master-thesis/p4src/actions_delta_checksum.p4
2019-07-16 10:55:17 +02:00

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#ifndef NICO_DELTA_CHECKSUM
#define NICO_DELTA_CHECKSUM
action v4sum() {
bit<32> tmp = 0;
bit<32> carryover = 0;
tmp = tmp + (bit<32>) hdr.ipv4.src_addr[15:0]; // 16 bit
tmp = tmp + (bit<32>) hdr.ipv4.src_addr[31:16]; // 16 bit
tmp = tmp + (bit<32>) hdr.ipv4.dst_addr[15:0]; // 16 bit
tmp = tmp + (bit<32>) hdr.ipv4.dst_addr[31:16]; // 16 bit
tmp = tmp + (bit<32>) hdr.ipv4.totalLen -20; // 16 bit
tmp = tmp + (bit<32>) hdr.ipv4.protocol; // 8 bit
/* filtering code copied from scapy */
tmp = (tmp >> 16) + (tmp & 0xffff);
tmp = (tmp >> 16) + (tmp & 0xffff);
tmp = ~tmp;
// meta.v4sum = (bit<16>) ((((tmp>>8) & 0xff)|tmp<<8) & 0xffff);
meta.v4sum = (bit<16>) tmp;
}
action v6sum() {
bit<32> tmp = 0;
bit<32> carryover = 0;
tmp = tmp + (bit<32>) hdr.ipv6.src_addr[15:0]; // 16 bit
tmp = tmp + (bit<32>) hdr.ipv6.src_addr[31:16]; // 16 bit
tmp = tmp + (bit<32>) hdr.ipv6.src_addr[47:32]; // 16 bit
tmp = tmp + (bit<32>) hdr.ipv6.src_addr[63:48]; // 16 bit
tmp = tmp + (bit<32>) hdr.ipv6.src_addr[79:64]; // 16 bit
tmp = tmp + (bit<32>) hdr.ipv6.src_addr[95:80]; // 16 bit
tmp = tmp + (bit<32>) hdr.ipv6.src_addr[111:96]; // 16 bit
tmp = tmp + (bit<32>) hdr.ipv6.src_addr[127:112]; // 16 bit
tmp = tmp + (bit<32>) hdr.ipv6.dst_addr[15:0]; // 16 bit
tmp = tmp + (bit<32>) hdr.ipv6.dst_addr[31:16]; // 16 bit
tmp = tmp + (bit<32>) hdr.ipv6.dst_addr[47:32]; // 16 bit
tmp = tmp + (bit<32>) hdr.ipv6.dst_addr[63:48]; // 16 bit
tmp = tmp + (bit<32>) hdr.ipv6.dst_addr[79:64]; // 16 bit
tmp = tmp + (bit<32>) hdr.ipv6.dst_addr[95:80]; // 16 bit
tmp = tmp + (bit<32>) hdr.ipv6.dst_addr[111:96]; // 16 bit
tmp = tmp + (bit<32>) hdr.ipv6.dst_addr[127:112]; // 16 bit
tmp = tmp + (bit<32>) hdr.ipv6.payload_length; // 16 bit
tmp = tmp + (bit<32>) hdr.ipv6.next_header; // 8 bit
/* filtering code copied from scapy */
tmp = (tmp >> 16) + (tmp & 0xffff);
tmp = (tmp >> 16) + (tmp & 0xffff);
// tmp = tmp + (tmp >> 16);
tmp = ~tmp;
// meta.v6sum = (bit<16>) ((((tmp>>8) & 0xff)|tmp<<8) & 0xffff) ;
meta.v6sum = (bit<16>) tmp;
}
action delta_prepare()
{
v4sum();
v6sum();
if(meta.v6sum > meta.v4sum) {
meta.headerdiff = meta.v6sum - meta.v4sum;
} else {
meta.headerdiff = meta.v4sum - meta.v6sum;
}
}
action delta_udp_from_v4_to_v6()
{
v4sum();
v6sum();
/* here is also a possible overflow in both directions */
hdr.udp.checksum = hdr.udp.checksum + meta.v6sum - meta.v4sum;
}
action delta_tcp_from_v4_to_v6()
{
v4sum();
v6sum();
/* here is also a possible overflow in both directions */
hdr.tcp.checksum = hdr.tcp.checksum + meta.v6sum - meta.v4sum;
}
action delta_ipv4_from_v6_to_v4()
{
delta_prepare();
/* TO BE DONE! */
}
#endif