cgen: fix port range bytecode generation#239
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A port range matcher is composed of two ports: the lower bound and the higher bound. Because those are in the host's bytes order, bpfilter will use htobe16() on both port before comparing them to the packet's data. This is done to compare the packet's port against a specific value and works flawlessly. However, the port range matcher doesn't work as expected due to the comparison being performed in network byte order! Hence, the most significant bytes are not located where the host expects them to, which is an issue for JLT/JGT operations. Convert the packet's source/destination port to the host byte order before comparing the port range.
End-to-end tests are run for each hook, but bpfilter will generate the same BPF bytecode for most of them. Instead, for each test, generate (and test) a BPF program for each flavor.
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A port range matcher is composed of two ports: the lower bound and the higher bound. Because those are in the host's bytes order, bpfilter will use
htobe16()on both port before comparing them to the packet's data. This is done to compare the packet's port against a specific value and works flawlessly.However, the port range matcher doesn't work as expected due to the comparison being performed in network byte order! Hence, the most significant bytes are not located where the host expects them to, which is an issue for JLT/JGT operations.
Convert the packet's source/destination port to the host byte order before comparing the port range.