On Thursday 2020-10-08 18:07, Phil Sutter wrote: >> iptables does not rely or even do such embedding nonsense. When we >> have a flexible array member T x[0] or T x[] somewhere, we really do >> mean that Ts follow, not some Us like in the RDMA case. > >In fact, struct ipt_replace has a zero-length array as last field of >type struct ipt_entry which in turn has a zero-length array as last >field. :) In the RDMA thread, I was informed that the trailing members' only purpose is to serve as something of a shorthand: Shortcut: struct ipt_entry *e = replace->elements; The long way: struct ipt_entry *e = (void *)((char *)replace + sizeof(*replace)); But such gritty detail is often stowed away in some nice accessor functions or macros. That's what's currently missing in spots apprently. struct ipt_entry *next = get_next_blah(replace); Then the get_next can do that arithmetic, we won't need ipt_replace::elements, and could do away with the flexible array member altogether, especially when it's not used with equal-sized elements, and ipt_entry is of variadic size.
