52 lines
1.6 KiB
C++
52 lines
1.6 KiB
C++
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#include "ethernet_header.hpp"
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#include <algorithm>
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#include <cassert>
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#include <stdexcept>
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namespace vanetza
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{
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ByteBuffer create_ethernet_header(const MacAddress& dest, const MacAddress& src, uint16be_t proto)
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{
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ByteBuffer buffer;
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buffer.reserve(EthernetHeader::length_bytes);
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auto inserter = std::back_inserter(buffer);
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std::copy(dest.octets.begin(), dest.octets.end(), inserter);
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std::copy(src.octets.begin(), src.octets.end(), inserter);
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uint16_t host_proto = proto.host();
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inserter = (host_proto >> 8) & 0xff;
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inserter = host_proto & 0xff;
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assert(buffer.size() == EthernetHeader::length_bytes);
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return buffer;
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}
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ByteBuffer create_ethernet_header(const EthernetHeader& hdr)
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{
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return create_ethernet_header(hdr.destination, hdr.source, hdr.type);
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}
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EthernetHeader decode_ethernet_header(ByteBuffer::const_iterator begin, ByteBuffer::const_iterator end)
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{
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EthernetHeader hdr;
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const std::size_t buflen = std::distance(begin, end);
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if (buflen < EthernetHeader::length_bytes) {
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throw std::runtime_error("buffer is too short for EthernetHeader decoding");
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} else {
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std::copy_n(begin, MacAddress::length_bytes, hdr.destination.octets.begin());
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begin += MacAddress::length_bytes;
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std::copy_n(begin, MacAddress::length_bytes, hdr.source.octets.begin());
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begin += MacAddress::length_bytes;
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uint16_t proto = (begin[0] << 8) | begin[1];
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hdr.type = host_cast(proto);
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}
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return hdr;
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}
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EthernetHeader decode_ethernet_header(const ByteBuffer& buf)
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{
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return decode_ethernet_header(buf.begin(), buf.end());
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}
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} // namespace vanetza
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