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xf#ifndef NICO_NAT64_GENERIC
#define NICO_NAT64_GENERIC
#include "actions_egress.p4"
#include "actions_delta_checksum.p4"
/********************** 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;
/* FIXME: for delta */
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();
/* Stuff that might need to be fixed */
hdr.ipv4.version = (bit<4>)4;
hdr.ipv4.ihl = (bit<4>)5; // internet header length: 4*5 = 20
/* 5 is ok as long as
we don't use options / padding /
anything after the destination address */
hdr.ipv4.diff_serv = (bit<6>)0; // no ToS
hdr.ipv4.ecn = (bit<2>)0; // unsupported
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
hdr.ipv4.ttl = hdr.ipv6.hop_limit;
hdr.ipv4.protocol = hdr.ipv6.next_header;
hdr.ipv4.src_addr = src;
hdr.ipv4.dst_addr = dst;
/* Stuff that should be fine */
hdr.ethernet.ethertype = TYPE_IPV4;
#ifdef _SUME_SWITCH_P4_
delta_ipv4_from_v6_to_v4();
#else
meta.chk_ipv4 = 1; /* need to calculate the hdrchecksum */
#endif
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 = {
#ifndef _SUME_SWITCH_P4_
hdr.ipv6.dst_addr: lpm;
#else
hdr.ipv6.dst_addr: exact;
#endif
}
actions = {
controller_debug;
nat64_static;
controller_debug_table_id;
NoAction;
}
size = NAT64_TABLE_SIZE;
default_action = NoAction;
}
table nat46 {
key = {
#ifndef _SUME_SWITCH_P4_
hdr.ipv4.dst_addr: lpm;
#else
hdr.ipv4.dst_addr: exact;
#endif
}
actions = {
controller_debug;
nat46_static;
controller_debug_table_id;
NoAction;
}
size = NAT64_TABLE_SIZE;
#ifndef _SUME_SWITCH_P4_
default_action = controller_debug_table_id(TABLE_NAT46);
#else
default_action = controller_debug;
#endif
}
#endif