master-thesis/p4src/actions_delta_checksum.p4
2019-07-16 13:05:13 +02:00

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#ifndef NICO_DELTA_CHECKSUM
#define NICO_DELTA_CHECKSUM
action v4sum() {
bit<16> tmp = 0;
tmp = tmp + (bit<16>) hdr.ipv4.src_addr[15:0]; // 16 bit
tmp = tmp + (bit<16>) hdr.ipv4.src_addr[31:16]; // 16 bit
tmp = tmp + (bit<16>) hdr.ipv4.dst_addr[15:0]; // 16 bit
tmp = tmp + (bit<16>) hdr.ipv4.dst_addr[31:16]; // 16 bit
tmp = tmp + (bit<16>) hdr.ipv4.totalLen -20; // 16 bit
tmp = tmp + (bit<16>) hdr.ipv4.protocol; // 8 bit
tmp = ~tmp;
meta.v4sum = tmp;
}
action v6sum() {
bit<16> tmp = 0;
tmp = tmp + (bit<16>) hdr.ipv6.src_addr[15:0]; // 16 bit
tmp = tmp + (bit<16>) hdr.ipv6.src_addr[31:16]; // 16 bit
tmp = tmp + (bit<16>) hdr.ipv6.src_addr[47:32]; // 16 bit
tmp = tmp + (bit<16>) hdr.ipv6.src_addr[63:48]; // 16 bit
tmp = tmp + (bit<16>) hdr.ipv6.src_addr[79:64]; // 16 bit
tmp = tmp + (bit<16>) hdr.ipv6.src_addr[95:80]; // 16 bit
tmp = tmp + (bit<16>) hdr.ipv6.src_addr[111:96]; // 16 bit
tmp = tmp + (bit<16>) hdr.ipv6.src_addr[127:112]; // 16 bit
tmp = tmp + (bit<16>) hdr.ipv6.dst_addr[15:0]; // 16 bit
tmp = tmp + (bit<16>) hdr.ipv6.dst_addr[31:16]; // 16 bit
tmp = tmp + (bit<16>) hdr.ipv6.dst_addr[47:32]; // 16 bit
tmp = tmp + (bit<16>) hdr.ipv6.dst_addr[63:48]; // 16 bit
tmp = tmp + (bit<16>) hdr.ipv6.dst_addr[79:64]; // 16 bit
tmp = tmp + (bit<16>) hdr.ipv6.dst_addr[95:80]; // 16 bit
tmp = tmp + (bit<16>) hdr.ipv6.dst_addr[111:96]; // 16 bit
tmp = tmp + (bit<16>) hdr.ipv6.dst_addr[127:112]; // 16 bit
tmp = tmp + (bit<16>) hdr.ipv6.payload_length; // 16 bit
tmp = tmp + (bit<16>) hdr.ipv6.next_header; // 8 bit
tmp = ~tmp;
meta.v6sum = tmp;
}
action delta_prepare()
{
v4sum();
v6sum();
}
action delta_udp_from_v4_to_v6()
{
delta_prepare();
hdr.udp.checksum = hdr.udp.checksum + meta.v6sum;
/* prevent negative wrap around that loses 1 */
if(meta.v4sum > hdr.udp.checksum) {
bit<16> tmp = 0xffff - meta.v4sum;
hdr.udp.checksum = hdr.udp.checksum + tmp;
} else {
hdr.udp.checksum = hdr.udp.checksum - meta.v4sum;
}
}
action delta_tcp_from_v4_to_v6()
{
delta_prepare();
hdr.tcp.checksum = hdr.tcp.checksum + meta.v6sum;
/* prevent negative wrap around that loses 1 */
if(meta.v4sum > hdr.tcp.checksum) {
bit<16> tmp = 0xffff - meta.v4sum;
hdr.tcp.checksum = hdr.tcp.checksum + tmp;
} else {
hdr.tcp.checksum = hdr.tcp.checksum - meta.v4sum;
}
}
action delta_ipv4_from_v6_to_v4()
{
delta_prepare();
/* we don't have ANY checksum, but tcp or udp: we can
base on that ones for calculating the diff for IPv4
*/
hdr.ipv4.checksum = 0; /* TO BE DONE! */
}
#endif