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[p4] begin icmp6 checksum

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Nico Schottelius 2019-02-23 21:05:46 +01:00
parent c38eb0dfc4
commit a5c8be40be
2 changed files with 36 additions and 31 deletions
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26
doc/plan.org
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@ -66,6 +66,7 @@
**** DONE Parse icmp
**** DONE Parse icmpv6
**** DONE Add (static) egress configuration
**** TODO Calculate ICMP6 checksums
**** TODO Make switch answer icmp6 echo request for
**** TODO Make switch answer icmp echo request for
**** TODO Add default route for v6 and v4 hosts
@ -144,6 +145,29 @@ user@T:~# iptables -t mangle -A PREROUTING \
**** Static mappings
- likely need table(s)
- need tcp & udp translation
**** ICMPv6
Different lengths possible
[20:35] line:~% ping -6 -s 20 ::1
PING ::1(::1) 20 data bytes
28 bytes from ::1: icmp_seq=1 ttl=64 time=0.045 ms
28 bytes from ::1: icmp_seq=2 ttl=64 time=0.064 ms
^C
--- ::1 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1018ms
rtt min/avg/max/mdev = 0.045/0.054/0.064/0.012 ms
[20:36] line:~% ping -6 -s 80 ::1
PING ::1(::1) 80 data bytes
88 bytes from ::1: icmp_seq=1 ttl=64 time=0.053 ms
88 bytes from ::1: icmp_seq=2 ttl=64 time=0.095 ms
^C
--- ::1 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1001ms
rtt min/avg/max/mdev = 0.053/0.074/0.095/0.021 ms
[20:36] line:~%
Different checksum in most packets.
***** Hosts
****** Left side: IPv6
****** Right side: IPv4
@ -157,6 +181,8 @@ user@T:~# iptables -t mangle -A PREROUTING \
**** RFC 6052: https://tools.ietf.org/html/rfc6052 IPv6 Addressing of IPv4/IPv6 Translators
**** RFC 6586 for deployment experiences using Stateful NAT64.
**** RFC 7757 Explicit Address Mappings for Stateless IP/ICMP Translation
**** RFC 4443 ICMPv6 https://tools.ietf.org/html/rfc4443
**** RFC 2460 IPv6 (Checksum https://tools.ietf.org/html/rfc2460#section-8.1)
**** EAMT/Jool: https://www.jool.mx/en/eamt.html
* Proposal / task description
** Task description for mystudies

41
p4src/checksums.p4
View file

@ -21,38 +21,17 @@ control MyVerifyChecksum(inout headers hdr, inout metadata meta) {
control MyComputeChecksum(inout headers hdr, inout metadata meta) {
apply {
/* 512 bit+ according to
https://en.wikipedia.org/wiki/Transmission_Control_Protocol#TCP_checksum_for_IPv4
*/
update_checksum_with_payload(
hdr.ipv6.isValid(),
update_checksum (
hdr.icmp6.isValid(),
{
hdr.ipv6.src_addr, /* 128 */
hdr.ipv6.dst_addr, /* 128 */
meta.tcpLength,
24w0,
hdr.ipv6.next_header,
// TCP header
hdr.tcp.src_port,
hdr.tcp.dst_port,
hdr.tcp.seqNo,
hdr.tcp.ackNo,
hdr.tcp.data_offset,
hdr.tcp.res,
hdr.tcp.cwr,
hdr.tcp.ece,
hdr.tcp.urg,
hdr.tcp.ack,
hdr.tcp.psh,
hdr.tcp.rst,
hdr.tcp.syn,
hdr.tcp.fin,
hdr.tcp.window,
hdr.tcp.urgentPtr
},
hdr.tcp.checksum,
HashAlgorithm.csum16);
hdr.ipv6.src_addr, /* 128 */
hdr.ipv6.dst_addr, /* 128 */
hdr.ipv6.payload_length, /* 16 -> should be 32 according to RFC2460 - also static number? */
24w0, /* 24 0's */
PROTO_ICMP6 /* 8 */
}
hdr.icmp6.checksum,
HashAlgorithm.csum16);
}
}