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