr.ipv4.dst_addr = dst;
hdr.ipv4.src_addr = src;
hdr.ipv4.ttl = hdr.ipv6.hop_limit;
hdr.ipv4.protocol = hdr.ipv6.next_header;
hdr.ipv6.setInvalid();
}
/* nat64_prefix is the same as the matching key, but without the mask */
action nat64_static(ipv6_addr_t v6_src, ipv4_addr_t v4_dst, ipv6_addr_t nat64_prefix) {
ipv6_addr_t src_offset = hdr.ipv6.src_addr - v6_src;
ipv4_addr_t src = v4_dst + (ipv4_addr_t) src_offset;
ipv4_addr_t dst = (ipv4_addr_t) (hdr.ipv6.dst_addr - nat64_prefix);
nat64_generic(src, dst);
}
/* From https://tools.ietf.org/html/rfc792 (IPv4)
Echo or Echo Reply Message
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Identifier | Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data ...
+-+-+-+-+-
From https://tools.ietf.org/html/rfc4443#section-4.1
4.1. Echo Request Message
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Identifier | Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data ...
+-+-+-+-+-
4.2. Echo Reply Message
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Identifier | Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data ...
+-+-+-+-+-
Type / code are different in ICMP4 and ICMP6!
*/
/* changes for icmp6 -> icmp */
action nat46_icmp_generic()
{
hdr.icmp6.setValid();
hdr.ipv6.next_header = PROTO_ICMP6;
meta.chk_icmp6 = 1;
meta.cast_length = (bit<32>) hdr.ipv6.payload_length;
hdr.icmp.setInvalid();
}
/* NAT46: protocol unspecific changes */
action nat46_generic(ipv6_addr_t src, ipv6_addr_t dst) {
hdr.ipv6.setValid();
hdr.ipv4.setInvalid();
hdr.ethernet.ethertype = TYPE_IPV6;
hdr.ipv6.dst_addr = dst;
hdr.ipv6.src_addr = src;
hdr.ipv6.version = (bit<4>)6;
hdr.ipv6.traffic_class = (bit<8>) hdr.ipv4.diff_serv;
hdr.ipv6.flow_label = (bit<20>) 0;
hdr.ipv6.payload_length = (bit<16>) hdr.ipv4.totalLen - 20;
hdr.ipv6.next_header = hdr.ipv4.protocol;
hdr.ipv6.hop_limit = hdr.ipv4.ttl;
}
/* matching key: v4_network specified again */
action nat46_static(ipv6_addr_t v6_src, ipv4_addr_t v4_dst, ipv6_addr_t nat64_prefix) {
ipv6_addr_t src = nat64_prefix + (ipv6_addr_t) hdr.ipv4.src_addr;
ipv4_addr_t dst_offset = hdr.ipv4.dst_addr - v4_dst;
ipv6_addr_t dst = v6_src + (ipv6_addr_t) dst_offset;
nat46_generic(src, dst);
}
table nat64 {
key = {
hdr.ipv6.dst_addr: lpm;
}
actions = {
controller_debug;
nat64_static;
controller_debug_table_id;
NoAction;
}
size = NAT64_TABLE_SIZE;
// default_action = controller_debug_table_id(TABLE_NAT64);
default_action = NoAction;
}
table nat46 {
key = {
hdr.ipv4.dst_addr: lpm;
}
actions = {
controller_debug;
nat46_static;
controller_debug_table_id;
NoAction;
}
size = NAT64_TABLE_SIZE;
default_action = controller_debug_table_id(TABLE_NAT46);
}
/********************** NAT64 sessions ***********************************/
/* automatic translations */
action nat64_tcp_session_translate(
ipv4_addr_t src_addr,
bit<16> src_port,
