nl_l3: fix nh_stub::operator<() strict weak ordering #430
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According to [1], std::set requires a Compare function that has strict weak ordering [2], but the current implementation violates the second requirement: * If comp(a, b) == true then comp(b, a) == false. E.g. given the nh_stubs a = <169.254.0.1,62> and b = <172.16.111.1,4>: * comp(a, b) is true, as 172.16.111.1 isn't < 169.254.0.1, but 4 < 62 * comp(b, a) is true, as 169.254.0.1 < 172.16.111.1. This breaks e.g. lookups in sets, causing element not being deleted or being found. Fix this by comparing the ifindex only if the addresses are equal, not only if the other one's is larger. [1] https://en.cppreference.com/w/cpp/container/set [2] https://en.cppreference.com/w/cpp/named_req/Compare Fixes: 0fdba0d ("nl_l3: only route l3 neighs if we have a route for them") Signed-off-by: Jonas Gorski <[email protected]>
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According to [1], std::set requires a Compare function that has strict weak ordering [2], but the current implementation violates the second requirement:
comp(a, b) == truethencomp(b, a) == false.E.g. given the nh_stubs a = <169.254.0.1,62> and b = <172.16.111.1,4>:
comp(a, b) == true, as 172.16.111.1 isn't < 169.254.0.1, but 4 < 62comp(b, a) == true, as 169.254.0.1 < 172.16.111.1.This breaks e.g. lookups in sets, causing element not being deleted or being found.
Fix this by comparing the ifindex only if the addresses are equal, not only if the other one's is larger.
[1] https://en.cppreference.com/w/cpp/container/set
[2] https://en.cppreference.com/w/cpp/named_req/Compare
Fixes: 0fdba0d ("nl_l3: only route l3 neighs if we have a route for them")