ipv4_addr_t dst_addr,
bit<16> dst_port)
{
hdr.ipv4.setValid();
hdr.tcp.src_port = src_port;
hdr.tcp.dst_port = dst_port;
nat64_generic(src_addr, dst_addr);
}
action nat46_tcp_session_translate(
ipv6_addr_t src_addr,
bit<16> src_port,
ipv6_addr_t dst_addr,
bit<16> dst_port)
{
hdr.ipv6.setValid();
hdr.tcp.src_port = src_port;
hdr.tcp.dst_port = dst_port;
nat46_generic(src_addr, dst_addr);
}
/* We are in the right range, need to create a session entry */
action nat64_tcp_session_create()
{
controller_reply(TASK_NAT64_TCP_SESSION);
}
/* Used for detecting traffic that should have a session */
table nat64_session {
key = {
hdr.ipv6.dst_addr: lpm;
}
actions = {
controller_debug_table_id;
NoAction;
}
size = NAT64_TABLE_SIZE;
default_action = controller_debug_table_id(TABLE_NAT64_SESSION);
}
table nat64_tcp_session {
key = {
hdr.ipv6.src_addr: exact;
hdr.ipv6.dst_addr: exact;
hdr.tcp.src_port: exact;
hdr.tcp.dst_port: exact;
}
actions = {
controller_debug_table_id;
nat64_tcp_session_create;
nat64_tcp_session_translate;
NoAction;
}
size = NAT64_TABLE_SIZE;
default_action = nat64_tcp_session_create;
}
table nat46_tcp_session {
key = {
hdr.ipv6.src_addr: exact;
hdr.ipv6.dst_addr: exact;
hdr.tcp.src_port: exact;
hdr.tcp.dst_port: exact;
}
actions = {
controller_debug_table_id;
nat46_tcp_session_translate;
NoAction;
}
size = NAT64_TABLE_SIZE;
//default_action = controller_debug_table_id(TABLE_NAT64_TCP);
default_action = NoAction;
}
/********************** ICMP6 + NDP + ICMP ***********************************/
/* old/unused action -- is it??*/
action icmp6_answer() {
if(hdr.icmp6.isValid()) {
if(hdr.icmp6.code == ICMP6_ECHO_REQUEST) {
ipv6_addr_t tmp = hdr.ipv6.src_addr;
hdr.ipv6.src_addr = hdr.ipv6.dst_addr;
hdr.ipv6.dst_addr = tmp;
hdr.icmp6.code = ICMP6_ECHO_REPLY;
}
}
}
action icmp6_neighbor_solicitation(ipv6_addr_t addr, mac_addr_t mac_addr) {
/* egress = ingress */
standard_metadata.egress_spec = standard_metadata.ingress_port;
/* 1. IPv6 changes */
hdr.ipv6.dst_addr = hdr.ipv6.src_addr;
hdr.ipv6.src_addr = addr;
/* 2. ICMP6 changes */
hdr.icmp6.type = ICMP6_NA;
hdr.icmp6.code = 0;
hdr.icmp6.checksum = 42; // checksum is calculated in deparser - marking with 42 to see whether it is calculated
/* 3. icmp6/neighbor advertisement: values taken from real world answers */
hdr.icmp6_na_ns.router = 0;
hdr.icmp6_na_ns.solicitated = 1;
hdr.icmp6_na_ns.override = 1;
hdr.icmp6_na_ns.reserved = 0;
hdr.icmp6_na_ns.target_addr = addr;
/* 4. Link layer options */
hdr.icmp6_option_link_layer_addr.type = ICMP6_NDP_OPT_TARGET_LL;
hdr.icmp6_option_link_layer_addr.ll_length = 1; /* 1* 64 bit */
hdr.icmp6_option_link_layer_addr.mac_addr = mac_addr;
/* 5. Checksum trigger/info */
meta.chk_icmp6_na_ns = 1;
meta.cast_length = (bit<32>) hdr.ipv6.payload_length;
}
action icmp6_echo_reply() {
mac_addr_t mac_tmp = hdr.ethernet.dst_addr;
hdr.ethernet.dst_addr = hdr.ethernet.src_addr;
hdr.ethernet.src_addr = mac_tmp;
ipv6_addr_t addr_tmp = hdr.ipv6.dst_addr;
hdr.ipv6.dst_addr = hdr.ipv6.src_addr;
hdr.ipv6.src_addr = addr_tmp;
hdr.icmp6.type = ICMP6_ECHO_REPLY;
meta.chk_icmp6 = 1;
meta.cast_length = (bit<32>) hdr.ipv6.payload_length;
}
table icmp6 {
key = {
hdr.ipv6.dst_addr: lpm;
hdr.icmp6.type: exact;
}
actions = {
controller_debug;
icmp6_neighbor_solicitation;
icmp6_echo_reply;
controller_debug_table_id;
NoAction;
}
size = ICMP6_TABLE_SIZE;
default_action = controller_debug_table_id(TABLE_ICMP6);
}
action icmp_echo_reply() {
mac_addr_t mac_tmp = hdr.ethernet.dst_addr;
ipv4_addr_t ipv4_tmp = hdr.ipv4.src_addr;
/* swap ethernet addresses */
hdr.ethernet.dst_addr = hdr.ethernet.src_addr;
hdr.ethernet.src_addr = mac_tmp;
/* swap ipv4 addresses */
hdr.ipv4.src_addr = hdr.ipv4.dst_addr;
hdr.ipv4.dst_addr = ipv4_tmp;
/* set correct type */
hdr.icmp.type = ICMP_ECHO_REPLY;
meta.chk_icmp = 1;
}
table icmp {
key = {
hdr.ipv4.dst_addr: lpm;
hdr.icmp.type: exact;
}
actions = {
icmp_echo_reply;
controller_debug_table_id;
NoAction;
}
size = ICMP_TABLE_SIZE;
// default_action = controller_debug_table_id(TABLE_ICMP);
default_action = NoAction; /* do not clone on miss */
}
/********************** ARP ***********************************/
action arp_reply(mac_addr_t mac_addr) {
/* swap */
ipv4_addr_t ipv4_src = hdr.arp.dst_ipv4_addr;
ipv4_addr_t ipv4_dst = hdr.arp.src_ipv4_addr;
/* swap/add */
mac_addr_t mac_src = mac_addr;
mac_addr_t mac_dst = hdr.arp.src_mac_addr;
/* fill the ethernet header */
hdr.ethernet.dst_addr = mac_dst;
hdr.ethernet.src_addr = mac_src;
/* fill the arp header */
hdr.arp.dst_mac_addr = mac_dst;
hdr.arp.src_mac_addr = mac_src;
/* swapping */
hdr.arp.dst_ipv4_addr = ipv4_dst;
hdr.arp.src_ipv4_addr = ipv4_src;
hdr.arp.opcode = ARP_REPLY;
}
table v4_arp {
key = {
hdr.ethernet.dst_addr: exact;
hdr.arp.opcode: exact;
hdr.arp.dst_ipv4_addr: lpm;
}
actions = {
controller_debug_table_id;
arp_reply;
NoAction;
}
size = ICMP6_TABLE_SIZE;
default_action = controller_debug_table_id(TABLE_ARP);
}
table v4_arp_egress {
key = {
hdr.arp.dst_ipv4_addr: lpm;
}
actions = {
controller_debug_table_id;
set_egress_port;
NoAction;
}
size = ICMP6_TABLE_SIZE;
default_action = controller_debug_table_id(TABLE_ARP_EGRESS);
}
/********************** ROUTING (egress definiton) TABLES ***********************************/
table v6_networks {
key = {
hdr.ipv6.dst_addr: lpm;
}
actions = {
set_egress_port;
set_egress_port_and_mac;
controller_debug;
controller_reply;
controller_debug_table_id;
NoAction;
}
size = ROUTING_TABLE_SIZE;
default_action = controller_debug_table_id(TABLE_V6_NETWORKS);
}
table v4_networks {
key = {
hdr.ipv4.dst_addr: lpm;
}
actions = {
set_egress_port;
set_egress_port_and_mac;
controller_debug;
controller_debug_table_id;
NoAction;
}
size = ROUTING_TABLE_SIZE;
default_action = controller_debug_table_id(TABLE_V4_NETWORKS);
}
/********************** APPLYING TABLES ***********************************/
apply {
if(hdr.ipv6.isValid()) {
/* We hit an entry in the dynamic IPv6 range */
if(nat64_session.apply().hit) {
if(hdr.tcp.isValid()) {
if(nat64_tcp_session.apply().hit) {
meta.chk_tcp_v4 = 1;
v4_networks.apply(); /* apply egress for IPv4 */
}
}
// if(hdr.icmp6.isValid()) {
// /* If this is not a hit => will escalate to controller
// * If this is a hit, it has a mapping */
// nat64_icmp6_session.apply();
// }
// if(hdr.udp.isValid()) {
// nat64_udp_session.apply();
// meta.chk_udp_v4 = 1;
// }
exit; /* no further v6 processing */
}
if(nat64.apply().hit) { /* generic / static nat64 done */
if(hdr.icmp6.isValid()) {
nat64_icmp6_generic();
if(hdr.icmp6.type == ICMP6_ECHO_REPLY) {
hdr.icmp.type = ICMP_ECHO_REPLY;
hdr.icmp.code = 0;
}
if(hdr.icmp6.type == ICMP6_ECHO_REQUEST) {
hdr.icmp.type = ICMP_ECHO_REQUEST;
hdr.icmp.code = 0;
}
}
if(hdr.udp.isValid()) {
meta.chk_udp_v4 = 1;
}
if(hdr.tcp.isValid()) {
meta.chk_tcp_v4 = 1;
}
v4_networks.apply(); /* apply egress for IPv4 */
exit; /* no further v6 processing */
}
icmp6.apply(); /* icmp6 echo, icmp6 ndp */
v6_networks.apply(); /* regular egress / routing */
} else if(hdr.ipv4.isValid()) {
if(icmp.apply().hit) {
v4_networks.apply();
exit;
} else if(nat46.apply().hit) {
if(hdr.icmp.isValid()) {
nat46_icmp_generic();
if(hdr.icmp.type == ICMP_ECHO_REPLY) {
hdr.icmp6.type = ICMP6_ECHO_REPLY;
}
if(hdr.icmp.type == ICMP_ECHO_REQUEST) {
hdr.icmp6.type = ICMP6_ECHO_REQUEST;
}
}
if(hdr.udp.isValid()) {
meta.chk_udp_v6 = 1;
}
if(hdr.tcp.isValid()) {
meta.chk_tcp_v6 = 1;
}
v6_networks.apply();
exit;
}
v4_networks.apply(); /* regular routing, egress */
} else if(hdr.arp.isValid()) {
if(v4_arp.apply().hit) {
v4_arp_egress.apply();
}
}
}
}
/*************************************************************************
**************** E G R E S S P R O C E S S I N G *******************
*************************************************************************/
control MyEgress(inout headers hdr,
inout metadata meta,
inout standard_metadata_t standard_metadata) {
apply {
// ingress clone
if (standard_metadata.instance_type == 1){
hdr.cpu.setValid();
hdr.cpu.task = meta.task;
hdr.cpu.ethertype = hdr.ethernet.ethertype;
hdr.cpu.ingress_port = (bit<16>) meta.ingress_port;
hdr.cpu.table_id = meta.table_id;
hdr.ethernet.ethertype = TYPE_CPU;
}
}
}
/*************************************************************************
*********************** S W I T C H *******************************
*************************************************************************/
V1Switch(
MyParser(),
MyVerifyChecksum(),
MyIngress(),
MyEgress(),
MyComputeChecksum(),
MyDeparser()
) main;